OpenCloudOS-Kernel/virt/kvm/kvm_main.c

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// SPDX-License-Identifier: GPL-2.0-only
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
/*
* Kernel-based Virtual Machine driver for Linux
*
* This module enables machines with Intel VT-x extensions to run virtual
* machines without emulation or binary translation.
*
* Copyright (C) 2006 Qumranet, Inc.
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
*
* Authors:
* Avi Kivity <avi@qumranet.com>
* Yaniv Kamay <yaniv@qumranet.com>
*/
#include <kvm/iodev.h>
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
#include <linux/kvm_host.h>
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
#include <linux/kvm.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/percpu.h>
#include <linux/mm.h>
#include <linux/miscdevice.h>
#include <linux/vmalloc.h>
#include <linux/reboot.h>
#include <linux/debugfs.h>
#include <linux/highmem.h>
#include <linux/file.h>
#include <linux/syscore_ops.h>
#include <linux/cpu.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/sched/stat.h>
#include <linux/cpumask.h>
#include <linux/smp.h>
#include <linux/anon_inodes.h>
#include <linux/profile.h>
#include <linux/kvm_para.h>
#include <linux/pagemap.h>
#include <linux/mman.h>
#include <linux/swap.h>
#include <linux/bitops.h>
#include <linux/spinlock.h>
#include <linux/compat.h>
#include <linux/srcu.h>
#include <linux/hugetlb.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/sort.h>
#include <linux/bsearch.h>
#include <linux/io.h>
#include <linux/lockdep.h>
#include <linux/kthread.h>
#include <linux/suspend.h>
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
#include <asm/processor.h>
#include <asm/ioctl.h>
#include <linux/uaccess.h>
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
#include "coalesced_mmio.h"
#include "async_pf.h"
#include "mmu_lock.h"
#include "vfio.h"
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
#define CREATE_TRACE_POINTS
#include <trace/events/kvm.h>
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
#include <linux/kvm_dirty_ring.h>
/* Worst case buffer size needed for holding an integer. */
#define ITOA_MAX_LEN 12
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
/* Architectures should define their poll value according to the halt latency */
unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
module_param(halt_poll_ns, uint, 0644);
EXPORT_SYMBOL_GPL(halt_poll_ns);
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
/* Default doubles per-vcpu halt_poll_ns. */
unsigned int halt_poll_ns_grow = 2;
module_param(halt_poll_ns_grow, uint, 0644);
EXPORT_SYMBOL_GPL(halt_poll_ns_grow);
/* The start value to grow halt_poll_ns from */
unsigned int halt_poll_ns_grow_start = 10000; /* 10us */
module_param(halt_poll_ns_grow_start, uint, 0644);
EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start);
/* Default resets per-vcpu halt_poll_ns . */
unsigned int halt_poll_ns_shrink;
module_param(halt_poll_ns_shrink, uint, 0644);
EXPORT_SYMBOL_GPL(halt_poll_ns_shrink);
/*
* Ordering of locks:
*
* kvm->lock --> kvm->slots_lock --> kvm->irq_lock
*/
DEFINE_MUTEX(kvm_lock);
static DEFINE_RAW_SPINLOCK(kvm_count_lock);
LIST_HEAD(vm_list);
static cpumask_var_t cpus_hardware_enabled;
static int kvm_usage_count;
static atomic_t hardware_enable_failed;
static struct kmem_cache *kvm_vcpu_cache;
static __read_mostly struct preempt_ops kvm_preempt_ops;
static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);
struct dentry *kvm_debugfs_dir;
EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
static const struct file_operations stat_fops_per_vm;
static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
unsigned long arg);
#ifdef CONFIG_KVM_COMPAT
static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
unsigned long arg);
#define KVM_COMPAT(c) .compat_ioctl = (c)
#else
/*
* For architectures that don't implement a compat infrastructure,
* adopt a double line of defense:
* - Prevent a compat task from opening /dev/kvm
* - If the open has been done by a 64bit task, and the KVM fd
* passed to a compat task, let the ioctls fail.
*/
static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl,
unsigned long arg) { return -EINVAL; }
static int kvm_no_compat_open(struct inode *inode, struct file *file)
{
return is_compat_task() ? -ENODEV : 0;
}
#define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \
.open = kvm_no_compat_open
#endif
static int hardware_enable_all(void);
static void hardware_disable_all(void);
static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
__visible bool kvm_rebooting;
EXPORT_SYMBOL_GPL(kvm_rebooting);
#define KVM_EVENT_CREATE_VM 0
#define KVM_EVENT_DESTROY_VM 1
static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
static unsigned long long kvm_createvm_count;
static unsigned long long kvm_active_vms;
KVM: x86: Fix APIC page invalidation race Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried to fix inappropriate APIC page invalidation by re-introducing arch specific kvm_arch_mmu_notifier_invalidate_range() and calling it from kvm_mmu_notifier_invalidate_range_start. However, the patch left a possible race where the VMCS APIC address cache is updated *before* it is unmapped: (Invalidator) kvm_mmu_notifier_invalidate_range_start() (Invalidator) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD) (KVM VCPU) vcpu_enter_guest() (KVM VCPU) kvm_vcpu_reload_apic_access_page() (Invalidator) actually unmap page Because of the above race, there can be a mismatch between the host physical address stored in the APIC_ACCESS_PAGE VMCS field and the host physical address stored in the EPT entry for the APIC GPA (0xfee0000). When this happens, the processor will not trap APIC accesses, and will instead show the raw contents of the APIC-access page. Because Windows OS periodically checks for unexpected modifications to the LAPIC register, this will show up as a BSOD crash with BugCheck CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in https://bugzilla.redhat.com/show_bug.cgi?id=1751017. The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range() cannot guarantee that no additional references are taken to the pages in the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately, this case is supported by the MMU notifier API, as documented in include/linux/mmu_notifier.h: * If the subsystem * can't guarantee that no additional references are taken to * the pages in the range, it has to implement the * invalidate_range() notifier to remove any references taken * after invalidate_range_start(). The fix therefore is to reload the APIC-access page field in the VMCS from kvm_mmu_notifier_invalidate_range() instead of ..._range_start(). Cc: stable@vger.kernel.org Fixes: b1394e745b94 ("KVM: x86: fix APIC page invalidation") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=197951 Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Message-Id: <20200606042627.61070-1-eiichi.tsukata@nutanix.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-06 12:26:27 +08:00
__weak void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
unsigned long start, unsigned long end)
{
}
KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and instead manually handle ZONE_DEVICE on a case-by-case basis. For things like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal pages, e.g. put pages grabbed via gup(). But for flows such as setting A/D bits or shifting refcounts for transparent huge pages, KVM needs to to avoid processing ZONE_DEVICE pages as the flows in question lack the underlying machinery for proper handling of ZONE_DEVICE pages. This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup() when running a KVM guest backed with /dev/dax memory, as KVM straight up doesn't put any references to ZONE_DEVICE pages acquired by gup(). Note, Dan Williams proposed an alternative solution of doing put_page() on ZONE_DEVICE pages immediately after gup() in order to simplify the auditing needed to ensure is_zone_device_page() is called if and only if the backing device is pinned (via gup()). But that approach would break kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til unmap() when accessing guest memory, unlike KVM's secondary MMU, which coordinates with mmu_notifier invalidations to avoid creating stale page references, i.e. doesn't rely on pages being pinned. [*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.pl Reported-by: Adam Borowski <kilobyte@angband.pl> Analyzed-by: David Hildenbrand <david@redhat.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-12 06:12:27 +08:00
bool kvm_is_zone_device_pfn(kvm_pfn_t pfn)
{
/*
* The metadata used by is_zone_device_page() to determine whether or
* not a page is ZONE_DEVICE is guaranteed to be valid if and only if
* the device has been pinned, e.g. by get_user_pages(). WARN if the
* page_count() is zero to help detect bad usage of this helper.
*/
if (!pfn_valid(pfn) || WARN_ON_ONCE(!page_count(pfn_to_page(pfn))))
return false;
return is_zone_device_page(pfn_to_page(pfn));
}
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
bool kvm_is_reserved_pfn(kvm_pfn_t pfn)
{
KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and instead manually handle ZONE_DEVICE on a case-by-case basis. For things like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal pages, e.g. put pages grabbed via gup(). But for flows such as setting A/D bits or shifting refcounts for transparent huge pages, KVM needs to to avoid processing ZONE_DEVICE pages as the flows in question lack the underlying machinery for proper handling of ZONE_DEVICE pages. This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup() when running a KVM guest backed with /dev/dax memory, as KVM straight up doesn't put any references to ZONE_DEVICE pages acquired by gup(). Note, Dan Williams proposed an alternative solution of doing put_page() on ZONE_DEVICE pages immediately after gup() in order to simplify the auditing needed to ensure is_zone_device_page() is called if and only if the backing device is pinned (via gup()). But that approach would break kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til unmap() when accessing guest memory, unlike KVM's secondary MMU, which coordinates with mmu_notifier invalidations to avoid creating stale page references, i.e. doesn't rely on pages being pinned. [*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.pl Reported-by: Adam Borowski <kilobyte@angband.pl> Analyzed-by: David Hildenbrand <david@redhat.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-12 06:12:27 +08:00
/*
* ZONE_DEVICE pages currently set PG_reserved, but from a refcounting
* perspective they are "normal" pages, albeit with slightly different
* usage rules.
*/
if (pfn_valid(pfn))
KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and instead manually handle ZONE_DEVICE on a case-by-case basis. For things like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal pages, e.g. put pages grabbed via gup(). But for flows such as setting A/D bits or shifting refcounts for transparent huge pages, KVM needs to to avoid processing ZONE_DEVICE pages as the flows in question lack the underlying machinery for proper handling of ZONE_DEVICE pages. This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup() when running a KVM guest backed with /dev/dax memory, as KVM straight up doesn't put any references to ZONE_DEVICE pages acquired by gup(). Note, Dan Williams proposed an alternative solution of doing put_page() on ZONE_DEVICE pages immediately after gup() in order to simplify the auditing needed to ensure is_zone_device_page() is called if and only if the backing device is pinned (via gup()). But that approach would break kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til unmap() when accessing guest memory, unlike KVM's secondary MMU, which coordinates with mmu_notifier invalidations to avoid creating stale page references, i.e. doesn't rely on pages being pinned. [*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.pl Reported-by: Adam Borowski <kilobyte@angband.pl> Analyzed-by: David Hildenbrand <david@redhat.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-12 06:12:27 +08:00
return PageReserved(pfn_to_page(pfn)) &&
KVM: fix overflow of zero page refcount with ksm running We are testing Virtual Machine with KSM on v5.4-rc2 kernel, and found the zero_page refcount overflow. The cause of refcount overflow is increased in try_async_pf (get_user_page) without being decreased in mmu_set_spte() while handling ept violation. In kvm_release_pfn_clean(), only unreserved page will call put_page. However, zero page is reserved. So, as well as creating and destroy vm, the refcount of zero page will continue to increase until it overflows. step1: echo 10000 > /sys/kernel/pages_to_scan/pages_to_scan echo 1 > /sys/kernel/pages_to_scan/run echo 1 > /sys/kernel/pages_to_scan/use_zero_pages step2: just create several normal qemu kvm vms. And destroy it after 10s. Repeat this action all the time. After a long period of time, all domains hang because of the refcount of zero page overflow. Qemu print error log as follow: … error: kvm run failed Bad address EAX=00006cdc EBX=00000008 ECX=80202001 EDX=078bfbfd ESI=ffffffff EDI=00000000 EBP=00000008 ESP=00006cc4 EIP=000efd75 EFL=00010002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] CS =0008 00000000 ffffffff 00c09b00 DPL=0 CS32 [-RA] SS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] DS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] FS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] GS =0010 00000000 ffffffff 00c09300 DPL=0 DS [-WA] LDT=0000 00000000 0000ffff 00008200 DPL=0 LDT TR =0000 00000000 0000ffff 00008b00 DPL=0 TSS32-busy GDT= 000f7070 00000037 IDT= 000f70ae 00000000 CR0=00000011 CR2=00000000 CR3=00000000 CR4=00000000 DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 DR6=00000000ffff0ff0 DR7=0000000000000400 EFER=0000000000000000 Code=00 01 00 00 00 e9 e8 00 00 00 c7 05 4c 55 0f 00 01 00 00 00 <8b> 35 00 00 01 00 8b 3d 04 00 01 00 b8 d8 d3 00 00 c1 e0 08 0c ea a3 00 00 01 00 c7 05 04 … Meanwhile, a kernel warning is departed. [40914.836375] WARNING: CPU: 3 PID: 82067 at ./include/linux/mm.h:987 try_get_page+0x1f/0x30 [40914.836412] CPU: 3 PID: 82067 Comm: CPU 0/KVM Kdump: loaded Tainted: G OE 5.2.0-rc2 #5 [40914.836415] RIP: 0010:try_get_page+0x1f/0x30 [40914.836417] Code: 40 00 c3 0f 1f 84 00 00 00 00 00 48 8b 47 08 a8 01 75 11 8b 47 34 85 c0 7e 10 f0 ff 47 34 b8 01 00 00 00 c3 48 8d 78 ff eb e9 <0f> 0b 31 c0 c3 66 90 66 2e 0f 1f 84 00 0 0 00 00 00 48 8b 47 08 a8 [40914.836418] RSP: 0018:ffffb4144e523988 EFLAGS: 00010286 [40914.836419] RAX: 0000000080000000 RBX: 0000000000000326 RCX: 0000000000000000 [40914.836420] RDX: 0000000000000000 RSI: 00004ffdeba10000 RDI: ffffdf07093f6440 [40914.836421] RBP: ffffdf07093f6440 R08: 800000424fd91225 R09: 0000000000000000 [40914.836421] R10: ffff9eb41bfeebb8 R11: 0000000000000000 R12: ffffdf06bbd1e8a8 [40914.836422] R13: 0000000000000080 R14: 800000424fd91225 R15: ffffdf07093f6440 [40914.836423] FS: 00007fb60ffff700(0000) GS:ffff9eb4802c0000(0000) knlGS:0000000000000000 [40914.836425] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [40914.836426] CR2: 0000000000000000 CR3: 0000002f220e6002 CR4: 00000000003626e0 [40914.836427] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [40914.836427] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [40914.836428] Call Trace: [40914.836433] follow_page_pte+0x302/0x47b [40914.836437] __get_user_pages+0xf1/0x7d0 [40914.836441] ? irq_work_queue+0x9/0x70 [40914.836443] get_user_pages_unlocked+0x13f/0x1e0 [40914.836469] __gfn_to_pfn_memslot+0x10e/0x400 [kvm] [40914.836486] try_async_pf+0x87/0x240 [kvm] [40914.836503] tdp_page_fault+0x139/0x270 [kvm] [40914.836523] kvm_mmu_page_fault+0x76/0x5e0 [kvm] [40914.836588] vcpu_enter_guest+0xb45/0x1570 [kvm] [40914.836632] kvm_arch_vcpu_ioctl_run+0x35d/0x580 [kvm] [40914.836645] kvm_vcpu_ioctl+0x26e/0x5d0 [kvm] [40914.836650] do_vfs_ioctl+0xa9/0x620 [40914.836653] ksys_ioctl+0x60/0x90 [40914.836654] __x64_sys_ioctl+0x16/0x20 [40914.836658] do_syscall_64+0x5b/0x180 [40914.836664] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [40914.836666] RIP: 0033:0x7fb61cb6bfc7 Signed-off-by: LinFeng <linfeng23@huawei.com> Signed-off-by: Zhuang Yanying <ann.zhuangyanying@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-12 11:37:31 +08:00
!is_zero_pfn(pfn) &&
KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and instead manually handle ZONE_DEVICE on a case-by-case basis. For things like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal pages, e.g. put pages grabbed via gup(). But for flows such as setting A/D bits or shifting refcounts for transparent huge pages, KVM needs to to avoid processing ZONE_DEVICE pages as the flows in question lack the underlying machinery for proper handling of ZONE_DEVICE pages. This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup() when running a KVM guest backed with /dev/dax memory, as KVM straight up doesn't put any references to ZONE_DEVICE pages acquired by gup(). Note, Dan Williams proposed an alternative solution of doing put_page() on ZONE_DEVICE pages immediately after gup() in order to simplify the auditing needed to ensure is_zone_device_page() is called if and only if the backing device is pinned (via gup()). But that approach would break kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til unmap() when accessing guest memory, unlike KVM's secondary MMU, which coordinates with mmu_notifier invalidations to avoid creating stale page references, i.e. doesn't rely on pages being pinned. [*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.pl Reported-by: Adam Borowski <kilobyte@angband.pl> Analyzed-by: David Hildenbrand <david@redhat.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-12 06:12:27 +08:00
!kvm_is_zone_device_pfn(pfn);
return true;
}
bool kvm_is_transparent_hugepage(kvm_pfn_t pfn)
{
struct page *page = pfn_to_page(pfn);
if (!PageTransCompoundMap(page))
return false;
return is_transparent_hugepage(compound_head(page));
}
/*
* Switches to specified vcpu, until a matching vcpu_put()
*/
void vcpu_load(struct kvm_vcpu *vcpu)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
int cpu = get_cpu();
__this_cpu_write(kvm_running_vcpu, vcpu);
preempt_notifier_register(&vcpu->preempt_notifier);
kvm_arch_vcpu_load(vcpu, cpu);
put_cpu();
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
EXPORT_SYMBOL_GPL(vcpu_load);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
void vcpu_put(struct kvm_vcpu *vcpu)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
preempt_disable();
kvm_arch_vcpu_put(vcpu);
preempt_notifier_unregister(&vcpu->preempt_notifier);
__this_cpu_write(kvm_running_vcpu, NULL);
preempt_enable();
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
EXPORT_SYMBOL_GPL(vcpu_put);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
/* TODO: merge with kvm_arch_vcpu_should_kick */
static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req)
{
int mode = kvm_vcpu_exiting_guest_mode(vcpu);
/*
* We need to wait for the VCPU to reenable interrupts and get out of
* READING_SHADOW_PAGE_TABLES mode.
*/
if (req & KVM_REQUEST_WAIT)
return mode != OUTSIDE_GUEST_MODE;
/*
* Need to kick a running VCPU, but otherwise there is nothing to do.
*/
return mode == IN_GUEST_MODE;
}
static void ack_flush(void *_completed)
{
}
static inline bool kvm_kick_many_cpus(const struct cpumask *cpus, bool wait)
{
if (unlikely(!cpus))
cpus = cpu_online_mask;
if (cpumask_empty(cpus))
return false;
smp_call_function_many(cpus, ack_flush, NULL, wait);
return true;
}
bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
struct kvm_vcpu *except,
unsigned long *vcpu_bitmap, cpumask_var_t tmp)
{
int i, cpu, me;
struct kvm_vcpu *vcpu;
bool called;
me = get_cpu();
kvm_for_each_vcpu(i, vcpu, kvm) {
if ((vcpu_bitmap && !test_bit(i, vcpu_bitmap)) ||
vcpu == except)
continue;
kvm_make_request(req, vcpu);
cpu = vcpu->cpu;
if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu))
continue;
if (tmp != NULL && cpu != -1 && cpu != me &&
kvm_request_needs_ipi(vcpu, req))
__cpumask_set_cpu(cpu, tmp);
}
called = kvm_kick_many_cpus(tmp, !!(req & KVM_REQUEST_WAIT));
put_cpu();
return called;
}
bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req,
struct kvm_vcpu *except)
{
cpumask_var_t cpus;
bool called;
zalloc_cpumask_var(&cpus, GFP_ATOMIC);
called = kvm_make_vcpus_request_mask(kvm, req, except, NULL, cpus);
free_cpumask_var(cpus);
return called;
}
bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
{
return kvm_make_all_cpus_request_except(kvm, req, NULL);
}
KVM: VMX: update vcpu posted-interrupt descriptor when assigning device For VMX, when a vcpu enters HLT emulation, pi_post_block will: 1) Add vcpu to per-cpu list of blocked vcpus. 2) Program the posted-interrupt descriptor "notification vector" to POSTED_INTR_WAKEUP_VECTOR With interrupt remapping, an interrupt will set the PIR bit for the vector programmed for the device on the CPU, test-and-set the ON bit on the posted interrupt descriptor, and if the ON bit is clear generate an interrupt for the notification vector. This way, the target CPU wakes upon a device interrupt and wakes up the target vcpu. Problem is that pi_post_block only programs the notification vector if kvm_arch_has_assigned_device() is true. Its possible for the following to happen: 1) vcpu V HLTs on pcpu P, kvm_arch_has_assigned_device is false, notification vector is not programmed 2) device is assigned to VM 3) device interrupts vcpu V, sets ON bit (notification vector not programmed, so pcpu P remains in idle) 4) vcpu 0 IPIs vcpu V (in guest), but since pi descriptor ON bit is set, kvm_vcpu_kick is skipped 5) vcpu 0 busy spins on vcpu V's response for several seconds, until RCU watchdog NMIs all vCPUs. To fix this, use the start_assignment kvm_x86_ops callback to kick vcpus out of the halt loop, so the notification vector is properly reprogrammed to the wakeup vector. Reported-by: Pei Zhang <pezhang@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Message-Id: <20210526172014.GA29007@fuller.cnet> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 01:20:14 +08:00
EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request);
#ifndef CONFIG_HAVE_KVM_ARCH_TLB_FLUSH_ALL
void kvm_flush_remote_tlbs(struct kvm *kvm)
{
/*
* Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in
* kvm_make_all_cpus_request.
*/
long dirty_count = smp_load_acquire(&kvm->tlbs_dirty);
/*
* We want to publish modifications to the page tables before reading
* mode. Pairs with a memory barrier in arch-specific code.
* - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest
* and smp_mb in walk_shadow_page_lockless_begin/end.
* - powerpc: smp_mb in kvmppc_prepare_to_enter.
*
* There is already an smp_mb__after_atomic() before
* kvm_make_all_cpus_request() reads vcpu->mode. We reuse that
* barrier here.
*/
if (!kvm_arch_flush_remote_tlb(kvm)
|| kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
++kvm->stat.generic.remote_tlb_flush;
cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
}
EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
#endif
void kvm_reload_remote_mmus(struct kvm *kvm)
{
kvm_make_all_cpus_request(kvm, KVM_REQ_MMU_RELOAD);
}
#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc,
gfp_t gfp_flags)
{
gfp_flags |= mc->gfp_zero;
if (mc->kmem_cache)
return kmem_cache_alloc(mc->kmem_cache, gfp_flags);
else
return (void *)__get_free_page(gfp_flags);
}
int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min)
{
void *obj;
if (mc->nobjs >= min)
return 0;
while (mc->nobjs < ARRAY_SIZE(mc->objects)) {
obj = mmu_memory_cache_alloc_obj(mc, GFP_KERNEL_ACCOUNT);
if (!obj)
return mc->nobjs >= min ? 0 : -ENOMEM;
mc->objects[mc->nobjs++] = obj;
}
return 0;
}
int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc)
{
return mc->nobjs;
}
void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
{
while (mc->nobjs) {
if (mc->kmem_cache)
kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
else
free_page((unsigned long)mc->objects[--mc->nobjs]);
}
}
void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
{
void *p;
if (WARN_ON(!mc->nobjs))
p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT);
else
p = mc->objects[--mc->nobjs];
BUG_ON(!p);
return p;
}
#endif
static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id)
{
mutex_init(&vcpu->mutex);
vcpu->cpu = -1;
vcpu->kvm = kvm;
vcpu->vcpu_id = id;
vcpu->pid = NULL;
rcuwait_init(&vcpu->wait);
kvm_async_pf_vcpu_init(vcpu);
vcpu->pre_pcpu = -1;
INIT_LIST_HEAD(&vcpu->blocked_vcpu_list);
kvm_vcpu_set_in_spin_loop(vcpu, false);
kvm_vcpu_set_dy_eligible(vcpu, false);
vcpu->preempted = false;
KVM: Boost vCPUs that are delivering interrupts Inspired by commit 9cac38dd5d (KVM/s390: Set preempted flag during vcpu wakeup and interrupt delivery), we want to also boost not just lock holders but also vCPUs that are delivering interrupts. Most smp_call_function_many calls are synchronous, so the IPI target vCPUs are also good yield candidates. This patch introduces vcpu->ready to boost vCPUs during wakeup and interrupt delivery time; unlike s390 we do not reuse vcpu->preempted so that voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin, but vmx_vcpu_pi_put is not affected (VT-d PI handles voluntary preemption separately, in pi_pre_block). Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM: ebizzy -M vanilla boosting improved 1VM 21443 23520 9% 2VM 2800 8000 180% 3VM 1800 3100 72% Testing on my Haswell desktop 8 HT, with 8 vCPUs VM 8GB RAM, two VMs, one running ebizzy -M, the other running 'stress --cpu 2': w/ boosting + w/o pv sched yield(vanilla) vanilla boosting improved 1570 4000 155% w/ boosting + w/ pv sched yield(vanilla) vanilla boosting improved 1844 5157 179% w/o boosting, perf top in VM: 72.33% [kernel] [k] smp_call_function_many 4.22% [kernel] [k] call_function_i 3.71% [kernel] [k] async_page_fault w/ boosting, perf top in VM: 38.43% [kernel] [k] smp_call_function_many 6.31% [kernel] [k] async_page_fault 6.13% libc-2.23.so [.] __memcpy_avx_unaligned 4.88% [kernel] [k] call_function_interrupt Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Marc Zyngier <maz@kernel.org> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-18 19:39:06 +08:00
vcpu->ready = false;
preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops);
KVM: Cache the last used slot index per vCPU The memslot for a given gfn is looked up multiple times during page fault handling. Avoid binary searching for it multiple times by caching the most recently used slot. There is an existing VM-wide last_used_slot but that does not work well for cases where vCPUs are accessing memory in different slots (see performance data below). Another benefit of caching the most recently use slot (versus looking up the slot once and passing around a pointer) is speeding up memslot lookups *across* faults and during spte prefetching. To measure the performance of this change I ran dirty_log_perf_test with 64 vCPUs and 64 memslots and measured "Populate memory time" and "Iteration 2 dirty memory time". Tests were ran with eptad=N to force dirty logging to use fast_page_fault so its performance could be measured. Config | Metric | Before | After ---------- | ----------------------------- | ------ | ------ tdp_mmu=Y | Populate memory time | 6.76s | 5.47s tdp_mmu=Y | Iteration 2 dirty memory time | 2.83s | 0.31s tdp_mmu=N | Populate memory time | 20.4s | 18.7s tdp_mmu=N | Iteration 2 dirty memory time | 2.65s | 0.30s The "Iteration 2 dirty memory time" results are especially compelling because they are equivalent to running the same test with a single memslot. In other words, fast_page_fault performance no longer scales with the number of memslots. Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20210804222844.1419481-4-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-05 06:28:40 +08:00
vcpu->last_used_slot = 0;
}
void kvm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
kvm_dirty_ring_free(&vcpu->dirty_ring);
kvm_arch_vcpu_destroy(vcpu);
/*
* No need for rcu_read_lock as VCPU_RUN is the only place that changes
* the vcpu->pid pointer, and at destruction time all file descriptors
* are already gone.
*/
put_pid(rcu_dereference_protected(vcpu->pid, 1));
free_page((unsigned long)vcpu->run);
kmem_cache_free(kvm_vcpu_cache, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_destroy);
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
{
return container_of(mn, struct kvm, mmu_notifier);
}
KVM: x86: Fix APIC page invalidation race Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried to fix inappropriate APIC page invalidation by re-introducing arch specific kvm_arch_mmu_notifier_invalidate_range() and calling it from kvm_mmu_notifier_invalidate_range_start. However, the patch left a possible race where the VMCS APIC address cache is updated *before* it is unmapped: (Invalidator) kvm_mmu_notifier_invalidate_range_start() (Invalidator) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD) (KVM VCPU) vcpu_enter_guest() (KVM VCPU) kvm_vcpu_reload_apic_access_page() (Invalidator) actually unmap page Because of the above race, there can be a mismatch between the host physical address stored in the APIC_ACCESS_PAGE VMCS field and the host physical address stored in the EPT entry for the APIC GPA (0xfee0000). When this happens, the processor will not trap APIC accesses, and will instead show the raw contents of the APIC-access page. Because Windows OS periodically checks for unexpected modifications to the LAPIC register, this will show up as a BSOD crash with BugCheck CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in https://bugzilla.redhat.com/show_bug.cgi?id=1751017. The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range() cannot guarantee that no additional references are taken to the pages in the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately, this case is supported by the MMU notifier API, as documented in include/linux/mmu_notifier.h: * If the subsystem * can't guarantee that no additional references are taken to * the pages in the range, it has to implement the * invalidate_range() notifier to remove any references taken * after invalidate_range_start(). The fix therefore is to reload the APIC-access page field in the VMCS from kvm_mmu_notifier_invalidate_range() instead of ..._range_start(). Cc: stable@vger.kernel.org Fixes: b1394e745b94 ("KVM: x86: fix APIC page invalidation") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=197951 Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Message-Id: <20200606042627.61070-1-eiichi.tsukata@nutanix.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-06 12:26:27 +08:00
static void kvm_mmu_notifier_invalidate_range(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start, unsigned long end)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
int idx;
idx = srcu_read_lock(&kvm->srcu);
kvm_arch_mmu_notifier_invalidate_range(kvm, start, end);
srcu_read_unlock(&kvm->srcu, idx);
}
typedef bool (*hva_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range);
typedef void (*on_lock_fn_t)(struct kvm *kvm, unsigned long start,
unsigned long end);
struct kvm_hva_range {
unsigned long start;
unsigned long end;
pte_t pte;
hva_handler_t handler;
on_lock_fn_t on_lock;
bool flush_on_ret;
bool may_block;
};
/*
* Use a dedicated stub instead of NULL to indicate that there is no callback
* function/handler. The compiler technically can't guarantee that a real
* function will have a non-zero address, and so it will generate code to
* check for !NULL, whereas comparing against a stub will be elided at compile
* time (unless the compiler is getting long in the tooth, e.g. gcc 4.9).
*/
static void kvm_null_fn(void)
{
}
#define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn)
static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
const struct kvm_hva_range *range)
{
KVM: Take mmu_lock when handling MMU notifier iff the hva hits a memslot Defer acquiring mmu_lock in the MMU notifier paths until a "hit" has been detected in the memslots, i.e. don't take the lock for notifications that don't affect the guest. For small VMs, spurious locking is a minor annoyance. And for "volatile" setups where the majority of notifications _are_ relevant, this barely qualifies as an optimization. But, for large VMs (hundreds of threads) with static setups, e.g. no page migration, no swapping, etc..., the vast majority of MMU notifier callbacks will be unrelated to the guest, e.g. will often be in response to the userspace VMM adjusting its own virtual address space. In such large VMs, acquiring mmu_lock can be painful as it blocks vCPUs from handling page faults. In some scenarios it can even be "fatal" in the sense that it causes unacceptable brownouts, e.g. when rebuilding huge pages after live migration, a significant percentage of vCPUs will be attempting to handle page faults. x86's TDP MMU implementation is especially susceptible to spurious locking due it taking mmu_lock for read when handling page faults. Because rwlock is fair, a single writer will stall future readers, while the writer is itself stalled waiting for in-progress readers to complete. This is exacerbated by the MMU notifiers often firing multiple times in quick succession, e.g. moving a page will (always?) invoke three separate notifiers: .invalidate_range_start(), invalidate_range_end(), and .change_pte(). Unnecessarily taking mmu_lock each time means even a single spurious sequence can be problematic. Note, this optimizes only the unpaired callbacks. Optimizing the .invalidate_range_{start,end}() pairs is more complex and will be done in a future patch. Suggested-by: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210402005658.3024832-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-02 08:56:56 +08:00
bool ret = false, locked = false;
struct kvm_gfn_range gfn_range;
struct kvm_memory_slot *slot;
struct kvm_memslots *slots;
int i, idx;
/* A null handler is allowed if and only if on_lock() is provided. */
if (WARN_ON_ONCE(IS_KVM_NULL_FN(range->on_lock) &&
IS_KVM_NULL_FN(range->handler)))
return 0;
idx = srcu_read_lock(&kvm->srcu);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
slots = __kvm_memslots(kvm, i);
kvm_for_each_memslot(slot, slots) {
unsigned long hva_start, hva_end;
hva_start = max(range->start, slot->userspace_addr);
hva_end = min(range->end, slot->userspace_addr +
(slot->npages << PAGE_SHIFT));
if (hva_start >= hva_end)
continue;
/*
* To optimize for the likely case where the address
* range is covered by zero or one memslots, don't
* bother making these conditional (to avoid writes on
* the second or later invocation of the handler).
*/
gfn_range.pte = range->pte;
gfn_range.may_block = range->may_block;
/*
* {gfn(page) | page intersects with [hva_start, hva_end)} =
* {gfn_start, gfn_start+1, ..., gfn_end-1}.
*/
gfn_range.start = hva_to_gfn_memslot(hva_start, slot);
gfn_range.end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, slot);
gfn_range.slot = slot;
KVM: Take mmu_lock when handling MMU notifier iff the hva hits a memslot Defer acquiring mmu_lock in the MMU notifier paths until a "hit" has been detected in the memslots, i.e. don't take the lock for notifications that don't affect the guest. For small VMs, spurious locking is a minor annoyance. And for "volatile" setups where the majority of notifications _are_ relevant, this barely qualifies as an optimization. But, for large VMs (hundreds of threads) with static setups, e.g. no page migration, no swapping, etc..., the vast majority of MMU notifier callbacks will be unrelated to the guest, e.g. will often be in response to the userspace VMM adjusting its own virtual address space. In such large VMs, acquiring mmu_lock can be painful as it blocks vCPUs from handling page faults. In some scenarios it can even be "fatal" in the sense that it causes unacceptable brownouts, e.g. when rebuilding huge pages after live migration, a significant percentage of vCPUs will be attempting to handle page faults. x86's TDP MMU implementation is especially susceptible to spurious locking due it taking mmu_lock for read when handling page faults. Because rwlock is fair, a single writer will stall future readers, while the writer is itself stalled waiting for in-progress readers to complete. This is exacerbated by the MMU notifiers often firing multiple times in quick succession, e.g. moving a page will (always?) invoke three separate notifiers: .invalidate_range_start(), invalidate_range_end(), and .change_pte(). Unnecessarily taking mmu_lock each time means even a single spurious sequence can be problematic. Note, this optimizes only the unpaired callbacks. Optimizing the .invalidate_range_{start,end}() pairs is more complex and will be done in a future patch. Suggested-by: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210402005658.3024832-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-02 08:56:56 +08:00
if (!locked) {
locked = true;
KVM_MMU_LOCK(kvm);
if (!IS_KVM_NULL_FN(range->on_lock))
range->on_lock(kvm, range->start, range->end);
if (IS_KVM_NULL_FN(range->handler))
break;
KVM: Take mmu_lock when handling MMU notifier iff the hva hits a memslot Defer acquiring mmu_lock in the MMU notifier paths until a "hit" has been detected in the memslots, i.e. don't take the lock for notifications that don't affect the guest. For small VMs, spurious locking is a minor annoyance. And for "volatile" setups where the majority of notifications _are_ relevant, this barely qualifies as an optimization. But, for large VMs (hundreds of threads) with static setups, e.g. no page migration, no swapping, etc..., the vast majority of MMU notifier callbacks will be unrelated to the guest, e.g. will often be in response to the userspace VMM adjusting its own virtual address space. In such large VMs, acquiring mmu_lock can be painful as it blocks vCPUs from handling page faults. In some scenarios it can even be "fatal" in the sense that it causes unacceptable brownouts, e.g. when rebuilding huge pages after live migration, a significant percentage of vCPUs will be attempting to handle page faults. x86's TDP MMU implementation is especially susceptible to spurious locking due it taking mmu_lock for read when handling page faults. Because rwlock is fair, a single writer will stall future readers, while the writer is itself stalled waiting for in-progress readers to complete. This is exacerbated by the MMU notifiers often firing multiple times in quick succession, e.g. moving a page will (always?) invoke three separate notifiers: .invalidate_range_start(), invalidate_range_end(), and .change_pte(). Unnecessarily taking mmu_lock each time means even a single spurious sequence can be problematic. Note, this optimizes only the unpaired callbacks. Optimizing the .invalidate_range_{start,end}() pairs is more complex and will be done in a future patch. Suggested-by: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210402005658.3024832-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-02 08:56:56 +08:00
}
ret |= range->handler(kvm, &gfn_range);
}
}
if (range->flush_on_ret && (ret || kvm->tlbs_dirty))
kvm_flush_remote_tlbs(kvm);
KVM: Take mmu_lock when handling MMU notifier iff the hva hits a memslot Defer acquiring mmu_lock in the MMU notifier paths until a "hit" has been detected in the memslots, i.e. don't take the lock for notifications that don't affect the guest. For small VMs, spurious locking is a minor annoyance. And for "volatile" setups where the majority of notifications _are_ relevant, this barely qualifies as an optimization. But, for large VMs (hundreds of threads) with static setups, e.g. no page migration, no swapping, etc..., the vast majority of MMU notifier callbacks will be unrelated to the guest, e.g. will often be in response to the userspace VMM adjusting its own virtual address space. In such large VMs, acquiring mmu_lock can be painful as it blocks vCPUs from handling page faults. In some scenarios it can even be "fatal" in the sense that it causes unacceptable brownouts, e.g. when rebuilding huge pages after live migration, a significant percentage of vCPUs will be attempting to handle page faults. x86's TDP MMU implementation is especially susceptible to spurious locking due it taking mmu_lock for read when handling page faults. Because rwlock is fair, a single writer will stall future readers, while the writer is itself stalled waiting for in-progress readers to complete. This is exacerbated by the MMU notifiers often firing multiple times in quick succession, e.g. moving a page will (always?) invoke three separate notifiers: .invalidate_range_start(), invalidate_range_end(), and .change_pte(). Unnecessarily taking mmu_lock each time means even a single spurious sequence can be problematic. Note, this optimizes only the unpaired callbacks. Optimizing the .invalidate_range_{start,end}() pairs is more complex and will be done in a future patch. Suggested-by: Ben Gardon <bgardon@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210402005658.3024832-9-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-02 08:56:56 +08:00
if (locked)
KVM_MMU_UNLOCK(kvm);
srcu_read_unlock(&kvm->srcu, idx);
/* The notifiers are averse to booleans. :-( */
return (int)ret;
}
static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn,
unsigned long start,
unsigned long end,
pte_t pte,
hva_handler_t handler)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
const struct kvm_hva_range range = {
.start = start,
.end = end,
.pte = pte,
.handler = handler,
.on_lock = (void *)kvm_null_fn,
.flush_on_ret = true,
.may_block = false,
};
return __kvm_handle_hva_range(kvm, &range);
}
static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn,
unsigned long start,
unsigned long end,
hva_handler_t handler)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
const struct kvm_hva_range range = {
.start = start,
.end = end,
.pte = __pte(0),
.handler = handler,
.on_lock = (void *)kvm_null_fn,
.flush_on_ret = false,
.may_block = false,
};
return __kvm_handle_hva_range(kvm, &range);
}
static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long address,
pte_t pte)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
trace_kvm_set_spte_hva(address);
KVM: Assert that notifier count is elevated in .change_pte() In KVM's .change_pte() notification callback, replace the notifier sequence bump with a WARN_ON assertion that the notifier count is elevated. An elevated count provides stricter protections than bumping the sequence, and the sequence is guarnateed to be bumped before the count hits zero. When .change_pte() was added by commit 828502d30073 ("ksm: add mmu_notifier set_pte_at_notify()"), bumping the sequence was necessary as .change_pte() would be invoked without any surrounding notifications. However, since commit 6bdb913f0a70 ("mm: wrap calls to set_pte_at_notify with invalidate_range_start and invalidate_range_end"), all calls to .change_pte() are guaranteed to be surrounded by start() and end(), and so are guaranteed to run with an elevated notifier count. Note, wrapping .change_pte() with .invalidate_range_{start,end}() is a bug of sorts, as invalidating the secondary MMU's (KVM's) PTE defeats the purpose of .change_pte(). Every arch's kvm_set_spte_hva() assumes .change_pte() is called when the relevant SPTE is present in KVM's MMU, as the original goal was to accelerate Kernel Samepage Merging (KSM) by updating KVM's SPTEs without requiring a VM-Exit (due to invalidating the SPTE). I.e. it means that .change_pte() is effectively dead code on _all_ architectures. x86 and MIPS are clearcut nops if the old SPTE is not-present, and that is guaranteed due to the prior invalidation. PPC simply unmaps the SPTE, which again should be a nop due to the invalidation. arm64 is a bit murky, but it's also likely a nop because kvm_pgtable_stage2_map() is called without a cache pointer, which means it will map an entry if and only if an existing PTE was found. For now, take advantage of the bug to simplify future consolidation of KVMs's MMU notifier code. Doing so will not greatly complicate fixing .change_pte(), assuming it's even worth fixing. .change_pte() has been broken for 8+ years and no one has complained. Even if there are KSM+KVM users that care deeply about its performance, the benefits of avoiding VM-Exits via .change_pte() need to be reevaluated to justify the added complexity and testing burden. Ripping out .change_pte() entirely would be a lot easier. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-02 08:56:49 +08:00
/*
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
* .change_pte() must be surrounded by .invalidate_range_{start,end}().
* If mmu_notifier_count is zero, then no in-progress invalidations,
* including this one, found a relevant memslot at start(); rechecking
* memslots here is unnecessary. Note, a false positive (count elevated
* by a different invalidation) is sub-optimal but functionally ok.
KVM: Assert that notifier count is elevated in .change_pte() In KVM's .change_pte() notification callback, replace the notifier sequence bump with a WARN_ON assertion that the notifier count is elevated. An elevated count provides stricter protections than bumping the sequence, and the sequence is guarnateed to be bumped before the count hits zero. When .change_pte() was added by commit 828502d30073 ("ksm: add mmu_notifier set_pte_at_notify()"), bumping the sequence was necessary as .change_pte() would be invoked without any surrounding notifications. However, since commit 6bdb913f0a70 ("mm: wrap calls to set_pte_at_notify with invalidate_range_start and invalidate_range_end"), all calls to .change_pte() are guaranteed to be surrounded by start() and end(), and so are guaranteed to run with an elevated notifier count. Note, wrapping .change_pte() with .invalidate_range_{start,end}() is a bug of sorts, as invalidating the secondary MMU's (KVM's) PTE defeats the purpose of .change_pte(). Every arch's kvm_set_spte_hva() assumes .change_pte() is called when the relevant SPTE is present in KVM's MMU, as the original goal was to accelerate Kernel Samepage Merging (KSM) by updating KVM's SPTEs without requiring a VM-Exit (due to invalidating the SPTE). I.e. it means that .change_pte() is effectively dead code on _all_ architectures. x86 and MIPS are clearcut nops if the old SPTE is not-present, and that is guaranteed due to the prior invalidation. PPC simply unmaps the SPTE, which again should be a nop due to the invalidation. arm64 is a bit murky, but it's also likely a nop because kvm_pgtable_stage2_map() is called without a cache pointer, which means it will map an entry if and only if an existing PTE was found. For now, take advantage of the bug to simplify future consolidation of KVMs's MMU notifier code. Doing so will not greatly complicate fixing .change_pte(), assuming it's even worth fixing. .change_pte() has been broken for 8+ years and no one has complained. Even if there are KSM+KVM users that care deeply about its performance, the benefits of avoiding VM-Exits via .change_pte() need to be reevaluated to justify the added complexity and testing burden. Ripping out .change_pte() entirely would be a lot easier. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-02 08:56:49 +08:00
*/
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
WARN_ON_ONCE(!READ_ONCE(kvm->mn_active_invalidate_count));
if (!READ_ONCE(kvm->mmu_notifier_count))
return;
KVM: Assert that notifier count is elevated in .change_pte() In KVM's .change_pte() notification callback, replace the notifier sequence bump with a WARN_ON assertion that the notifier count is elevated. An elevated count provides stricter protections than bumping the sequence, and the sequence is guarnateed to be bumped before the count hits zero. When .change_pte() was added by commit 828502d30073 ("ksm: add mmu_notifier set_pte_at_notify()"), bumping the sequence was necessary as .change_pte() would be invoked without any surrounding notifications. However, since commit 6bdb913f0a70 ("mm: wrap calls to set_pte_at_notify with invalidate_range_start and invalidate_range_end"), all calls to .change_pte() are guaranteed to be surrounded by start() and end(), and so are guaranteed to run with an elevated notifier count. Note, wrapping .change_pte() with .invalidate_range_{start,end}() is a bug of sorts, as invalidating the secondary MMU's (KVM's) PTE defeats the purpose of .change_pte(). Every arch's kvm_set_spte_hva() assumes .change_pte() is called when the relevant SPTE is present in KVM's MMU, as the original goal was to accelerate Kernel Samepage Merging (KSM) by updating KVM's SPTEs without requiring a VM-Exit (due to invalidating the SPTE). I.e. it means that .change_pte() is effectively dead code on _all_ architectures. x86 and MIPS are clearcut nops if the old SPTE is not-present, and that is guaranteed due to the prior invalidation. PPC simply unmaps the SPTE, which again should be a nop due to the invalidation. arm64 is a bit murky, but it's also likely a nop because kvm_pgtable_stage2_map() is called without a cache pointer, which means it will map an entry if and only if an existing PTE was found. For now, take advantage of the bug to simplify future consolidation of KVMs's MMU notifier code. Doing so will not greatly complicate fixing .change_pte(), assuming it's even worth fixing. .change_pte() has been broken for 8+ years and no one has complained. Even if there are KSM+KVM users that care deeply about its performance, the benefits of avoiding VM-Exits via .change_pte() need to be reevaluated to justify the added complexity and testing burden. Ripping out .change_pte() entirely would be a lot easier. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-02 08:56:49 +08:00
kvm_handle_hva_range(mn, address, address + 1, pte, kvm_set_spte_gfn);
}
void kvm_inc_notifier_count(struct kvm *kvm, unsigned long start,
unsigned long end)
{
/*
* The count increase must become visible at unlock time as no
* spte can be established without taking the mmu_lock and
* count is also read inside the mmu_lock critical section.
*/
kvm->mmu_notifier_count++;
if (likely(kvm->mmu_notifier_count == 1)) {
kvm->mmu_notifier_range_start = start;
kvm->mmu_notifier_range_end = end;
} else {
/*
* Fully tracking multiple concurrent ranges has dimishing
* returns. Keep things simple and just find the minimal range
* which includes the current and new ranges. As there won't be
* enough information to subtract a range after its invalidate
* completes, any ranges invalidated concurrently will
* accumulate and persist until all outstanding invalidates
* complete.
*/
kvm->mmu_notifier_range_start =
min(kvm->mmu_notifier_range_start, start);
kvm->mmu_notifier_range_end =
max(kvm->mmu_notifier_range_end, end);
}
}
EXPORT_SYMBOL_GPL(kvm_inc_notifier_count);
static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
const struct mmu_notifier_range *range)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
const struct kvm_hva_range hva_range = {
.start = range->start,
.end = range->end,
.pte = __pte(0),
.handler = kvm_unmap_gfn_range,
.on_lock = kvm_inc_notifier_count,
.flush_on_ret = true,
.may_block = mmu_notifier_range_blockable(range),
};
trace_kvm_unmap_hva_range(range->start, range->end);
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
/*
* Prevent memslot modification between range_start() and range_end()
* so that conditionally locking provides the same result in both
* functions. Without that guarantee, the mmu_notifier_count
* adjustments will be imbalanced.
*
* Pairs with the decrement in range_end().
*/
spin_lock(&kvm->mn_invalidate_lock);
kvm->mn_active_invalidate_count++;
spin_unlock(&kvm->mn_invalidate_lock);
__kvm_handle_hva_range(kvm, &hva_range);
mm, oom: distinguish blockable mode for mmu notifiers There are several blockable mmu notifiers which might sleep in mmu_notifier_invalidate_range_start and that is a problem for the oom_reaper because it needs to guarantee a forward progress so it cannot depend on any sleepable locks. Currently we simply back off and mark an oom victim with blockable mmu notifiers as done after a short sleep. That can result in selecting a new oom victim prematurely because the previous one still hasn't torn its memory down yet. We can do much better though. Even if mmu notifiers use sleepable locks there is no reason to automatically assume those locks are held. Moreover majority of notifiers only care about a portion of the address space and there is absolutely zero reason to fail when we are unmapping an unrelated range. Many notifiers do really block and wait for HW which is harder to handle and we have to bail out though. This patch handles the low hanging fruit. __mmu_notifier_invalidate_range_start gets a blockable flag and callbacks are not allowed to sleep if the flag is set to false. This is achieved by using trylock instead of the sleepable lock for most callbacks and continue as long as we do not block down the call chain. I think we can improve that even further because there is a common pattern to do a range lookup first and then do something about that. The first part can be done without a sleeping lock in most cases AFAICS. The oom_reaper end then simply retries if there is at least one notifier which couldn't make any progress in !blockable mode. A retry loop is already implemented to wait for the mmap_sem and this is basically the same thing. The simplest way for driver developers to test this code path is to wrap userspace code which uses these notifiers into a memcg and set the hard limit to hit the oom. This can be done e.g. after the test faults in all the mmu notifier managed memory and set the hard limit to something really small. Then we are looking for a proper process tear down. [akpm@linux-foundation.org: coding style fixes] [akpm@linux-foundation.org: minor code simplification] Link: http://lkml.kernel.org/r/20180716115058.5559-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Christian König <christian.koenig@amd.com> # AMD notifiers Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx and umem_odp Reported-by: David Rientjes <rientjes@google.com> Cc: "David (ChunMing) Zhou" <David1.Zhou@amd.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: David Airlie <airlied@linux.ie> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Mike Marciniszyn <mike.marciniszyn@intel.com> Cc: Dennis Dalessandro <dennis.dalessandro@intel.com> Cc: Sudeep Dutt <sudeep.dutt@intel.com> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Felix Kuehling <felix.kuehling@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 12:52:33 +08:00
KVM: x86: Fix APIC page invalidation race Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried to fix inappropriate APIC page invalidation by re-introducing arch specific kvm_arch_mmu_notifier_invalidate_range() and calling it from kvm_mmu_notifier_invalidate_range_start. However, the patch left a possible race where the VMCS APIC address cache is updated *before* it is unmapped: (Invalidator) kvm_mmu_notifier_invalidate_range_start() (Invalidator) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD) (KVM VCPU) vcpu_enter_guest() (KVM VCPU) kvm_vcpu_reload_apic_access_page() (Invalidator) actually unmap page Because of the above race, there can be a mismatch between the host physical address stored in the APIC_ACCESS_PAGE VMCS field and the host physical address stored in the EPT entry for the APIC GPA (0xfee0000). When this happens, the processor will not trap APIC accesses, and will instead show the raw contents of the APIC-access page. Because Windows OS periodically checks for unexpected modifications to the LAPIC register, this will show up as a BSOD crash with BugCheck CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in https://bugzilla.redhat.com/show_bug.cgi?id=1751017. The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range() cannot guarantee that no additional references are taken to the pages in the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately, this case is supported by the MMU notifier API, as documented in include/linux/mmu_notifier.h: * If the subsystem * can't guarantee that no additional references are taken to * the pages in the range, it has to implement the * invalidate_range() notifier to remove any references taken * after invalidate_range_start(). The fix therefore is to reload the APIC-access page field in the VMCS from kvm_mmu_notifier_invalidate_range() instead of ..._range_start(). Cc: stable@vger.kernel.org Fixes: b1394e745b94 ("KVM: x86: fix APIC page invalidation") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=197951 Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Message-Id: <20200606042627.61070-1-eiichi.tsukata@nutanix.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-06 12:26:27 +08:00
return 0;
}
void kvm_dec_notifier_count(struct kvm *kvm, unsigned long start,
unsigned long end)
{
/*
* This sequence increase will notify the kvm page fault that
* the page that is going to be mapped in the spte could have
* been freed.
*/
kvm->mmu_notifier_seq++;
smp_wmb();
/*
* The above sequence increase must be visible before the
* below count decrease, which is ensured by the smp_wmb above
* in conjunction with the smp_rmb in mmu_notifier_retry().
*/
kvm->mmu_notifier_count--;
}
EXPORT_SYMBOL_GPL(kvm_dec_notifier_count);
static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
const struct mmu_notifier_range *range)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
const struct kvm_hva_range hva_range = {
.start = range->start,
.end = range->end,
.pte = __pte(0),
.handler = (void *)kvm_null_fn,
.on_lock = kvm_dec_notifier_count,
.flush_on_ret = false,
.may_block = mmu_notifier_range_blockable(range),
};
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
bool wake;
__kvm_handle_hva_range(kvm, &hva_range);
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
/* Pairs with the increment in range_start(). */
spin_lock(&kvm->mn_invalidate_lock);
wake = (--kvm->mn_active_invalidate_count == 0);
spin_unlock(&kvm->mn_invalidate_lock);
/*
* There can only be one waiter, since the wait happens under
* slots_lock.
*/
if (wake)
rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait);
BUG_ON(kvm->mmu_notifier_count < 0);
}
static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
unsigned long end)
{
trace_kvm_age_hva(start, end);
return kvm_handle_hva_range(mn, start, end, __pte(0), kvm_age_gfn);
}
static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
unsigned long end)
{
trace_kvm_age_hva(start, end);
/*
* Even though we do not flush TLB, this will still adversely
* affect performance on pre-Haswell Intel EPT, where there is
* no EPT Access Bit to clear so that we have to tear down EPT
* tables instead. If we find this unacceptable, we can always
* add a parameter to kvm_age_hva so that it effectively doesn't
* do anything on clear_young.
*
* Also note that currently we never issue secondary TLB flushes
* from clear_young, leaving this job up to the regular system
* cadence. If we find this inaccurate, we might come up with a
* more sophisticated heuristic later.
*/
return kvm_handle_hva_range_no_flush(mn, start, end, kvm_age_gfn);
}
static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long address)
{
trace_kvm_test_age_hva(address);
return kvm_handle_hva_range_no_flush(mn, address, address + 1,
kvm_test_age_gfn);
}
static void kvm_mmu_notifier_release(struct mmu_notifier *mn,
struct mm_struct *mm)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
KVM: Add missing srcu_read_lock() for kvm_mmu_notifier_release() I got this dmesg due to srcu_read_lock() is missing in kvm_mmu_notifier_release(). =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/x86.h:72 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/3100: #0: (rcu_read_lock){.+.+..}, at: [<ffffffff810d73dc>] __mmu_notifier_release+0x38/0xdf #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa0130a6a>] kvm_mmu_zap_all+0x21/0x5e [kvm] stack backtrace: Pid: 3100, comm: qemu-system-x86 Not tainted 2.6.34-rc3-22949-gbc8a97a-dirty #2 Call Trace: [<ffffffff8106afd9>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa0123a89>] unalias_gfn+0x56/0xab [kvm] [<ffffffffa0119600>] gfn_to_memslot+0x16/0x25 [kvm] [<ffffffffa012ffca>] gfn_to_rmap+0x17/0x6e [kvm] [<ffffffffa01300c1>] rmap_remove+0xa0/0x19d [kvm] [<ffffffffa0130649>] kvm_mmu_zap_page+0x109/0x34d [kvm] [<ffffffffa0130a7e>] kvm_mmu_zap_all+0x35/0x5e [kvm] [<ffffffffa0122870>] kvm_arch_flush_shadow+0x16/0x22 [kvm] [<ffffffffa01189e0>] kvm_mmu_notifier_release+0x15/0x17 [kvm] [<ffffffff810d742c>] __mmu_notifier_release+0x88/0xdf [<ffffffff810d73dc>] ? __mmu_notifier_release+0x38/0xdf [<ffffffff81040848>] ? exit_mm+0xe0/0x115 [<ffffffff810c2cb0>] exit_mmap+0x2c/0x17e [<ffffffff8103c472>] mmput+0x2d/0xd4 [<ffffffff81040870>] exit_mm+0x108/0x115 [...] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-20 14:29:29 +08:00
int idx;
idx = srcu_read_lock(&kvm->srcu);
kvm_arch_flush_shadow_all(kvm);
KVM: Add missing srcu_read_lock() for kvm_mmu_notifier_release() I got this dmesg due to srcu_read_lock() is missing in kvm_mmu_notifier_release(). =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/x86.h:72 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/3100: #0: (rcu_read_lock){.+.+..}, at: [<ffffffff810d73dc>] __mmu_notifier_release+0x38/0xdf #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa0130a6a>] kvm_mmu_zap_all+0x21/0x5e [kvm] stack backtrace: Pid: 3100, comm: qemu-system-x86 Not tainted 2.6.34-rc3-22949-gbc8a97a-dirty #2 Call Trace: [<ffffffff8106afd9>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa0123a89>] unalias_gfn+0x56/0xab [kvm] [<ffffffffa0119600>] gfn_to_memslot+0x16/0x25 [kvm] [<ffffffffa012ffca>] gfn_to_rmap+0x17/0x6e [kvm] [<ffffffffa01300c1>] rmap_remove+0xa0/0x19d [kvm] [<ffffffffa0130649>] kvm_mmu_zap_page+0x109/0x34d [kvm] [<ffffffffa0130a7e>] kvm_mmu_zap_all+0x35/0x5e [kvm] [<ffffffffa0122870>] kvm_arch_flush_shadow+0x16/0x22 [kvm] [<ffffffffa01189e0>] kvm_mmu_notifier_release+0x15/0x17 [kvm] [<ffffffff810d742c>] __mmu_notifier_release+0x88/0xdf [<ffffffff810d73dc>] ? __mmu_notifier_release+0x38/0xdf [<ffffffff81040848>] ? exit_mm+0xe0/0x115 [<ffffffff810c2cb0>] exit_mmap+0x2c/0x17e [<ffffffff8103c472>] mmput+0x2d/0xd4 [<ffffffff81040870>] exit_mm+0x108/0x115 [...] Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-20 14:29:29 +08:00
srcu_read_unlock(&kvm->srcu, idx);
}
static const struct mmu_notifier_ops kvm_mmu_notifier_ops = {
KVM: x86: Fix APIC page invalidation race Commit b1394e745b94 ("KVM: x86: fix APIC page invalidation") tried to fix inappropriate APIC page invalidation by re-introducing arch specific kvm_arch_mmu_notifier_invalidate_range() and calling it from kvm_mmu_notifier_invalidate_range_start. However, the patch left a possible race where the VMCS APIC address cache is updated *before* it is unmapped: (Invalidator) kvm_mmu_notifier_invalidate_range_start() (Invalidator) kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD) (KVM VCPU) vcpu_enter_guest() (KVM VCPU) kvm_vcpu_reload_apic_access_page() (Invalidator) actually unmap page Because of the above race, there can be a mismatch between the host physical address stored in the APIC_ACCESS_PAGE VMCS field and the host physical address stored in the EPT entry for the APIC GPA (0xfee0000). When this happens, the processor will not trap APIC accesses, and will instead show the raw contents of the APIC-access page. Because Windows OS periodically checks for unexpected modifications to the LAPIC register, this will show up as a BSOD crash with BugCheck CRITICAL_STRUCTURE_CORRUPTION (109) we are currently seeing in https://bugzilla.redhat.com/show_bug.cgi?id=1751017. The root cause of the issue is that kvm_arch_mmu_notifier_invalidate_range() cannot guarantee that no additional references are taken to the pages in the range before kvm_mmu_notifier_invalidate_range_end(). Fortunately, this case is supported by the MMU notifier API, as documented in include/linux/mmu_notifier.h: * If the subsystem * can't guarantee that no additional references are taken to * the pages in the range, it has to implement the * invalidate_range() notifier to remove any references taken * after invalidate_range_start(). The fix therefore is to reload the APIC-access page field in the VMCS from kvm_mmu_notifier_invalidate_range() instead of ..._range_start(). Cc: stable@vger.kernel.org Fixes: b1394e745b94 ("KVM: x86: fix APIC page invalidation") Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=197951 Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com> Message-Id: <20200606042627.61070-1-eiichi.tsukata@nutanix.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-06 12:26:27 +08:00
.invalidate_range = kvm_mmu_notifier_invalidate_range,
.invalidate_range_start = kvm_mmu_notifier_invalidate_range_start,
.invalidate_range_end = kvm_mmu_notifier_invalidate_range_end,
.clear_flush_young = kvm_mmu_notifier_clear_flush_young,
.clear_young = kvm_mmu_notifier_clear_young,
.test_young = kvm_mmu_notifier_test_young,
.change_pte = kvm_mmu_notifier_change_pte,
.release = kvm_mmu_notifier_release,
};
static int kvm_init_mmu_notifier(struct kvm *kvm)
{
kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops;
return mmu_notifier_register(&kvm->mmu_notifier, current->mm);
}
#else /* !(CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER) */
static int kvm_init_mmu_notifier(struct kvm *kvm)
{
return 0;
}
#endif /* CONFIG_MMU_NOTIFIER && KVM_ARCH_WANT_MMU_NOTIFIER */
#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
static int kvm_pm_notifier_call(struct notifier_block *bl,
unsigned long state,
void *unused)
{
struct kvm *kvm = container_of(bl, struct kvm, pm_notifier);
return kvm_arch_pm_notifier(kvm, state);
}
static void kvm_init_pm_notifier(struct kvm *kvm)
{
kvm->pm_notifier.notifier_call = kvm_pm_notifier_call;
/* Suspend KVM before we suspend ftrace, RCU, etc. */
kvm->pm_notifier.priority = INT_MAX;
register_pm_notifier(&kvm->pm_notifier);
}
static void kvm_destroy_pm_notifier(struct kvm *kvm)
{
unregister_pm_notifier(&kvm->pm_notifier);
}
#else /* !CONFIG_HAVE_KVM_PM_NOTIFIER */
static void kvm_init_pm_notifier(struct kvm *kvm)
{
}
static void kvm_destroy_pm_notifier(struct kvm *kvm)
{
}
#endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */
static struct kvm_memslots *kvm_alloc_memslots(void)
{
int i;
struct kvm_memslots *slots;
slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT);
if (!slots)
return NULL;
for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
slots->id_to_index[i] = -1;
return slots;
}
static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
{
if (!memslot->dirty_bitmap)
return;
kvfree(memslot->dirty_bitmap);
memslot->dirty_bitmap = NULL;
}
static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
{
kvm_destroy_dirty_bitmap(slot);
kvm_arch_free_memslot(kvm, slot);
slot->flags = 0;
slot->npages = 0;
}
static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
{
struct kvm_memory_slot *memslot;
if (!slots)
return;
kvm_for_each_memslot(memslot, slots)
kvm_free_memslot(kvm, memslot);
kvfree(slots);
}
static umode_t kvm_stats_debugfs_mode(const struct _kvm_stats_desc *pdesc)
{
switch (pdesc->desc.flags & KVM_STATS_TYPE_MASK) {
case KVM_STATS_TYPE_INSTANT:
return 0444;
case KVM_STATS_TYPE_CUMULATIVE:
case KVM_STATS_TYPE_PEAK:
default:
return 0644;
}
}
static void kvm_destroy_vm_debugfs(struct kvm *kvm)
{
int i;
int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
kvm_vcpu_stats_header.num_desc;
if (!kvm->debugfs_dentry)
return;
debugfs_remove_recursive(kvm->debugfs_dentry);
if (kvm->debugfs_stat_data) {
for (i = 0; i < kvm_debugfs_num_entries; i++)
kfree(kvm->debugfs_stat_data[i]);
kfree(kvm->debugfs_stat_data);
}
}
static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
{
KVM: Do not leak memory for duplicate debugfs directories KVM creates a debugfs directory for each VM in order to store statistics about the virtual machine. The directory name is built from the process pid and a VM fd. While generally unique, it is possible to keep a file descriptor alive in a way that causes duplicate directories, which manifests as these messages: [ 471.846235] debugfs: Directory '20245-4' with parent 'kvm' already present! Even though this should not happen in practice, it is more or less expected in the case of KVM for testcases that call KVM_CREATE_VM and close the resulting file descriptor repeatedly and in parallel. When this happens, debugfs_create_dir() returns an error but kvm_create_vm_debugfs() goes on to allocate stat data structs which are later leaked. The slow memory leak was spotted by syzkaller, where it caused OOM reports. Since the issue only affects debugfs, do a lookup before calling debugfs_create_dir, so that the message is downgraded and rate-limited. While at it, ensure kvm->debugfs_dentry is NULL rather than an error if it is not created. This fixes kvm_destroy_vm_debugfs, which was not checking IS_ERR_OR_NULL correctly. Cc: stable@vger.kernel.org Fixes: 536a6f88c49d ("KVM: Create debugfs dir and stat files for each VM") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-04 17:28:52 +08:00
static DEFINE_MUTEX(kvm_debugfs_lock);
struct dentry *dent;
char dir_name[ITOA_MAX_LEN * 2];
struct kvm_stat_data *stat_data;
const struct _kvm_stats_desc *pdesc;
int i, ret;
int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
kvm_vcpu_stats_header.num_desc;
if (!debugfs_initialized())
return 0;
snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd);
KVM: Do not leak memory for duplicate debugfs directories KVM creates a debugfs directory for each VM in order to store statistics about the virtual machine. The directory name is built from the process pid and a VM fd. While generally unique, it is possible to keep a file descriptor alive in a way that causes duplicate directories, which manifests as these messages: [ 471.846235] debugfs: Directory '20245-4' with parent 'kvm' already present! Even though this should not happen in practice, it is more or less expected in the case of KVM for testcases that call KVM_CREATE_VM and close the resulting file descriptor repeatedly and in parallel. When this happens, debugfs_create_dir() returns an error but kvm_create_vm_debugfs() goes on to allocate stat data structs which are later leaked. The slow memory leak was spotted by syzkaller, where it caused OOM reports. Since the issue only affects debugfs, do a lookup before calling debugfs_create_dir, so that the message is downgraded and rate-limited. While at it, ensure kvm->debugfs_dentry is NULL rather than an error if it is not created. This fixes kvm_destroy_vm_debugfs, which was not checking IS_ERR_OR_NULL correctly. Cc: stable@vger.kernel.org Fixes: 536a6f88c49d ("KVM: Create debugfs dir and stat files for each VM") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-04 17:28:52 +08:00
mutex_lock(&kvm_debugfs_lock);
dent = debugfs_lookup(dir_name, kvm_debugfs_dir);
if (dent) {
pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name);
dput(dent);
mutex_unlock(&kvm_debugfs_lock);
return 0;
}
dent = debugfs_create_dir(dir_name, kvm_debugfs_dir);
mutex_unlock(&kvm_debugfs_lock);
if (IS_ERR(dent))
return 0;
KVM: Do not leak memory for duplicate debugfs directories KVM creates a debugfs directory for each VM in order to store statistics about the virtual machine. The directory name is built from the process pid and a VM fd. While generally unique, it is possible to keep a file descriptor alive in a way that causes duplicate directories, which manifests as these messages: [ 471.846235] debugfs: Directory '20245-4' with parent 'kvm' already present! Even though this should not happen in practice, it is more or less expected in the case of KVM for testcases that call KVM_CREATE_VM and close the resulting file descriptor repeatedly and in parallel. When this happens, debugfs_create_dir() returns an error but kvm_create_vm_debugfs() goes on to allocate stat data structs which are later leaked. The slow memory leak was spotted by syzkaller, where it caused OOM reports. Since the issue only affects debugfs, do a lookup before calling debugfs_create_dir, so that the message is downgraded and rate-limited. While at it, ensure kvm->debugfs_dentry is NULL rather than an error if it is not created. This fixes kvm_destroy_vm_debugfs, which was not checking IS_ERR_OR_NULL correctly. Cc: stable@vger.kernel.org Fixes: 536a6f88c49d ("KVM: Create debugfs dir and stat files for each VM") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-04 17:28:52 +08:00
kvm->debugfs_dentry = dent;
kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries,
sizeof(*kvm->debugfs_stat_data),
GFP_KERNEL_ACCOUNT);
if (!kvm->debugfs_stat_data)
return -ENOMEM;
for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
pdesc = &kvm_vm_stats_desc[i];
stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
if (!stat_data)
return -ENOMEM;
stat_data->kvm = kvm;
stat_data->desc = pdesc;
stat_data->kind = KVM_STAT_VM;
kvm->debugfs_stat_data[i] = stat_data;
debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
kvm->debugfs_dentry, stat_data,
&stat_fops_per_vm);
}
for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
pdesc = &kvm_vcpu_stats_desc[i];
stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
if (!stat_data)
return -ENOMEM;
stat_data->kvm = kvm;
stat_data->desc = pdesc;
stat_data->kind = KVM_STAT_VCPU;
kvm->debugfs_stat_data[i + kvm_vm_stats_header.num_desc] = stat_data;
debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
kvm->debugfs_dentry, stat_data,
&stat_fops_per_vm);
}
ret = kvm_arch_create_vm_debugfs(kvm);
if (ret) {
kvm_destroy_vm_debugfs(kvm);
return i;
}
return 0;
}
/*
* Called after the VM is otherwise initialized, but just before adding it to
* the vm_list.
*/
int __weak kvm_arch_post_init_vm(struct kvm *kvm)
{
return 0;
}
/*
* Called just after removing the VM from the vm_list, but before doing any
* other destruction.
*/
void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm)
{
}
/*
* Called after per-vm debugfs created. When called kvm->debugfs_dentry should
* be setup already, so we can create arch-specific debugfs entries under it.
* Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so
* a per-arch destroy interface is not needed.
*/
int __weak kvm_arch_create_vm_debugfs(struct kvm *kvm)
{
return 0;
}
static struct kvm *kvm_create_vm(unsigned long type)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
struct kvm *kvm = kvm_arch_alloc_vm();
int r = -ENOMEM;
int i;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (!kvm)
return ERR_PTR(-ENOMEM);
KVM_MMU_LOCK_INIT(kvm);
mmgrab(current->mm);
kvm->mm = current->mm;
kvm_eventfd_init(kvm);
mutex_init(&kvm->lock);
mutex_init(&kvm->irq_lock);
mutex_init(&kvm->slots_lock);
mutex_init(&kvm->slots_arch_lock);
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
spin_lock_init(&kvm->mn_invalidate_lock);
rcuwait_init(&kvm->mn_memslots_update_rcuwait);
INIT_LIST_HEAD(&kvm->devices);
BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX);
KVM: Fix NULL-ptr deref after kvm_create_vm fails Reported by syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 14727 Comm: syz-executor.3 Not tainted 5.4.0-rc4+ #0 RIP: 0010:kvm_coalesced_mmio_init+0x5d/0x110 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:121 Call Trace: kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3446 [inline] kvm_dev_ioctl+0x781/0x1490 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3494 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x196/0x1150 fs/ioctl.c:696 ksys_ioctl+0x62/0x90 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:718 do_syscall_64+0xca/0x5d0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Commit 9121923c457d ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm") moves memslots and buses allocations around, however, if kvm->srcu/irq_srcu fails initialization, NULL will be returned instead of error code, NULL will not be intercepted in kvm_dev_ioctl_create_vm() and be dereferenced by kvm_coalesced_mmio_init(), this patch fixes it. Moving the initialization is required anyway to avoid an incorrect synchronize_srcu that was also reported by syzkaller: wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline] synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997 kvm_page_track_unregister_notifier+0xe7/0x130 arch/x86/kvm/page_track.c:212 kvm_mmu_uninit_vm+0x1e/0x30 arch/x86/kvm/mmu.c:5828 kvm_arch_destroy_vm+0x4a2/0x5f0 arch/x86/kvm/x86.c:9579 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:702 [inline] so do it. Reported-by: syzbot+89a8060879fa0bd2db4f@syzkaller.appspotmail.com Reported-by: syzbot+e27e7027eb2b80e44225@syzkaller.appspotmail.com Fixes: 9121923c457d ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm") Cc: Jim Mattson <jmattson@google.com> Cc: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-04 19:16:49 +08:00
if (init_srcu_struct(&kvm->srcu))
goto out_err_no_srcu;
if (init_srcu_struct(&kvm->irq_srcu))
goto out_err_no_irq_srcu;
refcount_set(&kvm->users_count, 1);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
struct kvm_memslots *slots = kvm_alloc_memslots();
if (!slots)
goto out_err_no_arch_destroy_vm;
KVM: Remove the hack to trigger memslot generation wraparound x86 captures a subset of the memslot generation (19 bits) in its MMIO sptes so that it can expedite emulated MMIO handling by checking only the releveant spte, i.e. doesn't need to do a full page fault walk. Because the MMIO sptes capture only 19 bits (due to limited space in the sptes), there is a non-zero probability that the MMIO generation could wrap, e.g. after 500k memslot updates. Since normal usage is extremely unlikely to result in 500k memslot updates, a hack was added by commit 69c9ea93eaea ("KVM: MMU: init kvm generation close to mmio wrap-around value") to offset the MMIO generation in order to trigger a wraparound, e.g. after 150 memslot updates. When separate memslot generation sequences were assigned to each address space, commit 00f034a12fdd ("KVM: do not bias the generation number in kvm_current_mmio_generation") moved the offset logic into the initialization of the memslot generation itself so that the per-address space bit(s) were not dropped/corrupted by the MMIO shenanigans. Remove the offset hack for three reasons: - While it does exercise x86's kvm_mmu_invalidate_mmio_sptes(), simply wrapping the generation doesn't actually test the interesting case of having stale MMIO sptes with the new generation number, e.g. old sptes with a generation number of 0. - Triggering kvm_mmu_invalidate_mmio_sptes() prematurely makes its performance rather important since the probability of invalidating MMIO sptes jumps from "effectively never" to "fairly likely". This limits what can be done in future patches, e.g. to simplify the invalidation code, as doing so without proper caution could lead to a noticeable performance regression. - Forcing the memslots generation, which is a 64-bit number, to wrap prevents KVM from assuming the memslots generation will never wrap. This in turn prevents KVM from using an arbitrary bit for the "update in-progress" flag, e.g. using bit 63 would immediately collide with using a large value as the starting generation number. The "update in-progress" flag is effectively forced into bit 0 so that it's (subtly) taken into account when incrementing the generation. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-06 05:01:17 +08:00
/* Generations must be different for each address space. */
slots->generation = i;
rcu_assign_pointer(kvm->memslots[i], slots);
}
for (i = 0; i < KVM_NR_BUSES; i++) {
rcu_assign_pointer(kvm->buses[i],
kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
if (!kvm->buses[i])
goto out_err_no_arch_destroy_vm;
}
kvm->max_halt_poll_ns = halt_poll_ns;
r = kvm_arch_init_vm(kvm, type);
if (r)
goto out_err_no_arch_destroy_vm;
r = hardware_enable_all();
if (r)
kvm/irqchip: Speed up KVM_SET_GSI_ROUTING When starting lots of dataplane devices the bootup takes very long on Christian's s390 with irqfd patches. With larger setups he is even able to trigger some timeouts in some components. Turns out that the KVM_SET_GSI_ROUTING ioctl takes very long (strace claims up to 0.1 sec) when having multiple CPUs. This is caused by the synchronize_rcu and the HZ=100 of s390. By changing the code to use a private srcu we can speed things up. This patch reduces the boot time till mounting root from 8 to 2 seconds on my s390 guest with 100 disks. Uses of hlist_for_each_entry_rcu, hlist_add_head_rcu, hlist_del_init_rcu are fine because they do not have lockdep checks (hlist_for_each_entry_rcu uses rcu_dereference_raw rather than rcu_dereference, and write-sides do not do rcu lockdep at all). Note that we're hardly relying on the "sleepable" part of srcu. We just want SRCU's faster detection of grace periods. Testing was done by Andrew Theurer using netperf tests STREAM, MAERTS and RR. The difference between results "before" and "after" the patch has mean -0.2% and standard deviation 0.6%. Using a paired t-test on the data points says that there is a 2.5% probability that the patch is the cause of the performance difference (rather than a random fluctuation). (Restricting the t-test to RR, which is the most likely to be affected, changes the numbers to respectively -0.3% mean, 0.7% stdev, and 8% probability that the numbers actually say something about the patch. The probability increases mostly because there are fewer data points). Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # s390 Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-16 20:44:20 +08:00
goto out_err_no_disable;
#ifdef CONFIG_HAVE_KVM_IRQFD
INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list);
#endif
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = kvm_init_mmu_notifier(kvm);
if (r)
goto out_err_no_mmu_notifier;
r = kvm_arch_post_init_vm(kvm);
if (r)
goto out_err;
mutex_lock(&kvm_lock);
list_add(&kvm->vm_list, &vm_list);
mutex_unlock(&kvm_lock);
preempt_notifier_inc();
kvm_init_pm_notifier(kvm);
return kvm;
out_err:
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
if (kvm->mmu_notifier.ops)
mmu_notifier_unregister(&kvm->mmu_notifier, current->mm);
#endif
out_err_no_mmu_notifier:
hardware_disable_all();
kvm/irqchip: Speed up KVM_SET_GSI_ROUTING When starting lots of dataplane devices the bootup takes very long on Christian's s390 with irqfd patches. With larger setups he is even able to trigger some timeouts in some components. Turns out that the KVM_SET_GSI_ROUTING ioctl takes very long (strace claims up to 0.1 sec) when having multiple CPUs. This is caused by the synchronize_rcu and the HZ=100 of s390. By changing the code to use a private srcu we can speed things up. This patch reduces the boot time till mounting root from 8 to 2 seconds on my s390 guest with 100 disks. Uses of hlist_for_each_entry_rcu, hlist_add_head_rcu, hlist_del_init_rcu are fine because they do not have lockdep checks (hlist_for_each_entry_rcu uses rcu_dereference_raw rather than rcu_dereference, and write-sides do not do rcu lockdep at all). Note that we're hardly relying on the "sleepable" part of srcu. We just want SRCU's faster detection of grace periods. Testing was done by Andrew Theurer using netperf tests STREAM, MAERTS and RR. The difference between results "before" and "after" the patch has mean -0.2% and standard deviation 0.6%. Using a paired t-test on the data points says that there is a 2.5% probability that the patch is the cause of the performance difference (rather than a random fluctuation). (Restricting the t-test to RR, which is the most likely to be affected, changes the numbers to respectively -0.3% mean, 0.7% stdev, and 8% probability that the numbers actually say something about the patch. The probability increases mostly because there are fewer data points). Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> # s390 Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-01-16 20:44:20 +08:00
out_err_no_disable:
kvm_arch_destroy_vm(kvm);
out_err_no_arch_destroy_vm:
WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count));
for (i = 0; i < KVM_NR_BUSES; i++)
kfree(kvm_get_bus(kvm, i));
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
kvm_free_memslots(kvm, __kvm_memslots(kvm, i));
KVM: Fix NULL-ptr deref after kvm_create_vm fails Reported by syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 14727 Comm: syz-executor.3 Not tainted 5.4.0-rc4+ #0 RIP: 0010:kvm_coalesced_mmio_init+0x5d/0x110 arch/x86/kvm/../../../virt/kvm/coalesced_mmio.c:121 Call Trace: kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3446 [inline] kvm_dev_ioctl+0x781/0x1490 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3494 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0x196/0x1150 fs/ioctl.c:696 ksys_ioctl+0x62/0x90 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:718 do_syscall_64+0xca/0x5d0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Commit 9121923c457d ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm") moves memslots and buses allocations around, however, if kvm->srcu/irq_srcu fails initialization, NULL will be returned instead of error code, NULL will not be intercepted in kvm_dev_ioctl_create_vm() and be dereferenced by kvm_coalesced_mmio_init(), this patch fixes it. Moving the initialization is required anyway to avoid an incorrect synchronize_srcu that was also reported by syzkaller: wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline] synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997 kvm_page_track_unregister_notifier+0xe7/0x130 arch/x86/kvm/page_track.c:212 kvm_mmu_uninit_vm+0x1e/0x30 arch/x86/kvm/mmu.c:5828 kvm_arch_destroy_vm+0x4a2/0x5f0 arch/x86/kvm/x86.c:9579 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:702 [inline] so do it. Reported-by: syzbot+89a8060879fa0bd2db4f@syzkaller.appspotmail.com Reported-by: syzbot+e27e7027eb2b80e44225@syzkaller.appspotmail.com Fixes: 9121923c457d ("kvm: Allocate memslots and buses before calling kvm_arch_init_vm") Cc: Jim Mattson <jmattson@google.com> Cc: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-04 19:16:49 +08:00
cleanup_srcu_struct(&kvm->irq_srcu);
out_err_no_irq_srcu:
cleanup_srcu_struct(&kvm->srcu);
out_err_no_srcu:
kvm_arch_free_vm(kvm);
mmdrop(current->mm);
return ERR_PTR(r);
}
static void kvm_destroy_devices(struct kvm *kvm)
{
struct kvm_device *dev, *tmp;
/*
* We do not need to take the kvm->lock here, because nobody else
* has a reference to the struct kvm at this point and therefore
* cannot access the devices list anyhow.
*/
list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) {
list_del(&dev->vm_node);
dev->ops->destroy(dev);
}
}
static void kvm_destroy_vm(struct kvm *kvm)
{
int i;
struct mm_struct *mm = kvm->mm;
kvm_destroy_pm_notifier(kvm);
kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm);
kvm_destroy_vm_debugfs(kvm);
kvm_arch_sync_events(kvm);
mutex_lock(&kvm_lock);
list_del(&kvm->vm_list);
mutex_unlock(&kvm_lock);
kvm_arch_pre_destroy_vm(kvm);
kvm_free_irq_routing(kvm);
for (i = 0; i < KVM_NR_BUSES; i++) {
struct kvm_io_bus *bus = kvm_get_bus(kvm, i);
if (bus)
kvm_io_bus_destroy(bus);
kvm->buses[i] = NULL;
}
kvm_coalesced_mmio_free(kvm);
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
/*
* At this point, pending calls to invalidate_range_start()
* have completed but no more MMU notifiers will run, so
* mn_active_invalidate_count may remain unbalanced.
* No threads can be waiting in install_new_memslots as the
* last reference on KVM has been dropped, but freeing
* memslots would deadlock without this manual intervention.
*/
WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait));
kvm->mn_active_invalidate_count = 0;
#else
kvm_arch_flush_shadow_all(kvm);
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
#endif
kvm_arch_destroy_vm(kvm);
kvm_destroy_devices(kvm);
for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
kvm_free_memslots(kvm, __kvm_memslots(kvm, i));
cleanup_srcu_struct(&kvm->irq_srcu);
cleanup_srcu_struct(&kvm->srcu);
kvm_arch_free_vm(kvm);
preempt_notifier_dec();
hardware_disable_all();
mmdrop(mm);
}
void kvm_get_kvm(struct kvm *kvm)
{
refcount_inc(&kvm->users_count);
}
EXPORT_SYMBOL_GPL(kvm_get_kvm);
/*
* Make sure the vm is not during destruction, which is a safe version of
* kvm_get_kvm(). Return true if kvm referenced successfully, false otherwise.
*/
bool kvm_get_kvm_safe(struct kvm *kvm)
{
return refcount_inc_not_zero(&kvm->users_count);
}
EXPORT_SYMBOL_GPL(kvm_get_kvm_safe);
void kvm_put_kvm(struct kvm *kvm)
{
if (refcount_dec_and_test(&kvm->users_count))
kvm_destroy_vm(kvm);
}
EXPORT_SYMBOL_GPL(kvm_put_kvm);
/*
* Used to put a reference that was taken on behalf of an object associated
* with a user-visible file descriptor, e.g. a vcpu or device, if installation
* of the new file descriptor fails and the reference cannot be transferred to
* its final owner. In such cases, the caller is still actively using @kvm and
* will fail miserably if the refcount unexpectedly hits zero.
*/
void kvm_put_kvm_no_destroy(struct kvm *kvm)
{
WARN_ON(refcount_dec_and_test(&kvm->users_count));
}
EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy);
static int kvm_vm_release(struct inode *inode, struct file *filp)
{
struct kvm *kvm = filp->private_data;
kvm_irqfd_release(kvm);
kvm_put_kvm(kvm);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
return 0;
}
/*
* Allocation size is twice as large as the actual dirty bitmap size.
* See kvm_vm_ioctl_get_dirty_log() why this is needed.
*/
static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot)
{
unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
memslot->dirty_bitmap = kvzalloc(dirty_bytes, GFP_KERNEL_ACCOUNT);
if (!memslot->dirty_bitmap)
return -ENOMEM;
return 0;
}
/*
2020-02-19 05:07:31 +08:00
* Delete a memslot by decrementing the number of used slots and shifting all
* other entries in the array forward one spot.
*/
2020-02-19 05:07:31 +08:00
static inline void kvm_memslot_delete(struct kvm_memslots *slots,
struct kvm_memory_slot *memslot)
{
struct kvm_memory_slot *mslots = slots->memslots;
2020-02-19 05:07:31 +08:00
int i;
2020-02-19 05:07:31 +08:00
if (WARN_ON(slots->id_to_index[memslot->id] == -1))
return;
2020-02-19 05:07:31 +08:00
slots->used_slots--;
if (atomic_read(&slots->last_used_slot) >= slots->used_slots)
atomic_set(&slots->last_used_slot, 0);
2020-02-19 05:07:31 +08:00
for (i = slots->id_to_index[memslot->id]; i < slots->used_slots; i++) {
mslots[i] = mslots[i + 1];
slots->id_to_index[mslots[i].id] = i;
}
2020-02-19 05:07:31 +08:00
mslots[i] = *memslot;
slots->id_to_index[memslot->id] = -1;
}
/*
* "Insert" a new memslot by incrementing the number of used slots. Returns
* the new slot's initial index into the memslots array.
*/
static inline int kvm_memslot_insert_back(struct kvm_memslots *slots)
{
return slots->used_slots++;
}
/*
* Move a changed memslot backwards in the array by shifting existing slots
* with a higher GFN toward the front of the array. Note, the changed memslot
* itself is not preserved in the array, i.e. not swapped at this time, only
* its new index into the array is tracked. Returns the changed memslot's
* current index into the memslots array.
*/
static inline int kvm_memslot_move_backward(struct kvm_memslots *slots,
struct kvm_memory_slot *memslot)
{
struct kvm_memory_slot *mslots = slots->memslots;
int i;
if (WARN_ON_ONCE(slots->id_to_index[memslot->id] == -1) ||
WARN_ON_ONCE(!slots->used_slots))
return -1;
/*
2020-02-19 05:07:31 +08:00
* Move the target memslot backward in the array by shifting existing
* memslots with a higher GFN (than the target memslot) towards the
* front of the array.
*/
2020-02-19 05:07:31 +08:00
for (i = slots->id_to_index[memslot->id]; i < slots->used_slots - 1; i++) {
if (memslot->base_gfn > mslots[i + 1].base_gfn)
break;
WARN_ON_ONCE(memslot->base_gfn == mslots[i + 1].base_gfn);
2020-02-19 05:07:31 +08:00
/* Shift the next memslot forward one and update its index. */
mslots[i] = mslots[i + 1];
slots->id_to_index[mslots[i].id] = i;
}
return i;
}
/*
* Move a changed memslot forwards in the array by shifting existing slots with
* a lower GFN toward the back of the array. Note, the changed memslot itself
* is not preserved in the array, i.e. not swapped at this time, only its new
* index into the array is tracked. Returns the changed memslot's final index
* into the memslots array.
*/
static inline int kvm_memslot_move_forward(struct kvm_memslots *slots,
struct kvm_memory_slot *memslot,
int start)
{
struct kvm_memory_slot *mslots = slots->memslots;
int i;
for (i = start; i > 0; i--) {
if (memslot->base_gfn < mslots[i - 1].base_gfn)
break;
WARN_ON_ONCE(memslot->base_gfn == mslots[i - 1].base_gfn);
/* Shift the next memslot back one and update its index. */
mslots[i] = mslots[i - 1];
slots->id_to_index[mslots[i].id] = i;
}
return i;
}
/*
* Re-sort memslots based on their GFN to account for an added, deleted, or
* moved memslot. Sorting memslots by GFN allows using a binary search during
* memslot lookup.
*
* IMPORTANT: Slots are sorted from highest GFN to lowest GFN! I.e. the entry
* at memslots[0] has the highest GFN.
*
* The sorting algorithm takes advantage of having initially sorted memslots
* and knowing the position of the changed memslot. Sorting is also optimized
* by not swapping the updated memslot and instead only shifting other memslots
* and tracking the new index for the update memslot. Only once its final
* index is known is the updated memslot copied into its position in the array.
*
* - When deleting a memslot, the deleted memslot simply needs to be moved to
* the end of the array.
*
* - When creating a memslot, the algorithm "inserts" the new memslot at the
* end of the array and then it forward to its correct location.
*
* - When moving a memslot, the algorithm first moves the updated memslot
* backward to handle the scenario where the memslot's GFN was changed to a
* lower value. update_memslots() then falls through and runs the same flow
* as creating a memslot to move the memslot forward to handle the scenario
* where its GFN was changed to a higher value.
*
* Note, slots are sorted from highest->lowest instead of lowest->highest for
* historical reasons. Originally, invalid memslots where denoted by having
* GFN=0, thus sorting from highest->lowest naturally sorted invalid memslots
* to the end of the array. The current algorithm uses dedicated logic to
* delete a memslot and thus does not rely on invalid memslots having GFN=0.
*
* The other historical motiviation for highest->lowest was to improve the
* performance of memslot lookup. KVM originally used a linear search starting
* at memslots[0]. On x86, the largest memslot usually has one of the highest,
* if not *the* highest, GFN, as the bulk of the guest's RAM is located in a
* single memslot above the 4gb boundary. As the largest memslot is also the
* most likely to be referenced, sorting it to the front of the array was
* advantageous. The current binary search starts from the middle of the array
* and uses an LRU pointer to improve performance for all memslots and GFNs.
*/
static void update_memslots(struct kvm_memslots *slots,
struct kvm_memory_slot *memslot,
enum kvm_mr_change change)
{
int i;
if (change == KVM_MR_DELETE) {
kvm_memslot_delete(slots, memslot);
} else {
if (change == KVM_MR_CREATE)
i = kvm_memslot_insert_back(slots);
else
i = kvm_memslot_move_backward(slots, memslot);
i = kvm_memslot_move_forward(slots, memslot, i);
/*
* Copy the memslot to its new position in memslots and update
* its index accordingly.
*/
slots->memslots[i] = *memslot;
slots->id_to_index[memslot->id] = i;
}
}
static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem)
{
u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
#ifdef __KVM_HAVE_READONLY_MEM
valid_flags |= KVM_MEM_READONLY;
#endif
if (mem->flags & ~valid_flags)
return -EINVAL;
return 0;
}
static struct kvm_memslots *install_new_memslots(struct kvm *kvm,
int as_id, struct kvm_memslots *slots)
{
struct kvm_memslots *old_memslots = __kvm_memslots(kvm, as_id);
KVM: Explicitly define the "memslot update in-progress" bit KVM uses bit 0 of the memslots generation as an "update in-progress" flag, which is used by x86 to prevent caching MMIO access while the memslots are changing. Although the intended behavior is flag-like, e.g. MMIO sptes intentionally drop the in-progress bit so as to avoid caching data from in-flux memslots, the implementation oftentimes treats the bit as part of the generation number itself, e.g. incrementing the generation increments twice, once to set the flag and once to clear it. Prior to commit 4bd518f1598d ("KVM: use separate generations for each address space"), incorporating the "update in-progress" bit into the generation number largely made sense, e.g. "real" generations are even, "bogus" generations are odd, most code doesn't need to be aware of the bit, etc... Now that unique memslots generation numbers are assigned to each address space, stealthing the in-progress status into the generation number results in a wide variety of subtle code, e.g. kvm_create_vm() jumps over bit 0 when initializing the memslots generation without any hint as to why. Explicitly define the flag and convert as much code as possible (which isn't much) to actually treat it like a flag. This paves the way for eventually using a different bit for "update in-progress" so that it can be a flag in truth instead of a awkward extension to the generation number. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-06 05:01:14 +08:00
u64 gen = old_memslots->generation;
KVM: Explicitly define the "memslot update in-progress" bit KVM uses bit 0 of the memslots generation as an "update in-progress" flag, which is used by x86 to prevent caching MMIO access while the memslots are changing. Although the intended behavior is flag-like, e.g. MMIO sptes intentionally drop the in-progress bit so as to avoid caching data from in-flux memslots, the implementation oftentimes treats the bit as part of the generation number itself, e.g. incrementing the generation increments twice, once to set the flag and once to clear it. Prior to commit 4bd518f1598d ("KVM: use separate generations for each address space"), incorporating the "update in-progress" bit into the generation number largely made sense, e.g. "real" generations are even, "bogus" generations are odd, most code doesn't need to be aware of the bit, etc... Now that unique memslots generation numbers are assigned to each address space, stealthing the in-progress status into the generation number results in a wide variety of subtle code, e.g. kvm_create_vm() jumps over bit 0 when initializing the memslots generation without any hint as to why. Explicitly define the flag and convert as much code as possible (which isn't much) to actually treat it like a flag. This paves the way for eventually using a different bit for "update in-progress" so that it can be a flag in truth instead of a awkward extension to the generation number. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-06 05:01:14 +08:00
WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS);
slots->generation = gen | KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;
kvm: fix potentially corrupt mmio cache vcpu exits and memslot mutations can run concurrently as long as the vcpu does not aquire the slots mutex. Thus it is theoretically possible for memslots to change underneath a vcpu that is handling an exit. If we increment the memslot generation number again after synchronize_srcu_expedited(), vcpus can safely cache memslot generation without maintaining a single rcu_dereference through an entire vm exit. And much of the x86/kvm code does not maintain a single rcu_dereference of the current memslots during each exit. We can prevent the following case: vcpu (CPU 0) | thread (CPU 1) --------------------------------------------+-------------------------- 1 vm exit | 2 srcu_read_unlock(&kvm->srcu) | 3 decide to cache something based on | old memslots | 4 | change memslots | (increments generation) 5 | synchronize_srcu(&kvm->srcu); 6 retrieve generation # from new memslots | 7 tag cache with new memslot generation | 8 srcu_read_unlock(&kvm->srcu) | ... | <action based on cache occurs even | though the caching decision was based | on the old memslots> | ... | <action *continues* to occur until next | memslot generation change, which may | be never> | | By incrementing the generation after synchronizing with kvm->srcu readers, we ensure that the generation retrieved in (6) will become invalid soon after (8). Keeping the existing increment is not strictly necessary, but we do keep it and just move it for consistency from update_memslots to install_new_memslots. It invalidates old cached MMIOs immediately, instead of having to wait for the end of synchronize_srcu_expedited, which makes the code more clearly correct in case CPU 1 is preempted right after synchronize_srcu() returns. To avoid halving the generation space in SPTEs, always presume that the low bit of the generation is zero when reconstructing a generation number out of an SPTE. This effectively disables MMIO caching in SPTEs during the call to synchronize_srcu_expedited. Using the low bit this way is somewhat like a seqcount---where the protected thing is a cache, and instead of retrying we can simply punt if we observe the low bit to be 1. Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-19 06:46:06 +08:00
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
/*
* Do not store the new memslots while there are invalidations in
* progress, otherwise the locking in invalidate_range_start and
* invalidate_range_end will be unbalanced.
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
*/
spin_lock(&kvm->mn_invalidate_lock);
prepare_to_rcuwait(&kvm->mn_memslots_update_rcuwait);
while (kvm->mn_active_invalidate_count) {
set_current_state(TASK_UNINTERRUPTIBLE);
spin_unlock(&kvm->mn_invalidate_lock);
schedule();
spin_lock(&kvm->mn_invalidate_lock);
}
finish_rcuwait(&kvm->mn_memslots_update_rcuwait);
rcu_assign_pointer(kvm->memslots[as_id], slots);
KVM: Block memslot updates across range_start() and range_end() We would like to avoid taking mmu_lock for .invalidate_range_{start,end}() notifications that are unrelated to KVM. Because mmu_notifier_count must be modified while holding mmu_lock for write, and must always be paired across start->end to stay balanced, lock elision must happen in both or none. Therefore, in preparation for this change, this patch prevents memslot updates across range_start() and range_end(). Note, technically flag-only memslot updates could be allowed in parallel, but stalling a memslot update for a relatively short amount of time is not a scalability issue, and this is all more than complex enough. A long note on the locking: a previous version of the patch used an rwsem to block the memslot update while the MMU notifier run, but this resulted in the following deadlock involving the pseudo-lock tagged as "mmu_notifier_invalidate_range_start". ====================================================== WARNING: possible circular locking dependency detected 5.12.0-rc3+ #6 Tainted: G OE ------------------------------------------------------ qemu-system-x86/3069 is trying to acquire lock: ffffffff9c775ca0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: __mmu_notifier_invalidate_range_end+0x5/0x190 but task is already holding lock: ffffaff7410a9160 (&kvm->mmu_notifier_slots_lock){.+.+}-{3:3}, at: kvm_mmu_notifier_invalidate_range_start+0x36d/0x4f0 [kvm] which lock already depends on the new lock. This corresponds to the following MMU notifier logic: invalidate_range_start take pseudo lock down_read() (*) release pseudo lock invalidate_range_end take pseudo lock (**) up_read() release pseudo lock At point (*) we take the mmu_notifiers_slots_lock inside the pseudo lock; at point (**) we take the pseudo lock inside the mmu_notifiers_slots_lock. This could cause a deadlock (ignoring for a second that the pseudo lock is not a lock): - invalidate_range_start waits on down_read(), because the rwsem is held by install_new_memslots - install_new_memslots waits on down_write(), because the rwsem is held till (another) invalidate_range_end finishes - invalidate_range_end sits waits on the pseudo lock, held by invalidate_range_start. Removing the fairness of the rwsem breaks the cycle (in lockdep terms, it would change the *shared* rwsem readers into *shared recursive* readers), so open-code the wait using a readers count and a spinlock. This also allows handling blockable and non-blockable critical section in the same way. Losing the rwsem fairness does theoretically allow MMU notifiers to block install_new_memslots forever. Note that mm/mmu_notifier.c's own retry scheme in mmu_interval_read_begin also uses wait/wake_up and is likewise not fair. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-27 20:09:15 +08:00
spin_unlock(&kvm->mn_invalidate_lock);
/*
* Acquired in kvm_set_memslot. Must be released before synchronize
* SRCU below in order to avoid deadlock with another thread
* acquiring the slots_arch_lock in an srcu critical section.
*/
mutex_unlock(&kvm->slots_arch_lock);
synchronize_srcu_expedited(&kvm->srcu);
kvm: fix potentially corrupt mmio cache vcpu exits and memslot mutations can run concurrently as long as the vcpu does not aquire the slots mutex. Thus it is theoretically possible for memslots to change underneath a vcpu that is handling an exit. If we increment the memslot generation number again after synchronize_srcu_expedited(), vcpus can safely cache memslot generation without maintaining a single rcu_dereference through an entire vm exit. And much of the x86/kvm code does not maintain a single rcu_dereference of the current memslots during each exit. We can prevent the following case: vcpu (CPU 0) | thread (CPU 1) --------------------------------------------+-------------------------- 1 vm exit | 2 srcu_read_unlock(&kvm->srcu) | 3 decide to cache something based on | old memslots | 4 | change memslots | (increments generation) 5 | synchronize_srcu(&kvm->srcu); 6 retrieve generation # from new memslots | 7 tag cache with new memslot generation | 8 srcu_read_unlock(&kvm->srcu) | ... | <action based on cache occurs even | though the caching decision was based | on the old memslots> | ... | <action *continues* to occur until next | memslot generation change, which may | be never> | | By incrementing the generation after synchronizing with kvm->srcu readers, we ensure that the generation retrieved in (6) will become invalid soon after (8). Keeping the existing increment is not strictly necessary, but we do keep it and just move it for consistency from update_memslots to install_new_memslots. It invalidates old cached MMIOs immediately, instead of having to wait for the end of synchronize_srcu_expedited, which makes the code more clearly correct in case CPU 1 is preempted right after synchronize_srcu() returns. To avoid halving the generation space in SPTEs, always presume that the low bit of the generation is zero when reconstructing a generation number out of an SPTE. This effectively disables MMIO caching in SPTEs during the call to synchronize_srcu_expedited. Using the low bit this way is somewhat like a seqcount---where the protected thing is a cache, and instead of retrying we can simply punt if we observe the low bit to be 1. Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-19 06:46:06 +08:00
/*
KVM: Explicitly define the "memslot update in-progress" bit KVM uses bit 0 of the memslots generation as an "update in-progress" flag, which is used by x86 to prevent caching MMIO access while the memslots are changing. Although the intended behavior is flag-like, e.g. MMIO sptes intentionally drop the in-progress bit so as to avoid caching data from in-flux memslots, the implementation oftentimes treats the bit as part of the generation number itself, e.g. incrementing the generation increments twice, once to set the flag and once to clear it. Prior to commit 4bd518f1598d ("KVM: use separate generations for each address space"), incorporating the "update in-progress" bit into the generation number largely made sense, e.g. "real" generations are even, "bogus" generations are odd, most code doesn't need to be aware of the bit, etc... Now that unique memslots generation numbers are assigned to each address space, stealthing the in-progress status into the generation number results in a wide variety of subtle code, e.g. kvm_create_vm() jumps over bit 0 when initializing the memslots generation without any hint as to why. Explicitly define the flag and convert as much code as possible (which isn't much) to actually treat it like a flag. This paves the way for eventually using a different bit for "update in-progress" so that it can be a flag in truth instead of a awkward extension to the generation number. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-06 05:01:14 +08:00
* Increment the new memslot generation a second time, dropping the
* update in-progress flag and incrementing the generation based on
KVM: Explicitly define the "memslot update in-progress" bit KVM uses bit 0 of the memslots generation as an "update in-progress" flag, which is used by x86 to prevent caching MMIO access while the memslots are changing. Although the intended behavior is flag-like, e.g. MMIO sptes intentionally drop the in-progress bit so as to avoid caching data from in-flux memslots, the implementation oftentimes treats the bit as part of the generation number itself, e.g. incrementing the generation increments twice, once to set the flag and once to clear it. Prior to commit 4bd518f1598d ("KVM: use separate generations for each address space"), incorporating the "update in-progress" bit into the generation number largely made sense, e.g. "real" generations are even, "bogus" generations are odd, most code doesn't need to be aware of the bit, etc... Now that unique memslots generation numbers are assigned to each address space, stealthing the in-progress status into the generation number results in a wide variety of subtle code, e.g. kvm_create_vm() jumps over bit 0 when initializing the memslots generation without any hint as to why. Explicitly define the flag and convert as much code as possible (which isn't much) to actually treat it like a flag. This paves the way for eventually using a different bit for "update in-progress" so that it can be a flag in truth instead of a awkward extension to the generation number. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-06 05:01:14 +08:00
* the number of address spaces. This provides a unique and easily
* identifiable generation number while the memslots are in flux.
*/
gen = slots->generation & ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS;
/*
* Generations must be unique even across address spaces. We do not need
* a global counter for that, instead the generation space is evenly split
* across address spaces. For example, with two address spaces, address
* space 0 will use generations 0, 2, 4, ... while address space 1 will
* use generations 1, 3, 5, ...
kvm: fix potentially corrupt mmio cache vcpu exits and memslot mutations can run concurrently as long as the vcpu does not aquire the slots mutex. Thus it is theoretically possible for memslots to change underneath a vcpu that is handling an exit. If we increment the memslot generation number again after synchronize_srcu_expedited(), vcpus can safely cache memslot generation without maintaining a single rcu_dereference through an entire vm exit. And much of the x86/kvm code does not maintain a single rcu_dereference of the current memslots during each exit. We can prevent the following case: vcpu (CPU 0) | thread (CPU 1) --------------------------------------------+-------------------------- 1 vm exit | 2 srcu_read_unlock(&kvm->srcu) | 3 decide to cache something based on | old memslots | 4 | change memslots | (increments generation) 5 | synchronize_srcu(&kvm->srcu); 6 retrieve generation # from new memslots | 7 tag cache with new memslot generation | 8 srcu_read_unlock(&kvm->srcu) | ... | <action based on cache occurs even | though the caching decision was based | on the old memslots> | ... | <action *continues* to occur until next | memslot generation change, which may | be never> | | By incrementing the generation after synchronizing with kvm->srcu readers, we ensure that the generation retrieved in (6) will become invalid soon after (8). Keeping the existing increment is not strictly necessary, but we do keep it and just move it for consistency from update_memslots to install_new_memslots. It invalidates old cached MMIOs immediately, instead of having to wait for the end of synchronize_srcu_expedited, which makes the code more clearly correct in case CPU 1 is preempted right after synchronize_srcu() returns. To avoid halving the generation space in SPTEs, always presume that the low bit of the generation is zero when reconstructing a generation number out of an SPTE. This effectively disables MMIO caching in SPTEs during the call to synchronize_srcu_expedited. Using the low bit this way is somewhat like a seqcount---where the protected thing is a cache, and instead of retrying we can simply punt if we observe the low bit to be 1. Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-19 06:46:06 +08:00
*/
gen += KVM_ADDRESS_SPACE_NUM;
kvm: fix potentially corrupt mmio cache vcpu exits and memslot mutations can run concurrently as long as the vcpu does not aquire the slots mutex. Thus it is theoretically possible for memslots to change underneath a vcpu that is handling an exit. If we increment the memslot generation number again after synchronize_srcu_expedited(), vcpus can safely cache memslot generation without maintaining a single rcu_dereference through an entire vm exit. And much of the x86/kvm code does not maintain a single rcu_dereference of the current memslots during each exit. We can prevent the following case: vcpu (CPU 0) | thread (CPU 1) --------------------------------------------+-------------------------- 1 vm exit | 2 srcu_read_unlock(&kvm->srcu) | 3 decide to cache something based on | old memslots | 4 | change memslots | (increments generation) 5 | synchronize_srcu(&kvm->srcu); 6 retrieve generation # from new memslots | 7 tag cache with new memslot generation | 8 srcu_read_unlock(&kvm->srcu) | ... | <action based on cache occurs even | though the caching decision was based | on the old memslots> | ... | <action *continues* to occur until next | memslot generation change, which may | be never> | | By incrementing the generation after synchronizing with kvm->srcu readers, we ensure that the generation retrieved in (6) will become invalid soon after (8). Keeping the existing increment is not strictly necessary, but we do keep it and just move it for consistency from update_memslots to install_new_memslots. It invalidates old cached MMIOs immediately, instead of having to wait for the end of synchronize_srcu_expedited, which makes the code more clearly correct in case CPU 1 is preempted right after synchronize_srcu() returns. To avoid halving the generation space in SPTEs, always presume that the low bit of the generation is zero when reconstructing a generation number out of an SPTE. This effectively disables MMIO caching in SPTEs during the call to synchronize_srcu_expedited. Using the low bit this way is somewhat like a seqcount---where the protected thing is a cache, and instead of retrying we can simply punt if we observe the low bit to be 1. Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-19 06:46:06 +08:00
kvm_arch_memslots_updated(kvm, gen);
kvm: fix potentially corrupt mmio cache vcpu exits and memslot mutations can run concurrently as long as the vcpu does not aquire the slots mutex. Thus it is theoretically possible for memslots to change underneath a vcpu that is handling an exit. If we increment the memslot generation number again after synchronize_srcu_expedited(), vcpus can safely cache memslot generation without maintaining a single rcu_dereference through an entire vm exit. And much of the x86/kvm code does not maintain a single rcu_dereference of the current memslots during each exit. We can prevent the following case: vcpu (CPU 0) | thread (CPU 1) --------------------------------------------+-------------------------- 1 vm exit | 2 srcu_read_unlock(&kvm->srcu) | 3 decide to cache something based on | old memslots | 4 | change memslots | (increments generation) 5 | synchronize_srcu(&kvm->srcu); 6 retrieve generation # from new memslots | 7 tag cache with new memslot generation | 8 srcu_read_unlock(&kvm->srcu) | ... | <action based on cache occurs even | though the caching decision was based | on the old memslots> | ... | <action *continues* to occur until next | memslot generation change, which may | be never> | | By incrementing the generation after synchronizing with kvm->srcu readers, we ensure that the generation retrieved in (6) will become invalid soon after (8). Keeping the existing increment is not strictly necessary, but we do keep it and just move it for consistency from update_memslots to install_new_memslots. It invalidates old cached MMIOs immediately, instead of having to wait for the end of synchronize_srcu_expedited, which makes the code more clearly correct in case CPU 1 is preempted right after synchronize_srcu() returns. To avoid halving the generation space in SPTEs, always presume that the low bit of the generation is zero when reconstructing a generation number out of an SPTE. This effectively disables MMIO caching in SPTEs during the call to synchronize_srcu_expedited. Using the low bit this way is somewhat like a seqcount---where the protected thing is a cache, and instead of retrying we can simply punt if we observe the low bit to be 1. Cc: stable@vger.kernel.org Signed-off-by: David Matlack <dmatlack@google.com> Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: David Matlack <dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-08-19 06:46:06 +08:00
slots->generation = gen;
return old_memslots;
}
static size_t kvm_memslots_size(int slots)
{
return sizeof(struct kvm_memslots) +
(sizeof(struct kvm_memory_slot) * slots);
}
static void kvm_copy_memslots(struct kvm_memslots *to,
struct kvm_memslots *from)
{
memcpy(to, from, kvm_memslots_size(from->used_slots));
}
/*
* Note, at a minimum, the current number of used slots must be allocated, even
* when deleting a memslot, as we need a complete duplicate of the memslots for
* use when invalidating a memslot prior to deleting/moving the memslot.
*/
static struct kvm_memslots *kvm_dup_memslots(struct kvm_memslots *old,
enum kvm_mr_change change)
{
struct kvm_memslots *slots;
size_t new_size;
if (change == KVM_MR_CREATE)
new_size = kvm_memslots_size(old->used_slots + 1);
else
new_size = kvm_memslots_size(old->used_slots);
slots = kvzalloc(new_size, GFP_KERNEL_ACCOUNT);
if (likely(slots))
kvm_copy_memslots(slots, old);
return slots;
}
static int kvm_set_memslot(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem,
struct kvm_memory_slot *old,
struct kvm_memory_slot *new, int as_id,
enum kvm_mr_change change)
{
struct kvm_memory_slot *slot;
struct kvm_memslots *slots;
int r;
/*
* Released in install_new_memslots.
*
* Must be held from before the current memslots are copied until
* after the new memslots are installed with rcu_assign_pointer,
* then released before the synchronize srcu in install_new_memslots.
*
* When modifying memslots outside of the slots_lock, must be held
* before reading the pointer to the current memslots until after all
* changes to those memslots are complete.
*
* These rules ensure that installing new memslots does not lose
* changes made to the previous memslots.
*/
mutex_lock(&kvm->slots_arch_lock);
slots = kvm_dup_memslots(__kvm_memslots(kvm, as_id), change);
if (!slots) {
mutex_unlock(&kvm->slots_arch_lock);
return -ENOMEM;
}
if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
/*
* Note, the INVALID flag needs to be in the appropriate entry
* in the freshly allocated memslots, not in @old or @new.
*/
slot = id_to_memslot(slots, old->id);
slot->flags |= KVM_MEMSLOT_INVALID;
/*
* We can re-use the memory from the old memslots.
* It will be overwritten with a copy of the new memslots
* after reacquiring the slots_arch_lock below.
*/
slots = install_new_memslots(kvm, as_id, slots);
/* From this point no new shadow pages pointing to a deleted,
* or moved, memslot will be created.
*
* validation of sp->gfn happens in:
* - gfn_to_hva (kvm_read_guest, gfn_to_pfn)
* - kvm_is_visible_gfn (mmu_check_root)
*/
kvm_arch_flush_shadow_memslot(kvm, slot);
/* Released in install_new_memslots. */
mutex_lock(&kvm->slots_arch_lock);
/*
* The arch-specific fields of the memslots could have changed
* between releasing the slots_arch_lock in
* install_new_memslots and here, so get a fresh copy of the
* slots.
*/
kvm_copy_memslots(slots, __kvm_memslots(kvm, as_id));
}
r = kvm_arch_prepare_memory_region(kvm, new, mem, change);
if (r)
goto out_slots;
update_memslots(slots, new, change);
slots = install_new_memslots(kvm, as_id, slots);
kvm_arch_commit_memory_region(kvm, mem, old, new, change);
kvfree(slots);
return 0;
out_slots:
if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) {
slot = id_to_memslot(slots, old->id);
slot->flags &= ~KVM_MEMSLOT_INVALID;
slots = install_new_memslots(kvm, as_id, slots);
} else {
mutex_unlock(&kvm->slots_arch_lock);
}
kvfree(slots);
return r;
}
static int kvm_delete_memslot(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem,
struct kvm_memory_slot *old, int as_id)
{
struct kvm_memory_slot new;
int r;
if (!old->npages)
return -EINVAL;
memset(&new, 0, sizeof(new));
new.id = old->id;
/*
* This is only for debugging purpose; it should never be referenced
* for a removed memslot.
*/
new.as_id = as_id;
r = kvm_set_memslot(kvm, mem, old, &new, as_id, KVM_MR_DELETE);
if (r)
return r;
kvm_free_memslot(kvm, old);
return 0;
}
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
/*
* Allocate some memory and give it an address in the guest physical address
* space.
*
* Discontiguous memory is allowed, mostly for framebuffers.
*
* Must be called holding kvm->slots_lock for write.
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
*/
int __kvm_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
struct kvm_memory_slot old, new;
struct kvm_memory_slot *tmp;
enum kvm_mr_change change;
int as_id, id;
int r;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = check_memory_region_flags(mem);
if (r)
return r;
as_id = mem->slot >> 16;
id = (u16)mem->slot;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
/* General sanity checks */
if (mem->memory_size & (PAGE_SIZE - 1))
return -EINVAL;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (mem->guest_phys_addr & (PAGE_SIZE - 1))
return -EINVAL;
/* We can read the guest memory with __xxx_user() later on. */
if ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
(mem->userspace_addr != untagged_addr(mem->userspace_addr)) ||
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 10:57:57 +08:00
!access_ok((void __user *)(unsigned long)mem->userspace_addr,
mem->memory_size))
return -EINVAL;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
return -EINVAL;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
return -EINVAL;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
/*
* Make a full copy of the old memslot, the pointer will become stale
* when the memslots are re-sorted by update_memslots(), and the old
* memslot needs to be referenced after calling update_memslots(), e.g.
* to free its resources and for arch specific behavior.
*/
2020-02-19 05:07:31 +08:00
tmp = id_to_memslot(__kvm_memslots(kvm, as_id), id);
if (tmp) {
old = *tmp;
tmp = NULL;
} else {
memset(&old, 0, sizeof(old));
old.id = id;
}
if (!mem->memory_size)
return kvm_delete_memslot(kvm, mem, &old, as_id);
new.as_id = as_id;
new.id = id;
new.base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
new.npages = mem->memory_size >> PAGE_SHIFT;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
new.flags = mem->flags;
new.userspace_addr = mem->userspace_addr;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (new.npages > KVM_MEM_MAX_NR_PAGES)
return -EINVAL;
if (!old.npages) {
change = KVM_MR_CREATE;
new.dirty_bitmap = NULL;
memset(&new.arch, 0, sizeof(new.arch));
} else { /* Modify an existing slot. */
if ((new.userspace_addr != old.userspace_addr) ||
(new.npages != old.npages) ||
((new.flags ^ old.flags) & KVM_MEM_READONLY))
return -EINVAL;
if (new.base_gfn != old.base_gfn)
change = KVM_MR_MOVE;
else if (new.flags != old.flags)
change = KVM_MR_FLAGS_ONLY;
else /* Nothing to change. */
return 0;
/* Copy dirty_bitmap and arch from the current memslot. */
new.dirty_bitmap = old.dirty_bitmap;
memcpy(&new.arch, &old.arch, sizeof(new.arch));
}
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
/* Check for overlaps */
kvm_for_each_memslot(tmp, __kvm_memslots(kvm, as_id)) {
if (tmp->id == id)
continue;
if (!((new.base_gfn + new.npages <= tmp->base_gfn) ||
(new.base_gfn >= tmp->base_gfn + tmp->npages)))
return -EEXIST;
}
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
/* Allocate/free page dirty bitmap as needed */
if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
new.dirty_bitmap = NULL;
else if (!new.dirty_bitmap && !kvm->dirty_ring_size) {
r = kvm_alloc_dirty_bitmap(&new);
if (r)
return r;
if (kvm_dirty_log_manual_protect_and_init_set(kvm))
bitmap_set(new.dirty_bitmap, 0, new.npages);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
r = kvm_set_memslot(kvm, mem, &old, &new, as_id, change);
if (r)
goto out_bitmap;
if (old.dirty_bitmap && !new.dirty_bitmap)
kvm_destroy_dirty_bitmap(&old);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
return 0;
out_bitmap:
if (new.dirty_bitmap && !old.dirty_bitmap)
kvm_destroy_dirty_bitmap(&new);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
return r;
}
EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
int kvm_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem)
{
int r;
mutex_lock(&kvm->slots_lock);
r = __kvm_set_memory_region(kvm, mem);
mutex_unlock(&kvm->slots_lock);
return r;
}
EXPORT_SYMBOL_GPL(kvm_set_memory_region);
static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem)
{
if ((u16)mem->slot >= KVM_USER_MEM_SLOTS)
return -EINVAL;
return kvm_set_memory_region(kvm, mem);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
#ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
/**
* kvm_get_dirty_log - get a snapshot of dirty pages
* @kvm: pointer to kvm instance
* @log: slot id and address to which we copy the log
* @is_dirty: set to '1' if any dirty pages were found
* @memslot: set to the associated memslot, always valid on success
*/
int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
int *is_dirty, struct kvm_memory_slot **memslot)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
struct kvm_memslots *slots;
int i, as_id, id;
unsigned long n;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
unsigned long any = 0;
/* Dirty ring tracking is exclusive to dirty log tracking */
if (kvm->dirty_ring_size)
return -ENXIO;
*memslot = NULL;
*is_dirty = 0;
as_id = log->slot >> 16;
id = (u16)log->slot;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
return -EINVAL;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
slots = __kvm_memslots(kvm, as_id);
*memslot = id_to_memslot(slots, id);
2020-02-19 05:07:31 +08:00
if (!(*memslot) || !(*memslot)->dirty_bitmap)
return -ENOENT;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
kvm_arch_sync_dirty_log(kvm, *memslot);
n = kvm_dirty_bitmap_bytes(*memslot);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
for (i = 0; !any && i < n/sizeof(long); ++i)
any = (*memslot)->dirty_bitmap[i];
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n))
return -EFAULT;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (any)
*is_dirty = 1;
return 0;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
EXPORT_SYMBOL_GPL(kvm_get_dirty_log);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
#else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
/**
* kvm_get_dirty_log_protect - get a snapshot of dirty pages
* and reenable dirty page tracking for the corresponding pages.
* @kvm: pointer to kvm instance
* @log: slot id and address to which we copy the log
*
* We need to keep it in mind that VCPU threads can write to the bitmap
* concurrently. So, to avoid losing track of dirty pages we keep the
* following order:
*
* 1. Take a snapshot of the bit and clear it if needed.
* 2. Write protect the corresponding page.
* 3. Copy the snapshot to the userspace.
* 4. Upon return caller flushes TLB's if needed.
*
* Between 2 and 4, the guest may write to the page using the remaining TLB
* entry. This is not a problem because the page is reported dirty using
* the snapshot taken before and step 4 ensures that writes done after
* exiting to userspace will be logged for the next call.
*
*/
static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
int i, as_id, id;
unsigned long n;
unsigned long *dirty_bitmap;
unsigned long *dirty_bitmap_buffer;
bool flush;
/* Dirty ring tracking is exclusive to dirty log tracking */
if (kvm->dirty_ring_size)
return -ENXIO;
as_id = log->slot >> 16;
id = (u16)log->slot;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
return -EINVAL;
slots = __kvm_memslots(kvm, as_id);
memslot = id_to_memslot(slots, id);
2020-02-19 05:07:31 +08:00
if (!memslot || !memslot->dirty_bitmap)
return -ENOENT;
dirty_bitmap = memslot->dirty_bitmap;
kvm_arch_sync_dirty_log(kvm, memslot);
n = kvm_dirty_bitmap_bytes(memslot);
flush = false;
if (kvm->manual_dirty_log_protect) {
/*
* Unlike kvm_get_dirty_log, we always return false in *flush,
* because no flush is needed until KVM_CLEAR_DIRTY_LOG. There
* is some code duplication between this function and
* kvm_get_dirty_log, but hopefully all architecture
* transition to kvm_get_dirty_log_protect and kvm_get_dirty_log
* can be eliminated.
*/
dirty_bitmap_buffer = dirty_bitmap;
} else {
dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
memset(dirty_bitmap_buffer, 0, n);
KVM_MMU_LOCK(kvm);
for (i = 0; i < n / sizeof(long); i++) {
unsigned long mask;
gfn_t offset;
if (!dirty_bitmap[i])
continue;
flush = true;
mask = xchg(&dirty_bitmap[i], 0);
dirty_bitmap_buffer[i] = mask;
offset = i * BITS_PER_LONG;
kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
offset, mask);
}
KVM_MMU_UNLOCK(kvm);
}
if (flush)
kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n))
return -EFAULT;
return 0;
}
/**
* kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
* @kvm: kvm instance
* @log: slot id and address to which we copy the log
*
* Steps 1-4 below provide general overview of dirty page logging. See
* kvm_get_dirty_log_protect() function description for additional details.
*
* We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
* always flush the TLB (step 4) even if previous step failed and the dirty
* bitmap may be corrupt. Regardless of previous outcome the KVM logging API
* does not preclude user space subsequent dirty log read. Flushing TLB ensures
* writes will be marked dirty for next log read.
*
* 1. Take a snapshot of the bit and clear it if needed.
* 2. Write protect the corresponding page.
* 3. Copy the snapshot to the userspace.
* 4. Flush TLB's if needed.
*/
static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
struct kvm_dirty_log *log)
{
int r;
mutex_lock(&kvm->slots_lock);
r = kvm_get_dirty_log_protect(kvm, log);
mutex_unlock(&kvm->slots_lock);
return r;
}
/**
* kvm_clear_dirty_log_protect - clear dirty bits in the bitmap
* and reenable dirty page tracking for the corresponding pages.
* @kvm: pointer to kvm instance
* @log: slot id and address from which to fetch the bitmap of dirty pages
*/
static int kvm_clear_dirty_log_protect(struct kvm *kvm,
struct kvm_clear_dirty_log *log)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
int as_id, id;
gfn_t offset;
unsigned long i, n;
unsigned long *dirty_bitmap;
unsigned long *dirty_bitmap_buffer;
bool flush;
/* Dirty ring tracking is exclusive to dirty log tracking */
if (kvm->dirty_ring_size)
return -ENXIO;
as_id = log->slot >> 16;
id = (u16)log->slot;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_USER_MEM_SLOTS)
return -EINVAL;
if (log->first_page & 63)
return -EINVAL;
slots = __kvm_memslots(kvm, as_id);
memslot = id_to_memslot(slots, id);
2020-02-19 05:07:31 +08:00
if (!memslot || !memslot->dirty_bitmap)
return -ENOENT;
dirty_bitmap = memslot->dirty_bitmap;
n = ALIGN(log->num_pages, BITS_PER_LONG) / 8;
if (log->first_page > memslot->npages ||
log->num_pages > memslot->npages - log->first_page ||
(log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63)))
return -EINVAL;
kvm_arch_sync_dirty_log(kvm, memslot);
flush = false;
dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot);
if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n))
return -EFAULT;
KVM_MMU_LOCK(kvm);
for (offset = log->first_page, i = offset / BITS_PER_LONG,
n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--;
i++, offset += BITS_PER_LONG) {
unsigned long mask = *dirty_bitmap_buffer++;
atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i];
if (!mask)
continue;
mask &= atomic_long_fetch_andnot(mask, p);
/*
* mask contains the bits that really have been cleared. This
* never includes any bits beyond the length of the memslot (if
* the length is not aligned to 64 pages), therefore it is not
* a problem if userspace sets them in log->dirty_bitmap.
*/
if (mask) {
flush = true;
kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot,
offset, mask);
}
}
KVM_MMU_UNLOCK(kvm);
if (flush)
kvm_arch_flush_remote_tlbs_memslot(kvm, memslot);
return 0;
}
static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
struct kvm_clear_dirty_log *log)
{
int r;
mutex_lock(&kvm->slots_lock);
r = kvm_clear_dirty_log_protect(kvm, log);
mutex_unlock(&kvm->slots_lock);
return r;
}
#endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
{
return __gfn_to_memslot(kvm_memslots(kvm), gfn);
}
EXPORT_SYMBOL_GPL(gfn_to_memslot);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn)
{
KVM: Cache the last used slot index per vCPU The memslot for a given gfn is looked up multiple times during page fault handling. Avoid binary searching for it multiple times by caching the most recently used slot. There is an existing VM-wide last_used_slot but that does not work well for cases where vCPUs are accessing memory in different slots (see performance data below). Another benefit of caching the most recently use slot (versus looking up the slot once and passing around a pointer) is speeding up memslot lookups *across* faults and during spte prefetching. To measure the performance of this change I ran dirty_log_perf_test with 64 vCPUs and 64 memslots and measured "Populate memory time" and "Iteration 2 dirty memory time". Tests were ran with eptad=N to force dirty logging to use fast_page_fault so its performance could be measured. Config | Metric | Before | After ---------- | ----------------------------- | ------ | ------ tdp_mmu=Y | Populate memory time | 6.76s | 5.47s tdp_mmu=Y | Iteration 2 dirty memory time | 2.83s | 0.31s tdp_mmu=N | Populate memory time | 20.4s | 18.7s tdp_mmu=N | Iteration 2 dirty memory time | 2.65s | 0.30s The "Iteration 2 dirty memory time" results are especially compelling because they are equivalent to running the same test with a single memslot. In other words, fast_page_fault performance no longer scales with the number of memslots. Signed-off-by: David Matlack <dmatlack@google.com> Message-Id: <20210804222844.1419481-4-dmatlack@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-05 06:28:40 +08:00
struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu);
struct kvm_memory_slot *slot;
int slot_index;
slot = try_get_memslot(slots, vcpu->last_used_slot, gfn);
if (slot)
return slot;
/*
* Fall back to searching all memslots. We purposely use
* search_memslots() instead of __gfn_to_memslot() to avoid
* thrashing the VM-wide last_used_index in kvm_memslots.
*/
slot = search_memslots(slots, gfn, &slot_index);
if (slot) {
vcpu->last_used_slot = slot_index;
return slot;
}
return NULL;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot);
bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn);
return kvm_is_visible_memslot(memslot);
}
EXPORT_SYMBOL_GPL(kvm_is_visible_gfn);
bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_memory_slot *memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
return kvm_is_visible_memslot(memslot);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn);
unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct vm_area_struct *vma;
unsigned long addr, size;
size = PAGE_SIZE;
addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL);
if (kvm_is_error_hva(addr))
return PAGE_SIZE;
mmap locking API: use coccinelle to convert mmap_sem rwsem call sites This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 12:33:25 +08:00
mmap_read_lock(current->mm);
vma = find_vma(current->mm, addr);
if (!vma)
goto out;
size = vma_kernel_pagesize(vma);
out:
mmap locking API: use coccinelle to convert mmap_sem rwsem call sites This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 12:33:25 +08:00
mmap_read_unlock(current->mm);
return size;
}
static bool memslot_is_readonly(struct kvm_memory_slot *slot)
{
return slot->flags & KVM_MEM_READONLY;
}
static unsigned long __gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
gfn_t *nr_pages, bool write)
{
if (!slot || slot->flags & KVM_MEMSLOT_INVALID)
return KVM_HVA_ERR_BAD;
if (memslot_is_readonly(slot) && write)
return KVM_HVA_ERR_RO_BAD;
if (nr_pages)
*nr_pages = slot->npages - (gfn - slot->base_gfn);
return __gfn_to_hva_memslot(slot, gfn);
}
static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn,
gfn_t *nr_pages)
{
return __gfn_to_hva_many(slot, gfn, nr_pages, true);
}
unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
gfn_t gfn)
{
return gfn_to_hva_many(slot, gfn, NULL);
}
EXPORT_SYMBOL_GPL(gfn_to_hva_memslot);
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn)
{
return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
}
EXPORT_SYMBOL_GPL(gfn_to_hva);
unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn)
{
return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva);
/*
* Return the hva of a @gfn and the R/W attribute if possible.
*
* @slot: the kvm_memory_slot which contains @gfn
* @gfn: the gfn to be translated
* @writable: used to return the read/write attribute of the @slot if the hva
* is valid and @writable is not NULL
*/
unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot,
gfn_t gfn, bool *writable)
{
unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false);
if (!kvm_is_error_hva(hva) && writable)
*writable = !memslot_is_readonly(slot);
return hva;
}
unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
return gfn_to_hva_memslot_prot(slot, gfn, writable);
}
unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable)
{
struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
return gfn_to_hva_memslot_prot(slot, gfn, writable);
}
static inline int check_user_page_hwpoison(unsigned long addr)
{
int rc, flags = FOLL_HWPOISON | FOLL_WRITE;
rc = get_user_pages(addr, 1, flags, NULL, NULL);
return rc == -EHWPOISON;
}
/*
* The fast path to get the writable pfn which will be stored in @pfn,
* true indicates success, otherwise false is returned. It's also the
* only part that runs if we can in atomic context.
*/
static bool hva_to_pfn_fast(unsigned long addr, bool write_fault,
bool *writable, kvm_pfn_t *pfn)
{
struct page *page[1];
/*
* Fast pin a writable pfn only if it is a write fault request
* or the caller allows to map a writable pfn for a read fault
* request.
*/
if (!(write_fault || writable))
return false;
mm/gup.c: convert to use get_user_{page|pages}_fast_only() API __get_user_pages_fast() renamed to get_user_pages_fast_only() to align with pin_user_pages_fast_only(). As part of this we will get rid of write parameter. Instead caller will pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any existing functionality of the API. All the callers are changed to pass FOLL_WRITE. Also introduce get_user_page_fast_only(), and use it in a few places that hard-code nr_pages to 1. Updated the documentation of the API. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm] Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Suchanek <msuchanek@suse.de> Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08 12:40:55 +08:00
if (get_user_page_fast_only(addr, FOLL_WRITE, page)) {
*pfn = page_to_pfn(page[0]);
if (writable)
*writable = true;
return true;
}
return false;
}
/*
* The slow path to get the pfn of the specified host virtual address,
* 1 indicates success, -errno is returned if error is detected.
*/
static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
bool *writable, kvm_pfn_t *pfn)
{
unsigned int flags = FOLL_HWPOISON;
struct page *page;
int npages = 0;
might_sleep();
if (writable)
*writable = write_fault;
if (write_fault)
flags |= FOLL_WRITE;
if (async)
flags |= FOLL_NOWAIT;
npages = get_user_pages_unlocked(addr, 1, &page, flags);
if (npages != 1)
return npages;
/* map read fault as writable if possible */
if (unlikely(!write_fault) && writable) {
struct page *wpage;
mm/gup.c: convert to use get_user_{page|pages}_fast_only() API __get_user_pages_fast() renamed to get_user_pages_fast_only() to align with pin_user_pages_fast_only(). As part of this we will get rid of write parameter. Instead caller will pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any existing functionality of the API. All the callers are changed to pass FOLL_WRITE. Also introduce get_user_page_fast_only(), and use it in a few places that hard-code nr_pages to 1. Updated the documentation of the API. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm] Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Suchanek <msuchanek@suse.de> Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08 12:40:55 +08:00
if (get_user_page_fast_only(addr, FOLL_WRITE, &wpage)) {
*writable = true;
put_page(page);
page = wpage;
}
}
*pfn = page_to_pfn(page);
return npages;
}
static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault)
{
if (unlikely(!(vma->vm_flags & VM_READ)))
return false;
if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE))))
return false;
return true;
}
static int kvm_try_get_pfn(kvm_pfn_t pfn)
{
if (kvm_is_reserved_pfn(pfn))
return 1;
return get_page_unless_zero(pfn_to_page(pfn));
}
static int hva_to_pfn_remapped(struct vm_area_struct *vma,
unsigned long addr, bool *async,
bool write_fault, bool *writable,
kvm_pfn_t *p_pfn)
{
kvm_pfn_t pfn;
pte_t *ptep;
spinlock_t *ptl;
int r;
r = follow_pte(vma->vm_mm, addr, &ptep, &ptl);
if (r) {
/*
* get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
* not call the fault handler, so do it here.
*/
bool unlocked = false;
r = fixup_user_fault(current->mm, addr,
(write_fault ? FAULT_FLAG_WRITE : 0),
&unlocked);
if (unlocked)
return -EAGAIN;
if (r)
return r;
r = follow_pte(vma->vm_mm, addr, &ptep, &ptl);
if (r)
return r;
}
if (write_fault && !pte_write(*ptep)) {
pfn = KVM_PFN_ERR_RO_FAULT;
goto out;
}
if (writable)
*writable = pte_write(*ptep);
pfn = pte_pfn(*ptep);
/*
* Get a reference here because callers of *hva_to_pfn* and
* *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the
* returned pfn. This is only needed if the VMA has VM_MIXEDMAP
* set, but the kvm_get_pfn/kvm_release_pfn_clean pair will
* simply do nothing for reserved pfns.
*
* Whoever called remap_pfn_range is also going to call e.g.
* unmap_mapping_range before the underlying pages are freed,
* causing a call to our MMU notifier.
*
* Certain IO or PFNMAP mappings can be backed with valid
* struct pages, but be allocated without refcounting e.g.,
* tail pages of non-compound higher order allocations, which
* would then underflow the refcount when the caller does the
* required put_page. Don't allow those pages here.
*/
if (!kvm_try_get_pfn(pfn))
r = -EFAULT;
out:
pte_unmap_unlock(ptep, ptl);
*p_pfn = pfn;
return r;
}
/*
* Pin guest page in memory and return its pfn.
* @addr: host virtual address which maps memory to the guest
* @atomic: whether this function can sleep
* @async: whether this function need to wait IO complete if the
* host page is not in the memory
* @write_fault: whether we should get a writable host page
* @writable: whether it allows to map a writable host page for !@write_fault
*
* The function will map a writable host page for these two cases:
* 1): @write_fault = true
* 2): @write_fault = false && @writable, @writable will tell the caller
* whether the mapping is writable.
*/
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
bool write_fault, bool *writable)
{
struct vm_area_struct *vma;
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t pfn = 0;
int npages, r;
/* we can do it either atomically or asynchronously, not both */
BUG_ON(atomic && async);
if (hva_to_pfn_fast(addr, write_fault, writable, &pfn))
return pfn;
if (atomic)
return KVM_PFN_ERR_FAULT;
npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn);
if (npages == 1)
return pfn;
mmap locking API: use coccinelle to convert mmap_sem rwsem call sites This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 12:33:25 +08:00
mmap_read_lock(current->mm);
if (npages == -EHWPOISON ||
(!async && check_user_page_hwpoison(addr))) {
pfn = KVM_PFN_ERR_HWPOISON;
goto exit;
}
retry:
vma = vma_lookup(current->mm, addr);
if (vma == NULL)
pfn = KVM_PFN_ERR_FAULT;
else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) {
r = hva_to_pfn_remapped(vma, addr, async, write_fault, writable, &pfn);
if (r == -EAGAIN)
goto retry;
if (r < 0)
pfn = KVM_PFN_ERR_FAULT;
} else {
if (async && vma_is_valid(vma, write_fault))
*async = true;
pfn = KVM_PFN_ERR_FAULT;
}
exit:
mmap locking API: use coccinelle to convert mmap_sem rwsem call sites This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 12:33:25 +08:00
mmap_read_unlock(current->mm);
return pfn;
}
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t __gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn,
bool atomic, bool *async, bool write_fault,
bool *writable, hva_t *hva)
{
unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault);
if (hva)
*hva = addr;
if (addr == KVM_HVA_ERR_RO_BAD) {
if (writable)
*writable = false;
return KVM_PFN_ERR_RO_FAULT;
}
if (kvm_is_error_hva(addr)) {
if (writable)
*writable = false;
return KVM_PFN_NOSLOT;
}
/* Do not map writable pfn in the readonly memslot. */
if (writable && memslot_is_readonly(slot)) {
*writable = false;
writable = NULL;
}
return hva_to_pfn(addr, atomic, async, write_fault,
writable);
}
EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
bool *writable)
{
return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, NULL,
write_fault, writable, NULL);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn_prot);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t gfn_to_pfn_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
{
return __gfn_to_pfn_memslot(slot, gfn, false, NULL, true, NULL, NULL);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t gfn_to_pfn_memslot_atomic(struct kvm_memory_slot *slot, gfn_t gfn)
{
return __gfn_to_pfn_memslot(slot, gfn, true, NULL, true, NULL, NULL);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn)
{
return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn)
{
return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn);
}
EXPORT_SYMBOL_GPL(gfn_to_pfn);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn);
int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
struct page **pages, int nr_pages)
{
unsigned long addr;
gfn_t entry = 0;
addr = gfn_to_hva_many(slot, gfn, &entry);
if (kvm_is_error_hva(addr))
return -1;
if (entry < nr_pages)
return 0;
mm/gup.c: convert to use get_user_{page|pages}_fast_only() API __get_user_pages_fast() renamed to get_user_pages_fast_only() to align with pin_user_pages_fast_only(). As part of this we will get rid of write parameter. Instead caller will pass FOLL_WRITE to get_user_pages_fast_only(). This will not change any existing functionality of the API. All the callers are changed to pass FOLL_WRITE. Also introduce get_user_page_fast_only(), and use it in a few places that hard-code nr_pages to 1. Updated the documentation of the API. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Paul Mackerras <paulus@ozlabs.org> [arch/powerpc/kvm] Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michal Suchanek <msuchanek@suse.de> Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-08 12:40:55 +08:00
return get_user_pages_fast_only(addr, nr_pages, FOLL_WRITE, pages);
}
EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
static struct page *kvm_pfn_to_page(kvm_pfn_t pfn)
{
if (is_error_noslot_pfn(pfn))
return KVM_ERR_PTR_BAD_PAGE;
if (kvm_is_reserved_pfn(pfn)) {
WARN_ON(1);
return KVM_ERR_PTR_BAD_PAGE;
}
return pfn_to_page(pfn);
}
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
{
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t pfn;
pfn = gfn_to_pfn(kvm, gfn);
return kvm_pfn_to_page(pfn);
}
EXPORT_SYMBOL_GPL(gfn_to_page);
void kvm_release_pfn(kvm_pfn_t pfn, bool dirty, struct gfn_to_pfn_cache *cache)
{
if (pfn == 0)
return;
if (cache)
cache->pfn = cache->gfn = 0;
if (dirty)
kvm_release_pfn_dirty(pfn);
else
kvm_release_pfn_clean(pfn);
}
static void kvm_cache_gfn_to_pfn(struct kvm_memory_slot *slot, gfn_t gfn,
struct gfn_to_pfn_cache *cache, u64 gen)
{
kvm_release_pfn(cache->pfn, cache->dirty, cache);
cache->pfn = gfn_to_pfn_memslot(slot, gfn);
cache->gfn = gfn;
cache->dirty = false;
cache->generation = gen;
}
static int __kvm_map_gfn(struct kvm_memslots *slots, gfn_t gfn,
struct kvm_host_map *map,
struct gfn_to_pfn_cache *cache,
bool atomic)
{
kvm_pfn_t pfn;
void *hva = NULL;
struct page *page = KVM_UNMAPPED_PAGE;
struct kvm_memory_slot *slot = __gfn_to_memslot(slots, gfn);
u64 gen = slots->generation;
if (!map)
return -EINVAL;
if (cache) {
if (!cache->pfn || cache->gfn != gfn ||
cache->generation != gen) {
if (atomic)
return -EAGAIN;
kvm_cache_gfn_to_pfn(slot, gfn, cache, gen);
}
pfn = cache->pfn;
} else {
if (atomic)
return -EAGAIN;
pfn = gfn_to_pfn_memslot(slot, gfn);
}
if (is_error_noslot_pfn(pfn))
return -EINVAL;
if (pfn_valid(pfn)) {
page = pfn_to_page(pfn);
if (atomic)
hva = kmap_atomic(page);
else
hva = kmap(page);
#ifdef CONFIG_HAS_IOMEM
} else if (!atomic) {
hva = memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB);
} else {
return -EINVAL;
#endif
}
if (!hva)
return -EFAULT;
map->page = page;
map->hva = hva;
map->pfn = pfn;
map->gfn = gfn;
return 0;
}
int kvm_map_gfn(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map,
struct gfn_to_pfn_cache *cache, bool atomic)
{
return __kvm_map_gfn(kvm_memslots(vcpu->kvm), gfn, map,
cache, atomic);
}
EXPORT_SYMBOL_GPL(kvm_map_gfn);
int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map)
{
return __kvm_map_gfn(kvm_vcpu_memslots(vcpu), gfn, map,
NULL, false);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_map);
static void __kvm_unmap_gfn(struct kvm *kvm,
struct kvm_memory_slot *memslot,
struct kvm_host_map *map,
struct gfn_to_pfn_cache *cache,
bool dirty, bool atomic)
{
if (!map)
return;
if (!map->hva)
return;
if (map->page != KVM_UNMAPPED_PAGE) {
if (atomic)
kunmap_atomic(map->hva);
else
kunmap(map->page);
}
#ifdef CONFIG_HAS_IOMEM
else if (!atomic)
memunmap(map->hva);
else
WARN_ONCE(1, "Unexpected unmapping in atomic context");
#endif
if (dirty)
mark_page_dirty_in_slot(kvm, memslot, map->gfn);
if (cache)
cache->dirty |= dirty;
else
kvm_release_pfn(map->pfn, dirty, NULL);
map->hva = NULL;
map->page = NULL;
}
int kvm_unmap_gfn(struct kvm_vcpu *vcpu, struct kvm_host_map *map,
struct gfn_to_pfn_cache *cache, bool dirty, bool atomic)
{
__kvm_unmap_gfn(vcpu->kvm, gfn_to_memslot(vcpu->kvm, map->gfn), map,
cache, dirty, atomic);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_unmap_gfn);
void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty)
{
__kvm_unmap_gfn(vcpu->kvm, kvm_vcpu_gfn_to_memslot(vcpu, map->gfn),
map, NULL, dirty, false);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_unmap);
struct page *kvm_vcpu_gfn_to_page(struct kvm_vcpu *vcpu, gfn_t gfn)
{
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
kvm_pfn_t pfn;
pfn = kvm_vcpu_gfn_to_pfn(vcpu, gfn);
return kvm_pfn_to_page(pfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_page);
void kvm_release_page_clean(struct page *page)
{
WARN_ON(is_error_page(page));
kvm_release_pfn_clean(page_to_pfn(page));
}
EXPORT_SYMBOL_GPL(kvm_release_page_clean);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
void kvm_release_pfn_clean(kvm_pfn_t pfn)
{
if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn))
put_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_clean);
void kvm_release_page_dirty(struct page *page)
{
WARN_ON(is_error_page(page));
kvm_release_pfn_dirty(page_to_pfn(page));
}
EXPORT_SYMBOL_GPL(kvm_release_page_dirty);
void kvm_release_pfn_dirty(kvm_pfn_t pfn)
{
kvm_set_pfn_dirty(pfn);
kvm_release_pfn_clean(pfn);
}
EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
void kvm_set_pfn_dirty(kvm_pfn_t pfn)
{
if (!kvm_is_reserved_pfn(pfn) && !kvm_is_zone_device_pfn(pfn))
SetPageDirty(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
void kvm_set_pfn_accessed(kvm_pfn_t pfn)
{
KVM: MMU: Do not treat ZONE_DEVICE pages as being reserved Explicitly exempt ZONE_DEVICE pages from kvm_is_reserved_pfn() and instead manually handle ZONE_DEVICE on a case-by-case basis. For things like page refcounts, KVM needs to treat ZONE_DEVICE pages like normal pages, e.g. put pages grabbed via gup(). But for flows such as setting A/D bits or shifting refcounts for transparent huge pages, KVM needs to to avoid processing ZONE_DEVICE pages as the flows in question lack the underlying machinery for proper handling of ZONE_DEVICE pages. This fixes a hang reported by Adam Borowski[*] in dev_pagemap_cleanup() when running a KVM guest backed with /dev/dax memory, as KVM straight up doesn't put any references to ZONE_DEVICE pages acquired by gup(). Note, Dan Williams proposed an alternative solution of doing put_page() on ZONE_DEVICE pages immediately after gup() in order to simplify the auditing needed to ensure is_zone_device_page() is called if and only if the backing device is pinned (via gup()). But that approach would break kvm_vcpu_{un}map() as KVM requires the page to be pinned from map() 'til unmap() when accessing guest memory, unlike KVM's secondary MMU, which coordinates with mmu_notifier invalidations to avoid creating stale page references, i.e. doesn't rely on pages being pinned. [*] http://lkml.kernel.org/r/20190919115547.GA17963@angband.pl Reported-by: Adam Borowski <kilobyte@angband.pl> Analyzed-by: David Hildenbrand <david@redhat.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: stable@vger.kernel.org Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-12 06:12:27 +08:00
if (!kvm_is_reserved_pfn(pfn) && !kvm_is_zone_device_pfn(pfn))
mark_page_accessed(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed);
kvm: rename pfn_t to kvm_pfn_t To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 18): The core has developed a need for a "pfn_t" type [1]. Move the existing pfn_t in KVM to kvm_pfn_t [2]. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html [2]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002218.html Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16 08:56:11 +08:00
void kvm_get_pfn(kvm_pfn_t pfn)
{
if (!kvm_is_reserved_pfn(pfn))
get_page(pfn_to_page(pfn));
}
EXPORT_SYMBOL_GPL(kvm_get_pfn);
static int next_segment(unsigned long len, int offset)
{
if (len > PAGE_SIZE - offset)
return PAGE_SIZE - offset;
else
return len;
}
static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn,
void *data, int offset, int len)
{
int r;
unsigned long addr;
addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
if (kvm_is_error_hva(addr))
return -EFAULT;
r = __copy_from_user(data, (void __user *)addr + offset, len);
if (r)
return -EFAULT;
return 0;
}
int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
int len)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
return __kvm_read_guest_page(slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_read_guest_page);
int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data,
int offset, int len)
{
struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
return __kvm_read_guest_page(slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page);
int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_read_guest_page(kvm, gfn, data, offset, seg);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
data += seg;
++gfn;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_read_guest);
int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
data += seg;
++gfn;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest);
static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
void *data, int offset, unsigned long len)
{
int r;
unsigned long addr;
addr = gfn_to_hva_memslot_prot(slot, gfn, NULL);
if (kvm_is_error_hva(addr))
return -EFAULT;
pagefault_disable();
r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
pagefault_enable();
if (r)
return -EFAULT;
return 0;
}
int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa,
void *data, unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
int offset = offset_in_page(gpa);
return __kvm_read_guest_atomic(slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic);
static int __kvm_write_guest_page(struct kvm *kvm,
struct kvm_memory_slot *memslot, gfn_t gfn,
const void *data, int offset, int len)
{
int r;
unsigned long addr;
addr = gfn_to_hva_memslot(memslot, gfn);
if (kvm_is_error_hva(addr))
return -EFAULT;
r = __copy_to_user((void __user *)addr + offset, data, len);
if (r)
return -EFAULT;
mark_page_dirty_in_slot(kvm, memslot, gfn);
return 0;
}
int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn,
const void *data, int offset, int len)
{
struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn);
return __kvm_write_guest_page(kvm, slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_write_guest_page);
int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
const void *data, int offset, int len)
{
struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
return __kvm_write_guest_page(vcpu->kvm, slot, gfn, data, offset, len);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page);
int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_write_guest_page(kvm, gfn, data, offset, seg);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
data += seg;
++gfn;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_write_guest);
int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
unsigned long len)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
data += seg;
++gfn;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest);
static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots,
struct gfn_to_hva_cache *ghc,
gpa_t gpa, unsigned long len)
{
int offset = offset_in_page(gpa);
gfn_t start_gfn = gpa >> PAGE_SHIFT;
gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT;
gfn_t nr_pages_needed = end_gfn - start_gfn + 1;
gfn_t nr_pages_avail;
/* Update ghc->generation before performing any error checks. */
ghc->generation = slots->generation;
if (start_gfn > end_gfn) {
ghc->hva = KVM_HVA_ERR_BAD;
return -EINVAL;
}
/*
* If the requested region crosses two memslots, we still
* verify that the entire region is valid here.
*/
for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) {
ghc->memslot = __gfn_to_memslot(slots, start_gfn);
ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn,
&nr_pages_avail);
if (kvm_is_error_hva(ghc->hva))
return -EFAULT;
}
/* Use the slow path for cross page reads and writes. */
if (nr_pages_needed == 1)
ghc->hva += offset;
else
ghc->memslot = NULL;
ghc->gpa = gpa;
ghc->len = len;
return 0;
}
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
gpa_t gpa, unsigned long len)
{
struct kvm_memslots *slots = kvm_memslots(kvm);
return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len);
}
EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned int offset,
unsigned long len)
{
struct kvm_memslots *slots = kvm_memslots(kvm);
int r;
gpa_t gpa = ghc->gpa + offset;
BUG_ON(len + offset > ghc->len);
if (slots->generation != ghc->generation) {
if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
return -EFAULT;
}
if (kvm_is_error_hva(ghc->hva))
return -EFAULT;
KVM: Check for a bad hva before dropping into the ghc slow path When reading/writing using the guest/host cache, check for a bad hva before checking for a NULL memslot, which triggers the slow path for handing cross-page accesses. Because the memslot is nullified on error by __kvm_gfn_to_hva_cache_init(), if the bad hva is encountered after crossing into a new page, then the kvm_{read,write}_guest() slow path could potentially write/access the first chunk prior to detecting the bad hva. Arguably, performing a partial access is semantically correct from an architectural perspective, but that behavior is certainly not intended. In the original implementation, memslot was not explicitly nullified and therefore the partial access behavior varied based on whether the memslot itself was null, or if the hva was simply bad. The current behavior was introduced as a seemingly unintentional side effect in commit f1b9dd5eb86c ("kvm: Disallow wraparound in kvm_gfn_to_hva_cache_init"), which justified the change with "since some callers don't check the return code from this function, it sit seems prudent to clear ghc->memslot in the event of an error". Regardless of intent, the partial access is dependent on _not_ checking the result of the cache initialization, which is arguably a bug in its own right, at best simply weird. Fixes: 8f964525a121 ("KVM: Allow cross page reads and writes from cached translations.") Cc: Jim Mattson <jmattson@google.com> Cc: Andrew Honig <ahonig@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-10 07:56:18 +08:00
if (unlikely(!ghc->memslot))
return kvm_write_guest(kvm, gpa, data, len);
r = __copy_to_user((void __user *)ghc->hva + offset, data, len);
if (r)
return -EFAULT;
mark_page_dirty_in_slot(kvm, ghc->memslot, gpa >> PAGE_SHIFT);
return 0;
}
EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached);
int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned long len)
{
return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len);
}
EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned int offset,
unsigned long len)
{
struct kvm_memslots *slots = kvm_memslots(kvm);
int r;
gpa_t gpa = ghc->gpa + offset;
BUG_ON(len + offset > ghc->len);
if (slots->generation != ghc->generation) {
if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len))
return -EFAULT;
}
if (kvm_is_error_hva(ghc->hva))
return -EFAULT;
KVM: Check for a bad hva before dropping into the ghc slow path When reading/writing using the guest/host cache, check for a bad hva before checking for a NULL memslot, which triggers the slow path for handing cross-page accesses. Because the memslot is nullified on error by __kvm_gfn_to_hva_cache_init(), if the bad hva is encountered after crossing into a new page, then the kvm_{read,write}_guest() slow path could potentially write/access the first chunk prior to detecting the bad hva. Arguably, performing a partial access is semantically correct from an architectural perspective, but that behavior is certainly not intended. In the original implementation, memslot was not explicitly nullified and therefore the partial access behavior varied based on whether the memslot itself was null, or if the hva was simply bad. The current behavior was introduced as a seemingly unintentional side effect in commit f1b9dd5eb86c ("kvm: Disallow wraparound in kvm_gfn_to_hva_cache_init"), which justified the change with "since some callers don't check the return code from this function, it sit seems prudent to clear ghc->memslot in the event of an error". Regardless of intent, the partial access is dependent on _not_ checking the result of the cache initialization, which is arguably a bug in its own right, at best simply weird. Fixes: 8f964525a121 ("KVM: Allow cross page reads and writes from cached translations.") Cc: Jim Mattson <jmattson@google.com> Cc: Andrew Honig <ahonig@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-10 07:56:18 +08:00
if (unlikely(!ghc->memslot))
return kvm_read_guest(kvm, gpa, data, len);
KVM: Check for a bad hva before dropping into the ghc slow path When reading/writing using the guest/host cache, check for a bad hva before checking for a NULL memslot, which triggers the slow path for handing cross-page accesses. Because the memslot is nullified on error by __kvm_gfn_to_hva_cache_init(), if the bad hva is encountered after crossing into a new page, then the kvm_{read,write}_guest() slow path could potentially write/access the first chunk prior to detecting the bad hva. Arguably, performing a partial access is semantically correct from an architectural perspective, but that behavior is certainly not intended. In the original implementation, memslot was not explicitly nullified and therefore the partial access behavior varied based on whether the memslot itself was null, or if the hva was simply bad. The current behavior was introduced as a seemingly unintentional side effect in commit f1b9dd5eb86c ("kvm: Disallow wraparound in kvm_gfn_to_hva_cache_init"), which justified the change with "since some callers don't check the return code from this function, it sit seems prudent to clear ghc->memslot in the event of an error". Regardless of intent, the partial access is dependent on _not_ checking the result of the cache initialization, which is arguably a bug in its own right, at best simply weird. Fixes: 8f964525a121 ("KVM: Allow cross page reads and writes from cached translations.") Cc: Jim Mattson <jmattson@google.com> Cc: Andrew Honig <ahonig@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-10 07:56:18 +08:00
r = __copy_from_user(data, (void __user *)ghc->hva + offset, len);
if (r)
return -EFAULT;
return 0;
}
EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached);
int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned long len)
{
return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len);
}
EXPORT_SYMBOL_GPL(kvm_read_guest_cached);
int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len)
{
const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0)));
gfn_t gfn = gpa >> PAGE_SHIFT;
int seg;
int offset = offset_in_page(gpa);
int ret;
while ((seg = next_segment(len, offset)) != 0) {
ret = kvm_write_guest_page(kvm, gfn, zero_page, offset, len);
if (ret < 0)
return ret;
offset = 0;
len -= seg;
++gfn;
}
return 0;
}
EXPORT_SYMBOL_GPL(kvm_clear_guest);
void mark_page_dirty_in_slot(struct kvm *kvm,
struct kvm_memory_slot *memslot,
gfn_t gfn)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
if (memslot && kvm_slot_dirty_track_enabled(memslot)) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
u32 slot = (memslot->as_id << 16) | memslot->id;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
if (kvm->dirty_ring_size)
kvm_dirty_ring_push(kvm_dirty_ring_get(kvm),
slot, rel_gfn);
else
set_bit_le(rel_gfn, memslot->dirty_bitmap);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
}
EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
{
struct kvm_memory_slot *memslot;
memslot = gfn_to_memslot(kvm, gfn);
mark_page_dirty_in_slot(kvm, memslot, gfn);
}
EXPORT_SYMBOL_GPL(mark_page_dirty);
void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_memory_slot *memslot;
memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn);
mark_page_dirty_in_slot(vcpu->kvm, memslot, gfn);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty);
void kvm_sigset_activate(struct kvm_vcpu *vcpu)
{
if (!vcpu->sigset_active)
return;
/*
* This does a lockless modification of ->real_blocked, which is fine
* because, only current can change ->real_blocked and all readers of
* ->real_blocked don't care as long ->real_blocked is always a subset
* of ->blocked.
*/
sigprocmask(SIG_SETMASK, &vcpu->sigset, &current->real_blocked);
}
void kvm_sigset_deactivate(struct kvm_vcpu *vcpu)
{
if (!vcpu->sigset_active)
return;
sigprocmask(SIG_SETMASK, &current->real_blocked, NULL);
sigemptyset(&current->real_blocked);
}
static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)
{
unsigned int old, val, grow, grow_start;
old = val = vcpu->halt_poll_ns;
grow_start = READ_ONCE(halt_poll_ns_grow_start);
grow = READ_ONCE(halt_poll_ns_grow);
if (!grow)
goto out;
val *= grow;
if (val < grow_start)
val = grow_start;
if (val > vcpu->kvm->max_halt_poll_ns)
val = vcpu->kvm->max_halt_poll_ns;
vcpu->halt_poll_ns = val;
out:
trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old);
}
static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu)
{
unsigned int old, val, shrink;
old = val = vcpu->halt_poll_ns;
shrink = READ_ONCE(halt_poll_ns_shrink);
if (shrink == 0)
val = 0;
else
val /= shrink;
vcpu->halt_poll_ns = val;
trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old);
}
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu)
{
int ret = -EINTR;
int idx = srcu_read_lock(&vcpu->kvm->srcu);
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
if (kvm_arch_vcpu_runnable(vcpu)) {
kvm_make_request(KVM_REQ_UNHALT, vcpu);
goto out;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
}
if (kvm_cpu_has_pending_timer(vcpu))
goto out;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
if (signal_pending(current))
goto out;
if (kvm_check_request(KVM_REQ_UNBLOCK, vcpu))
goto out;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
ret = 0;
out:
srcu_read_unlock(&vcpu->kvm->srcu, idx);
return ret;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
}
static inline void
update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited)
{
if (waited)
vcpu->stat.generic.halt_poll_fail_ns += poll_ns;
else
vcpu->stat.generic.halt_poll_success_ns += poll_ns;
}
/*
* The vCPU has executed a HLT instruction with in-kernel mode enabled.
*/
void kvm_vcpu_block(struct kvm_vcpu *vcpu)
{
ktime_t start, cur, poll_end;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
bool waited = false;
u64 block_ns;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
kvm_arch_vcpu_blocking(vcpu);
start = cur = poll_end = ktime_get();
if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) {
ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
++vcpu->stat.generic.halt_attempted_poll;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
do {
/*
* This sets KVM_REQ_UNHALT if an interrupt
* arrives.
*/
if (kvm_vcpu_check_block(vcpu) < 0) {
++vcpu->stat.generic.halt_successful_poll;
KVM: halt_polling: provide a way to qualify wakeups during poll Some wakeups should not be considered a sucessful poll. For example on s390 I/O interrupts are usually floating, which means that _ALL_ CPUs would be considered runnable - letting all vCPUs poll all the time for transactional like workload, even if one vCPU would be enough. This can result in huge CPU usage for large guests. This patch lets architectures provide a way to qualify wakeups if they should be considered a good/bad wakeups in regard to polls. For s390 the implementation will fence of halt polling for anything but known good, single vCPU events. The s390 implementation for floating interrupts does a wakeup for one vCPU, but the interrupt will be delivered by whatever CPU checks first for a pending interrupt. We prefer the woken up CPU by marking the poll of this CPU as "good" poll. This code will also mark several other wakeup reasons like IPI or expired timers as "good". This will of course also mark some events as not sucessful. As KVM on z runs always as a 2nd level hypervisor, we prefer to not poll, unless we are really sure, though. This patch successfully limits the CPU usage for cases like uperf 1byte transactional ping pong workload or wakeup heavy workload like OLTP while still providing a proper speedup. This also introduced a new vcpu stat "halt_poll_no_tuning" that marks wakeups that are considered not good for polling. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version) Cc: David Matlack <dmatlack@google.com> Cc: Wanpeng Li <kernellwp@gmail.com> [Rename config symbol. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-13 18:16:35 +08:00
if (!vcpu_valid_wakeup(vcpu))
++vcpu->stat.generic.halt_poll_invalid;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
goto out;
}
cpu_relax();
poll_end = cur = ktime_get();
} while (kvm_vcpu_can_poll(cur, stop));
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
}
prepare_to_rcuwait(&vcpu->wait);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
if (kvm_vcpu_check_block(vcpu) < 0)
break;
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
waited = true;
schedule();
}
finish_rcuwait(&vcpu->wait);
kvm: add halt_poll_ns module parameter This patch introduces a new module parameter for the KVM module; when it is present, KVM attempts a bit of polling on every HLT before scheduling itself out via kvm_vcpu_block. This parameter helps a lot for latency-bound workloads---in particular I tested it with O_DSYNC writes with a battery-backed disk in the host. In this case, writes are fast (because the data doesn't have to go all the way to the platters) but they cannot be merged by either the host or the guest. KVM's performance here is usually around 30% of bare metal, or 50% if you use cache=directsync or cache=writethrough (these parameters avoid that the guest sends pointless flush requests, and at the same time they are not slow because of the battery-backed cache). The bad performance happens because on every halt the host CPU decides to halt itself too. When the interrupt comes, the vCPU thread is then migrated to a new physical CPU, and in general the latency is horrible because the vCPU thread has to be scheduled back in. With this patch performance reaches 60-65% of bare metal and, more important, 99% of what you get if you use idle=poll in the guest. This means that the tunable gets rid of this particular bottleneck, and more work can be done to improve performance in the kernel or QEMU. Of course there is some price to pay; every time an otherwise idle vCPUs is interrupted by an interrupt, it will poll unnecessarily and thus impose a little load on the host. The above results were obtained with a mostly random value of the parameter (500000), and the load was around 1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU. The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll, that can be used to tune the parameter. It counts how many HLT instructions received an interrupt during the polling period; each successful poll avoids that Linux schedules the VCPU thread out and back in, and may also avoid a likely trip to C1 and back for the physical CPU. While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second. Of these halts, almost all are failed polls. During the benchmark, instead, basically all halts end within the polling period, except a more or less constant stream of 50 per second coming from vCPUs that are not running the benchmark. The wasted time is thus very low. Things may be slightly different for Windows VMs, which have a ~10 ms timer tick. The effect is also visible on Marcelo's recently-introduced latency test for the TSC deadline timer. Though of course a non-RT kernel has awful latency bounds, the latency of the timer is around 8000-10000 clock cycles compared to 20000-120000 without setting halt_poll_ns. For the TSC deadline timer, thus, the effect is both a smaller average latency and a smaller variance. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-02-05 01:20:58 +08:00
cur = ktime_get();
out:
kvm_arch_vcpu_unblocking(vcpu);
block_ns = ktime_to_ns(cur) - ktime_to_ns(start);
update_halt_poll_stats(
vcpu, ktime_to_ns(ktime_sub(poll_end, start)), waited);
if (!kvm_arch_no_poll(vcpu)) {
if (!vcpu_valid_wakeup(vcpu)) {
shrink_halt_poll_ns(vcpu);
} else if (vcpu->kvm->max_halt_poll_ns) {
if (block_ns <= vcpu->halt_poll_ns)
;
/* we had a long block, shrink polling */
else if (vcpu->halt_poll_ns &&
block_ns > vcpu->kvm->max_halt_poll_ns)
shrink_halt_poll_ns(vcpu);
/* we had a short halt and our poll time is too small */
else if (vcpu->halt_poll_ns < vcpu->kvm->max_halt_poll_ns &&
block_ns < vcpu->kvm->max_halt_poll_ns)
grow_halt_poll_ns(vcpu);
} else {
vcpu->halt_poll_ns = 0;
}
}
KVM: halt_polling: provide a way to qualify wakeups during poll Some wakeups should not be considered a sucessful poll. For example on s390 I/O interrupts are usually floating, which means that _ALL_ CPUs would be considered runnable - letting all vCPUs poll all the time for transactional like workload, even if one vCPU would be enough. This can result in huge CPU usage for large guests. This patch lets architectures provide a way to qualify wakeups if they should be considered a good/bad wakeups in regard to polls. For s390 the implementation will fence of halt polling for anything but known good, single vCPU events. The s390 implementation for floating interrupts does a wakeup for one vCPU, but the interrupt will be delivered by whatever CPU checks first for a pending interrupt. We prefer the woken up CPU by marking the poll of this CPU as "good" poll. This code will also mark several other wakeup reasons like IPI or expired timers as "good". This will of course also mark some events as not sucessful. As KVM on z runs always as a 2nd level hypervisor, we prefer to not poll, unless we are really sure, though. This patch successfully limits the CPU usage for cases like uperf 1byte transactional ping pong workload or wakeup heavy workload like OLTP while still providing a proper speedup. This also introduced a new vcpu stat "halt_poll_no_tuning" that marks wakeups that are considered not good for polling. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Radim Krčmář <rkrcmar@redhat.com> (for an earlier version) Cc: David Matlack <dmatlack@google.com> Cc: Wanpeng Li <kernellwp@gmail.com> [Rename config symbol. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-13 18:16:35 +08:00
trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
kvm_arch_vcpu_block_finish(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_block);
bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
{
struct rcuwait *waitp;
waitp = kvm_arch_vcpu_get_wait(vcpu);
if (rcuwait_wake_up(waitp)) {
KVM: Boost vCPUs that are delivering interrupts Inspired by commit 9cac38dd5d (KVM/s390: Set preempted flag during vcpu wakeup and interrupt delivery), we want to also boost not just lock holders but also vCPUs that are delivering interrupts. Most smp_call_function_many calls are synchronous, so the IPI target vCPUs are also good yield candidates. This patch introduces vcpu->ready to boost vCPUs during wakeup and interrupt delivery time; unlike s390 we do not reuse vcpu->preempted so that voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin, but vmx_vcpu_pi_put is not affected (VT-d PI handles voluntary preemption separately, in pi_pre_block). Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM: ebizzy -M vanilla boosting improved 1VM 21443 23520 9% 2VM 2800 8000 180% 3VM 1800 3100 72% Testing on my Haswell desktop 8 HT, with 8 vCPUs VM 8GB RAM, two VMs, one running ebizzy -M, the other running 'stress --cpu 2': w/ boosting + w/o pv sched yield(vanilla) vanilla boosting improved 1570 4000 155% w/ boosting + w/ pv sched yield(vanilla) vanilla boosting improved 1844 5157 179% w/o boosting, perf top in VM: 72.33% [kernel] [k] smp_call_function_many 4.22% [kernel] [k] call_function_i 3.71% [kernel] [k] async_page_fault w/ boosting, perf top in VM: 38.43% [kernel] [k] smp_call_function_many 6.31% [kernel] [k] async_page_fault 6.13% libc-2.23.so [.] __memcpy_avx_unaligned 4.88% [kernel] [k] call_function_interrupt Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Marc Zyngier <maz@kernel.org> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-18 19:39:06 +08:00
WRITE_ONCE(vcpu->ready, true);
++vcpu->stat.generic.halt_wakeup;
return true;
}
return false;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up);
#ifndef CONFIG_S390
/*
* Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode.
*/
void kvm_vcpu_kick(struct kvm_vcpu *vcpu)
{
int me;
int cpu = vcpu->cpu;
if (kvm_vcpu_wake_up(vcpu))
return;
me = get_cpu();
if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu))
if (kvm_arch_vcpu_should_kick(vcpu))
smp_send_reschedule(cpu);
put_cpu();
}
EXPORT_SYMBOL_GPL(kvm_vcpu_kick);
#endif /* !CONFIG_S390 */
int kvm_vcpu_yield_to(struct kvm_vcpu *target)
{
struct pid *pid;
struct task_struct *task = NULL;
int ret = 0;
rcu_read_lock();
pid = rcu_dereference(target->pid);
if (pid)
task = get_pid_task(pid, PIDTYPE_PID);
rcu_read_unlock();
if (!task)
2013-01-22 15:39:24 +08:00
return ret;
ret = yield_to(task, 1);
put_task_struct(task);
2013-01-22 15:39:24 +08:00
return ret;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to);
/*
* Helper that checks whether a VCPU is eligible for directed yield.
* Most eligible candidate to yield is decided by following heuristics:
*
* (a) VCPU which has not done pl-exit or cpu relax intercepted recently
* (preempted lock holder), indicated by @in_spin_loop.
* Set at the beginning and cleared at the end of interception/PLE handler.
*
* (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get
* chance last time (mostly it has become eligible now since we have probably
* yielded to lockholder in last iteration. This is done by toggling
* @dy_eligible each time a VCPU checked for eligibility.)
*
* Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding
* to preempted lock-holder could result in wrong VCPU selection and CPU
* burning. Giving priority for a potential lock-holder increases lock
* progress.
*
* Since algorithm is based on heuristics, accessing another VCPU data without
* locking does not harm. It may result in trying to yield to same VCPU, fail
* and continue with next VCPU and so on.
*/
static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
bool eligible;
eligible = !vcpu->spin_loop.in_spin_loop ||
vcpu->spin_loop.dy_eligible;
if (vcpu->spin_loop.in_spin_loop)
kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible);
return eligible;
#else
return true;
#endif
}
2013-01-22 15:39:24 +08:00
2019-08-05 10:03:19 +08:00
/*
* Unlike kvm_arch_vcpu_runnable, this function is called outside
* a vcpu_load/vcpu_put pair. However, for most architectures
* kvm_arch_vcpu_runnable does not require vcpu_load.
*/
bool __weak kvm_arch_dy_runnable(struct kvm_vcpu *vcpu)
{
return kvm_arch_vcpu_runnable(vcpu);
}
static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu)
{
if (kvm_arch_dy_runnable(vcpu))
return true;
#ifdef CONFIG_KVM_ASYNC_PF
if (!list_empty_careful(&vcpu->async_pf.done))
return true;
#endif
return false;
}
bool __weak kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu)
{
return false;
}
void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode)
{
struct kvm *kvm = me->kvm;
struct kvm_vcpu *vcpu;
int last_boosted_vcpu = me->kvm->last_boosted_vcpu;
int yielded = 0;
2013-01-22 15:39:24 +08:00
int try = 3;
int pass;
int i;
kvm_vcpu_set_in_spin_loop(me, true);
/*
* We boost the priority of a VCPU that is runnable but not
* currently running, because it got preempted by something
* else and called schedule in __vcpu_run. Hopefully that
* VCPU is holding the lock that we need and will release it.
* We approximate round-robin by starting at the last boosted VCPU.
*/
2013-01-22 15:39:24 +08:00
for (pass = 0; pass < 2 && !yielded && try; pass++) {
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!pass && i <= last_boosted_vcpu) {
i = last_boosted_vcpu;
continue;
} else if (pass && i > last_boosted_vcpu)
break;
KVM: Boost vCPUs that are delivering interrupts Inspired by commit 9cac38dd5d (KVM/s390: Set preempted flag during vcpu wakeup and interrupt delivery), we want to also boost not just lock holders but also vCPUs that are delivering interrupts. Most smp_call_function_many calls are synchronous, so the IPI target vCPUs are also good yield candidates. This patch introduces vcpu->ready to boost vCPUs during wakeup and interrupt delivery time; unlike s390 we do not reuse vcpu->preempted so that voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin, but vmx_vcpu_pi_put is not affected (VT-d PI handles voluntary preemption separately, in pi_pre_block). Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM: ebizzy -M vanilla boosting improved 1VM 21443 23520 9% 2VM 2800 8000 180% 3VM 1800 3100 72% Testing on my Haswell desktop 8 HT, with 8 vCPUs VM 8GB RAM, two VMs, one running ebizzy -M, the other running 'stress --cpu 2': w/ boosting + w/o pv sched yield(vanilla) vanilla boosting improved 1570 4000 155% w/ boosting + w/ pv sched yield(vanilla) vanilla boosting improved 1844 5157 179% w/o boosting, perf top in VM: 72.33% [kernel] [k] smp_call_function_many 4.22% [kernel] [k] call_function_i 3.71% [kernel] [k] async_page_fault w/ boosting, perf top in VM: 38.43% [kernel] [k] smp_call_function_many 6.31% [kernel] [k] async_page_fault 6.13% libc-2.23.so [.] __memcpy_avx_unaligned 4.88% [kernel] [k] call_function_interrupt Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Marc Zyngier <maz@kernel.org> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-18 19:39:06 +08:00
if (!READ_ONCE(vcpu->ready))
continue;
if (vcpu == me)
continue;
if (rcuwait_active(&vcpu->wait) &&
!vcpu_dy_runnable(vcpu))
continue;
if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode &&
!kvm_arch_dy_has_pending_interrupt(vcpu) &&
!kvm_arch_vcpu_in_kernel(vcpu))
continue;
if (!kvm_vcpu_eligible_for_directed_yield(vcpu))
continue;
2013-01-22 15:39:24 +08:00
yielded = kvm_vcpu_yield_to(vcpu);
if (yielded > 0) {
kvm->last_boosted_vcpu = i;
break;
2013-01-22 15:39:24 +08:00
} else if (yielded < 0) {
try--;
if (!try)
break;
}
}
}
kvm_vcpu_set_in_spin_loop(me, false);
/* Ensure vcpu is not eligible during next spinloop */
kvm_vcpu_set_dy_eligible(me, false);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin);
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
static bool kvm_page_in_dirty_ring(struct kvm *kvm, unsigned long pgoff)
{
#if KVM_DIRTY_LOG_PAGE_OFFSET > 0
return (pgoff >= KVM_DIRTY_LOG_PAGE_OFFSET) &&
(pgoff < KVM_DIRTY_LOG_PAGE_OFFSET +
kvm->dirty_ring_size / PAGE_SIZE);
#else
return false;
#endif
}
static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf)
{
struct kvm_vcpu *vcpu = vmf->vma->vm_file->private_data;
struct page *page;
if (vmf->pgoff == 0)
page = virt_to_page(vcpu->run);
#ifdef CONFIG_X86
else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
page = virt_to_page(vcpu->arch.pio_data);
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
#endif
#ifdef CONFIG_KVM_MMIO
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
#endif
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
else if (kvm_page_in_dirty_ring(vcpu->kvm, vmf->pgoff))
page = kvm_dirty_ring_get_page(
&vcpu->dirty_ring,
vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET);
else
return kvm_arch_vcpu_fault(vcpu, vmf);
get_page(page);
vmf->page = page;
return 0;
}
static const struct vm_operations_struct kvm_vcpu_vm_ops = {
.fault = kvm_vcpu_fault,
};
static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
{
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
struct kvm_vcpu *vcpu = file->private_data;
unsigned long pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
if ((kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff) ||
kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff + pages - 1)) &&
((vma->vm_flags & VM_EXEC) || !(vma->vm_flags & VM_SHARED)))
return -EINVAL;
vma->vm_ops = &kvm_vcpu_vm_ops;
return 0;
}
static int kvm_vcpu_release(struct inode *inode, struct file *filp)
{
struct kvm_vcpu *vcpu = filp->private_data;
kvm_put_kvm(vcpu->kvm);
return 0;
}
static struct file_operations kvm_vcpu_fops = {
.release = kvm_vcpu_release,
.unlocked_ioctl = kvm_vcpu_ioctl,
.mmap = kvm_vcpu_mmap,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-16 00:52:59 +08:00
.llseek = noop_llseek,
KVM_COMPAT(kvm_vcpu_compat_ioctl),
};
/*
* Allocates an inode for the vcpu.
*/
static int create_vcpu_fd(struct kvm_vcpu *vcpu)
{
kvm: embed vcpu id to dentry of vcpu anon inode All d-entries for vcpu have the same, "anon_inode:kvm-vcpu". That means it is impossible to know the mapping between fds for vcpu and vcpu from userland. # LC_ALL=C ls -l /proc/617/fd | grep vcpu lrwx------. 1 qemu qemu 64 Jan 7 16:50 18 -> anon_inode:kvm-vcpu lrwx------. 1 qemu qemu 64 Jan 7 16:50 19 -> anon_inode:kvm-vcpu It is also impossible to know the mapping between vma for kvm_run structure and vcpu from userland. # LC_ALL=C grep vcpu /proc/617/maps 7f9d842d0000-7f9d842d3000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu 7f9d842d3000-7f9d842d6000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu This change adds vcpu id to d-entries for vcpu. With this change you can get the following output: # LC_ALL=C ls -l /proc/617/fd | grep vcpu lrwx------. 1 qemu qemu 64 Jan 7 16:50 18 -> anon_inode:kvm-vcpu:0 lrwx------. 1 qemu qemu 64 Jan 7 16:50 19 -> anon_inode:kvm-vcpu:1 # LC_ALL=C grep vcpu /proc/617/maps 7f9d842d0000-7f9d842d3000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu:0 7f9d842d3000-7f9d842d6000 rw-s 00000000 00:0d 20393 anon_inode:kvm-vcpu:1 With the mappings known from the output, a tool like strace can report more details of qemu-kvm process activities. Here is the strace output of my local prototype: # ./strace -KK -f -p 617 2>&1 | grep 'KVM_RUN\| K' ... [pid 664] ioctl(18, KVM_RUN, 0) = 0 (KVM_EXIT_MMIO) K ready_for_interrupt_injection=1, if_flag=0, flags=0, cr8=0000000000000000, apic_base=0x000000fee00d00 K phys_addr=0, len=1634035803, [33, 0, 0, 0, 0, 0, 0, 0], is_write=112 [pid 664] ioctl(18, KVM_RUN, 0) = 0 (KVM_EXIT_MMIO) K ready_for_interrupt_injection=1, if_flag=1, flags=0, cr8=0000000000000000, apic_base=0x000000fee00d00 K phys_addr=0, len=1634035803, [33, 0, 0, 0, 0, 0, 0, 0], is_write=112 ... Signed-off-by: Masatake YAMATO <yamato@redhat.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-01-20 03:04:22 +08:00
char name[8 + 1 + ITOA_MAX_LEN + 1];
snprintf(name, sizeof(name), "kvm-vcpu:%d", vcpu->vcpu_id);
return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
}
static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
{
#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
struct dentry *debugfs_dentry;
char dir_name[ITOA_MAX_LEN * 2];
if (!debugfs_initialized())
return;
snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id);
debugfs_dentry = debugfs_create_dir(dir_name,
vcpu->kvm->debugfs_dentry);
kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry);
#endif
}
/*
* Creates some virtual cpus. Good luck creating more than one.
*/
static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
{
int r;
struct kvm_vcpu *vcpu;
struct page *page;
if (id >= KVM_MAX_VCPU_ID)
return -EINVAL;
mutex_lock(&kvm->lock);
if (kvm->created_vcpus == KVM_MAX_VCPUS) {
mutex_unlock(&kvm->lock);
return -EINVAL;
}
kvm->created_vcpus++;
mutex_unlock(&kvm->lock);
r = kvm_arch_vcpu_precreate(kvm, id);
if (r)
goto vcpu_decrement;
vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT);
if (!vcpu) {
r = -ENOMEM;
goto vcpu_decrement;
}
BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE);
page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
if (!page) {
r = -ENOMEM;
goto vcpu_free;
}
vcpu->run = page_address(page);
kvm_vcpu_init(vcpu, kvm, id);
r = kvm_arch_vcpu_create(vcpu);
if (r)
goto vcpu_free_run_page;
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
if (kvm->dirty_ring_size) {
r = kvm_dirty_ring_alloc(&vcpu->dirty_ring,
id, kvm->dirty_ring_size);
if (r)
goto arch_vcpu_destroy;
}
mutex_lock(&kvm->lock);
if (kvm_get_vcpu_by_id(kvm, id)) {
r = -EEXIST;
goto unlock_vcpu_destroy;
}
vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus);
BUG_ON(kvm->vcpus[vcpu->vcpu_idx]);
/* Fill the stats id string for the vcpu */
snprintf(vcpu->stats_id, sizeof(vcpu->stats_id), "kvm-%d/vcpu-%d",
task_pid_nr(current), id);
/* Now it's all set up, let userspace reach it */
kvm_get_kvm(kvm);
r = create_vcpu_fd(vcpu);
if (r < 0) {
kvm_put_kvm_no_destroy(kvm);
goto unlock_vcpu_destroy;
}
kvm->vcpus[vcpu->vcpu_idx] = vcpu;
/*
* Pairs with smp_rmb() in kvm_get_vcpu. Write kvm->vcpus
* before kvm->online_vcpu's incremented value.
*/
smp_wmb();
atomic_inc(&kvm->online_vcpus);
mutex_unlock(&kvm->lock);
kvm_arch_vcpu_postcreate(vcpu);
kvm_create_vcpu_debugfs(vcpu);
return r;
unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
kvm_dirty_ring_free(&vcpu->dirty_ring);
arch_vcpu_destroy:
kvm_arch_vcpu_destroy(vcpu);
vcpu_free_run_page:
free_page((unsigned long)vcpu->run);
vcpu_free:
kmem_cache_free(kvm_vcpu_cache, vcpu);
vcpu_decrement:
mutex_lock(&kvm->lock);
kvm->created_vcpus--;
mutex_unlock(&kvm->lock);
return r;
}
static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
{
if (sigset) {
sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP));
vcpu->sigset_active = 1;
vcpu->sigset = *sigset;
} else
vcpu->sigset_active = 0;
return 0;
}
static ssize_t kvm_vcpu_stats_read(struct file *file, char __user *user_buffer,
size_t size, loff_t *offset)
{
struct kvm_vcpu *vcpu = file->private_data;
return kvm_stats_read(vcpu->stats_id, &kvm_vcpu_stats_header,
&kvm_vcpu_stats_desc[0], &vcpu->stat,
sizeof(vcpu->stat), user_buffer, size, offset);
}
static const struct file_operations kvm_vcpu_stats_fops = {
.read = kvm_vcpu_stats_read,
.llseek = noop_llseek,
};
static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu)
{
int fd;
struct file *file;
char name[15 + ITOA_MAX_LEN + 1];
snprintf(name, sizeof(name), "kvm-vcpu-stats:%d", vcpu->vcpu_id);
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
return fd;
file = anon_inode_getfile(name, &kvm_vcpu_stats_fops, vcpu, O_RDONLY);
if (IS_ERR(file)) {
put_unused_fd(fd);
return PTR_ERR(file);
}
file->f_mode |= FMODE_PREAD;
fd_install(fd, file);
return fd;
}
static long kvm_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = (void __user *)arg;
int r;
struct kvm_fpu *fpu = NULL;
struct kvm_sregs *kvm_sregs = NULL;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_bugged)
return -EIO;
if (unlikely(_IOC_TYPE(ioctl) != KVMIO))
return -EINVAL;
/*
* Some architectures have vcpu ioctls that are asynchronous to vcpu
* execution; mutex_lock() would break them.
*/
r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg);
if (r != -ENOIOCTLCMD)
return r;
if (mutex_lock_killable(&vcpu->mutex))
return -EINTR;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
switch (ioctl) {
case KVM_RUN: {
struct pid *oldpid;
r = -EINVAL;
if (arg)
goto out;
oldpid = rcu_access_pointer(vcpu->pid);
if (unlikely(oldpid != task_pid(current))) {
/* The thread running this VCPU changed. */
struct pid *newpid;
r = kvm_arch_vcpu_run_pid_change(vcpu);
if (r)
break;
newpid = get_task_pid(current, PIDTYPE_PID);
rcu_assign_pointer(vcpu->pid, newpid);
if (oldpid)
synchronize_rcu();
put_pid(oldpid);
}
r = kvm_arch_vcpu_ioctl_run(vcpu);
trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
break;
}
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
case KVM_GET_REGS: {
struct kvm_regs *kvm_regs;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = -ENOMEM;
kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL_ACCOUNT);
if (!kvm_regs)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
if (r)
goto out_free1;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = -EFAULT;
if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
goto out_free1;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = 0;
out_free1:
kfree(kvm_regs);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
break;
}
case KVM_SET_REGS: {
struct kvm_regs *kvm_regs;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
kvm_regs = memdup_user(argp, sizeof(*kvm_regs));
if (IS_ERR(kvm_regs)) {
r = PTR_ERR(kvm_regs);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
}
r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
kfree(kvm_regs);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
break;
}
case KVM_GET_SREGS: {
kvm_sregs = kzalloc(sizeof(struct kvm_sregs),
GFP_KERNEL_ACCOUNT);
r = -ENOMEM;
if (!kvm_sregs)
goto out;
r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
r = 0;
break;
}
case KVM_SET_SREGS: {
kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs));
if (IS_ERR(kvm_sregs)) {
r = PTR_ERR(kvm_sregs);
kvm_sregs = NULL;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
}
r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
break;
}
case KVM_GET_MP_STATE: {
struct kvm_mp_state mp_state;
r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &mp_state, sizeof(mp_state)))
goto out;
r = 0;
break;
}
case KVM_SET_MP_STATE: {
struct kvm_mp_state mp_state;
r = -EFAULT;
if (copy_from_user(&mp_state, argp, sizeof(mp_state)))
goto out;
r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state);
break;
}
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
case KVM_TRANSLATE: {
struct kvm_translation tr;
r = -EFAULT;
if (copy_from_user(&tr, argp, sizeof(tr)))
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &tr, sizeof(tr)))
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
r = 0;
break;
}
case KVM_SET_GUEST_DEBUG: {
struct kvm_guest_debug dbg;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = -EFAULT;
if (copy_from_user(&dbg, argp, sizeof(dbg)))
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
break;
}
case KVM_SET_SIGNAL_MASK: {
struct kvm_signal_mask __user *sigmask_arg = argp;
struct kvm_signal_mask kvm_sigmask;
sigset_t sigset, *p;
p = NULL;
if (argp) {
r = -EFAULT;
if (copy_from_user(&kvm_sigmask, argp,
sizeof(kvm_sigmask)))
goto out;
r = -EINVAL;
if (kvm_sigmask.len != sizeof(sigset))
goto out;
r = -EFAULT;
if (copy_from_user(&sigset, sigmask_arg->sigset,
sizeof(sigset)))
goto out;
p = &sigset;
}
r = kvm_vcpu_ioctl_set_sigmask(vcpu, p);
break;
}
case KVM_GET_FPU: {
fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL_ACCOUNT);
r = -ENOMEM;
if (!fpu)
goto out;
r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))
goto out;
r = 0;
break;
}
case KVM_SET_FPU: {
fpu = memdup_user(argp, sizeof(*fpu));
if (IS_ERR(fpu)) {
r = PTR_ERR(fpu);
fpu = NULL;
goto out;
}
r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
break;
}
case KVM_GET_STATS_FD: {
r = kvm_vcpu_ioctl_get_stats_fd(vcpu);
break;
}
default:
r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
}
out:
mutex_unlock(&vcpu->mutex);
kfree(fpu);
kfree(kvm_sregs);
return r;
}
#ifdef CONFIG_KVM_COMPAT
static long kvm_vcpu_compat_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = compat_ptr(arg);
int r;
if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_bugged)
return -EIO;
switch (ioctl) {
case KVM_SET_SIGNAL_MASK: {
struct kvm_signal_mask __user *sigmask_arg = argp;
struct kvm_signal_mask kvm_sigmask;
sigset_t sigset;
if (argp) {
r = -EFAULT;
if (copy_from_user(&kvm_sigmask, argp,
sizeof(kvm_sigmask)))
goto out;
r = -EINVAL;
if (kvm_sigmask.len != sizeof(compat_sigset_t))
goto out;
r = -EFAULT;
if (get_compat_sigset(&sigset,
(compat_sigset_t __user *)sigmask_arg->sigset))
goto out;
r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset);
} else
r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL);
break;
}
default:
r = kvm_vcpu_ioctl(filp, ioctl, arg);
}
out:
return r;
}
#endif
static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct kvm_device *dev = filp->private_data;
if (dev->ops->mmap)
return dev->ops->mmap(dev, vma);
return -ENODEV;
}
static int kvm_device_ioctl_attr(struct kvm_device *dev,
int (*accessor)(struct kvm_device *dev,
struct kvm_device_attr *attr),
unsigned long arg)
{
struct kvm_device_attr attr;
if (!accessor)
return -EPERM;
if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
return -EFAULT;
return accessor(dev, &attr);
}
static long kvm_device_ioctl(struct file *filp, unsigned int ioctl,
unsigned long arg)
{
struct kvm_device *dev = filp->private_data;
if (dev->kvm->mm != current->mm || dev->kvm->vm_bugged)
return -EIO;
switch (ioctl) {
case KVM_SET_DEVICE_ATTR:
return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg);
case KVM_GET_DEVICE_ATTR:
return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg);
case KVM_HAS_DEVICE_ATTR:
return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg);
default:
if (dev->ops->ioctl)
return dev->ops->ioctl(dev, ioctl, arg);
return -ENOTTY;
}
}
static int kvm_device_release(struct inode *inode, struct file *filp)
{
struct kvm_device *dev = filp->private_data;
struct kvm *kvm = dev->kvm;
if (dev->ops->release) {
mutex_lock(&kvm->lock);
list_del(&dev->vm_node);
dev->ops->release(dev);
mutex_unlock(&kvm->lock);
}
kvm_put_kvm(kvm);
return 0;
}
static const struct file_operations kvm_device_fops = {
.unlocked_ioctl = kvm_device_ioctl,
.release = kvm_device_release,
KVM_COMPAT(kvm_device_ioctl),
.mmap = kvm_device_mmap,
};
struct kvm_device *kvm_device_from_filp(struct file *filp)
{
if (filp->f_op != &kvm_device_fops)
return NULL;
return filp->private_data;
}
static const struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = {
#ifdef CONFIG_KVM_MPIC
[KVM_DEV_TYPE_FSL_MPIC_20] = &kvm_mpic_ops,
[KVM_DEV_TYPE_FSL_MPIC_42] = &kvm_mpic_ops,
#endif
};
int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type)
{
if (type >= ARRAY_SIZE(kvm_device_ops_table))
return -ENOSPC;
if (kvm_device_ops_table[type] != NULL)
return -EEXIST;
kvm_device_ops_table[type] = ops;
return 0;
}
kvm: vfio: fix unregister kvm_device_ops of vfio After commit 80ce163 (KVM: VFIO: register kvm_device_ops dynamically), kvm_device_ops of vfio can be registered dynamically. Commit 3c3c29fd (kvm-vfio: do not use module_init) move the dynamic register invoked by kvm_init in order to fix broke unloading of the kvm module. However, kvm_device_ops of vfio is unregistered after rmmod kvm-intel module which lead to device type collision detection warning after kvm-intel module reinsmod. WARNING: CPU: 1 PID: 10358 at /root/cathy/kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:3289 kvm_init+0x234/0x282 [kvm]() Modules linked in: kvm_intel(O+) kvm(O) nfsv3 nfs_acl auth_rpcgss oid_registry nfsv4 dns_resolver nfs fscache lockd sunrpc pci_stub bridge stp llc autofs4 8021q cpufreq_ondemand ipv6 joydev microcode pcspkr igb i2c_algo_bit ehci_pci ehci_hcd e1000e i2c_i801 ixgbe ptp pps_core hwmon mdio tpm_tis tpm ipmi_si ipmi_msghandler acpi_cpufreq isci libsas scsi_transport_sas button dm_mirror dm_region_hash dm_log dm_mod [last unloaded: kvm_intel] CPU: 1 PID: 10358 Comm: insmod Tainted: G W O 3.17.0-rc1 #2 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 0000000000000cd9 ffff880ff08cfd18 ffffffff814a61d9 0000000000000cd9 0000000000000000 ffff880ff08cfd58 ffffffff810417b7 ffff880ff08cfd48 ffffffffa045bcac ffffffffa049c420 0000000000000040 00000000000000ff Call Trace: [<ffffffff814a61d9>] dump_stack+0x49/0x60 [<ffffffff810417b7>] warn_slowpath_common+0x7c/0x96 [<ffffffffa045bcac>] ? kvm_init+0x234/0x282 [kvm] [<ffffffff810417e6>] warn_slowpath_null+0x15/0x17 [<ffffffffa045bcac>] kvm_init+0x234/0x282 [kvm] [<ffffffffa016e995>] vmx_init+0x1bf/0x42a [kvm_intel] [<ffffffffa016e7d6>] ? vmx_check_processor_compat+0x64/0x64 [kvm_intel] [<ffffffff810002ab>] do_one_initcall+0xe3/0x170 [<ffffffff811168a9>] ? __vunmap+0xad/0xb8 [<ffffffff8109c58f>] do_init_module+0x2b/0x174 [<ffffffff8109d414>] load_module+0x43e/0x569 [<ffffffff8109c6d8>] ? do_init_module+0x174/0x174 [<ffffffff8109c75a>] ? copy_module_from_user+0x39/0x82 [<ffffffff8109b7dd>] ? module_sect_show+0x20/0x20 [<ffffffff8109d65f>] SyS_init_module+0x54/0x81 [<ffffffff814a9a12>] system_call_fastpath+0x16/0x1b ---[ end trace 0626f4a3ddea56f3 ]--- The bug can be reproduced by: rmmod kvm_intel.ko insmod kvm_intel.ko without rmmod/insmod kvm.ko This patch fixes the bug by unregistering kvm_device_ops of vfio when the kvm-intel module is removed. Reported-by: Liu Rongrong <rongrongx.liu@intel.com> Fixes: 3c3c29fd0d7cddc32862c350d0700ce69953e3bd Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-09 18:30:08 +08:00
void kvm_unregister_device_ops(u32 type)
{
if (kvm_device_ops_table[type] != NULL)
kvm_device_ops_table[type] = NULL;
}
static int kvm_ioctl_create_device(struct kvm *kvm,
struct kvm_create_device *cd)
{
const struct kvm_device_ops *ops = NULL;
struct kvm_device *dev;
bool test = cd->flags & KVM_CREATE_DEVICE_TEST;
int type;
int ret;
if (cd->type >= ARRAY_SIZE(kvm_device_ops_table))
return -ENODEV;
type = array_index_nospec(cd->type, ARRAY_SIZE(kvm_device_ops_table));
ops = kvm_device_ops_table[type];
if (ops == NULL)
return -ENODEV;
if (test)
return 0;
dev = kzalloc(sizeof(*dev), GFP_KERNEL_ACCOUNT);
if (!dev)
return -ENOMEM;
dev->ops = ops;
dev->kvm = kvm;
mutex_lock(&kvm->lock);
ret = ops->create(dev, type);
if (ret < 0) {
mutex_unlock(&kvm->lock);
kfree(dev);
return ret;
}
list_add(&dev->vm_node, &kvm->devices);
mutex_unlock(&kvm->lock);
if (ops->init)
ops->init(dev);
kvm_get_kvm(kvm);
ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC);
if (ret < 0) {
kvm_put_kvm_no_destroy(kvm);
mutex_lock(&kvm->lock);
list_del(&dev->vm_node);
mutex_unlock(&kvm->lock);
ops->destroy(dev);
return ret;
}
cd->fd = ret;
return 0;
}
static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
{
switch (arg) {
case KVM_CAP_USER_MEMORY:
case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS:
case KVM_CAP_INTERNAL_ERROR_DATA:
#ifdef CONFIG_HAVE_KVM_MSI
case KVM_CAP_SIGNAL_MSI:
#endif
#ifdef CONFIG_HAVE_KVM_IRQFD
case KVM_CAP_IRQFD:
case KVM_CAP_IRQFD_RESAMPLE:
#endif
case KVM_CAP_IOEVENTFD_ANY_LENGTH:
case KVM_CAP_CHECK_EXTENSION_VM:
case KVM_CAP_ENABLE_CAP_VM:
case KVM_CAP_HALT_POLL:
return 1;
#ifdef CONFIG_KVM_MMIO
case KVM_CAP_COALESCED_MMIO:
return KVM_COALESCED_MMIO_PAGE_OFFSET;
case KVM_CAP_COALESCED_PIO:
return 1;
#endif
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2:
return KVM_DIRTY_LOG_MANUAL_CAPS;
#endif
#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
case KVM_CAP_IRQ_ROUTING:
return KVM_MAX_IRQ_ROUTES;
#endif
#if KVM_ADDRESS_SPACE_NUM > 1
case KVM_CAP_MULTI_ADDRESS_SPACE:
return KVM_ADDRESS_SPACE_NUM;
#endif
case KVM_CAP_NR_MEMSLOTS:
return KVM_USER_MEM_SLOTS;
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
case KVM_CAP_DIRTY_LOG_RING:
#if KVM_DIRTY_LOG_PAGE_OFFSET > 0
return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn);
#else
return 0;
#endif
case KVM_CAP_BINARY_STATS_FD:
return 1;
default:
break;
}
return kvm_vm_ioctl_check_extension(kvm, arg);
}
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size)
{
int r;
if (!KVM_DIRTY_LOG_PAGE_OFFSET)
return -EINVAL;
/* the size should be power of 2 */
if (!size || (size & (size - 1)))
return -EINVAL;
/* Should be bigger to keep the reserved entries, or a page */
if (size < kvm_dirty_ring_get_rsvd_entries() *
sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE)
return -EINVAL;
if (size > KVM_DIRTY_RING_MAX_ENTRIES *
sizeof(struct kvm_dirty_gfn))
return -E2BIG;
/* We only allow it to set once */
if (kvm->dirty_ring_size)
return -EINVAL;
mutex_lock(&kvm->lock);
if (kvm->created_vcpus) {
/* We don't allow to change this value after vcpu created */
r = -EINVAL;
} else {
kvm->dirty_ring_size = size;
r = 0;
}
mutex_unlock(&kvm->lock);
return r;
}
static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm)
{
int i;
struct kvm_vcpu *vcpu;
int cleared = 0;
if (!kvm->dirty_ring_size)
return -EINVAL;
mutex_lock(&kvm->slots_lock);
kvm_for_each_vcpu(i, vcpu, kvm)
cleared += kvm_dirty_ring_reset(vcpu->kvm, &vcpu->dirty_ring);
mutex_unlock(&kvm->slots_lock);
if (cleared)
kvm_flush_remote_tlbs(kvm);
return cleared;
}
int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm,
struct kvm_enable_cap *cap)
{
return -EINVAL;
}
static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
struct kvm_enable_cap *cap)
{
switch (cap->cap) {
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: {
u64 allowed_options = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE;
if (cap->args[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE)
allowed_options = KVM_DIRTY_LOG_MANUAL_CAPS;
if (cap->flags || (cap->args[0] & ~allowed_options))
return -EINVAL;
kvm->manual_dirty_log_protect = cap->args[0];
return 0;
}
#endif
case KVM_CAP_HALT_POLL: {
if (cap->flags || cap->args[0] != (unsigned int)cap->args[0])
return -EINVAL;
kvm->max_halt_poll_ns = cap->args[0];
return 0;
}
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
case KVM_CAP_DIRTY_LOG_RING:
return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]);
default:
return kvm_vm_ioctl_enable_cap(kvm, cap);
}
}
static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer,
size_t size, loff_t *offset)
{
struct kvm *kvm = file->private_data;
return kvm_stats_read(kvm->stats_id, &kvm_vm_stats_header,
&kvm_vm_stats_desc[0], &kvm->stat,
sizeof(kvm->stat), user_buffer, size, offset);
}
static const struct file_operations kvm_vm_stats_fops = {
.read = kvm_vm_stats_read,
.llseek = noop_llseek,
};
static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm)
{
int fd;
struct file *file;
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
return fd;
file = anon_inode_getfile("kvm-vm-stats",
&kvm_vm_stats_fops, kvm, O_RDONLY);
if (IS_ERR(file)) {
put_unused_fd(fd);
return PTR_ERR(file);
}
file->f_mode |= FMODE_PREAD;
fd_install(fd, file);
return fd;
}
static long kvm_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm *kvm = filp->private_data;
void __user *argp = (void __user *)arg;
int r;
if (kvm->mm != current->mm || kvm->vm_bugged)
return -EIO;
switch (ioctl) {
case KVM_CREATE_VCPU:
r = kvm_vm_ioctl_create_vcpu(kvm, arg);
break;
case KVM_ENABLE_CAP: {
struct kvm_enable_cap cap;
r = -EFAULT;
if (copy_from_user(&cap, argp, sizeof(cap)))
goto out;
r = kvm_vm_ioctl_enable_cap_generic(kvm, &cap);
break;
}
case KVM_SET_USER_MEMORY_REGION: {
struct kvm_userspace_memory_region kvm_userspace_mem;
r = -EFAULT;
if (copy_from_user(&kvm_userspace_mem, argp,
sizeof(kvm_userspace_mem)))
goto out;
r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
break;
}
case KVM_GET_DIRTY_LOG: {
struct kvm_dirty_log log;
r = -EFAULT;
if (copy_from_user(&log, argp, sizeof(log)))
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
goto out;
r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
break;
}
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
case KVM_CLEAR_DIRTY_LOG: {
struct kvm_clear_dirty_log log;
r = -EFAULT;
if (copy_from_user(&log, argp, sizeof(log)))
goto out;
r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);
break;
}
#endif
#ifdef CONFIG_KVM_MMIO
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
case KVM_REGISTER_COALESCED_MMIO: {
struct kvm_coalesced_mmio_zone zone;
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
r = -EFAULT;
if (copy_from_user(&zone, argp, sizeof(zone)))
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
goto out;
r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
break;
}
case KVM_UNREGISTER_COALESCED_MMIO: {
struct kvm_coalesced_mmio_zone zone;
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
r = -EFAULT;
if (copy_from_user(&zone, argp, sizeof(zone)))
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
goto out;
r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
break;
}
#endif
case KVM_IRQFD: {
struct kvm_irqfd data;
r = -EFAULT;
if (copy_from_user(&data, argp, sizeof(data)))
goto out;
r = kvm_irqfd(kvm, &data);
break;
}
KVM: add ioeventfd support ioeventfd is a mechanism to register PIO/MMIO regions to trigger an eventfd signal when written to by a guest. Host userspace can register any arbitrary IO address with a corresponding eventfd and then pass the eventfd to a specific end-point of interest for handling. Normal IO requires a blocking round-trip since the operation may cause side-effects in the emulated model or may return data to the caller. Therefore, an IO in KVM traps from the guest to the host, causes a VMX/SVM "heavy-weight" exit back to userspace, and is ultimately serviced by qemu's device model synchronously before returning control back to the vcpu. However, there is a subclass of IO which acts purely as a trigger for other IO (such as to kick off an out-of-band DMA request, etc). For these patterns, the synchronous call is particularly expensive since we really only want to simply get our notification transmitted asychronously and return as quickly as possible. All the sychronous infrastructure to ensure proper data-dependencies are met in the normal IO case are just unecessary overhead for signalling. This adds additional computational load on the system, as well as latency to the signalling path. Therefore, we provide a mechanism for registration of an in-kernel trigger point that allows the VCPU to only require a very brief, lightweight exit just long enough to signal an eventfd. This also means that any clients compatible with the eventfd interface (which includes userspace and kernelspace equally well) can now register to be notified. The end result should be a more flexible and higher performance notification API for the backend KVM hypervisor and perhipheral components. To test this theory, we built a test-harness called "doorbell". This module has a function called "doorbell_ring()" which simply increments a counter for each time the doorbell is signaled. It supports signalling from either an eventfd, or an ioctl(). We then wired up two paths to the doorbell: One via QEMU via a registered io region and through the doorbell ioctl(). The other is direct via ioeventfd. You can download this test harness here: ftp://ftp.novell.com/dev/ghaskins/doorbell.tar.bz2 The measured results are as follows: qemu-mmio: 110000 iops, 9.09us rtt ioeventfd-mmio: 200100 iops, 5.00us rtt ioeventfd-pio: 367300 iops, 2.72us rtt I didn't measure qemu-pio, because I have to figure out how to register a PIO region with qemu's device model, and I got lazy. However, for now we can extrapolate based on the data from the NULLIO runs of +2.56us for MMIO, and -350ns for HC, we get: qemu-pio: 153139 iops, 6.53us rtt ioeventfd-hc: 412585 iops, 2.37us rtt these are just for fun, for now, until I can gather more data. Here is a graph for your convenience: http://developer.novell.com/wiki/images/7/76/Iofd-chart.png The conclusion to draw is that we save about 4us by skipping the userspace hop. -------------------- Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-07-08 05:08:49 +08:00
case KVM_IOEVENTFD: {
struct kvm_ioeventfd data;
r = -EFAULT;
if (copy_from_user(&data, argp, sizeof(data)))
KVM: add ioeventfd support ioeventfd is a mechanism to register PIO/MMIO regions to trigger an eventfd signal when written to by a guest. Host userspace can register any arbitrary IO address with a corresponding eventfd and then pass the eventfd to a specific end-point of interest for handling. Normal IO requires a blocking round-trip since the operation may cause side-effects in the emulated model or may return data to the caller. Therefore, an IO in KVM traps from the guest to the host, causes a VMX/SVM "heavy-weight" exit back to userspace, and is ultimately serviced by qemu's device model synchronously before returning control back to the vcpu. However, there is a subclass of IO which acts purely as a trigger for other IO (such as to kick off an out-of-band DMA request, etc). For these patterns, the synchronous call is particularly expensive since we really only want to simply get our notification transmitted asychronously and return as quickly as possible. All the sychronous infrastructure to ensure proper data-dependencies are met in the normal IO case are just unecessary overhead for signalling. This adds additional computational load on the system, as well as latency to the signalling path. Therefore, we provide a mechanism for registration of an in-kernel trigger point that allows the VCPU to only require a very brief, lightweight exit just long enough to signal an eventfd. This also means that any clients compatible with the eventfd interface (which includes userspace and kernelspace equally well) can now register to be notified. The end result should be a more flexible and higher performance notification API for the backend KVM hypervisor and perhipheral components. To test this theory, we built a test-harness called "doorbell". This module has a function called "doorbell_ring()" which simply increments a counter for each time the doorbell is signaled. It supports signalling from either an eventfd, or an ioctl(). We then wired up two paths to the doorbell: One via QEMU via a registered io region and through the doorbell ioctl(). The other is direct via ioeventfd. You can download this test harness here: ftp://ftp.novell.com/dev/ghaskins/doorbell.tar.bz2 The measured results are as follows: qemu-mmio: 110000 iops, 9.09us rtt ioeventfd-mmio: 200100 iops, 5.00us rtt ioeventfd-pio: 367300 iops, 2.72us rtt I didn't measure qemu-pio, because I have to figure out how to register a PIO region with qemu's device model, and I got lazy. However, for now we can extrapolate based on the data from the NULLIO runs of +2.56us for MMIO, and -350ns for HC, we get: qemu-pio: 153139 iops, 6.53us rtt ioeventfd-hc: 412585 iops, 2.37us rtt these are just for fun, for now, until I can gather more data. Here is a graph for your convenience: http://developer.novell.com/wiki/images/7/76/Iofd-chart.png The conclusion to draw is that we save about 4us by skipping the userspace hop. -------------------- Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2009-07-08 05:08:49 +08:00
goto out;
r = kvm_ioeventfd(kvm, &data);
break;
}
#ifdef CONFIG_HAVE_KVM_MSI
case KVM_SIGNAL_MSI: {
struct kvm_msi msi;
r = -EFAULT;
if (copy_from_user(&msi, argp, sizeof(msi)))
goto out;
r = kvm_send_userspace_msi(kvm, &msi);
break;
}
#endif
#ifdef __KVM_HAVE_IRQ_LINE
case KVM_IRQ_LINE_STATUS:
case KVM_IRQ_LINE: {
struct kvm_irq_level irq_event;
r = -EFAULT;
if (copy_from_user(&irq_event, argp, sizeof(irq_event)))
goto out;
r = kvm_vm_ioctl_irq_line(kvm, &irq_event,
ioctl == KVM_IRQ_LINE_STATUS);
if (r)
goto out;
r = -EFAULT;
if (ioctl == KVM_IRQ_LINE_STATUS) {
if (copy_to_user(argp, &irq_event, sizeof(irq_event)))
goto out;
}
r = 0;
break;
}
#endif
#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
case KVM_SET_GSI_ROUTING: {
struct kvm_irq_routing routing;
struct kvm_irq_routing __user *urouting;
struct kvm_irq_routing_entry *entries = NULL;
r = -EFAULT;
if (copy_from_user(&routing, argp, sizeof(routing)))
goto out;
r = -EINVAL;
if (!kvm_arch_can_set_irq_routing(kvm))
goto out;
kvm: Fix irq route entries exceeding KVM_MAX_IRQ_ROUTES These days, we experienced one guest crash with 8 cores and 3 disks, with qemu error logs as bellow: qemu-system-x86_64: /build/qemu-2.0.0/kvm-all.c:984: kvm_irqchip_commit_routes: Assertion `ret == 0' failed. And then we found one patch(bdf026317d) in qemu tree, which said could fix this bug. Execute the following script will reproduce the BUG quickly: irq_affinity.sh ======================================================================== vda_irq_num=25 vdb_irq_num=27 while [ 1 ] do for irq in {1,2,4,8,10,20,40,80} do echo $irq > /proc/irq/$vda_irq_num/smp_affinity echo $irq > /proc/irq/$vdb_irq_num/smp_affinity dd if=/dev/vda of=/dev/zero bs=4K count=100 iflag=direct dd if=/dev/vdb of=/dev/zero bs=4K count=100 iflag=direct done done ======================================================================== The following qemu log is added in the qemu code and is displayed when this bug reproduced: kvm_irqchip_commit_routes: max gsi: 1008, nr_allocated_irq_routes: 1024, irq_routes->nr: 1024, gsi_count: 1024. That's to say when irq_routes->nr == 1024, there are 1024 routing entries, but in the kernel code when routes->nr >= 1024, will just return -EINVAL; The nr is the number of the routing entries which is in of [1 ~ KVM_MAX_IRQ_ROUTES], not the index in [0 ~ KVM_MAX_IRQ_ROUTES - 1]. This patch fix the BUG above. Cc: stable@vger.kernel.org Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com> Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com> Signed-off-by: Zhang Zhuoyu <zhangzhuoyu@cmss.chinamobile.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-15 18:00:33 +08:00
if (routing.nr > KVM_MAX_IRQ_ROUTES)
goto out;
if (routing.flags)
goto out;
if (routing.nr) {
urouting = argp;
entries = vmemdup_user(urouting->entries,
array_size(sizeof(*entries),
routing.nr));
if (IS_ERR(entries)) {
r = PTR_ERR(entries);
goto out;
}
}
r = kvm_set_irq_routing(kvm, entries, routing.nr,
routing.flags);
kvfree(entries);
break;
}
#endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */
case KVM_CREATE_DEVICE: {
struct kvm_create_device cd;
r = -EFAULT;
if (copy_from_user(&cd, argp, sizeof(cd)))
goto out;
r = kvm_ioctl_create_device(kvm, &cd);
if (r)
goto out;
r = -EFAULT;
if (copy_to_user(argp, &cd, sizeof(cd)))
goto out;
r = 0;
break;
}
case KVM_CHECK_EXTENSION:
r = kvm_vm_ioctl_check_extension_generic(kvm, arg);
break;
KVM: X86: Implement ring-based dirty memory tracking This patch is heavily based on previous work from Lei Cao <lei.cao@stratus.com> and Paolo Bonzini <pbonzini@redhat.com>. [1] KVM currently uses large bitmaps to track dirty memory. These bitmaps are copied to userspace when userspace queries KVM for its dirty page information. The use of bitmaps is mostly sufficient for live migration, as large parts of memory are be dirtied from one log-dirty pass to another. However, in a checkpointing system, the number of dirty pages is small and in fact it is often bounded---the VM is paused when it has dirtied a pre-defined number of pages. Traversing a large, sparsely populated bitmap to find set bits is time-consuming, as is copying the bitmap to user-space. A similar issue will be there for live migration when the guest memory is huge while the page dirty procedure is trivial. In that case for each dirty sync we need to pull the whole dirty bitmap to userspace and analyse every bit even if it's mostly zeros. The preferred data structure for above scenarios is a dense list of guest frame numbers (GFN). This patch series stores the dirty list in kernel memory that can be memory mapped into userspace to allow speedy harvesting. This patch enables dirty ring for X86 only. However it should be easily extended to other archs as well. [1] https://patchwork.kernel.org/patch/10471409/ Signed-off-by: Lei Cao <lei.cao@stratus.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Message-Id: <20201001012222.5767-1-peterx@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-01 09:22:22 +08:00
case KVM_RESET_DIRTY_RINGS:
r = kvm_vm_ioctl_reset_dirty_pages(kvm);
break;
case KVM_GET_STATS_FD:
r = kvm_vm_ioctl_get_stats_fd(kvm);
break;
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}
out:
return r;
}
#ifdef CONFIG_KVM_COMPAT
struct compat_kvm_dirty_log {
__u32 slot;
__u32 padding1;
union {
compat_uptr_t dirty_bitmap; /* one bit per page */
__u64 padding2;
};
};
struct compat_kvm_clear_dirty_log {
__u32 slot;
__u32 num_pages;
__u64 first_page;
union {
compat_uptr_t dirty_bitmap; /* one bit per page */
__u64 padding2;
};
};
static long kvm_vm_compat_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm *kvm = filp->private_data;
int r;
if (kvm->mm != current->mm || kvm->vm_bugged)
return -EIO;
switch (ioctl) {
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
case KVM_CLEAR_DIRTY_LOG: {
struct compat_kvm_clear_dirty_log compat_log;
struct kvm_clear_dirty_log log;
if (copy_from_user(&compat_log, (void __user *)arg,
sizeof(compat_log)))
return -EFAULT;
log.slot = compat_log.slot;
log.num_pages = compat_log.num_pages;
log.first_page = compat_log.first_page;
log.padding2 = compat_log.padding2;
log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
r = kvm_vm_ioctl_clear_dirty_log(kvm, &log);
break;
}
#endif
case KVM_GET_DIRTY_LOG: {
struct compat_kvm_dirty_log compat_log;
struct kvm_dirty_log log;
if (copy_from_user(&compat_log, (void __user *)arg,
sizeof(compat_log)))
return -EFAULT;
log.slot = compat_log.slot;
log.padding1 = compat_log.padding1;
log.padding2 = compat_log.padding2;
log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap);
r = kvm_vm_ioctl_get_dirty_log(kvm, &log);
break;
}
default:
r = kvm_vm_ioctl(filp, ioctl, arg);
}
return r;
}
#endif
static struct file_operations kvm_vm_fops = {
.release = kvm_vm_release,
.unlocked_ioctl = kvm_vm_ioctl,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-16 00:52:59 +08:00
.llseek = noop_llseek,
KVM_COMPAT(kvm_vm_compat_ioctl),
};
KVM: x86: Support KVM VMs sharing SEV context Add a capability for userspace to mirror SEV encryption context from one vm to another. On our side, this is intended to support a Migration Helper vCPU, but it can also be used generically to support other in-guest workloads scheduled by the host. The intention is for the primary guest and the mirror to have nearly identical memslots. The primary benefits of this are that: 1) The VMs do not share KVM contexts (think APIC/MSRs/etc), so they can't accidentally clobber each other. 2) The VMs can have different memory-views, which is necessary for post-copy migration (the migration vCPUs on the target need to read and write to pages, when the primary guest would VMEXIT). This does not change the threat model for AMD SEV. Any memory involved is still owned by the primary guest and its initial state is still attested to through the normal SEV_LAUNCH_* flows. If userspace wanted to circumvent SEV, they could achieve the same effect by simply attaching a vCPU to the primary VM. This patch deliberately leaves userspace in charge of the memslots for the mirror, as it already has the power to mess with them in the primary guest. This patch does not support SEV-ES (much less SNP), as it does not handle handing off attested VMSAs to the mirror. For additional context, we need a Migration Helper because SEV PSP migration is far too slow for our live migration on its own. Using an in-guest migrator lets us speed this up significantly. Signed-off-by: Nathan Tempelman <natet@google.com> Message-Id: <20210408223214.2582277-1-natet@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-09 06:32:14 +08:00
bool file_is_kvm(struct file *file)
{
return file && file->f_op == &kvm_vm_fops;
}
EXPORT_SYMBOL_GPL(file_is_kvm);
static int kvm_dev_ioctl_create_vm(unsigned long type)
{
int r;
struct kvm *kvm;
struct file *file;
kvm = kvm_create_vm(type);
if (IS_ERR(kvm))
return PTR_ERR(kvm);
#ifdef CONFIG_KVM_MMIO
r = kvm_coalesced_mmio_init(kvm);
if (r < 0)
goto put_kvm;
#endif
r = get_unused_fd_flags(O_CLOEXEC);
if (r < 0)
goto put_kvm;
snprintf(kvm->stats_id, sizeof(kvm->stats_id),
"kvm-%d", task_pid_nr(current));
file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
if (IS_ERR(file)) {
put_unused_fd(r);
r = PTR_ERR(file);
goto put_kvm;
}
/*
* Don't call kvm_put_kvm anymore at this point; file->f_op is
* already set, with ->release() being kvm_vm_release(). In error
* cases it will be called by the final fput(file) and will take
* care of doing kvm_put_kvm(kvm).
*/
if (kvm_create_vm_debugfs(kvm, r) < 0) {
put_unused_fd(r);
fput(file);
return -ENOMEM;
}
kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm);
fd_install(r, file);
return r;
put_kvm:
kvm_put_kvm(kvm);
return r;
}
static long kvm_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
long r = -EINVAL;
switch (ioctl) {
case KVM_GET_API_VERSION:
if (arg)
goto out;
r = KVM_API_VERSION;
break;
case KVM_CREATE_VM:
r = kvm_dev_ioctl_create_vm(arg);
break;
case KVM_CHECK_EXTENSION:
r = kvm_vm_ioctl_check_extension_generic(NULL, arg);
break;
case KVM_GET_VCPU_MMAP_SIZE:
if (arg)
goto out;
r = PAGE_SIZE; /* struct kvm_run */
#ifdef CONFIG_X86
r += PAGE_SIZE; /* pio data page */
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
#endif
#ifdef CONFIG_KVM_MMIO
KVM: Add coalesced MMIO support (common part) This patch adds all needed structures to coalesce MMIOs. Until an architecture uses it, it is not compiled. Coalesced MMIO introduces two ioctl() to define where are the MMIO zones that can be coalesced: - KVM_REGISTER_COALESCED_MMIO registers a coalesced MMIO zone. It requests one parameter (struct kvm_coalesced_mmio_zone) which defines a memory area where MMIOs can be coalesced until the next switch to user space. The maximum number of MMIO zones is KVM_COALESCED_MMIO_ZONE_MAX. - KVM_UNREGISTER_COALESCED_MMIO cancels all registered zones inside the given bounds (bounds are also given by struct kvm_coalesced_mmio_zone). The userspace client can check kernel coalesced MMIO availability by asking ioctl(KVM_CHECK_EXTENSION) for the KVM_CAP_COALESCED_MMIO capability. The ioctl() call to KVM_CAP_COALESCED_MMIO will return 0 if not supported, or the page offset where will be stored the ring buffer. The page offset depends on the architecture. After an ioctl(KVM_RUN), the first page of the KVM memory mapped points to a kvm_run structure. The offset given by KVM_CAP_COALESCED_MMIO is an offset to the coalesced MMIO ring expressed in PAGE_SIZE relatively to the address of the start of th kvm_run structure. The MMIO ring buffer is defined by the structure kvm_coalesced_mmio_ring. [akio: fix oops during guest shutdown] Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Akio Takebe <takebe_akio@jp.fujitsu.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-05-30 22:05:54 +08:00
r += PAGE_SIZE; /* coalesced mmio ring page */
#endif
break;
case KVM_TRACE_ENABLE:
case KVM_TRACE_PAUSE:
case KVM_TRACE_DISABLE:
r = -EOPNOTSUPP;
break;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
default:
return kvm_arch_dev_ioctl(filp, ioctl, arg);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
out:
return r;
}
static struct file_operations kvm_chardev_ops = {
.unlocked_ioctl = kvm_dev_ioctl,
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-16 00:52:59 +08:00
.llseek = noop_llseek,
KVM_COMPAT(kvm_dev_ioctl),
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
};
static struct miscdevice kvm_dev = {
KVM_MINOR,
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
"kvm",
&kvm_chardev_ops,
};
static void hardware_enable_nolock(void *junk)
{
int cpu = raw_smp_processor_id();
int r;
if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
return;
cpumask_set_cpu(cpu, cpus_hardware_enabled);
r = kvm_arch_hardware_enable();
if (r) {
cpumask_clear_cpu(cpu, cpus_hardware_enabled);
atomic_inc(&hardware_enable_failed);
pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
}
}
static int kvm_starting_cpu(unsigned int cpu)
{
raw_spin_lock(&kvm_count_lock);
if (kvm_usage_count)
hardware_enable_nolock(NULL);
raw_spin_unlock(&kvm_count_lock);
return 0;
}
static void hardware_disable_nolock(void *junk)
{
int cpu = raw_smp_processor_id();
if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
return;
cpumask_clear_cpu(cpu, cpus_hardware_enabled);
kvm_arch_hardware_disable();
}
static int kvm_dying_cpu(unsigned int cpu)
{
raw_spin_lock(&kvm_count_lock);
if (kvm_usage_count)
hardware_disable_nolock(NULL);
raw_spin_unlock(&kvm_count_lock);
return 0;
}
static void hardware_disable_all_nolock(void)
{
BUG_ON(!kvm_usage_count);
kvm_usage_count--;
if (!kvm_usage_count)
on_each_cpu(hardware_disable_nolock, NULL, 1);
}
static void hardware_disable_all(void)
{
raw_spin_lock(&kvm_count_lock);
hardware_disable_all_nolock();
raw_spin_unlock(&kvm_count_lock);
}
static int hardware_enable_all(void)
{
int r = 0;
raw_spin_lock(&kvm_count_lock);
kvm_usage_count++;
if (kvm_usage_count == 1) {
atomic_set(&hardware_enable_failed, 0);
on_each_cpu(hardware_enable_nolock, NULL, 1);
if (atomic_read(&hardware_enable_failed)) {
hardware_disable_all_nolock();
r = -EBUSY;
}
}
raw_spin_unlock(&kvm_count_lock);
return r;
}
static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
void *v)
{
/*
* Some (well, at least mine) BIOSes hang on reboot if
* in vmx root mode.
*
* And Intel TXT required VMX off for all cpu when system shutdown.
*/
pr_info("kvm: exiting hardware virtualization\n");
kvm_rebooting = true;
on_each_cpu(hardware_disable_nolock, NULL, 1);
return NOTIFY_OK;
}
static struct notifier_block kvm_reboot_notifier = {
.notifier_call = kvm_reboot,
.priority = 0,
};
static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
{
int i;
for (i = 0; i < bus->dev_count; i++) {
struct kvm_io_device *pos = bus->range[i].dev;
kvm_iodevice_destructor(pos);
}
kfree(bus);
}
static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
const struct kvm_io_range *r2)
{
gpa_t addr1 = r1->addr;
gpa_t addr2 = r2->addr;
if (addr1 < addr2)
return -1;
/* If r2->len == 0, match the exact address. If r2->len != 0,
* accept any overlapping write. Any order is acceptable for
* overlapping ranges, because kvm_io_bus_get_first_dev ensures
* we process all of them.
*/
if (r2->len) {
addr1 += r1->len;
addr2 += r2->len;
}
if (addr1 > addr2)
return 1;
return 0;
}
static int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
{
return kvm_io_bus_cmp(p1, p2);
}
static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus,
gpa_t addr, int len)
{
struct kvm_io_range *range, key;
int off;
key = (struct kvm_io_range) {
.addr = addr,
.len = len,
};
range = bsearch(&key, bus->range, bus->dev_count,
sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp);
if (range == NULL)
return -ENOENT;
off = range - bus->range;
while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0)
off--;
return off;
}
static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
struct kvm_io_range *range, const void *val)
{
int idx;
idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
if (idx < 0)
return -EOPNOTSUPP;
while (idx < bus->dev_count &&
kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr,
range->len, val))
return idx;
idx++;
}
return -EOPNOTSUPP;
}
/* kvm_io_bus_write - called under kvm->slots_lock */
int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
int len, const void *val)
{
KVM: use the correct RCU API for PROVE_RCU=y The RCU/SRCU API have already changed for proving RCU usage. I got the following dmesg when PROVE_RCU=y because we used incorrect API. This patch coverts rcu_deference() to srcu_dereference() or family API. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/8550: #0: (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm] #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm] stack backtrace: Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27 Call Trace: [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm] [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm] [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm] [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm] [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel] [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm] [<ffffffff810a8692>] ? unlock_page+0x27/0x2c [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm] [<ffffffff81060cfa>] ? up_read+0x23/0x3d [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a [<ffffffff810021db>] system_call_fastpath+0x16/0x1b Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-19 17:41:23 +08:00
struct kvm_io_bus *bus;
struct kvm_io_range range;
int r;
range = (struct kvm_io_range) {
.addr = addr,
.len = len,
};
KVM: use the correct RCU API for PROVE_RCU=y The RCU/SRCU API have already changed for proving RCU usage. I got the following dmesg when PROVE_RCU=y because we used incorrect API. This patch coverts rcu_deference() to srcu_dereference() or family API. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/8550: #0: (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm] #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm] stack backtrace: Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27 Call Trace: [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm] [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm] [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm] [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm] [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel] [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm] [<ffffffff810a8692>] ? unlock_page+0x27/0x2c [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm] [<ffffffff81060cfa>] ? up_read+0x23/0x3d [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a [<ffffffff810021db>] system_call_fastpath+0x16/0x1b Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-19 17:41:23 +08:00
bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
if (!bus)
return -ENOMEM;
r = __kvm_io_bus_write(vcpu, bus, &range, val);
return r < 0 ? r : 0;
}
EXPORT_SYMBOL_GPL(kvm_io_bus_write);
/* kvm_io_bus_write_cookie - called under kvm->slots_lock */
int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx,
gpa_t addr, int len, const void *val, long cookie)
{
struct kvm_io_bus *bus;
struct kvm_io_range range;
range = (struct kvm_io_range) {
.addr = addr,
.len = len,
};
bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
if (!bus)
return -ENOMEM;
/* First try the device referenced by cookie. */
if ((cookie >= 0) && (cookie < bus->dev_count) &&
(kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len,
val))
return cookie;
/*
* cookie contained garbage; fall back to search and return the
* correct cookie value.
*/
return __kvm_io_bus_write(vcpu, bus, &range, val);
}
static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus,
struct kvm_io_range *range, void *val)
{
int idx;
idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len);
if (idx < 0)
return -EOPNOTSUPP;
while (idx < bus->dev_count &&
kvm_io_bus_cmp(range, &bus->range[idx]) == 0) {
if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr,
range->len, val))
return idx;
idx++;
}
return -EOPNOTSUPP;
}
/* kvm_io_bus_read - called under kvm->slots_lock */
int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
int len, void *val)
{
KVM: use the correct RCU API for PROVE_RCU=y The RCU/SRCU API have already changed for proving RCU usage. I got the following dmesg when PROVE_RCU=y because we used incorrect API. This patch coverts rcu_deference() to srcu_dereference() or family API. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/8550: #0: (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm] #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm] stack backtrace: Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27 Call Trace: [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm] [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm] [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm] [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm] [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel] [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm] [<ffffffff810a8692>] ? unlock_page+0x27/0x2c [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm] [<ffffffff81060cfa>] ? up_read+0x23/0x3d [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a [<ffffffff810021db>] system_call_fastpath+0x16/0x1b Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-19 17:41:23 +08:00
struct kvm_io_bus *bus;
struct kvm_io_range range;
int r;
range = (struct kvm_io_range) {
.addr = addr,
.len = len,
};
bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu);
if (!bus)
return -ENOMEM;
r = __kvm_io_bus_read(vcpu, bus, &range, val);
return r < 0 ? r : 0;
}
/* Caller must hold slots_lock. */
int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
int len, struct kvm_io_device *dev)
{
int i;
struct kvm_io_bus *new_bus, *bus;
struct kvm_io_range range;
bus = kvm_get_bus(kvm, bus_idx);
if (!bus)
return -ENOMEM;
/* exclude ioeventfd which is limited by maximum fd */
if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1)
return -ENOSPC;
new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1),
GFP_KERNEL_ACCOUNT);
if (!new_bus)
return -ENOMEM;
range = (struct kvm_io_range) {
.addr = addr,
.len = len,
.dev = dev,
};
for (i = 0; i < bus->dev_count; i++)
if (kvm_io_bus_cmp(&bus->range[i], &range) > 0)
break;
memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
new_bus->dev_count++;
new_bus->range[i] = range;
memcpy(new_bus->range + i + 1, bus->range + i,
(bus->dev_count - i) * sizeof(struct kvm_io_range));
rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
synchronize_srcu_expedited(&kvm->srcu);
kfree(bus);
return 0;
}
int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
struct kvm_io_device *dev)
{
int i, j;
struct kvm_io_bus *new_bus, *bus;
lockdep_assert_held(&kvm->slots_lock);
bus = kvm_get_bus(kvm, bus_idx);
if (!bus)
return 0;
for (i = 0; i < bus->dev_count; i++) {
if (bus->range[i].dev == dev) {
break;
}
}
if (i == bus->dev_count)
return 0;
new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1),
GFP_KERNEL_ACCOUNT);
if (new_bus) {
memcpy(new_bus, bus, struct_size(bus, range, i));
new_bus->dev_count--;
memcpy(new_bus->range + i, bus->range + i + 1,
flex_array_size(new_bus, range, new_bus->dev_count - i));
}
rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
synchronize_srcu_expedited(&kvm->srcu);
/* Destroy the old bus _after_ installing the (null) bus. */
if (!new_bus) {
pr_err("kvm: failed to shrink bus, removing it completely\n");
for (j = 0; j < bus->dev_count; j++) {
if (j == i)
continue;
kvm_iodevice_destructor(bus->range[j].dev);
}
}
kfree(bus);
return new_bus ? 0 : -ENOMEM;
}
struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
gpa_t addr)
{
struct kvm_io_bus *bus;
int dev_idx, srcu_idx;
struct kvm_io_device *iodev = NULL;
srcu_idx = srcu_read_lock(&kvm->srcu);
bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
if (!bus)
goto out_unlock;
dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1);
if (dev_idx < 0)
goto out_unlock;
iodev = bus->range[dev_idx].dev;
out_unlock:
srcu_read_unlock(&kvm->srcu, srcu_idx);
return iodev;
}
EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev);
static int kvm_debugfs_open(struct inode *inode, struct file *file,
int (*get)(void *, u64 *), int (*set)(void *, u64),
const char *fmt)
{
struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
inode->i_private;
/*
* The debugfs files are a reference to the kvm struct which
* is still valid when kvm_destroy_vm is called. kvm_get_kvm_safe
* avoids the race between open and the removal of the debugfs directory.
*/
if (!kvm_get_kvm_safe(stat_data->kvm))
return -ENOENT;
if (simple_attr_open(inode, file, get,
kvm_stats_debugfs_mode(stat_data->desc) & 0222
? set : NULL,
fmt)) {
kvm_put_kvm(stat_data->kvm);
return -ENOMEM;
}
return 0;
}
static int kvm_debugfs_release(struct inode *inode, struct file *file)
{
struct kvm_stat_data *stat_data = (struct kvm_stat_data *)
inode->i_private;
simple_attr_release(inode, file);
kvm_put_kvm(stat_data->kvm);
return 0;
}
static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
{
*val = *(u64 *)((void *)(&kvm->stat) + offset);
return 0;
}
static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
{
*(u64 *)((void *)(&kvm->stat) + offset) = 0;
return 0;
}
static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
{
int i;
struct kvm_vcpu *vcpu;
*val = 0;
kvm_for_each_vcpu(i, vcpu, kvm)
*val += *(u64 *)((void *)(&vcpu->stat) + offset);
return 0;
}
static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
{
int i;
struct kvm_vcpu *vcpu;
kvm_for_each_vcpu(i, vcpu, kvm)
*(u64 *)((void *)(&vcpu->stat) + offset) = 0;
return 0;
}
static int kvm_stat_data_get(void *data, u64 *val)
{
int r = -EFAULT;
struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
switch (stat_data->kind) {
case KVM_STAT_VM:
r = kvm_get_stat_per_vm(stat_data->kvm,
stat_data->desc->desc.offset, val);
break;
case KVM_STAT_VCPU:
r = kvm_get_stat_per_vcpu(stat_data->kvm,
stat_data->desc->desc.offset, val);
break;
}
return r;
}
static int kvm_stat_data_clear(void *data, u64 val)
{
int r = -EFAULT;
struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
if (val)
return -EINVAL;
switch (stat_data->kind) {
case KVM_STAT_VM:
r = kvm_clear_stat_per_vm(stat_data->kvm,
stat_data->desc->desc.offset);
break;
case KVM_STAT_VCPU:
r = kvm_clear_stat_per_vcpu(stat_data->kvm,
stat_data->desc->desc.offset);
break;
}
return r;
}
static int kvm_stat_data_open(struct inode *inode, struct file *file)
{
__simple_attr_check_format("%llu\n", 0ull);
return kvm_debugfs_open(inode, file, kvm_stat_data_get,
kvm_stat_data_clear, "%llu\n");
}
static const struct file_operations stat_fops_per_vm = {
.owner = THIS_MODULE,
.open = kvm_stat_data_open,
.release = kvm_debugfs_release,
.read = simple_attr_read,
.write = simple_attr_write,
.llseek = no_llseek,
};
static int vm_stat_get(void *_offset, u64 *val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
u64 tmp_val;
*val = 0;
mutex_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_get_stat_per_vm(kvm, offset, &tmp_val);
*val += tmp_val;
}
mutex_unlock(&kvm_lock);
return 0;
}
static int vm_stat_clear(void *_offset, u64 val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
if (val)
return -EINVAL;
mutex_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_clear_stat_per_vm(kvm, offset);
}
mutex_unlock(&kvm_lock);
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n");
DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops, vm_stat_get, NULL, "%llu\n");
static int vcpu_stat_get(void *_offset, u64 *val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
u64 tmp_val;
*val = 0;
mutex_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_get_stat_per_vcpu(kvm, offset, &tmp_val);
*val += tmp_val;
}
mutex_unlock(&kvm_lock);
return 0;
}
static int vcpu_stat_clear(void *_offset, u64 val)
{
unsigned offset = (long)_offset;
struct kvm *kvm;
if (val)
return -EINVAL;
mutex_lock(&kvm_lock);
list_for_each_entry(kvm, &vm_list, vm_list) {
kvm_clear_stat_per_vcpu(kvm, offset);
}
mutex_unlock(&kvm_lock);
return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear,
"%llu\n");
DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops, vcpu_stat_get, NULL, "%llu\n");
static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
{
struct kobj_uevent_env *env;
unsigned long long created, active;
if (!kvm_dev.this_device || !kvm)
return;
mutex_lock(&kvm_lock);
if (type == KVM_EVENT_CREATE_VM) {
kvm_createvm_count++;
kvm_active_vms++;
} else if (type == KVM_EVENT_DESTROY_VM) {
kvm_active_vms--;
}
created = kvm_createvm_count;
active = kvm_active_vms;
mutex_unlock(&kvm_lock);
env = kzalloc(sizeof(*env), GFP_KERNEL_ACCOUNT);
if (!env)
return;
add_uevent_var(env, "CREATED=%llu", created);
add_uevent_var(env, "COUNT=%llu", active);
if (type == KVM_EVENT_CREATE_VM) {
add_uevent_var(env, "EVENT=create");
kvm->userspace_pid = task_pid_nr(current);
} else if (type == KVM_EVENT_DESTROY_VM) {
add_uevent_var(env, "EVENT=destroy");
}
add_uevent_var(env, "PID=%d", kvm->userspace_pid);
KVM: Do not leak memory for duplicate debugfs directories KVM creates a debugfs directory for each VM in order to store statistics about the virtual machine. The directory name is built from the process pid and a VM fd. While generally unique, it is possible to keep a file descriptor alive in a way that causes duplicate directories, which manifests as these messages: [ 471.846235] debugfs: Directory '20245-4' with parent 'kvm' already present! Even though this should not happen in practice, it is more or less expected in the case of KVM for testcases that call KVM_CREATE_VM and close the resulting file descriptor repeatedly and in parallel. When this happens, debugfs_create_dir() returns an error but kvm_create_vm_debugfs() goes on to allocate stat data structs which are later leaked. The slow memory leak was spotted by syzkaller, where it caused OOM reports. Since the issue only affects debugfs, do a lookup before calling debugfs_create_dir, so that the message is downgraded and rate-limited. While at it, ensure kvm->debugfs_dentry is NULL rather than an error if it is not created. This fixes kvm_destroy_vm_debugfs, which was not checking IS_ERR_OR_NULL correctly. Cc: stable@vger.kernel.org Fixes: 536a6f88c49d ("KVM: Create debugfs dir and stat files for each VM") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-08-04 17:28:52 +08:00
if (kvm->debugfs_dentry) {
char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL_ACCOUNT);
if (p) {
tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX);
if (!IS_ERR(tmp))
add_uevent_var(env, "STATS_PATH=%s", tmp);
kfree(p);
}
}
/* no need for checks, since we are adding at most only 5 keys */
env->envp[env->envp_idx++] = NULL;
kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, env->envp);
kfree(env);
}
static void kvm_init_debug(void)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
const struct file_operations *fops;
const struct _kvm_stats_desc *pdesc;
int i;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
pdesc = &kvm_vm_stats_desc[i];
if (kvm_stats_debugfs_mode(pdesc) & 0222)
fops = &vm_stat_fops;
else
fops = &vm_stat_readonly_fops;
debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
kvm_debugfs_dir,
(void *)(long)pdesc->desc.offset, fops);
}
for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
pdesc = &kvm_vcpu_stats_desc[i];
if (kvm_stats_debugfs_mode(pdesc) & 0222)
fops = &vcpu_stat_fops;
else
fops = &vcpu_stat_readonly_fops;
debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
kvm_debugfs_dir,
(void *)(long)pdesc->desc.offset, fops);
}
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
static int kvm_suspend(void)
{
if (kvm_usage_count)
hardware_disable_nolock(NULL);
return 0;
}
static void kvm_resume(void)
{
if (kvm_usage_count) {
#ifdef CONFIG_LOCKDEP
WARN_ON(lockdep_is_held(&kvm_count_lock));
#endif
hardware_enable_nolock(NULL);
}
}
static struct syscore_ops kvm_syscore_ops = {
.suspend = kvm_suspend,
.resume = kvm_resume,
};
static inline
struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
{
return container_of(pn, struct kvm_vcpu, preempt_notifier);
}
static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
{
struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
WRITE_ONCE(vcpu->preempted, false);
KVM: Boost vCPUs that are delivering interrupts Inspired by commit 9cac38dd5d (KVM/s390: Set preempted flag during vcpu wakeup and interrupt delivery), we want to also boost not just lock holders but also vCPUs that are delivering interrupts. Most smp_call_function_many calls are synchronous, so the IPI target vCPUs are also good yield candidates. This patch introduces vcpu->ready to boost vCPUs during wakeup and interrupt delivery time; unlike s390 we do not reuse vcpu->preempted so that voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin, but vmx_vcpu_pi_put is not affected (VT-d PI handles voluntary preemption separately, in pi_pre_block). Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM: ebizzy -M vanilla boosting improved 1VM 21443 23520 9% 2VM 2800 8000 180% 3VM 1800 3100 72% Testing on my Haswell desktop 8 HT, with 8 vCPUs VM 8GB RAM, two VMs, one running ebizzy -M, the other running 'stress --cpu 2': w/ boosting + w/o pv sched yield(vanilla) vanilla boosting improved 1570 4000 155% w/ boosting + w/ pv sched yield(vanilla) vanilla boosting improved 1844 5157 179% w/o boosting, perf top in VM: 72.33% [kernel] [k] smp_call_function_many 4.22% [kernel] [k] call_function_i 3.71% [kernel] [k] async_page_fault w/ boosting, perf top in VM: 38.43% [kernel] [k] smp_call_function_many 6.31% [kernel] [k] async_page_fault 6.13% libc-2.23.so [.] __memcpy_avx_unaligned 4.88% [kernel] [k] call_function_interrupt Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Marc Zyngier <maz@kernel.org> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-18 19:39:06 +08:00
WRITE_ONCE(vcpu->ready, false);
__this_cpu_write(kvm_running_vcpu, vcpu);
kvm_arch_sched_in(vcpu, cpu);
kvm_arch_vcpu_load(vcpu, cpu);
}
static void kvm_sched_out(struct preempt_notifier *pn,
struct task_struct *next)
{
struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
if (current->on_rq) {
WRITE_ONCE(vcpu->preempted, true);
KVM: Boost vCPUs that are delivering interrupts Inspired by commit 9cac38dd5d (KVM/s390: Set preempted flag during vcpu wakeup and interrupt delivery), we want to also boost not just lock holders but also vCPUs that are delivering interrupts. Most smp_call_function_many calls are synchronous, so the IPI target vCPUs are also good yield candidates. This patch introduces vcpu->ready to boost vCPUs during wakeup and interrupt delivery time; unlike s390 we do not reuse vcpu->preempted so that voluntarily preempted vCPUs are taken into account by kvm_vcpu_on_spin, but vmx_vcpu_pi_put is not affected (VT-d PI handles voluntary preemption separately, in pi_pre_block). Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM: ebizzy -M vanilla boosting improved 1VM 21443 23520 9% 2VM 2800 8000 180% 3VM 1800 3100 72% Testing on my Haswell desktop 8 HT, with 8 vCPUs VM 8GB RAM, two VMs, one running ebizzy -M, the other running 'stress --cpu 2': w/ boosting + w/o pv sched yield(vanilla) vanilla boosting improved 1570 4000 155% w/ boosting + w/ pv sched yield(vanilla) vanilla boosting improved 1844 5157 179% w/o boosting, perf top in VM: 72.33% [kernel] [k] smp_call_function_many 4.22% [kernel] [k] call_function_i 3.71% [kernel] [k] async_page_fault w/ boosting, perf top in VM: 38.43% [kernel] [k] smp_call_function_many 6.31% [kernel] [k] async_page_fault 6.13% libc-2.23.so [.] __memcpy_avx_unaligned 4.88% [kernel] [k] call_function_interrupt Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Marc Zyngier <maz@kernel.org> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-18 19:39:06 +08:00
WRITE_ONCE(vcpu->ready, true);
}
kvm_arch_vcpu_put(vcpu);
__this_cpu_write(kvm_running_vcpu, NULL);
}
/**
* kvm_get_running_vcpu - get the vcpu running on the current CPU.
*
* We can disable preemption locally around accessing the per-CPU variable,
* and use the resolved vcpu pointer after enabling preemption again,
* because even if the current thread is migrated to another CPU, reading
* the per-CPU value later will give us the same value as we update the
* per-CPU variable in the preempt notifier handlers.
*/
struct kvm_vcpu *kvm_get_running_vcpu(void)
{
struct kvm_vcpu *vcpu;
preempt_disable();
vcpu = __this_cpu_read(kvm_running_vcpu);
preempt_enable();
return vcpu;
}
EXPORT_SYMBOL_GPL(kvm_get_running_vcpu);
/**
* kvm_get_running_vcpus - get the per-CPU array of currently running vcpus.
*/
struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
{
return &kvm_running_vcpu;
}
struct kvm_cpu_compat_check {
void *opaque;
int *ret;
};
static void check_processor_compat(void *data)
{
struct kvm_cpu_compat_check *c = data;
*c->ret = kvm_arch_check_processor_compat(c->opaque);
}
int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
struct module *module)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
struct kvm_cpu_compat_check c;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
int r;
int cpu;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = kvm_arch_init(opaque);
if (r)
goto out_fail;
KVM: Fix kvm_irqfd_init initialization In commit a0f155e96 'KVM: Initialize irqfd from kvm_init()', when kvm_init() is called the second time (e.g kvm-amd.ko and kvm-intel.ko), kvm_arch_init() will fail with -EEXIST, then kvm_irqfd_exit() will be called on the error handling path. This way, the kvm_irqfd system will not be ready. This patch fix the following: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 PGD 0 Oops: 0002 [#1] SMP Modules linked in: vhost_net CPU 6 Pid: 4257, comm: qemu-system-x86 Not tainted 3.9.0-rc3+ #757 Dell Inc. OptiPlex 790/0V5HMK RIP: 0010:[<ffffffff81c0721e>] [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP: 0018:ffff880221721cc8 EFLAGS: 00010046 RAX: 0000000000000100 RBX: ffff88022dcc003f RCX: ffff880221734950 RDX: ffff8802208f6ca8 RSI: 000000007fffffff RDI: 0000000000000000 RBP: ffff880221721cc8 R08: 0000000000000002 R09: 0000000000000002 R10: 00007f7fd01087e0 R11: 0000000000000246 R12: ffff8802208f6ca8 R13: 0000000000000080 R14: ffff880223e2a900 R15: 0000000000000000 FS: 00007f7fd38488e0(0000) GS:ffff88022dcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000022309f000 CR4: 00000000000427e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process qemu-system-x86 (pid: 4257, threadinfo ffff880221720000, task ffff880222bd5640) Stack: ffff880221721d08 ffffffff810ac5c5 ffff88022431dc00 0000000000000086 0000000000000080 ffff880223e2a900 ffff8802208f6ca8 0000000000000000 ffff880221721d48 ffffffff810ac8fe 0000000000000000 ffff880221734000 Call Trace: [<ffffffff810ac5c5>] __queue_work+0x45/0x2d0 [<ffffffff810ac8fe>] queue_work_on+0x8e/0xa0 [<ffffffff810ac949>] queue_work+0x19/0x20 [<ffffffff81009b6b>] irqfd_deactivate+0x4b/0x60 [<ffffffff8100a69d>] kvm_irqfd+0x39d/0x580 [<ffffffff81007a27>] kvm_vm_ioctl+0x207/0x5b0 [<ffffffff810c9545>] ? update_curr+0xf5/0x180 [<ffffffff811b66e8>] do_vfs_ioctl+0x98/0x550 [<ffffffff810c1f5e>] ? finish_task_switch+0x4e/0xe0 [<ffffffff81c054aa>] ? __schedule+0x2ea/0x710 [<ffffffff811b6bf7>] sys_ioctl+0x57/0x90 [<ffffffff8140ae9e>] ? trace_hardirqs_on_thunk+0x3a/0x3c [<ffffffff81c0f602>] system_call_fastpath+0x16/0x1b Code: c1 ea 08 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f b6 03 38 c2 75 f7 48 83 c4 08 5b c9 c3 55 48 89 e5 66 66 66 66 90 b8 00 01 00 00 <f0> 66 0f c1 07 89 c2 66 c1 ea 08 38 c2 74 0c 0f 1f 00 f3 90 0f RIP [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP <ffff880221721cc8> CR2: 0000000000000000 ---[ end trace 13fb1e4b6e5ab21f ]--- Signed-off-by: Asias He <asias@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-08 10:57:29 +08:00
/*
* kvm_arch_init makes sure there's at most one caller
* for architectures that support multiple implementations,
* like intel and amd on x86.
* kvm_arch_init must be called before kvm_irqfd_init to avoid creating
* conflicts in case kvm is already setup for another implementation.
KVM: Fix kvm_irqfd_init initialization In commit a0f155e96 'KVM: Initialize irqfd from kvm_init()', when kvm_init() is called the second time (e.g kvm-amd.ko and kvm-intel.ko), kvm_arch_init() will fail with -EEXIST, then kvm_irqfd_exit() will be called on the error handling path. This way, the kvm_irqfd system will not be ready. This patch fix the following: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 PGD 0 Oops: 0002 [#1] SMP Modules linked in: vhost_net CPU 6 Pid: 4257, comm: qemu-system-x86 Not tainted 3.9.0-rc3+ #757 Dell Inc. OptiPlex 790/0V5HMK RIP: 0010:[<ffffffff81c0721e>] [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP: 0018:ffff880221721cc8 EFLAGS: 00010046 RAX: 0000000000000100 RBX: ffff88022dcc003f RCX: ffff880221734950 RDX: ffff8802208f6ca8 RSI: 000000007fffffff RDI: 0000000000000000 RBP: ffff880221721cc8 R08: 0000000000000002 R09: 0000000000000002 R10: 00007f7fd01087e0 R11: 0000000000000246 R12: ffff8802208f6ca8 R13: 0000000000000080 R14: ffff880223e2a900 R15: 0000000000000000 FS: 00007f7fd38488e0(0000) GS:ffff88022dcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000022309f000 CR4: 00000000000427e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process qemu-system-x86 (pid: 4257, threadinfo ffff880221720000, task ffff880222bd5640) Stack: ffff880221721d08 ffffffff810ac5c5 ffff88022431dc00 0000000000000086 0000000000000080 ffff880223e2a900 ffff8802208f6ca8 0000000000000000 ffff880221721d48 ffffffff810ac8fe 0000000000000000 ffff880221734000 Call Trace: [<ffffffff810ac5c5>] __queue_work+0x45/0x2d0 [<ffffffff810ac8fe>] queue_work_on+0x8e/0xa0 [<ffffffff810ac949>] queue_work+0x19/0x20 [<ffffffff81009b6b>] irqfd_deactivate+0x4b/0x60 [<ffffffff8100a69d>] kvm_irqfd+0x39d/0x580 [<ffffffff81007a27>] kvm_vm_ioctl+0x207/0x5b0 [<ffffffff810c9545>] ? update_curr+0xf5/0x180 [<ffffffff811b66e8>] do_vfs_ioctl+0x98/0x550 [<ffffffff810c1f5e>] ? finish_task_switch+0x4e/0xe0 [<ffffffff81c054aa>] ? __schedule+0x2ea/0x710 [<ffffffff811b6bf7>] sys_ioctl+0x57/0x90 [<ffffffff8140ae9e>] ? trace_hardirqs_on_thunk+0x3a/0x3c [<ffffffff81c0f602>] system_call_fastpath+0x16/0x1b Code: c1 ea 08 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f b6 03 38 c2 75 f7 48 83 c4 08 5b c9 c3 55 48 89 e5 66 66 66 66 90 b8 00 01 00 00 <f0> 66 0f c1 07 89 c2 66 c1 ea 08 38 c2 74 0c 0f 1f 00 f3 90 0f RIP [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP <ffff880221721cc8> CR2: 0000000000000000 ---[ end trace 13fb1e4b6e5ab21f ]--- Signed-off-by: Asias He <asias@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-08 10:57:29 +08:00
*/
r = kvm_irqfd_init();
if (r)
goto out_irqfd;
KVM: Fix kvm_irqfd_init initialization In commit a0f155e96 'KVM: Initialize irqfd from kvm_init()', when kvm_init() is called the second time (e.g kvm-amd.ko and kvm-intel.ko), kvm_arch_init() will fail with -EEXIST, then kvm_irqfd_exit() will be called on the error handling path. This way, the kvm_irqfd system will not be ready. This patch fix the following: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 PGD 0 Oops: 0002 [#1] SMP Modules linked in: vhost_net CPU 6 Pid: 4257, comm: qemu-system-x86 Not tainted 3.9.0-rc3+ #757 Dell Inc. OptiPlex 790/0V5HMK RIP: 0010:[<ffffffff81c0721e>] [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP: 0018:ffff880221721cc8 EFLAGS: 00010046 RAX: 0000000000000100 RBX: ffff88022dcc003f RCX: ffff880221734950 RDX: ffff8802208f6ca8 RSI: 000000007fffffff RDI: 0000000000000000 RBP: ffff880221721cc8 R08: 0000000000000002 R09: 0000000000000002 R10: 00007f7fd01087e0 R11: 0000000000000246 R12: ffff8802208f6ca8 R13: 0000000000000080 R14: ffff880223e2a900 R15: 0000000000000000 FS: 00007f7fd38488e0(0000) GS:ffff88022dcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000022309f000 CR4: 00000000000427e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process qemu-system-x86 (pid: 4257, threadinfo ffff880221720000, task ffff880222bd5640) Stack: ffff880221721d08 ffffffff810ac5c5 ffff88022431dc00 0000000000000086 0000000000000080 ffff880223e2a900 ffff8802208f6ca8 0000000000000000 ffff880221721d48 ffffffff810ac8fe 0000000000000000 ffff880221734000 Call Trace: [<ffffffff810ac5c5>] __queue_work+0x45/0x2d0 [<ffffffff810ac8fe>] queue_work_on+0x8e/0xa0 [<ffffffff810ac949>] queue_work+0x19/0x20 [<ffffffff81009b6b>] irqfd_deactivate+0x4b/0x60 [<ffffffff8100a69d>] kvm_irqfd+0x39d/0x580 [<ffffffff81007a27>] kvm_vm_ioctl+0x207/0x5b0 [<ffffffff810c9545>] ? update_curr+0xf5/0x180 [<ffffffff811b66e8>] do_vfs_ioctl+0x98/0x550 [<ffffffff810c1f5e>] ? finish_task_switch+0x4e/0xe0 [<ffffffff81c054aa>] ? __schedule+0x2ea/0x710 [<ffffffff811b6bf7>] sys_ioctl+0x57/0x90 [<ffffffff8140ae9e>] ? trace_hardirqs_on_thunk+0x3a/0x3c [<ffffffff81c0f602>] system_call_fastpath+0x16/0x1b Code: c1 ea 08 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f b6 03 38 c2 75 f7 48 83 c4 08 5b c9 c3 55 48 89 e5 66 66 66 66 90 b8 00 01 00 00 <f0> 66 0f c1 07 89 c2 66 c1 ea 08 38 c2 74 0c 0f 1f 00 f3 90 0f RIP [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP <ffff880221721cc8> CR2: 0000000000000000 ---[ end trace 13fb1e4b6e5ab21f ]--- Signed-off-by: Asias He <asias@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-08 10:57:29 +08:00
kvm: fix kvm reboot crash when MAXSMP is used one system was found there is crash during reboot then kvm/MAXSMP Sending all processes the KILL signal... done Please stand by while rebooting the system... [ 1721.856538] md: stopping all md devices. [ 1722.852139] kvm: exiting hardware virtualization [ 1722.854601] BUG: unable to handle kernel NULL pointer dereference at (null) [ 1722.872219] IP: [<ffffffff8102c6b6>] hardware_disable+0x4c/0xb4 [ 1722.877955] PGD 0 [ 1722.880042] Oops: 0000 [#1] SMP [ 1722.892548] last sysfs file: /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/host0/target0:2:0/0:2:0:0/vendor [ 1722.900977] CPU 9 [ 1722.912606] Modules linked in: [ 1722.914226] Pid: 0, comm: swapper Not tainted 2.6.30-rc7-tip-01843-g2305324-dirty #299 ... [ 1722.932589] RIP: 0010:[<ffffffff8102c6b6>] [<ffffffff8102c6b6>] hardware_disable+0x4c/0xb4 [ 1722.942709] RSP: 0018:ffffc900010b6ed8 EFLAGS: 00010046 [ 1722.956121] RAX: 0000000000000000 RBX: ffffc9000e253140 RCX: 0000000000000009 [ 1722.972202] RDX: 000000000000b020 RSI: ffffc900010c3220 RDI: ffffffffffffd790 [ 1722.977399] RBP: ffffc900010b6f08 R08: 0000000000000000 R09: 0000000000000000 [ 1722.995149] R10: 00000000000004b8 R11: 966912b6c78fddbd R12: 0000000000000009 [ 1723.011551] R13: 000000000000b020 R14: 0000000000000009 R15: 0000000000000000 [ 1723.019898] FS: 0000000000000000(0000) GS:ffffc900010b3000(0000) knlGS:0000000000000000 [ 1723.034389] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b [ 1723.041164] CR2: 0000000000000000 CR3: 0000000001001000 CR4: 00000000000006e0 [ 1723.056192] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1723.072546] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 1723.080562] Process swapper (pid: 0, threadinfo ffff88107e464000, task ffff88047e5a2550) [ 1723.096144] Stack: [ 1723.099071] 0000000000000046 ffffc9000e253168 966912b6c78fddbd ffffc9000e253140 [ 1723.115471] ffff880c7d4304d0 ffffc9000e253168 ffffc900010b6f28 ffffffff81011022 [ 1723.132428] ffffc900010b6f48 966912b6c78fddbd ffffc900010b6f48 ffffffff8100b83b [ 1723.141973] Call Trace: [ 1723.142981] <IRQ> <0> [<ffffffff81011022>] kvm_arch_hardware_disable+0x26/0x3c [ 1723.158153] [<ffffffff8100b83b>] hardware_disable+0x3f/0x55 [ 1723.172168] [<ffffffff810b95f6>] generic_smp_call_function_interrupt+0x76/0x13c [ 1723.178836] [<ffffffff8104cbea>] smp_call_function_interrupt+0x3a/0x5e [ 1723.194689] [<ffffffff81035bf3>] call_function_interrupt+0x13/0x20 [ 1723.199750] <EOI> <0> [<ffffffff814ad3b4>] ? acpi_idle_enter_c1+0xd3/0xf4 [ 1723.217508] [<ffffffff814ad3ae>] ? acpi_idle_enter_c1+0xcd/0xf4 [ 1723.232172] [<ffffffff814ad4bc>] ? acpi_idle_enter_bm+0xe7/0x2ce [ 1723.235141] [<ffffffff81a8d93f>] ? __atomic_notifier_call_chain+0x0/0xac [ 1723.253381] [<ffffffff818c3dff>] ? menu_select+0x58/0xd2 [ 1723.258179] [<ffffffff818c2c9d>] ? cpuidle_idle_call+0xa4/0xf3 [ 1723.272828] [<ffffffff81034085>] ? cpu_idle+0xb8/0x101 [ 1723.277085] [<ffffffff81a80163>] ? start_secondary+0x1bc/0x1d7 [ 1723.293708] Code: b0 00 00 65 48 8b 04 25 28 00 00 00 48 89 45 e0 31 c0 48 8b 04 cd 30 ee 27 82 49 89 cc 49 89 d5 48 8b 04 10 48 8d b8 90 d7 ff ff <48> 8b 87 70 28 00 00 48 8d 98 90 d7 ff ff eb 16 e8 e9 fe ff ff [ 1723.335524] RIP [<ffffffff8102c6b6>] hardware_disable+0x4c/0xb4 [ 1723.342076] RSP <ffffc900010b6ed8> [ 1723.352021] CR2: 0000000000000000 [ 1723.354348] ---[ end trace e2aec53dae150aa1 ]--- it turns out that we need clear cpus_hardware_enabled in that case. Reported-and-tested-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-07 05:52:35 +08:00
if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
r = -ENOMEM;
goto out_free_0;
}
r = kvm_arch_hardware_setup(opaque);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
if (r < 0)
goto out_free_1;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
c.ret = &r;
c.opaque = opaque;
for_each_online_cpu(cpu) {
smp_call_function_single(cpu, check_processor_compat, &c, 1);
if (r < 0)
goto out_free_2;
}
r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
kvm_starting_cpu, kvm_dying_cpu);
if (r)
goto out_free_2;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
register_reboot_notifier(&kvm_reboot_notifier);
/* A kmem cache lets us meet the alignment requirements of fx_save. */
if (!vcpu_align)
vcpu_align = __alignof__(struct kvm_vcpu);
kvm_vcpu_cache =
kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align,
SLAB_ACCOUNT,
offsetof(struct kvm_vcpu, arch),
offsetofend(struct kvm_vcpu, stats_id)
- offsetof(struct kvm_vcpu, arch),
NULL);
if (!kvm_vcpu_cache) {
r = -ENOMEM;
goto out_free_3;
}
r = kvm_async_pf_init();
if (r)
goto out_free;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
kvm_chardev_ops.owner = module;
kvm_vm_fops.owner = module;
kvm_vcpu_fops.owner = module;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
r = misc_register(&kvm_dev);
if (r) {
pr_err("kvm: misc device register failed\n");
goto out_unreg;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
register_syscore_ops(&kvm_syscore_ops);
kvm_preempt_ops.sched_in = kvm_sched_in;
kvm_preempt_ops.sched_out = kvm_sched_out;
kvm_init_debug();
r = kvm_vfio_ops_init();
WARN_ON(r);
return 0;
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
out_unreg:
kvm_async_pf_deinit();
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
out_free:
kmem_cache_destroy(kvm_vcpu_cache);
out_free_3:
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
unregister_reboot_notifier(&kvm_reboot_notifier);
cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
out_free_2:
kvm_arch_hardware_unsetup();
out_free_1:
free_cpumask_var(cpus_hardware_enabled);
out_free_0:
kvm_irqfd_exit();
out_irqfd:
KVM: Fix kvm_irqfd_init initialization In commit a0f155e96 'KVM: Initialize irqfd from kvm_init()', when kvm_init() is called the second time (e.g kvm-amd.ko and kvm-intel.ko), kvm_arch_init() will fail with -EEXIST, then kvm_irqfd_exit() will be called on the error handling path. This way, the kvm_irqfd system will not be ready. This patch fix the following: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 PGD 0 Oops: 0002 [#1] SMP Modules linked in: vhost_net CPU 6 Pid: 4257, comm: qemu-system-x86 Not tainted 3.9.0-rc3+ #757 Dell Inc. OptiPlex 790/0V5HMK RIP: 0010:[<ffffffff81c0721e>] [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP: 0018:ffff880221721cc8 EFLAGS: 00010046 RAX: 0000000000000100 RBX: ffff88022dcc003f RCX: ffff880221734950 RDX: ffff8802208f6ca8 RSI: 000000007fffffff RDI: 0000000000000000 RBP: ffff880221721cc8 R08: 0000000000000002 R09: 0000000000000002 R10: 00007f7fd01087e0 R11: 0000000000000246 R12: ffff8802208f6ca8 R13: 0000000000000080 R14: ffff880223e2a900 R15: 0000000000000000 FS: 00007f7fd38488e0(0000) GS:ffff88022dcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000022309f000 CR4: 00000000000427e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process qemu-system-x86 (pid: 4257, threadinfo ffff880221720000, task ffff880222bd5640) Stack: ffff880221721d08 ffffffff810ac5c5 ffff88022431dc00 0000000000000086 0000000000000080 ffff880223e2a900 ffff8802208f6ca8 0000000000000000 ffff880221721d48 ffffffff810ac8fe 0000000000000000 ffff880221734000 Call Trace: [<ffffffff810ac5c5>] __queue_work+0x45/0x2d0 [<ffffffff810ac8fe>] queue_work_on+0x8e/0xa0 [<ffffffff810ac949>] queue_work+0x19/0x20 [<ffffffff81009b6b>] irqfd_deactivate+0x4b/0x60 [<ffffffff8100a69d>] kvm_irqfd+0x39d/0x580 [<ffffffff81007a27>] kvm_vm_ioctl+0x207/0x5b0 [<ffffffff810c9545>] ? update_curr+0xf5/0x180 [<ffffffff811b66e8>] do_vfs_ioctl+0x98/0x550 [<ffffffff810c1f5e>] ? finish_task_switch+0x4e/0xe0 [<ffffffff81c054aa>] ? __schedule+0x2ea/0x710 [<ffffffff811b6bf7>] sys_ioctl+0x57/0x90 [<ffffffff8140ae9e>] ? trace_hardirqs_on_thunk+0x3a/0x3c [<ffffffff81c0f602>] system_call_fastpath+0x16/0x1b Code: c1 ea 08 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f b6 03 38 c2 75 f7 48 83 c4 08 5b c9 c3 55 48 89 e5 66 66 66 66 90 b8 00 01 00 00 <f0> 66 0f c1 07 89 c2 66 c1 ea 08 38 c2 74 0c 0f 1f 00 f3 90 0f RIP [<ffffffff81c0721e>] _raw_spin_lock+0xe/0x30 RSP <ffff880221721cc8> CR2: 0000000000000000 ---[ end trace 13fb1e4b6e5ab21f ]--- Signed-off-by: Asias He <asias@redhat.com> Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-05-08 10:57:29 +08:00
kvm_arch_exit();
out_fail:
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
return r;
}
EXPORT_SYMBOL_GPL(kvm_init);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
void kvm_exit(void)
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
{
debugfs_remove_recursive(kvm_debugfs_dir);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
misc_deregister(&kvm_dev);
kmem_cache_destroy(kvm_vcpu_cache);
kvm_async_pf_deinit();
unregister_syscore_ops(&kvm_syscore_ops);
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
unregister_reboot_notifier(&kvm_reboot_notifier);
cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
on_each_cpu(hardware_disable_nolock, NULL, 1);
kvm_arch_hardware_unsetup();
kvm_arch_exit();
kvm_irqfd_exit();
free_cpumask_var(cpus_hardware_enabled);
kvm: vfio: fix unregister kvm_device_ops of vfio After commit 80ce163 (KVM: VFIO: register kvm_device_ops dynamically), kvm_device_ops of vfio can be registered dynamically. Commit 3c3c29fd (kvm-vfio: do not use module_init) move the dynamic register invoked by kvm_init in order to fix broke unloading of the kvm module. However, kvm_device_ops of vfio is unregistered after rmmod kvm-intel module which lead to device type collision detection warning after kvm-intel module reinsmod. WARNING: CPU: 1 PID: 10358 at /root/cathy/kvm/arch/x86/kvm/../../../virt/kvm/kvm_main.c:3289 kvm_init+0x234/0x282 [kvm]() Modules linked in: kvm_intel(O+) kvm(O) nfsv3 nfs_acl auth_rpcgss oid_registry nfsv4 dns_resolver nfs fscache lockd sunrpc pci_stub bridge stp llc autofs4 8021q cpufreq_ondemand ipv6 joydev microcode pcspkr igb i2c_algo_bit ehci_pci ehci_hcd e1000e i2c_i801 ixgbe ptp pps_core hwmon mdio tpm_tis tpm ipmi_si ipmi_msghandler acpi_cpufreq isci libsas scsi_transport_sas button dm_mirror dm_region_hash dm_log dm_mod [last unloaded: kvm_intel] CPU: 1 PID: 10358 Comm: insmod Tainted: G W O 3.17.0-rc1 #2 Hardware name: Intel Corporation S2600CP/S2600CP, BIOS RMLSDP.86I.00.29.D696.1311111329 11/11/2013 0000000000000cd9 ffff880ff08cfd18 ffffffff814a61d9 0000000000000cd9 0000000000000000 ffff880ff08cfd58 ffffffff810417b7 ffff880ff08cfd48 ffffffffa045bcac ffffffffa049c420 0000000000000040 00000000000000ff Call Trace: [<ffffffff814a61d9>] dump_stack+0x49/0x60 [<ffffffff810417b7>] warn_slowpath_common+0x7c/0x96 [<ffffffffa045bcac>] ? kvm_init+0x234/0x282 [kvm] [<ffffffff810417e6>] warn_slowpath_null+0x15/0x17 [<ffffffffa045bcac>] kvm_init+0x234/0x282 [kvm] [<ffffffffa016e995>] vmx_init+0x1bf/0x42a [kvm_intel] [<ffffffffa016e7d6>] ? vmx_check_processor_compat+0x64/0x64 [kvm_intel] [<ffffffff810002ab>] do_one_initcall+0xe3/0x170 [<ffffffff811168a9>] ? __vunmap+0xad/0xb8 [<ffffffff8109c58f>] do_init_module+0x2b/0x174 [<ffffffff8109d414>] load_module+0x43e/0x569 [<ffffffff8109c6d8>] ? do_init_module+0x174/0x174 [<ffffffff8109c75a>] ? copy_module_from_user+0x39/0x82 [<ffffffff8109b7dd>] ? module_sect_show+0x20/0x20 [<ffffffff8109d65f>] SyS_init_module+0x54/0x81 [<ffffffff814a9a12>] system_call_fastpath+0x16/0x1b ---[ end trace 0626f4a3ddea56f3 ]--- The bug can be reproduced by: rmmod kvm_intel.ko insmod kvm_intel.ko without rmmod/insmod kvm.ko This patch fixes the bug by unregistering kvm_device_ops of vfio when the kvm-intel module is removed. Reported-by: Liu Rongrong <rongrongx.liu@intel.com> Fixes: 3c3c29fd0d7cddc32862c350d0700ce69953e3bd Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-10-09 18:30:08 +08:00
kvm_vfio_ops_exit();
[PATCH] kvm: userspace interface web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 18:21:36 +08:00
}
EXPORT_SYMBOL_GPL(kvm_exit);
struct kvm_vm_worker_thread_context {
struct kvm *kvm;
struct task_struct *parent;
struct completion init_done;
kvm_vm_thread_fn_t thread_fn;
uintptr_t data;
int err;
};
static int kvm_vm_worker_thread(void *context)
{
/*
* The init_context is allocated on the stack of the parent thread, so
* we have to locally copy anything that is needed beyond initialization
*/
struct kvm_vm_worker_thread_context *init_context = context;
struct kvm *kvm = init_context->kvm;
kvm_vm_thread_fn_t thread_fn = init_context->thread_fn;
uintptr_t data = init_context->data;
int err;
err = kthread_park(current);
/* kthread_park(current) is never supposed to return an error */
WARN_ON(err != 0);
if (err)
goto init_complete;
err = cgroup_attach_task_all(init_context->parent, current);
if (err) {
kvm_err("%s: cgroup_attach_task_all failed with err %d\n",
__func__, err);
goto init_complete;
}
set_user_nice(current, task_nice(init_context->parent));
init_complete:
init_context->err = err;
complete(&init_context->init_done);
init_context = NULL;
if (err)
return err;
/* Wait to be woken up by the spawner before proceeding. */
kthread_parkme();
if (!kthread_should_stop())
err = thread_fn(kvm, data);
return err;
}
int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn,
uintptr_t data, const char *name,
struct task_struct **thread_ptr)
{
struct kvm_vm_worker_thread_context init_context = {};
struct task_struct *thread;
*thread_ptr = NULL;
init_context.kvm = kvm;
init_context.parent = current;
init_context.thread_fn = thread_fn;
init_context.data = data;
init_completion(&init_context.init_done);
thread = kthread_run(kvm_vm_worker_thread, &init_context,
"%s-%d", name, task_pid_nr(current));
if (IS_ERR(thread))
return PTR_ERR(thread);
/* kthread_run is never supposed to return NULL */
WARN_ON(thread == NULL);
wait_for_completion(&init_context.init_done);
if (!init_context.err)
*thread_ptr = thread;
return init_context.err;
}