OpenCloudOS-Kernel/include/linux/kvm_host.h

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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __KVM_HOST_H
#define __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/types.h>
#include <linux/hardirq.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/list.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/sched/stat.h>
#include <linux/bug.h>
#include <linux/minmax.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/mm.h>
#include <linux/mmu_notifier.h>
#include <linux/preempt.h>
#include <linux/msi.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/rcupdate.h>
#include <linux/ratelimit.h>
#include <linux/err.h>
#include <linux/irqflags.h>
#include <linux/context_tracking.h>
#include <linux/irqbypass.h>
#include <linux/rcuwait.h>
#include <linux/refcount.h>
#include <linux/nospec.h>
#include <linux/notifier.h>
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
#include <linux/ftrace.h>
#include <linux/hashtable.h>
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
#include <linux/instrumentation.h>
#include <linux/interval_tree.h>
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
#include <linux/rbtree.h>
#include <linux/xarray.h>
#include <asm/signal.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/kvm_para.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_types.h>
#include <asm/kvm_host.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>
#ifndef KVM_MAX_VCPU_IDS
#define KVM_MAX_VCPU_IDS KVM_MAX_VCPUS
#endif
/*
* The bit 16 ~ bit 31 of kvm_memory_region::flags are internally used
* in kvm, other bits are visible for userspace which are defined in
* include/linux/kvm_h.
*/
#define KVM_MEMSLOT_INVALID (1UL << 16)
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
/*
* Bit 63 of the memslot generation number is an "update in-progress flag",
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
* e.g. is temporarily set for the duration of install_new_memslots().
* This flag effectively creates a unique generation number that is used to
* mark cached memslot data, e.g. MMIO accesses, as potentially being stale,
* i.e. may (or may not) have come from the previous memslots generation.
*
* This is necessary because the actual memslots update is not atomic with
* respect to the generation number update. Updating the generation number
* first would allow a vCPU to cache a spte from the old memslots using the
* new generation number, and updating the generation number after switching
* to the new memslots would allow cache hits using the old generation number
* to reference the defunct memslots.
*
* This mechanism is used to prevent getting hits in KVM's caches while a
* memslot update is in-progress, and to prevent cache hits *after* updating
* the actual generation number against accesses that were inserted into the
* cache *before* the memslots were updated.
*/
#define KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS BIT_ULL(63)
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
/* Two fragments for cross MMIO pages. */
#define KVM_MAX_MMIO_FRAGMENTS 2
#ifndef KVM_ADDRESS_SPACE_NUM
#define KVM_ADDRESS_SPACE_NUM 1
#endif
/*
* For the normal pfn, the highest 12 bits should be zero,
* so we can mask bit 62 ~ bit 52 to indicate the error pfn,
* mask bit 63 to indicate the noslot pfn.
*/
#define KVM_PFN_ERR_MASK (0x7ffULL << 52)
#define KVM_PFN_ERR_NOSLOT_MASK (0xfffULL << 52)
#define KVM_PFN_NOSLOT (0x1ULL << 63)
#define KVM_PFN_ERR_FAULT (KVM_PFN_ERR_MASK)
#define KVM_PFN_ERR_HWPOISON (KVM_PFN_ERR_MASK + 1)
#define KVM_PFN_ERR_RO_FAULT (KVM_PFN_ERR_MASK + 2)
/*
* error pfns indicate that the gfn is in slot but faild to
* translate it to pfn on host.
*/
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 inline bool is_error_pfn(kvm_pfn_t pfn)
{
return !!(pfn & KVM_PFN_ERR_MASK);
}
/*
* error_noslot pfns indicate that the gfn can not be
* translated to pfn - it is not in slot or failed to
* translate it 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
static inline bool is_error_noslot_pfn(kvm_pfn_t pfn)
{
return !!(pfn & KVM_PFN_ERR_NOSLOT_MASK);
}
/* noslot pfn indicates that the gfn is not in slot. */
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 inline bool is_noslot_pfn(kvm_pfn_t pfn)
{
return pfn == KVM_PFN_NOSLOT;
}
/*
* architectures with KVM_HVA_ERR_BAD other than PAGE_OFFSET (e.g. s390)
* provide own defines and kvm_is_error_hva
*/
#ifndef KVM_HVA_ERR_BAD
#define KVM_HVA_ERR_BAD (PAGE_OFFSET)
#define KVM_HVA_ERR_RO_BAD (PAGE_OFFSET + PAGE_SIZE)
static inline bool kvm_is_error_hva(unsigned long addr)
{
return addr >= PAGE_OFFSET;
}
#endif
#define KVM_ERR_PTR_BAD_PAGE (ERR_PTR(-ENOENT))
static inline bool is_error_page(struct page *page)
{
return IS_ERR(page);
}
#define KVM_REQUEST_MASK GENMASK(7,0)
#define KVM_REQUEST_NO_WAKEUP BIT(8)
#define KVM_REQUEST_WAIT BIT(9)
KVM: Don't actually set a request when evicting vCPUs for GFN cache invd Don't actually set a request bit in vcpu->requests when making a request purely to force a vCPU to exit the guest. Logging a request but not actually consuming it would cause the vCPU to get stuck in an infinite loop during KVM_RUN because KVM would see the pending request and bail from VM-Enter to service the request. Note, it's currently impossible for KVM to set KVM_REQ_GPC_INVALIDATE as nothing in KVM is wired up to set guest_uses_pa=true. But, it'd be all too easy for arch code to introduce use of kvm_gfn_to_pfn_cache_init() without implementing handling of the request, especially since getting test coverage of MMU notifier interaction with specific KVM features usually requires a directed test. Opportunistically rename gfn_to_pfn_cache_invalidate_start()'s wake_vcpus to evict_vcpus. The purpose of the request is to get vCPUs out of guest mode, it's supposed to _avoid_ waking vCPUs that are blocking. Opportunistically rename KVM_REQ_GPC_INVALIDATE to be more specific as to what it wants to accomplish, and to genericize the name so that it can used for similar but unrelated scenarios, should they arise in the future. Add a comment and documentation to explain why the "no action" request exists. Add compile-time assertions to help detect improper usage. Use the inner assertless helper in the one s390 path that makes requests without a hardcoded request. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220223165302.3205276-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-24 00:53:02 +08:00
#define KVM_REQUEST_NO_ACTION BIT(10)
/*
* Architecture-independent vcpu->requests bit members
* Bits 3-7 are reserved for more arch-independent bits.
*/
#define KVM_REQ_TLB_FLUSH (0 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_VM_DEAD (1 | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_REQ_UNBLOCK 2
#define KVM_REQUEST_ARCH_BASE 8
KVM: Don't actually set a request when evicting vCPUs for GFN cache invd Don't actually set a request bit in vcpu->requests when making a request purely to force a vCPU to exit the guest. Logging a request but not actually consuming it would cause the vCPU to get stuck in an infinite loop during KVM_RUN because KVM would see the pending request and bail from VM-Enter to service the request. Note, it's currently impossible for KVM to set KVM_REQ_GPC_INVALIDATE as nothing in KVM is wired up to set guest_uses_pa=true. But, it'd be all too easy for arch code to introduce use of kvm_gfn_to_pfn_cache_init() without implementing handling of the request, especially since getting test coverage of MMU notifier interaction with specific KVM features usually requires a directed test. Opportunistically rename gfn_to_pfn_cache_invalidate_start()'s wake_vcpus to evict_vcpus. The purpose of the request is to get vCPUs out of guest mode, it's supposed to _avoid_ waking vCPUs that are blocking. Opportunistically rename KVM_REQ_GPC_INVALIDATE to be more specific as to what it wants to accomplish, and to genericize the name so that it can used for similar but unrelated scenarios, should they arise in the future. Add a comment and documentation to explain why the "no action" request exists. Add compile-time assertions to help detect improper usage. Use the inner assertless helper in the one s390 path that makes requests without a hardcoded request. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220223165302.3205276-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-24 00:53:02 +08:00
/*
* KVM_REQ_OUTSIDE_GUEST_MODE exists is purely as way to force the vCPU to
* OUTSIDE_GUEST_MODE. KVM_REQ_OUTSIDE_GUEST_MODE differs from a vCPU "kick"
* in that it ensures the vCPU has reached OUTSIDE_GUEST_MODE before continuing
* on. A kick only guarantees that the vCPU is on its way out, e.g. a previous
* kick may have set vcpu->mode to EXITING_GUEST_MODE, and so there's no
* guarantee the vCPU received an IPI and has actually exited guest mode.
*/
#define KVM_REQ_OUTSIDE_GUEST_MODE (KVM_REQUEST_NO_ACTION | KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP)
#define KVM_ARCH_REQ_FLAGS(nr, flags) ({ \
BUILD_BUG_ON((unsigned)(nr) >= (sizeof_field(struct kvm_vcpu, requests) * 8) - KVM_REQUEST_ARCH_BASE); \
(unsigned)(((nr) + KVM_REQUEST_ARCH_BASE) | (flags)); \
})
#define KVM_ARCH_REQ(nr) KVM_ARCH_REQ_FLAGS(nr, 0)
bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req,
unsigned long *vcpu_bitmap);
bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req);
bool kvm_make_all_cpus_request_except(struct kvm *kvm, unsigned int req,
struct kvm_vcpu *except);
bool kvm_make_cpus_request_mask(struct kvm *kvm, unsigned int req,
unsigned long *vcpu_bitmap);
#define KVM_USERSPACE_IRQ_SOURCE_ID 0
#define KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1
extern struct mutex kvm_lock;
extern struct list_head vm_list;
struct kvm_io_range {
gpa_t addr;
int len;
struct kvm_io_device *dev;
};
#define NR_IOBUS_DEVS 1000
struct kvm_io_bus {
int dev_count;
int ioeventfd_count;
struct kvm_io_range range[];
};
enum kvm_bus {
KVM_MMIO_BUS,
KVM_PIO_BUS,
KVM_VIRTIO_CCW_NOTIFY_BUS,
KVM_FAST_MMIO_BUS,
KVM_NR_BUSES
};
int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
int len, const void *val);
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);
int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr,
int len, void *val);
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 kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
struct kvm_io_device *dev);
struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx,
gpa_t addr);
#ifdef CONFIG_KVM_ASYNC_PF
struct kvm_async_pf {
struct work_struct work;
struct list_head link;
struct list_head queue;
struct kvm_vcpu *vcpu;
struct mm_struct *mm;
KVM: x86: Use gpa_t for cr2/gpa to fix TDP support on 32-bit KVM Convert a plethora of parameters and variables in the MMU and page fault flows from type gva_t to gpa_t to properly handle TDP on 32-bit KVM. Thanks to PSE and PAE paging, 32-bit kernels can access 64-bit physical addresses. When TDP is enabled, the fault address is a guest physical address and thus can be a 64-bit value, even when both KVM and its guest are using 32-bit virtual addressing, e.g. VMX's VMCS.GUEST_PHYSICAL is a 64-bit field, not a natural width field. Using a gva_t for the fault address means KVM will incorrectly drop the upper 32-bits of the GPA. Ditto for gva_to_gpa() when it is used to translate L2 GPAs to L1 GPAs. Opportunistically rename variables and parameters to better reflect the dual address modes, e.g. use "cr2_or_gpa" for fault addresses and plain "addr" instead of "vaddr" when the address may be either a GVA or an L2 GPA. Similarly, use "gpa" in the nonpaging_page_fault() flows to avoid a confusing "gpa_t gva" declaration; this also sets the stage for a future patch to combing nonpaging_page_fault() and tdp_page_fault() with minimal churn. Sprinkle in a few comments to document flows where an address is known to be a GVA and thus can be safely truncated to a 32-bit value. Add WARNs in kvm_handle_page_fault() and FNAME(gva_to_gpa_nested)() to help document such cases and detect bugs. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-07 07:57:14 +08:00
gpa_t cr2_or_gpa;
unsigned long addr;
struct kvm_arch_async_pf arch;
bool wakeup_all;
bool notpresent_injected;
};
void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
bool kvm_setup_async_pf(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
unsigned long hva, struct kvm_arch_async_pf *arch);
int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu);
#endif
#ifdef KVM_ARCH_WANT_MMU_NOTIFIER
struct kvm_gfn_range {
struct kvm_memory_slot *slot;
gfn_t start;
gfn_t end;
pte_t pte;
bool may_block;
};
bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range);
#endif
enum {
OUTSIDE_GUEST_MODE,
IN_GUEST_MODE,
EXITING_GUEST_MODE,
READING_SHADOW_PAGE_TABLES,
};
#define KVM_UNMAPPED_PAGE ((void *) 0x500 + POISON_POINTER_DELTA)
struct kvm_host_map {
/*
* Only valid if the 'pfn' is managed by the host kernel (i.e. There is
* a 'struct page' for it. When using mem= kernel parameter some memory
* can be used as guest memory but they are not managed by host
* kernel).
* If 'pfn' is not managed by the host kernel, this field is
* initialized to KVM_UNMAPPED_PAGE.
*/
struct page *page;
void *hva;
kvm_pfn_t pfn;
kvm_pfn_t gfn;
};
/*
* Used to check if the mapping is valid or not. Never use 'kvm_host_map'
* directly to check for that.
*/
static inline bool kvm_vcpu_mapped(struct kvm_host_map *map)
{
return !!map->hva;
}
static inline bool kvm_vcpu_can_poll(ktime_t cur, ktime_t stop)
{
return single_task_running() && !need_resched() && ktime_before(cur, stop);
}
/*
* Sometimes a large or cross-page mmio needs to be broken up into separate
* exits for userspace servicing.
*/
struct kvm_mmio_fragment {
gpa_t gpa;
void *data;
unsigned len;
};
struct kvm_vcpu {
struct kvm *kvm;
#ifdef CONFIG_PREEMPT_NOTIFIERS
struct preempt_notifier preempt_notifier;
#endif
int cpu;
int vcpu_id; /* id given by userspace at creation */
int vcpu_idx; /* index in kvm->vcpus array */
int ____srcu_idx; /* Don't use this directly. You've been warned. */
#ifdef CONFIG_PROVE_RCU
int srcu_depth;
#endif
int mode;
u64 requests;
unsigned long guest_debug;
struct mutex mutex;
struct kvm_run *run;
#ifndef __KVM_HAVE_ARCH_WQP
struct rcuwait wait;
#endif
struct pid __rcu *pid;
int sigset_active;
sigset_t sigset;
unsigned int halt_poll_ns;
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
bool valid_wakeup;
#ifdef CONFIG_HAS_IOMEM
int mmio_needed;
int mmio_read_completed;
int mmio_is_write;
int mmio_cur_fragment;
int mmio_nr_fragments;
struct kvm_mmio_fragment mmio_fragments[KVM_MAX_MMIO_FRAGMENTS];
#endif
#ifdef CONFIG_KVM_ASYNC_PF
struct {
u32 queued;
struct list_head queue;
struct list_head done;
spinlock_t lock;
} async_pf;
#endif
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
/*
* Cpu relax intercept or pause loop exit optimization
* in_spin_loop: set when a vcpu does a pause loop exit
* or cpu relax intercepted.
* dy_eligible: indicates whether vcpu is eligible for directed yield.
*/
struct {
bool in_spin_loop;
bool dy_eligible;
} spin_loop;
#endif
bool preempted;
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
bool ready;
struct kvm_vcpu_arch arch;
struct kvm_vcpu_stat stat;
char stats_id[KVM_STATS_NAME_SIZE];
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_dirty_ring dirty_ring;
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
/*
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
* The most recently used memslot by this vCPU and the slots generation
* for which it is valid.
* No wraparound protection is needed since generations won't overflow in
* thousands of years, even assuming 1M memslot operations per second.
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
*/
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
struct kvm_memory_slot *last_used_slot;
u64 last_used_slot_gen;
};
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
/*
* Start accounting time towards a guest.
* Must be called before entering guest context.
*/
static __always_inline void guest_timing_enter_irqoff(void)
{
/*
* This is running in ioctl context so its safe to assume that it's the
* stime pending cputime to flush.
*/
instrumentation_begin();
vtime_account_guest_enter();
instrumentation_end();
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
}
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
/*
* Enter guest context and enter an RCU extended quiescent state.
*
* Between guest_context_enter_irqoff() and guest_context_exit_irqoff() it is
* unsafe to use any code which may directly or indirectly use RCU, tracing
* (including IRQ flag tracing), or lockdep. All code in this period must be
* non-instrumentable.
*/
static __always_inline void guest_context_enter_irqoff(void)
{
/*
* KVM does not hold any references to rcu protected data when it
* switches CPU into a guest mode. In fact switching to a guest mode
* is very similar to exiting to userspace from rcu point of view. In
* addition CPU may stay in a guest mode for quite a long time (up to
* one time slice). Lets treat guest mode as quiescent state, just like
* we do with user-mode execution.
*/
if (!context_tracking_guest_enter()) {
instrumentation_begin();
rcu_virt_note_context_switch(smp_processor_id());
instrumentation_end();
}
}
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
/*
* Deprecated. Architectures should move to guest_timing_enter_irqoff() and
* guest_state_enter_irqoff().
*/
static __always_inline void guest_enter_irqoff(void)
{
guest_timing_enter_irqoff();
guest_context_enter_irqoff();
}
/**
* guest_state_enter_irqoff - Fixup state when entering a guest
*
* Entry to a guest will enable interrupts, but the kernel state is interrupts
* disabled when this is invoked. Also tell RCU about it.
*
* 1) Trace interrupts on state
* 2) Invoke context tracking if enabled to adjust RCU state
* 3) Tell lockdep that interrupts are enabled
*
* Invoked from architecture specific code before entering a guest.
* Must be called with interrupts disabled and the caller must be
* non-instrumentable.
* The caller has to invoke guest_timing_enter_irqoff() before this.
*
* Note: this is analogous to exit_to_user_mode().
*/
static __always_inline void guest_state_enter_irqoff(void)
{
instrumentation_begin();
trace_hardirqs_on_prepare();
lockdep_hardirqs_on_prepare();
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
instrumentation_end();
guest_context_enter_irqoff();
lockdep_hardirqs_on(CALLER_ADDR0);
}
/*
* Exit guest context and exit an RCU extended quiescent state.
*
* Between guest_context_enter_irqoff() and guest_context_exit_irqoff() it is
* unsafe to use any code which may directly or indirectly use RCU, tracing
* (including IRQ flag tracing), or lockdep. All code in this period must be
* non-instrumentable.
*/
static __always_inline void guest_context_exit_irqoff(void)
{
context_tracking_guest_exit();
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
}
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
/*
* Stop accounting time towards a guest.
* Must be called after exiting guest context.
*/
static __always_inline void guest_timing_exit_irqoff(void)
{
instrumentation_begin();
/* Flush the guest cputime we spent on the guest */
vtime_account_guest_exit();
instrumentation_end();
}
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
/*
* Deprecated. Architectures should move to guest_state_exit_irqoff() and
* guest_timing_exit_irqoff().
*/
static __always_inline void guest_exit_irqoff(void)
{
guest_context_exit_irqoff();
guest_timing_exit_irqoff();
}
static inline void guest_exit(void)
{
unsigned long flags;
local_irq_save(flags);
guest_exit_irqoff();
local_irq_restore(flags);
}
kvm: add guest_state_{enter,exit}_irqoff() When transitioning to/from guest mode, it is necessary to inform lockdep, tracing, and RCU in a specific order, similar to the requirements for transitions to/from user mode. Additionally, it is necessary to perform vtime accounting for a window around running the guest, with RCU enabled, such that timer interrupts taken from the guest can be accounted as guest time. Most architectures don't handle all the necessary pieces, and a have a number of common bugs, including unsafe usage of RCU during the window between guest_enter() and guest_exit(). On x86, this was dealt with across commits: 87fa7f3e98a1310e ("x86/kvm: Move context tracking where it belongs") 0642391e2139a2c1 ("x86/kvm/vmx: Add hardirq tracing to guest enter/exit") 9fc975e9efd03e57 ("x86/kvm/svm: Add hardirq tracing on guest enter/exit") 3ebccdf373c21d86 ("x86/kvm/vmx: Move guest enter/exit into .noinstr.text") 135961e0a7d555fc ("x86/kvm/svm: Move guest enter/exit into .noinstr.text") 160457140187c5fb ("KVM: x86: Defer vtime accounting 'til after IRQ handling") bc908e091b326467 ("KVM: x86: Consolidate guest enter/exit logic to common helpers") ... but those fixes are specific to x86, and as the resulting logic (while correct) is split across generic helper functions and x86-specific helper functions, it is difficult to see that the entry/exit accounting is balanced. This patch adds generic helpers which architectures can use to handle guest entry/exit consistently and correctly. The guest_{enter,exit}() helpers are split into guest_timing_{enter,exit}() to perform vtime accounting, and guest_context_{enter,exit}() to perform the necessary context tracking and RCU management. The existing guest_{enter,exit}() heleprs are left as wrappers of these. Atop this, new guest_state_enter_irqoff() and guest_state_exit_irqoff() helpers are added to handle the ordering of lockdep, tracing, and RCU manageent. These are inteneded to mirror exit_to_user_mode() and enter_from_user_mode(). Subsequent patches will migrate architectures over to the new helpers, following a sequence: guest_timing_enter_irqoff(); guest_state_enter_irqoff(); < run the vcpu > guest_state_exit_irqoff(); < take any pending IRQs > guest_timing_exit_irqoff(); This sequences handles all of the above correctly, and more clearly balances the entry and exit portions, making it easier to understand. The existing helpers are marked as deprecated, and will be removed once all architectures have been converted. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Message-Id: <20220201132926.3301912-2-mark.rutland@arm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-01 21:29:22 +08:00
/**
* guest_state_exit_irqoff - Establish state when returning from guest mode
*
* Entry from a guest disables interrupts, but guest mode is traced as
* interrupts enabled. Also with NO_HZ_FULL RCU might be idle.
*
* 1) Tell lockdep that interrupts are disabled
* 2) Invoke context tracking if enabled to reactivate RCU
* 3) Trace interrupts off state
*
* Invoked from architecture specific code after exiting a guest.
* Must be invoked with interrupts disabled and the caller must be
* non-instrumentable.
* The caller has to invoke guest_timing_exit_irqoff() after this.
*
* Note: this is analogous to enter_from_user_mode().
*/
static __always_inline void guest_state_exit_irqoff(void)
{
lockdep_hardirqs_off(CALLER_ADDR0);
guest_context_exit_irqoff();
instrumentation_begin();
trace_hardirqs_off_finish();
instrumentation_end();
}
static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
{
/*
* The memory barrier ensures a previous write to vcpu->requests cannot
* be reordered with the read of vcpu->mode. It pairs with the general
* memory barrier following the write of vcpu->mode in VCPU RUN.
*/
smp_mb__before_atomic();
return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
}
/*
* Some of the bitops functions do not support too long bitmaps.
* This number must be determined not to exceed such limits.
*/
#define KVM_MEM_MAX_NR_PAGES ((1UL << 31) - 1)
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
/*
* Since at idle each memslot belongs to two memslot sets it has to contain
* two embedded nodes for each data structure that it forms a part of.
*
* Two memslot sets (one active and one inactive) are necessary so the VM
* continues to run on one memslot set while the other is being modified.
*
* These two memslot sets normally point to the same set of memslots.
* They can, however, be desynchronized when performing a memslot management
* operation by replacing the memslot to be modified by its copy.
* After the operation is complete, both memslot sets once again point to
* the same, common set of memslot data.
*
* The memslots themselves are independent of each other so they can be
* individually added or deleted.
*/
[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: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
struct hlist_node id_node[2];
struct interval_tree_node hva_node[2];
struct rb_node gfn_node[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
gfn_t base_gfn;
unsigned long npages;
unsigned long *dirty_bitmap;
struct kvm_arch_memory_slot arch;
unsigned long userspace_addr;
u32 flags;
short id;
u16 as_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
};
static inline bool kvm_slot_dirty_track_enabled(const struct kvm_memory_slot *slot)
{
return slot->flags & KVM_MEM_LOG_DIRTY_PAGES;
}
static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
{
return ALIGN(memslot->npages, BITS_PER_LONG) / 8;
}
static inline unsigned long *kvm_second_dirty_bitmap(struct kvm_memory_slot *memslot)
{
unsigned long len = kvm_dirty_bitmap_bytes(memslot);
return memslot->dirty_bitmap + len / sizeof(*memslot->dirty_bitmap);
}
#ifndef KVM_DIRTY_LOG_MANUAL_CAPS
#define KVM_DIRTY_LOG_MANUAL_CAPS KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE
#endif
struct kvm_s390_adapter_int {
u64 ind_addr;
u64 summary_addr;
u64 ind_offset;
u32 summary_offset;
u32 adapter_id;
};
kvm/x86: Hyper-V synthetic interrupt controller SynIC (synthetic interrupt controller) is a lapic extension, which is controlled via MSRs and maintains for each vCPU - 16 synthetic interrupt "lines" (SINT's); each can be configured to trigger a specific interrupt vector optionally with auto-EOI semantics - a message page in the guest memory with 16 256-byte per-SINT message slots - an event flag page in the guest memory with 16 2048-bit per-SINT event flag areas The host triggers a SINT whenever it delivers a new message to the corresponding slot or flips an event flag bit in the corresponding area. The guest informs the host that it can try delivering a message by explicitly asserting EOI in lapic or writing to End-Of-Message (EOM) MSR. The userspace (qemu) triggers interrupts and receives EOM notifications via irqfd with resampler; for that, a GSI is allocated for each configured SINT, and irq_routing api is extended to support GSI-SINT mapping. Changes v4: * added activation of SynIC by vcpu KVM_ENABLE_CAP * added per SynIC active flag * added deactivation of APICv upon SynIC activation Changes v3: * added KVM_CAP_HYPERV_SYNIC and KVM_IRQ_ROUTING_HV_SINT notes into docs Changes v2: * do not use posted interrupts for Hyper-V SynIC AutoEOI vectors * add Hyper-V SynIC vectors into EOI exit bitmap * Hyper-V SyniIC SINT msr write logic simplified Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-10 20:36:34 +08:00
struct kvm_hv_sint {
u32 vcpu;
u32 sint;
};
struct kvm_xen_evtchn {
u32 port;
u32 vcpu_id;
int vcpu_idx;
u32 priority;
};
struct kvm_kernel_irq_routing_entry {
u32 gsi;
u32 type;
int (*set)(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id, int level,
bool line_status);
union {
struct {
unsigned irqchip;
unsigned pin;
} irqchip;
struct {
u32 address_lo;
u32 address_hi;
u32 data;
u32 flags;
u32 devid;
} msi;
struct kvm_s390_adapter_int adapter;
kvm/x86: Hyper-V synthetic interrupt controller SynIC (synthetic interrupt controller) is a lapic extension, which is controlled via MSRs and maintains for each vCPU - 16 synthetic interrupt "lines" (SINT's); each can be configured to trigger a specific interrupt vector optionally with auto-EOI semantics - a message page in the guest memory with 16 256-byte per-SINT message slots - an event flag page in the guest memory with 16 2048-bit per-SINT event flag areas The host triggers a SINT whenever it delivers a new message to the corresponding slot or flips an event flag bit in the corresponding area. The guest informs the host that it can try delivering a message by explicitly asserting EOI in lapic or writing to End-Of-Message (EOM) MSR. The userspace (qemu) triggers interrupts and receives EOM notifications via irqfd with resampler; for that, a GSI is allocated for each configured SINT, and irq_routing api is extended to support GSI-SINT mapping. Changes v4: * added activation of SynIC by vcpu KVM_ENABLE_CAP * added per SynIC active flag * added deactivation of APICv upon SynIC activation Changes v3: * added KVM_CAP_HYPERV_SYNIC and KVM_IRQ_ROUTING_HV_SINT notes into docs Changes v2: * do not use posted interrupts for Hyper-V SynIC AutoEOI vectors * add Hyper-V SynIC vectors into EOI exit bitmap * Hyper-V SyniIC SINT msr write logic simplified Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com> Reviewed-by: Roman Kagan <rkagan@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> CC: Gleb Natapov <gleb@kernel.org> CC: Paolo Bonzini <pbonzini@redhat.com> CC: Roman Kagan <rkagan@virtuozzo.com> CC: Denis V. Lunev <den@openvz.org> CC: qemu-devel@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-10 20:36:34 +08:00
struct kvm_hv_sint hv_sint;
struct kvm_xen_evtchn xen_evtchn;
};
struct hlist_node link;
};
#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
struct kvm_irq_routing_table {
int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];
u32 nr_rt_entries;
/*
* Array indexed by gsi. Each entry contains list of irq chips
* the gsi is connected to.
*/
struct hlist_head map[];
};
#endif
#ifndef KVM_INTERNAL_MEM_SLOTS
#define KVM_INTERNAL_MEM_SLOTS 0
#endif
#define KVM_MEM_SLOTS_NUM SHRT_MAX
#define KVM_USER_MEM_SLOTS (KVM_MEM_SLOTS_NUM - KVM_INTERNAL_MEM_SLOTS)
#ifndef __KVM_VCPU_MULTIPLE_ADDRESS_SPACE
static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu)
{
return 0;
}
#endif
struct kvm_memslots {
u64 generation;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
atomic_long_t last_used_slot;
struct rb_root_cached hva_tree;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
struct rb_root gfn_tree;
/*
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
* The mapping table from slot id to memslot.
*
* 7-bit bucket count matches the size of the old id to index array for
* 512 slots, while giving good performance with this slot count.
* Higher bucket counts bring only small performance improvements but
* always result in higher memory usage (even for lower memslot counts).
*/
DECLARE_HASHTABLE(id_hash, 7);
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
int node_idx;
};
[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 {
#ifdef KVM_HAVE_MMU_RWLOCK
rwlock_t mmu_lock;
#else
spinlock_t mmu_lock;
#endif /* KVM_HAVE_MMU_RWLOCK */
struct mutex slots_lock;
/*
* Protects the arch-specific fields of struct kvm_memory_slots in
* use by the VM. To be used under the slots_lock (above) or in a
* kvm->srcu critical section where acquiring the slots_lock would
* lead to deadlock with the synchronize_srcu in
* install_new_memslots.
*/
struct mutex slots_arch_lock;
struct mm_struct *mm; /* userspace tied to this vm */
KVM: Require total number of memslot pages to fit in an unsigned long Explicitly disallow creating more memslot pages than can fit in an unsigned long, KVM doesn't correctly handle a total number of memslot pages that doesn't fit in an unsigned long and remedying that would be a waste of time. For a 64-bit kernel, this is a nop as memslots are not allowed to overlap in the gfn address space. With a 32-bit kernel, userspace can at most address 3gb of virtual memory, whereas wrapping the total number of pages would require 4tb+ of guest physical memory. Even with x86's second address space for SMM, userspace would need to alias all of guest memory more than one _thousand_ times. And on older x86 hardware with MAXPHYADDR < 43, the guest couldn't actually access any of those aliases even if userspace lied about guest.MAXPHYADDR. On 390 and arm64, this is a nop as they don't support 32-bit hosts. On x86, practically speaking this is simply acknowledging reality as the existing kvm_mmu_calculate_default_mmu_pages() assumes the total number of pages fits in an "unsigned long". On PPC, this is likely a nop as every flavor of PPC KVM assumes gfns (and gpas!) fit in unsigned long. arch/powerpc/kvm/book3s_32_mmu_host.c goes a step further and fails the build if CONFIG_PTE_64BIT=y, which presumably means that it does't support 64-bit physical addresses. On MIPS, this is also likely a nop as the core MMU helpers assume gpas fit in unsigned long, e.g. see kvm_mips_##name##_pte. And finally, RISC-V is a "don't care" as it doesn't exist in any release, i.e. there is no established ABI to break. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <1c2c91baf8e78acccd4dad38da591002e61c013c.1638817638.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:07 +08:00
unsigned long nr_memslot_pages;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
/* The two memslot sets - active and inactive (per address space) */
struct kvm_memslots __memslots[KVM_ADDRESS_SPACE_NUM][2];
/* The current active memslot set for each address space */
struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
struct xarray vcpu_array;
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
/* Used to wait for completion of MMU notifiers. */
spinlock_t mn_invalidate_lock;
unsigned long mn_active_invalidate_count;
struct rcuwait mn_memslots_update_rcuwait;
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
/* For management / invalidation of gfn_to_pfn_caches */
spinlock_t gpc_lock;
struct list_head gpc_list;
/*
* created_vcpus is protected by kvm->lock, and is incremented
* at the beginning of KVM_CREATE_VCPU. online_vcpus is only
* incremented after storing the kvm_vcpu pointer in vcpus,
* and is accessed atomically.
*/
atomic_t online_vcpus;
int max_vcpus;
int created_vcpus;
int last_boosted_vcpu;
struct list_head vm_list;
struct mutex lock;
struct kvm_io_bus __rcu *buses[KVM_NR_BUSES];
#ifdef CONFIG_HAVE_KVM_EVENTFD
struct {
spinlock_t lock;
struct list_head items;
struct list_head resampler_list;
struct mutex resampler_lock;
} irqfds;
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
struct list_head ioeventfds;
#endif
struct kvm_vm_stat stat;
struct kvm_arch arch;
refcount_t users_count;
#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
struct kvm_coalesced_mmio_ring *coalesced_mmio_ring;
spinlock_t ring_lock;
struct list_head coalesced_zones;
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
struct mutex irq_lock;
#ifdef CONFIG_HAVE_KVM_IRQCHIP
/*
* Update side is protected by irq_lock.
*/
struct kvm_irq_routing_table __rcu *irq_routing;
#endif
#ifdef CONFIG_HAVE_KVM_IRQFD
struct hlist_head irq_ack_notifier_list;
#endif
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
struct mmu_notifier mmu_notifier;
unsigned long mmu_invalidate_seq;
long mmu_invalidate_in_progress;
unsigned long mmu_invalidate_range_start;
unsigned long mmu_invalidate_range_end;
#endif
struct list_head devices;
u64 manual_dirty_log_protect;
struct dentry *debugfs_dentry;
struct kvm_stat_data **debugfs_stat_data;
struct srcu_struct srcu;
struct srcu_struct irq_srcu;
pid_t userspace_pid;
unsigned int max_halt_poll_ns;
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 dirty_ring_size;
bool vm_bugged;
bool vm_dead;
#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
struct notifier_block pm_notifier;
#endif
char stats_id[KVM_STATS_NAME_SIZE];
[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
};
#define kvm_err(fmt, ...) \
pr_err("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
#define kvm_info(fmt, ...) \
pr_info("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
#define kvm_debug(fmt, ...) \
pr_debug("kvm [%i]: " fmt, task_pid_nr(current), ## __VA_ARGS__)
#define kvm_debug_ratelimited(fmt, ...) \
pr_debug_ratelimited("kvm [%i]: " fmt, task_pid_nr(current), \
## __VA_ARGS__)
#define kvm_pr_unimpl(fmt, ...) \
pr_err_ratelimited("kvm [%i]: " fmt, \
task_tgid_nr(current), ## __VA_ARGS__)
/* The guest did something we don't support. */
#define vcpu_unimpl(vcpu, fmt, ...) \
kvm_pr_unimpl("vcpu%i, guest rIP: 0x%lx " fmt, \
(vcpu)->vcpu_id, kvm_rip_read(vcpu), ## __VA_ARGS__)
[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
#define vcpu_debug(vcpu, fmt, ...) \
kvm_debug("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
#define vcpu_debug_ratelimited(vcpu, fmt, ...) \
kvm_debug_ratelimited("vcpu%i " fmt, (vcpu)->vcpu_id, \
## __VA_ARGS__)
#define vcpu_err(vcpu, fmt, ...) \
kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
static inline void kvm_vm_dead(struct kvm *kvm)
{
kvm->vm_dead = true;
kvm_make_all_cpus_request(kvm, KVM_REQ_VM_DEAD);
}
static inline void kvm_vm_bugged(struct kvm *kvm)
{
kvm->vm_bugged = true;
kvm_vm_dead(kvm);
}
#define KVM_BUG(cond, kvm, fmt...) \
({ \
int __ret = (cond); \
\
if (WARN_ONCE(__ret && !(kvm)->vm_bugged, fmt)) \
kvm_vm_bugged(kvm); \
unlikely(__ret); \
})
#define KVM_BUG_ON(cond, kvm) \
({ \
int __ret = (cond); \
\
if (WARN_ON_ONCE(__ret && !(kvm)->vm_bugged)) \
kvm_vm_bugged(kvm); \
unlikely(__ret); \
})
static inline void kvm_vcpu_srcu_read_lock(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_PROVE_RCU
WARN_ONCE(vcpu->srcu_depth++,
"KVM: Illegal vCPU srcu_idx LOCK, depth=%d", vcpu->srcu_depth - 1);
#endif
vcpu->____srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
}
static inline void kvm_vcpu_srcu_read_unlock(struct kvm_vcpu *vcpu)
{
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->____srcu_idx);
#ifdef CONFIG_PROVE_RCU
WARN_ONCE(--vcpu->srcu_depth,
"KVM: Illegal vCPU srcu_idx UNLOCK, depth=%d", vcpu->srcu_depth);
#endif
}
static inline bool kvm_dirty_log_manual_protect_and_init_set(struct kvm *kvm)
{
return !!(kvm->manual_dirty_log_protect & KVM_DIRTY_LOG_INITIALLY_SET);
}
static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
{
return srcu_dereference_check(kvm->buses[idx], &kvm->srcu,
lockdep_is_held(&kvm->slots_lock) ||
!refcount_read(&kvm->users_count));
}
static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
{
int num_vcpus = atomic_read(&kvm->online_vcpus);
i = array_index_nospec(i, num_vcpus);
/* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu. */
smp_rmb();
return xa_load(&kvm->vcpu_array, i);
}
#define kvm_for_each_vcpu(idx, vcpup, kvm) \
xa_for_each_range(&kvm->vcpu_array, idx, vcpup, 0, \
(atomic_read(&kvm->online_vcpus) - 1))
static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
{
struct kvm_vcpu *vcpu = NULL;
unsigned long i;
if (id < 0)
return NULL;
if (id < KVM_MAX_VCPUS)
vcpu = kvm_get_vcpu(kvm, id);
if (vcpu && vcpu->vcpu_id == id)
return vcpu;
kvm_for_each_vcpu(i, vcpu, kvm)
if (vcpu->vcpu_id == id)
return vcpu;
return NULL;
}
void kvm_destroy_vcpus(struct kvm *kvm);
void vcpu_load(struct kvm_vcpu *vcpu);
void vcpu_put(struct kvm_vcpu *vcpu);
#ifdef __KVM_HAVE_IOAPIC
void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm);
void kvm_arch_post_irq_routing_update(struct kvm *kvm);
#else
static inline void kvm_arch_post_irq_ack_notifier_list_update(struct kvm *kvm)
{
}
static inline void kvm_arch_post_irq_routing_update(struct kvm *kvm)
{
}
#endif
#ifdef CONFIG_HAVE_KVM_IRQFD
int kvm_irqfd_init(void);
void kvm_irqfd_exit(void);
#else
static inline int kvm_irqfd_init(void)
{
return 0;
}
static inline void kvm_irqfd_exit(void)
{
}
#endif
int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
struct module *module);
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
void kvm_get_kvm(struct kvm *kvm);
bool kvm_get_kvm_safe(struct kvm *kvm);
void kvm_put_kvm(struct kvm *kvm);
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);
void kvm_put_kvm_no_destroy(struct kvm *kvm);
static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id)
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
{
as_id = array_index_nospec(as_id, KVM_ADDRESS_SPACE_NUM);
return srcu_dereference_check(kvm->memslots[as_id], &kvm->srcu,
lockdep_is_held(&kvm->slots_lock) ||
!refcount_read(&kvm->users_count));
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
}
static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
{
return __kvm_memslots(kvm, 0);
}
static inline struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu)
{
int as_id = kvm_arch_vcpu_memslots_id(vcpu);
return __kvm_memslots(vcpu->kvm, as_id);
}
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
static inline bool kvm_memslots_empty(struct kvm_memslots *slots)
{
return RB_EMPTY_ROOT(&slots->gfn_tree);
}
#define kvm_for_each_memslot(memslot, bkt, slots) \
hash_for_each(slots->id_hash, bkt, memslot, id_node[slots->node_idx]) \
if (WARN_ON_ONCE(!memslot->npages)) { \
} else
2020-02-19 05:07:31 +08:00
static inline
struct kvm_memory_slot *id_to_memslot(struct kvm_memslots *slots, int id)
{
struct kvm_memory_slot *slot;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
int idx = slots->node_idx;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
hash_for_each_possible(slots->id_hash, slot, id_node[idx], id) {
if (slot->id == id)
return slot;
}
return NULL;
}
/* Iterator used for walking memslots that overlap a gfn range. */
struct kvm_memslot_iter {
struct kvm_memslots *slots;
struct rb_node *node;
struct kvm_memory_slot *slot;
};
static inline void kvm_memslot_iter_next(struct kvm_memslot_iter *iter)
{
iter->node = rb_next(iter->node);
if (!iter->node)
return;
iter->slot = container_of(iter->node, struct kvm_memory_slot, gfn_node[iter->slots->node_idx]);
}
static inline void kvm_memslot_iter_start(struct kvm_memslot_iter *iter,
struct kvm_memslots *slots,
gfn_t start)
{
int idx = slots->node_idx;
struct rb_node *tmp;
struct kvm_memory_slot *slot;
iter->slots = slots;
/*
* Find the so called "upper bound" of a key - the first node that has
* its key strictly greater than the searched one (the start gfn in our case).
*/
iter->node = NULL;
for (tmp = slots->gfn_tree.rb_node; tmp; ) {
slot = container_of(tmp, struct kvm_memory_slot, gfn_node[idx]);
if (start < slot->base_gfn) {
iter->node = tmp;
tmp = tmp->rb_left;
} else {
tmp = tmp->rb_right;
}
}
/*
* Find the slot with the lowest gfn that can possibly intersect with
* the range, so we'll ideally have slot start <= range start
*/
if (iter->node) {
/*
* A NULL previous node means that the very first slot
* already has a higher start gfn.
* In this case slot start > range start.
*/
tmp = rb_prev(iter->node);
if (tmp)
iter->node = tmp;
} else {
/* a NULL node below means no slots */
iter->node = rb_last(&slots->gfn_tree);
}
if (iter->node) {
iter->slot = container_of(iter->node, struct kvm_memory_slot, gfn_node[idx]);
/*
* It is possible in the slot start < range start case that the
* found slot ends before or at range start (slot end <= range start)
* and so it does not overlap the requested range.
*
* In such non-overlapping case the next slot (if it exists) will
* already have slot start > range start, otherwise the logic above
* would have found it instead of the current slot.
*/
if (iter->slot->base_gfn + iter->slot->npages <= start)
kvm_memslot_iter_next(iter);
}
}
static inline bool kvm_memslot_iter_is_valid(struct kvm_memslot_iter *iter, gfn_t end)
{
if (!iter->node)
return false;
/*
* If this slot starts beyond or at the end of the range so does
* every next one
*/
return iter->slot->base_gfn < end;
}
/* Iterate over each memslot at least partially intersecting [start, end) range */
#define kvm_for_each_memslot_in_gfn_range(iter, slots, start, end) \
for (kvm_memslot_iter_start(iter, slots, start); \
kvm_memslot_iter_is_valid(iter, end); \
kvm_memslot_iter_next(iter))
/*
* KVM_SET_USER_MEMORY_REGION ioctl allows the following operations:
* - create a new memory slot
* - delete an existing memory slot
* - modify an existing memory slot
* -- move it in the guest physical memory space
* -- just change its flags
*
* Since flags can be changed by some of these operations, the following
* differentiation is the best we can do for __kvm_set_memory_region():
*/
enum kvm_mr_change {
KVM_MR_CREATE,
KVM_MR_DELETE,
KVM_MR_MOVE,
KVM_MR_FLAGS_ONLY,
};
int kvm_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem);
int __kvm_set_memory_region(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem);
void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot);
void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen);
int kvm_arch_prepare_memory_region(struct kvm *kvm,
const struct kvm_memory_slot *old,
struct kvm_memory_slot *new,
enum kvm_mr_change change);
void kvm_arch_commit_memory_region(struct kvm *kvm,
struct kvm_memory_slot *old,
const struct kvm_memory_slot *new,
enum kvm_mr_change change);
/* flush all memory translations */
void kvm_arch_flush_shadow_all(struct kvm *kvm);
/* flush memory translations pointing to 'slot' */
void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot);
int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn,
struct page **pages, int nr_pages);
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn);
unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable);
unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn);
unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot, gfn_t gfn,
bool *writable);
void kvm_release_page_clean(struct page *page);
void kvm_release_page_dirty(struct page *page);
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);
kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault,
bool *writable);
kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn);
kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn);
kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, 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
bool atomic, bool *async, bool write_fault,
bool *writable, hva_t *hva);
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);
void kvm_release_pfn_dirty(kvm_pfn_t 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
void kvm_set_pfn_dirty(kvm_pfn_t pfn);
void kvm_set_pfn_accessed(kvm_pfn_t pfn);
2021-11-16 00:50:27 +08:00
void kvm_release_pfn(kvm_pfn_t pfn, bool dirty);
int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,
int len);
int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len);
int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned long len);
int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned int offset,
unsigned long len);
int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data,
int offset, int len);
int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
unsigned long len);
int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned long len);
int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned int offset,
unsigned long len);
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
gpa_t gpa, unsigned long len);
#define __kvm_get_guest(kvm, gfn, offset, v) \
({ \
unsigned long __addr = gfn_to_hva(kvm, gfn); \
typeof(v) __user *__uaddr = (typeof(__uaddr))(__addr + offset); \
int __ret = -EFAULT; \
\
if (!kvm_is_error_hva(__addr)) \
__ret = get_user(v, __uaddr); \
__ret; \
})
#define kvm_get_guest(kvm, gpa, v) \
({ \
gpa_t __gpa = gpa; \
struct kvm *__kvm = kvm; \
\
__kvm_get_guest(__kvm, __gpa >> PAGE_SHIFT, \
offset_in_page(__gpa), v); \
})
#define __kvm_put_guest(kvm, gfn, offset, v) \
({ \
unsigned long __addr = gfn_to_hva(kvm, gfn); \
typeof(v) __user *__uaddr = (typeof(__uaddr))(__addr + offset); \
int __ret = -EFAULT; \
\
if (!kvm_is_error_hva(__addr)) \
__ret = put_user(v, __uaddr); \
if (!__ret) \
mark_page_dirty(kvm, gfn); \
__ret; \
})
#define kvm_put_guest(kvm, gpa, v) \
({ \
gpa_t __gpa = gpa; \
struct kvm *__kvm = kvm; \
\
__kvm_put_guest(__kvm, __gpa >> PAGE_SHIFT, \
offset_in_page(__gpa), v); \
})
int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len);
[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 *gfn_to_memslot(struct kvm *kvm, gfn_t gfn);
bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn);
bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn);
unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn);
void mark_page_dirty_in_slot(struct kvm *kvm, const 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
void mark_page_dirty(struct kvm *kvm, gfn_t gfn);
struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu);
struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(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 kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn);
kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn);
int kvm_vcpu_map(struct kvm_vcpu *vcpu, gpa_t gpa, struct kvm_host_map *map);
void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty);
unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn);
unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable);
int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, int offset,
int len);
int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, void *data,
unsigned long len);
int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data,
unsigned long len);
int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, const void *data,
int offset, int len);
int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data,
unsigned long len);
void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn);
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
/**
* kvm_gpc_init - initialize gfn_to_pfn_cache.
*
* @gpc: struct gfn_to_pfn_cache object.
*
* This sets up a gfn_to_pfn_cache by initializing locks. Note, the cache must
* be zero-allocated (or zeroed by the caller before init).
*/
void kvm_gpc_init(struct gfn_to_pfn_cache *gpc);
/**
* kvm_gpc_activate - prepare a cached kernel mapping and HPA for a given guest
* physical address.
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
*
* @kvm: pointer to kvm instance.
* @gpc: struct gfn_to_pfn_cache object.
* @vcpu: vCPU to be used for marking pages dirty and to be woken on
* invalidation.
* @usage: indicates if the resulting host physical PFN is used while
* the @vcpu is IN_GUEST_MODE (in which case invalidation of
* the cache from MMU notifiers---but not for KVM memslot
* changes!---will also force @vcpu to exit the guest and
* refresh the cache); and/or if the PFN used directly
* by KVM (and thus needs a kernel virtual mapping).
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
* @gpa: guest physical address to map.
* @len: sanity check; the range being access must fit a single page.
*
* @return: 0 for success.
* -EINVAL for a mapping which would cross a page boundary.
* -EFAULT for an untranslatable guest physical address.
*
* This primes a gfn_to_pfn_cache and links it into the @kvm's list for
KVM: Don't actually set a request when evicting vCPUs for GFN cache invd Don't actually set a request bit in vcpu->requests when making a request purely to force a vCPU to exit the guest. Logging a request but not actually consuming it would cause the vCPU to get stuck in an infinite loop during KVM_RUN because KVM would see the pending request and bail from VM-Enter to service the request. Note, it's currently impossible for KVM to set KVM_REQ_GPC_INVALIDATE as nothing in KVM is wired up to set guest_uses_pa=true. But, it'd be all too easy for arch code to introduce use of kvm_gfn_to_pfn_cache_init() without implementing handling of the request, especially since getting test coverage of MMU notifier interaction with specific KVM features usually requires a directed test. Opportunistically rename gfn_to_pfn_cache_invalidate_start()'s wake_vcpus to evict_vcpus. The purpose of the request is to get vCPUs out of guest mode, it's supposed to _avoid_ waking vCPUs that are blocking. Opportunistically rename KVM_REQ_GPC_INVALIDATE to be more specific as to what it wants to accomplish, and to genericize the name so that it can used for similar but unrelated scenarios, should they arise in the future. Add a comment and documentation to explain why the "no action" request exists. Add compile-time assertions to help detect improper usage. Use the inner assertless helper in the one s390 path that makes requests without a hardcoded request. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220223165302.3205276-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-24 00:53:02 +08:00
* invalidations to be processed. Callers are required to use
* kvm_gfn_to_pfn_cache_check() to ensure that the cache is valid before
* accessing the target page.
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
*/
int kvm_gpc_activate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
struct kvm_vcpu *vcpu, enum pfn_cache_usage usage,
gpa_t gpa, unsigned long len);
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
/**
* kvm_gfn_to_pfn_cache_check - check validity of a gfn_to_pfn_cache.
*
* @kvm: pointer to kvm instance.
* @gpc: struct gfn_to_pfn_cache object.
* @gpa: current guest physical address to map.
* @len: sanity check; the range being access must fit a single page.
*
* @return: %true if the cache is still valid and the address matches.
* %false if the cache is not valid.
*
* Callers outside IN_GUEST_MODE context should hold a read lock on @gpc->lock
* while calling this function, and then continue to hold the lock until the
* access is complete.
*
* Callers in IN_GUEST_MODE may do so without locking, although they should
* still hold a read lock on kvm->scru for the memslot checks.
*/
bool kvm_gfn_to_pfn_cache_check(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
gpa_t gpa, unsigned long len);
/**
* kvm_gfn_to_pfn_cache_refresh - update a previously initialized cache.
*
* @kvm: pointer to kvm instance.
* @gpc: struct gfn_to_pfn_cache object.
* @gpa: updated guest physical address to map.
* @len: sanity check; the range being access must fit a single page.
*
* @return: 0 for success.
* -EINVAL for a mapping which would cross a page boundary.
* -EFAULT for an untranslatable guest physical address.
*
* This will attempt to refresh a gfn_to_pfn_cache. Note that a successful
* returm from this function does not mean the page can be immediately
* accessed because it may have raced with an invalidation. Callers must
* still lock and check the cache status, as this function does not return
* with the lock still held to permit access.
*/
int kvm_gfn_to_pfn_cache_refresh(struct kvm *kvm, struct gfn_to_pfn_cache *gpc,
KVM: Remove dirty handling from gfn_to_pfn_cache completely It isn't OK to cache the dirty status of a page in internal structures for an indefinite period of time. Any time a vCPU exits the run loop to userspace might be its last; the VMM might do its final check of the dirty log, flush the last remaining dirty pages to the destination and complete a live migration. If we have internal 'dirty' state which doesn't get flushed until the vCPU is finally destroyed on the source after migration is complete, then we have lost data because that will escape the final copy. This problem already exists with the use of kvm_vcpu_unmap() to mark pages dirty in e.g. VMX nesting. Note that the actual Linux MM already considers the page to be dirty since we have a writeable mapping of it. This is just about the KVM dirty logging. For the nesting-style use cases (KVM_GUEST_USES_PFN) we will need to track which gfn_to_pfn_caches have been used and explicitly mark the corresponding pages dirty before returning to userspace. But we would have needed external tracking of that anyway, rather than walking the full list of GPCs to find those belonging to this vCPU which are dirty. So let's rely *solely* on that external tracking, and keep it simple rather than laying a tempting trap for callers to fall into. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220303154127.202856-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-03 23:41:12 +08:00
gpa_t gpa, unsigned long len);
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
/**
* kvm_gfn_to_pfn_cache_unmap - temporarily unmap a gfn_to_pfn_cache.
*
* @kvm: pointer to kvm instance.
* @gpc: struct gfn_to_pfn_cache object.
*
KVM: Remove dirty handling from gfn_to_pfn_cache completely It isn't OK to cache the dirty status of a page in internal structures for an indefinite period of time. Any time a vCPU exits the run loop to userspace might be its last; the VMM might do its final check of the dirty log, flush the last remaining dirty pages to the destination and complete a live migration. If we have internal 'dirty' state which doesn't get flushed until the vCPU is finally destroyed on the source after migration is complete, then we have lost data because that will escape the final copy. This problem already exists with the use of kvm_vcpu_unmap() to mark pages dirty in e.g. VMX nesting. Note that the actual Linux MM already considers the page to be dirty since we have a writeable mapping of it. This is just about the KVM dirty logging. For the nesting-style use cases (KVM_GUEST_USES_PFN) we will need to track which gfn_to_pfn_caches have been used and explicitly mark the corresponding pages dirty before returning to userspace. But we would have needed external tracking of that anyway, rather than walking the full list of GPCs to find those belonging to this vCPU which are dirty. So let's rely *solely* on that external tracking, and keep it simple rather than laying a tempting trap for callers to fall into. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20220303154127.202856-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-03-03 23:41:12 +08:00
* This unmaps the referenced page. The cache is left in the invalid state
* but at least the mapping from GPA to userspace HVA will remain cached
* and can be reused on a subsequent refresh.
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
*/
void kvm_gfn_to_pfn_cache_unmap(struct kvm *kvm, struct gfn_to_pfn_cache *gpc);
/**
* kvm_gpc_deactivate - deactivate and unlink a gfn_to_pfn_cache.
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
*
* @kvm: pointer to kvm instance.
* @gpc: struct gfn_to_pfn_cache object.
*
* This removes a cache from the @kvm's list to be processed on MMU notifier
* invocation.
*/
void kvm_gpc_deactivate(struct kvm *kvm, struct gfn_to_pfn_cache *gpc);
KVM: Reinstate gfn_to_pfn_cache with invalidation support This can be used in two modes. There is an atomic mode where the cached mapping is accessed while holding the rwlock, and a mode where the physical address is used by a vCPU in guest mode. For the latter case, an invalidation will wake the vCPU with the new KVM_REQ_GPC_INVALIDATE, and the architecture will need to refresh any caches it still needs to access before entering guest mode again. Only one vCPU can be targeted by the wake requests; it's simple enough to make it wake all vCPUs or even a mask but I don't see a use case for that additional complexity right now. Invalidation happens from the invalidate_range_start MMU notifier, which needs to be able to sleep in order to wake the vCPU and wait for it. This means that revalidation potentially needs to "wait" for the MMU operation to complete and the invalidate_range_end notifier to be invoked. Like the vCPU when it takes a page fault in that period, we just spin — fixing that in a future patch by implementing an actual *wait* may be another part of shaving this particularly hirsute yak. As noted in the comments in the function itself, the only case where the invalidate_range_start notifier is expected to be called *without* being able to sleep is when the OOM reaper is killing the process. In that case, we expect the vCPU threads already to have exited, and thus there will be nothing to wake, and no reason to wait. So we clear the KVM_REQUEST_WAIT bit and send the request anyway, then complain loudly if there actually *was* anything to wake up. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Message-Id: <20211210163625.2886-3-dwmw2@infradead.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-11 00:36:21 +08:00
void kvm_sigset_activate(struct kvm_vcpu *vcpu);
void kvm_sigset_deactivate(struct kvm_vcpu *vcpu);
void kvm_vcpu_halt(struct kvm_vcpu *vcpu);
bool kvm_vcpu_block(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu);
bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu);
void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
int kvm_vcpu_yield_to(struct kvm_vcpu *target);
void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu, bool usermode_vcpu_not_eligible);
void kvm_flush_remote_tlbs(struct kvm *kvm);
#ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE
int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min);
int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min);
int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc);
void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc);
void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);
#endif
void kvm_mmu_invalidate_begin(struct kvm *kvm, unsigned long start,
unsigned long end);
void kvm_mmu_invalidate_end(struct kvm *kvm, unsigned long start,
unsigned long end);
long kvm_arch_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg);
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg);
vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf);
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext);
void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
struct kvm_memory_slot *slot,
gfn_t gfn_offset,
unsigned long mask);
void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot);
#ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT
void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
const struct kvm_memory_slot *memslot);
#else /* !CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */
int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log);
int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log,
int *is_dirty, struct kvm_memory_slot **memslot);
#endif
int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
bool line_status);
int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
struct kvm_enable_cap *cap);
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg);
long kvm_arch_vm_compat_ioctl(struct file *filp, unsigned int ioctl,
unsigned long arg);
int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu);
int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu);
int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
struct kvm_translation *tr);
int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs);
int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs);
int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs);
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state);
int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state);
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg);
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu);
int kvm_arch_init(void *opaque);
void kvm_arch_exit(void);
void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu);
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id);
int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);
#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state);
#endif
#ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry);
#else
static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
#endif
int kvm_arch_hardware_enable(void);
void kvm_arch_hardware_disable(void);
int kvm_arch_hardware_setup(void *opaque);
void kvm_arch_hardware_unsetup(void);
int kvm_arch_check_processor_compat(void *opaque);
int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu);
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu);
2019-08-05 10:03:19 +08:00
bool kvm_arch_dy_runnable(struct kvm_vcpu *vcpu);
bool kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu);
int kvm_arch_post_init_vm(struct kvm *kvm);
void kvm_arch_pre_destroy_vm(struct kvm *kvm);
int kvm_arch_create_vm_debugfs(struct kvm *kvm);
#ifndef __KVM_HAVE_ARCH_VM_ALLOC
/*
* All architectures that want to use vzalloc currently also
* need their own kvm_arch_alloc_vm implementation.
*/
static inline struct kvm *kvm_arch_alloc_vm(void)
{
return kzalloc(sizeof(struct kvm), GFP_KERNEL);
}
#endif
static inline void __kvm_arch_free_vm(struct kvm *kvm)
{
kvfree(kvm);
}
#ifndef __KVM_HAVE_ARCH_VM_FREE
static inline void kvm_arch_free_vm(struct kvm *kvm)
{
__kvm_arch_free_vm(kvm);
}
#endif
#ifndef __KVM_HAVE_ARCH_FLUSH_REMOTE_TLB
static inline int kvm_arch_flush_remote_tlb(struct kvm *kvm)
{
return -ENOTSUPP;
}
#endif
#ifdef __KVM_HAVE_ARCH_NONCOHERENT_DMA
void kvm_arch_register_noncoherent_dma(struct kvm *kvm);
void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm);
bool kvm_arch_has_noncoherent_dma(struct kvm *kvm);
#else
static inline void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
{
}
static inline void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
{
}
static inline bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
{
return false;
}
#endif
#ifdef __KVM_HAVE_ARCH_ASSIGNED_DEVICE
void kvm_arch_start_assignment(struct kvm *kvm);
void kvm_arch_end_assignment(struct kvm *kvm);
bool kvm_arch_has_assigned_device(struct kvm *kvm);
#else
static inline void kvm_arch_start_assignment(struct kvm *kvm)
{
}
static inline void kvm_arch_end_assignment(struct kvm *kvm)
{
}
static __always_inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
{
return false;
}
#endif
static inline struct rcuwait *kvm_arch_vcpu_get_wait(struct kvm_vcpu *vcpu)
{
#ifdef __KVM_HAVE_ARCH_WQP
return vcpu->arch.waitp;
#else
return &vcpu->wait;
#endif
}
/*
* Wake a vCPU if necessary, but don't do any stats/metadata updates. Returns
* true if the vCPU was blocking and was awakened, false otherwise.
*/
static inline bool __kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
{
return !!rcuwait_wake_up(kvm_arch_vcpu_get_wait(vcpu));
}
static inline bool kvm_vcpu_is_blocking(struct kvm_vcpu *vcpu)
{
return rcuwait_active(kvm_arch_vcpu_get_wait(vcpu));
}
#ifdef __KVM_HAVE_ARCH_INTC_INITIALIZED
/*
* returns true if the virtual interrupt controller is initialized and
* ready to accept virtual IRQ. On some architectures the virtual interrupt
* controller is dynamically instantiated and this is not always true.
*/
bool kvm_arch_intc_initialized(struct kvm *kvm);
#else
static inline bool kvm_arch_intc_initialized(struct kvm *kvm)
{
return true;
}
#endif
#ifdef CONFIG_GUEST_PERF_EVENTS
unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu);
void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void));
void kvm_unregister_perf_callbacks(void);
#else
static inline void kvm_register_perf_callbacks(void *ign) {}
static inline void kvm_unregister_perf_callbacks(void) {}
#endif /* CONFIG_GUEST_PERF_EVENTS */
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type);
void kvm_arch_destroy_vm(struct kvm *kvm);
void kvm_arch_sync_events(struct kvm *kvm);
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu);
struct page *kvm_pfn_to_refcounted_page(kvm_pfn_t pfn);
bool kvm_is_zone_device_page(struct page *page);
struct kvm_irq_ack_notifier {
struct hlist_node link;
unsigned gsi;
void (*irq_acked)(struct kvm_irq_ack_notifier *kian);
};
int kvm_irq_map_gsi(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *entries, int gsi);
int kvm_irq_map_chip_pin(struct kvm *kvm, unsigned irqchip, unsigned pin);
int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
bool line_status);
int kvm_set_msi(struct kvm_kernel_irq_routing_entry *irq_entry, struct kvm *kvm,
int irq_source_id, int level, bool line_status);
int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
struct kvm *kvm, int irq_source_id,
int level, bool line_status);
bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin);
void kvm_notify_acked_gsi(struct kvm *kvm, int gsi);
void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
int kvm_request_irq_source_id(struct kvm *kvm);
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
/*
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
* Returns a pointer to the memslot if it contains gfn.
* Otherwise returns NULL.
*/
static inline struct kvm_memory_slot *
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
try_get_memslot(struct kvm_memory_slot *slot, gfn_t gfn)
{
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
if (!slot)
return NULL;
if (gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages)
return slot;
else
return NULL;
}
/*
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
* Returns a pointer to the memslot that contains gfn. Otherwise returns NULL.
2020-02-19 05:07:31 +08:00
*
* With "approx" set returns the memslot also when the address falls
* in a hole. In that case one of the memslots bordering the hole is
* returned.
*/
static inline struct kvm_memory_slot *
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
search_memslots(struct kvm_memslots *slots, gfn_t gfn, bool approx)
{
struct kvm_memory_slot *slot;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
struct rb_node *node;
int idx = slots->node_idx;
slot = NULL;
for (node = slots->gfn_tree.rb_node; node; ) {
slot = container_of(node, struct kvm_memory_slot, gfn_node[idx]);
if (gfn >= slot->base_gfn) {
if (gfn < slot->base_gfn + slot->npages)
return slot;
node = node->rb_right;
} else
node = node->rb_left;
}
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
return approx ? slot : NULL;
}
static inline struct kvm_memory_slot *
____gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn, bool approx)
{
struct kvm_memory_slot *slot;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
slot = (struct kvm_memory_slot *)atomic_long_read(&slots->last_used_slot);
slot = try_get_memslot(slot, gfn);
if (slot)
return slot;
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
slot = search_memslots(slots, gfn, approx);
if (slot) {
KVM: Keep memslots in tree-based structures instead of array-based ones The current memslot code uses a (reverse gfn-ordered) memslot array for keeping track of them. Because the memslot array that is currently in use cannot be modified every memslot management operation (create, delete, move, change flags) has to make a copy of the whole array so it has a scratch copy to work on. Strictly speaking, however, it is only necessary to make copy of the memslot that is being modified, copying all the memslots currently present is just a limitation of the array-based memslot implementation. Two memslot sets, however, are still needed so the VM continues to run on the currently active set while the requested operation is being performed on the second, currently inactive one. In order to have two memslot sets, but only one copy of actual memslots it is necessary to split out the memslot data from the memslot sets. The memslots themselves should be also kept independent of each other so they can be individually added or deleted. These two memslot sets should normally point to the same set of memslots. They can, however, be desynchronized when performing a memslot management operation by replacing the memslot to be modified by its copy. After the operation is complete, both memslot sets once again point to the same, common set of memslot data. This commit implements the aforementioned idea. For tracking of gfns an ordinary rbtree is used since memslots cannot overlap in the guest address space and so this data structure is sufficient for ensuring that lookups are done quickly. The "last used slot" mini-caches (both per-slot set one and per-vCPU one), that keep track of the last found-by-gfn memslot, are still present in the new code. Co-developed-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com> Message-Id: <17c0cf3663b760a0d3753d4ac08c0753e941b811.1638817641.git.maciej.szmigiero@oracle.com>
2021-12-07 03:54:30 +08:00
atomic_long_set(&slots->last_used_slot, (unsigned long)slot);
return slot;
}
return NULL;
}
/*
* __gfn_to_memslot() and its descendants are here to allow arch code to inline
* the lookups in hot paths. gfn_to_memslot() itself isn't here as an inline
* because that would bloat other code too much.
*/
static inline struct kvm_memory_slot *
__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
{
return ____gfn_to_memslot(slots, gfn, false);
}
static inline unsigned long
__gfn_to_hva_memslot(const struct kvm_memory_slot *slot, gfn_t gfn)
{
kvm: avoid speculation-based attacks from out-of-range memslot accesses KVM's mechanism for accessing guest memory translates a guest physical address (gpa) to a host virtual address using the right-shifted gpa (also known as gfn) and a struct kvm_memory_slot. The translation is performed in __gfn_to_hva_memslot using the following formula: hva = slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE It is expected that gfn falls within the boundaries of the guest's physical memory. However, a guest can access invalid physical addresses in such a way that the gfn is invalid. __gfn_to_hva_memslot is called from kvm_vcpu_gfn_to_hva_prot, which first retrieves a memslot through __gfn_to_memslot. While __gfn_to_memslot does check that the gfn falls within the boundaries of the guest's physical memory or not, a CPU can speculate the result of the check and continue execution speculatively using an illegal gfn. The speculation can result in calculating an out-of-bounds hva. If the resulting host virtual address is used to load another guest physical address, this is effectively a Spectre gadget consisting of two consecutive reads, the second of which is data dependent on the first. Right now it's not clear if there are any cases in which this is exploitable. One interesting case was reported by the original author of this patch, and involves visiting guest page tables on x86. Right now these are not vulnerable because the hva read goes through get_user(), which contains an LFENCE speculation barrier. However, there are patches in progress for x86 uaccess.h to mask kernel addresses instead of using LFENCE; once these land, a guest could use speculation to read from the VMM's ring 3 address space. Other architectures such as ARM already use the address masking method, and would be susceptible to this same kind of data-dependent access gadgets. Therefore, this patch proactively protects from these attacks by masking out-of-bounds gfns in __gfn_to_hva_memslot, which blocks speculation of invalid hvas. Sean Christopherson noted that this patch does not cover kvm_read_guest_offset_cached. This however is limited to a few bytes past the end of the cache, and therefore it is unlikely to be useful in the context of building a chain of data dependent accesses. Reported-by: Artemiy Margaritov <artemiy.margaritov@gmail.com> Co-developed-by: Artemiy Margaritov <artemiy.margaritov@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-09 03:31:42 +08:00
/*
* The index was checked originally in search_memslots. To avoid
* that a malicious guest builds a Spectre gadget out of e.g. page
* table walks, do not let the processor speculate loads outside
* the guest's registered memslots.
*/
unsigned long offset = gfn - slot->base_gfn;
offset = array_index_nospec(offset, slot->npages);
kvm: avoid speculation-based attacks from out-of-range memslot accesses KVM's mechanism for accessing guest memory translates a guest physical address (gpa) to a host virtual address using the right-shifted gpa (also known as gfn) and a struct kvm_memory_slot. The translation is performed in __gfn_to_hva_memslot using the following formula: hva = slot->userspace_addr + (gfn - slot->base_gfn) * PAGE_SIZE It is expected that gfn falls within the boundaries of the guest's physical memory. However, a guest can access invalid physical addresses in such a way that the gfn is invalid. __gfn_to_hva_memslot is called from kvm_vcpu_gfn_to_hva_prot, which first retrieves a memslot through __gfn_to_memslot. While __gfn_to_memslot does check that the gfn falls within the boundaries of the guest's physical memory or not, a CPU can speculate the result of the check and continue execution speculatively using an illegal gfn. The speculation can result in calculating an out-of-bounds hva. If the resulting host virtual address is used to load another guest physical address, this is effectively a Spectre gadget consisting of two consecutive reads, the second of which is data dependent on the first. Right now it's not clear if there are any cases in which this is exploitable. One interesting case was reported by the original author of this patch, and involves visiting guest page tables on x86. Right now these are not vulnerable because the hva read goes through get_user(), which contains an LFENCE speculation barrier. However, there are patches in progress for x86 uaccess.h to mask kernel addresses instead of using LFENCE; once these land, a guest could use speculation to read from the VMM's ring 3 address space. Other architectures such as ARM already use the address masking method, and would be susceptible to this same kind of data-dependent access gadgets. Therefore, this patch proactively protects from these attacks by masking out-of-bounds gfns in __gfn_to_hva_memslot, which blocks speculation of invalid hvas. Sean Christopherson noted that this patch does not cover kvm_read_guest_offset_cached. This however is limited to a few bytes past the end of the cache, and therefore it is unlikely to be useful in the context of building a chain of data dependent accesses. Reported-by: Artemiy Margaritov <artemiy.margaritov@gmail.com> Co-developed-by: Artemiy Margaritov <artemiy.margaritov@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-09 03:31:42 +08:00
return slot->userspace_addr + offset * PAGE_SIZE;
}
static inline int memslot_id(struct kvm *kvm, gfn_t gfn)
{
return gfn_to_memslot(kvm, gfn)->id;
}
static inline gfn_t
hva_to_gfn_memslot(unsigned long hva, struct kvm_memory_slot *slot)
{
gfn_t gfn_offset = (hva - slot->userspace_addr) >> PAGE_SHIFT;
return slot->base_gfn + gfn_offset;
}
static inline gpa_t gfn_to_gpa(gfn_t gfn)
{
return (gpa_t)gfn << 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
static inline gfn_t gpa_to_gfn(gpa_t gpa)
{
return (gfn_t)(gpa >> PAGE_SHIFT);
}
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 inline hpa_t pfn_to_hpa(kvm_pfn_t pfn)
{
return (hpa_t)pfn << PAGE_SHIFT;
}
static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa)
{
unsigned long hva = gfn_to_hva(kvm, gpa_to_gfn(gpa));
return kvm_is_error_hva(hva);
}
enum kvm_stat_kind {
KVM_STAT_VM,
KVM_STAT_VCPU,
};
struct kvm_stat_data {
struct kvm *kvm;
const struct _kvm_stats_desc *desc;
enum kvm_stat_kind kind;
};
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
struct _kvm_stats_desc {
struct kvm_stats_desc desc;
char name[KVM_STATS_NAME_SIZE];
};
#define STATS_DESC_COMMON(type, unit, base, exp, sz, bsz) \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
.flags = type | unit | base | \
BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \
BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \
BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \
.exponent = exp, \
.size = sz, \
.bucket_size = bsz
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
{ \
{ \
STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
.offset = offsetof(struct kvm_vm_stat, generic.stat) \
}, \
.name = #stat, \
}
#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
{ \
{ \
STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
.offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
}, \
.name = #stat, \
}
#define VM_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
{ \
{ \
STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
.offset = offsetof(struct kvm_vm_stat, stat) \
}, \
.name = #stat, \
}
#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
{ \
{ \
STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
.offset = offsetof(struct kvm_vcpu_stat, stat) \
}, \
.name = #stat, \
}
/* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
#define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, bsz) \
SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, bsz)
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
#define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent) \
STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, \
unit, base, exponent, 1, 0)
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
#define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent) \
STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, \
unit, base, exponent, 1, 0)
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
#define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent) \
STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, \
unit, base, exponent, 1, 0)
#define STATS_DESC_LINEAR_HIST(SCOPE, name, unit, base, exponent, sz, bsz) \
STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LINEAR_HIST, \
unit, base, exponent, sz, bsz)
#define STATS_DESC_LOG_HIST(SCOPE, name, unit, base, exponent, sz) \
STATS_DESC(SCOPE, name, KVM_STATS_TYPE_LOG_HIST, \
unit, base, exponent, sz, 0)
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
/* Cumulative counter, read/write */
#define STATS_DESC_COUNTER(SCOPE, name) \
STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_NONE, \
KVM_STATS_BASE_POW10, 0)
/* Instantaneous counter, read only */
#define STATS_DESC_ICOUNTER(SCOPE, name) \
STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_NONE, \
KVM_STATS_BASE_POW10, 0)
/* Peak counter, read/write */
#define STATS_DESC_PCOUNTER(SCOPE, name) \
STATS_DESC_PEAK(SCOPE, name, KVM_STATS_UNIT_NONE, \
KVM_STATS_BASE_POW10, 0)
/* Instantaneous boolean value, read only */
#define STATS_DESC_IBOOLEAN(SCOPE, name) \
STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_BOOLEAN, \
KVM_STATS_BASE_POW10, 0)
/* Peak (sticky) boolean value, read/write */
#define STATS_DESC_PBOOLEAN(SCOPE, name) \
STATS_DESC_PEAK(SCOPE, name, KVM_STATS_UNIT_BOOLEAN, \
KVM_STATS_BASE_POW10, 0)
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
/* Cumulative time in nanosecond */
#define STATS_DESC_TIME_NSEC(SCOPE, name) \
STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
KVM_STATS_BASE_POW10, -9)
/* Linear histogram for time in nanosecond */
#define STATS_DESC_LINHIST_TIME_NSEC(SCOPE, name, sz, bsz) \
STATS_DESC_LINEAR_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
KVM_STATS_BASE_POW10, -9, sz, bsz)
/* Logarithmic histogram for time in nanosecond */
#define STATS_DESC_LOGHIST_TIME_NSEC(SCOPE, name, sz) \
STATS_DESC_LOG_HIST(SCOPE, name, KVM_STATS_UNIT_SECONDS, \
KVM_STATS_BASE_POW10, -9, sz)
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
#define KVM_GENERIC_VM_STATS() \
STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush), \
STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush_requests)
#define KVM_GENERIC_VCPU_STATS() \
STATS_DESC_COUNTER(VCPU_GENERIC, halt_successful_poll), \
STATS_DESC_COUNTER(VCPU_GENERIC, halt_attempted_poll), \
STATS_DESC_COUNTER(VCPU_GENERIC, halt_poll_invalid), \
STATS_DESC_COUNTER(VCPU_GENERIC, halt_wakeup), \
STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_success_ns), \
STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns), \
STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_wait_ns), \
STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_success_hist, \
HALT_POLL_HIST_COUNT), \
STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_hist, \
HALT_POLL_HIST_COUNT), \
STATS_DESC_LOGHIST_TIME_NSEC(VCPU_GENERIC, halt_wait_hist, \
HALT_POLL_HIST_COUNT), \
STATS_DESC_IBOOLEAN(VCPU_GENERIC, blocking)
extern struct dentry *kvm_debugfs_dir;
KVM: stats: Add fd-based API to read binary stats data This commit defines the API for userspace and prepare the common functionalities to support per VM/VCPU binary stats data readings. The KVM stats now is only accessible by debugfs, which has some shortcomings this change series are supposed to fix: 1. The current debugfs stats solution in KVM could be disabled when kernel Lockdown mode is enabled, which is a potential rick for production. 2. The current debugfs stats solution in KVM is organized as "one stats per file", it is good for debugging, but not efficient for production. 3. The stats read/clear in current debugfs solution in KVM are protected by the global kvm_lock. Besides that, there are some other benefits with this change: 1. All KVM VM/VCPU stats can be read out in a bulk by one copy to userspace. 2. A schema is used to describe KVM statistics. From userspace's perspective, the KVM statistics are self-describing. 3. With the fd-based solution, a separate telemetry would be able to read KVM stats in a less privileged environment. 4. After the initial setup by reading in stats descriptors, a telemetry only needs to read the stats data itself, no more parsing or setup is needed. Reviewed-by: David Matlack <dmatlack@google.com> Reviewed-by: Ricardo Koller <ricarkol@google.com> Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com> Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> #arm64 Signed-off-by: Jing Zhang <jingzhangos@google.com> Message-Id: <20210618222709.1858088-3-jingzhangos@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-19 06:27:04 +08:00
ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
const struct _kvm_stats_desc *desc,
void *stats, size_t size_stats,
char __user *user_buffer, size_t size, loff_t *offset);
/**
* kvm_stats_linear_hist_update() - Update bucket value for linear histogram
* statistics data.
*
* @data: start address of the stats data
* @size: the number of bucket of the stats data
* @value: the new value used to update the linear histogram's bucket
* @bucket_size: the size (width) of a bucket
*/
static inline void kvm_stats_linear_hist_update(u64 *data, size_t size,
u64 value, size_t bucket_size)
{
size_t index = div64_u64(value, bucket_size);
index = min(index, size - 1);
++data[index];
}
/**
* kvm_stats_log_hist_update() - Update bucket value for logarithmic histogram
* statistics data.
*
* @data: start address of the stats data
* @size: the number of bucket of the stats data
* @value: the new value used to update the logarithmic histogram's bucket
*/
static inline void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value)
{
size_t index = fls64(value);
index = min(index, size - 1);
++data[index];
}
#define KVM_STATS_LINEAR_HIST_UPDATE(array, value, bsize) \
kvm_stats_linear_hist_update(array, ARRAY_SIZE(array), value, bsize)
#define KVM_STATS_LOG_HIST_UPDATE(array, value) \
kvm_stats_log_hist_update(array, ARRAY_SIZE(array), value)
extern const struct kvm_stats_header kvm_vm_stats_header;
extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
extern const struct kvm_stats_header kvm_vcpu_stats_header;
extern const struct _kvm_stats_desc kvm_vcpu_stats_desc[];
#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
static inline int mmu_invalidate_retry(struct kvm *kvm, unsigned long mmu_seq)
{
if (unlikely(kvm->mmu_invalidate_in_progress))
return 1;
/*
* Ensure the read of mmu_invalidate_in_progress happens before
* the read of mmu_invalidate_seq. This interacts with the
* smp_wmb() in mmu_notifier_invalidate_range_end to make sure
* that the caller either sees the old (non-zero) value of
* mmu_invalidate_in_progress or the new (incremented) value of
* mmu_invalidate_seq.
*
* PowerPC Book3s HV KVM calls this under a per-page lock rather
* than under kvm->mmu_lock, for scalability, so can't rely on
* kvm->mmu_lock to keep things ordered.
*/
smp_rmb();
if (kvm->mmu_invalidate_seq != mmu_seq)
return 1;
return 0;
}
static inline int mmu_invalidate_retry_hva(struct kvm *kvm,
unsigned long mmu_seq,
unsigned long hva)
{
lockdep_assert_held(&kvm->mmu_lock);
/*
* If mmu_invalidate_in_progress is non-zero, then the range maintained
* by kvm_mmu_notifier_invalidate_range_start contains all addresses
* that might be being invalidated. Note that it may include some false
* positives, due to shortcuts when handing concurrent invalidations.
*/
if (unlikely(kvm->mmu_invalidate_in_progress) &&
hva >= kvm->mmu_invalidate_range_start &&
hva < kvm->mmu_invalidate_range_end)
return 1;
if (kvm->mmu_invalidate_seq != mmu_seq)
return 1;
return 0;
}
#endif
#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
#define KVM_MAX_IRQ_ROUTES 4096 /* might need extension/rework in the future */
bool kvm_arch_can_set_irq_routing(struct kvm *kvm);
int kvm_set_irq_routing(struct kvm *kvm,
const struct kvm_irq_routing_entry *entries,
unsigned nr,
unsigned flags);
int kvm_set_routing_entry(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue);
void kvm_free_irq_routing(struct kvm *kvm);
#else
static inline void kvm_free_irq_routing(struct kvm *kvm) {}
#endif
int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi);
#ifdef CONFIG_HAVE_KVM_EVENTFD
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
void kvm_eventfd_init(struct kvm *kvm);
int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args);
#ifdef CONFIG_HAVE_KVM_IRQFD
int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args);
void kvm_irqfd_release(struct kvm *kvm);
void kvm_irq_routing_update(struct kvm *);
#else
static inline int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
{
return -EINVAL;
}
static inline void kvm_irqfd_release(struct kvm *kvm) {}
#endif
#else
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
static inline void kvm_eventfd_init(struct kvm *kvm) {}
static inline int kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
{
return -EINVAL;
}
static inline void kvm_irqfd_release(struct kvm *kvm) {}
#ifdef CONFIG_HAVE_KVM_IRQCHIP
static inline void kvm_irq_routing_update(struct kvm *kvm)
{
}
#endif
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
static inline int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
{
return -ENOSYS;
}
#endif /* CONFIG_HAVE_KVM_EVENTFD */
void kvm_arch_irq_routing_update(struct kvm *kvm);
KVM: Don't actually set a request when evicting vCPUs for GFN cache invd Don't actually set a request bit in vcpu->requests when making a request purely to force a vCPU to exit the guest. Logging a request but not actually consuming it would cause the vCPU to get stuck in an infinite loop during KVM_RUN because KVM would see the pending request and bail from VM-Enter to service the request. Note, it's currently impossible for KVM to set KVM_REQ_GPC_INVALIDATE as nothing in KVM is wired up to set guest_uses_pa=true. But, it'd be all too easy for arch code to introduce use of kvm_gfn_to_pfn_cache_init() without implementing handling of the request, especially since getting test coverage of MMU notifier interaction with specific KVM features usually requires a directed test. Opportunistically rename gfn_to_pfn_cache_invalidate_start()'s wake_vcpus to evict_vcpus. The purpose of the request is to get vCPUs out of guest mode, it's supposed to _avoid_ waking vCPUs that are blocking. Opportunistically rename KVM_REQ_GPC_INVALIDATE to be more specific as to what it wants to accomplish, and to genericize the name so that it can used for similar but unrelated scenarios, should they arise in the future. Add a comment and documentation to explain why the "no action" request exists. Add compile-time assertions to help detect improper usage. Use the inner assertless helper in the one s390 path that makes requests without a hardcoded request. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220223165302.3205276-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-24 00:53:02 +08:00
static inline void __kvm_make_request(int req, struct kvm_vcpu *vcpu)
{
/*
* Ensure the rest of the request is published to kvm_check_request's
* caller. Paired with the smp_mb__after_atomic in kvm_check_request.
*/
smp_wmb();
set_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
}
KVM: Don't actually set a request when evicting vCPUs for GFN cache invd Don't actually set a request bit in vcpu->requests when making a request purely to force a vCPU to exit the guest. Logging a request but not actually consuming it would cause the vCPU to get stuck in an infinite loop during KVM_RUN because KVM would see the pending request and bail from VM-Enter to service the request. Note, it's currently impossible for KVM to set KVM_REQ_GPC_INVALIDATE as nothing in KVM is wired up to set guest_uses_pa=true. But, it'd be all too easy for arch code to introduce use of kvm_gfn_to_pfn_cache_init() without implementing handling of the request, especially since getting test coverage of MMU notifier interaction with specific KVM features usually requires a directed test. Opportunistically rename gfn_to_pfn_cache_invalidate_start()'s wake_vcpus to evict_vcpus. The purpose of the request is to get vCPUs out of guest mode, it's supposed to _avoid_ waking vCPUs that are blocking. Opportunistically rename KVM_REQ_GPC_INVALIDATE to be more specific as to what it wants to accomplish, and to genericize the name so that it can used for similar but unrelated scenarios, should they arise in the future. Add a comment and documentation to explain why the "no action" request exists. Add compile-time assertions to help detect improper usage. Use the inner assertless helper in the one s390 path that makes requests without a hardcoded request. Cc: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220223165302.3205276-1-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-24 00:53:02 +08:00
static __always_inline void kvm_make_request(int req, struct kvm_vcpu *vcpu)
{
/*
* Request that don't require vCPU action should never be logged in
* vcpu->requests. The vCPU won't clear the request, so it will stay
* logged indefinitely and prevent the vCPU from entering the guest.
*/
BUILD_BUG_ON(!__builtin_constant_p(req) ||
(req & KVM_REQUEST_NO_ACTION));
__kvm_make_request(req, vcpu);
}
static inline bool kvm_request_pending(struct kvm_vcpu *vcpu)
{
return READ_ONCE(vcpu->requests);
}
static inline bool kvm_test_request(int req, struct kvm_vcpu *vcpu)
{
return test_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
}
static inline void kvm_clear_request(int req, struct kvm_vcpu *vcpu)
{
clear_bit(req & KVM_REQUEST_MASK, (void *)&vcpu->requests);
}
static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
{
if (kvm_test_request(req, vcpu)) {
kvm_clear_request(req, vcpu);
/*
* Ensure the rest of the request is visible to kvm_check_request's
* caller. Paired with the smp_wmb in kvm_make_request.
*/
smp_mb__after_atomic();
return true;
} else {
return false;
}
}
extern bool kvm_rebooting;
extern unsigned int halt_poll_ns;
extern unsigned int halt_poll_ns_grow;
extern unsigned int halt_poll_ns_grow_start;
extern unsigned int halt_poll_ns_shrink;
struct kvm_device {
const struct kvm_device_ops *ops;
struct kvm *kvm;
void *private;
struct list_head vm_node;
};
/* create, destroy, and name are mandatory */
struct kvm_device_ops {
const char *name;
/*
* create is called holding kvm->lock and any operations not suitable
* to do while holding the lock should be deferred to init (see
* below).
*/
int (*create)(struct kvm_device *dev, u32 type);
/*
* init is called after create if create is successful and is called
* outside of holding kvm->lock.
*/
void (*init)(struct kvm_device *dev);
/*
* Destroy is responsible for freeing dev.
*
* Destroy may be called before or after destructors are called
* on emulated I/O regions, depending on whether a reference is
* held by a vcpu or other kvm component that gets destroyed
* after the emulated I/O.
*/
void (*destroy)(struct kvm_device *dev);
/*
* Release is an alternative method to free the device. It is
* called when the device file descriptor is closed. Once
* release is called, the destroy method will not be called
* anymore as the device is removed from the device list of
* the VM. kvm->lock is held.
*/
void (*release)(struct kvm_device *dev);
int (*set_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
int (*get_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
int (*has_attr)(struct kvm_device *dev, struct kvm_device_attr *attr);
long (*ioctl)(struct kvm_device *dev, unsigned int ioctl,
unsigned long arg);
int (*mmap)(struct kvm_device *dev, struct vm_area_struct *vma);
};
void kvm_device_get(struct kvm_device *dev);
void kvm_device_put(struct kvm_device *dev);
struct kvm_device *kvm_device_from_filp(struct file *filp);
int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type);
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);
extern struct kvm_device_ops kvm_mpic_ops;
extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
extern struct kvm_device_ops kvm_arm_vgic_v3_ops;
#ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val)
{
vcpu->spin_loop.in_spin_loop = val;
}
static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
{
vcpu->spin_loop.dy_eligible = val;
}
#else /* !CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
static inline void kvm_vcpu_set_in_spin_loop(struct kvm_vcpu *vcpu, bool val)
{
}
static inline void kvm_vcpu_set_dy_eligible(struct kvm_vcpu *vcpu, bool val)
{
}
#endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
static inline bool kvm_is_visible_memslot(struct kvm_memory_slot *memslot)
{
return (memslot && memslot->id < KVM_USER_MEM_SLOTS &&
!(memslot->flags & KVM_MEMSLOT_INVALID));
}
struct kvm_vcpu *kvm_get_running_vcpu(void);
struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);
#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
bool kvm_arch_has_irq_bypass(void);
int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *,
struct irq_bypass_producer *);
void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *,
struct irq_bypass_producer *);
void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *);
void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *);
int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,
uint32_t guest_irq, bool set);
bool kvm_arch_irqfd_route_changed(struct kvm_kernel_irq_routing_entry *,
struct kvm_kernel_irq_routing_entry *);
#endif /* CONFIG_HAVE_KVM_IRQ_BYPASS */
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
#ifdef CONFIG_HAVE_KVM_INVALID_WAKEUPS
/* If we wakeup during the poll time, was it a sucessful poll? */
static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu)
{
return vcpu->valid_wakeup;
}
#else
static inline bool vcpu_valid_wakeup(struct kvm_vcpu *vcpu)
{
return true;
}
#endif /* CONFIG_HAVE_KVM_INVALID_WAKEUPS */
#ifdef CONFIG_HAVE_KVM_NO_POLL
/* Callback that tells if we must not poll */
bool kvm_arch_no_poll(struct kvm_vcpu *vcpu);
#else
static inline bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
{
return false;
}
#endif /* CONFIG_HAVE_KVM_NO_POLL */
#ifdef CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL
long kvm_arch_vcpu_async_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg);
#else
static inline long kvm_arch_vcpu_async_ioctl(struct file *filp,
unsigned int ioctl,
unsigned long arg)
{
return -ENOIOCTLCMD;
}
#endif /* CONFIG_HAVE_KVM_VCPU_ASYNC_IOCTL */
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
void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
unsigned long start, unsigned long end);
KVM: SEV: add cache flush to solve SEV cache incoherency issues Flush the CPU caches when memory is reclaimed from an SEV guest (where reclaim also includes it being unmapped from KVM's memslots). Due to lack of coherency for SEV encrypted memory, failure to flush results in silent data corruption if userspace is malicious/broken and doesn't ensure SEV guest memory is properly pinned and unpinned. Cache coherency is not enforced across the VM boundary in SEV (AMD APM vol.2 Section 15.34.7). Confidential cachelines, generated by confidential VM guests have to be explicitly flushed on the host side. If a memory page containing dirty confidential cachelines was released by VM and reallocated to another user, the cachelines may corrupt the new user at a later time. KVM takes a shortcut by assuming all confidential memory remain pinned until the end of VM lifetime. Therefore, KVM does not flush cache at mmu_notifier invalidation events. Because of this incorrect assumption and the lack of cache flushing, malicous userspace can crash the host kernel: creating a malicious VM and continuously allocates/releases unpinned confidential memory pages when the VM is running. Add cache flush operations to mmu_notifier operations to ensure that any physical memory leaving the guest VM get flushed. In particular, hook mmu_notifier_invalidate_range_start and mmu_notifier_release events and flush cache accordingly. The hook after releasing the mmu lock to avoid contention with other vCPUs. Cc: stable@vger.kernel.org Suggested-by: Sean Christpherson <seanjc@google.com> Reported-by: Mingwei Zhang <mizhang@google.com> Signed-off-by: Mingwei Zhang <mizhang@google.com> Message-Id: <20220421031407.2516575-4-mizhang@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-21 11:14:07 +08:00
void kvm_arch_guest_memory_reclaimed(struct kvm *kvm);
#ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu);
#else
static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
{
return 0;
}
#endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
typedef int (*kvm_vm_thread_fn_t)(struct kvm *kvm, uintptr_t data);
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);
#ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
{
vcpu->run->exit_reason = KVM_EXIT_INTR;
vcpu->stat.signal_exits++;
}
#endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
/*
* If more than one page is being (un)accounted, @virt must be the address of
* the first page of a block of pages what were allocated together (i.e
* accounted together).
*
* kvm_account_pgtable_pages() is thread-safe because mod_lruvec_page_state()
* is thread-safe.
*/
static inline void kvm_account_pgtable_pages(void *virt, int nr)
{
mod_lruvec_page_state(virt_to_page(virt), NR_SECONDARY_PAGETABLE, nr);
}
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
/*
* This defines how many reserved entries we want to keep before we
* kick the vcpu to the userspace to avoid dirty ring full. This
* value can be tuned to higher if e.g. PML is enabled on the host.
*/
#define KVM_DIRTY_RING_RSVD_ENTRIES 64
/* Max number of entries allowed for each kvm dirty ring */
#define KVM_DIRTY_RING_MAX_ENTRIES 65536
#endif