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linux-sg2042/arch/powerpc/kvm/book3s_64_mmu_hv.c

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KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/hugetlb.h>
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
#include <linux/vmalloc.h>
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
#include <linux/srcu.h>
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
#include <linux/anon_inodes.h>
#include <linux/file.h>
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/mmu-hash64.h>
#include <asm/hvcall.h>
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
#include <asm/cputable.h>
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:40:08 +08:00
/* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
#define MAX_LPID_970 63
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
/* Power architecture requires HPT is at least 256kB */
#define PPC_MIN_HPT_ORDER 18
KVM: PPC: Book3S HV: Restructure HPT entry creation code This restructures the code that creates HPT (hashed page table) entries so that it can be called in situations where we don't have a struct vcpu pointer, only a struct kvm pointer. It also fixes a bug where kvmppc_map_vrma() would corrupt the guest R4 value. Most of the work of kvmppc_virtmode_h_enter is now done by a new function, kvmppc_virtmode_do_h_enter, which itself calls another new function, kvmppc_do_h_enter, which contains most of the old kvmppc_h_enter. The new kvmppc_do_h_enter takes explicit arguments for the place to return the HPTE index, the Linux page tables to use, and whether it is being called in real mode, thus removing the need for it to have the vcpu as an argument. Currently kvmppc_map_vrma creates the VRMA (virtual real mode area) HPTEs by calling kvmppc_virtmode_h_enter, which is designed primarily to handle H_ENTER hcalls from the guest that need to pin a page of memory. Since H_ENTER returns the index of the created HPTE in R4, kvmppc_virtmode_h_enter updates the guest R4, corrupting the guest R4 in the case when it gets called from kvmppc_map_vrma on the first VCPU_RUN ioctl. With this, kvmppc_map_vrma instead calls kvmppc_virtmode_do_h_enter with the address of a dummy word as the place to store the HPTE index, thus avoiding corrupting the guest R4. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-14 02:31:32 +08:00
static long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
long pte_index, unsigned long pteh,
unsigned long ptel, unsigned long *pte_idx_ret);
KVM: PPC: Book3S HV: Reset reverse-map chains when resetting the HPT With HV-style KVM, we maintain reverse-mapping lists that enable us to find all the HPT (hashed page table) entries that reference each guest physical page, with the heads of the lists in the memslot->arch.rmap arrays. When we reset the HPT (i.e. when we reboot the VM), we clear out all the HPT entries but we were not clearing out the reverse mapping lists. The result is that as we create new HPT entries, the lists get corrupted, which can easily lead to loops, resulting in the host kernel hanging when it tries to traverse those lists. This fixes the problem by zeroing out all the reverse mapping lists when we zero out the HPT. This incidentally means that we are also zeroing our record of the referenced and changed bits (not the bits in the Linux PTEs, used by the Linux MM subsystem, but the bits used by the KVM_GET_DIRTY_LOG ioctl, and those used by kvm_age_hva() and kvm_test_age_hva()). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-22 07:27:19 +08:00
static void kvmppc_rmap_reset(struct kvm *kvm);
KVM: PPC: Book3S HV: Restructure HPT entry creation code This restructures the code that creates HPT (hashed page table) entries so that it can be called in situations where we don't have a struct vcpu pointer, only a struct kvm pointer. It also fixes a bug where kvmppc_map_vrma() would corrupt the guest R4 value. Most of the work of kvmppc_virtmode_h_enter is now done by a new function, kvmppc_virtmode_do_h_enter, which itself calls another new function, kvmppc_do_h_enter, which contains most of the old kvmppc_h_enter. The new kvmppc_do_h_enter takes explicit arguments for the place to return the HPTE index, the Linux page tables to use, and whether it is being called in real mode, thus removing the need for it to have the vcpu as an argument. Currently kvmppc_map_vrma creates the VRMA (virtual real mode area) HPTEs by calling kvmppc_virtmode_h_enter, which is designed primarily to handle H_ENTER hcalls from the guest that need to pin a page of memory. Since H_ENTER returns the index of the created HPTE in R4, kvmppc_virtmode_h_enter updates the guest R4, corrupting the guest R4 in the case when it gets called from kvmppc_map_vrma on the first VCPU_RUN ioctl. With this, kvmppc_map_vrma instead calls kvmppc_virtmode_do_h_enter with the address of a dummy word as the place to store the HPTE index, thus avoiding corrupting the guest R4. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-14 02:31:32 +08:00
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
long kvmppc_alloc_hpt(struct kvm *kvm, u32 *htab_orderp)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
{
KVM: PPC: BOOK3S: HV: Prefer CMA region for hash page table allocation Today when KVM tries to reserve memory for the hash page table it allocates from the normal page allocator first. If that fails it falls back to CMA's reserved region. One of the side effects of this is that we could end up exhausting the page allocator and get linux into OOM conditions while we still have plenty of space available in CMA. This patch addresses this issue by first trying hash page table allocation from CMA's reserved region before falling back to the normal page allocator. So if we run out of memory, we really are out of memory. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-06 23:54:18 +08:00
unsigned long hpt = 0;
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
struct revmap_entry *rev;
powerpc/kvm: Contiguous memory allocator based hash page table allocation Powerpc architecture uses a hash based page table mechanism for mapping virtual addresses to physical address. The architecture require this hash page table to be physically contiguous. With KVM on Powerpc currently we use early reservation mechanism for allocating guest hash page table. This implies that we need to reserve a big memory region to ensure we can create large number of guest simultaneously with KVM on Power. Another disadvantage is that the reserved memory is not available to rest of the subsystems and and that implies we limit the total available memory in the host. This patch series switch the guest hash page table allocation to use contiguous memory allocator. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-07-02 13:45:16 +08:00
struct page *page = NULL;
long order = KVM_DEFAULT_HPT_ORDER;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
if (htab_orderp) {
order = *htab_orderp;
if (order < PPC_MIN_HPT_ORDER)
order = PPC_MIN_HPT_ORDER;
}
powerpc/kvm: Contiguous memory allocator based hash page table allocation Powerpc architecture uses a hash based page table mechanism for mapping virtual addresses to physical address. The architecture require this hash page table to be physically contiguous. With KVM on Powerpc currently we use early reservation mechanism for allocating guest hash page table. This implies that we need to reserve a big memory region to ensure we can create large number of guest simultaneously with KVM on Power. Another disadvantage is that the reserved memory is not available to rest of the subsystems and and that implies we limit the total available memory in the host. This patch series switch the guest hash page table allocation to use contiguous memory allocator. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-07-02 13:45:16 +08:00
kvm->arch.hpt_cma_alloc = 0;
powerpc/kvm/cma: Fix panic introduces by signed shift operation fc95ca7284bc54953165cba76c3228bd2cdb9591 introduces a memset in kvmppc_alloc_hpt since the general CMA doesn't clear the memory it allocates. However, the size argument passed to memset is computed from a signed value and its signed bit is extended by the cast the compiler is doing. This lead to extremely large size value when dealing with order value >= 31, and almost all the memory following the allocated space is cleaned. As a consequence, the system is panicing and may even fail spawning the kdump kernel. This fix makes use of an unsigned value for the memset's size argument to avoid sign extension. Among this fix, another shift operation which may lead to signed extended value too is also fixed. Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Paul Mackerras <paulus@samba.org> Cc: Alexander Graf <agraf@suse.de> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 00:13:01 +08:00
page = kvm_alloc_hpt(1ul << (order - PAGE_SHIFT));
KVM: PPC: BOOK3S: HV: Prefer CMA region for hash page table allocation Today when KVM tries to reserve memory for the hash page table it allocates from the normal page allocator first. If that fails it falls back to CMA's reserved region. One of the side effects of this is that we could end up exhausting the page allocator and get linux into OOM conditions while we still have plenty of space available in CMA. This patch addresses this issue by first trying hash page table allocation from CMA's reserved region before falling back to the normal page allocator. So if we run out of memory, we really are out of memory. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-06 23:54:18 +08:00
if (page) {
hpt = (unsigned long)pfn_to_kaddr(page_to_pfn(page));
powerpc/kvm/cma: Fix panic introduces by signed shift operation fc95ca7284bc54953165cba76c3228bd2cdb9591 introduces a memset in kvmppc_alloc_hpt since the general CMA doesn't clear the memory it allocates. However, the size argument passed to memset is computed from a signed value and its signed bit is extended by the cast the compiler is doing. This lead to extremely large size value when dealing with order value >= 31, and almost all the memory following the allocated space is cleaned. As a consequence, the system is panicing and may even fail spawning the kdump kernel. This fix makes use of an unsigned value for the memset's size argument to avoid sign extension. Among this fix, another shift operation which may lead to signed extended value too is also fixed. Cc: Alexey Kardashevskiy <aik@ozlabs.ru> Cc: Paul Mackerras <paulus@samba.org> Cc: Alexander Graf <agraf@suse.de> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-03 00:13:01 +08:00
memset((void *)hpt, 0, (1ul << order));
KVM: PPC: BOOK3S: HV: Prefer CMA region for hash page table allocation Today when KVM tries to reserve memory for the hash page table it allocates from the normal page allocator first. If that fails it falls back to CMA's reserved region. One of the side effects of this is that we could end up exhausting the page allocator and get linux into OOM conditions while we still have plenty of space available in CMA. This patch addresses this issue by first trying hash page table allocation from CMA's reserved region before falling back to the normal page allocator. So if we run out of memory, we really are out of memory. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-06 23:54:18 +08:00
kvm->arch.hpt_cma_alloc = 1;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
}
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
/* Lastly try successively smaller sizes from the page allocator */
while (!hpt && order > PPC_MIN_HPT_ORDER) {
hpt = __get_free_pages(GFP_KERNEL|__GFP_ZERO|__GFP_REPEAT|
__GFP_NOWARN, order - PAGE_SHIFT);
if (!hpt)
--order;
}
if (!hpt)
return -ENOMEM;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
kvm->arch.hpt_virt = hpt;
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
kvm->arch.hpt_order = order;
/* HPTEs are 2**4 bytes long */
kvm->arch.hpt_npte = 1ul << (order - 4);
/* 128 (2**7) bytes in each HPTEG */
kvm->arch.hpt_mask = (1ul << (order - 7)) - 1;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
/* Allocate reverse map array */
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
rev = vmalloc(sizeof(struct revmap_entry) * kvm->arch.hpt_npte);
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
if (!rev) {
pr_err("kvmppc_alloc_hpt: Couldn't alloc reverse map array\n");
goto out_freehpt;
}
kvm->arch.revmap = rev;
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
kvm->arch.sdr1 = __pa(hpt) | (order - 18);
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
pr_info("KVM guest htab at %lx (order %ld), LPID %x\n",
hpt, order, kvm->arch.lpid);
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
if (htab_orderp)
*htab_orderp = order;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
return 0;
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
out_freehpt:
powerpc/kvm: Contiguous memory allocator based hash page table allocation Powerpc architecture uses a hash based page table mechanism for mapping virtual addresses to physical address. The architecture require this hash page table to be physically contiguous. With KVM on Powerpc currently we use early reservation mechanism for allocating guest hash page table. This implies that we need to reserve a big memory region to ensure we can create large number of guest simultaneously with KVM on Power. Another disadvantage is that the reserved memory is not available to rest of the subsystems and and that implies we limit the total available memory in the host. This patch series switch the guest hash page table allocation to use contiguous memory allocator. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-07-02 13:45:16 +08:00
if (kvm->arch.hpt_cma_alloc)
kvm_release_hpt(page, 1 << (order - PAGE_SHIFT));
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
else
free_pages(hpt, order - PAGE_SHIFT);
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
return -ENOMEM;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
}
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
long kvmppc_alloc_reset_hpt(struct kvm *kvm, u32 *htab_orderp)
{
long err = -EBUSY;
long order;
mutex_lock(&kvm->lock);
if (kvm->arch.rma_setup_done) {
kvm->arch.rma_setup_done = 0;
/* order rma_setup_done vs. vcpus_running */
smp_mb();
if (atomic_read(&kvm->arch.vcpus_running)) {
kvm->arch.rma_setup_done = 1;
goto out;
}
}
if (kvm->arch.hpt_virt) {
order = kvm->arch.hpt_order;
/* Set the entire HPT to 0, i.e. invalid HPTEs */
memset((void *)kvm->arch.hpt_virt, 0, 1ul << order);
KVM: PPC: Book3S HV: Reset reverse-map chains when resetting the HPT With HV-style KVM, we maintain reverse-mapping lists that enable us to find all the HPT (hashed page table) entries that reference each guest physical page, with the heads of the lists in the memslot->arch.rmap arrays. When we reset the HPT (i.e. when we reboot the VM), we clear out all the HPT entries but we were not clearing out the reverse mapping lists. The result is that as we create new HPT entries, the lists get corrupted, which can easily lead to loops, resulting in the host kernel hanging when it tries to traverse those lists. This fixes the problem by zeroing out all the reverse mapping lists when we zero out the HPT. This incidentally means that we are also zeroing our record of the referenced and changed bits (not the bits in the Linux PTEs, used by the Linux MM subsystem, but the bits used by the KVM_GET_DIRTY_LOG ioctl, and those used by kvm_age_hva() and kvm_test_age_hva()). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-22 07:27:19 +08:00
/*
* Reset all the reverse-mapping chains for all memslots
*/
kvmppc_rmap_reset(kvm);
KVM: PPC: Book3S HV: Improve handling of local vs. global TLB invalidations When we change or remove a HPT (hashed page table) entry, we can do either a global TLB invalidation (tlbie) that works across the whole machine, or a local invalidation (tlbiel) that only affects this core. Currently we do local invalidations if the VM has only one vcpu or if the guest requests it with the H_LOCAL flag, though the guest Linux kernel currently doesn't ever use H_LOCAL. Then, to cope with the possibility that vcpus moving around to different physical cores might expose stale TLB entries, there is some code in kvmppc_hv_entry to flush the whole TLB of entries for this VM if either this vcpu is now running on a different physical core from where it last ran, or if this physical core last ran a different vcpu. There are a number of problems on POWER7 with this as it stands: - The TLB invalidation is done per thread, whereas it only needs to be done per core, since the TLB is shared between the threads. - With the possibility of the host paging out guest pages, the use of H_LOCAL by an SMP guest is dangerous since the guest could possibly retain and use a stale TLB entry pointing to a page that had been removed from the guest. - The TLB invalidations that we do when a vcpu moves from one physical core to another are unnecessary in the case of an SMP guest that isn't using H_LOCAL. - The optimization of using local invalidations rather than global should apply to guests with one virtual core, not just one vcpu. (None of this applies on PPC970, since there we always have to invalidate the whole TLB when entering and leaving the guest, and we can't support paging out guest memory.) To fix these problems and simplify the code, we now maintain a simple cpumask of which cpus need to flush the TLB on entry to the guest. (This is indexed by cpu, though we only ever use the bits for thread 0 of each core.) Whenever we do a local TLB invalidation, we set the bits for every cpu except the bit for thread 0 of the core that we're currently running on. Whenever we enter a guest, we test and clear the bit for our core, and flush the TLB if it was set. On initial startup of the VM, and when resetting the HPT, we set all the bits in the need_tlb_flush cpumask, since any core could potentially have stale TLB entries from the previous VM to use the same LPID, or the previous contents of the HPT. Then, we maintain a count of the number of online virtual cores, and use that when deciding whether to use a local invalidation rather than the number of online vcpus. The code to make that decision is extracted out into a new function, global_invalidates(). For multi-core guests on POWER7 (i.e. when we are using mmu notifiers), we now never do local invalidations regardless of the H_LOCAL flag. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-22 07:28:08 +08:00
/* Ensure that each vcpu will flush its TLB on next entry. */
cpumask_setall(&kvm->arch.need_tlb_flush);
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
*htab_orderp = order;
err = 0;
} else {
err = kvmppc_alloc_hpt(kvm, htab_orderp);
order = *htab_orderp;
}
out:
mutex_unlock(&kvm->lock);
return err;
}
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
void kvmppc_free_hpt(struct kvm *kvm)
{
KVM: PPC: factor out lpid allocator from book3s_64_mmu_hv We'll use it on e500mc as well. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-20 23:34:20 +08:00
kvmppc_free_lpid(kvm->arch.lpid);
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
vfree(kvm->arch.revmap);
powerpc/kvm: Contiguous memory allocator based hash page table allocation Powerpc architecture uses a hash based page table mechanism for mapping virtual addresses to physical address. The architecture require this hash page table to be physically contiguous. With KVM on Powerpc currently we use early reservation mechanism for allocating guest hash page table. This implies that we need to reserve a big memory region to ensure we can create large number of guest simultaneously with KVM on Power. Another disadvantage is that the reserved memory is not available to rest of the subsystems and and that implies we limit the total available memory in the host. This patch series switch the guest hash page table allocation to use contiguous memory allocator. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-07-02 13:45:16 +08:00
if (kvm->arch.hpt_cma_alloc)
kvm_release_hpt(virt_to_page(kvm->arch.hpt_virt),
1 << (kvm->arch.hpt_order - PAGE_SHIFT));
KVM: PPC: Add HPT preallocator We're currently allocating 16MB of linear memory on demand when creating a guest. That does work some times, but finding 16MB of linear memory available in the system at runtime is definitely not a given. So let's add another command line option similar to the RMA preallocator, that we can use to keep a pool of page tables around. Now, when a guest gets created it has a pretty low chance of receiving an OOM. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-01-17 02:12:11 +08:00
else
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
free_pages(kvm->arch.hpt_virt,
kvm->arch.hpt_order - PAGE_SHIFT);
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
}
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
/* Bits in first HPTE dword for pagesize 4k, 64k or 16M */
static inline unsigned long hpte0_pgsize_encoding(unsigned long pgsize)
{
return (pgsize > 0x1000) ? HPTE_V_LARGE : 0;
}
/* Bits in second HPTE dword for pagesize 4k, 64k or 16M */
static inline unsigned long hpte1_pgsize_encoding(unsigned long pgsize)
{
return (pgsize == 0x10000) ? 0x1000 : 0;
}
void kvmppc_map_vrma(struct kvm_vcpu *vcpu, struct kvm_memory_slot *memslot,
unsigned long porder)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
{
unsigned long i;
KVM: PPC: Keep page physical addresses in per-slot arrays This allocates an array for each memory slot that is added to store the physical addresses of the pages in the slot. This array is vmalloc'd and accessed in kvmppc_h_enter using real_vmalloc_addr(). This allows us to remove the ram_pginfo field from the kvm_arch struct, and removes the 64GB guest RAM limit that we had. We use the low-order bits of the array entries to store a flag indicating that we have done get_page on the corresponding page, and therefore need to call put_page when we are finished with the page. Currently this is set for all pages except those in our special RMO regions. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:21 +08:00
unsigned long npages;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
unsigned long hp_v, hp_r;
unsigned long addr, hash;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
unsigned long psize;
unsigned long hp0, hp1;
KVM: PPC: Book3S HV: Restructure HPT entry creation code This restructures the code that creates HPT (hashed page table) entries so that it can be called in situations where we don't have a struct vcpu pointer, only a struct kvm pointer. It also fixes a bug where kvmppc_map_vrma() would corrupt the guest R4 value. Most of the work of kvmppc_virtmode_h_enter is now done by a new function, kvmppc_virtmode_do_h_enter, which itself calls another new function, kvmppc_do_h_enter, which contains most of the old kvmppc_h_enter. The new kvmppc_do_h_enter takes explicit arguments for the place to return the HPTE index, the Linux page tables to use, and whether it is being called in real mode, thus removing the need for it to have the vcpu as an argument. Currently kvmppc_map_vrma creates the VRMA (virtual real mode area) HPTEs by calling kvmppc_virtmode_h_enter, which is designed primarily to handle H_ENTER hcalls from the guest that need to pin a page of memory. Since H_ENTER returns the index of the created HPTE in R4, kvmppc_virtmode_h_enter updates the guest R4, corrupting the guest R4 in the case when it gets called from kvmppc_map_vrma on the first VCPU_RUN ioctl. With this, kvmppc_map_vrma instead calls kvmppc_virtmode_do_h_enter with the address of a dummy word as the place to store the HPTE index, thus avoiding corrupting the guest R4. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-14 02:31:32 +08:00
unsigned long idx_ret;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
long ret;
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
struct kvm *kvm = vcpu->kvm;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
psize = 1ul << porder;
npages = memslot->npages >> (porder - PAGE_SHIFT);
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
/* VRMA can't be > 1TB */
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
if (npages > 1ul << (40 - porder))
npages = 1ul << (40 - porder);
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
/* Can't use more than 1 HPTE per HPTEG */
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
if (npages > kvm->arch.hpt_mask + 1)
npages = kvm->arch.hpt_mask + 1;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
hp0 = HPTE_V_1TB_SEG | (VRMA_VSID << (40 - 16)) |
HPTE_V_BOLTED | hpte0_pgsize_encoding(psize);
hp1 = hpte1_pgsize_encoding(psize) |
HPTE_R_R | HPTE_R_C | HPTE_R_M | PP_RWXX;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
for (i = 0; i < npages; ++i) {
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
addr = i << porder;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
/* can't use hpt_hash since va > 64 bits */
KVM: PPC: Book3S HV: Make the guest hash table size configurable This adds a new ioctl to enable userspace to control the size of the guest hashed page table (HPT) and to clear it out when resetting the guest. The KVM_PPC_ALLOCATE_HTAB ioctl is a VM ioctl and takes as its parameter a pointer to a u32 containing the desired order of the HPT (log base 2 of the size in bytes), which is updated on successful return to the actual order of the HPT which was allocated. There must be no vcpus running at the time of this ioctl. To enforce this, we now keep a count of the number of vcpus running in kvm->arch.vcpus_running. If the ioctl is called when a HPT has already been allocated, we don't reallocate the HPT but just clear it out. We first clear the kvm->arch.rma_setup_done flag, which has two effects: (a) since we hold the kvm->lock mutex, it will prevent any vcpus from starting to run until we're done, and (b) it means that the first vcpu to run after we're done will re-establish the VRMA if necessary. If userspace doesn't call this ioctl before running the first vcpu, the kernel will allocate a default-sized HPT at that point. We do it then rather than when creating the VM, as the code did previously, so that userspace has a chance to do the ioctl if it wants. When allocating the HPT, we can allocate either from the kernel page allocator, or from the preallocated pool. If userspace is asking for a different size from the preallocated HPTs, we first try to allocate using the kernel page allocator. Then we try to allocate from the preallocated pool, and then if that fails, we try allocating decreasing sizes from the kernel page allocator, down to the minimum size allowed (256kB). Note that the kernel page allocator limits allocations to 1 << CONFIG_FORCE_MAX_ZONEORDER pages, which by default corresponds to 16MB (on 64-bit powerpc, at least). Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix module compilation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-05-04 10:32:53 +08:00
hash = (i ^ (VRMA_VSID ^ (VRMA_VSID << 25))) & kvm->arch.hpt_mask;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
/*
* We assume that the hash table is empty and no
* vcpus are using it at this stage. Since we create
* at most one HPTE per HPTEG, we just assume entry 7
* is available and use it.
*/
KVM: PPC: Keep a record of HV guest view of hashed page table entries This adds an array that parallels the guest hashed page table (HPT), that is, it has one entry per HPTE, used to store the guest's view of the second doubleword of the corresponding HPTE. The first doubleword in the HPTE is the same as the guest's idea of it, so we don't need to store a copy, but the second doubleword in the HPTE has the real page number rather than the guest's logical page number. This allows us to remove the back_translate() and reverse_xlate() functions. This "reverse mapping" array is vmalloc'd, meaning that to access it in real mode we have to walk the kernel's page tables explicitly. That is done by the new real_vmalloc_addr() function. (In fact this returns an address in the linear mapping, so the result is usable both in real mode and in virtual mode.) There are also some minor cleanups here: moving the definitions of HPT_ORDER etc. to a header file and defining HPT_NPTE for HPT_NPTEG << 3. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:27:39 +08:00
hash = (hash << 3) + 7;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
hp_v = hp0 | ((addr >> 16) & ~0x7fUL);
hp_r = hp1 | addr;
KVM: PPC: Book3S HV: Restructure HPT entry creation code This restructures the code that creates HPT (hashed page table) entries so that it can be called in situations where we don't have a struct vcpu pointer, only a struct kvm pointer. It also fixes a bug where kvmppc_map_vrma() would corrupt the guest R4 value. Most of the work of kvmppc_virtmode_h_enter is now done by a new function, kvmppc_virtmode_do_h_enter, which itself calls another new function, kvmppc_do_h_enter, which contains most of the old kvmppc_h_enter. The new kvmppc_do_h_enter takes explicit arguments for the place to return the HPTE index, the Linux page tables to use, and whether it is being called in real mode, thus removing the need for it to have the vcpu as an argument. Currently kvmppc_map_vrma creates the VRMA (virtual real mode area) HPTEs by calling kvmppc_virtmode_h_enter, which is designed primarily to handle H_ENTER hcalls from the guest that need to pin a page of memory. Since H_ENTER returns the index of the created HPTE in R4, kvmppc_virtmode_h_enter updates the guest R4, corrupting the guest R4 in the case when it gets called from kvmppc_map_vrma on the first VCPU_RUN ioctl. With this, kvmppc_map_vrma instead calls kvmppc_virtmode_do_h_enter with the address of a dummy word as the place to store the HPTE index, thus avoiding corrupting the guest R4. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-14 02:31:32 +08:00
ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, hash, hp_v, hp_r,
&idx_ret);
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
if (ret != H_SUCCESS) {
pr_err("KVM: map_vrma at %lx failed, ret=%ld\n",
addr, ret);
break;
}
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
}
}
int kvmppc_mmu_hv_init(void)
{
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:40:08 +08:00
unsigned long host_lpid, rsvd_lpid;
if (!cpu_has_feature(CPU_FTR_HVMODE))
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
return -EINVAL;
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:40:08 +08:00
KVM: PPC: factor out lpid allocator from book3s_64_mmu_hv We'll use it on e500mc as well. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-20 23:34:20 +08:00
/* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:40:08 +08:00
if (cpu_has_feature(CPU_FTR_ARCH_206)) {
host_lpid = mfspr(SPRN_LPID); /* POWER7 */
rsvd_lpid = LPID_RSVD;
} else {
host_lpid = 0; /* PPC970 */
rsvd_lpid = MAX_LPID_970;
}
KVM: PPC: factor out lpid allocator from book3s_64_mmu_hv We'll use it on e500mc as well. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-20 23:34:20 +08:00
kvmppc_init_lpid(rsvd_lpid + 1);
kvmppc_claim_lpid(host_lpid);
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:40:08 +08:00
/* rsvd_lpid is reserved for use in partition switching */
KVM: PPC: factor out lpid allocator from book3s_64_mmu_hv We'll use it on e500mc as well. Signed-off-by: Scott Wood <scottwood@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-20 23:34:20 +08:00
kvmppc_claim_lpid(rsvd_lpid);
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
return 0;
}
static void kvmppc_mmu_book3s_64_hv_reset_msr(struct kvm_vcpu *vcpu)
{
KVM: PPC: Book3S HV: Add transactional memory support This adds saving of the transactional memory (TM) checkpointed state on guest entry and exit. We only do this if we see that the guest has an active transaction. It also adds emulation of the TM state changes when delivering IRQs into the guest. According to the architecture, if we are transactional when an IRQ occurs, the TM state is changed to suspended, otherwise it's left unchanged. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Scott Wood <scottwood@freescale.com>
2014-03-25 07:47:02 +08:00
unsigned long msr = vcpu->arch.intr_msr;
/* If transactional, change to suspend mode on IRQ delivery */
if (MSR_TM_TRANSACTIONAL(vcpu->arch.shregs.msr))
msr |= MSR_TS_S;
else
msr |= vcpu->arch.shregs.msr & MSR_TS_MASK;
kvmppc_set_msr(vcpu, msr);
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
}
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
/*
* This is called to get a reference to a guest page if there isn't
KVM: PPC: Move kvm->arch.slot_phys into memslot.arch Now that we have an architecture-specific field in the kvm_memory_slot structure, we can use it to store the array of page physical addresses that we need for Book3S HV KVM on PPC970 processors. This reduces the size of struct kvm_arch for Book3S HV, and also reduces the size of struct kvm_arch_memory_slot for other PPC KVM variants since the fields in it are now only compiled in for Book3S HV. This necessitates making the kvm_arch_create_memslot and kvm_arch_free_memslot operations specific to each PPC KVM variant. That in turn means that we now don't allocate the rmap arrays on Book3S PR and Book E. Since we now unpin pages and free the slot_phys array in kvmppc_core_free_memslot, we no longer need to do it in kvmppc_core_destroy_vm, since the generic code takes care to free all the memslots when destroying a VM. We now need the new memslot to be passed in to kvmppc_core_prepare_memory_region, since we need to initialize its arch.slot_phys member on Book3S HV. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:46 +08:00
* one already in the memslot->arch.slot_phys[] array.
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
*/
static long kvmppc_get_guest_page(struct kvm *kvm, unsigned long gfn,
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
struct kvm_memory_slot *memslot,
unsigned long psize)
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
{
unsigned long start;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
long np, err;
struct page *page, *hpage, *pages[1];
unsigned long s, pgsize;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
unsigned long *physp;
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
unsigned int is_io, got, pgorder;
struct vm_area_struct *vma;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
unsigned long pfn, i, npages;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
KVM: PPC: Move kvm->arch.slot_phys into memslot.arch Now that we have an architecture-specific field in the kvm_memory_slot structure, we can use it to store the array of page physical addresses that we need for Book3S HV KVM on PPC970 processors. This reduces the size of struct kvm_arch for Book3S HV, and also reduces the size of struct kvm_arch_memory_slot for other PPC KVM variants since the fields in it are now only compiled in for Book3S HV. This necessitates making the kvm_arch_create_memslot and kvm_arch_free_memslot operations specific to each PPC KVM variant. That in turn means that we now don't allocate the rmap arrays on Book3S PR and Book E. Since we now unpin pages and free the slot_phys array in kvmppc_core_free_memslot, we no longer need to do it in kvmppc_core_destroy_vm, since the generic code takes care to free all the memslots when destroying a VM. We now need the new memslot to be passed in to kvmppc_core_prepare_memory_region, since we need to initialize its arch.slot_phys member on Book3S HV. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:46 +08:00
physp = memslot->arch.slot_phys;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
if (!physp)
return -EINVAL;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
if (physp[gfn - memslot->base_gfn])
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
return 0;
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
is_io = 0;
got = 0;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
page = NULL;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
pgsize = psize;
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
err = -EINVAL;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
start = gfn_to_hva_memslot(memslot, gfn);
/* Instantiate and get the page we want access to */
np = get_user_pages_fast(start, 1, 1, pages);
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
if (np != 1) {
/* Look up the vma for the page */
down_read(&current->mm->mmap_sem);
vma = find_vma(current->mm, start);
if (!vma || vma->vm_start > start ||
start + psize > vma->vm_end ||
!(vma->vm_flags & VM_PFNMAP))
goto up_err;
is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
pfn = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
/* check alignment of pfn vs. requested page size */
if (psize > PAGE_SIZE && (pfn & ((psize >> PAGE_SHIFT) - 1)))
goto up_err;
up_read(&current->mm->mmap_sem);
} else {
page = pages[0];
got = KVMPPC_GOT_PAGE;
/* See if this is a large page */
s = PAGE_SIZE;
if (PageHuge(page)) {
hpage = compound_head(page);
s <<= compound_order(hpage);
/* Get the whole large page if slot alignment is ok */
if (s > psize && slot_is_aligned(memslot, s) &&
!(memslot->userspace_addr & (s - 1))) {
start &= ~(s - 1);
pgsize = s;
KVM: PPC: Book3S HV: Fix refcounting of hugepages The H_REGISTER_VPA hcall implementation in HV Power KVM needs to pin some guest memory pages into host memory so that they can be safely accessed from usermode. It does this used get_user_pages_fast(). When the VPA is unregistered, or the VCPUs are cleaned up, these pages are released using put_page(). However, the get_user_pages() is invoked on the specific memory are of the VPA which could lie within hugepages. In case the pinned page is huge, we explicitly find the head page of the compound page before calling put_page() on it. At least with the latest kernel, this is not correct. put_page() already handles finding the correct head page of a compound, and also deals with various counts on the individual tail page which are important for transparent huge pages. We don't support transparent hugepages on Power, but even so, bypassing this count maintenance can lead (when the VM ends) to a hugepage being released back to the pool with a non-zero mapcount on one of the tail pages. This can then lead to a bad_page() when the page is released from the hugepage pool. This removes the explicit compound_head() call to correct this bug. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-08 18:24:08 +08:00
get_page(hpage);
put_page(page);
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
page = hpage;
}
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
}
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
if (s < psize)
goto out;
pfn = page_to_pfn(page);
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
}
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
npages = pgsize >> PAGE_SHIFT;
pgorder = __ilog2(npages);
physp += (gfn - memslot->base_gfn) & ~(npages - 1);
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
spin_lock(&kvm->arch.slot_phys_lock);
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
for (i = 0; i < npages; ++i) {
if (!physp[i]) {
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
physp[i] = ((pfn + i) << PAGE_SHIFT) +
got + is_io + pgorder;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
got = 0;
}
}
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
spin_unlock(&kvm->arch.slot_phys_lock);
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
err = 0;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
out:
KVM: PPC: Book3S HV: Fix refcounting of hugepages The H_REGISTER_VPA hcall implementation in HV Power KVM needs to pin some guest memory pages into host memory so that they can be safely accessed from usermode. It does this used get_user_pages_fast(). When the VPA is unregistered, or the VCPUs are cleaned up, these pages are released using put_page(). However, the get_user_pages() is invoked on the specific memory are of the VPA which could lie within hugepages. In case the pinned page is huge, we explicitly find the head page of the compound page before calling put_page() on it. At least with the latest kernel, this is not correct. put_page() already handles finding the correct head page of a compound, and also deals with various counts on the individual tail page which are important for transparent huge pages. We don't support transparent hugepages on Power, but even so, bypassing this count maintenance can lead (when the VM ends) to a hugepage being released back to the pool with a non-zero mapcount on one of the tail pages. This can then lead to a bad_page() when the page is released from the hugepage pool. This removes the explicit compound_head() call to correct this bug. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-08 18:24:08 +08:00
if (got)
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
put_page(page);
return err;
KVM: PPC: Allow I/O mappings in memory slots This provides for the case where userspace maps an I/O device into the address range of a memory slot using a VM_PFNMAP mapping. In that case, we work out the pfn from vma->vm_pgoff, and record the cache enable bits from vma->vm_page_prot in two low-order bits in the slot_phys array entries. Then, in kvmppc_h_enter() we check that the cache bits in the HPTE that the guest wants to insert match the cache bits in the slot_phys array entry. However, we do allow the guest to create what it thinks is a non-cacheable or write-through mapping to memory that is actually cacheable, so that we can use normal system memory as part of an emulated device later on. In that case the actual HPTE we insert is a cacheable HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:32:27 +08:00
up_err:
up_read(&current->mm->mmap_sem);
return err;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
}
KVM: PPC: Book3S HV: Restructure HPT entry creation code This restructures the code that creates HPT (hashed page table) entries so that it can be called in situations where we don't have a struct vcpu pointer, only a struct kvm pointer. It also fixes a bug where kvmppc_map_vrma() would corrupt the guest R4 value. Most of the work of kvmppc_virtmode_h_enter is now done by a new function, kvmppc_virtmode_do_h_enter, which itself calls another new function, kvmppc_do_h_enter, which contains most of the old kvmppc_h_enter. The new kvmppc_do_h_enter takes explicit arguments for the place to return the HPTE index, the Linux page tables to use, and whether it is being called in real mode, thus removing the need for it to have the vcpu as an argument. Currently kvmppc_map_vrma creates the VRMA (virtual real mode area) HPTEs by calling kvmppc_virtmode_h_enter, which is designed primarily to handle H_ENTER hcalls from the guest that need to pin a page of memory. Since H_ENTER returns the index of the created HPTE in R4, kvmppc_virtmode_h_enter updates the guest R4, corrupting the guest R4 in the case when it gets called from kvmppc_map_vrma on the first VCPU_RUN ioctl. With this, kvmppc_map_vrma instead calls kvmppc_virtmode_do_h_enter with the address of a dummy word as the place to store the HPTE index, thus avoiding corrupting the guest R4. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-14 02:31:32 +08:00
long kvmppc_virtmode_do_h_enter(struct kvm *kvm, unsigned long flags,
long pte_index, unsigned long pteh,
unsigned long ptel, unsigned long *pte_idx_ret)
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
{
unsigned long psize, gpa, gfn;
struct kvm_memory_slot *memslot;
long ret;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (kvm->arch.using_mmu_notifiers)
goto do_insert;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
psize = hpte_page_size(pteh, ptel);
if (!psize)
return H_PARAMETER;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID);
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
/* Find the memslot (if any) for this address */
gpa = (ptel & HPTE_R_RPN) & ~(psize - 1);
gfn = gpa >> PAGE_SHIFT;
memslot = gfn_to_memslot(kvm, gfn);
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) {
if (!slot_is_aligned(memslot, psize))
return H_PARAMETER;
if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0)
return H_PARAMETER;
}
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
do_insert:
/* Protect linux PTE lookup from page table destruction */
rcu_read_lock_sched(); /* this disables preemption too */
KVM: PPC: Book3S HV: Restructure HPT entry creation code This restructures the code that creates HPT (hashed page table) entries so that it can be called in situations where we don't have a struct vcpu pointer, only a struct kvm pointer. It also fixes a bug where kvmppc_map_vrma() would corrupt the guest R4 value. Most of the work of kvmppc_virtmode_h_enter is now done by a new function, kvmppc_virtmode_do_h_enter, which itself calls another new function, kvmppc_do_h_enter, which contains most of the old kvmppc_h_enter. The new kvmppc_do_h_enter takes explicit arguments for the place to return the HPTE index, the Linux page tables to use, and whether it is being called in real mode, thus removing the need for it to have the vcpu as an argument. Currently kvmppc_map_vrma creates the VRMA (virtual real mode area) HPTEs by calling kvmppc_virtmode_h_enter, which is designed primarily to handle H_ENTER hcalls from the guest that need to pin a page of memory. Since H_ENTER returns the index of the created HPTE in R4, kvmppc_virtmode_h_enter updates the guest R4, corrupting the guest R4 in the case when it gets called from kvmppc_map_vrma on the first VCPU_RUN ioctl. With this, kvmppc_map_vrma instead calls kvmppc_virtmode_do_h_enter with the address of a dummy word as the place to store the HPTE index, thus avoiding corrupting the guest R4. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-14 02:31:32 +08:00
ret = kvmppc_do_h_enter(kvm, flags, pte_index, pteh, ptel,
current->mm->pgd, false, pte_idx_ret);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
rcu_read_unlock_sched();
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
if (ret == H_TOO_HARD) {
/* this can't happen */
pr_err("KVM: Oops, kvmppc_h_enter returned too hard!\n");
ret = H_RESOURCE; /* or something */
}
return ret;
}
KVM: PPC: Book3S HV: Restructure HPT entry creation code This restructures the code that creates HPT (hashed page table) entries so that it can be called in situations where we don't have a struct vcpu pointer, only a struct kvm pointer. It also fixes a bug where kvmppc_map_vrma() would corrupt the guest R4 value. Most of the work of kvmppc_virtmode_h_enter is now done by a new function, kvmppc_virtmode_do_h_enter, which itself calls another new function, kvmppc_do_h_enter, which contains most of the old kvmppc_h_enter. The new kvmppc_do_h_enter takes explicit arguments for the place to return the HPTE index, the Linux page tables to use, and whether it is being called in real mode, thus removing the need for it to have the vcpu as an argument. Currently kvmppc_map_vrma creates the VRMA (virtual real mode area) HPTEs by calling kvmppc_virtmode_h_enter, which is designed primarily to handle H_ENTER hcalls from the guest that need to pin a page of memory. Since H_ENTER returns the index of the created HPTE in R4, kvmppc_virtmode_h_enter updates the guest R4, corrupting the guest R4 in the case when it gets called from kvmppc_map_vrma on the first VCPU_RUN ioctl. With this, kvmppc_map_vrma instead calls kvmppc_virtmode_do_h_enter with the address of a dummy word as the place to store the HPTE index, thus avoiding corrupting the guest R4. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-14 02:31:32 +08:00
/*
* We come here on a H_ENTER call from the guest when we are not
* using mmu notifiers and we don't have the requested page pinned
* already.
*/
long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags,
long pte_index, unsigned long pteh,
unsigned long ptel)
{
return kvmppc_virtmode_do_h_enter(vcpu->kvm, flags, pte_index,
pteh, ptel, &vcpu->arch.gpr[4]);
}
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu,
gva_t eaddr)
{
u64 mask;
int i;
for (i = 0; i < vcpu->arch.slb_nr; i++) {
if (!(vcpu->arch.slb[i].orige & SLB_ESID_V))
continue;
if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T)
mask = ESID_MASK_1T;
else
mask = ESID_MASK;
if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0)
return &vcpu->arch.slb[i];
}
return NULL;
}
static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r,
unsigned long ea)
{
unsigned long ra_mask;
ra_mask = hpte_page_size(v, r) - 1;
return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask);
}
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-20 12:52:51 +08:00
struct kvmppc_pte *gpte, bool data, bool iswrite)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
{
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
struct kvm *kvm = vcpu->kvm;
struct kvmppc_slb *slbe;
unsigned long slb_v;
unsigned long pp, key;
unsigned long v, gr;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
__be64 *hptep;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
int index;
int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
/* Get SLB entry */
if (virtmode) {
slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr);
if (!slbe)
return -EINVAL;
slb_v = slbe->origv;
} else {
/* real mode access */
slb_v = vcpu->kvm->arch.vrma_slb_v;
}
powerpc: kvm: fix rare but potential deadlock scene Since kvmppc_hv_find_lock_hpte() is called from both virtmode and realmode, so it can trigger the deadlock. Suppose the following scene: Two physical cpuM, cpuN, two VM instances A, B, each VM has a group of vcpus. If on cpuM, vcpu_A_1 holds bitlock X (HPTE_V_HVLOCK), then is switched out, and on cpuN, vcpu_A_2 try to lock X in realmode, then cpuN will be caught in realmode for a long time. What makes things even worse if the following happens, On cpuM, bitlockX is hold, on cpuN, Y is hold. vcpu_B_2 try to lock Y on cpuM in realmode vcpu_A_2 try to lock X on cpuN in realmode Oops! deadlock happens Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com> Reviewed-by: Paul Mackerras <paulus@samba.org> CC: stable@vger.kernel.org Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-15 16:35:00 +08:00
preempt_disable();
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
/* Find the HPTE in the hash table */
index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v,
HPTE_V_VALID | HPTE_V_ABSENT);
powerpc: kvm: fix rare but potential deadlock scene Since kvmppc_hv_find_lock_hpte() is called from both virtmode and realmode, so it can trigger the deadlock. Suppose the following scene: Two physical cpuM, cpuN, two VM instances A, B, each VM has a group of vcpus. If on cpuM, vcpu_A_1 holds bitlock X (HPTE_V_HVLOCK), then is switched out, and on cpuN, vcpu_A_2 try to lock X in realmode, then cpuN will be caught in realmode for a long time. What makes things even worse if the following happens, On cpuM, bitlockX is hold, on cpuN, Y is hold. vcpu_B_2 try to lock Y on cpuM in realmode vcpu_A_2 try to lock X on cpuN in realmode Oops! deadlock happens Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com> Reviewed-by: Paul Mackerras <paulus@samba.org> CC: stable@vger.kernel.org Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-15 16:35:00 +08:00
if (index < 0) {
preempt_enable();
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
return -ENOENT;
powerpc: kvm: fix rare but potential deadlock scene Since kvmppc_hv_find_lock_hpte() is called from both virtmode and realmode, so it can trigger the deadlock. Suppose the following scene: Two physical cpuM, cpuN, two VM instances A, B, each VM has a group of vcpus. If on cpuM, vcpu_A_1 holds bitlock X (HPTE_V_HVLOCK), then is switched out, and on cpuN, vcpu_A_2 try to lock X in realmode, then cpuN will be caught in realmode for a long time. What makes things even worse if the following happens, On cpuM, bitlockX is hold, on cpuN, Y is hold. vcpu_B_2 try to lock Y on cpuM in realmode vcpu_A_2 try to lock X on cpuN in realmode Oops! deadlock happens Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com> Reviewed-by: Paul Mackerras <paulus@samba.org> CC: stable@vger.kernel.org Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-15 16:35:00 +08:00
}
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4));
v = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
gr = kvm->arch.revmap[index].guest_rpte;
/* Unlock the HPTE */
asm volatile("lwsync" : : : "memory");
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] = cpu_to_be64(v);
powerpc: kvm: fix rare but potential deadlock scene Since kvmppc_hv_find_lock_hpte() is called from both virtmode and realmode, so it can trigger the deadlock. Suppose the following scene: Two physical cpuM, cpuN, two VM instances A, B, each VM has a group of vcpus. If on cpuM, vcpu_A_1 holds bitlock X (HPTE_V_HVLOCK), then is switched out, and on cpuN, vcpu_A_2 try to lock X in realmode, then cpuN will be caught in realmode for a long time. What makes things even worse if the following happens, On cpuM, bitlockX is hold, on cpuN, Y is hold. vcpu_B_2 try to lock Y on cpuM in realmode vcpu_A_2 try to lock X on cpuN in realmode Oops! deadlock happens Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com> Reviewed-by: Paul Mackerras <paulus@samba.org> CC: stable@vger.kernel.org Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-15 16:35:00 +08:00
preempt_enable();
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
gpte->eaddr = eaddr;
gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff);
/* Get PP bits and key for permission check */
pp = gr & (HPTE_R_PP0 | HPTE_R_PP);
key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS;
key &= slb_v;
/* Calculate permissions */
gpte->may_read = hpte_read_permission(pp, key);
gpte->may_write = hpte_write_permission(pp, key);
gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G));
/* Storage key permission check for POWER7 */
if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) {
int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr);
if (amrfield & 1)
gpte->may_read = 0;
if (amrfield & 2)
gpte->may_write = 0;
}
/* Get the guest physical address */
gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr);
return 0;
}
/*
* Quick test for whether an instruction is a load or a store.
* If the instruction is a load or a store, then this will indicate
* which it is, at least on server processors. (Embedded processors
* have some external PID instructions that don't follow the rule
* embodied here.) If the instruction isn't a load or store, then
* this doesn't return anything useful.
*/
static int instruction_is_store(unsigned int instr)
{
unsigned int mask;
mask = 0x10000000;
if ((instr & 0xfc000000) == 0x7c000000)
mask = 0x100; /* major opcode 31 */
return (instr & mask) != 0;
}
static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu,
KVM: PPC: Pass EA to updating emulation ops When emulating updating load/store instructions (lwzu, stwu, ...) we need to write the effective address of the load/store into a register. Currently, we write the physical address in there, which is very wrong. So instead let's save off where the virtual fault was on MMIO and use that information as value to put into the register. While at it, also move the XOP variants of the above instructions to the new scheme of using the already known vaddr instead of calculating it themselves. Reported-by: Jörg Sommer <joerg@alea.gnuu.de> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-12 09:26:30 +08:00
unsigned long gpa, gva_t ea, int is_store)
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
{
u32 last_inst;
KVM: PPC: Allow kvmppc_get_last_inst() to fail On book3e, guest last instruction is read on the exit path using load external pid (lwepx) dedicated instruction. This load operation may fail due to TLB eviction and execute-but-not-read entries. This patch lay down the path for an alternative solution to read the guest last instruction, by allowing kvmppc_get_lat_inst() function to fail. Architecture specific implmentations of kvmppc_load_last_inst() may read last guest instruction and instruct the emulation layer to re-execute the guest in case of failure. Make kvmppc_get_last_inst() definition common between architectures. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-24 00:06:21 +08:00
/*
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
* If we fail, we just return to the guest and try executing it again.
*/
KVM: PPC: Allow kvmppc_get_last_inst() to fail On book3e, guest last instruction is read on the exit path using load external pid (lwepx) dedicated instruction. This load operation may fail due to TLB eviction and execute-but-not-read entries. This patch lay down the path for an alternative solution to read the guest last instruction, by allowing kvmppc_get_lat_inst() function to fail. Architecture specific implmentations of kvmppc_load_last_inst() may read last guest instruction and instruct the emulation layer to re-execute the guest in case of failure. Make kvmppc_get_last_inst() definition common between architectures. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-24 00:06:21 +08:00
if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) !=
EMULATE_DONE)
return RESUME_GUEST;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
/*
* WARNING: We do not know for sure whether the instruction we just
* read from memory is the same that caused the fault in the first
* place. If the instruction we read is neither an load or a store,
* then it can't access memory, so we don't need to worry about
* enforcing access permissions. So, assuming it is a load or
* store, we just check that its direction (load or store) is
* consistent with the original fault, since that's what we
* checked the access permissions against. If there is a mismatch
* we just return and retry the instruction.
*/
KVM: PPC: Allow kvmppc_get_last_inst() to fail On book3e, guest last instruction is read on the exit path using load external pid (lwepx) dedicated instruction. This load operation may fail due to TLB eviction and execute-but-not-read entries. This patch lay down the path for an alternative solution to read the guest last instruction, by allowing kvmppc_get_lat_inst() function to fail. Architecture specific implmentations of kvmppc_load_last_inst() may read last guest instruction and instruct the emulation layer to re-execute the guest in case of failure. Make kvmppc_get_last_inst() definition common between architectures. Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-24 00:06:21 +08:00
if (instruction_is_store(last_inst) != !!is_store)
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
return RESUME_GUEST;
/*
* Emulated accesses are emulated by looking at the hash for
* translation once, then performing the access later. The
* translation could be invalidated in the meantime in which
* point performing the subsequent memory access on the old
* physical address could possibly be a security hole for the
* guest (but not the host).
*
* This is less of an issue for MMIO stores since they aren't
* globally visible. It could be an issue for MMIO loads to
* a certain extent but we'll ignore it for now.
*/
vcpu->arch.paddr_accessed = gpa;
KVM: PPC: Pass EA to updating emulation ops When emulating updating load/store instructions (lwzu, stwu, ...) we need to write the effective address of the load/store into a register. Currently, we write the physical address in there, which is very wrong. So instead let's save off where the virtual fault was on MMIO and use that information as value to put into the register. While at it, also move the XOP variants of the above instructions to the new scheme of using the already known vaddr instead of calculating it themselves. Reported-by: Jörg Sommer <joerg@alea.gnuu.de> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-12 09:26:30 +08:00
vcpu->arch.vaddr_accessed = ea;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
return kvmppc_emulate_mmio(run, vcpu);
}
int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned long ea, unsigned long dsisr)
{
struct kvm *kvm = vcpu->kvm;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
unsigned long hpte[3], r;
__be64 *hptep;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
unsigned long mmu_seq, psize, pte_size;
KVM: PPC: Book3S HV: Put huge-page HPTEs in rmap chain for base address Currently, when a huge page is faulted in for a guest, we select the rmap chain to insert the HPTE into based on the guest physical address that the guest tried to access. Since there is an rmap chain for each system page, there are many rmap chains for the area covered by a huge page (e.g. 256 for 16MB pages when PAGE_SIZE = 64kB), and the huge-page HPTE could end up in any one of them. For consistency, and to make the huge-page HPTEs easier to find, we now put huge-page HPTEs in the rmap chain corresponding to the base address of the huge page. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:37 +08:00
unsigned long gpa_base, gfn_base;
KVM: PPC: Book3S HV: Fix calculation of guest phys address for MMIO emulation In the case where the host kernel is using a 64kB base page size and the guest uses a 4k HPTE (hashed page table entry) to map an emulated MMIO device, we were calculating the guest physical address wrongly. We were calculating a gfn as the guest physical address shifted right 16 bits (PAGE_SHIFT) but then only adding back in 12 bits from the effective address, since the HPTE had a 4k page size. Thus the gpa reported to userspace was missing 4 bits. Instead, we now compute the guest physical address from the HPTE without reference to the host page size, and then compute the gfn by shifting the gpa right PAGE_SHIFT bits. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-21 03:39:21 +08:00
unsigned long gpa, gfn, hva, pfn;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
struct kvm_memory_slot *memslot;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
unsigned long *rmap;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
struct revmap_entry *rev;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
struct page *page, *pages[1];
long index, ret, npages;
unsigned long is_io;
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
unsigned int writing, write_ok;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
struct vm_area_struct *vma;
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
unsigned long rcbits;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
/*
* Real-mode code has already searched the HPT and found the
* entry we're interested in. Lock the entry and check that
* it hasn't changed. If it has, just return and re-execute the
* instruction.
*/
if (ea != vcpu->arch.pgfault_addr)
return RESUME_GUEST;
index = vcpu->arch.pgfault_index;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep = (__be64 *)(kvm->arch.hpt_virt + (index << 4));
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
rev = &kvm->arch.revmap[index];
preempt_disable();
while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
cpu_relax();
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hpte[0] = be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK;
hpte[1] = be64_to_cpu(hptep[1]);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
hpte[2] = r = rev->guest_rpte;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
asm volatile("lwsync" : : : "memory");
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] = cpu_to_be64(hpte[0]);
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
preempt_enable();
if (hpte[0] != vcpu->arch.pgfault_hpte[0] ||
hpte[1] != vcpu->arch.pgfault_hpte[1])
return RESUME_GUEST;
/* Translate the logical address and get the page */
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
psize = hpte_page_size(hpte[0], r);
KVM: PPC: Book3S HV: Put huge-page HPTEs in rmap chain for base address Currently, when a huge page is faulted in for a guest, we select the rmap chain to insert the HPTE into based on the guest physical address that the guest tried to access. Since there is an rmap chain for each system page, there are many rmap chains for the area covered by a huge page (e.g. 256 for 16MB pages when PAGE_SIZE = 64kB), and the huge-page HPTE could end up in any one of them. For consistency, and to make the huge-page HPTEs easier to find, we now put huge-page HPTEs in the rmap chain corresponding to the base address of the huge page. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:37 +08:00
gpa_base = r & HPTE_R_RPN & ~(psize - 1);
gfn_base = gpa_base >> PAGE_SHIFT;
gpa = gpa_base | (ea & (psize - 1));
KVM: PPC: Book3S HV: Fix calculation of guest phys address for MMIO emulation In the case where the host kernel is using a 64kB base page size and the guest uses a 4k HPTE (hashed page table entry) to map an emulated MMIO device, we were calculating the guest physical address wrongly. We were calculating a gfn as the guest physical address shifted right 16 bits (PAGE_SHIFT) but then only adding back in 12 bits from the effective address, since the HPTE had a 4k page size. Thus the gpa reported to userspace was missing 4 bits. Instead, we now compute the guest physical address from the HPTE without reference to the host page size, and then compute the gfn by shifting the gpa right PAGE_SHIFT bits. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-21 03:39:21 +08:00
gfn = gpa >> PAGE_SHIFT;
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
memslot = gfn_to_memslot(kvm, gfn);
/* No memslot means it's an emulated MMIO region */
KVM: PPC: Book3S HV: Fix calculation of guest phys address for MMIO emulation In the case where the host kernel is using a 64kB base page size and the guest uses a 4k HPTE (hashed page table entry) to map an emulated MMIO device, we were calculating the guest physical address wrongly. We were calculating a gfn as the guest physical address shifted right 16 bits (PAGE_SHIFT) but then only adding back in 12 bits from the effective address, since the HPTE had a 4k page size. Thus the gpa reported to userspace was missing 4 bits. Instead, we now compute the guest physical address from the HPTE without reference to the host page size, and then compute the gfn by shifting the gpa right PAGE_SHIFT bits. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-21 03:39:21 +08:00
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
KVM: PPC: Pass EA to updating emulation ops When emulating updating load/store instructions (lwzu, stwu, ...) we need to write the effective address of the load/store into a register. Currently, we write the physical address in there, which is very wrong. So instead let's save off where the virtual fault was on MMIO and use that information as value to put into the register. While at it, also move the XOP variants of the above instructions to the new scheme of using the already known vaddr instead of calculating it themselves. Reported-by: Jörg Sommer <joerg@alea.gnuu.de> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-12 09:26:30 +08:00
return kvmppc_hv_emulate_mmio(run, vcpu, gpa, ea,
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:36:37 +08:00
dsisr & DSISR_ISSTORE);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (!kvm->arch.using_mmu_notifiers)
return -EFAULT; /* should never get here */
KVM: PPC: Book3S HV: Put huge-page HPTEs in rmap chain for base address Currently, when a huge page is faulted in for a guest, we select the rmap chain to insert the HPTE into based on the guest physical address that the guest tried to access. Since there is an rmap chain for each system page, there are many rmap chains for the area covered by a huge page (e.g. 256 for 16MB pages when PAGE_SIZE = 64kB), and the huge-page HPTE could end up in any one of them. For consistency, and to make the huge-page HPTEs easier to find, we now put huge-page HPTEs in the rmap chain corresponding to the base address of the huge page. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:37 +08:00
/*
* This should never happen, because of the slot_is_aligned()
* check in kvmppc_do_h_enter().
*/
if (gfn_base < memslot->base_gfn)
return -EFAULT;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
/* used to check for invalidations in progress */
mmu_seq = kvm->mmu_notifier_seq;
smp_rmb();
is_io = 0;
pfn = 0;
page = NULL;
pte_size = PAGE_SIZE;
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
writing = (dsisr & DSISR_ISSTORE) != 0;
/* If writing != 0, then the HPTE must allow writing, if we get here */
write_ok = writing;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
hva = gfn_to_hva_memslot(memslot, gfn);
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
npages = get_user_pages_fast(hva, 1, writing, pages);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (npages < 1) {
/* Check if it's an I/O mapping */
down_read(&current->mm->mmap_sem);
vma = find_vma(current->mm, hva);
if (vma && vma->vm_start <= hva && hva + psize <= vma->vm_end &&
(vma->vm_flags & VM_PFNMAP)) {
pfn = vma->vm_pgoff +
((hva - vma->vm_start) >> PAGE_SHIFT);
pte_size = psize;
is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
write_ok = vma->vm_flags & VM_WRITE;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
}
up_read(&current->mm->mmap_sem);
if (!pfn)
return -EFAULT;
} else {
page = pages[0];
KVM: PPC: Book3S HV: Fix physical address calculations This fixes a bug in kvmppc_do_h_enter() where the physical address for a page can be calculated incorrectly if transparent huge pages (THP) are active. Until THP came along, it was true that if we encountered a large (16M) page in kvmppc_do_h_enter(), then the associated memslot must be 16M aligned for both its guest physical address and the userspace address, and the physical address calculations in kvmppc_do_h_enter() assumed that. With THP, that is no longer true. In the case where we are using MMU notifiers and the page size that we get from the Linux page tables is larger than the page being mapped by the guest, we need to fill in some low-order bits of the physical address. Without THP, these bits would be the same in the guest physical address (gpa) and the host virtual address (hva). With THP, they can be different, and we need to use the bits from hva rather than gpa. In the case where we are not using MMU notifiers, the host physical address we get from the memslot->arch.slot_phys[] array already includes the low-order bits down to the PAGE_SIZE level, even if we are using large pages. Thus we can simplify the calculation in this case to just add in the remaining bits in the case where PAGE_SIZE is 64k and the guest is mapping a 4k page. The same bug exists in kvmppc_book3s_hv_page_fault(). The basic fix is to use psize (the page size from the HPTE) rather than pte_size (the page size from the Linux PTE) when updating the HPTE low word in r. That means that pfn needs to be computed to PAGE_SIZE granularity even if the Linux PTE is a huge page PTE. That can be arranged simply by doing the page_to_pfn() before setting page to the head of the compound page. If psize is less than PAGE_SIZE, then we need to make sure we only update the bits from PAGE_SIZE upwards, in order not to lose any sub-page offset bits in r. On the other hand, if psize is greater than PAGE_SIZE, we need to make sure we don't bring in non-zero low order bits in pfn, hence we mask (pfn << PAGE_SHIFT) with ~(psize - 1). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-16 14:46:02 +08:00
pfn = page_to_pfn(page);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (PageHuge(page)) {
page = compound_head(page);
pte_size <<= compound_order(page);
}
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
/* if the guest wants write access, see if that is OK */
if (!writing && hpte_is_writable(r)) {
powerpc/kvm: Handle transparent hugepage in KVM We can find pte that are splitting while walking page tables. Return None pte in that case. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-20 17:00:19 +08:00
unsigned int hugepage_shift;
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
pte_t *ptep, pte;
/*
* We need to protect against page table destruction
* while looking up and updating the pte.
*/
rcu_read_lock_sched();
ptep = find_linux_pte_or_hugepte(current->mm->pgd,
powerpc/kvm: Handle transparent hugepage in KVM We can find pte that are splitting while walking page tables. Return None pte in that case. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-20 17:00:19 +08:00
hva, &hugepage_shift);
if (ptep) {
pte = kvmppc_read_update_linux_pte(ptep, 1,
hugepage_shift);
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
if (pte_write(pte))
write_ok = 1;
}
rcu_read_unlock_sched();
}
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
}
ret = -EFAULT;
if (psize > pte_size)
goto out_put;
/* Check WIMG vs. the actual page we're accessing */
if (!hpte_cache_flags_ok(r, is_io)) {
if (is_io)
return -EFAULT;
/*
* Allow guest to map emulated device memory as
* uncacheable, but actually make it cacheable.
*/
r = (r & ~(HPTE_R_W|HPTE_R_I|HPTE_R_G)) | HPTE_R_M;
}
KVM: PPC: Book3S HV: Fix physical address calculations This fixes a bug in kvmppc_do_h_enter() where the physical address for a page can be calculated incorrectly if transparent huge pages (THP) are active. Until THP came along, it was true that if we encountered a large (16M) page in kvmppc_do_h_enter(), then the associated memslot must be 16M aligned for both its guest physical address and the userspace address, and the physical address calculations in kvmppc_do_h_enter() assumed that. With THP, that is no longer true. In the case where we are using MMU notifiers and the page size that we get from the Linux page tables is larger than the page being mapped by the guest, we need to fill in some low-order bits of the physical address. Without THP, these bits would be the same in the guest physical address (gpa) and the host virtual address (hva). With THP, they can be different, and we need to use the bits from hva rather than gpa. In the case where we are not using MMU notifiers, the host physical address we get from the memslot->arch.slot_phys[] array already includes the low-order bits down to the PAGE_SIZE level, even if we are using large pages. Thus we can simplify the calculation in this case to just add in the remaining bits in the case where PAGE_SIZE is 64k and the guest is mapping a 4k page. The same bug exists in kvmppc_book3s_hv_page_fault(). The basic fix is to use psize (the page size from the HPTE) rather than pte_size (the page size from the Linux PTE) when updating the HPTE low word in r. That means that pfn needs to be computed to PAGE_SIZE granularity even if the Linux PTE is a huge page PTE. That can be arranged simply by doing the page_to_pfn() before setting page to the head of the compound page. If psize is less than PAGE_SIZE, then we need to make sure we only update the bits from PAGE_SIZE upwards, in order not to lose any sub-page offset bits in r. On the other hand, if psize is greater than PAGE_SIZE, we need to make sure we don't bring in non-zero low order bits in pfn, hence we mask (pfn << PAGE_SHIFT) with ~(psize - 1). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-11-16 14:46:02 +08:00
/*
* Set the HPTE to point to pfn.
* Since the pfn is at PAGE_SIZE granularity, make sure we
* don't mask out lower-order bits if psize < PAGE_SIZE.
*/
if (psize < PAGE_SIZE)
psize = PAGE_SIZE;
r = (r & ~(HPTE_R_PP0 - psize)) | ((pfn << PAGE_SHIFT) & ~(psize - 1));
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
if (hpte_is_writable(r) && !write_ok)
r = hpte_make_readonly(r);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
ret = RESUME_GUEST;
preempt_disable();
while (!try_lock_hpte(hptep, HPTE_V_HVLOCK))
cpu_relax();
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if ((be64_to_cpu(hptep[0]) & ~HPTE_V_HVLOCK) != hpte[0] ||
be64_to_cpu(hptep[1]) != hpte[1] ||
rev->guest_rpte != hpte[2])
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
/* HPTE has been changed under us; let the guest retry */
goto out_unlock;
hpte[0] = (hpte[0] & ~HPTE_V_ABSENT) | HPTE_V_VALID;
KVM: PPC: Book3S HV: Put huge-page HPTEs in rmap chain for base address Currently, when a huge page is faulted in for a guest, we select the rmap chain to insert the HPTE into based on the guest physical address that the guest tried to access. Since there is an rmap chain for each system page, there are many rmap chains for the area covered by a huge page (e.g. 256 for 16MB pages when PAGE_SIZE = 64kB), and the huge-page HPTE could end up in any one of them. For consistency, and to make the huge-page HPTEs easier to find, we now put huge-page HPTEs in the rmap chain corresponding to the base address of the huge page. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:37 +08:00
/* Always put the HPTE in the rmap chain for the page base address */
rmap = &memslot->arch.rmap[gfn_base - memslot->base_gfn];
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
lock_rmap(rmap);
/* Check if we might have been invalidated; let the guest retry if so */
ret = RESUME_GUEST;
KVM: Take kvm instead of vcpu to mmu_notifier_retry The mmu_notifier_retry is not specific to any vcpu (and never will be) so only take struct kvm as a parameter. The motivation is the ARM mmu code that needs to call this from somewhere where we long let go of the vcpu pointer. Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-10-15 11:10:18 +08:00
if (mmu_notifier_retry(vcpu->kvm, mmu_seq)) {
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
unlock_rmap(rmap);
goto out_unlock;
}
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
/* Only set R/C in real HPTE if set in both *rmap and guest_rpte */
rcbits = *rmap >> KVMPPC_RMAP_RC_SHIFT;
r &= rcbits | ~(HPTE_R_R | HPTE_R_C);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (be64_to_cpu(hptep[0]) & HPTE_V_VALID) {
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
/* HPTE was previously valid, so we need to invalidate it */
unlock_rmap(rmap);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
kvmppc_invalidate_hpte(kvm, hptep, index);
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
/* don't lose previous R and C bits */
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
r |= be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
} else {
kvmppc_add_revmap_chain(kvm, rev, rmap, index, 0);
}
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[1] = cpu_to_be64(r);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
eieio();
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] = cpu_to_be64(hpte[0]);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
asm volatile("ptesync" : : : "memory");
preempt_enable();
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:51 +08:00
if (page && hpte_is_writable(r))
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
SetPageDirty(page);
out_put:
KVM: PPC: Book3S HV: Fix refcounting of hugepages The H_REGISTER_VPA hcall implementation in HV Power KVM needs to pin some guest memory pages into host memory so that they can be safely accessed from usermode. It does this used get_user_pages_fast(). When the VPA is unregistered, or the VCPUs are cleaned up, these pages are released using put_page(). However, the get_user_pages() is invoked on the specific memory are of the VPA which could lie within hugepages. In case the pinned page is huge, we explicitly find the head page of the compound page before calling put_page() on it. At least with the latest kernel, this is not correct. put_page() already handles finding the correct head page of a compound, and also deals with various counts on the individual tail page which are important for transparent huge pages. We don't support transparent hugepages on Power, but even so, bypassing this count maintenance can lead (when the VM ends) to a hugepage being released back to the pool with a non-zero mapcount on one of the tail pages. This can then lead to a bad_page() when the page is released from the hugepage pool. This removes the explicit compound_head() call to correct this bug. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-08 18:24:08 +08:00
if (page) {
/*
* We drop pages[0] here, not page because page might
* have been set to the head page of a compound, but
* we have to drop the reference on the correct tail
* page to match the get inside gup()
*/
put_page(pages[0]);
}
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
return ret;
out_unlock:
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
preempt_enable();
goto out_put;
}
KVM: PPC: Book3S HV: Reset reverse-map chains when resetting the HPT With HV-style KVM, we maintain reverse-mapping lists that enable us to find all the HPT (hashed page table) entries that reference each guest physical page, with the heads of the lists in the memslot->arch.rmap arrays. When we reset the HPT (i.e. when we reboot the VM), we clear out all the HPT entries but we were not clearing out the reverse mapping lists. The result is that as we create new HPT entries, the lists get corrupted, which can easily lead to loops, resulting in the host kernel hanging when it tries to traverse those lists. This fixes the problem by zeroing out all the reverse mapping lists when we zero out the HPT. This incidentally means that we are also zeroing our record of the referenced and changed bits (not the bits in the Linux PTEs, used by the Linux MM subsystem, but the bits used by the KVM_GET_DIRTY_LOG ioctl, and those used by kvm_age_hva() and kvm_test_age_hva()). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-22 07:27:19 +08:00
static void kvmppc_rmap_reset(struct kvm *kvm)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
int srcu_idx;
srcu_idx = srcu_read_lock(&kvm->srcu);
slots = kvm->memslots;
kvm_for_each_memslot(memslot, slots) {
/*
* This assumes it is acceptable to lose reference and
* change bits across a reset.
*/
memset(memslot->arch.rmap, 0,
memslot->npages * sizeof(*memslot->arch.rmap));
}
srcu_read_unlock(&kvm->srcu, srcu_idx);
}
KVM: MMU: Make kvm_handle_hva() handle range of addresses When guest's memory is backed by THP pages, MMU notifier needs to call kvm_unmap_hva(), which in turn leads to kvm_handle_hva(), in a loop to invalidate a range of pages which constitute one huge page: for each page for each memslot if page is in memslot unmap using rmap This means although every page in that range is expected to be found in the same memslot, we are forced to check unrelated memslots many times. If the guest has more memslots, the situation will become worse. Furthermore, if the range does not include any pages in the guest's memory, the loop over the pages will just consume extra time. This patch, together with the following patches, solves this problem by introducing kvm_handle_hva_range() which makes the loop look like this: for each memslot for each page in memslot unmap using rmap In this new processing, the actual work is converted to a loop over rmap which is much more cache friendly than before. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Cc: Alexander Graf <agraf@suse.de> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 16:55:48 +08:00
static int kvm_handle_hva_range(struct kvm *kvm,
unsigned long start,
unsigned long end,
int (*handler)(struct kvm *kvm,
unsigned long *rmapp,
unsigned long gfn))
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
{
int ret;
int retval = 0;
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots) {
KVM: MMU: Make kvm_handle_hva() handle range of addresses When guest's memory is backed by THP pages, MMU notifier needs to call kvm_unmap_hva(), which in turn leads to kvm_handle_hva(), in a loop to invalidate a range of pages which constitute one huge page: for each page for each memslot if page is in memslot unmap using rmap This means although every page in that range is expected to be found in the same memslot, we are forced to check unrelated memslots many times. If the guest has more memslots, the situation will become worse. Furthermore, if the range does not include any pages in the guest's memory, the loop over the pages will just consume extra time. This patch, together with the following patches, solves this problem by introducing kvm_handle_hva_range() which makes the loop look like this: for each memslot for each page in memslot unmap using rmap In this new processing, the actual work is converted to a loop over rmap which is much more cache friendly than before. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Cc: Alexander Graf <agraf@suse.de> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 16:55:48 +08:00
unsigned long hva_start, hva_end;
gfn_t gfn, gfn_end;
hva_start = max(start, memslot->userspace_addr);
hva_end = min(end, memslot->userspace_addr +
(memslot->npages << PAGE_SHIFT));
if (hva_start >= hva_end)
continue;
/*
* {gfn(page) | page intersects with [hva_start, hva_end)} =
* {gfn, gfn+1, ..., gfn_end-1}.
*/
gfn = hva_to_gfn_memslot(hva_start, memslot);
gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
KVM: MMU: Make kvm_handle_hva() handle range of addresses When guest's memory is backed by THP pages, MMU notifier needs to call kvm_unmap_hva(), which in turn leads to kvm_handle_hva(), in a loop to invalidate a range of pages which constitute one huge page: for each page for each memslot if page is in memslot unmap using rmap This means although every page in that range is expected to be found in the same memslot, we are forced to check unrelated memslots many times. If the guest has more memslots, the situation will become worse. Furthermore, if the range does not include any pages in the guest's memory, the loop over the pages will just consume extra time. This patch, together with the following patches, solves this problem by introducing kvm_handle_hva_range() which makes the loop look like this: for each memslot for each page in memslot unmap using rmap In this new processing, the actual work is converted to a loop over rmap which is much more cache friendly than before. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Cc: Alexander Graf <agraf@suse.de> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 16:55:48 +08:00
for (; gfn < gfn_end; ++gfn) {
KVM: Introduce hva_to_gfn_memslot() for kvm_handle_hva() This restricts hva handling in mmu code and makes it easier to extend kvm_handle_hva() so that it can treat a range of addresses later in this patch series. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Cc: Alexander Graf <agraf@suse.de> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 16:54:30 +08:00
gfn_t gfn_offset = gfn - memslot->base_gfn;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
KVM: Push rmap into kvm_arch_memory_slot Two reasons: - x86 can integrate rmap and rmap_pde and remove heuristics in __gfn_to_rmap(). - Some architectures do not need rmap. Since rmap is one of the most memory consuming stuff in KVM, ppc'd better restrict the allocation to Book3S HV. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-01 17:03:28 +08:00
ret = handler(kvm, &memslot->arch.rmap[gfn_offset], gfn);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
retval |= ret;
}
}
return retval;
}
KVM: MMU: Make kvm_handle_hva() handle range of addresses When guest's memory is backed by THP pages, MMU notifier needs to call kvm_unmap_hva(), which in turn leads to kvm_handle_hva(), in a loop to invalidate a range of pages which constitute one huge page: for each page for each memslot if page is in memslot unmap using rmap This means although every page in that range is expected to be found in the same memslot, we are forced to check unrelated memslots many times. If the guest has more memslots, the situation will become worse. Furthermore, if the range does not include any pages in the guest's memory, the loop over the pages will just consume extra time. This patch, together with the following patches, solves this problem by introducing kvm_handle_hva_range() which makes the loop look like this: for each memslot for each page in memslot unmap using rmap In this new processing, the actual work is converted to a loop over rmap which is much more cache friendly than before. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Cc: Alexander Graf <agraf@suse.de> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 16:55:48 +08:00
static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
int (*handler)(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn))
{
return kvm_handle_hva_range(kvm, hva, hva + 1, handler);
}
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn)
{
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long h, i, j;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
__be64 *hptep;
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
unsigned long ptel, psize, rcbits;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
for (;;) {
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
lock_rmap(rmapp);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
unlock_rmap(rmapp);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
break;
}
/*
* To avoid an ABBA deadlock with the HPTE lock bit,
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
* we can't spin on the HPTE lock while holding the
* rmap chain lock.
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
*/
i = *rmapp & KVMPPC_RMAP_INDEX;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
cpu_relax();
continue;
}
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
j = rev[i].forw;
if (j == i) {
/* chain is now empty */
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
*rmapp &= ~(KVMPPC_RMAP_PRESENT | KVMPPC_RMAP_INDEX);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
} else {
/* remove i from chain */
h = rev[i].back;
rev[h].forw = j;
rev[j].back = h;
rev[i].forw = rev[i].back = i;
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
*rmapp = (*rmapp & ~KVMPPC_RMAP_INDEX) | j;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
}
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
/* Now check and modify the HPTE */
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
ptel = rev[i].guest_rpte;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
psize = hpte_page_size(be64_to_cpu(hptep[0]), ptel);
if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
hpte_rpn(ptel, psize) == gfn) {
KVM: PPC: Book3S HV: Handle memory slot deletion and modification correctly This adds an implementation of kvm_arch_flush_shadow_memslot for Book3S HV, and arranges for kvmppc_core_commit_memory_region to flush the dirty log when modifying an existing slot. With this, we can handle deletion and modification of memory slots. kvm_arch_flush_shadow_memslot calls kvmppc_core_flush_memslot, which on Book3S HV now traverses the reverse map chains to remove any HPT (hashed page table) entries referring to pages in the memslot. This gets called by generic code whenever deleting a memslot or changing the guest physical address for a memslot. We flush the dirty log in kvmppc_core_commit_memory_region for consistency with what x86 does. We only need to flush when an existing memslot is being modified, because for a new memslot the rmap array (which stores the dirty bits) is all zero, meaning that every page is considered clean already, and when deleting a memslot we obviously don't care about the dirty bits any more. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:28:18 +08:00
if (kvm->arch.using_mmu_notifiers)
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
kvmppc_invalidate_hpte(kvm, hptep, i);
/* Harvest R and C */
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
rcbits = be64_to_cpu(hptep[1]) & (HPTE_R_R | HPTE_R_C);
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
*rmapp |= rcbits << KVMPPC_RMAP_RC_SHIFT;
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
if (rcbits & ~rev[i].guest_rpte) {
rev[i].guest_rpte = ptel | rcbits;
note_hpte_modification(kvm, &rev[i]);
}
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
}
KVM: PPC: Book3s HV: Maintain separate guest and host views of R and C bits This allows both the guest and the host to use the referenced (R) and changed (C) bits in the guest hashed page table. The guest has a view of R and C that is maintained in the guest_rpte field of the revmap entry for the HPTE, and the host has a view that is maintained in the rmap entry for the associated gfn. Both view are updated from the guest HPT. If a bit (R or C) is zero in either view, it will be initially set to zero in the HPTE (or HPTEs), until set to 1 by hardware. When an HPTE is removed for any reason, the R and C bits from the HPTE are ORed into both views. We have to be careful to read the R and C bits from the HPTE after invalidating it, but before unlocking it, in case of any late updates by the hardware. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:02 +08:00
unlock_rmap(rmapp);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
}
return 0;
}
kvm: powerpc: Add kvmppc_ops callback This patch add a new callback kvmppc_ops. This will help us in enabling both HV and PR KVM together in the same kernel. The actual change to enable them together is done in the later patch in the series. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [agraf: squash in booke changes] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-08 00:47:53 +08:00
int kvm_unmap_hva_hv(struct kvm *kvm, unsigned long hva)
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
{
if (kvm->arch.using_mmu_notifiers)
kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
return 0;
}
kvm: powerpc: Add kvmppc_ops callback This patch add a new callback kvmppc_ops. This will help us in enabling both HV and PR KVM together in the same kernel. The actual change to enable them together is done in the later patch in the series. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [agraf: squash in booke changes] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-08 00:47:53 +08:00
int kvm_unmap_hva_range_hv(struct kvm *kvm, unsigned long start, unsigned long end)
KVM: Introduce kvm_unmap_hva_range() for kvm_mmu_notifier_invalidate_range_start() When we tested KVM under memory pressure, with THP enabled on the host, we noticed that MMU notifier took a long time to invalidate huge pages. Since the invalidation was done with mmu_lock held, it not only wasted the CPU but also made the host harder to respond. This patch mitigates this by using kvm_handle_hva_range(). Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Cc: Alexander Graf <agraf@suse.de> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-07-02 16:56:33 +08:00
{
if (kvm->arch.using_mmu_notifiers)
kvm_handle_hva_range(kvm, start, end, kvm_unmap_rmapp);
return 0;
}
kvm: powerpc: Add kvmppc_ops callback This patch add a new callback kvmppc_ops. This will help us in enabling both HV and PR KVM together in the same kernel. The actual change to enable them together is done in the later patch in the series. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [agraf: squash in booke changes] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-08 00:47:53 +08:00
void kvmppc_core_flush_memslot_hv(struct kvm *kvm,
struct kvm_memory_slot *memslot)
KVM: PPC: Book3S HV: Handle memory slot deletion and modification correctly This adds an implementation of kvm_arch_flush_shadow_memslot for Book3S HV, and arranges for kvmppc_core_commit_memory_region to flush the dirty log when modifying an existing slot. With this, we can handle deletion and modification of memory slots. kvm_arch_flush_shadow_memslot calls kvmppc_core_flush_memslot, which on Book3S HV now traverses the reverse map chains to remove any HPT (hashed page table) entries referring to pages in the memslot. This gets called by generic code whenever deleting a memslot or changing the guest physical address for a memslot. We flush the dirty log in kvmppc_core_commit_memory_region for consistency with what x86 does. We only need to flush when an existing memslot is being modified, because for a new memslot the rmap array (which stores the dirty bits) is all zero, meaning that every page is considered clean already, and when deleting a memslot we obviously don't care about the dirty bits any more. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:28:18 +08:00
{
unsigned long *rmapp;
unsigned long gfn;
unsigned long n;
rmapp = memslot->arch.rmap;
gfn = memslot->base_gfn;
for (n = memslot->npages; n; --n) {
/*
* Testing the present bit without locking is OK because
* the memslot has been marked invalid already, and hence
* no new HPTEs referencing this page can be created,
* thus the present bit can't go from 0 to 1.
*/
if (*rmapp & KVMPPC_RMAP_PRESENT)
kvm_unmap_rmapp(kvm, rmapp, gfn);
++rmapp;
++gfn;
}
}
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn)
{
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long head, i, j;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
__be64 *hptep;
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
int ret = 0;
retry:
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_REFERENCED) {
*rmapp &= ~KVMPPC_RMAP_REFERENCED;
ret = 1;
}
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
return ret;
}
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
j = rev[i].forw;
/* If this HPTE isn't referenced, ignore it */
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (!(be64_to_cpu(hptep[1]) & HPTE_R_R))
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
continue;
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
while (be64_to_cpu(hptep[0]) & HPTE_V_HVLOCK)
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
cpu_relax();
goto retry;
}
/* Now check and modify the HPTE */
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if ((be64_to_cpu(hptep[0]) & HPTE_V_VALID) &&
(be64_to_cpu(hptep[1]) & HPTE_R_R)) {
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
kvmppc_clear_ref_hpte(kvm, hptep, i);
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
if (!(rev[i].guest_rpte & HPTE_R_R)) {
rev[i].guest_rpte |= HPTE_R_R;
note_hpte_modification(kvm, &rev[i]);
}
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
ret = 1;
}
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
} while ((i = j) != head);
unlock_rmap(rmapp);
return ret;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
}
kvm: powerpc: Add kvmppc_ops callback This patch add a new callback kvmppc_ops. This will help us in enabling both HV and PR KVM together in the same kernel. The actual change to enable them together is done in the later patch in the series. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [agraf: squash in booke changes] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-08 00:47:53 +08:00
int kvm_age_hva_hv(struct kvm *kvm, unsigned long hva)
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
{
if (!kvm->arch.using_mmu_notifiers)
return 0;
return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
}
static int kvm_test_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
unsigned long gfn)
{
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long head, i, j;
unsigned long *hp;
int ret = 1;
if (*rmapp & KVMPPC_RMAP_REFERENCED)
return 1;
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_REFERENCED)
goto out;
if (*rmapp & KVMPPC_RMAP_PRESENT) {
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
hp = (unsigned long *)(kvm->arch.hpt_virt + (i << 4));
j = rev[i].forw;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (be64_to_cpu(hp[1]) & HPTE_R_R)
KVM: PPC: Book3S HV: Use the hardware referenced bit for kvm_age_hva This uses the host view of the hardware R (referenced) bit to speed up kvm_age_hva() and kvm_test_age_hva(). Instead of removing all the relevant HPTEs in kvm_age_hva(), we now just reset their R bits if set. Also, kvm_test_age_hva() now scans the relevant HPTEs to see if any of them have R set. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:02:47 +08:00
goto out;
} while ((i = j) != head);
}
ret = 0;
out:
unlock_rmap(rmapp);
return ret;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
}
kvm: powerpc: Add kvmppc_ops callback This patch add a new callback kvmppc_ops. This will help us in enabling both HV and PR KVM together in the same kernel. The actual change to enable them together is done in the later patch in the series. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [agraf: squash in booke changes] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-08 00:47:53 +08:00
int kvm_test_age_hva_hv(struct kvm *kvm, unsigned long hva)
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
{
if (!kvm->arch.using_mmu_notifiers)
return 0;
return kvm_handle_hva(kvm, hva, kvm_test_age_rmapp);
}
kvm: powerpc: Add kvmppc_ops callback This patch add a new callback kvmppc_ops. This will help us in enabling both HV and PR KVM together in the same kernel. The actual change to enable them together is done in the later patch in the series. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [agraf: squash in booke changes] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-10-08 00:47:53 +08:00
void kvm_set_spte_hva_hv(struct kvm *kvm, unsigned long hva, pte_t pte)
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
{
if (!kvm->arch.using_mmu_notifiers)
return;
kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
}
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
static int vcpus_running(struct kvm *kvm)
{
return atomic_read(&kvm->arch.vcpus_running) != 0;
}
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
/*
* Returns the number of system pages that are dirty.
* This can be more than 1 if we find a huge-page HPTE.
*/
static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
{
struct revmap_entry *rev = kvm->arch.revmap;
unsigned long head, i, j;
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
unsigned long n;
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
unsigned long v, r;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
__be64 *hptep;
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
int npages_dirty = 0;
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
retry:
lock_rmap(rmapp);
if (*rmapp & KVMPPC_RMAP_CHANGED) {
*rmapp &= ~KVMPPC_RMAP_CHANGED;
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
npages_dirty = 1;
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
}
if (!(*rmapp & KVMPPC_RMAP_PRESENT)) {
unlock_rmap(rmapp);
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
return npages_dirty;
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
}
i = head = *rmapp & KVMPPC_RMAP_INDEX;
do {
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
unsigned long hptep1;
hptep = (__be64 *) (kvm->arch.hpt_virt + (i << 4));
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
j = rev[i].forw;
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
/*
* Checking the C (changed) bit here is racy since there
* is no guarantee about when the hardware writes it back.
* If the HPTE is not writable then it is stable since the
* page can't be written to, and we would have done a tlbie
* (which forces the hardware to complete any writeback)
* when making the HPTE read-only.
* If vcpus are running then this call is racy anyway
* since the page could get dirtied subsequently, so we
* expect there to be a further call which would pick up
* any delayed C bit writeback.
* Otherwise we need to do the tlbie even if C==0 in
* order to pick up any delayed writeback of C.
*/
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep1 = be64_to_cpu(hptep[1]);
if (!(hptep1 & HPTE_R_C) &&
(!hpte_is_writable(hptep1) || vcpus_running(kvm)))
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
continue;
if (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) {
/* unlock rmap before spinning on the HPTE lock */
unlock_rmap(rmapp);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
while (hptep[0] & cpu_to_be64(HPTE_V_HVLOCK))
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
cpu_relax();
goto retry;
}
/* Now check and modify the HPTE */
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID)))
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
continue;
/* need to make it temporarily absent so C is stable */
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
kvmppc_invalidate_hpte(kvm, hptep, i);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
v = be64_to_cpu(hptep[0]);
r = be64_to_cpu(hptep[1]);
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
if (r & HPTE_R_C) {
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[1] = cpu_to_be64(r & ~HPTE_R_C);
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
if (!(rev[i].guest_rpte & HPTE_R_C)) {
rev[i].guest_rpte |= HPTE_R_C;
note_hpte_modification(kvm, &rev[i]);
}
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
n = hpte_page_size(v, r);
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT;
if (n > npages_dirty)
npages_dirty = n;
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
eieio();
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
}
KVM: PPC: Book3S HV: Make sure we don't miss dirty pages Current, when testing whether a page is dirty (when constructing the bitmap for the KVM_GET_DIRTY_LOG ioctl), we test the C (changed) bit in the HPT entries mapping the page, and if it is 0, we consider the page to be clean. However, the Power ISA doesn't require processors to set the C bit to 1 immediately when writing to a page, and in fact allows them to delay the writeback of the C bit until they receive a TLB invalidation for the page. Thus it is possible that the page could be dirty and we miss it. Now, if there are vcpus running, this is not serious since the collection of the dirty log is racy already - some vcpu could dirty the page just after we check it. But if there are no vcpus running we should return definitive results, in case we are in the final phase of migrating the guest. Also, if the permission bits in the HPTE don't allow writing, then we know that no CPU can set C. If the HPTE was previously writable and the page was modified, any C bit writeback would have been flushed out by the tlbie that we did when changing the HPTE to read-only. Otherwise we need to do a TLB invalidation even if the C bit is 0, and then check the C bit. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:39 +08:00
v &= ~(HPTE_V_ABSENT | HPTE_V_HVLOCK);
v |= HPTE_V_VALID;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptep[0] = cpu_to_be64(v);
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
} while ((i = j) != head);
unlock_rmap(rmapp);
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
return npages_dirty;
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
}
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
static void harvest_vpa_dirty(struct kvmppc_vpa *vpa,
struct kvm_memory_slot *memslot,
unsigned long *map)
{
unsigned long gfn;
if (!vpa->dirty || !vpa->pinned_addr)
return;
gfn = vpa->gpa >> PAGE_SHIFT;
if (gfn < memslot->base_gfn ||
gfn >= memslot->base_gfn + memslot->npages)
return;
vpa->dirty = false;
if (map)
__set_bit_le(gfn - memslot->base_gfn, map);
}
KVM: PPC: Book3S HV: Handle memory slot deletion and modification correctly This adds an implementation of kvm_arch_flush_shadow_memslot for Book3S HV, and arranges for kvmppc_core_commit_memory_region to flush the dirty log when modifying an existing slot. With this, we can handle deletion and modification of memory slots. kvm_arch_flush_shadow_memslot calls kvmppc_core_flush_memslot, which on Book3S HV now traverses the reverse map chains to remove any HPT (hashed page table) entries referring to pages in the memslot. This gets called by generic code whenever deleting a memslot or changing the guest physical address for a memslot. We flush the dirty log in kvmppc_core_commit_memory_region for consistency with what x86 does. We only need to flush when an existing memslot is being modified, because for a new memslot the rmap array (which stores the dirty bits) is all zero, meaning that every page is considered clean already, and when deleting a memslot we obviously don't care about the dirty bits any more. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:28:18 +08:00
long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot,
unsigned long *map)
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
{
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
unsigned long i, j;
KVM: PPC: Book3S HV: Handle memory slot deletion and modification correctly This adds an implementation of kvm_arch_flush_shadow_memslot for Book3S HV, and arranges for kvmppc_core_commit_memory_region to flush the dirty log when modifying an existing slot. With this, we can handle deletion and modification of memory slots. kvm_arch_flush_shadow_memslot calls kvmppc_core_flush_memslot, which on Book3S HV now traverses the reverse map chains to remove any HPT (hashed page table) entries referring to pages in the memslot. This gets called by generic code whenever deleting a memslot or changing the guest physical address for a memslot. We flush the dirty log in kvmppc_core_commit_memory_region for consistency with what x86 does. We only need to flush when an existing memslot is being modified, because for a new memslot the rmap array (which stores the dirty bits) is all zero, meaning that every page is considered clean already, and when deleting a memslot we obviously don't care about the dirty bits any more. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:28:18 +08:00
unsigned long *rmapp;
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
struct kvm_vcpu *vcpu;
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
preempt_disable();
KVM: Push rmap into kvm_arch_memory_slot Two reasons: - x86 can integrate rmap and rmap_pde and remove heuristics in __gfn_to_rmap(). - Some architectures do not need rmap. Since rmap is one of the most memory consuming stuff in KVM, ppc'd better restrict the allocation to Book3S HV. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-08-01 17:03:28 +08:00
rmapp = memslot->arch.rmap;
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
for (i = 0; i < memslot->npages; ++i) {
KVM: PPC: Book3S HV: Fix dirty map for hugepages The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty (and rename it to kvm_test_clear_dirty_npages() to emphasize that that's what it returns). In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-26 17:48:38 +08:00
int npages = kvm_test_clear_dirty_npages(kvm, rmapp);
/*
* Note that if npages > 0 then i must be a multiple of npages,
* since we always put huge-page HPTEs in the rmap chain
* corresponding to their page base address.
*/
if (npages && map)
for (j = i; npages; ++j, --npages)
__set_bit_le(j, map);
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
++rmapp;
}
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
/* Harvest dirty bits from VPA and DTL updates */
/* Note: we never modify the SLB shadow buffer areas */
kvm_for_each_vcpu(i, vcpu, kvm) {
spin_lock(&vcpu->arch.vpa_update_lock);
harvest_vpa_dirty(&vcpu->arch.vpa, memslot, map);
harvest_vpa_dirty(&vcpu->arch.dtl, memslot, map);
spin_unlock(&vcpu->arch.vpa_update_lock);
}
KVM: PPC: Book3s HV: Implement get_dirty_log using hardware changed bit This changes the implementation of kvm_vm_ioctl_get_dirty_log() for Book3s HV guests to use the hardware C (changed) bits in the guest hashed page table. Since this makes the implementation quite different from the Book3s PR case, this moves the existing implementation from book3s.c to book3s_pr.c and creates a new implementation in book3s_hv.c. That implementation calls kvmppc_hv_get_dirty_log() to do the actual work by calling kvm_test_clear_dirty on each page. It iterates over the HPTEs, clearing the C bit if set, and returns 1 if any C bit was set (including the saved C bit in the rmap entry). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-15 10:03:22 +08:00
preempt_enable();
return 0;
}
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa,
unsigned long *nb_ret)
{
struct kvm_memory_slot *memslot;
unsigned long gfn = gpa >> PAGE_SHIFT;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
struct page *page, *pages[1];
int npages;
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
unsigned long hva, offset;
KVM: PPC: Allow use of small pages to back Book3S HV guests This relaxes the requirement that the guest memory be provided as 16MB huge pages, allowing it to be provided as normal memory, i.e. in pages of PAGE_SIZE bytes (4k or 64k). To allow this, we index the kvm->arch.slot_phys[] arrays with a small page index, even if huge pages are being used, and use the low-order 5 bits of each entry to store the order of the enclosing page with respect to normal pages, i.e. log_2(enclosing_page_size / PAGE_SIZE). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:41 +08:00
unsigned long pa;
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
unsigned long *physp;
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
int srcu_idx;
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
srcu_idx = srcu_read_lock(&kvm->srcu);
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
memslot = gfn_to_memslot(kvm, gfn);
if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID))
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
goto err;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (!kvm->arch.using_mmu_notifiers) {
KVM: PPC: Move kvm->arch.slot_phys into memslot.arch Now that we have an architecture-specific field in the kvm_memory_slot structure, we can use it to store the array of page physical addresses that we need for Book3S HV KVM on PPC970 processors. This reduces the size of struct kvm_arch for Book3S HV, and also reduces the size of struct kvm_arch_memory_slot for other PPC KVM variants since the fields in it are now only compiled in for Book3S HV. This necessitates making the kvm_arch_create_memslot and kvm_arch_free_memslot operations specific to each PPC KVM variant. That in turn means that we now don't allocate the rmap arrays on Book3S PR and Book E. Since we now unpin pages and free the slot_phys array in kvmppc_core_free_memslot, we no longer need to do it in kvmppc_core_destroy_vm, since the generic code takes care to free all the memslots when destroying a VM. We now need the new memslot to be passed in to kvmppc_core_prepare_memory_region, since we need to initialize its arch.slot_phys member on Book3S HV. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:46 +08:00
physp = memslot->arch.slot_phys;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (!physp)
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
goto err;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
physp += gfn - memslot->base_gfn;
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
pa = *physp;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
if (!pa) {
if (kvmppc_get_guest_page(kvm, gfn, memslot,
PAGE_SIZE) < 0)
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
goto err;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
pa = *physp;
}
page = pfn_to_page(pa >> PAGE_SHIFT);
KVM: PPC: Book3S HV: Fix refcounting of hugepages The H_REGISTER_VPA hcall implementation in HV Power KVM needs to pin some guest memory pages into host memory so that they can be safely accessed from usermode. It does this used get_user_pages_fast(). When the VPA is unregistered, or the VCPUs are cleaned up, these pages are released using put_page(). However, the get_user_pages() is invoked on the specific memory are of the VPA which could lie within hugepages. In case the pinned page is huge, we explicitly find the head page of the compound page before calling put_page() on it. At least with the latest kernel, this is not correct. put_page() already handles finding the correct head page of a compound, and also deals with various counts on the individual tail page which are important for transparent huge pages. We don't support transparent hugepages on Power, but even so, bypassing this count maintenance can lead (when the VM ends) to a hugepage being released back to the pool with a non-zero mapcount on one of the tail pages. This can then lead to a bad_page() when the page is released from the hugepage pool. This removes the explicit compound_head() call to correct this bug. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-05-08 18:24:08 +08:00
get_page(page);
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
} else {
hva = gfn_to_hva_memslot(memslot, gfn);
npages = get_user_pages_fast(hva, 1, 1, pages);
if (npages < 1)
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
goto err;
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:38:05 +08:00
page = pages[0];
KVM: PPC: Only get pages when actually needed, not in prepare_memory_region() This removes the code from kvmppc_core_prepare_memory_region() that looked up the VMA for the region being added and called hva_to_page to get the pfns for the memory. We have no guarantee that there will be anything mapped there at the time of the KVM_SET_USER_MEMORY_REGION ioctl call; userspace can do that ioctl and then map memory into the region later. Instead we defer looking up the pfn for each memory page until it is needed, which generally means when the guest does an H_ENTER hcall on the page. Since we can't call get_user_pages in real mode, if we don't already have the pfn for the page, kvmppc_h_enter() will return H_TOO_HARD and we then call kvmppc_virtmode_h_enter() once we get back to kernel context. That calls kvmppc_get_guest_page() to get the pfn for the page, and then calls back to kvmppc_h_enter() to redo the HPTE insertion. When the first vcpu starts executing, we need to have the RMO or VRMA region mapped so that the guest's real mode accesses will work. Thus we now have a check in kvmppc_vcpu_run() to see if the RMO/VRMA is set up and if not, call kvmppc_hv_setup_rma(). It checks if the memslot starting at guest physical 0 now has RMO memory mapped there; if so it sets it up for the guest, otherwise on POWER7 it sets up the VRMA. The function that does that, kvmppc_map_vrma, is now a bit simpler, as it calls kvmppc_virtmode_h_enter instead of creating the HPTE itself. Since we are now potentially updating entries in the slot_phys[] arrays from multiple vcpu threads, we now have a spinlock protecting those updates to ensure that we don't lose track of any references to pages. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:31:00 +08:00
}
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
srcu_read_unlock(&kvm->srcu, srcu_idx);
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
offset = gpa & (PAGE_SIZE - 1);
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
if (nb_ret)
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
*nb_ret = PAGE_SIZE - offset;
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
return page_address(page) + offset;
KVM: PPC: Book3S HV: Take the SRCU read lock before looking up memslots The generic KVM code uses SRCU (sleeping RCU) to protect accesses to the memslots data structures against updates due to userspace adding, modifying or removing memory slots. We need to do that too, both to avoid accessing stale copies of the memslots and to avoid lockdep warnings. This therefore adds srcu_read_lock/unlock pairs around code that accesses and uses memslots. Since the real-mode handlers for H_ENTER, H_REMOVE and H_BULK_REMOVE need to access the memslots, and we don't want to call the SRCU code in real mode (since we have no assurance that it would only access the linear mapping), we hold the SRCU read lock for the VM while in the guest. This does mean that adding or removing memory slots while some vcpus are executing in the guest will block for up to two jiffies. This tradeoff is acceptable since adding/removing memory slots only happens rarely, while H_ENTER/H_REMOVE/H_BULK_REMOVE are performance-critical hot paths. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-09-11 21:27:01 +08:00
err:
srcu_read_unlock(&kvm->srcu, srcu_idx);
return NULL;
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
}
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
void kvmppc_unpin_guest_page(struct kvm *kvm, void *va, unsigned long gpa,
bool dirty)
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
{
struct page *page = virt_to_page(va);
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
struct kvm_memory_slot *memslot;
unsigned long gfn;
unsigned long *rmap;
int srcu_idx;
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
put_page(page);
KVM: PPC: Book3S HV: Report VPA and DTL modifications in dirty map At present, the KVM_GET_DIRTY_LOG ioctl doesn't report modifications done by the host to the virtual processor areas (VPAs) and dispatch trace logs (DTLs) registered by the guest. This is because those modifications are done either in real mode or in the host kernel context, and in neither case does the access go through the guest's HPT, and thus no change (C) bit gets set in the guest's HPT. However, the changes done by the host do need to be tracked so that the modified pages get transferred when doing live migration. In order to track these modifications, this adds a dirty flag to the struct representing the VPA/DTL areas, and arranges to set the flag when the VPA/DTL gets modified by the host. Then, when we are collecting the dirty log, we also check the dirty flags for the VPA and DTL for each vcpu and set the relevant bit in the dirty log if necessary. Doing this also means we now need to keep track of the guest physical address of the VPA/DTL areas. So as not to lose track of modifications to a VPA/DTL area when it gets unregistered, or when a new area gets registered in its place, we need to transfer the dirty state to the rmap chain. This adds code to kvmppc_unpin_guest_page() to do that if the area was dirty. To simplify that code, we now require that all VPA, DTL and SLB shadow buffer areas fit within a single host page. Guests already comply with this requirement because pHyp requires that these areas not cross a 4k boundary. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:51:04 +08:00
if (!dirty || !kvm->arch.using_mmu_notifiers)
return;
/* We need to mark this page dirty in the rmap chain */
gfn = gpa >> PAGE_SHIFT;
srcu_idx = srcu_read_lock(&kvm->srcu);
memslot = gfn_to_memslot(kvm, gfn);
if (memslot) {
rmap = &memslot->arch.rmap[gfn - memslot->base_gfn];
lock_rmap(rmap);
*rmap |= KVMPPC_RMAP_CHANGED;
unlock_rmap(rmap);
}
srcu_read_unlock(&kvm->srcu, srcu_idx);
KVM: PPC: Add an interface for pinning guest pages in Book3s HV guests This adds two new functions, kvmppc_pin_guest_page() and kvmppc_unpin_guest_page(), and uses them to pin the guest pages where the guest has registered areas of memory for the hypervisor to update, (i.e. the per-cpu virtual processor areas, SLB shadow buffers and dispatch trace logs) and then unpin them when they are no longer required. Although it is not strictly necessary to pin the pages at this point, since all guest pages are already pinned, later commits in this series will mean that guest pages aren't all pinned. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 20:28:55 +08:00
}
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
/*
* Functions for reading and writing the hash table via reads and
* writes on a file descriptor.
*
* Reads return the guest view of the hash table, which has to be
* pieced together from the real hash table and the guest_rpte
* values in the revmap array.
*
* On writes, each HPTE written is considered in turn, and if it
* is valid, it is written to the HPT as if an H_ENTER with the
* exact flag set was done. When the invalid count is non-zero
* in the header written to the stream, the kernel will make
* sure that that many HPTEs are invalid, and invalidate them
* if not.
*/
struct kvm_htab_ctx {
unsigned long index;
unsigned long flags;
struct kvm *kvm;
int first_pass;
};
#define HPTE_SIZE (2 * sizeof(unsigned long))
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
/*
* Returns 1 if this HPT entry has been modified or has pending
* R/C bit changes.
*/
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
static int hpte_dirty(struct revmap_entry *revp, __be64 *hptp)
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
{
unsigned long rcbits_unset;
if (revp->guest_rpte & HPTE_GR_MODIFIED)
return 1;
/* Also need to consider changes in reference and changed bits */
rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if ((be64_to_cpu(hptp[0]) & HPTE_V_VALID) &&
(be64_to_cpu(hptp[1]) & rcbits_unset))
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
return 1;
return 0;
}
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
static long record_hpte(unsigned long flags, __be64 *hptp,
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
unsigned long *hpte, struct revmap_entry *revp,
int want_valid, int first_pass)
{
unsigned long v, r;
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
unsigned long rcbits_unset;
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
int ok = 1;
int valid, dirty;
/* Unmodified entries are uninteresting except on the first pass */
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
dirty = hpte_dirty(revp, hptp);
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
if (!first_pass && !dirty)
return 0;
valid = 0;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT)) {
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
valid = 1;
if ((flags & KVM_GET_HTAB_BOLTED_ONLY) &&
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
!(be64_to_cpu(hptp[0]) & HPTE_V_BOLTED))
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
valid = 0;
}
if (valid != want_valid)
return 0;
v = r = 0;
if (valid || dirty) {
/* lock the HPTE so it's stable and read it */
preempt_disable();
while (!try_lock_hpte(hptp, HPTE_V_HVLOCK))
cpu_relax();
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
v = be64_to_cpu(hptp[0]);
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
/* re-evaluate valid and dirty from synchronized HPTE value */
valid = !!(v & HPTE_V_VALID);
dirty = !!(revp->guest_rpte & HPTE_GR_MODIFIED);
/* Harvest R and C into guest view if necessary */
rcbits_unset = ~revp->guest_rpte & (HPTE_R_R | HPTE_R_C);
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (valid && (rcbits_unset & be64_to_cpu(hptp[1]))) {
revp->guest_rpte |= (be64_to_cpu(hptp[1]) &
(HPTE_R_R | HPTE_R_C)) | HPTE_GR_MODIFIED;
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
dirty = 1;
}
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
if (v & HPTE_V_ABSENT) {
v &= ~HPTE_V_ABSENT;
v |= HPTE_V_VALID;
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
valid = 1;
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
}
if ((flags & KVM_GET_HTAB_BOLTED_ONLY) && !(v & HPTE_V_BOLTED))
valid = 0;
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
r = revp->guest_rpte;
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
/* only clear modified if this is the right sort of entry */
if (valid == want_valid && dirty) {
r &= ~HPTE_GR_MODIFIED;
revp->guest_rpte = r;
}
asm volatile(PPC_RELEASE_BARRIER "" : : : "memory");
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptp[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
preempt_enable();
if (!(valid == want_valid && (first_pass || dirty)))
ok = 0;
}
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hpte[0] = cpu_to_be64(v);
hpte[1] = cpu_to_be64(r);
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
return ok;
}
static ssize_t kvm_htab_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct kvm_htab_ctx *ctx = file->private_data;
struct kvm *kvm = ctx->kvm;
struct kvm_get_htab_header hdr;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
__be64 *hptp;
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
struct revmap_entry *revp;
unsigned long i, nb, nw;
unsigned long __user *lbuf;
struct kvm_get_htab_header __user *hptr;
unsigned long flags;
int first_pass;
unsigned long hpte[2];
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
first_pass = ctx->first_pass;
flags = ctx->flags;
i = ctx->index;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
revp = kvm->arch.revmap + i;
lbuf = (unsigned long __user *)buf;
nb = 0;
while (nb + sizeof(hdr) + HPTE_SIZE < count) {
/* Initialize header */
hptr = (struct kvm_get_htab_header __user *)buf;
hdr.n_valid = 0;
hdr.n_invalid = 0;
nw = nb;
nb += sizeof(hdr);
lbuf = (unsigned long __user *)(buf + sizeof(hdr));
/* Skip uninteresting entries, i.e. clean on not-first pass */
if (!first_pass) {
while (i < kvm->arch.hpt_npte &&
KVM: PPC: Book3S HV: Make HPT reading code notice R/C bit changes At present, the code that determines whether a HPT entry has changed, and thus needs to be sent to userspace when it is copying the HPT, doesn't consider a hardware update to the reference and change bits (R and C) in the HPT entries to constitute a change that needs to be sent to userspace. This adds code to check for changes in R and C when we are scanning the HPT to find changed entries, and adds code to set the changed flag for the HPTE when we update the R and C bits in the guest view of the HPTE. Since we now need to set the HPTE changed flag in book3s_64_mmu_hv.c as well as book3s_hv_rm_mmu.c, we move the note_hpte_modification() function into kvm_book3s_64.h. Current Linux guest kernels don't use the hardware updates of R and C in the HPT, so this change won't affect them. Linux (or other) kernels might in future want to use the R and C bits and have them correctly transferred across when a guest is migrated, so it is better to correct this deficiency. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-04-19 03:50:24 +08:00
!hpte_dirty(revp, hptp)) {
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
++i;
hptp += 2;
++revp;
}
}
KVM: PPC: Book3S HV: Report correct HPT entry index when reading HPT This fixes a bug in the code which allows userspace to read out the contents of the guest's hashed page table (HPT). On the second and subsequent passes through the HPT, when we are reporting only those entries that have changed, we were incorrectly initializing the index field of the header with the index of the first entry we skipped rather than the first changed entry. This fixes it. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-22 07:29:12 +08:00
hdr.index = i;
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
/* Grab a series of valid entries */
while (i < kvm->arch.hpt_npte &&
hdr.n_valid < 0xffff &&
nb + HPTE_SIZE < count &&
record_hpte(flags, hptp, hpte, revp, 1, first_pass)) {
/* valid entry, write it out */
++hdr.n_valid;
if (__put_user(hpte[0], lbuf) ||
__put_user(hpte[1], lbuf + 1))
return -EFAULT;
nb += HPTE_SIZE;
lbuf += 2;
++i;
hptp += 2;
++revp;
}
/* Now skip invalid entries while we can */
while (i < kvm->arch.hpt_npte &&
hdr.n_invalid < 0xffff &&
record_hpte(flags, hptp, hpte, revp, 0, first_pass)) {
/* found an invalid entry */
++hdr.n_invalid;
++i;
hptp += 2;
++revp;
}
if (hdr.n_valid || hdr.n_invalid) {
/* write back the header */
if (__copy_to_user(hptr, &hdr, sizeof(hdr)))
return -EFAULT;
nw = nb;
buf = (char __user *)lbuf;
} else {
nb = nw;
}
/* Check if we've wrapped around the hash table */
if (i >= kvm->arch.hpt_npte) {
i = 0;
ctx->first_pass = 0;
break;
}
}
ctx->index = i;
return nb;
}
static ssize_t kvm_htab_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct kvm_htab_ctx *ctx = file->private_data;
struct kvm *kvm = ctx->kvm;
struct kvm_get_htab_header hdr;
unsigned long i, j;
unsigned long v, r;
unsigned long __user *lbuf;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
__be64 *hptp;
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
unsigned long tmp[2];
ssize_t nb;
long int err, ret;
int rma_setup;
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
/* lock out vcpus from running while we're doing this */
mutex_lock(&kvm->lock);
rma_setup = kvm->arch.rma_setup_done;
if (rma_setup) {
kvm->arch.rma_setup_done = 0; /* temporarily */
/* order rma_setup_done vs. vcpus_running */
smp_mb();
if (atomic_read(&kvm->arch.vcpus_running)) {
kvm->arch.rma_setup_done = 1;
mutex_unlock(&kvm->lock);
return -EBUSY;
}
}
err = 0;
for (nb = 0; nb + sizeof(hdr) <= count; ) {
err = -EFAULT;
if (__copy_from_user(&hdr, buf, sizeof(hdr)))
break;
err = 0;
if (nb + hdr.n_valid * HPTE_SIZE > count)
break;
nb += sizeof(hdr);
buf += sizeof(hdr);
err = -EINVAL;
i = hdr.index;
if (i >= kvm->arch.hpt_npte ||
i + hdr.n_valid + hdr.n_invalid > kvm->arch.hpt_npte)
break;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
hptp = (__be64 *)(kvm->arch.hpt_virt + (i * HPTE_SIZE));
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
lbuf = (unsigned long __user *)buf;
for (j = 0; j < hdr.n_valid; ++j) {
err = -EFAULT;
if (__get_user(v, lbuf) || __get_user(r, lbuf + 1))
goto out;
err = -EINVAL;
if (!(v & HPTE_V_VALID))
goto out;
lbuf += 2;
nb += HPTE_SIZE;
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
err = -EIO;
ret = kvmppc_virtmode_do_h_enter(kvm, H_EXACT, i, v, r,
tmp);
if (ret != H_SUCCESS) {
pr_err("kvm_htab_write ret %ld i=%ld v=%lx "
"r=%lx\n", ret, i, v, r);
goto out;
}
if (!rma_setup && is_vrma_hpte(v)) {
KVM: PPC: BOOK3S: HV: Use base page size when comparing against slb value With guests supporting Multiple page size per segment (MPSS), hpte_page_size returns the actual page size used. Add a new function to return base page size and use that to compare against the the page size calculated from SLB. Without this patch a hpte lookup can fail since we are comparing wrong page size in kvmppc_hv_find_lock_hpte. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-16 02:47:07 +08:00
unsigned long psize = hpte_base_page_size(v, r);
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
unsigned long senc = slb_pgsize_encoding(psize);
unsigned long lpcr;
kvm->arch.vrma_slb_v = senc | SLB_VSID_B_1T |
(VRMA_VSID << SLB_VSID_SHIFT_1T);
KVM: PPC: Book3S HV: Store LPCR value for each virtual core This adds the ability to have a separate LPCR (Logical Partitioning Control Register) value relating to a guest for each virtual core, rather than only having a single value for the whole VM. This corresponds to what real POWER hardware does, where there is a LPCR per CPU thread but most of the fields are required to have the same value on all active threads in a core. The per-virtual-core LPCR can be read and written using the GET/SET_ONE_REG interface. Userspace can can only modify the following fields of the LPCR value: DPFD Default prefetch depth ILE Interrupt little-endian TC Translation control (secondary HPT hash group search disable) We still maintain a per-VM default LPCR value in kvm->arch.lpcr, which contains bits relating to memory management, i.e. the Virtualized Partition Memory (VPM) bits and the bits relating to guest real mode. When this default value is updated, the update needs to be propagated to the per-vcore values, so we add a kvmppc_update_lpcr() helper to do that. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix whitespace] Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-20 12:52:38 +08:00
lpcr = senc << (LPCR_VRMASD_SH - 4);
kvmppc_update_lpcr(kvm, lpcr, LPCR_VRMASD);
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
rma_setup = 1;
}
++i;
hptp += 2;
}
for (j = 0; j < hdr.n_invalid; ++j) {
KVM: PPC: Book3S HV: Make HTAB code LE host aware When running on an LE host all data structures are kept in little endian byte order. However, the HTAB still needs to be maintained in big endian. So every time we access any HTAB we need to make sure we do so in the right byte order. Fix up all accesses to manually byte swap. Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-11 16:16:06 +08:00
if (be64_to_cpu(hptp[0]) & (HPTE_V_VALID | HPTE_V_ABSENT))
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
kvmppc_do_h_remove(kvm, 0, i, 0, tmp);
++i;
hptp += 2;
}
err = 0;
}
out:
/* Order HPTE updates vs. rma_setup_done */
smp_wmb();
kvm->arch.rma_setup_done = rma_setup;
mutex_unlock(&kvm->lock);
if (err)
return err;
return nb;
}
static int kvm_htab_release(struct inode *inode, struct file *filp)
{
struct kvm_htab_ctx *ctx = filp->private_data;
filp->private_data = NULL;
if (!(ctx->flags & KVM_GET_HTAB_WRITE))
atomic_dec(&ctx->kvm->arch.hpte_mod_interest);
kvm_put_kvm(ctx->kvm);
kfree(ctx);
return 0;
}
constify a bunch of struct file_operations instances Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-05 07:09:41 +08:00
static const struct file_operations kvm_htab_fops = {
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
.read = kvm_htab_read,
.write = kvm_htab_write,
.llseek = default_llseek,
.release = kvm_htab_release,
};
int kvm_vm_ioctl_get_htab_fd(struct kvm *kvm, struct kvm_get_htab_fd *ghf)
{
int ret;
struct kvm_htab_ctx *ctx;
int rwflag;
/* reject flags we don't recognize */
if (ghf->flags & ~(KVM_GET_HTAB_BOLTED_ONLY | KVM_GET_HTAB_WRITE))
return -EINVAL;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
kvm_get_kvm(kvm);
ctx->kvm = kvm;
ctx->index = ghf->start_index;
ctx->flags = ghf->flags;
ctx->first_pass = 1;
rwflag = (ghf->flags & KVM_GET_HTAB_WRITE) ? O_WRONLY : O_RDONLY;
ppc: kvm: use anon_inode_getfd() with O_CLOEXEC flag KVM uses anon_inode_get() to allocate file descriptors as part of some of its ioctls. But those ioctls are lacking a flag argument allowing userspace to choose options for the newly opened file descriptor. In such case it's advised to use O_CLOEXEC by default so that userspace is allowed to choose, without race, if the file descriptor is going to be inherited across exec(). This patch set O_CLOEXEC flag on all file descriptors created with anon_inode_getfd() to not leak file descriptors across exec(). Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Link: http://lkml.kernel.org/r/cover.1377372576.git.ydroneaud@opteya.com Reviewed-by: Alexander Graf <agraf@suse.de> Signed-off-by: Gleb Natapov <gleb@redhat.com>
2013-08-25 04:14:08 +08:00
ret = anon_inode_getfd("kvm-htab", &kvm_htab_fops, ctx, rwflag | O_CLOEXEC);
KVM: PPC: Book3S HV: Provide a method for userspace to read and write the HPT A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on this fd return the contents of the HPT (hashed page table), writes create and/or remove entries in the HPT. There is a new capability, KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl takes an argument structure with the index of the first HPT entry to read out and a set of flags. The flags indicate whether the user is intending to read or write the HPT, and whether to return all entries or only the "bolted" entries (those with the bolted bit, 0x10, set in the first doubleword). This is intended for use in implementing qemu's savevm/loadvm and for live migration. Therefore, on reads, the first pass returns information about all HPTEs (or all bolted HPTEs). When the first pass reaches the end of the HPT, it returns from the read. Subsequent reads only return information about HPTEs that have changed since they were last read. A read that finds no changed HPTEs in the HPT following where the last read finished will return 0 bytes. The format of the data provides a simple run-length compression of the invalid entries. Each block of data starts with a header that indicates the index (position in the HPT, which is just an array), the number of valid entries starting at that index (may be zero), and the number of invalid entries following those valid entries. The valid entries, 16 bytes each, follow the header. The invalid entries are not explicitly represented. Signed-off-by: Paul Mackerras <paulus@samba.org> [agraf: fix documentation] Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-20 06:57:20 +08:00
if (ret < 0) {
kvm_put_kvm(kvm);
return ret;
}
if (rwflag == O_RDONLY) {
mutex_lock(&kvm->slots_lock);
atomic_inc(&kvm->arch.hpte_mod_interest);
/* make sure kvmppc_do_h_enter etc. see the increment */
synchronize_srcu_expedited(&kvm->srcu);
mutex_unlock(&kvm->slots_lock);
}
return ret;
}
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
void kvmppc_mmu_book3s_hv_init(struct kvm_vcpu *vcpu)
{
struct kvmppc_mmu *mmu = &vcpu->arch.mmu;
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:40:08 +08:00
if (cpu_has_feature(CPU_FTR_ARCH_206))
vcpu->arch.slb_nr = 32; /* POWER7 */
else
vcpu->arch.slb_nr = 64;
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 08:21:34 +08:00
mmu->xlate = kvmppc_mmu_book3s_64_hv_xlate;
mmu->reset_msr = kvmppc_mmu_book3s_64_hv_reset_msr;
vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
}