diff options
| -rw-r--r-- | Documentation/virtual/kvm/mmu.txt | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 25 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 14 |
4 files changed, 25 insertions, 22 deletions
diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt index daf9c0f742d2..dda2e9316701 100644 --- a/Documentation/virtual/kvm/mmu.txt +++ b/Documentation/virtual/kvm/mmu.txt @@ -391,11 +391,11 @@ To instantiate a large spte, four constraints must be satisfied: write-protected pages - the guest page must be wholly contained by a single memory slot -To check the last two conditions, the mmu maintains a ->write_count set of +To check the last two conditions, the mmu maintains a ->disallow_lpage set of arrays for each memory slot and large page size. Every write protected page -causes its write_count to be incremented, thus preventing instantiation of +causes its disallow_lpage to be incremented, thus preventing instantiation of a large spte. The frames at the end of an unaligned memory slot have -artificially inflated ->write_counts so they can never be instantiated. +artificially inflated ->disallow_lpages so they can never be instantiated. Zapping all pages (page generation count) ========================================= diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7b5459982433..1f7fed5f35fc 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -644,7 +644,7 @@ struct kvm_vcpu_arch { }; struct kvm_lpage_info { - int write_count; + int disallow_lpage; }; struct kvm_arch_memory_slot { diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 07f4c26a10d3..06dd4abfeaa3 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -789,7 +789,7 @@ static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) slot = __gfn_to_memslot(slots, gfn); for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) { linfo = lpage_info_slot(gfn, slot, i); - linfo->write_count += 1; + linfo->disallow_lpage += 1; } kvm->arch.indirect_shadow_pages++; } @@ -807,31 +807,32 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) slot = __gfn_to_memslot(slots, gfn); for (i = PT_DIRECTORY_LEVEL; i <= PT_MAX_HUGEPAGE_LEVEL; ++i) { linfo = lpage_info_slot(gfn, slot, i); - linfo->write_count -= 1; - WARN_ON(linfo->write_count < 0); + linfo->disallow_lpage -= 1; + WARN_ON(linfo->disallow_lpage < 0); } kvm->arch.indirect_shadow_pages--; } -static int __has_wrprotected_page(gfn_t gfn, int level, - struct kvm_memory_slot *slot) +static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level, + struct kvm_memory_slot *slot) { struct kvm_lpage_info *linfo; if (slot) { linfo = lpage_info_slot(gfn, slot, level); - return linfo->write_count; + return !!linfo->disallow_lpage; } - return 1; + return true; } -static int has_wrprotected_page(struct kvm_vcpu *vcpu, gfn_t gfn, int level) +static bool mmu_gfn_lpage_is_disallowed(struct kvm_vcpu *vcpu, gfn_t gfn, + int level) { struct kvm_memory_slot *slot; slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); - return __has_wrprotected_page(gfn, level, slot); + return __mmu_gfn_lpage_is_disallowed(gfn, level, slot); } static int host_mapping_level(struct kvm *kvm, gfn_t gfn) @@ -897,7 +898,7 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn, max_level = min(kvm_x86_ops->get_lpage_level(), host_level); for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level) - if (__has_wrprotected_page(large_gfn, level, slot)) + if (__mmu_gfn_lpage_is_disallowed(large_gfn, level, slot)) break; return level - 1; @@ -2503,7 +2504,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep, * be fixed if guest refault. */ if (level > PT_PAGE_TABLE_LEVEL && - has_wrprotected_page(vcpu, gfn, level)) + mmu_gfn_lpage_is_disallowed(vcpu, gfn, level)) goto done; spte |= PT_WRITABLE_MASK | SPTE_MMU_WRITEABLE; @@ -2768,7 +2769,7 @@ static void transparent_hugepage_adjust(struct kvm_vcpu *vcpu, if (!is_error_noslot_pfn(pfn) && !kvm_is_reserved_pfn(pfn) && level == PT_PAGE_TABLE_LEVEL && PageTransCompound(pfn_to_page(pfn)) && - !has_wrprotected_page(vcpu, gfn, PT_DIRECTORY_LEVEL)) { + !mmu_gfn_lpage_is_disallowed(vcpu, gfn, PT_DIRECTORY_LEVEL)) { unsigned long mask; /* * mmu_notifier_retry was successful and we hold the diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2fb92c0af803..668625e47102 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7879,6 +7879,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, int i; for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) { + struct kvm_lpage_info *linfo; unsigned long ugfn; int lpages; int level = i + 1; @@ -7893,15 +7894,16 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, if (i == 0) continue; - slot->arch.lpage_info[i - 1] = kvm_kvzalloc(lpages * - sizeof(*slot->arch.lpage_info[i - 1])); - if (!slot->arch.lpage_info[i - 1]) + linfo = kvm_kvzalloc(lpages * sizeof(*linfo)); + if (!linfo) goto out_free; + slot->arch.lpage_info[i - 1] = linfo; + if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1)) - slot->arch.lpage_info[i - 1][0].write_count = 1; + linfo[0].disallow_lpage = 1; if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1)) - slot->arch.lpage_info[i - 1][lpages - 1].write_count = 1; + linfo[lpages - 1].disallow_lpage = 1; ugfn = slot->userspace_addr >> PAGE_SHIFT; /* * If the gfn and userspace address are not aligned wrt each @@ -7913,7 +7915,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, unsigned long j; for (j = 0; j < lpages; ++j) - slot->arch.lpage_info[i - 1][j].write_count = 1; + linfo[j].disallow_lpage = 1; } } |