| Message ID | 1455449503-20993-2-git-send-email-guangrong.xiao@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 14/02/2016 12:31, Xiao Guangrong wrote: > kvm_lpage_info->write_count is used to detect if the large page mapping > for the gfn on the specified level is allowed, rename it to disallow_lpage > to reflect its purpose, also we rename has_wrprotected_page() to > mmu_gfn_lpage_is_disallowed() to make the code more clearer > > Later we will extend this mechanism for page tracking: if the gfn is > tracked then large mapping for that gfn on any level is not allowed. > The new name is more straightforward > > Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> > --- > Documentation/virtual/kvm/mmu.txt | 6 +++--- > arch/x86/include/asm/kvm_host.h | 2 +- > arch/x86/kvm/mmu.c | 25 +++++++++++++------------ > 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 daf9c0f..dda2e93 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 7dd6d55..e1c1f57 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 95a955d..de9e992 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 cf15bc5..f448e64 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -7903,6 +7903,7 @@ 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; > @@ -7917,15 +7918,16 @@ 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 > @@ -7937,7 +7939,7 @@ 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; > } > } > > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/virtual/kvm/mmu.txt b/Documentation/virtual/kvm/mmu.txt index daf9c0f..dda2e93 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 7dd6d55..e1c1f57 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 95a955d..de9e992 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 cf15bc5..f448e64 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7903,6 +7903,7 @@ 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; @@ -7917,15 +7918,16 @@ 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 @@ -7937,7 +7939,7 @@ 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; } }
kvm_lpage_info->write_count is used to detect if the large page mapping for the gfn on the specified level is allowed, rename it to disallow_lpage to reflect its purpose, also we rename has_wrprotected_page() to mmu_gfn_lpage_is_disallowed() to make the code more clearer Later we will extend this mechanism for page tracking: if the gfn is tracked then large mapping for that gfn on any level is not allowed. The new name is more straightforward Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> --- Documentation/virtual/kvm/mmu.txt | 6 +++--- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/mmu.c | 25 +++++++++++++------------ arch/x86/kvm/x86.c | 14 ++++++++------ 4 files changed, 25 insertions(+), 22 deletions(-)