From 56ca57f9fe553da122472a15e49c2d808123ff0a Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Wed, 24 Feb 2016 17:51:14 +0800 Subject: [PATCH] KVM: MMU: use page track for non-leaf shadow pages non-leaf shadow pages are always write protected, it can be the user of page track Signed-off-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 58c067da6efc..fe03d2a1d4d3 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -806,11 +806,17 @@ static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) struct kvm_memory_slot *slot; gfn_t gfn; + kvm->arch.indirect_shadow_pages++; gfn = sp->gfn; slots = kvm_memslots_for_spte_role(kvm, sp->role); slot = __gfn_to_memslot(slots, gfn); + + /* the non-leaf shadow pages are keeping readonly. */ + if (sp->role.level > PT_PAGE_TABLE_LEVEL) + return kvm_slot_page_track_add_page(kvm, slot, gfn, + KVM_PAGE_TRACK_WRITE); + kvm_mmu_gfn_disallow_lpage(slot, gfn); - kvm->arch.indirect_shadow_pages++; } static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) @@ -819,11 +825,15 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) struct kvm_memory_slot *slot; gfn_t gfn; + kvm->arch.indirect_shadow_pages--; gfn = sp->gfn; slots = kvm_memslots_for_spte_role(kvm, sp->role); slot = __gfn_to_memslot(slots, gfn); + if (sp->role.level > PT_PAGE_TABLE_LEVEL) + return kvm_slot_page_track_remove_page(kvm, slot, gfn, + KVM_PAGE_TRACK_WRITE); + kvm_mmu_gfn_allow_lpage(slot, gfn); - kvm->arch.indirect_shadow_pages--; } static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level, @@ -2132,12 +2142,18 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, hlist_add_head(&sp->hash_link, &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]); if (!direct) { - if (rmap_write_protect(vcpu, gfn)) + /* + * we should do write protection before syncing pages + * otherwise the content of the synced shadow page may + * be inconsistent with guest page table. + */ + account_shadowed(vcpu->kvm, sp); + if (level == PT_PAGE_TABLE_LEVEL && + rmap_write_protect(vcpu, gfn)) kvm_flush_remote_tlbs(vcpu->kvm); + if (level > PT_PAGE_TABLE_LEVEL && need_sync) kvm_sync_pages(vcpu, gfn); - - account_shadowed(vcpu->kvm, sp); } sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; clear_page(sp->spt); -- 2.20.1