3 files changed, 19 insertions, 2 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 8e449dbcc596..53f1ed852ca2 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1122,8 +1122,10 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte,
                 else
                         kvm_release_pfn_clean(pfn);
         }
-        if (!ptwrite || !*ptwrite)
+        if (speculative) {
                 vcpu->arch.last_pte_updated = shadow_pte;
+                vcpu->arch.last_pte_gfn = gfn;
+        }
 }
 
 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
@@ -1671,6 +1673,18 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
         vcpu->arch.update_pte.pfn = pfn;
 }
 
+static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
+{
+        u64 *spte = vcpu->arch.last_pte_updated;
+
+        if (spte
+            && vcpu->arch.last_pte_gfn == gfn
+            && shadow_accessed_mask
+            && !(*spte & shadow_accessed_mask)
+            && is_shadow_present_pte(*spte))
+                set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
+}
+
 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                        const u8 *new, int bytes)
 {
@@ -1694,6 +1708,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
         pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes);
         mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes);
         spin_lock(&vcpu->kvm->mmu_lock);
+        kvm_mmu_access_page(vcpu, gfn);
         kvm_mmu_free_some_pages(vcpu);
         ++vcpu->kvm->stat.mmu_pte_write;
         kvm_mmu_audit(vcpu, "pre pte write");
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 1730757bbc7a..258e5d56298e 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -15,7 +15,8 @@
 #define PT_USER_MASK (1ULL << 2)
 #define PT_PWT_MASK (1ULL << 3)
 #define PT_PCD_MASK (1ULL << 4)
-#define PT_ACCESSED_MASK (1ULL << 5)
+#define PT_ACCESSED_SHIFT 5
+#define PT_ACCESSED_MASK (1ULL << PT_ACCESSED_SHIFT)
 #define PT_DIRTY_MASK (1ULL << 6)
 #define PT_PAGE_SIZE_MASK (1ULL << 7)
 #define PT_PAT_MASK (1ULL << 7)
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 844f2a89afbc..c2d066e185f4 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -243,6 +243,7 @@ struct kvm_vcpu_arch {
         gfn_t last_pt_write_gfn;
         int   last_pt_write_count;
         u64  *last_pte_updated;
+        gfn_t last_pte_gfn;
 
         struct {
                 gfn_t gfn;      /* presumed gfn during guest pte update */