3 files changed, 22 insertions, 12 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 22e7ad235123..2401606db260 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3364,18 +3364,6 @@ static bool fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu,
 	return true;
 }
 
-static bool is_access_allowed(struct kvm_page_fault *fault, u64 spte)
-{
-	if (fault->exec)
-		return is_executable_pte(spte);
-
-	if (fault->write)
-		return is_writable_pte(spte);
-
-	/* Fault was on Read access */
-	return spte & PT_PRESENT_MASK;
-}
-
 /*
  * Returns the last level spte pointer of the shadow page walk for the given
  * gpa, and sets *spte to the spte value. This spte may be non-preset. If no
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index f332b33bc817..af10bc0380a3 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -462,6 +462,23 @@ static inline bool is_mmu_writable_spte(u64 spte)
 }
 
 /*
+ * Returns true if the access indicated by @fault is allowed by the existing
+ * SPTE protections.  Note, the caller is responsible for checking that the
+ * SPTE is a shadow-present, leaf SPTE (either before or after).
+ */
+static inline bool is_access_allowed(struct kvm_page_fault *fault, u64 spte)
+{
+	if (fault->exec)
+		return is_executable_pte(spte);
+
+	if (fault->write)
+		return is_writable_pte(spte);
+
+	/* Fault was on Read access */
+	return spte & PT_PRESENT_MASK;
+}
+
+/*
  * If the MMU-writable flag is cleared, i.e. the SPTE is write-protected for
  * write-tracking, remote TLBs must be flushed, even if the SPTE was read-only,
  * as KVM allows stale Writable TLB entries to exist.  When dirty logging, KVM
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 4508d868f1cd..2f15e0e33903 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -985,6 +985,11 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
 	if (fault->prefetch && is_shadow_present_pte(iter->old_spte))
 		return RET_PF_SPURIOUS;
 
+	if (is_shadow_present_pte(iter->old_spte) &&
+	    is_access_allowed(fault, iter->old_spte) &&
+	    is_last_spte(iter->old_spte, iter->level))
+		return RET_PF_SPURIOUS;
+
 	if (unlikely(!fault->slot))
 		new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL);
 	else