4 files changed, 17 insertions, 19 deletions

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c8ebe542c565..144c5a01cd77 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4203,7 +4203,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
 	      work->arch.cr3 != vcpu->arch.mmu->get_guest_pgd(vcpu))
 		return;
 
-	kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true);
+	kvm_mmu_do_page_fault(vcpu, work->cr2_or_gpa, 0, true, NULL);
 }
 
 static int __kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
@@ -5664,7 +5664,8 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err
 
 	if (r == RET_PF_INVALID) {
 		r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa,
-					  lower_32_bits(error_code), false);
+					  lower_32_bits(error_code), false,
+					  &emulation_type);
 		if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm))
 			return -EIO;
 	}
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index cc58631e2336..2cbb155c686c 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -240,6 +240,13 @@ struct kvm_page_fault {
 	kvm_pfn_t pfn;
 	hva_t hva;
 	bool map_writable;
+
+	/*
+	 * Indicates the guest is trying to write a gfn that contains one or
+	 * more of the PTEs used to translate the write itself, i.e. the access
+	 * is changing its own translation in the guest page tables.
+	 */
+	bool write_fault_to_shadow_pgtable;
 };
 
 int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
@@ -273,7 +280,7 @@ enum {
 };
 
 static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
-					u32 err, bool prefetch)
+					u32 err, bool prefetch, int *emulation_type)
 {
 	struct kvm_page_fault fault = {
 		.addr = cr2_or_gpa,
@@ -312,6 +319,9 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 	else
 		r = vcpu->arch.mmu->page_fault(vcpu, &fault);
 
+	if (fault.write_fault_to_shadow_pgtable && emulation_type)
+		*emulation_type |= EMULTYPE_WRITE_PF_TO_SP;
+
 	/*
 	 * Similar to above, prefetch faults aren't truly spurious, and the
 	 * async #PF path doesn't do emulation.  Do count faults that are fixed
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index 57f0b75c80f9..5d2958299b4f 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -825,10 +825,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault
 	if (r)
 		return r;
 
-	vcpu->arch.write_fault_to_shadow_pgtable = false;
-
 	is_self_change_mapping = FNAME(is_self_change_mapping)(vcpu,
-	      &walker, fault->user, &vcpu->arch.write_fault_to_shadow_pgtable);
+	      &walker, fault->user, &fault->write_fault_to_shadow_pgtable);
 
 	if (is_self_change_mapping)
 		fault->max_level = PG_LEVEL_4K;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7713420abab0..ff7f398a0c6a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8463,7 +8463,6 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
 }
 
 static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
-				  bool write_fault_to_shadow_pgtable,
 				  int emulation_type)
 {
 	gpa_t gpa = cr2_or_gpa;
@@ -8534,7 +8533,7 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 	 * be fixed by unprotecting shadow page and it should
 	 * be reported to userspace.
 	 */
-	return !write_fault_to_shadow_pgtable;
+	return !(emulation_type & EMULTYPE_WRITE_PF_TO_SP);
 }
 
 static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
@@ -8782,20 +8781,12 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 	int r;
 	struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
 	bool writeback = true;
-	bool write_fault_to_spt;
 
 	if (unlikely(!kvm_can_emulate_insn(vcpu, emulation_type, insn, insn_len)))
 		return 1;
 
 	vcpu->arch.l1tf_flush_l1d = true;
 
-	/*
-	 * Clear write_fault_to_shadow_pgtable here to ensure it is
-	 * never reused.
-	 */
-	write_fault_to_spt = vcpu->arch.write_fault_to_shadow_pgtable;
-	vcpu->arch.write_fault_to_shadow_pgtable = false;
-
 	if (!(emulation_type & EMULTYPE_NO_DECODE)) {
 		kvm_clear_exception_queue(vcpu);
 
@@ -8816,7 +8807,6 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
 				return 1;
 			}
 			if (reexecute_instruction(vcpu, cr2_or_gpa,
-						  write_fault_to_spt,
 						  emulation_type))
 				return 1;
 
@@ -8895,8 +8885,7 @@ restart:
 		return 1;
 
 	if (r == EMULATION_FAILED) {
-		if (reexecute_instruction(vcpu, cr2_or_gpa, write_fault_to_spt,
-					emulation_type))
+		if (reexecute_instruction(vcpu, cr2_or_gpa, emulation_type))
 			return 1;
 
 		return handle_emulation_failure(vcpu, emulation_type);