1 files changed, 25 insertions, 7 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3d72fc067059..d51eed239b47 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3930,6 +3930,29 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu)
         return EMULATE_FAIL;
 }
 
+static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)
+{
+        gpa_t gpa;
+
+        /*
+         * if emulation was due to access to shadowed page table
+         * and it failed try to unshadow page and re-entetr the
+         * guest to let CPU execute the instruction.
+         */
+        if (kvm_mmu_unprotect_page_virt(vcpu, gva))
+                return true;
+
+        gpa = kvm_mmu_gva_to_gpa_system(vcpu, gva, NULL);
+
+        if (gpa == UNMAPPED_GVA)
+                return true; /* let cpu generate fault */
+
+        if (!kvm_is_error_hva(gfn_to_hva(vcpu->kvm, gpa >> PAGE_SHIFT)))
+                return true;
+
+        return false;
+}
+
 int emulate_instruction(struct kvm_vcpu *vcpu,
                         unsigned long cr2,
                         u16 error_code,
@@ -3998,7 +4021,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
 
                 ++vcpu->stat.insn_emulation;
                 if (r)  {
-                        if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
+                        if (reexecute_instruction(vcpu, cr2))
                                 return EMULATE_DONE;
                         if (emulation_type & EMULTYPE_SKIP)
                                 return EMULATE_FAIL;
@@ -4019,12 +4042,7 @@ restart:
         r = x86_emulate_insn(&vcpu->arch.emulate_ctxt, &emulate_ops);
 
         if (r) { /* emulation failed */
-                /*
-                 * if emulation was due to access to shadowed page table
-                 * and it failed try to unshadow page and re-entetr the
-                 * guest to let CPU execute the instruction.
-                 */
-                if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
+                if (reexecute_instruction(vcpu, cr2))
                         return EMULATE_DONE;
 
                 return handle_emulation_failure(vcpu);