kvm: x86: don't kill guest on unknown exit reason

KVM_EXIT_UNKNOWN is a kvm bug, we don't really know whether it was
triggered by a priveledged application.  Let's not kill the guest: WARN
and inject #UD instead.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

2 files changed, 6 insertions, 6 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 00bed2c5e948..7527cefc5a43 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3551,9 +3551,9 @@ static int handle_exit(struct kvm_vcpu *vcpu)
 
         if (exit_code >= ARRAY_SIZE(svm_exit_handlers)
             || !svm_exit_handlers[exit_code]) {
-                kvm_run->exit_reason = KVM_EXIT_UNKNOWN;
-                kvm_run->hw.hardware_exit_reason = exit_code;
-                return 0;
+                WARN_ONCE(1, "vmx: unexpected exit reason 0x%x\n", exit_code);
+                kvm_queue_exception(vcpu, UD_VECTOR);
+                return 1;
         }
 
         return svm_exit_handlers[exit_code](svm);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cf3cd079ec52..a8b76c4c95e2 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7174,10 +7174,10 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
             && kvm_vmx_exit_handlers[exit_reason])
                 return kvm_vmx_exit_handlers[exit_reason](vcpu);
         else {
-                vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
-                vcpu->run->hw.hardware_exit_reason = exit_reason;
+                WARN_ONCE(1, "vmx: unexpected exit reason 0x%x\n", exit_reason);
+                kvm_queue_exception(vcpu, UD_VECTOR);
+                return 1;
         }
-        return 0;
 }
 
 static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)