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>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 00bed2c..7527cef 100644 (file)
--- 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 cf3cd07..a8b76c4 100644 (file)
--- 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)