kvm: nVMX: Fix fault priority for VMX operations

When checking emulated VMX instructions for faults, the #UD for "IF
(not in VMX operation)" should take precedence over the #GP for "ELSIF
CPL > 0."
Suggested-by: NEric Northup <digitaleric@google.com>
Signed-off-by: NJim Mattson <jmattson@google.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

@@ -8159,15 +8159,16 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
  */
 static int nested_vmx_check_permission(struct kvm_vcpu *vcpu)
 {
-	if (vmx_get_cpl(vcpu)) {
-		kvm_inject_gp(vcpu, 0);
+	if (!to_vmx(vcpu)->nested.vmxon) {
+		kvm_queue_exception(vcpu, UD_VECTOR);
 		return 0;
 	}
 
-	if (!to_vmx(vcpu)->nested.vmxon) {
-		kvm_queue_exception(vcpu, UD_VECTOR);
+	if (vmx_get_cpl(vcpu)) {
+		kvm_inject_gp(vcpu, 0);
 		return 0;
 	}
+
 	return 1;
 }