s390/kvm: Interrupt injection bugfix

EXTERNAL_CALL and EMERGENCY type interrupts need to preserve their interrupt
code parameter when being injected from user space.

Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index ff1e2f8..c30615e 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -629,11 +629,28 @@
 		break;
 	case KVM_S390_SIGP_STOP:
 	case KVM_S390_RESTART:
-	case KVM_S390_INT_EXTERNAL_CALL:
-	case KVM_S390_INT_EMERGENCY:
 		VCPU_EVENT(vcpu, 3, "inject: type %x", s390int->type);
 		inti->type = s390int->type;
 		break;
+	case KVM_S390_INT_EXTERNAL_CALL:
+		if (s390int->parm & 0xffff0000) {
+			kfree(inti);
+			return -EINVAL;
+		}
+		VCPU_EVENT(vcpu, 3, "inject: external call source-cpu:%u",
+			   s390int->parm);
+		inti->type = s390int->type;
+		inti->extcall.code = s390int->parm;
+		break;
+	case KVM_S390_INT_EMERGENCY:
+		if (s390int->parm & 0xffff0000) {
+			kfree(inti);
+			return -EINVAL;
+		}
+		VCPU_EVENT(vcpu, 3, "inject: emergency %u\n", s390int->parm);
+		inti->type = s390int->type;
+		inti->emerg.code = s390int->parm;
+		break;
 	case KVM_S390_INT_VIRTIO:
 	case KVM_S390_INT_SERVICE:
 	default: