KVM: s390: implement sigp external call

Implement sigp external call, which might be required for guests that
issue an external call instead of an emergency signal for IPI.

This fixes an issue with "KVM: unknown SIGP: 0x02" when booting
such an SMP guest.

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 6884054..f47fcd3 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -371,6 +371,7 @@
 #define KVM_S390_INT_VIRTIO		0xffff2603u
 #define KVM_S390_INT_SERVICE		0xffff2401u
 #define KVM_S390_INT_EMERGENCY		0xffff1201u
+#define KVM_S390_INT_EXTERNAL_CALL	0xffff1202u
 
 struct kvm_s390_interrupt {
 	__u32 type;