KVM: s390: protvirt: introduce and enable KVM_CAP_S390_PROTECTED

Now that everything is in place, we can announce the feature.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>

arch/s390/kvm/kvm-s390.c

@@ -574,6 +574,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_S390_BPB:
 		r = test_facility(82);
 		break;
+	case KVM_CAP_S390_PROTECTED:
+		r = is_prot_virt_host();
+		break;
 	default:
 		r = 0;
 	}

include/uapi/linux/kvm.h

@@ -1015,6 +1015,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_ARM_NISV_TO_USER 177
 #define KVM_CAP_ARM_INJECT_EXT_DABT 178
 #define KVM_CAP_S390_VCPU_RESETS 179
+#define KVM_CAP_S390_PROTECTED 180
 
 #ifdef KVM_CAP_IRQ_ROUTING