KVM: async_pf: Exploit one reg interface for pfault

To enable pfault after live migration we need to expose pfault_token,
pfault_select and pfault_compare, as one reg registers to userspace.

So that qemu is able to transfer this between the source and the target.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d8e9f04..a5da2cc 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -561,6 +561,18 @@
 		r = put_user(vcpu->arch.sie_block->ckc,
 			     (u64 __user *)reg->addr);
 		break;
+	case KVM_REG_S390_PFTOKEN:
+		r = put_user(vcpu->arch.pfault_token,
+			     (u64 __user *)reg->addr);
+		break;
+	case KVM_REG_S390_PFCOMPARE:
+		r = put_user(vcpu->arch.pfault_compare,
+			     (u64 __user *)reg->addr);
+		break;
+	case KVM_REG_S390_PFSELECT:
+		r = put_user(vcpu->arch.pfault_select,
+			     (u64 __user *)reg->addr);
+		break;
 	default:
 		break;
 	}
@@ -590,6 +602,18 @@
 		r = get_user(vcpu->arch.sie_block->ckc,
 			     (u64 __user *)reg->addr);
 		break;
+	case KVM_REG_S390_PFTOKEN:
+		r = get_user(vcpu->arch.pfault_token,
+			     (u64 __user *)reg->addr);
+		break;
+	case KVM_REG_S390_PFCOMPARE:
+		r = get_user(vcpu->arch.pfault_compare,
+			     (u64 __user *)reg->addr);
+		break;
+	case KVM_REG_S390_PFSELECT:
+		r = get_user(vcpu->arch.pfault_select,
+			     (u64 __user *)reg->addr);
+		break;
 	default:
 		break;
 	}