s390: vfio-ap: implement VFIO_DEVICE_RESET ioctl

Implements the VFIO_DEVICE_RESET ioctl. This ioctl zeroizes
all of the AP queues assigned to the guest.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Tested-by: Pierre Morel <pmorel@linux.ibm.com>
Message-Id: <20180925231641.4954-15-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

drivers/s390/crypto/vfio_ap_ops.c

@@ -917,7 +917,7 @@ static int vfio_ap_mdev_get_device_info(unsigned long arg)
 	if (info.argsz < minsz)
 		return -EINVAL;
 
-	info.flags = VFIO_DEVICE_FLAGS_AP;
+	info.flags = VFIO_DEVICE_FLAGS_AP | VFIO_DEVICE_FLAGS_RESET;
 	info.num_regions = 0;
 	info.num_irqs = 0;
 
@@ -933,6 +933,9 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
 	case VFIO_DEVICE_GET_INFO:
 		ret = vfio_ap_mdev_get_device_info(arg);
 		break;
+	case VFIO_DEVICE_RESET:
+		ret = vfio_ap_mdev_reset_queues(mdev);
+		break;
 	default:
 		ret = -EOPNOTSUPP;
 		break;