s390/vfio-ap: wait for response code 05 to clear on queue reset

Response code 05, AP busy, is a valid response code for a ZAPQ or TAPQ.
Instead of returning error -EIO when a ZAPQ fails with response code 05,
let's wait until the queue is no longer busy and try the ZAPQ again.

Signed-off-by: Tony Krowiak <[email protected]>
Acked-by: Janosch Frank <[email protected]>
Tested-by: Viktor Mihajlovski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>

Author: Tony Krowiak

drivers/s390/crypto/vfio_ap_ops.c

@@ -1611,6 +1611,7 @@ static int apq_status_check(int apqn, struct ap_queue_status *status)
 	case AP_RESPONSE_DECONFIGURED:
 		return 0;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
+	case AP_RESPONSE_BUSY:
 		return -EBUSY;
 	default:
 		WARN(true,
@@ -1663,6 +1664,7 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
 		}
 		break;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
+	case AP_RESPONSE_BUSY:
 		/*
 		 * There is a reset issued by another process in progress. Let's wait
 		 * for that to complete. Since we have no idea whether it was a RAPQ or