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 <akrowiak@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Tested-by: Viktor Mihajlovski <mihajlov@linux.ibm.com>
Link: https://lore.kernel.org/r/20230815184333.6554-4-akrowiak@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index be92ba4..3f67cfb 100644 (file)
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/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 @@ retry_zapq:
                }
                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