[PATCH v2 5/6] s390/vfio_ap: fix handling of error response codes

[Tony Krowiak <akrowiak@linux.ibm.com>]

Some response codes returned from the queue reset function are not being
handled correctly; this patch fixes them:

1. Response code 3, AP queue deconfigured: Deconfiguring an AP adapter
   resets all of its queues, so this is handled by indicating the reset
   verification completed successfully.

2. For all response codes other than 0 (normal reset completion), 2
   (queue reset in progress) and 3 (AP deconfigured), the -EIO error will
   be returned from the vfio_ap_mdev_reset_queue() function. In all cases,
   all fields of the status word other than the response code will be
   set to zero, so it makes no sense to check status bits.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
---
 drivers/s390/crypto/vfio_ap_ops.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e1b05e749570..68be34362680 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1670,17 +1670,15 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
 		if (ret)
 			break;
 		goto retry_zapq;
-	case AP_RESPONSE_Q_NOT_AVAIL:
 	case AP_RESPONSE_DECONFIGURED:
-	case AP_RESPONSE_CHECKSTOPPED:
-		WARN_ONCE(status.irq_enabled,
-			  "PQAP/ZAPQ for %02x.%04x failed with rc=%u while IRQ enabled",
-			  AP_QID_CARD(q->apqn), AP_QID_QUEUE(q->apqn),
-			  status.response_code);
-		ret = -EBUSY;
-		goto free_resources;
+		/*
+		 * When an AP adapter is deconfigured, the associated
+		 * queues are reset, so let's return a value indicating the reset
+		 * completed successfully.
+		 */
+		ret = 0;
+		break;
 	default:
-		/* things are really broken, give up */
 		WARN(true,
 		     "PQAP/ZAPQ for %02x.%04x failed with invalid rc=%u\n",
 		     AP_QID_CARD(q->apqn), AP_QID_QUEUE(q->apqn),
@@ -1688,7 +1686,6 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
 		return -EIO;
 	}
 
-free_resources:
 	vfio_ap_free_aqic_resources(q);
 
 	return ret;
-- 
2.31.1