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

From: Tony Krowiak
Date: Wed Jan 18 2023 - 15:32:49 EST


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@xxxxxxxxxxxxx>
Reviewed-by: Jason J. Herne <jjherne@xxxxxxxxxxxxx>
Reviewed-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
---
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