[GIT PULL 10/22] s390/vfio-ap: allow deconfigured queue to be passed through to a guest

Janosch Frank
2023-08-24T12:47:29Z

From: Tony Krowiak <akrowiak@linux.ibm.com>

When a queue is reset, the status response code returned from the reset
operation is stored in the reset_rc field of the vfio_ap_queue structure
representing the queue being reset. This field is later used to decide
whether the queue should be passed through to a guest. If the reset_rc
field is a non-zero value, the queue will be filtered from the list of
queues passed through.

When an adapter is deconfigured, all queues associated with that adapter
are reset. That being the case, it is not necessary to filter those queues;
so, if the status response code returned from a reset operation indicates
the queue is deconfigured, the reset_rc field of the vfio_ap_queue
structure will be set to zero so it will be passed through (i.e., not
filtered).

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Viktor Mihajlovski <mihajlov@linux.ibm.com>
Link: https://lore.kernel.org/r/20230815184333.6554-5-akrowiak@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 3f67cfb53d0c..a489536c508a 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1677,9 +1677,11 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
case AP_RESPONSE_DECONFIGURED:
/*
* When an AP adapter is deconfigured, the associated
- * queues are reset, so let's return a value indicating the reset
- * completed successfully.
+ * queues are reset, so let's set the status response code to 0
+ * so the queue may be passed through (i.e., not filtered) and
+ * return a value indicating the reset completed successfully.
*/
+ q->reset_rc = 0;
ret = 0;
vfio_ap_free_aqic_resources(q);
break;
--
2.41.0