[GIT PULL 08/22] s390/vfio-ap: clean up irq resources if possible

Janosch Frank
2023-08-24T13:40:39Z

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

The architecture does not specify whether interrupts are disabled as part
of the asynchronous reset or upon return from the PQAP/ZAPQ instruction.
If, however, PQAP/ZAPQ completes with APQSW response code 0 and the
interrupt bit in the status word is also 0, we know the interrupts are
disabled and we can go ahead and clean up the corresponding resources;
otherwise, we must wait until the asynchronous reset has completed.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Acked-by: Halil Pasic <pasic@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/20230815184333.6554-3-akrowiak@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 3fd80533194b..be92ba45226d 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1654,9 +1654,13 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
switch (status.response_code) {
case AP_RESPONSE_NORMAL:
ret = 0;
- /* if the reset has not completed, wait for it to take effect */
- if (!status.queue_empty || status.irq_enabled)
+ if (!status.irq_enabled)
+ vfio_ap_free_aqic_resources(q);
+ if (!status.queue_empty || status.irq_enabled) {
ret = apq_reset_check(q);
+ if (status.irq_enabled && ret == 0)
+ vfio_ap_free_aqic_resources(q);
+ }
break;
case AP_RESPONSE_RESET_IN_PROGRESS:
/*
@@ -1675,6 +1679,7 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
* completed successfully.
*/
ret = 0;
+ vfio_ap_free_aqic_resources(q);
break;
default:
WARN(true,
@@ -1684,8 +1689,6 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)
return -EIO;
}

- vfio_ap_free_aqic_resources(q);
-
return ret;
}

--
2.41.0