[PATCH v3 3/3] s390/vfio-ap: improve reaction to response code 07 from PQAP(AQIC) command

Tony Krowiak
2023-10-26T18:34:33Z

Let's improve the vfio_ap driver's reaction to reception of response code
07 from the PQAP(AQIC) command when enabling interrupts on behalf of a
guest:

* Unregister the guest's ISC before the pages containing the notification
indicator bytes are unpinned.

* Capture the return code from the kvm_s390_gisc_unregister function and
log a DBF warning if it fails.

Suggested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 25d7ce2094f8..4e80c211ba47 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -476,8 +476,11 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
break;
case AP_RESPONSE_OTHERWISE_CHANGED:
/* We could not modify IRQ settings: clear new configuration */
+ ret = kvm_s390_gisc_unregister(kvm, isc);
+ if (ret)
+ VFIO_AP_DBF_WARN("%s: kvm_s390_gisc_unregister: rc=%d isc=%d, apqn=%#04x\n",
+ __func__, ret, isc, q->apqn);
vfio_unpin_pages(&q->matrix_mdev->vdev, nib, 1);
- kvm_s390_gisc_unregister(kvm, isc);
break;
default:
pr_warn("%s: apqn %04x: response: %02x\n", __func__, q->apqn,
--
2.41.0