On 2022-12-13 16:44, Tony Krowiak wrote:
The vfio_ap_mdev_reset_queue() function does not check the status
response code returned form the PQAP(TAPQ) function when verifying the
queue's status; consequently, there is no way of knowing whether
verification failed because the wait time was exceeded, or because the
PQAP(TAPQ) failed.
This patch adds a function to check the status response code from the
PQAP(TAPQ) instruction and logs an appropriate message if it fails.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 36 ++++++++++++++++++++++++++-----
1 file changed, 31 insertions(+), 5 deletions(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c
b/drivers/s390/crypto/vfio_ap_ops.c
index 83ff94a38102..a5530a46cf31 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1587,23 +1587,49 @@ static struct vfio_ap_queue
*vfio_ap_find_queue(int apqn)
return q;
}
+static int apq_status_check(int apqn, struct ap_queue_status *status)
+{
+ switch (status->response_code) {
+ case AP_RESPONSE_NORMAL:
+ case AP_RESPONSE_RESET_IN_PROGRESS:
+ if (status->queue_empty && !status->irq_enabled)
+ return 0;
+ return -EBUSY;
+ case AP_RESPONSE_DECONFIGURED:
+ /*
+ * If the AP queue is deconfigured, any subsequent AP command
+ * targeting the queue will fail with the same response code. On the
+ * other hand, when an AP adapter is deconfigured, the associated
+ * queues are reset, so let's return a value indicating the reset
+ * for which we're waiting completed successfully.
+ */
+ return 0;
+ default:
+ WARN(true,
+ "failed to verify reset of queue %02x.%04x: TAPQ rc=%u\n",
+ AP_QID_CARD(apqn), AP_QID_QUEUE(apqn),
+ status->response_code);
+ return -EIO;
+ }
+}
+
static int apq_reset_check(struct vfio_ap_queue *q)
{
- int iters = 2;
+ int iters = 2, ret;
struct ap_queue_status status;
while (iters--) {
msleep(20);
status = ap_tapq(q->apqn, NULL);
- if (status.queue_empty && !status.irq_enabled)
- return 0;
+ ret = apq_status_check(q->apqn, &status);
+ if (ret != -EBUSY)
+ return ret;
}
WARN_ONCE(iters <= 0,
"timeout verifying reset of queue %02x.%04x (%u, %u, %u)",
AP_QID_CARD(q->apqn), AP_QID_QUEUE(q->apqn),
status.queue_empty, status.irq_enabled, status.response_code);
-
- return -EBUSY;
+ return ret;
}
static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
Reviewed-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
Just one word here: this function is only called once and it is very
very special
to just check the status after RAPQ/ZAPQ. I would merge this function
into the
calling code or rename the function to reflect the special condition
under which
it is called. However - this is not my code and I don't need to maintain
it, so
maybe simple ignore my words.
