[PATCH v11 13/26] s390: vfio-ap: zeroize the AP queues

Tony Krowiak
2018-09-25T23:17:56Z

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

Let's call PAPQ(ZAPQ) to zeroize a queue for each queue configured
for a mediated matrix device when it is released.

Zeroizing a queue resets the queue, clears all pending
messages for the queue entries and disables adapter interruptions
associated with the queue.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 44 +++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index b4f67d547493..1943e47d7d78 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -816,6 +816,49 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
return NOTIFY_OK;
}

+static int vfio_ap_mdev_reset_queue(unsigned int apid, unsigned int apqi,
+ unsigned int retry)
+{
+ struct ap_queue_status status;
+
+ do {
+ status = ap_zapq(AP_MKQID(apid, apqi));
+ switch (status.response_code) {
+ case AP_RESPONSE_NORMAL:
+ return 0;
+ case AP_RESPONSE_RESET_IN_PROGRESS:
+ case AP_RESPONSE_BUSY:
+ msleep(20);
+ break;
+ default:
+ /* things are really broken, give up */
+ return -EIO;
+ }
+ } while (retry--);
+
+ return -EBUSY;
+}
+
+static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
+{
+ int ret;
+ int rc = 0;
+ unsigned long apid, apqi;
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ for_each_set_bit_inv(apid, matrix_mdev->matrix.apm,
+ matrix_mdev->matrix.apm_max + 1) {
+ for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
+ matrix_mdev->matrix.aqm_max + 1) {
+ ret = vfio_ap_mdev_reset_queue(apid, apqi, 1);
+ if (ret)
+ rc = ret;
+ }
+ }
+
+ return rc;
+}
+
static int vfio_ap_mdev_open(struct mdev_device *mdev)
{
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
@@ -846,6 +889,7 @@ static void vfio_ap_mdev_release(struct mdev_device *mdev)
if (matrix_mdev->kvm)
kvm_arch_crypto_clear_masks(matrix_mdev->kvm);

+ vfio_ap_mdev_reset_queues(mdev);
vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
&matrix_mdev->group_notifier);
matrix_mdev->kvm = NULL;
--
2.19.0.221.g150f307