[PATCH v9 17/22] s390: vfio-ap: zeroize the AP queues.

Tony Krowiak
2018-08-13T21:48:14Z

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>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
drivers/s390/crypto/vfio_ap_ops.c | 25 +++++++++++++++++++++++++
drivers/s390/crypto/vfio_ap_private.h | 25 +++++++++++++++++++++++++
2 files changed, 50 insertions(+), 0 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 368b559..cc90323 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -758,6 +758,30 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
return NOTIFY_OK;
}

+static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev, bool force)
+{
+ 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_reset_queue(apid, apqi, 1);
+ if (ret) {
+ if (force)
+ rc = ret;
+ else
+ return ret;
+ }
+ }
+ }
+
+ return rc;
+}
+
static int vfio_ap_mdev_open(struct mdev_device *mdev)
{
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
@@ -788,6 +812,7 @@ 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, true);
vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
&matrix_mdev->group_notifier);
matrix_mdev->kvm = NULL;
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index 3e8534b..34f982a 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -74,4 +74,29 @@ struct ap_matrix_mdev {
extern int vfio_ap_mdev_register(void);
extern void vfio_ap_mdev_unregister(void);

+static inline int vfio_ap_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:
+ pr_warn("%s: error zeroizing %02x.%04x: response code %d\n",
+ VFIO_AP_MODULE_NAME, apid, apqi,
+ status.response_code);
+ return -EIO;
+ }
+ } while (retry--);
+
+ return -EBUSY;
+}
+
#endif /* _VFIO_AP_PRIVATE_H_ */
--
1.7.1