Commit 9261f043 authored by Tony Krowiak's avatar Tony Krowiak Committed by Heiko Carstens
Browse files

s390/vfio-ap: use work struct to verify queue reset 



Instead of waiting to verify that a queue is reset in the
vfio_ap_mdev_reset_queue function, let's use a wait queue to check the
the state of the reset. This way, when resetting all of the queues assigned
to a matrix mdev, we don't have to wait for each queue to be reset before
initiating a reset on the next queue to be reset.

Signed-off-by: default avatarTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: default avatarJason J. Herne <jjherne@linux.ibm.com>
Suggested-by: default avatarHalil Pasic <pasic@linux.ibm.com>
Acked-by: default avatarJanosch Frank <frankja@linux.ibm.com>
Tested-by: default avatarViktor Mihajlovski <mihajlov@linux.ibm.com>
Link: https://lore.kernel.org/r/20230815184333.6554-8-akrowiak@linux.ibm.com


Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 62aab082

drivers/s390/crypto/vfio_ap_ops.c

+23 −25
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ 
static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable);

static struct vfio_ap_queue *vfio_ap_find_queue(int apqn);

static const struct vfio_device_ops vfio_ap_matrix_dev_ops;

static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q);

static void vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q);



/**

 * get_update_locks_for_kvm: Acquire the locks required to dynamically update a
@@ -1623,11 +1623,13 @@ static int apq_status_check(int apqn, struct ap_queue_status *status) 


#define WAIT_MSG "Waited %dms for reset of queue %02x.%04x (%u, %u, %u)"



static int apq_reset_check(struct vfio_ap_queue *q)

static void apq_reset_check(struct work_struct *reset_work)

{

	int ret = -EBUSY, elapsed = 0;

	struct ap_queue_status status;

	struct vfio_ap_queue *q;



	q = container_of(reset_work, struct vfio_ap_queue, reset_work);

	memcpy(&status, &q->reset_status, sizeof(status));

	while (true) {

		msleep(AP_RESET_INTERVAL);
@@ -1635,7 +1637,7 @@ static int apq_reset_check(struct vfio_ap_queue *q) 
		status = ap_tapq(q->apqn, NULL);

		ret = apq_status_check(q->apqn, &status);

		if (ret == -EIO)

			return ret;

			return;

		if (ret == -EBUSY) {

			pr_notice_ratelimited(WAIT_MSG, elapsed,

					      AP_QID_CARD(q->apqn),
@@ -1663,34 +1665,32 @@ static int apq_reset_check(struct vfio_ap_queue *q) 
			break;

		}

	}

	return ret;

}



static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)

static void vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q)

{

	struct ap_queue_status status;

	int ret = 0;



	if (!q)

		return 0;

		return;

	status = ap_zapq(q->apqn, 0);

	memcpy(&q->reset_status, &status, sizeof(status));

	switch (status.response_code) {

	case AP_RESPONSE_NORMAL:

	case AP_RESPONSE_RESET_IN_PROGRESS:

	case AP_RESPONSE_BUSY:

		/* Let's verify whether the ZAPQ completed successfully */

		ret = apq_reset_check(q);

		/*

		 * Let's verify whether the ZAPQ completed successfully on a work queue.

		 */

		queue_work(system_long_wq, &q->reset_work);

		break;

	case AP_RESPONSE_DECONFIGURED:

		/*

		 * When an AP adapter is deconfigured, the associated

		 * queues are reset, so let's set the status response code to 0

		 * so the queue may be passed through (i.e., not filtered) and

		 * return a value indicating the reset completed successfully.

		 * so the queue may be passed through (i.e., not filtered).

		 */

		q->reset_status.response_code = 0;

		ret = 0;

		vfio_ap_free_aqic_resources(q);

		break;

	default:
@@ -1698,29 +1698,25 @@ static int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q) 
		     "PQAP/ZAPQ for %02x.%04x failed with invalid rc=%u\n",

		     AP_QID_CARD(q->apqn), AP_QID_QUEUE(q->apqn),

		     status.response_code);

		return -EIO;

	}



	return ret;

}



static int vfio_ap_mdev_reset_queues(struct ap_queue_table *qtable)

{

	int ret, loop_cursor, rc = 0;

	int ret = 0, loop_cursor;

	struct vfio_ap_queue *q;



	hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode)

		vfio_ap_mdev_reset_queue(q);



	hash_for_each(qtable->queues, loop_cursor, q, mdev_qnode) {

		ret = vfio_ap_mdev_reset_queue(q);

		/*

		 * Regardless whether a queue turns out to be busy, or

		 * is not operational, we need to continue resetting

		 * the remaining queues.

		 */

		if (ret)

			rc = ret;

		flush_work(&q->reset_work);



		if (q->reset_status.response_code)

			ret = -EIO;

	}



	return rc;

	return ret;

}



static int vfio_ap_mdev_open_device(struct vfio_device *vdev)
@@ -2045,6 +2041,7 @@ int vfio_ap_mdev_probe_queue(struct ap_device *apdev) 
	q->apqn = to_ap_queue(&apdev->device)->qid;

	q->saved_isc = VFIO_AP_ISC_INVALID;

	memset(&q->reset_status, 0, sizeof(q->reset_status));

	INIT_WORK(&q->reset_work, apq_reset_check);

	matrix_mdev = get_update_locks_by_apqn(q->apqn);



	if (matrix_mdev) {
@@ -2094,6 +2091,7 @@ void vfio_ap_mdev_remove_queue(struct ap_device *apdev) 
	}



	vfio_ap_mdev_reset_queue(q);

	flush_work(&q->reset_work);

	dev_set_drvdata(&apdev->device, NULL);

	kfree(q);

	release_update_locks_for_mdev(matrix_mdev);

drivers/s390/crypto/vfio_ap_private.h

+2 −0
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ struct ap_matrix_mdev { 
 * @saved_isc: the guest ISC registered with the GIB interface

 * @mdev_qnode: allows the vfio_ap_queue struct to be added to a hashtable

 * @reset_status: the status from the last reset of the queue

 * @reset_work: work to wait for queue reset to complete

 */

struct vfio_ap_queue {

	struct ap_matrix_mdev *matrix_mdev;
@@ -143,6 +144,7 @@ struct vfio_ap_queue { 
	unsigned char saved_isc;

	struct hlist_node mdev_qnode;

	struct ap_queue_status reset_status;

	struct work_struct reset_work;

};



int vfio_ap_mdev_register(void);