From 9261f0438835a97254590046e1be83733cca440f Mon Sep 17 00:00:00 2001 From: Tony Krowiak Date: Tue, 15 Aug 2023 14:43:28 -0400 Subject: [PATCH] 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: Tony Krowiak Reviewed-by: Jason J. Herne Suggested-by: Halil Pasic Acked-by: Janosch Frank Tested-by: Viktor Mihajlovski Link: https://lore.kernel.org/r/20230815184333.6554-8-akrowiak@linux.ibm.com Signed-off-by: Heiko Carstens --- drivers/s390/crypto/vfio_ap_ops.c | 48 +++++++++++++-------------- drivers/s390/crypto/vfio_ap_private.h | 2 ++ 2 files changed, 25 insertions(+), 25 deletions(-) diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 43224f7a40ea..3a59f1c5390f 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -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); diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h index d6eb3527e056..88aff8b81f2f 100644 --- a/drivers/s390/crypto/vfio_ap_private.h +++ b/drivers/s390/crypto/vfio_ap_private.h @@ -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);