Commit 0dbc1b4a authored by Eli Cohen's avatar Eli Cohen Committed by Michael S. Tsirkin
Browse files

vdpa/mlx5: Avoid using reslock in event_handler 



event_handler runs under atomic context and may not acquire reslock. We
can still guarantee that the handler won't be called after suspend by
clearing nb_registered, unregistering the handler and flushing the
workqueue.

Signed-off-by: default avatarEli Cohen <elic@nvidia.com>
Message-Id: <20221114131759.57883-5-elic@nvidia.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 1ab53760

drivers/vdpa/mlx5/net/mlx5_vnet.c

+4 −12
Original line number Diff line number Diff line
@@ -2845,8 +2845,8 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev) 
	int i;



	down_write(&ndev->reslock);

	mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);

	ndev->nb_registered = false;

	mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);

	flush_workqueue(ndev->mvdev.wq);

	for (i = 0; i < ndev->cur_num_vqs; i++) {

		mvq = &ndev->vqs[i];
@@ -3024,7 +3024,7 @@ static void update_carrier(struct work_struct *work) 
	else

		ndev->config.status &= cpu_to_mlx5vdpa16(mvdev, ~VIRTIO_NET_S_LINK_UP);



	if (ndev->config_cb.callback)

	if (ndev->nb_registered && ndev->config_cb.callback)

		ndev->config_cb.callback(ndev->config_cb.private);



	kfree(wqent);
@@ -3041,21 +3041,13 @@ static int event_handler(struct notifier_block *nb, unsigned long event, void *p 
		switch (eqe->sub_type) {

		case MLX5_PORT_CHANGE_SUBTYPE_DOWN:

		case MLX5_PORT_CHANGE_SUBTYPE_ACTIVE:

			down_read(&ndev->reslock);

			if (!ndev->nb_registered) {

				up_read(&ndev->reslock);

				return NOTIFY_DONE;

			}

			wqent = kzalloc(sizeof(*wqent), GFP_ATOMIC);

			if (!wqent) {

				up_read(&ndev->reslock);

			if (!wqent)

				return NOTIFY_DONE;

			}



			wqent->mvdev = &ndev->mvdev;

			INIT_WORK(&wqent->work, update_carrier);

			queue_work(ndev->mvdev.wq, &wqent->work);

			up_read(&ndev->reslock);

			ret = NOTIFY_OK;

			break;

		default:
@@ -3242,8 +3234,8 @@ static void mlx5_vdpa_dev_del(struct vdpa_mgmt_dev *v_mdev, struct vdpa_device * 
	struct workqueue_struct *wq;



	if (ndev->nb_registered) {

		mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);

		ndev->nb_registered = false;

		mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);

	}

	wq = mvdev->wq;

	mvdev->wq = NULL;