Commit 5eb8c7eb authored by Dragos Tatulea's avatar Dragos Tatulea Committed by Michael S. Tsirkin
Browse files

vdpa/mlx5: Parallelize device resume 



Currently device resume works on vqs serially. Building up on previous
changes that converted vq operations to the async api, this patch
parallelizes the device resume.

For 1 vDPA device x 32 VQs (16 VQPs) attached to a large VM (256 GB RAM,
32 CPUs x 2 threads per core), the device resume time is reduced from
~16 ms to ~4.5 ms.

Signed-off-by: default avatarDragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: default avatarTariq Toukan <tariqt@nvidia.com>
Acked-by: default avatarEugenio Pérez <eperezma@redhat.com>
Message-Id: <20240816090159.1967650-8-dtatulea@nvidia.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Tested-by: default avatarLei Yang <leiyang@redhat.com>
parent dcf3eac0

drivers/vdpa/mlx5/net/mlx5_vnet.c

+14 −26
Original line number Diff line number Diff line
@@ -1675,10 +1675,15 @@ static int suspend_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mv 
	return suspend_vqs(ndev, mvq->index, 1);

}



static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)

static int resume_vqs(struct mlx5_vdpa_net *ndev, int start_vq, int num_vqs)

{

	struct mlx5_vdpa_virtqueue *mvq;

	int err;



	if (start_vq >= ndev->mvdev.max_vqs)

		return -EINVAL;



	mvq = &ndev->vqs[start_vq];

	if (!mvq->initialized)

		return 0;
@@ -1690,13 +1695,9 @@ static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq 
		/* Due to a FW quirk we need to modify the VQ fields first then change state.

		 * This should be fixed soon. After that, a single command can be used.

		 */

		err = modify_virtqueues(ndev, mvq->index, 1, mvq->fw_state);

		if (err) {

			mlx5_vdpa_err(&ndev->mvdev,

				"modify vq properties failed for vq %u, err: %d\n",

				mvq->index, err);

		err = modify_virtqueues(ndev, start_vq, num_vqs, mvq->fw_state);

		if (err)

			return err;

		}

		break;

	case MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND:

		if (!is_resumable(ndev)) {
@@ -1712,25 +1713,12 @@ static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq 
		return -EINVAL;

	}



	err = modify_virtqueues(ndev, mvq->index, 1, MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY);

	if (err)

		mlx5_vdpa_err(&ndev->mvdev, "modify to resume failed for vq %u, err: %d\n",

			      mvq->index, err);



	return err;

	return modify_virtqueues(ndev, start_vq, num_vqs, MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY);

}



static int resume_vqs(struct mlx5_vdpa_net *ndev)

static int resume_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)

{

	int err = 0;



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

		int local_err = resume_vq(ndev, &ndev->vqs[i]);



		err = local_err ? local_err : err;

	}



	return err;

	return resume_vqs(ndev, mvq->index, 1);

}



static void teardown_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
@@ -3080,7 +3068,7 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_dev *mvdev, 
			return err;

	}



	resume_vqs(ndev);

	resume_vqs(ndev, 0, ndev->cur_num_vqs);



	return 0;

}
@@ -3204,7 +3192,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) 
				teardown_vq_resources(ndev);



			if (ndev->setup) {

				err = resume_vqs(ndev);

				err = resume_vqs(ndev, 0, ndev->cur_num_vqs);

				if (err) {

					mlx5_vdpa_warn(mvdev, "failed to resume VQs\n");

					goto err_driver;
@@ -3628,7 +3616,7 @@ static int mlx5_vdpa_resume(struct vdpa_device *vdev) 


	down_write(&ndev->reslock);

	mvdev->suspended = false;

	err = resume_vqs(ndev);

	err = resume_vqs(ndev, 0, ndev->cur_num_vqs);

	register_link_notifier(ndev);

	up_write(&ndev->reslock);