diff mbox series

[vhost,19/23] vdpa/mlx5: Use suspend/resume during VQP change

Message ID 20240617-stage-vdpa-vq-precreate-v1-19-8c0483f0ca2a@nvidia.com (mailing list archive)
State Superseded
Headers show
Series vdpa/mlx5: Pre-create HW VQs to reduce LM downtime | expand

Commit Message

Dragos Tatulea June 17, 2024, 3:07 p.m. UTC
Resume a VQ if it is already created when the number of VQ pairs
increases. This is done in preparation for VQ pre-creation which is
coming in a later patch. It is necessary because calling setup_vq() on
an already created VQ will return early and will not enable the queue.

For symmetry, suspend a VQ instead of tearing it down when the number of
VQ pairs decreases. But only if the resume operation is supported.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
---
 drivers/vdpa/mlx5/net/mlx5_vnet.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

Comments

Eugenio Perez Martin June 19, 2024, 3:46 p.m. UTC | #1
On Mon, Jun 17, 2024 at 5:09 PM Dragos Tatulea <dtatulea@nvidia.com> wrote:
>
> Resume a VQ if it is already created when the number of VQ pairs
> increases. This is done in preparation for VQ pre-creation which is
> coming in a later patch. It is necessary because calling setup_vq() on
> an already created VQ will return early and will not enable the queue.
>
> For symmetry, suspend a VQ instead of tearing it down when the number of
> VQ pairs decreases. But only if the resume operation is supported.
>
> Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
> Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>

Acked-by: Eugenio Pérez <eperezma@redhat.com>

> ---
>  drivers/vdpa/mlx5/net/mlx5_vnet.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 0e1c1b7ff297..249b5afbe34a 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -2130,14 +2130,22 @@ static int change_num_qps(struct mlx5_vdpa_dev *mvdev, int newqps)
>                 if (err)
>                         return err;
>
> -               for (i = ndev->cur_num_vqs - 1; i >= 2 * newqps; i--)
> -                       teardown_vq(ndev, &ndev->vqs[i]);
> +               for (i = ndev->cur_num_vqs - 1; i >= 2 * newqps; i--) {
> +                       struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i];
> +
> +                       if (is_resumable(ndev))
> +                               suspend_vq(ndev, mvq);
> +                       else
> +                               teardown_vq(ndev, mvq);
> +               }
>
>                 ndev->cur_num_vqs = 2 * newqps;
>         } else {
>                 ndev->cur_num_vqs = 2 * newqps;
>                 for (i = cur_qps * 2; i < 2 * newqps; i++) {
> -                       err = setup_vq(ndev, &ndev->vqs[i], true);
> +                       struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i];
> +
> +                       err = mvq->initialized ? resume_vq(ndev, mvq) : setup_vq(ndev, mvq, true);
>                         if (err)
>                                 goto clean_added;
>                 }
>
> --
> 2.45.1
>
diff mbox series

Patch

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 0e1c1b7ff297..249b5afbe34a 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -2130,14 +2130,22 @@  static int change_num_qps(struct mlx5_vdpa_dev *mvdev, int newqps)
 		if (err)
 			return err;
 
-		for (i = ndev->cur_num_vqs - 1; i >= 2 * newqps; i--)
-			teardown_vq(ndev, &ndev->vqs[i]);
+		for (i = ndev->cur_num_vqs - 1; i >= 2 * newqps; i--) {
+			struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i];
+
+			if (is_resumable(ndev))
+				suspend_vq(ndev, mvq);
+			else
+				teardown_vq(ndev, mvq);
+		}
 
 		ndev->cur_num_vqs = 2 * newqps;
 	} else {
 		ndev->cur_num_vqs = 2 * newqps;
 		for (i = cur_qps * 2; i < 2 * newqps; i++) {
-			err = setup_vq(ndev, &ndev->vqs[i], true);
+			struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i];
+
+			err = mvq->initialized ? resume_vq(ndev, mvq) : setup_vq(ndev, mvq, true);
 			if (err)
 				goto clean_added;
 		}