Re: [PATCH vhost 11/23] vdpa/mlx5: Set an initial size on the VQ

Eugenio Perez Martin
2024-06-19T15:09:15Z

On Mon, Jun 17, 2024 at 5:09 PM Dragos Tatulea <dtatulea@nvidia.com> wrote:
>
> The virtqueue size is a pre-requisite for setting up any virtqueue
> resources. For the upcoming optimization of creating virtqueues at
> device add, the virtqueue size has to be configured.
>
> Store the default queue size in struct mlx5_vdpa_net to make it easy in
> the future to pre-configure this default value via vdpa tool.
>
> The queue size check in setup_vq() will always be false. So remove it.
>
> Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
> Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
> ---
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 7 ++++---
> drivers/vdpa/mlx5/net/mlx5_vnet.h | 1 +
> 2 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 245b5dac98d3..1181e0ac3671 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -58,6 +58,8 @@ MODULE_LICENSE("Dual BSD/GPL");
> */
> #define MLX5V_DEFAULT_VQ_COUNT 2
>
> +#define MLX5V_DEFAULT_VQ_SIZE 256
> +
> struct mlx5_vdpa_cq_buf {
> struct mlx5_frag_buf_ctrl fbc;
> struct mlx5_frag_buf frag_buf;
> @@ -1445,9 +1447,6 @@ static int setup_vq(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue *mvq)
> u16 idx = mvq->index;
> int err;
>
> - if (!mvq->num_ent)
> - return 0;
> -
> if (mvq->initialized)
> return 0;
>
> @@ -3523,6 +3522,7 @@ static void init_mvqs(struct mlx5_vdpa_net *ndev)
> mvq->ndev = ndev;
> mvq->fwqp.fw = true;
> mvq->fw_state = MLX5_VIRTIO_NET_Q_OBJECT_NONE;
> + mvq->num_ent = ndev->default_queue_size;
> }
> }
>
> @@ -3660,6 +3660,7 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
> goto err_alloc;
> }
> ndev->cur_num_vqs = MLX5V_DEFAULT_VQ_COUNT;
> + ndev->default_queue_size = MLX5V_DEFAULT_VQ_SIZE;
>
> init_mvqs(ndev);
> allocate_irqs(ndev);
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.h b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> index 90b556a57971..2ada29767cc5 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.h
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.h
> @@ -58,6 +58,7 @@ struct mlx5_vdpa_net {
> bool setup;
> u32 cur_num_vqs;
> u32 rqt_size;
> + u16 default_queue_size;

It seems to me this is only assigned here and not used in the rest of
the series, why allocate a member here instead of using macro
directly?

> bool nb_registered;
> struct notifier_block nb;
> struct vdpa_callback config_cb;
>
> --
> 2.45.1
>