RE: [PATCH v3 02/9] common/mlx5: query packet pacing rate table capabilities

Slava Ovsiienko
2026-03-20T12:02:58Z

Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

> -----Original Message-----
> From: Vincent Jardin <vjardin@free.fr>
> Sent: Friday, March 13, 2026 12:01 AM
> To: dev@dpdk.org
> Cc: Raslan Darawsheh <rasland@nvidia.com>; NBU-Contact-Thomas Monjalon
> (EXTERNAL) <thomas@monjalon.net>; andrew.rybchenko@oktetlabs.ru;
> Dariusz Sosnowski <dsosnowski@nvidia.com>; Slava Ovsiienko
> <viacheslavo@nvidia.com>; Bing Zhao <bingz@nvidia.com>; Ori Kam
> <orika@nvidia.com>; Suanming Mou <suanmingm@nvidia.com>; Matan Azrad
> <matan@nvidia.com>; stephen@networkplumber.org; Vincent Jardin
> <vjardin@free.fr>
> Subject: [PATCH v3 02/9] common/mlx5: query packet pacing rate table
> capabilities
>
> Query additional QoS packet pacing capabilities from HCA attributes:
> - packet_pacing_burst_bound: HW supports burst_upper_bound parameter
> - packet_pacing_typical_size: HW supports typical_packet_size parameter
> - packet_pacing_max_rate / packet_pacing_min_rate: rate range in kbps
> - packet_pacing_rate_table_size: number of HW rate table entries
>
> These capabilities are needed by the upcoming per-queue rate limiting feature
> to validate devarg values and report HW limits.
>
> Supported hardware:
> - ConnectX-6 Dx and later (different boards expose different subsets)
> - ConnectX-5 reports packet_pacing but not all extended fields
> - ConnectX-7/8 report the full capability set
> - BlueField-2 and later DPUs also report these capabilities
>
> Not supported:
> - ConnectX-4 Lx and earlier (no packet_pacing capability at all)
> - ConnectX-5 Ex may not report burst_bound or typical_size
>
> Signed-off-by: Vincent Jardin <vjardin@free.fr>
> ---
> drivers/common/mlx5/mlx5_devx_cmds.c | 15 +++++++++++++++
> drivers/common/mlx5/mlx5_devx_cmds.h | 11 ++++++++++-
> 2 files changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/common/mlx5/mlx5_devx_cmds.c
> b/drivers/common/mlx5/mlx5_devx_cmds.c
> index d12ebf8487..8f53303fa7 100644
> --- a/drivers/common/mlx5/mlx5_devx_cmds.c
> +++ b/drivers/common/mlx5/mlx5_devx_cmds.c
> @@ -1244,6 +1244,21 @@ mlx5_devx_cmd_query_hca_attr(void *ctx,
> MLX5_GET(qos_cap, hcattr, packet_pacing);
> attr->qos.wqe_rate_pp =
> MLX5_GET(qos_cap, hcattr, wqe_rate_pp);
> + attr->qos.packet_pacing_burst_bound =
> + MLX5_GET(qos_cap, hcattr,
> + packet_pacing_burst_bound);
> + attr->qos.packet_pacing_typical_size =
> + MLX5_GET(qos_cap, hcattr,
> + packet_pacing_typical_size);
> + attr->qos.packet_pacing_max_rate =
> + MLX5_GET(qos_cap, hcattr,
> + packet_pacing_max_rate);
> + attr->qos.packet_pacing_min_rate =
> + MLX5_GET(qos_cap, hcattr,
> + packet_pacing_min_rate);
> + attr->qos.packet_pacing_rate_table_size =
> + MLX5_GET(qos_cap, hcattr,
> + packet_pacing_rate_table_size);
> if (attr->qos.flow_meter_aso_sup) {
> attr->qos.log_meter_aso_granularity =
> MLX5_GET(qos_cap, hcattr,
> diff --git a/drivers/common/mlx5/mlx5_devx_cmds.h
> b/drivers/common/mlx5/mlx5_devx_cmds.h
> index da50fc686c..930ae2c072 100644
> --- a/drivers/common/mlx5/mlx5_devx_cmds.h
> +++ b/drivers/common/mlx5/mlx5_devx_cmds.h
> @@ -67,7 +67,16 @@ struct mlx5_hca_qos_attr {
> /* Power of the maximum allocation granularity Object. */
> uint32_t log_max_num_meter_aso:5;
> /* Power of the maximum number of supported objects. */
> -
> + uint32_t packet_pacing_burst_bound:1;
> + /* HW supports burst_upper_bound PP parameter. */
> + uint32_t packet_pacing_typical_size:1;
> + /* HW supports typical_packet_size PP parameter. */
> + uint32_t packet_pacing_max_rate;
> + /* Maximum supported pacing rate in kbps. */
> + uint32_t packet_pacing_min_rate;
> + /* Minimum supported pacing rate in kbps. */
> + uint16_t packet_pacing_rate_table_size;
> + /* Number of entries in the HW rate table. */
> };
>
> struct mlx5_hca_vdpa_attr {
> --
> 2.43.0