mlx5dv_create_flow(3)

okay bestie, this is mlx5dv_create_flow(3) straight out of the mlx5 Programmer’s Manual — and yes, the manual name is folded in right here near the top, no copied header line, we’re doing this 💅✨

✨ NAME ✨

mlx5dv_create_flow — creates a steering flow rule 🎀

🦋 SYNOPSIS 🦋

              #include <infiniband/mlx5dv.h>

              struct ibv_flow *
              mlx5dv_create_flow(struct mlx5dv_flow_matcher *flow_matcher,
                         struct mlx5dv_flow_match_parameters *match_value,
                         size_t num_actions,
                         struct mlx5dv_flow_action_attr actions_attr[])

💖 DESCRIPTION 💖

mlx5dv_create_flow() creates a steering flow rule with the ability to specify specific driver properties. it’s giving “make me a flow rule, but make it driver-property-specific” fr fr 👑

🧚 ARGUMENTS 🧚

bestie, for flow_matcher and match_value, please see mlx5dv_create_flow_matcher(3) — they’re literally the whole setup vibe 🌸

• num_actions — specifies how many actions are passed in actions_attr 🔢

🫶 actions_attr 🫶

              struct mlx5dv_flow_action_attr {
                  enum mlx5dv_flow_action_type type;
                  union {
                      struct ibv_qp *qp;
                      struct ibv_counters *counter;
                      struct ibv_flow_action *action;
                      uint32_t tag_value;
                      struct mlx5dv_devx_obj *obj;
                      struct {
                          struct mlx5dv_devx_obj *obj;
                          uint32_t offset;
                      } bulk_obj;
                  };
              };

type is the main-character field here; it tells the flow rule what kind of action it’s getting. the values are:

• MLX5DV_FLOW_ACTION_DEST_IBV_QP — the QP passed will receive the matched packets 💌
• MLX5DV_FLOW_ACTION_IBV_FLOW_ACTION — the flow action to be applied ✨
• MLX5DV_FLOW_ACTION_TAG — flow tag to be provided in work completion 🏷️
• MLX5DV_FLOW_ACTION_DEST_DEVX — the DEVX destination object for the matched packets 🎯
• MLX5DV_FLOW_ACTION_COUNTERS_DEVX — the DEVX counter object for the matched packets 🧮
• MLX5DV_FLOW_ACTION_DEFAULT_MISS — steer the packet to the default miss destination 🫥
• MLX5DV_FLOW_ACTION_DROP — action is dropping the matched packet 💀
• MLX5DV_FLOW_ACTION_COUNTERS_DEVX_WITH_OFFSET — the DEVX bulk counter object and its counter offset for the matched packets 🍓

and now the field lowdown:

• qp — QP passed, to be used with type MLX5DV_FLOW_ACTION_DEST_IBV_QP 🐇
• action — flow action, to be used with type MLX5DV_FLOW_ACTION_IBV_FLOW_ACTION; see mlx5dv_create_flow_action_modify_header(3) and mlx5dv_create_flow_action_packet_reformat(3) 🎀
• tag_value — tag value to be passed in the work completion, to be used with type MLX5DV_FLOW_ACTION_TAG; see ibv_create_cq_ex(3) 🏷️
• obj — DEVX object, to be used with type MLX5DV_FLOW_ACTION_DEST_DEVX or by MLX5DV_FLOW_ACTION_COUNTERS_DEVX or by MLX5DV_FLOW_ACTION_COUNTERS_DEVX_WITH_OFFSET 🧚
• offset — offset to the target counter within a bulk DEVX object, to be used with type MLX5DV_FLOW_ACTION_COUNTERS_DEVX_WITH_OFFSET 🎯

🌈 RETURN VALUE 🌈

mlx5dv_create_flow returns a pointer to the created flow rule. on error, NULL will be returned and errno will be set. no cap, that’s the whole return-value tea 😭

👑 SEE ALSO 👑

• mlx5dv_create_flow_action_modify_header(3)
• mlx5dv_create_flow_action_packet_reformat(3)
• mlx5dv_create_flow_matcher(3)
• mlx5dv_create_qp(3)
• ibv_create_qp_ex(3)
• ibv_create_cq_ex(3)
• ibv_create_counters(3)

🌸 AUTHOR 🌸

Mark Bloch <marb@mellanox.com> 💖

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and that’s the page, bestie — cute little footer sign-off: source/version mlx5, date 2018-9-19, page title mlx5dv_create_flow(3). slay, go build that flow rule 🫶✨