Re: [dpdk-dev] [PATCH v5 1/2] ethdev: add flow shared action API

[Ajit Khaparde <ajit.khaparde@broadcom.com>]

Please see inline..

On Wed, Oct 7, 2020 at 5:56 AM Andrey Vesnovaty <andreyv@nvidia.com> wrote:
>
> This commit introduces extension of DPDK flow action API enabling
> sharing of single rte_flow_action in multiple flows. The API intended for
> PMDs, where multiple HW offloaded flows can reuse the same HW
> essence/object representing flow action and modification of such an
> essence/object affects all the rules using it.
>
> Motivation and example
> ===
> Adding or removing one or more queues to RSS used by multiple flow rules
> imposes per rule toll for current DPDK flow API; the scenario requires
> for each flow sharing cloned RSS action:
> - call `rte_flow_destroy()`
> - call `rte_flow_create()` with modified RSS action
>

[snip]
> Shared action create/use/destroy
> ===
> Shared action may be reused by some or none flow rules at any given
> moment, i.e. shared action reside outside of the context of any flow.
s/reside/resides

[snip]
> testpmd
> ===
> In order to utilize introduced API testpmd cli may implement following
> extension
> create/update/destroy/query shared action accordingly
>
> flow shared_action (port) create {action_id (id)} (action) / end
Same comment as in testpmd patch. Please add the ability to specify
and parse direction.

> flow shared_action (port) update (id) (action) / end
> flow shared_action (port) destroy action_id (id) {action_id (id) [...]}
> flow shared_action (port) query (id)
>
> testpmd example
> ===
>
> configure rss to queues 1 & 2
>
> > flow shared_action 0 create action_id 100 rss queues 1 2 end / end
>
> create flow rule utilizing shared action
>
> > flow create 0 ingress \
>     pattern eth dst is 0c:42:a1:15:fd:ac / ipv6 / tcp / end \
>   actions shared 100 / end
>
> add 2 more queues
>
> > flow shared_action 0 modify 100 rss queues 1 2 3 4 end / end
>
> example
> ===
>
> struct rte_flow_action actions[2];
> struct rte_flow_action action;
> /* skipped: initialize action */
> struct rte_flow_shared_action *handle = rte_flow_shared_action_create(
>                                         port_id, &action, &error);
> actions[0].type = RTE_FLOW_ACTION_TYPE_SHARED;
> actions[0].conf = handle;
direction?

> actions[1].type = RTE_FLOW_ACTION_TYPE_END;
> /* skipped: init attr0 & pattern0 args */
[snip]

> diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
> index da8bfa5489..383d516fbd 100644
> --- a/lib/librte_ethdev/rte_flow.h
> +++ b/lib/librte_ethdev/rte_flow.h
> @@ -1714,7 +1714,8 @@ enum rte_flow_action_type {
>         /**
>          * Enables counters for this flow rule.
>          *
> -        * These counters can be retrieved and reset through rte_flow_query(),
> +        * These counters can be retrieved and reset through rte_flow_query() or
> +        * rte_flow_shared_action_query() if the action provided via handle,
>          * see struct rte_flow_query_count.
>          *
>          * See struct rte_flow_action_count.
> @@ -2132,6 +2133,14 @@ enum rte_flow_action_type {
>          * see enum RTE_ETH_EVENT_FLOW_AGED
>          */
>         RTE_FLOW_ACTION_TYPE_AGE,
> +
> +       /**
> +        * Describe action shared a cross multiple flow rules.
s/a cross/across

> +        *
> +        * Allow multiple rules reference the same action by handle (see
> +        * struct rte_flow_shared_action).
> +        */
> +       RTE_FLOW_ACTION_TYPE_SHARED,
>  };
>
>  /**
> @@ -2693,6 +2702,20 @@ struct rte_flow_action_set_dscp {
>         uint8_t dscp;
>  };
>
> +
> +/**
> + * RTE_FLOW_ACTION_TYPE_SHARED
> + *
> + * Opaque type returned after successfully creating a shared action.
> + *
> + * This handle can be used to manage and query the related action:
> + * - share it a cross multiple flow rules
s/a cross/across

> + * - update action configuration
> + * - query action data
> + * - destroy action
> + */
> +struct rte_flow_shared_action;
> +
>  /* Mbuf dynamic field offset for metadata. */
>  extern int32_t rte_flow_dynf_metadata_offs;
>
> @@ -3357,6 +3380,144 @@ int
>  rte_flow_get_aged_flows(uint16_t port_id, void **contexts,
>                         uint32_t nb_contexts, struct rte_flow_error *error);
>
> +/**
> + * Specify shared action configuration
> + */
> +struct rte_flow_shared_action_conf {
> +       uint32_t ingress:1;
> +       /**< Action valid for rules applied to ingress traffic. */
> +       uint32_t egress:1;
> +       /**< Action valid for rules applied to egress traffic. */
Add a note to indicate only one of these shall be set.

> +};
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
[snip]