[RFC] ethdev: sharing indirect actions between ports

[Ori Kam]

Hi Slava,

Looks good to me,
Best,
Ori

> -----Original Message-----
> From: Slava Ovsiienko <viacheslavo at nvidia.com>
> Sent: Wednesday, 28 December 2022 18:55
> 
> The RTE Flow API implements the concept of shared objects,
> known as indirect actions (RTE_FLOW_ACTION_TYPE_INDIRECT).
> An application can create the indirect action of desired
> type and configuration with rte_flow_action_handle_create
> call and then specify the obtained action handle in multiple
> flows.
> 
> The initial concept supposes the action handle has strict
> attachment to the port it was created on and to be used
> exclusively in the flows being installed on the port.
> 
> Nowadays the multipath network topologies are quite common,
> packets belonging to the same connection might arrive and
> be sent over multiple ports, and there is the raising demand
> to handle these "spread" connections. To fulfil this demand
> it is proposed to extend indirect action sharing across the
> multiple ports. This kind of sharing would be extremely useful
> for the meters and counters, allowing to manage the single
> connection over the multiple ports.
> 
> This cross-port object sharing is hard to implement in
> generic way merely with software on the upper layers, but
> can be provided by the driver over the single hardware
> instance, where  multiple ports reside on the same physical
> NIC and share the same hardware context.
> 
> To allow this action sharing application should specify
> the "host port" during flow configuring to claim the intention
> to share the indirect actions. All indirect actions reside within
> "host port" context and can be shared in flows being installed
> on the host port and on all the ports referencing this one.
> 
> If sharing between host and port being configured is not supported
> the configuration should be rejected with error. There might be
> multiple independent (mutual exclusive) sharing domains with
> dedicated host and referencing ports.
> 
> To manage the shared indirect action any port from sharing domain
> can be specified. To share or not the created action is up to
> application, no API change is needed.
> 
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
> ---
>  lib/ethdev/rte_flow.c |  6 ++++++
>  lib/ethdev/rte_flow.h | 11 +++++++++++
>  2 files changed, 17 insertions(+)
> 
> diff --git a/lib/ethdev/rte_flow.c b/lib/ethdev/rte_flow.c
> index 7d0c24366c..692d37925a 100644
> --- a/lib/ethdev/rte_flow.c
> +++ b/lib/ethdev/rte_flow.c
> @@ -1476,6 +1476,12 @@ rte_flow_configure(uint16_t port_id,
>  		RTE_FLOW_LOG(ERR, "Port %"PRIu16" queue info is
> NULL.\n", port_id);
>  		return -EINVAL;
>  	}
> +	if ((port_attr->flags & RTE_FLOW_PORT_FLAG_SHARE_INDIRECT) &&
> +	     !rte_eth_dev_is_valid_port(port_attr->host_port_id)) {
> +		return rte_flow_error_set(error, ENODEV,
> +
> RTE_FLOW_ERROR_TYPE_UNSPECIFIED,
> +					  NULL, rte_strerror(ENODEV));
> +	}
>  	if (likely(!!ops->configure)) {
>  		ret = ops->configure(dev, port_attr, nb_queue, queue_attr,
> error);
>  		if (ret == 0)
> diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
> index b60987db4b..c784f4ec30 100644
> --- a/lib/ethdev/rte_flow.h
> +++ b/lib/ethdev/rte_flow.h
> @@ -4903,6 +4903,13 @@ rte_flow_info_get(uint16_t port_id,
>  		  struct rte_flow_queue_info *queue_info,
>  		  struct rte_flow_error *error);
> 
> +/**
> + * Indicate all steering objects should be created on contexts
> + * of the host port, providing indirect object sharing beetween
> + * ports.
> + */
> +#define RTE_FLOW_PORT_FLAG_SHARE_INDIRECT RTE_BIT32(0)
> +
>  /**
>   * @warning
>   * @b EXPERIMENTAL: this API may change without prior notice.
> @@ -4932,6 +4939,10 @@ struct rte_flow_port_attr {
>  	 * @see RTE_FLOW_ACTION_TYPE_CONNTRACK
>  	 */
>  	uint32_t nb_conn_tracks;
> +	/**
> +	 * Port to base shared objects on.
> +	 */
> +	uint16_t host_port_id;
>  	/**
>  	 * Port flags (RTE_FLOW_PORT_FLAG_*).
>  	 */
> --
> 2.18.1