RE: [PATCH] ethdev: introduce generic flow item and action

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Zhang, Qi Z <qi.z.zhang@intel.com>
> Sent: Thursday, August 3, 2023 1:35 AM
> To: thomas@monjalon.net; orika@nvidia.com; david.marchand@redhat.com;
> Richardson, Bruce <bruce.richardson@intel.com>; jerinj@marvell.com;
> ferruh.yigit@amd.com
> Cc: cristian.dumiterscu@intel.com; techboard@dpdk.org; Mcnamara, John
> <john.mcnamara@intel.com>; Zhang, Helin <helin.zhang@intel.com>;
> dev@dpdk.org; Dumitrescu, Cristian <cristian.dumitrescu@intel.com>; Zhang,
> Qi Z <qi.z.zhang@intel.com>
> Subject: [PATCH] ethdev: introduce generic flow item and action

Sorry, this is supposed to be an RFC

> 
> From: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
> 
> For network devices that are programmable through languages such as the P4
> language, there are no pre-defined flow items and actions.
> 
> The format of the protocol header and metadata fields that are used to specify
> the flow items that make up the flow pattern, as well as the flow actions, are
> all defined by the program, with an infinity of possible combinations, as
> opposed to being selected from a finite pre-defined list.
> 
> It is virtually impossible to pre-define all the flow items and the flow actions
> that programs might ever use, as these are only limited by the set of HW
> resources and the program developer's imagination.
> 
> To support the programmable network devices, we are introducing:
> 
> * A generic flow item: The flow item is expressed as an array of bytes of a given
> length, whose meaning is defined by the program loaded by the network
> device. The device is still expected to accept the existing pre-defined flow items
> such as Ethernet, IPv4/IPv6 headers, etc, as long as the program currently
> loaded on the device is defining and using flow items with identical format, but
> the device is not limited to the current set of pre-defined RTE_FLOW flow items.
> 
> * A generic flow action: The flow action exact processing is defined by the
> program loaded by the network device, with the user expected to know the set
> of program actions for the purpose of assigning actions to flows. The device is
> still expected to accept the existing pre-defined flow actions such as packet
> drop, packet redirection to output queues, packet modifications, etc, as long as
> the program currently loaded on the device is defining and using flow actions
> that perform identical processing, but the device is not limited to the current
> set of pre-defined RTE_FLOW flow actions.
> 
> Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
> ---
>  lib/ethdev/rte_flow.h | 82 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 82 insertions(+)
> 
> diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h index
> 3fe57140f9..f7889d7dd0 100644
> --- a/lib/ethdev/rte_flow.h
> +++ b/lib/ethdev/rte_flow.h
> @@ -688,6 +688,15 @@ enum rte_flow_item_type {
>  	 * @see struct rte_flow_item_ib_bth.
>  	 */
>  	RTE_FLOW_ITEM_TYPE_IB_BTH,
> +
> +	/**
> +	 * Matches a custom protocol header or metadata field represented
> +	 * as a byte string of a given length, whose meaning is typically
> +	 * defined by the data plane program.
> +	 *
> +	 * @see struct rte_flow_item_generic.
> +	 */
> +	RTE_FLOW_ITEM_TYPE_GENERIC,
>  };
> 
>  /**
> @@ -2311,6 +2320,32 @@ static const struct rte_flow_item_tx_queue
> rte_flow_item_tx_queue_mask = {  };  #endif
> 
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this structure may change without prior notice
> + *
> + * RTE_FLOW_ITEM_TYPE_GENERIC
> + *
> + * Matches a custom protocol header or metadata field represented as a
> +byte
> + * array of a given length, whose meaning is typically defined by the
> +data
> + * plane program.
> + *
> + * The field length must be non-zero. The field value must be non-NULL,
> +with the
> + * value bytes specified in network byte order.
> + */
> +struct rte_flow_item_generic {
> +	uint32_t length; /**< Field length. */
> +	const uint8_t *value; /**< Field value. */ };
> +
> +/** Default mask for RTE_FLOW_ITEM_TYPE_GENERIC. */ #ifndef __cplusplus
> +static const struct rte_flow_item_generic rte_flow_item_generic_mask = {
> +	.length = 0xffffffff,
> +	.value = NULL,
> +};
> +#endif
> +
>  /**
>   * Action types.
>   *
> @@ -2989,6 +3024,14 @@ enum rte_flow_action_type {
>  	 * @see struct rte_flow_action_indirect_list
>  	 */
>  	RTE_FLOW_ACTION_TYPE_INDIRECT_LIST,
> +
> +	/**
> +	 * Custom action whose processing is typically defined by the data
> plane
> +	 * program.
> +	 *
> +	 * @see struct rte_flow_action_generic.
> +	 */
> +	RTE_FLOW_ACTION_TYPE_GENERIC,
>  };
> 
>  /**
> @@ -4064,6 +4107,45 @@ struct
> rte_flow_indirect_update_flow_meter_mark {
>  	enum rte_color init_color;
>  };
> 
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this structure may change without prior notice.
> + *
> + * Generic action argument configuration parameters.
> + *
> + * The action argument field length must be non-zero. The action
> +argument field
> + * value must be non-NULL, with the value bytes specified in network byte
> order.
> + *
> + * @see struct rte_flow_action_generic
> + */
> +struct rte_flow_action_generic_argument {
> +	/** Argument field length. */
> +	uint32_t length;
> +	/** Argument field value. */
> +	const uint8_t *value;
> +};
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this structure may change without prior notice.
> + *
> + * RTE_FLOW_ACTION_TYPE_GENERIC
> + *
> + * Generic action configuration parameters.
> + *
> + * Each action can have zero or more arguments.
> + *
> + * @see RTE_FLOW_ACTION_TYPE_GENERIC
> + */
> +struct rte_flow_action_generic {
> +	/** Action ID. */
> +	uint32_t action_id;
> +	/** Number of action arguments. */
> +	uint32_t action_args_num;
> +	/** Action arguments array. */
> +	const struct rte_flow_action_generic_argument *action_args; };
> +
>  /* Mbuf dynamic field offset for metadata. */  extern int32_t
> rte_flow_dynf_metadata_offs;
> 
> --
> 2.31.1