Re: [PATCH v3 1/3] ethdev: support metadata as flow rule criteria

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 9/27/2018 2:57 PM, Dekel Peled wrote:
> As described in [1], a new rte_flow item is added to support metadata
> to use as flow rule match pattern.
> The metadata is an opaque item, fully controlled by the application.
> 
> The use of metadata is relevant for egress rules only.
> It can be set in the flow rule using the RTE_FLOW_ITEM_META.
> 
> In order to avoid change in mbuf API, exisitng field buf.hash.fdir.hi
> is used to carry the metadata item. This field is used only in
> ingress packets, so using it for egress metadata will not cause
> conflicts.
> 
> Application should set the packet metadata in the mbuf dedicated field,
> and set the PKT_TX_METADATA flag in the mbuf->ol_flags.
> The NIC will use the packet metadata as match criteria for relevant
> flow rules.
> 
> This patch introduces metadata item type for rte_flow RTE_FLOW_ITEM_META,
> along with corresponding struct rte_flow_item_meta and ol_flag
> PKT_TX_METADATA.
> 
> [1] "[RFC,v2] ethdev: support metadata as flow rule criteria"
>     http://mails.dpdk.org/archives/dev/2018-August/110194.html
> 
> Signed-off-by: Dekel Peled <dekelp@mellanox.com>

<...>

> @@ -526,6 +532,12 @@ struct rte_mbuf {
>  			uint32_t hi;
>  			/**< First 4 flexible bytes or FD ID, dependent on
>  			     PKT_RX_FDIR_* flag in ol_flags. */
> +			/**
> +			 * Above member has optional use on egress:
> +			 * Application specific metadata value
> +			 * for flow rule match.
> +			 * Valid if PKT_TX_METADATA is set.
> +			 */
>  		} fdir;           /**< Filter identifier if FDIR enabled */

Any objection/comment to use hash.fdir.hi for this new "metadata" meaning? Olivier?