Deprecated packet modification flow actions

[Chaoyong He]

> -----Original Message-----
> From: Dariusz Sosnowski <dsosnowski at nvidia.com>
> Sent: Saturday, March 9, 2024 12:17 AM
> To: NBU-Contact-Thomas Monjalon (EXTERNAL) <thomas at monjalon.net>;
> Ferruh Yigit <ferruh.yigit at amd.com>; Andrew Rybchenko
> <andrew.rybchenko at oktetlabs.ru>; Ori Kam <orika at nvidia.com>; Ajit
> Khaparde <ajit.khaparde at broadcom.com>; Somnath Kotur
> <somnath.kotur at broadcom.com>; Rahul Lakkireddy
> <rahul.lakkireddy at chelsio.com>; Chaoyong He <chaoyong.he at corigine.com>
> Cc: dev at dpdk.org; techboard at dpdk.org
> Subject: Deprecated packet modification flow actions
> 
> Hi all,
> 
> I would like to start a discussion about legacy flow actions for packet
> modification.
> As of DPDK 21.11 many packet modification flow actions were deprecated in
> favor of generic RTE_FLOW_ACTION_TYPE_MODIFY_FIELD action (see [1]).
> I compiled a review of the current state of all deprecated actions along with
> changes since 21.11:
> 
> RTE_FLOW_ACTION_TYPE_OF_SET_MPLS_TTL    removed in 22.11
> RTE_FLOW_ACTION_TYPE_OF_DEC_MPLS_TTL    removed in 22.11
> RTE_FLOW_ACTION_TYPE_OF_SET_NW_TTL      removed in 22.11
> RTE_FLOW_ACTION_TYPE_OF_DEC_NW_TTL      bnxt*, sfc
> RTE_FLOW_ACTION_TYPE_OF_COPY_TTL_OUT    removed in 22.11
> RTE_FLOW_ACTION_TYPE_OF_COPY_TTL_IN     removed in 22.11
> RTE_FLOW_ACTION_TYPE_SET_IPV4_SRC       bnxt, cxgbe, mlx5, nfp (from
> 22.11), sfc (from 23.07)
> RTE_FLOW_ACTION_TYPE_SET_IPV4_DST       bnxt, cxgbe, mlx5, nfp (from
> 22.11), sfc (from 23.07)
> RTE_FLOW_ACTION_TYPE_SET_IPV6_SRC       bnxt*, cxgbe, mlx5, nfp (from
> 22.11)
> RTE_FLOW_ACTION_TYPE_SET_IPV6_DST       bnxt*, cxgbe, mlx5, nfp (from
> 22.11)
> RTE_FLOW_ACTION_TYPE_SET_TP_SRC         bnxt, cxgbe, mlx5, nfp (from
> 22.11), sfc (from 23.07)
> RTE_FLOW_ACTION_TYPE_SET_TP_DST         bnxt, cxgbe, mlx5, nfp (from
> 22.11), sfc (from 23.07)
> RTE_FLOW_ACTION_TYPE_DEC_TTL            bnxt, mlx5, sfc
> RTE_FLOW_ACTION_TYPE_SET_TTL            bnxt*, mlx5, nfp (from 22.11)
> RTE_FLOW_ACTION_TYPE_SET_MAC_SRC        bnxt, cxgbe, mlx5, nfp (from
> 22.11), sfc
> RTE_FLOW_ACTION_TYPE_SET_MAC_DST        bnxt, cxgbe, mlx5, nfp (from
> 22.11), sfc
> RTE_FLOW_ACTION_TYPE_INC_TCP_SEQ        bnxt*, mlx5
> RTE_FLOW_ACTION_TYPE_DEC_TCP_SEQ        bnxt*, mlx5
> RTE_FLOW_ACTION_TYPE_INC_TCP_ACK        bnxt*, mlx5
> RTE_FLOW_ACTION_TYPE_DEC_TCP_ACK        bnxt*, mlx5
> RTE_FLOW_ACTION_TYPE_SET_IPV4_DSCP      mlx5, nfp (from 22.11)
> RTE_FLOW_ACTION_TYPE_SET_IPV6_DSCP      mlx5, nfp (from 22.11)
> RTE_FLOW_ACTION_TYPE_SET_TAG            mlx5
> RTE_FLOW_ACTION_TYPE_SET_META           mlx5
> 
> bnxt* - Based on my analysis, this action type is used only to reject
> unsupported actions.
> 
> RTE_FLOW_ACTION_TYPE_MODIFY_FIELD flow action itself is supported only
> by mlx5 PMD.
> 
> Question to ethdev and flow API maintainers, and to technical board:
> 
> As of now, MODIFY_FIELD action support in mlx5 PMD covers all deprecated
> modify actions.
> Legacy flow actions can be removed from mlx5 PMD.
> What in your opinion would be an appropriate timeline for removing them?
> Should we wait until 24.11 LTS release?
> 
> Question to driver maintainers:
> 
> Do you have plans to add support for
> RTE_FLOW_ACTION_TYPE_MODIFY_FIELD flow action in future releases?

NFP plans support RTE_FLOW_ACTION_TYPE_MODIFY_FIELD flow action in 24.07 or 24.11.
For remove of legacy flow, does there also correspond patches in OVS project?

> 
> [1]: commit bef7c9ff285a ("ethdev: announce migration to generic flow
> modify action")
> 
> Best regards,
> Dariusz Sosnowski