Re: [PATCH v2] ethdev: deprecate header fields and metadata flow actions

[Thomas Monjalon <thomas@monjalon.net>]

+Cc some maintainers

24/11/2021 09:06, Viacheslav Ovsiienko:
> There generic RTE_FLOW_ACTION_TYPE_MODIFY_FIELD action was

s/There/The/

> introduced by [1]. This action provides the unified way

s/the/an/

> to perform various arithmetic and transfer operations over
> packet network header fields and packet metadata.
> 
> [1] commit 641dbe4fb053 ("net/mlx5: support modify field flow action")
> 
> On other side there are a bunch of multiple legacy actions,
> that can be superseded by the generic modify field action:
> 
> RTE_FLOW_ACTION_TYPE_OF_SET_MPLS_TTL    bnxt*
> RTE_FLOW_ACTION_TYPE_OF_DEC_MPLS_TTL    bnxt*
> RTE_FLOW_ACTION_TYPE_OF_SET_NW_TTL      bnxt*
> RTE_FLOW_ACTION_TYPE_OF_DEC_NW_TTL      bnxt*, sfc
> RTE_FLOW_ACTION_TYPE_OF_COPY_TTL_OUT    bnxt*
> RTE_FLOW_ACTION_TYPE_OF_COPY_TTL_IN     bnxt*
> RTE_FLOW_ACTION_TYPE_SET_IPV4_SRC       bnxt,  cxgbe, mlx5
> RTE_FLOW_ACTION_TYPE_SET_IPV4_DST       bnxt,  cxgbe, mlx5
> RTE_FLOW_ACTION_TYPE_SET_IPV6_SRC       bnxt*, cxgbe, mlx5
> RTE_FLOW_ACTION_TYPE_SET_IPV6_DST       bnxt*, cxgbe, mlx5
> RTE_FLOW_ACTION_TYPE_SET_TP_SRC         bnxt,  cxgbe, mlx5
> RTE_FLOW_ACTION_TYPE_SET_TP_DST         bnxt,  cxgbe, mlx5
> RTE_FLOW_ACTION_TYPE_DEC_TTL            bnxt,  mlx5, sfc
> RTE_FLOW_ACTION_TYPE_SET_TTL            bnxt*, mlx5
> RTE_FLOW_ACTION_TYPE_SET_MAC_SRC        bnxt*,  cxgbe, mlx5
> RTE_FLOW_ACTION_TYPE_SET_MAC_DST        bnxt*,  cxgbe, mlx5
> 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
> RTE_FLOW_ACTION_TYPE_SET_IPV6_DSCP      mlx5
> RTE_FLOW_ACTION_TYPE_OF_SET_VLAN_VID    bnxt, cnxk, cxgbe, enic,
>                                         mlx5, octeontx2, sfc
> RTE_FLOW_ACTION_TYPE_OF_SET_VLAN_PCP    bnxt, cnxk, cxgbe, enic,
>                                         mlx5, octeontx2, sfc
> RTE_FLOW_ACTION_TYPE_SET_TAG            mlx5
> RTE_FLOW_ACTION_TYPE_SET_META           mlx5
> 
> [bnxt*] means the PMD source code references the action, but there
>         is no support implemented (actions rejected with ENOTSUP error)

You can drop these "bnxt*", it is not relevant.

> This note deprecates the following RTE Flow actions:
> 1. As not supported by any of PMDs:
> 
> RTE_FLOW_ACTION_TYPE_OF_SET_MPLS_TTL
> RTE_FLOW_ACTION_TYPE_OF_DEC_MPLS_TTL
> RTE_FLOW_ACTION_TYPE_OF_SET_NW_TTL
> RTE_FLOW_ACTION_TYPE_OF_COPY_TTL_OUT
> RTE_FLOW_ACTION_TYPE_OF_COPY_TTL_IN
> 
> 2. As supposed to be replaced by generig field modify action:
> RTE_FLOW_ACTION_TYPE_OF_DEC_NW_TTL
> RTE_FLOW_ACTION_TYPE_SET_IPV4_SRC
> RTE_FLOW_ACTION_TYPE_SET_IPV4_DST
> RTE_FLOW_ACTION_TYPE_SET_IPV6_SRC
> RTE_FLOW_ACTION_TYPE_SET_IPV6_DST
> RTE_FLOW_ACTION_TYPE_SET_TP_SRC
> RTE_FLOW_ACTION_TYPE_SET_TP_DST
> RTE_FLOW_ACTION_TYPE_DEC_TTL
> RTE_FLOW_ACTION_TYPE_SET_TTL
> RTE_FLOW_ACTION_TYPE_SET_MAC_SRC
> RTE_FLOW_ACTION_TYPE_SET_MAC_DST
> RTE_FLOW_ACTION_TYPE_INC_TCP_SEQ
> RTE_FLOW_ACTION_TYPE_DEC_TCP_SEQ
> RTE_FLOW_ACTION_TYPE_INC_TCP_ACK
> RTE_FLOW_ACTION_TYPE_DEC_TCP_ACK
> RTE_FLOW_ACTION_TYPE_SET_IPV4_DSCP
> RTE_FLOW_ACTION_TYPE_SET_IPV6_DSCP
> RTE_FLOW_ACTION_TYPE_SET_TAG
> RTE_FLOW_ACTION_TYPE_SET_META
> 
> The VLAN set actions are interrelated to VLAN header insertion/removal

What means "interrelated" here?

> and supported by multiple PMDs and supposed not to be deprecated.

I think it should be deprecated but not removed,
so users can be aware of the possible (better) replacement.

> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
[...]
>  Action: ``OF_SET_MPLS_TTL``
>  ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> +This action is deprecated as there are no PMDs supporting this.

The true reason is that it is replaced.
I think you should mention the replacement for each action.

[...]
>  Action: ``OF_DEC_NW_TTL``
>  ^^^^^^^^^^^^^^^^^^^^^^^^^
> +This action is deprecated. Consider:
> + - `Action: MODIFY_FIELD`_

The syntax is surprising. Please make it a single line:
	This action is deprecated. Consider `Action: MODIFY_FIELD`_.

[...]
> +* ethdev: Actions ``OF_SET_MPLS_TTL``, ``OF_DEC_MPLS_TTL``, ``OF_SET_NW_TTL``,
> +  ``OF_COPY_TTL_OUT``, ``OF_COPY_TTL_IN`` are deprecated as not supported by
> +  PMDs, will be removed in DPDK 22.11.

+1

> +* ethdev: Actions ``OF_DEC_NW_TTL``, ``SET_IPV4_SRC``, ``SET_IPV4_DST``,
> +  ``SET_IPV6_SRC``, ``SET_IPV6_DST``, ``SET_TP_SRC``, ``SET_TP_DST``,
> +  ``DEC_TTL``, ``SET_TTL``, ``SET_MAC_SRC``, ``SET_MAC_DST``, ``INC_TCP_SEQ``,
> +  ``DEC_TCP_SEQ``, ``INC_TCP_ACK``, ``DEC_TCP_ACK``, ``SET_IPV4_DSCP``,
> +  ``SET_IPV6_DSCP``, ``SET_TAG``, ``SET_META`` are deprecated as superseded
> +  by generic MODIFY_FIELD action, will be removed in DPDK 22.11.

+1

[...]
>  	/**
> +	 * @deprecated
> +	 * @see RTE_FLOW_ACTION_TYPE_MODIFY_FIELD
> +	 *
>  	 * Implements OFPAT_SET_MPLS_TTL ("MPLS TTL") as defined by the
>  	 * OpenFlow Switch Specification.
>  	 *

+1 for this comment on each action.

I have minor comments, but overrall,
Acked-by: Thomas Monjalon <thomas@monjalon.net>