Re: [dpdk-dev] [PATCH 2/2] pipeline: autodetect endianness of action args

[Thomas Monjalon <thomas@monjalon.net>]

12/04/2021 01:23, Cristian Dumitrescu:
> Each table entry is made up of match fields and action data, with the
> latter made up of the action ID and the action arguments. The approach
> of having the user specify explicitly the endianness of the action
> arguments is difficult to be picked up by P4 compilers, as the P4
> compiler is generally unaware about this aspect.
> 
> This commit introduces the auto-detection of the endianness of the
> action arguments by examining the endianness of the their destination:
> network byte order (NBO) when they get copied to headers and host byte
> order (HBO) when they get copied to packet meta-data or mailboxes.
> 
> The endianness specification of each action argument as part of the
> rule specification, e.g. H(...) and N(...) is removed from the rule
> file and auto-detected based on their destination. The DMA instruction
> scope is made internal, so mov instructions need to be used. The
> pattern of transferring complete headers from table entry action args
> to headers is detected, and the associated set of mov instructions
> plus header validate is internally detected and replaced with the
> internal-only DMA instruction to preserve performance.
> 
> Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
> ---
>  examples/pipeline/examples/vxlan.spec      |  41 ++-
>  examples/pipeline/examples/vxlan_table.py  |  44 ++--
>  examples/pipeline/examples/vxlan_table.txt |  32 +--
>  lib/librte_pipeline/rte_swx_ctl.c          |  15 +-
>  lib/librte_pipeline/rte_swx_ctl.h          |   6 +
>  lib/librte_pipeline/rte_swx_pipeline.c     | 282 ++++++++++++++++++---
>  lib/librte_pipeline/rte_swx_pipeline.h     |   4 -

There are compilation issues in the CI:
https://patches.dpdk.org/project/dpdk/patch/20210411232338.4005-2-cristian.dumitrescu@intel.com/