Re: [dpdk-dev] [PATCH] ethdev: add RSS offload type for L3 checksum

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 6/3/21 6:12 AM, Alvin Zhang wrote:
> Add ETH_RSS_L3_CHKSUM macro.

Sorry, too short description. I could be an existing practice
to add more RSS offload types, but I want to break it.
Please, add motivation in the description why it is useful etc.

> 
> Signed-off-by: Alvin Zhang <alvinx.zhang@intel.com>
> ---
>  lib/ethdev/rte_ethdev.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index faf3bd9..4220ec5 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -537,6 +537,7 @@ struct rte_eth_rss_conf {
>  #define ETH_RSS_PPPOE		   (1ULL << 31)
>  #define ETH_RSS_ECPRI		   (1ULL << 32)
>  #define ETH_RSS_MPLS		   (1ULL << 33)

Please, add a comment what does it mean in various cases
covering various L3 protocols. IMHO, we must be explicit
here since addition of a new L3 protocol will make it
ambiguous if some drivers/HW use its checksum, but some
do not.

> +#define ETH_RSS_L3_CHKSUM	   (1ULL << 34)
>  
>  /*
>   * We use the following macros to combine with above ETH_RSS_* for
>