Re: [dpdk-dev] [PATCH v3] ethdev: add IPv4 and L4 checksum RSS offload types

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Zhang, AlvinX <alvinx.zhang@intel.com>
> Sent: Tuesday, July 6, 2021 3:06 PM
> To: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>; Zhang, Qi Z
> <qi.z.zhang@intel.com>; ajit.khaparde@broadcom.com
> Cc: dev@dpdk.org
> Subject: RE: [PATCH v3] ethdev: add IPv4 and L4 checksum RSS offload types
> 
> > > @@ -537,6 +537,8 @@ struct rte_eth_rss_conf {
> > >  #define ETH_RSS_PPPOE		   (1ULL << 31)
> > >  #define ETH_RSS_ECPRI		   (1ULL << 32)
> > >  #define ETH_RSS_MPLS		   (1ULL << 33)
> > > +#define ETH_RSS_IPV4_CHKSUM	   (1ULL << 34)
> > > +#define ETH_RSS_L4_CHKSUM	   (1ULL << 35)
> >
> > What does efine which L4 protocols are supported? How user will know?
> 
> I think if we want to support L4 checksum RSS by using below command port
> config all rss (all|default|eth|vlan|...)
> 
> We must define TCP/UDP/SCTP checksum RSS separately:
> #define ETH_RSS_TCP_CHKSUM	(1ULL << 35)
> #define ETH_RSS_UDP_CHKSUM	(1ULL << 36)
> #deifne ETH_RSS_SCTP_CHKSUM	(1ULL << 37)
> 
> Here 3 bits are occupied, this is not good for there are not many bits available.
> 
> If we only want to using it in flows, we only need to define
> ETH_RSS_L4_CHKSUM, because the flow pattern pointed out the L4 protocol
> type.
> flow create 0 ingress pattern eth / ipv4 / tcp / end actions rss types l4-chksum
> end queues end / end

+1, the pattern already give the hint to avoid the ambiguity and I think we already have ETH_RSS_LEVEL to figure out inner or outer.
 
> 
> So what's your opinions?
> 
> Thanks
> Alvin