[dpdk-dev] [RFC] ethdev: support input set change by RSS action

[Jerin Jacob Kollanukkaran]

> -----Original Message-----
> From: dev <dev-bounces at dpdk.org> On Behalf Of Zhang, Qi Z
> Sent: Tuesday, July 9, 2019 11:11 AM
> To: Adrien Mazarguil <adrien.mazarguil at 6wind.com>
> Cc: Su, Simei <simei.su at intel.com>; Wu, Jingjing <jingjing.wu at intel.com>;
> Xing, Beilei <beilei.xing at intel.com>; Yang, Qiming <qiming.yang at intel.com>;
> dev at dpdk.org
> Subject: Re: [dpdk-dev] [RFC] ethdev: support input set change by RSS action
> > Right, I had symmetric Toeplitz in mind and wondered what would happen
> > when users would not select the required fields. I guess the PMD would
> > have to reject unsupported combinations.
> >
> > > anything I missed, would you share more insight?
> >
> > No, that answers the question, thanks.
> >
> > Now what about my suggestion below? In short: extending ETH_RSS_*
> > assuming there's enough bits left in there, instead of adding a whole
> > new framework and breaking ABI in the process.
> 
> Since the hardware can support any combination of input set (not just 5
> tuples), we'd like to make it more generic.
> Those will be some pain due to ABI break, but we think its worth for long
> term.

# IMO, The decided method should be compatible with normal RSS(without rte_flow) case 
as well(Currently is struct rte_eth_conf.rx_adv_conf.rss_conf.rss_hf used 
in the dev_configure()) as from HW perspective it will be same  the HW block which does 
both.
# From Marvell HW point of view, We can support any combination of input set.
But it is more of a micro code(i.e need to first provide the list protocol supported to HW)
and then use it latter. So, I think, extending the ETH_RSS_* would be more portable
approach __without loosing__ the functionality. Since there is around 40 bits are left, I think
more standard protocol can fit in the 40 bits.