Re: [dpdk-dev] [PATCH v5] app/testpmd: fix the default RSS key configuration

[Ophir Munk <ophirmu@nvidia.com>]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
<..>
> >>
> >
> > Ferruh, your suggestion ([1] + update) looks correct. I also verified it on
> mlx5 PMD.
> > Advantage: it's a generic fix for all dpdk applications using rte_flows (not
> just testpmd).
> > It reduces code.
> > With this fix the responsibility of handling key==NULL and/or len==0 is
> moved to the PMDs (which is good).
> >
> > With regard to Lijun patch - I liked the approach of overriding the default
> testpmd key with the default PMD key.
> > But it only addresses testpmd. More code was added.
> > It seems OK to call rte_eth_dev_rss_hash_conf_get() as part of parsing
> RSS, but it would feel more confident if we could confirm it for all the PMDs
> (by testing) or at least review the PMDs rss_hash_conf_get()
> implementations.
> >
> 
> Lijun's idea can work. There was a problem in implementation related to the
> key size assumption, which can be fixed.
> 
> Even it is fixed, when user gives a rss rule without a key, we are getting key
> from device and feeding same key back to device, this is unnecessary I think.

I agree.

> When user didn't provide a key, rss rule shouldn't touch the key at all.

Agreed as well.

> Complication was when user provides key_len without a key, I think both
> ignoring or returning error in this case is OK.

I think that in general flow rules should arrive "as is" to the PMD which has its
validation and translation APIs to handle all cases.