Re: [PATCH net-next 09/11] ethtool: rss: support setting input-xfrm via Netlink

[Jakub Kicinski <kuba@kernel.org>]

On Sun, 13 Jul 2025 14:11:34 +0300 Gal Pressman wrote:
> > +	/* xfrm_input is NO_CHANGE AKA 0xff if per-context not supported */  
> 
> Can you please explain this comment? Shouldn't we fail in this case?
> Nit: xfrm_input -> input_xfrm.
> 
> > +	if (!request->rss_context || ops->rxfh_per_ctx_key)
> > +		xfrm_sym = !!rxfh.input_xfrm;

xfrm_sym is supposed to indicate whether input_xfrm is set to symmetric.
Normally !!input_xfrm will tell us, but if we're dealing with a request
for an RSS context and driver doesn't support per ctx key input_xfrm
will be 0xff so we'd false positive xfrm_sym and most likely fail the
SET request if the field config is not symmeric. I'll rewrite this.

BTW I have a check at netdev reg time to make sure all drivers which
support xfrm_sym and contexts also support per-context xfrm_sym, but 
it will conflict with your fix so I didn't include it, yet.