[PATCH net-next v3 1/3] net: rss: Require indir table size or hash key size to support RSS

[Jakub Kicinski]

On Tue, 6 Oct 2026 09:59:29 +0200 Maxime Chevallier wrote:
> > [Severity: Medium]
> > rss_get_data_alloc() is shared by RSS_GET, RSS_SET and RSS_CREATE. Does
> > this drop flow-hash reporting for devices that have ->get_rxfh but report
> > 0/0 sizes?  
> 
> Yes it does, that's the intended behaviour here. RSS bits are all optional,
> but does it make sense to report hashing params when the indirection table
> is size 0 and key len is 0 ?

Not sure if there's an implementation in the tree but 
it's possible to implement poor man's RSS on strict
power-of-2 queue set with some hashing built into the
Rx engine, without a key. We'd still want to control
which fields are hashed in this case.

In the Netlink API we combine the two so we'd break this?