[PATCH v12 04/12] net/tap: validate and setup parameters for BPF RSS

[Stephen Hemminger]

On Mon, 20 May 2024 18:47:08 +0100
Ferruh Yigit <ferruh.yigit at amd.com> wrote:

> > +
> >  
> 
> Why 'rte_convert_rss_key()' is required? Is this making an assumption on
> the CPU architecture?


What is happening here is that the key passed in is in cpu native
order, but the SW RSS algorithm needs it to be in big-endian to
work with IP protocols that are big-endian.

In rte_thash the code to convert key is: rte_convert_rss_key()
and the code use the converted key is rte_softrss_be().

The BPF code doesn't (and cant easily because of license/validator) use the same
exact routine but it is equivalent to rte_softrss_be and uses pre-converted
key for performance.