RE: [PATCH v13] virtio-net: support inner header hash

[Parav Pandit <parav@nvidia.com>]

> From: Heng Qi <hengqi@linux.alibaba.com>
> Sent: Wednesday, April 26, 2023 9:43 AM

> > "With that no need to define two fields at two different places in
> > config area and also in cvq."
> 
> I'm not sure if this is sufficiently motivated, RSS also has supports_hash_types
> in config space.
>
There are many fields grown to MMIO config space because 0.9.5 has config space there.
These are usually one time read or rarely used; hence it doesnât need to come from this area of the device to be _always_ available.
 
> We don't actually need cvq and config to sync on
> supported_tunnel_hash_types, since it doesn't need to change (meaning
> supported_tunnel_hash_types doesn't send configuration change
> notifications).
> 
It doesnât but device is expected to publish the value at two places.

> >> +For scenarios with sufficient external entropy or no internal
> >> hashing requirements, inner header hash may not be needed:
> >> +A tunnel is often expected to isolate the external network from the
> >> internal one. By completely ignoring entropy
> >> +in the external header and replacing it with entropy from the
> >> internal header, for hash calculations, this expectation
> > You wanted to say inner here like rest of the places.
> >
> > s/internal header/inner header
> 
> I want to make the 'external' and 'internal' correspond, but avoid the internal
> header, and use a unified 'inner header' is also reasonable.:)
>
Since in rest of other description, we refer to it as "outer", it is better to keep it consistent as outer instead of external here.