Re: [virtio-comment] Re: [PATCH] virtio-net: define feature of per-packet RSS hash delivery

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Dec 13, 2019 at 03:38:11AM -0500, Michael S. Tsirkin wrote:
> On Fri, Dec 13, 2019 at 10:21:53AM +0200, Yuri Benditovich wrote:
> > On Fri, Dec 13, 2019 at 9:16 AM Michael S. Tsirkin <mst@redhat.com> wrote:
> > >
> > > On Fri, Dec 13, 2019 at 06:34:39AM +0200, Yuri Benditovich wrote:
> > > >
> > > > So there are 2 possible profiles of devices that 'do not have RSS' but
> > > > deliver hash:
> > > > 1. The device is in general can do RSS, but has only one pair of
> > > > queues and does only hash calculation
> > > > 2. The device has multiple queues but is configured to do auto
> > > > steering and we want also hash from it.
> > > >
> > > > My impression is that case 2 is rather academic one (at least looking forward).
> > > > Do you agree?
> > >
> > > I am not sure I agree. auto mq is much easier to configure than RSS
> > > so I image it's useful even if one wants hash.
> > 
> > With RSS and hash delivery we're mainly targeting virtio-net in hardware.
> > Auto mq is much more complicated, correct?
> 
> Hardware implementing it exists, it's not too hard, just some tables
> to maintain.

So what is the resolution here? To me it seems easier to just allow
this than worry whether it's useful. And devices that do not
want to support some combinations, don't have to, right?

> > >
> > > --
> > > MST
> > >
> 
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