Re: [PATCH v6 4/4] transport-pci: Introduce group legacy group member config region access

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

On Mon, Jun 19, 2023 at 05:26:22PM +0000, Parav Pandit wrote:
> 
> > From: Michael S. Tsirkin <mst@redhat.com>
> > Sent: Monday, June 19, 2023 1:20 PM
> 
> > > It is reused, but it doesnt come for free.
> > > Do you want to re-consider AQ notify query command?
> > > Or continue as proposed in v6?
> > 
> > 
> > If we can't just make it come for free then maybe
> > VIRTIO_PCI_CAP_LEGACY_NOTIFY_CFG is better, we can just list the number in
> > the common section and then link to the description in the new section.
> >
> How is it better? It requires burning more bytes.
> Is it better because it is self contained?

Mostly yes. But it also adds a bit more flexibility, right?
I thought avoiding touching transport-pci is worth less
flexibility but if we can't avoid that...


> > I also feel we want ability to have such a capability in the owner too.
> > Would prefer including it now though I guess we can add it as an extension.
> 
> Re-opening the past discussion.. amazing. :)

OK fair enough.. I guess both of us are not 100% happy but
it's a compromize for now. And maybe we'll add one of AQ
and / or PF cap down the road.

> Why? How is it different and better than querying over AQ?

Wait a second let me clarify. I am talking about notification
in the PCI BAR of the PF. *Not* offset in PF capability
but in the VF BAR.


> I see the AQ is better than group owner and group member specific cap.