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

[Parav Pandit <parav@nvidia.com>]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Tuesday, June 20, 2023 6:22 AM
> 
> On Tue, Jun 20, 2023 at 12:14:16AM +0000, Parav Pandit wrote:
> >
> >
> > > From: virtio-dev@lists.oasis-open.org
> > > <virtio-dev@lists.oasis-open.org> On Behalf Of Michael S. Tsirkin
> > > Sent: Monday, June 19, 2023 1:46 PM
> >
> > > These devices have a legacy interface yes?
> > Yes. partially.
> >
> > > So they should be transitional to avoid breaking assumption.
> > >
> > >
> > > But they are not *exactly*
> > > in that they don't have a transitional device ID.
> > >
> > Right. They do not have transitional device ID.
> 
> I was trying to think whether we need a conformance statement stating so. I
> guess this is up to the device?
> Then let's make it clear. Something like:
> 	For the SR-IOV group type,
> 	the owner device supporting legacy configuration access commands
> 	[assuming this is the term - do we define it somewhere? or just
> 	list the commands]
This term is largely defined as section name currently.

> 	MAY follow the rules for the PCI Device ID, Revision ID
> 	and Subsystem Device ID for the non-transitional devices
> 	documented in
> 	{Virtio Transport Options / Virtio Over PCI Bus / PCI Device Discovery}
> 
> or do you want to make it a SHOULD?
>
SHOULD seems fine to me as one cannot build PCI VF hw practically with IOBAR anyway.
So better to extended above line as,

For the SR-IOV group type, the owner device ... and member device SHOULD fllow the rules for...
 
> 
> > > At least the device id section needs extra text then to explain this?
> > >
> > We don't modify any of the transitional device attributes.
> > In respective conformance section, it is described what requirements of
> legacy interface to follow.
> > > Or do you just want to make them have transitional ID?
> > Don't want to do that.
> > Non transitional device id with the extension is just fine.