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

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

On Wed, Jun 21, 2023 at 04:01:00PM +0000, Parav Pandit wrote:
> 
> 
> > From: Michael S. Tsirkin <mst@redhat.com>
> > Sent: Wednesday, June 21, 2023 11:56 AM
> 
> > Not like v3 please. If you want to re-open this:
> > 
> > 
> > First I think we need multiple offsets just like notification capaiblity, sorted by
> > priority. Second I think we need ability to report offset within owner not
> > member.
> >
> > So please add ability to report multiple offsets, and add e.g.
> > a flags field, with bits for owner, member.
> 
> What are these multiple offsets for?

Different BARs.  For example, IO versus memory. Yes I know VFs don't
support IO but PFs do. prefetch vs non-prefetch might matter too
(non-prefetch is mostly limited to 32 bit).


> Do you mean two offsets? One for owner and one for member?
> Both bits are optional. Do you agree? 

I agree that everything should be optional sure. Let's not limit it to
two though.  There could be multiple BARs or whatever. We have ability
to pass buffers of arbitrary length and device reports the length.
Maybe have a SHOULD recommending not more than 10 of these (1 for each
possible PCI BAR one for each possible VF BAR).

This is to match the functionality that notification capability has.



> This publicly archived list offers a means to provide input to the
> OASIS Virtual I/O Device (VIRTIO) TC.
> 
> In order to verify user consent to the Feedback License terms and
> to minimize spam in the list archive, subscription is required
> before posting.
> 
> Subscribe: virtio-comment-subscribe@lists.oasis-open.org
> Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org
> List help: virtio-comment-help@lists.oasis-open.org
> List archive: https://lists.oasis-open.org/archives/virtio-comment/
> Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf
> List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists
> Committee: https://www.oasis-open.org/committees/virtio/
> Join OASIS: https://www.oasis-open.org/join/