[virtio-dev] Re: [PATCH v2 0/2] transport-pci: Introduce legacy registers access using AQ

Michael S. Tsirkin
2023-05-15T10:08:55Z

On Mon, May 15, 2023 at 03:30:47PM +0800, Jason Wang wrote:
>
> 在 2023/5/11 21:02, Parav Pandit 写道:
> >
> > > From: Michael S. Tsirkin <mst@redhat.com>
> > > Sent: Thursday, May 11, 2023 8:55 AM
> > > > 1) device features
> > > > 2) driver features
> > > > 3) queue address
> > > > 4) queue size
> > > > 5) queue select
> > > > 6) queue notify
> > > > 7) device status
> > > > 8) ISR status
> > > > 9) config msix
> > > > 10) queue msix
> > > > 11) device configuration space
> > > >
> > #9 may not even go to the group owner device.
>
>
> It the config_msix_vector register so I don't understand why it can't work
> but can work with your proposal.
>
>
> > What do we gain from bisecting it?
>
>
> 1) No need to deal with the offset in the hardware
>
> 2) transport independent
>
> 3) avoid duplication with the (legacy support of) transport virtqueue

To be more specific, device config often has the same layout under
legacy and modern. Thus if getting an offset within device config,
same decoding logic should be reusable between legacy and modern.

--
MST