Re: [virtio-dev] [PATCH 08/11] transport-pci: Introduce virtio extended capability

Michael S. Tsirkin
2023-04-11T14:02:56Z

On Tue, Apr 11, 2023 at 09:47:50AM -0400, Parav Pandit wrote:
>
>
> On 4/11/2023 3:00 AM, Michael S. Tsirkin wrote:
>
> > > I meant, it depends on the capability semantics. Both PASID and legacy
> > > MMIO don't need to be accessed by BIOS. We can't change legacy BIOS to
> > > use legacy MMIO bars.
> > >
> > > Thanks
> >
> > makes sense.
> >
> >
> > now, imagine someone building a new device. if existing drivers are not
> > a concern, it is possible to move capabilities all to extended space. is
> > that possible while keeping the bios working?
> >
> unlikely as bios is looking in the legacy section.

what do you mean by the legacy section?

> New capabilities like legacy (and pasid) has no backward compat requirement
> from bios and drivers.
> so they can start from new.

sure.

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MST