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

Parav Pandit
2023-04-11T13:48:03Z

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.

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