Re: [Qemu-devel] [PATCH V7 23/24] apci: fix PXB behaviour if used with unsupported BIOS

[Marcel Apfelbaum <marcel@redhat.com>]

On 06/01/2015 03:27 PM, Michael S. Tsirkin wrote:
> On Mon, Jun 01, 2015 at 03:21:19PM +0300, Marcel Apfelbaum wrote:
>> On 06/01/2015 03:17 PM, Michael S. Tsirkin wrote:
>>> On Mon, Jun 01, 2015 at 01:40:19PM +0200, Gerd Hoffmann wrote:
>>>> On Mo, 2015-06-01 at 12:44 +0300, Marcel Apfelbaum wrote:
>>>>> On 05/31/2015 09:12 PM, Michael S. Tsirkin wrote:
>>>>>> On Mon, May 25, 2015 at 06:34:01PM +0300, Marcel Apfelbaum wrote:
>>>>>>> PXB does not work with unsupported bioses, but should
>>>>>>> not interfere with normal OS operation.
>>>>>>> We don't ship them anymore, but it's reasonable
>>>>>>> to keep the work-around until we update the bios in qemu.
>>>>>>
>>>>>> We already did, did we not?
>>>>> Yes, we did, but Gerd preferred to keep this patch around.
>>>>> Adding him to thread.
>>>>
>>>> seabios bundled with qemu isn't the only possible firmware.
>>>>
>>>> We have ovmf, coreboot, qboot.
>>>
>>> ovmf is especially interesting. Marcel, did you look at what
>>> happens with pxb and ovmf?
>> No, I talked to Laszlo about it, he said ovmf is not there yet.
>> OVMF will not query the extra buses, so the devices on the extra bus will not be visible.
>> Adding him to the thread.
>>
>> Thanks,
>> Marcel
>
> But does OVMF need this specific patch?
I don't think so because more than likely it doesn't scan for the extra buses,
so it will not try to configure these devices.
Laszlo, am I right?

Thanks,
Marcel

>
>>>
>>>> You might boot with old seabios for
>>>> whatever reasons (say bisecting down something).
>>>
>>> But then you won't have pxb, will you?
>>>
>>>> IMO qemu should deal
>>>> with pxe not being initialized by the firmware in a sensible way, for
>>>> robustness reasons.
>>>>
>>>> cheers,
>>>>    Gerd
>>>>
>