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

[Michael S. Tsirkin]

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?

> >
> >>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
> >>