Re: [Qemu-devel] VFIO-VGA Issue

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 2013-04-10 at 16:32 -0400, deniv@lavabit.com wrote:
> >> However, turning gfx_passthru off did
> >> the trick. Win7 started loading with cirrus and switched to HD7750
> >> halfway
> >> through boot proccess. I didn't do any testing just let Windows
> >> calculate
> >> its score. The result was 7.4 and Aero was working.
> >
> > You should be able to do this with vfio too, use -vga cirrus and don't
> > use the x-vga option on pci-assign.  The x-vga enables legacy VGA
> > support for boot and primary console, as a secondary head normal PCI
> > device assignment should be sufficient.
> >
> Oh, how I wish it was true! Trying to load with cirrus and vfio-pci
> results in BSOD:
> Attemp to reset the display driver and recover from timeout failed.

Is this a fresh windows install?  Windows doesn't like change and will
BSOD pretty easily when attaching graphics to an existing image.

> Trying the old pci-assign with kvm results in non-working GFX. Windows
> shows code 10 and sometimes code 43 for the card.

What happens if you don't use a q35 machine?  Windows is very particular
about the PCIe type of a device and will often show Code 10 if it
doesn't have a type compatible with a root complex.  Alternatively you
can use the q35 config in the docs directory with the -readconfig option
and the bus= option on the pci-assign device to place the graphics
behind a root port.

> P.S. I'm starting to go nuts because VGA assignment doesn't work. The
> system was built with this sole intention. So, now I'm considering buying
> another graphic card. Can you suggest any consumer card that is easy to
> pass and can leave through vm resets? This HD7750 just hung the host when
> I tried destroying Xen's VM and running it again.

Nope, VGA assignment is pretty bleeding edge here, but we've gotta start
somewhere.  Thanks,

Alex