Re: [Xen-users] VGA passthough still not working

[Konrad Rzeszutek Wilk <konrad@darnok.org>]

On Wed, Jan 25, 2012 at 08:52:17PM +0100, Pavel Mat??ja wrote:
> On Wed 25. of January 2012 20:29:12 Pavel Mat??ja wrote:
> > On Wed 25. of January 2012 17:52:11 Doug Magee wrote:
> > > Also, i believe you said the card you're trying to pass through is not
> > > the primary card in your host system.  If that's the case, don't use
> > > gfx_passthru or expect to get the video bios working.  The 'primary'
> > > video adapter owns certain io ports and memory areas that are consitent
> > > from machine to machine.  Also, the system will copy the vbios from the
> > > card to a location in memory (0xc0000) so it can execute at boot time.
> > > 
> > > Xen's gfx_passthru code depends on all of these factors.  As the code
> > > stands, if you use gfx_passthru on a secondary card, it will still copy
> > > the vbios from the primary card (as it simply reads memory from
> > > 0xc0000), and directly map io ports and low memory areas to those used
> > > by the primary card in the host system.  In this case the guest will
> > > almost certainly never get past executing ROMBIOS, and the host may or
> > > may not lock up or experience 'issues'.
> > 
> > This will do the trick with secondary card (replace path to VGA BIOS):
> > 
> > --- xen-unstable.hg.working/tools/ioemu-remote/hw/pt-graphics.c 2012-01-25
> > 20:26:37.927654890 +0100
> > +++ xen-unstable.hg.working.generic/tools/ioemu-remote/hw/pt-graphics.c
> > 2011-07-30 13:57:57.347396095 +0200
> > @@ -487,10 +487,10 @@
> >  {
> >      int fd;
> >      uint32_t bios_size = 0;
> > -    uint32_t start = 0;
> > +    uint32_t start = 0xC0000;
> >      uint16_t magic = 0;
> > 
> > -    if ( (fd = open("/lib/firmware/ASUS.HD6850.1024.101007.bin",
> > O_RDONLY)) < 0 )

How does one "extract" the bios from the ATI cards? With NVidia I
noticed could do it via /sys/kernel/debug/dri/0/vbios.rom.

But that is not present on ATI cards. Did you instrument the radeon
driver to dump it somewhere?