[SeaBIOS] Graphics card pass-through working with two pass pci-initialization

[André Weidemann]

Hi Gerd,
I managed to pass through a graphics card to a Windows7 VM using your 
kraxel.q35 seabios branch 
(http://www.kraxel.org/cgit/seabios/log/?h=kraxel.q35).

Here is my setup:
Intel DX58SO
Core i7 920
Radeon HD 6950
Kernel 2.6.35.7
qemu-kvm git pull from May 26th

The gfx card is working well on the desktop even with Aero turned on.
I tried various 3D Games which worked good (some were a bit choppy ;-) 
though).

There were 2 games that made Windows crash.
What is the way to debug what went wrong here?

One thing that is not working is the pass-through of a second device, a 
sound card in my case. As soon as I pass 2 devices to the VM, Windows 
does not boot anymore.
If I continue and remove the second device from the command line the VM 
does not boot anymore with the passed through gfx card. The graphics 
card drivers crashes Windows, with the error message of not being able 
to reset the graphics card. A reboot of the host cures this problem.

These are the command lines I used to start the VM:

echo "1002 6719" > /sys/bus/pci/drivers/pci-stub/new_id
echo 0000:03:00.0 > /sys/bus/pci/devices/0000\:03\:00.0/driver/unbind
echo 0000:03:00.0 > /sys/bus/pci/drivers/pci-stub/bind
echo "1002 6719" > /sys/bus/pci/drivers/pci-stub/remove_id

qemu-system-x86_64 \
-boot order=cd -cpu host -vnc 192.168.3.1:0 -k de \
-smp 2,cores=2,sockets=1 \
-drive file=${IMAGE},if=ide,index=0,cache=writeback -m 4096 \
-drive file=/dev/sda3,if=ide,index=1,cache=none \ 
-drive file=/dev/sdb3,if=ide,index=2,cache=none \
-drive file=/dev/cdrom,if=ide,index=3,media=cdrom,cache=none \
-device pci-assign,host=03:00.0 \
-net nic,model=e1000,macaddr=DE:AD:BE:EF:42:42 \
-net tap,script=/usr/local/bin/qemu-ifup \
-usb -usbdevice host:045e:00f9 \
-monitor telnet:192.168.3.1:11111,server,nowait,nodelay

Thank you very much for your work.

Regards
  André