Disable emulated VGA card

posted in General
Thursday, July 10 2014, 07:48 PM
Csaba Nagy
Csaba Nagy
Hi everyone!

I've just started up with Xen, so sorry if I ask some very easy stuff. I have Ubuntu Dom0 and Win7 guest. The hardware:

Gigabyte Z97M D3H board (with VT-d)
Intel i7 4770 main processor (with VT-d)
Intel HD 4600 integrated graphics for Ubuntu
Ati HD4850 graphics for Win7 (with PCI passtrough)
20 GB ram (12 for Ubuntu, 1 for Intel graphics and 7 for the Winsh*t)

My only problem is if I give more than 2 GB RAM for the Windows, I cannot use the ATI card (code 12 in Win device management). As I read on Microsoft forums, it can be solved with disabling the integrated graphics card in BIOS (it is possibly a Win problem). However I cannot do that in the virtual machine.

If I disable the Standard VGA card in Win, nothing changes. If I remove it completely, it comes back after Win reboot. How is it possible to disable the standard VGA card. nographic=1 option does not work.

With max 2048 MB RAM, everything is fine.

I have Ubuntu 14.04 LTS with Xen 4.4 & xl toolstack. I've installed this system regarding to the instructions of "powerhouse" on Linux Mint forum: http://forums.linuxmint.com/viewtopic.php?f=42&t=112013 (many thanks for it!!!)

My config file for Win7:

memory = 7168
#memory = 2048
name = 'win7'
vif = ['bridge=xenbr0']
disk = [ 'phy:/dev/vg0/Win,hda,w','file:/home/nts/Win7/Win7x64.iso,hdc:cdrom,r']


pci=[ '01:00.0','01:00.1']

# ,'phy:/dev/sr0/,hdc:cdrom,r'
# ,'file:/media/nts/Work/Store/Mikrofos/Office2010_Uni.iso,hdc:cdrom,r'
# ,'file:/home/nts/Win7/Office2010_Uni.iso,hdc:cdrom,r' 

Please help me!
Responses (2)
  • Accepted Answer

    Friday, July 11 2014, 01:44 AM - #permalink

    I have been Googling this problem for a while and I am not finding a decent solution.

    If no one else comes up with anything, I'd suggest asking the question on the xen-users mailing list. There is a much larger number of people there, so there is a greater chance that someone might know what to do.

    You can find out about xen-users here:


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  • Accepted Answer

    Csaba Nagy
    Csaba Nagy
    Saturday, July 12 2014, 09:52 AM - #permalink
    Dear Russel,

    Sorry for the late answer, I had plenty of stuffs to do and I also tried some other stuff. I've found from other sources that it could be good to use "device_model_override=qemu-xen-traditional" because the new Xen has bugs for correct PCI/VGA passtrough. I've tried to use it on an already installed HVM and also to install a new one with traditional device model. In short words neither of them worked. Some details:

    - With the already installed system. As soon as the traditional override is NOT used, I can use the windows on my second graphical connection on my monitor. If I tur the override on, the vnc behaves the same. The screen freezes during the Windows boot - with the shiny logo - but when I change the screen source to the secondary, there is no signal in the cable. So the passtrough is dead. After this, the guest is dead also without the device_model_override.

    - With the fresh install, the guest is extremely slow - like a Pentium 3 (?) - and even if I wait until the installation is done (2-3 hours!!!!), at the end, I get blue screen. So it still doesn't work.

    I will need to write to the guys on the mailing list. Thanks for the source.

    Do you have any experiences with the "device_model_override=qemu-xen-traditional" method?
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