Hide secondary GPU at startup

[bradbury9]

Hi,

I have an integrated Intel graphics card and a Nvidia GTX 1080. I want to set the integrated GPU as primary device, and create a windows standalone VM (without qubes tools) for gaming.

My motherboard, don't know why, ignores when I set the integrated card as primary GPU and default to "automatic", so now I am trying to hide the 1080 devices (VGA is 01:00.0 and audio is 01:00.1) so Xen defaults to the Intel graphics card and I could passthrough the NVidia card.

I have googled a bit, and looks like I have to add to /etc/default/grub the following content:

rd.qubes.hide_pci=01:00.0,01:00.1 modprobe=xen-pciback.passthrough=1 xen-pciback.permissive

Problem: I see no /etc/default/grub nor /usr/share/grub/default in dom0...

How can I do the PCI hiding? Is there a sample grub config file anywhere?

Disk is encrypted, what additional steps should I do to get LUKS working after the grub reinstall?

And finally, has anyone got experience with standalone windows VM with GPU attached instalation? Any tips would be appreciated. :-)

[Mike Keehan]

1. /etc is on the encrypted disk, so is not available at boot time.
2. You might find some grub files in /boot, if Qubes was installed
with grub (I don't use grub). For EFI, look for xen.cfg in
/boot/efi/EFI....
3. nVidia is fairly antagonistic to virtual machines. There are
many stories online about problems making nVidia cards work
with Qubes.

Best of luck,

Mike.

[Qubes]

I am interested in exactly the same. My machine has integrated gpu and
discreet nvidia nvs 4200m. I do have an option in my BIOS that allows
the OS to automatically pass video processing to the discreet gpu if
demand is more than what the integrated gpu can handle. This happens
seamlessly to the OS. The description next to the setting says that it
should only be enabled with windowz 7 but I have it enabled with Qubes
and it works perfectly fine. If I disable the BIOS setting I suspect the
discreet gpu is not used by Qubes at all but I must still verify that.

If what I suspect is true I should be able to pass the discreet pci
device through to a vm. If I try that with the setting enabled Qubes
farts and restarts. Expected obviously as the pci device is in use. So I
know it is definitely using it right now.