steam in linux appvm

[john.david.r.smith]

hi.
i want to play some linux games through steam in a appvm (based on debian).

when starting steam i get this error:
"OpenGL GLX extension not supported by display"

i guess this is the case, since i did not pass any GPU to the vm.

So i tried passing my nvidia gt 740m. If i set up its device to pass to
the vm and start the vm, my desktop freezes.

So i tried passing the gpu of my i7. If i set up its device to pass to
the vm and start the vm, my system reboots.

Was anyone able to pass a gpu to a linux vm?
has anyone an idea how i could solve the problem? (if passing does not
work, maybe some virtual gpu is enough, since the game should not
require much graphics power)
is there maybe some additional device i have to pass (e.g. similar to
the cpu controller for a usb-vm).

-john

Ps:
i passed following devices
nvidia: "3d controller: NVIDIA Corporation GK208M [GeForce GT 740M] (rev
a1)"
i7: "VGA compatible controller: IntelCorporation 4th Gen Core Processor
Integrated Graphics Contoller (rev 06)"

[Chris Laprise]

Two issues here:

1. Qubes needs to continue using its own graphics after passing a
(secondary) graphic card to a vm. If your system has two GPUs, you
cannot pass both to a vm.

2. Graphics cards/GPUs often employ proprietary tricks and shortcuts on
the PCI bus, and IOMMU passthrough is not one of the situations the
designers intended to use those tricks... so compatibility suffers.
Nvidia is probably the last brand I would expect to behave under unusual
circumstances... I would consider it a poor choice even for regular
Linux use.

Assuming there is some chance it could work, you would want to assign
your integrated GPU as the primary graphics adapter (probably in BIOS
settings) and pass only the Nvidia GPU to the vm. You may also have to
blacklist the Nvidia GPU in Qubes dom0.

Check out the other threads such as this:
https://groups.google.com/d/msgid/qubes-users/eb5bc2c6-cb40-432c-94cd-7dcc49b83b95%40googlegroups.com

Chris