I am attempting to passthrough an NVIDIA GPU on an optimus-enabled laptop and use it in conjuction with Intel GVT-g. The host system is Ubuntu, guest is Windows 7.

After setting up Intel GVT-g according to the iGVT setup guide, the Intel card is successfully shared between the guest and host.

The GTX 960M vBIOS was obtained as follows: AFUWIN was used to dump the Aptio BIOS on the laptop, then the GTX 960M vBIOS was extracted using MMTool. The BIOS seems valid, but does not appear to have EFI support.

The GPU was passed through as follows:

qemu-system-x86_64 \
  -m 2048 -smp 2 \
  -bios /usr/bin/bios.bin \
  -enable-kvm -M pc -cpu host \
  -machine kernel_irqchip=on \
  -hda /home/user/VM/win7.img \
  -net nic -net tap,script=/home/user/VM/qemu-ifup \
  -vgt -vga vgt -vgt_low_gm_sz 128 -vgt_high_gm_sz 384 -vgt_fence_sz 4 \
  -device vfio-pci,host=02:00.0,romfile=/home/user/VM/optionrom_nvidia.rom

This seems to pass the NVIDIA GPU through to the guest, where it shows up as a 3D Video Controller in the device manager. The vendor and device ID show up fine in the device manager, but the subsystem shows as 00000000, making it impossible to install the NVIDIA drivers.

The question here is, why is the subsystem not showing up correctly, and how can it be fixed?

  • Just out of curiosity: did you ever get this working? I'm thinking of doing this on my 2016 Razer blade. – bge0 Mar 6 '17 at 17:37

That seems like your rom file isn't working as expected or complete as expected.

Try (dual)booting into Windows and extracting the vbios with GPU-Z.

Refer here to someone who had the same issue as you: https://www.redhat.com/archives/vfio-users/2016-July/msg00050.html

Also, be sure of which Intel processor generation you've got. 4th generation GVT-g is only supported on XENGT.

  • The processor is a i7-6700HQ which is listed as supporting VT-d. GPU-Z claims BIOS reading is not supported on this device, I assume that's because the BIOS is embedded into the laptop BIOS, not on the graphics card. I already saw the thread you referred to but unfortunately it offered nothing new. – Mikaello Dec 16 '16 at 19:50

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