GPU passthrough

[Square]

Hey. Posting here as you seem to be internet's leading experts on GPU passthrough.

I’m trying to do GPU pass through on a NixOS 25.11 host running Incus, but this is sort of besides the point of this post as I'm sort of seeking Proxmox users who accomplished this in Proxmox. The guest running ubuntu 24.04. I’m trying to pass the Intel Core Ultra 5 225 CPU’s (on a Asus B860-i mobo) integrated GPU but screen goes black when guest boots. I launch my system with kernelParams =`intel_iommu=on iommu=pt vfio.ids=8086:7d67`and kernelModules = `vfio vfio_pci vfio_iommu_type1 i915`. The system has no other GPU's attached.

On host:

user@host:~#  lspci -nnk -d 8086:7d67
00:02.0 VGA compatible controller [0300]: Intel Corporation Arrow Lake-S [Intel Graphics] [8086:7d67] (rev 06)
        DeviceName: Onboard IGD
        Subsystem: ASUSTeK Computer Inc. Device [1043:88ef]
        Kernel driver in use: vfio-pci
        Kernel modules: i915, xe

On guest:

root@test2:~# lspci -nnk -d 1af4:1050
04:00.0 VGA compatible controller [0300]: Red Hat, Inc. Virtio 1.0 GPU [1af4:1050] (rev 01)
        Subsystem: Red Hat, Inc. Virtio 1.0 GPU [1af4:1100]
        Kernel driver in use: virtio-pci
root@test2:~# lspci -nnk -d 8086:7d67
06:00.0 VGA compatible controller [0300]: Intel Corporation Arrow Lake-U [Intel Graphics] [8086:7d67] (rev 06)
        Subsystem: ASUSTeK Computer Inc. Device [1043:88ef]
        Kernel driver in use: i915
        Kernel modules: i915, xe

Furthermore, the guest seems to fail on loading the driver:

root@test2:~# vainfo
error: XDG_RUNTIME_DIR is invalid or not set in the environment.
error: can't connect to X server!
libva info: VA-API version 1.23.0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/virtio_gpu_drv_video.so
libva info: Found init function __vaDriverInit_1_20
libva error: /usr/lib/x86_64-linux-gnu/dri/virtio_gpu_drv_video.so init failed
libva info: va_openDriver() returns 2
vaInitialize failed with error code 2 (resource allocation failed),exit

root@test2:~# ls /usr/lib/x86_64-linux-gnu/dri | grep -iE 'virtio|virgl|i915'
i915_dri.so
virtio_gpu_dri.so
virtio_gpu_drv_video.so
root@test2:~#

Anyone see anything fishy? Personally I find it odd I have 2 gpu’s on the guest?

 

[LongQT-sea]

Don't expect the latest hardware (Arrow Lake-S) to work on older operating systems. Your safest option is to use Ubuntu 26.04 LTS as the guest VM and carefully follow the official QEMU documentation for Intel iGPU passthrough: https://github.com/qemu/qemu/blob/master/docs/igd-assign.txt

For a prebuilt OpROM, take a look at: https://github.com/LongQT-sea/intel-igpu-passthru

 

[Square]

I tinkered some tonight. And for the first time in weeks I finally got display working. It was either

* blacklisting both graphics drivers in kernelParams (of host):

module_blacklist=i915
module_blacklist=xe

* ...or passing the romfile to the VM, as you instructed.

Thanks a bunch!

...now I seem to have a new problem to hammer on. Mouse and keyboard is not working but I figured that's also passthrough affair.