VM iGPU Passthrough

Working setup

The following shows the versions that are known to be working at the time of writing:

CachyOS is not necessarily needed, but it's a convenient way to get a rolling distro in a friendly way. Once you've got it working, it's much easier to know if it's a guest issue.

Setting Up

There are various guides out there, but the following gives precise instructions that result in a confirmed working setup with iGPU passthrough.

1. Install Proxmox 9.1 and run an apt dist-upgrade after installing. Ensure you have kernel 6.17.4 or later
2. Setup the following config

# /etc/kernel/cmdline
... initcall_blacklist=sysfb_init

# /etc/modprobe.d/pve-blacklist.conf
blacklist radeon
blacklist amdgpu
blacklist snd_hda_intel

# /etc/modprobe.d/vfio.conf
options vfio-pci ids=1002:1586,1002:1640 disable_vga=1

3. Create a VM. Settings don't matter too much for now, but ensure the following:

   • 32GB memory, no baloon
   • 'host' setting on CPU arch
   • q35 machine
   • Use the latest CachyOS desktop ISO

   Do NOT yet try to passthrough any devices

4. Boot the VM and install Cachy via the Proxmox console.

5. Open a shell within Cachy and type "update", to get the latest.

6. Edit the config of vi /etc/pve/qemu-server/100.conf and add these lines, but making sure the devices match the output of lspci on your particular machine:

hostpci0: 0000:c5:00.0,pcie=1,romfile=vbios.bin,x-vga=1
hostpci1: 0000:c5:00.1,pcie=1,rombar=0
hostpci3: 0000:c5:00.4,pcie=1,rombar=0

Note that the last one is a USB controller - you'll need to plugin a keyboard and mouse initially. Also not that you do not need a BIOS for the audio device.

7. Extract your own VBIOS according to https://github.com/isc30/ryzen-gpu-passthrough-proxmox?tab=readme-ov-file#configuring-the-gpu-in-the-windows-vm. There's no guarantee someone else's VBIOS will work for you.

After that, you should now be able to start the VM, and CachyOS will show up on your monitor.

USB passthrough

As noted above, in order to use a desktop environment, you can passthrough a USB controller. On the Bosgame M5, the USB controller in the same group as the iGPU is the physical USB 3 port at the back, next to the power supply connector. It might not start with "5"

Proxmox VM:

Windows VMs

• hardware IDs are 1002:1586 (iGPU) and 1002:1640 (audio)
• the 'reset bug' is here, I found no way to avoid it, so you can passthrough the iGPU to a Windows guest only once per boot of the host
• don't bother with vendor-reset module and/or RadeonResetBugFix service, they are severely outdated and don't do anything in our case
• if your VM crashes during GPU driver install, switch the CPU type to something generic (x86-64-v4 for example seems to work fine), install the driver, then return it back to host
• if you see unknown PCI device (1af4:1057) in your Device Manager, install viomem driver manually from virtio drivers ISO
• set the fixed VRAM amount in the BIOS and never change it on the OS level, otherwise expect major slowdowns and crashes
• this issue might be worth looking into

Linux VMs

• the guide and configuration are valid for Linux too
• Proxmox 9 seems to be a must to avoid the reset bug
• use recent kernels (6.15+), if you see amdgpu driver errors during boot most likely your kernel is too old
• just like with Windows, dynamic VRAM allocation seems to be very unstable, set the fixed amount in the BIOS

Additional Info (Discord)

• my personal experience and why I gave up on the idea of the iGPU passthrough
• a discussion thread with additional links for LXC passthrough

Forums

The following forums can help with Proxmox and passthrough issues in general:

• Reddit

  • https://www.reddit.com/r/Proxmox/
  • https://www.reddit.com/r/VFIO/ ("VFIO" stands for "Virtual Function I/O", and is the tech behind hardware pasthrough)

• Proxmox https://forum.proxmox.com

Other guides

This guide seems to work for Strix Halo:
https://github.com/isc30/ryzen-gpu-passthrough-proxmox

There's also a guide from a Framework Desktop owner available here:
https://community.frame.work/t/anyone-using-proxmox-ve/74863/6?u=beralt

Files

(taken from EVO-X2, BIOS version 1.04)

• vbios_8060s.bin
• AMDGopDriver.rom