Note: Intel GVT-g is currently only supported by fifth, sixth, and seventh generation Intel Core processors and Xeon E3 v4/v5/v6 processors on PVE. My tests show that 8th generation and newer CPUs are not supported for now -_-! If this changes, feel free to contact me. Reference: https://pve.proxmox.com/wiki/PCI(e)_Passthrough

I finally got an experiment machine. The test environment is:

PVE: 6.2
CPU: g5400
Motherboard: Maxsun H110

Step 1: Enable virtualization in the motherboard BIOS.

Step 2: Enable passthrough on PVE

• Enable IOMMU and GVT-g support

# Enable IOMMU and GVT kernel support
# Edit grub
vi /etc/default/grub
Find:
GRUB_CMDLINE_LINUX_DEFAULT="quiet"
Then change it to:
GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on i915.enable_gvt=1"

# Update grub
update-grub

• Load passthrough kernel modules

echo vfio >> /etc/modules
echo vfio_iommu_type1 >> /etc/modules
echo vfio_pci >> /etc/modules
echo vfio_virqfd >> /etc/modules
echo kvmgt >> /etc/modules

• Blacklist drivers

echo "blacklist radeon" >> /etc/modprobe.d/blacklist.conf 
echo "blacklist nouveau" >> /etc/modprobe.d/blacklist.conf 
echo "blacklist nvidia" >> /etc/modprobe.d/blacklist.conf 
echo "blacklist nvidiafb" >> /etc/modprobe.d/blacklist.conf 
echo "blacklist amdgpu" >> /etc/modprobe.d/blacklist.conf 
echo "blacklist snd_hda_intel" >> /etc/modprobe.d/blacklist.conf 
echo "blacklist snd_hda_codec_hdmi" >> /etc/modprobe.d/blacklist.conf 
echo "blacklist i915" >> /etc/modprobe.d/blacklist.conf 

• Add the graphics card to passthrough
• Use lspci to check the integrated graphics device ID, usually 00:02.0. Here 00:02.0 is used as an example

# Check passthrough device
root@pve2:~# lspci -n -s 00:02.0
00:02.0 0380: 8086:3e90
# Add device 8086:3e90 to the passthrough group
echo "options vfio-pci ids=8086:3e90" > /etc/modprobe.d/vfio.conf

Step 3: Reboot the host

Step 4: Verify GVT is enabled

ls /sys/bus/pci/devices/0000:00:02.0/mdev_supported_types/  # Replace 00:02 with your own device ID.

If the following four options or similar appear, it worked.

i915-GVTg_V5_1	i915-GVTg_V5_2	i915-GVTg_V5_4	i915-GVTg_V5_8

Step 5: Create a virtual machine

Create a new OVMF EFI virtual machine, set the CPU type to HOST, and set the motherboard to q35. After installing the system and enabling Remote Desktop, shut it down, set the VM graphics device to none, and add the PCIE device.

Summary

Setup is simple, but the performance is a bit weak. The GVT-G technology does not split the GPU into isolated modules like s7150/nvidia k1; instead, it shares GPU performance. I ran two VMs, and when one of them was doing a 3D test, the other VM’s GPU usage was also fully loaded.