Intel GPU pass-through on ProxMox for an HP EliteDesk 800 series

README.md

Shamelessly copied from https://forum.proxmox.com/threads/gpu-passthrough-hp-elitedesk-800-35w-g2-core-i5-vpro-6500t.135888/ with some adjustments and reported for posterity/self history.

First make sure all virtualization stuff, includint VT-d are enabled in the BIOS

Install ProxMox, then login into the console as root

vi /etc/default/grub

Change the GRUB_CMDLINE_LINUX_DEFAULT to the value below

GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on iommu=pt textonly vfio_iommu_type1.allow_unsafe_interrupts=1 nofb nomodeset vfio-pci.ids=8086:1912 video=vesafb:off video=efifb:off video=simplefb:off"

Then

update-initramfs -u
update-grub
reboot

After the reboot:

vi /etc/modprobe.d/vfio.conf  

Fill it with:

options vfio-pci ids=8086:1912 disable_vga=1

Then

echo 'vfio' >> /etc/modules
echo 'vfio_iommu_type1' >> /etc/modules
echo 'vfio_pci' >> /etc/modules
echo 'vfio_virqfd' >> /etc/modules
echo 'blacklist i915' >> /etc/modprobe.d/blacklist.conf
update-initramfs -u
update-grub
reboot

Finally create a VM:

• Display should be "None" (one of the Serial options probably also works)
• Add PCI Device corresponding to the GPU, in this case 0000:00:02; pass-through all the functions but do not set it as primary GPU
• Optionally (likely) also redirect the USB devices. Either your local USB devices or, as I did, the entire xHCI Controller (from PCI devices).
• Had not great success redirecting the audio, because it's on the same ISA bus as the network adapter and while the VM starts with audio, it starts without networking and breaking ProxMox itself. I just plugged an old USB audio adapter I had around (a Creative X-Fi I bought in around 2008, still works great and finally has a decent use).