This repository contains information on running a virtual machine with GPU passthrough for systems with a single Intel GPU.
GPU: Intel
Passthrough technology: GVT-d
Host OS: GNU/Linux
Host firmware: BIOS
Guest OS: GNU/Linux
Guest firmware: UEFI (OVMF)
Virtualization software: QEMU (KVM)
Guest software: QEMU with KVM, configured using virt-manager
Since passhrough is done using GVT-d, the host cannot use the GPU while the guest is using it. For this reason, before starting the guest virtual machine, the GPU needs to be disassociated from the host. Also, after the guest shuts down, this needs to be reversed so that the host can run properly again.
This can be achieved by unloading i915 kernel module. To do this, all other software that is using the module must stop using it. This includes vtconsoles and the desktop environment. Since Intel audio device also uses the module (HDMI audio), it must also be unloaded, along with userspace processes like pulseaudio. After unloading the module, the GPU can be bound to vfio-pci and used by the guest.
This can be done automatically when starting the guest using a libvirt QEMU hook script which can also revert the changes after guest shuts down.
Use the provided script by placing it in /etc/libvirt/hooks/qemu on
Debian based systems or integrating it into an existing script. Make sure you
set the name of the virtual machine which requires GPU passthrough in the
gpu_domains array.
The recommended way to test the configuration is to connect via SSH from another device and run the hooks manually.
# /etc/libvirt/hooks/qemu gpu prepare begin
# /etc/libvirt/hooks/qemu gpu release end
Using virt-manager, create a new virtual machine. At the end of the process,
before pressing Finish, click on Customize configuration before install. In
the Overview section under Hypervisor Details make sure that Firmware is set to
UEFI (e.g. UEFI x86_64: /usr/share/OVMF/OVMF_CODE_4M.fd).
At this point you can install the system without GPU passthrough, but make sure that the virtual machine name is not in the hook script as you will lose the ability to control the guest using the host GUI.
In order to switch to using GPU passthrough, add the GPU as a PCI Host Device and make sure that the hook script contains the virtual machine name. You should also add input devices like a USB mouse and a USB keyboard. Finally, make sure that all graphics related virtual hardware is removed from the guest (Video and Display devices).