Single GPU passthrough with QEMU and VFIO

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What this does

In one command it kills X, frees the GPU from drivers and console, detaches the GPU from the host, starts the VM with the GPU, waits until the VM is off, reattaches the GPU to the host and starts lightdm.

ToC (Table of Contents)

What you need

• An IOMMU enabled motherboard. Check your motherboard manual.
• CPU support for AMD-v/VT-x and AMD-Vi/VT-d (AMD/Intel). And virtualization support enabled on BIOS.
• One GPU that supports UEFI and its BIOS. All GPUs from 2012 and later should support this.
• QEMU, OVMF UEFI and VIRTIO drivers for Windows.
• [Optional] HDD only for Windows

My system

                                                [Hardware]
                                                 CPU: AMD Ryzen 5 2600
                                         Motherboard: Gigabyte AB350M-Gaming 3 rev1.1
                                    Motherboard BIOS: F23d
                                                 RAM: 16GB
                                                 GPU: Gigabyte Nvidia GeForce GTX 770
                                           GPU model: GV-N770OC-2GD
                                            GPU BIOS: 80.04.C3.00.0F
                                        GPU codename: GK104

                                                [Software]
                                        Linux Distro: ArchLinux
                                        Linux Kernel: 4.17.11 vanilla
                                       Nvidia divers: 396.45-2
                                        QEMU version: 2.12.0-2
                                        OVMF version: r24021

                                                 [Guests]
                                             Windows: Windows 10 Pro 1709 x64
                                               MacOS: MacOS 10.13.3

Configure

1. Clone this repository

git clone https://gitlab.com/YuriAlek/vfio.git

2. Enable vfio at boot. Edit /etc/mkinitcpio.conf

MODULES=(... vfio_pci vfio vfio_iommu_type1 vfio_virqfd ...)
HOOKS=(... modconf ...)

3. [Regenerate the initramfs][initramfs_archwiki]

sudo mkinitcpio -p linux

4. Reboot the system to load the vfio drivers

5. (Optional)[Download virtio drivers][virtio_drivers]

wget -o virtio-win.iso "https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/stable-virtio/virtio-win.iso"

6. Get the GPU BIOS [Source][GPU_BIOS_video] [Why?][] [You can download the bios.][techpowerup vgabios] If you do so, download a HEX editor and skip to step 4.
7. Boot the host into Windows.
8. [Download and install GPU-Z][GPU-Z].
9. [Download and install a HEX editor][bless].
10. Open GPU-Z and backup the GPU BIOS. Right next to the Bios Version; in my case 80.04.C3.00.0F, there is an icon for backup. A file named GK104.rom will be created. [There is also a way of doing it in Linux][] but it did not work for me.
11. Open the ROM (GK104.rom) in the HEX editor.
12. After a bunch of 00 there is a 55 or U in HEX, delete everything before the 55, and save. I strongly recommend not to overwrite the original ROM.

And you must supply QEMU with the Full GPU's ROM extracted extracted using a tool called "nvagetbios" , which you can find in a package called "envytools"

\ Mod this section, refer to guide 7. Get the iommu groups needed for the VM (GPU, GPU audio and USB controller)

chmod +x scripts/iommu.sh
bash scripts/iommu.sh
----
# GPU
IOMMU group 13
	06:00.0 VGA compatible controller [0300]: NVIDIA Corporation GK104 [GeForce GTX 770] [10de:1184] (rev a1)
	06:00.1 Audio device [0403]: NVIDIA Corporation GK104 HDMI Audio Controller [10de:0e0a] (rev a1)
# USB 3.0 Controller
IOMMU group 16
	07:00.3 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] USB 3.0 Host controller [1022:145f]
# SATA Controller
IOMMU group 18
	08:00.2 SATA controller [0106]: Advanced Micro Devices, Inc. [AMD] FCH SATA Controller [AHCI mode] [1022:7901] (rev 51)

8. (Optional) Create the image for the VM

qemu-img create -f raw windows.raw 60G

9. Edit the script windows-install.sh and windows.sh to convenience Things you may have to edit:

10. PCI devices

11. User

12. Location of HDD, vBIOS and OVMF image

13. The Desktop Environment, Display Manager, Windows Manager, etc.

14. QEMU options like RAM and CPU config

15. Kernel modules Check the guides [IOMMU][], [other guide, may be important][]

16. Start the VM

sudo scripts/windows-install.sh

11. Install Windows When you are asked for a hard drive there will be none.

12. Load driver

13. Browse

14. CD Drive (E:) virtio-win-0.1.1

15. vioscsi

16. w10

17. amd64

18. ok

19. Load driver Red Hat VirtIO SCSI pass-through controller (E:\vioscsi\w10\amd64\vioscsi.inf)

20. Next

21. Select the Unallocated Space

22. Proceed as normal.

23. Let Windows find the drivers for the GPU (if Windows has network) or [download the updated ones from NVIDIA][GPU_drivers].

24. Once installed Windows, run the VM with

sudo scripts/windows.sh

For the sake of convenience

sudo ln -s /home/yu/scripts/qemu@.service /usr/lib/systemd/system/ alias fuckmicrosoft="sudo systemctl start qemu@windows.service"

About peripherals

For audio I use an USB sound card. For internet I use network.sh For USB I simply passthrough an USB 3.0 controller.

Known problems

Race condition

There is something somewhere that makes it crash. That's why there is so many sleep 1

Root

QEMU should never be run as root. If you must launch it in a script as root, you should use the -runas option to make QEMU drop root privileges.