LXC GPU Passthrough

Ensure IOMMU Is Activated

First step of this process is to make sure that your hardware is even capable of this type of virtualization. You need to have a motherboard, CPU, and BIOS that has an IOMMU controller and supports Intel-VT-x and Intel-VT-d or AMD-v and AMD-vi. Some motherboards use different terminology for these, for example they may list AMD-v as SVM and AMD-vi as IOMMU controller.

Update Bootloader

Update Kernel Parameters

**NOTE** Be sure to replace intel_iommu=on with amd_iommu=on if you're running on AMD instead of Intel.

Grub2

# /etc/default/grub
- GRUB_CMDLINE_LINUX_DEFAULT="quiet"
+ GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on iommu=pt

Systemd

# /etc/kernel/cmdline
- root=ZFS=rpool/ROOT/pve-1 boot=zfs
+ root=ZFS=rpool/ROOT/pve-1 boot=zfs intel_iommu=on iommu=pt

Rebuild Bootloader Options

Grub

update-grub

systemd-boot

bootctl update

Proxmox

pve-efiboot-tool refresh

Enable Virtual Functions

Find the link name you want to add virtual function to using ip link. In this scenario we're going to say we want to add 4 virtual functions to link eth2. You can find the maximum number of virtual function possible by reading the sriov_totalvfs from sysfs...

cat /sys/class/net/enp10s0f0/device/sriov_totalvfs
7

To enable virtual functions you just echo the number you want to sriov_numvfs in sysfs...

echo 4 > /sys/class/net/enp10s0f0/device/sriov_numvfs

Make Persistent

Sysfs is a virtual file system in Linux kernel 2.5+ that provides a tree of system devices. This package provides the program 'systool' to query it: it can list devices by bus, class, and topology.

In addition this package ships a configuration file /etc/sysfs.conf which allows one to conveniently set sysfs attributes at system bootup (in the init script etc/init.d/sysfsutils).

apt install sysfsutils

Configure sysfsutils

To make these changes persistent, you need to update /etc/sysfs.conf so that it gets set on startup.

echo "class/net/eth2/device/sriov_numvfs = 4" >> /etc/sysfs.conf