Proxmox passing device in LXC

Option 1: Mount device

Check device information

ls -lah /dev/net/
total 0
drwxr-xr-x  2 root root      60 Feb 22 10:53 .
drwxr-xr-x 21 root root    5.3K Feb 22 10:53 ..
crw-rw-rw-  1 root root 10, 200 Feb 22 10:53 tun

As we can see, /dev/net/tun identified by major number 10 and minor number 200

Modify /etc/pve/lxc/<lxc-id>.conf

lxc.cgroup2.devices.allow: c 10:200 rwm
lxc.mount.entry: /dev/net dev/net none bind,create=dir

In above example:

• The first line instruct the kernel to allow access to specific device
  1. c indicates that this is a character device (as opposed to a block device, which would start with b).
  2. 10:200 represents the major and minor numbers of the device.
  3. rwm : This specifies the permissions for the device:
     • r means read access
     • w means write access
     • m means memory map access
• The second line specifies that a container should be allowed to mount a specific directory inside its root file system. In this example, it is specifying that the /dev/net directory should be mounted as /dev/net in the container's root file system. This allows the container to access the network devices and interfaces on the host system.

You can also mount specific file instead of directory

lxc.mount.entry = /dev/net/tun dev/net/tun none bind,create=file

Option 2: New way

dev0: /dev/dri/card0,gid=44,uid=0

• gid (optional): specifies the group ID of the user who owns the device inside container.
• uid (optional): specifies the user ID of the user who owns the device inside container

Reference

Proxmox-share-GPU-multiple-LXC