Configure ARC A380 GPU and unprivileged LXC Device Passthrough

[glowplug]

Howdy,

I have replaced a GPU (ASUS 710-2-SL-BRK) on my Proxmox server with a Sparkle ELF Intel ARC A380 GPU, and have not been able to passthrough to LXCs. I have followed parts of several threads and how to's without luck.
It would be greatly appreciated if someone could help steer me in the right direction to get this working.

System Details:
Motherboard: Gigabyte AX370 Gaming K7
CPU: 6 x AMD Ryzen 7 1700 Eight-Core Processor (1 Socket)
GPU: ARC A380 6GB (Intel)
Kernel Version: Linux 6.8.12-2-pve (2024-09-05T10:03Z
LXC OS: Debian 12

Running lspci -nnk gives;

0a:00.0 VGA compatible controller [0300]: Intel Corporation DG2 [Arc A380] [8086:56a5] (rev 05)
        Subsystem: Device [172f:3943]
        Kernel driver in use: i915
        Kernel modules: i915, xe
0b:00.0 Audio device [0403]: Intel Corporation DG2 Audio Controller [8086:4f92]
        Subsystem: Device [172f:3943]
        Kernel driver in use: snd_hda_intel
        Kernel modules: snd_hda_intel

Running ls -l /dev/dri gives;

total 0
drwxr-xr-x 2 root root         80 Sep 26 19:35 by-path
crw-rw---- 1 root video  226,   1 Sep 26 19:35 card1
crw-rw---- 1 root render 226, 128 Sep 26 19:35 renderD128

Running grep render /etc/group on the Proxmox Node gives;

render:x:104:

Running grep render /etc/group on the LXC gives;

render:x:104:root

On the LXC (Container 122) under "Resources"; when I try to add the logical path (/dev/dri/card1 and/or /dev/dri/renderD128) the LXC fails to start with the bellow message from the Task Viewer:

safe_mount: 1425 No such file or directory - Failed to mount "/dev/serial/by-id" onto "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/serial/by-id"
safe_mount: 1425 No such file or directory - Failed to mount "/dev/ttyUSB0" onto "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/ttyUSB0"
safe_mount: 1425 No such file or directory - Failed to mount "/dev/ttyUSB1" onto "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/ttyUSB1"
safe_mount: 1425 No such file or directory - Failed to mount "/dev/ttyACM0" onto "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/ttyACM0"
safe_mount: 1425 No such file or directory - Failed to mount "/dev/ttyACM1" onto "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/ttyACM1"
safe_mount: 1425 No such file or directory - Failed to mount "/dev/fb0" onto "/usr/lib/x86_64-linux-gnu/lxc/rootfs/dev/fb0"
run_buffer: 571 Script exited with status 17
lxc_setup: 3948 Failed to run autodev hooks
do_start: 1273 Failed to setup container "122"
sync_wait: 34 An error occurred in another process (expected sequence number 4)
TASK ERROR: startup for container '122' failed

Below is the LXC config;

arch: amd64
cores: 10
dev0: /dev/dri/card1
features: nesting=1
hostname: tdarr2-lxc
memory: 2048
net0: name=eth0,bridge=vmbr1,hwaddr=BC:24:11:B3:34:1F,ip=dhcp,type=veth
onboot: 1
ostype: debian
rootfs: local-lvm:vm-122-disk-0,size=4G
swap: 512
tags: proxmox-helper-scripts
lxc.cgroup2.devices.allow: a
lxc.cap.drop:
lxc.cgroup2.devices.allow: c 188:* rwm
lxc.cgroup2.devices.allow: c 189:* rwm
lxc.mount.entry: /dev/serial/by-id  dev/serial/by-id  none bind,optional,create=dir
lxc.mount.entry: /dev/ttyUSB0       dev/ttyUSB0       none bind,optional,create=file
lxc.mount.entry: /dev/ttyUSB1       dev/ttyUSB1       none bind,optional,create=file
lxc.mount.entry: /dev/ttyACM0       dev/ttyACM0       none bind,optional,create=file
lxc.mount.entry: /dev/ttyACM1       dev/ttyACM1       none bind,optional,create=file
lxc.cgroup2.devices.allow: c 226:0 rwm
lxc.cgroup2.devices.allow: c 226:128 rwm
lxc.cgroup2.devices.allow: c 29:0 rwm
lxc.mount.entry: /dev/fb0 dev/fb0 none bind,optional,create=file
lxc.mount.entry: /dev/dri dev/dri none bind,optional,create=dir
lxc.cgroup.devices.allow: c 226:* rwm
lxc.mount.entry: /dev/dri dev/dri none bind,optional,create=dir

Thanks again for any help