OpenVINO GPU Intel i7-4785T (4th gen/Haswell) not working in LXC Docker container on Proxmox 9

Hi,

I'm running Frigate NVR in a Docker container inside an unprivileged LXC on Proxmox VE 9.1.7. My CPU is an Intel Core i7-4785T (Haswell, 4th gen).

Setup:

• Proxmox VE 9.1.7 (kernel 6.17.13-2-pve)
• Unprivileged LXC with nesting=1
• Docker inside LXC
• Frigate 0.17.1 stable
• /dev/dri/renderD128 visible inside container

Config in LXC:

lxc.cgroup2.devices.allow: c 226:* rwm
lxc.mount.entry: /dev/dri/renderD128 dev/dri/renderD128 none bind,optional,create=file

Intel IOMMU enabled in GRUB: intel_iommu=on iommu=pt

Error in Frigate logs:

RuntimeError: [GPU] Context was not initialized for 0 device
Unable to poll vaapi: XDG_RUNTIME_DIR is invalid
Failed to initialize PMU! (Permission denied)

What I've tried:

• Unprivileged → Privileged → back to unprivileged LXC
• kernel.perf_event_paranoid=0
• LIBVA_DRIVER_NAME=i965
• Passing /dev/dri/renderD128 via --device in Docker run

Frigate worked perfectly before on the same machine running Debian bare metal. Has anyone successfully run OpenVINO with a 4th gen Intel CPU on Proxmox 9 in an LXC? Is the i7-4785T just too old for the current Intel GPU drivers?

Thanks!