Arrow Lake NPU 8086:ad1d — No available backend with intel-level-zero-npu 1.35.0 on System76 kernel 7.0.11

Title: Arrow Lake NPU 8086:ad1d — No available backend with intel-level-zero-npu 1.35.0 on System76 kernel 7.0.11

Hardware:

Intel Core Ultra 9 275HX (Arrow Lake)
NPU PCI ID: 8086:ad1d at 00:0b.0
/dev/accel/accel0 present, render group permissions correct
Firmware loading: vpu_37xx_v1.bin (MTL_CLIENT_SILICON)

Software:

Pop!_OS 24.04 (Noble), System76 kernel 7.0.11-76070011-generic
intel-level-zero-npu 1.35.0.20260722~ubuntu24.04 (installed local)
intel-fw-npu 1.35.0 + intel-driver-compiler-npu 1.35.0
OpenVINO 2026.3.0
libze_intel_npu.so.1 loads successfully via ctypes
ICD file correct: /etc/level_zero/icd.d/intel_npu.icd → libze_intel_npu.so.1

Symptoms:

text

ov.Core().available_devices → ['CPU', 'GPU.0', 'GPU.1'] # NPU missing
core.get_property('NPU', 'NPU_DRIVER_VERSION') → "No available backend"
core.get_property('NPU', 'AVAILABLE_DEVICES') → []

What works:

NPU plugin IS registered in OpenVINO (re-registering throws "already registered")
libze_intel_npu.so.1 loads via ctypes without error
intel_vpu kernel module loads, /dev/accel/accel0 exists
User is in render group

Questions:

Is intel-level-zero-npu 1.35.0 compatible with kernel 7.0.11 (non-mainline)?
Does Arrow Lake 8086:ad1d require vpu_40xx firmware instead of vpu_37xx?
Is there a diagnostic tool to verify Level Zero ↔ kernel driver communication?

Start by reproducing the OpenVINO calls for NPU availability and property queries, then inspect the reported ICD path, libze_intel_npu.so.1 loading, firmware vpu_37xx_v1.bin, and /dev/accel/accel0 on the System76 kernel. Compare the Arrow Lake 8086:ad1d setup with the stated kernel, firmware, and intel-level-zero-npu versions. Done means identifying the compatibility or communication failure and documenting a verified diagnostic or required configuration.

Written by the indexing model from the issue text.