Physical NIC device fails configuration

Hi,

After recent upgrades of the kernel and Incus on our ubuntu / Noble host, VMs with attached physical NIC devices fail to start with the message

Failed setting up device via monitor: Failed setting up device "mce0": Failed adding NIC device: Monitor command timed out: "device_add" after 30s

Earlier, this has been due to incompatibilities between Incus and Qemu. So I wonder if that is the case again.
Best regards, Fredrik

VM devices section (for FreeBSD/pfsense VM with Mellanox 25Gb/s NIC)



devices:
  mce0:
    name: mce0
    nictype: physical
    parent: e3d0
    type: nic
  mce1:
    name: mce1
    nictype: physical
    parent: e3d1
type: nic


Journalctl on host:

Aug 29 11:48:29 gojira kernel: mlx5_core 0000:01:00.1: MLX5E: StrdRq(1) RqSz(8) StrdSz(2048) RxCqeCmprss(0 enhanced)
Aug 29 11:48:29 gojira kernel: mlx5_core 0000:01:00.1 e3d1: renamed from eth0
Aug 29 11:48:29 gojira kernel: mlx5_core 0000:01:00.1: is_dpll_supported:213:(pid 610): Missing SyncE capability


Instance Qemu log

[2026-08-29T11:47:58Z] QUERY: {"execute":"device_add","arguments":{"addr":"00.0","bootindex":1,"bus":"qemu_pcie4","driver":"vfio-pci","host":"0000:01:00.0","id":"dev-incus_mce0"},"id":28}


$ incus --version
7.4

$sudo /opt/incus/bin/qemu-system-x86_64 --version
/opt/incus/bin/qemu-system-x86_64: error while loading shared libraries: liburing.so.2: cannot open shared object file: No such file or directory

Correction:

$ LD_LIBRARY_PATH=/opt/incus/lib /opt/incus/bin/qemu-system-x86_64 --version
QEMU emulator version 11.1.1 (v11.1.1-dirty)
Copyright (c) 2003-2026 Fabrice Bellard and the QEMU Project developers

@cfenell please let your community members know how usefull this link to this post, about incus user / incus group, is.