Containers with type virtual-machine suddenly stopped working

Hi, i use lxd on arch linux.

I use several linux containers with the virtual-machine type. A while ago, all of these containers stopped working, e.g.

lxc start ubuntu-desktop
Error: Failed setting up device via monitor: Failed adding block device for disk device "root": Failed adding block device: Failed to find file descriptor with matching flags=0x4002
Try `lxc info --show-log ubuntu-desktop` for more info
lxc info --show-log ubuntu-desktop
Name: ubuntu-desktop
Status: STOPPED
Type: virtual-machine
Architecture: x86_64
Created: 2024/08/21 07:13
Last Used: 2024/09/05 21:08

Log:

qemu-system-x86_64:/var/log/lxd/ubuntu-desktop/qemu.conf:273: warning: '-fsdev proxy' and '-virtfs proxy' are deprecated, use 'local' instead of 'proxy, or consider deploying virtiofsd as alternative to 9p
qemu-system-x86_64:/var/log/lxd/ubuntu-desktop/qemu.conf:298: warning: '-fsdev proxy' and '-virtfs proxy' are deprecated, use 'local' instead of 'proxy, or consider deploying virtiofsd as alternative to 9p

Сontainer settings have not been changed, newly created containers with the virtual-machine type fail with exactly the same error.

Linux containers work correctly.

Versions:
lxc 6.0.2
lxcfs 6.0.1
lxd 6.1
qemu 9.1.0

What could be the problem?

Update. Migrating to a incus version 6.5 does not solve the problem.

Welcome!

Can you update the post with the details for Incus only?
Try to describe the steps so that a person can try to replicate the results you are getting.