Cannot kill VM - BUG: soft lockup - CPU#2 stuck for 22s

[justjosh]

Am passing /dev/ttyACM0 from host to VM. After USB device disconnects and reconnects, VM can no longer use the passthrough serial. Trying to restart the VM via init 6 throws soft lockup error and VM refuses to power down.

Tried to stop via qm stop, no errors

# qm stop 100

Message from syslogd@proxmox at Dec 14 22:10:43 ...
kernel:[22492.839326] watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [kworker/2:2:5329]

Message from syslogd@proxmox at Dec 14 22:11:11 ...
kernel:[22520.839320] watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [kworker/2:2:5329]
VM still running - terminating now with SIGTERM

Message from syslogd@proxmox at Dec 14 22:11:39 ...
kernel:[22548.839308] watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [kworker/2:2:5329]
VM still running - terminating now with SIGKILL

Killed the scope

Dec 14 15:59:04 proxmox systemd[1]: Started 100.scope.
Dec 14 22:12:02 proxmox systemd[1]: 100.scope: Succeeded.
Dec 14 22:12:02 proxmox systemd[1]: Stopped 100.scope.

Still cannot start

root@proxmox:~# qm start 100
generating cloud-init ISO
timeout waiting on systemd
root@proxmox:~#
Message from syslogd@proxmox at Dec 14 22:15:47 ...
kernel:[22796.839223] watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [kworker/2:2:5329]


Message from syslogd@proxmox at Dec 14 22:16:15 ...
kernel:[22824.839214] watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [kworker/2:2:5329]


Message from syslogd@proxmox at Dec 14 22:16:43 ...
kernel:[22852.839205] watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [kworker/2:2:5329]

Tried to kill process 5329 but it won't go

root@proxmox:~# ps aux | grep 5329
root      5329 19.1  0.0      0     0 ?        R    20:49  18:03 [kworker/2:2+usb_hub_wq]
root      5511  0.0  0.0   6072   892 pts/6    S+   22:23   0:00 grep 5329
root@proxmox:~# kill -9 5329
root@proxmox:~# ps aux | grep 5329
root      5329 19.2  0.0      0     0 ?        R    20:49  18:12 [kworker/2:2+usb_hub_wq]
root      6886  0.0  0.0   6072   888 pts/6    S+   22:23   0:00 grep 5329

 

[aforsgren]

Did you ever find a reason or workaround for this? I'm having similar issues with USB

https://forum.proxmox.com/threads/vm-fails-to-stop-start-timeout-when-using-usb.83864/