Error after upgrade systemd in guest. Failed to set devices.allow on /system.slice/systemd-logind.service: Operation not permitted

I have a privileged Archlinux lxc container running under ubuntu 19.04 host.
I have GPU passthrough/sharring with the host. (cuda, nvidia gtx 1070)

I have recomplied gdm with the following flag
So that gdm will start in VT 8, which it did (until the upgrade to systemd)
The guest has full access to /dev/tty4 - /dev/tty9

After upgrading systemd to version 243.0:
gdm does run, but it does not spawn in any of the VTs including VT8

I am getting now the following new error in journalctl:

Sep 13 20:16:54 arch systemd[1]: Failed to set devices.allow on /system.slice/systemd-logind.service: Operation not permitted

subsequently I am getting this error:

Sep 13 20:16:54 arch systemd-logind[153]: Failed to pin reserved VT: Operation not permitted

Sep 13 20:16:54 arch systemd-logind[153]: New seat seat0.

And then finally getting the following error

Sep 13 20:16:55 arch gdm-launch-environment][172]: pam_systemd(gdm-launch-environment:session): Failed to create session: Seat has no VTs but VT number not 0

I am able to run X11/Gnome (using startx, but when I do that I get a lot of keyring notification that I did not get before.

Is there a workaround to avoid the “Failed to set devices.allow…” It looks like some kind of permission issue that I might be able to fix in the config file of the guest. Any help will be appreciate.
Do I need to file a bug?


The issue is resolved. I had to add the following to the config file.

lxc.cgroup.devices.allow=a sys:ro cgroup:ro

I am just wandering why this issue surfaced for me in systemd-243 while others had similar issue with much older versions of systemd.