snapd 2.53.3 now has code to enable the microstack-support interface to disable the udev backend entirely when used, so microstack snap should not have any device cgroup enforced for it and it is free to use any device node that it is permitted to via AppArmor
snapd 2.53.3 now has code to enable the microstack-support interface to disable the udev backend entirely when used, so microstack snap should not have any device cgroup enforced for it and it is free to use any device node that it is permitted to via AppArmor