I made a fresh installed 3.2.3 x86_64 grsec alpinelinux host for libvirt
qemu vm's. When I start a vm, it must register itself in control groups but
it doesn't. When vm is shutted down, libvirt reports an error to its log:
virCgroupFree:4275 : Control groups not supported on this platform: No such
device or address.
I upgrade this host to the edge but the problem remained.
I think now it's not a problem when 1-2 qemu vm-s are running, but when
20-30 lxc- or dockerized-vm are comes it's would be a really problem
because cgroups are used to control of shared resources.
BTW: on my laptop (ubuntu) libvirt register in cgroups any started vm. On
my old gentoo-server with about 600 days uptime libvirt does it too.
Don't know why on alpinelinux it does not...
Mor about libvirt cgroups: https://libvirt.org/cgroups.html