Hello. On Tue, Oct 25, 2022 at 11:33:56AM +0200, Pavel Hrdina <phrdina@redhat.com> wrote:
Unfortunately this breaks a lot of things and we cannot use it even as workaround. Libvirt code has few assumptions as that's how unified mode works and when the cgroups v2 backend is enabled for hybrid topology we assume that cpuacct, devices controllers are enabled.
To be on the same side -- there's no cpuacct and devices on cgroup v2 (regardless of hybrid or unified mode).
But in the case of hybrid topology they are enabled by cgroups v1. Due to this change we no longer limit access to devices and cpu accounting no longer works.
Shouldn't v1 backend still carry that out? (On a higher level -- I understand that having both backends enabled for the hybrid mode is what's not working well.)
I'm going to send a patch to revert this one and we need to find yet another solution to the issue.
BTW do you have any pointers (a commit) when the hybrid mode could have become broken for libvirt/lxc? (I estimate from the (lack of) user reports that it must have worked at the time of libvirt 4.0.) Thanks, Michal