Comment 2 for bug 1845562

Hi,
on my end I rechecked and can start a guest with virt-manager just fine.
So we would need to find what is different on your configuration.

Usual good data is:
1. the guest XML representation (virsh dumpxml ...)
2. a list of installed packages (apport would have provided that, but it seems you skipped)
3. dmesg (in case there are apparmor denials)

Related to the error I found was some cgroupv2 code that isn't ready in 19.04 yet and should not be used. Actually it shouldn't be in there. Other people have ran into similar [1] and only with libvirt >=5.5 [2] I'd expect that to work which would mean Ubuntu 20.04.

Have you enabled/configured/tested cgroupv2 to maybe trigger this?

[1]: https://unix.stackexchange.com/questions/525498/libvirt-will-not-start-vms-with-error-invalid-value-cpu-for-cgroup-subtree
[2]: https://bugzilla.redhat.com/show_bug.cgi?id=1727149