Hi,

I'm facing a strange issue with libvirt and the Xen driver.

Whenever I try to define or start a domain, I always get this error:

"libvirt.libvirtError: An error occurred, but the cause is unknown" (in Python virt-manager interface)

Which is not very helpful.

Trying to use virsh directly leads to the same error message:

virsh # start win10_xen

error: Failed to start domain win10_xen

error: An error occurred, but the cause is unknown

I checked /var/log/libvirt/libxl/libxl-driver.log, but the log file is empty.

However, using the xl toolstack directly to start a new domain works fine,

so the issue doesn't seem to come from Xen.

My environment:

- Ubuntu 20.04 LTS

- xen-hypervisor-4.11-amd64 (4.11.3+24-g14b62ab3e5-1ubuntu2)

- libvirt0 (6.0.0-0ubuntu8.8)

I really like libvirt and virt-manager to manage my VMs.