Comment 6 for bug 1797715

Knowing that it affects Linux systems as well for you I upgraded on a few of my test systems but they all still worked just fine.

Also the configs and processes you have LGTM.

I have no great working theory right now :-/
The only thing left is the virNetDevSendEthtoolIoctl Error, I don't expect that this is it, but since it is the only lead we have left lets dive on this a bit.
It is used for two things:
- probing of ethdev features, but even failing it would just assume the feature isn't available and go on so it should mostly be fine without
- Manage Coalesce config of a device (sounds even less to be related)

@Jürgen, could you:
- Follow [1] to enable more verbose libvirt debugging, then start a guest (note the time) and wait a few minutes. Attach the created log here and mention the time the guest was started (the log is very noisy, so the time is helpful)
- If available use a fresh host to set up an Ubuntu the way you do it and check a Linux guest there. That would allow us to identify if we are looking for a special setting of your current vs a clean host or if it is a reproducible issue.
- If the latter reproduces on the second host, it would be great to get all steps you have done from install to failure to reproduce the issue

@Everyone - if there is anyone else with issues like this please let me know so we might use the different cases to isolate what actually triggers it.

[1]: https://libvirt.org/logging.html