What were you trying to do that didn't work?

Problem happens during OpenStack upgrade from Train to Wallaby.

We have existing and running VMs on RHEL 8.6 and libvirt 8.0.0-5.10.module+el8.6.0+18949+ba4ca8a3.x86_64 and qemu 6.2.0-11.module+el8.6.0+20793+2184cc28.11.x86_64, this is OpenStack Train.

Now these VMs need to be live migrated to the freshly upgraded computes which are running on OpenStack Wallaby, libvirt 10.0.0-6.7.el9_4.x86_64 and qemu 8.2.0-11.el9_4.6.x86_64.

The VM migration failes with error like below

 Live Migration failure: operation failed: guest CPU doesn't match specification: missing features: waitpkg: libvirt.libvirtError: operation failed: guest CPU doesn't match specification: missing features: waitpkg 

What is the impact of this issue to you?

Lack of LM ability blocks in service upgrade for  our telco customers.

How reproducible is this bug?:

Again this is happening in the middle of the OpenStack computes upgrade when we have a mixture of old and new computes.

Steps to reproduce

1. Any live migration attempts fails on early stage.

Of course problem does not happen on servers with CPUs which don't have the waitpkg flag, we checked it on some older CPUs and than live migration works fine.

Additional links:
https://access.redhat.com/solutions/7104785
https://access.redhat.com/support/cases/#/case/04039977
https://issues.redhat.com/browse/CNV-55362