Cold migrations across different QEMU/Libvirt versions cause boot failure

[OpenNebulaSupport]

Description
When doing a cold migration from a higher libvirt/qemu to lower versions, the VM will fail to boot until it's configuration has been updated.

To Reproduce
Migrate a VM to another host which has a lower version of qemu/libvirt installed.

Expected behavior
The VM configuration should be automatically updated so the XML is generated properly

Details

• Affected Component: Virtualization
• Hypervisor: KVM
• Version: 6.8

Progress Status

• Code committed
• Testing - QA
• Documentation (Release notes - resolved issues, compatibility, known issues)