Description of problem:
Created a headless service and populated to VMs so they could be able to resolve the A record in an FQDN manner of: <vmi.spec.hostname>.<vmi.spec.subdomain>.<vmi.metadata.namespace>.svc.cluster.local.

Creation of their VMs seems to work, underlying Pod has its subdomain and hostname fields populated and resolution for the FQDN is functional.

However, when a live migration is triggered and the target Pod is created, it's created with the subdomain field populated but without the hostname field.

Version-Release number of selected component (if applicable):
All versions

How reproducible:
Always

Steps to Reproduce:

• Created a headless service. My env headless service "subdomain"
• Populated the VM yaml with subdomain and hostname :
  ~~
  hostname: hostname
  networks:
• name: nic
  pod: {}
  subdomain: mysubdomain <----- Headless service
  ~~

• Started VM and I can see the virt-launcher has a hostname and subdomain spec :

~~

1. oc get pod virt-launcher -o yaml |egrep 'hostame|subdomain'
   hostname: hostname
   subdomain: mysubdomain
   ~

– After live migration, the target virt-launcher pod is missing Hostname. The subdomain spec is still there.

~~

1. oc get pod virt-launcher -o yaml |egrep 'hostame|subdomain'
   subdomain: mysubdomain
   ~~

Actual results:

The hostname spec is missing after VM live migration on virt-launcher pod.

Expected results:

The hostname spec should also be shown on the target virt-launcher pod after migration.