[CentOS] kvm: C8 as guest on C6 host / huge delay while booting

Mon May 11 13:59:46 UTC 2020
Leon Fauster <leonfauster at googlemail.com>

Since C8.1  kvm guests have a huge delay while booting on a kvm host 
based on C6. This delay was not present with C8.0. The "pause" happend
direct after the grub step. The VNC session shows only a "_" character.

Any ideas what changes?