How to pin CPU core to VM?

Please, describe the problem here and provide additional information below (if applicable) …
I am using opennebula 4.14 with KVM virtualization. I see 100% CPU spikes on random cores on host but none of the guests have 100 % CPU usage. I would like to pin specific cores to specific VMs if it is all possible?

Versions of the related components and OS (frontend, hypervisors, VMs):

Steps to reproduce:

Current results:

Expected results: