If the Vmkernel has to perform CPU operations for the guest, such as iSCSI or NFS disk access and this causes CPU on the host - this will also be accounted to the VM, even if it is not the VM vCPU that actually runs the code. It might be this that is shown here.
Not able to understand?...Plz help
Actions performed on *behalf* of the VM (like IO operations by the vmkernel) but not *by* the VM are still counted against that VM.