About the kvm-no-adjvtime CPU property

[Ying Fang]

About the kvm-no-adjvtime CPU property

Hi Andrew,
To adjust virutal time, a new kvm cpu property kvm-no-adjvtime
was introduced to 5.0 virt machine types. However the cpu
property was enabled only for host-passthrough and max cpu model.
As for other cpu model like cortex-a57, cortex-a53, cortex-a72,
this kvm-adjvtime is not enabled by default, which means the
virutal time can not be adjust for them.

Here, for example, if VM is configured with kvm enabled:

  <cpu mode='custom' match='exact' check='partial'>
    <model fallback='allow'>cortex-a72</model>
    <topology sockets='2' dies='1' cores='2' threads='1'/>
    <numa>
      <cell id='0' cpus='0-1' memory='16777216' unit='KiB'/>
      <cell id='1' cpus='2-3' memory='16777216' unit='KiB'/>
    </numa>
  </cpu>

We cannot adjust virtual time even if 5.0 virt machine is used.
So i'd like to add it to other cpu model, do you have any
suggestions here ?