Comment 5 for bug 2012028

This is as early as when doing the the domain capability checks.

Jammy:
    <tpm supported='yes'>
      <enum name='model'>
        <value>tpm-tis</value>
        <value>tpm-crb</value>
      </enum>
      <enum name='backendModel'>
        <value>passthrough</value>
        <value>emulator</value>
      </enum>
      <enum name='backendVersion'>
        <value>1.2</value>
        <value>2.0</value>
      </enum>
    </tpm>

Lunar (and also Kinetic):
    <tpm supported='yes'>
      <enum name='model'>
        <value>tpm-tis</value>
        <value>tpm-crb</value>
      </enum>
      <enum name='backendModel'>
        <value>passthrough</value>
        <value>emulator</value>
        <value>external</value>
      </enum>
    </tpm>

We see "external" is added (we know that from libvirt changelog), but at the same time the versions vanished in Lunar.

We need to check changes in that regard and what is executed to probe those.