We got the following feedback in the Adopting Compute services to the RHOSO data plane chapter in the 18.0 adoption guide:

• Section 5.2 mentions pre-requisites:
  "You have configured the Ceph back end for the NovaLibvirt service. For more information, see Configuring a Ceph back end."
  However, Ceph isn't mandatory.
•  in chapter 5.2, step3, it says:
  "If TLS Everywhere is enabled, set LIBVIRT_PASSWORD to match the existing RHOSP deployment password:"
  However, I think this is needed whether TLS-e is used or not.