cpumodel qemu64 blocker, security issue:
OpenStack Open Source Cloud Computing Software » Message: CentOS-9 guests & 'qemu64' CPU model are incompatible; and reasons to avoid 'qemu64' in general
The same thing is being repeated here:
https://events19.linuxfoundation.org/wp-content/uploads/2017/12/Kashyap-Chamarthy_Effective-Virtual-CPU-Configuration-OSS-EU2018.pdf
Also refer to, Quote Recommendations for KVM CPU model configuration on x86 hosts — QEMU documentation
Important CPU features for Intel x86 hosts
The following are important CPU features that should be used on Intel x86 hosts, when available in the host CPU. Some of them require explicit configuration to enable, as they are not included by default in some, or all, of the named CPU models listed above. In general all of these features are included if using “Host passthrough” or “Host model”.
How documented here: Dev/KVM wiki chapter cpumodel qemu64
For other configuration change requests that should be applied to the default configuration files, if still relevant, please open separate forum threads.