I have been checking oVirt latest (4.3.4) with adding various bare metal hosts with various CPU's: I'm asking on this mailing list if I should open a ticket and if so what ticket (bug? RFE?).
The main oVirt machine (and the HE) is running on Xeon E3-1225 V3 CPU.

The big problem is that when you add for example any AMD processor (whatever it's a low end Ryzen 5 or a high end 32 cores EPYC) to such a setup, it will fail because it tries to add the AMD machine to the default cluster which is defined as Intel based VT-X. If I'll try to add any non Xeon V3 CPU, it will succeed, but any live migration of VM's inside the cluster will fail since any Xeon chip version has various VT flags.

So, my suggestion is that when adding nodes/hosts to oVirt, they will be added to a new "non clustered" place without any features allowed (live migration, for example) and after the admin will add the machines, he/she can assign nodes to a defined cluster (prepared or that he/she can create)

Another problem with cluster defining is that the CPU type is too complicated for any admin who doesn't know the nuts and bolts of each CPU. For example - the Haswell CPU type got *6* CPU types. Do you really expect an admin to know which one to select? IMHO, a good solution would be to add some "detect" button to hosts, and the result from clicking this button should be a window with options like:
I'll be happy to hear your thoughts about this issue.