Hi Simon,
In Keycloak there is a way to create a 'bootstrap' administrator user (a user that belong do Administrator group) that is automatically recognised as oVirt admin.
Typically, you want to use that user to assign permissions in oVirt Administrator panel[1]. I suspect that is what you really wanted to ask for.
To directly answer your question. Any Keycloak user that does not belong to Administrator group is treated a 'regular' oVirt user (without any specifi permissions).
I hope this helps a bit.
Artur