Hi Nir,
performance is not really an issue here, we're most interested in functional testing
and migration support.
That's where nesting 4.4 on top of 4.3 would be a crucial migration enabler,
especially since you don't support a 7/8 or 4.3/4.4 mix that much elsewhere.
Currently my tests reveal, that ovirt/ovirt nesting does not work at all, oVirt on KVM is
the only case useds/tested by Redhat internally.
The other issue is that OVA exports on oVirt fail silently, which is about the worst to
happen. I get full sized OVA files full of zeros that obviously won't work imported
(without errors, btw).
And for lack of 4.4. nested on 4.3 I couldn't even tell if the export domains already
deprecated on 4.3 would work at all on 4.4, which would be the only other alternative to
migrate VMs.
Please, please, please, if you can make OVA export/import, export domains and even nested
oVirt working, I'd kiss your feet (wearing my Corona mask, of course ;-)