[SirGiggles]

I think you could also add Xen to that list. IIRC, the old Xen PV mode was purely paravirtualized without using any hardware extensions.

[eru]

Yes, Xen was big on paravirtualisation but started supporting the other kinds pretty soon, too. (At least they were supported around 2009-2012, when I was working on XenServer.)

[SirGiggles]

I think things are swinging back the other way if I have understood the more recent PVHv2 stuff correctly.