I'm pretty sure Linux has hypervisor hooks to allow the hypervisor to tell a hosted OS to give back pages, and for a hosted OS to tell the hypervisor when it may have back pages. I don't know what Windows offers here.
I get the sense though that such changes in page ownership are coarse grain, not fine grain, since there's cost in passing the ownership back and forth.
(Note that I'm not actually super familiar with the paravirt_ops interface. I just remember reading about it here.)
Copyright © 2018, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds