From: Evgeniy Polyakov <redacted>
Date: Fri, 11 Aug 2006 10:33:53 +0400

That requires mmap hacks to substitute pages in run-time without user
notifications. I do not expect it is a good solution, since on x86 it
requires full TLB flush (at least when I did it there were no exported
methods to flush separate addresses).

You just need to provide a do_no_page method, the VM layer will
take care of the page level flushing or whatever else might be
needed.