== Notes on Mach VM object copy strategies ==
But first, what's a VM object, even? A VM object (also called a pager) is something that can be mapped into an address space. For that to happen, it must implement the memory object API, which is basically:
* please give me the page at offset x!
* here, have your page at offset x back, maybe write it to persistent storage or something
(but actually much more complicated than that)