[CRIU] [RFC PATCH] Try to include userfaultfd with criu

[Adrian Reber]

Pavel, thanks for the comments on the userfaultfd integration. I am
trying to integrate all your suggestions. I have question about
restoring pages... Or rather about not restoring pages.

My current approach is, if the parameter --lazy-pages is specified, to
skip pages with MAP_ANONYMOUS. I thought about skipping the pages in
restore_priv_vma_content(). If I skip pages I need to seek with a
different value then '0' in read_pagemap_page() to read from the right
position from the pages-x.img file. Before overlooking something obvious
I thought I will ask here to see what the right solution would be to
seek over the skipped userfaultfd pages. Would an additional parameter
be the right approach to handle the seek in read_pagemap_page() or is
there another way of skipping userfaultfd pages?

		Adrian