userfaultfd is a mechanism that allows user-space paging implementation. Originally designed for post-copy migration of virtual machines, it applies to different use cases, such as implementation of volatile ranges, container migration, improvement of robustness of shared memory, efficient memory snapshotting and more. This talk covers the current status and supported features of userfaultfd, work currently in progress and future development plans. Mike Rapoport Mike has been hacking on the Linux kernel for over a decade. He has added his 2 cents to the mess in arch/arm, contributed to several device drivers and now he is focused on userfaultfd and CRIU. Mike’s current position is a researcher at IBM.