On Mon, Aug 05, 2024 at 10:01:51PM +0200, Jan Kara wrote: > > 4. Device assignment: being able to use guestmemfs memory for > > VFIO/iommufd mappings, and allow those mappings to survive and continue > > to be used across kexec. That's a fun one. Proposals for that will be very interesting! > To me the basic functionality resembles a lot hugetlbfs. Now I know very > little details about hugetlbfs so I've added relevant folks to CC. Have you > considered to extend hugetlbfs with the functionality you need (such as > preservation across kexec) instead of implementing completely new filesystem? In mm circles we've broadly been talking about splitting the "memory provider" part out of hugetlbfs into its own layer. This would include the carving out of kernel memory at boot and organizing it by page size to allow huge ptes. It would make alot of sense to have only one carve out mechanism, and several consumers - hugetlbfs, the new private guestmemfd, this thing, for example. Jason