[$] The state of guest_memfd

A typical cloud-computing host will share some of its memory with eachguest that it runs. The host retains its access to that memory, though,meaning that it can readily dig through that memory in search of data thatthe guest would prefer to keep private. The guest_memfd subsystem removes (most of) thehost's access to guest memory, making the guest's data more secure. In thememory-management track of the 2025 Linux Storage, Filesystem,Memory-Management, and BPF Summit, David Hildenbrand ran a discussion onthe state and future of this feature.