Re: [PATCH v2 4/5] guest_memfd: add support for userfaultfd minor mode

On 11/25/25 19:38, Mike Rapoport wrote:

From: "Mike Rapoport (Microsoft)" rppt@kernel.org

userfaultfd notifications about minor page faults used for live migration and snapshotting of VMs with memory backed by shared hugetlbfs or tmpfs mappings as described in detail in commit 7677f7fd8be7 ("userfaultfd: add minor fault registration mode").

To use the same mechanism for VMs that use guest_memfd to map their memory, guest_memfd should support userfaultfd minor mode.

Extend ->fault() method of guest_memfd with ability to notify core page fault handler that a page fault requires handle_userfault(VM_UFFD_MINOR) to complete and add implementation of ->get_shared_folio() to guest_memfd vm_ops.

Signed-off-by: Mike Rapoport (Microsoft) rppt@kernel.org

No exports and still looks clean to me, nice. :)