[PATCH man-pages v1 0/6] userfaultfd: document read-write protect mode
Kiryl Shutsemau <[email protected]> Mon, 25 May 2026 13:28:10 +0100
| Newsgroups | org.kernel.vger.linux-man,org.kvack.linux-mm |
|---|---|
| Message-ID | <[email protected]> |
This series documents userfaultfd read-write protection tracking
(UFFDIO_REGISTER_MODE_RWP), a working-set tracking mechanism for VM
guest memory landing in Linux 7.2.
The matching kernel series ("userfaultfd: working set tracking for VM
guest memory") was sent against the mm tree:
https://lore.kernel.org/all/[email protected]/
== New UAPI documented ==
UFFDIO_REGISTER_MODE_RWP registration-mode bit (UFFDIO_REGISTER.2const)
UFFD_FEATURE_RWP capability bit (UFFDIO_API.2const)
UFFD_FEATURE_RWP_ASYNC async resolution (UFFDIO_API.2const)
UFFDIO_RWPROTECT install/remove RWP (new page)
UFFDIO_SET_MODE runtime mode toggle (new page)
UFFD_PAGEFAULT_FLAG_RWP new pagefault.flags bit (userfaultfd.2)
PAGE_IS_ACCESSED PAGEMAP_SCAN bit (kernel docs only)
== Series layout ==
1. userfaultfd.2: overview, registration mode entry, new pagefault
flag, VERSIONS line, and an "Userfaultfd read-write protect mode"
section.
2-3. New UFFDIO_RWPROTECT.2const and UFFDIO_SET_MODE.2const pages.
4. UFFDIO_API.2const: UFFD_FEATURE_RWP, UFFD_FEATURE_RWP_ASYNC,
and 1 << _UFFDIO_SET_MODE.
5. UFFDIO_REGISTER.2const: UFFDIO_REGISTER_MODE_RWP and
1 << _UFFDIO_RWPROTECT.
6. ioctl_userfaultfd.2: reference the two new ioctls.
Order: new pages first so the cross-references in patches 4-6 link
to pages that already exist.
Kiryl Shutsemau (5):
UFFDIO_RWPROTECT.2const: New page
UFFDIO_SET_MODE.2const: New page
UFFDIO_API.2const: Document UFFD_FEATURE_RWP{,_ASYNC} and 1 <<
_UFFDIO_SET_MODE
UFFDIO_REGISTER.2const: Document UFFDIO_REGISTER_MODE_RWP and 1 <<
_UFFDIO_RWPROTECT
ioctl_userfaultfd.2: Reference UFFDIO_RWPROTECT and UFFDIO_SET_MODE
Kiryl Shutsemau (Meta) (1):
userfaultfd.2: Add read-write protect mode
man/man2/ioctl_userfaultfd.2 | 4 +
man/man2/userfaultfd.2 | 152 +++++++++++++++++++++++++-
man/man2const/UFFDIO_API.2const | 29 +++++
man/man2const/UFFDIO_REGISTER.2const | 21 ++++
man/man2const/UFFDIO_RWPROTECT.2const | 117 ++++++++++++++++++++
man/man2const/UFFDIO_SET_MODE.2const | 95 ++++++++++++++++
6 files changed, 414 insertions(+), 4 deletions(-)
create mode 100644 man/man2const/UFFDIO_RWPROTECT.2const
create mode 100644 man/man2const/UFFDIO_SET_MODE.2const
base-commit: 9a4bfd0e50745c2649b6291db40b58e37c9c1c6b
--
2.54.0