| From: |
| Pasha Tatashin <pasha.tatashin-AT-soleen.com> |
| To: |
| akpm-AT-linux-foundation.org, brauner-AT-kernel.org, corbet-AT-lwn.net, graf-AT-amazon.com, jgg-AT-ziepe.ca, linux-kernel-AT-vger.kernel.org, linux-kselftest-AT-vger.kernel.org, linux-mm-AT-kvack.org, masahiroy-AT-kernel.org, ojeda-AT-kernel.org, pasha.tatashin-AT-soleen.com, pratyush-AT-kernel.org, rdunlap-AT-infradead.org, rppt-AT-kernel.org, tj-AT-kernel.org |
| Subject: |
| [PATCH v8 0/8] liveupdate: Rework KHO for in-kernel users |
| Date: |
| Fri, 24 Oct 2025 12:09:54 -0400 |
| Message-ID: |
| <20251024161002.747372-1-pasha.tatashin@soleen.com> |
| Archive-link: |
| Article |
Changelog:
v8:
Added review-bys and addressed comments from Mike Rapoport and
Pratyush Yadav.
Added "memblock: Unpreserve memory in case of error" to handle
rollback if preserve fails half way through.
This series refactors the KHO framework to better support in-kernel
users like the upcoming LUO. The current design, which relies on a
notifier chain and debugfs for control, is too restrictive for direct
programmatic use.
The core of this rework is the removal of the notifier chain in favor of
a direct registration API. This decouples clients from the shutdown-time
finalization sequence, allowing them to manage their preserved state
more flexibly and at any time.
In support of this new model, this series also:
- Exports kho_finalize() and kho_abort() for programmatic control.
- Makes the debugfs interface optional.
- Introduces APIs to unpreserve memory and fixes a bug in the abort
path where client state was being incorrectly discarded. Note that
this is an interim step, as a more comprehensive fix is planned as
part of the stateless KHO work [1].
- Moves all KHO code into a new kernel/liveupdate/ directory to
consolidate live update components.
[1] https://lore.kernel.org/all/20251020100306.2709352-1-jaso...
Mike Rapoport (Microsoft) (1):
kho: drop notifiers
Pasha Tatashin (7):
kho: allow to drive kho from within kernel
kho: make debugfs interface optional
kho: add interfaces to unpreserve folios and page ranges
kho: don't unpreserve memory during abort
liveupdate: kho: move to kernel/liveupdate
liveupdate: kho: move kho debugfs directory to liveupdate
memblock: Unpreserve memory in case of error
Documentation/core-api/kho/concepts.rst | 2 +-
MAINTAINERS | 3 +-
include/linux/kexec_handover.h | 53 +-
init/Kconfig | 2 +
kernel/Kconfig.kexec | 24 -
kernel/Makefile | 3 +-
kernel/kexec_handover_internal.h | 16 -
kernel/liveupdate/Kconfig | 39 ++
kernel/liveupdate/Makefile | 5 +
kernel/{ => liveupdate}/kexec_handover.c | 508 +++++++-----------
.../{ => liveupdate}/kexec_handover_debug.c | 0
kernel/liveupdate/kexec_handover_debugfs.c | 219 ++++++++
kernel/liveupdate/kexec_handover_internal.h | 56 ++
lib/test_kho.c | 33 +-
mm/memblock.c | 82 ++-
tools/testing/selftests/kho/init.c | 2 +-
tools/testing/selftests/kho/vmtest.sh | 1 +
17 files changed, 590 insertions(+), 458 deletions(-)
delete mode 100644 kernel/kexec_handover_internal.h
create mode 100644 kernel/liveupdate/Kconfig
create mode 100644 kernel/liveupdate/Makefile
rename kernel/{ => liveupdate}/kexec_handover.c (80%)
rename kernel/{ => liveupdate}/kexec_handover_debug.c (100%)
create mode 100644 kernel/liveupdate/kexec_handover_debugfs.c
create mode 100644 kernel/liveupdate/kexec_handover_internal.h
base-commit: 72fb0170ef1f45addf726319c52a0562b6913707
--
2.51.1.821.gb6fe4d2222-goog
