Re: [PATCH v8 02/18] liveupdate: luo_core: integrate with KHO

[Mike Rapoport <rppt@kernel.org>]

On Tue, Nov 25, 2025 at 11:58:32AM -0500, Pasha Tatashin wrote:
> Integrate the LUO with the KHO framework to enable passing LUO state
> across a kexec reboot.
> 
> This patch implements the lifecycle integration with KHO:
> 
> 1. Incoming State: During early boot (`early_initcall`), LUO checks if
>    KHO is active. If so, it retrieves the "LUO" subtree, verifies the
>    "luo-v1" compatibility string, and reads the `liveupdate-number` to
>    track the update count.
> 
> 2. Outgoing State: During late initialization (`late_initcall`), LUO
>    allocates a new FDT for the next kernel, populates it with the basic
>    header (compatible string and incremented update number), and
>    registers it with KHO (`kho_add_subtree`).
> 
> 3. Finalization: The `liveupdate_reboot()` notifier is updated to invoke
>    `kho_finalize()`. This ensures that all memory segments marked for
>    preservation are properly serialized before the kexec jump.
> 
> Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
> Reviewed-by: Pratyush Yadav <pratyush@kernel.org>

Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

> ---
>  include/linux/kho/abi/luo.h      |  58 ++++++++++++
>  kernel/liveupdate/luo_core.c     | 154 ++++++++++++++++++++++++++++++-
>  kernel/liveupdate/luo_internal.h |  22 +++++
>  3 files changed, 233 insertions(+), 1 deletion(-)
>  create mode 100644 include/linux/kho/abi/luo.h
>  create mode 100644 kernel/liveupdate/luo_internal.h

-- 
Sincerely yours,
Mike.