Re: [PATCH v7 02/22] liveupdate: luo_core: integrate with KHO

From: Pasha Tatashin
Date: Tue Nov 25 2025 - 11:10:40 EST


On Mon, Nov 24, 2025 at 9:21 AM Pratyush Yadav <pratyush@xxxxxxxxxx> wrote:
>
> On Sat, Nov 22 2025, 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.
> >
> > LUO now depends on `CONFIG_KEXEC_HANDOVER`.
>
> Nit: This patch does not add the dependency. That is done by patch 1. I
> guess that change needs to be moved here or the comment removed?
>
> Other than this,
>
> Reviewed-by: Pratyush Yadav <pratyush@xxxxxxxxxx>

Done, thank you for review!

>
> [...]
>
> --
> Regards,
> Pratyush Yadav