Re: [PATCH v4 00/14] kexec: introduce Kexec HandOver (KHO)

[Pasha Tatashin]

On Thu, Feb 6, 2025 at 7:29 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Thu,  6 Feb 2025 15:27:40 +0200 Mike Rapoport <rppt@xxxxxxxxxx> wrote:
>
> > This a next version of Alex's "kexec: Allow preservation of ftrace buffers"
> > series (https://lore.kernel.org/all/20240117144704.602-1-graf@xxxxxxxxxx),
> > just to make things simpler instead of ftrace we decided to preserve
> > "reserve_mem" regions.
> >
> > The patches are also available in git:
> > https://git.kernel.org/rppt/h/kho/v4
> >
> >
> > Kexec today considers itself purely a boot loader: When we enter the new
> > kernel, any state the previous kernel left behind is irrelevant and the
> > new kernel reinitializes the system.
>
> I tossed this into mm.git for some testing and exposure.
>
> What merge path are you anticipating?
>
> Review activity seems pretty thin thus far?

KHO is going to be discussed at the upcoming lsfmm, we are also
planning to send v5 of this patch series (discussed with Mike
Rapoport) in a couple of weeks. It will include enhancements needed
for the hypervisor live update scenario:

1. Allow nodes to be added to the KHO tree at any time
2. Remove "activate" (I will also send a live update framework that
provides the activate functionality).
3. Allow serialization during shutdown.
4. Decouple KHO from kexec_file_load(), as kexec_file_load() should
not be used during live update blackout time.
5. Enable multithreaded serialization by using hash-table as an
intermediate step before conversion to FDT.

Pasha