On Thu, Dec 18, 2025 at 07:26:19PM -0500, Pasha Tatashin wrote: > On Thu, Dec 18, 2025 at 4:49 PM Ricardo Neri > <[email protected]> wrote: > > > > On Fri, Nov 14, 2025 at 02:00:00PM -0500, Pasha Tatashin wrote: > > > Currently, kho_fill_kimage() checks kho_out.finalized and returns > > > early if KHO is not yet finalized. This enforces a strict ordering where > > > userspace must finalize KHO *before* loading the kexec image. > > > > > > This is restrictive, as standard workflows often involve loading the > > > target kernel early in the lifecycle and finalizing the state (FDT) > > > only immediately before the reboot. > > > > > > Since the KHO FDT resides at a physical address allocated during boot > > > (kho_init), its location is stable. We can attach this stable address > > > to the kimage regardless of whether the content has been finalized yet. > > > > > > Relax the check to only require kho_enable, allowing kexec_file_load > > > to proceed at any time. > > > > > > Signed-off-by: Pasha Tatashin <[email protected]> > > > Reviewed-by: Mike Rapoport (Microsoft) <[email protected]> > > > Reviewed-by: Pratyush Yadav <[email protected]> > > > --- > > > kernel/liveupdate/kexec_handover.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/kernel/liveupdate/kexec_handover.c > > > b/kernel/liveupdate/kexec_handover.c > > > index 461d96084c12..4596e67de832 100644 > > > --- a/kernel/liveupdate/kexec_handover.c > > > +++ b/kernel/liveupdate/kexec_handover.c > > > @@ -1550,7 +1550,7 @@ int kho_fill_kimage(struct kimage *image) > > > int err = 0; > > > struct kexec_buf scratch; > > > > > > - if (!kho_out.finalized) > > > + if (!kho_enable) > > > return 0; > > > > Hi Pasha, > > > > Using v6.19-rc1 (which has this changeset) and with: > > > > CONFIG_KEXEC_HANDOVER=y > > CONFIG_KEXEC_HANDOVER_ENABLE_DEFAULT=y > > CONFIG_LIVEUPDATE=n (i.e., nobody calling kho_finalize()) > > no reserve_mem= entries in the kernel command line > > > > I omit doing > > > > echo 1 > /sys/kernel/debug/kho/out/finalize > > > > before doing > > > > kexec -l <kernel> --initrd=<initrd> --commandline="$(cat /proc/cmdline)" > > kexec -e > > Hi Ricardo, > > Thank you for reporting this bug. I created a fix here: > https://lore.kernel.org/lkml/[email protected] > > Please let me know if it works.
Thanks for the quick reply, Pasha. Your patch does work for me (I saw you will post a v2). >From this patchset, I gather that kho_finalize() can be called multiple times and in-kernel users of KHO should call it when done preparing their subrees. Is that correct?
