Re: [RFC PATCH 0/2] memblock: keep reserve_mem regions out of KHO bootmem

[Pratyush Yadav]

On Wed, Nov 04 2026, Jose A. Perez de Azpillaga wrote:

> On 10/22/26 10:16 PM, Jose A. Perez de Azpillaga wrote:
>> On 10/22/26 3:37 PM, Pratyush Yadav wrote:
>>> On Wed, Oct 21 2026, Jose A. Perez de Azpillaga wrote:
>>>
>>>> On a KHO boot, a reserve_mem= region that can't be revived (new name,
>>>> size or alignment) can be allocated from KHO bootmem, which the next
>>>> kernel boots out of. With CONFIG_KEXEC_HANDOVER_DEBUG preserving it
>>>> fails; without it, the next kernel's memmap ends up on top of it.
>>> What's your use-case? Why are you adding new reserve_mem regions after
>>> cold boot? I'd rather avoid making purely theoretical fixes.
>> 
>> I don't have one, I found it through the TODO. a different reserve_mem=
>> in the cmdline passed to kexec is enough to hit it.

If there was a use case, I wouldn't mind fixing it. But I'd rather not
add code we don't have a use case for.

>> 
>> if it isn't meant to work across a live update, would you rather have
>> reserve_mem() fail on KHO boot when it can't revive the region?

This sounds good I think.

>> 
>
> ping, I can send a v2 either way.

-- 
Regards,
Pratyush Yadav