Re: [PATCH] x86/kexec: Add ACPI NVS region to the ident map

[Junichi Nomura]

Hi Kairui, Boris,

On 6/10/19 7:59 PM, Borislav Petkov wrote:
> On Mon, Jun 10, 2019 at 06:18:50PM +0800, Kairui Song wrote:
>> Hi Boris, unfortunately I don't have a real machine which only have
>> the NVS region. I did fake the memmap to emulate such problem but
>> can't really promise this will fix the real case. So just declare it
>> won't break anything that is already working. And I'm asking Junichi
>> to have a try as he reported this issue on the machines he has.
> 
> Yes, this is how you should do it. First you test on a real hardware -
> if the issue is such that needs a real hardware to verify - and if it
> passes, *then* you send the patch.
> 
> If you don't have access to the box, then ask someone who has.
> 
> But for the future, please do not send untested patches in a hurry,
> hoping that they would work. This could cause more trouble than the
> little time you might save speculating it'll all go fine.

I tested the patch on such a machine on top of the current tip/master
f9818950848 ("Marge branch 'linus'") and it works fine.
Without the patch, kexec -l fails.

I had tested the version I posted here on bunch of physical machines
I had access and confirmed it didn't broke working setups:
https://lore.kernel.org/lkml/20190515051717.GA13703@xxxxxxxxxxxxxxxxxxxxxxxxxxx/

Since the logic in the patch seems unchanged, I'm very sure it's ok.

-- 
Jun'ichi Nomura, NEC Corporation / NEC Solution Innovators, Ltd.