Re: [PATCH v6 1/2] x86/kexec: Build identity mapping for EFI systab and ACPI tables
From: Junichi Nomura
Date: Tue May 21 2019 - 06:49:59 EST
On 2019/05/21 18:02, Kairui Song wrote:
> On Wed, May 15, 2019 at 3:10 PM Junichi Nomura <j-nomura@xxxxxxxxxxxxx> wrote:
>> On 5/15/19 3:58 PM, Borislav Petkov wrote:
>>> On Wed, May 15, 2019 at 05:17:19AM +0000, Junichi Nomura wrote:
>>>> I found kexec(1) fails to load kernel on a few machines if this patch
>>>> is applied. Those machines don't have IORES_DESC_ACPI_TABLES region
>>>> and have ACPI tables in IORES_DESC_ACPI_NV_STORAGE region instead.
>>>
>>> Why? What kind of machines are those?
>>
>> I don't know. They are just general purpose Xeon-based servers
>> and not some special purpose machines. So I guess there are other
>> such machines in the wild.
>
> Hi, I think it's reasonable to update the patch to include the
> NV_STORAGE regions as well, most likely the firmware only provided
> NV_STORAGE region? Can you help confirm if the e820 didn't contain
> ACPI data, and only ACPI NVS?
Yes, those machines only have ACPI NVS region as far as I see from kernel log.
> I had a try with this update patch, it worked and didn't break anything.
>
> Hi Boris, would you prefer to just fold Junichi update patch into the
> previous one or I should send an updated patch?
--
Jun'ichi Nomura, NEC Corporation / NEC Solution Innovators, Ltd.