Re: [PATCH v2] hvmloader: flip "ACPI data" to "ACPI NVS" type for ACPI table region

[Sander Eikelenboom <linux@xxxxxxxxxxxxxx>]

On 16/10/2020 08:34, Jan Beulich wrote:
> On 16.10.2020 02:39, Igor Druzhinin wrote:
>> ACPI specification contains statements describing memory marked with regular
>> "ACPI data" type as reclaimable by the guest. Although the guest shouldn't
>> really do it if it wants kexec or similar functionality to work, there
>> could still be ambiguities in treating these regions as potentially regular
>> RAM.
>>
>> One such example is SeaBIOS which currently reports "ACPI data" regions as
>> RAM to the guest in its e801 call. Which it might have the right to do as any
>> user of this is expected to be ACPI unaware. But a QEMU bootloader later 
>> seems
>> to ignore that fact and is instead using e801 to find a place for initrd 
>> which
>> causes the tables to be erased. While arguably QEMU bootloader or SeaBIOS 
>> need
>> to be fixed / improved here, that is just one example of the potential 
>> problems
>> from using a reclaimable memory type.
>>
>> Flip the type to "ACPI NVS" which doesn't have this ambiguity in it and is
>> described by the spec as non-reclaimable (so cannot ever be treated like 
>> RAM).
>>
>> Signed-off-by: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
> 
> Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> 

I don't see any stable and or fixes tags, but I assume this will go to
the stable trees (which have (a backport of)
8efa46516c5f4cf185c8df179812c185d3c27eb6 in their staging branches) ?

(and as reporter it would have been nice to have been CC'ed on the patch)

--
Sander