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

[Jan Beulich <jbeulich@xxxxxxxx>]

On 13.10.2020 14:59, Igor Druzhinin wrote:
> On 13/10/2020 13:51, Jan Beulich wrote:
>> As a consequence I think we will also want to adjust Xen itself to
>> automatically disable ACPI when it ends up consuming E801 data. Or
>> alternatively we should consider dropping all E801-related code (as
>> being inapplicable to 64-bit systems).
> 
> I'm not following here. What Xen has to do with E801? It's a SeaBIOS 
> implemented
> call that happened to be used by QEMU option ROM. We cannot drop it from there
> as it's part of BIOS spec.

Any ACPI aware OS has to use E820 (and nothing else). Hence our
own use of E801 should either be dropped, or lead to the
disabling of ACPI. Otherwise real firmware using logic similar
to SeaBIOS'es (but hopefully properly accounting for holes)
could make us use ACPI table space as normal RAM.

Jan