Re: [PATCH for-7.1] hw/mips/malta: turn off x86 specific features of PIIX4_PM

[BB]

Am 8. August 2022 20:02:50 MESZ schrieb Peter Maydell 
<peter.maydell@linaro.org>:
>On Mon, 8 Aug 2022 at 18:57, BB <shentey@gmail.com> wrote:
>> Am 8. August 2022 14:15:40 MESZ schrieb Igor Mammedov <imammedo@redhat.com>:
>> >On Wed, 3 Aug 2022 19:26:30 +0200
>> >While refactoring we should keep migration stream compatible with older
>> >QEMU versions (we must not regress widely x86 code path). Which might be
>> >tricky in this case.
>>
>> Does this particular fix make future compatibility harder or easier or is it 
>> that hard already? IIUC it omits the hotplug bits in the vm state for Malta 
>> which is what one would expect there, right?
>
>This patch's fix only affects Malta. It is (I suspect but have
>not tested) a migration compat break on Malta, but we don't
>care about cross-version migration compat for that board anyway.
>Migration compat matters (to a first approximation) only for
>those boards which have versioned machine types (eg pc-7.0,
>pc-7.1, etc). For all other machine types we retain compat
>only if it's easy.

I see. Thanks for the clarification!

Best regards,
Bernhard
>
>thanks
>-- PMM