Re: [Qemu-devel] [PATCH] hw/arm/virt-acpi-build: drop _ADR entry from SPCR

[Shannon Zhao <shannon.zhao@linaro.org>]

On 2015/8/20 18:48, G Gregory wrote:
> On 20 August 2015 at 11:18, Leif Lindholm <leif.lindholm@linaro.org> wrote:
>> On Thu, Aug 20, 2015 at 01:24:39AM +0100, Peter Maydell wrote:
>>> On 6 August 2015 at 14:25, Andrew Jones <drjones@redhat.com> wrote:
>>>> On Thu, Aug 06, 2015 at 01:55:14PM +0100, Leif Lindholm wrote:
>>>>> On Thu, Aug 06, 2015 at 02:28:03PM +0200, Andrew Jones wrote:
>>>>>> In the least I wouldn't want to get burned twice, so I'd prefer to
>>>>>> see the SPCR code actually get into Linux first this time. That
>>>>>> would also allow us to point at something when we start breaking
>>>>>> guests.
>>>>>
>>>>> So, if that's the way it has to be, that's the way it has to be.
>>>>> I'd just prefer not having different pieces of firmware validating
>>>>> different software behaviours for the same thing.
>>>>
>>>> Yeah, now it's messy. I'm actually OK with this QEMU patch, with regard
>>>> to the downstream stuff that I'm involved with, but other downstreams
>>>> may not be so flexible... We need Peter to chime in with his opinion,
>>>> CCed.
>>>
>>> Could somebody who understands ACPI and the ramifications
>>> here let me know if I should apply this patch, please?
>>> (since we're now post-2.4)
>>
>> I presume my opinion is clear, but I'm cc:ing some of the Linaro ACPI
>> team.
>>
>> Graeme, Al - the patch in question is:
>> https://www.mail-archive.com/qemu-devel%40nongnu.org/msg314356.html
>>
> Using _ADR for a non enumerable bus is undefined behaviour in the ACPI
> specification.
>
> How it is used in Redhats SPCR patch is IMO wrong becuase there is no
> guarantee that _ADR will be defined for any MMIO device in DSDT.
>
> I believe QEMU should not follow this just to make a non upstreamed
> Redhat patch work.
>
Yeah, but when will the right kernel patch be upstreamed? Do you have a 
plan for upstreaming it? Or it's on the list already?

As said before, we can apply this patch after the kernel patch upstreamed.

Thanks,
-- 
Shannon