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

[Shannon Zhao]

On 2015/8/20 18:48, G Gregory wrote:
> On 20 August 2015 at 11:18, Leif Lindholm <address@hidden> wrote:
> > On Thu, Aug 20, 2015 at 01:24:39AM +0100, Peter Maydell wrote:
> > > On 6 August 2015 at 14:25, Andrew Jones <address@hidden> 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