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From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 13 Oct 2015 13:33:25 +0100
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Subject: Re: [Qemu-devel] [PATCH] hw/arm/virt: Allow zero address for PCI IO
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To: Alexander Gordeev <agordeev@redhat.com>
Cc: Laurent Vivier <lvivier@redhat.com>, Andrew Jones <drjones@redhat.com>, QEMU Developers <qemu-devel@nongnu.org>

On 13 October 2015 at 13:48, Alexander Gordeev <agordeev@redhat.com> wrote:
> On Tue, Oct 13, 2015 at 09:16:34AM +0100, Peter Maydell wrote:
>> In any case, setting pci_allow_0_address is the right thing,
>> so we can just change the commit message in this patch.
>
> I will post v2 with an updated changelog then.
>
>> Incidentally, why is this a property on the machine
>> and not on the PCI controller device?
>
> I am CC-ing Laurent Vivier who introduced the flag.
>
> But IMO it *is* a machine property, not PCI controller's
> one, unless I am missing something.

I think "does this PCI controller handle BARs with
zero addresses, or does it treat them as if the BAR
was unmapped" is definitely a controller property...
you might have in theory a machine with two PCI
controllers, one of which could deal with zero-addresses
and one of which could not.

thanks
-- PMM