Re: [Qemu-devel] [PATCH v2 10/14] pci: allow 0 address for PCI IO regions

[Peter Maydell]

On 5 December 2013 22:33, Michael Roth <address@hidden> wrote:
> Some kernels program a 0 address for io regions. PCI 3.0 spec
> sectio 6.2.5.1 doesn't seem to disallow this.

Hmm. The last PCI spec I looked at said 0 wasn't a valid MMIO
address, so the variant of this patch I wrote a while back made it
a per PCI device flag whether a particular device let you get away
with it:
 http://patchwork.ozlabs.org/patch/269133/

(the device in question for me was the versatile-pci host bridge).

And presumably whoever put that specific check for 0 into
QEMU had a reason for it.

On the other hand I can't now find whatever document it was
that I was reading that claimed 0 wasn't valid :-(

thanks
-- PMM