Re: [Qemu-devel] [PATCH] hw/arm/virt: Allow zero address for PCI IO space

[Laurent Vivier <lvivier@redhat.com>]

On 16/10/2015 11:32, Peter Maydell wrote:
> On 16 October 2015 at 09:52, Laurent Vivier <lvivier@redhat.com> wrote:
>> I'm going to remove the zero address checking and try to start a qemu
>> for each of them to see which ones are broken.
> 
> You need to also make sure there's a PCI card in there
> and that the guest maps it with a BAR at address zero
> (testing both MMIO BARs and IO BARs), and then exercise
> the guest sufficiently to check that behaviour of whatever
> it might be overlapping is still OK.

I think it will be hard to trigger this case. :(

For instance, on pseries, the card is put at address 0 only when it is
hotplugged, and on reboot it is moved to another address.

> You might find it easier to do by code inspection in
> some cases (boards which implement PCI as a simple
> "memory window into the PCI space" rather than with
> x86-style "anything in the background not covered by
> another device is PCI space" should be ok).

OK, I will...

Laurent