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

[Michael S. Tsirkin]

On Fri, Jul 24, 2015 at 07:46:55AM +1000, Benjamin Herrenschmidt wrote:
> On Thu, 2015-07-23 at 22:00 +0100, Peter Maydell wrote:
> > (Also, none of our PCI device models actually try to do
> > the "BAR at zero means I won't respond" behaviour, which
> > presumably they might do in real life.)
> 
> Devices aren't supposed to do that ... In fact, I don't see HW designers
> adding a comparator if they don't have to :-)
> 
> Cheers,
> Ben.
> 

You never can tell with HW designers. For example, maybe they
used this as a trick to avoid implementing memory/io enable
properly.

-- 
MST