Re: [Qemu-devel] [PATCH RFC v2 2/2] hw/pci: handle unassigned pci addresses

[Michael S. Tsirkin]

On Mon, Sep 09, 2013 at 03:58:36PM +0100, Peter Maydell wrote:
> On 9 September 2013 15:51, Marcel Apfelbaum <address@hidden> wrote:
> > On Mon, 2013-09-09 at 15:21 +0100, Peter Maydell wrote:
> >> No, it's perfectly possible for a bus master transaction
> >> to abort. The PC's host controller happens to be set up so
> >> that bus master DMA covers the whole of the PCI memory space
> >> and so it's probably not possible to get an abort on that
> >> platform, but this isn't necessarily the case. For instance
> >> the versatilePB's PCI controller only responds to accesses
> >> within its programmed MMIO BAR ranges, so if the device
> >> or the controller have been misconfigured you can get an
> >> abort when the device tries to do DMA. (This usually causes
> >> the device to decide something has gone seriously wrong.
> > Thanks, I am not familiar with versatilePB, I may be able
> > to code it, I don't know how to test it
> 
> Don't worry about testing versatilePB particularly; you
> just need to make sure your code can cope with master
> aborts by device initiated transactions.
> 
> -- PMM

Device in question being PCI host right?
Just remove the assumption it's device 0...