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

[Peter Maydell]

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