Re: vfio: missing patch in linux 3.6

[Andreas Hartmann <andihartmann@01019freenet.de>]

Roedel, Joerg wrote:
> On Thu, Oct 04, 2012 at 10:28:00AM -0600, Alex Williamson wrote:
>> There are a couple questions in the link above.  Since the devices don't
>> expose a PCIe capability, we probably need to add a check to look at the
>> upstream device and verify we're not on a legacy bus where ACS can't be
>> enforced.
> 
> You can certainly do that, but for existing hardware (with an AMD IOMMU)
> this check would never be true. These devices are always on a seperate
> south-bridge chip which is connected to the north-bridge via PCIe. So
> the topology where you find these devices is always the same in an AMD
> IOMMU system.
> 
>> Then there's the general question of whether the confirmation
>> of no peer-to-peer applies to every case where we might see this device
>> (some of them seem to have history that pre-dates this specific package
>> implementation) or do we need to try to identify specific package
>> properties in addition to just a device ID?
> 
> The device ids are kept the same to maintain compatability with older
> software. Besides that, my statement about the peer-2-peer safety is
> true for all south-bridges that you can find in an AMD IOMMU capable
> system.

http://news.gmane.org/find-root.php?group=gmane.linux.kernel.pci&article=16422

I think, Joerg wrote clearly that there is no problem any more to apply
this patch. I run it since a long time meanwhile without any problem.
Please, why aren't these patches applied?


Thanks,
kind regards,
Andreas Hartmann