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 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
