On Fri, Nov 20, 2015 at 01:56:39PM +1100, Benjamin Herrenschmidt wrote: > On Thu, 2015-11-19 at 23:38 +0000, David Woodhouse wrote: > > > > I understand that POWER and other platforms don't currently have a > > clean way to indicate that certain device don't have translation. And I > > understand that we may end up with a *quirk* which ensures that the DMA > > API does the right thing (i.e. nothing) in certain cases. > > > > But we should *NOT* be involving the virtio device drivers in that > > quirk, in any way. And putting a feature bit in the virtio device > > itself doesn't seem at all sane either. > > > > Bear in mind that qemu-system-x86_64 currently has the *same* problem > > with assigned physical devices. It's claiming they're translated, and > > they're not. > > It's not that clear but yeah ... as I mentioned, I can't find a > way to do that quirk that won't break when we want to actually use > the iommu... > > Ben. Yes, I am not at all sure we need a quirk for assigned devices. Better teach QEMU to make iommu work for them. -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
