From: Linus Torvalds Date: Fri, 12 Jun 2015 18:28:57 +0000 (-0700) Subject: Merge git://git.infradead.org/intel-iommu X-Git-Tag: submit/tizen/20160607.132125~2346 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c39f3bc659b6f32e0e88113ec359a504be259e4f;p=sdk%2Femulator%2Femulator-kernel.git Merge git://git.infradead.org/intel-iommu Pull VT-d hardware workarounds from David Woodhouse: "This contains a workaround for hardware issues which I *thought* were never going to be seen on production hardware. I'm glad I checked that before the 4.1 release... Firstly, PASID support is so broken on existing chips that we're just going to declare the old capability bit 28 as 'reserved' and change the VT-d spec to move PASID support to another bit. So any existing hardware doesn't support SVM; it only sets that (now) meaningless bit 28. That patch *wasn't* imperative for 4.1 because we don't have PASID support yet. But *even* the extended context tables are broken — if you just enable the wider tables and use none of the new bits in them, which is precisely what 4.1 does, you find that translations don't work. It's this problem which I thought was caught in time to be fixed before production, but wasn't. To avoid triggering this issue, we now *only* enable the extended context tables on hardware which also advertises "we have PASID support and we actually tested it this time" with the new PASID feature bit. In addition, I've added an 'intel_iommu=ecs_off' command line parameter to allow us to disable it manually if we need to" * git://git.infradead.org/intel-iommu: iommu/vt-d: Only enable extended context tables if PASID is supported iommu/vt-d: Change PASID support to bit 40 of Extended Capability Register --- c39f3bc659b6f32e0e88113ec359a504be259e4f