From: David Woodhouse Date: Mon, 11 May 2015 13:59:20 +0000 (+0100) Subject: iommu/vt-d: Fix passthrough mode with translation-disabled devices X-Git-Tag: omap-for-v4.2/fixes-rc1^2~217^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ed6a540fab8ea4388c1703b73ecfed68a2009d1;p=pandora-kernel.git iommu/vt-d: Fix passthrough mode with translation-disabled devices When we use 'intel_iommu=igfx_off' to disable translation for the graphics, and when we discover that the BIOS has misconfigured the DMAR setup for I/OAT, we use a special DUMMY_DEVICE_DOMAIN_INFO value in dev->archdata.iommu to indicate that translation is disabled. With passthrough mode, we were attempting to dereference that as a normal pointer to a struct device_domain_info when setting up an identity mapping for the affected device. This fixes the problem by making device_to_iommu() explicitly check for the special value and indicate that no IOMMU was found to handle the devices in question. Signed-off-by: David Woodhouse Cc: stable@vger.kernel.org (which means you can pick up 18436afdc now too) --- Reading git-diff-tree failed