iommu/vt-d: Make kernel parameter igfx_off work with vIOMMU

[ Upstream commit 5daab58043ee2bca861068e2595564828f3bc663 ]

The kernel parameter igfx_off is used by users to disable
DMA remapping for the Intel integrated graphic device. It
was designed for bare metal cases where a dedicated IOMMU
is used for graphic. This doesn't apply to virtual IOMMU
case where an include-all IOMMU is used.  This makes the
kernel parameter work with virtual IOMMU as well.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Fixes: c0771df8d5 ("intel-iommu: Export a flag indicating that the IOMMU is used for iGFX.")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Lu Baolu 2019-05-02 09:34:26 +08:00 committed by Greg Kroah-Hartman
parent b626b8340e
commit 5b824a6a43

View file

@ -3387,9 +3387,12 @@ static int __init init_dmars(void)
iommu_identity_mapping |= IDENTMAP_ALL;
#ifdef CONFIG_INTEL_IOMMU_BROKEN_GFX_WA
iommu_identity_mapping |= IDENTMAP_GFX;
dmar_map_gfx = 0;
#endif
if (!dmar_map_gfx)
iommu_identity_mapping |= IDENTMAP_GFX;
check_tylersburg_isoch();
if (iommu_identity_mapping) {