From: Lu Baolu baolu.lu@linux.intel.com
[ 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: c0771df8d5297 ("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 --- drivers/iommu/intel-iommu.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index b9af2419006f..abbbc614c522 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -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) {