From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> [ 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@xxxxxxxxx> Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> Suggested-by: Kevin Tian <kevin.tian@xxxxxxxxx> Fixes: c0771df8d5297 ("intel-iommu: Export a flag indicating that the IOMMU is used for iGFX.") Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> Tested-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 b965561a41627..a2005b82ec8ff 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3259,9 +3259,12 @@ 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) { -- 2.20.1