Supervisor Request Enable (SRE) bit in a PASID entry is for permission checking on DMA requests. When SRE = 0, DMA with supervisor privilege will be blocked. However, for in-kernel DMA this is not necessary in that we are targeting kernel memory anyway. There's no need to differentiate user and kernel for in-kernel DMA. Let's use non-privileged (user) permission for all PASIDs used in kernel, it will be consistent with DMA without PASID (RID_PASID) as well. Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> --- drivers/iommu/intel/iommu.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 0768dcae90fd..9f737ef55463 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -2338,8 +2338,6 @@ static int domain_setup_first_level(struct intel_iommu *iommu, if (level != 4 && level != 5) return -EINVAL; - if (pasid != PASID_RID2PASID) - flags |= PASID_FLAG_SUPERVISOR_MODE; if (level == 5) flags |= PASID_FLAG_FL5LP; -- 2.25.1
