From: Lu Baolu <baolu.lu@linux.intel.com>
Date: Wed, 19 May 2021 09:50:27 +0800
Subject: iommu/vt-d: Use user privilege for RID2PASID translation
Git-commit: 54c80d907400189b09548039be8f3b6e297e8ae3
Patch-mainline: v5.13-rc4
References: bsc#1187348

When first-level page tables are used for IOVA translation, we use user
privilege by setting U/S bit in the page table entry. This is to make it
consistent with the second level translation, where the U/S enforcement
is not available. Clear the SRE (Supervisor Request Enable) field in the
pasid table entry of RID2PASID so that requests requesting the supervisor
privilege are blocked and treated as DMA remapping faults.

Fixes: b802d070a52a1 ("iommu/vt-d: Use iova over first level")
Suggested-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210512064426.3440915-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210519015027.108468-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/intel/iommu.c |    7 +++++--
 drivers/iommu/intel/pasid.c |    3 ++-
 2 files changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2545,9 +2545,9 @@ static int domain_setup_first_level(stru
 				    struct device *dev,
 				    u32 pasid)
 {
-	int flags = PASID_FLAG_SUPERVISOR_MODE;
 	struct dma_pte *pgd = domain->pgd;
 	int agaw, level;
+	int flags = 0;
 
 	/*
 	 * Skip top levels of page tables for iommu which has
@@ -2563,7 +2563,10 @@ static int domain_setup_first_level(stru
 	if (level != 4 && level != 5)
 		return -EINVAL;
 
-	flags |= (level == 5) ? PASID_FLAG_FL5LP : 0;
+	if (pasid != PASID_RID2PASID)
+		flags |= PASID_FLAG_SUPERVISOR_MODE;
+	if (level == 5)
+		flags |= PASID_FLAG_FL5LP;
 
 	if (domain->domain.type == IOMMU_DOMAIN_UNMANAGED)
 		flags |= PASID_FLAG_PAGE_SNOOP;
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -677,7 +677,8 @@ int intel_pasid_setup_second_level(struc
 	 * Since it is a second level only translation setup, we should
 	 * set SRE bit as well (addresses are expected to be GPAs).
 	 */
-	pasid_set_sre(pte);
+	if (pasid != PASID_RID2PASID)
+		pasid_set_sre(pte);
 	pasid_set_present(pte);
 	pasid_flush_caches(iommu, pte, pasid, did);