Implement the SMMUv3 equivalent of d346180e70b9 ("iommu/arm-smmu: Treat
all device transactions as unprivileged"), so that once again those
pesky DMA controllers with their privileged instruction fetches don't
unexpectedly fault in stage 1 domains due to VMSAv8 rules.

Acked-by: Will Deacon <will.dea...@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Signed-off-by: Robin Murphy <robin.mur...@arm.com>
---
 drivers/iommu/arm-smmu-v3.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 52860bcf80f2..0c45c1e02e04 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -267,6 +267,9 @@
 #define STRTAB_STE_1_SHCFG_INCOMING    1UL
 #define STRTAB_STE_1_SHCFG_SHIFT       44
 
+#define STRTAB_STE_1_PRIVCFG_UNPRIV    2UL
+#define STRTAB_STE_1_PRIVCFG_SHIFT     48
+
 #define STRTAB_STE_2_S2VMID_SHIFT      0
 #define STRTAB_STE_2_S2VMID_MASK       0xffffUL
 #define STRTAB_STE_2_VTCR_SHIFT                32
@@ -1068,7 +1071,9 @@ static void arm_smmu_write_strtab_ent(struct 
arm_smmu_device *smmu, u32 sid,
 #ifdef CONFIG_PCI_ATS
                         STRTAB_STE_1_EATS_TRANS << STRTAB_STE_1_EATS_SHIFT |
 #endif
-                        STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT);
+                        STRTAB_STE_1_STRW_NSEL1 << STRTAB_STE_1_STRW_SHIFT |
+                        STRTAB_STE_1_PRIVCFG_UNPRIV <<
+                        STRTAB_STE_1_PRIVCFG_SHIFT);
 
                if (smmu->features & ARM_SMMU_FEAT_STALLS)
                        dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
-- 
2.8.1.dirty

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