When using first-level translation for IOVA, currently the U/S bit in the page table is cleared which implies DMA requests with user privilege are blocked. As the result, following error messages might be observed when passing through a device to user level:
DMAR: DRHD: handling fault status reg 3 DMAR: [DMA Read] Request device [41:00.0] PASID 1 fault addr 7ecdcd000 [fault reason 129] SM: U/S set 0 for first-level translation with user privilege This fixes it by setting U/S bit in the first level page table and makes IOVA over first level compatible with previous second-level translation. Fixes: b802d070a52a1 ("iommu/vt-d: Use iova over first level") Reported-by: Xin Zeng <xin.z...@intel.com> Signed-off-by: Lu Baolu <baolu...@linux.intel.com> --- drivers/iommu/intel-iommu.c | 5 ++--- include/linux/intel-iommu.h | 1 + 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 648a785e078a..d148712466b4 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -921,7 +921,7 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, domain_flush_cache(domain, tmp_page, VTD_PAGE_SIZE); pteval = ((uint64_t)virt_to_dma_pfn(tmp_page) << VTD_PAGE_SHIFT) | DMA_PTE_READ | DMA_PTE_WRITE; if (domain_use_first_level(domain)) - pteval |= DMA_FL_PTE_XD; + pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US; if (cmpxchg64(&pte->val, 0ULL, pteval)) /* Someone else set it while we were thinking; use theirs. */ free_pgtable_page(tmp_page); @@ -1951,7 +1951,6 @@ static inline void context_set_sm_rid2pasid(struct context_entry *context, unsigned long pasid) { context->hi |= pasid & ((1 << 20) - 1); - context->hi |= (1 << 20); } /* @@ -2243,7 +2242,7 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, attr = prot & (DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP); if (domain_use_first_level(domain)) - attr |= DMA_FL_PTE_PRESENT | DMA_FL_PTE_XD; + attr |= DMA_FL_PTE_PRESENT | DMA_FL_PTE_XD | DMA_FL_PTE_US; if (!sg) { sg_res = nr_pages; diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 4100bd224f5c..3e8fa1c7a1e6 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -41,6 +41,7 @@ #define DMA_PTE_SNP BIT_ULL(11) #define DMA_FL_PTE_PRESENT BIT_ULL(0) +#define DMA_FL_PTE_US BIT_ULL(2) #define DMA_FL_PTE_XD BIT_ULL(63) #define ADDR_WIDTH_5LEVEL (57) -- 2.17.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu