Messages in this thread Patch in this message | | | From | Lu Baolu <> | Subject | [PATCH 1/1] iommu/vt-d: Preset Access/Dirty bits for IOVA over FL | Date | Fri, 15 Jan 2021 08:42:02 +0800 |
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The Access/Dirty bits in the first level page table entry will be set whenever a page table entry was used for address translation or write permission was successfully translated. This is always true when using the first-level page table for kernel IOVA. Instead of wasting hardware cycles to update the certain bits, it's better to set them up at the beginning.
Suggested-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- drivers/iommu/intel/iommu.c | 14 ++++++++++++-- include/linux/intel-iommu.h | 2 ++ 2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 0ea2e1440a9b..54b8d1bf2009 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1018,8 +1018,11 @@ 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)) + if (domain_use_first_level(domain)) { pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US; + if (domain->domain.type == IOMMU_DOMAIN_DMA) + pteval |= DMA_FL_PTE_ACCESS; + } if (cmpxchg64(&pte->val, 0ULL, pteval)) /* Someone else set it while we were thinking; use theirs. */ free_pgtable_page(tmp_page); @@ -2293,9 +2296,16 @@ __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn, return -EINVAL; attr = prot & (DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP); - if (domain_use_first_level(domain)) + if (domain_use_first_level(domain)) { attr |= DMA_FL_PTE_PRESENT | DMA_FL_PTE_XD | DMA_FL_PTE_US; + if (domain->domain.type == IOMMU_DOMAIN_DMA) { + attr |= DMA_FL_PTE_ACCESS; + if (prot & DMA_PTE_WRITE) + attr |= DMA_FL_PTE_DIRTY; + } + } + pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | attr; while (nr_pages > 0) { diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index 65aa963cc115..832730549c52 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -42,6 +42,8 @@ #define DMA_FL_PTE_PRESENT BIT_ULL(0) #define DMA_FL_PTE_US BIT_ULL(2) +#define DMA_FL_PTE_ACCESS BIT_ULL(5) +#define DMA_FL_PTE_DIRTY BIT_ULL(6) #define DMA_FL_PTE_XD BIT_ULL(63) #define ADDR_WIDTH_5LEVEL (57) -- 2.25.1
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