Commit a8ce9ebb authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
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iommu/vt-d: Preset Access/Dirty bits for IOVA over FL 



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: default avatarAshok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent f2dd8717

drivers/iommu/intel/iommu.c

+12 −2
Original line number Diff line number Diff line
@@ -1017,8 +1017,11 @@ 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);
@@ -2310,9 +2313,16 @@ __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) {

include/linux/intel-iommu.h

+2 −0
Original line number Diff line number Diff line
@@ -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)