Skip to content

Commit

Permalink
iommu/vt-d: Preset Access/Dirty bits for IOVA over FL
Browse files Browse the repository at this point in the history
commit a8ce9eb upstream.

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>
Link: https://lore.kernel.org/r/20210115004202.953965-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  • Loading branch information
LuBaolu authored and gregkh committed May 19, 2021
1 parent a282b76 commit 0160f62
Show file tree
Hide file tree
Showing 2 changed files with 14 additions and 2 deletions.
14 changes: 12 additions & 2 deletions drivers/iommu/intel/iommu.c
Expand Up @@ -1028,8 +1028,11 @@ 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);
Expand Down Expand Up @@ -2359,9 +2362,16 @@ static int __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;
}
}

if (!sg) {
sg_res = nr_pages;
pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | attr;
Expand Down
2 changes: 2 additions & 0 deletions include/linux/intel-iommu.h
Expand Up @@ -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)
Expand Down

0 comments on commit 0160f62

Please sign in to comment.