Skip to content

Commit

Permalink
iommu/vt-d: Preset Access bit for IOVA in FL non-leaf paging entries
Browse files Browse the repository at this point in the history
commit 242b0aa upstream.

The A/D bits are preseted for IOVA over first level(FL) usage for both
kernel DMA (i.e, domain typs is IOMMU_DOMAIN_DMA) and user space DMA
usage (i.e., domain type is IOMMU_DOMAIN_UNMANAGED).

Presetting A bit in FL requires to preset the bit in every related paging
entries, including the non-leaf ones. Otherwise, hardware may treat this
as an error. For example, in a case of ECAP_REG.SMPWC==0, DMA faults might
occur with below DMAR fault messages (wrapped for line length) dumped.

 DMAR: DRHD: handling fault status reg 2
 DMAR: [DMA Read NO_PASID] Request device [aa:00.0] fault addr 0x10c3a6000
    [fault reason 0x90]
    SM: A/D bit update needed in first-level entry when set up in no snoop

Fixes: 289b3b0 ("iommu/vt-d: Preset A/D bits for user space DMA usage")
Cc: stable@vger.kernel.org
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Link: https://lore.kernel.org/r/20221113010324.1094483-1-tina.zhang@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20221116051544.26540-2-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
TinaZhangZW authored and gregkh committed Nov 26, 2022
1 parent 90a49a6 commit 97f91aa
Showing 1 changed file with 3 additions and 5 deletions.
8 changes: 3 additions & 5 deletions drivers/iommu/intel/iommu.c
Original file line number Diff line number Diff line change
Expand Up @@ -954,11 +954,9 @@ 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 | DMA_FL_PTE_US;
if (iommu_is_dma_domain(&domain->domain))
pteval |= DMA_FL_PTE_ACCESS;
}
if (domain_use_first_level(domain))
pteval |= DMA_FL_PTE_XD | DMA_FL_PTE_US | 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

0 comments on commit 97f91aa

Please sign in to comment.