6.6-stable review patch. If anyone has any objections, please let me know.
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From: Zhenzhong Duan zhenzhong.duan@intel.com
[ Upstream commit f1645676f25d2c846798f0233c3a953efd62aafb ]
There are some issues in pgtable_walk():
1. Super page is dumped as non-present page 2. dma_pte_superpage() should not check against leaf page table entries 3. Pointer pte is never NULL so checking it is meaningless 4. When an entry is not present, it still makes sense to dump the entry content.
Fix 1,2 by checking dma_pte_superpage()'s returned value after level check. Fix 3 by removing pte check. Fix 4 by checking present bit after printing.
By this chance, change to print "page table not present" instead of "PTE not present" to be clearer.
Fixes: 914ff7719e8a ("iommu/vt-d: Dump DMAR translation structure when DMA fault occurs") Signed-off-by: Zhenzhong Duan zhenzhong.duan@intel.com Link: https://lore.kernel.org/r/20241024092146.715063-3-zhenzhong.duan@intel.com Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/intel/iommu.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 7d00e9cf7db02..d6381c00bb8dd 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -815,14 +815,15 @@ static void pgtable_walk(struct intel_iommu *iommu, unsigned long pfn, while (1) { offset = pfn_level_offset(pfn, level); pte = &parent[offset]; - if (!pte || (dma_pte_superpage(pte) || !dma_pte_present(pte))) { - pr_info("PTE not present at level %d\n", level); - break; - }
pr_info("pte level: %d, pte value: 0x%016llx\n", level, pte->val);
- if (level == 1) + if (!dma_pte_present(pte)) { + pr_info("page table not present at level %d\n", level - 1); + break; + } + + if (level == 1 || dma_pte_superpage(pte)) break;
parent = phys_to_virt(dma_pte_addr(pte));