From 4399c8bf2b9093696fa8160d79712e7346989c46 Mon Sep 17 00:00:00 2001 From: Allen Kay Date: Fri, 14 Oct 2011 12:32:46 -0700 Subject: [PATCH] intel-iommu: fix superpage support in pfn_to_dma_pte() If target_level == 0, current code breaks out of the while-loop if SUPERPAGE bit is set. We should also break out if PTE is not present. If we don't do this, KVM calls to iommu_iova_to_phys() will cause pfn_to_dma_pte() to create mapping for 4KiB pages. Signed-off-by: Allen Kay Signed-off-by: David Woodhouse --- drivers/iommu/intel-iommu.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index e5883602cb35..a88f3cbb100b 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -306,6 +306,11 @@ static inline bool dma_pte_present(struct dma_pte *pte) return (pte->val & 3) != 0; } +static inline bool dma_pte_superpage(struct dma_pte *pte) +{ + return (pte->val & (1 << 7)); +} + static inline int first_pte_in_page(struct dma_pte *pte) { return !((unsigned long)pte & ~VTD_PAGE_MASK); @@ -734,29 +739,23 @@ out: } static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain, - unsigned long pfn, int large_level) + unsigned long pfn, int target_level) { int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT; struct dma_pte *parent, *pte = NULL; int level = agaw_to_level(domain->agaw); - int offset, target_level; + int offset; BUG_ON(!domain->pgd); BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width); parent = domain->pgd; - /* Search pte */ - if (!large_level) - target_level = 1; - else - target_level = large_level; - while (level > 0) { void *tmp_page; offset = pfn_level_offset(pfn, level); pte = &parent[offset]; - if (!large_level && (pte->val & DMA_PTE_LARGE_PAGE)) + if (!target_level && (dma_pte_superpage(pte) || !dma_pte_present(pte))) break; if (level == target_level) break; -- 2.34.1