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Commit 4399c8bf authored by Allen Kay's avatar Allen Kay Committed by David Woodhouse
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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: default avatarAllen Kay <allen.m.kay@intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 8140a95d

drivers/iommu/intel-iommu.c

+8 −9
Original line number Diff line number Diff line
@@ -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 @@ static void free_context_table(struct intel_iommu *iommu) 
}



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;