4ed0d3e6c6
The patch adds kernel parameter intel_iommu=pt to set up pass through mode in context mapping entry. This disables DMAR in linux kernel; but KVM still runs on VT-d and interrupt remapping still works. In this mode, kernel uses swiotlb for DMA API functions but other VT-d functionalities are enabled for KVM. KVM always uses multi level translation page table in VT-d. By default, pass though mode is disabled in kernel. This is useful when people don't want to enable VT-d DMAR in kernel but still want to use KVM and interrupt remapping for reasons like DMAR performance concern or debug purpose. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Weidong Han <weidong@intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
42 lines
957 B
C
42 lines
957 B
C
#ifndef _DMA_REMAPPING_H
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#define _DMA_REMAPPING_H
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/*
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* VT-d hardware uses 4KiB page size regardless of host page size.
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*/
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#define VTD_PAGE_SHIFT (12)
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#define VTD_PAGE_SIZE (1UL << VTD_PAGE_SHIFT)
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#define VTD_PAGE_MASK (((u64)-1) << VTD_PAGE_SHIFT)
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#define VTD_PAGE_ALIGN(addr) (((addr) + VTD_PAGE_SIZE - 1) & VTD_PAGE_MASK)
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#define DMA_PTE_READ (1)
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#define DMA_PTE_WRITE (2)
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#define DMA_PTE_SNP (1 << 11)
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#define CONTEXT_TT_MULTI_LEVEL 0
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#define CONTEXT_TT_PASS_THROUGH 2
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struct intel_iommu;
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struct dmar_domain;
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struct root_entry;
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extern void free_dmar_iommu(struct intel_iommu *iommu);
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#ifdef CONFIG_DMAR
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extern int iommu_calculate_agaw(struct intel_iommu *iommu);
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extern int iommu_calculate_max_sagaw(struct intel_iommu *iommu);
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#else
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static inline int iommu_calculate_agaw(struct intel_iommu *iommu)
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{
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return 0;
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}
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static inline int iommu_calculate_max_sagaw(struct intel_iommu *iommu)
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{
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return 0;
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}
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#endif
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extern int dmar_disabled;
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#endif
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