diff options
| author | Fenghua Yu <fenghua.yu@intel.com> | 2009-04-24 17:30:20 -0700 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-04-29 06:54:34 +0100 |
| commit | 4ed0d3e6c64cfd9ba4ceb2099b10d1cf8ece4320 (patch) | |
| tree | 950bacfaf57040aafbcc2ea9b52eb171d35c23bd /include/linux/dma_remapping.h | |
| parent | 091069740304c979f957ceacec39c461d0192158 (diff) | |
Intel IOMMU Pass Through Support
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>
Diffstat (limited to 'include/linux/dma_remapping.h')
| -rw-r--r-- | include/linux/dma_remapping.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/dma_remapping.h b/include/linux/dma_remapping.h index 1a455f1f86d7..e0a03aff63d9 100644 --- a/include/linux/dma_remapping.h +++ b/include/linux/dma_remapping.h @@ -13,6 +13,9 @@ #define DMA_PTE_WRITE (2) #define DMA_PTE_SNP (1 << 11) +#define CONTEXT_TT_MULTI_LEVEL 0 +#define CONTEXT_TT_PASS_THROUGH 2 + struct intel_iommu; struct dmar_domain; struct root_entry; @@ -21,11 +24,16 @@ extern void free_dmar_iommu(struct intel_iommu *iommu); #ifdef CONFIG_DMAR extern int iommu_calculate_agaw(struct intel_iommu *iommu); +extern int iommu_calculate_max_sagaw(struct intel_iommu *iommu); #else static inline int iommu_calculate_agaw(struct intel_iommu *iommu) { return 0; } +static inline int iommu_calculate_max_sagaw(struct intel_iommu *iommu) +{ + return 0; +} #endif extern int dmar_disabled; |