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authorFenghua Yu <fenghua.yu@intel.com>2009-04-24 17:30:20 -0700
committerDavid Woodhouse <David.Woodhouse@intel.com>2009-04-29 06:54:34 +0100
commit4ed0d3e6c64cfd9ba4ceb2099b10d1cf8ece4320 (patch)
tree950bacfaf57040aafbcc2ea9b52eb171d35c23bd /include/linux
parent091069740304c979f957ceacec39c461d0192158 (diff)
downloadop-kernel-dev-4ed0d3e6c64cfd9ba4ceb2099b10d1cf8ece4320.zip
op-kernel-dev-4ed0d3e6c64cfd9ba4ceb2099b10d1cf8ece4320.tar.gz
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')
-rw-r--r--include/linux/dma_remapping.h8
-rw-r--r--include/linux/intel-iommu.h2
2 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/dma_remapping.h b/include/linux/dma_remapping.h
index 1a455f1..e0a03af 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;
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index aa8c531..7246971 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -120,6 +120,7 @@ static inline void dmar_writeq(void __iomem *addr, u64 val)
(ecap_iotlb_offset(e) + ecap_niotlb_iunits(e) * 16)
#define ecap_coherent(e) ((e) & 0x1)
#define ecap_qis(e) ((e) & 0x2)
+#define ecap_pass_through(e) ((e >> 6) & 0x1)
#define ecap_eim_support(e) ((e >> 4) & 0x1)
#define ecap_ir_support(e) ((e >> 3) & 0x1)
#define ecap_max_handle_mask(e) ((e >> 20) & 0xf)
@@ -302,6 +303,7 @@ struct intel_iommu {
spinlock_t register_lock; /* protect register handling */
int seq_id; /* sequence id of the iommu */
int agaw; /* agaw of this iommu */
+ int msagaw; /* max sagaw of this iommu */
unsigned int irq;
unsigned char name[13]; /* Device Name */
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