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/intel-iommu.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/intel-iommu.h')
| -rw-r--r-- | include/linux/intel-iommu.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index aa8c5317123..7246971a7fe 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 */ |