Messages in this thread Patch in this message | | | From | Lu Baolu <> | Subject | [PATCH v5 05/12] iommu/vt-d: Reserve a domain id for FL and PT modes | Date | Wed, 28 Nov 2018 11:54:42 +0800 |
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Vt-d spec rev3.0 (section 6.2.3.1) requires that each pasid entry for first-level or pass-through translation should be programmed with a domain id different from those used for second-level or nested translation. It is recommended that software could use a same domain id for all first-only and pass-through translations.
This reserves a domain id for first-level and pass-through translations.
Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Liu Yi L <yi.l.liu@intel.com> Cc: Sanjay Kumar <sanjay.k.kumar@intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- drivers/iommu/intel-iommu.c | 10 ++++++++++ drivers/iommu/intel-pasid.h | 6 ++++++ 2 files changed, 16 insertions(+)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 4866bdeb932d..b521d648db9d 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -1618,6 +1618,16 @@ static int iommu_init_domains(struct intel_iommu *iommu) */ set_bit(0, iommu->domain_ids); + /* + * Vt-d spec rev3.0 (section 6.2.3.1) requires that each pasid + * entry for first-level or pass-through translation modes should + * be programmed with a domain id different from those used for + * second-level or nested translation. We reserve a domain id for + * this purpose. + */ + if (sm_supported(iommu)) + set_bit(FLPT_DEFAULT_DID, iommu->domain_ids); + return 0; } diff --git a/drivers/iommu/intel-pasid.h b/drivers/iommu/intel-pasid.h index 12f480c2bb8b..03c1612d173c 100644 --- a/drivers/iommu/intel-pasid.h +++ b/drivers/iommu/intel-pasid.h @@ -17,6 +17,12 @@ #define PDE_PFN_MASK PAGE_MASK #define PASID_PDE_SHIFT 6 +/* + * Domain ID reserved for pasid entries programmed for first-level + * only and pass-through transfer modes. + */ +#define FLPT_DEFAULT_DID 1 + struct pasid_dir_entry { u64 val; }; -- 2.17.1
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