Hi Baolu, > From: Lu Baolu [mailto:baolu...@linux.intel.com] > Sent: Monday, November 5, 2018 1:32 PM > Subject: [PATCH v4 05/12] iommu/vt-d: Reserve a domain id for FL and PT modes > > 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....@intel.com> > Cc: Jacob Pan <jacob.jun....@linux.intel.com> > Cc: Kevin Tian <kevin.t...@intel.com> > Cc: Liu Yi L <yi.l....@intel.com> > Cc: Sanjay Kumar <sanjay.k.ku...@intel.com> > Signed-off-by: Lu Baolu <baolu...@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 9331240c70b8..2f7455ee4e7a 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);
"FLPT_DEFAULT_DID" looks very likely for first level translation. How about "PT_FL_DEFAULT_DID"? > 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 Would be helpful to elaborate why DID 1 is selected in the patch description. Regards, Yi Liu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
