> -----Original Message----- > From: iommu-bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx [mailto:iommu- > bounces@xxxxxxxxxxxxxxxxxxxxxxxxxx] On Behalf Of valmiki > Sent: Sunday, July 9, 2017 11:16 AM > To: Alex Williamson <alex.williamson@xxxxxxxxxx> > Cc: Lan, Tianyu <tianyu.lan@xxxxxxxxx>; Tian, Kevin <kevin.tian@xxxxxxxxx>; > kvm@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; > Pan, Jacob jun <jacob.jun.pan@xxxxxxxxx> > Subject: Re: Support SVM without PASID > > >> Hi, > >> > >> In SMMUv3 architecture document i see "PASIDs are optional, > >> configurable, and of a size determined by the minimum of the > >> endpoint". > >> > >> So if PASID's are optional and not supported by PCIe end point, how > >> SVM can be achieved ? > > > > It cannot be inferred from that statement that PASID support is not > > required for SVM. AIUI, SVM is a software feature enabled by numerous > > "optional" hardware features, including PASID. Features that are > > optional per the hardware specification may be required for specific > > software features. Thanks, > > > Thanks for the information Alex. Suppose if an End point doesn't support PASID, is it > still possible to achieve SVM ? > Are there any such features in SMMUv3 with which we can achieve it ? If endpoint has no PASID support, I don't think it is SVM capable. For SMMU, maybe you can get more info from Jean. Regards, Yi L
