> From: Lu Baolu <[email protected]> > Sent: Saturday, April 16, 2022 8:31 PM > > This field make the requests snoop processor caches irrespective of other > attributes in the request or other fields in paging structure entries > used to translate the request. The latest VT-d specification states that > this field is treated as Reserved(0) for implementations not supporting > Snoop Control (SC=0 in the Extended Capability Register). Hence add a > check in the code. > > Signed-off-by: Lu Baolu <[email protected]> > --- > drivers/iommu/intel/pasid.c | 2 +- > drivers/iommu/intel/svm.c | 1 + > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c > index f8d215d85695..9ca3c67a2058 100644 > --- a/drivers/iommu/intel/pasid.c > +++ b/drivers/iommu/intel/pasid.c > @@ -625,7 +625,7 @@ int intel_pasid_setup_first_level(struct intel_iommu > *iommu, > } > } > > - if (flags & PASID_FLAG_PAGE_SNOOP) > + if ((flags & PASID_FLAG_PAGE_SNOOP) && ecap_sc_support(iommu- > >ecap)) > pasid_set_pgsnp(pte);
If the caller wants snoop for some reason is it correct to simply ignore the request when lacking of hw support? Suppose certain errno should be returned here... > > pasid_set_domain_id(pte, did); > diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c > index 23a38763c1d1..d88af37c20ef 100644 > --- a/drivers/iommu/intel/svm.c > +++ b/drivers/iommu/intel/svm.c > @@ -394,6 +394,7 @@ static struct iommu_sva *intel_svm_bind_mm(struct > intel_iommu *iommu, > sflags = (flags & SVM_FLAG_SUPERVISOR_MODE) ? > PASID_FLAG_SUPERVISOR_MODE : 0; > sflags |= cpu_feature_enabled(X86_FEATURE_LA57) ? > PASID_FLAG_FL5LP : 0; > + sflags |= PASID_FLAG_PAGE_SNOOP; > spin_lock_irqsave(&iommu->lock, iflags); > ret = intel_pasid_setup_first_level(iommu, dev, mm->pgd, mm- > >pasid, > FLPT_DEFAULT_DID, sflags); > -- > 2.25.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
