> From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> > Sent: Tuesday, February 7, 2023 1:25 AM > > > > @@ -1976,6 +1976,12 @@ static int > domain_context_mapping_one(struct > > > dmar_domain *domain, pds = context_get_sm_pds(table); > > > context->lo = (u64)virt_to_phys(table->table) | > > > context_pdts(pds); > > > + /* > > > + * Scalable-mode PASID directory pointer is not > > > snooped if the > > > + * coherent bit is not set. > > > + */ > > > + if (!ecap_coherent(iommu->ecap)) > > > + clflush_cache_range(table->table, sizeof(void > > > *)); > > > > This isn't comprehensive. The clflush should be called whenever the > > pasid directory table is allocated or updated. > > > allocate a pasid table does not mean it gets used by iommu hw, not until it > is programmed into context entry. > this is insufficient. Even after this point the PASID directory entry could be changed when a new PASID table is allocated, e.g. in intel_pasid_get_entry().
