Re: [PATCH v4 04/12] iommu/vt-d: Add helper to setup pasid nested translation

[Baolu Lu]

On 2023/8/2 15:10, Tian, Kevin wrote:
> > +
> > +	pasid_set_slptr(pte, virt_to_phys(pgd));
> > +	pasid_set_fault_enable(pte);
> > +	pasid_set_domain_id(pte, did);
> > +	pasid_set_address_width(pte, s2_domain->agaw);
> > +	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
> > +	pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
> > +	pasid_set_present(pte);
> > +	spin_unlock(&iommu->lock);
> > +
> this lacks of handling of force_snooping

If stage-2 domain has force_snooping attribute set, then we should set
the bit field in the pasid entry, right?

How about below additional change?

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index 19ac4084913b..86db81ec91f1 100644
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -827,6 +827,9 @@ int intel_pasid_setup_nested(struct intel_iommu 
*iommu, struct device *dev,
        if (s1_cfg->flags & IOMMU_VTD_S1_EAFE)
                pasid_set_eafe(pte);

+       if (s2_domain>force_snooping)
+               pasid_set_pgsnp(pte);
+
        pasid_set_slptr(pte, virt_to_phys(pgd));
        pasid_set_fault_enable(pte);
        pasid_set_domain_id(pte, did);

Best regards,
baolu