Re: [PATCH 01/12] iommu/vt-d: Add cache tag assignment interface

[Baolu Lu]

On 4/6/24 8:55 PM, Baolu Lu wrote:
> > > @@ -4607,10 +4623,11 @@ static void
> > > intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
> > >        */
> > >       if (domain->type == IOMMU_DOMAIN_SVA) {
> > >           intel_svm_remove_dev_pasid(dev, pasid);
> > > +        cache_tag_unassign_domain(dmar_domain,
> > > +                      FLPT_DEFAULT_DID, dev, pasid);
> >
> > is it correct to destroy the tag before teardown completes, e.g. iotlb 
> > still
> > needs to be flushed in intel_pasid_tear_down_entry()?
>
> You are right. iotlb still needs to be there until the teardown
> completes. I will investigate this more later.

I reviewed this again. Cache tags are designed specifically for mapping
and unmapping paths. Therefore, there is no required order for attaching
and detaching paths.

Best regards,
baolu