Re: [PATCH v2 12/12] iommu/vt-d: Retire struct intel_svm

[Baolu Lu]

On 2024/4/11 21:07, Jason Gunthorpe wrote:
> > +static void intel_mm_free_notifier(struct mmu_notifier *mn)
> > +{
> > +       kfree(container_of(mn, struct dmar_domain, notifier));
> > +}
> > +
> >   static const struct mmu_notifier_ops intel_mmuops = {
> >          .release = intel_mm_release,
> >          .arch_invalidate_secondary_tlbs =
> > intel_arch_invalidate_secondary_tlbs,
> > +       .free_notifier = intel_mm_free_notifier,
> >   };
> >
> >   static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
> > @@ -598,10 +604,8 @@ static void intel_svm_domain_free(struct iommu_domain
> > *domain)
> >   {
> >          struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> >
> > -       if (dmar_domain->notifier.ops)
> > -               mmu_notifier_unregister(&dmar_domain->notifier, domain->mm);
> > -
> > -       kfree(dmar_domain);
> > +       /* dmar_domain free is defered to the mmu free_notifier callback. */
> > +       mmu_notifier_put(&dmar_domain->notifier);
> >   }
> Yeah, that is better.
>
> Also you need to have mmu notifier call on module unload when using
> this scheme.

The Intel IOMMU driver doesn't support being a module. It's always
built-in.

Best regards,
baolu