Re: [PATCH v2 4/5] iommu: Support mm PASID 1:n with sva domains

[Jason Gunthorpe]

On Mon, Aug 28, 2023 at 02:02:52PM +0530, Vasant Hegde wrote:

> I am not sure whether I understood the flow completely. Just wondering why you
> are not freeing pasid in iommu_sva_unbind_device().
> I mean once iommu_mm->sva_domains becomes free shouldn't we free the
> iommu_mm->pasid?

No, for Intel use cases that PASID permanently becomes part of the
ENQCMD MSR and cannot be revoked once it has been set
 
> Also in this function (mm_pasid_drop()), should we check/free sva domains?

No, the driver must support a SVA domain with an empty mm_struct, eg
by hooking release.

Jason