RE: [PATCH v6 08/12] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces

[Tian, Kevin]

> From: Baolu Lu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Thursday, May 12, 2022 11:03 AM
> 
> On 2022/5/11 22:53, Jason Gunthorpe wrote:
> >>> Also, given the current arrangement it might make sense to have a
> >>> struct iommu_domain_sva given that no driver is wrappering this in
> >>> something else.
> >> Fair enough. How about below wrapper?
> >>
> >> +struct iommu_sva_domain {
> >> +       /*
> >> +        * Common iommu domain header,*must*  be put at the top
> >> +        * of the structure.
> >> +        */
> >> +       struct iommu_domain domain;
> >> +       struct mm_struct *mm;
> >> +       struct iommu_sva bond;
> >> +}
> >>
> >> The refcount is wrapped in bond.
> > I'm still not sure that bond is necessary
> 
> "bond" is the sva handle that the device drivers get through calling
> iommu_sva_bind().
> 

'bond' was required before because we didn't have a domain to wrap
the page table at that time.

Now we have a domain and it is 1:1 associated to bond. Probably
make sense now by just returning the domain as the sva handle
instead?