Re: [PATCH RFC 06/11] iommu/sva: Use attach/detach_pasid_dev in SVA interfaces

[Jason Gunthorpe]

On Mon, Mar 21, 2022 at 07:01:45PM +0800, Lu Baolu wrote:

> > one domain can be attached by multiple devices, so this should not be
> > a blind alloc.
> 
> Indeed. Perhaps we could associate the SVA domain with the mm->pasid and
> add a user counter inside the domain.

This has the same problem as VFIO it needs to keep a list of
automatically created iommu domains in the mm_struct and try to re-use
them every time a device is bound.

Jason