Re: [PATCH 7/7] iommu: Add iommu_domain::domain_ops

[Jason Gunthorpe]

On Mon, Jan 24, 2022 at 09:58:18AM +0000, Tian, Kevin wrote:
> > From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Sent: Monday, January 24, 2022 3:11 PM
> > +/**
> > + * struct domain_ops - per-domain ops
> > + * @attach_dev: attach an iommu domain to a device
> > + * @detach_dev: detach an iommu domain from a device
> 
> What is the criteria about whether an op should be iommu_ops or domain_ops
> when it requires both domain and device pointers like above two (and future
> PASID-based attach)?
> 
> Other examples include:
> 	@apply_resv_region

For apply_resv_region the 'dev' argument is really selecting a device
that is already attached to the domain, so it should be in the domain
ops.

> 	@is_attach_deferred

Only two drivers implement this and neither use the domain
argument. Remove the domain argument and keep it in the iommu_ops

Jason