On Mon, Jan 24, 2022 at 12:33:02PM -0400, Jason Gunthorpe wrote: > On Mon, Jan 24, 2022 at 10:16:07AM +0000, Jean-Philippe Brucker wrote: > > On Mon, Jan 24, 2022 at 09:58:18AM +0000, Tian, Kevin wrote: > > > > From: Lu Baolu <[email protected]> > > > > 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 > > > @is_attach_deferred > > > > Could attach_dev() be an IOMMU op? So a driver could set the domain ops > > in attach_dev() rather than domain_alloc(). That would allow to install > > map()/unmap() ops that are tailored for the device's IOMMU, which we don't > > know at domain_alloc() time. > > I think we should be moving toward 'domain_alloc' returning the > correct domain and the way the driver implements the domain shouldn't > change after that. > > > I'm thinking about a guest that has both physical and virtual > > endpoints, which would ideally use different kinds of domain ops to > > support both efficiently (caching mode vs page tables) > > In this case shouldn't domain_alloc() reached from the struct device > already do the correct thing?
Sure, if we can finalise the domains before attach that could also clean up the drivers a bit. Thanks, Jean _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
