On Thu, Apr 16, 2020 at 10:54:02AM +0200, Jean-Philippe Brucker wrote: > On Thu, Apr 16, 2020 at 12:28:52AM -0700, Christoph Hellwig wrote: > > > + rcu_read_lock(); > > > + hlist_for_each_entry_rcu(bond, &io_mm->devices, mm_node) > > > + io_mm->ops->invalidate(bond->sva.dev, io_mm->pasid, io_mm->ctx, > > > + start, end - start); > > > + rcu_read_unlock(); > > > +} > > > > What is the reason that the devices don't register their own notifiers? > > This kinds of multiplexing is always rather messy, and you do it for > > all the methods. > > This sends TLB and ATC invalidations through the IOMMU, it doesn't go > through device drivers I don't think we mean the same thing, probably because of my rather imprecise use of the word device. What I mean is that the mmu_notifier should not be embedded into the io_mm structure (whch btw, seems to have a way to generic name, just like all other io_* prefixed names), but instead into the iommu_bond structure. That avoid the whole multiplexing layer.