> From: Alex Williamson [mailto:alex.william...@redhat.com] > Sent: Monday, October 24, 2016 10:32 AM > > > >> -static long vfio_unpin_pages(unsigned long pfn, long npage, > > >> - int prot, bool do_accounting) > > >> +static long __vfio_unpin_pages_remote(struct vfio_iommu *iommu, > > >> + unsigned long pfn, long npage, > > >> int prot, > > >> + bool do_accounting) > > > > > > Have you noticed that it's kind of confusing that > > > __vfio_{un}pin_pages_remote() uses current, which does a > > > get_user_pages_fast() while "local" uses a provided task_struct and > > > uses get_user_pages_*remote*()? And also what was effectively local > > > (ie. we're pinning for our own use here) is now "remote" and pinning > > > for a remote, vendor driver consumer, is now "local". It's not very > > > intuitive. > > >
I questioned this confusing naming in v8 too... > > > > 'local' in local_domain was suggested to describe the domain for local > > page tracking. Earlier suggestions to have 'mdev' or 'noimmu' in this > > name were discarded. May be we should revisit what the name should be. > > Any suggestion? > > > > For local_domain, to pin pages, flow is: > > > > for local_domain > > |- vfio_pin_pages() > > |- vfio_iommu_type1_pin_pages() > > |- __vfio_pin_page_local() > > |- vaddr_get_pfn(task->mm) > > |- get_user_pages_remote() > > > > __vfio_pin_page_local() --> get_user_pages_remote() > > > In vfio.c we have the concept of an external user, perhaps that could > be continued here. An mdev driver would be an external, or remote > pinning. > I prefer to use remote here. It's aligned with underlying mm operations Thanks Kevin
