On Mon, Nov 02, 2020 at 11:52:56AM -0400, Jason Gunthorpe wrote: > Need to hold the lock to check that and there are two ways to register > notifiers these days, so it feels to expensive to me. > > CH's 'export symbol only for kvm' really does seem the most robust way > to handle this though. I hope I can get that done for this merge window, but I'm not sure. I still think we should at least have a new name for the old follow_pfn that no one should use. And it should sound more scary than unsafe_follow_pfn :)