On Wed, Jan 30, 2019 at 01:50:27PM -0500, Jerome Glisse wrote: > I do not see how VMA changes are any different than using struct page > in respect to userspace exposure. Those vma callback do not need to be > set by everyone, in fact expectation is that only handful of driver > will set those. > > How can we do p2p between RDMA and GPU for instance, without exposure > to userspace ? At some point you need to tell userspace hey this kernel > does allow you to do that :) To do RDMA on a memory region you need struct page backіng to start with..
