On Tue, Jan 09, 2018 at 05:46:40PM +0100, Christoph Hellwig wrote: > On Mon, Jan 08, 2018 at 12:49:50PM -0700, Jason Gunthorpe wrote: > > Pretty sure P2P capable IOMMU hardware exists. > > > > With SOC's we also have the scenario that an DMA originated from an > > on-die device wishes to target an off-die PCI BAR (through the IOMMU), > > that definitely exists today, and people care about it :) > > Then people will have to help and contribute support for it. Sure. But my point was all this will have to migrate under the dma_ops for that to work, so why the resistance to using dma_ops right away? Jason