Re: [PATCH 06/12] IB/core: Add optional PCI P2P flag to rdma_rw_ctx_[init|destroy]()

From: Jason Gunthorpe
Date: Tue Jan 09 2018 - 12:10:41 EST


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