Re: [Linaro-mm-sig] [PATCH v8 06/11] dma-buf: provide phys_vec to scatter-gather mapping routine

Jason Gunthorpe
2025-11-20T13:20:48Z

On Thu, Nov 20, 2025 at 08:08:27AM +0100, Christian König wrote:
> >> The exporter should be able to decide if it actually wants to use
> >> P2P when the transfer has to go through the host bridge (e.g. when
> >> IOMMU/bridge routing bits are enabled).
> >
> > Sure, but this is a simplified helper for exporters that don't have
> > choices where the memory comes from.
>
> That is extremely questionable as justification to put that in common DMA-buf code.

FWIW we already have patches for a RDMA exporter lined up to use it as
well. That's two users already...

Jason