On Fri, Mar 22, 2024 at 10:40:26AM -0700, Mina Almasry wrote: > Hi Christoph, > > Sorry for the late reply, I've been out for a few days. > > On Mon, Mar 18, 2024 at 4:22 PM Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > > > On Sun, Mar 17, 2024 at 07:49:43PM -0700, David Wei wrote: > > > I'm working on a similar proposal for zero copy Rx but to host memory > > > and depend on this memory provider API. > > > > How do you need a different provider for that vs just udmabuf? > > > > This was discussed on the io_uring ZC RFC in one of the earliest RFCs. > Here is a link to Pavel's response: > > https://patchwork.kernel.org/project/netdevbpf/patch/20231106024413.2801438-6-almasrymina@xxxxxxxxxx/#25589471 Undesirable is not a good argument. We need one proper API that different subsystems share for this use case (this is the same Feedback I gave Keith for the similar block proposal btw, not picking on the net folks here). If dmabuf/udmabuf doesn't work for that we need to enhance or replace it, but not come up with little subsystem specific side channels.