On Wed, Oct 23, 2024 at 03:34:53PM +0100, Pavel Begunkov wrote: > It doesn't care much what kind of memory it is, nor it's important > for internals how it's imported, it's user addresses -> pages for > user convenience sake. All the net_iov setup code is in the page pool > core code. What it does, however, is implementing the user API, so That's not what this series does. It adds the new memory_provider_ops set of hooks, with once implementation for dmabufs, and one for io_uring zero copy. So you are precluding zero copy RX into anything but your magic io_uring buffers, and using an odd abstraction for that. The right way would be to support zero copy RX into every designated dmabuf, and make io_uring work with udmabuf or if absolutely needed it's own kind of dmabuf. Instead we create a maze of incompatible abstractions here. The use case of e.g. doing zero copy receive into a NVMe CMB using PCIe P2P transactions is every but made up, so this does create a problem.
