On Mon, Apr 17, 2023 at 07:54:00PM -0700, Jakub Kicinski wrote: > AF_XDP, io_uring, and increasing number of pinned memory / zero copy > implementations need to do DMA mapping outside the drivers. You can't just do dma mapping outside the driver, because there are drivers that do not require DMA mapping at all. virtio is an example, but all the classic s390 drivers and some other odd virtualization ones are others. > I don't think it's reasonable to be bubbling up custom per-subsystem > DMA ops into all of them for the sake of virtio. dma addresses and thus dma mappings are completely driver specific. Upper layers have no business looking at them.
