On Tue, 18 Apr 2023 10:19:39 +0800 Xuan Zhuo wrote: > > Can we not push this down to be bus level? virtio has its own bus it > > can plug in whatever magic it wants into dma ops. > > It is actually not possible. > > [1] https://lore.kernel.org/virtualization/ZDUCDeYLqAwQVJe7@xxxxxxxxxxxxx/ Maybe Christoph, or Greg can comment. AF_XDP, io_uring, and increasing number of pinned memory / zero copy implementations need to do DMA mapping outside the drivers. 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. > > Otherwise it really seems like we're bubbling up a virtio hack into > > generic code :( > > Can we understand the purpose of this matter to back the DMA operation to the > driver? We understand what your code does.
