On Thu, Jul 20, 2023 at 03:41:56PM +0800, Jason Wang wrote: > > Did you actually check that it works though? > > Looks like with swiotlb you need to synch to trigger a copy > > before unmap, and I don't see where it's done in the current > > patch. > > And this is needed for XDP_REDIRECT as well. DMA always needs proper syncs, be that for swiotlb or for cache maintainance, yes.