[PATCH v4 0/6] zcrx huge pages support Vol 1

[Pavel Begunkov <asml.silence@gmail.com>]

Use sgtable as the common format b/w dmabuf and user pages, deduplicate
dma address propagation handling, and use it to omptimise dma mappings.
It also prepares it for larger size for NIC pages.

v4: further restrict kmap fallback length, v3 isn't be generic
    enough to cover future uses.

v3: truncate kmap'ed length by both pages

v2: Don't coalesce into folios, just use sg_alloc_table_from_pages()
    for now. Coalescing will return back later.

    Improve some fallback copy code. Patch 1, and Patch 6 adding a
    helper to work with larger pages, which also allows to get rid
    of skb_frag_foreach_page.

    Return copy fallback helpers back to pages instead of folios,
    the latter wouldn't be correct in all cases.

Pavel Begunkov (6):
  io_uring/zcrx: always pass page to io_zcrx_copy_chunk
  io_uring/zcrx: return error from io_zcrx_map_area_*
  io_uring/zcrx: introduce io_populate_area_dma
  io_uring/zcrx: allocate sgtable for umem areas
  io_uring/zcrx: assert area type in io_zcrx_iov_page
  io_uring/zcrx: prepare fallback for larger pages

 io_uring/zcrx.c | 241 +++++++++++++++++++++++++-----------------------
 io_uring/zcrx.h |   1 +
 2 files changed, 128 insertions(+), 114 deletions(-)

-- 
2.49.0