virtqueue_add() only supports virtual addresses, dma is completed in
virtqueue_add().

In some scenarios (such as the AF_XDP scenario), DMA is completed in advance, so
it is necessary for us to support passing the DMA address to virtqueue_add().

v2:
    1. rename predma -> premapped
    2. virtio net xdp tx use virtio dma api

v1:
   1. All sgs requested at one time are required to be unified PREDMA, and several
      of them are not supported to be PREDMA
   2. virtio_dma_map() is removed from this patch set and will be submitted
      together with the next time AF_XDP supports virtio dma
   3. Added patch #2 #3 to remove the check for flags when performing unmap
      indirect desc

Xuan Zhuo (9):
  virtio_ring: rename vring_unmap_state_packed() to
    vring_unmap_extra_packed()
  virtio_ring: remove flags check for unmap split indirect desc
  virtio_ring: remove flags check for unmap packed indirect desc
  virtio_ring: virtqueue_add() support premapped
  virtio_ring: split: virtqueue_add_split() support premapped
  virtio_ring: packed: virtqueue_add_packed() support premapped
  virtio_ring: add api virtio_dma_map() for advance dma
  virtio_ring: introduce virtqueue_add_outbuf_premapped()
  virtio_net: xdp xmit use virtio dma api

 drivers/net/virtio_net.c     |  42 +++++-
 drivers/virtio/virtio_ring.c | 280 ++++++++++++++++++++++++++---------
 include/linux/virtio.h       |  12 ++
 3 files changed, 254 insertions(+), 80 deletions(-)

--
2.31.0