[dpdk-dev] [PATCH v9 0/8] implement packed virtqueues

[Jens Freimann <jfreimann@redhat.com>]

This is a basic implementation of packed virtqueues as specified in the
Virtio 1.1 draft. A compiled version of the current draft is available
at https://github.com/oasis-tcs/virtio-docs.git (or as .pdf at
https://github.com/oasis-tcs/virtio-docs/blob/master/virtio-v1.1-packed-wd10.pdf

A packed virtqueue is different from a split virtqueue in that it
consists of only a single descriptor ring that replaces available and
used ring, index and descriptor pointers.

Each descriptor is readable and writable and has a flags field. These flags
will mark if a descriptor is available or used.  To detect new available descriptors
even after the ring has wrapped, device and driver each have a
single-bit wrap counter that is flipped from 0 to 1 and vice versa every time
the last descriptor in the ring is used/made available.

v8-v9:
 * fix virtio_ring_free_chain_packed() to handle descriptors
   correctly in case of out-of-order
 * fix check in virtqueue_xmit_cleanup_packed() to improve performance

v7->v8:
 * move desc_is_used change to correct patch
 * remove trailing newline
 * correct xmit code, flags update and memory barrier
 * move packed desc init to dedicated function, split
   and packed variant


Jens Freimann (8):
  net/virtio: vring init for packed queues
  net/virtio: add packed virtqueue defines
  net/virtio: add packed virtqueue helpers
  net/virtio: dump packed virtqueue data
  net/virtio: implement transmit path for packed queues
  net/virtio: implement receive path for packed queues
  net/virtio: add virtio send command packed queue support
  net/virtio: enable packed virtqueues by default

 drivers/net/virtio/virtio_ethdev.c | 154 ++++++--
 drivers/net/virtio/virtio_ethdev.h |   5 +
 drivers/net/virtio/virtio_pci.h    |   7 +
 drivers/net/virtio/virtio_ring.h   | 105 +++++-
 drivers/net/virtio/virtio_rxtx.c   | 560 +++++++++++++++++++++++++++--
 drivers/net/virtio/virtqueue.c     |  22 ++
 drivers/net/virtio/virtqueue.h     |  42 ++-
 7 files changed, 841 insertions(+), 54 deletions(-)

-- 
2.17.1