[PATCH V11 00/19] virtio_ring in order support

[Jason Wang <jasowang@redhat.com>]

Hello all:

This sereis tries to implement the VIRTIO_F_IN_ORDER to
virtio_ring. This is done by introducing virtqueue ops so we can
implement separate helpers for different virtqueue layout/features
then the in-order were implemented on top.

Tests shows 2%-19% imporvment with packed virtqueue PPS with KVM guest
vhost-net/testpmd on the host.

Changes since v10:

- Add comment to explain the total_in_len
- Tweak the VIRTQUEUE_CALL/VOID_VIRTQUEUE_CALL to use temporary
  instead of evaluating vq multiple times
- Rewind avail_wrap_counter on failure in virtqueue_add_packed_in_order()
- Fix coding style issues

Changes sinve v9:

- Fix the total_len calcuation and count only in buffer length
- Fix the comment for the condtiion when batching is not detected

Changes since v8:

- Rebase to vhost.git linux-next branch
- Fix issue when indirect descriptor is disabled
- use UINT_MAX instead of vq->num to indicate no batching is pending
- Tweak the comments for used_entry
- Various coding style tweaks and typo fixes
- Try to use in_order varianet in in_order ops

Changes since v7:

- Rebase on vhost.git linux-next branch
- Tweak the comment to explain the usage of free_head

Changes since v6:

- Rebase on vhost.git linux-next branch
- Fix poking packed virtqueue in more_used_split_in_order()
- Fix calling detach_buf_packed_in_order() unconditonally in
  virtqueue_detach_unused_buf_packed()
- Typo and indentation fixes
- Fix wrong changelog of patch 7

Changes since v5:

- rebase on vhost.git linux-next branch
- reorder the total_len to reduce memory comsuming

Changes since v4:

- Fix build error when DEBUG is enabled
- Fix function duplications
- Remove unnecessary new lines

Changes since v3:

- Re-benchmark with the recent vhost-net in order support
- Rename the batched used id and length
- Other minor tweaks

Changes since v2:

- Fix build warning when DEBUG is enabled

Changes since v1:

- use const global array of function pointers to avoid indirect
  branches to eliminate retpoline when mitigation is enabled
- fix used length calculation when processing used ids in a batch
- fix sparse warnings

Jason Wang (19):
  virtio_ring: rename virtqueue_reinit_xxx to virtqueue_reset_xxx()
  virtio_ring: switch to use vring_virtqueue in virtqueue_poll variants
  virtio_ring: unify logic of virtqueue_poll() and more_used()
  virtio_ring: switch to use vring_virtqueue for virtqueue resize
    variants
  virtio_ring: switch to use vring_virtqueue for virtqueue_kick_prepare
    variants
  virtio_ring: switch to use vring_virtqueue for virtqueue_add variants
  virtio: switch to use vring_virtqueue for virtqueue_get variants
  virtio_ring: switch to use vring_virtqueue for enable_cb_prepare
    variants
  virtio_ring: use vring_virtqueue for enable_cb_delayed variants
  virtio_ring: switch to use vring_virtqueue for disable_cb variants
  virtio_ring: switch to use vring_virtqueue for detach_unused_buf
    variants
  virtio_ring: switch to use unsigned int for virtqueue_poll_packed()
  virtio_ring: introduce virtqueue ops
  virtio_ring: determine descriptor flags at one time
  virtio_ring: factor out core logic of buffer detaching
  virtio_ring: factor out core logic for updating last_used_idx
  virtio_ring: factor out split indirect detaching logic
  virtio_ring: factor out split detaching logic
  virtio_ring: add in order support

 drivers/virtio/virtio_ring.c | 928 +++++++++++++++++++++++++++--------
 1 file changed, 713 insertions(+), 215 deletions(-)

-- 
2.31.1