[dpdk-dev] [RFC 0/7] hide eth dev related structures

[Konstantin Ananyev <konstantin.ananyev@intel.com>]

NOTE: This is just an RFC to start further discussion and collect the feedback.
Due to significant amount of work, changes required are applied only to two
PMDs so far: net/i40e and net/ice.
So to build it you'll need to add:
-Denable_drivers='common/*,mempool/*,net/ice,net/i40e'
to your config options. 

The aim of these patch series is to make rte_ethdev core data structures
(rte_eth_dev, rte_eth_dev_data, rte_eth_rxtx_callback, etc.) internal to DPDK
and not visible to the user.
That should allow future possible changes to core ethdev related structures
to be transparent to the user and help to improve ABI/API stability.
Note that current ethdev API is preserved, though it is an ABI break for sure.

The work is based on previous discussion at:
https://www.mail-archive.com/dev@dpdk.org/msg211405.html
and consists of the following main points:
1. Move public 'fast' function pointers (rx_pkt_burst(), etc.) from
   rte_eth_dev into a separate flat array. We keep it public to still be
   able to use inline functions for these 'fast' calls
   (like rte_eth_rx_burst(), etc.) to avoid/minimize slowdown.
2. Change prototype within PMDs for these 'fast' functions
   (pkt_rx_burst(), etc.) to accept pair of <port_id, queue_id>
   instead of queue pointer.
3. Also some mechanical changes in function start/finish code is required.
   Basically to avoid extra level of indirection - PMD required to do some
   preliminary checks and data retrieval that are currently done at user level
   by inline rte_eth* functions. 
4. Special _rte_eth_*_prolog(/epilog) inline functions and helper macros
   are provided to make these changes inside PMDs as straightforward
   as possible.
5. Change implementation of 'fast' ethdev functions (rte_eth_rx_burst(), etc.)
   to use new public flat array. 
6. Move rte_eth_dev, rte_eth_dev_data, rte_eth_rxtx_callback and related things
   into internal header: <ethdev_driver.h>.

That approach was selected to avoid(/minimize) possible performance losses.
 
So far I done only limited amount functional and performance testing.
Didn't spot any functional problems, and performance numbers
remains the same before and after the patch on my box (testpmd, macswap fwd).

Remaining items:
==============
- implement required changes for all PMD at drivers/net.
  So far I done changes only for two drivers, and definitely would use some
  help from other PMD maintainers. Required changes are mechanical,
  but we have a lot of drivers these days.
- <rte_bus_pci.h> contains reference to rte_eth_dev field
  RTE_ETH_DEV_TO_PCI(eth_dev).
  Need to move this macro into some internal header.
- Extra testing
- checkpatch warnings
- docs update

Konstantin Ananyev (7):
  eth: move ethdev 'burst' API into separate structure
  eth: make drivers to use new API for Rx
  eth: make drivers to use new API for Tx
  eth: make drivers to use new API for Tx prepare
  eth: make drivers to use new API to obtain descriptor status
  eth: make drivers to use new API for Rx queue count
  eth: hide eth dev related structures

 app/test-pmd/config.c                         |  23 +-
 app/test/virtual_pmd.c                        |  27 +-
 drivers/common/octeontx2/otx2_sec_idev.c      |   2 +-
 drivers/crypto/octeontx2/otx2_cryptodev_ops.c |   2 +-
 drivers/net/i40e/i40e_ethdev.c                |  15 +-
 drivers/net/i40e/i40e_ethdev_vf.c             |  15 +-
 drivers/net/i40e/i40e_rxtx.c                  | 243 ++++---
 drivers/net/i40e/i40e_rxtx.h                  |  68 +-
 drivers/net/i40e/i40e_rxtx_vec_avx2.c         |  11 +-
 drivers/net/i40e/i40e_rxtx_vec_avx512.c       |  12 +-
 drivers/net/i40e/i40e_rxtx_vec_sse.c          |   8 +-
 drivers/net/i40e/i40e_vf_representor.c        |  10 +-
 drivers/net/ice/ice_dcf_ethdev.c              |  10 +-
 drivers/net/ice/ice_dcf_vf_representor.c      |  10 +-
 drivers/net/ice/ice_ethdev.c                  |  15 +-
 drivers/net/ice/ice_rxtx.c                    | 236 ++++---
 drivers/net/ice/ice_rxtx.h                    |  73 +--
 drivers/net/ice/ice_rxtx_vec_avx2.c           |  24 +-
 drivers/net/ice/ice_rxtx_vec_avx512.c         |  24 +-
 drivers/net/ice/ice_rxtx_vec_common.h         |   7 +-
 drivers/net/ice/ice_rxtx_vec_sse.c            |  12 +-
 lib/ethdev/ethdev_driver.h                    | 601 ++++++++++++++++++
 lib/ethdev/ethdev_private.c                   |  74 +++
 lib/ethdev/ethdev_private.h                   |   3 +
 lib/ethdev/rte_ethdev.c                       | 176 ++++-
 lib/ethdev/rte_ethdev.h                       | 194 ++----
 lib/ethdev/rte_ethdev_core.h                  | 182 ++----
 lib/ethdev/version.map                        |  16 +
 lib/eventdev/rte_event_eth_rx_adapter.c       |   2 +-
 lib/eventdev/rte_event_eth_tx_adapter.c       |   2 +-
 lib/eventdev/rte_eventdev.c                   |   2 +-
 31 files changed, 1488 insertions(+), 611 deletions(-)

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2.26.3