1 .. SPDX-License-Identifier: BSD-3-Clause
2 Copyright 2018 The DPDK contributors
4 ABI and API Deprecation
5 =======================
7 See the guidelines document for details of the :doc:`ABI policy
8 <../contributing/abi_policy>`. API and ABI deprecation notices are to be posted
14 * meson: The minimum supported version of meson for configuring and building
15 DPDK will be increased to v0.47.1 (from 0.41) from DPDK 19.05 onwards. For
16 those users with a version earlier than 0.47.1, an updated copy of meson
17 can be got using the ``pip``, or ``pip3``, tool for downloading python
20 * kvargs: The function ``rte_kvargs_process`` will get a new parameter
21 for returning key match count. It will ease handling of no-match case.
23 * eal: The function ``rte_eal_remote_launch`` will return new error codes
24 after read or write error on the pipe, instead of calling ``rte_panic``.
26 * eal: both declaring and identifying devices will be streamlined in v18.11.
27 New functions will appear to query a specific port from buses, classes of
28 device and device drivers. Device declaration will be made coherent with the
29 new scheme of device identification.
30 As such, ``rte_devargs`` device representation will change.
32 - The enum ``rte_devtype`` was used to identify a bus and will disappear.
33 - Functions previously deprecated will change or disappear:
35 + ``rte_eal_devargs_type_count``
37 * eal: The ``rte_logs`` struct and global symbol will be made private to
38 remove it from the externally visible ABI and allow it to be updated in the
41 * rte_atomicNN_xxx: These APIs do not take memory order parameter. This does
42 not allow for writing optimized code for all the CPU architectures supported
43 in DPDK. DPDK will adopt C11 atomic operations semantics and provide wrappers
44 using C11 atomic built-ins. These wrappers must be used for patches that
45 need to be merged in 20.08 onwards. This change will not introduce any
46 performance degradation.
48 * rte_smp_*mb: These APIs provide full barrier functionality. However, many
49 use cases do not require full barriers. To support such use cases, DPDK will
50 adopt C11 barrier semantics and provide wrappers using C11 atomic built-ins.
51 These wrappers must be used for patches that need to be merged in 20.08
52 onwards. This change will not introduce any performance degradation.
54 * igb_uio: In the view of reducing the kernel dependency from the main tree,
55 as a first step, the Technical Board decided to move ``igb_uio``
56 kernel module to the dpdk-kmods repository in the /linux/igb_uio/ directory
58 Minutes of Technical Board Meeting of `2019-11-06
59 <https://mails.dpdk.org/archives/dev/2019-November/151763.html>`_.
61 * lib: will fix extending some enum/define breaking the ABI. There are multiple
62 samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is
63 used by iterators, and arrays holding these values are sized with this
64 ``.*MAX.*`` value. So extending this enum/define increases the ``.*MAX.*``
65 value which increases the size of the array and depending on how/where the
66 array is used this may break the ABI.
67 ``RTE_ETH_FLOW_MAX`` is one sample of the mentioned case, adding a new flow
68 type will break the ABI because of ``flex_mask[RTE_ETH_FLOW_MAX]`` array
69 usage in following public struct hierarchy:
70 ``rte_eth_fdir_flex_conf -> rte_fdir_conf -> rte_eth_conf (in the middle)``.
71 Need to identify this kind of usages and fix in 20.11, otherwise this blocks
72 us extending existing enum/define.
73 One solution can be using a fixed size array instead of ``.*MAX.*`` value.
75 * ethdev: Split the ``struct eth_dev_ops`` struct to hide it as much as possible
76 will be done in 20.11.
77 Currently the ``struct eth_dev_ops`` struct is accessible by the application
78 because some inline functions, like ``rte_eth_tx_descriptor_status()``,
79 access the struct directly.
80 The struct will be separate in two, the ops used by inline functions will be
81 moved next to Rx/Tx burst functions, rest of the ``struct eth_dev_ops`` struct
82 will be moved to header file for drivers to hide it from applications.
84 * ethdev: the legacy filter API, including
85 ``rte_eth_dev_filter_supported()``, ``rte_eth_dev_filter_ctrl()`` as well
86 as filter types MACVLAN, ETHERTYPE, FLEXIBLE, SYN, NTUPLE, TUNNEL, FDIR,
87 HASH and L2_TUNNEL, is superseded by the generic flow API (rte_flow) in
88 PMDs that implement the latter.
89 Target release for removal of the legacy API will be defined once most
90 PMDs have switched to rte_flow.
92 * ethdev: Update API functions returning ``void`` to return ``int`` with
93 negative errno values to indicate various error conditions (e.g.
94 invalid port ID, unsupported operation, failed operation):
96 - ``rte_eth_dev_stop``
97 - ``rte_eth_dev_close``
99 * ethdev: New offload flags ``DEV_RX_OFFLOAD_FLOW_MARK`` will be added in 19.11.
100 This will allow application to enable or disable PMDs from updating
101 ``rte_mbuf::hash::fdir``.
102 This scheme will allow PMDs to avoid writes to ``rte_mbuf`` fields on Rx and
103 thereby improve Rx performance if application wishes do so.
104 In 19.11 PMDs will still update the field even when the offload is not
107 * ethdev: ``rx_descriptor_done`` dev_ops and ``rte_eth_rx_descriptor_done``
108 will be deprecated in 20.11 and will be removed in 21.11.
109 Existing ``rte_eth_rx_descriptor_status`` and ``rte_eth_tx_descriptor_status``
110 APIs can be used as replacement.
112 * traffic manager: All traffic manager API's in ``rte_tm.h`` were mistakenly made
113 ABI stable in the v19.11 release. The TM maintainer and other contributors have
114 agreed to keep the TM APIs as experimental in expectation of additional spec
115 improvements. Therefore, all APIs in ``rte_tm.h`` will be marked back as
116 experimental in v20.11 DPDK release. For more details, please see `the thread
117 <https://mails.dpdk.org/archives/dev/2020-April/164970.html>`_.
119 * cryptodev: support for using IV with all sizes is added, J0 still can
120 be used but only when IV length in following structs ``rte_crypto_auth_xform``,
121 ``rte_crypto_aead_xform`` is set to zero. When IV length is greater or equal
122 to one it means it represents IV, when is set to zero it means J0 is used
123 directly, in this case 16 bytes of J0 need to be passed.
125 * sched: To allow more traffic classes, flexible mapping of pipe queues to
126 traffic classes, and subport level configuration of pipes and queues
127 changes will be made to macros, data structures and API functions defined
128 in "rte_sched.h". These changes are aligned to improvements suggested in the
129 RFC https://mails.dpdk.org/archives/dev/2018-November/120035.html.
131 * metrics: The function ``rte_metrics_init`` will have a non-void return
132 in order to notify errors instead of calling ``rte_exit``.
134 * power: ``rte_power_set_env`` function will no longer return 0 on attempt
135 to set new power environment if power environment was already initialized.
136 In this case the function will return -1 unless the environment is unset first
137 (using ``rte_power_unset_env``). Other function usage scenarios will not change.
139 * python: Since the beginning of 2020, Python 2 has officially reached
140 end-of-support: https://www.python.org/doc/sunset-python-2/.
141 Python 2 support will be completely removed in 20.11.
142 In 20.08, explicit deprecation warnings will be displayed when running
143 scripts with Python 2.