xref: /dpdk/doc/guides/rel_notes/deprecation.rst (revision 4aa10e5dc1b0fd6cc5b1b18770ac603e2c33a66c)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright 2018 The DPDK contributors
3
4ABI and API Deprecation
5=======================
6
7See the guidelines document for details of the :doc:`ABI policy
8<../contributing/abi_policy>`. API and ABI deprecation notices are to be posted
9here.
10
11Deprecation Notices
12-------------------
13
14* kvargs: The function ``rte_kvargs_process`` will get a new parameter
15  for returning key match count. It will ease handling of no-match case.
16
17* telemetry: The functions ``rte_tel_data_add_array_u64`` and ``rte_tel_data_add_dict_u64``,
18  used by telemetry callbacks for adding unsigned integer values to be returned to the user,
19  are renamed to ``rte_tel_data_add_array_uint`` and ``rte_tel_data_add_dict_uint`` respectively.
20  As such, the old function names are deprecated and will be removed in a future release.
21
22* eal: RTE_FUNC_PTR_OR_* macros have been marked deprecated and will be removed
23  in the future. Applications can use ``devtools/cocci/func_or_ret.cocci``
24  to update their code.
25
26* eal: The functions ``rte_thread_setname`` and ``rte_ctrl_thread_create``
27  are planned to be deprecated starting with the 23.07 release, subject to
28  the replacement API rte_thread_set_name and rte_thread_create_control being
29  marked as stable, and planned to be removed by the 23.11 release.
30
31* rte_atomicNN_xxx: These APIs do not take memory order parameter. This does
32  not allow for writing optimized code for all the CPU architectures supported
33  in DPDK. DPDK has adopted the atomic operations from
34  https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. These
35  operations must be used for patches that need to be merged in 20.08 onwards.
36  This change will not introduce any performance degradation.
37
38* rte_smp_*mb: These APIs provide full barrier functionality. However, many
39  use cases do not require full barriers. To support such use cases, DPDK has
40  adopted atomic operations from
41  https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. These
42  operations and a new wrapper ``rte_atomic_thread_fence`` instead of
43  ``__atomic_thread_fence`` must be used for patches that need to be merged in
44  20.08 onwards. This change will not introduce any performance degradation.
45
46* kni: The KNI kernel module and library are not recommended for use by new
47  applications - other technologies such as virtio-user are recommended instead.
48  Following the DPDK technical board
49  `decision <https://mails.dpdk.org/archives/dev/2021-January/197077.html>`_
50  and `refinement <https://mails.dpdk.org/archives/dev/2022-June/243596.html>`_,
51  the KNI kernel module, library and PMD will be removed from the DPDK 23.11 release.
52
53* lib: will fix extending some enum/define breaking the ABI. There are multiple
54  samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is
55  used by iterators, and arrays holding these values are sized with this
56  ``.*MAX.*`` value. So extending this enum/define increases the ``.*MAX.*``
57  value which increases the size of the array and depending on how/where the
58  array is used this may break the ABI.
59  ``RTE_ETH_FLOW_MAX`` is one sample of the mentioned case, adding a new flow
60  type will break the ABI because of ``flex_mask[RTE_ETH_FLOW_MAX]`` array
61  usage in following public struct hierarchy:
62  ``rte_eth_fdir_flex_conf -> rte_eth_fdir_conf -> rte_eth_conf (in the middle)``.
63  Need to identify this kind of usages and fix in 20.11, otherwise this blocks
64  us extending existing enum/define.
65  One solution can be using a fixed size array instead of ``.*MAX.*`` value.
66
67* ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
68  should start with relevant protocol header structure from lib/net/.
69  The individual protocol header fields and the protocol header struct
70  may be kept together in a union as a first migration step.
71  In future (target is DPDK 23.11), the protocol header fields will be cleaned
72  and only protocol header struct will remain.
73
74  These items are not compliant (not including struct from lib/net/):
75
76  - ``rte_flow_item_ah``
77  - ``rte_flow_item_e_tag``
78  - ``rte_flow_item_geneve``
79  - ``rte_flow_item_geneve_opt``
80  - ``rte_flow_item_gre``
81  - ``rte_flow_item_icmp6``
82  - ``rte_flow_item_icmp6_nd_na``
83  - ``rte_flow_item_icmp6_nd_ns``
84  - ``rte_flow_item_icmp6_nd_opt``
85  - ``rte_flow_item_icmp6_nd_opt_sla_eth``
86  - ``rte_flow_item_icmp6_nd_opt_tla_eth``
87  - ``rte_flow_item_igmp``
88  - ``rte_flow_item_ipv6_ext``
89  - ``rte_flow_item_l2tpv3oip``
90  - ``rte_flow_item_mpls``
91  - ``rte_flow_item_nsh``
92  - ``rte_flow_item_nvgre``
93  - ``rte_flow_item_pfcp``
94  - ``rte_flow_item_pppoe``
95  - ``rte_flow_item_pppoe_proto_id``
96
97* ethdev: Queue specific stats fields will be removed from ``struct rte_eth_stats``.
98  Mentioned fields are: ``q_ipackets``, ``q_opackets``, ``q_ibytes``, ``q_obytes``,
99  ``q_errors``.
100  Instead queue stats will be received via xstats API. Current method support
101  will be limited to maximum 256 queues.
102  Also compile time flag ``RTE_ETHDEV_QUEUE_STAT_CNTRS`` will be removed.
103
104* ethdev: Flow actions ``PF`` and ``VF`` have been deprecated since DPDK 21.11
105  and are yet to be removed. That still has not happened because there are net
106  drivers which support combined use of either action ``PF`` or action ``VF``
107  with action ``QUEUE``, namely, i40e, ixgbe and txgbe (L2 tunnel rule).
108  It is unclear whether it is acceptable to just drop support for
109  such a complex use case, so maintainers of the said drivers
110  should take a closer look at this and provide assistance.
111
112* ethdev: Actions ``OF_DEC_NW_TTL``, ``SET_IPV4_SRC``, ``SET_IPV4_DST``,
113  ``SET_IPV6_SRC``, ``SET_IPV6_DST``, ``SET_TP_SRC``, ``SET_TP_DST``,
114  ``DEC_TTL``, ``SET_TTL``, ``SET_MAC_SRC``, ``SET_MAC_DST``, ``INC_TCP_SEQ``,
115  ``DEC_TCP_SEQ``, ``INC_TCP_ACK``, ``DEC_TCP_ACK``, ``SET_IPV4_DSCP``,
116  ``SET_IPV6_DSCP``, ``SET_TAG``, ``SET_META`` are marked as legacy and
117  superseded by the generic ``RTE_FLOW_ACTION_TYPE_MODIFY_FIELD``.
118  The legacy actions should be removed
119  once ``MODIFY_FIELD`` alternative is implemented in drivers.
120
121* cryptodev: The function ``rte_cryptodev_cb_fn`` will be updated
122  to have another parameter ``qp_id`` to return the queue pair ID
123  which got error interrupt to the application,
124  so that application can reset that particular queue pair.
125
126* cryptodev: The arrays of algorithm strings ``rte_crypto_cipher_algorithm_strings``,
127  ``rte_crypto_auth_algorithm_strings``, ``rte_crypto_aead_algorithm_strings`` and
128  ``rte_crypto_asym_xform_strings`` are deprecated and will be removed in DPDK 23.11.
129  Application can use the new APIs ``rte_cryptodev_get_cipher_algo_string``,
130  ``rte_cryptodev_get_auth_algo_string``, ``rte_cryptodev_get_aead_algo_string`` and
131  ``rte_cryptodev_asym_get_xform_string`` respectively.
132
133* flow_classify: The flow_classify library and example have no maintainer.
134  The library is experimental and, as such, it could be removed from DPDK.
135  Its removal has been postponed to let potential users report interest
136  in maintaining it.
137  In the absence of such interest, this library will be removed in DPDK 23.11.
138