xref: /dpdk/doc/guides/rel_notes/deprecation.rst (revision 3a80d7fb2ecdd6e8e48e56e3726b26980fa2a089)
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* eal: RTE_FUNC_PTR_OR_* macros have been marked deprecated and will be removed
18  in the future. Applications can use ``devtools/cocci/func_or_ret.cocci``
19  to update their code.
20
21* rte_atomicNN_xxx: These APIs do not take memory order parameter. This does
22  not allow for writing optimized code for all the CPU architectures supported
23  in DPDK. DPDK has adopted the atomic operations from
24  https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. These
25  operations must be used for patches that need to be merged in 20.08 onwards.
26  This change will not introduce any performance degradation.
27
28* rte_smp_*mb: These APIs provide full barrier functionality. However, many
29  use cases do not require full barriers. To support such use cases, DPDK has
30  adopted atomic operations from
31  https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. These
32  operations and a new wrapper ``rte_atomic_thread_fence`` instead of
33  ``__atomic_thread_fence`` must be used for patches that need to be merged in
34  20.08 onwards. This change will not introduce any performance degradation.
35
36* kni: The KNI kernel module and library are not recommended for use by new
37  applications - other technologies such as virtio-user are recommended instead.
38  Following the DPDK technical board
39  `decision <https://mails.dpdk.org/archives/dev/2021-January/197077.html>`_
40  and `refinement <https://mails.dpdk.org/archives/dev/2022-June/243596.html>`_,
41  the KNI kernel module, library and PMD will be removed from the DPDK 23.11 release.
42
43* lib: will fix extending some enum/define breaking the ABI. There are multiple
44  samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is
45  used by iterators, and arrays holding these values are sized with this
46  ``.*MAX.*`` value. So extending this enum/define increases the ``.*MAX.*``
47  value which increases the size of the array and depending on how/where the
48  array is used this may break the ABI.
49  ``RTE_ETH_FLOW_MAX`` is one sample of the mentioned case, adding a new flow
50  type will break the ABI because of ``flex_mask[RTE_ETH_FLOW_MAX]`` array
51  usage in following public struct hierarchy:
52  ``rte_eth_fdir_flex_conf -> rte_eth_fdir_conf -> rte_eth_conf (in the middle)``.
53  Need to identify this kind of usages and fix in 20.11, otherwise this blocks
54  us extending existing enum/define.
55  One solution can be using a fixed size array instead of ``.*MAX.*`` value.
56
57* ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
58  should start with relevant protocol header structure from lib/net/.
59  The individual protocol header fields and the protocol header struct
60  may be kept together in a union as a first migration step.
61
62  These items are not compliant (not including struct from lib/net/):
63
64  - ``rte_flow_item_ah``
65  - ``rte_flow_item_arp_eth_ipv4``
66  - ``rte_flow_item_e_tag``
67  - ``rte_flow_item_geneve``
68  - ``rte_flow_item_geneve_opt``
69  - ``rte_flow_item_gre``
70  - ``rte_flow_item_gtp``
71  - ``rte_flow_item_icmp6``
72  - ``rte_flow_item_icmp6_nd_na``
73  - ``rte_flow_item_icmp6_nd_ns``
74  - ``rte_flow_item_icmp6_nd_opt``
75  - ``rte_flow_item_icmp6_nd_opt_sla_eth``
76  - ``rte_flow_item_icmp6_nd_opt_tla_eth``
77  - ``rte_flow_item_igmp``
78  - ``rte_flow_item_ipv6_ext``
79  - ``rte_flow_item_l2tpv3oip``
80  - ``rte_flow_item_mpls``
81  - ``rte_flow_item_nsh``
82  - ``rte_flow_item_nvgre``
83  - ``rte_flow_item_pfcp``
84  - ``rte_flow_item_pppoe``
85  - ``rte_flow_item_pppoe_proto_id``
86  - ``rte_flow_item_vxlan_gpe``
87
88* ethdev: Queue specific stats fields will be removed from ``struct rte_eth_stats``.
89  Mentioned fields are: ``q_ipackets``, ``q_opackets``, ``q_ibytes``, ``q_obytes``,
90  ``q_errors``.
91  Instead queue stats will be received via xstats API. Current method support
92  will be limited to maximum 256 queues.
93  Also compile time flag ``RTE_ETHDEV_QUEUE_STAT_CNTRS`` will be removed.
94
95* ethdev: Flow actions ``PF`` and ``VF`` have been deprecated since DPDK 21.11
96  and are yet to be removed. That still has not happened because there are net
97  drivers which support combined use of either action ``PF`` or action ``VF``
98  with action ``QUEUE``, namely, i40e, ixgbe and txgbe (L2 tunnel rule).
99  It is unclear whether it is acceptable to just drop support for
100  such a complex use case, so maintainers of the said drivers
101  should take a closer look at this and provide assistance.
102
103* ethdev: Actions ``OF_DEC_NW_TTL``, ``SET_IPV4_SRC``, ``SET_IPV4_DST``,
104  ``SET_IPV6_SRC``, ``SET_IPV6_DST``, ``SET_TP_SRC``, ``SET_TP_DST``,
105  ``DEC_TTL``, ``SET_TTL``, ``SET_MAC_SRC``, ``SET_MAC_DST``, ``INC_TCP_SEQ``,
106  ``DEC_TCP_SEQ``, ``INC_TCP_ACK``, ``DEC_TCP_ACK``, ``SET_IPV4_DSCP``,
107  ``SET_IPV6_DSCP``, ``SET_TAG``, ``SET_META`` are marked as legacy and
108  superseded by the generic ``RTE_FLOW_ACTION_TYPE_MODIFY_FIELD``.
109  The legacy actions should be removed
110  once ``MODIFY_FIELD`` alternative is implemented in drivers.
111
112* cryptodev: The function ``rte_cryptodev_cb_fn`` will be updated
113  to have another parameter ``qp_id`` to return the queue pair ID
114  which got error interrupt to the application,
115  so that application can reset that particular queue pair.
116
117* cryptodev: The arrays of algorithm strings ``rte_crypto_cipher_algorithm_strings``,
118  ``rte_crypto_auth_algorithm_strings``, ``rte_crypto_aead_algorithm_strings`` and
119  ``rte_crypto_asym_xform_strings`` are deprecated and will be removed in DPDK 23.11.
120  Application can use the new APIs ``rte_cryptodev_get_cipher_algo_string``,
121  ``rte_cryptodev_get_auth_algo_string``, ``rte_cryptodev_get_aead_algo_string`` and
122  ``rte_cryptodev_asym_get_xform_string`` respectively.
123
124* flow_classify: The flow_classify library and example have no maintainer.
125  The library is experimental and, as such, it could be removed from DPDK.
126  Its removal has been postponed to let potential users report interest
127  in maintaining it.
128  In the absence of such interest, this library will be removed in DPDK 23.11.
129