xref: /dpdk/doc/guides/rel_notes/deprecation.rst (revision 8809f78c7dd9f33a44a4f89c58fc91ded34296ed)
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* build: The macros defined to indicate which DPDK libraries and drivers
15  are included in the meson build are changing to a standardized format of
16  ``RTE_LIB_<NAME>`` and ``RTE_<CLASS>_<NAME>``, where ``NAME`` is the
17  upper-case component name, e.g. EAL, ETHDEV, IXGBE, and ``CLASS`` is the
18  upper-case name of the device class to which a driver belongs e.g.
19  ``NET``, ``CRYPTO``, ``VDPA``. The old macros are deprecated and will be
20  removed in a future release.
21
22* meson: The minimum supported version of meson for configuring and building
23  DPDK will be increased to v0.47.1 (from 0.41) from DPDK 19.05 onwards. For
24  those users with a version earlier than 0.47.1, an updated copy of meson
25  can be got using the ``pip3`` tool (or ``python3 -m pip``) for downloading
26  python packages.
27
28* kvargs: The function ``rte_kvargs_process`` will get a new parameter
29  for returning key match count. It will ease handling of no-match case.
30
31* eal: The terms blacklist and whitelist to describe devices used
32  by DPDK will be replaced in the 20.11 relase.
33  This will apply to command line arguments as well as macros.
34
35  The macro ``RTE_DEV_BLACKLISTED`` will be replaced with ``RTE_DEV_EXCLUDED``
36  and ``RTE_DEV_WHITELISTED`` will be replaced with ``RTE_DEV_INCLUDED``
37  ``RTE_BUS_SCAN_BLACKLIST`` and ``RTE_BUS_SCAN_WHITELIST`` will be
38  replaced with ``RTE_BUS_SCAN_EXCLUDED`` and ``RTE_BUS_SCAN_INCLUDED``
39  respectively. Likewise ``RTE_DEVTYPE_BLACKLISTED_PCI`` and
40  ``RTE_DEVTYPE_WHITELISTED_PCI`` will be replaced with
41  ``RTE_DEVTYPE_EXCLUDED`` and ``RTE_DEVTYPE_INCLUDED``.
42
43  The old macros will be marked as deprecated in 20.11 and any
44  usage will cause a compile warning. They will be removed in
45  a future release.
46
47  The command line arguments to ``rte_eal_init`` will change from
48  ``-b, --pci-blacklist`` to ``-x, --exclude`` and
49  ``-w, --pci-whitelist`` to ``-i, --include``.
50  The old command line arguments will continue to be accepted in 20.11
51  but will cause a runtime warning message. The old arguments will
52  be removed in a future release.
53
54* eal: The function ``rte_eal_remote_launch`` will return new error codes
55  after read or write error on the pipe, instead of calling ``rte_panic``.
56
57* rte_atomicNN_xxx: These APIs do not take memory order parameter. This does
58  not allow for writing optimized code for all the CPU architectures supported
59  in DPDK. DPDK will adopt C11 atomic operations semantics and provide wrappers
60  using C11 atomic built-ins. These wrappers must be used for patches that
61  need to be merged in 20.08 onwards. This change will not introduce any
62  performance degradation.
63
64* rte_smp_*mb: These APIs provide full barrier functionality. However, many
65  use cases do not require full barriers. To support such use cases, DPDK will
66  adopt C11 barrier semantics and provide wrappers using C11 atomic built-ins.
67  These wrappers must be used for patches that need to be merged in 20.08
68  onwards. This change will not introduce any performance degradation.
69
70* lib: will fix extending some enum/define breaking the ABI. There are multiple
71  samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is
72  used by iterators, and arrays holding these values are sized with this
73  ``.*MAX.*`` value. So extending this enum/define increases the ``.*MAX.*``
74  value which increases the size of the array and depending on how/where the
75  array is used this may break the ABI.
76  ``RTE_ETH_FLOW_MAX`` is one sample of the mentioned case, adding a new flow
77  type will break the ABI because of ``flex_mask[RTE_ETH_FLOW_MAX]`` array
78  usage in following public struct hierarchy:
79  ``rte_eth_fdir_flex_conf -> rte_fdir_conf -> rte_eth_conf (in the middle)``.
80  Need to identify this kind of usages and fix in 20.11, otherwise this blocks
81  us extending existing enum/define.
82  One solution can be using a fixed size array instead of ``.*MAX.*`` value.
83
84* mbuf: Some fields will be converted to dynamic API in DPDK 20.11
85  in order to reserve more space for the dynamic fields, as explained in
86  `this presentation <https://www.youtube.com/watch?v=Ttl6MlhmzWY>`_.
87  As a consequence, the layout of the ``struct rte_mbuf`` will be re-arranged,
88  avoiding impact on vectorized implementation of the driver datapaths,
89  while evaluating performance gains of a better use of the first cache line.
90
91
92* ethdev: the legacy filter API, including
93  ``rte_eth_dev_filter_supported()``, ``rte_eth_dev_filter_ctrl()`` as well
94  as filter types MACVLAN, ETHERTYPE, FLEXIBLE, SYN, NTUPLE, TUNNEL, FDIR,
95  HASH and L2_TUNNEL, is superseded by the generic flow API (rte_flow) in
96  PMDs that implement the latter.
97  The legacy API will be removed in DPDK 20.11.
98
99* ethdev: The flow director API, including ``rte_eth_conf.fdir_conf`` field,
100  and the related structures (``rte_fdir_*`` and ``rte_eth_fdir_*``),
101  will be removed in DPDK 20.11.
102
103* ethdev: The legacy L2 tunnel filtering API is deprecated as the rest of
104  the legacy filtering API.
105  The functions ``rte_eth_dev_l2_tunnel_eth_type_conf`` and
106  ``rte_eth_dev_l2_tunnel_offload_set`` which were not marked as deprecated,
107  will be removed in DPDK 20.11.
108
109* ethdev: New offload flags ``DEV_RX_OFFLOAD_FLOW_MARK`` will be added in 19.11.
110  This will allow application to enable or disable PMDs from updating
111  ``rte_mbuf::hash::fdir``.
112  This scheme will allow PMDs to avoid writes to ``rte_mbuf`` fields on Rx and
113  thereby improve Rx performance if application wishes do so.
114  In 19.11 PMDs will still update the field even when the offload is not
115  enabled.
116
117* ethdev: ``rx_descriptor_done`` dev_ops and ``rte_eth_rx_descriptor_done``
118  will be removed in 21.11.
119  Existing ``rte_eth_rx_descriptor_status`` and ``rte_eth_tx_descriptor_status``
120  APIs can be used as replacement.
121
122* ethdev: The port mirroring API can be replaced with a more fine grain flow API.
123  The structs ``rte_eth_mirror_conf``, ``rte_eth_vlan_mirror`` and the functions
124  ``rte_eth_mirror_rule_set``, ``rte_eth_mirror_rule_reset`` will be marked
125  as deprecated in DPDK 20.11, along with the associated macros ``ETH_MIRROR_*``.
126  This API will be fully removed in DPDK 21.11.
127
128* ethdev: Queue specific stats fields will be removed from ``struct rte_eth_stats``.
129  Mentioned fields are: ``q_ipackets``, ``q_opackets``, ``q_ibytes``, ``q_obytes``,
130  ``q_errors``.
131  Instead queue stats will be received via xstats API. Current method support
132  will be limited to maximum 256 queues.
133  Also compile time flag ``RTE_ETHDEV_QUEUE_STAT_CNTRS`` will be removed.
134
135* cryptodev: support for using IV with all sizes is added, J0 still can
136  be used but only when IV length in following structs ``rte_crypto_auth_xform``,
137  ``rte_crypto_aead_xform`` is set to zero. When IV length is greater or equal
138  to one it means it represents IV, when is set to zero it means J0 is used
139  directly, in this case 16 bytes of J0 need to be passed.
140
141* sched: To allow more traffic classes, flexible mapping of pipe queues to
142  traffic classes, and subport level configuration of pipes and queues
143  changes will be made to macros, data structures and API functions defined
144  in "rte_sched.h". These changes are aligned to improvements suggested in the
145  RFC https://mails.dpdk.org/archives/dev/2018-November/120035.html.
146
147* metrics: The function ``rte_metrics_init`` will have a non-void return
148  in order to notify errors instead of calling ``rte_exit``.
149
150* power: ``rte_power_set_env`` function will no longer return 0 on attempt
151  to set new power environment if power environment was already initialized.
152  In this case the function will return -1 unless the environment is unset first
153  (using ``rte_power_unset_env``). Other function usage scenarios will not change.
154
155* cmdline: ``cmdline`` structure will be made opaque to hide platform-specific
156  content. On Linux and FreeBSD, supported prior to DPDK 20.11,
157  original structure will be kept until DPDK 21.11.
158
159* dpdk-setup.sh: This old script relies on deprecated stuff, and especially
160  ``make``. Given environments are too much variables for such a simple script,
161  it will be removed in DPDK 20.11.
162  Some useful parts may be converted into specific scripts.
163