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: The function ``rte_eal_remote_launch`` will return new error codes 18 after read or write error on the pipe, instead of calling ``rte_panic``. 19 20* rte_atomicNN_xxx: These APIs do not take memory order parameter. This does 21 not allow for writing optimized code for all the CPU architectures supported 22 in DPDK. DPDK will adopt C11 atomic operations semantics and provide wrappers 23 using C11 atomic built-ins. These wrappers must be used for patches that 24 need to be merged in 20.08 onwards. This change will not introduce any 25 performance degradation. 26 27* rte_smp_*mb: These APIs provide full barrier functionality. However, many 28 use cases do not require full barriers. To support such use cases, DPDK will 29 adopt C11 barrier semantics and provide wrappers using C11 atomic built-ins. 30 These wrappers must be used for patches that need to be merged in 20.08 31 onwards. This change will not introduce any performance degradation. 32 33* lib: will fix extending some enum/define breaking the ABI. There are multiple 34 samples in DPDK that enum/define terminated with a ``.*MAX.*`` value which is 35 used by iterators, and arrays holding these values are sized with this 36 ``.*MAX.*`` value. So extending this enum/define increases the ``.*MAX.*`` 37 value which increases the size of the array and depending on how/where the 38 array is used this may break the ABI. 39 ``RTE_ETH_FLOW_MAX`` is one sample of the mentioned case, adding a new flow 40 type will break the ABI because of ``flex_mask[RTE_ETH_FLOW_MAX]`` array 41 usage in following public struct hierarchy: 42 ``rte_eth_fdir_flex_conf -> rte_fdir_conf -> rte_eth_conf (in the middle)``. 43 Need to identify this kind of usages and fix in 20.11, otherwise this blocks 44 us extending existing enum/define. 45 One solution can be using a fixed size array instead of ``.*MAX.*`` value. 46 47* ethdev: The flow director API, including ``rte_eth_conf.fdir_conf`` field, 48 and the related structures (``rte_fdir_*`` and ``rte_eth_fdir_*``), 49 will be removed in DPDK 20.11. 50 51* ethdev: New offload flags ``DEV_RX_OFFLOAD_FLOW_MARK`` will be added in 19.11. 52 This will allow application to enable or disable PMDs from updating 53 ``rte_mbuf::hash::fdir``. 54 This scheme will allow PMDs to avoid writes to ``rte_mbuf`` fields on Rx and 55 thereby improve Rx performance if application wishes do so. 56 In 19.11 PMDs will still update the field even when the offload is not 57 enabled. 58 59* ethdev: ``uint32_t max_rx_pkt_len`` field of ``struct rte_eth_rxmode``, will be 60 replaced by a new ``uint32_t mtu`` field of ``struct rte_eth_conf`` in v21.11. 61 The new ``mtu`` field will be used to configure the initial device MTU via 62 ``rte_eth_dev_configure()`` API. 63 Later MTU can be changed by ``rte_eth_dev_set_mtu()`` API as done now. 64 The existing ``(struct rte_eth_dev)->data->mtu`` variable will be used to store 65 the configured ``mtu`` value, 66 and this new ``(struct rte_eth_dev)->data->dev_conf.mtu`` variable will 67 be used to store the user configuration request. 68 Unlike ``max_rx_pkt_len``, which was valid only when ``JUMBO_FRAME`` enabled, 69 ``mtu`` field will be always valid. 70 When ``mtu`` config is not provided by the application, default ``RTE_ETHER_MTU`` 71 value will be used. 72 ``(struct rte_eth_dev)->data->mtu`` should be updated after MTU set successfully, 73 either by ``rte_eth_dev_configure()`` or ``rte_eth_dev_set_mtu()``. 74 75 An application may need to configure device for a specific Rx packet size, like for 76 cases ``DEV_RX_OFFLOAD_SCATTER`` is not supported and device received packet size 77 can't be bigger than Rx buffer size. 78 To cover these cases an application needs to know the device packet overhead to be 79 able to calculate the ``mtu`` corresponding to a Rx buffer size, for this 80 ``(struct rte_eth_dev_info).max_rx_pktlen`` will be kept, 81 the device packet overhead can be calculated as: 82 ``(struct rte_eth_dev_info).max_rx_pktlen - (struct rte_eth_dev_info).max_mtu`` 83 84* ethdev: ``rx_descriptor_done`` dev_ops and ``rte_eth_rx_descriptor_done`` 85 will be removed in 21.11. 86 Existing ``rte_eth_rx_descriptor_status`` and ``rte_eth_tx_descriptor_status`` 87 APIs can be used as replacement. 88 89* ethdev: The port mirroring API can be replaced with a more fine grain flow API. 90 The structs ``rte_eth_mirror_conf``, ``rte_eth_vlan_mirror`` and the functions 91 ``rte_eth_mirror_rule_set``, ``rte_eth_mirror_rule_reset`` will be marked 92 as deprecated in DPDK 20.11, along with the associated macros ``ETH_MIRROR_*``. 93 This API will be fully removed in DPDK 21.11. 94 95* ethdev: Attribute ``shared`` of the ``struct rte_flow_action_count`` 96 is deprecated and will be removed in DPDK 21.11. Shared counters should 97 be managed using shared actions API (``rte_flow_shared_action_create`` etc). 98 99* ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``, 100 should start with relevant protocol header. 101 Some matching pattern structures implements this by duplicating protocol header 102 fields in the struct. To clarify the intention and to be sure protocol header 103 is intact, will replace those fields with relevant protocol header struct. 104 In v21.02 both individual protocol header fields and the protocol header struct 105 will be added as union, target is switch usage to the protocol header by time. 106 In v21.11 LTS, protocol header fields will be cleaned and only protocol header 107 struct will remain. 108 109* ethdev: Queue specific stats fields will be removed from ``struct rte_eth_stats``. 110 Mentioned fields are: ``q_ipackets``, ``q_opackets``, ``q_ibytes``, ``q_obytes``, 111 ``q_errors``. 112 Instead queue stats will be received via xstats API. Current method support 113 will be limited to maximum 256 queues. 114 Also compile time flag ``RTE_ETHDEV_QUEUE_STAT_CNTRS`` will be removed. 115 116* ethdev: The offload flag ``PKT_RX_EIP_CKSUM_BAD`` will be removed and 117 replaced by the new flag ``PKT_RX_OUTER_IP_CKSUM_BAD``. The new name is more 118 consistent with existing outer header checksum status flag naming, which 119 should help in reducing confusion about its usage. 120 121* sched: To allow more traffic classes, flexible mapping of pipe queues to 122 traffic classes, and subport level configuration of pipes and queues 123 changes will be made to macros, data structures and API functions defined 124 in "rte_sched.h". These changes are aligned to improvements suggested in the 125 RFC https://mails.dpdk.org/archives/dev/2018-November/120035.html. 126 127* metrics: The function ``rte_metrics_init`` will have a non-void return 128 in order to notify errors instead of calling ``rte_exit``. 129 130* cmdline: ``cmdline`` structure will be made opaque to hide platform-specific 131 content. On Linux and FreeBSD, supported prior to DPDK 20.11, 132 original structure will be kept until DPDK 21.11. 133