31. ABI and API Deprecation
See the guidelines document for details of the ABI policy. API and ABI deprecation notices are to be posted here.
31.1. Deprecation Notices
- kvargs: The function
rte_kvargs_processwill get a new parameter for returning key match count. It will ease handling of no-match case.
- eal: The function
rte_eal_remote_launchwill return new error codes after read or write error on the pipe, instead of calling
- rte_atomicNN_xxx: These APIs do not take memory order parameter. This does not allow for writing optimized code for all the CPU architectures supported in DPDK. DPDK has adopted the atomic operations from https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html. These operations must be used for patches that need to be merged in 20.08 onwards. This change will not introduce any performance degradation.
- rte_smp_*mb: These APIs provide full barrier functionality. However, many
use cases do not require full barriers. To support such use cases, DPDK has
adopted atomic operations from
operations and a new wrapper
__atomic_thread_fencemust be used for patches that need to be merged in 20.08 onwards. This change will not introduce any performance degradation.
- mempool: Helper macro
MEMPOOL_HEADER_SIZE()is deprecated and will be removed in DPDK 22.11. The replacement macro
RTE_MEMPOOL_HEADER_SIZE()is internal only.
- mempool: Macro to register mempool driver
MEMPOOL_REGISTER_OPS()is deprecated and will be removed in DPDK 22.11. Use replacement macro
- mempool: The mempool API macros
MEMPOOL_PG_*are deprecated and will be removed in DPDK 22.11.
- bus: The
rte_busobject will be made opaque in DPDK 22.11. The goal is to remove it from the public ABI and make this object extendable. As a side effect, registering a bus will be marked as an internal API: external users may still register their bus using a new driver header (see
- drivers: As a follow-up of the work on the
rte_deviceobjects (and as a domino effect, their bus-specific counterparts) will be made opaque in DPDK 22.11. Registering a driver on a bus will be marked as an internal API: external users may still register their drivers using the bus-specific driver header (see
- bus: The
dev->device.numa_nodefield is set by each bus driver for every device it manages to indicate on which NUMA node this device lies. When this information is unknown, the assigned value is not consistent across the bus drivers. In DPDK 22.11, the default value will be set to -1 by all bus drivers when the NUMA information is unavailable.
- kni: The KNI kernel module and library are not recommended for use by new
applications - other technologies such as virtio-user are recommended instead.
Following the DPDK technical board
- Some deprecation warnings will be added in DPDK 22.11.
- The KNI example application will be removed from DPDK 22.11.
- The KNI kernel module, library and PMD will be removed from the DPDK 23.11.
- lib: will fix extending some enum/define breaking the ABI. There are multiple
samples in DPDK that enum/define terminated with a
.*MAX.*value which is used by iterators, and arrays holding these values are sized with this
.*MAX.*value. So extending this enum/define increases the
.*MAX.*value which increases the size of the array and depending on how/where the array is used this may break the ABI.
RTE_ETH_FLOW_MAXis one sample of the mentioned case, adding a new flow type will break the ABI because of
flex_mask[RTE_ETH_FLOW_MAX]array usage in following public struct hierarchy:
rte_eth_fdir_flex_conf -> rte_eth_fdir_conf -> rte_eth_conf (in the middle). Need to identify this kind of usages and fix in 20.11, otherwise this blocks us extending existing enum/define. One solution can be using a fixed size array instead of
- ethdev: The function
ratein Mbps. The queue rate is limited to 64 Gbps because declared as
rateparameter will be modified to
uint32_tin DPDK 22.11 so that it can work for more than 64 Gbps.
- ethdev: Since no single PMD supports
RTE_ETH_RX_OFFLOAD_HEADER_SPLIToffload and the
split_hdr_sizefield in structure
rte_eth_rxmodeto enable per-port header split, they will be removed in DPDK 22.11. The per-queue Rx packet split offload
RTE_ETH_RX_OFFLOAD_BUFFER_SPLITcan still be used, and it is configured by
- ethdev: The flow director API, including
rte_eth_conf.fdir_conffield, and the related structures (
rte_eth_fdir_*), will be removed in DPDK 20.11.
- ethdev: Announce moving from dedicated modify function for each field,
to using the general
- ethdev: The flow API matching pattern structures,
struct rte_flow_item_*, should start with relevant protocol header. Some matching pattern structures implements this by duplicating protocol header fields in the struct. To clarify the intention and to be sure protocol header is intact, will replace those fields with relevant protocol header struct. In v21.02 both individual protocol header fields and the protocol header struct will be added as union, target is switch usage to the protocol header by time. In v21.11 LTS, protocol header fields will be cleaned and only protocol header struct will remain.
- ethdev: Queue specific stats fields will be removed from
struct rte_eth_stats. Mentioned fields are:
q_errors. Instead queue stats will be received via xstats API. Current method support will be limited to maximum 256 queues. Also compile time flag
RTE_ETHDEV_QUEUE_STAT_CNTRSwill be removed.
- ethdev: Items and actions
PORT_IDare deprecated as hard-to-use / ambiguous and will be removed in DPDK 22.11.
- ethdev: The use of attributes
egressin “transfer” flows is deprecated as ambiguous with respect to the embedded switch. The use of these attributes will become invalid starting from DPDK 22.11.
- ethdev: Actions
OF_COPY_TTL_INare deprecated as not supported by any PMD, so they will be removed in DPDK 22.11.
- ethdev: Actions
SET_METAare marked as legacy and superseded by the generic MODIFY_FIELD action. The legacy actions should be deprecated in 22.07, once MODIFY_FIELD alternative is implemented. The legacy actions should be removed in DPDK 22.11.
- ethdev: The enum
rte_eth_event_ipsec_subtypewill be extended to add new subtype values
RTE_ETH_EVENT_IPSEC_SA_PKT_HARD_EXPIRYin DPDK 22.11.
rte_bbdev_op_typeenum will be deprecated and instead use fixed array size when required to allow for future enum extension. Will extend API to support new operation type
RTE_BBDEV_OP_FFTas per this RFC. New members will be added in
rte_bbdev_driver_infoto expose PMD queue topology inspired by this RFC. New member will be added in
rte_bbdev_driver_infoto expose the device status as per this RFC. This should be updated in DPDK 22.11.
- cryptodev: Hide structures
rte_cryptodev_asym_sessionto remove unnecessary indirection between session and the private data of session. An opaque pointer can be exposed directly to application which can be attached to the
- cryptodev: The function
rte_cryptodev_cb_fnwill be updated to have another parameter
qp_idto return the queue pair ID which got error interrupt to the application, so that application can reset that particular queue pair.
- security: Hide structure
rte_security_sessionand expose an opaque pointer for the private data to the application which can be attached to the packet while enqueuing.
- security: MACsec support is planned to be added in DPDK 22.11,
which would result in updates to structures
rte_security_macsec_statsand security capability structure
rte_security_capabilityto accommodate MACsec capabilities.
- eventdev: The function
rte_event_crypto_adapter_queue_pair_addwill accept configuration of type
rte_event, similar to
rte_event_eth_rx_adapter_queue_addsignature. Event will be one of the configuration fields, together with additional vector parameters.
- eventdev: The structure
rte_event_timer_adapter_statswill be extended by adding a new field
evtim_drop_count. This counter will represent the number of times an event_timer expiry event is dropped by the timer adapter. This field will be used to add periodic mode support to the software timer adapter in DPDK 22.11.
- eventdev: The function pointer declaration
eventdev_stop_flush_twill be renamed to
rte_eventdev_stop_flush_tin DPDK 22.11.
- eventdev: The element
*u64sin the structure
rte_event_vectoris deprecated and will be replaced with
u64sin DPDK 22.11.
- eventdev: The structure
rte_event_vectorwill be modified to include
elem_offset:12bits taken from
elem_offsetdefines the offset into the vector array from which valid elements are present. The difference between
rte_event_vector::elem_offsetgives the number of valid elements left to process from the
- eventdev: New fields to represent event queue weight and affinity
will be added to
rte_event_queue_confstructure in DPDK 22.11.
- metrics: The function
rte_metrics_initwill have a non-void return in order to notify errors instead of calling
- telemetry: The allowed characters in names for dictionary values will be limited to alphanumeric characters and a small subset of additional printable characters. This will ensure that all dictionary parameter names can be output without escaping in JSON - or in any future output format used. Names for the telemetry commands will be similarly limited. The parameters for telemetry commands are unaffected by this change.
- net/octeontx_ep: The driver
octeontx_epwas to support OCTEON TX line of products. It will be renamed to
octeon_epin DPDK 22.11 to apply for all OCTEON EP products: OCTEON TX and future OCTEON chipsets.
- raw/dpaa2_cmdif: The
dpaa2_cmdifrawdev driver will be deprecated in DPDK 22.11, as it is no longer in use, no active user known.
- raw/ifgpa: The function
rte_pmd_ifpga_get_pci_buswill be removed in DPDK 22.11.
- raw/ioat: The
ioatrawdev driver has been deprecated, since it’s functionality is provided through the new
dmadevinfrastructure. To continue to use hardware previously supported by the
ioatrawdev driver, applications should be updated to use the
dmadevlibrary instead, with the underlying HW-functionality being provided by the