12. ABI and API Deprecation

See the guidelines document for details of the ABI policy. API and ABI deprecation notices are to be posted here.

12.1. Deprecation Notices

  • ring: Changes are planned to rte_ring APIs in release 17.05. Proposed changes include:

    • Removing build time options for the ring: CONFIG_RTE_RING_SPLIT_PROD_CONS CONFIG_RTE_RING_PAUSE_REP_COUNT
    • Adding an additional parameter to enqueue functions to return the amount of free space in the ring
    • Adding an additional parameter to dequeue functions to return the number of remaining elements in the ring
    • Removing direct support for watermarks in the rings, since the additional return value from the enqueue function makes it unneeded
    • Adjusting the return values of the bulk() enq/deq functions to make them consistent with the burst() equivalents. [Note, parameter to these functions are changing too, per points above, so compiler will flag them as needing update in legacy code]
    • Updates to some library functions e.g. rte_ring_get_memsize() to allow for variably-sized ring elements.
  • igb_uio: iomem mapping and sysfs files created for iomem and ioport in igb_uio will be removed, because we are able to detect these from what Linux has exposed, like the way we have done with uio-pci-generic. This change targets release 17.05.

  • vfio: Some functions are planned to be exported outside librte_eal in 17.05. VFIO APIs like vfio_setup_device, vfio_get_group_fd can be used by subsystem other than EAL/PCI. For that, these need to be exported symbols. Such APIs are planned to be renamed according to rte_* naming convention and exported from librte_eal.

  • The PCI and VDEV subsystems will be converted as drivers of the new bus model. It will imply some EAL API changes in 17.05.

  • eth_driver is planned to be removed in 17.05. This currently serves as a placeholder for PMDs to register themselves. Changes for rte_bus will provide a way to handle device initialization currently being done in eth_driver. Similarly, rte_pci_driver is planned to be removed from rte_cryptodev_driver in 17.05.

  • ethdev: An API change is planned for 17.05 for the function _rte_eth_dev_callback_process. In 17.05 the function will return an int instead of void and a fourth parameter void *ret_param will be added.

  • ethdev: for 17.05 it is planned to deprecate the following nine rte_eth_dev_* functions and move them into the ixgbe PMD:

    rte_eth_dev_bypass_init, rte_eth_dev_bypass_state_set, rte_eth_dev_bypass_state_show, rte_eth_dev_bypass_event_store, rte_eth_dev_bypass_event_show, rte_eth_dev_wd_timeout_store, rte_eth_dev_bypass_wd_timeout_show, rte_eth_dev_bypass_ver_show, rte_eth_dev_bypass_wd_reset.

    The following fields will be removed from struct eth_dev_ops:

    bypass_init_t, bypass_state_set_t, bypass_state_show_t, bypass_event_set_t, bypass_event_show_t, bypass_wd_timeout_set_t, bypass_wd_timeout_show_t, bypass_ver_show_t, bypass_wd_reset_t.

    The functions will be renamed to the following, and moved to the ixgbe PMD:

    rte_pmd_ixgbe_bypass_init, rte_pmd_ixgbe_bypass_state_set, rte_pmd_ixgbe_bypass_state_show, rte_pmd_ixgbe_bypass_event_set, rte_pmd_ixgbe_bypass_event_show, rte_pmd_ixgbe_bypass_wd_timeout_set, rte_pmd_ixgbe_bypass_wd_timeout_show, rte_pmd_ixgbe_bypass_ver_show, rte_pmd_ixgbe_bypass_wd_reset.

  • ABI changes are planned for 17.05 in the rte_mbuf structure: some fields may be reordered to facilitate the writing of data_off, refcnt, and nb_segs in one operation, because some platforms have an overhead if the store address is not naturally aligned. Other mbuf fields, such as the port field, may be moved or removed as part of this mbuf work. A timestamp will also be added.

  • The mbuf flags PKT_RX_VLAN_PKT and PKT_RX_QINQ_PKT are deprecated and are respectively replaced by PKT_RX_VLAN_STRIPPED and PKT_RX_QINQ_STRIPPED, that are better described. The old flags and their behavior will be kept until 17.02 and will be removed in 17.05.

  • mempool: The functions rte_mempool_count and rte_mempool_free_count will be removed in 17.05. They are replaced by rte_mempool_avail_count and rte_mempool_in_use_count respectively.

  • mempool: The functions for single/multi producer/consumer are deprecated and will be removed in 17.05. It is replaced by rte_mempool_generic_get/put functions.

  • ethdev: the legacy filter API, including rte_eth_dev_filter_supported(), rte_eth_dev_filter_ctrl() as well as filter types MACVLAN, ETHERTYPE, FLEXIBLE, SYN, NTUPLE, TUNNEL, FDIR, HASH and L2_TUNNEL, is superseded by the generic flow API (rte_flow) in PMDs that implement the latter. Target release for removal of the legacy API will be defined once most PMDs have switched to rte_flow.

  • vhost: API/ABI changes are planned for 17.05, for making DPDK vhost library generic enough so that applications can build different vhost-user drivers (instead of vhost-user net only) on top of that. Specifically, virtio_net_device_ops will be renamed to vhost_device_ops. Correspondingly, some API’s parameter need be changed. Few more functions also need be reworked to let it be device aware. For example, different virtio device has different feature set, meaning functions like rte_vhost_feature_disable need be changed. Last, file rte_virtio_net.h will be renamed to rte_vhost.h.

  • kni: Remove KNI Working as a Kernel vHost Backend feature (KNI_VHOST) in 17.05 release. Vhost Library is currently preferred method for guest - host communication. Just for clarification, this is not to remove KNI or VHOST feature, but KNI_VHOST which is a KNI feature enabled via a compile time option, and disabled by default.

  • ABI changes are planned for 17.05 in the rte_cryptodev_ops structure. A pointer to a rte_cryptodev_config structure will be added to the function prototype cryptodev_configure_t, as a new parameter.

  • cryptodev: A new parameter max_nb_sessions_per_qp will be added to rte_cryptodev_info.sym. Some drivers may support limited number of sessions per queue_pair. With this new parameter application will know how many sessions can be mapped to each queue_pair of a device.

  • distributor: library API will be changed to incorporate a burst-oriented API. This will include a change to rte_distributor_create to specify which type of instance to create (single or burst), and additional calls for rte_distributor_poll_pkt_burst and rte_distributor_return_pkt_burst, among others.

  • The architecture TILE-Gx and the associated mpipe driver are not maintained and will be removed in 17.05.