xref: /spdk/CHANGELOG.md (revision 990cd38a8c3bf7a00beee980b604783d63cbdaa5)
1# Changelog
2
3## v23.01: (Upcoming Release)
4
5### accel
6
7New library isa-l-crypto has been added, it is used by accel library in crypto operations.
8
9### bdev
10
11Both of interleaved and separated metadata are now supported by the malloc bdev module.
12
13Protection information is now supported by the malloc bdev module.
14
15A new API `spkd_bdev_part_submit_request_ext` was added to specify a custom completion callback.
16
17### scheduler
18
19Changing scheduler from dynamic back to static is no longer possible,
20as there is no way of saving original SPDK thread distribution on reactors.
21
22### bdev
23
24New APIs `spdk_bdev_for_each_channel` and `spdk_bdev_for_each_channel_continue` and
25associated function pointers were added to iterate each channel of the required bdev.
26
27The RPC `bdev_get_iostat` now allows a user to query the per channel IO statistics for
28required bdev, and displays maximum and minimum latencies and I/O error counts.
29
30New `spdk_bdev_copy_blocks` and `spdk_bdev_get_max_copy` APIs to support copy commands.
31
32A new API `spdk_bdev_io_get_submit_tsc` was added to get the submit_tsc of the bdev I/O.
33
34Bdevs will no longer have UUIDs generated based on timestamp and are responsible for
35setting this field themselves. Generation of UUIDs for NVMe bdevs may be enabled by
36running `bdev_nvme_set_options` RPC with `--generate-uuids` option. These identifiers
37are based on serial number and namespace ID and will always be the same for a given
38device.
39
40A new API `spdk_bdev_channel_get_histogram` was added to get the histogram of a specified
41channel for a bdev.
42
43Converted internal use of `pthread_mutex_t` to `struct spdk_spinlock`. Consumers of bdev
44API functions must be on an SPDK thread or the program will abort. It is now enforced
45that no internal bdev locks can be held when a poller or message goes off CPU.
46
47A new RPC `bdev_reset_iostat` was added to reset I/O statistics of bdevs. Note that if one
48consumer reset I/O statistics, it affects all other consumers.
49
50Add function pointers, `dump_device_stat_json` and `reset_device_stat` to the bdev module
51function table to display and reset I/O statistics specific for the module specific bdev
52context.
53
54### event
55
56Added core lock file mechanism to prevent the same CPU cores from being used by multiple
57SPDK application instances.
58
59Added a command line switch to disable CPU locks on SPDK startup.
60
61Added RPCs framework_enable_cpumask_locks and framework_disable_cpumask_locks to enable
62and disable CPU core locks in runtime.
63
64Added --rpcs-allowed command line option. Users can specify a comma-separated list of RPC
65names with this option to restrict allowed RPCs to only that list.
66
67### rpc
68
69Added spdk_rpc_set_allowlist to restrict allowed RPCs to the specified list.
70
71Changed `bdev_raid_get_bdevs` RPC output format to include raid_bdev details.
72
73### bdevperf
74
75Promoted the application to example to match similar programs: fio_plugin and perf.
76It can now be found inside `examples/bdev/bdevperf`.
77
78### trace
79
80New `trace_get_info` RPC was added to get name of shared memory file, list of the
81available trace point groups and mask of the available trace points for each group.
82
83### util
84
85New API `spdk_fd_group_get_epoll_event` that returns the epoll(7) event that
86caused a function callback in file descriptor group to execute.
87
88### json
89
90Added API `spdk_json_write_double` and `spdk_json_write_named_double` to allow
91for writing and decoding of the the double data type.
92
93### thread
94
95Added `spdk_thread_get_app_thread` which returns the first thread that was created using
96`spdk_thread_create`.
97
98Added `spdk_thread_is_running`.  This returns `true` for a running thread, or `false` if
99its exit process has started using `spdk_thread_exit`.
100
101Added API `spdk_spin_init`, `spdk_spin_destroy`, `spdk_spin_lock`, `spdk_spin_unlock`, and
102`spdk_spin_held` to support spinlocks that are aware of the SPDK concurrency model.
103
104### log
105
106Added consistent tracking of use of deprecated behavior. Deprecations continue to be
107listed in deprecation.md and now are in subsections with headers matching a tag
108used in `SPDK_LOG_DEPRECATED()` calls. When deprecated behavior is used, these
109tags will appear in SPDK's log at the warn level. As the SPDK application exits, it
110will log a summary of how many times `SPDK_LOG_DEPRECATED()` was called for each
111tag that was logged at least once.
112
113### nvme
114
115Added `transport_tos` to `spdk_nvme_ctrlr_opts` to support setting of the "type of service"
116value in the IPv4 header. Only RDMA is supported at this time.
117
118### bdev_nvme
119
120Updated `bdev_nvme_set_options` RPC (and rpc.py) to support the new `transport_tos` parameter.
121
122## v22.09
123
124### accel
125
126Many names were changed in the accel framework to make them consistent both with themselves and
127the rest of SPDK. The primary public header file is now named `include/spdk/accel.h`.
128
129Added a new runtime RPC `accel_get_opc_assignments` to get a list of current opcode to engine
130assignments.
131
132Added a new startup RPC `accel_assign_opc` to assign/override a specific opcode to
133an engine.
134
135### bdev
136
137New RPCs `bdev_xnvme_create` and `bdev_xnvme_delete` were added to support the xNVMe bdev.
138
139A new API `spdk_bdev_for_each_bdev_io` was added to execute the function on the appropriate
140thread for each bdev_io submitted to the bdev.
141
142A new API `spdk_bdev_get_current_qd` was added to measure and return the queue depth from a
143bdev. This API is available even when queue depth sampling is disabled.
144
145Added `spdk_bdev_seek_data`, `spdk_bdev_seek_hole` and `spdk_bdev_io_get_seek_offset` functions
146that start from a given offset and seek for next data or for next hole. At this time only
147supported by lvol bdev module.
148
149A new parameter `io_drain_timeout` has been added to `spdk_bdev` structure. It controls how long
150a bdev reset must wait for IO to complete prior to issuing a reset to the underlying device.
151If there is no outstanding IO at the end of that period, the reset is skipped.
152Best defined for bdevs that share an underlying bdev, such as multiple lvol bdevs sharing
153an nvme device, to avoid unnecessarily resetting the underlying bdev and affecting other
154bdevs that are sharing it.
155Modifying this field is optional. Setting the value to 0 keeps the original behavior
156to always send resets immediately, even if there is no I/O outstanding.
157
158### blobstore
159
160Reserve space for `used_clusters` bitmap. The reserved space could be used for blobstore growing
161in the future.
162
163Added `is_zeroes` operation to `spdk_bs_dev`. It allows to detect if logical blocks are backed
164by zeroes device and do a shortcut in copy-on-write flow by excluding copy part from zeroes device.
165
166Added `spdk_blob_get_next_allocated_io_unit` and `spdk_blob_get_next_unallocated_io_unit` functions
167that start from a given offset and seek for first io_unit belonging to an allocated cluster
168or first io_unit belonging to an unallocated cluster.
169
170Added `spdk_bs_grow` function to grow blobstore size if the underlying bdev size is increased.
171This is used by lvol bdev via `bdev_lvol_grow_lvstore` RPC.
172
173### daos
174
175Added new DAOS bdev module, that creates SPDK block device on top of DAOS DFS.
176Please see [documentation](https://spdk.io/doc/bdev.html#bdev_config_daos) for more details.
177
178### env
179
180Added `spdk_pci_register_device_provider` and matching `SPDK_PCI_REGISTER_DEVICE_PROVIDER`
181functions for registering PCI device providers. That allow the VMD driver to be notified
182when users want to attach a device under a given BDF and when a device is detached.
183
184### init
185
186`spdk_subsystem_init_from_json_config` now fails if the JSON configuration file is not
187an object with an array named "subsystems".
188
189### iscsi
190
191Added `bdev_iscsi_set_options` RPC to modify options of the iSCSI bdev module.
192
193### json
194
195Added `spdk_json_find` API return errcode: EPROTOTYPE - json not enclosed in {}.
196`spdk_json_find` now returns -EPROTOTYPE instead of -ENOENT if the object parameter
197does not point to a JSON object (i.e. is not enclosed with {}).
198
199### lvol
200
201Add `num_md_pages_per_cluster_ratio` parameter to the `bdev_lvol_create_lvstore` RPC.
202Calculate `num_md_pages` from `num_md_pages_per_cluster_ratio`, and pass it to `spdk_bs_opts`.
203
204### nvme
205
206Added SPDK_NVME_TRANSPORT_CUSTOM_FABRICS to enum `spdk_nvme_transport_type` to support custom
207fabric transport. SPDK_NVME_TRANSPORT_CUSTOM was intended to be non-fabric custom transport.
208
209Added a new function `spdk_nvme_ns_cmd_verify` to submit a Verify Command to a Namespace.
210
211Added `spdk_nvme_ctrlr_disable_read_changed_ns_list_log_page` to allow an application to
212tell the driver to not read the CHANGED_NS_LIST log page in response to a NS_ATTR_CHANGED
213AEN.  When called the application is required to read this log page instead to clear the
214AEN.
215
216Added `psk` field to `spdk_nvme_ctrlr_opts` struct in order to enable SSL socket implementation
217of TCP connection and set the PSK. Applicable for TCP transport only.
218
219### raid
220
221Renamed the `raid5` module to `raid5f` to reflect that it is not a traditional
222RAID5 implementation - only full stripe writes are supported, partial stripe
223writes (read-modify-write) are not.
224
225### rpc
226
227Added `psk` parameter to `bdev_nvme_attach_controller` RPC in order to enable SSL socket implementation
228of TCP connection and set the PSK. Applicable for TCP transport only.
229
230New options `enable_ktls` and `tls_version` were added to the `sock_impl_set_options` structure.
231New options `psk_key` and `psk_identity` were added to the `sock_impl_set_options` structure.
232
233Added warning message for `bdev_rbd_create`, if it is used without -c.
234`bdev_rbd_create()` API without specifying -c is deprecated and will be removed in future release.
235
236Renamed `enable_vmd` RPC to `vmd_enable` to make it consistent with our naming scheme of
237`<subsystem>_<action>`.  For now, the old name is still available, but is marked as deprecated.
238
239New function `spdk_rpc_get_method_state_mask` was added to RPC library.
240
241### sma
242
243Extended `VolumeParameters` with crypto parameters allowing the user to configure crypto when
244attaching a volume to a device.  This interface is now supported by all upstream device types
245(nvmf-tcp, virtio-blk, vfio-user) using `bdev_crypto`.  Users must specify the crypto engine to use
246under `crypto` section in config.  It is also possible to register out-of-tree crypto engines by
247inheriting from the `CryptoEngine` class.
248
249Added two new methods: `SetQos` and `GetQosCapabilities` allowing the user to configure QoS on a
250per-device or per-volume level.  Not all QoS settings have to be supported by each device, so users
251can use `GetQosCapabilities` to query them for that.  All upstream device types support QoS on a
252per-volume level using bdev layer's QoS mechanism.
253
254### sock
255
256Added new `ssl` based socket implementation, the code is located in `module/sock/posix`.
257For now we are using hard-coded PSK and only support TLS 1.3.
258
259### util
260
261Added new functions: `spdk_hexlify` and `spdk_unhexlify`.
262
263A new API `spdk_xor_gen` was added to generate XOR from multiple source buffers. It is going to be
264used by `raid5f` for calculating parity.
265
266### vfu_tgt
267
268Added vfu_tgt library abstraction based on libvfio-user for PCI device emulation.
269Besides the NVMe device emulation, its now possible to emulate virtio-blk and virtio-scsi
270devices.
271
272### virtio
273
274virtio-vhost-user no longer tries to support dynamic memory allocation.  The vhost target does
275not support the high rate of SET_MEM_TABLE vhost messages that result from dynamic memory
276allocation, so a virtio-vhost-user device will now present an ERRLOG, assert, and skip the
277SET_MEM_TABLE vhost message if a memory notification is received outside of the normal device
278start/stop. Applications using the virtio library in vhost-user mode should now pre-allocate
279the application's memory using the -s/--mem-size option and use single shared memory file
280segments using the -g/--single-file-segments option.
281
282Added `vfio-user` transport type for virtio-blk and virtio-scsi devices.
283
284### vmd
285
286Fixed hotplug when a device is inserted in a slot in which a disk was already enumerated previously.
287Added two new RPCs: `vmd_remove_device` simulating a hotremove, and `vmd_rescan`, which rescans all
288buses managed by the VMD driver and hotplugs all newfound devices.
289
290## v22.05
291
292### sock
293
294A new option `ack_timeout` was added to the `spdk_sock_opts` structure.
295
296### util
297
298A new parameter `bounce_iovcnt` was added to `spdk_dif_generate_copy` and `spdk_dif_verify_copy`.
299The `bounce_iovcnt` is used to specify the number of bounce_iov to support multiple block-aligned
300fragment copies.
301
302A new API `spdk_copy_iovs_to_buf` and `spdk_copy_buf_to_iovs` were added to copy iovs to buf or
303copy buf to iovs. There're many cases need to use these two APIs.
304
305### bdev
306
307Removed deprecated spdk_bdev_module_finish_done(). Use spdk_bdev_module_fini_done() instead.
308
309A new API `spdk_bdev_unregister_by_name` was added to handle race conditions correctly.
310
311New APIs, `spdk_for_each_bdev` and `spdk_for_each_bdev_leaf`, were added to provide iteration
312safe for race conditions.
313
314A new RPC `bdev_nvme_get_io_paths` was added to get all active I/O paths.
315
316A new RPC `bdev_nvme_set_preferred_path` was added to set preferred I/O path for an NVMe bdev
317when in multipath mode. This RPC does not support NVMe bdevs in failover mode.
318
319A new RPC `bdev_nvme_set_multipath_policy` was added to set multipath policy of a NVMe bdev
320in multipath mode.
321
322A new option `disable_auto_failback` was added to the `bdev_nvme_set_options` RPC to disable
323automatic failback.
324
325### idxd / dsa
326
327A new parameter `flags` was added to all low level submission and preparation
328APIs to enable the caller to pass operation flags per the DSA specification.
329
330A new flag 'SPDK_IDXD_FLAG_PERSISTENT' was added to let DSA know that
331the destination is persistent.
332
333The RPC `idxd_scan_accel_engine` has been renamed to `dsa_scan_accel_engine`
334
335The RPC `iaa_scan_accel_engine` has been added.
336
337Many HW related structs/functions with the name `idxd` have been renamed `dsa`
338to more accurately represent the HW they are associated with.
339
340Two new functions were added to the library `spdk_idxd_submit_compress` and
341`spdk_idxd_submit_decompress`
342
343### accel_fw
344
345A new parameter `flags` was added to accel API.
346The APIs include:
347`spdk_accel_submit_copy`
348`spdk_accel_submit_dualcast`
349`spdk_accel_submit_fill`
350`spdk_accel_submit_copy_crc32c`
351`spdk_accel_submit_copy_crc32cv`
352`spdk_accel_submit_compress`
353`spdk_accel_submit_decompress`
354
355A new flag `ACCEL_FLAG_PERSISTENT` was added to indicate the target memory is PMEM.
356
357The API `spdk_accel_get_capabilities` has been removed.
358
359### crypto
360
361Support for AES_XTS was added for MLX5 polled mode driver (pmd).
362
363bdev_crypto_create RPC now requires hexlified 'key' and 'key2' params for all pmd drivers.
364Unhexlifying is performed during RPC command processing and the vbdev crypto module runs on
365binary keys as before.
366
367### bdev
368
369Added a timeout option to the `bdev_get_bdevs` RPC.  It allows the user to specify the amount of
370time to wait until a bdev with a given name appears in the system.
371
372### bdev_nvme
373
374Added `bdev_nvme_add_error_injection` and `bdev_nvme_remove_error_injection` RPCs to add and
375remove NVMe error injections.
376
377New parameters, `ctrlr_loss_timeout_sec`, `reconnect_delay_sec`, and `fast_io_fail_timeout_sec`, are
378added to the RPC `bdev_nvme_set_options`. They can be overridden if they are given by the RPC
379`bdev_nvme_attach_controller`.
380
381### blobstore
382
383New functions `spdk_blob_io_writev_ext` and `spdk_blob_io_readv_ext` are added. The new functions accept
384`spdk_blob_ext_io_opts` structure with extended IO request options.
385
386### event
387
388Added `msg_mempool_size` parameter to `spdk_reactors_init` and `spdk_thread_lib_init_ext`.
389The size of `g_spdk_msg_mempool` can now be controlled through the same-named
390user option of `spdk_app_opts` structure.
391
392### nvme
393
394The API `spdk_nvme_ctrlr_prepare_for_reset()` was deprecated. The functionality provided by the
395`spdk_nvme_ctrlr_prepare_for_reset()` was merged into the API `spdk_nvme_ctrlr_disconnect()`.
396
397### nvmf
398
399Removed deprecated max_qpairs_per_ctrlr parameter from nvmf_create_transport RPC. Use
400max_io_qpairs_per_ctrlr instead.
401
402Deprecated the ability for hosts to connect to the discovery subsystem automatically on any
403existing listener. Users should now explicitly add listeners for the discovery subsystem.
404Host can still connect to the discovery subsystem as before, but a warning message will be
405emitted if no listener was configured for the transport ID of the incoming connection.
406
407Added adaptive interrupt feature for vfio-user transport. New parameter `disable_adaptive_irq`
408is added to the RPC `nvmf_create_transport`.
409
410### thread
411
412Added `spdk_thread_exec_msg()` API.
413
414### scheduler
415
416`framework_set_scheduler` can now be called after application initialization.
417Added callbacks to set custom parameters specific for each scheduler implementation
418and `framework_get_scheduler` to retrieve them.
419
420Added `dynamic` scheduler options: load_limit, core_limit, core_busy. Their descriptions
421are available in JSON-RPC document, in section
422[framework_set_scheduler](jsonrpc.html#rpc_framework_set_scheduler).
423
424### raid
425
426Add concat as a special raid module. The concat module could create a virtual bdev.  The
427virtual bdev combines multiple underlying bdevs together. The layout of the underlying
428bdevs is one after another. The concat bdev is extendable. When the free space of the
429concat bdev is not enough, the user can deconstruct the concat bdev, then reconstruct it
430with an additional underlying bdev.
431
432### sock
433
434Allow MSG_ZEROCOPY flag to be set or not according to data size, which can be enabled and
435set by setting "zerocopy_threshold". zerocopy_threshold = 0 means disable this function;
436zerocopy_threshold > 0 means enable it and use this value as the threshold.
437
438### rpc
439
440Introduced `zerocopy_threshold` to enable zerocopy on send for server sockets according to
441data size to be flushed.
442
443## v22.01
444
445### accel
446
447The batching capability was removed. Batching is now considered an implementation
448detail of the low level drivers.
449
450### bdev
451
452The NVMe bdev module supports multipath and improved I/O error resiliency.
453
454The parameter `retry_count` of the RPC `bdev_nvme_set_options` was deprecated and will be
455removed in SPDK 22.04, and the parameter `transport_retry_count` is added and used instead.
456
457An new parameter `bdev_retry_count` is added to the RPC `bdev_nvme_set_options`.
458
459New parameters, `ctrlr_loss_timeout_sec`, `reconnect_delay_sec`, and `fast_io_fail_timeout_sec`, are
460added to the RPC `bdev_nvme_attach_controller`.
461
462An new parameter `num_io_queues` is added to `bdev_nvme_attach_controller` RPC to allow specifying amount
463of requested IO queues.
464
465Added `key_file` parameter to the `rbd_register_cluster` RPC.  It is an optional parameter to
466specify a keyring file to connect to a RADOS cluster.
467
468Added `spdk_bdev_get_zone_id` API to retrieve zone_id for a certain LBA.
469
470### bdev_aio
471
472Added `bdev_aio_rescan` RPC to allow rescanning the size of aio bdev.
473
474### bdev_nvme
475
476Added discovery service to bdev_nvme module, which now can connect to a discovery controller.
477bdev_nvme will connect to all current and future subsystems in the discovery controller.
478Added `bdev_nvme_start_discovery` and `bdev_nvme_stop_discovery` RPC.
479
480### dpdk
481
482Updated DPDK submodule to DPDK 21.11.
483
484### env
485
486Added `spdk_pci_for_each_device`.
487
488Removed `spdk_pci_get_first_device` and `spdk_pci_get_next_device`.  These APIs were unsafe, because
489they did not account for PCI devices being inserted or removed while the caller was using handles
490returned from these APIs.  Existing users of these APIs should switch to `spdk_pci_for_each_device`
491instead.
492
493Added 3 experimental APIs to handle PCI device interrupts (`spdk_pci_device_enable_interrupt`,
494`spdk_pci_device_disable_interrupt`, `spdk_pci_device_get_interrupt_efd`).
495
496Added `framework_get_pci_devices` RPC to list PCIe devices attached to an SPDK application.
497
498### idxd
499
500Many APIs are now vectored rather than scalar, meaning they take iovecs instead of individual pointers.
501
502### json
503
504Added `spdk_json_write_bytearray` API to serialize a buffer as a hex string.
505
506### nvme
507
508API `spdk_nvme_trtype_is_fabrics` was added to return existing transport type
509is fabric or not.
510
511API `spdk_nvme_poll_group_remove` was limited to be available only for a
512disconnected qpair in the group.
513
514New APIs, `spdk_nvme_ctrlr_disconnect`, `spdk_nvme_ctrlr_reconnect_async`, and
515`spdk_nvme_ctrlr_reconnect_poll_async`, have been added to improve error recovery, and
516the existing APIs,`spdk_nvme_ctrlr_reset_async` and `spdk_nvme_ctrlr_reset_poll_async`
517were deprecated.
518
519Added `spdk_nvme_ctrlr_get_discovery_log_page` API for getting the full discovery log page
520from a discovery controller.
521
522### nvmf
523
524Added support for zero-copy operations in the NVMe-oF TCP target. It can be enabled via
525the `zcopy` parameter when creating a transport. The zero-copy operations are only used
526for requests not using in-capsule data.
527
528Added a `subsystem` parameter to `spdk_nvmf_transport_stop_listen_async`. When not NULL,
529it will only disconnect qpairs for controllers associated with the specified subsystem.
530
531Removed accept poller from transport layer. Each transport can have its own policy of
532handling new connections. To notify transport layer `spdk_nvmf_poll_group_add` and
533`spdk_nvmf_tgt_new_qpair` can be used.
534
535### scsi
536
537Structure `spdk_scsi_lun` has been extended with new member `resizing` so that SCSI layer now reports
538unit attention for disk resize.
539
540### trace
541
542Added `spdk_trace_create_tpoint_group_mask` to return tracepoint group mask from
543a tracepoint group name.
544
545Added `trace_set_tpoint_mask` and `trace_clear_tpoint_mask` RPC to allow enabling
546individual traces.
547
548### util
549
550Added `spdk_ioviter_first` and `spdk_ioviter_next` to iterate over two iovecs and
551yield pointers to common length segments.
552
553### sock
554
555A new parameter `hint` is added to `spdk_sock_get_optimal_sock_group`. It allows to suggest
556a poll group when no optimal poll group is found.
557
558## v21.10
559
560Structure `spdk_nvmf_target_opts` has been extended with new member `discovery_filter` which allows to specify
561filtering rules applied during discovery log generation. Refer to `enum spdk_nvmf_tgt_discovery_filter` for more info.
562
563### bdev
564
565New API `spdk_bdev_get_memory_domains` has been added, it allows to get SPDK memory domains used by bdev.
566
567New API functions `spdk_bdev_readv_blocks_ext` and `spdk_bdev_writev_blocks_ext` have been added.
568These functions accept `spdk_bdev_ext_io_opts` structure with extended IO request
569options, e.g. DMA memory domain which describes data that may belong to another memory domain and
570can't be accessed directly.
571
572Added `async_fini_start` to allow bdev modules to complete the `fini_start` asynchronously,
573with new `spdk_bdev_module_fini_start_done` API.
574
575Deprecated `spdk_bdev_module_finish_done()` API, which will be removed in SPDK 22.01.
576Bdev modules should use `spdk_bdev_module_fini_done()` instead.
577
578The `ocssd` bdev has been removed. The Open Channel specification has been largely superseded by
579zoned namespaces, few if any devices have been brought to market, and there is little reason to
580continue to support this. OCSSD support in the nvme driver will remain for now.
581
582### dma
583
584A new library, lib/dma, has been added. This library provides the necessary infrastructure for
585handling systems and devices with multiple memory domains. For example, a PCIe add-in card with an
586SoC may be running SPDK on the SoC. That SoC has its own local memory, but SPDK may be controlling
587devices that can also access the host system memory. This library provides infrastructure to enumerate
588the memory domains and request hardware perform DMA transfers between them.
589
590### dpdk
591
592Updated DPDK submodule to DPDK 21.08.
593
594### event
595
596Added the `disable_signal_handlers` flag to the `spdk_app_opts` struct.
597
598### idxd
599
600Added `spdk_idxd_get_socket` to query the socket that the idxd device
601is on.
602
603### json
604
605Added API to allow for writing and decoding of new types:
606
607- `spdk_json_write_named_uint16`
608- `spdk_json_write_named_uint8`
609- `spdk_json_write_uint16`
610- `spdk_json_write_uint8`
611- `spdk_json_number_to_uint8`
612- `spdk_json_decode_uint8`
613
614### log
615
616Added API `spdk_log_to_syslog_level` to return syslog level based on SPDK's
617log level.
618
619### nvme
620
621Added new functions `spdk_nvme_zns_set_zone_desc_ext` and `spdk_nvme_zns_ext_report_zones`
622to set zone descriptor extension and to get extended zone report respectively.
623
624New API `spdk_nvme_ctrlr_get_memory_domains` has been added, it allows to get SPDK memory domains used by nvme controller.
625
626New API functions `spdk_nvme_ns_cmd_readv_ext` and `spdk_nvme_ns_cmd_writev_ext`
627have been added. These functions accept `spdk_nvme_ns_cmd_ext_io_opts` structure with extended IO request
628options, e.g. DMA memory domain which describes data that may belong to another memory domain and
629can't be accessed directly.
630
631Added a new function `spdk_nvme_ctrlr_get_regs_bpinfo` to get boot partition info of a controller.
632Added new functions `spdk_nvme_ctrlr_write_boot_partition`,
633`spdk_nvme_ctrlr_read_boot_partition_start` and `spdk_nvme_ctrlr_read_boot_partition_poll`
634to write and read the boot partitions of a controller.
635
636Added `spdk_nvme_ctrlr_get_opts` to retrieve the current controller options.
637
638Added `async_mode` to `spdk_nvme_io_qpair_opts` to enable creation of submission and completion
639queues asynchronously. This mode is currently supported at PCIe layer,
640which tracks the qpair creation with state machine and returns to the user immediately.
641Default mode is set to false to create io qpairs synchronously.
642
643Added `spdk_nvme_ctrlr_get_regs_cc` to retrieve NVMe controller CC (Configuration) register.
644
645Added `spdk_nvme_ctrlr_prepare_for_reset` to inform the driver that the application is preparing
646to reset the specified NVMe controller. This function allows the driver to make decisions
647knowing that a reset is about to happen.
648
649### nvmf
650
651Added `oncs` to `struct spdk_nvmf_ctrlr_data` so that the transport layer
652can decide support RESERVATION feature or not.
653
654An `opts_size` element was added in the `spdk_nvmf_ns_opts` structure to solve the
655ABI compatibility issue between different SPDK version. An new option `anagrpid` was
656added in the `spdk_nvmf_ns_opts` structure.
657
658An new parameter `anagrpid` was added to the RPC `nvmf_subsystem_add_ns`.
659
660An new parameter `anagrpid` was added to the RPC `nvmf_subsystem_listener_set_ana_state`.
661
662`spdk_nvmf_subsystem_destroy` is now can be asynchronous, it accepts a callback and callback argument.
663
664A new parameter, `poll_groups_mask` was added to the `nvmf_set_config` RPC that allows specifying
665a subset of cores for the nvmf poll groups. This helps to avoid imbalances when some cores are
666busy with periodic timer tasks that run very frequently.
667
668A new parameter, `commit` was added to `nvmf_bdev_ctrlr_end_zcopy` that allows indicating whether
669the buffers should be committed.
670
671Added `listen_dump_opts` to `spdk_nvmf_transport_ops` so that the transport layer can display
672listen opts.
673
674Added `fabrics_connect_timeout_us` to `bdev_nvme_attach_controller` RPC to allow specifying
675timeout for connect operation.
676
677Added `multipath` to `bdev_nvme_attach_controller` RPC to allow specifying multipath behavior.
678
679### scheduler
680
681New API for implementing schedulers and governors. Please see `include/spdk/scheduler.h` for details.
682
683### scsi
684
685New functions, `spdk_scsi_dev_get_first_lun` and `spdk_scsi_dev_get_next_lun`
686have been added to iterate LUNs of a SCSI device.
687
688Each SCSI device supports 256 LUNs at the maximum now and the macro constant
689`SPDK_SCSI_DEV_MAX_LUN` was removed.
690
691### trace_parser
692
693A new library, lib/trace_parser, has been added. This library provides functions that parse traces
694recorded by an SPDK application. That includes merging traces from multiple cores,
695sorting them by their timestamp and constructing trace entries spanning across multiple buffers.
696
697### util
698
699The `spdk_fd_group_add` API now takes a `name` parameter.
700
701## v21.07
702
703### accel_fw
704
705Added API `spdk_accel_submit_copy_crc32c` to perform a CRC32C while copying data.
706
707Added API `spdk_accel_batch_prep_copy_crc32c` to batch CRC32C + copy commands.
708
709Added API `spdk_accel_submit_copy_crc32cv` to submit chained CRC32C + copy commands.
710
711### bdev
712
713Change `spdk_bdev_read_blocks_with_md` arg offset definition from int64_t to uint64_t.
714
715Red-black tree has been used to organize the bdev names and aliases uniformly
716to provide faster lookup.
717
718Removed ZCOPY emulation: The bdev module can be checked to see if it supports ZCOPY
719and if not supported then use existing READ/WRITE commands.
720
721Added iov to spdk_bdev_zcopy_start.
722
723### dpdk
724
725Updated DPDK submodule to DPDK 21.05.
726
727### idxd
728
729Remove the `probe_cb` parameter in `spdk_idxd_probe` function. And remove the definition
730of `spdk_idxd_probe_cb` function pointer. It should be implemented in idxd_user.c.
731
732Added API `spdk_idxd_submit_copy_crc32c` to perform a CRC32C while copying data.
733
734Added API `spdk_idxd_batch_prep_copy_crc32c` to prepare a batch operation to perform
735a CRC32C while copying data.
736
737We have userspace idxd driver under accel_engine library (module/accel/idxd/accel_engine).
738And kernel idxd driver usage is also added under the accel_engine library. This approach
739implemented a wrapper library to use IDXD device by leveraging the kernel DSA driver in
740SPDK idxd library (lib/idxd). Then users can leverage the RPC later to configure how to
741use the DSA device by user space driver or kernel driver.
742
743### init
744
745Added new `init` library that initializes the SPDK subsystems, which previously was
746internal to application framework. That functionality has been made public and for
747use by applications which don't leverage SPDK's application framework.
748
749### iscsi
750
751New parameters, `pdu_pool_size`, `immediate_data_pool_size`, and `data_out_pool_size`,
752were added to the RPC `iscsi_set_options` to run iSCSI target with varying amount of
753available memory.
754
755### json
756
757Added API `spdk_json_write_named_uint128` and `spdk_json_write_uint128` to perform
758the uint128 related data.
759
760### net
761
762Removed deprecated `net` library.
763
764Added support for ZCOPY.  ZCOPY is used in preference to READ and WRITE if the
765bdev module supports ZCOPY and the bdev module has ZCOPY enabled.
766
767### nvme
768
769`spdk_nvme_map_prps` and `spdk_nvme_map_cmd` were moved to nvmf/vfio-user as internal APIs
770as vfio-user is the only user for the above two APIs.
771
772Added a new function `spdk_nvme_ns_cmd_copy` to submit a Simple Copy Command to a Namespace.
773
774Update the `spdk_nvme_generic_command_status_code` structure with new status code
775according to the definition in NVMe 1.4 spec.
776
777`spdk_nvme_ctrlr_get_default_ctrlr_opts` now sets `use_cmb_sqs` to false. This means
778that if a controller has a CMB and supports SQs in the CMB, SPDK will not use
779the CMB for SQs by default - the user must set `use_cmb_sqs` to true in
780the `spdk_nvme_ctrlr_opts` structure prior to controller attach.
781
782Add a new function `spdk_nvme_detach_poll` to simplify a common use case to continue
783polling until all detachments complete.
784
785Added new argument `timeout_admin_us` to `spdk_nvme_ctrlr_register_timeout_callback` so callers
786can specify a different timeout for admin commands vs. io commands.
787
788An existing function `spdk_nvme_detach_async` was updated to add one or more detachments
789to an active context while it is being polled.
790
791Rename a variable in the member `cmic` of the struct `spdk_nvme_ctrlr_data` from
792`multi_host` to `multi_ctrlr`. The variable means that the NVM subsystem may have two or
793more controllers if set to 1. However `multi_host` had indicated a particular use case
794such that the NVM subsystem is used by multiple hosts.
795
796A new option `disable_read_ana_log_page` was added to struct `spdk_nvme_ctrlr_opts` to disable
797reading ANA log page. The upper layer is expected to read ANA log page instead if `true`.
798The default value is `false`.
799
800New APIs, `spdk_nvme_ctrlr_reset_async` and `spdk_nvme_ctrlr_reset_poll_async`, have been added to
801reset a controller asynchronously.
802
803New RPC `bdev_nvme_reset_controller` was added, to reset an NVMe controller.
804
805Added `spdk_nvme_ns_get_nguid` function to get NGUID for the given namespace.
806
807Added `spdk_nvme_ctrlr_is_fabrics` function to indicate whether a ctrlr handle
808is associated with a fabrics controller.
809
810### nvmf
811
812Added `min_cntlid` and `max_cntlid` to `nvmf_create_subsystem` to limit the controller ID range.
813Added `spdk_nvmf_subsystem_get_min_cntlid` and `spdk_nvmf_subsystem_get_max_cntlid` to request those values.
814
815`spdk_nvmf_request_get_buffers_multi` API is removed.
816
817Added the `nvmf_set_crdt` RPC for setting command retry delay times.
818
819Expanded `spdk_nvmf_poll_group_stat` with current qpair count statistics.
820
821Removed following deprecated APIs:
822
823- `spdk_nvmf_poll_group_get_stat` (function in `nvmf.h`),
824- `spdk_nvmf_transport_poll_group_get_stat` (function in `nvmf.h`),
825- `spdk_nvmf_transport_poll_group_free_stat`(function in `nvmf.h`),
826- `spdk_nvmf_rdma_device_stat` (struct in `nvmf.h`),
827- `spdk_nvmf_transport_poll_group_stat` (struct in `nvmf.h`),
828- `poll_group_get_stat` (transport op in `nvmf_transport.h`),
829- `poll_group_free_stat` (transport op in `nvmf_transport.h`).
830
831### rpc
832
833New RPC `bdev_rbd_register_cluster` and `bdev_rbd_unregister_cluster` was added, it allows to create
834and delete the rados object cluster, then users can choose the cluster to create related rbd
835device.
836
837Revised `bdev_rbd_create` parameter, it allows to use an optional parameter `--cluster-name`
838to create a rbd bdev with  an already registered Rados Cluster Object.
839
840New RPC `bdev_rbd_get_clusters_info` was added, it allows to get the info of the registered
841Rados Cluster names.
842
843New optional parameter, `timeout_admin_us`, added to the bdev_nvme_set_options RPC.
844
845Revised a parameter `--stripe-size_kb` to `--stripe-size-kb` of `bdev_raid_create` method
846provided in `scripts/rpc.py` for consistency.
847
848An new optional parameter `config_kernel_mode` was added to the RPC `idxd_scan_accel_engine`,
849and this is used to enable using the kernel mode IDXD driver.
850
851Removed deprecated parameter `enable-zerocopy-send` of RPC `sock_impl_set_options`,
852use `enable-zerocopy-send-server` or `enable-zerocopy-send-client` instead.
853Removed deprecated parameter `disable-zerocopy-send` of RPC `sock_impl_set_options`,
854use `disable-zerocopy-send-server` or `disable-zerocopy-send-client` instead.
855
856### rpm
857
858Removed deprecated `pkg/spdk.spec`, please use `rpmbuild/spdk.spec` instead.
859See [RPM documentation](https://spdk.io/doc/rpm.html) for more details.
860
861### thread
862
863Red-black tree has been used for timed pollers to provide faster insertion and deletion
864and for io_devices to provide faster lookup.
865
866Removed `spdk_io_channel` structure from public header and moved it to thread_internal.h.
867
868### trace
869
870Added `spdk_trace_register_description_ext` function to register variable number of tracepoint arguments.
871
872Added ability to chain multiple trace entries together to extend the size of the argument buffer.
873
874### util
875
876Red-black tree macros has been added by using the macros provided by the FreeBSD operating system
877under the same BSD license.
878
879Add an new macro `SPDK_SIZEOF_MEMBER` to get the size of a member of a struct.
880
881`spdk_crc32c_iov_update` function was added to support calculating the crc32c of the iovs.
882
883Added zipf random number generator with power law probability distribution.
884When applied to performance testing of block devices, it will select blocks over
885the full range of LBAs, but will more frequently select lower-numbered LBAs.
886
887## v21.04
888
889### accel
890
891Two new accelerated crc32 functions `spdk_accel_submit_crc32cv` and
892`spdk_accel_batch_prep_crc32cv` are added in order to provide the
893chained accelerated CRC32 computation support.
894
895### bdev
896
897For `bdev_ocssd_create` RPC, the optional parameter `range` was removed.
898Only one OCSSD bdev can be created for one OCSSD namespace.
899
900Removed the `spdk_bdev_open` from bdev library API.
901Removed the `spdk_vbdev_register` and `spdk_bdev_part_base_construct` from bdev module API.
902Removed the `config_text` function for bdev modules to report legacy config.
903
904Added `spdk_bdev_get_max_active_zones` API to display maximum number active zones of a given bdev.
905
906Added `spdk_bdev_get_max_zone_append_size` API to display maximum zone append data transfer size.
907
908### bdev_nvme
909
910Added support for zoned namespaces.
911
912### blobstore
913
914Removed the `spdk_bdev_create_bs_dev_from_desc` and `spdk_bdev_create_bs_dev` API.
915
916### env
917
918Added `spdk_pci_device_allow` API to allow applications to add PCI addresses to
919the allowed list after the application has started.
920
921Removed the `pci_whitelist`, `pci_blacklist` and `master_core` members of struct `spdk_env_opts`.
922
923Added hotplug support based on uevent in `pci_event.c`. Added usage of this functionality in
924nvme, virtio-scsi and virtio_blk libraries. Please see the new API `spdk_pci_event_listen`,
925`spdk_pci_get_event`, `spdk_pci_register_error_handler` and `spdk_pci_unregister_error_handler`.
926
927### event
928
929Removed the `config_file`, `max_delay_us`, `pci_whitelist`
930and `pci_blacklist` members of struct `spdk_app_opts`.
931
932### idxd
933
934A new API `spdk_idxd_device_needs_rebalance` was added so that users of the library
935can know whether they need to rebalance the flow control for the channel
936that was just added/removed.  This is based on how the low level library
937shares devices amongst channels.
938
939The API `spdk_idxd_reconfigure_chan` had the `num_channels` removed as this
940is now tracked in the library.  The app makes use the new API above to
941determine whether to rebalance or not. This applies to `spdk_idxd_configure_chan`
942as well.
943
944The API `spdk_idxd_put_channel` now returns the rebalance state for the
945underlying device.
946
947### iscsi
948
949A security vulnerability has been identified and fixed in the SPDK iSCSI target.
950A TEXT PDU with no data, but CONTINUE flag set, would result in a NULL pointer dereference
951and crash the SPDK iSCSI target process. All users of the SPDK iSCSI target
952are recommended to update. All SPDK versions <= v21.01 are affected.
953
954### net
955
956The net library is deprecated and will be removed in the 21.07 release.
957
958### nvme
959
960Added a new function `spdk_nvme_ctrlr_get_regs_pmrcap` to get the PMR capabilities.
961
962Added an accelerated table pointer in `spdk_nvme_poll_group`
963which can be used to provide the accelerated functions by users with
964hardware engine, such as crc32c accelerated function.
965
966Added new functions `spdk_nvme_ctrlr_get_pmrsz`, `spdk_nvme_ctrlr_enable_pmr`,
967`spdk_nvme_ctrlr_disable_pmr`, `spdk_nvme_ctrlr_map_pmr` and `spdk_nvme_ctrlr_unmap_pmr`.
968
969Added NVMe transport operations to enable, disable, map and unmap the PMR.
970
971Added `spdk_nvme_qpair_get_optimal_poll_group` function and `qpair_get_optimal_poll_group`
972function pointer in spdk_nvmf_transport_ops structure in order to add the qpair to the most
973suitable polling group.
974
975Added OPTPERF and namespace optimal performance fields to nvme_spec.h.
976
977Added `spdk_nvme_set_hotplug_filter` API to allow applications to choose which
978hot-inserted SSDs should be probed. This is useful for use cases where multiple
979independent SPDK processes are running on one node. The filter function can
980then be implemented in these processes to decide which SSDs to probe based on
981the new SSD's PCI address.
982
983New functions `spdk_nvme_poll_group_get_stats` and `spdk_nvme_poll_group_free_stats`
984were added. These functions allow to get transport statistics per NVME poll group.
985
986Added `spdk_nvme_map_cmd` API to map the NVMe command with SGL cases.
987
988Added support for vector variant of ZNS zone append commands with new API
989`spdk_nvme_zns_zone_appendv` and `spdk_nvme_zns_zone_appendv_with_md`.
990
991Added `spdk_nvme_zns_ns_get_max_open_zones` and `spdk_nvme_zns_ns_get_max_active_zones` API,
992to display maximum number of open and active zones of the given namespace.
993
994Added `spdk_nvme_zns_ns_get_zone_size_sectors` API to provide size of zone in number of
995sectors.
996
997Added `spdk_nvme_qpair_get_id` API to display the ID of the specified qpair.
998
999### nvmf
1000
1001Removed the `spdk_nvmf_tgt_listen` and `spdk_nvmf_subsystem_add_ns` API.
1002
1003Added new APIs:
1004
1005- `spdk_nvmf_poll_group_dump_stat` (function in `nvmf.h`).
1006- `poll_group_dump_stat` (transport op in `nvmf_transport.h`).
1007
1008The following APIs have been deprecated and will be removed in SPDK 21.07:
1009
1010- `spdk_nvmf_poll_group_get_stat` (function in `nvmf.h`),
1011- `spdk_nvmf_transport_poll_group_get_stat` (function in `nvmf.h`),
1012- `spdk_nvmf_transport_poll_group_free_stat`(function in `nvmf.h`),
1013- `spdk_nvmf_rdma_device_stat` (struct in `nvmf.h`),
1014- `spdk_nvmf_transport_poll_group_stat` (struct in `nvmf.h`),
1015- `poll_group_get_stat` (transport op in `nvmf_transport.h`),
1016- `poll_group_free_stat` (transport op in `nvmf_transport.h`).
1017
1018See header files for details.
1019
1020The `trtype` field in JSON returned by `nvmf_get_stats` RPC contains now the name of the transport,
1021which is the same as the type for defined transports and more informative for a custom transport.
1022
1023Added `hdgst` and `ddgst` parameters to `bdev_nvme_attach_controller` RPC in order change
1024state of TCP header and data digest.
1025
1026Added `num_cqe` parameter to `nvmf_create_transport` RPC to set number of completion queues (CQ)
1027for RDMA transport. Useful when CQ resize operation is not supported, for example iWARP.
1028
1029### ocf
1030
1031Updated OCF submodule to v20.12.2
1032
1033Added `bdev_ocf_set_cache_mode` RPC to dynamically switch cache mode of OCF bdev.
1034
1035### opal
1036
1037Removed the `spdk_opal_supported` API.
1038
1039### raid
1040
1041For `bdev_raid_create` RPC, the deprecated parameter `strip_size` was removed.
1042
1043### rpc
1044
1045New RPC `bdev_nvme_get_transport_statistics` was added, it allows to get transport statistics
1046of nvme poll groups.
1047
1048Parameter `enable-zerocopy-send` of RPC `sock_impl_set_options` is deprecated and will be removed in SPDK 21.07,
1049use `enable-zerocopy-send-server` or `enable-zerocopy-send-client` instead.
1050Parameter `disable-zerocopy-send` of RPC `sock_impl_set_options` is deprecated and will be removed in SPDK 21.07,
1051use `disable-zerocopy-send-server` or `disable-zerocopy-send-client` instead.
1052
1053Added cmd_parser.py used to parse the args from argparse. There are
1054two benefit to use command parser:
1055
1056- Simplify the definition of rpc method. It will reduce the rpc method code.
1057- Make the rpc call more versatile. User can add private args into rpc method.
1058
1059### rpm
1060
1061Added support for new RPM spec, rpmbuild/spdk.spec, which can be used for packaging the
1062SPDK. The pkg/spdk.spec is considered to be deprecated and scheduled for removal in SPDK 21.07.
1063See [RPM documentation](https://spdk.io/doc/rpm.html) for more details.
1064
1065### sock
1066
1067The type of `enable_placement_id` in struct `spdk_sock_impl_opts` is changed from
1068bool to int. We can use RPC to configure different value of `enable_placement_id`.
1069Then we can leverage SO_INCOMING_CPU to get placement_id, which aims to utilize
1070CPU cache locality, enabled by setting enable_placement_id=2.
1071
1072A new socket placement mode called PLACEMENT_MARK has been added. Some NICs allow
1073sockets to be marked using the SO_MARK socket option as a hint for which hardware
1074queue they should be associated with. This mode leverages that by setting the same
1075value for all sockets within a poll group.
1076
1077New parameters `enable_zerocopy_send_server` and `enable_zerocopy_send_client` were added
1078to struct spdk_sock_impl_opts, these parameters enable or disable zero copy send for server
1079and client sockets which are created using `spdk_sock_listen` and `spdk_sock_listen_ext` (server);
1080`spdk_sock_connect` and `spdk_sock_connect_ext` (client) functions. Existing parameter
1081`enable_zerocopy_send`  enables or disables zero copy send for both server and client sockets.
1082
1083### thread
1084
1085A new API `spdk_io_channel_get_io_device` was added to get the io_device for the specified
1086I/O channel.
1087
1088Added `spdk_thread_set_interrupt_mode` function in order to set present spdk_thread into
1089interrupt mode or back to poll mode. It is valid only when thread interrupt facility is
1090enabled by `spdk_interrupt_mode_enable`.
1091
1092Added `spdk_poller_register_interrupt` function to mark that the poller is capable of
1093entering interrupt mode. Callback function will be called when the poller must transition
1094into or out of interrupt mode.
1095
1096### virtio
1097
1098Added the `bdev_virtio_blk_set_hotplug` RPC for the virtio blk pci device.
1099
1100## v21.01
1101
1102### bdev
1103
1104An `opts_size` element was added in the `spdk_bdev_opts` structure to solve the
1105ABI compatibility issue between different SPDK version. And also add `opts_size`
1106parameter in spdk_bdev_get_opts function. Two fields `small_buf_pool_size` and
1107`large_buf_pool_size` were added into spdk_bdev_opts, which were used to determine
1108the small and large buffer pool size of the whole bdev module.
1109
1110A new API `spdk_bdev_wait_for_examine` was added to allow for checking state of
1111examine process. Along with corresponding `bdev_wait_for_examine` RPC, which
1112is now always called during `spdk_bdev_subsystem_config_json` making sure
1113every bdev is ready to be used.
1114
1115A new API `spdk_bdev_io_get_aio_status` was added for getting the status of
1116bdev_io as Linux AIO errno. Also `spdk_bdev_io_complete_aio_status` function
1117and `SPDK_BDEV_IO_STATUS_AIO_ERROR` were added for bdev module to complete
1118a bdev_io with Linux AIO errno.
1119
1120A new API `spdk_bdev_get_module_name` was added for getting block device module name.
1121Also `spdk_bdev_get_module_ctx` was added to obtain a bdev module context for
1122the block device opened by the specified descriptor.
1123
1124Added `max_segment_size` and `max_num_segments` to `spdk_bdev` structure for
1125bdev modules to specify splitting requirements.
1126
1127### blob
1128
1129An `opts_size` element was added in the `spdk_bs_opts` structure to solve the
1130ABI compatibility issue between different SPDK version. And also add `opts_size`
1131parameter in `spdk_bs_opts_init` function.
1132
1133An `opts_size` element was added in the `spdk_blob_opts` structure to solve the
1134ABI compatibility issue between different SPDK version. And also add `opts_size`
1135parameter in `spdk_blob_opts_init` function.
1136
1137An `opts_size` element was added in the `spdk_blob_open_opts` structure to solve the
1138ABI compatibility issue between different SPDK version. And also add `opts_size`
1139parameter in `spdk_blob_open_opts_init` function.
1140
1141### build
1142
1143SPDK now generates pkg-config files to simplify the process of determining which
1144libraries must be linked into an SPDK application.
1145
1146### dpdk
1147
1148Updated DPDK submodule to DPDK 20.11.
1149
1150Removed `--with-igb-uio-driver` configure option. Since DPDK 20.11 igb_uio driver
1151was moved to separate dpdk-kmods repository. If required, users need to refer to
1152dpdk-kmods repository to build the driver.
1153
1154### env
1155
1156The `pci_whitelist`, `pci_blacklist` and `master_core` members of struct `spdk_env_opts`
1157have been deprecated.  The new members are named `pci_allowed`, `pci_blocked` and
1158`main_core` respectively.
1159
1160An `opts_size` element was added in the `spdk_app_opts` structure
1161to solve the ABI compatibility issue between different SPDK version. An `opts_size`
1162parameter is added into `spdk_app_opts_init` function.
1163
1164### event
1165
1166The `pci_whitelist` and `pci_blacklist` members of struct `spdk_app_opts` have been
1167deprecated.  The new members are named `pci_allowed` and `pci_blocked` respectively.
1168
1169The `--pci-blacklist` command line option has been deprecated, replaced with
1170`--pci-blocked`.
1171
1172The `--pci-whitelist/-W` command line options have been deprecated, replaced with
1173`--pci-allowed/-A`.
1174
1175Added new experimental `dynamic` scheduler that rebalances idle threads, adjusts CPU frequency
1176using dpdk_governor and turns idle reactor cores to interrupt mode. Please see
1177[scheduler documentation](https://www.spdk.io/doc/scheduler.html) for details.
1178
1179## ioat
1180
1181The PCI BDF whitelist option has been removed from the `ioat_scan_accel_engine` RPC.
1182IOAT PCI functions can still be allowed or denied using SPDK application command
1183line options.
1184
1185### isa-l
1186
1187Updated ISA-L submodule to v2.30.0.
1188
1189### json
1190
1191A new API `spdk_jsonrpc_send_bool_response` was added to allow sending response for
1192writing json bool results into one function.
1193Update API `bdev_nvme_set_options` and add a `keep_alive_timeout_ms` parameter. Now you
1194can specify the `keep_alive_timeout` before creating NVMe bdev.
1195
1196### nbd
1197
1198Change the return type of function `spdk_nbd_stop` from void to int. And update the
1199`spdk_nbd_fini` with two parameters to make its behavior from sync to async.
1200
1201### nvme
1202
1203Directives support was added to the NVMe driver.
1204
1205Two async APIs `spdk_nvme_ctrlr_cmd_directive_receive` and `spdk_nvme_ctrlr_cmd_directive_send`
1206are added for Directive Send and Directive Receive command, respectively.
1207
1208Added a new function `spdk_nvme_ctrlr_reset_subsystem` to perform a NVMe
1209subsystem reset. Note: The NVMe-oF target does not support the subsystem reset yet.
1210
1211Add a new function `spdk_nvme_bytes_to_numd` to transfer bytes to number of
1212dwords.
1213
1214Added a new custom transport `SPDK_NVME_TRANSPORT_VFIOUSER` to enable NVMe
1215driver running with NVMe over vfio-user target.
1216
1217Added the vfio-user custom transport implementation in NVMe driver which can connect
1218to NVMe over vfio-user target via vfio-user transport.
1219
1220Added a new function `spdk_nvme_ctrlr_set_remove_cb` to remove or override
1221`remove_cb` and `remove_ctx` specified when the controller was probed.
1222
1223Added support for ZNS zone append command with new API `spdk_nvme_zns_zone_append` and
1224`spdk_nvme_zns_zone_append_with_md`.
1225
1226### nvmf
1227
1228`nvmf_fc_lld_fini` now takes callback and hence updating FC Broadcom LLD driver
1229to the latest is required.
1230
1231FC transport supported primary tagging and VMID.
1232
1233Broadcom FC LLD driver and SPDK NVMe-oF FC transport consolidated one LLD API,
1234`nvmf_fc_init_poller_queues` into another LLD API `nvmf_fc_init_q`.
1235Hence updating Broadcom FC LLD driver to the latest is required.
1236
1237The functions `destroy` and `qpair_fini` in the transport interface now accept a
1238`cb_fn` and `cb_arg` to call upon completion, and their execution can be asynchronous.
1239
1240The SPDK NVMe-oF target now supports async event notification for discovery log changes.
1241This allows the initiator to create persistent connection to discovery controller and
1242be notified of any discovery log changes.
1243
1244An `opts_size` element was added in the `spdk_nvmf_transport_opts` structure
1245to solve the ABI compatibility issue between different SPDK version. And also add
1246`opts_size` parameter in `spdk_nvmf_transport_opts_init` function.
1247
1248Added a new custom vfio-user transport implementation in NVMe-oF which can provide
1249emulated NVMe devices to QEMU and SPDK NVMe driver.
1250
1251Added new API `spdk_nvmf_tgt_listen_ext` that uses `spdk_nvmf_listen_opts` to allow
1252passing generic options to specific transport. This functionality replaces one provided
1253with `nvmf_subsystem_set_options`. Also removed `nvmf_subsystem_set_options` RPC
1254that allowed transport specific options within subsystem.
1255
1256The `trsvcid` in `nvmf_subsystem_add_listener` RPC is now optional.
1257
1258Pausing a subsystem now only pauses all admin queues. This allows for the
1259management of hosts and listeners, plus the addition of namespaces without a
1260full subsystem pause. Additionally, the target now allows for pausing
1261individual namespaces within a subsystem. To remove a namespace from a
1262subsystem, only the specific namespace must be paused. I/O will continue to
1263other namespaces while these operations execute.
1264
1265### rpc
1266
1267An new optional parameter `wait` was added to the RPC `iscsi_create_portal_group`,
1268and an new RPC `iscsi_start_portal_group` was added. They will be used not to start
1269listening on portals for a portal group until all associated target nodes are created
1270at startup, otherwise some iSCSI initiators may fail to re-login when SPDK iSCSI
1271target application restarts.
1272
1273Two optional parameter `--small-buf-pool-size` and `--large-buf-pool-size` were added
1274into `bdev_set_options` function.
1275
1276### vhost
1277
1278Added optional `packed_ring_recovery` parameter to `vhost_create_blk_controller` RPC
1279enabling packed ring live recovery.
1280
1281## v20.10
1282
1283### accel
1284
1285New APIs `spdk_accel_batch_cancel` and `spdk_idxd_batch_cancel` were added to allow
1286cancelling a batch sequence.
1287
1288### bdev
1289
1290A new `spdk_bdev_part_base_construct_ext` function has been added and the
1291`spdk_bdev_part_base_construct` has been deprecated.  The
1292`spdk_bdev_part_base_construct_ext` function takes bdev name as an argument instead
1293of bdev structure to avoid a race condition that can happen when the bdev is being
1294removed between a call to get its structure based on a name and actually opening it.
1295
1296Removed `spdk_bdev_config_text` function for bdev modules to report legacy config.
1297
1298### blobstore
1299
1300A new `spdk_bdev_create_bs_dev_ext` function has been added and `spdk_bdev_create_bs_dev_from_desc`
1301function has been deprecated.
1302
1303### dpdk
1304
1305Updated DPDK submodule to DPDK 20.08.
1306
1307### env
1308
1309A new API `spdk_mem_get_fd_and_offset` was added to get file descriptor and offset for
1310a given virtual address.
1311
1312### event
1313
1314Removed `spdk_subsystem_config` callback for submodules as part of legacy config removal.
1315
1316Removed `spdk_app_get_running_config` function that printed configuration in legacy format,
1317and removed `usr1_handler` from `struct spdk_app_opts` callback that was used to call it.
1318
1319Added SPDK thread scheduler framework which is used to rebalance load among CPU cores.
1320The scheduler implementation is pluggable and two schedulers are added first, `static` scheduler
1321and `gscheduler` scheduler.
1322
1323`static` scheduler is used by default and does not reschedule threads and keeps the initial
1324assignments.
1325
1326CPU frequency governor framework and implementation are also added.
1327`dpdk_governor` is the first implementation and is based on rte_power library of DPDK.
1328`gscheduler` scheduler utilizes the CPU frequency governor.
1329
1330Scheduler and governor frameworks are experimental features.
1331
1332### fio
1333
1334Bdev fio_plugin no longer supports legacy configuration files. Options `spdk_conf` and
1335`spdk_json_conf` have to point to valid JSON configuration.
1336
1337### gpt
1338
1339Removed option to disable GPT probing via legacy configuration. Please use generic
1340bdev functionality to replicate the behavior. See `bdev_set_options --disable-auto-examine`
1341and `bdev_examine` RPC.
1342
1343### intel-ipsec-mb
1344
1345Updated intel-ipsec-mb submodule to v0.54
1346
1347### isa-l
1348
1349Updated ISA-L submodule to v2.29.0.
1350
1351### iscsi
1352
1353The iSCSI target supports iSCSI login redirection feature to achieve fault tolerance
1354and load balancing particularly in scale out iSCSI target system, which runs multiple
1355SPDK iSCSI targets.
1356
1357### json
1358
1359A new API `spdk_json_decode_object_relaxed` was added to allow parsing json values
1360even if decoder for a given key is not found.
1361
1362A new API `spdk_json_free_object` was added to free memory allocated by `spdk_json_decode_object`.
1363
1364### log
1365
1366A log flag structure, `spdk_log_register_flag`, `spdk_log_get_first_flag`,
1367`spdk_log_get_next_flag` and macro `SPDK_LOG_REGISTER_COMPONENT`, have been added which
1368enable registering and interacting with log flags. Added `SPDK_INFOLOG`, `SPDK_DEBUGLOG`
1369and `SPDK_LOGDUMP` macros to display logs for specified log flag.
1370
1371The log flags in the event framework `-L` and several SPDK applications has been enabled on
1372release builds of SPDK. On debug builds this option will additionally set
1373log print level to `SPDK_LOG_DEBUG`.
1374
1375A new API `spdk_log_enable_timestamps` and new RPC `log_enable_timestamps` was added to
1376toggle log timestamps.
1377
1378### miscellaneous
1379
1380The contents of the log_rpc library have been moved to the event library. The log_rpc
1381library now no longer exists.
1382
1383The contents of the app_rpc library have been moved to the event library. The app_rpc
1384library now no longer exists.
1385
1386The contents of the bdev_rpc library have been moved to the bdev library. The app_rpc
1387library now no longer exists.
1388
1389The bdevperf application now disables the zcopy API by default. Prior to this change,
1390bdevperf enabled using the zcopy API by default which caused a performance impact of
1391up to 25% on bdevs that don't natively support zcopy because the API emulates zero-copy
1392by allocating a buffer. The bdevperf `-x` param was renamed to `-Z` and the default
1393value changed to false. For bdevs that support zcopy, use the -Z flag to enable
1394using zcopy API.
1395
1396### net
1397
1398Net framework intended for use by user-space TCP stacks was removed.
1399
1400### nvme
1401
1402Zoned Namespace Command Set support has been added to NVMe driver, see `nvme_zns.h` for details.
1403
1404New APIs, `spdk_nvme_detach_async` and `spdk_nvme_detach_poll_async`, have been added to
1405detach multiple controllers in parallel to mitigate lengthy shutdown notification of
1406a few NVMe SSDs.
1407
1408New APIs, `spdk_nvme_ns_get_ana_group_id` and `spdk_nvme_ns_get_ana_state`, have been
1409added to get ANA group ID and ANA state of the given namespace, respectively.
1410
1411If no specific command set is requested (by setting the command_set member in the
1412`spdk_nvme_ctrlr_opts` structure), SPDK will automatically select the most appropriate
1413command set based on what the controller supports.
1414
1415### nvmf
1416
1417A new API `spdk_nvmf_subsystem_add_ns_ext` has been added and the API `spdk_nvmf_subsystem_add_ns`
1418has been deprecated.
1419
1420The NVMe-oF target now supports Asymmetric Namespace Access (ANA) Reporting to provide
1421multipath to NVMe-oF initiator.
1422
1423Add `no_wr_batching` parameter to `spdk_nvmf_transport_opts` struct to disable
1424Work Requests batching in RDMA transport.
1425
1426NVMf Target transports can now parse any additional JSON params in the nvmf_create_transport RPC
1427through the JSON context provided via spdk_nvmf_target_opts->transport_specific.
1428
1429A new RPC `nvmf_subsystem_set_options` was added to allow transport specific options within subsystem.
1430
1431A new API `spdk_nvmf_transport_stop_listen_async` was added to stop accepting new connections
1432at the provided address. `nvmf_subsystem_remove_listener` RPC now uses this function.
1433
1434A new API `spdk_nvmf_subsystem_disconnect_host` was added to disconnect all connections
1435originating from the provided hostnqn. `nvmf_subsystem_remove_host` RPC now uses this function.
1436
1437### ocf
1438
1439Updated OCF submodule to v20.03.1
1440
1441### rpc
1442
1443New optional parameters, `enable_placement_id` and `enable_quickack` were added to the
1444`sock_impl_set_options` RPC.
1445
1446A new RPC `bdev_examine_bdev` was added to allow users to examine a bdev explicitly.
1447It can be used only if bdev_auto_examine is set to false by the RPC `bdev_set_options`.
1448
1449New optional parameters `no_wr_batching` and `control_msg_num` were added to the RPC
1450'nvmf_create_transport'.
1451
1452New RPCs, `iscsi_target_node_set_redirect` and `iscsi_target_node_request_logout`, have
1453been added, and a new optional parameter `private` has been added to the RPC
1454`iscsi_create_portal_group` to support iSCSI login redirection feature.
1455
1456A new optional parameter `ana_reporting` was added to the RPC `nvmf_create_subsystem`, and
1457a new RPC `nvmf_subsystem_listener_set_ana_state` was added for ANA reporting.
1458
1459New RPCs, `nvmf_subsystem_get_listeners` and `nvmf_subsystem_get_qpairs`, were added to
1460retrieve configuration of the NVMe-oF subsystem.
1461
1462### scsi
1463
1464Two new APIs have been added `spdk_scsi_dev_construct_ext` and
1465`spdk_scsi_dev_add_lun_ext` that allow the upper layer(e.g. vhost-scsi) to
1466receive the notification when the scsi bdev has been resized.
1467
1468The `spdk_scsi_dev_construct` and `spdk_scsi_dev_add_lun` eventually may be
1469deprecated and removed.
1470
1471### sock
1472
1473The `enable_placement_id` field was added in the `struct spdk_sock_impl_opts` to
1474make the placement_id feature configurable by users. The default setting is
1475not enabled.
1476
1477The `enable_quick_ack` field was added in the `struct spdk_sock_impl_opts` to enable
1478or disable quick ack for the POSIX sock module. The default setting is not enabled.
1479
1480### thread
1481
1482`fd_group` is applied to support interrupt mode.
1483New APIs were added to support an experimental interrupt mode.  This allows modules or
1484libraries to selectively register file descriptors that the spdk_thread can wait on,
1485as an alternative to polling. In v20.10, this functionality is enabled in a very small
1486subset of SPDK libraries and modules.
1487
1488### util
1489
1490A new utility named `fd_group` was add. It is now
1491implemented by epoll on Linux platform. It can be used by
1492spdk_thread and reactor to implement interrupt mode.
1493
1494Added `spdk_bit_pool` utility, see `bit_pool.h` for details.
1495
1496### vhost
1497
1498SPDK has switched to DPDK's rte_vhost library since 19.07 release, removed the internal
1499rte_vhost library which is used for DPDK older than 19.05, removed the experimental vhost
1500nvme target which depends on the internal rte_vhost library.
1501
1502### vpp
1503
1504Removed socket abstraction for VPP.
1505
1506## v20.07: SPDK CSI driver, new accel_fw commands, I/O abort support
1507
1508spdk_json_free_object() was added to free memory allocated by spdk_json_decode_object().
1509
1510### accel
1511
1512A new API was added `spdk_accel_get_capabilities` that allows applications to
1513query the capabilities of the currently enabled accel engine back-end.
1514
1515A new capability, CRC-32C, was added via `spdk_accel_submit_crc32c`.
1516
1517The software accel engine implementation has added support for CRC-32C.
1518
1519A new capability, compare, was added via `spdk_accel_submit_compare`.
1520
1521The software accel engine implementation has added support for compare.
1522
1523Several APIs were added to `accel_engine.h` to support batched submission
1524of operations.
1525
1526Several APIs were added to `accel_engine.h` to support dualcast operations.
1527
1528### accel_fw
1529
1530The accel_fw was updated to no longer require the app to allocate an
1531accel_task on its behalf. All public APIs now take a callback arg as
1532the parameter that used to be the accel_task.
1533
1534The accel_fw API `spdk_accel_task_size` was removed as it is no longer
1535required.
1536
1537The accel_fw was updated to support compare, dualcast, crc32c.
1538
1539The accel_fw introduced batching support for all commands in all plug-ins.
1540See docs for detailed information.
1541
1542### bdev
1543
1544A new API `spdk_bdev_abort` has been added to submit abort requests to abort all I/Os
1545whose callback context match to the bdev on the given channel.
1546
1547### build
1548
1549The fio plugins now compile to `build/fio` and are named `spdk_bdev` and `spdk_nvme`.
1550Existing fio configuration files will need to be updated.
1551
1552### dpdk
1553
1554Updated DPDK submodule to DPDK 20.05.
1555
1556### env
1557
1558Several new APIs have been added to provide greater flexibility in registering and
1559accessing polled mode PCI drivers. See `env.h` for more details.
1560
1561### idxd
1562
1563The idxd library and plug-in module for the accel_fw were updated to support
1564all accel_fw commands as well as batching.  Batching is supported both
1565through the library and the plug-in module.
1566
1567IDXD engine support for CRC-32C has been added.
1568
1569### ioat
1570
1571A new API `spdk_ioat_get_max_descriptors` was added.
1572
1573### nvme
1574
1575An `opts_size`element was added in the  `spdk_nvme_ctrlr_opts` structure
1576to solve the ABI compatibility issue between different SPDK version.
1577
1578A new API `spdk_nvme_ctrlr_cmd_abort_ext` has been added to abort previously submitted
1579commands whose callback argument match.
1580
1581Convenience functions, `spdk_nvme_print_command` and `spdk_nvme-print_completion` were added
1582to the public API.
1583
1584A new function, `spdk_nvmf_cuse_update_namespaces`, updates the cuse representation of an NVMe
1585controller.
1586
1587A new function `qpair_iterate_requests` has been added to the nvme transport interface. ALl
1588implementations of the transport interface will have to implement that function.
1589
1590### nvmf
1591
1592The NVMe-oF target no longer supports connecting scheduling configuration and instead
1593always uses what was previously called "transport" scheduling.
1594
1595`spdk_nvmf_tgt_accept` no longer exists. The accept process now occurs automatically after
1596the creation of an nvmf target and queue pairs are assigned to poll groups by the underlying
1597transport. Further, `spdk_nvmf_transport_ops` has changed such that the accept function
1598pointer no longer takes a function pointer as an argument. Instead, transports should call
1599`spdk_nvmf_tgt_new_qpair` whenever they previously would have called that callback.
1600
1601The NVMe-oF target now supports aborting any submitted NVM or Admin command. Previously,
1602the NVMe-oF target could abort only Asynchronous Event Request commands.
1603
1604### rdma
1605
1606A new `rdma` library has been added. It is an abstraction layer over different RDMA providers.
1607Two providers are available - verbs (used by default when RDMA is enabled or enabled explicitly
1608using --with-rdma=verbs) and mlx5 Direct Verbs aka DV (enabled by --with-rdma=mlx5_dv).
1609Using mlx5_dv requires libmlx5 installed on the system.
1610
1611### rpc
1612
1613Parameter `-p` or `--max-qpairs-per-ctrlr` of `nvmf_create_transport` RPC command accepted by the
1614rpc.py script is deprecated, new parameter `-m` or `--max-io-qpairs-per-ctrlr` was added.
1615
1616Added `sock_impl_get_options` and `sock_impl_set_options` RPC methods.
1617
1618Command line parameters `-r` and `--rpc-socket` will longer accept TCP ports. RPC server
1619must now be started on a Unix domain socket. Exposing RPC on the network, as well as providing
1620proper authentication (if needed) is now a responsibility of the user.
1621
1622The `bdev_set_options` RPC has a new option, `bdev_auto_examine` to control the auto examine function
1623of bdev modules.
1624
1625New RPCs `sock_impl_get_options` and `sock_impl_set_options` been added to expose new socket features.
1626See `sock` section for more details.
1627
1628### sock
1629
1630Added `spdk_sock_impl_get_opts` and `spdk_sock_impl_set_opts` functions to set/get socket layer configuration
1631options. Options can be set independently for each implementation.
1632
1633Added `recv_buf_size` and 'send_buf_size' socket layer options. They are used only in posix implementation.
1634
1635Added `uring` based socket implementation, the code is located in module/sock/uring. This feature is only
1636available in Linux which requires kernel version is greater than 5.4.3. Currently, our CI pool added the uring
1637based socket tests for iSCSI target and also the tests for SPDK NVMe-oF tcp transport.
1638
1639Added `enable_recv_pipe` socket layer option to allow disabling of double buffering on receive.
1640New option is used only in posix implementation.
1641
1642Added `enable_zerocopy_send` socket layer option to allow disabling of zero copy flow on send.
1643New option is used only in posix implementation.
1644
1645### util
1646
1647Some previously exposed CRC32 functions have been removed from the public API -
1648`spdk_crc32_update`, `spdk_crc32_table_init`, and the `spdk_crc32_table` struct.
1649
1650### vhost
1651
1652The function `spdk_vhost_blk_get_dev` has been removed.
1653
1654## v20.04: SPDK Top, IDXD, NVMe qpair groups
1655
1656IDXD engine support for compare has been added.
1657
1658### configuration
1659
1660Legacy INI style configuration for SPDK applications has been deprecated and will be
1661removed in future release.
1662Please switch to JSON-RPC configuration files and/or RPC driven run-time configuration.
1663
1664### copy
1665
1666The copy engine library, modules and public APIs have been renamed. Use of the word `copy`
1667has been replaced with the word `accel` short for accelerator in preparation for adding new
1668capabilities in the future. Additionally, APIs for what was previously called the `memcpy`
1669engine have been renamed to identify the engine as a software accelerator.
1670
1671### crypto
1672
1673Support for AES_XTS was added for the QAT polled mode driver (pmd).  The create RPC
1674`bdev_crypto_create` has 2 new optional parameters: cipher and key2. Cipher can be either
1675AES_CBC (default) or AES_XTS. AES_XTS is only valid when using the QAT polled mode driver.
1676The key2 parameter is the second key required for AES_XTS.
1677
1678### event
1679
1680Reactors now accumulate CPU stats and they are retrieved by the RPC `framework_get_reactors`.
1681
1682### idxd
1683
1684IDXD support was added in the form of a low level library that can directly
1685utilize the IDXD offload engine as well as an accel plug-in module allowing for use
1686with the generic accel framework API. IDXD is the first in a family of offload
1687engines that share the same interface, specifically DSA is added here. More info
1688can be found here: https://01.org/blogs/2019/introducing-intel-data-streaming-accelerator
1689
1690Much of the implementation models IOAT, however the low level interfaces are very
1691different. The RPC to enable IDXD requires a configuration number as well. The
1692code includes two pre-defined configurations of IDXD groups/work queues/engines. A future
1693version will provide an interface to allow for setting of individual configuration
1694parameters.
1695
1696IDXD is not yet available so this feature should be considered experimental. It will
1697be built up with additional documentation as an ongoing activity.
1698
1699### iscsi
1700
1701The iSCSI target now creates a lightweight thread per poll group instead of assuming a pool
1702of lightweight threads already exist at start up time. A poll group is a collection of
1703unrelated iSCSI connections. Each poll group is only accessed from the associated
1704lightweight thread.
1705
1706### ftl
1707
1708Several changes have been made to the `spdk_ftl_conf`, `spdk_ftl_dev_init_ops`, and
1709`spdk_ftl_attrs` structs. Please see `include/spdk/ftl.h` for more details.
1710
1711### miscellaneous
1712
1713The `--json-ignore-init-errors` command line parameter has been added to ignore
1714initialization errors on JSON config load.
1715
1716The public header file io_channel.h has been removed. Please use thread.h which has the
1717exact same API.
1718
1719### nvme
1720
1721Exported internal nvme_ctrlr_cmd_security_receive/send() APIs as public APIs with "the spdk_"
1722prefix.
1723
1724Added `priority` field in `spdk_nvme_transport_id`, this field is used to specify the priority
1725of the NVMe-oF connection, and currently it is used for NVMe-oF tcp connection.
1726
1727A new poll group API has been added to allow for pooling of nvme qpairs across a single
1728entity which can be polled for completions. This new API consists of the `spdk_nvme_poll_group`
1729family of functions. As a result of this new API, all NVMe transports are expected to implement
1730several poll group related functions.
1731
1732A new flag, `create_only`, has been added to the `spdk_nvme_io_qpair_opts` structure. This flag
1733allows a user to call `spdk_nvme_ctrlr_get_default_io_qpair` without also connecting the qpair
1734within the context of that call.
1735
1736As a result of the `create_only` flag, two new API functions, `spdk_nvme_ctrlr_connect_io_qpair`
1737and `spdk_nvme_ctrlr_disconnect_io_qpair`, have been added to facilitate connecting newly created
1738qpairs (for example, after they have been added to a poll group) and disconnecting qpairs without
1739destroying them (for example to disconnect a qpair before migrating it to a new poll group and
1740reconnecting it).
1741
1742The functions `spdk_nvme_ctrlr_alloc_cmb_io_buffer` and `spdk_nvme_ctrlr_free_cmb_io_buffer`
1743have been changed to `spdk_nvme_ctrlr_map_cmb` and `spdk_nvme_ctrlr_unmap_cmb` respectively.
1744
1745An additional function, `spdk_nvme_ctrlr_reserve_cmb`, has been added to facilitate reserving
1746the entire size of the controller memory buffer for data transfer.
1747
1748### nvme_cuse
1749
1750`spdk_nvme_cuse_get_ctrlr_name` now takes two additional parameters, `char *name` which
1751stores the pointer to the controller name, and `size_t *size` which stores the length of
1752the name. The return type has also been changed from char * to int.
1753
1754`spdk_nvme_cuse_get_ns_name` now takes two additional parameters, `char *name` which
1755stores the pointer to the namespace name, and `size_t *size` which stores the length of
1756the name. The return type has also been changed from char * to int.
1757
1758### nvme_opal
1759
1760Several public OPAL structure definitions have been changed since the last release.
1761
1762### nvmf
1763
1764`spdk_nvmf_poll_group_destroy()` is now asynchronous and accepts a completion callback.
1765
1766The NVMe-oF target now creates a lightweight thread per poll group instead of assuming a pool
1767of lightweight threads already exist at start up time. A poll group is a collection of
1768unrelated NVMe-oF connections. Each poll group is only accessed from the associated
1769lightweight thread.
1770
1771A new struct, `spdk_nvmf_subsystem_listener`, has been added to encapsulate the subsystem specific
1772nature of a listener object.
1773
1774`spdk_nvmf_tgt_listen` no longer accepts a callback function or argument. It also returns an
1775int to indicate the status of the listen call.
1776
1777The execution of `spdk_nvme_poll_group_destroy` is now asynchronous and the function accepts
1778a cb_fn and cb_arg to call upon completion.
1779
1780The execution of `spdk_nvmf_subsystem_add_listener` is now asynchronous and the function accepts
1781a cb_fn and cb_arg to call upon completion.
1782
1783The `nvmf_transport.h` header has been made public to allow custom NVMe-oF transports to integrate
1784with NVMe-oF libraries without using internal APIs.
1785
1786### ocf
1787
1788Updated the OCF submodule to OCF v20.03
1789
1790New version of OCF comes with API changes and bug fixes
1791
1792### rpc
1793
1794A new RPC `thread_set_cpumask` has been added to set the cpumask of the thread
1795to the specified value.
1796
1797A new RPC `thread_get_pollers` has been added to retrieve pollers from SPDK threads.
1798
1799A new RPC `thread_get_io_channels` has been added to retrieve I/O channels from SPDK threads.
1800
1801A new RPC `bdev_rbd_resize` has been added to resize Ceph RBD bdevs.
1802
1803### sock
1804
1805The `spdk_sock_set_priority` function has been removed since the feature to set the sock priority
1806will be contained in two new functions, i.e., `spdk_sock_listen_ext` and `spdk_sock_connect_ext`.
1807Users may now specify the priority of the socket in the opts that they want to use.
1808
1809### spdk_top
1810
1811A new application, `spdk_top`, has been added which allows users to monitor resource consumption
1812by a running SPDK application. More information on this application can be found in
1813`app/spdk_top/README`.
1814
1815### thread
1816
1817A new function `spdk_thread_lib_init_ext` has been added, and the function
1818`spdk_thread_lib_init` has been deprecated. The user of `spdk_thread_lib_init_ext` is
1819expected to implement both functions `spdk_thread_op_fn` and `spdk_thread_op_supported_fn`.
1820`spdk_thread_op_supported_fn` is called to check whether the SPDK thread operation
1821is supported. `spdk_thread_op_fn` is called to execute the SPDK thread operation.
1822Current SPDK operation types are `SPDK_THREAD_OP_NEW` and `SPDK_THREAD_OP_RESCHED`.
1823The operation `SPDK_THREAD_OP_NEW` is called each time a new thread is created.
1824The operation `SPDK_THREAD_OP_RESCHED` is called when SPDK thread needs to be rescheduled.
1825
1826A unique ID has been added for each created SPDK thread, it is retrieved by a new function
1827`spdk_thread_get_id`, and the SPDK thread which has the specific ID is got by
1828a new function `spdk_thread_get_by_id`.
1829
1830A new function `spdk_thread_cpumask` has been added to set the current thread's cpumask
1831to the specified value. The function requires the operation `SPDK_THREAD_OP_RESCHED`
1832is supported.
1833
1834A new function `spdk_poller_register_named` has been added to set arbitrary name to the
1835created poller. If NULL, the name is set to the pointer of the poller function.
1836
1837The function `spdk_thread_poll` now measures run time per call correctly on multiple SPDK
1838threads configuration, and a new function `spdk_thread_get_last_tsc` has been added to use together.
1839
1840Voluntary termination of SPDK thread has been supported by refining the functions `spdk_thread_exit`
1841and `spdk_thread_poll`.
1842
1843### util
1844
1845New functions `spdk_sn32_lt` and `spdk_sn32_gt` have been added. They compare two sequence
1846numbers based on serial number arithmetic.
1847
1848### vhost
1849
1850Poll groups per session have been replaced by SPDK threads per vhost controller.
1851
1852### vmd
1853
1854A new function, `spdk_vmd_fini`, has been added. It releases all resources acquired by the VMD
1855library through the `spdk_vmd_init` call.
1856
1857## v20.01: Optimized thin provisioning, FTL bdev, VMD hot plug, FUSED support
1858
1859### bdev
1860
1861A new function, `spdk_bdev_set_timeout`, has been added to set per descriptor I/O timeouts.
1862
1863A new class of functions `spdk_bdev_compare*`, have been added to allow native bdev support
1864of block comparisons and compare-and-write.
1865
1866A new class of bdev events, `SPDK_BDEV_EVENT_MEDIA_MANAGEMENT`, has been added to allow bdevs
1867which expose raw media to alert all I/O channels of pending media management events.
1868
1869A new API was added `spdk_bdev_io_get_aux_buf` allowing the caller to request
1870an auxiliary buffer for its own private use. The API is used in the same manner that
1871`spdk_bdev_io_get_buf` is used and the length of the buffer is always the same as the
1872bdev_io primary buffer. 'spdk_bdev_io_put_aux_buf' frees the allocated auxiliary
1873buffer.
1874
1875### blobfs
1876
1877Added boolean return value for function spdk_fs_set_cache_size to indicate its operation result.
1878
1879Added `blobfs_set_cache_size` RPC method to set cache size for blobstore filesystem.
1880
1881### blobstore
1882
1883Added new `use_extent_table` option to `spdk_blob_opts` for creating blobs with Extent Table descriptor.
1884Using this metadata format, dramatically decreases number of writes required to persist each cluster allocation
1885for thin provisioned blobs. Extent Table descriptor is enabled by default.
1886See the [Blobstore Programmer's Guide](https://spdk.io/doc/blob.html#blob_pg_cluster_layout) for more details.
1887
1888### dpdk
1889
1890Updated DPDK submodule to DPDK 19.11.
1891
1892### env_dpdk
1893
1894`spdk_env_dpdk_post_init` now takes a boolean, `legacy_mem`, as an argument.
1895
1896A new function, `spdk_env_dpdk_dump_mem_stats`, prints information about the memory consumed by DPDK to a file specified by
1897the user. A new utility, `scripts/dpdk_mem_info.py`, wraps this function and prints the output in an easy to read way.
1898
1899### event
1900
1901The functions `spdk_reactor_enable_framework_monitor_context_switch()` and
1902`spdk_reactor_framework_monitor_context_switch_enabled()` have been changed to
1903`spdk_framework_enable_context_switch_monitor()` and
1904`spdk_framework_context_switch_monitor_enabled()`, respectively.
1905
1906### ftl
1907
1908All NVMe dependencies were removed from ftl library.
1909From now ftl library is using bdev_zone API.
1910bdev_ftl becomes virtual bdev.
1911
1912`ctrlr` and `trid` fields in `spdk_ftl_dev_init_opts` structure  were replaced by
1913`base_bdev_desc`.
1914
1915`bdev_ftl_create` RPC method `trtype` and `traddr` parameters were replaced by `base_bdev`
1916parameter.
1917
1918`spdk_ftl_module_init` and `spdk_ftl_module_fini` functions were removed.
1919
1920`spdk_ftl_punit_range` and `ftl_module_init_opts` structures were removed.
1921
1922### isa-l
1923
1924Updated ISA-L submodule to commit f3993f5c0b6911 which includes implementation and
1925optimization for aarch64.
1926
1927Enabled ISA-L on aarch64 by default in addition to x86.
1928
1929### nvme
1930
1931`delayed_pcie_doorbell` parameter in `spdk_nvme_io_qpair_opts` was renamed to `delay_cmd_submit`
1932to allow reuse in other transports.
1933
1934Added RDMA WR batching to NVMf RDMA initiator. Send and receive WRs are chained together
1935and posted with a single call to ibv_post_send(receive) in the next call to qpair completion
1936processing function. Batching is controlled by 'delay_cmd_submit' qpair option.
1937
1938The NVMe-oF initiator now supports plugging out of tree NVMe-oF transports. In order
1939to facilitate this feature, several small API changes have been made:
1940
1941The `spdk_nvme_transport_id` struct now contains a trstring member used to identify the transport.
1942A new function, `spdk_nvme_transport_available_by_name`, has been added.
1943A function table, `spdk_nvme_transport_ops`, and macro, `SPDK_NVME_TRANSPORT_REGISTER`, have been added which
1944enable registering out of tree transports.
1945
1946A new function, `spdk_nvme_ns_supports_compare`, allows a user to check whether a given namespace supports the compare
1947operation.
1948
1949A new family of functions, `spdk_nvme_ns_compare*`, give the user access to submitting compare commands to NVMe namespaces.
1950
1951A new function, `spdk_nvme_ctrlr_cmd_get_log_page_ext`, gives users more granular control over the command dwords sent in
1952log page requests.
1953
1954### nvmf
1955
1956Add SockPriority option in [Transport] section, this can be used for NVMe-oF target
1957on TCP transport to set sock priority for the incoming TCP connections.
1958
1959The NVMe-oF target now supports plugging out of tree NVMe-oF transports. In order
1960to facilitate this feature, several small API changes have been made:
1961
1962The `spdk_nvme_transport_id` struct now contains a trstring member used to identify the transport.
1963`spdk_nvmf_tgt_get_transport`, `spdk_nvmf_transport_opts_init`, and `spdk_nvmf_transport_create` all have been
1964modified to take a string.
1965A function table, `spdk_nvmf_transport_ops`, and macro, `SPDK_NVMF_TRANSPORT_REGISTER`, have been added which
1966enable registering out of tree transports.
1967
1968Add `spdk_nvmf_tgt_stop_listen()` that can be used to stop listening for
1969incoming connections for specified target and trid. Listener is not stopped
1970implicitly upon destruction of a subsystem any more.
1971
1972A custom NVMe admin command handler has been added which allows the user to use the real drive
1973attributes from one of the target NVMe drives when reporting drive attributes to the initiator.
1974This handler can be enabled via the `nvmf_set_config` RPC.
1975Note: In a future version of SPDK, this handler will be enabled by default.
1976
1977The SPDK target and initiator both now include compare-and-write functionality with one caveat. If using the RDMA transport,
1978the target expects the initiator to send both the compare command and write command either with, or without inline data. The
1979SPDK initiator currently respects this requirement, but this note is included as a flag for other initiators attempting
1980compatibility with this version of SPDK.
1981
1982The `spdk_nvme_ctrlr_opts` struct has been extended with new field `transport_ack_timeout` which allows
1983to configure transport ACK timeout. Applicable for RDMA transport only.
1984
1985### rpc
1986
1987A new RPC, `bdev_zone_block_create`, enables creating an emulated zoned bdev on top of a standard block device.
1988
1989A new RPC, `bdev_ocssd_create`, enables creating an emulated zoned bdev on top of an Open Channel SSD.
1990
1991A new RPC, `blobfs_set_cache_size`, enables managing blobfs cache size.
1992
1993A new RPC, `env_dpdk_get_mem_stats`, has been added to facilitate reading DPDK related memory
1994consumption stats. Please see the env_dpdk section above for more details.
1995
1996A new RPC, `framework_get_reactors`, has been added to retrieve a list of all reactors.
1997
1998`bdev_ftl_create` now takes a `base_bdev` argument in lieu of `trtype`, `traddr`, and `punits`.
1999
2000`bdev_nvme_set_options` now allows users to disable I/O submission batching with the `-d` flag
2001
2002`bdev_nvme_cuse_register` now accepts a `name` parameter.
2003
2004`bdev_uring_create` now takes arguments for `bdev_name` and `block_size`
2005
2006`nvmf_set_config` now takes an argument to enable passthru of identify commands to base NVMe devices.
2007Please see the nvmf section above for more details.
2008
2009### scsi
2010
2011`spdk_scsi_lun_get_dif_ctx` now takes an additional argument of type `spdk_scsi_task`.
2012
2013### sock
2014
2015Added spdk_sock_writev_async for performing asynchronous writes to sockets. This call will
2016never return EAGAIN, instead queueing internally until the data has all been sent. This can
2017simplify many code flows that create pollers to continue attempting to flush writes
2018on sockets.
2019
2020Added `impl_name` parameter in spdk_sock_listen and spdk_sock_connect functions. Users may now
2021specify the sock layer implementation they'd prefer to use. Valid implementations are currently
2022"vpp" and "posix" and NULL, where NULL results in the previous behavior of the functions.
2023
2024### thread
2025
2026`spdk_thread_send_msg` now returns int indicating if the message was successfully
2027sent.
2028
2029A new function `spdk_thread_send_critical_msg`, has been added to support sending a single message from
2030a context that may be interrupted, e.g. a signal handler.
2031
2032Two new functions, `spdk_poller_pause`, and `spdk_poller_resume`, have been added to give greater control
2033of pollers to the application owner.
2034
2035### util
2036
2037`spdk_pipe`, a new utility for buffering data from sockets or files for parsing
2038has been added. The public API is available at `include/spdk/pipe.h`.
2039
2040### bdev
2041
2042Added spdk_bdev_io_get_nvme_fused_status function for translating bdev_io status to NVMe status
2043code for fused compare-and-write operation.
2044
2045Added spdk_bdev_get_acwu function for getting block device atomic compare and write unit size.
2046
2047## v19.10: Zoned bdev API, Opal bdev, NVMe character devices
2048
2049### rpc
2050
2051Many of SPDK's RPCs were renamed to be more consistent and intuitive in this release.
2052The old names will continue to function, but will display a deprecation warning.
2053
2054Added optional parameters '--arbitration-burst' and '--low/medium/high-priority-weight' to
2055'bdev_nvme_set_options' RPC method.
2056
2057Added optional parameter '--md-size' to 'construct_null_bdev' RPC method.
2058
2059Added optional parameters '--dif-type' and '--dif-is-head-of-md' to 'construct_null_bdev'
2060RPC method.
2061
2062Added `blobfs_detect` RPC method to detect whether a blobfs exists on given bdev.
2063
2064Added `blobfs_create` RPC method to build blobfs on given bdev.
2065
2066Added `blobfs_mount` RPC method to mount blobfs on given bdev to a host path by FUSE.
2067Then on the host path, user can directly do some file operations which will be mapped
2068to blobfs.
2069
2070### bdev
2071
2072Added new parameter `cdw0` to `spdk_bdev_io_complete_nvme_status()` and
2073`spdk_bdev_io_get_nvme_status()` that allows setting/getting
2074the NVMe completion queue DW0 entry. This allows vendor specific IO commands
2075to return command specific completion info back to the initiator.
2076
2077Added `spdk_bdev_get_write_unit_size()` function for retrieving required number
2078of logical blocks for write operation.
2079
2080New zone-related fields were added to the result of the `get_bdevs` RPC call:
2081
2082- `zoned`: indicates whether the device is zoned or a regular
2083  block device
2084- `zone_size`: number of blocks in a single zone
2085- `max_open_zones`: maximum number of open zones
2086- `optimal_open_zones`: optimal number of open zones
2087
2088The `zoned` field is a boolean and is always present, while the rest is only available for zoned
2089bdevs.
2090
2091A new `spdk_bdev_open_ext` function has been added and `spdk_bdev_open` function has been deprecated.
2092The new open function introduces requirement to provide callback function that will be called by
2093asynchronous event such as bdev removal. `spdk_bdev_open_ext` function takes bdev name as
2094an argument instead of bdev structure to avoid a race condition that can happen when the bdev
2095is being removed between a call to get its structure based on a name and actually opening it.
2096
2097New 'resize' event has been added to notify about change of block count property of block device.
2098Event is delivered only if block device was opened with `spdk_bdev_open_ext` function.
2099
2100### bdev zone
2101
2102Added new public header for zoned bdev. Zoned bdev is an extension
2103of the bdev interface.
2104
2105`spdk_bdev_get_zone_size()`, `spdk_bdev_get_max_open_zones()`, `spdk_bdev_get_optimal_open_zones()`
2106APIs were added for retrieving zoned device information.
2107`spdk_bdev_get_zone_info()` API was added for retrieving information about zones in zoned
2108device.
2109Added `spdk_bdev_zone_management()` API for changing zone state.
2110`spdk_bdev_zone_append()` and `spdk_bdev_zone_append_with_md()` APIs were added for
2111appending data to a zone.
2112Added `spdk_bdev_io_get_append location()` function for retrieving append location for I/O.
2113Added `spdk_bdev_is_zoned()` function for checking if bdev supports zoned namespace semantics.
2114
2115### bdev opal
2116
2117EXPERIMENTAL: A new opal bdev has been added to support management of
2118NVMe self-encrypting drives through the Opal specification. Users can
2119create opal bdevs from an NVMe namespace bdev, if the controller
2120containing that namespace supports Opal. Currently this is only
2121supported for namespace ID=1. The following RPCs have been added to
2122support Opal: `bdev_nvme_opal_init`, `bdev_nvme_opal_revert`,
2123`bdev_opal_create`, `bdev_opal_delete`, `bdev_opal_get_info`,
2124`bdev_opal_new_user`, `bdev_opal_set_lock_state`.
2125It does not yet support recreating the opal bdevs after application restart.
2126This bdev module should be considered very experimental, and the RPCs may
2127change significantly in future releases.
2128
2129### delay bdev
2130
2131The `bdev_delay_update_latency` has been added to allow users to update
2132a latency value for a given delay bdev.
2133
2134### compress bdev
2135
2136A new RPC `bdev_compress_get_orphans` has been added to list compress bdevs
2137that were not loaded due to a missing pm metadata file. In this state they
2138can only be deleted.
2139
2140### null bdev
2141
2142Metadata support has been added to Null bdev module.
2143
2144Protection information support has been added to Null bdev module.
2145
2146### nvme
2147
2148Added `no_shn_notification` to NVMe controller initialization options, users can enable
2149it for NVMe controllers.  When the option is enabled, the controller will not do the
2150shutdown process and just disable the controller, users can start their application
2151later again to initialize the controller to the ready state.
2152
2153A controller flag `SPDK_NVME_CTRLR_WRR_SUPPORTED` was added to indicate the controller
2154can support weighted round robin arbitration feature with submission queue.
2155
2156Added `arbitration_burst` option for arbitration feature, and added three
2157`low/medium/high_priority_weight` options for weighted round robin arbitration.
2158
2159Added `spdk_nvme_ns_cmd_write_uncorrectable`.
2160
2161Added new error handling and reporting functionality. This includes several
2162new API functions to facilitate applications recovering when a qpair or
2163controller fails.
2164
2165`spdk_nvme_ctrlr_reconnect_io_qpair` - Reconnects a failed I/O qpair.
2166`spdk_nvme_ctrlr_set_trid` - Sets the trid of an existing controller. Can be used to
2167change the trid for failover cases.
2168`spdk_nvme_ctrlr_is_failed` - Returns the failed state of a controller.
2169`spdk_nvme_ctrlr_fail` - Forces a controller into a failed state.
2170
2171Modified the return behavior of several API functions to better indicate to
2172applications when a qpair is failed. This list of functions includes:
2173
2174`spdk_nvme_qpair_process_completions`
2175`spdk_nvme_ns_cmd_*`
2176`spdk_nvme_ctrlr_process_admin_completions`
2177`spdk_nvme_ctrlr_cmd_*`
2178
2179These functions now return -ENXIO when the qpair or controller on which they
2180operate is failed.
2181
2182EXPERIMENTAL: Added NVMe character device support to allow to create NVMe device nodes in Linux
2183kernel for controller as well as for namespace and process ioctl requests as usual
2184from linux environment.
2185
2186### nvmf
2187
2188The `spdk_nvmf_tgt_create` function now accepts an object of type `spdk_nvmf_target_opts`
2189as its only parameter. This new structure contains the max_subsystems parameter previously
2190passed into that function.
2191
2192A new public API function `spdk_nvmf_get_tgt` has been added which allows users to
2193retrieve a pointer to an `spdk_nvmf_tgt` object by supplying its name. In the special
2194case where an RPC or application only creates a single target, this function can accept
2195a null name parameter and will return the only available target.
2196
2197The majority of the NVMe-oF RPCs now accept an optional tgt_name parameter. This will
2198allow those RPCs to work with applications that create more than one target.
2199
2200Three new NVMe-oF RPCs have been added `nvmf_create_target`, `nvmf_delete_target`, and
2201`nvmf_get_targets`. These new RPCs provide a basic interface for managing multiple target
2202objects. In SPDK the target object defines a unique discovery service. As of this release,
2203these RPCs are not intended to be used with the in-tree SPDK target applications, spdk_tgt and
2204nvmf_tgt, which use a single, global target structure. As such, they are not included in scripts/rpc.py
2205
2206Three new header functions have also been added to help deal with multiple targets.
2207`spdk_nvmf_tgt_get_name` takes a target pointer as an argument and returns its human readable name.
2208`spdk_nvmf_get_first_target` takes no arguments and returns the first target in the global list.
2209`spdk_nvmf_get_next_tgt` takes a target pointer as an argument and returns the next one in the global list.
2210
2211The `spdk_nvmf_tgt_accept` takes additional argument allowing to pass arbitrary context
2212information to the `new_qpair` callback. This will simplify the code when having multiple
2213nvmf targets or when retrieving the context information from globals is not suitable.
2214
2215### blobstore
2216
2217A new `spdk_bdev_create_bs_dev_from_desc` function has been added and `spdk_bdev_create_bs_dev`
2218function has been deprecated.
2219The new create function can cowork with `spdk_bdev_open_ext` function, which provides callback
2220function that will be called by asynchronous event such as bdev removal.
2221
2222### blobfs_bdev
2223
2224A new blobfs module `bdev` has been added to simplify the operations of blobfs on bdev.
2225
2226Function `spdk_blobfs_bdev_detect` is added to detect whether blobfs exists on the given block device.
2227
2228Function `spdk_blobfs_bdev_create` is added to create a blobfs on the given block device.
2229
2230Function `spdk_blobfs_bdev_mount` is added to mount a blobfs on the given block device to
2231a host path by FUSE. Then, a new thread is created dedicatedly for one mountpoint to handle
2232FUSE request by blobfs API.
2233
2234### build
2235
2236Option to build FUSE components into blobfs_bdev module for mounting a blobfs filesystem.
2237It requires the installation of libfuse3. By default, it is disabled. And it will be
2238enabled if run `./configure` with `--with-fuse` option.
2239
2240### iSCSI
2241
2242Portals may no longer be associated with a cpumask. The scheduling of
2243connections is moving to a more dynamic model.
2244
2245An new RPC `iscsi_portal_group_set_auth` has been added to set CHAP authentication
2246for discovery sessions specific for the existing iSCSI portal group. This RPC overwrites
2247the setting by the global parameters for the iSCSI portal group.
2248
2249### socket
2250
2251Added `spdk_sock_is_connected` to check whether the socket is currently connected.
2252`spdk_sock_group_poll` now returns number of events on success.
2253
2254### env
2255
2256Added `spdk_pci_device_unclaim()` function to cleanup pci claim file.
2257
2258### event
2259
2260`framework_start_init` RPC no longer stops the application on error during
2261initialization.
2262
2263### DPDK
2264
2265Updated DPDK submodule to DPDK 19.08.
2266
2267### ocf
2268
2269Updated OCF submodule to OCF v19.06
2270
2271Along with update, new cache mode 'write only' was added.
2272
2273New cache modes added to use via RPC, wi - write invalidate and wa - write around.
2274
2275New version of OCF provides fully asynchronous management API.
2276
2277## v19.07: NVMe-oF FC Transport, VMD, NVMe-oF Persistent reservations, Bdev I/O with separate metadata
2278
2279### ftl
2280
2281EXPERIMENTAL: Added ability to mirror writes to persistent write buffer cache
2282to allow for recovery from dirty shutdown event.
2283
2284Added handling of Asynchronous Nand Management Events (ANM).
2285
2286### vmd
2287
2288EXPERIMENTAL: Added Intel Volume Management Device (VMD) driver. VMD is an integrated
2289controller inside the CPU PCIe root complex. It enables virtual HBAs for the connected
2290NVMe SSDs. `spdk_vmd_init()` enumerates NVMe SSDs behind VMD device and hook them into
2291SPDK PCI subsystem. `spdk_nvme_probe()` or `spdk_nvme_connect()` can be used to connect
2292NVMe driver to the device located at the given transport ID.
2293
2294To obtain transport ID of NVMe SSD behind VMD `spdk_lspci` can be used.
2295
2296Current implementation does not support hotplug.
2297
2298### blobfs
2299
2300Blobfs file asynchronous operations were added to public APIs.
2301
2302### util
2303
2304A new file API `spdk_posix_file_load` was added to load file content into a data buffer.
2305
2306New APIs `spdk_dif_ctx_set_data_offset`, `spdk_dif_verify_stream`,
2307`spdk_dif_get_range_with_md`, `spdk_dif_get_length_with_md` have been added,
2308and existing APIs `spdk_dif_ctx_init`, `spdk_dif_set_md_interleave_iovs`, and
2309`spdk_dif_generate_stream` have been refined to insert or strip DIF into iovs
2310windows of any alignment.
2311
2312New APIs `spdk_dif_ctx_set_remapped_init_ref_tag`, `spdk_dif_remap_ref_tag`,
2313and `spdk_dix_remap_ref_tag` have been added to remap DIF reference tag.
2314
2315New APIs `spdk_dif_update_crc32c` and `spdk_dif_update_crc32c_stream` have been
2316added to compute CRC-32C checksum for extended LBA payload.
2317
2318Bdevperf and bdevio applications now support starting tests with application specific
2319RPCs. Please see helper Python scripts in their respective directories.
2320This is a move towards simpler RPC-only configuration for all main
2321and auxiliary applications.
2322
2323Legacy INI style configuration for SPDK applications will become deprecated in SPDK 19.10,
2324and removed in SPDK 20.01. Please consider moving to JSON-RPC configuration files and/or
2325RPC driven run-time configuration.
2326
2327### nvmf
2328
2329EXPERIMENTAL: A Fibre Channel transport that supports Broadcom HBAs has been
2330added. This depends on the FC HBA driver at
2331https://github.com/ecdufcdrvr/bcmufctdrvr. See [the documentation](https://spdk.io/doc/nvmf.html#nvmf_fc_transport)
2332for more information.
2333
2334Persistent reservation emulation has been added to the NVMe-oF target. Persistent reservation
2335state is stored in a JSON file on the local filesystem between target restart. To support this,
2336an optional parameter to the RPC method `nvmf_subsystem_add_ns` called `--ptpl-file` was added.
2337This allows the user to specify which file to store the persistent reservation state in.  Note
2338that this is done per namespace.
2339
2340The c2h success optimization under which a command capsule response is not sent
2341for reads is turned on by default. A config knob was added to allow disabling
2342the optimization. This will mostly be used for integration testing with 5.0.x kernels
2343while some compatibility fixes make their way down the pipeline for 5.1.x kernels.
2344
2345The sock priority setting of the TCP connection owned by the tcp transport is added. It is
2346used to optimize the TCP connection performance under designated traffic classes. And the
2347priority is used to differentiate the sock priority between SPDK NVMe-oF TCP target application
2348and other TCP based applications.
2349
2350Shared receive queue can now be disabled even for NICs that support it using the
2351`nvmf_create_transport` RPC method parameter `no_srq`. The actual use of a shared
2352receive queue is predicated on hardware support when this flag is not used.
2353
2354spdk_nvmf_get_optimal_poll_group was added, which is used to return the optimal
2355poll group for the qpair. And `ConnectionScheduler` configuration is added into the
2356[Nvmf] section in etc/spdk/nvmf.conf.in to demonstrate how to configure the connection
2357scheduling strategy among different spdk threads.
2358
2359Added infrastructure to retrieve global and per poll group NVMf statistics.
2360
2361DIF strip and insert is now supported for TCP transport. When it is enabled, DIF
2362setting is not exposed to the NVMe-oF initiator, and DIF is attached into data
2363for write I/O and stripped from data for read I/O.
2364
2365Added a field `dif_insert_or_strip` to struct spdk_nvmf_transport_opts, and
2366updated the related rpc function nvmf_create_transport to make this
2367configurable parameter available to users. The `dif_insert_or_strip` is relevant
2368for TCP transport for now and used to configure the DIF strip and insert.
2369
2370Added infrastructure to retrieve NVMf transport statistics.
2371
2372### notify
2373
2374The function `spdk_notify_get_types()` and `spdk_notify_get_events()` were
2375renamed to `spdk_notify_foreach_type()` and `spdk_notify_foreach_event()`,
2376respectively. And update type name of callback accordingly.
2377
2378### bdev
2379
2380The format of the data returned by the get_bdevs_iostat RPC has changed to
2381make it easier to parse.  It now returns an object with a "ticks" object
2382and "bdevs" array with the per-bdev statistics.
2383
2384A new bdev module `delay` has been added which simulates a drive latency when placed
2385on top of a Null bdev. This module is intended only for testing and can be created using
2386the new RPC `bdev_delay_create`. That RPC takes the name of the underlying bdev as well
2387as average and p99 latency arguments for both read and write operations. Average latency is
2388defined as a value close to what you would expect a perf tool such as FIO to report back as
2389the mean latency of all I/O submitted to the drive. p99 latency is defined as the value one
2390would expect the drive to see the slowest 1% of I/O report. For underlying drives with already
2391significant latency, the latency values provided to the drive will be additive. This should be
2392taken into account if trying to achieve an artificial latency on top of an nvme drive or aio device.
2393
2394DIF reference tag remapping is now supported for partition type virtual bdev
2395modules. When using partition type virtual bdevs, block address space is
2396remapped during I/O processing and DIF reference tag is remapped accordingly.
2397
2398Added spdk_bdev_*_with_md() functions allowing for IO with metadata being transferred in
2399separate buffer. To check support for separate metadata, use spdk_bdev_is_md_separate().
2400
2401All bdevs now have a UUID. For devices whose backing hardware does not provide a UUID,
2402one is automatically generated. Across runs of SPDK, bdevs whose UUID is automatically
2403generated may change.
2404
2405A new virtual bdev module `compress` has been added to provide compression services on top of
2406a thinly provisioned logical volume.  See documentation for complete details.
2407
2408### nvme
2409
2410Added an optional parameter `--io-queue-requests` to RPC `set_bdev_nvme_options`, which
2411can be used to change the number of requests allocated for one NVMe I/O queue.  For
2412very big I/O size, e.g. 128MiB, with this option user will not get an error due to
2413limited requests in NVMe driver layer.
2414
2415Added spdk_nvme_ctrlr_get_transport_id() to get the transport ID from a
2416previously attached controller.
2417
2418Nvme Opal library spdk_opal_cmd deprecated. Adding separate command APIs.
2419NVMe Opal library add support for activating locking SP which will make the transaction
2420from "Manufactured-Inactive" state to "Manufactured" state. Upon successfully invoking
2421of this method, lock and unlock features will be enabled.
2422NVMe Opal library add support for locking/unlocking range and list locking range info.
2423NVMe opal library add support for multiuser. Admin can enable user and add user to specific
2424locking range and the user can lock/unlock his range.
2425
2426Added spdk_nvme_ctrlr_io_cmd_raw_no_payload_build() allowing a caller to pass
2427a completely formed command to an NVMe submission queue (buffer addresses and all).
2428This is supported on the PCIe transport only.
2429
2430Added spdk_nvme_get_ctrlr_registers() to return a pointer to the virtual address
2431of the NVMe controller registers.  This is supported on the PCIe transport only.
2432
2433Added additional options to the spdk_nvme_ctrlr_alloc_qpair() option parameter
2434structure to allow caller to override the virtual and optionally physical address
2435of the submission and completion queue pair to be created.  This is supported on
2436the PCIe transport only.
2437
2438Added `disable_error_logging` to struct spdk_nvme_ctrlr_opts, which disables
2439logging of failed requests. By default logging is enabled.
2440
2441Added spdk_nvme_qpair_print_command(), spdk_nvme_qpair_print_completion() and
2442spdk_nvme_cpl_get_status_string(). Allowing for easier display of error messages.
2443
2444Added support for NVMe Sanitize command.
2445
2446### env
2447
2448The parameter `free_space` has been added to spdk_ring_enqueue() to wait when
2449the ring is almost full and resume when there is enough space available in
2450the ring.
2451
2452A new API `spdk_mempool_lookup` has been added to lookup the memory pool created
2453by the primary process.
2454
2455Added spdk_pci_get_first_device() and spdk_pci_get_next_device() to allow
2456iterating over PCI devices detected by SPDK. Because of this, all SPDK APIs
2457to attach/detach PCI devices are no longer thread safe. They are now meant to
2458be called from only a single thread only, the same only that called spdk_env_init().
2459This applies to the newly added APIs as well.
2460
2461### vpp
2462
2463SPDK now supports VPP version 19.04.2, up from VPP 18.01.
2464
2465VPP socket abstraction now uses VPP Session API, instead of VLC (VPP Communications Library).
2466This allows for better control over sessions and queues.
2467Please see VPP documentation for more details:
2468[VPP Host Stack](https://wiki.fd.io/view/VPP/HostStack)
2469
2470### sock
2471
2472Add spdk_sock_get_optimal_sock_group(), which returns the optimal sock group for
2473this socket. When a socket is created, it is often assigned to a sock group using
2474spdk_sock_group_add_sock so that a set of sockets can be polled more efficiently.
2475For some network devices, it is optimal to assign particular sockets to specific
2476sock groups. This API is intended to provide the user with that information.
2477
2478spdk_sock_group_get_ctx() was added to return the context of the spdk_sock_group.
2479spdk_sock_group_create() is updated to allow input the user provided ctx.
2480spdk_sock_set_priority() is added to set the priority of the socket.
2481
2482### rpc
2483
2484Added thread_get_stats RPC method to retrieve existing statistics.
2485
2486Added nvmf_get_stats RPC method to retrieve NVMf subsystem statistics.
2487
2488Response buffers for RPC requests are now always pre-allocated, which implies
2489that all spdk_jsonrpc_begin_result() calls always succeed and return a valid
2490buffer for JSON response. RPC calls no longer need to check if the buffer is
2491non-NULL.
2492
2493Added SPDK_RPC_REGISTER_ALIAS_DEPRECATED to help with deprecation process when
2494renaming existing RPC. First time a deprecated alias is used, it will print
2495a warning message.
2496
2497RPC `get_rpc_methods` was renamed `rpc_get_methods`. The old name is still usable,
2498but is now deprecated.
2499
2500### blobstore
2501
2502A snapshot can now be deleted if there is only a single clone on top of it.
2503
2504### build
2505
2506Preliminary support for cross compilation is now available. Targeting an older
2507CPU on the same architecture using your native compiler can be accomplished by
2508using the `--target-arch` option to `configure` as follows:
2509
2510~~~bash
2511./configure --target-arch=broadwell
2512~~~
2513
2514Additionally, some support for cross-compiling to other architectures has been
2515added via the `--cross-prefix` argument to `configure`. To cross-compile, set CC
2516and CXX to the cross compilers, then run configure as follows:
2517
2518~~~bash
2519./configure --target-arch=aarm64 --cross-prefix=aarch64-linux-gnu
2520~~~
2521
2522### vhost
2523
2524A security vulnerability has been identified and fixed in SPDK Vhost-SCSI target.
2525A malicious client (e.g. a virtual machine) could send a carefully prepared,
2526invalid I/O request to crash the entire SPDK process. All users of SPDK Vhost-SCSI
2527target are strongly recommended to update. All SPDK versions < 19.07 are affected.
2528
2529By default, SPDK will now rely on upstream DPDK's rte_vhost instead of its fork
2530located inside SPDK repo. The internal fork is still kept around to support older
2531DPDK versions, but is considered legacy and will be eventually removed.
2532
2533`configure` will now automatically use the upstream rte_vhost if the used DPDK
2534version is >= 19.05.
2535
2536spdk_vhost_init() is now asynchronous and accepts a completion callback.
2537
2538### iscsi target
2539
2540A security vulnerability has been identified and fixed in SPDK iSCSI target.
2541A malicious client (e.g. an iSCSI initiator) could send a carefully prepared,
2542invalid I/O request to crash the entire SPDK process. All users of SPDK iSCSI
2543target are strongly recommended to update. All SPDK versions < 19.07 are affected.
2544
2545### thread
2546
2547Exposed spdk_set_thread() in order for applications to associate
2548with SPDK thread when necessary.
2549
2550Added spdk_thread_destroy() to allow framework polling the thread to
2551release resources associated with that thread.
2552
2553## v19.04: Compression bdev, Notification library, NVMe Opal support
2554
2555### nvme
2556
2557Added asynchronous probe support. New APIs spdk_nvme_probe_async(),
2558spdk_nvme_connect_async() and spdk_nvme_probe_poll_async() were added to enable
2559this feature. spdk_nvme_probe_async() and spdk_nvme_connect_async() return a
2560context associated with the specified controllers. Users then call
2561spdk_nvme_probe_poll_async() until it returns 0, indicating that the operation
2562completed.
2563
2564A new qpair creation option, delay_pcie_doorbell, was added. This can be passed
2565to spdk_nvme_alloc_io_qpair(). This makes the I/O submission functions, such as
2566spdk_nvme_ns_writev(), skip ringing the submission queue doorbell. Instead the
2567doorbell will be rung as necessary inside spdk_nvme_qpair_process_completions().
2568This can result in significantly fewer MMIO writes to the doorbell register
2569under heavy load, greatly improving performance.
2570
2571spdk_nvme_ctrlr_get_regs_cmbsz() was added to report the size of the controller
2572memory buffer, if available.
2573
2574spdk_nvme_ctrlr_get_flags() was added to return controller feature
2575flags. Two flags are currently tracked:
2576SPDK_NVME_CTRLR_SGL_SUPPORTED
2577SPDK_NVME_CTRLR_SECURITY_SEND_RECV_SUPPORTED
2578
2579The NVMe hotplug poller is now able to detach devices hot-removed from the system
2580via `/sys/bus/pci/devices/<bdf>/remove` and `/sys/bus/pci/devices/<bdf>/driver/unbind`.
2581
2582Opal support was added for scan, take ownership, revert TPer, and dumping device
2583info. The nvme_manage tool can be used to perform these operations. The public
2584API functions are spdk_nvme_ctrlr_security_receive() and
2585spdk_nvme_ctrlr_security_send(). This module should be considered experimental
2586pending additional features and tests.
2587
2588The NVMe-oF initiator is now able to transfer IO whose size is more than 128KiB
2589if the corresponding NVMe-oF target allows.
2590
2591### raid
2592
2593Added new strip_size_kb rpc param on create to replace the more ambiguous
2594strip_size. The strip_size rpc param is deprecated.
2595
2596Changed the raid bdev product_name from "Pooled Device" to "Raid Volume"
2597
2598### thread
2599
2600Added spdk_thread_has_pollers() function to verify if there are any registered
2601pollers to be run on the thread. Added spdk_thread_is_idle() function to check
2602if there are any scheduled operations to be performed on the thread at given
2603time.
2604
2605spdk_thread_create() now takes an optional CPU affinity mask that is passed to
2606the scheduler.
2607
2608spdk_thread_lib_init() now takes an optional context size. For each thread
2609created, an additional region of memory of this size will be allocated. A
2610pointer to this region of memory can be obtained by calling
2611spdk_thread_get_ctx(). The inverse operation is also available via
2612spdk_thread_get_from_ctx().
2613
2614spdk_thread_poll() now optionally accepts the current time, in ticks. This can
2615be used to avoid some calls to spdk_get_ticks() internally.
2616
2617spdk_app_start() now only accepts a single context argument.
2618
2619### bdev
2620
2621An new API `spdk_bdev_get_data_block_size` has been added to get size of data
2622block except for metadata.
2623
2624spdk_vbdev_register() has been deprecated.  spdk_bdev_register() should be used
2625instead.
2626
2627A mechanism for acquiring and releasing data buffers from bdev modules, used
2628to perform zero copy operations, was added.
2629
2630New APIs spdk_bdev_get_md_size(), spdk_bdev_is_md_interleaved(), spdk_bdev_get_dif_type(),
2631spdk_bdev_is_dif_head_of_md(), and spdk_bdev_is_dif_check_enabled() have been
2632added to get metadata and DIF settings.
2633
2634Bdevs claimed by the `examine_config` callback will be now further examined in the
2635`examine_disk` callback.
2636
2637spdk_bdev_io_get_io_channel() was added as a convenient way to get an io_channel
2638from a bdev_io.
2639
2640### ocf
2641
2642Updated OCF submodule to OCF v19.3.2
2643
2644Added support for many-to-one configuration for OCF bdev.
2645Multiple core devices can now be cached on single cache device.
2646
2647Added persistent metadata support, allowing to restore cache state after shutdown.
2648During start of SPDK application, the devices are examined and if OCF metadata
2649is present - appropriate OCF bdevs will be recreated.
2650
2651Added Write-Back mode support. In this mode, data is first written to
2652caching device and periodically synchronized to the core devices.
2653Dirty data is saved as persistent metadata on cache device,
2654allowing for safe restore during application restart.
2655For more details please see OCF documentation:
2656[OpenCAS cache configuration](https://open-cas.github.io/cache_configuration.html)
2657
2658### NVMe-oF Target
2659
2660Support for per-device shared receive queues in the RDMA transport has been added.
2661It is enabled by default for any device that supports it.
2662
2663The size of a shared receive queue is defined by transport configuration file parameter
2664`MaxSRQDepth` and `nvmf_create_transport` RPC method parameter `max_srq_depth`.
2665Default size is 4096.
2666
2667Add model number as parameter to construct_nvmf_subsystem (-d option),
2668rather than using hardcoded define.
2669
2670DIF passthrough feature has been added. DIF setting of the allocated bdevs is
2671exposed to the NVMe-oF initiator and data with DIF from the NVMe-oF initiator is
2672passed through to the allocated bdevs.
2673
2674### env
2675
2676The `phys_addr` parameter in spdk_malloc() and spdk_zmalloc() has been deprecated.
2677For retrieving physical addresses, spdk_vtophys() should be used instead.
2678
2679spdk_realloc() has been added to reallocate DMA/shared memory.
2680
2681spdk_pci_device_is_removed() has been added to let the upper-layer SPDK drivers know
2682that device has a pending external hotremove request.
2683
2684spdk_env_fini() and spdk_env_dpdk_post_fini() were added to release any resources
2685allocated by spdk_env_init() or spdk_env_dpdk_post_init() respectively. It is expected
2686that common usage of those functions is to call them just before terminating the process.
2687
2688Added spdk_iommu_is_enabled() to report if SPDK application is using IOMMU for DMA.
2689
2690### DPDK
2691
2692Dropped support for DPDK 17.07 and earlier, which SPDK won't even compile with right now.
2693
2694Updated DPDK submodule to DPDK 19.02.
2695
2696### rpc
2697
2698New `get_spdk_version` RPC method is introduced to get version info of the running SPDK application.
2699
2700The `start_nbd_disk` RPC method now take nbd_device as an optional parameter. If nbd_device
2701is specified, use that specified nbd device. If it's not specified, pick available one.
2702
2703### iSCSI target
2704
2705DIF strip and insert is now supported. DIF settings are not exposed to the iSCSI initiator.
2706DIF is attached into data for write I/O and stripped from data for read I/O.
2707
2708### vhost
2709
2710Added experimental support for running with the external, upstream rte_vhost library.
2711This can be enabled by configuring SPDK with an `--without-internal-vhost-lib` flag.
2712The minimum supported rte_vhost version (DPDK version) is 19.05-rc1.
2713
2714As a result of fuzz testing, a lot of data races in vhost-scsi LUN hotplug path were identified and
2715fixed. Those data races could have potentially resulted in SPDK crashes, RPC hangs, or memory leaks
2716if Vhost-SCSI LUN hotplug RPCs were executed while connected VMs were in the middle of restarting.
2717
2718The SCSI target id in `add_vhost_scsi_lun` RPC is now optional. If `-1` is passed, the first
2719unoccupied target id will be used.
2720
2721### AIO
2722
2723AIO bdev module can now reap I/O completions directly from userspace, significantly improving
2724the overall performance.
2725
2726### blobfs
2727
2728Synchronous IO operations no longer use spdk_io_channel, but instead use
2729spdk_fs_thread_ctx. The behavior is otherwise identical.
2730
2731### OCF
2732
2733Added support for caching multiple bdevs using a single bdev as a cache.
2734
2735### notify
2736
2737Added the notify library that provides a high performance local event bus
2738between libraries. Example usage was added to bdev module, which reports
2739notifications for added and removed bdevs via RPC.
2740
2741### sock
2742
2743Added new API spdk_sock_readv() to the sock library for performing vectored
2744reads.
2745
2746### event
2747
2748The function spdk_subsystem_init() no longer requires spdk_event as an argument.
2749
2750Changed API of spdk_subsystem_config_json() to no longer be asynchronous.
2751
2752### io_uring
2753
2754A bdev module that issues I/O to kernel block devices using the new io_uring Linux kernel
2755API was added. This module requires liburing.
2756
2757### build
2758
2759Options to easily compile with profile guided optimization have been added to
2760`configure`. To use profile guided optimization with SPDK, run
2761`./configure --with-pgo-capture`, build SPDK, then run a workload of your
2762choosing. Then, simply run `./configure --with-pgo-enable` and recompile to
2763build using the generated profile data. Profile guided optimization can yield
2764very large performance improvements, especially on GCC 8 and clang 7. This may
2765be combined with link time optimization which has been available under the
2766`--enable-lto` configure option for several releases.
2767
2768### compression bdev/reduce library
2769
2770Added "reduce" block compression scheme based on using SSDs for storing
2771compressed blocks of storage and persistent memory for metadata. Please see
2772[compression](https://spdk.io/doc/bdev.html) for more details.
2773
2774## v19.01: NVMe-oF TCP/IP Transport, Open Channel SSD Flash Translation Layer, Caching bdev based on OCF, ISA-L Support, DIF/DIX library
2775
2776### ocf bdev
2777
2778New virtual bdev module based on [Open CAS Framework](https://open-cas.github.io/) has been added.
2779This module allows for the use of one bdev to act as a high performance cache in front of another bdev.
2780Please see [documentation](https://spdk.io/doc/bdev.html#bdev_config_cas) for more details.
2781Only write through mode is currently supported and this feature is considered experimental.
2782
2783### event framework
2784
2785For `spdk_app_parse_args`, add return value to the callback which parses application
2786specific command line parameters to protect SPDK applications from crashing by invalid
2787values from user input.
2788
2789By default, all SPDK applications will now reserve all hugepages at runtime. The pre-reserved
2790memory size can be still set with `-s` or `--mem-size` option, although the default value
2791was reduced down to 0.
2792
2793A custom hugetlbfs directory can now be specified via spdk_app_opts.
2794This can be used to configure hugepages with different sizes, a different size limit,
2795or different access permissions than the system's default hugepage pool.
2796SPDK applications can specify a custom hugetlbfs mount with the `--huge-dir` option.
2797
2798### environment
2799
2800spdk_vtophys() has been refactored to accept length of the translated region as a new
2801parameter. The function will now update that parameter with the largest possible value
2802for which the memory is contiguous in the physical memory address space.
2803
2804The following functions were removed:
2805
2806- spdk_pci_nvme_device_attach()
2807- spdk_pci_nvme_enumerate()
2808- spdk_pci_ioat_device_attach()
2809- spdk_pci_ioat_enumerate()
2810- spdk_pci_virtio_device_attach()
2811- spdk_pci_virtio_enumerate()
2812
2813They were replaced with generic spdk_pci_device_attach() and spdk_pci_enumerate() which
2814require a new spdk_pci_driver object to be provided. It can be one of the following:
2815
2816- spdk_pci_nvme_get_driver()
2817- spdk_pci_ioat_get_driver()
2818- spdk_pci_virtio_get_driver()
2819
2820spdk_pci_hook_device() and spdk_pci_unhook_device() were added. Those allow adding a virtual
2821spdk_pci_device into the SPDK PCI subsystem. A virtual device calls provided callbacks for
2822each BAR mapping request or PCI config access. It's attachable with spdk_pci_device_attach()
2823or spdk_pci_enumerate() like any other device.
2824
2825A new spdk_pause() function was added to pause CPU execution for an implementation specific
2826amount of time. Quoting from DPDK function this is based on: "This call is intended for
2827tight loops which poll a shared resource or wait for an event. A short pause within the loop
2828may reduce the power consumption."
2829
2830A new public header file env_dpdk.h has been introduced, and function spdk_env_dpdk_post_init
2831is added into it. If user is using DPDK, and already called rte_eal_init, then include
2832include/spdk/env_dpdk.h, and call spdk_env_dpdk_post_init() instead of spdk_env_init.
2833
2834ISA-L has been added as an SPDK submodule.  ISA-L is enabled by default on x86 architecture
2835to accelerate algorithms such as CRC for iSCSI and NVMe-oF.  Users may still disable ISA-L
2836by explicitly passing --without-isal to the configure script.
2837
2838### util
2839
2840A new uuid API `spdk_uuid_copy` was added to make a copy of the source uuid.
2841
2842An new parameter `init_crc` representing the initial CRC value was added to
2843`spdk_crc16_t10dif`. The parameter can be used to calculate a CRC value spanning
2844multiple separate buffers.
2845
2846New DIF APIs were added to generate and verify DIF by byte granularity for both DIF and DIX
2847formats. Among them, DIF with copy APIs will be usable to emulate DIF operations such as DIF
2848insert and strip.
2849
2850Added `spdk_strtol` and `spdk_strtoll` to provide additional error checking around `strtol`
2851and `strtoll`.
2852
2853Added `spdk_sprintf_append_realloc` and `spdk_vsprintf_append_realloc` for appending a string
2854with automatic buffer re-allocation.
2855
2856### nvme
2857
2858Wrapper functions spdk_nvme_ctrlr_security_send() and spdk_nvme_ctrlr_security_receive() are
2859introduced to support further security protocol development.
2860
2861admin_timeout_ms was added to NVMe controller initialization options, users
2862can change the default value when probing a controller.
2863
2864Add two new fields "header_digest" and "data_digest" in struct spdk_nvme_ctrlr_opts,
2865it will be used to enable the digest support for the NVMe/TCP transport.
2866
2867Add a new TCP/IP transport(located in lib/nvme/nvme_tcp.c) in nvme driver. With
2868this new transport, it can be used to connect the NVMe-oF target with the
2869same TCP/IP support.
2870
2871Added API, spdk_nvme_ctrlr_is_discovery(), to indicate whether the ctrlr
2872arg refers to a Discovery Controller or not.
2873
2874Added an API function `spdk_nvme_host_id_parse` and corresponding object `spdk_nvme_host_id`
2875for parsing host address and host service ID arguments on a per connection basis.
2876
2877The RPC `construct_nvme_bdev` now allows a user to specify a source address and service id for the host to
2878use when connecting to the controller backing the NVMe bdev.
2879
2880### NVMe-oF Target
2881
2882The `spdk_nvmf_tgt_opts` struct has been deprecated in favor of `spdk_nvmf_transport_opts`.
2883Users will no longer be able to specify target wide I/O parameters. `spdk_nvmf_tgt_listen`
2884will also no longer implicitly initialize a transport with the default target options (since
2885there are none). Instead, a user must manually instantiate the transport with `spdk_nvmf_transport_create`
2886prior to calling `spdk_nvmf_tgt_listen`.
2887
2888Related to the previous change, the rpc `set_nvmf_target_options` has been renamed to
2889`set_nvmf_target_max_subsystems` to indicate that this is the only target option available for the user to edit.
2890
2891Added fields `num_shared_buffers` and `buf_cache_size` in struct spdk_nvmf_transport_opts,
2892and also updated the related rpc function nvmf_create_transport, to make this
2893configurable parameter available to users. The `num_shared_buffers` is used to
2894configure the shared buffer numbers of the transport used by RDMA or TCP transport.
2895`buf_cache_size` configures number of shared buffers to cache per poll group.
2896
2897### nvmf
2898
2899Add a new TCP/IP transport (located in lib/nvmf/tcp.c). With this transport,
2900the SPDK NVMe-oF target can have a new transport, and can serve the NVMe-oF
2901protocol via TCP/IP from the host.
2902
2903Added optional mechanism to modify the RDMA transport's behavior when creating protection domains and registering memory.
2904By default, the RDMA transport will use the ibverbs library to create protection domains and register memory.
2905Using `spdk_nvme_rdma_init_hooks` will subvert that and use an existing registration.
2906
2907### bdev
2908
2909Added `enable_bdev_histogram` and `get_bdev_histogram` RPC commands to allow gathering latency data for specified bdev.
2910Please see [documentation](https://spdk.io/doc/bdev.html#rpc_bdev_histogram) for more details.
2911
2912Added `required_alignment` field to `spdk_bdev`, that specifies an alignment requirement for data buffers associated with an spdk_bdev_io.
2913Bdev layer will automatically double buffer any spdk_bdev_io that violates this alignment, before the spdk_bdev_io is submitted to the bdev module.
2914
2915On shutdown, bdev unregister now proceeds in top-down fashion, with
2916claimed bdevs skipped (these will be unregistered later, when virtual
2917bdev built on top of the respective base bdev unclaims it). This
2918allows virtual bdevs to be shut down cleanly as opposed to the
2919previous behavior that didn't differentiate between hotremove and
2920planned shutdown.
2921
2922The `delete_bdev` RPC is now deprecated. Users should instead use the specific deletion RPC
2923for the bdev type to be removed (i.e. delete_malloc_bdev).
2924
2925Added support for separate bandwidth rate limits for read and write to QoS in bdev layer.
2926
2927Bdev I/O statistics now track unmap operations.
2928
2929### logical volumes
2930
2931Logical volume bdev can now be marked as read only using `set_read_only_lvol_bdev` RPC.
2932This allows for basing clones on top of lvol_bdev without first creating a snapshot.
2933
2934Added option to change method for data erasure when deleting lvol or resizing down.
2935Default of unmapping clusters can now be changed to writing zeroes or no operation.
2936
2937Added option to change method for erasing data region on lvol store creation.
2938Default of unmapping can now be changed to writing zeroes or no operation.
2939
2940### log
2941
2942"trace flags" are now referred to as "log flags" in the SPDK log API.  The
2943set_trace_flag, clear_trace_flag and get_trace_flags RPCs are now deprecated,
2944and set_log_flag, clear_log_flag and get_log_flags RPCs have been added.
2945
2946### trace
2947
2948New `trace_record` application was added. It can be used to poll spdk trace shm file and
2949append any new trace entries into another specified file. This can help retain those entries
2950that would otherwise be overwritten in the shm file. See
2951[Capturing sufficient trace events](https://spdk.io/doc/nvmf_tgt_tracepoints.html#capture_trace_events)
2952for more details.
2953
2954Number of trace entries in circular buffer per lcore can now be assigned by starting SPDK app
2955with argument "--num-trace-entries <NUM>" provided.
2956
2957New `get_tpoint_group_mask` RPC was added to get current tpoint_group_mask, and
2958each tpoint group status.
2959New `enable_tpoint_group` and `disable_tpoint_group` RPC were added to enable or
2960disable a specific tpoint group.
2961
2962### ftl
2963
2964EXPERIMENTAL: Added basic flash translation layer module allowing for using Open Channel SSDs as
2965block devices. The module is split into the library (located in lib/ftl) and bdev_ftl
2966(lib/bdev/ftl). See the [documentation](https://spdk.io/doc/ftl.html) for more details.
2967
2968### vhost
2969
2970A security vulnerability has been identified and fixed in the SPDK vhost target.  A malicious
2971vhost client (i.e. virtual machine) could carefully construct a circular descriptor chain which
2972would result in a partial denial of service in the SPDK vhost target.  These types of descriptor
2973chains are now properly detected by the vhost target.  All SPDK vhost users serving untrusted
2974vhost clients are strongly recommended to upgrade. (Reported by Dima Stepanov and Evgeny
2975Yakovlev.)
2976
2977Vhost SCSI and Vhost Block devices can now accept multiple connections on the same socket file.
2978Each connection (internally called a vhost session) will have access to the same storage, but
2979will use different virtqueues, different features and possibly different memory.
2980
2981### vhost scsi
2982
2983SCSI target hotremove can now be performed even without the VIRTIO_SCSI_F_HOTPLUG feature negotiated.
2984Regardless of VIRTIO_SCSI_F_HOTPLUG support, the hotremoval will be still reported through SCSI sense codes.
2985
2986### DPDK
2987
2988DPDK submodule was updated to DPDK 18.11. Note that SPDK does not fully leverage the new
2989multi-process device hotplug yet and continues to work the same way it always did.
2990
2991Dropped support for DPDK 16.07 and earlier, which SPDK won't even compile with right now.
2992
2993### RPC
2994
2995The following RPC commands deprecated in the previous release are now removed:
2996
2997- construct_virtio_user_scsi_bdev
2998- construct_virtio_pci_scsi_bdev
2999- construct_virtio_user_blk_bdev
3000- construct_virtio_pci_blk_bdev
3001- remove_virtio_scsi_bdev
3002- construct_nvmf_subsystem
3003
3004### Miscellaneous
3005
3006The configure options `--with-raid` and `--without-raid` that were deprecated in the previous
3007release are now removed.
3008
3009### nbd
3010
3011Starting nbd using `spdk_nbd_start` is now performed asynchronously.
3012
3013### net framework
3014
3015Net framework initialization and finish is now done asynchronously.
3016
3017### rpc
3018
3019Added `spdk_rpc_is_method_allowed` function for checking whether method is permitted in a given state.
3020Added `spdk_rpc_get_state` to check current state of RPC server.
3021RPC `wait_subsystem_init` has been added to allow clients to block until all subsystems are initialized.
3022
3023### json rpc
3024
3025JSON RPC client is now running in non-blocking mode. Requests are sent and received during spdk_jsonrpc_client_poll.
3026JSON RPC server can now receive a callback on connection termination or server shutdown using `spdk_jsonrpc_conn_add_close_cb`
3027and `spdk_jsonrpc_conn_del_close_cb`.
3028
3029## v18.10: Dynamic memory allocation, Crypto Virtual Bdev, jsonrpc-client, SPDKCLI iSCSI and NVMe-oF support
3030
3031### nvme
3032
3033spdk_nvme_ctrlr_cmd_security_send() and spdk_nvme_ctrlr_cmd_security_receive()
3034were added to support sending or receiving security protocol data to or from
3035nvme controller.
3036
3037spdk_nvme_ns_get_extended_sector_size() was added.  This function includes
3038the metadata size per sector (if any).  spdk_nvme_ns_get_sector_size() still
3039returns only the data size per sector, not including metadata.
3040
3041New `send_nvme_cmd` RPC was added to allow sending NVMe commands directly to NVMe controller.
3042See the [send_nvme_cmd](http://spdk.io/doc/jsonrpc.html#rpc_send_nvme_cmd) documentation
3043for more details.
3044
3045### Build System
3046
3047New `configure` options, `--with-shared` and `--without-shared`
3048[default], provide the capability to build, or not, SPDK shared libraries.
3049This includes the single SPDK shared lib encompassing all of the SPDK
3050static libs as well as individual SPDK shared libs corresponding to
3051each of the SPDK static ones.  Although the production of the shared
3052libs conforms with conventional version naming practices, such naming
3053does not at this time confer any SPDK ABI compatibility claims.
3054
3055### bdev
3056
3057spdk_bdev_alias_del_all() was added to delete all alias from block device.
3058
3059A new virtual bdev module has been added to perform at rest data encryption using the DPDK CryptoDev
3060Framework.  The module initially uses a software AESNI CBC cipher with experimental support for the
3061Intel QAT hardware accelerator also currently implemented with support for CBC cipher. Future work
3062may include additional ciphers as well as consideration for authentication.
3063
3064The RAID virtual bdev module is now always enabled by default.  The configure --with-raid and
3065--without-raid options are now ignored and deprecated and will be removed in the next release.
3066
3067Enforcement of bandwidth limits for quality of service (QoS) has been added to the bdev layer.
3068See the new [set_bdev_qos_limit](http://www.spdk.io/doc/jsonrpc.html#rpc_set_bdev_qos_limit)
3069documentation for more details. The previous set_bdev_qos_limit_iops RPC method introduced at
307018.04 release has been deprecated. The new set_bdev_qos_limit RPC method can support both
3071bandwidth and IOPS limits.
3072
3073spdk_bdev_config_json() and corresponding `get_bdevs_config` RPC was removed.
3074
3075### Environment Abstraction Layer and Event Framework
3076
3077The size parameter of spdk_mem_map_translate is now a pointer. This allows the
3078function to report back the actual size of the translation relative to the original
3079request made by the user.
3080
3081A new structure spdk_mem_map_ops has been introduced to hold memory map related
3082callbacks. This structure is now passed as the second argument of spdk_mem_map_alloc
3083in lieu of the notify callback.
3084
3085### DPDK 18.08
3086
3087The DPDK submodule has been updated to the DPDK 18.08 release. SPDK will now automatically
3088utilize DPDK's dynamic memory management with DPDK versions >= 18.05.1.
3089
3090Hugepages can be still reserved with `[-s|--mem-size <size>]` option at application startup,
3091but once we use them all up, instead of failing user allocations with -ENOMEM, we'll try
3092to dynamically reserve even more. This allows starting SPDK with `--mem-size 0` and using
3093only as many hugepages as it is really needed.
3094
3095Due to this change, the memory buffers returned by `spdk_*malloc()` are no longer guaranteed
3096to be physically contiguous.
3097
3098### I/OAT
3099
3100I/OAT driver can now reinitialize I/OAT channels after encountering DMA errors.
3101
3102### iscsi target
3103
3104Parameter names of `set_iscsi_options` and `get_iscsi_global_params` RPC
3105method for CHAP authentication in discovery sessions have been changed to
3106align with `construct_target_node` RPC method. Old names are still usable
3107but will be removed in future release.
3108
3109`set_iscsi_discovery_auth` and `set_iscsi_target_node_auth` RPC methods have
3110been added to set CHAP authentication for discovery sessions and existing
3111target nodes, respectively.
3112
3113The SPDK iSCSI target supports an AuthFile which can be used to load CHAP
3114shared secrets when the iSCSI target starts. SPDK previously provided a
3115default location for this file (`/usr/local/etc/spdk/auth.conf`) if none was
3116specified. This default has been removed. Users must now explicitly specify
3117the location of this file to load CHAP shared secrets from a file, or use
3118the related iSCSI RPC methods to add them at runtime.
3119
3120### iscsi initiator
3121
3122The SPDK iSCSI initiator is no longer considered experimental and becomes
3123a first-class citizen among bdev modules. The basic usage has been briefly
3124described in the bdev user guide: [iSCSI bdev](https://spdk.io/doc/bdev.html#bdev_config_iscsi)
3125
3126### Miscellaneous
3127
3128The SPDK application framework can now parse long name command line parameters.
3129Most single-character parameters have a long name equivalent now. See the
3130[Command Line Parameters](https://spdk.io/doc/app_overview.html) documentation
3131for details or use the `--help` command line parameter to list all available
3132params.
3133
3134bdevperf `-s` param (io size) was renamed to `-o` as `-s` had been already
3135used by existing apps for memory size.
3136
3137bdevio can now accept all SPDK command line parameters. The config now has to
3138be provided with `-c` or `--config` param.
3139
3140The following ioat/perf and nvme/perf parameters were renamed as well:
3141 `-s` (io size) to `-o`
3142 `-d` (mem size) to `-s`
3143
3144The ReactorMask config file parameter has been deprecated.  Users should
3145use the -m or --cpumask command line option to specify the CPU core mask
3146for the application.
3147
3148Default config file pathnames have been removed from iscsi_tgt, nvmf_tgt
3149and vhost.  Config file pathnames may now only be specified using the
3150-c command line option.
3151
3152Users may no longer set DPDK_DIR in their environment to specify the
3153location of the DPDK installation used to build SPDK.  Using DPDK_DIR
3154has not been the documented nor recommended way to specify the DPDK
3155location for several releases, but removing it ensures no unexpected
3156surprises for users who may have DPDK_DIR defined for other reasons.
3157Users should just use the "configure" script to specify the DPDK
3158location before building SPDK.
3159
3160Although we know that many developers still use Python 2 we are officially
3161switching to Python3 with requirement that all new code must be valid also
3162for Python 2 up to the EOL which is year 2020.
3163
3164Invoking interpreter explicitly is forbidden for executable scripts. There
3165is no need to use syntax like "python ./scripts/rpc.py". All executable
3166scripts must contain proper shebang pointing to the right interpreter.
3167Scripts without shebang mustn't be executable.
3168
3169A Python script has been added to enable conversion of old INI config file
3170to new JSON-RPC config file format. This script can be found at
3171scripts/config_converter.py. Example how this script can be used:
3172~~~{.sh}
3173cat old_format.ini | scripts/config_converter.py > new_json_format.json
3174~~~
3175
3176### Sock
3177
3178Two additional parameters were added to spdk_sock_get_addr() for the server
3179port and client port. These parameters are named "sport" and "cport"
3180respectively.
3181
3182### Virtio
3183
3184The following RPC commands have been deprecated:
3185
3186- construct_virtio_user_scsi_bdev
3187- construct_virtio_pci_scsi_bdev
3188- construct_virtio_user_blk_bdev
3189- construct_virtio_pci_blk_bdev
3190- remove_virtio_scsi_bdev
3191
3192The `construct_virtio_*` ones were replaced with a single `construct_virtio_dev`
3193command that can create any type of Virtio bdev(s). `remove_virtio_scsi_bdev`
3194was replaced with `remove_virtio_bdev` that can delete both Virtio Block and SCSI
3195devices.
3196
3197### Blobfs
3198
3199spdk_file_get_id() returning unique ID for the file was added.
3200
3201### JSON
3202
3203Added jsonrpc-client C library intended for issuing RPC commands from applications.
3204
3205Added API enabling iteration over JSON object:
3206
3207- spdk_json_find()
3208- spdk_json_find_string()
3209- spdk_json_find_array()
3210- spdk_json_object_first()
3211- spdk_json_array_first()
3212- spdk_json_next()
3213
3214### Blobstore
3215
3216Blobstore I/O operations are now based on io_units, instead of blobstore page size.
3217The io_unit size is now the same as the underlying block device's block size.
3218Logical volumes built on a block device with 512B block size can now be used as boot devices
3219in QEMU.
3220
3221### SPDKCLI
3222
3223The SPDKCLI interactive command tool for managing SPDK is no longer considered experimental.
3224Support for the iSCSI and NVMe-oF targets has been added.
3225
3226## v18.07: Raid, Infrastructure Improvements, Bug Fixes
3227
3228### bdev
3229
3230A new public header file bdev_module.h has been introduced to facilitate the
3231development of new bdev modules. This header includes an interface for the
3232spdk_bdev_part and spdk_bdev_part_base objects to enable the creation of
3233multiple virtual bdevs on top of a single base bdev and should act as the
3234primary API for module authors.
3235
3236spdk_bdev_get_opts() and spdk_bdev_set_opts() were added to set bdev-wide
3237options.
3238
3239A mechanism for handling out of memory condition errors (ENOMEM) returned from
3240I/O submission requests at the bdev layer has been added. See
3241spdk_bdev_queue_io_wait().
3242
3243The spdk_bdev_get_io_stat() function now returns cumulative totals instead of
3244resetting on each call. This allows multiple callers to query I/O statistics
3245without conflicting with each other. Existing users will need to adjust their
3246code to record the previous I/O statistics to calculate the delta between calls.
3247
3248I/O queue depth tracking and samples options have been added. See
3249spdk_bdev_get_qd(), spdk_bdev_get_qd_sampling_period(), and
3250spdk_bdev_set_qd_sampling_period().
3251
3252### RAID module
3253
3254A new bdev module called "raid" has been added as experimental module which
3255aggregates underlying NVMe bdevs and exposes a single raid bdev. Please note
3256that vhost will not work with this module because it does not yet have support
3257for multi-element io vectors.
3258
3259### Log
3260
3261The debug log component flag available on several SPDK applications has been
3262renamed from `-t` to `-L` to prevent confusion with tracepoints and to allow the
3263option to be added to tools that already use `-t` to mean something else.
3264
3265### Blobstore
3266
3267A new function, spdk_bs_dump(), has been added that dumps all of the contents of
3268a blobstore to a file pointer. This includes the metadata and is very useful for
3269debugging.
3270
3271Two new operations have been added for thin-provisioned blobs.
3272spdk_bs_inflate_blob() will allocate clusters for all thinly provisioned regions
3273of the blob and populate them with the correct data by reading from the backing
3274blob(s). spdk_bs_blob_decouple_parent() works similarly, but will only allocate
3275clusters that correspond to data in the blob's immediate parent. Clusters
3276allocated to grandparents or that aren't allocated at all will remain
3277thin-provisioned.
3278
3279### BlobFS
3280
3281Changed the return type of spdk_file_truncate() from void to int to allow the
3282propagation of `ENOMEM` errors.
3283
3284### NVMe Driver
3285
3286The new API functions spdk_nvme_qpair_add_cmd_error_injection() and
3287spdk_nvme_qpair_remove_cmd_error_injection() have been added for NVMe error
3288emulation. Users can set a specified command to fail with a particular error
3289status.
3290
3291Changed the name `timeout_sec` parameter to `timeout_us` in
3292spdk_nvme_ctrlr_register_timeout_callback(), and also changed the type from
3293uint32_t to uint64_t. This will give users more fine-grained control over the
3294timeout period.
3295
3296Basic support for Open Channel SSDs was added. See nvme_ocssd.h
3297
3298### NVMe Over Fabrics
3299
3300The spdk_nvmf_tgt_destroy() function is now asynchronous and takes a callback
3301as a parameter.
3302
3303spdk_nvmf_qpair_disconnect() was added to allow the user to disconnect qpairs.
3304
3305spdk_nvmf_subsystem_get_max_namespaces() was added to query the maximum allowed
3306number of namespaces for a given subsystem.
3307
3308### Build System
3309
3310The build system now generates a combined shared library (libspdk.so) that may
3311be used in place of the individual static libraries (libspdk_*.a). The combined
3312library includes all components of SPDK and is intended to make linking against
3313SPDK easier. The static libraries are also still provided for users that prefer
3314to link only the minimal set of components required.
3315
3316### git pre-commit and pre-push hooks
3317
3318The pre-commit hook will run `scripts/check_format.sh` and verify there are no
3319formatting errors before allowing `git commit` to run. The pre-push hook runs
3320`make CONFIG_WERROR=y` with and without `CONFIG_DEBUG=y` using both the gcc and
3321clang compiler before allowing `git push` to run. Following each DEBUG build
3322`test/unit/unittest.sh` is run and verified. Results are recorded in the
3323`make.log` file.
3324
3325To enable type: 'git config core.hooksPath .githooks'. To override after
3326configuration use the `git --no-verify` flag.
3327
3328### RPC
3329
3330The `start_nbd_disk` RPC method now returns the path to the kernel NBD device node
3331rather than always returning `true`.
3332
3333### DPDK 18.05
3334
3335The DPDK submodule has been rebased on the DPDK 18.05 release.  DPDK 18.05 supports
3336dynamic memory allocation, but due to some issues found after the DPDK 18.05 release,
3337that support is not enabled for SPDK 18.07.  Therefore, SPDK 18.07 will continue to use
3338the legacy memory allocation model.  The plan is to enable dynamic memory allocation
3339after the DPDK 18.08 release which should fix these issues.
3340
3341### Environment Abstraction Layer and Event Framework
3342
3343The spdk_mem_map_translate() function now takes a size parameter to indicate the size of
3344the memory region.  This can be used by environment implementations to validate the
3345requested translation.
3346
3347The I/O Channel implementation has been moved to its own library - lib/thread. The
3348public API that was previously in spdk/io_channel.h is now in spdk/thread.h The
3349file spdk/io_channel.h remains and includes spdk/thread.h.
3350
3351spdk_reactor_get_tsc_stats was added to return interesting statistics for each
3352reactor.
3353
3354### IOAT
3355
3356IOAT for copy engine is disabled by default. It can be enabled by specifying the Enable
3357option with "Yes" in `[Ioat]` section of the configuration file. The Disable option is
3358now deprecated and will be removed in a future release.
3359
3360## v18.04: Logical Volume Snapshot/Clone, iSCSI Initiator, Bdev QoS, VPP Userspace TCP/IP
3361
3362### vhost
3363
3364The SPDK vhost-scsi, vhost-blk and vhost-nvme applications have fixes to address the
3365DPDK rte_vhost vulnerability [CVE-2018-1059](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-1059).
3366Please see this [security advisory](https://access.redhat.com/security/cve/cve-2018-1059)
3367for additional information on the DPDK vulnerability.
3368
3369Workarounds have been added to ensure vhost compatibility with QEMU 2.12.
3370
3371EXPERIMENTAL: Support for vhost-nvme has been added to the SPDK vhost target. See the
3372[vhost documentation](http://www.spdk.io/doc/vhost.html) for more details.
3373
3374### Unified Target Application
3375
3376A new unified SPDK target application, `spdk_tgt`, has been added. This application combines the
3377functionality of several existing SPDK applications, including the iSCSI target, NVMe-oF target,
3378and vhost target. The new application can be managed through the existing configuration file and
3379[JSON-RPC](http://www.spdk.io/doc/jsonrpc.html) methods.
3380
3381### Env
3382
3383spdk_mempool_get_bulk() has been added to wrap DPDK rte_mempool_get_bulk().
3384
3385New memory management functions spdk_malloc(), spdk_zmalloc(), and spdk_free() have been added.
3386These new functions have a `flags` parameter that allows the user to specify whether the allocated
3387memory needs to be suitable for DMA and whether it should be shared across processes with the same
3388shm_id. The new functions are intended to replace spdk_dma_malloc() and related functions, which will
3389eventually be deprecated and removed.
3390
3391### Bdev
3392
3393A new optional bdev module interface function, `init_complete`, has been added to notify bdev modules
3394when the bdev subsystem initialization is complete. This may be useful for virtual bdevs that require
3395notification that the set of initialization examine() calls is complete.
3396
3397The bdev layer now allows modules to provide an optional per-bdev UUID, which can be retrieved with
3398the spdk_bdev_get_uuid() function.
3399
3400Enforcement of IOPS limits for quality of service (QoS) has been added to the bdev layer. See the
3401[set_bdev_qos_limit_iops](http://www.spdk.io/doc/jsonrpc.html#rpc_set_bdev_qos_limit_iops) documentation
3402for more details.
3403
3404### RPC
3405
3406The `[Rpc]` configuration file section, which was deprecated in v18.01, has been removed.
3407Users should switch to the `-r` command-line parameter instead.
3408
3409The JSON-RPC server implementation now allows up to 32 megabyte responses, growing as
3410needed; previously, the response was limited to 32 kilobytes.
3411
3412### SPDKCLI
3413
3414EXPERIMENTAL: New SPDKCLI interactive command tool for managing SPDK is available.
3415See the [SPDKCLI](http://www.spdk.io/doc/spdkcli.html) documentation for more details.
3416
3417### NVMe Driver
3418
3419EXPERIMENTAL: Support for WDS and RDS capable CMBs in NVMe controllers has been added. This support is
3420experimental pending a functional allocator to free and reallocate CMB buffers.
3421
3422spdk_nvme_ns_get_uuid() has been added to allow retrieval of per-namespace UUIDs when available.
3423
3424New API functions spdk_nvme_ctrlr_get_first_active_ns() and spdk_nvme_ctrlr_get_next_active_ns()
3425have been added to iterate active namespaces, as well as spdk_nvme_ctrlr_is_active_ns() to check if
3426a namespace ID is active.
3427
3428### NVMe-oF Target
3429
3430Namespaces may now be assigned unique identifiers via new optional `eui64` and `nguid` parameters
3431to the `nvmf_subsystem_add_ns` RPC method. Additionally, the NVMe-oF target automatically exposes
3432the backing bdev's UUID as the namespace UUID when available.
3433
3434spdk_nvmf_subsystem_remove_ns() is now asynchronous and requires a callback to indicate completion.
3435
3436### Blobstore
3437
3438A number of functions have been renamed:
3439
3440- spdk_bs_io_write_blob() => spdk_blob_io_write()
3441- spdk_bs_io_read_blob() => spdk_blob_io_read()
3442- spdk_bs_io_writev_blob() => spdk_blob_io_writev()
3443- spdk_bs_io_readv_blob() => spdk_blob_io_readv()
3444- spdk_bs_io_unmap_blob() => spdk_blob_io_unmap()
3445- spdk_bs_io_write_zeroes_blob() => spdk_blob_io_write_zeroes()
3446
3447The old names still exist but are deprecated.  They will be removed in the v18.07 release.
3448
3449spdk_blob_resize() is now an asynchronous operation to enable resizing a blob while I/O
3450are in progress to that blob on other threads.  An explicit spdk_blob_sync_md() is still
3451required to sync the updated metadata to disk.
3452
3453### Logical Volumes
3454
3455A new `destroy_lvol_bdev` RPC method to delete logical volumes has been added.
3456
3457Lvols now have their own UUIDs which replace previous LvolStoreUUID_BlobID combination.
3458
3459New Snapshot and Clone functionalities have been added. User may create Snapshots of existing Lvols
3460and Clones of existing Snapshots.
3461See the [lvol snapshots](http://www.spdk.io/doc/logical_volumes.html#lvol_snapshots) documentation
3462for more details.
3463
3464Resizing logical volumes is now supported via the `resize_lvol_bdev` RPC method.
3465
3466### Lib
3467
3468A set of changes were made in the SPDK's lib code altering
3469instances of calls to `exit()` and `abort()` to return a failure instead
3470wherever reasonably possible.
3471
3472spdk_app_start() no longer exit()'s on an internal failure, but
3473instead returns a non-zero error status.
3474
3475spdk_app_parse_args() no longer exit()'s on help, '-h', or an invalid
3476option, but instead returns SPDK_APP_PARSE_ARGS_HELP and
3477SPDK_APP_PARSE_ARGS_FAIL, respectively, and SPDK_APP_PARSE_ARGS_SUCCESS
3478on success.
3479
3480spdk_pci_get_device() has been deprecated and will be removed in SPDK v18.07.
3481
3482### I/O Channels
3483
3484The prototype for spdk_poller_fn() has been modified; it now returns a value indicating
3485whether or not the poller did any work.  Existing pollers will need to be updated to
3486return a value.
3487
3488### iSCSI Target
3489
3490The SPDK iSCSI target now supports the fd.io Vector Packet Processing (VPP) framework userspace
3491TCP/IP stack. See the [iSCSI VPP documentation](http://www.spdk.io/doc/iscsi.html#vpp) for more
3492details.
3493
3494### iSCSI initiator
3495
3496An iSCSI initiator bdev module has been added to SPDK.  This module should be considered
3497experimental pending additional features and tests.  More details can be found in
3498lib/bdev/iscsi/README.
3499
3500### PMDK
3501
3502The persistent memory (PMDK) bdev module is now enabled using `--with-pmdk` instead of
3503`--with-nvml`.  This reflects the renaming of the persistent memory library from NVML to
3504PMDK.
3505
3506### Virtio Block driver
3507
3508A userspace driver for Virtio Block devices has been added. It was built on top of the
3509[Virtio](http://www.spdk.io/doc/virtio.html) library and can be managed similarly to
3510the Virtio SCSI driver. See the
3511[Virtio Block](http://www.spdk.io/doc/bdev.html#bdev_config_virtio_blk) reference for
3512more information.
3513
3514### Virtio with 2MB hugepages
3515
3516The previous 1GB hugepage limitation has now been lifted. A new `-g` command-line option
3517enables SPDK Virtio to work with 2MB hugepages.
3518See [2MB hugepages](http://www.spdk.io/doc/virtio.html#virtio_2mb) for details.
3519
3520## v18.01: Blobstore Thin Provisioning
3521
3522### Build System
3523
3524The build system now includes a `make install` rule, including support for the common
3525`DESTDIR` and `prefix` variables as used in other build systems.  Additionally, the prefix
3526may be set via the configure `--prefix` option.  Example: `make install prefix=/usr`.
3527
3528### RPC
3529
3530A JSON RPC listener is now enabled by default using a UNIX domain socket at /var/tmp/spdk.sock.
3531A -r option command line option has been added to enable an alternative UNIX domain socket location,
3532or a TCP port in the format ip_addr:tcp_port (i.e. 127.0.0.1:5260).  The Rpc configuration file
3533section is now deprecated and will be removed in the v18.04 release.
3534
3535### I/O Channels
3536
3537spdk_poller_register() and spdk_poller_unregister() were moved from the event
3538framework (include/spdk/event.h) to the I/O channel library
3539(include/spdk/io_channel.h). This allows code that doesn't depend on the event
3540framework to request registration and unregistration of pollers.
3541
3542spdk_for_each_channel() now allows asynchronous operations during iteration.
3543Instead of immediately continuing the interaction upon returning from the iteration
3544callback, the user must call spdk_for_each_channel_continue() to resume iteration.
3545
3546### Block Device Abstraction Layer (bdev)
3547
3548The poller abstraction was removed from the bdev layer. There is now a general purpose
3549abstraction for pollers available in include/spdk/io_channel.h
3550
3551### Lib
3552
3553A set of changes were made in the SPDK's lib code altering,
3554instances of calls to `exit()` and `abort()` to return a failure instead
3555wherever reasonably possible.  This has resulted in return type changes of
3556the API for:
3557
3558- spdk_env_init() from type `void` to `int`.
3559- spdk_mem_map_init() from type `void` to `int`.
3560
3561Applications making use of these APIs should be modified to check for
3562a non-zero return value instead of relying on them to fail without return.
3563
3564### NVMe Driver
3565
3566SPDK now supports hotplug for vfio-attached devices. But there is one thing keep in mind:
3567Only physical removal events are supported; removing devices via the sysfs `remove` file will not work.
3568
3569### NVMe-oF Target
3570
3571Subsystems are no longer tied explicitly to CPU cores. Instead, connections are handed out to the available
3572cores round-robin. The "Core" option in the configuration file has been removed.
3573
3574### Blobstore
3575
3576A number of functions have been renamed:
3577
3578- spdk_bs_md_resize_blob() => spdk_blob_resize()
3579- spdk_bs_md_sync_blob() => spdk_blob_sync_md()
3580- spdk_bs_md_close_blob() => spdk_blob_close()
3581- spdk_bs_md_get_xattr_names() => spdk_blob_get_xattr_names()
3582- spdk_bs_md_get_xattr_value() => spdk_blob_get_xattr_value()
3583- spdk_blob_md_set_xattr() => spdk_blob_set_xattr()
3584- spdk_blob_md_remove_xattr() => spdk_blob_remove_xattr()
3585- spdk_bs_md_create_blob() => spdk_bs_create_blob()
3586- spdk_bs_md_open_blob() => spdk_bs_open_blob()
3587- spdk_bs_md_delete_blob() => spdk_bs_delete_blob()
3588- spdk_bs_md_iter_first() => spdk_bs_iter_first()
3589- spdk_bs_md_iter_next() => spdk_bs_iter_next()
3590
3591The function signature of spdk_blob_close() has changed.  It now takes a struct spdk_blob * argument
3592rather than struct spdk_blob **.
3593
3594The function signature of spdk_bs_iter_next() has changed.  It now takes a struct spdk_blob * argument
3595rather than struct spdk_blob **.
3596
3597Thin provisioning support has been added to the blobstore.  It can be enabled by setting the
3598`thin_provision` flag in struct spdk_blob_opts when calling spdk_bs_create_blob_ext().
3599
3600### NBD device
3601
3602The NBD application (test/lib/bdev/nbd) has been removed; Same functionality can now be
3603achieved by using the test/app/bdev_svc application and start_nbd_disk RPC method.
3604See the [GPT](http://www.spdk.io/doc/bdev.html#bdev_config_gpt) documentation for more details.
3605
3606### FIO plugin
3607
3608SPDK `fio_plugin` now supports FIO 3.3. The support for previous FIO 2.21 has been dropped,
3609although it still remains to work for now. The new FIO contains huge amount of bugfixes and
3610it's recommended to do an update.
3611
3612### Virtio library
3613
3614Previously a part of the bdev_virtio module, now a separate library. Virtio is now available
3615via `spdk_internal/virtio.h` file. This is an internal interface to be used when implementing
3616new Virtio backends, namely Virtio-BLK.
3617
3618### iSCSI
3619
3620The MinConnectionIdleInterval parameter has been removed, and connections are no longer migrated
3621to an epoll/kqueue descriptor on the master core when idle.
3622
3623## v17.10: Logical Volumes
3624
3625### New dependencies
3626
3627libuuid was added as new dependency for logical volumes.
3628
3629libnuma is now required unconditionally now that the DPDK submodule has been updated to DPDK 17.08.
3630
3631### Block Device Abstraction Layer (bdev)
3632
3633An [fio](http://github.com/axboe/fio) plugin was added that can route
3634I/O to the bdev layer. See the [plugin documentation](https://github.com/spdk/spdk/tree/master/examples/bdev/fio_plugin/)
3635for more information.
3636
3637spdk_bdev_unmap() was modified to take an offset and a length in bytes as
3638arguments instead of requiring the user to provide an array of SCSI
3639unmap descriptors. This limits unmaps to a single contiguous range.
3640
3641spdk_bdev_write_zeroes() was introduced.  It ensures that all specified blocks will be zeroed out.
3642If a block device doesn't natively support a write zeroes command, the bdev layer emulates it using
3643write commands.
3644
3645New API functions that accept I/O parameters in units of blocks instead of bytes
3646have been added:
3647
3648- spdk_bdev_read_blocks(), spdk_bdev_readv_blocks()
3649- spdk_bdev_write_blocks(), spdk_bdev_writev_blocks()
3650- spdk_bdev_write_zeroes_blocks()
3651- spdk_bdev_unmap_blocks()
3652
3653The bdev layer now handles temporary out-of-memory I/O failures internally by queueing the I/O to be
3654retried later.
3655
3656### Linux AIO bdev
3657
3658The AIO bdev now allows the user to override the auto-detected block size.
3659
3660### NVMe driver
3661
3662The NVMe driver now recognizes the NVMe 1.3 Namespace Optimal I/O Boundary field.
3663NVMe 1.3 devices may report an optimal I/O boundary, which the driver will take
3664into account when splitting I/O requests.
3665
3666The HotplugEnable option in `[Nvme]` sections of the configuration file is now
3667"No" by default. It was previously "Yes".
3668
3669The NVMe library now includes a spdk_nvme_ns_get_ctrlr() function which returns the
3670NVMe Controller associated with a given namespace.
3671
3672The NVMe library now allows the user to specify a host identifier when attaching
3673to a controller.  The host identifier is used as part of the Reservations feature,
3674as well as in the NVMe-oF Connect command.  The default host ID is also now a
3675randomly-generated UUID, and the default host NQN uses the host ID to generate
3676a UUID-based NQN.
3677
3678spdk_nvme_connect() was added to allow the user to connect directly to a single
3679NVMe or NVMe-oF controller.
3680
3681### NVMe-oF Target (nvmf_tgt)
3682
3683The NVMe-oF target no longer requires any in-capsule data buffers to run, and
3684the feature is now entirely optional. Previously, at least 4 KiB in-capsule
3685data buffers were required.
3686
3687NVMe-oF subsystems have a new configuration option, AllowAnyHost, to control
3688whether the host NQN whitelist is enforced when accepting new connections.
3689If no Host options have been specified and AllowAnyHost is disabled, the
3690connection will be denied; this is a behavior change from previous releases,
3691which allowed any host NQN to connect if the Host list was empty.
3692AllowAnyHost is disabled by default.
3693
3694NVMe-oF namespaces may now be assigned arbitrary namespace IDs, and the number
3695of namespaces per subsystem is no longer limited.
3696
3697The NVMe-oF target now supports the Write Zeroes command.
3698
3699### Environment Abstraction Layer
3700
3701A new default value, SPDK_MEMPOOL_DEFAULT_CACHE_SIZE, was added to provide
3702additional clarity when constructing spdk_mempools. Previously, -1 could be
3703passed and the library would choose a reasonable default, but this new value
3704makes it explicit that the default is being used.
3705
3706### Blobstore
3707
3708The blobstore super block now contains a bstype field to identify the type of the blobstore.
3709Existing code should be updated to fill out bstype when calling spdk_bs_init() and spdk_bs_load().
3710
3711spdk_bs_destroy() was added to allow destroying blobstore on device
3712with an initialized blobstore.
3713
3714spdk_bs_io_readv_blob() and spdk_bs_io_writev_blob() were added to enable
3715scattered payloads.
3716
3717A CLI tool for blobstore has been added, allowing basic operations through either command
3718line or shell interface.  See the [blobcli](https://github.com/spdk/spdk/tree/master/examples/blob/cli)
3719documentation for more details.
3720
3721### Event Framework
3722
3723The ability to set a thread name, previously only used by the reactor code, is
3724now part of the spdk_thread_allocate() API.  Users may specify a thread name
3725which will show up in tools like `gdb`.
3726
3727### Log
3728
3729The spdk_trace_dump() function now takes a new parameter to allow the caller to
3730specify an output file handle (stdout or stderr, for example).
3731
3732### Logical Volumes
3733
3734Logical volumes library built on top of SPDK blobstore has been added.
3735It is possible to create logical volumes on top of other devices using RPC.
3736
3737See the [logical volumes](http://www.spdk.io/doc/logical_volumes.html) documentation for more information.
3738
3739### Persistent Memory
3740
3741A new persistent memory bdev type has been added.
3742The persistent memory block device is built on top of [libpmemblk](http://pmem.io/nvml/libpmemblk/).
3743It is possible to create pmem devices on top of pmem pool files using RPC.
3744
3745See the [Pmem Block Device](http://www.spdk.io/doc/bdev.html#bdev_config_pmem) documentation for more information.
3746
3747### Virtio SCSI driver
3748
3749A userspace driver for Virtio SCSI devices has been added.
3750The driver is capable of creating block devices on top of LUNs exposed by another SPDK vhost-scsi application.
3751
3752See the [Virtio SCSI](http://www.spdk.io/doc/virtio.html) documentation and
3753[Getting Started](http://www.spdk.io/doc/bdev.html#bdev_config_virtio_scsi) guide for more information.
3754
3755### Vhost target
3756
3757The vhost target application now supports live migration between QEMU instances.
3758
3759## v17.07: Build system improvements, userspace vhost-blk target, and GPT bdev
3760
3761### Build System
3762
3763A `configure` script has been added to simplify the build configuration process.
3764The existing CONFIG file and `make CONFIG_...` options are also still supported.
3765Run `./configure --help` for information about available configuration options.
3766
3767A DPDK submodule has been added to make building SPDK easier.  If no `--with-dpdk`
3768option is specified to configure, the SPDK build system will automatically build a
3769known-good configuration of DPDK with the minimal options enabled.  See the Building
3770section of README.md for more information.
3771
3772A [Vagrant](https://www.vagrantup.com/) setup has been added to make it easier to
3773develop and use SPDK on systems without suitable NVMe hardware.  See the Vagrant
3774section of README.md for more information.
3775
3776### Userspace vhost-blk target
3777
3778The vhost library and example app have been updated to support the vhost-blk
3779protocol in addition to the existing vhost-scsi protocol.
3780See the [vhost documentation](http://www.spdk.io/doc/vhost.html) for more details.
3781
3782### Block device abstraction layer (bdev)
3783
3784A GPT virtual block device has been added, which automatically exposes GPT partitions
3785with a special SPDK-specific partition type as bdevs.
3786See the [GPT bdev documentation](http://www.spdk.io/doc/bdev.md#bdev_config_gpt) for
3787more information.
3788
3789### NVMe driver
3790
3791The NVMe driver has been updated to support recent Intel SSDs, including the Intel®
3792Optane™ SSD DC P4800X series.
3793
3794A workaround has been added for devices that failed to recognize register writes
3795during controller reset.
3796
3797The NVMe driver now allocates request tracking objects on a per-queue basis.  The
3798number of requests allowed on an I/O queue may be set during `spdk_nvme_probe()` by
3799modifying `io_queue_requests` in the opts structure.
3800
3801The SPDK NVMe `fio_plugin` has been updated to support multiple threads (`numjobs`).
3802
3803spdk_nvme_ctrlr_alloc_io_qpair() has been modified to allow the user to override
3804controller-level options for each individual I/O queue pair.
3805Existing callers with qprio == 0 can be updated to:
3806~~~
3807... = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, NULL, 0);
3808~~~
3809Callers that need to specify a non-default qprio should be updated to:
3810~~~
3811struct spdk_nvme_io_qpair_opts opts;
3812spdk_nvme_ctrlr_get_default_io_qpair_opts(ctrlr, &opts, sizeof(opts));
3813opts.qprio = SPDK_NVME_QPRIO_...;
3814... = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, &opts, sizeof(opts));
3815~~~
3816
3817### Environment Abstraction Layer
3818
3819The environment abstraction layer has been updated to include several new functions
3820in order to wrap additional DPDK functionality. See `include/spdk/env.h` for the
3821current set of functions.
3822
3823### SPDK Performance Analysis with Intel® VTune™ Amplifier
3824
3825Support for SPDK performance analysis has been added to Intel® VTune™ Amplifier 2018.
3826
3827This analysis provides:
3828
3829- I/O performance monitoring (calculating standard I/O metrics like IOPS, throughput, etc.)
3830- Tuning insights on the interplay of I/O and compute devices by estimating how many cores
3831  would be reasonable to provide for SPDK to keep up with a current storage workload.
3832
3833See the VTune Amplifier documentation for more information.
3834
3835## v17.03: Blobstore and userspace vhost-scsi target
3836
3837### Blobstore and BlobFS
3838
3839The blobstore is a persistent, power-fail safe block allocator designed to be
3840used as the local storage system backing a higher-level storage service.
3841See the [blobstore documentation](http://www.spdk.io/doc/blob.html) for more details.
3842
3843BlobFS adds basic filesystem functionality like filenames on top of the blobstore.
3844This release also includes a RocksDB Env implementation using BlobFS in place of the
3845kernel filesystem.
3846See the [BlobFS documentation](http://www.spdk.io/doc/blobfs.html) for more details.
3847
3848### Userspace vhost-scsi target
3849
3850A userspace implementation of the QEMU vhost-scsi protocol has been added.
3851The vhost target is capable of exporting SPDK bdevs to QEMU-based VMs as virtio devices.
3852See the [vhost documentation](http://www.spdk.io/doc/vhost.html) for more details.
3853
3854### Event framework
3855
3856The overhead of the main reactor event loop was reduced by optimizing the number of
3857calls to spdk_get_ticks() per iteration.
3858
3859### NVMe library
3860
3861The NVMe library will now automatically split readv/writev requests with scatter-gather
3862lists that do not map to valid PRP lists when the NVMe controller does not natively
3863support SGLs.
3864
3865The `identify` and `perf` NVMe examples were modified to add a consistent format for
3866specifying remote NVMe over Fabrics devices via the `-r` option.
3867This is implemented using the new `spdk_nvme_transport_id_parse()` function.
3868
3869### iSCSI Target
3870
3871The [Nvme] section of the configuration file was modified to remove the `BDF` directive
3872and replace it with a `TransportID` directive. Both local (PCIe) and remote (NVMe-oF)
3873devices can now be specified as the backing block device. A script to generate an
3874entire [Nvme] section based on the local NVMe devices attached was added at
3875`scripts/gen_nvme.sh`.
3876
3877### NVMe-oF Target
3878
3879The [Nvme] section of the configuration file was modified to remove the `BDF` directive
3880and replace it with a `TransportID` directive. Both local (PCIe) and remote (NVMe-oF)
3881devices can now be specified as the backing block device. A script to generate an
3882entire [Nvme] section based on the local NVMe devices attached was added at
3883`scripts/gen_nvme.sh`.
3884
3885## v16.12: NVMe over Fabrics host, hotplug, and multi-process
3886
3887### NVMe library
3888
3889The NVMe library has been changed to create its own request memory pool rather than
3890requiring the user to initialize the global `request_mempool` variable.  Apps can be
3891updated by simply removing the initialization of `request_mempool`.  Since the NVMe
3892library user no longer needs to know the size of the internal NVMe request
3893structure to create the pool, the `spdk_nvme_request_size()` function was also removed.
3894
3895The `spdk_nvme_ns_cmd_deallocate()` function was renamed and extended to become
3896`spdk_nvme_ns_cmd_dataset_management()`, which allows access to all of the NVMe
3897Dataset Management command's parameters.  Existing callers can be updated to use
3898`spdk_nvme_ns_cmd_dataset_management()` with `SPDK_NVME_DSM_ATTR_DEALLOCATE` as the
3899`type` parameter.
3900
3901The NVMe library SGL callback prototype has been changed to return virtual addresses
3902rather than physical addresses.  Callers of `spdk_nvme_ns_cmd_readv()` and
3903`spdk_nvme_ns_cmd_writev()` must update their `next_sge_fn` callbacks to match.
3904
3905The NVMe library now supports NVMe over Fabrics devices in addition to the existing
3906support for local PCIe-attached NVMe devices.  For an example of how to enable
3907NVMe over Fabrics support in an application, see `examples/nvme/identify` and
3908`examples/nvme/perf`.
3909
3910Hot insert/remove support for NVMe devices has been added.  To enable NVMe hotplug
3911support, an application should call the `spdk_nvme_probe()` function on a regular
3912basis to probe for new devices (reported via the existing `probe_cb` callback) and
3913removed devices (reported via a new `remove_cb` callback).  Hotplug is currently
3914only supported on Linux with the `uio_pci_generic` driver, and newly-added NVMe
3915devices must be bound to `uio_pci_generic` by an external script or tool.
3916
3917Multiple processes may now coordinate and use a single NVMe device simultaneously
3918using [DPDK Multi-process Support](http://dpdk.org/doc/guides/prog_guide/multi_proc_support.html).
3919
3920### NVMe over Fabrics target (`nvmf_tgt`)
3921
3922The `nvmf_tgt` configuration file format has been updated significantly to enable
3923new features.  See the example configuration file `etc/spdk/nvmf.conf.in` for
3924more details on the new and changed options.
3925
3926The NVMe over Fabrics target now supports virtual mode subsystems, which allow the
3927user to export devices from the SPDK block device abstraction layer as NVMe over
3928Fabrics subsystems.  Direct mode (raw NVMe device access) is also still supported,
3929and a single `nvmf_tgt` may export both types of subsystems simultaneously.
3930
3931### Block device abstraction layer (bdev)
3932
3933The bdev layer now supports scatter/gather read and write I/O APIs, and the NVMe
3934blockdev driver has been updated to support scatter/gather.  Apps can use the
3935new scatter/gather support via the `spdk_bdev_readv()` and `spdk_bdev_writev()`
3936functions.
3937
3938The bdev status returned from each I/O has been extended to pass through NVMe
3939or SCSI status codes directly in cases where the underlying device can provide
3940a more specific status code.
3941
3942A Ceph RBD (RADOS Block Device) blockdev driver has been added.  This allows the
3943`iscsi_tgt` and `nvmf_tgt` apps to export Ceph RBD volumes as iSCSI LUNs or
3944NVMe namespaces.
3945
3946### General changes
3947
3948`libpciaccess` has been removed as a dependency and DPDK PCI enumeration is
3949used instead. Prior to DPDK 16.07 enumeration by class code was not supported,
3950so for earlier DPDK versions, only Intel SSD DC P3x00 devices will be discovered
3951by the NVMe library.
3952
3953The `env` environment abstraction library has been introduced, and a default
3954DPDK-based implementation is provided as part of SPDK.  The goal of the `env`
3955layer is to enable use of alternate user-mode memory allocation and PCI access
3956libraries.  See `doc/porting.md` for more details.
3957
3958The build process has been modified to produce all of the library files in the
3959`build/lib` directory.  This is intended to simplify the use of SPDK from external
3960projects, which can now link to SPDK libraries by adding the `build/lib` directory
3961to the library path via `-L` and linking the SPDK libraries by name (for example,
3962`-lspdk_nvme -lspdk_log -lspdk_util`).
3963
3964`nvmf_tgt` and `iscsi_tgt` now have a JSON-RPC interface, which allows the user
3965to query and modify the configuration at runtime.  The RPC service is disabled by
3966default, since it currently does not provide any authentication or security
3967mechanisms; it should only be enabled on systems with controlled user access
3968behind a firewall. An example RPC client implemented in Python is provided in
3969`scripts/rpc.py`.
3970
3971## v16.08: iSCSI target, NVMe over Fabrics maturity
3972
3973This release adds a userspace iSCSI target. The iSCSI target is capable of exporting
3974NVMe devices over a network using the iSCSI protocol. The application is located
3975in app/iscsi_tgt and a documented configuration file can be found at etc/spdk/spdk.conf.in.
3976
3977This release also significantly improves the existing NVMe over Fabrics target.
3978
3979- The configuration file format was changed, which will require updates to
3980  any existing nvmf.conf files (see `etc/spdk/nvmf.conf.in`):
3981  - `SubsystemGroup` was renamed to `Subsystem`.
3982  - `AuthFile` was removed (it was unimplemented).
3983  - `nvmf_tgt` was updated to correctly recognize NQN (NVMe Qualified Names)
3984    when naming subsystems.  The default node name was changed to reflect this;
3985    it is now "nqn.2016-06.io.spdk".
3986  - `Port` and `Host` sections were merged into the `Subsystem` section
3987  - Global options to control max queue depth, number of queues, max I/O
3988    size, and max in-capsule data size were added.
3989  - The Nvme section was removed. Now a list of devices is specified by
3990    bus/device/function directly in the Subsystem section.
3991  - Subsystems now have a Mode, which can be Direct or Virtual. This is an attempt
3992    to future-proof the interface, so the only mode supported by this release
3993    is "Direct".
3994- Many bug fixes and cleanups were applied to the `nvmf_tgt` app and library.
3995- The target now supports discovery.
3996
3997This release also adds one new feature and provides some better examples and tools
3998for the NVMe driver.
3999
4000- The Weighted Round Robin arbitration method is now supported. This allows
4001  the user to specify different priorities on a per-I/O-queue basis.  To
4002  enable WRR, set the `arb_mechanism` field during `spdk_nvme_probe()`.
4003- A simplified "Hello World" example was added to show the proper way to use
4004  the NVMe library API; see `examples/nvme/hello_world/hello_world.c`.
4005- A test for measuring software overhead was added. See `test/lib/nvme/overhead`.
4006
4007## v16.06: NVMf userspace target
4008
4009This release adds a userspace NVMf (NVMe over Fabrics) target, conforming to the
4010newly-released NVMf 1.0/NVMe 1.2.1 specification.  The NVMf target exports NVMe
4011devices from a host machine over the network via RDMA.  Currently, the target is
4012limited to directly exporting physical NVMe devices, and the discovery subsystem
4013is not supported.
4014
4015This release includes a general API cleanup, including renaming all declarations
4016in public headers to include a `spdk` prefix to prevent namespace clashes with
4017user code.
4018
4019- NVMe
4020  - The `nvme_attach()` API was reworked into a new probe/attach model, which
4021  moves device detection into the NVMe library.  The new API also allows
4022  parallel initialization of NVMe controllers, providing a major reduction in
4023  startup time when using multiple controllers.
4024  - I/O queue allocation was changed to be explicit in the API.  Each function
4025  that generates I/O requests now takes a queue pair (`spdk_nvme_qpair *`)
4026  argument, and I/O queues may be allocated using
4027  `spdk_nvme_ctrlr_alloc_io_qpair()`.  This allows more flexible assignment of
4028  queue pairs than the previous model, which only allowed a single queue
4029  per thread and limited the total number of I/O queues to the lowest number
4030  supported on any attached controller.
4031  - Added support for the Write Zeroes command.
4032  - `examples/nvme/perf` can now report I/O command latency from the
4033  the controller's viewpoint using the Intel vendor-specific read/write latency
4034  log page.
4035  - Added namespace reservation command support, which can be used to coordinate
4036  sharing of a namespace between multiple hosts.
4037  - Added hardware SGL support, which enables use of scattered buffers that
4038  don't conform to the PRP list alignment and length requirements on supported
4039  NVMe controllers.
4040  - Added end-to-end data protection support, including the ability to write and
4041  read metadata in extended LBA (metadata appended to each block of data in the
4042  buffer) and separate metadata buffer modes.
4043  See `spdk_nvme_ns_cmd_write_with_md()` and `spdk_nvme_ns_cmd_read_with_md()`
4044  for details.
4045- IOAT
4046  - The DMA block fill feature is now exposed via the `ioat_submit_fill()`
4047  function.  This is functionally similar to `memset()`, except the memory is
4048  filled with an 8-byte repeating pattern instead of a single byte like memset.
4049- PCI
4050  - Added support for using DPDK for PCI device mapping in addition to the
4051  existing libpciaccess option.  Using the DPDK PCI support also allows use of
4052  the Linux VFIO driver model, which means that SPDK userspace drivers will work
4053  with the IOMMU enabled.  Additionally, SPDK applications may be run as an
4054  unprivileged user with access restricted to a specific set of PCIe devices.
4055  - The PCI library API was made more generic to abstract away differences
4056  between the underlying PCI access implementations.
4057
4058## v1.2.0: IOAT user-space driver
4059
4060This release adds a user-space driver with support for the Intel I/O Acceleration Technology
4061(I/OAT, also known as "Crystal Beach") DMA offload engine.
4062
4063- IOAT
4064  - New user-space driver supporting DMA memory copy offload
4065  - Example programs `ioat/perf` and `ioat/verify`
4066  - Kernel-mode DMA engine test driver `kperf` for performance comparison
4067- NVMe
4068  - Per-I/O flags for Force Unit Access (FUA) and Limited Retry
4069  - Public API for retrieving log pages
4070  - Reservation register/acquire/release/report command support
4071  - Scattered payload support - an alternate API to provide I/O buffers via a sequence of callbacks
4072  - Declarations and `nvme/identify` support for Intel SSD DC P3700 series vendor-specific log pages and features
4073- Updated to support DPDK 2.2.0
4074
4075## v1.0.0: NVMe user-space driver
4076
4077This is the initial open source release of the Storage Performance Development Kit (SPDK).
4078
4079Features:
4080
4081- NVMe user-space driver
4082- NVMe example programs
4083  - `examples/nvme/perf` tests performance (IOPS) using the NVMe user-space driver
4084  - `examples/nvme/identify` displays NVMe controller information in a human-readable format
4085- Linux and FreeBSD support
4086