xref: /spdk/CHANGELOG.md (revision c680e3a05b1a903c18bf3f75b732765607126f45)
1# Changelog
2
3## v23.01: (Upcoming Release)
4
5### bdev
6
7Both of interleaved and separated metadata are now supported by the malloc bdev module.
8
9Protection information is now supported by the malloc bdev module.
10
11A new API `spkd_bdev_part_submit_request_ext` was added to specify a custom completion callback.
12
13### scheduler
14
15Changing scheduler from dynamic back to static is no longer possible,
16as there is no way of saving original SPDK thread distribution on reactors.
17
18### bdev
19
20New APIs `spdk_bdev_for_each_channel` and `spdk_bdev_for_each_channel_continue` and
21associated function pointers were added to iterate each channel of the required bdev.
22
23The RPC `bdev_get_iostat` now allows a user to query the per channel IO statistics for
24required bdev.
25
26New `spdk_bdev_copy_blocks` and `spdk_bdev_get_max_copy` APIs to support copy commands.
27
28A new API `spdk_bdev_io_get_submit_tsc` was added to get the submit_tsc of the bdev I/O.
29
30Bdevs will no longer have UUIDs generated based on timestamp and are responsible for
31setting this field themselves. Generation of UUIDs for NVMe bdevs may be enabled by
32running `bdev_nvme_set_options` RPC with `--generate-uuids` option. These identifiers
33are based on serial number and namespace ID and will always be the same for a given
34device.
35
36A new API `spdk_bdev_channel_get_histogram` was added to get the histogram of a specified
37channel for a bdev.
38
39### event
40
41Added core lock file mechanism to prevent the same CPU cores from being used by multiple
42SPDK application instances.
43
44Added a command line switch to disable CPU locks on SPDK startup.
45
46Added RPCs framework_enable_cpumask_locks and framework_disable_cpumask_locks to enable
47and disable CPU core locks in runtime.
48
49Added --rpcs-allowed command line option. Users can specify a comma-separated list of RPC
50names with this option to restrict allowed RPCs to only that list.
51
52### rpc
53
54Added spdk_rpc_set_allowlist to restrict allowed RPCs to the specified list.
55
56### bdevperf
57
58Promoted the application to example to match similar programs: fio_plugin and perf.
59It can now be found inside `examples/bdev/bdevperf`.
60
61### util
62
63New API `spdk_fd_group_get_epoll_event` that returns the epoll(7) event that
64caused a function callback in file descriptor group to execute.
65
66### json
67
68Added API `spdk_json_write_double` and `spdk_json_write_named_double` to allow
69for writing and decoding of the the double data type.
70
71### thread
72
73Added `spdk_thread_get_app_thread` which returns the first thread that was created using
74`spdk_thread_create`.
75
76Added `spdk_thread_is_running`.  This returns `true` for a running thread, or `false` if
77its exit process has started using `spdk_thread_exit`.
78
79## v22.09
80
81### accel
82
83Many names were changed in the accel framework to make them consistent both with themselves and
84the rest of SPDK. The primary public header file is now named `include/spdk/accel.h`.
85
86Added a new runtime RPC `accel_get_opc_assignments` to get a list of current opcode to engine
87assignments.
88
89Added a new startup RPC `accel_assign_opc` to assign/override a specific opcode to
90an engine.
91
92### bdev
93
94New RPCs `bdev_xnvme_create` and `bdev_xnvme_delete` were added to support the xNVMe bdev.
95
96A new API `spdk_bdev_for_each_bdev_io` was added to execute the function on the appropriate
97thread for each bdev_io submitted to the bdev.
98
99A new API `spdk_bdev_get_current_qd` was added to measure and return the queue depth from a
100bdev. This API is available even when queue depth sampling is disabled.
101
102Added `spdk_bdev_seek_data`, `spdk_bdev_seek_hole` and `spdk_bdev_io_get_seek_offset` functions
103that start from a given offset and seek for next data or for next hole. At this time only
104supported by lvol bdev module.
105
106A new parameter `io_drain_timeout` has been added to `spdk_bdev` structure. It controls how long
107a bdev reset must wait for IO to complete prior to issuing a reset to the underlying device.
108If there is no outstanding IO at the end of that period, the reset is skipped.
109Best defined for bdevs that share an underlying bdev, such as multiple lvol bdevs sharing
110an nvme device, to avoid unnecessarily resetting the underlying bdev and affecting other
111bdevs that are sharing it.
112Modifying this field is optional. Setting the value to 0 keeps the original behavior
113to always send resets immediately, even if there is no I/O outstanding.
114
115### blobstore
116
117Reserve space for `used_clusters` bitmap. The reserved space could be used for blobstore growing
118in the future.
119
120Added `is_zeroes` operation to `spdk_bs_dev`. It allows to detect if logical blocks are backed
121by zeroes device and do a shortcut in copy-on-write flow by excluding copy part from zeroes device.
122
123Added `spdk_blob_get_next_allocated_io_unit` and `spdk_blob_get_next_unallocated_io_unit` functions
124that start from a given offset and seek for first io_unit belonging to an allocated cluster
125or first io_unit belonging to an unallocated cluster.
126
127Added `spdk_bs_grow` function to grow blobstore size if the underlying bdev size is increased.
128This is used by lvol bdev via `bdev_lvol_grow_lvstore` RPC.
129
130### daos
131
132Added new DAOS bdev module, that creates SPDK block device on top of DAOS DFS.
133Please see [documentation](https://spdk.io/doc/bdev.html#bdev_config_daos) for more details.
134
135### env
136
137Added `spdk_pci_register_device_provider` and matching `SPDK_PCI_REGISTER_DEVICE_PROVIDER`
138functions for registering PCI device providers. That allow the VMD driver to be notified
139when users want to attach a device under a given BDF and when a device is detached.
140
141### init
142
143`spdk_subsystem_init_from_json_config` now fails if the JSON configuration file is not
144an object with an array named "subsystems".
145
146### iscsi
147
148Added `bdev_iscsi_set_options` RPC to modify options of the iSCSI bdev module.
149
150### json
151
152Added `spdk_json_find` API return errcode: EPROTOTYPE - json not enclosed in {}.
153`spdk_json_find` now returns -EPROTOTYPE instead of -ENOENT if the object parameter
154does not point to a JSON object (i.e. is not enclosed with {}).
155
156### lvol
157
158Add `num_md_pages_per_cluster_ratio` parameter to the `bdev_lvol_create_lvstore` RPC.
159Calculate `num_md_pages` from `num_md_pages_per_cluster_ratio`, and pass it to `spdk_bs_opts`.
160
161### nvme
162
163Added SPDK_NVME_TRANSPORT_CUSTOM_FABRICS to enum `spdk_nvme_transport_type` to support custom
164fabric transport. SPDK_NVME_TRANSPORT_CUSTOM was intended to be non-fabric custom transport.
165
166Added a new function `spdk_nvme_ns_cmd_verify` to submit a Verify Command to a Namespace.
167
168Added `spdk_nvme_ctrlr_disable_read_changed_ns_list_log_page` to allow an application to
169tell the driver to not read the CHANGED_NS_LIST log page in response to a NS_ATTR_CHANGED
170AEN.  When called the application is required to read this log page instead to clear the
171AEN.
172
173Added `psk` field to `spdk_nvme_ctrlr_opts` struct in order to enable SSL socket implementation
174of TCP connection and set the PSK. Applicable for TCP transport only.
175
176### raid
177
178Renamed the `raid5` module to `raid5f` to reflect that it is not a traditional
179RAID5 implementation - only full stripe writes are supported, partial stripe
180writes (read-modify-write) are not.
181
182### rpc
183
184Added `psk` parameter to `bdev_nvme_attach_controller` RPC in order to enable SSL socket implementation
185of TCP connection and set the PSK. Applicable for TCP transport only.
186
187New options `enable_ktls` and `tls_version` were added to the `sock_impl_set_options` structure.
188New options `psk_key` and `psk_identity` were added to the `sock_impl_set_options` structure.
189
190Added warning message for `bdev_rbd_create`, if it is used without -c.
191`bdev_rbd_create()` API without specifying -c is deprecated and will be removed in future release.
192
193Renamed `enable_vmd` RPC to `vmd_enable` to make it consistent with our naming scheme of
194`<subsystem>_<action>`.  For now, the old name is still available, but is marked as deprecated.
195
196New function `spdk_rpc_get_method_state_mask` was added to RPC library.
197
198### sma
199
200Extended `VolumeParameters` with crypto parameters allowing the user to configure crypto when
201attaching a volume to a device.  This interface is now supported by all upstream device types
202(nvmf-tcp, virtio-blk, vfio-user) using `bdev_crypto`.  Users must specify the crypto engine to use
203under `crypto` section in config.  It is also possible to register out-of-tree crypto engines by
204inheriting from the `CryptoEngine` class.
205
206Added two new methods: `SetQos` and `GetQosCapabilities` allowing the user to configure QoS on a
207per-device or per-volume level.  Not all QoS settings have to be supported by each device, so users
208can use `GetQosCapabilities` to query them for that.  All upstream device types support QoS on a
209per-volume level using bdev layer's QoS mechanism.
210
211### sock
212
213Added new `ssl` based socket implementation, the code is located in `module/sock/posix`.
214For now we are using hard-coded PSK and only support TLS 1.3.
215
216### util
217
218Added new functions: `spdk_hexlify` and `spdk_unhexlify`.
219
220A new API `spdk_xor_gen` was added to generate XOR from multiple source buffers. It is going to be
221used by `raid5f` for calculating parity.
222
223### vfu_tgt
224
225Added vfu_tgt library abstraction based on libvfio-user for PCI device emulation.
226Besides the NVMe device emulation, its now possible to emulate virtio-blk and virtio-scsi
227devices.
228
229### virtio
230
231virtio-vhost-user no longer tries to support dynamic memory allocation.  The vhost target does
232not support the high rate of SET_MEM_TABLE vhost messages that result from dynamic memory
233allocation, so a virtio-vhost-user device will now present an ERRLOG, assert, and skip the
234SET_MEM_TABLE vhost message if a memory notification is received outside of the normal device
235start/stop. Applications using the virtio library in vhost-user mode should now pre-allocate
236the application's memory using the -s/--mem-size option and use single shared memory file
237segments using the -g/--single-file-segments option.
238
239Added `vfio-user` transport type for virtio-blk and virtio-scsi devices.
240
241### vmd
242
243Fixed hotplug when a device is inserted in a slot in which a disk was already enumerated previously.
244Added two new RPCs: `vmd_remove_device` simulating a hotremove, and `vmd_rescan`, which rescans all
245buses managed by the VMD driver and hotplugs all newfound devices.
246
247## v22.05
248
249### sock
250
251A new option `ack_timeout` was added to the `spdk_sock_opts` structure.
252
253### util
254
255A new parameter `bounce_iovcnt` was added to `spdk_dif_generate_copy` and `spdk_dif_verify_copy`.
256The `bounce_iovcnt` is used to specify the number of bounce_iov to support multiple block-aligned
257fragment copies.
258
259A new API `spdk_copy_iovs_to_buf` and `spdk_copy_buf_to_iovs` were added to copy iovs to buf or
260copy buf to iovs. There're many cases need to use these two APIs.
261
262### bdev
263
264Removed deprecated spdk_bdev_module_finish_done(). Use spdk_bdev_module_fini_done() instead.
265
266A new API `spdk_bdev_unregister_by_name` was added to handle race conditions correctly.
267
268New APIs, `spdk_for_each_bdev` and `spdk_for_each_bdev_leaf`, were added to provide iteration
269safe for race conditions.
270
271A new RPC `bdev_nvme_get_io_paths` was added to get all active I/O paths.
272
273A new RPC `bdev_nvme_set_preferred_path` was added to set preferred I/O path for an NVMe bdev
274when in multipath mode. This RPC does not support NVMe bdevs in failover mode.
275
276A new RPC `bdev_nvme_set_multipath_policy` was added to set multipath policy of a NVMe bdev
277in multipath mode.
278
279A new option `disable_auto_failback` was added to the `bdev_nvme_set_options` RPC to disable
280automatic failback.
281
282### idxd / dsa
283
284A new parameter `flags` was added to all low level submission and preparation
285APIs to enable the caller to pass operation flags per the DSA specification.
286
287A new flag 'SPDK_IDXD_FLAG_PERSISTENT' was added to let DSA know that
288the destination is persistent.
289
290The RPC `idxd_scan_accel_engine` has been renamed to `dsa_scan_accel_engine`
291
292The RPC `iaa_scan_accel_engine` has been added.
293
294Many HW related structs/functions with the name `idxd` have been renamed `dsa`
295to more accurately represent the HW they are associated with.
296
297Two new functions were added to the library `spdk_idxd_submit_compress` and
298`spdk_idxd_submit_decompress`
299
300### accel_fw
301
302A new parameter `flags` was added to accel API.
303The APIs include:
304`spdk_accel_submit_copy`
305`spdk_accel_submit_dualcast`
306`spdk_accel_submit_fill`
307`spdk_accel_submit_copy_crc32c`
308`spdk_accel_submit_copy_crc32cv`
309`spdk_accel_submit_compress`
310`spdk_accel_submit_decompress`
311
312A new flag `ACCEL_FLAG_PERSISTENT` was added to indicate the target memory is PMEM.
313
314The API `spdk_accel_get_capabilities` has been removed.
315
316### crypto
317
318Support for AES_XTS was added for MLX5 polled mode driver (pmd).
319
320bdev_crypto_create RPC now requires hexlified 'key' and 'key2' params for all pmd drivers.
321Unhexlifying is performed during RPC command processing and the vbdev crypto module runs on
322binary keys as before.
323
324### bdev
325
326Added a timeout option to the `bdev_get_bdevs` RPC.  It allows the user to specify the amount of
327time to wait until a bdev with a given name appears in the system.
328
329### bdev_nvme
330
331Added `bdev_nvme_add_error_injection` and `bdev_nvme_remove_error_injection` RPCs to add and
332remove NVMe error injections.
333
334New parameters, `ctrlr_loss_timeout_sec`, `reconnect_delay_sec`, and `fast_io_fail_timeout_sec`, are
335added to the RPC `bdev_nvme_set_options`. They can be overridden if they are given by the RPC
336`bdev_nvme_attach_controller`.
337
338### blobstore
339
340New functions `spdk_blob_io_writev_ext` and `spdk_blob_io_readv_ext` are added. The new functions accept
341`spdk_blob_ext_io_opts` structure with extended IO request options.
342
343### event
344
345Added `msg_mempool_size` parameter to `spdk_reactors_init` and `spdk_thread_lib_init_ext`.
346The size of `g_spdk_msg_mempool` can now be controlled through the same-named
347user option of `spdk_app_opts` structure.
348
349### nvme
350
351The API `spdk_nvme_ctrlr_prepare_for_reset()` was deprecated. The functionality provided by the
352`spdk_nvme_ctrlr_prepare_for_reset()` was merged into the API `spdk_nvme_ctrlr_disconnect()`.
353
354### nvmf
355
356Removed deprecated max_qpairs_per_ctrlr parameter from nvmf_create_transport RPC. Use
357max_io_qpairs_per_ctrlr instead.
358
359Deprecated the ability for hosts to connect to the discovery subsystem automatically on any
360existing listener. Users should now explicitly add listeners for the discovery subsystem.
361Host can still connect to the discovery subsystem as before, but a warning message will be
362emitted if no listener was configured for the transport ID of the incoming connection.
363
364Added adaptive interrupt feature for vfio-user transport. New parameter `disable_adaptive_irq`
365is added to the RPC `nvmf_create_transport`.
366
367### thread
368
369Added `spdk_thread_exec_msg()` API.
370
371### scheduler
372
373`framework_set_scheduler` can now be called after application initialization.
374Added callbacks to set custom parameters specific for each scheduler implementation
375and `framework_get_scheduler` to retrieve them.
376
377Added `dynamic` scheduler options: load_limit, core_limit, core_busy. Their descriptions
378are available in JSON-RPC document, in section
379[framework_set_scheduler](jsonrpc.html#rpc_framework_set_scheduler).
380
381### raid
382
383Add concat as a special raid module. The concat module could create a virtual bdev.  The
384virtual bdev combines multiple underlying bdevs together. The layout of the underlying
385bdevs is one after another. The concat bdev is extendable. When the free space of the
386concat bdev is not enough, the user can deconstruct the concat bdev, then reconstruct it
387with an additional underlying bdev.
388
389### sock
390
391Allow MSG_ZEROCOPY flag to be set or not according to data size, which can be enabled and
392set by setting "zerocopy_threshold". zerocopy_threshold = 0 means disable this function;
393zerocopy_threshold > 0 means enable it and use this value as the threshold.
394
395### rpc
396
397Introduced `zerocopy_threshold` to enable zerocopy on send for server sockets according to
398data size to be flushed.
399
400## v22.01
401
402### accel
403
404The batching capability was removed. Batching is now considered an implementation
405detail of the low level drivers.
406
407### bdev
408
409The NVMe bdev module supports multipath and improved I/O error resiliency.
410
411The parameter `retry_count` of the RPC `bdev_nvme_set_options` was deprecated and will be
412removed in SPDK 22.04, and the parameter `transport_retry_count` is added and used instead.
413
414An new parameter `bdev_retry_count` is added to the RPC `bdev_nvme_set_options`.
415
416New parameters, `ctrlr_loss_timeout_sec`, `reconnect_delay_sec`, and `fast_io_fail_timeout_sec`, are
417added to the RPC `bdev_nvme_attach_controller`.
418
419An new parameter `num_io_queues` is added to `bdev_nvme_attach_controller` RPC to allow specifying amount
420of requested IO queues.
421
422Added `key_file` parameter to the `rbd_register_cluster` RPC.  It is an optional parameter to
423specify a keyring file to connect to a RADOS cluster.
424
425Added `spdk_bdev_get_zone_id` API to retrieve zone_id for a certain LBA.
426
427### bdev_aio
428
429Added `bdev_aio_rescan` RPC to allow rescanning the size of aio bdev.
430
431### bdev_nvme
432
433Added discovery service to bdev_nvme module, which now can connect to a discovery controller.
434bdev_nvme will connect to all current and future subsystems in the discovery controller.
435Added `bdev_nvme_start_discovery` and `bdev_nvme_stop_discovery` RPC.
436
437### dpdk
438
439Updated DPDK submodule to DPDK 21.11.
440
441### env
442
443Added `spdk_pci_for_each_device`.
444
445Removed `spdk_pci_get_first_device` and `spdk_pci_get_next_device`.  These APIs were unsafe, because
446they did not account for PCI devices being inserted or removed while the caller was using handles
447returned from these APIs.  Existing users of these APIs should switch to `spdk_pci_for_each_device`
448instead.
449
450Added 3 experimental APIs to handle PCI device interrupts (`spdk_pci_device_enable_interrupt`,
451`spdk_pci_device_disable_interrupt`, `spdk_pci_device_get_interrupt_efd`).
452
453Added `framework_get_pci_devices` RPC to list PCIe devices attached to an SPDK application.
454
455### idxd
456
457Many APIs are now vectored rather than scalar, meaning they take iovecs instead of individual pointers.
458
459### json
460
461Added `spdk_json_write_bytearray` API to serialize a buffer as a hex string.
462
463### nvme
464
465API `spdk_nvme_trtype_is_fabrics` was added to return existing transport type
466is fabric or not.
467
468API `spdk_nvme_poll_group_remove` was limited to be available only for a
469disconnected qpair in the group.
470
471New APIs, `spdk_nvme_ctrlr_disconnect`, `spdk_nvme_ctrlr_reconnect_async`, and
472`spdk_nvme_ctrlr_reconnect_poll_async`, have been added to improve error recovery, and
473the existing APIs,`spdk_nvme_ctrlr_reset_async` and `spdk_nvme_ctrlr_reset_poll_async`
474were deprecated.
475
476Added `spdk_nvme_ctrlr_get_discovery_log_page` API for getting the full discovery log page
477from a discovery controller.
478
479### nvmf
480
481Added support for zero-copy operations in the NVMe-oF TCP target. It can be enabled via
482the `zcopy` parameter when creating a transport. The zero-copy operations are only used
483for requests not using in-capsule data.
484
485Added a `subsystem` parameter to `spdk_nvmf_transport_stop_listen_async`. When not NULL,
486it will only disconnect qpairs for controllers associated with the specified subsystem.
487
488Removed accept poller from transport layer. Each transport can have its own policy of
489handling new connections. To notify transport layer `spdk_nvmf_poll_group_add` and
490`spdk_nvmf_tgt_new_qpair` can be used.
491
492### scsi
493
494Structure `spdk_scsi_lun` has been extended with new member `resizing` so that SCSI layer now reports
495unit attention for disk resize.
496
497### trace
498
499Added `spdk_trace_create_tpoint_group_mask` to return tracepoint group mask from
500a tracepoint group name.
501
502Added `trace_set_tpoint_mask` and `trace_clear_tpoint_mask` RPC to allow enabling
503individual traces.
504
505### util
506
507Added `spdk_ioviter_first` and `spdk_ioviter_next` to iterate over two iovecs and
508yield pointers to common length segments.
509
510### sock
511
512A new parameter `hint` is added to `spdk_sock_get_optimal_sock_group`. It allows to suggest
513a poll group when no optimal poll group is found.
514
515## v21.10
516
517Structure `spdk_nvmf_target_opts` has been extended with new member `discovery_filter` which allows to specify
518filtering rules applied during discovery log generation. Refer to `enum spdk_nvmf_tgt_discovery_filter` for more info.
519
520### bdev
521
522New API `spdk_bdev_get_memory_domains` has been added, it allows to get SPDK memory domains used by bdev.
523
524New API functions `spdk_bdev_readv_blocks_ext` and `spdk_bdev_writev_blocks_ext` have been added.
525These functions accept `spdk_bdev_ext_io_opts` structure with extended IO request
526options, e.g. DMA memory domain which describes data that may belong to another memory domain and
527can't be accessed directly.
528
529Added `async_fini_start` to allow bdev modules to complete the `fini_start` asynchronously,
530with new `spdk_bdev_module_fini_start_done` API.
531
532Deprecated `spdk_bdev_module_finish_done()` API, which will be removed in SPDK 22.01.
533Bdev modules should use `spdk_bdev_module_fini_done()` instead.
534
535The `ocssd` bdev has been removed. The Open Channel specification has been largely superseded by
536zoned namespaces, few if any devices have been brought to market, and there is little reason to
537continue to support this. OCSSD support in the nvme driver will remain for now.
538
539### dma
540
541A new library, lib/dma, has been added. This library provides the necessary infrastructure for
542handling systems and devices with multiple memory domains. For example, a PCIe add-in card with an
543SoC may be running SPDK on the SoC. That SoC has its own local memory, but SPDK may be controlling
544devices that can also access the host system memory. This library provides infrastructure to enumerate
545the memory domains and request hardware perform DMA transfers between them.
546
547### dpdk
548
549Updated DPDK submodule to DPDK 21.08.
550
551### event
552
553Added the `disable_signal_handlers` flag to the `spdk_app_opts` struct.
554
555### idxd
556
557Added `spdk_idxd_get_socket` to query the socket that the idxd device
558is on.
559
560### json
561
562Added API to allow for writing and decoding of new types:
563
564- `spdk_json_write_named_uint16`
565- `spdk_json_write_named_uint8`
566- `spdk_json_write_uint16`
567- `spdk_json_write_uint8`
568- `spdk_json_number_to_uint8`
569- `spdk_json_decode_uint8`
570
571### log
572
573Added API `spdk_log_to_syslog_level` to return syslog level based on SPDK's
574log level.
575
576### nvme
577
578Added new functions `spdk_nvme_zns_set_zone_desc_ext` and `spdk_nvme_zns_ext_report_zones`
579to set zone descriptor extension and to get extended zone report respectively.
580
581New API `spdk_nvme_ctrlr_get_memory_domains` has been added, it allows to get SPDK memory domains used by nvme controller.
582
583New API functions `spdk_nvme_ns_cmd_readv_ext` and `spdk_nvme_ns_cmd_writev_ext`
584have been added. These functions accept `spdk_nvme_ns_cmd_ext_io_opts` structure with extended IO request
585options, e.g. DMA memory domain which describes data that may belong to another memory domain and
586can't be accessed directly.
587
588Added a new function `spdk_nvme_ctrlr_get_regs_bpinfo` to get boot partition info of a controller.
589Added new functions `spdk_nvme_ctrlr_write_boot_partition`,
590`spdk_nvme_ctrlr_read_boot_partition_start` and `spdk_nvme_ctrlr_read_boot_partition_poll`
591to write and read the boot partitions of a controller.
592
593Added `spdk_nvme_ctrlr_get_opts` to retrieve the current controller options.
594
595Added `async_mode` to `spdk_nvme_io_qpair_opts` to enable creation of submission and completion
596queues asynchronously. This mode is currently supported at PCIe layer,
597which tracks the qpair creation with state machine and returns to the user immediately.
598Default mode is set to false to create io qpairs synchronously.
599
600Added `spdk_nvme_ctrlr_get_regs_cc` to retrieve NVMe controller CC (Configuration) register.
601
602Added `spdk_nvme_ctrlr_prepare_for_reset` to inform the driver that the application is preparing
603to reset the specified NVMe controller. This function allows the driver to make decisions
604knowing that a reset is about to happen.
605
606### nvmf
607
608Added `oncs` to `struct spdk_nvmf_ctrlr_data` so that the transport layer
609can decide support RESERVATION feature or not.
610
611An `opts_size` element was added in the `spdk_nvmf_ns_opts` structure to solve the
612ABI compatibility issue between different SPDK version. An new option `anagrpid` was
613added in the `spdk_nvmf_ns_opts` structure.
614
615An new parameter `anagrpid` was added to the RPC `nvmf_subsystem_add_ns`.
616
617An new parameter `anagrpid` was added to the RPC `nvmf_subsystem_listener_set_ana_state`.
618
619`spdk_nvmf_subsystem_destroy` is now can be asynchronous, it accepts a callback and callback argument.
620
621A new parameter, `poll_groups_mask` was added to the `nvmf_set_config` RPC that allows specifying
622a subset of cores for the nvmf poll groups. This helps to avoid imbalances when some cores are
623busy with periodic timer tasks that run very frequently.
624
625A new parameter, `commit` was added to `nvmf_bdev_ctrlr_end_zcopy` that allows indicating whether
626the buffers should be committed.
627
628Added `listen_dump_opts` to `spdk_nvmf_transport_ops` so that the transport layer can display
629listen opts.
630
631Added `fabrics_connect_timeout_us` to `bdev_nvme_attach_controller` RPC to allow specifying
632timeout for connect operation.
633
634Added `multipath` to `bdev_nvme_attach_controller` RPC to allow specifying multipath behavior.
635
636### scheduler
637
638New API for implementing schedulers and governors. Please see `include/spdk/scheduler.h` for details.
639
640### scsi
641
642New functions, `spdk_scsi_dev_get_first_lun` and `spdk_scsi_dev_get_next_lun`
643have been added to iterate LUNs of a SCSI device.
644
645Each SCSI device supports 256 LUNs at the maximum now and the macro constant
646`SPDK_SCSI_DEV_MAX_LUN` was removed.
647
648### trace_parser
649
650A new library, lib/trace_parser, has been added. This library provides functions that parse traces
651recorded by an SPDK application. That includes merging traces from multiple cores,
652sorting them by their timestamp and constructing trace entries spanning across multiple buffers.
653
654### util
655
656The `spdk_fd_group_add` API now takes a `name` parameter.
657
658## v21.07
659
660### accel_fw
661
662Added API `spdk_accel_submit_copy_crc32c` to perform a CRC32C while copying data.
663
664Added API `spdk_accel_batch_prep_copy_crc32c` to batch CRC32C + copy commands.
665
666Added API `spdk_accel_submit_copy_crc32cv` to submit chained CRC32C + copy commands.
667
668### bdev
669
670Change `spdk_bdev_read_blocks_with_md` arg offset definition from int64_t to uint64_t.
671
672Red-black tree has been used to organize the bdev names and aliases uniformly
673to provide faster lookup.
674
675Removed ZCOPY emulation: The bdev module can be checked to see if it supports ZCOPY
676and if not supported then use existing READ/WRITE commands.
677
678Added iov to spdk_bdev_zcopy_start.
679
680### dpdk
681
682Updated DPDK submodule to DPDK 21.05.
683
684### idxd
685
686Remove the `probe_cb` parameter in `spdk_idxd_probe` function. And remove the definition
687of `spdk_idxd_probe_cb` function pointer. It should be implemented in idxd_user.c.
688
689Added API `spdk_idxd_submit_copy_crc32c` to perform a CRC32C while copying data.
690
691Added API `spdk_idxd_batch_prep_copy_crc32c` to prepare a batch operation to perform
692a CRC32C while copying data.
693
694We have userspace idxd driver under accel_engine library (module/accel/idxd/accel_engine).
695And kernel idxd driver usage is also added under the accel_engine library. This approach
696implemented a wrapper library to use IDXD device by leveraging the kernel DSA driver in
697SPDK idxd library (lib/idxd). Then users can leverage the RPC later to configure how to
698use the DSA device by user space driver or kernel driver.
699
700### init
701
702Added new `init` library that initializes the SPDK subsystems, which previously was
703internal to application framework. That functionality has been made public and for
704use by applications which don't leverage SPDK's application framework.
705
706### iscsi
707
708New parameters, `pdu_pool_size`, `immediate_data_pool_size`, and `data_out_pool_size`,
709were added to the RPC `iscsi_set_options` to run iSCSI target with varying amount of
710available memory.
711
712### json
713
714Added API `spdk_json_write_named_uint128` and `spdk_json_write_uint128` to perform
715the uint128 related data.
716
717### net
718
719Removed deprecated `net` library.
720
721Added support for ZCOPY.  ZCOPY is used in preference to READ and WRITE if the
722bdev module supports ZCOPY and the bdev module has ZCOPY enabled.
723
724### nvme
725
726`spdk_nvme_map_prps` and `spdk_nvme_map_cmd` were moved to nvmf/vfio-user as internal APIs
727as vfio-user is the only user for the above two APIs.
728
729Added a new function `spdk_nvme_ns_cmd_copy` to submit a Simple Copy Command to a Namespace.
730
731Update the `spdk_nvme_generic_command_status_code` structure with new status code
732according to the definition in NVMe 1.4 spec.
733
734`spdk_nvme_ctrlr_get_default_ctrlr_opts` now sets `use_cmb_sqs` to false. This means
735that if a controller has a CMB and supports SQs in the CMB, SPDK will not use
736the CMB for SQs by default - the user must set `use_cmb_sqs` to true in
737the `spdk_nvme_ctrlr_opts` structure prior to controller attach.
738
739Add a new function `spdk_nvme_detach_poll` to simplify a common use case to continue
740polling until all detachments complete.
741
742Added new argument `timeout_admin_us` to `spdk_nvme_ctrlr_register_timeout_callback` so callers
743can specify a different timeout for admin commands vs. io commands.
744
745An existing function `spdk_nvme_detach_async` was updated to add one or more detachments
746to an active context while it is being polled.
747
748Rename a variable in the member `cmic` of the struct `spdk_nvme_ctrlr_data` from
749`multi_host` to `multi_ctrlr`. The variable means that the NVM subsystem may have two or
750more controllers if set to 1. However `multi_host` had indicated a particular use case
751such that the NVM subsystem is used by multiple hosts.
752
753A new option `disable_read_ana_log_page` was added to struct `spdk_nvme_ctrlr_opts` to disable
754reading ANA log page. The upper layer is expected to read ANA log page instead if `true`.
755The default value is `false`.
756
757New APIs, `spdk_nvme_ctrlr_reset_async` and `spdk_nvme_ctrlr_reset_poll_async`, have been added to
758reset a controller asynchronously.
759
760New RPC `bdev_nvme_reset_controller` was added, to reset an NVMe controller.
761
762Added `spdk_nvme_ns_get_nguid` function to get NGUID for the given namespace.
763
764Added `spdk_nvme_ctrlr_is_fabrics` function to indicate whether a ctrlr handle
765is associated with a fabrics controller.
766
767### nvmf
768
769Added `min_cntlid` and `max_cntlid` to `nvmf_create_subsystem` to limit the controller ID range.
770Added `spdk_nvmf_subsystem_get_min_cntlid` and `spdk_nvmf_subsystem_get_max_cntlid` to request those values.
771
772`spdk_nvmf_request_get_buffers_multi` API is removed.
773
774Added the `nvmf_set_crdt` RPC for setting command retry delay times.
775
776Expanded `spdk_nvmf_poll_group_stat` with current qpair count statistics.
777
778Removed following deprecated APIs:
779
780- `spdk_nvmf_poll_group_get_stat` (function in `nvmf.h`),
781- `spdk_nvmf_transport_poll_group_get_stat` (function in `nvmf.h`),
782- `spdk_nvmf_transport_poll_group_free_stat`(function in `nvmf.h`),
783- `spdk_nvmf_rdma_device_stat` (struct in `nvmf.h`),
784- `spdk_nvmf_transport_poll_group_stat` (struct in `nvmf.h`),
785- `poll_group_get_stat` (transport op in `nvmf_transport.h`),
786- `poll_group_free_stat` (transport op in `nvmf_transport.h`).
787
788### rpc
789
790New RPC `bdev_rbd_register_cluster` and `bdev_rbd_unregister_cluster` was added, it allows to create
791and delete the rados object cluster, then users can choose the cluster to create related rbd
792device.
793
794Revised `bdev_rbd_create` parameter, it allows to use an optional parameter `--cluster-name`
795to create a rbd bdev with  an already registered Rados Cluster Object.
796
797New RPC `bdev_rbd_get_clusters_info` was added, it allows to get the info of the registered
798Rados Cluster names.
799
800New optional parameter, `timeout_admin_us`, added to the bdev_nvme_set_options RPC.
801
802Revised a parameter `--stripe-size_kb` to `--stripe-size-kb` of `bdev_raid_create` method
803provided in `scripts/rpc.py` for consistency.
804
805An new optional parameter `config_kernel_mode` was added to the RPC `idxd_scan_accel_engine`,
806and this is used to enable using the kernel mode IDXD driver.
807
808Removed deprecated parameter `enable-zerocopy-send` of RPC `sock_impl_set_options`,
809use `enable-zerocopy-send-server` or `enable-zerocopy-send-client` instead.
810Removed deprecated parameter `disable-zerocopy-send` of RPC `sock_impl_set_options`,
811use `disable-zerocopy-send-server` or `disable-zerocopy-send-client` instead.
812
813### rpm
814
815Removed deprecated `pkg/spdk.spec`, please use `rpmbuild/spdk.spec` instead.
816See [RPM documentation](https://spdk.io/doc/rpm.html) for more details.
817
818### thread
819
820Red-black tree has been used for timed pollers to provide faster insertion and deletion
821and for io_devices to provide faster lookup.
822
823Removed `spdk_io_channel` structure from public header and moved it to thread_internal.h.
824
825### trace
826
827Added `spdk_trace_register_description_ext` function to register variable number of tracepoint arguments.
828
829Added ability to chain multiple trace entries together to extend the size of the argument buffer.
830
831### util
832
833Red-black tree macros has been added by using the macros provided by the FreeBSD operating system
834under the same BSD license.
835
836Add an new macro `SPDK_SIZEOF_MEMBER` to get the size of a member of a struct.
837
838`spdk_crc32c_iov_update` function was added to support calculating the crc32c of the iovs.
839
840Added zipf random number generator with power law probability distribution.
841When applied to performance testing of block devices, it will select blocks over
842the full range of LBAs, but will more frequently select lower-numbered LBAs.
843
844## v21.04
845
846### accel
847
848Two new accelerated crc32 functions `spdk_accel_submit_crc32cv` and
849`spdk_accel_batch_prep_crc32cv` are added in order to provide the
850chained accelerated CRC32 computation support.
851
852### bdev
853
854For `bdev_ocssd_create` RPC, the optional parameter `range` was removed.
855Only one OCSSD bdev can be created for one OCSSD namespace.
856
857Removed the `spdk_bdev_open` from bdev library API.
858Removed the `spdk_vbdev_register` and `spdk_bdev_part_base_construct` from bdev module API.
859Removed the `config_text` function for bdev modules to report legacy config.
860
861Added `spdk_bdev_get_max_active_zones` API to display maximum number active zones of a given bdev.
862
863Added `spdk_bdev_get_max_zone_append_size` API to display maximum zone append data transfer size.
864
865### bdev_nvme
866
867Added support for zoned namespaces.
868
869### blobstore
870
871Removed the `spdk_bdev_create_bs_dev_from_desc` and `spdk_bdev_create_bs_dev` API.
872
873### env
874
875Added `spdk_pci_device_allow` API to allow applications to add PCI addresses to
876the allowed list after the application has started.
877
878Removed the `pci_whitelist`, `pci_blacklist` and `master_core` members of struct `spdk_env_opts`.
879
880Added hotplug support based on uevent in `pci_event.c`. Added usage of this functionality in
881nvme, virtio-scsi and virtio_blk libraries. Please see the new API `spdk_pci_event_listen`,
882`spdk_pci_get_event`, `spdk_pci_register_error_handler` and `spdk_pci_unregister_error_handler`.
883
884### event
885
886Removed the `config_file`, `max_delay_us`, `pci_whitelist`
887and `pci_blacklist` members of struct `spdk_app_opts`.
888
889### idxd
890
891A new API `spdk_idxd_device_needs_rebalance` was added so that users of the library
892can know whether they need to rebalance the flow control for the channel
893that was just added/removed.  This is based on how the low level library
894shares devices amongst channels.
895
896The API `spdk_idxd_reconfigure_chan` had the `num_channels` removed as this
897is now tracked in the library.  The app makes use the new API above to
898determine whether to rebalance or not. This applies to `spdk_idxd_configure_chan`
899as well.
900
901The API `spdk_idxd_put_channel` now returns the rebalance state for the
902underlying device.
903
904### iscsi
905
906A security vulnerability has been identified and fixed in the SPDK iSCSI target.
907A TEXT PDU with no data, but CONTINUE flag set, would result in a NULL pointer dereference
908and crash the SPDK iSCSI target process. All users of the SPDK iSCSI target
909are recommended to update. All SPDK versions <= v21.01 are affected.
910
911### net
912
913The net library is deprecated and will be removed in the 21.07 release.
914
915### nvme
916
917Added a new function `spdk_nvme_ctrlr_get_regs_pmrcap` to get the PMR capabilities.
918
919Added an accelerated table pointer in `spdk_nvme_poll_group`
920which can be used to provide the accelerated functions by users with
921hardware engine, such as crc32c accelerated function.
922
923Added new functions `spdk_nvme_ctrlr_get_pmrsz`, `spdk_nvme_ctrlr_enable_pmr`,
924`spdk_nvme_ctrlr_disable_pmr`, `spdk_nvme_ctrlr_map_pmr` and `spdk_nvme_ctrlr_unmap_pmr`.
925
926Added NVMe transport operations to enable, disable, map and unmap the PMR.
927
928Added `spdk_nvme_qpair_get_optimal_poll_group` function and `qpair_get_optimal_poll_group`
929function pointer in spdk_nvmf_transport_ops structure in order to add the qpair to the most
930suitable polling group.
931
932Added OPTPERF and namespace optimal performance fields to nvme_spec.h.
933
934Added `spdk_nvme_set_hotplug_filter` API to allow applications to choose which
935hot-inserted SSDs should be probed. This is useful for use cases where multiple
936independent SPDK processes are running on one node. The filter function can
937then be implemented in these processes to decide which SSDs to probe based on
938the new SSD's PCI address.
939
940New functions `spdk_nvme_poll_group_get_stats` and `spdk_nvme_poll_group_free_stats`
941were added. These functions allow to get transport statistics per NVME poll group.
942
943Added `spdk_nvme_map_cmd` API to map the NVMe command with SGL cases.
944
945Added support for vector variant of ZNS zone append commands with new API
946`spdk_nvme_zns_zone_appendv` and `spdk_nvme_zns_zone_appendv_with_md`.
947
948Added `spdk_nvme_zns_ns_get_max_open_zones` and `spdk_nvme_zns_ns_get_max_active_zones` API,
949to display maximum number of open and active zones of the given namespace.
950
951Added `spdk_nvme_zns_ns_get_zone_size_sectors` API to provide size of zone in number of
952sectors.
953
954Added `spdk_nvme_qpair_get_id` API to display the ID of the specified qpair.
955
956### nvmf
957
958Removed the `spdk_nvmf_tgt_listen` and `spdk_nvmf_subsystem_add_ns` API.
959
960Added new APIs:
961
962- `spdk_nvmf_poll_group_dump_stat` (function in `nvmf.h`).
963- `poll_group_dump_stat` (transport op in `nvmf_transport.h`).
964
965The following APIs have been deprecated and will be removed in SPDK 21.07:
966
967- `spdk_nvmf_poll_group_get_stat` (function in `nvmf.h`),
968- `spdk_nvmf_transport_poll_group_get_stat` (function in `nvmf.h`),
969- `spdk_nvmf_transport_poll_group_free_stat`(function in `nvmf.h`),
970- `spdk_nvmf_rdma_device_stat` (struct in `nvmf.h`),
971- `spdk_nvmf_transport_poll_group_stat` (struct in `nvmf.h`),
972- `poll_group_get_stat` (transport op in `nvmf_transport.h`),
973- `poll_group_free_stat` (transport op in `nvmf_transport.h`).
974
975See header files for details.
976
977The `trtype` field in JSON returned by `nvmf_get_stats` RPC contains now the name of the transport,
978which is the same as the type for defined transports and more informative for a custom transport.
979
980Added `hdgst` and `ddgst` parameters to `bdev_nvme_attach_controller` RPC in order change
981state of TCP header and data digest.
982
983Added `num_cqe` parameter to `nvmf_create_transport` RPC to set number of completion queues (CQ)
984for RDMA transport. Useful when CQ resize operation is not supported, for example iWARP.
985
986### ocf
987
988Updated OCF submodule to v20.12.2
989
990Added `bdev_ocf_set_cache_mode` RPC to dynamically switch cache mode of OCF bdev.
991
992### opal
993
994Removed the `spdk_opal_supported` API.
995
996### raid
997
998For `bdev_raid_create` RPC, the deprecated parameter `strip_size` was removed.
999
1000### rpc
1001
1002New RPC `bdev_nvme_get_transport_statistics` was added, it allows to get transport statistics
1003of nvme poll groups.
1004
1005Parameter `enable-zerocopy-send` of RPC `sock_impl_set_options` is deprecated and will be removed in SPDK 21.07,
1006use `enable-zerocopy-send-server` or `enable-zerocopy-send-client` instead.
1007Parameter `disable-zerocopy-send` of RPC `sock_impl_set_options` is deprecated and will be removed in SPDK 21.07,
1008use `disable-zerocopy-send-server` or `disable-zerocopy-send-client` instead.
1009
1010Added cmd_parser.py used to parse the args from argparse. There are
1011two benefit to use command parser:
1012
1013- Simplify the definition of rpc method. It will reduce the rpc method code.
1014- Make the rpc call more versatile. User can add private args into rpc method.
1015
1016### rpm
1017
1018Added support for new RPM spec, rpmbuild/spdk.spec, which can be used for packaging the
1019SPDK. The pkg/spdk.spec is considered to be deprecated and scheduled for removal in SPDK 21.07.
1020See [RPM documentation](https://spdk.io/doc/rpm.html) for more details.
1021
1022### sock
1023
1024The type of `enable_placement_id` in struct `spdk_sock_impl_opts` is changed from
1025bool to int. We can use RPC to configure different value of `enable_placement_id`.
1026Then we can leverage SO_INCOMING_CPU to get placement_id, which aims to utilize
1027CPU cache locality, enabled by setting enable_placement_id=2.
1028
1029A new socket placement mode called PLACEMENT_MARK has been added. Some NICs allow
1030sockets to be marked using the SO_MARK socket option as a hint for which hardware
1031queue they should be associated with. This mode leverages that by setting the same
1032value for all sockets within a poll group.
1033
1034New parameters `enable_zerocopy_send_server` and `enable_zerocopy_send_client` were added
1035to struct spdk_sock_impl_opts, these parameters enable or disable zero copy send for server
1036and client sockets which are created using `spdk_sock_listen` and `spdk_sock_listen_ext` (server);
1037`spdk_sock_connect` and `spdk_sock_connect_ext` (client) functions. Existing parameter
1038`enable_zerocopy_send`  enables or disables zero copy send for both server and client sockets.
1039
1040### thread
1041
1042A new API `spdk_io_channel_get_io_device` was added to get the io_device for the specified
1043I/O channel.
1044
1045Added `spdk_thread_set_interrupt_mode` function in order to set present spdk_thread into
1046interrupt mode or back to poll mode. It is valid only when thread interrupt facility is
1047enabled by `spdk_interrupt_mode_enable`.
1048
1049Added `spdk_poller_register_interrupt` function to mark that the poller is capable of
1050entering interrupt mode. Callback function will be called when the poller must transition
1051into or out of interrupt mode.
1052
1053### virtio
1054
1055Added the `bdev_virtio_blk_set_hotplug` RPC for the virtio blk pci device.
1056
1057## v21.01
1058
1059### bdev
1060
1061An `opts_size` element was added in the `spdk_bdev_opts` structure to solve the
1062ABI compatibility issue between different SPDK version. And also add `opts_size`
1063parameter in spdk_bdev_get_opts function. Two fields `small_buf_pool_size` and
1064`large_buf_pool_size` were added into spdk_bdev_opts, which were used to determine
1065the small and large buffer pool size of the whole bdev module.
1066
1067A new API `spdk_bdev_wait_for_examine` was added to allow for checking state of
1068examine process. Along with corresponding `bdev_wait_for_examine` RPC, which
1069is now always called during `spdk_bdev_subsystem_config_json` making sure
1070every bdev is ready to be used.
1071
1072A new API `spdk_bdev_io_get_aio_status` was added for getting the status of
1073bdev_io as Linux AIO errno. Also `spdk_bdev_io_complete_aio_status` function
1074and `SPDK_BDEV_IO_STATUS_AIO_ERROR` were added for bdev module to complete
1075a bdev_io with Linux AIO errno.
1076
1077A new API `spdk_bdev_get_module_name` was added for getting block device module name.
1078Also `spdk_bdev_get_module_ctx` was added to obtain a bdev module context for
1079the block device opened by the specified descriptor.
1080
1081Added `max_segment_size` and `max_num_segments` to `spdk_bdev` structure for
1082bdev modules to specify splitting requirements.
1083
1084### blob
1085
1086An `opts_size` element was added in the `spdk_bs_opts` structure to solve the
1087ABI compatibility issue between different SPDK version. And also add `opts_size`
1088parameter in `spdk_bs_opts_init` function.
1089
1090An `opts_size` element was added in the `spdk_blob_opts` structure to solve the
1091ABI compatibility issue between different SPDK version. And also add `opts_size`
1092parameter in `spdk_blob_opts_init` function.
1093
1094An `opts_size` element was added in the `spdk_blob_open_opts` structure to solve the
1095ABI compatibility issue between different SPDK version. And also add `opts_size`
1096parameter in `spdk_blob_open_opts_init` function.
1097
1098### build
1099
1100SPDK now generates pkg-config files to simplify the process of determining which
1101libraries must be linked into an SPDK application.
1102
1103### dpdk
1104
1105Updated DPDK submodule to DPDK 20.11.
1106
1107Removed `--with-igb-uio-driver` configure option. Since DPDK 20.11 igb_uio driver
1108was moved to separate dpdk-kmods repository. If required, users need to refer to
1109dpdk-kmods repository to build the driver.
1110
1111### env
1112
1113The `pci_whitelist`, `pci_blacklist` and `master_core` members of struct `spdk_env_opts`
1114have been deprecated.  The new members are named `pci_allowed`, `pci_blocked` and
1115`main_core` respectively.
1116
1117An `opts_size` element was added in the `spdk_app_opts` structure
1118to solve the ABI compatibility issue between different SPDK version. An `opts_size`
1119parameter is added into `spdk_app_opts_init` function.
1120
1121### event
1122
1123The `pci_whitelist` and `pci_blacklist` members of struct `spdk_app_opts` have been
1124deprecated.  The new members are named `pci_allowed` and `pci_blocked` respectively.
1125
1126The `--pci-blacklist` command line option has been deprecated, replaced with
1127`--pci-blocked`.
1128
1129The `--pci-whitelist/-W` command line options have been deprecated, replaced with
1130`--pci-allowed/-A`.
1131
1132Added new experimental `dynamic` scheduler that rebalances idle threads, adjusts CPU frequency
1133using dpdk_governor and turns idle reactor cores to interrupt mode. Please see
1134[scheduler documentation](https://www.spdk.io/doc/scheduler.html) for details.
1135
1136## ioat
1137
1138The PCI BDF whitelist option has been removed from the `ioat_scan_accel_engine` RPC.
1139IOAT PCI functions can still be allowed or denied using SPDK application command
1140line options.
1141
1142### isa-l
1143
1144Updated ISA-L submodule to v2.30.0.
1145
1146### json
1147
1148A new API `spdk_jsonrpc_send_bool_response` was added to allow sending response for
1149writing json bool results into one function.
1150Update API `bdev_nvme_set_options` and add a `keep_alive_timeout_ms` parameter. Now you
1151can specify the `keep_alive_timeout` before creating NVMe bdev.
1152
1153### nbd
1154
1155Change the return type of function `spdk_nbd_stop` from void to int. And update the
1156`spdk_nbd_fini` with two parameters to make its behavior from sync to async.
1157
1158### nvme
1159
1160Directives support was added to the NVMe driver.
1161
1162Two async APIs `spdk_nvme_ctrlr_cmd_directive_receive` and `spdk_nvme_ctrlr_cmd_directive_send`
1163are added for Directive Send and Directive Receive command, respectively.
1164
1165Added a new function `spdk_nvme_ctrlr_reset_subsystem` to perform a NVMe
1166subsystem reset. Note: The NVMe-oF target does not support the subsystem reset yet.
1167
1168Add a new function `spdk_nvme_bytes_to_numd` to transfer bytes to number of
1169dwords.
1170
1171Added a new custom transport `SPDK_NVME_TRANSPORT_VFIOUSER` to enable NVMe
1172driver running with NVMe over vfio-user target.
1173
1174Added the vfio-user custom transport implementation in NVMe driver which can connect
1175to NVMe over vfio-user target via vfio-user transport.
1176
1177Added a new function `spdk_nvme_ctrlr_set_remove_cb` to remove or override
1178`remove_cb` and `remove_ctx` specified when the controller was probed.
1179
1180Added support for ZNS zone append command with new API `spdk_nvme_zns_zone_append` and
1181`spdk_nvme_zns_zone_append_with_md`.
1182
1183### nvmf
1184
1185`nvmf_fc_lld_fini` now takes callback and hence updating FC Broadcom LLD driver
1186to the latest is required.
1187
1188FC transport supported primary tagging and VMID.
1189
1190Broadcom FC LLD driver and SPDK NVMe-oF FC transport consolidated one LLD API,
1191`nvmf_fc_init_poller_queues` into another LLD API `nvmf_fc_init_q`.
1192Hence updating Broadcom FC LLD driver to the latest is required.
1193
1194The functions `destroy` and `qpair_fini` in the transport interface now accept a
1195`cb_fn` and `cb_arg` to call upon completion, and their execution can be asynchronous.
1196
1197The SPDK NVMe-oF target now supports async event notification for discovery log changes.
1198This allows the initiator to create persistent connection to discovery controller and
1199be notified of any discovery log changes.
1200
1201An `opts_size` element was added in the `spdk_nvmf_transport_opts` structure
1202to solve the ABI compatibility issue between different SPDK version. And also add
1203`opts_size` parameter in `spdk_nvmf_transport_opts_init` function.
1204
1205Added a new custom vfio-user transport implementation in NVMe-oF which can provide
1206emulated NVMe devices to QEMU and SPDK NVMe driver.
1207
1208Added new API `spdk_nvmf_tgt_listen_ext` that uses `spdk_nvmf_listen_opts` to allow
1209passing generic options to specific transport. This functionality replaces one provided
1210with `nvmf_subsystem_set_options`. Also removed `nvmf_subsystem_set_options` RPC
1211that allowed transport specific options within subsystem.
1212
1213The `trsvcid` in `nvmf_subsystem_add_listener` RPC is now optional.
1214
1215Pausing a subsystem now only pauses all admin queues. This allows for the
1216management of hosts and listeners, plus the addition of namespaces without a
1217full subsystem pause. Additionally, the target now allows for pausing
1218individual namespaces within a subsystem. To remove a namespace from a
1219subsystem, only the specific namespace must be paused. I/O will continue to
1220other namespaces while these operations execute.
1221
1222### rpc
1223
1224An new optional parameter `wait` was added to the RPC `iscsi_create_portal_group`,
1225and an new RPC `iscsi_start_portal_group` was added. They will be used not to start
1226listening on portals for a portal group until all associated target nodes are created
1227at startup, otherwise some iSCSI initiators may fail to re-login when SPDK iSCSI
1228target application restarts.
1229
1230Two optional parameter `--small-buf-pool-size` and `--large-buf-pool-size` were added
1231into `bdev_set_options` function.
1232
1233### vhost
1234
1235Added optional `packed_ring_recovery` parameter to `vhost_create_blk_controller` RPC
1236enabling packed ring live recovery.
1237
1238## v20.10
1239
1240### accel
1241
1242New APIs `spdk_accel_batch_cancel` and `spdk_idxd_batch_cancel` were added to allow
1243cancelling a batch sequence.
1244
1245### bdev
1246
1247A new `spdk_bdev_part_base_construct_ext` function has been added and the
1248`spdk_bdev_part_base_construct` has been deprecated.  The
1249`spdk_bdev_part_base_construct_ext` function takes bdev name as an argument instead
1250of bdev structure to avoid a race condition that can happen when the bdev is being
1251removed between a call to get its structure based on a name and actually opening it.
1252
1253Removed `spdk_bdev_config_text` function for bdev modules to report legacy config.
1254
1255### blobstore
1256
1257A new `spdk_bdev_create_bs_dev_ext` function has been added and `spdk_bdev_create_bs_dev_from_desc`
1258function has been deprecated.
1259
1260### dpdk
1261
1262Updated DPDK submodule to DPDK 20.08.
1263
1264### env
1265
1266A new API `spdk_mem_get_fd_and_offset` was added to get file descriptor and offset for
1267a given virtual address.
1268
1269### event
1270
1271Removed `spdk_subsystem_config` callback for submodules as part of legacy config removal.
1272
1273Removed `spdk_app_get_running_config` function that printed configuration in legacy format,
1274and removed `usr1_handler` from `struct spdk_app_opts` callback that was used to call it.
1275
1276Added SPDK thread scheduler framework which is used to rebalance load among CPU cores.
1277The scheduler implementation is pluggable and two schedulers are added first, `static` scheduler
1278and `gscheduler` scheduler.
1279
1280`static` scheduler is used by default and does not reschedule threads and keeps the initial
1281assignments.
1282
1283CPU frequency governor framework and implementation are also added.
1284`dpdk_governor` is the first implementation and is based on rte_power library of DPDK.
1285`gscheduler` scheduler utilizes the CPU frequency governor.
1286
1287Scheduler and governor frameworks are experimental features.
1288
1289### fio
1290
1291Bdev fio_plugin no longer supports legacy configuration files. Options `spdk_conf` and
1292`spdk_json_conf` have to point to valid JSON configuration.
1293
1294### gpt
1295
1296Removed option to disable GPT probing via legacy configuration. Please use generic
1297bdev functionality to replicate the behavior. See `bdev_set_options --disable-auto-examine`
1298and `bdev_examine` RPC.
1299
1300### intel-ipsec-mb
1301
1302Updated intel-ipsec-mb submodule to v0.54
1303
1304### isa-l
1305
1306Updated ISA-L submodule to v2.29.0.
1307
1308### iscsi
1309
1310The iSCSI target supports iSCSI login redirection feature to achieve fault tolerance
1311and load balancing particularly in scale out iSCSI target system, which runs multiple
1312SPDK iSCSI targets.
1313
1314### json
1315
1316A new API `spdk_json_decode_object_relaxed` was added to allow parsing json values
1317even if decoder for a given key is not found.
1318
1319A new API `spdk_json_free_object` was added to free memory allocated by `spdk_json_decode_object`.
1320
1321### log
1322
1323A log flag structure, `spdk_log_register_flag`, `spdk_log_get_first_flag`,
1324`spdk_log_get_next_flag` and macro `SPDK_LOG_REGISTER_COMPONENT`, have been added which
1325enable registering and interacting with log flags. Added `SPDK_INFOLOG`, `SPDK_DEBUGLOG`
1326and `SPDK_LOGDUMP` macros to display logs for specified log flag.
1327
1328The log flags in the event framework `-L` and several SPDK applications has been enabled on
1329release builds of SPDK. On debug builds this option will additionally set
1330log print level to `SPDK_LOG_DEBUG`.
1331
1332A new API `spdk_log_enable_timestamps` and new RPC `log_enable_timestamps` was added to
1333toggle log timestamps.
1334
1335### miscellaneous
1336
1337The contents of the log_rpc library have been moved to the event library. The log_rpc
1338library now no longer exists.
1339
1340The contents of the app_rpc library have been moved to the event library. The app_rpc
1341library now no longer exists.
1342
1343The contents of the bdev_rpc library have been moved to the bdev library. The app_rpc
1344library now no longer exists.
1345
1346The bdevperf application now disables the zcopy API by default. Prior to this change,
1347bdevperf enabled using the zcopy API by default which caused a performance impact of
1348up to 25% on bdevs that don't natively support zcopy because the API emulates zero-copy
1349by allocating a buffer. The bdevperf `-x` param was renamed to `-Z` and the default
1350value changed to false. For bdevs that support zcopy, use the -Z flag to enable
1351using zcopy API.
1352
1353### net
1354
1355Net framework intended for use by user-space TCP stacks was removed.
1356
1357### nvme
1358
1359Zoned Namespace Command Set support has been added to NVMe driver, see `nvme_zns.h` for details.
1360
1361New APIs, `spdk_nvme_detach_async` and `spdk_nvme_detach_poll_async`, have been added to
1362detach multiple controllers in parallel to mitigate lengthy shutdown notification of
1363a few NVMe SSDs.
1364
1365New APIs, `spdk_nvme_ns_get_ana_group_id` and `spdk_nvme_ns_get_ana_state`, have been
1366added to get ANA group ID and ANA state of the given namespace, respectively.
1367
1368If no specific command set is requested (by setting the command_set member in the
1369`spdk_nvme_ctrlr_opts` structure), SPDK will automatically select the most appropriate
1370command set based on what the controller supports.
1371
1372### nvmf
1373
1374A new API `spdk_nvmf_subsystem_add_ns_ext` has been added and the API `spdk_nvmf_subsystem_add_ns`
1375has been deprecated.
1376
1377The NVMe-oF target now supports Asymmetric Namespace Access (ANA) Reporting to provide
1378multipath to NVMe-oF initiator.
1379
1380Add `no_wr_batching` parameter to `spdk_nvmf_transport_opts` struct to disable
1381Work Requests batching in RDMA transport.
1382
1383NVMf Target transports can now parse any additional JSON params in the nvmf_create_transport RPC
1384through the JSON context provided via spdk_nvmf_target_opts->transport_specific.
1385
1386A new RPC `nvmf_subsystem_set_options` was added to allow transport specific options within subsystem.
1387
1388A new API `spdk_nvmf_transport_stop_listen_async` was added to stop accepting new connections
1389at the provided address. `nvmf_subsystem_remove_listener` RPC now uses this function.
1390
1391A new API `spdk_nvmf_subsystem_disconnect_host` was added to disconnect all connections
1392originating from the provided hostnqn. `nvmf_subsystem_remove_host` RPC now uses this function.
1393
1394### ocf
1395
1396Updated OCF submodule to v20.03.1
1397
1398### rpc
1399
1400New optional parameters, `enable_placement_id` and `enable_quickack` were added to the
1401`sock_impl_set_options` RPC.
1402
1403A new RPC `bdev_examine_bdev` was added to allow users to examine a bdev explicitly.
1404It can be used only if bdev_auto_examine is set to false by the RPC `bdev_set_options`.
1405
1406New optional parameters `no_wr_batching` and `control_msg_num` were added to the RPC
1407'nvmf_create_transport'.
1408
1409New RPCs, `iscsi_target_node_set_redirect` and `iscsi_target_node_request_logout`, have
1410been added, and a new optional parameter `private` has been added to the RPC
1411`iscsi_create_portal_group` to support iSCSI login redirection feature.
1412
1413A new optional parameter `ana_reporting` was added to the RPC `nvmf_create_subsystem`, and
1414a new RPC `nvmf_subsystem_listener_set_ana_state` was added for ANA reporting.
1415
1416New RPCs, `nvmf_subsystem_get_listeners` and `nvmf_subsystem_get_qpairs`, were added to
1417retrieve configuration of the NVMe-oF subsystem.
1418
1419### scsi
1420
1421Two new APIs have been added `spdk_scsi_dev_construct_ext` and
1422`spdk_scsi_dev_add_lun_ext` that allow the upper layer(e.g. vhost-scsi) to
1423receive the notification when the scsi bdev has been resized.
1424
1425The `spdk_scsi_dev_construct` and `spdk_scsi_dev_add_lun` eventually may be
1426deprecated and removed.
1427
1428### sock
1429
1430The `enable_placement_id` field was added in the `struct spdk_sock_impl_opts` to
1431make the placement_id feature configurable by users. The default setting is
1432not enabled.
1433
1434The `enable_quick_ack` field was added in the `struct spdk_sock_impl_opts` to enable
1435or disable quick ack for the POSIX sock module. The default setting is not enabled.
1436
1437### thread
1438
1439`fd_group` is applied to support interrupt mode.
1440New APIs were added to support an experimental interrupt mode.  This allows modules or
1441libraries to selectively register file descriptors that the spdk_thread can wait on,
1442as an alternative to polling. In v20.10, this functionality is enabled in a very small
1443subset of SPDK libraries and modules.
1444
1445### util
1446
1447A new utility named `fd_group` was add. It is now
1448implemented by epoll on Linux platform. It can be used by
1449spdk_thread and reactor to implement interrupt mode.
1450
1451Added `spdk_bit_pool` utility, see `bit_pool.h` for details.
1452
1453### vhost
1454
1455SPDK has switched to DPDK's rte_vhost library since 19.07 release, removed the internal
1456rte_vhost library which is used for DPDK older than 19.05, removed the experimental vhost
1457nvme target which depends on the internal rte_vhost library.
1458
1459### vpp
1460
1461Removed socket abstraction for VPP.
1462
1463## v20.07: SPDK CSI driver, new accel_fw commands, I/O abort support
1464
1465spdk_json_free_object() was added to free memory allocated by spdk_json_decode_object().
1466
1467### accel
1468
1469A new API was added `spdk_accel_get_capabilities` that allows applications to
1470query the capabilities of the currently enabled accel engine back-end.
1471
1472A new capability, CRC-32C, was added via `spdk_accel_submit_crc32c`.
1473
1474The software accel engine implementation has added support for CRC-32C.
1475
1476A new capability, compare, was added via `spdk_accel_submit_compare`.
1477
1478The software accel engine implementation has added support for compare.
1479
1480Several APIs were added to `accel_engine.h` to support batched submission
1481of operations.
1482
1483Several APIs were added to `accel_engine.h` to support dualcast operations.
1484
1485### accel_fw
1486
1487The accel_fw was updated to no longer require the app to allocate an
1488accel_task on its behalf. All public APIs now take a callback arg as
1489the parameter that used to be the accel_task.
1490
1491The accel_fw API `spdk_accel_task_size` was removed as it is no longer
1492required.
1493
1494The accel_fw was updated to support compare, dualcast, crc32c.
1495
1496The accel_fw introduced batching support for all commands in all plug-ins.
1497See docs for detailed information.
1498
1499### bdev
1500
1501A new API `spdk_bdev_abort` has been added to submit abort requests to abort all I/Os
1502whose callback context match to the bdev on the given channel.
1503
1504### build
1505
1506The fio plugins now compile to `build/fio` and are named `spdk_bdev` and `spdk_nvme`.
1507Existing fio configuration files will need to be updated.
1508
1509### dpdk
1510
1511Updated DPDK submodule to DPDK 20.05.
1512
1513### env
1514
1515Several new APIs have been added to provide greater flexibility in registering and
1516accessing polled mode PCI drivers. See `env.h` for more details.
1517
1518### idxd
1519
1520The idxd library and plug-in module for the accel_fw were updated to support
1521all accel_fw commands as well as batching.  Batching is supported both
1522through the library and the plug-in module.
1523
1524IDXD engine support for CRC-32C has been added.
1525
1526### ioat
1527
1528A new API `spdk_ioat_get_max_descriptors` was added.
1529
1530### nvme
1531
1532An `opts_size`element was added in the  `spdk_nvme_ctrlr_opts` structure
1533to solve the ABI compatibility issue between different SPDK version.
1534
1535A new API `spdk_nvme_ctrlr_cmd_abort_ext` has been added to abort previously submitted
1536commands whose callback argument match.
1537
1538Convenience functions, `spdk_nvme_print_command` and `spdk_nvme-print_completion` were added
1539to the public API.
1540
1541A new function, `spdk_nvmf_cuse_update_namespaces`, updates the cuse representation of an NVMe
1542controller.
1543
1544A new function `qpair_iterate_requests` has been added to the nvme transport interface. ALl
1545implementations of the transport interface will have to implement that function.
1546
1547### nvmf
1548
1549The NVMe-oF target no longer supports connecting scheduling configuration and instead
1550always uses what was previously called "transport" scheduling.
1551
1552`spdk_nvmf_tgt_accept` no longer exists. The accept process now occurs automatically after
1553the creation of an nvmf target and queue pairs are assigned to poll groups by the underlying
1554transport. Further, `spdk_nvmf_transport_ops` has changed such that the accept function
1555pointer no longer takes a function pointer as an argument. Instead, transports should call
1556`spdk_nvmf_tgt_new_qpair` whenever they previously would have called that callback.
1557
1558The NVMe-oF target now supports aborting any submitted NVM or Admin command. Previously,
1559the NVMe-oF target could abort only Asynchronous Event Request commands.
1560
1561### rdma
1562
1563A new `rdma` library has been added. It is an abstraction layer over different RDMA providers.
1564Two providers are available - verbs (used by default when RDMA is enabled or enabled explicitly
1565using --with-rdma=verbs) and mlx5 Direct Verbs aka DV (enabled by --with-rdma=mlx5_dv).
1566Using mlx5_dv requires libmlx5 installed on the system.
1567
1568### rpc
1569
1570Parameter `-p` or `--max-qpairs-per-ctrlr` of `nvmf_create_transport` RPC command accepted by the
1571rpc.py script is deprecated, new parameter `-m` or `--max-io-qpairs-per-ctrlr` was added.
1572
1573Added `sock_impl_get_options` and `sock_impl_set_options` RPC methods.
1574
1575Command line parameters `-r` and `--rpc-socket` will longer accept TCP ports. RPC server
1576must now be started on a Unix domain socket. Exposing RPC on the network, as well as providing
1577proper authentication (if needed) is now a responsibility of the user.
1578
1579The `bdev_set_options` RPC has a new option, `bdev_auto_examine` to control the auto examine function
1580of bdev modules.
1581
1582New RPCs `sock_impl_get_options` and `sock_impl_set_options` been added to expose new socket features.
1583See `sock` section for more details.
1584
1585### sock
1586
1587Added `spdk_sock_impl_get_opts` and `spdk_sock_impl_set_opts` functions to set/get socket layer configuration
1588options. Options can be set independently for each implementation.
1589
1590Added `recv_buf_size` and 'send_buf_size' socket layer options. They are used only in posix implementation.
1591
1592Added `uring` based socket implementation, the code is located in module/sock/uring. This feature is only
1593available in Linux which requires kernel version is greater than 5.4.3. Currently, our CI pool added the uring
1594based socket tests for iSCSI target and also the tests for SPDK NVMe-oF tcp transport.
1595
1596Added `enable_recv_pipe` socket layer option to allow disabling of double buffering on receive.
1597New option is used only in posix implementation.
1598
1599Added `enable_zerocopy_send` socket layer option to allow disabling of zero copy flow on send.
1600New option is used only in posix implementation.
1601
1602### util
1603
1604Some previously exposed CRC32 functions have been removed from the public API -
1605`spdk_crc32_update`, `spdk_crc32_table_init`, and the `spdk_crc32_table` struct.
1606
1607### vhost
1608
1609The function `spdk_vhost_blk_get_dev` has been removed.
1610
1611## v20.04: SPDK Top, IDXD, NVMe qpair groups
1612
1613IDXD engine support for compare has been added.
1614
1615### configuration
1616
1617Legacy INI style configuration for SPDK applications has been deprecated and will be
1618removed in future release.
1619Please switch to JSON-RPC configuration files and/or RPC driven run-time configuration.
1620
1621### copy
1622
1623The copy engine library, modules and public APIs have been renamed. Use of the word `copy`
1624has been replaced with the word `accel` short for accelerator in preparation for adding new
1625capabilities in the future. Additionally, APIs for what was previously called the `memcpy`
1626engine have been renamed to identify the engine as a software accelerator.
1627
1628### crypto
1629
1630Support for AES_XTS was added for the QAT polled mode driver (pmd).  The create RPC
1631`bdev_crypto_create` has 2 new optional parameters: cipher and key2. Cipher can be either
1632AES_CBC (default) or AES_XTS. AES_XTS is only valid when using the QAT polled mode driver.
1633The key2 parameter is the second key required for AES_XTS.
1634
1635### event
1636
1637Reactors now accumulate CPU stats and they are retrieved by the RPC `framework_get_reactors`.
1638
1639### idxd
1640
1641IDXD support was added in the form of a low level library that can directly
1642utilize the IDXD offload engine as well as an accel plug-in module allowing for use
1643with the generic accel framework API. IDXD is the first in a family of offload
1644engines that share the same interface, specifically DSA is added here. More info
1645can be found here: https://01.org/blogs/2019/introducing-intel-data-streaming-accelerator
1646
1647Much of the implementation models IOAT, however the low level interfaces are very
1648different. The RPC to enable IDXD requires a configuration number as well. The
1649code includes two pre-defined configurations of IDXD groups/work queues/engines. A future
1650version will provide an interface to allow for setting of individual configuration
1651parameters.
1652
1653IDXD is not yet available so this feature should be considered experimental. It will
1654be built up with additional documentation as an ongoing activity.
1655
1656### iscsi
1657
1658The iSCSI target now creates a lightweight thread per poll group instead of assuming a pool
1659of lightweight threads already exist at start up time. A poll group is a collection of
1660unrelated iSCSI connections. Each poll group is only accessed from the associated
1661lightweight thread.
1662
1663### ftl
1664
1665Several changes have been made to the `spdk_ftl_conf`, `spdk_ftl_dev_init_ops`, and
1666`spdk_ftl_attrs` structs. Please see `include/spdk/ftl.h` for more details.
1667
1668### miscellaneous
1669
1670The `--json-ignore-init-errors` command line parameter has been added to ignore
1671initialization errors on JSON config load.
1672
1673The public header file io_channel.h has been removed. Please use thread.h which has the
1674exact same API.
1675
1676### nvme
1677
1678Exported internal nvme_ctrlr_cmd_security_receive/send() APIs as public APIs with "the spdk_"
1679prefix.
1680
1681Added `priority` field in `spdk_nvme_transport_id`, this field is used to specify the priority
1682of the NVMe-oF connection, and currently it is used for NVMe-oF tcp connection.
1683
1684A new poll group API has been added to allow for pooling of nvme qpairs across a single
1685entity which can be polled for completions. This new API consists of the `spdk_nvme_poll_group`
1686family of functions. As a result of this new API, all NVMe transports are expected to implement
1687several poll group related functions.
1688
1689A new flag, `create_only`, has been added to the `spdk_nvme_io_qpair_opts` structure. This flag
1690allows a user to call `spdk_nvme_ctrlr_get_default_io_qpair` without also connecting the qpair
1691within the context of that call.
1692
1693As a result of the `create_only` flag, two new API functions, `spdk_nvme_ctrlr_connect_io_qpair`
1694and `spdk_nvme_ctrlr_disconnect_io_qpair`, have been added to facilitate connecting newly created
1695qpairs (for example, after they have been added to a poll group) and disconnecting qpairs without
1696destroying them (for example to disconnect a qpair before migrating it to a new poll group and
1697reconnecting it).
1698
1699The functions `spdk_nvme_ctrlr_alloc_cmb_io_buffer` and `spdk_nvme_ctrlr_free_cmb_io_buffer`
1700have been changed to `spdk_nvme_ctrlr_map_cmb` and `spdk_nvme_ctrlr_unmap_cmb` respectively.
1701
1702An additional function, `spdk_nvme_ctrlr_reserve_cmb`, has been added to facilitate reserving
1703the entire size of the controller memory buffer for data transfer.
1704
1705### nvme_cuse
1706
1707`spdk_nvme_cuse_get_ctrlr_name` now takes two additional parameters, `char *name` which
1708stores the pointer to the controller name, and `size_t *size` which stores the length of
1709the name. The return type has also been changed from char * to int.
1710
1711`spdk_nvme_cuse_get_ns_name` now takes two additional parameters, `char *name` which
1712stores the pointer to the namespace name, and `size_t *size` which stores the length of
1713the name. The return type has also been changed from char * to int.
1714
1715### nvme_opal
1716
1717Several public OPAL structure definitions have been changed since the last release.
1718
1719### nvmf
1720
1721`spdk_nvmf_poll_group_destroy()` is now asynchronous and accepts a completion callback.
1722
1723The NVMe-oF target now creates a lightweight thread per poll group instead of assuming a pool
1724of lightweight threads already exist at start up time. A poll group is a collection of
1725unrelated NVMe-oF connections. Each poll group is only accessed from the associated
1726lightweight thread.
1727
1728A new struct, `spdk_nvmf_subsystem_listener`, has been added to encapsulate the subsystem specific
1729nature of a listener object.
1730
1731`spdk_nvmf_tgt_listen` no longer accepts a callback function or argument. It also returns an
1732int to indicate the status of the listen call.
1733
1734The execution of `spdk_nvme_poll_group_destroy` is now asynchronous and the function accepts
1735a cb_fn and cb_arg to call upon completion.
1736
1737The execution of `spdk_nvmf_subsystem_add_listener` is now asynchronous and the function accepts
1738a cb_fn and cb_arg to call upon completion.
1739
1740The `nvmf_transport.h` header has been made public to allow custom NVMe-oF transports to integrate
1741with NVMe-oF libraries without using internal APIs.
1742
1743### ocf
1744
1745Updated the OCF submodule to OCF v20.03
1746
1747New version of OCF comes with API changes and bug fixes
1748
1749### rpc
1750
1751A new RPC `thread_set_cpumask` has been added to set the cpumask of the thread
1752to the specified value.
1753
1754A new RPC `thread_get_pollers` has been added to retrieve pollers from SPDK threads.
1755
1756A new RPC `thread_get_io_channels` has been added to retrieve I/O channels from SPDK threads.
1757
1758A new RPC `bdev_rbd_resize` has been added to resize Ceph RBD bdevs.
1759
1760### sock
1761
1762The `spdk_sock_set_priority` function has been removed since the feature to set the sock priority
1763will be contained in two new functions, i.e., `spdk_sock_listen_ext` and `spdk_sock_connect_ext`.
1764Users may now specify the priority of the socket in the opts that they want to use.
1765
1766### spdk_top
1767
1768A new application, `spdk_top`, has been added which allows users to monitor resource consumption
1769by a running SPDK application. More information on this application can be found in
1770`app/spdk_top/README`.
1771
1772### thread
1773
1774A new function `spdk_thread_lib_init_ext` has been added, and the function
1775`spdk_thread_lib_init` has been deprecated. The user of `spdk_thread_lib_init_ext` is
1776expected to implement both functions `spdk_thread_op_fn` and `spdk_thread_op_supported_fn`.
1777`spdk_thread_op_supported_fn` is called to check whether the SPDK thread operation
1778is supported. `spdk_thread_op_fn` is called to execute the SPDK thread operation.
1779Current SPDK operation types are `SPDK_THREAD_OP_NEW` and `SPDK_THREAD_OP_RESCHED`.
1780The operation `SPDK_THREAD_OP_NEW` is called each time a new thread is created.
1781The operation `SPDK_THREAD_OP_RESCHED` is called when SPDK thread needs to be rescheduled.
1782
1783A unique ID has been added for each created SPDK thread, it is retrieved by a new function
1784`spdk_thread_get_id`, and the SPDK thread which has the specific ID is got by
1785a new function `spdk_thread_get_by_id`.
1786
1787A new function `spdk_thread_cpumask` has been added to set the current thread's cpumask
1788to the specified value. The function requires the operation `SPDK_THREAD_OP_RESCHED`
1789is supported.
1790
1791A new function `spdk_poller_register_named` has been added to set arbitrary name to the
1792created poller. If NULL, the name is set to the pointer of the poller function.
1793
1794The function `spdk_thread_poll` now measures run time per call correctly on multiple SPDK
1795threads configuration, and a new function `spdk_thread_get_last_tsc` has been added to use together.
1796
1797Voluntary termination of SPDK thread has been supported by refining the functions `spdk_thread_exit`
1798and `spdk_thread_poll`.
1799
1800### util
1801
1802New functions `spdk_sn32_lt` and `spdk_sn32_gt` have been added. They compare two sequence
1803numbers based on serial number arithmetic.
1804
1805### vhost
1806
1807Poll groups per session have been replaced by SPDK threads per vhost controller.
1808
1809### vmd
1810
1811A new function, `spdk_vmd_fini`, has been added. It releases all resources acquired by the VMD
1812library through the `spdk_vmd_init` call.
1813
1814## v20.01: Optimized thin provisioning, FTL bdev, VMD hot plug, FUSED support
1815
1816### bdev
1817
1818A new function, `spdk_bdev_set_timeout`, has been added to set per descriptor I/O timeouts.
1819
1820A new class of functions `spdk_bdev_compare*`, have been added to allow native bdev support
1821of block comparisons and compare-and-write.
1822
1823A new class of bdev events, `SPDK_BDEV_EVENT_MEDIA_MANAGEMENT`, has been added to allow bdevs
1824which expose raw media to alert all I/O channels of pending media management events.
1825
1826A new API was added `spdk_bdev_io_get_aux_buf` allowing the caller to request
1827an auxiliary buffer for its own private use. The API is used in the same manner that
1828`spdk_bdev_io_get_buf` is used and the length of the buffer is always the same as the
1829bdev_io primary buffer. 'spdk_bdev_io_put_aux_buf' frees the allocated auxiliary
1830buffer.
1831
1832### blobfs
1833
1834Added boolean return value for function spdk_fs_set_cache_size to indicate its operation result.
1835
1836Added `blobfs_set_cache_size` RPC method to set cache size for blobstore filesystem.
1837
1838### blobstore
1839
1840Added new `use_extent_table` option to `spdk_blob_opts` for creating blobs with Extent Table descriptor.
1841Using this metadata format, dramatically decreases number of writes required to persist each cluster allocation
1842for thin provisioned blobs. Extent Table descriptor is enabled by default.
1843See the [Blobstore Programmer's Guide](https://spdk.io/doc/blob.html#blob_pg_cluster_layout) for more details.
1844
1845### dpdk
1846
1847Updated DPDK submodule to DPDK 19.11.
1848
1849### env_dpdk
1850
1851`spdk_env_dpdk_post_init` now takes a boolean, `legacy_mem`, as an argument.
1852
1853A new function, `spdk_env_dpdk_dump_mem_stats`, prints information about the memory consumed by DPDK to a file specified by
1854the user. A new utility, `scripts/dpdk_mem_info.py`, wraps this function and prints the output in an easy to read way.
1855
1856### event
1857
1858The functions `spdk_reactor_enable_framework_monitor_context_switch()` and
1859`spdk_reactor_framework_monitor_context_switch_enabled()` have been changed to
1860`spdk_framework_enable_context_switch_monitor()` and
1861`spdk_framework_context_switch_monitor_enabled()`, respectively.
1862
1863### ftl
1864
1865All NVMe dependencies were removed from ftl library.
1866From now ftl library is using bdev_zone API.
1867bdev_ftl becomes virtual bdev.
1868
1869`ctrlr` and `trid` fields in `spdk_ftl_dev_init_opts` structure  were replaced by
1870`base_bdev_desc`.
1871
1872`bdev_ftl_create` RPC method `trtype` and `traddr` parameters were replaced by `base_bdev`
1873parameter.
1874
1875`spdk_ftl_module_init` and `spdk_ftl_module_fini` functions were removed.
1876
1877`spdk_ftl_punit_range` and `ftl_module_init_opts` structures were removed.
1878
1879### isa-l
1880
1881Updated ISA-L submodule to commit f3993f5c0b6911 which includes implementation and
1882optimization for aarch64.
1883
1884Enabled ISA-L on aarch64 by default in addition to x86.
1885
1886### nvme
1887
1888`delayed_pcie_doorbell` parameter in `spdk_nvme_io_qpair_opts` was renamed to `delay_cmd_submit`
1889to allow reuse in other transports.
1890
1891Added RDMA WR batching to NVMf RDMA initiator. Send and receive WRs are chained together
1892and posted with a single call to ibv_post_send(receive) in the next call to qpair completion
1893processing function. Batching is controlled by 'delay_cmd_submit' qpair option.
1894
1895The NVMe-oF initiator now supports plugging out of tree NVMe-oF transports. In order
1896to facilitate this feature, several small API changes have been made:
1897
1898The `spdk_nvme_transport_id` struct now contains a trstring member used to identify the transport.
1899A new function, `spdk_nvme_transport_available_by_name`, has been added.
1900A function table, `spdk_nvme_transport_ops`, and macro, `SPDK_NVME_TRANSPORT_REGISTER`, have been added which
1901enable registering out of tree transports.
1902
1903A new function, `spdk_nvme_ns_supports_compare`, allows a user to check whether a given namespace supports the compare
1904operation.
1905
1906A new family of functions, `spdk_nvme_ns_compare*`, give the user access to submitting compare commands to NVMe namespaces.
1907
1908A new function, `spdk_nvme_ctrlr_cmd_get_log_page_ext`, gives users more granular control over the command dwords sent in
1909log page requests.
1910
1911### nvmf
1912
1913Add SockPriority option in [Transport] section, this can be used for NVMe-oF target
1914on TCP transport to set sock priority for the incoming TCP connections.
1915
1916The NVMe-oF target now supports plugging out of tree NVMe-oF transports. In order
1917to facilitate this feature, several small API changes have been made:
1918
1919The `spdk_nvme_transport_id` struct now contains a trstring member used to identify the transport.
1920`spdk_nvmf_tgt_get_transport`, `spdk_nvmf_transport_opts_init`, and `spdk_nvmf_transport_create` all have been
1921modified to take a string.
1922A function table, `spdk_nvmf_transport_ops`, and macro, `SPDK_NVMF_TRANSPORT_REGISTER`, have been added which
1923enable registering out of tree transports.
1924
1925Add `spdk_nvmf_tgt_stop_listen()` that can be used to stop listening for
1926incoming connections for specified target and trid. Listener is not stopped
1927implicitly upon destruction of a subsystem any more.
1928
1929A custom NVMe admin command handler has been added which allows the user to use the real drive
1930attributes from one of the target NVMe drives when reporting drive attributes to the initiator.
1931This handler can be enabled via the `nvmf_set_config` RPC.
1932Note: In a future version of SPDK, this handler will be enabled by default.
1933
1934The SPDK target and initiator both now include compare-and-write functionality with one caveat. If using the RDMA transport,
1935the target expects the initiator to send both the compare command and write command either with, or without inline data. The
1936SPDK initiator currently respects this requirement, but this note is included as a flag for other initiators attempting
1937compatibility with this version of SPDK.
1938
1939The `spdk_nvme_ctrlr_opts` struct has been extended with new field `transport_ack_timeout` which allows
1940to configure transport ACK timeout. Applicable for RDMA transport only.
1941
1942### rpc
1943
1944A new RPC, `bdev_zone_block_create`, enables creating an emulated zoned bdev on top of a standard block device.
1945
1946A new RPC, `bdev_ocssd_create`, enables creating an emulated zoned bdev on top of an Open Channel SSD.
1947
1948A new RPC, `blobfs_set_cache_size`, enables managing blobfs cache size.
1949
1950A new RPC, `env_dpdk_get_mem_stats`, has been added to facilitate reading DPDK related memory
1951consumption stats. Please see the env_dpdk section above for more details.
1952
1953A new RPC, `framework_get_reactors`, has been added to retrieve a list of all reactors.
1954
1955`bdev_ftl_create` now takes a `base_bdev` argument in lieu of `trtype`, `traddr`, and `punits`.
1956
1957`bdev_nvme_set_options` now allows users to disable I/O submission batching with the `-d` flag
1958
1959`bdev_nvme_cuse_register` now accepts a `name` parameter.
1960
1961`bdev_uring_create` now takes arguments for `bdev_name` and `block_size`
1962
1963`nvmf_set_config` now takes an argument to enable passthru of identify commands to base NVMe devices.
1964Please see the nvmf section above for more details.
1965
1966### scsi
1967
1968`spdk_scsi_lun_get_dif_ctx` now takes an additional argument of type `spdk_scsi_task`.
1969
1970### sock
1971
1972Added spdk_sock_writev_async for performing asynchronous writes to sockets. This call will
1973never return EAGAIN, instead queueing internally until the data has all been sent. This can
1974simplify many code flows that create pollers to continue attempting to flush writes
1975on sockets.
1976
1977Added `impl_name` parameter in spdk_sock_listen and spdk_sock_connect functions. Users may now
1978specify the sock layer implementation they'd prefer to use. Valid implementations are currently
1979"vpp" and "posix" and NULL, where NULL results in the previous behavior of the functions.
1980
1981### thread
1982
1983`spdk_thread_send_msg` now returns int indicating if the message was successfully
1984sent.
1985
1986A new function `spdk_thread_send_critical_msg`, has been added to support sending a single message from
1987a context that may be interrupted, e.g. a signal handler.
1988
1989Two new functions, `spdk_poller_pause`, and `spdk_poller_resume`, have been added to give greater control
1990of pollers to the application owner.
1991
1992### util
1993
1994`spdk_pipe`, a new utility for buffering data from sockets or files for parsing
1995has been added. The public API is available at `include/spdk/pipe.h`.
1996
1997### bdev
1998
1999Added spdk_bdev_io_get_nvme_fused_status function for translating bdev_io status to NVMe status
2000code for fused compare-and-write operation.
2001
2002Added spdk_bdev_get_acwu function for getting block device atomic compare and write unit size.
2003
2004## v19.10: Zoned bdev API, Opal bdev, NVMe character devices
2005
2006### rpc
2007
2008Many of SPDK's RPCs were renamed to be more consistent and intuitive in this release.
2009The old names will continue to function, but will display a deprecation warning.
2010
2011Added optional parameters '--arbitration-burst' and '--low/medium/high-priority-weight' to
2012'bdev_nvme_set_options' RPC method.
2013
2014Added optional parameter '--md-size' to 'construct_null_bdev' RPC method.
2015
2016Added optional parameters '--dif-type' and '--dif-is-head-of-md' to 'construct_null_bdev'
2017RPC method.
2018
2019Added `blobfs_detect` RPC method to detect whether a blobfs exists on given bdev.
2020
2021Added `blobfs_create` RPC method to build blobfs on given bdev.
2022
2023Added `blobfs_mount` RPC method to mount blobfs on given bdev to a host path by FUSE.
2024Then on the host path, user can directly do some file operations which will be mapped
2025to blobfs.
2026
2027### bdev
2028
2029Added new parameter `cdw0` to `spdk_bdev_io_complete_nvme_status()` and
2030`spdk_bdev_io_get_nvme_status()` that allows setting/getting
2031the NVMe completion queue DW0 entry. This allows vendor specific IO commands
2032to return command specific completion info back to the initiator.
2033
2034Added `spdk_bdev_get_write_unit_size()` function for retrieving required number
2035of logical blocks for write operation.
2036
2037New zone-related fields were added to the result of the `get_bdevs` RPC call:
2038
2039- `zoned`: indicates whether the device is zoned or a regular
2040  block device
2041- `zone_size`: number of blocks in a single zone
2042- `max_open_zones`: maximum number of open zones
2043- `optimal_open_zones`: optimal number of open zones
2044
2045The `zoned` field is a boolean and is always present, while the rest is only available for zoned
2046bdevs.
2047
2048A new `spdk_bdev_open_ext` function has been added and `spdk_bdev_open` function has been deprecated.
2049The new open function introduces requirement to provide callback function that will be called by
2050asynchronous event such as bdev removal. `spdk_bdev_open_ext` function takes bdev name as
2051an argument instead of bdev structure to avoid a race condition that can happen when the bdev
2052is being removed between a call to get its structure based on a name and actually openning it.
2053
2054New 'resize' event has been added to notify about change of block count property of block device.
2055Event is delivered only if block device was opened with `spdk_bdev_open_ext` function.
2056
2057### bdev zone
2058
2059Added new public header for zoned bdev. Zoned bdev is an extension
2060of the bdev interface.
2061
2062`spdk_bdev_get_zone_size()`, `spdk_bdev_get_max_open_zones()`, `spdk_bdev_get_optimal_open_zones()`
2063APIs were added for retrieving zoned device information.
2064`spdk_bdev_get_zone_info()` API was added for retrieving information about zones in zoned
2065device.
2066Added `spdk_bdev_zone_management()` API for changing zone state.
2067`spdk_bdev_zone_append()` and `spdk_bdev_zone_append_with_md()` APIs were added for
2068appending data to a zone.
2069Added `spdk_bdev_io_get_append location()` function for retrieving append location for I/O.
2070Added `spdk_bdev_is_zoned()` function for checking if bdev supports zoned namespace semantics.
2071
2072### bdev opal
2073
2074EXPERIMENTAL: A new opal bdev has been added to support management of
2075NVMe self-encrypting drives through the Opal specification. Users can
2076create opal bdevs from an NVMe namespace bdev, if the controller
2077containing that namespace supports Opal. Currently this is only
2078supported for namespace ID=1. The following RPCs have been added to
2079support Opal: `bdev_nvme_opal_init`, `bdev_nvme_opal_revert`,
2080`bdev_opal_create`, `bdev_opal_delete`, `bdev_opal_get_info`,
2081`bdev_opal_new_user`, `bdev_opal_set_lock_state`.
2082It does not yet support recreating the opal bdevs after application restart.
2083This bdev module should be considered very experimental, and the RPCs may
2084change significantly in future releases.
2085
2086### delay bdev
2087
2088The `bdev_delay_update_latency` has been added to allow users to update
2089a latency value for a given delay bdev.
2090
2091### compress bdev
2092
2093A new RPC `bdev_compress_get_orphans` has been added to list compress bdevs
2094that were not loaded due to a missing pm metadata file. In this state they
2095can only be deleted.
2096
2097### null bdev
2098
2099Metadata support has been added to Null bdev module.
2100
2101Protection information support has been added to Null bdev module.
2102
2103### nvme
2104
2105Added `no_shn_notification` to NVMe controller initialization options, users can enable
2106it for NVMe controllers.  When the option is enabled, the controller will not do the
2107shutdown process and just disable the controller, users can start their application
2108later again to initialize the controller to the ready state.
2109
2110A controller flag `SPDK_NVME_CTRLR_WRR_SUPPORTED` was added to indicate the controller
2111can support weighted round robin arbitration feature with submission queue.
2112
2113Added `arbitration_burst` option for arbitration feature, and added three
2114`low/medium/high_priority_weight` options for weighted round robin arbitration.
2115
2116Added `spdk_nvme_ns_cmd_write_uncorrectable`.
2117
2118Added new error handling and reporting functionality. This includes several
2119new API functions to facilitate applications recovering when a qpair or
2120controller fails.
2121
2122`spdk_nvme_ctrlr_reconnect_io_qpair` - Reconnects a failed I/O qpair.
2123`spdk_nvme_ctrlr_set_trid` - Sets the trid of an existing controller. Can be used to
2124change the trid for failover cases.
2125`spdk_nvme_ctrlr_is_failed` - Returns the failed state of a controller.
2126`spdk_nvme_ctrlr_fail` - Forces a controller into a failed state.
2127
2128Modified the return behavior of several API functions to better indicate to
2129applications when a qpair is failed. This list of functions includes:
2130
2131`spdk_nvme_qpair_process_completions`
2132`spdk_nvme_ns_cmd_*`
2133`spdk_nvme_ctrlr_process_admin_completions`
2134`spdk_nvme_ctrlr_cmd_*`
2135
2136These functions now return -ENXIO when the qpair or controller on which they
2137operate is failed.
2138
2139EXPERIMENTAL: Added NVMe character device support to allow to create NVMe device nodes in Linux
2140kernel for controller as well as for namespace and process ioctl requests as usual
2141from linux environment.
2142
2143### nvmf
2144
2145The `spdk_nvmf_tgt_create` function now accepts an object of type `spdk_nvmf_target_opts`
2146as its only parameter. This new structure contains the max_subsystems parameter previously
2147passed into that function.
2148
2149A new public API function `spdk_nvmf_get_tgt` has been added which allows users to
2150retrieve a pointer to an `spdk_nvmf_tgt` object by supplying its name. In the special
2151case where an RPC or application only creates a single target, this function can accept
2152a null name parameter and will return the only available target.
2153
2154The majority of the NVMe-oF RPCs now accept an optional tgt_name parameter. This will
2155allow those RPCs to work with applications that create more than one target.
2156
2157Three new NVMe-oF RPCs have been added `nvmf_create_target`, `nvmf_delete_target`, and
2158`nvmf_get_targets`. These new RPCs provide a basic interface for managing multiple target
2159objects. In SPDK the target object defines a unique discovery service. As of this release,
2160these RPCs are not intended to be used with the in-tree SPDK target applications, spdk_tgt and
2161nvmf_tgt, which use a single, global target structure. As such, they are not included in scripts/rpc.py
2162
2163Three new header functions have also been added to help deal with multiple targets.
2164`spdk_nvmf_tgt_get_name` takes a target pointer as an argument and returns its human readable name.
2165`spdk_nvmf_get_first_target` takes no arguments and returns the first target in the global list.
2166`spdk_nvmf_get_next_tgt` takes a target pointer as an argument and returns the next one in the global list.
2167
2168The `spdk_nvmf_tgt_accept` takes additional argument allowing to pass arbitrary context
2169information to the `new_qpair` callback. This will simplify the code when having multiple
2170nvmf targets or when retrieving the context information from globals is not suitable.
2171
2172### blobstore
2173
2174A new `spdk_bdev_create_bs_dev_from_desc` function has been added and `spdk_bdev_create_bs_dev`
2175function has been deprecated.
2176The new create function can cowork with `spdk_bdev_open_ext` function, which provides callback
2177function that will be called by asynchronous event such as bdev removal.
2178
2179### blobfs_bdev
2180
2181A new blobfs module `bdev` has been added to simplify the operations of blobfs on bdev.
2182
2183Function `spdk_blobfs_bdev_detect` is added to detect whether blobfs exists on the given block device.
2184
2185Function `spdk_blobfs_bdev_create` is added to create a blobfs on the given block device.
2186
2187Function `spdk_blobfs_bdev_mount` is added to mount a blobfs on the given block device to
2188a host path by FUSE. Then, a new thread is created dedicatedly for one mountpoint to handle
2189FUSE request by blobfs API.
2190
2191### build
2192
2193Option to build FUSE components into blobfs_bdev module for mounting a blobfs filesystem.
2194It requires the installation of libfuse3. By default, it is disabled. And it will be
2195enabled if run `./configure` with `--with-fuse` option.
2196
2197### iSCSI
2198
2199Portals may no longer be associated with a cpumask. The scheduling of
2200connections is moving to a more dynamic model.
2201
2202An new RPC `iscsi_portal_group_set_auth` has been added to set CHAP authentication
2203for discovery sessions specific for the existing iSCSI portal group. This RPC overwrites
2204the setting by the global parameters for the iSCSI portal group.
2205
2206### socket
2207
2208Added `spdk_sock_is_connected` to check whether the socket is currently connected.
2209`spdk_sock_group_poll` now returns number of events on success.
2210
2211### env
2212
2213Added `spdk_pci_device_unclaim()` function to cleanup pci claim file.
2214
2215### event
2216
2217`framework_start_init` RPC no longer stops the application on error during
2218initialization.
2219
2220### DPDK
2221
2222Updated DPDK submodule to DPDK 19.08.
2223
2224### ocf
2225
2226Updated OCF submodule to OCF v19.06
2227
2228Along with update, new cache mode 'write only' was added.
2229
2230New cache modes added to use via RPC, wi - write invalidate and wa - write around.
2231
2232New version of OCF provides fully asynchronous management API.
2233
2234## v19.07: NVMe-oF FC Transport, VMD, NVMe-oF Persistent reservations, Bdev I/O with separate metadata
2235
2236### ftl
2237
2238EXPERIMENTAL: Added ability to mirror writes to persistent write buffer cache
2239to allow for recovery from dirty shutdown event.
2240
2241Added handling of Asynchronous Nand Management Events (ANM).
2242
2243### vmd
2244
2245EXPERIMENTAL: Added Intel Volume Management Device (VMD) driver. VMD is an integrated
2246controller inside the CPU PCIe root complex. It enables virtual HBAs for the connected
2247NVMe SSDs. `spdk_vmd_init()` enumerates NVMe SSDs behind VMD device and hook them into
2248SPDK PCI subsystem. `spdk_nvme_probe()` or `spdk_nvme_connect()` can be used to connect
2249NVMe driver to the device located at the given transport ID.
2250
2251To obtain transport ID of NVMe SSD behind VMD `spdk_lspci` can be used.
2252
2253Current implementation does not support hotplug.
2254
2255### blobfs
2256
2257Blobfs file asynchronous operations were added to public APIs.
2258
2259### util
2260
2261A new file API `spdk_posix_file_load` was added to load file content into a data buffer.
2262
2263New APIs `spdk_dif_ctx_set_data_offset`, `spdk_dif_verify_stream`,
2264`spdk_dif_get_range_with_md`, `spdk_dif_get_length_with_md` have been added,
2265and existing APIs `spdk_dif_ctx_init`, `spdk_dif_set_md_interleave_iovs`, and
2266`spdk_dif_generate_stream` have been refined to insert or strip DIF into iovs
2267windows of any alignment.
2268
2269New APIs `spdk_dif_ctx_set_remapped_init_ref_tag`, `spdk_dif_remap_ref_tag`,
2270and `spdk_dix_remap_ref_tag` have been added to remap DIF reference tag.
2271
2272New APIs `spdk_dif_update_crc32c` and `spdk_dif_update_crc32c_stream` have been
2273added to compute CRC-32C checksum for extended LBA payload.
2274
2275Bdevperf and bdevio applications now support starting tests with application specific
2276RPCs. Please see helper Python scripts in their respective directories.
2277This is a move towards simpler RPC-only configuration for all main
2278and auxiliary applications.
2279
2280Legacy INI style configuration for SPDK applications will become deprecated in SPDK 19.10,
2281and removed in SPDK 20.01. Please consider moving to JSON-RPC configuration files and/or
2282RPC driven run-time configuration.
2283
2284### nvmf
2285
2286EXPERIMENTAL: A Fibre Channel transport that supports Broadcom HBAs has been
2287added. This depends on the FC HBA driver at
2288https://github.com/ecdufcdrvr/bcmufctdrvr. See [the documentation](https://spdk.io/doc/nvmf.html#nvmf_fc_transport)
2289for more information.
2290
2291Persistent reservation emulation has been added to the NVMe-oF target. Persistent reservation
2292state is stored in a JSON file on the local filesystem between target restart. To support this,
2293an optional parameter to the RPC method `nvmf_subsystem_add_ns` called `--ptpl-file` was added.
2294This allows the user to specify which file to store the persistent reservation state in.  Note
2295that this is done per namespace.
2296
2297The c2h success optimization under which a command capsule response is not sent
2298for reads is turned on by default. A config knob was added to allow disabling
2299the optimization. This will mostly be used for integration testing with 5.0.x kernels
2300while some compatibility fixes make their way down the pipeline for 5.1.x kernels.
2301
2302The sock priority setting of the TCP connection owned by the tcp transport is added. It is
2303used to optimize the TCP connection performance under designated traffic classes. And the
2304priority is used to differentiate the sock priority between SPDK NVMe-oF TCP target application
2305and other TCP based applications.
2306
2307Shared receive queue can now be disabled even for NICs that support it using the
2308`nvmf_create_transport` RPC method parameter `no_srq`. The actual use of a shared
2309receive queue is predicated on hardware support when this flag is not used.
2310
2311spdk_nvmf_get_optimal_poll_group was added, which is used to return the optimal
2312poll group for the qpair. And `ConnectionScheduler` configuration is added into the
2313[Nvmf] section in etc/spdk/nvmf.conf.in to demonstrate how to configure the connection
2314scheduling strategy among different spdk threads.
2315
2316Added infrastructure to retrieve global and per poll group NVMf statistics.
2317
2318DIF strip and insert is now supported for TCP transport. When it is enabled, DIF
2319setting is not exposed to the NVMe-oF initiator, and DIF is attached into data
2320for write I/O and stripped from data for read I/O.
2321
2322Added a field `dif_insert_or_strip` to struct spdk_nvmf_transport_opts, and
2323updated the related rpc function nvmf_create_transport to make this
2324configurable parameter available to users. The `dif_insert_or_strip` is relevant
2325for TCP transport for now and used to configure the DIF strip and insert.
2326
2327Added infrastructure to retrieve NVMf transport statistics.
2328
2329### notify
2330
2331The function `spdk_notify_get_types()` and `spdk_notify_get_events()` were
2332renamed to `spdk_notify_foreach_type()` and `spdk_notify_foreach_event()`,
2333respectively. And update type name of callback accordingly.
2334
2335### bdev
2336
2337The format of the data returned by the get_bdevs_iostat RPC has changed to
2338make it easier to parse.  It now returns an object with a "ticks" object
2339and "bdevs" array with the per-bdev statistics.
2340
2341A new bdev module `delay` has been added which simulates a drive latency when placed
2342on top of a Null bdev. This module is intended only for testing and can be created using
2343the new RPC `bdev_delay_create`. That RPC takes the name of the underlying bdev as well
2344as average and p99 latency arguments for both read and write operations. Average latency is
2345defined as a value close to what you would expect a perf tool such as FIO to report back as
2346the mean latency of all I/O submitted to the drive. p99 latency is defined as the value one
2347would expect the drive to see the slowest 1% of I/O report. For underlying drives with already
2348significant latency, the latency values provided to the drive will be additive. This should be
2349taken into account if trying to achieve an artificial latency on top of an nvme drive or aio device.
2350
2351DIF reference tag remapping is now supported for partition type virtual bdev
2352modules. When using partition type virtual bdevs, block address space is
2353remapped during I/O processing and DIF reference tag is remapped accordingly.
2354
2355Added spdk_bdev_*_with_md() functions allowing for IO with metadata being transferred in
2356separate buffer. To check support for separate metadata, use spdk_bdev_is_md_separate().
2357
2358All bdevs now have a UUID. For devices whose backing hardware does not provide a UUID,
2359one is automatically generated. Across runs of SPDK, bdevs whose UUID is automatically
2360generated may change.
2361
2362A new virtual bdev module `compress` has been added to provide compression services on top of
2363a thinly provisioned logical volume.  See documentation for complete details.
2364
2365### nvme
2366
2367Added an optional parameter `--io-queue-requests` to RPC `set_bdev_nvme_options`, which
2368can be used to change the number of requests allocated for one NVMe I/O queue.  For
2369very big I/O size, e.g. 128MiB, with this option user will not get an error due to
2370limited requests in NVMe driver layer.
2371
2372Added spdk_nvme_ctrlr_get_transport_id() to get the transport ID from a
2373previously attached controller.
2374
2375Nvme Opal library spdk_opal_cmd deprecated. Adding separate command APIs.
2376NVMe Opal library add support for activating locking SP which will make the transaction
2377from "Manufactured-Inactive" state to "Manufactured" state. Upon successfully invoking
2378of this method, lock and unlock features will be enabled.
2379NVMe Opal library add support for locking/unlocking range and list locking range info.
2380NVMe opal library add support for multiuser. Admin can enable user and add user to specific
2381locking range and the user can lock/unlock his range.
2382
2383Added spdk_nvme_ctrlr_io_cmd_raw_no_payload_build() allowing a caller to pass
2384a completely formed command to an NVMe submission queue (buffer addresses and all).
2385This is supported on the PCIe transport only.
2386
2387Added spdk_nvme_get_ctrlr_registers() to return a pointer to the virtual address
2388of the NVMe controller registers.  This is supported on the PCIe transport only.
2389
2390Added additional options to the spdk_nvme_ctrlr_alloc_qpair() option parameter
2391structure to allow caller to override the virtual and optionally physical address
2392of the submission and completion queue pair to be created.  This is supported on
2393the PCIe transport only.
2394
2395Added `disable_error_logging` to struct spdk_nvme_ctrlr_opts, which disables
2396logging of failed requests. By default logging is enabled.
2397
2398Added spdk_nvme_qpair_print_command(), spdk_nvme_qpair_print_completion() and
2399spdk_nvme_cpl_get_status_string(). Allowing for easier display of error messages.
2400
2401Added support for NVMe Sanitize command.
2402
2403### env
2404
2405The parameter `free_space` has been added to spdk_ring_enqueue() to wait when
2406the ring is almost full and resume when there is enough space available in
2407the ring.
2408
2409A new API `spdk_mempool_lookup` has been added to lookup the memory pool created
2410by the primary process.
2411
2412Added spdk_pci_get_first_device() and spdk_pci_get_next_device() to allow
2413iterating over PCI devices detected by SPDK. Because of this, all SPDK APIs
2414to attach/detach PCI devices are no longer thread safe. They are now meant to
2415be called from only a single thread only, the same only that called spdk_env_init().
2416This applies to the newly added APIs as well.
2417
2418### vpp
2419
2420SPDK now supports VPP version 19.04.2, up from VPP 18.01.
2421
2422VPP socket abstraction now uses VPP Session API, instead of VLC (VPP Communications Library).
2423This allows for better control over sessions and queues.
2424Please see VPP documentation for more details:
2425[VPP Host Stack](https://wiki.fd.io/view/VPP/HostStack)
2426
2427### sock
2428
2429Add spdk_sock_get_optimal_sock_group(), which returns the optimal sock group for
2430this socket. When a socket is created, it is often assigned to a sock group using
2431spdk_sock_group_add_sock so that a set of sockets can be polled more efficiently.
2432For some network devices, it is optimal to assign particular sockets to specific
2433sock groups. This API is intended to provide the user with that information.
2434
2435spdk_sock_group_get_ctx() was added to return the context of the spdk_sock_group.
2436spdk_sock_group_create() is updated to allow input the user provided ctx.
2437spdk_sock_set_priority() is added to set the priority of the socket.
2438
2439### rpc
2440
2441Added thread_get_stats RPC method to retrieve existing statistics.
2442
2443Added nvmf_get_stats RPC method to retrieve NVMf subsystem statistics.
2444
2445Response buffers for RPC requests are now always pre-allocated, which implies
2446that all spdk_jsonrpc_begin_result() calls always succeed and return a valid
2447buffer for JSON response. RPC calls no longer need to check if the buffer is
2448non-NULL.
2449
2450Added SPDK_RPC_REGISTER_ALIAS_DEPRECATED to help with deprecation process when
2451renaming existing RPC. First time a deprecated alias is used, it will print
2452a warning message.
2453
2454RPC `get_rpc_methods` was renamed `rpc_get_methods`. The old name is still usable,
2455but is now deprecated.
2456
2457### blobstore
2458
2459A snapshot can now be deleted if there is only a single clone on top of it.
2460
2461### build
2462
2463Preliminary support for cross compilation is now available. Targeting an older
2464CPU on the same architecture using your native compiler can be accomplished by
2465using the `--target-arch` option to `configure` as follows:
2466
2467~~~bash
2468./configure --target-arch=broadwell
2469~~~
2470
2471Additionally, some support for cross-compiling to other architectures has been
2472added via the `--cross-prefix` argument to `configure`. To cross-compile, set CC
2473and CXX to the cross compilers, then run configure as follows:
2474
2475~~~bash
2476./configure --target-arch=aarm64 --cross-prefix=aarch64-linux-gnu
2477~~~
2478
2479### vhost
2480
2481A security vulnerability has been identified and fixed in SPDK Vhost-SCSI target.
2482A malicious client (e.g. a virtual machine) could send a carefully prepared,
2483invalid I/O request to crash the entire SPDK process. All users of SPDK Vhost-SCSI
2484target are strongly recommended to update. All SPDK versions < 19.07 are affected.
2485
2486By default, SPDK will now rely on upstream DPDK's rte_vhost instead of its fork
2487located inside SPDK repo. The internal fork is still kept around to support older
2488DPDK versions, but is considered legacy and will be eventually removed.
2489
2490`configure` will now automatically use the upstream rte_vhost if the used DPDK
2491version is >= 19.05.
2492
2493spdk_vhost_init() is now asynchronous and accepts a completion callback.
2494
2495### iscsi target
2496
2497A security vulnerability has been identified and fixed in SPDK iSCSI target.
2498A malicious client (e.g. an iSCSI initiator) could send a carefully prepared,
2499invalid I/O request to crash the entire SPDK process. All users of SPDK iSCSI
2500target are strongly recommended to update. All SPDK versions < 19.07 are affected.
2501
2502### thread
2503
2504Exposed spdk_set_thread() in order for applications to associate
2505with SPDK thread when necessary.
2506
2507Added spdk_thread_destroy() to allow framework polling the thread to
2508release resources associated with that thread.
2509
2510## v19.04: Compression bdev, Notification library, NVMe Opal support
2511
2512### nvme
2513
2514Added asynchronous probe support. New APIs spdk_nvme_probe_async(),
2515spdk_nvme_connect_async() and spdk_nvme_probe_poll_async() were added to enable
2516this feature. spdk_nvme_probe_async() and spdk_nvme_connect_async() return a
2517context associated with the specified controllers. Users then call
2518spdk_nvme_probe_poll_async() until it returns 0, indicating that the operation
2519completed.
2520
2521A new qpair creation option, delay_pcie_doorbell, was added. This can be passed
2522to spdk_nvme_alloc_io_qpair(). This makes the I/O submission functions, such as
2523spdk_nvme_ns_writev(), skip ringing the submission queue doorbell. Instead the
2524doorbell will be rung as necessary inside spdk_nvme_qpair_process_completions().
2525This can result in significantly fewer MMIO writes to the doorbell register
2526under heavy load, greatly improving performance.
2527
2528spdk_nvme_ctrlr_get_regs_cmbsz() was added to report the size of the controller
2529memory buffer, if available.
2530
2531spdk_nvme_ctrlr_get_flags() was added to return controller feature
2532flags. Two flags are currently tracked:
2533SPDK_NVME_CTRLR_SGL_SUPPORTED
2534SPDK_NVME_CTRLR_SECURITY_SEND_RECV_SUPPORTED
2535
2536The NVMe hotplug poller is now able to detach devices hot-removed from the system
2537via `/sys/bus/pci/devices/<bdf>/remove` and `/sys/bus/pci/devices/<bdf>/driver/unbind`.
2538
2539Opal support was added for scan, take ownership, revert TPer, and dumping device
2540info. The nvme_manage tool can be used to perform these operations. The public
2541API functions are spdk_nvme_ctrlr_security_receive() and
2542spdk_nvme_ctrlr_security_send(). This module should be considered experimental
2543pending additional features and tests.
2544
2545The NVMe-oF initiator is now able to transfer IO whose size is more than 128KiB
2546if the corresponding NVMe-oF target allows.
2547
2548### raid
2549
2550Added new strip_size_kb rpc param on create to replace the more ambiguous
2551strip_size. The strip_size rpc param is deprecated.
2552
2553Changed the raid bdev product_name from "Pooled Device" to "Raid Volume"
2554
2555### thread
2556
2557Added spdk_thread_has_pollers() function to verify if there are any registered
2558pollers to be run on the thread. Added spdk_thread_is_idle() function to check
2559if there are any scheduled operations to be performed on the thread at given
2560time.
2561
2562spdk_thread_create() now takes an optional CPU affinity mask that is passed to
2563the scheduler.
2564
2565spdk_thread_lib_init() now takes an optional context size. For each thread
2566created, an additional region of memory of this size will be allocated. A
2567pointer to this region of memory can be obtained by calling
2568spdk_thread_get_ctx(). The inverse operation is also available via
2569spdk_thread_get_from_ctx().
2570
2571spdk_thread_poll() now optionally accepts the current time, in ticks. This can
2572be used to avoid some calls to spdk_get_ticks() internally.
2573
2574spdk_app_start() now only accepts a single context argument.
2575
2576### bdev
2577
2578An new API `spdk_bdev_get_data_block_size` has been added to get size of data
2579block except for metadata.
2580
2581spdk_vbdev_register() has been deprecated.  spdk_bdev_register() should be used
2582instead.
2583
2584A mechanism for acquiring and releasing data buffers from bdev modules, used
2585to perform zero copy operations, was added.
2586
2587New APIs spdk_bdev_get_md_size(), spdk_bdev_is_md_interleaved(), spdk_bdev_get_dif_type(),
2588spdk_bdev_is_dif_head_of_md(), and spdk_bdev_is_dif_check_enabled() have been
2589added to get metadata and DIF settings.
2590
2591Bdevs claimed by the `examine_config` callback will be now further examined in the
2592`examine_disk` callback.
2593
2594spdk_bdev_io_get_io_channel() was added as a convenient way to get an io_channel
2595from a bdev_io.
2596
2597### ocf
2598
2599Updated OCF submodule to OCF v19.3.2
2600
2601Added support for many-to-one configuration for OCF bdev.
2602Multiple core devices can now be cached on single cache device.
2603
2604Added persistent metadata support, allowing to restore cache state after shutdown.
2605During start of SPDK application, the devices are examined and if OCF metadata
2606is present - appropriate OCF bdevs will be recreated.
2607
2608Added Write-Back mode support. In this mode, data is first written to
2609caching device and periodically synchronized to the core devices.
2610Dirty data is saved as persistent metadata on cache device,
2611allowing for safe restore during application restart.
2612For more details please see OCF documentation:
2613[OpenCAS cache configuration](https://open-cas.github.io/cache_configuration.html)
2614
2615### NVMe-oF Target
2616
2617Support for per-device shared receive queues in the RDMA transport has been added.
2618It is enabled by default for any device that supports it.
2619
2620The size of a shared receive queue is defined by transport configuration file parameter
2621`MaxSRQDepth` and `nvmf_create_transport` RPC method parameter `max_srq_depth`.
2622Default size is 4096.
2623
2624Add model number as parameter to construct_nvmf_subsystem (-d option),
2625rather than using hardcoded define.
2626
2627DIF passthrough feature has been added. DIF setting of the allocated bdevs is
2628exposed to the NVMe-oF initiator and data with DIF from the NVMe-oF initiator is
2629passed through to the allocated bdevs.
2630
2631### env
2632
2633The `phys_addr` parameter in spdk_malloc() and spdk_zmalloc() has been deprecated.
2634For retrieving physical addresses, spdk_vtophys() should be used instead.
2635
2636spdk_realloc() has been added to reallocate DMA/shared memory.
2637
2638spdk_pci_device_is_removed() has been added to let the upper-layer SPDK drivers know
2639that device has a pending external hotremove request.
2640
2641spdk_env_fini() and spdk_env_dpdk_post_fini() were added to release any resources
2642allocated by spdk_env_init() or spdk_env_dpdk_post_init() respectively. It is expected
2643that common usage of those functions is to call them just before terminating the process.
2644
2645Added spdk_iommu_is_enabled() to report if SPDK application is using IOMMU for DMA.
2646
2647### DPDK
2648
2649Dropped support for DPDK 17.07 and earlier, which SPDK won't even compile with right now.
2650
2651Updated DPDK submodule to DPDK 19.02.
2652
2653### rpc
2654
2655New `get_spdk_version` RPC method is introduced to get version info of the running SPDK application.
2656
2657The `start_nbd_disk` RPC method now take nbd_device as an optional parameter. If nbd_device
2658is specified, use that specified nbd device. If it's not specified, pick available one.
2659
2660### iSCSI target
2661
2662DIF strip and insert is now supported. DIF settings are not exposed to the iSCSI initiator.
2663DIF is attached into data for write I/O and stripped from data for read I/O.
2664
2665### vhost
2666
2667Added experimental support for running with the external, upstream rte_vhost library.
2668This can be enabled by configuring SPDK with an `--without-internal-vhost-lib` flag.
2669The minimum supported rte_vhost version (DPDK version) is 19.05-rc1.
2670
2671As a result of fuzz testing, a lot of data races in vhost-scsi LUN hotplug path were identified and
2672fixed. Those data races could have potentially resulted in SPDK crashes, RPC hangs, or memory leaks
2673if Vhost-SCSI LUN hotplug RPCs were executed while connected VMs were in the middle of restarting.
2674
2675The SCSI target id in `add_vhost_scsi_lun` RPC is now optional. If `-1` is passed, the first
2676unoccupied target id will be used.
2677
2678### AIO
2679
2680AIO bdev module can now reap I/O completions directly from userspace, significantly improving
2681the overall performance.
2682
2683### blobfs
2684
2685Synchronous IO operations no longer use spdk_io_channel, but instead use
2686spdk_fs_thread_ctx. The behavior is otherwise identical.
2687
2688### OCF
2689
2690Added support for caching multiple bdevs using a single bdev as a cache.
2691
2692### notify
2693
2694Added the notify library that provides a high performance local event bus
2695between libraries. Example usage was added to bdev module, which reports
2696notifications for added and removed bdevs via RPC.
2697
2698### sock
2699
2700Added new API spdk_sock_readv() to the sock library for performing vectored
2701reads.
2702
2703### event
2704
2705The function spdk_subsystem_init() no longer requires spdk_event as an argument.
2706
2707Changed API of spdk_subsystem_config_json() to no longer be asynchronous.
2708
2709### io_uring
2710
2711A bdev module that issues I/O to kernel block devices using the new io_uring Linux kernel
2712API was added. This module requires liburing.
2713
2714### build
2715
2716Options to easily compile with profile guided optimization have been added to
2717`configure`. To use profile guided optimization with SPDK, run
2718`./configure --with-pgo-capture`, build SPDK, then run a workload of your
2719choosing. Then, simply run `./configure --with-pgo-enable` and recompile to
2720build using the generated profile data. Profile guided optimization can yield
2721very large performance improvements, especially on GCC 8 and clang 7. This may
2722be combined with link time optimization which has been available under the
2723`--enable-lto` configure option for several releases.
2724
2725### compression bdev/reduce library
2726
2727Added "reduce" block compression scheme based on using SSDs for storing
2728compressed blocks of storage and persistent memory for metadata. Please see
2729[compression](https://spdk.io/doc/bdev.html) for more details.
2730
2731## v19.01: NVMe-oF TCP/IP Transport, Open Channel SSD Flash Translation Layer, Caching bdev based on OCF, ISA-L Support, DIF/DIX library
2732
2733### ocf bdev
2734
2735New virtual bdev module based on [Open CAS Framework](https://open-cas.github.io/) has been added.
2736This module allows for the use of one bdev to act as a high performance cache in front of another bdev.
2737Please see [documentation](https://spdk.io/doc/bdev.html#bdev_config_cas) for more details.
2738Only write through mode is currently supported and this feature is considered experimental.
2739
2740### event framework
2741
2742For `spdk_app_parse_args`, add return value to the callback which parses application
2743specific command line parameters to protect SPDK applications from crashing by invalid
2744values from user input.
2745
2746By default, all SPDK applications will now reserve all hugepages at runtime. The pre-reserved
2747memory size can be still set with `-s` or `--mem-size` option, although the default value
2748was reduced down to 0.
2749
2750A custom hugetlbfs directory can now be specified via spdk_app_opts.
2751This can be used to configure hugepages with different sizes, a different size limit,
2752or different access permissions than the system's default hugepage pool.
2753SPDK applications can specify a custom hugetlbfs mount with the `--huge-dir` option.
2754
2755### environment
2756
2757spdk_vtophys() has been refactored to accept length of the translated region as a new
2758parameter. The function will now update that parameter with the largest possible value
2759for which the memory is contiguous in the physical memory address space.
2760
2761The following functions were removed:
2762
2763- spdk_pci_nvme_device_attach()
2764- spdk_pci_nvme_enumerate()
2765- spdk_pci_ioat_device_attach()
2766- spdk_pci_ioat_enumerate()
2767- spdk_pci_virtio_device_attach()
2768- spdk_pci_virtio_enumerate()
2769
2770They were replaced with generic spdk_pci_device_attach() and spdk_pci_enumerate() which
2771require a new spdk_pci_driver object to be provided. It can be one of the following:
2772
2773- spdk_pci_nvme_get_driver()
2774- spdk_pci_ioat_get_driver()
2775- spdk_pci_virtio_get_driver()
2776
2777spdk_pci_hook_device() and spdk_pci_unhook_device() were added. Those allow adding a virtual
2778spdk_pci_device into the SPDK PCI subsystem. A virtual device calls provided callbacks for
2779each BAR mapping request or PCI config access. It's attachable with spdk_pci_device_attach()
2780or spdk_pci_enumerate() like any other device.
2781
2782A new spdk_pause() function was added to pause CPU execution for an implementation specific
2783amount of time. Quoting from DPDK function this is based on: "This call is intended for
2784tight loops which poll a shared resource or wait for an event. A short pause within the loop
2785may reduce the power consumption."
2786
2787A new public header file env_dpdk.h has been introduced, and function spdk_env_dpdk_post_init
2788is added into it. If user is using DPDK, and already called rte_eal_init, then include
2789include/spdk/env_dpdk.h, and call spdk_env_dpdk_post_init() instead of spdk_env_init.
2790
2791ISA-L has been added as an SPDK submodule.  ISA-L is enabled by default on x86 architecture
2792to accelerate algorithms such as CRC for iSCSI and NVMe-oF.  Users may still disable ISA-L
2793by explicitly passing --without-isal to the configure script.
2794
2795### util
2796
2797A new uuid API `spdk_uuid_copy` was added to make a copy of the source uuid.
2798
2799An new parameter `init_crc` representing the initial CRC value was added to
2800`spdk_crc16_t10dif`. The parameter can be used to calculate a CRC value spanning
2801multiple separate buffers.
2802
2803New DIF APIs were added to generate and verify DIF by byte granularity for both DIF and DIX
2804formats. Among them, DIF with copy APIs will be usable to emulate DIF operations such as DIF
2805insert and strip.
2806
2807Added `spdk_strtol` and `spdk_strtoll` to provide additional error checking around `strtol`
2808and `strtoll`.
2809
2810Added `spdk_sprintf_append_realloc` and `spdk_vsprintf_append_realloc` for appending a string
2811with automatic buffer re-allocation.
2812
2813### nvme
2814
2815Wrapper functions spdk_nvme_ctrlr_security_send() and spdk_nvme_ctrlr_security_receive() are
2816introduced to support further security protocol development.
2817
2818admin_timeout_ms was added to NVMe controller initialization options, users
2819can change the default value when probing a controller.
2820
2821Add two new fields "header_digest" and "data_digest" in struct spdk_nvme_ctrlr_opts,
2822it will be used to enable the digest support for the NVMe/TCP transport.
2823
2824Add a new TCP/IP transport(located in lib/nvme/nvme_tcp.c) in nvme driver. With
2825this new transport, it can be used to connect the NVMe-oF target with the
2826same TCP/IP support.
2827
2828Added API, spdk_nvme_ctrlr_is_discovery(), to indicate whether the ctrlr
2829arg refers to a Discovery Controller or not.
2830
2831Added an API function `spdk_nvme_host_id_parse` and corresponding object `spdk_nvme_host_id`
2832for parsing host address and host service ID arguments on a per connection basis.
2833
2834The RPC `construct_nvme_bdev` now allows a user to specify a source address and service id for the host to
2835use when connecting to the controller backing the NVMe bdev.
2836
2837### NVMe-oF Target
2838
2839The `spdk_nvmf_tgt_opts` struct has been deprecated in favor of `spdk_nvmf_transport_opts`.
2840Users will no longer be able to specify target wide I/O parameters. `spdk_nvmf_tgt_listen`
2841will also no longer implicitly initialize a transport with the default target options (since
2842there are none). Instead, a user must manually instantiate the transport with `spdk_nvmf_transport_create`
2843prior to calling `spdk_nvmf_tgt_listen`.
2844
2845Related to the previous change, the rpc `set_nvmf_target_options` has been renamed to
2846`set_nvmf_target_max_subsystems` to indicate that this is the only target option available for the user to edit.
2847
2848Added fields `num_shared_buffers` and `buf_cache_size` in struct spdk_nvmf_transport_opts,
2849and also updated the related rpc function nvmf_create_transport, to make this
2850configurable parameter available to users. The `num_shared_buffers` is used to
2851configure the shared buffer numbers of the transport used by RDMA or TCP transport.
2852`buf_cache_size` configures number of shared buffers to cache per poll group.
2853
2854### nvmf
2855
2856Add a new TCP/IP transport (located in lib/nvmf/tcp.c). With this transport,
2857the SPDK NVMe-oF target can have a new transport, and can serve the NVMe-oF
2858protocol via TCP/IP from the host.
2859
2860Added optional mechanism to modify the RDMA transport's behavior when creating protection domains and registering memory.
2861By default, the RDMA transport will use the ibverbs library to create protection domains and register memory.
2862Using `spdk_nvme_rdma_init_hooks` will subvert that and use an existing registration.
2863
2864### bdev
2865
2866Added `enable_bdev_histogram` and `get_bdev_histogram` RPC commands to allow gathering latency data for specified bdev.
2867Please see [documentation](https://spdk.io/doc/bdev.html#rpc_bdev_histogram) for more details.
2868
2869Added `required_alignment` field to `spdk_bdev`, that specifies an alignment requirement for data buffers associated with an spdk_bdev_io.
2870Bdev layer will automatically double buffer any spdk_bdev_io that violates this alignment, before the spdk_bdev_io is submitted to the bdev module.
2871
2872On shutdown, bdev unregister now proceeds in top-down fashion, with
2873claimed bdevs skipped (these will be unregistered later, when virtual
2874bdev built on top of the respective base bdev unclaims it). This
2875allows virtual bdevs to be shut down cleanly as opposed to the
2876previous behavior that didn't differentiate between hotremove and
2877planned shutdown.
2878
2879The `delete_bdev` RPC is now deprecated. Users should instead use the specific deletion RPC
2880for the bdev type to be removed (i.e. delete_malloc_bdev).
2881
2882Added support for separate bandwidth rate limits for read and write to QoS in bdev layer.
2883
2884Bdev I/O statistics now track unmap operations.
2885
2886### logical volumes
2887
2888Logical volume bdev can now be marked as read only using `set_read_only_lvol_bdev` RPC.
2889This allows for basing clones on top of lvol_bdev without first creating a snapshot.
2890
2891Added option to change method for data erasure when deleting lvol or resizing down.
2892Default of unmapping clusters can now be changed to writing zeroes or no operation.
2893
2894Added option to change method for erasing data region on lvol store creation.
2895Default of unmapping can now be changed to writing zeroes or no operation.
2896
2897### log
2898
2899"trace flags" are now referred to as "log flags" in the SPDK log API.  The
2900set_trace_flag, clear_trace_flag and get_trace_flags RPCs are now deprecated,
2901and set_log_flag, clear_log_flag and get_log_flags RPCs have been added.
2902
2903### trace
2904
2905New `trace_record` application was added. It can be used to poll spdk trace shm file and
2906append any new trace entries into another specified file. This can help retain those entries
2907that would otherwise be overwritten in the shm file. See
2908[Capturing sufficient trace events](https://spdk.io/doc/nvmf_tgt_tracepoints.html#capture_trace_events)
2909for more details.
2910
2911Number of trace entries in circular buffer per lcore can now be assigned by starting SPDK app
2912with argument "--num-trace-entries <NUM>" provided.
2913
2914New `get_tpoint_group_mask` RPC was added to get current tpoint_group_mask, and
2915each tpoint group status.
2916New `enable_tpoint_group` and `disable_tpoint_group` RPC were added to enable or
2917disable a specific tpoint group.
2918
2919### ftl
2920
2921EXPERIMENTAL: Added basic flash translation layer module allowing for using Open Channel SSDs as
2922block devices. The module is split into the library (located in lib/ftl) and bdev_ftl
2923(lib/bdev/ftl). See the [documentation](https://spdk.io/doc/ftl.html) for more details.
2924
2925### vhost
2926
2927A security vulnerability has been identified and fixed in the SPDK vhost target.  A malicious
2928vhost client (i.e. virtual machine) could carefully construct a circular descriptor chain which
2929would result in a partial denial of service in the SPDK vhost target.  These types of descriptor
2930chains are now properly detected by the vhost target.  All SPDK vhost users serving untrusted
2931vhost clients are strongly recommended to upgrade. (Reported by Dima Stepanov and Evgeny
2932Yakovlev.)
2933
2934Vhost SCSI and Vhost Block devices can now accept multiple connections on the same socket file.
2935Each connection (internally called a vhost session) will have access to the same storage, but
2936will use different virtqueues, different features and possibly different memory.
2937
2938### vhost scsi
2939
2940SCSI target hotremove can now be performed even without the VIRTIO_SCSI_F_HOTPLUG feature negotiated.
2941Regardless of VIRTIO_SCSI_F_HOTPLUG support, the hotremoval will be still reported through SCSI sense codes.
2942
2943### DPDK
2944
2945DPDK submodule was updated to DPDK 18.11. Note that SPDK does not fully leverage the new
2946multi-process device hotplug yet and continues to work the same way it always did.
2947
2948Dropped support for DPDK 16.07 and earlier, which SPDK won't even compile with right now.
2949
2950### RPC
2951
2952The following RPC commands deprecated in the previous release are now removed:
2953
2954- construct_virtio_user_scsi_bdev
2955- construct_virtio_pci_scsi_bdev
2956- construct_virtio_user_blk_bdev
2957- construct_virtio_pci_blk_bdev
2958- remove_virtio_scsi_bdev
2959- construct_nvmf_subsystem
2960
2961### Miscellaneous
2962
2963The configure options `--with-raid` and `--without-raid` that were deprecated in the previous
2964release are now removed.
2965
2966### nbd
2967
2968Starting nbd using `spdk_nbd_start` is now performed asynchronously.
2969
2970### net framework
2971
2972Net framework initialization and finish is now done asynchronously.
2973
2974### rpc
2975
2976Added `spdk_rpc_is_method_allowed` function for checking whether method is permitted in a given state.
2977Added `spdk_rpc_get_state` to check current state of RPC server.
2978RPC `wait_subsystem_init` has been added to allow clients to block untill all subsystems are initialized.
2979
2980### json rpc
2981
2982JSON RPC client is now running in non-blocking mode. Requests are sent and received during spdk_jsonrpc_client_poll.
2983JSON RPC server can now receive a callback on connection termination or server shutdown using `spdk_jsonrpc_conn_add_close_cb`
2984and `spdk_jsonrpc_conn_del_close_cb`.
2985
2986## v18.10: Dynamic memory allocation, Crypto Virtual Bdev, jsonrpc-client, SPDKCLI iSCSI and NVMe-oF support
2987
2988### nvme
2989
2990spdk_nvme_ctrlr_cmd_security_send() and spdk_nvme_ctrlr_cmd_security_receive()
2991were added to support sending or receiving security protocol data to or from
2992nvme controller.
2993
2994spdk_nvme_ns_get_extended_sector_size() was added.  This function includes
2995the metadata size per sector (if any).  spdk_nvme_ns_get_sector_size() still
2996returns only the data size per sector, not including metadata.
2997
2998New `send_nvme_cmd` RPC was added to allow sending NVMe commands directly to NVMe controller.
2999See the [send_nvme_cmd](http://spdk.io/doc/jsonrpc.html#rpc_send_nvme_cmd) documentation
3000for more details.
3001
3002### Build System
3003
3004New `configure` options, `--with-shared` and `--without-shared`
3005[default], provide the capability to build, or not, SPDK shared libraries.
3006This includes the single SPDK shared lib encompassing all of the SPDK
3007static libs as well as individual SPDK shared libs corresponding to
3008each of the SPDK static ones.  Although the production of the shared
3009libs conforms with conventional version naming practices, such naming
3010does not at this time confer any SPDK ABI compatibility claims.
3011
3012### bdev
3013
3014spdk_bdev_alias_del_all() was added to delete all alias from block device.
3015
3016A new virtual bdev module has been added to perform at rest data encryption using the DPDK CryptoDev
3017Framework.  The module initially uses a software AESNI CBC cipher with experimental support for the
3018Intel QAT hardware accelerator also currently implemented with support for CBC cipher. Future work
3019may include additional ciphers as well as consideration for authentication.
3020
3021The RAID virtual bdev module is now always enabled by default.  The configure --with-raid and
3022--without-raid options are now ignored and deprecated and will be removed in the next release.
3023
3024Enforcement of bandwidth limits for quality of service (QoS) has been added to the bdev layer.
3025See the new [set_bdev_qos_limit](http://www.spdk.io/doc/jsonrpc.html#rpc_set_bdev_qos_limit)
3026documentation for more details. The previous set_bdev_qos_limit_iops RPC method introduced at
302718.04 release has been deprecated. The new set_bdev_qos_limit RPC method can support both
3028bandwidth and IOPS limits.
3029
3030spdk_bdev_config_json() and corresponding `get_bdevs_config` RPC was removed.
3031
3032### Environment Abstraction Layer and Event Framework
3033
3034The size parameter of spdk_mem_map_translate is now a pointer. This allows the
3035function to report back the actual size of the translation relative to the original
3036request made by the user.
3037
3038A new structure spdk_mem_map_ops has been introduced to hold memory map related
3039callbacks. This structure is now passed as the second argument of spdk_mem_map_alloc
3040in lieu of the notify callback.
3041
3042### DPDK 18.08
3043
3044The DPDK submodule has been updated to the DPDK 18.08 release. SPDK will now automatically
3045utilize DPDK's dynamic memory management with DPDK versions >= 18.05.1.
3046
3047Hugepages can be still reserved with `[-s|--mem-size <size>]` option at application startup,
3048but once we use them all up, instead of failing user allocations with -ENOMEM, we'll try
3049to dynamically reserve even more. This allows starting SPDK with `--mem-size 0` and using
3050only as many hugepages as it is really needed.
3051
3052Due to this change, the memory buffers returned by `spdk_*malloc()` are no longer guaranteed
3053to be physically contiguous.
3054
3055### I/OAT
3056
3057I/OAT driver can now reinitialize I/OAT channels after encountering DMA errors.
3058
3059### iscsi target
3060
3061Parameter names of `set_iscsi_options` and `get_iscsi_global_params` RPC
3062method for CHAP authentication in discovery sessions have been changed to
3063align with `construct_target_node` RPC method. Old names are still usable
3064but will be removed in future release.
3065
3066`set_iscsi_discovery_auth` and `set_iscsi_target_node_auth` RPC methods have
3067been added to set CHAP authentication for discovery sessions and existing
3068target nodes, respectively.
3069
3070The SPDK iSCSI target supports an AuthFile which can be used to load CHAP
3071shared secrets when the iSCSI target starts. SPDK previously provided a
3072default location for this file (`/usr/local/etc/spdk/auth.conf`) if none was
3073specified. This default has been removed. Users must now explicitly specify
3074the location of this file to load CHAP shared secrets from a file, or use
3075the related iSCSI RPC methods to add them at runtime.
3076
3077### iscsi initiator
3078
3079The SPDK iSCSI initiator is no longer considered experimental and becomes
3080a first-class citizen among bdev modules. The basic usage has been briefly
3081described in the bdev user guide: [iSCSI bdev](https://spdk.io/doc/bdev.html#bdev_config_iscsi)
3082
3083### Miscellaneous
3084
3085The SPDK application framework can now parse long name command line parameters.
3086Most single-character parameters have a long name equivalent now. See the
3087[Command Line Parameters](https://spdk.io/doc/app_overview.html) documentation
3088for details or use the `--help` command line parameter to list all available
3089params.
3090
3091bdevperf `-s` param (io size) was renamed to `-o` as `-s` had been already
3092used by existing apps for memory size.
3093
3094bdevio can now accept all SPDK command line parameters. The config now has to
3095be provided with `-c` or `--config` param.
3096
3097The following ioat/perf and nvme/perf parameters were renamed as well:
3098 `-s` (io size) to `-o`
3099 `-d` (mem size) to `-s`
3100
3101The ReactorMask config file parameter has been deprecated.  Users should
3102use the -m or --cpumask command line option to specify the CPU core mask
3103for the application.
3104
3105Default config file pathnames have been removed from iscsi_tgt, nvmf_tgt
3106and vhost.  Config file pathnames may now only be specified using the
3107-c command line option.
3108
3109Users may no longer set DPDK_DIR in their environment to specify the
3110location of the DPDK installation used to build SPDK.  Using DPDK_DIR
3111has not been the documented nor recommended way to specify the DPDK
3112location for several releases, but removing it ensures no unexpected
3113surprises for users who may have DPDK_DIR defined for other reasons.
3114Users should just use the "configure" script to specify the DPDK
3115location before building SPDK.
3116
3117Although we know that many developers still use Python 2 we are officially
3118switching to Python3 with requirement that all new code must be valid also
3119for Python 2 up to the EOL which is year 2020.
3120
3121Invoking interpreter explicitly is forbidden for executable scripts. There
3122is no need to use syntax like "python ./scripts/rpc.py". All executable
3123scripts must contain proper shebang pointing to the right interpreter.
3124Scripts without shebang mustn't be executable.
3125
3126A Python script has been added to enable conversion of old INI config file
3127to new JSON-RPC config file format. This script can be found at
3128scripts/config_converter.py. Example how this script can be used:
3129~~~{.sh}
3130cat old_format.ini | scripts/config_converter.py > new_json_format.json
3131~~~
3132
3133### Sock
3134
3135Two additional parameters were added to spdk_sock_get_addr() for the server
3136port and client port. These parameters are named "sport" and "cport"
3137respectively.
3138
3139### Virtio
3140
3141The following RPC commands have been deprecated:
3142
3143- construct_virtio_user_scsi_bdev
3144- construct_virtio_pci_scsi_bdev
3145- construct_virtio_user_blk_bdev
3146- construct_virtio_pci_blk_bdev
3147- remove_virtio_scsi_bdev
3148
3149The `construct_virtio_*` ones were replaced with a single `construct_virtio_dev`
3150command that can create any type of Virtio bdev(s). `remove_virtio_scsi_bdev`
3151was replaced with `remove_virtio_bdev` that can delete both Virtio Block and SCSI
3152devices.
3153
3154### Blobfs
3155
3156spdk_file_get_id() returning unique ID for the file was added.
3157
3158### JSON
3159
3160Added jsonrpc-client C library intended for issuing RPC commands from applications.
3161
3162Added API enabling iteration over JSON object:
3163
3164- spdk_json_find()
3165- spdk_json_find_string()
3166- spdk_json_find_array()
3167- spdk_json_object_first()
3168- spdk_json_array_first()
3169- spdk_json_next()
3170
3171### Blobstore
3172
3173Blobstore I/O operations are now based on io_units, instead of blobstore page size.
3174The io_unit size is now the same as the underlying block device's block size.
3175Logical volumes built on a block device with 512B block size can now be used as boot devices
3176in QEMU.
3177
3178### SPDKCLI
3179
3180The SPDKCLI interactive command tool for managing SPDK is no longer considered experimental.
3181Support for the iSCSI and NVMe-oF targets has been added.
3182
3183## v18.07: Raid, Infrastructure Improvements, Bug Fixes
3184
3185### bdev
3186
3187A new public header file bdev_module.h has been introduced to facilitate the
3188development of new bdev modules. This header includes an interface for the
3189spdk_bdev_part and spdk_bdev_part_base objects to enable the creation of
3190multiple virtual bdevs on top of a single base bdev and should act as the
3191primary API for module authors.
3192
3193spdk_bdev_get_opts() and spdk_bdev_set_opts() were added to set bdev-wide
3194options.
3195
3196A mechanism for handling out of memory condition errors (ENOMEM) returned from
3197I/O submission requests at the bdev layer has been added. See
3198spdk_bdev_queue_io_wait().
3199
3200The spdk_bdev_get_io_stat() function now returns cumulative totals instead of
3201resetting on each call. This allows multiple callers to query I/O statistics
3202without conflicting with each other. Existing users will need to adjust their
3203code to record the previous I/O statistics to calculate the delta between calls.
3204
3205I/O queue depth tracking and samples options have been added. See
3206spdk_bdev_get_qd(), spdk_bdev_get_qd_sampling_period(), and
3207spdk_bdev_set_qd_sampling_period().
3208
3209### RAID module
3210
3211A new bdev module called "raid" has been added as experimental module which
3212aggregates underlying NVMe bdevs and exposes a single raid bdev. Please note
3213that vhost will not work with this module because it does not yet have support
3214for multi-element io vectors.
3215
3216### Log
3217
3218The debug log component flag available on several SPDK applications has been
3219renamed from `-t` to `-L` to prevent confusion with tracepoints and to allow the
3220option to be added to tools that already use `-t` to mean something else.
3221
3222### Blobstore
3223
3224A new function, spdk_bs_dump(), has been added that dumps all of the contents of
3225a blobstore to a file pointer. This includes the metadata and is very useful for
3226debugging.
3227
3228Two new operations have been added for thin-provisioned blobs.
3229spdk_bs_inflate_blob() will allocate clusters for all thinly provisioned regions
3230of the blob and populate them with the correct data by reading from the backing
3231blob(s). spdk_bs_blob_decouple_parent() works similarly, but will only allocate
3232clusters that correspond to data in the blob's immediate parent. Clusters
3233allocated to grandparents or that aren't allocated at all will remain
3234thin-provisioned.
3235
3236### BlobFS
3237
3238Changed the return type of spdk_file_truncate() from void to int to allow the
3239propagation of `ENOMEM` errors.
3240
3241### NVMe Driver
3242
3243The new API functions spdk_nvme_qpair_add_cmd_error_injection() and
3244spdk_nvme_qpair_remove_cmd_error_injection() have been added for NVMe error
3245emulation. Users can set a specified command to fail with a particular error
3246status.
3247
3248Changed the name `timeout_sec` parameter to `timeout_us` in
3249spdk_nvme_ctrlr_register_timeout_callback(), and also changed the type from
3250uint32_t to uint64_t. This will give users more fine-grained control over the
3251timeout period.
3252
3253Basic support for Open Channel SSDs was added. See nvme_ocssd.h
3254
3255### NVMe Over Fabrics
3256
3257The spdk_nvmf_tgt_destroy() function is now asynchronous and takes a callback
3258as a parameter.
3259
3260spdk_nvmf_qpair_disconnect() was added to allow the user to disconnect qpairs.
3261
3262spdk_nvmf_subsystem_get_max_namespaces() was added to query the maximum allowed
3263number of namespaces for a given subsystem.
3264
3265### Build System
3266
3267The build system now generates a combined shared library (libspdk.so) that may
3268be used in place of the individual static libraries (libspdk_*.a). The combined
3269library includes all components of SPDK and is intended to make linking against
3270SPDK easier. The static libraries are also still provided for users that prefer
3271to link only the minimal set of components required.
3272
3273### git pre-commit and pre-push hooks
3274
3275The pre-commit hook will run `scripts/check_format.sh` and verify there are no
3276formating errors before allowing `git commit` to run. The pre-push hook runs
3277`make CONFIG_WERROR=y` with and without `CONFIG_DEBUG=y` using both the gcc and
3278clang compiler before allowing `git push` to run. Following each DEBUG build
3279`test/unit/unittest.sh` is run and verified. Results are recorded in the
3280`make.log` file.
3281
3282To enable type: 'git config core.hooksPath .githooks'. To override after
3283configuration use the `git --no-verify` flag.
3284
3285### RPC
3286
3287The `start_nbd_disk` RPC method now returns the path to the kernel NBD device node
3288rather than always returning `true`.
3289
3290### DPDK 18.05
3291
3292The DPDK submodule has been rebased on the DPDK 18.05 release.  DPDK 18.05 supports
3293dynamic memory allocation, but due to some issues found after the DPDK 18.05 release,
3294that support is not enabled for SPDK 18.07.  Therefore, SPDK 18.07 will continue to use
3295the legacy memory allocation model.  The plan is to enable dynamic memory allocation
3296after the DPDK 18.08 release which should fix these issues.
3297
3298### Environment Abstraction Layer and Event Framework
3299
3300The spdk_mem_map_translate() function now takes a size parameter to indicate the size of
3301the memory region.  This can be used by environment implementations to validate the
3302requested translation.
3303
3304The I/O Channel implementation has been moved to its own library - lib/thread. The
3305public API that was previously in spdk/io_channel.h is now in spdk/thread.h The
3306file spdk/io_channel.h remains and includes spdk/thread.h.
3307
3308spdk_reactor_get_tsc_stats was added to return interesting statistics for each
3309reactor.
3310
3311### IOAT
3312
3313IOAT for copy engine is disabled by default. It can be enabled by specifying the Enable
3314option with "Yes" in `[Ioat]` section of the configuration file. The Disable option is
3315now deprecated and will be removed in a future release.
3316
3317## v18.04: Logical Volume Snapshot/Clone, iSCSI Initiator, Bdev QoS, VPP Userspace TCP/IP
3318
3319### vhost
3320
3321The SPDK vhost-scsi, vhost-blk and vhost-nvme applications have fixes to address the
3322DPDK rte_vhost vulnerability [CVE-2018-1059](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-1059).
3323Please see this [security advisory](https://access.redhat.com/security/cve/cve-2018-1059)
3324for additional information on the DPDK vulnerability.
3325
3326Workarounds have been added to ensure vhost compatibility with QEMU 2.12.
3327
3328EXPERIMENTAL: Support for vhost-nvme has been added to the SPDK vhost target. See the
3329[vhost documentation](http://www.spdk.io/doc/vhost.html) for more details.
3330
3331### Unified Target Application
3332
3333A new unified SPDK target application, `spdk_tgt`, has been added. This application combines the
3334functionality of several existing SPDK applications, including the iSCSI target, NVMe-oF target,
3335and vhost target. The new application can be managed through the existing configuration file and
3336[JSON-RPC](http://www.spdk.io/doc/jsonrpc.html) methods.
3337
3338### Env
3339
3340spdk_mempool_get_bulk() has been added to wrap DPDK rte_mempool_get_bulk().
3341
3342New memory management functions spdk_malloc(), spdk_zmalloc(), and spdk_free() have been added.
3343These new functions have a `flags` parameter that allows the user to specify whether the allocated
3344memory needs to be suitable for DMA and whether it should be shared across processes with the same
3345shm_id. The new functions are intended to replace spdk_dma_malloc() and related functions, which will
3346eventually be deprecated and removed.
3347
3348### Bdev
3349
3350A new optional bdev module interface function, `init_complete`, has been added to notify bdev modules
3351when the bdev subsystem initialization is complete. This may be useful for virtual bdevs that require
3352notification that the set of initialization examine() calls is complete.
3353
3354The bdev layer now allows modules to provide an optional per-bdev UUID, which can be retrieved with
3355the spdk_bdev_get_uuid() function.
3356
3357Enforcement of IOPS limits for quality of service (QoS) has been added to the bdev layer. See the
3358[set_bdev_qos_limit_iops](http://www.spdk.io/doc/jsonrpc.html#rpc_set_bdev_qos_limit_iops) documentation
3359for more details.
3360
3361### RPC
3362
3363The `[Rpc]` configuration file section, which was deprecated in v18.01, has been removed.
3364Users should switch to the `-r` command-line parameter instead.
3365
3366The JSON-RPC server implementation now allows up to 32 megabyte responses, growing as
3367needed; previously, the response was limited to 32 kilobytes.
3368
3369### SPDKCLI
3370
3371EXPERIMENTAL: New SPDKCLI interactive command tool for managing SPDK is available.
3372See the [SPDKCLI](http://www.spdk.io/doc/spdkcli.html) documentation for more details.
3373
3374### NVMe Driver
3375
3376EXPERIMENTAL: Support for WDS and RDS capable CMBs in NVMe controllers has been added. This support is
3377experimental pending a functional allocator to free and reallocate CMB buffers.
3378
3379spdk_nvme_ns_get_uuid() has been added to allow retrieval of per-namespace UUIDs when available.
3380
3381New API functions spdk_nvme_ctrlr_get_first_active_ns() and spdk_nvme_ctrlr_get_next_active_ns()
3382have been added to iterate active namespaces, as well as spdk_nvme_ctrlr_is_active_ns() to check if
3383a namespace ID is active.
3384
3385### NVMe-oF Target
3386
3387Namespaces may now be assigned unique identifiers via new optional `eui64` and `nguid` parameters
3388to the `nvmf_subsystem_add_ns` RPC method. Additionally, the NVMe-oF target automatically exposes
3389the backing bdev's UUID as the namespace UUID when available.
3390
3391spdk_nvmf_subsystem_remove_ns() is now asynchronous and requires a callback to indicate completion.
3392
3393### Blobstore
3394
3395A number of functions have been renamed:
3396
3397- spdk_bs_io_write_blob() => spdk_blob_io_write()
3398- spdk_bs_io_read_blob() => spdk_blob_io_read()
3399- spdk_bs_io_writev_blob() => spdk_blob_io_writev()
3400- spdk_bs_io_readv_blob() => spdk_blob_io_readv()
3401- spdk_bs_io_unmap_blob() => spdk_blob_io_unmap()
3402- spdk_bs_io_write_zeroes_blob() => spdk_blob_io_write_zeroes()
3403
3404The old names still exist but are deprecated.  They will be removed in the v18.07 release.
3405
3406spdk_blob_resize() is now an asynchronous operation to enable resizing a blob while I/O
3407are in progress to that blob on other threads.  An explicit spdk_blob_sync_md() is still
3408required to sync the updated metadata to disk.
3409
3410### Logical Volumes
3411
3412A new `destroy_lvol_bdev` RPC method to delete logical volumes has been added.
3413
3414Lvols now have their own UUIDs which replace previous LvolStoreUUID_BlobID combination.
3415
3416New Snapshot and Clone functionalities have been added. User may create Snapshots of existing Lvols
3417and Clones of existing Snapshots.
3418See the [lvol snapshots](http://www.spdk.io/doc/logical_volumes.html#lvol_snapshots) documentation
3419for more details.
3420
3421Resizing logical volumes is now supported via the `resize_lvol_bdev` RPC method.
3422
3423### Lib
3424
3425A set of changes were made in the SPDK's lib code altering
3426instances of calls to `exit()` and `abort()` to return a failure instead
3427wherever reasonably possible.
3428
3429spdk_app_start() no longer exit()'s on an internal failure, but
3430instead returns a non-zero error status.
3431
3432spdk_app_parse_args() no longer exit()'s on help, '-h', or an invalid
3433option, but instead returns SPDK_APP_PARSE_ARGS_HELP and
3434SPDK_APP_PARSE_ARGS_FAIL, respectively, and SPDK_APP_PARSE_ARGS_SUCCESS
3435on success.
3436
3437spdk_pci_get_device() has been deprecated and will be removed in SPDK v18.07.
3438
3439### I/O Channels
3440
3441The prototype for spdk_poller_fn() has been modified; it now returns a value indicating
3442whether or not the poller did any work.  Existing pollers will need to be updated to
3443return a value.
3444
3445### iSCSI Target
3446
3447The SPDK iSCSI target now supports the fd.io Vector Packet Processing (VPP) framework userspace
3448TCP/IP stack. See the [iSCSI VPP documentation](http://www.spdk.io/doc/iscsi.html#vpp) for more
3449details.
3450
3451### iSCSI initiator
3452
3453An iSCSI initiator bdev module has been added to SPDK.  This module should be considered
3454experimental pending additional features and tests.  More details can be found in
3455lib/bdev/iscsi/README.
3456
3457### PMDK
3458
3459The persistent memory (PMDK) bdev module is now enabled using `--with-pmdk` instead of
3460`--with-nvml`.  This reflects the renaming of the persistent memory library from NVML to
3461PMDK.
3462
3463### Virtio Block driver
3464
3465A userspace driver for Virtio Block devices has been added. It was built on top of the
3466[Virtio](http://www.spdk.io/doc/virtio.html) library and can be managed similarly to
3467the Virtio SCSI driver. See the
3468[Virtio Block](http://www.spdk.io/doc/bdev.html#bdev_config_virtio_blk) reference for
3469more information.
3470
3471### Virtio with 2MB hugepages
3472
3473The previous 1GB hugepage limitation has now been lifted. A new `-g` command-line option
3474enables SPDK Virtio to work with 2MB hugepages.
3475See [2MB hugepages](http://www.spdk.io/doc/virtio.html#virtio_2mb) for details.
3476
3477## v18.01: Blobstore Thin Provisioning
3478
3479### Build System
3480
3481The build system now includes a `make install` rule, including support for the common
3482`DESTDIR` and `prefix` variables as used in other build systems.  Additionally, the prefix
3483may be set via the configure `--prefix` option.  Example: `make install prefix=/usr`.
3484
3485### RPC
3486
3487A JSON RPC listener is now enabled by default using a UNIX domain socket at /var/tmp/spdk.sock.
3488A -r option command line option has been added to enable an alternative UNIX domain socket location,
3489or a TCP port in the format ip_addr:tcp_port (i.e. 127.0.0.1:5260).  The Rpc configuration file
3490section is now deprecated and will be removed in the v18.04 release.
3491
3492### I/O Channels
3493
3494spdk_poller_register() and spdk_poller_unregister() were moved from the event
3495framework (include/spdk/event.h) to the I/O channel library
3496(include/spdk/io_channel.h). This allows code that doesn't depend on the event
3497framework to request registration and unregistration of pollers.
3498
3499spdk_for_each_channel() now allows asynchronous operations during iteration.
3500Instead of immediately continuing the interaction upon returning from the iteration
3501callback, the user must call spdk_for_each_channel_continue() to resume iteration.
3502
3503### Block Device Abstraction Layer (bdev)
3504
3505The poller abstraction was removed from the bdev layer. There is now a general purpose
3506abstraction for pollers available in include/spdk/io_channel.h
3507
3508### Lib
3509
3510A set of changes were made in the SPDK's lib code altering,
3511instances of calls to `exit()` and `abort()` to return a failure instead
3512wherever reasonably possible.  This has resulted in return type changes of
3513the API for:
3514
3515- spdk_env_init() from type `void` to `int`.
3516- spdk_mem_map_init() from type `void` to `int`.
3517
3518Applications making use of these APIs should be modified to check for
3519a non-zero return value instead of relying on them to fail without return.
3520
3521### NVMe Driver
3522
3523SPDK now supports hotplug for vfio-attached devices. But there is one thing keep in mind:
3524Only physical removal events are supported; removing devices via the sysfs `remove` file will not work.
3525
3526### NVMe-oF Target
3527
3528Subsystems are no longer tied explicitly to CPU cores. Instead, connections are handed out to the available
3529cores round-robin. The "Core" option in the configuration file has been removed.
3530
3531### Blobstore
3532
3533A number of functions have been renamed:
3534
3535- spdk_bs_md_resize_blob() => spdk_blob_resize()
3536- spdk_bs_md_sync_blob() => spdk_blob_sync_md()
3537- spdk_bs_md_close_blob() => spdk_blob_close()
3538- spdk_bs_md_get_xattr_names() => spdk_blob_get_xattr_names()
3539- spdk_bs_md_get_xattr_value() => spdk_blob_get_xattr_value()
3540- spdk_blob_md_set_xattr() => spdk_blob_set_xattr()
3541- spdk_blob_md_remove_xattr() => spdk_blob_remove_xattr()
3542- spdk_bs_md_create_blob() => spdk_bs_create_blob()
3543- spdk_bs_md_open_blob() => spdk_bs_open_blob()
3544- spdk_bs_md_delete_blob() => spdk_bs_delete_blob()
3545- spdk_bs_md_iter_first() => spdk_bs_iter_first()
3546- spdk_bs_md_iter_next() => spdk_bs_iter_next()
3547
3548The function signature of spdk_blob_close() has changed.  It now takes a struct spdk_blob * argument
3549rather than struct spdk_blob **.
3550
3551The function signature of spdk_bs_iter_next() has changed.  It now takes a struct spdk_blob * argument
3552rather than struct spdk_blob **.
3553
3554Thin provisioning support has been added to the blobstore.  It can be enabled by setting the
3555`thin_provision` flag in struct spdk_blob_opts when calling spdk_bs_create_blob_ext().
3556
3557### NBD device
3558
3559The NBD application (test/lib/bdev/nbd) has been removed; Same functionality can now be
3560achieved by using the test/app/bdev_svc application and start_nbd_disk RPC method.
3561See the [GPT](http://www.spdk.io/doc/bdev.html#bdev_config_gpt) documentation for more details.
3562
3563### FIO plugin
3564
3565SPDK `fio_plugin` now supports FIO 3.3. The support for previous FIO 2.21 has been dropped,
3566although it still remains to work for now. The new FIO contains huge amount of bugfixes and
3567it's recommended to do an update.
3568
3569### Virtio library
3570
3571Previously a part of the bdev_virtio module, now a separate library. Virtio is now available
3572via `spdk_internal/virtio.h` file. This is an internal interface to be used when implementing
3573new Virtio backends, namely Virtio-BLK.
3574
3575### iSCSI
3576
3577The MinConnectionIdleInterval parameter has been removed, and connections are no longer migrated
3578to an epoll/kqueue descriptor on the master core when idle.
3579
3580## v17.10: Logical Volumes
3581
3582### New dependencies
3583
3584libuuid was added as new dependency for logical volumes.
3585
3586libnuma is now required unconditionally now that the DPDK submodule has been updated to DPDK 17.08.
3587
3588### Block Device Abstraction Layer (bdev)
3589
3590An [fio](http://github.com/axboe/fio) plugin was added that can route
3591I/O to the bdev layer. See the [plugin documentation](https://github.com/spdk/spdk/tree/master/examples/bdev/fio_plugin/)
3592for more information.
3593
3594spdk_bdev_unmap() was modified to take an offset and a length in bytes as
3595arguments instead of requiring the user to provide an array of SCSI
3596unmap descriptors. This limits unmaps to a single contiguous range.
3597
3598spdk_bdev_write_zeroes() was introduced.  It ensures that all specified blocks will be zeroed out.
3599If a block device doesn't natively support a write zeroes command, the bdev layer emulates it using
3600write commands.
3601
3602New API functions that accept I/O parameters in units of blocks instead of bytes
3603have been added:
3604
3605- spdk_bdev_read_blocks(), spdk_bdev_readv_blocks()
3606- spdk_bdev_write_blocks(), spdk_bdev_writev_blocks()
3607- spdk_bdev_write_zeroes_blocks()
3608- spdk_bdev_unmap_blocks()
3609
3610The bdev layer now handles temporary out-of-memory I/O failures internally by queueing the I/O to be
3611retried later.
3612
3613### Linux AIO bdev
3614
3615The AIO bdev now allows the user to override the auto-detected block size.
3616
3617### NVMe driver
3618
3619The NVMe driver now recognizes the NVMe 1.3 Namespace Optimal I/O Boundary field.
3620NVMe 1.3 devices may report an optimal I/O boundary, which the driver will take
3621into account when splitting I/O requests.
3622
3623The HotplugEnable option in `[Nvme]` sections of the configuration file is now
3624"No" by default. It was previously "Yes".
3625
3626The NVMe library now includes a spdk_nvme_ns_get_ctrlr() function which returns the
3627NVMe Controller associated with a given namespace.
3628
3629The NVMe library now allows the user to specify a host identifier when attaching
3630to a controller.  The host identifier is used as part of the Reservations feature,
3631as well as in the NVMe-oF Connect command.  The default host ID is also now a
3632randomly-generated UUID, and the default host NQN uses the host ID to generate
3633a UUID-based NQN.
3634
3635spdk_nvme_connect() was added to allow the user to connect directly to a single
3636NVMe or NVMe-oF controller.
3637
3638### NVMe-oF Target (nvmf_tgt)
3639
3640The NVMe-oF target no longer requires any in-capsule data buffers to run, and
3641the feature is now entirely optional. Previously, at least 4 KiB in-capsule
3642data buffers were required.
3643
3644NVMe-oF subsystems have a new configuration option, AllowAnyHost, to control
3645whether the host NQN whitelist is enforced when accepting new connections.
3646If no Host options have been specified and AllowAnyHost is disabled, the
3647connection will be denied; this is a behavior change from previous releases,
3648which allowed any host NQN to connect if the Host list was empty.
3649AllowAnyHost is disabled by default.
3650
3651NVMe-oF namespaces may now be assigned arbitrary namespace IDs, and the number
3652of namespaces per subsystem is no longer limited.
3653
3654The NVMe-oF target now supports the Write Zeroes command.
3655
3656### Environment Abstraction Layer
3657
3658A new default value, SPDK_MEMPOOL_DEFAULT_CACHE_SIZE, was added to provide
3659additional clarity when constructing spdk_mempools. Previously, -1 could be
3660passed and the library would choose a reasonable default, but this new value
3661makes it explicit that the default is being used.
3662
3663### Blobstore
3664
3665The blobstore super block now contains a bstype field to identify the type of the blobstore.
3666Existing code should be updated to fill out bstype when calling spdk_bs_init() and spdk_bs_load().
3667
3668spdk_bs_destroy() was added to allow destroying blobstore on device
3669with an initialized blobstore.
3670
3671spdk_bs_io_readv_blob() and spdk_bs_io_writev_blob() were added to enable
3672scattered payloads.
3673
3674A CLI tool for blobstore has been added, allowing basic operations through either command
3675line or shell interface.  See the [blobcli](https://github.com/spdk/spdk/tree/master/examples/blob/cli)
3676documentation for more details.
3677
3678### Event Framework
3679
3680The ability to set a thread name, previously only used by the reactor code, is
3681now part of the spdk_thread_allocate() API.  Users may specify a thread name
3682which will show up in tools like `gdb`.
3683
3684### Log
3685
3686The spdk_trace_dump() function now takes a new parameter to allow the caller to
3687specify an output file handle (stdout or stderr, for example).
3688
3689### Logical Volumes
3690
3691Logical volumes library built on top of SPDK blobstore has been added.
3692It is possible to create logical volumes on top of other devices using RPC.
3693
3694See the [logical volumes](http://www.spdk.io/doc/logical_volumes.html) documentation for more information.
3695
3696### Persistent Memory
3697
3698A new persistent memory bdev type has been added.
3699The persistent memory block device is built on top of [libpmemblk](http://pmem.io/nvml/libpmemblk/).
3700It is possible to create pmem devices on top of pmem pool files using RPC.
3701
3702See the [Pmem Block Device](http://www.spdk.io/doc/bdev.html#bdev_config_pmem) documentation for more information.
3703
3704### Virtio SCSI driver
3705
3706A userspace driver for Virtio SCSI devices has been added.
3707The driver is capable of creating block devices on top of LUNs exposed by another SPDK vhost-scsi application.
3708
3709See the [Virtio SCSI](http://www.spdk.io/doc/virtio.html) documentation and
3710[Getting Started](http://www.spdk.io/doc/bdev.html#bdev_config_virtio_scsi) guide for more information.
3711
3712### Vhost target
3713
3714The vhost target application now supports live migration between QEMU instances.
3715
3716## v17.07: Build system improvements, userspace vhost-blk target, and GPT bdev
3717
3718### Build System
3719
3720A `configure` script has been added to simplify the build configuration process.
3721The existing CONFIG file and `make CONFIG_...` options are also still supported.
3722Run `./configure --help` for information about available configuration options.
3723
3724A DPDK submodule has been added to make building SPDK easier.  If no `--with-dpdk`
3725option is specified to configure, the SPDK build system will automatically build a
3726known-good configuration of DPDK with the minimal options enabled.  See the Building
3727section of README.md for more information.
3728
3729A [Vagrant](https://www.vagrantup.com/) setup has been added to make it easier to
3730develop and use SPDK on systems without suitable NVMe hardware.  See the Vagrant
3731section of README.md for more information.
3732
3733### Userspace vhost-blk target
3734
3735The vhost library and example app have been updated to support the vhost-blk
3736protocol in addition to the existing vhost-scsi protocol.
3737See the [vhost documentation](http://www.spdk.io/doc/vhost.html) for more details.
3738
3739### Block device abstraction layer (bdev)
3740
3741A GPT virtual block device has been added, which automatically exposes GPT partitions
3742with a special SPDK-specific partition type as bdevs.
3743See the [GPT bdev documentation](http://www.spdk.io/doc/bdev.md#bdev_config_gpt) for
3744more information.
3745
3746### NVMe driver
3747
3748The NVMe driver has been updated to support recent Intel SSDs, including the Intel®
3749Optane™ SSD DC P4800X series.
3750
3751A workaround has been added for devices that failed to recognize register writes
3752during controller reset.
3753
3754The NVMe driver now allocates request tracking objects on a per-queue basis.  The
3755number of requests allowed on an I/O queue may be set during `spdk_nvme_probe()` by
3756modifying `io_queue_requests` in the opts structure.
3757
3758The SPDK NVMe `fio_plugin` has been updated to support multiple threads (`numjobs`).
3759
3760spdk_nvme_ctrlr_alloc_io_qpair() has been modified to allow the user to override
3761controller-level options for each individual I/O queue pair.
3762Existing callers with qprio == 0 can be updated to:
3763~~~
3764... = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, NULL, 0);
3765~~~
3766Callers that need to specify a non-default qprio should be updated to:
3767~~~
3768struct spdk_nvme_io_qpair_opts opts;
3769spdk_nvme_ctrlr_get_default_io_qpair_opts(ctrlr, &opts, sizeof(opts));
3770opts.qprio = SPDK_NVME_QPRIO_...;
3771... = spdk_nvme_ctrlr_alloc_io_qpair(ctrlr, &opts, sizeof(opts));
3772~~~
3773
3774### Environment Abstraction Layer
3775
3776The environment abstraction layer has been updated to include several new functions
3777in order to wrap additional DPDK functionality. See `include/spdk/env.h` for the
3778current set of functions.
3779
3780### SPDK Performance Analysis with Intel® VTune™ Amplifier
3781
3782Support for SPDK performance analysis has been added to Intel® VTune™ Amplifier 2018.
3783
3784This analysis provides:
3785
3786- I/O performance monitoring (calculating standard I/O metrics like IOPS, throughput, etc.)
3787- Tuning insights on the interplay of I/O and compute devices by estimating how many cores
3788  would be reasonable to provide for SPDK to keep up with a current storage workload.
3789
3790See the VTune Amplifier documentation for more information.
3791
3792## v17.03: Blobstore and userspace vhost-scsi target
3793
3794### Blobstore and BlobFS
3795
3796The blobstore is a persistent, power-fail safe block allocator designed to be
3797used as the local storage system backing a higher-level storage service.
3798See the [blobstore documentation](http://www.spdk.io/doc/blob.html) for more details.
3799
3800BlobFS adds basic filesystem functionality like filenames on top of the blobstore.
3801This release also includes a RocksDB Env implementation using BlobFS in place of the
3802kernel filesystem.
3803See the [BlobFS documentation](http://www.spdk.io/doc/blobfs.html) for more details.
3804
3805### Userspace vhost-scsi target
3806
3807A userspace implementation of the QEMU vhost-scsi protocol has been added.
3808The vhost target is capable of exporting SPDK bdevs to QEMU-based VMs as virtio devices.
3809See the [vhost documentation](http://www.spdk.io/doc/vhost.html) for more details.
3810
3811### Event framework
3812
3813The overhead of the main reactor event loop was reduced by optimizing the number of
3814calls to spdk_get_ticks() per iteration.
3815
3816### NVMe library
3817
3818The NVMe library will now automatically split readv/writev requests with scatter-gather
3819lists that do not map to valid PRP lists when the NVMe controller does not natively
3820support SGLs.
3821
3822The `identify` and `perf` NVMe examples were modified to add a consistent format for
3823specifying remote NVMe over Fabrics devices via the `-r` option.
3824This is implemented using the new `spdk_nvme_transport_id_parse()` function.
3825
3826### iSCSI Target
3827
3828The [Nvme] section of the configuration file was modified to remove the `BDF` directive
3829and replace it with a `TransportID` directive. Both local (PCIe) and remote (NVMe-oF)
3830devices can now be specified as the backing block device. A script to generate an
3831entire [Nvme] section based on the local NVMe devices attached was added at
3832`scripts/gen_nvme.sh`.
3833
3834### NVMe-oF Target
3835
3836The [Nvme] section of the configuration file was modified to remove the `BDF` directive
3837and replace it with a `TransportID` directive. Both local (PCIe) and remote (NVMe-oF)
3838devices can now be specified as the backing block device. A script to generate an
3839entire [Nvme] section based on the local NVMe devices attached was added at
3840`scripts/gen_nvme.sh`.
3841
3842## v16.12: NVMe over Fabrics host, hotplug, and multi-process
3843
3844### NVMe library
3845
3846The NVMe library has been changed to create its own request memory pool rather than
3847requiring the user to initialize the global `request_mempool` variable.  Apps can be
3848updated by simply removing the initialization of `request_mempool`.  Since the NVMe
3849library user no longer needs to know the size of the internal NVMe request
3850structure to create the pool, the `spdk_nvme_request_size()` function was also removed.
3851
3852The `spdk_nvme_ns_cmd_deallocate()` function was renamed and extended to become
3853`spdk_nvme_ns_cmd_dataset_management()`, which allows access to all of the NVMe
3854Dataset Management command's parameters.  Existing callers can be updated to use
3855`spdk_nvme_ns_cmd_dataset_management()` with `SPDK_NVME_DSM_ATTR_DEALLOCATE` as the
3856`type` parameter.
3857
3858The NVMe library SGL callback prototype has been changed to return virtual addresses
3859rather than physical addresses.  Callers of `spdk_nvme_ns_cmd_readv()` and
3860`spdk_nvme_ns_cmd_writev()` must update their `next_sge_fn` callbacks to match.
3861
3862The NVMe library now supports NVMe over Fabrics devices in addition to the existing
3863support for local PCIe-attached NVMe devices.  For an example of how to enable
3864NVMe over Fabrics support in an application, see `examples/nvme/identify` and
3865`examples/nvme/perf`.
3866
3867Hot insert/remove support for NVMe devices has been added.  To enable NVMe hotplug
3868support, an application should call the `spdk_nvme_probe()` function on a regular
3869basis to probe for new devices (reported via the existing `probe_cb` callback) and
3870removed devices (reported via a new `remove_cb` callback).  Hotplug is currently
3871only supported on Linux with the `uio_pci_generic` driver, and newly-added NVMe
3872devices must be bound to `uio_pci_generic` by an external script or tool.
3873
3874Multiple processes may now coordinate and use a single NVMe device simultaneously
3875using [DPDK Multi-process Support](http://dpdk.org/doc/guides/prog_guide/multi_proc_support.html).
3876
3877### NVMe over Fabrics target (`nvmf_tgt`)
3878
3879The `nvmf_tgt` configuration file format has been updated significantly to enable
3880new features.  See the example configuration file `etc/spdk/nvmf.conf.in` for
3881more details on the new and changed options.
3882
3883The NVMe over Fabrics target now supports virtual mode subsystems, which allow the
3884user to export devices from the SPDK block device abstraction layer as NVMe over
3885Fabrics subsystems.  Direct mode (raw NVMe device access) is also still supported,
3886and a single `nvmf_tgt` may export both types of subsystems simultaneously.
3887
3888### Block device abstraction layer (bdev)
3889
3890The bdev layer now supports scatter/gather read and write I/O APIs, and the NVMe
3891blockdev driver has been updated to support scatter/gather.  Apps can use the
3892new scatter/gather support via the `spdk_bdev_readv()` and `spdk_bdev_writev()`
3893functions.
3894
3895The bdev status returned from each I/O has been extended to pass through NVMe
3896or SCSI status codes directly in cases where the underlying device can provide
3897a more specific status code.
3898
3899A Ceph RBD (RADOS Block Device) blockdev driver has been added.  This allows the
3900`iscsi_tgt` and `nvmf_tgt` apps to export Ceph RBD volumes as iSCSI LUNs or
3901NVMe namespaces.
3902
3903### General changes
3904
3905`libpciaccess` has been removed as a dependency and DPDK PCI enumeration is
3906used instead. Prior to DPDK 16.07 enumeration by class code was not supported,
3907so for earlier DPDK versions, only Intel SSD DC P3x00 devices will be discovered
3908by the NVMe library.
3909
3910The `env` environment abstraction library has been introduced, and a default
3911DPDK-based implementation is provided as part of SPDK.  The goal of the `env`
3912layer is to enable use of alternate user-mode memory allocation and PCI access
3913libraries.  See `doc/porting.md` for more details.
3914
3915The build process has been modified to produce all of the library files in the
3916`build/lib` directory.  This is intended to simplify the use of SPDK from external
3917projects, which can now link to SPDK libraries by adding the `build/lib` directory
3918to the library path via `-L` and linking the SPDK libraries by name (for example,
3919`-lspdk_nvme -lspdk_log -lspdk_util`).
3920
3921`nvmf_tgt` and `iscsi_tgt` now have a JSON-RPC interface, which allows the user
3922to query and modify the configuration at runtime.  The RPC service is disabled by
3923default, since it currently does not provide any authentication or security
3924mechanisms; it should only be enabled on systems with controlled user access
3925behind a firewall. An example RPC client implemented in Python is provided in
3926`scripts/rpc.py`.
3927
3928## v16.08: iSCSI target, NVMe over Fabrics maturity
3929
3930This release adds a userspace iSCSI target. The iSCSI target is capable of exporting
3931NVMe devices over a network using the iSCSI protocol. The application is located
3932in app/iscsi_tgt and a documented configuration file can be found at etc/spdk/spdk.conf.in.
3933
3934This release also significantly improves the existing NVMe over Fabrics target.
3935
3936- The configuration file format was changed, which will require updates to
3937  any existing nvmf.conf files (see `etc/spdk/nvmf.conf.in`):
3938  - `SubsystemGroup` was renamed to `Subsystem`.
3939  - `AuthFile` was removed (it was unimplemented).
3940  - `nvmf_tgt` was updated to correctly recognize NQN (NVMe Qualified Names)
3941    when naming subsystems.  The default node name was changed to reflect this;
3942    it is now "nqn.2016-06.io.spdk".
3943  - `Port` and `Host` sections were merged into the `Subsystem` section
3944  - Global options to control max queue depth, number of queues, max I/O
3945    size, and max in-capsule data size were added.
3946  - The Nvme section was removed. Now a list of devices is specified by
3947    bus/device/function directly in the Subsystem section.
3948  - Subsystems now have a Mode, which can be Direct or Virtual. This is an attempt
3949    to future-proof the interface, so the only mode supported by this release
3950    is "Direct".
3951- Many bug fixes and cleanups were applied to the `nvmf_tgt` app and library.
3952- The target now supports discovery.
3953
3954This release also adds one new feature and provides some better examples and tools
3955for the NVMe driver.
3956
3957- The Weighted Round Robin arbitration method is now supported. This allows
3958  the user to specify different priorities on a per-I/O-queue basis.  To
3959  enable WRR, set the `arb_mechanism` field during `spdk_nvme_probe()`.
3960- A simplified "Hello World" example was added to show the proper way to use
3961  the NVMe library API; see `examples/nvme/hello_world/hello_world.c`.
3962- A test for measuring software overhead was added. See `test/lib/nvme/overhead`.
3963
3964## v16.06: NVMf userspace target
3965
3966This release adds a userspace NVMf (NVMe over Fabrics) target, conforming to the
3967newly-released NVMf 1.0/NVMe 1.2.1 specification.  The NVMf target exports NVMe
3968devices from a host machine over the network via RDMA.  Currently, the target is
3969limited to directly exporting physical NVMe devices, and the discovery subsystem
3970is not supported.
3971
3972This release includes a general API cleanup, including renaming all declarations
3973in public headers to include a `spdk` prefix to prevent namespace clashes with
3974user code.
3975
3976- NVMe
3977  - The `nvme_attach()` API was reworked into a new probe/attach model, which
3978  moves device detection into the NVMe library.  The new API also allows
3979  parallel initialization of NVMe controllers, providing a major reduction in
3980  startup time when using multiple controllers.
3981  - I/O queue allocation was changed to be explicit in the API.  Each function
3982  that generates I/O requests now takes a queue pair (`spdk_nvme_qpair *`)
3983  argument, and I/O queues may be allocated using
3984  `spdk_nvme_ctrlr_alloc_io_qpair()`.  This allows more flexible assignment of
3985  queue pairs than the previous model, which only allowed a single queue
3986  per thread and limited the total number of I/O queues to the lowest number
3987  supported on any attached controller.
3988  - Added support for the Write Zeroes command.
3989  - `examples/nvme/perf` can now report I/O command latency from the
3990  the controller's viewpoint using the Intel vendor-specific read/write latency
3991  log page.
3992  - Added namespace reservation command support, which can be used to coordinate
3993  sharing of a namespace between multiple hosts.
3994  - Added hardware SGL support, which enables use of scattered buffers that
3995  don't conform to the PRP list alignment and length requirements on supported
3996  NVMe controllers.
3997  - Added end-to-end data protection support, including the ability to write and
3998  read metadata in extended LBA (metadata appended to each block of data in the
3999  buffer) and separate metadata buffer modes.
4000  See `spdk_nvme_ns_cmd_write_with_md()` and `spdk_nvme_ns_cmd_read_with_md()`
4001  for details.
4002- IOAT
4003  - The DMA block fill feature is now exposed via the `ioat_submit_fill()`
4004  function.  This is functionally similar to `memset()`, except the memory is
4005  filled with an 8-byte repeating pattern instead of a single byte like memset.
4006- PCI
4007  - Added support for using DPDK for PCI device mapping in addition to the
4008  existing libpciaccess option.  Using the DPDK PCI support also allows use of
4009  the Linux VFIO driver model, which means that SPDK userspace drivers will work
4010  with the IOMMU enabled.  Additionally, SPDK applications may be run as an
4011  unprivileged user with access restricted to a specific set of PCIe devices.
4012  - The PCI library API was made more generic to abstract away differences
4013  between the underlying PCI access implementations.
4014
4015## v1.2.0: IOAT user-space driver
4016
4017This release adds a user-space driver with support for the Intel I/O Acceleration Technology
4018(I/OAT, also known as "Crystal Beach") DMA offload engine.
4019
4020- IOAT
4021  - New user-space driver supporting DMA memory copy offload
4022  - Example programs `ioat/perf` and `ioat/verify`
4023  - Kernel-mode DMA engine test driver `kperf` for performance comparison
4024- NVMe
4025  - Per-I/O flags for Force Unit Access (FUA) and Limited Retry
4026  - Public API for retrieving log pages
4027  - Reservation register/acquire/release/report command support
4028  - Scattered payload support - an alternate API to provide I/O buffers via a sequence of callbacks
4029  - Declarations and `nvme/identify` support for Intel SSD DC P3700 series vendor-specific log pages and features
4030- Updated to support DPDK 2.2.0
4031
4032## v1.0.0: NVMe user-space driver
4033
4034This is the initial open source release of the Storage Performance Development Kit (SPDK).
4035
4036Features:
4037
4038- NVMe user-space driver
4039- NVMe example programs
4040  - `examples/nvme/perf` tests performance (IOPS) using the NVMe user-space driver
4041  - `examples/nvme/identify` displays NVMe controller information in a human-readable format
4042- Linux and FreeBSD support
4043