xref: /spdk/lib/nvmf/rdma.c (revision 8afdeef3becfe9409cc9e7372bd0bc10e8b7d46d)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2016 Intel Corporation. All rights reserved.
3  *   Copyright (c) 2019-2021 Mellanox Technologies LTD. All rights reserved.
4  *   Copyright (c) 2021-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
5  */
6 
7 #include "spdk/stdinc.h"
8 
9 #include "spdk/config.h"
10 #include "spdk/thread.h"
11 #include "spdk/likely.h"
12 #include "spdk/nvmf_transport.h"
13 #include "spdk/string.h"
14 #include "spdk/trace.h"
15 #include "spdk/tree.h"
16 #include "spdk/util.h"
17 
18 #include "spdk_internal/assert.h"
19 #include "spdk/log.h"
20 #include "spdk_internal/rdma_provider.h"
21 #include "spdk_internal/rdma_utils.h"
22 
23 #include "nvmf_internal.h"
24 #include "transport.h"
25 
26 #include "spdk_internal/trace_defs.h"
27 
28 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
29 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
30 
31 /*
32  RDMA Connection Resource Defaults
33  */
34 #define NVMF_DEFAULT_MSDBD		16
35 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
36 #define NVMF_DEFAULT_RSP_SGE		1
37 #define NVMF_DEFAULT_RX_SGE		2
38 
39 #define NVMF_RDMA_MAX_EVENTS_PER_POLL	32
40 
41 SPDK_STATIC_ASSERT(NVMF_DEFAULT_MSDBD <= SPDK_NVMF_MAX_SGL_ENTRIES,
42 		   "MSDBD must not exceed SPDK_NVMF_MAX_SGL_ENTRIES");
43 
44 /* The RDMA completion queue size */
45 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
46 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
47 
48 enum spdk_nvmf_rdma_request_state {
49 	/* The request is not currently in use */
50 	RDMA_REQUEST_STATE_FREE = 0,
51 
52 	/* Initial state when request first received */
53 	RDMA_REQUEST_STATE_NEW,
54 
55 	/* The request is queued until a data buffer is available. */
56 	RDMA_REQUEST_STATE_NEED_BUFFER,
57 
58 	/* The request is waiting on RDMA queue depth availability
59 	 * to transfer data from the host to the controller.
60 	 */
61 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
62 
63 	/* The request is currently transferring data from the host to the controller. */
64 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
65 
66 	/* The request is ready to execute at the block device */
67 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
68 
69 	/* The request is currently executing at the block device */
70 	RDMA_REQUEST_STATE_EXECUTING,
71 
72 	/* The request finished executing at the block device */
73 	RDMA_REQUEST_STATE_EXECUTED,
74 
75 	/* The request is waiting on RDMA queue depth availability
76 	 * to transfer data from the controller to the host.
77 	 */
78 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
79 
80 	/* The request is waiting on RDMA queue depth availability
81 	 * to send response to the host.
82 	 */
83 	RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING,
84 
85 	/* The request is ready to send a completion */
86 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
87 
88 	/* The request is currently transferring data from the controller to the host. */
89 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
90 
91 	/* The request currently has an outstanding completion without an
92 	 * associated data transfer.
93 	 */
94 	RDMA_REQUEST_STATE_COMPLETING,
95 
96 	/* The request completed and can be marked free. */
97 	RDMA_REQUEST_STATE_COMPLETED,
98 
99 	/* Terminator */
100 	RDMA_REQUEST_NUM_STATES,
101 };
102 
103 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
104 {
105 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
106 
107 	struct spdk_trace_tpoint_opts opts[] = {
108 		{
109 			"RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
110 			OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 1,
111 			{
112 				{ "qpair", SPDK_TRACE_ARG_TYPE_PTR, 8 },
113 				{ "qd", SPDK_TRACE_ARG_TYPE_INT, 4 }
114 			}
115 		},
116 		{
117 			"RDMA_REQ_COMPLETED", TRACE_RDMA_REQUEST_STATE_COMPLETED,
118 			OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
119 			{
120 				{ "qpair", SPDK_TRACE_ARG_TYPE_PTR, 8 },
121 				{ "qd", SPDK_TRACE_ARG_TYPE_INT, 4 }
122 			}
123 		},
124 	};
125 
126 	spdk_trace_register_description_ext(opts, SPDK_COUNTOF(opts));
127 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
128 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
129 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
130 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
131 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
132 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
133 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
134 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
135 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
136 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
137 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
138 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
139 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
140 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
141 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
142 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
143 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
144 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
145 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
146 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
147 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
148 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
149 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
150 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
151 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
152 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
153 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
154 	spdk_trace_register_description("RDMA_REQ_RDY2COMPL_PEND",
155 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING,
156 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
157 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
158 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
159 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
160 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
161 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
162 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
163 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
164 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
165 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
166 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
167 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
168 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
169 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
170 
171 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
172 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
173 					SPDK_TRACE_ARG_TYPE_INT, "");
174 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
175 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
176 					SPDK_TRACE_ARG_TYPE_INT, "type");
177 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
178 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
179 					SPDK_TRACE_ARG_TYPE_INT, "type");
180 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
181 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
182 					SPDK_TRACE_ARG_TYPE_INT, "");
183 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
184 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
185 					SPDK_TRACE_ARG_TYPE_INT, "");
186 
187 	spdk_trace_tpoint_register_relation(TRACE_BDEV_IO_START, OBJECT_NVMF_RDMA_IO, 1);
188 	spdk_trace_tpoint_register_relation(TRACE_BDEV_IO_DONE, OBJECT_NVMF_RDMA_IO, 0);
189 }
190 
191 enum spdk_nvmf_rdma_wr_type {
192 	RDMA_WR_TYPE_RECV,
193 	RDMA_WR_TYPE_SEND,
194 	RDMA_WR_TYPE_DATA,
195 };
196 
197 struct spdk_nvmf_rdma_wr {
198 	/* Uses enum spdk_nvmf_rdma_wr_type */
199 	uint8_t type;
200 };
201 
202 /* This structure holds commands as they are received off the wire.
203  * It must be dynamically paired with a full request object
204  * (spdk_nvmf_rdma_request) to service a request. It is separate
205  * from the request because RDMA does not appear to order
206  * completions, so occasionally we'll get a new incoming
207  * command when there aren't any free request objects.
208  */
209 struct spdk_nvmf_rdma_recv {
210 	struct ibv_recv_wr			wr;
211 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
212 
213 	struct spdk_nvmf_rdma_qpair		*qpair;
214 
215 	/* In-capsule data buffer */
216 	uint8_t					*buf;
217 
218 	struct spdk_nvmf_rdma_wr		rdma_wr;
219 	uint64_t				receive_tsc;
220 
221 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
222 };
223 
224 struct spdk_nvmf_rdma_request_data {
225 	struct ibv_send_wr		wr;
226 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
227 };
228 
229 struct spdk_nvmf_rdma_request {
230 	struct spdk_nvmf_request		req;
231 
232 	bool					fused_failed;
233 
234 	struct spdk_nvmf_rdma_wr		data_wr;
235 	struct spdk_nvmf_rdma_wr		rsp_wr;
236 
237 	/* Uses enum spdk_nvmf_rdma_request_state */
238 	uint8_t					state;
239 
240 	/* Data offset in req.iov */
241 	uint32_t				offset;
242 
243 	struct spdk_nvmf_rdma_recv		*recv;
244 
245 	struct {
246 		struct	ibv_send_wr		wr;
247 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
248 	} rsp;
249 
250 	uint16_t				iovpos;
251 	uint16_t				num_outstanding_data_wr;
252 	/* Used to split Write IO with multi SGL payload */
253 	uint16_t				num_remaining_data_wr;
254 	uint64_t				receive_tsc;
255 	struct spdk_nvmf_rdma_request		*fused_pair;
256 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
257 	struct ibv_send_wr			*remaining_tranfer_in_wrs;
258 	struct ibv_send_wr			*transfer_wr;
259 	struct spdk_nvmf_rdma_request_data	data;
260 };
261 
262 struct spdk_nvmf_rdma_resource_opts {
263 	struct spdk_nvmf_rdma_qpair	*qpair;
264 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
265 	void				*qp;
266 	struct spdk_rdma_utils_mem_map	*map;
267 	uint32_t			max_queue_depth;
268 	uint32_t			in_capsule_data_size;
269 	bool				shared;
270 };
271 
272 struct spdk_nvmf_rdma_resources {
273 	/* Array of size "max_queue_depth" containing RDMA requests. */
274 	struct spdk_nvmf_rdma_request		*reqs;
275 
276 	/* Array of size "max_queue_depth" containing RDMA recvs. */
277 	struct spdk_nvmf_rdma_recv		*recvs;
278 
279 	/* Array of size "max_queue_depth" containing 64 byte capsules
280 	 * used for receive.
281 	 */
282 	union nvmf_h2c_msg			*cmds;
283 
284 	/* Array of size "max_queue_depth" containing 16 byte completions
285 	 * to be sent back to the user.
286 	 */
287 	union nvmf_c2h_msg			*cpls;
288 
289 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
290 	 * buffers to be used for in capsule data.
291 	 */
292 	void					*bufs;
293 
294 	/* Receives that are waiting for a request object */
295 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
296 
297 	/* Queue to track free requests */
298 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
299 };
300 
301 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
302 
303 typedef void (*spdk_poller_destroy_cb)(void *ctx);
304 
305 struct spdk_nvmf_rdma_ibv_event_ctx {
306 	struct spdk_nvmf_rdma_qpair			*rqpair;
307 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
308 	/* Link to other ibv events associated with this qpair */
309 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
310 };
311 
312 struct spdk_nvmf_rdma_qpair {
313 	struct spdk_nvmf_qpair			qpair;
314 
315 	struct spdk_nvmf_rdma_device		*device;
316 	struct spdk_nvmf_rdma_poller		*poller;
317 
318 	struct spdk_rdma_provider_qp		*rdma_qp;
319 	struct rdma_cm_id			*cm_id;
320 	struct spdk_rdma_provider_srq		*srq;
321 	struct rdma_cm_id			*listen_id;
322 
323 	/* Cache the QP number to improve QP search by RB tree. */
324 	uint32_t				qp_num;
325 
326 	/* The maximum number of I/O outstanding on this connection at one time */
327 	uint16_t				max_queue_depth;
328 
329 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
330 	uint16_t				max_read_depth;
331 
332 	/* The maximum number of RDMA SEND operations at one time */
333 	uint32_t				max_send_depth;
334 
335 	/* The current number of outstanding WRs from this qpair's
336 	 * recv queue. Should not exceed device->attr.max_queue_depth.
337 	 */
338 	uint16_t				current_recv_depth;
339 
340 	/* The current number of active RDMA READ operations */
341 	uint16_t				current_read_depth;
342 
343 	/* The current number of posted WRs from this qpair's
344 	 * send queue. Should not exceed max_send_depth.
345 	 */
346 	uint32_t				current_send_depth;
347 
348 	/* The maximum number of SGEs per WR on the send queue */
349 	uint32_t				max_send_sge;
350 
351 	/* The maximum number of SGEs per WR on the recv queue */
352 	uint32_t				max_recv_sge;
353 
354 	struct spdk_nvmf_rdma_resources		*resources;
355 
356 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
357 
358 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
359 
360 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_send_queue;
361 
362 	/* Number of requests not in the free state */
363 	uint32_t				qd;
364 
365 	bool					ibv_in_error_state;
366 
367 	RB_ENTRY(spdk_nvmf_rdma_qpair)		node;
368 
369 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
370 
371 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
372 
373 	/* Points to the a request that has fuse bits set to
374 	 * SPDK_NVME_CMD_FUSE_FIRST, when the qpair is waiting
375 	 * for the request that has SPDK_NVME_CMD_FUSE_SECOND.
376 	 */
377 	struct spdk_nvmf_rdma_request		*fused_first;
378 
379 	/*
380 	 * io_channel which is used to destroy qpair when it is removed from poll group
381 	 */
382 	struct spdk_io_channel		*destruct_channel;
383 
384 	/* List of ibv async events */
385 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
386 
387 	/* Lets us know that we have received the last_wqe event. */
388 	bool					last_wqe_reached;
389 
390 	/* Indicate that nvmf_rdma_close_qpair is called */
391 	bool					to_close;
392 };
393 
394 struct spdk_nvmf_rdma_poller_stat {
395 	uint64_t				completions;
396 	uint64_t				polls;
397 	uint64_t				idle_polls;
398 	uint64_t				requests;
399 	uint64_t				request_latency;
400 	uint64_t				pending_free_request;
401 	uint64_t				pending_rdma_read;
402 	uint64_t				pending_rdma_write;
403 	uint64_t				pending_rdma_send;
404 	struct spdk_rdma_provider_qp_stats	qp_stats;
405 };
406 
407 struct spdk_nvmf_rdma_poller {
408 	struct spdk_nvmf_rdma_device		*device;
409 	struct spdk_nvmf_rdma_poll_group	*group;
410 
411 	int					num_cqe;
412 	int					required_num_wr;
413 	struct ibv_cq				*cq;
414 
415 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
416 	uint16_t				max_srq_depth;
417 	bool					need_destroy;
418 
419 	/* Shared receive queue */
420 	struct spdk_rdma_provider_srq		*srq;
421 
422 	struct spdk_nvmf_rdma_resources		*resources;
423 	struct spdk_nvmf_rdma_poller_stat	stat;
424 
425 	spdk_poller_destroy_cb			destroy_cb;
426 	void					*destroy_cb_ctx;
427 
428 	RB_HEAD(qpairs_tree, spdk_nvmf_rdma_qpair) qpairs;
429 
430 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
431 
432 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
433 
434 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
435 };
436 
437 struct spdk_nvmf_rdma_poll_group_stat {
438 	uint64_t				pending_data_buffer;
439 };
440 
441 struct spdk_nvmf_rdma_poll_group {
442 	struct spdk_nvmf_transport_poll_group		group;
443 	struct spdk_nvmf_rdma_poll_group_stat		stat;
444 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
445 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
446 };
447 
448 struct spdk_nvmf_rdma_conn_sched {
449 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
450 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
451 };
452 
453 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
454 struct spdk_nvmf_rdma_device {
455 	struct ibv_device_attr			attr;
456 	struct ibv_context			*context;
457 
458 	struct spdk_rdma_utils_mem_map		*map;
459 	struct ibv_pd				*pd;
460 
461 	int					num_srq;
462 	bool					need_destroy;
463 	bool					ready_to_destroy;
464 	bool					is_ready;
465 
466 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
467 };
468 
469 struct spdk_nvmf_rdma_port {
470 	const struct spdk_nvme_transport_id	*trid;
471 	struct rdma_cm_id			*id;
472 	struct spdk_nvmf_rdma_device		*device;
473 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
474 };
475 
476 struct rdma_transport_opts {
477 	int		num_cqe;
478 	uint32_t	max_srq_depth;
479 	bool		no_srq;
480 	bool		no_wr_batching;
481 	int		acceptor_backlog;
482 };
483 
484 struct spdk_nvmf_rdma_transport {
485 	struct spdk_nvmf_transport	transport;
486 	struct rdma_transport_opts	rdma_opts;
487 
488 	struct spdk_nvmf_rdma_conn_sched conn_sched;
489 
490 	struct rdma_event_channel	*event_channel;
491 
492 	struct spdk_mempool		*data_wr_pool;
493 
494 	struct spdk_poller		*accept_poller;
495 
496 	/* fields used to poll RDMA/IB events */
497 	nfds_t			npoll_fds;
498 	struct pollfd		*poll_fds;
499 
500 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
501 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
502 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
503 
504 	/* ports that are removed unexpectedly and need retry listen */
505 	TAILQ_HEAD(, spdk_nvmf_rdma_port)		retry_ports;
506 };
507 
508 struct poller_manage_ctx {
509 	struct spdk_nvmf_rdma_transport		*rtransport;
510 	struct spdk_nvmf_rdma_poll_group	*rgroup;
511 	struct spdk_nvmf_rdma_poller		*rpoller;
512 	struct spdk_nvmf_rdma_device		*device;
513 
514 	struct spdk_thread			*thread;
515 	volatile int				*inflight_op_counter;
516 };
517 
518 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
519 	{
520 		"num_cqe", offsetof(struct rdma_transport_opts, num_cqe),
521 		spdk_json_decode_int32, true
522 	},
523 	{
524 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
525 		spdk_json_decode_uint32, true
526 	},
527 	{
528 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
529 		spdk_json_decode_bool, true
530 	},
531 	{
532 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
533 		spdk_json_decode_bool, true
534 	},
535 	{
536 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
537 		spdk_json_decode_int32, true
538 	},
539 };
540 
541 static int
542 nvmf_rdma_qpair_compare(struct spdk_nvmf_rdma_qpair *rqpair1, struct spdk_nvmf_rdma_qpair *rqpair2)
543 {
544 	return rqpair1->qp_num < rqpair2->qp_num ? -1 : rqpair1->qp_num > rqpair2->qp_num;
545 }
546 
547 RB_GENERATE_STATIC(qpairs_tree, spdk_nvmf_rdma_qpair, node, nvmf_rdma_qpair_compare);
548 
549 static bool nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
550 				      struct spdk_nvmf_rdma_request *rdma_req);
551 
552 static void _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
553 				 struct spdk_nvmf_rdma_poller *rpoller);
554 
555 static void _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
556 				 struct spdk_nvmf_rdma_poller *rpoller);
557 
558 static void _nvmf_rdma_remove_destroyed_device(void *c);
559 
560 static inline enum spdk_nvme_media_error_status_code
561 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
562 	enum spdk_nvme_media_error_status_code result;
563 	switch (err_type)
564 	{
565 	case SPDK_DIF_REFTAG_ERROR:
566 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
567 		break;
568 	case SPDK_DIF_APPTAG_ERROR:
569 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
570 		break;
571 	case SPDK_DIF_GUARD_ERROR:
572 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
573 		break;
574 	default:
575 		SPDK_UNREACHABLE();
576 	}
577 
578 	return result;
579 }
580 
581 /*
582  * Return data_wrs to pool starting from \b data_wr
583  * Request's own response and data WR are excluded
584  */
585 static void
586 _nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
587 			     struct ibv_send_wr *data_wr,
588 			     struct spdk_mempool *pool)
589 {
590 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
591 	struct spdk_nvmf_rdma_request_data	*nvmf_data;
592 	struct ibv_send_wr			*next_send_wr;
593 	uint64_t				req_wrid = (uint64_t)&rdma_req->data_wr;
594 	uint32_t				num_wrs = 0;
595 
596 	while (data_wr && data_wr->wr_id == req_wrid) {
597 		nvmf_data = SPDK_CONTAINEROF(data_wr, struct spdk_nvmf_rdma_request_data, wr);
598 		memset(nvmf_data->sgl, 0, sizeof(data_wr->sg_list[0]) * data_wr->num_sge);
599 		data_wr->num_sge = 0;
600 		next_send_wr = data_wr->next;
601 		if (data_wr != &rdma_req->data.wr) {
602 			data_wr->next = NULL;
603 			assert(num_wrs < SPDK_NVMF_MAX_SGL_ENTRIES);
604 			work_requests[num_wrs] = nvmf_data;
605 			num_wrs++;
606 		}
607 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL : next_send_wr;
608 	}
609 
610 	if (num_wrs) {
611 		spdk_mempool_put_bulk(pool, (void **) work_requests, num_wrs);
612 	}
613 }
614 
615 static void
616 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
617 			    struct spdk_nvmf_rdma_transport *rtransport)
618 {
619 	rdma_req->num_outstanding_data_wr = 0;
620 
621 	_nvmf_rdma_request_free_data(rdma_req, rdma_req->transfer_wr, rtransport->data_wr_pool);
622 
623 	if (rdma_req->remaining_tranfer_in_wrs) {
624 		_nvmf_rdma_request_free_data(rdma_req, rdma_req->remaining_tranfer_in_wrs,
625 					     rtransport->data_wr_pool);
626 		rdma_req->remaining_tranfer_in_wrs = NULL;
627 	}
628 
629 	rdma_req->data.wr.next = NULL;
630 	rdma_req->rsp.wr.next = NULL;
631 }
632 
633 static void
634 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
635 {
636 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
637 	if (req->req.cmd) {
638 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
639 	}
640 	if (req->recv) {
641 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
642 	}
643 }
644 
645 static void
646 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
647 {
648 	int i;
649 
650 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
651 	for (i = 0; i < rqpair->max_queue_depth; i++) {
652 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
653 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
654 		}
655 	}
656 }
657 
658 static void
659 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
660 {
661 	spdk_free(resources->cmds);
662 	spdk_free(resources->cpls);
663 	spdk_free(resources->bufs);
664 	spdk_free(resources->reqs);
665 	spdk_free(resources->recvs);
666 	free(resources);
667 }
668 
669 
670 static struct spdk_nvmf_rdma_resources *
671 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
672 {
673 	struct spdk_nvmf_rdma_resources		*resources;
674 	struct spdk_nvmf_rdma_request		*rdma_req;
675 	struct spdk_nvmf_rdma_recv		*rdma_recv;
676 	struct spdk_rdma_provider_qp		*qp = NULL;
677 	struct spdk_rdma_provider_srq		*srq = NULL;
678 	struct ibv_recv_wr			*bad_wr = NULL;
679 	struct spdk_rdma_utils_memory_translation translation;
680 	uint32_t				i;
681 	int					rc = 0;
682 
683 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
684 	if (!resources) {
685 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
686 		return NULL;
687 	}
688 
689 	resources->reqs = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->reqs),
690 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
691 	resources->recvs = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->recvs),
692 					0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
693 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
694 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
695 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
696 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
697 
698 	if (opts->in_capsule_data_size > 0) {
699 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
700 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
701 					       SPDK_MALLOC_DMA);
702 	}
703 
704 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
705 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
706 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
707 		goto cleanup;
708 	}
709 
710 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx\n",
711 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds));
712 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx\n",
713 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls));
714 	if (resources->bufs) {
715 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x\n",
716 			      resources->bufs, opts->max_queue_depth *
717 			      opts->in_capsule_data_size);
718 	}
719 
720 	/* Initialize queues */
721 	STAILQ_INIT(&resources->incoming_queue);
722 	STAILQ_INIT(&resources->free_queue);
723 
724 	if (opts->shared) {
725 		srq = (struct spdk_rdma_provider_srq *)opts->qp;
726 	} else {
727 		qp = (struct spdk_rdma_provider_qp *)opts->qp;
728 	}
729 
730 	for (i = 0; i < opts->max_queue_depth; i++) {
731 		rdma_recv = &resources->recvs[i];
732 		rdma_recv->qpair = opts->qpair;
733 
734 		/* Set up memory to receive commands */
735 		if (resources->bufs) {
736 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
737 						  opts->in_capsule_data_size));
738 		}
739 
740 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
741 
742 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
743 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
744 		rc = spdk_rdma_utils_get_translation(opts->map, &resources->cmds[i], sizeof(resources->cmds[i]),
745 						     &translation);
746 		if (rc) {
747 			goto cleanup;
748 		}
749 		rdma_recv->sgl[0].lkey = spdk_rdma_utils_memory_translation_get_lkey(&translation);
750 		rdma_recv->wr.num_sge = 1;
751 
752 		if (rdma_recv->buf) {
753 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
754 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
755 			rc = spdk_rdma_utils_get_translation(opts->map, rdma_recv->buf, opts->in_capsule_data_size,
756 							     &translation);
757 			if (rc) {
758 				goto cleanup;
759 			}
760 			rdma_recv->sgl[1].lkey = spdk_rdma_utils_memory_translation_get_lkey(&translation);
761 			rdma_recv->wr.num_sge++;
762 		}
763 
764 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
765 		rdma_recv->wr.sg_list = rdma_recv->sgl;
766 		if (srq) {
767 			spdk_rdma_provider_srq_queue_recv_wrs(srq, &rdma_recv->wr);
768 		} else {
769 			spdk_rdma_provider_qp_queue_recv_wrs(qp, &rdma_recv->wr);
770 		}
771 	}
772 
773 	for (i = 0; i < opts->max_queue_depth; i++) {
774 		rdma_req = &resources->reqs[i];
775 
776 		if (opts->qpair != NULL) {
777 			rdma_req->req.qpair = &opts->qpair->qpair;
778 		} else {
779 			rdma_req->req.qpair = NULL;
780 		}
781 		rdma_req->req.cmd = NULL;
782 		rdma_req->req.iovcnt = 0;
783 		rdma_req->req.stripped_data = NULL;
784 
785 		/* Set up memory to send responses */
786 		rdma_req->req.rsp = &resources->cpls[i];
787 
788 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
789 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
790 		rc = spdk_rdma_utils_get_translation(opts->map, &resources->cpls[i], sizeof(resources->cpls[i]),
791 						     &translation);
792 		if (rc) {
793 			goto cleanup;
794 		}
795 		rdma_req->rsp.sgl[0].lkey = spdk_rdma_utils_memory_translation_get_lkey(&translation);
796 
797 		rdma_req->rsp_wr.type = RDMA_WR_TYPE_SEND;
798 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp_wr;
799 		rdma_req->rsp.wr.next = NULL;
800 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
801 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
802 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
803 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
804 
805 		/* Set up memory for data buffers */
806 		rdma_req->data_wr.type = RDMA_WR_TYPE_DATA;
807 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data_wr;
808 		rdma_req->data.wr.next = NULL;
809 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
810 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
811 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
812 
813 		/* Initialize request state to FREE */
814 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
815 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
816 	}
817 
818 	if (srq) {
819 		rc = spdk_rdma_provider_srq_flush_recv_wrs(srq, &bad_wr);
820 	} else {
821 		rc = spdk_rdma_provider_qp_flush_recv_wrs(qp, &bad_wr);
822 	}
823 
824 	if (rc) {
825 		goto cleanup;
826 	}
827 
828 	return resources;
829 
830 cleanup:
831 	nvmf_rdma_resources_destroy(resources);
832 	return NULL;
833 }
834 
835 static void
836 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
837 {
838 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
839 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
840 		ctx->rqpair = NULL;
841 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
842 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
843 	}
844 }
845 
846 static void nvmf_rdma_poller_destroy(struct spdk_nvmf_rdma_poller *poller);
847 
848 static void
849 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
850 {
851 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
852 	struct ibv_recv_wr		*bad_recv_wr = NULL;
853 	int				rc;
854 
855 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair);
856 
857 	if (rqpair->qd != 0) {
858 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
859 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
860 				struct spdk_nvmf_rdma_transport, transport);
861 		struct spdk_nvmf_rdma_request *req;
862 		uint32_t i, max_req_count = 0;
863 
864 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
865 
866 		if (rqpair->srq == NULL) {
867 			nvmf_rdma_dump_qpair_contents(rqpair);
868 			max_req_count = rqpair->max_queue_depth;
869 		} else if (rqpair->poller && rqpair->resources) {
870 			max_req_count = rqpair->poller->max_srq_depth;
871 		}
872 
873 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
874 		for (i = 0; i < max_req_count; i++) {
875 			req = &rqpair->resources->reqs[i];
876 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
877 				/* nvmf_rdma_request_process checks qpair ibv and internal state
878 				 * and completes a request */
879 				nvmf_rdma_request_process(rtransport, req);
880 			}
881 		}
882 		assert(rqpair->qd == 0);
883 	}
884 
885 	if (rqpair->poller) {
886 		RB_REMOVE(qpairs_tree, &rqpair->poller->qpairs, rqpair);
887 
888 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
889 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
890 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
891 				if (rqpair == rdma_recv->qpair) {
892 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
893 					spdk_rdma_provider_srq_queue_recv_wrs(rqpair->srq, &rdma_recv->wr);
894 					rc = spdk_rdma_provider_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
895 					if (rc) {
896 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
897 					}
898 				}
899 			}
900 		}
901 	}
902 
903 	if (rqpair->cm_id) {
904 		if (rqpair->rdma_qp != NULL) {
905 			spdk_rdma_provider_qp_destroy(rqpair->rdma_qp);
906 			rqpair->rdma_qp = NULL;
907 		}
908 
909 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
910 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
911 		}
912 	}
913 
914 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
915 		nvmf_rdma_resources_destroy(rqpair->resources);
916 	}
917 
918 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
919 
920 	if (rqpair->destruct_channel) {
921 		spdk_put_io_channel(rqpair->destruct_channel);
922 		rqpair->destruct_channel = NULL;
923 	}
924 
925 	if (rqpair->poller && rqpair->poller->need_destroy && RB_EMPTY(&rqpair->poller->qpairs)) {
926 		nvmf_rdma_poller_destroy(rqpair->poller);
927 	}
928 
929 	/* destroy cm_id last so cma device will not be freed before we destroy the cq. */
930 	if (rqpair->cm_id) {
931 		rdma_destroy_id(rqpair->cm_id);
932 	}
933 
934 	free(rqpair);
935 }
936 
937 static int
938 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
939 {
940 	struct spdk_nvmf_rdma_poller	*rpoller;
941 	int				rc, num_cqe, required_num_wr;
942 
943 	/* Enlarge CQ size dynamically */
944 	rpoller = rqpair->poller;
945 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
946 	num_cqe = rpoller->num_cqe;
947 	if (num_cqe < required_num_wr) {
948 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
949 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
950 	}
951 
952 	if (rpoller->num_cqe != num_cqe) {
953 		if (device->context->device->transport_type == IBV_TRANSPORT_IWARP) {
954 			SPDK_ERRLOG("iWARP doesn't support CQ resize. Current capacity %u, required %u\n"
955 				    "Using CQ of insufficient size may lead to CQ overrun\n", rpoller->num_cqe, num_cqe);
956 			return -1;
957 		}
958 		if (required_num_wr > device->attr.max_cqe) {
959 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
960 				    required_num_wr, device->attr.max_cqe);
961 			return -1;
962 		}
963 
964 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
965 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
966 		if (rc) {
967 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
968 			return -1;
969 		}
970 
971 		rpoller->num_cqe = num_cqe;
972 	}
973 
974 	rpoller->required_num_wr = required_num_wr;
975 	return 0;
976 }
977 
978 static int
979 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
980 {
981 	struct spdk_nvmf_rdma_qpair		*rqpair;
982 	struct spdk_nvmf_rdma_transport		*rtransport;
983 	struct spdk_nvmf_transport		*transport;
984 	struct spdk_nvmf_rdma_resource_opts	opts;
985 	struct spdk_nvmf_rdma_device		*device;
986 	struct spdk_rdma_provider_qp_init_attr	qp_init_attr = {};
987 
988 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
989 	device = rqpair->device;
990 
991 	qp_init_attr.qp_context	= rqpair;
992 	qp_init_attr.pd		= device->pd;
993 	qp_init_attr.send_cq	= rqpair->poller->cq;
994 	qp_init_attr.recv_cq	= rqpair->poller->cq;
995 
996 	if (rqpair->srq) {
997 		qp_init_attr.srq		= rqpair->srq->srq;
998 	} else {
999 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
1000 	}
1001 
1002 	/* SEND, READ, and WRITE operations */
1003 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
1004 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1005 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1006 	qp_init_attr.stats		= &rqpair->poller->stat.qp_stats;
1007 
1008 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1009 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1010 		goto error;
1011 	}
1012 
1013 	rqpair->rdma_qp = spdk_rdma_provider_qp_create(rqpair->cm_id, &qp_init_attr);
1014 	if (!rqpair->rdma_qp) {
1015 		goto error;
1016 	}
1017 
1018 	rqpair->qp_num = rqpair->rdma_qp->qp->qp_num;
1019 
1020 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1021 					  qp_init_attr.cap.max_send_wr);
1022 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1023 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1024 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair);
1025 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1026 
1027 	if (rqpair->poller->srq == NULL) {
1028 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1029 		transport = &rtransport->transport;
1030 
1031 		opts.qp = rqpair->rdma_qp;
1032 		opts.map = device->map;
1033 		opts.qpair = rqpair;
1034 		opts.shared = false;
1035 		opts.max_queue_depth = rqpair->max_queue_depth;
1036 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1037 
1038 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1039 
1040 		if (!rqpair->resources) {
1041 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1042 			rdma_destroy_qp(rqpair->cm_id);
1043 			goto error;
1044 		}
1045 	} else {
1046 		rqpair->resources = rqpair->poller->resources;
1047 	}
1048 
1049 	rqpair->current_recv_depth = 0;
1050 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1051 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1052 	STAILQ_INIT(&rqpair->pending_rdma_send_queue);
1053 	rqpair->qpair.queue_depth = 0;
1054 
1055 	return 0;
1056 
1057 error:
1058 	rdma_destroy_id(rqpair->cm_id);
1059 	rqpair->cm_id = NULL;
1060 	return -1;
1061 }
1062 
1063 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1064 /* This function accepts either a single wr or the first wr in a linked list. */
1065 static void
1066 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1067 {
1068 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1069 			struct spdk_nvmf_rdma_transport, transport);
1070 
1071 	if (rqpair->srq != NULL) {
1072 		spdk_rdma_provider_srq_queue_recv_wrs(rqpair->srq, first);
1073 	} else {
1074 		if (spdk_rdma_provider_qp_queue_recv_wrs(rqpair->rdma_qp, first)) {
1075 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1076 		}
1077 	}
1078 
1079 	if (rtransport->rdma_opts.no_wr_batching) {
1080 		_poller_submit_recvs(rtransport, rqpair->poller);
1081 	}
1082 }
1083 
1084 static int
1085 request_transfer_in(struct spdk_nvmf_request *req)
1086 {
1087 	struct spdk_nvmf_rdma_request	*rdma_req;
1088 	struct spdk_nvmf_qpair		*qpair;
1089 	struct spdk_nvmf_rdma_qpair	*rqpair;
1090 	struct spdk_nvmf_rdma_transport *rtransport;
1091 
1092 	qpair = req->qpair;
1093 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1094 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1095 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1096 				      struct spdk_nvmf_rdma_transport, transport);
1097 
1098 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1099 	assert(rdma_req != NULL);
1100 
1101 	if (spdk_rdma_provider_qp_queue_send_wrs(rqpair->rdma_qp, rdma_req->transfer_wr)) {
1102 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1103 	}
1104 	if (rtransport->rdma_opts.no_wr_batching) {
1105 		_poller_submit_sends(rtransport, rqpair->poller);
1106 	}
1107 
1108 	assert(rqpair->current_read_depth + rdma_req->num_outstanding_data_wr <= rqpair->max_read_depth);
1109 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1110 	assert(rqpair->current_send_depth + rdma_req->num_outstanding_data_wr <= rqpair->max_send_depth);
1111 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1112 	return 0;
1113 }
1114 
1115 static inline void
1116 nvmf_rdma_request_reset_transfer_in(struct spdk_nvmf_rdma_request *rdma_req,
1117 				    struct spdk_nvmf_rdma_transport *rtransport)
1118 {
1119 	/* Put completed WRs back to pool and move transfer_wr pointer */
1120 	_nvmf_rdma_request_free_data(rdma_req, rdma_req->transfer_wr, rtransport->data_wr_pool);
1121 	rdma_req->transfer_wr = rdma_req->remaining_tranfer_in_wrs;
1122 	rdma_req->remaining_tranfer_in_wrs = NULL;
1123 	rdma_req->num_outstanding_data_wr = rdma_req->num_remaining_data_wr;
1124 	rdma_req->num_remaining_data_wr = 0;
1125 }
1126 
1127 static inline int
1128 request_prepare_transfer_in_part(struct spdk_nvmf_request *req, uint32_t num_reads_available)
1129 {
1130 	struct spdk_nvmf_rdma_request	*rdma_req;
1131 	struct ibv_send_wr		*wr;
1132 	uint32_t i;
1133 
1134 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1135 
1136 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1137 	assert(rdma_req != NULL);
1138 	assert(num_reads_available > 0);
1139 	assert(rdma_req->num_outstanding_data_wr > num_reads_available);
1140 	wr = rdma_req->transfer_wr;
1141 
1142 	for (i = 0; i < num_reads_available - 1; i++) {
1143 		wr = wr->next;
1144 	}
1145 
1146 	rdma_req->remaining_tranfer_in_wrs = wr->next;
1147 	rdma_req->num_remaining_data_wr = rdma_req->num_outstanding_data_wr - num_reads_available;
1148 	rdma_req->num_outstanding_data_wr = num_reads_available;
1149 	/* Break chain of WRs to send only part. Once this portion completes, we continue sending RDMA_READs */
1150 	wr->next = NULL;
1151 
1152 	return 0;
1153 }
1154 
1155 static int
1156 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1157 {
1158 	int				num_outstanding_data_wr = 0;
1159 	struct spdk_nvmf_rdma_request	*rdma_req;
1160 	struct spdk_nvmf_qpair		*qpair;
1161 	struct spdk_nvmf_rdma_qpair	*rqpair;
1162 	struct spdk_nvme_cpl		*rsp;
1163 	struct ibv_send_wr		*first = NULL;
1164 	struct spdk_nvmf_rdma_transport *rtransport;
1165 
1166 	*data_posted = 0;
1167 	qpair = req->qpair;
1168 	rsp = &req->rsp->nvme_cpl;
1169 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1170 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1171 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1172 				      struct spdk_nvmf_rdma_transport, transport);
1173 
1174 	/* Advance our sq_head pointer */
1175 	if (qpair->sq_head == qpair->sq_head_max) {
1176 		qpair->sq_head = 0;
1177 	} else {
1178 		qpair->sq_head++;
1179 	}
1180 	rsp->sqhd = qpair->sq_head;
1181 
1182 	/* queue the capsule for the recv buffer */
1183 	assert(rdma_req->recv != NULL);
1184 
1185 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1186 
1187 	rdma_req->recv = NULL;
1188 	assert(rqpair->current_recv_depth > 0);
1189 	rqpair->current_recv_depth--;
1190 
1191 	/* Build the response which consists of optional
1192 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1193 	 * containing the response.
1194 	 */
1195 	first = &rdma_req->rsp.wr;
1196 
1197 	if (spdk_unlikely(rsp->status.sc != SPDK_NVME_SC_SUCCESS)) {
1198 		/* On failure, data was not read from the controller. So clear the
1199 		 * number of outstanding data WRs to zero.
1200 		 */
1201 		rdma_req->num_outstanding_data_wr = 0;
1202 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1203 		first = rdma_req->transfer_wr;
1204 		*data_posted = 1;
1205 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1206 	}
1207 	if (spdk_rdma_provider_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1208 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1209 	}
1210 	if (rtransport->rdma_opts.no_wr_batching) {
1211 		_poller_submit_sends(rtransport, rqpair->poller);
1212 	}
1213 
1214 	/* +1 for the rsp wr */
1215 	assert(rqpair->current_send_depth + num_outstanding_data_wr + 1 <= rqpair->max_send_depth);
1216 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1217 
1218 	return 0;
1219 }
1220 
1221 static int
1222 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1223 {
1224 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1225 	struct rdma_conn_param				ctrlr_event_data = {};
1226 	int						rc;
1227 
1228 	accept_data.recfmt = 0;
1229 	accept_data.crqsize = rqpair->max_queue_depth;
1230 
1231 	ctrlr_event_data.private_data = &accept_data;
1232 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1233 	if (id->ps == RDMA_PS_TCP) {
1234 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1235 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1236 	}
1237 
1238 	/* Configure infinite retries for the initiator side qpair.
1239 	 * We need to pass this value to the initiator to prevent the
1240 	 * initiator side NIC from completing SEND requests back to the
1241 	 * initiator with status rnr_retry_count_exceeded. */
1242 	ctrlr_event_data.rnr_retry_count = 0x7;
1243 
1244 	/* When qpair is created without use of rdma cm API, an additional
1245 	 * information must be provided to initiator in the connection response:
1246 	 * whether qpair is using SRQ and its qp_num
1247 	 * Fields below are ignored by rdma cm if qpair has been
1248 	 * created using rdma cm API. */
1249 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1250 	ctrlr_event_data.qp_num = rqpair->qp_num;
1251 
1252 	rc = spdk_rdma_provider_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1253 	if (rc) {
1254 		SPDK_ERRLOG("Error %d on spdk_rdma_provider_qp_accept\n", errno);
1255 	} else {
1256 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1257 	}
1258 
1259 	return rc;
1260 }
1261 
1262 static void
1263 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1264 {
1265 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1266 
1267 	rej_data.recfmt = 0;
1268 	rej_data.sts = error;
1269 
1270 	rdma_reject(id, &rej_data, sizeof(rej_data));
1271 }
1272 
1273 static int
1274 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1275 {
1276 	struct spdk_nvmf_rdma_transport *rtransport;
1277 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1278 	struct spdk_nvmf_rdma_port	*port;
1279 	struct rdma_conn_param		*rdma_param = NULL;
1280 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1281 	uint16_t			max_queue_depth;
1282 	uint16_t			max_read_depth;
1283 
1284 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1285 
1286 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1287 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1288 
1289 	rdma_param = &event->param.conn;
1290 	if (rdma_param->private_data == NULL ||
1291 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1292 		SPDK_ERRLOG("connect request: no private data provided\n");
1293 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1294 		return -1;
1295 	}
1296 
1297 	private_data = rdma_param->private_data;
1298 	if (private_data->recfmt != 0) {
1299 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1300 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1301 		return -1;
1302 	}
1303 
1304 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1305 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1306 
1307 	port = event->listen_id->context;
1308 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1309 		      event->listen_id, event->listen_id->verbs, port);
1310 
1311 	/* Figure out the supported queue depth. This is a multi-step process
1312 	 * that takes into account hardware maximums, host provided values,
1313 	 * and our target's internal memory limits */
1314 
1315 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1316 
1317 	/* Start with the maximum queue depth allowed by the target */
1318 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1319 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1320 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1321 		      rtransport->transport.opts.max_queue_depth);
1322 
1323 	/* Next check the local NIC's hardware limitations */
1324 	SPDK_DEBUGLOG(rdma,
1325 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1326 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1327 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1328 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1329 
1330 	/* Next check the remote NIC's hardware limitations */
1331 	SPDK_DEBUGLOG(rdma,
1332 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1333 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1334 	/* from man3 rdma_get_cm_event
1335 	 * responder_resources - Specifies the number of responder resources that is requested by the recipient.
1336 	 * The responder_resources field must match the initiator depth specified by the remote node when running
1337 	 * the rdma_connect and rdma_accept functions. */
1338 	if (rdma_param->responder_resources != 0) {
1339 		if (private_data->qid) {
1340 			SPDK_DEBUGLOG(rdma, "Host (Initiator) is not allowed to use RDMA operations,"
1341 				      " responder_resources must be 0 but set to %u\n",
1342 				      rdma_param->responder_resources);
1343 		} else {
1344 			SPDK_WARNLOG("Host (Initiator) is not allowed to use RDMA operations,"
1345 				     " responder_resources must be 0 but set to %u\n",
1346 				     rdma_param->responder_resources);
1347 		}
1348 	}
1349 	/* from man3 rdma_get_cm_event
1350 	 * initiator_depth - Specifies the maximum number of outstanding RDMA read operations that the recipient holds.
1351 	 * The initiator_depth field must match the responder resources specified by the remote node when running
1352 	 * the rdma_connect and rdma_accept functions. */
1353 	if (rdma_param->initiator_depth == 0) {
1354 		SPDK_ERRLOG("Host (Initiator) doesn't support RDMA_READ or atomic operations\n");
1355 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_IRD);
1356 		return -1;
1357 	}
1358 	max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1359 
1360 	SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1361 	SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1362 	max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1363 	max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1364 
1365 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1366 		      max_queue_depth, max_read_depth);
1367 
1368 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1369 	if (rqpair == NULL) {
1370 		SPDK_ERRLOG("Could not allocate new connection.\n");
1371 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1372 		return -1;
1373 	}
1374 
1375 	rqpair->device = port->device;
1376 	rqpair->max_queue_depth = max_queue_depth;
1377 	rqpair->max_read_depth = max_read_depth;
1378 	rqpair->cm_id = event->id;
1379 	rqpair->listen_id = event->listen_id;
1380 	rqpair->qpair.transport = transport;
1381 	STAILQ_INIT(&rqpair->ibv_events);
1382 	/* use qid from the private data to determine the qpair type
1383 	   qid will be set to the appropriate value when the controller is created */
1384 	rqpair->qpair.qid = private_data->qid;
1385 
1386 	event->id->context = &rqpair->qpair;
1387 
1388 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1389 
1390 	return 0;
1391 }
1392 
1393 static inline void
1394 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1395 		   enum spdk_nvme_data_transfer xfer)
1396 {
1397 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1398 		wr->opcode = IBV_WR_RDMA_WRITE;
1399 		wr->send_flags = 0;
1400 		wr->next = next;
1401 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1402 		wr->opcode = IBV_WR_RDMA_READ;
1403 		wr->send_flags = IBV_SEND_SIGNALED;
1404 		wr->next = NULL;
1405 	} else {
1406 		assert(0);
1407 	}
1408 }
1409 
1410 static int
1411 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1412 		       struct spdk_nvmf_rdma_request *rdma_req,
1413 		       uint32_t num_sgl_descriptors)
1414 {
1415 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1416 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1417 	uint32_t				i;
1418 
1419 	if (spdk_unlikely(num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES)) {
1420 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1421 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1422 		return -EINVAL;
1423 	}
1424 
1425 	if (spdk_unlikely(spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests,
1426 						num_sgl_descriptors))) {
1427 		return -ENOMEM;
1428 	}
1429 
1430 	current_data_wr = &rdma_req->data;
1431 
1432 	for (i = 0; i < num_sgl_descriptors; i++) {
1433 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1434 		current_data_wr->wr.next = &work_requests[i]->wr;
1435 		current_data_wr = work_requests[i];
1436 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1437 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1438 	}
1439 
1440 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1441 
1442 	return 0;
1443 }
1444 
1445 static inline void
1446 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1447 {
1448 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1449 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1450 
1451 	wr->wr.rdma.rkey = sgl->keyed.key;
1452 	wr->wr.rdma.remote_addr = sgl->address;
1453 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1454 }
1455 
1456 static inline void
1457 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1458 {
1459 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1460 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1461 	uint32_t			i;
1462 	int				j;
1463 	uint64_t			remote_addr_offset = 0;
1464 
1465 	for (i = 0; i < num_wrs; ++i) {
1466 		wr->wr.rdma.rkey = sgl->keyed.key;
1467 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1468 		for (j = 0; j < wr->num_sge; ++j) {
1469 			remote_addr_offset += wr->sg_list[j].length;
1470 		}
1471 		wr = wr->next;
1472 	}
1473 }
1474 
1475 static int
1476 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_device *device,
1477 		      struct spdk_nvmf_rdma_request *rdma_req,
1478 		      struct ibv_send_wr *wr,
1479 		      uint32_t total_length)
1480 {
1481 	struct spdk_rdma_utils_memory_translation mem_translation;
1482 	struct ibv_sge	*sg_ele;
1483 	struct iovec *iov;
1484 	uint32_t lkey, remaining;
1485 	int rc;
1486 
1487 	wr->num_sge = 0;
1488 
1489 	while (total_length && wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES) {
1490 		iov = &rdma_req->req.iov[rdma_req->iovpos];
1491 		rc = spdk_rdma_utils_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1492 		if (spdk_unlikely(rc)) {
1493 			return rc;
1494 		}
1495 
1496 		lkey = spdk_rdma_utils_memory_translation_get_lkey(&mem_translation);
1497 		sg_ele = &wr->sg_list[wr->num_sge];
1498 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1499 
1500 		sg_ele->lkey = lkey;
1501 		sg_ele->addr = (uintptr_t)iov->iov_base + rdma_req->offset;
1502 		sg_ele->length = remaining;
1503 		SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele, sg_ele->addr,
1504 			      sg_ele->length);
1505 		rdma_req->offset += sg_ele->length;
1506 		total_length -= sg_ele->length;
1507 		wr->num_sge++;
1508 
1509 		if (rdma_req->offset == iov->iov_len) {
1510 			rdma_req->offset = 0;
1511 			rdma_req->iovpos++;
1512 		}
1513 	}
1514 
1515 	if (spdk_unlikely(total_length)) {
1516 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1517 		return -EINVAL;
1518 	}
1519 
1520 	return 0;
1521 }
1522 
1523 static int
1524 nvmf_rdma_fill_wr_sgl_with_dif(struct spdk_nvmf_rdma_device *device,
1525 			       struct spdk_nvmf_rdma_request *rdma_req,
1526 			       struct ibv_send_wr *wr,
1527 			       uint32_t total_length,
1528 			       uint32_t num_extra_wrs)
1529 {
1530 	struct spdk_rdma_utils_memory_translation mem_translation;
1531 	struct spdk_dif_ctx *dif_ctx = &rdma_req->req.dif.dif_ctx;
1532 	struct ibv_sge *sg_ele;
1533 	struct iovec *iov;
1534 	struct iovec *rdma_iov;
1535 	uint32_t lkey, remaining;
1536 	uint32_t remaining_data_block, data_block_size, md_size;
1537 	uint32_t sge_len;
1538 	int rc;
1539 
1540 	data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1541 
1542 	if (spdk_likely(!rdma_req->req.stripped_data)) {
1543 		rdma_iov = rdma_req->req.iov;
1544 		remaining_data_block = data_block_size;
1545 		md_size = dif_ctx->md_size;
1546 	} else {
1547 		rdma_iov = rdma_req->req.stripped_data->iov;
1548 		total_length = total_length / dif_ctx->block_size * data_block_size;
1549 		remaining_data_block = total_length;
1550 		md_size = 0;
1551 	}
1552 
1553 	wr->num_sge = 0;
1554 
1555 	while (total_length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1556 		iov = rdma_iov + rdma_req->iovpos;
1557 		rc = spdk_rdma_utils_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1558 		if (spdk_unlikely(rc)) {
1559 			return rc;
1560 		}
1561 
1562 		lkey = spdk_rdma_utils_memory_translation_get_lkey(&mem_translation);
1563 		sg_ele = &wr->sg_list[wr->num_sge];
1564 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1565 
1566 		while (remaining) {
1567 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1568 				if (num_extra_wrs > 0 && wr->next) {
1569 					wr = wr->next;
1570 					wr->num_sge = 0;
1571 					sg_ele = &wr->sg_list[wr->num_sge];
1572 					num_extra_wrs--;
1573 				} else {
1574 					break;
1575 				}
1576 			}
1577 			sg_ele->lkey = lkey;
1578 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + rdma_req->offset);
1579 			sge_len = spdk_min(remaining, remaining_data_block);
1580 			sg_ele->length = sge_len;
1581 			SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele,
1582 				      sg_ele->addr, sg_ele->length);
1583 			remaining -= sge_len;
1584 			remaining_data_block -= sge_len;
1585 			rdma_req->offset += sge_len;
1586 			total_length -= sge_len;
1587 
1588 			sg_ele++;
1589 			wr->num_sge++;
1590 
1591 			if (remaining_data_block == 0) {
1592 				/* skip metadata */
1593 				rdma_req->offset += md_size;
1594 				total_length -= md_size;
1595 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1596 				remaining -= spdk_min(remaining, md_size);
1597 				remaining_data_block = data_block_size;
1598 			}
1599 
1600 			if (remaining == 0) {
1601 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1602 				   the remaining metadata bits at the beginning of the next buffer */
1603 				rdma_req->offset -= spdk_min(iov->iov_len, rdma_req->offset);
1604 				rdma_req->iovpos++;
1605 			}
1606 		}
1607 	}
1608 
1609 	if (spdk_unlikely(total_length)) {
1610 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1611 		return -EINVAL;
1612 	}
1613 
1614 	return 0;
1615 }
1616 
1617 static inline uint32_t
1618 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1619 {
1620 	/* estimate the number of SG entries and WRs needed to process the request */
1621 	uint32_t num_sge = 0;
1622 	uint32_t i;
1623 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1624 
1625 	for (i = 0; i < num_buffers && length > 0; i++) {
1626 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1627 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1628 
1629 		if (num_sge_in_block * block_size > buffer_len) {
1630 			++num_sge_in_block;
1631 		}
1632 		num_sge += num_sge_in_block;
1633 		length -= buffer_len;
1634 	}
1635 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1636 }
1637 
1638 static int
1639 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1640 			    struct spdk_nvmf_rdma_device *device,
1641 			    struct spdk_nvmf_rdma_request *rdma_req)
1642 {
1643 	struct spdk_nvmf_rdma_qpair		*rqpair;
1644 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1645 	struct spdk_nvmf_request		*req = &rdma_req->req;
1646 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1647 	int					rc;
1648 	uint32_t				num_wrs = 1;
1649 	uint32_t				length;
1650 
1651 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1652 	rgroup = rqpair->poller->group;
1653 
1654 	/* rdma wr specifics */
1655 	nvmf_rdma_setup_request(rdma_req);
1656 
1657 	length = req->length;
1658 	if (spdk_unlikely(req->dif_enabled)) {
1659 		req->dif.orig_length = length;
1660 		length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1661 		req->dif.elba_length = length;
1662 	}
1663 
1664 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1665 					   length);
1666 	if (spdk_unlikely(rc != 0)) {
1667 		return rc;
1668 	}
1669 
1670 	assert(req->iovcnt <= rqpair->max_send_sge);
1671 
1672 	/* When dif_insert_or_strip is true and the I/O data length is greater than one block,
1673 	 * the stripped_buffers are got for DIF stripping. */
1674 	if (spdk_unlikely(req->dif_enabled && (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST)
1675 			  && (req->dif.elba_length > req->dif.dif_ctx.block_size))) {
1676 		rc = nvmf_request_get_stripped_buffers(req, &rgroup->group,
1677 						       &rtransport->transport, req->dif.orig_length);
1678 		if (rc != 0) {
1679 			SPDK_INFOLOG(rdma, "Get stripped buffers fail %d, fallback to req.iov.\n", rc);
1680 		}
1681 	}
1682 
1683 	rdma_req->iovpos = 0;
1684 
1685 	if (spdk_unlikely(req->dif_enabled)) {
1686 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1687 						 req->dif.dif_ctx.block_size);
1688 		if (num_wrs > 1) {
1689 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1690 			if (spdk_unlikely(rc != 0)) {
1691 				goto err_exit;
1692 			}
1693 		}
1694 
1695 		rc = nvmf_rdma_fill_wr_sgl_with_dif(device, rdma_req, wr, length, num_wrs - 1);
1696 		if (spdk_unlikely(rc != 0)) {
1697 			goto err_exit;
1698 		}
1699 
1700 		if (num_wrs > 1) {
1701 			nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1702 		}
1703 	} else {
1704 		rc = nvmf_rdma_fill_wr_sgl(device, rdma_req, wr, length);
1705 		if (spdk_unlikely(rc != 0)) {
1706 			goto err_exit;
1707 		}
1708 	}
1709 
1710 	/* set the number of outstanding data WRs for this request. */
1711 	rdma_req->num_outstanding_data_wr = num_wrs;
1712 
1713 	return rc;
1714 
1715 err_exit:
1716 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1717 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1718 	req->iovcnt = 0;
1719 	return rc;
1720 }
1721 
1722 static int
1723 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1724 				      struct spdk_nvmf_rdma_device *device,
1725 				      struct spdk_nvmf_rdma_request *rdma_req)
1726 {
1727 	struct spdk_nvmf_rdma_qpair		*rqpair;
1728 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1729 	struct ibv_send_wr			*current_wr;
1730 	struct spdk_nvmf_request		*req = &rdma_req->req;
1731 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1732 	uint32_t				num_sgl_descriptors;
1733 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES], total_length = 0;
1734 	uint32_t				i;
1735 	int					rc;
1736 
1737 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1738 	rgroup = rqpair->poller->group;
1739 
1740 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1741 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1742 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1743 
1744 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1745 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1746 
1747 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1748 	for (i = 0; i < num_sgl_descriptors; i++) {
1749 		if (spdk_likely(!req->dif_enabled)) {
1750 			lengths[i] = desc->keyed.length;
1751 		} else {
1752 			req->dif.orig_length += desc->keyed.length;
1753 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1754 			req->dif.elba_length += lengths[i];
1755 		}
1756 		total_length += lengths[i];
1757 		desc++;
1758 	}
1759 
1760 	if (spdk_unlikely(total_length > rtransport->transport.opts.max_io_size)) {
1761 		SPDK_ERRLOG("Multi SGL length 0x%x exceeds max io size 0x%x\n",
1762 			    total_length, rtransport->transport.opts.max_io_size);
1763 		req->rsp->nvme_cpl.status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1764 		return -EINVAL;
1765 	}
1766 
1767 	rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1);
1768 	if (spdk_unlikely(rc != 0)) {
1769 		return -ENOMEM;
1770 	}
1771 
1772 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport, total_length);
1773 	if (spdk_unlikely(rc != 0)) {
1774 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1775 		return rc;
1776 	}
1777 
1778 	/* When dif_insert_or_strip is true and the I/O data length is greater than one block,
1779 	 * the stripped_buffers are got for DIF stripping. */
1780 	if (spdk_unlikely(req->dif_enabled && (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST)
1781 			  && (req->dif.elba_length > req->dif.dif_ctx.block_size))) {
1782 		rc = nvmf_request_get_stripped_buffers(req, &rgroup->group,
1783 						       &rtransport->transport, req->dif.orig_length);
1784 		if (spdk_unlikely(rc != 0)) {
1785 			SPDK_INFOLOG(rdma, "Get stripped buffers fail %d, fallback to req.iov.\n", rc);
1786 		}
1787 	}
1788 
1789 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1790 	current_wr = &rdma_req->data.wr;
1791 	assert(current_wr != NULL);
1792 
1793 	req->length = 0;
1794 	rdma_req->iovpos = 0;
1795 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1796 	for (i = 0; i < num_sgl_descriptors; i++) {
1797 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1798 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1799 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1800 			rc = -EINVAL;
1801 			goto err_exit;
1802 		}
1803 
1804 		if (spdk_likely(!req->dif_enabled)) {
1805 			rc = nvmf_rdma_fill_wr_sgl(device, rdma_req, current_wr, lengths[i]);
1806 		} else {
1807 			rc = nvmf_rdma_fill_wr_sgl_with_dif(device, rdma_req, current_wr,
1808 							    lengths[i], 0);
1809 		}
1810 		if (spdk_unlikely(rc != 0)) {
1811 			rc = -ENOMEM;
1812 			goto err_exit;
1813 		}
1814 
1815 		req->length += desc->keyed.length;
1816 		current_wr->wr.rdma.rkey = desc->keyed.key;
1817 		current_wr->wr.rdma.remote_addr = desc->address;
1818 		current_wr = current_wr->next;
1819 		desc++;
1820 	}
1821 
1822 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1823 	/* Go back to the last descriptor in the list. */
1824 	desc--;
1825 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1826 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1827 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1828 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1829 		}
1830 	}
1831 #endif
1832 
1833 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1834 
1835 	return 0;
1836 
1837 err_exit:
1838 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1839 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1840 	return rc;
1841 }
1842 
1843 static int
1844 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1845 			    struct spdk_nvmf_rdma_device *device,
1846 			    struct spdk_nvmf_rdma_request *rdma_req)
1847 {
1848 	struct spdk_nvmf_request		*req = &rdma_req->req;
1849 	struct spdk_nvme_cpl			*rsp;
1850 	struct spdk_nvme_sgl_descriptor		*sgl;
1851 	int					rc;
1852 	uint32_t				length;
1853 
1854 	rsp = &req->rsp->nvme_cpl;
1855 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1856 
1857 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1858 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1859 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1860 
1861 		length = sgl->keyed.length;
1862 		if (spdk_unlikely(length > rtransport->transport.opts.max_io_size)) {
1863 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1864 				    length, rtransport->transport.opts.max_io_size);
1865 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1866 			return -1;
1867 		}
1868 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1869 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1870 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1871 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1872 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1873 			}
1874 		}
1875 #endif
1876 
1877 		/* fill request length and populate iovs */
1878 		req->length = length;
1879 
1880 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req);
1881 		if (spdk_unlikely(rc < 0)) {
1882 			if (rc == -EINVAL) {
1883 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1884 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1885 				return -1;
1886 			}
1887 			/* No available buffers. Queue this request up. */
1888 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1889 			return 0;
1890 		}
1891 
1892 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1893 			      req->iovcnt);
1894 
1895 		return 0;
1896 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1897 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1898 		uint64_t offset = sgl->address;
1899 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1900 
1901 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1902 			      offset, sgl->unkeyed.length);
1903 
1904 		if (spdk_unlikely(offset > max_len)) {
1905 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1906 				    offset, max_len);
1907 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1908 			return -1;
1909 		}
1910 		max_len -= (uint32_t)offset;
1911 
1912 		if (spdk_unlikely(sgl->unkeyed.length > max_len)) {
1913 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1914 				    sgl->unkeyed.length, max_len);
1915 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1916 			return -1;
1917 		}
1918 
1919 		rdma_req->num_outstanding_data_wr = 0;
1920 		req->data_from_pool = false;
1921 		req->length = sgl->unkeyed.length;
1922 
1923 		req->iov[0].iov_base = rdma_req->recv->buf + offset;
1924 		req->iov[0].iov_len = req->length;
1925 		req->iovcnt = 1;
1926 
1927 		return 0;
1928 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1929 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1930 
1931 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1932 		if (spdk_unlikely(rc == -ENOMEM)) {
1933 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1934 			return 0;
1935 		} else if (spdk_unlikely(rc == -EINVAL)) {
1936 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1937 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1938 			return -1;
1939 		}
1940 
1941 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1942 			      req->iovcnt);
1943 
1944 		return 0;
1945 	}
1946 
1947 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1948 		    sgl->generic.type, sgl->generic.subtype);
1949 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1950 	return -1;
1951 }
1952 
1953 static void
1954 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1955 			struct spdk_nvmf_rdma_transport	*rtransport)
1956 {
1957 	struct spdk_nvmf_rdma_qpair		*rqpair;
1958 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1959 
1960 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1961 	if (rdma_req->req.data_from_pool) {
1962 		rgroup = rqpair->poller->group;
1963 
1964 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1965 	}
1966 	if (rdma_req->req.stripped_data) {
1967 		nvmf_request_free_stripped_buffers(&rdma_req->req,
1968 						   &rqpair->poller->group->group,
1969 						   &rtransport->transport);
1970 	}
1971 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1972 	rdma_req->req.length = 0;
1973 	rdma_req->req.iovcnt = 0;
1974 	rdma_req->offset = 0;
1975 	rdma_req->req.dif_enabled = false;
1976 	rdma_req->fused_failed = false;
1977 	rdma_req->transfer_wr = NULL;
1978 	if (rdma_req->fused_pair) {
1979 		/* This req was part of a valid fused pair, but failed before it got to
1980 		 * READ_TO_EXECUTE state.  This means we need to fail the other request
1981 		 * in the pair, because it is no longer part of a valid pair.  If the pair
1982 		 * already reached READY_TO_EXECUTE state, we need to kick it.
1983 		 */
1984 		rdma_req->fused_pair->fused_failed = true;
1985 		if (rdma_req->fused_pair->state == RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
1986 			nvmf_rdma_request_process(rtransport, rdma_req->fused_pair);
1987 		}
1988 		rdma_req->fused_pair = NULL;
1989 	}
1990 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1991 	rqpair->qd--;
1992 
1993 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1994 	rqpair->qpair.queue_depth--;
1995 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1996 }
1997 
1998 static void
1999 nvmf_rdma_check_fused_ordering(struct spdk_nvmf_rdma_transport *rtransport,
2000 			       struct spdk_nvmf_rdma_qpair *rqpair,
2001 			       struct spdk_nvmf_rdma_request *rdma_req)
2002 {
2003 	enum spdk_nvme_cmd_fuse last, next;
2004 
2005 	last = rqpair->fused_first ? rqpair->fused_first->req.cmd->nvme_cmd.fuse : SPDK_NVME_CMD_FUSE_NONE;
2006 	next = rdma_req->req.cmd->nvme_cmd.fuse;
2007 
2008 	assert(last != SPDK_NVME_CMD_FUSE_SECOND);
2009 
2010 	if (spdk_likely(last == SPDK_NVME_CMD_FUSE_NONE && next == SPDK_NVME_CMD_FUSE_NONE)) {
2011 		return;
2012 	}
2013 
2014 	if (last == SPDK_NVME_CMD_FUSE_FIRST) {
2015 		if (next == SPDK_NVME_CMD_FUSE_SECOND) {
2016 			/* This is a valid pair of fused commands.  Point them at each other
2017 			 * so they can be submitted consecutively once ready to be executed.
2018 			 */
2019 			rqpair->fused_first->fused_pair = rdma_req;
2020 			rdma_req->fused_pair = rqpair->fused_first;
2021 			rqpair->fused_first = NULL;
2022 			return;
2023 		} else {
2024 			/* Mark the last req as failed since it wasn't followed by a SECOND. */
2025 			rqpair->fused_first->fused_failed = true;
2026 
2027 			/* If the last req is in READY_TO_EXECUTE state, then call
2028 			 * nvmf_rdma_request_process(), otherwise nothing else will kick it.
2029 			 */
2030 			if (rqpair->fused_first->state == RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
2031 				nvmf_rdma_request_process(rtransport, rqpair->fused_first);
2032 			}
2033 
2034 			rqpair->fused_first = NULL;
2035 		}
2036 	}
2037 
2038 	if (next == SPDK_NVME_CMD_FUSE_FIRST) {
2039 		/* Set rqpair->fused_first here so that we know to check that the next request
2040 		 * is a SECOND (and to fail this one if it isn't).
2041 		 */
2042 		rqpair->fused_first = rdma_req;
2043 	} else if (next == SPDK_NVME_CMD_FUSE_SECOND) {
2044 		/* Mark this req failed since it ia SECOND and the last one was not a FIRST. */
2045 		rdma_req->fused_failed = true;
2046 	}
2047 }
2048 
2049 bool
2050 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
2051 			  struct spdk_nvmf_rdma_request *rdma_req)
2052 {
2053 	struct spdk_nvmf_rdma_qpair	*rqpair;
2054 	struct spdk_nvmf_rdma_device	*device;
2055 	struct spdk_nvmf_rdma_poll_group *rgroup;
2056 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
2057 	int				rc;
2058 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2059 	enum spdk_nvmf_rdma_request_state prev_state;
2060 	bool				progress = false;
2061 	int				data_posted;
2062 	uint32_t			num_blocks, num_rdma_reads_available, qdepth;
2063 
2064 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2065 	device = rqpair->device;
2066 	rgroup = rqpair->poller->group;
2067 
2068 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
2069 
2070 	/* If the queue pair is in an error state, force the request to the completed state
2071 	 * to release resources. */
2072 	if (spdk_unlikely(rqpair->ibv_in_error_state || !spdk_nvmf_qpair_is_active(&rqpair->qpair))) {
2073 		switch (rdma_req->state) {
2074 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2075 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
2076 			break;
2077 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2078 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2079 			break;
2080 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2081 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2082 			break;
2083 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING:
2084 			STAILQ_REMOVE(&rqpair->pending_rdma_send_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2085 			break;
2086 		default:
2087 			break;
2088 		}
2089 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2090 	}
2091 
2092 	/* The loop here is to allow for several back-to-back state changes. */
2093 	do {
2094 		prev_state = rdma_req->state;
2095 
2096 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
2097 
2098 		switch (rdma_req->state) {
2099 		case RDMA_REQUEST_STATE_FREE:
2100 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
2101 			 * to escape this state. */
2102 			break;
2103 		case RDMA_REQUEST_STATE_NEW:
2104 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
2105 					  (uintptr_t)rdma_req, (uintptr_t)rqpair, rqpair->qpair.queue_depth);
2106 			rdma_recv = rdma_req->recv;
2107 
2108 			/* The first element of the SGL is the NVMe command */
2109 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
2110 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
2111 			rdma_req->transfer_wr = &rdma_req->data.wr;
2112 
2113 			if (spdk_unlikely(rqpair->ibv_in_error_state || !spdk_nvmf_qpair_is_active(&rqpair->qpair))) {
2114 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2115 				break;
2116 			}
2117 
2118 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
2119 				rdma_req->req.dif_enabled = true;
2120 			}
2121 
2122 			nvmf_rdma_check_fused_ordering(rtransport, rqpair, rdma_req);
2123 
2124 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2125 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
2126 			rdma_req->rsp.wr.imm_data = 0;
2127 #endif
2128 
2129 			/* The next state transition depends on the data transfer needs of this request. */
2130 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
2131 
2132 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
2133 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2134 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
2135 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2136 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2137 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
2138 				break;
2139 			}
2140 
2141 			/* If no data to transfer, ready to execute. */
2142 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2143 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2144 				break;
2145 			}
2146 
2147 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2148 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2149 			break;
2150 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2151 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2152 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2153 
2154 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2155 
2156 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2157 				/* This request needs to wait in line to obtain a buffer */
2158 				break;
2159 			}
2160 
2161 			/* Try to get a data buffer */
2162 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2163 			if (spdk_unlikely(rc < 0)) {
2164 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2165 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2166 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2167 				break;
2168 			}
2169 
2170 			if (rdma_req->req.iovcnt == 0) {
2171 				/* No buffers available. */
2172 				rgroup->stat.pending_data_buffer++;
2173 				break;
2174 			}
2175 
2176 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2177 
2178 			/* If data is transferring from host to controller and the data didn't
2179 			 * arrive using in capsule data, we need to do a transfer from the host.
2180 			 */
2181 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2182 			    rdma_req->req.data_from_pool) {
2183 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2184 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2185 				break;
2186 			}
2187 
2188 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2189 			break;
2190 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2191 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2192 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2193 
2194 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2195 				/* This request needs to wait in line to perform RDMA */
2196 				break;
2197 			}
2198 			assert(rqpair->max_send_depth >= rqpair->current_send_depth);
2199 			qdepth = rqpair->max_send_depth - rqpair->current_send_depth;
2200 			assert(rqpair->max_read_depth >= rqpair->current_read_depth);
2201 			num_rdma_reads_available = rqpair->max_read_depth - rqpair->current_read_depth;
2202 			if (rdma_req->num_outstanding_data_wr > qdepth ||
2203 			    rdma_req->num_outstanding_data_wr > num_rdma_reads_available) {
2204 				if (num_rdma_reads_available && qdepth) {
2205 					/* Send as much as we can */
2206 					request_prepare_transfer_in_part(&rdma_req->req, spdk_min(num_rdma_reads_available, qdepth));
2207 				} else {
2208 					/* We can only have so many WRs outstanding. we have to wait until some finish. */
2209 					rqpair->poller->stat.pending_rdma_read++;
2210 					break;
2211 				}
2212 			}
2213 
2214 			/* We have already verified that this request is the head of the queue. */
2215 			if (rdma_req->num_remaining_data_wr == 0) {
2216 				STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2217 			}
2218 
2219 			rc = request_transfer_in(&rdma_req->req);
2220 			if (spdk_likely(rc == 0)) {
2221 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2222 			} else {
2223 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2224 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2225 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2226 			}
2227 			break;
2228 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2229 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2230 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2231 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2232 			 * to escape this state. */
2233 			break;
2234 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2235 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2236 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2237 
2238 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2239 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2240 					/* generate DIF for write operation */
2241 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2242 					assert(num_blocks > 0);
2243 
2244 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2245 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2246 					if (rc != 0) {
2247 						SPDK_ERRLOG("DIF generation failed\n");
2248 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2249 						spdk_nvmf_qpair_disconnect(&rqpair->qpair);
2250 						break;
2251 					}
2252 				}
2253 
2254 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2255 				/* set extended length before IO operation */
2256 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2257 			}
2258 
2259 			if (rdma_req->req.cmd->nvme_cmd.fuse != SPDK_NVME_CMD_FUSE_NONE) {
2260 				if (rdma_req->fused_failed) {
2261 					/* This request failed FUSED semantics.  Fail it immediately, without
2262 					 * even sending it to the target layer.
2263 					 */
2264 					rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2265 					rsp->status.sc = SPDK_NVME_SC_ABORTED_MISSING_FUSED;
2266 					STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2267 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2268 					break;
2269 				}
2270 
2271 				if (rdma_req->fused_pair == NULL ||
2272 				    rdma_req->fused_pair->state != RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
2273 					/* This request is ready to execute, but either we don't know yet if it's
2274 					 * valid - i.e. this is a FIRST but we haven't received the next
2275 					 * request yet or the other request of this fused pair isn't ready to
2276 					 * execute.  So break here and this request will get processed later either
2277 					 * when the other request is ready or we find that this request isn't valid.
2278 					 */
2279 					break;
2280 				}
2281 			}
2282 
2283 			/* If we get to this point, and this request is a fused command, we know that
2284 			 * it is part of valid sequence (FIRST followed by a SECOND) and that both
2285 			 * requests are READY_TO_EXECUTE. So call spdk_nvmf_request_exec() both on this
2286 			 * request, and the other request of the fused pair, in the correct order.
2287 			 * Also clear the ->fused_pair pointers on both requests, since after this point
2288 			 * we no longer need to maintain the relationship between these two requests.
2289 			 */
2290 			if (rdma_req->req.cmd->nvme_cmd.fuse == SPDK_NVME_CMD_FUSE_SECOND) {
2291 				assert(rdma_req->fused_pair != NULL);
2292 				assert(rdma_req->fused_pair->fused_pair != NULL);
2293 				rdma_req->fused_pair->state = RDMA_REQUEST_STATE_EXECUTING;
2294 				spdk_nvmf_request_exec(&rdma_req->fused_pair->req);
2295 				rdma_req->fused_pair->fused_pair = NULL;
2296 				rdma_req->fused_pair = NULL;
2297 			}
2298 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2299 			spdk_nvmf_request_exec(&rdma_req->req);
2300 			if (rdma_req->req.cmd->nvme_cmd.fuse == SPDK_NVME_CMD_FUSE_FIRST) {
2301 				assert(rdma_req->fused_pair != NULL);
2302 				assert(rdma_req->fused_pair->fused_pair != NULL);
2303 				rdma_req->fused_pair->state = RDMA_REQUEST_STATE_EXECUTING;
2304 				spdk_nvmf_request_exec(&rdma_req->fused_pair->req);
2305 				rdma_req->fused_pair->fused_pair = NULL;
2306 				rdma_req->fused_pair = NULL;
2307 			}
2308 			break;
2309 		case RDMA_REQUEST_STATE_EXECUTING:
2310 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2311 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2312 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2313 			 * to escape this state. */
2314 			break;
2315 		case RDMA_REQUEST_STATE_EXECUTED:
2316 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2317 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2318 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2319 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2320 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2321 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2322 			} else {
2323 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2324 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2325 			}
2326 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2327 				/* restore the original length */
2328 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2329 
2330 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2331 					struct spdk_dif_error error_blk;
2332 
2333 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2334 					if (!rdma_req->req.stripped_data) {
2335 						rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2336 								     &rdma_req->req.dif.dif_ctx, &error_blk);
2337 					} else {
2338 						rc = spdk_dif_verify_copy(rdma_req->req.stripped_data->iov,
2339 									  rdma_req->req.stripped_data->iovcnt,
2340 									  rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2341 									  &rdma_req->req.dif.dif_ctx, &error_blk);
2342 					}
2343 					if (rc) {
2344 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2345 
2346 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2347 							    error_blk.err_offset);
2348 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2349 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2350 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2351 						STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2352 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2353 					}
2354 				}
2355 			}
2356 			break;
2357 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2358 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2359 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2360 
2361 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2362 				/* This request needs to wait in line to perform RDMA */
2363 				break;
2364 			}
2365 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2366 			    rqpair->max_send_depth) {
2367 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2368 				 * +1 since each request has an additional wr in the resp. */
2369 				rqpair->poller->stat.pending_rdma_write++;
2370 				break;
2371 			}
2372 
2373 			/* We have already verified that this request is the head of the queue. */
2374 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2375 
2376 			/* The data transfer will be kicked off from
2377 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2378 			 * We verified that data + response fit into send queue, so we can go to the next state directly
2379 			 */
2380 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2381 			break;
2382 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING:
2383 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING, 0, 0,
2384 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2385 
2386 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_send_queue)) {
2387 				/* This request needs to wait in line to send the completion */
2388 				break;
2389 			}
2390 
2391 			assert(rqpair->current_send_depth <= rqpair->max_send_depth);
2392 			if (rqpair->current_send_depth == rqpair->max_send_depth) {
2393 				/* We can only have so many WRs outstanding. we have to wait until some finish */
2394 				rqpair->poller->stat.pending_rdma_send++;
2395 				break;
2396 			}
2397 
2398 			/* We have already verified that this request is the head of the queue. */
2399 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_send_queue, state_link);
2400 
2401 			/* The response sending will be kicked off from
2402 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2403 			 */
2404 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2405 			break;
2406 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2407 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2408 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2409 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2410 			assert(rc == 0); /* No good way to handle this currently */
2411 			if (spdk_unlikely(rc)) {
2412 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2413 			} else {
2414 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2415 						  RDMA_REQUEST_STATE_COMPLETING;
2416 			}
2417 			break;
2418 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2419 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2420 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2421 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2422 			 * to escape this state. */
2423 			break;
2424 		case RDMA_REQUEST_STATE_COMPLETING:
2425 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2426 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2427 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2428 			 * to escape this state. */
2429 			break;
2430 		case RDMA_REQUEST_STATE_COMPLETED:
2431 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2432 					  (uintptr_t)rdma_req, (uintptr_t)rqpair, rqpair->qpair.queue_depth);
2433 
2434 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2435 			_nvmf_rdma_request_free(rdma_req, rtransport);
2436 			break;
2437 		case RDMA_REQUEST_NUM_STATES:
2438 		default:
2439 			assert(0);
2440 			break;
2441 		}
2442 
2443 		if (rdma_req->state != prev_state) {
2444 			progress = true;
2445 		}
2446 	} while (rdma_req->state != prev_state);
2447 
2448 	return progress;
2449 }
2450 
2451 /* Public API callbacks begin here */
2452 
2453 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2454 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2455 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2456 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2457 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2458 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2459 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2460 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2461 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE UINT32_MAX
2462 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2463 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2464 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2465 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2466 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2467 #define SPDK_NVMF_RDMA_DEFAULT_DATA_WR_POOL_SIZE 4095
2468 
2469 static void
2470 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2471 {
2472 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2473 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2474 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2475 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2476 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2477 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2478 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2479 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2480 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2481 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2482 	opts->transport_specific =      NULL;
2483 	opts->data_wr_pool_size	=	SPDK_NVMF_RDMA_DEFAULT_DATA_WR_POOL_SIZE;
2484 }
2485 
2486 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2487 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2488 
2489 static inline bool
2490 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2491 {
2492 	return device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_OLD ||
2493 	       device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_NEW;
2494 }
2495 
2496 static int nvmf_rdma_accept(void *ctx);
2497 static bool nvmf_rdma_retry_listen_port(struct spdk_nvmf_rdma_transport *rtransport);
2498 static void destroy_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
2499 			      struct spdk_nvmf_rdma_device *device);
2500 
2501 static int
2502 create_ib_device(struct spdk_nvmf_rdma_transport *rtransport, struct ibv_context *context,
2503 		 struct spdk_nvmf_rdma_device **new_device)
2504 {
2505 	struct spdk_nvmf_rdma_device	*device;
2506 	int				flag = 0;
2507 	int				rc = 0;
2508 
2509 	device = calloc(1, sizeof(*device));
2510 	if (!device) {
2511 		SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2512 		return -ENOMEM;
2513 	}
2514 	device->context = context;
2515 	rc = ibv_query_device(device->context, &device->attr);
2516 	if (rc < 0) {
2517 		SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2518 		free(device);
2519 		return rc;
2520 	}
2521 
2522 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2523 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2524 		SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2525 		SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2526 	}
2527 
2528 	/**
2529 	 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2530 	 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2531 	 * but incorrectly reports that it does. There are changes making their way
2532 	 * through the kernel now that will enable this feature. When they are merged,
2533 	 * we can conditionally enable this feature.
2534 	 *
2535 	 * TODO: enable this for versions of the kernel rxe driver that support it.
2536 	 */
2537 	if (nvmf_rdma_is_rxe_device(device)) {
2538 		device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2539 	}
2540 #endif
2541 
2542 	/* set up device context async ev fd as NON_BLOCKING */
2543 	flag = fcntl(device->context->async_fd, F_GETFL);
2544 	rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2545 	if (rc < 0) {
2546 		SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2547 		free(device);
2548 		return rc;
2549 	}
2550 
2551 	TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2552 	SPDK_DEBUGLOG(rdma, "New device %p is added to RDMA transport\n", device);
2553 
2554 	if (g_nvmf_hooks.get_ibv_pd) {
2555 		device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2556 	} else {
2557 		device->pd = ibv_alloc_pd(device->context);
2558 	}
2559 
2560 	if (!device->pd) {
2561 		SPDK_ERRLOG("Unable to allocate protection domain.\n");
2562 		destroy_ib_device(rtransport, device);
2563 		return -ENOMEM;
2564 	}
2565 
2566 	assert(device->map == NULL);
2567 
2568 	device->map = spdk_rdma_utils_create_mem_map(device->pd, &g_nvmf_hooks, IBV_ACCESS_LOCAL_WRITE);
2569 	if (!device->map) {
2570 		SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2571 		destroy_ib_device(rtransport, device);
2572 		return -ENOMEM;
2573 	}
2574 
2575 	assert(device->map != NULL);
2576 	assert(device->pd != NULL);
2577 
2578 	if (new_device) {
2579 		*new_device = device;
2580 	}
2581 	SPDK_NOTICELOG("Create IB device %s(%p/%p) succeed.\n", ibv_get_device_name(context->device),
2582 		       device, context);
2583 
2584 	return 0;
2585 }
2586 
2587 static void
2588 free_poll_fds(struct spdk_nvmf_rdma_transport *rtransport)
2589 {
2590 	if (rtransport->poll_fds) {
2591 		free(rtransport->poll_fds);
2592 		rtransport->poll_fds = NULL;
2593 	}
2594 	rtransport->npoll_fds = 0;
2595 }
2596 
2597 static int
2598 generate_poll_fds(struct spdk_nvmf_rdma_transport *rtransport)
2599 {
2600 	/* Set up poll descriptor array to monitor events from RDMA and IB
2601 	 * in a single poll syscall
2602 	 */
2603 	int device_count = 0;
2604 	int i = 0;
2605 	struct spdk_nvmf_rdma_device *device, *tmp;
2606 
2607 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2608 		device_count++;
2609 	}
2610 
2611 	rtransport->npoll_fds = device_count + 1;
2612 
2613 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2614 	if (rtransport->poll_fds == NULL) {
2615 		SPDK_ERRLOG("poll_fds allocation failed\n");
2616 		return -ENOMEM;
2617 	}
2618 
2619 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2620 	rtransport->poll_fds[i++].events = POLLIN;
2621 
2622 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2623 		rtransport->poll_fds[i].fd = device->context->async_fd;
2624 		rtransport->poll_fds[i++].events = POLLIN;
2625 	}
2626 
2627 	return 0;
2628 }
2629 
2630 static struct spdk_nvmf_transport *
2631 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2632 {
2633 	int rc;
2634 	struct spdk_nvmf_rdma_transport *rtransport;
2635 	struct spdk_nvmf_rdma_device	*device;
2636 	struct ibv_context		**contexts;
2637 	size_t				data_wr_pool_size;
2638 	uint32_t			i;
2639 	int				flag;
2640 	uint32_t			sge_count;
2641 	uint32_t			min_shared_buffers;
2642 	uint32_t			min_in_capsule_data_size;
2643 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2644 
2645 	rtransport = calloc(1, sizeof(*rtransport));
2646 	if (!rtransport) {
2647 		return NULL;
2648 	}
2649 
2650 	TAILQ_INIT(&rtransport->devices);
2651 	TAILQ_INIT(&rtransport->ports);
2652 	TAILQ_INIT(&rtransport->poll_groups);
2653 	TAILQ_INIT(&rtransport->retry_ports);
2654 
2655 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2656 	rtransport->rdma_opts.num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2657 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2658 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2659 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2660 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2661 	if (opts->transport_specific != NULL &&
2662 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2663 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2664 					    &rtransport->rdma_opts)) {
2665 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2666 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2667 		return NULL;
2668 	}
2669 
2670 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2671 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2672 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2673 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2674 		     "  num_shared_buffers=%d, num_cqe=%d, max_srq_depth=%d, no_srq=%d,"
2675 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2676 		     opts->max_queue_depth,
2677 		     opts->max_io_size,
2678 		     opts->max_qpairs_per_ctrlr - 1,
2679 		     opts->io_unit_size,
2680 		     opts->in_capsule_data_size,
2681 		     opts->max_aq_depth,
2682 		     opts->num_shared_buffers,
2683 		     rtransport->rdma_opts.num_cqe,
2684 		     rtransport->rdma_opts.max_srq_depth,
2685 		     rtransport->rdma_opts.no_srq,
2686 		     rtransport->rdma_opts.acceptor_backlog,
2687 		     rtransport->rdma_opts.no_wr_batching,
2688 		     opts->abort_timeout_sec);
2689 
2690 	/* I/O unit size cannot be larger than max I/O size */
2691 	if (opts->io_unit_size > opts->max_io_size) {
2692 		opts->io_unit_size = opts->max_io_size;
2693 	}
2694 
2695 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2696 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2697 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2698 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2699 	}
2700 
2701 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2702 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2703 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2704 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2705 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2706 		return NULL;
2707 	}
2708 
2709 	/* If buf_cache_size == UINT32_MAX, we will dynamically pick a cache size later that we know will fit. */
2710 	if (opts->buf_cache_size < UINT32_MAX) {
2711 		min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2712 		if (min_shared_buffers > opts->num_shared_buffers) {
2713 			SPDK_ERRLOG("There are not enough buffers to satisfy"
2714 				    "per-poll group caches for each thread. (%" PRIu32 ")"
2715 				    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2716 			SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2717 			nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2718 			return NULL;
2719 		}
2720 	}
2721 
2722 	sge_count = opts->max_io_size / opts->io_unit_size;
2723 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2724 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2725 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2726 		return NULL;
2727 	}
2728 
2729 	min_in_capsule_data_size = sizeof(struct spdk_nvme_sgl_descriptor) * SPDK_NVMF_MAX_SGL_ENTRIES;
2730 	if (opts->in_capsule_data_size < min_in_capsule_data_size) {
2731 		SPDK_WARNLOG("In capsule data size is set to %u, this is minimum size required to support msdbd=16\n",
2732 			     min_in_capsule_data_size);
2733 		opts->in_capsule_data_size = min_in_capsule_data_size;
2734 	}
2735 
2736 	rtransport->event_channel = rdma_create_event_channel();
2737 	if (rtransport->event_channel == NULL) {
2738 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2739 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2740 		return NULL;
2741 	}
2742 
2743 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2744 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2745 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2746 			    rtransport->event_channel->fd, spdk_strerror(errno));
2747 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2748 		return NULL;
2749 	}
2750 
2751 	data_wr_pool_size = opts->data_wr_pool_size;
2752 	if (data_wr_pool_size < SPDK_NVMF_MAX_SGL_ENTRIES * 2 * spdk_env_get_core_count()) {
2753 		data_wr_pool_size = SPDK_NVMF_MAX_SGL_ENTRIES * 2 * spdk_env_get_core_count();
2754 		SPDK_NOTICELOG("data_wr_pool_size is changed to %zu to guarantee enough cache for handling "
2755 			       "at least one IO in each core\n", data_wr_pool_size);
2756 	}
2757 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data", data_wr_pool_size,
2758 				   sizeof(struct spdk_nvmf_rdma_request_data), SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2759 				   SPDK_ENV_SOCKET_ID_ANY);
2760 	if (!rtransport->data_wr_pool) {
2761 		if (spdk_mempool_lookup("spdk_nvmf_rdma_wr_data") != NULL) {
2762 			SPDK_ERRLOG("Unable to allocate work request pool for poll group: already exists\n");
2763 			SPDK_ERRLOG("Probably running in multiprocess environment, which is "
2764 				    "unsupported by the nvmf library\n");
2765 		} else {
2766 			SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2767 		}
2768 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2769 		return NULL;
2770 	}
2771 
2772 	contexts = rdma_get_devices(NULL);
2773 	if (contexts == NULL) {
2774 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2775 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2776 		return NULL;
2777 	}
2778 
2779 	i = 0;
2780 	rc = 0;
2781 	while (contexts[i] != NULL) {
2782 		rc = create_ib_device(rtransport, contexts[i], &device);
2783 		if (rc < 0) {
2784 			break;
2785 		}
2786 		i++;
2787 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2788 		device->is_ready = true;
2789 	}
2790 	rdma_free_devices(contexts);
2791 
2792 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2793 		/* divide and round up. */
2794 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2795 
2796 		/* round up to the nearest 4k. */
2797 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2798 
2799 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2800 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2801 			       opts->io_unit_size);
2802 	}
2803 
2804 	if (rc < 0) {
2805 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2806 		return NULL;
2807 	}
2808 
2809 	rc = generate_poll_fds(rtransport);
2810 	if (rc < 0) {
2811 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2812 		return NULL;
2813 	}
2814 
2815 	rtransport->accept_poller = SPDK_POLLER_REGISTER(nvmf_rdma_accept, &rtransport->transport,
2816 				    opts->acceptor_poll_rate);
2817 	if (!rtransport->accept_poller) {
2818 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2819 		return NULL;
2820 	}
2821 
2822 	return &rtransport->transport;
2823 }
2824 
2825 static void
2826 destroy_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
2827 		  struct spdk_nvmf_rdma_device *device)
2828 {
2829 	TAILQ_REMOVE(&rtransport->devices, device, link);
2830 	spdk_rdma_utils_free_mem_map(&device->map);
2831 	if (device->pd) {
2832 		if (!g_nvmf_hooks.get_ibv_pd) {
2833 			ibv_dealloc_pd(device->pd);
2834 		}
2835 	}
2836 	SPDK_DEBUGLOG(rdma, "IB device [%p] is destroyed.\n", device);
2837 	free(device);
2838 }
2839 
2840 static void
2841 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2842 {
2843 	struct spdk_nvmf_rdma_transport	*rtransport;
2844 	assert(w != NULL);
2845 
2846 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2847 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2848 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2849 	if (rtransport->rdma_opts.no_srq == true) {
2850 		spdk_json_write_named_int32(w, "num_cqe", rtransport->rdma_opts.num_cqe);
2851 	}
2852 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2853 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2854 }
2855 
2856 static int
2857 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2858 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2859 {
2860 	struct spdk_nvmf_rdma_transport	*rtransport;
2861 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2862 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2863 
2864 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2865 
2866 	TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, port_tmp) {
2867 		TAILQ_REMOVE(&rtransport->retry_ports, port, link);
2868 		free(port);
2869 	}
2870 
2871 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2872 		TAILQ_REMOVE(&rtransport->ports, port, link);
2873 		rdma_destroy_id(port->id);
2874 		free(port);
2875 	}
2876 
2877 	free_poll_fds(rtransport);
2878 
2879 	if (rtransport->event_channel != NULL) {
2880 		rdma_destroy_event_channel(rtransport->event_channel);
2881 	}
2882 
2883 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2884 		destroy_ib_device(rtransport, device);
2885 	}
2886 
2887 	if (rtransport->data_wr_pool != NULL) {
2888 		if (spdk_mempool_count(rtransport->data_wr_pool) != transport->opts.data_wr_pool_size) {
2889 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2890 				    spdk_mempool_count(rtransport->data_wr_pool),
2891 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2892 		}
2893 	}
2894 
2895 	spdk_mempool_free(rtransport->data_wr_pool);
2896 
2897 	spdk_poller_unregister(&rtransport->accept_poller);
2898 	free(rtransport);
2899 
2900 	if (cb_fn) {
2901 		cb_fn(cb_arg);
2902 	}
2903 	return 0;
2904 }
2905 
2906 static int nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2907 				     struct spdk_nvme_transport_id *trid,
2908 				     bool peer);
2909 
2910 static bool nvmf_rdma_rescan_devices(struct spdk_nvmf_rdma_transport *rtransport);
2911 
2912 static int
2913 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2914 		 struct spdk_nvmf_listen_opts *listen_opts)
2915 {
2916 	struct spdk_nvmf_rdma_transport	*rtransport;
2917 	struct spdk_nvmf_rdma_device	*device;
2918 	struct spdk_nvmf_rdma_port	*port, *tmp_port;
2919 	struct addrinfo			*res;
2920 	struct addrinfo			hints;
2921 	int				family;
2922 	int				rc;
2923 	long int			port_val;
2924 	bool				is_retry = false;
2925 
2926 	if (!strlen(trid->trsvcid)) {
2927 		SPDK_ERRLOG("Service id is required\n");
2928 		return -EINVAL;
2929 	}
2930 
2931 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2932 	assert(rtransport->event_channel != NULL);
2933 
2934 	port = calloc(1, sizeof(*port));
2935 	if (!port) {
2936 		SPDK_ERRLOG("Port allocation failed\n");
2937 		return -ENOMEM;
2938 	}
2939 
2940 	port->trid = trid;
2941 
2942 	switch (trid->adrfam) {
2943 	case SPDK_NVMF_ADRFAM_IPV4:
2944 		family = AF_INET;
2945 		break;
2946 	case SPDK_NVMF_ADRFAM_IPV6:
2947 		family = AF_INET6;
2948 		break;
2949 	default:
2950 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2951 		free(port);
2952 		return -EINVAL;
2953 	}
2954 
2955 	memset(&hints, 0, sizeof(hints));
2956 	hints.ai_family = family;
2957 	hints.ai_flags = AI_NUMERICSERV;
2958 	hints.ai_socktype = SOCK_STREAM;
2959 	hints.ai_protocol = 0;
2960 
2961 	/* Range check the trsvcid. Fail in 3 cases:
2962 	 * < 0: means that spdk_strtol hit an error
2963 	 * 0: this results in ephemeral port which we don't want
2964 	 * > 65535: port too high
2965 	 */
2966 	port_val = spdk_strtol(trid->trsvcid, 10);
2967 	if (port_val <= 0 || port_val > 65535) {
2968 		SPDK_ERRLOG("invalid trsvcid %s\n", trid->trsvcid);
2969 		free(port);
2970 		return -EINVAL;
2971 	}
2972 
2973 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2974 	if (rc) {
2975 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2976 		free(port);
2977 		return -(abs(rc));
2978 	}
2979 
2980 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2981 	if (rc < 0) {
2982 		SPDK_ERRLOG("rdma_create_id() failed\n");
2983 		freeaddrinfo(res);
2984 		free(port);
2985 		return rc;
2986 	}
2987 
2988 	rc = rdma_bind_addr(port->id, res->ai_addr);
2989 	freeaddrinfo(res);
2990 
2991 	if (rc < 0) {
2992 		TAILQ_FOREACH(tmp_port, &rtransport->retry_ports, link) {
2993 			if (spdk_nvme_transport_id_compare(tmp_port->trid, trid) == 0) {
2994 				is_retry = true;
2995 				break;
2996 			}
2997 		}
2998 		if (!is_retry) {
2999 			SPDK_ERRLOG("rdma_bind_addr() failed\n");
3000 		}
3001 		rdma_destroy_id(port->id);
3002 		free(port);
3003 		return rc;
3004 	}
3005 
3006 	if (!port->id->verbs) {
3007 		SPDK_ERRLOG("ibv_context is null\n");
3008 		rdma_destroy_id(port->id);
3009 		free(port);
3010 		return -1;
3011 	}
3012 
3013 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
3014 	if (rc < 0) {
3015 		SPDK_ERRLOG("rdma_listen() failed\n");
3016 		rdma_destroy_id(port->id);
3017 		free(port);
3018 		return rc;
3019 	}
3020 
3021 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3022 		if (device->context == port->id->verbs && device->is_ready) {
3023 			port->device = device;
3024 			break;
3025 		}
3026 	}
3027 	if (!port->device) {
3028 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
3029 			    port->id->verbs);
3030 		rdma_destroy_id(port->id);
3031 		free(port);
3032 		nvmf_rdma_rescan_devices(rtransport);
3033 		return -EINVAL;
3034 	}
3035 
3036 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
3037 		       trid->traddr, trid->trsvcid);
3038 
3039 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
3040 	return 0;
3041 }
3042 
3043 static void
3044 nvmf_rdma_stop_listen_ex(struct spdk_nvmf_transport *transport,
3045 			 const struct spdk_nvme_transport_id *trid, bool need_retry)
3046 {
3047 	struct spdk_nvmf_rdma_transport	*rtransport;
3048 	struct spdk_nvmf_rdma_port	*port, *tmp;
3049 
3050 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3051 
3052 	if (!need_retry) {
3053 		TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, tmp) {
3054 			if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
3055 				TAILQ_REMOVE(&rtransport->retry_ports, port, link);
3056 				free(port);
3057 			}
3058 		}
3059 	}
3060 
3061 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
3062 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
3063 			SPDK_DEBUGLOG(rdma, "Port %s:%s removed. need retry: %d\n",
3064 				      port->trid->traddr, port->trid->trsvcid, need_retry);
3065 			TAILQ_REMOVE(&rtransport->ports, port, link);
3066 			rdma_destroy_id(port->id);
3067 			port->id = NULL;
3068 			port->device = NULL;
3069 			if (need_retry) {
3070 				TAILQ_INSERT_TAIL(&rtransport->retry_ports, port, link);
3071 			} else {
3072 				free(port);
3073 			}
3074 			break;
3075 		}
3076 	}
3077 }
3078 
3079 static void
3080 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
3081 		      const struct spdk_nvme_transport_id *trid)
3082 {
3083 	nvmf_rdma_stop_listen_ex(transport, trid, false);
3084 }
3085 
3086 static void _nvmf_rdma_register_poller_in_group(void *c);
3087 static void _nvmf_rdma_remove_poller_in_group(void *c);
3088 
3089 static bool
3090 nvmf_rdma_all_pollers_management_done(void *c)
3091 {
3092 	struct poller_manage_ctx	*ctx = c;
3093 	int				counter;
3094 
3095 	counter = __atomic_sub_fetch(ctx->inflight_op_counter, 1, __ATOMIC_SEQ_CST);
3096 	SPDK_DEBUGLOG(rdma, "nvmf_rdma_all_pollers_management_done called. counter: %d, poller: %p\n",
3097 		      counter, ctx->rpoller);
3098 
3099 	if (counter == 0) {
3100 		free((void *)ctx->inflight_op_counter);
3101 	}
3102 	free(ctx);
3103 
3104 	return counter == 0;
3105 }
3106 
3107 static int
3108 nvmf_rdma_manage_poller(struct spdk_nvmf_rdma_transport *rtransport,
3109 			struct spdk_nvmf_rdma_device *device, bool *has_inflight, bool is_add)
3110 {
3111 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3112 	struct spdk_nvmf_rdma_poller		*rpoller;
3113 	struct spdk_nvmf_poll_group		*poll_group;
3114 	struct poller_manage_ctx		*ctx;
3115 	bool					found;
3116 	int					*inflight_counter;
3117 	spdk_msg_fn				do_fn;
3118 
3119 	*has_inflight = false;
3120 	do_fn = is_add ? _nvmf_rdma_register_poller_in_group : _nvmf_rdma_remove_poller_in_group;
3121 	inflight_counter = calloc(1, sizeof(int));
3122 	if (!inflight_counter) {
3123 		SPDK_ERRLOG("Failed to allocate inflight counter when removing pollers\n");
3124 		return -ENOMEM;
3125 	}
3126 
3127 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3128 		(*inflight_counter)++;
3129 	}
3130 
3131 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3132 		found = false;
3133 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3134 			if (rpoller->device == device) {
3135 				found = true;
3136 				break;
3137 			}
3138 		}
3139 		if (found == is_add) {
3140 			__atomic_fetch_sub(inflight_counter, 1, __ATOMIC_SEQ_CST);
3141 			continue;
3142 		}
3143 
3144 		ctx = calloc(1, sizeof(struct poller_manage_ctx));
3145 		if (!ctx) {
3146 			SPDK_ERRLOG("Failed to allocate poller_manage_ctx when removing pollers\n");
3147 			if (!*has_inflight) {
3148 				free(inflight_counter);
3149 			}
3150 			return -ENOMEM;
3151 		}
3152 
3153 		ctx->rtransport = rtransport;
3154 		ctx->rgroup = rgroup;
3155 		ctx->rpoller = rpoller;
3156 		ctx->device = device;
3157 		ctx->thread = spdk_get_thread();
3158 		ctx->inflight_op_counter = inflight_counter;
3159 		*has_inflight = true;
3160 
3161 		poll_group = rgroup->group.group;
3162 		if (poll_group->thread != spdk_get_thread()) {
3163 			spdk_thread_send_msg(poll_group->thread, do_fn, ctx);
3164 		} else {
3165 			do_fn(ctx);
3166 		}
3167 	}
3168 
3169 	if (!*has_inflight) {
3170 		free(inflight_counter);
3171 	}
3172 
3173 	return 0;
3174 }
3175 
3176 static void nvmf_rdma_handle_device_removal(struct spdk_nvmf_rdma_transport *rtransport,
3177 		struct spdk_nvmf_rdma_device *device);
3178 
3179 static struct spdk_nvmf_rdma_device *
3180 nvmf_rdma_find_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
3181 			 struct ibv_context *context)
3182 {
3183 	struct spdk_nvmf_rdma_device	*device, *tmp_device;
3184 
3185 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp_device) {
3186 		if (device->need_destroy) {
3187 			continue;
3188 		}
3189 
3190 		if (strcmp(device->context->device->dev_name, context->device->dev_name) == 0) {
3191 			return device;
3192 		}
3193 	}
3194 
3195 	return NULL;
3196 }
3197 
3198 static bool
3199 nvmf_rdma_check_devices_context(struct spdk_nvmf_rdma_transport *rtransport,
3200 				struct ibv_context *context)
3201 {
3202 	struct spdk_nvmf_rdma_device	*old_device, *new_device;
3203 	int				rc = 0;
3204 	bool				has_inflight;
3205 
3206 	old_device = nvmf_rdma_find_ib_device(rtransport, context);
3207 
3208 	if (old_device) {
3209 		if (old_device->context != context && !old_device->need_destroy && old_device->is_ready) {
3210 			/* context may not have time to be cleaned when rescan. exactly one context
3211 			 * is valid for a device so this context must be invalid and just remove it. */
3212 			SPDK_WARNLOG("Device %p has a invalid context %p\n", old_device, old_device->context);
3213 			old_device->need_destroy = true;
3214 			nvmf_rdma_handle_device_removal(rtransport, old_device);
3215 		}
3216 		return false;
3217 	}
3218 
3219 	rc = create_ib_device(rtransport, context, &new_device);
3220 	/* TODO: update transport opts. */
3221 	if (rc < 0) {
3222 		SPDK_ERRLOG("Failed to create ib device for context: %s(%p)\n",
3223 			    ibv_get_device_name(context->device), context);
3224 		return false;
3225 	}
3226 
3227 	rc = nvmf_rdma_manage_poller(rtransport, new_device, &has_inflight, true);
3228 	if (rc < 0) {
3229 		SPDK_ERRLOG("Failed to add poller for device context: %s(%p)\n",
3230 			    ibv_get_device_name(context->device), context);
3231 		return false;
3232 	}
3233 
3234 	if (has_inflight) {
3235 		new_device->is_ready = true;
3236 	}
3237 
3238 	return true;
3239 }
3240 
3241 static bool
3242 nvmf_rdma_rescan_devices(struct spdk_nvmf_rdma_transport *rtransport)
3243 {
3244 	struct spdk_nvmf_rdma_device	*device;
3245 	struct ibv_device		**ibv_device_list = NULL;
3246 	struct ibv_context		**contexts = NULL;
3247 	int				i = 0;
3248 	int				num_dev = 0;
3249 	bool				new_create = false, has_new_device = false;
3250 	struct ibv_context		*tmp_verbs = NULL;
3251 
3252 	/* do not rescan when any device is destroying, or context may be freed when
3253 	 * regenerating the poll fds.
3254 	 */
3255 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3256 		if (device->need_destroy) {
3257 			return false;
3258 		}
3259 	}
3260 
3261 	ibv_device_list = ibv_get_device_list(&num_dev);
3262 
3263 	/* There is a bug in librdmacm. If verbs init failed in rdma_get_devices, it'll be
3264 	 * marked as dead verbs and never be init again. So we need to make sure the
3265 	 * verbs is available before we call rdma_get_devices. */
3266 	if (num_dev >= 0) {
3267 		for (i = 0; i < num_dev; i++) {
3268 			tmp_verbs = ibv_open_device(ibv_device_list[i]);
3269 			if (!tmp_verbs) {
3270 				SPDK_WARNLOG("Failed to init ibv device %p, err %d. Skip rescan.\n", ibv_device_list[i], errno);
3271 				break;
3272 			}
3273 			if (nvmf_rdma_find_ib_device(rtransport, tmp_verbs) == NULL) {
3274 				SPDK_DEBUGLOG(rdma, "Find new verbs init ibv device %p(%s).\n", ibv_device_list[i],
3275 					      tmp_verbs->device->dev_name);
3276 				has_new_device = true;
3277 			}
3278 			ibv_close_device(tmp_verbs);
3279 		}
3280 		ibv_free_device_list(ibv_device_list);
3281 		if (!tmp_verbs || !has_new_device) {
3282 			return false;
3283 		}
3284 	}
3285 
3286 	contexts = rdma_get_devices(NULL);
3287 
3288 	for (i = 0; contexts && contexts[i] != NULL; i++) {
3289 		new_create |= nvmf_rdma_check_devices_context(rtransport, contexts[i]);
3290 	}
3291 
3292 	if (new_create) {
3293 		free_poll_fds(rtransport);
3294 		generate_poll_fds(rtransport);
3295 	}
3296 
3297 	if (contexts) {
3298 		rdma_free_devices(contexts);
3299 	}
3300 
3301 	return new_create;
3302 }
3303 
3304 static bool
3305 nvmf_rdma_retry_listen_port(struct spdk_nvmf_rdma_transport *rtransport)
3306 {
3307 	struct spdk_nvmf_rdma_port	*port, *tmp_port;
3308 	int				rc = 0;
3309 	bool				new_create = false;
3310 
3311 	if (TAILQ_EMPTY(&rtransport->retry_ports)) {
3312 		return false;
3313 	}
3314 
3315 	new_create = nvmf_rdma_rescan_devices(rtransport);
3316 
3317 	TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, tmp_port) {
3318 		rc = nvmf_rdma_listen(&rtransport->transport, port->trid, NULL);
3319 
3320 		TAILQ_REMOVE(&rtransport->retry_ports, port, link);
3321 		if (rc) {
3322 			if (new_create) {
3323 				SPDK_ERRLOG("Found new IB device but port %s:%s is still failed(%d) to listen.\n",
3324 					    port->trid->traddr, port->trid->trsvcid, rc);
3325 			}
3326 			TAILQ_INSERT_TAIL(&rtransport->retry_ports, port, link);
3327 			break;
3328 		} else {
3329 			SPDK_NOTICELOG("Port %s:%s come back\n", port->trid->traddr, port->trid->trsvcid);
3330 			free(port);
3331 		}
3332 	}
3333 
3334 	return true;
3335 }
3336 
3337 static void
3338 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
3339 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
3340 {
3341 	struct spdk_nvmf_request *req, *tmp;
3342 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
3343 	struct spdk_nvmf_rdma_resources *resources;
3344 
3345 	/* First process requests which are waiting for response to be sent */
3346 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_send_queue, state_link, req_tmp) {
3347 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3348 			break;
3349 		}
3350 	}
3351 
3352 	/* We process I/O in the data transfer pending queue at the highest priority. */
3353 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
3354 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3355 			break;
3356 		}
3357 	}
3358 
3359 	/* Then RDMA writes since reads have stronger restrictions than writes */
3360 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
3361 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3362 			break;
3363 		}
3364 	}
3365 
3366 	/* Then we handle request waiting on memory buffers. */
3367 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
3368 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3369 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3370 			break;
3371 		}
3372 	}
3373 
3374 	resources = rqpair->resources;
3375 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
3376 		rdma_req = STAILQ_FIRST(&resources->free_queue);
3377 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
3378 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
3379 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
3380 
3381 		if (rqpair->srq != NULL) {
3382 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
3383 			rdma_req->recv->qpair->qd++;
3384 		} else {
3385 			rqpair->qd++;
3386 		}
3387 
3388 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
3389 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
3390 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
3391 			break;
3392 		}
3393 	}
3394 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
3395 		rqpair->poller->stat.pending_free_request++;
3396 	}
3397 }
3398 
3399 static void
3400 nvmf_rdma_poller_process_pending_buf_queue(struct spdk_nvmf_rdma_transport *rtransport,
3401 		struct spdk_nvmf_rdma_poller *rpoller)
3402 {
3403 	struct spdk_nvmf_request *req, *tmp;
3404 	struct spdk_nvmf_rdma_request *rdma_req;
3405 
3406 	STAILQ_FOREACH_SAFE(req, &rpoller->group->group.pending_buf_queue, buf_link, tmp) {
3407 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3408 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
3409 			break;
3410 		}
3411 	}
3412 }
3413 
3414 static inline bool
3415 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
3416 {
3417 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
3418 	return nvmf_rdma_is_rxe_device(device) ||
3419 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
3420 }
3421 
3422 static void
3423 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
3424 {
3425 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3426 			struct spdk_nvmf_rdma_transport, transport);
3427 
3428 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3429 
3430 	/* nvmf_rdma_close_qpair is not called */
3431 	if (!rqpair->to_close) {
3432 		return;
3433 	}
3434 
3435 	/* device is already destroyed and we should force destroy this qpair. */
3436 	if (rqpair->poller && rqpair->poller->need_destroy) {
3437 		nvmf_rdma_qpair_destroy(rqpair);
3438 		return;
3439 	}
3440 
3441 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
3442 	if (rqpair->current_send_depth != 0) {
3443 		return;
3444 	}
3445 
3446 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
3447 		return;
3448 	}
3449 
3450 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
3451 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
3452 		return;
3453 	}
3454 
3455 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
3456 
3457 	nvmf_rdma_qpair_destroy(rqpair);
3458 }
3459 
3460 static int
3461 nvmf_rdma_disconnect(struct rdma_cm_event *evt, bool *event_acked)
3462 {
3463 	struct spdk_nvmf_qpair		*qpair;
3464 	struct spdk_nvmf_rdma_qpair	*rqpair;
3465 
3466 	if (evt->id == NULL) {
3467 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
3468 		return -1;
3469 	}
3470 
3471 	qpair = evt->id->context;
3472 	if (qpair == NULL) {
3473 		SPDK_ERRLOG("disconnect request: no active connection\n");
3474 		return -1;
3475 	}
3476 
3477 	rdma_ack_cm_event(evt);
3478 	*event_acked = true;
3479 
3480 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3481 
3482 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair);
3483 
3484 	spdk_nvmf_qpair_disconnect(&rqpair->qpair);
3485 
3486 	return 0;
3487 }
3488 
3489 #ifdef DEBUG
3490 static const char *CM_EVENT_STR[] = {
3491 	"RDMA_CM_EVENT_ADDR_RESOLVED",
3492 	"RDMA_CM_EVENT_ADDR_ERROR",
3493 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
3494 	"RDMA_CM_EVENT_ROUTE_ERROR",
3495 	"RDMA_CM_EVENT_CONNECT_REQUEST",
3496 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
3497 	"RDMA_CM_EVENT_CONNECT_ERROR",
3498 	"RDMA_CM_EVENT_UNREACHABLE",
3499 	"RDMA_CM_EVENT_REJECTED",
3500 	"RDMA_CM_EVENT_ESTABLISHED",
3501 	"RDMA_CM_EVENT_DISCONNECTED",
3502 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
3503 	"RDMA_CM_EVENT_MULTICAST_JOIN",
3504 	"RDMA_CM_EVENT_MULTICAST_ERROR",
3505 	"RDMA_CM_EVENT_ADDR_CHANGE",
3506 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
3507 };
3508 #endif /* DEBUG */
3509 
3510 static void
3511 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
3512 				    struct spdk_nvmf_rdma_port *port)
3513 {
3514 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3515 	struct spdk_nvmf_rdma_poller		*rpoller;
3516 	struct spdk_nvmf_rdma_qpair		*rqpair;
3517 
3518 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3519 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3520 			RB_FOREACH(rqpair, qpairs_tree, &rpoller->qpairs) {
3521 				if (rqpair->listen_id == port->id) {
3522 					spdk_nvmf_qpair_disconnect(&rqpair->qpair);
3523 				}
3524 			}
3525 		}
3526 	}
3527 }
3528 
3529 static bool
3530 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
3531 				      struct rdma_cm_event *event)
3532 {
3533 	const struct spdk_nvme_transport_id	*trid;
3534 	struct spdk_nvmf_rdma_port		*port;
3535 	struct spdk_nvmf_rdma_transport		*rtransport;
3536 	bool					event_acked = false;
3537 
3538 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3539 	TAILQ_FOREACH(port, &rtransport->ports, link) {
3540 		if (port->id == event->id) {
3541 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
3542 			rdma_ack_cm_event(event);
3543 			event_acked = true;
3544 			trid = port->trid;
3545 			break;
3546 		}
3547 	}
3548 
3549 	if (event_acked) {
3550 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
3551 
3552 		nvmf_rdma_stop_listen(transport, trid);
3553 		nvmf_rdma_listen(transport, trid, NULL);
3554 	}
3555 
3556 	return event_acked;
3557 }
3558 
3559 static void
3560 nvmf_rdma_handle_device_removal(struct spdk_nvmf_rdma_transport *rtransport,
3561 				struct spdk_nvmf_rdma_device *device)
3562 {
3563 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
3564 	int				rc;
3565 	bool				has_inflight;
3566 
3567 	rc = nvmf_rdma_manage_poller(rtransport, device, &has_inflight, false);
3568 	if (rc) {
3569 		SPDK_ERRLOG("Failed to handle device removal, rc %d\n", rc);
3570 		return;
3571 	}
3572 
3573 	if (!has_inflight) {
3574 		/* no pollers, destroy the device */
3575 		device->ready_to_destroy = true;
3576 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_remove_destroyed_device, rtransport);
3577 	}
3578 
3579 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
3580 		if (port->device == device) {
3581 			SPDK_NOTICELOG("Port %s:%s on device %s is being removed.\n",
3582 				       port->trid->traddr,
3583 				       port->trid->trsvcid,
3584 				       ibv_get_device_name(port->device->context->device));
3585 
3586 			/* keep NVMF listener and only destroy structures of the
3587 			 * RDMA transport. when the device comes back we can retry listening
3588 			 * and the application's workflow will not be interrupted.
3589 			 */
3590 			nvmf_rdma_stop_listen_ex(&rtransport->transport, port->trid, true);
3591 		}
3592 	}
3593 }
3594 
3595 static void
3596 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
3597 				       struct rdma_cm_event *event)
3598 {
3599 	struct spdk_nvmf_rdma_port		*port, *tmp_port;
3600 	struct spdk_nvmf_rdma_transport		*rtransport;
3601 
3602 	port = event->id->context;
3603 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3604 
3605 	rdma_ack_cm_event(event);
3606 
3607 	/* if device removal happens during ctrl qpair disconnecting, it's possible that we receive
3608 	 * an DEVICE_REMOVAL event on qpair but the id->qp is just NULL. So we should make sure that
3609 	 * we are handling a port event here.
3610 	 */
3611 	TAILQ_FOREACH(tmp_port, &rtransport->ports, link) {
3612 		if (port == tmp_port && port->device && !port->device->need_destroy) {
3613 			port->device->need_destroy = true;
3614 			nvmf_rdma_handle_device_removal(rtransport, port->device);
3615 		}
3616 	}
3617 }
3618 
3619 static void
3620 nvmf_process_cm_events(struct spdk_nvmf_transport *transport, uint32_t max_events)
3621 {
3622 	struct spdk_nvmf_rdma_transport *rtransport;
3623 	struct rdma_cm_event		*event;
3624 	uint32_t			i;
3625 	int				rc;
3626 	bool				event_acked;
3627 
3628 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3629 
3630 	if (rtransport->event_channel == NULL) {
3631 		return;
3632 	}
3633 
3634 	for (i = 0; i < max_events; i++) {
3635 		event_acked = false;
3636 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
3637 		if (rc) {
3638 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
3639 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
3640 			}
3641 			break;
3642 		}
3643 
3644 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
3645 
3646 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
3647 
3648 		switch (event->event) {
3649 		case RDMA_CM_EVENT_ADDR_RESOLVED:
3650 		case RDMA_CM_EVENT_ADDR_ERROR:
3651 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
3652 		case RDMA_CM_EVENT_ROUTE_ERROR:
3653 			/* No action required. The target never attempts to resolve routes. */
3654 			break;
3655 		case RDMA_CM_EVENT_CONNECT_REQUEST:
3656 			rc = nvmf_rdma_connect(transport, event);
3657 			if (rc < 0) {
3658 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
3659 				break;
3660 			}
3661 			break;
3662 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
3663 			/* The target never initiates a new connection. So this will not occur. */
3664 			break;
3665 		case RDMA_CM_EVENT_CONNECT_ERROR:
3666 			/* Can this happen? The docs say it can, but not sure what causes it. */
3667 			break;
3668 		case RDMA_CM_EVENT_UNREACHABLE:
3669 		case RDMA_CM_EVENT_REJECTED:
3670 			/* These only occur on the client side. */
3671 			break;
3672 		case RDMA_CM_EVENT_ESTABLISHED:
3673 			/* TODO: Should we be waiting for this event anywhere? */
3674 			break;
3675 		case RDMA_CM_EVENT_DISCONNECTED:
3676 			rc = nvmf_rdma_disconnect(event, &event_acked);
3677 			if (rc < 0) {
3678 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3679 				break;
3680 			}
3681 			break;
3682 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
3683 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
3684 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
3685 			 * Once these events are sent to SPDK, we should release all IB resources and
3686 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
3687 			 * ibv_destroy* functions to release user space memory allocated by IB. All kernel
3688 			 * resources are already cleaned. */
3689 			if (event->id->qp) {
3690 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
3691 				 * corresponding qpair. Otherwise the event refers to a listening device. */
3692 				rc = nvmf_rdma_disconnect(event, &event_acked);
3693 				if (rc < 0) {
3694 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3695 					break;
3696 				}
3697 			} else {
3698 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3699 				event_acked = true;
3700 			}
3701 			break;
3702 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3703 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3704 			/* Multicast is not used */
3705 			break;
3706 		case RDMA_CM_EVENT_ADDR_CHANGE:
3707 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3708 			break;
3709 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3710 			/* For now, do nothing. The target never re-uses queue pairs. */
3711 			break;
3712 		default:
3713 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3714 			break;
3715 		}
3716 		if (!event_acked) {
3717 			rdma_ack_cm_event(event);
3718 		}
3719 	}
3720 }
3721 
3722 static void
3723 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3724 {
3725 	rqpair->last_wqe_reached = true;
3726 	nvmf_rdma_destroy_drained_qpair(rqpair);
3727 }
3728 
3729 static void
3730 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3731 {
3732 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3733 
3734 	if (event_ctx->rqpair) {
3735 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3736 		if (event_ctx->cb_fn) {
3737 			event_ctx->cb_fn(event_ctx->rqpair);
3738 		}
3739 	}
3740 	free(event_ctx);
3741 }
3742 
3743 static int
3744 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3745 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3746 {
3747 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3748 	struct spdk_thread *thr = NULL;
3749 	int rc;
3750 
3751 	if (rqpair->qpair.group) {
3752 		thr = rqpair->qpair.group->thread;
3753 	} else if (rqpair->destruct_channel) {
3754 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3755 	}
3756 
3757 	if (!thr) {
3758 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3759 		return -EINVAL;
3760 	}
3761 
3762 	ctx = calloc(1, sizeof(*ctx));
3763 	if (!ctx) {
3764 		return -ENOMEM;
3765 	}
3766 
3767 	ctx->rqpair = rqpair;
3768 	ctx->cb_fn = fn;
3769 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3770 
3771 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3772 	if (rc) {
3773 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3774 		free(ctx);
3775 	}
3776 
3777 	return rc;
3778 }
3779 
3780 static int
3781 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3782 {
3783 	int				rc;
3784 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3785 	struct ibv_async_event		event;
3786 
3787 	rc = ibv_get_async_event(device->context, &event);
3788 
3789 	if (rc) {
3790 		/* In non-blocking mode -1 means there are no events available */
3791 		return rc;
3792 	}
3793 
3794 	switch (event.event_type) {
3795 	case IBV_EVENT_QP_FATAL:
3796 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3797 	case IBV_EVENT_QP_REQ_ERR:
3798 	case IBV_EVENT_QP_ACCESS_ERR:
3799 	case IBV_EVENT_COMM_EST:
3800 	case IBV_EVENT_PATH_MIG:
3801 	case IBV_EVENT_PATH_MIG_ERR:
3802 		rqpair = event.element.qp->qp_context;
3803 		if (!rqpair) {
3804 			/* Any QP event for NVMe-RDMA initiator may be returned. */
3805 			SPDK_NOTICELOG("Async QP event for unknown QP: %s\n",
3806 				       ibv_event_type_str(event.event_type));
3807 			break;
3808 		}
3809 
3810 		switch (event.event_type) {
3811 		case IBV_EVENT_QP_FATAL:
3812 			SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3813 			spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3814 					  (uintptr_t)rqpair, event.event_type);
3815 			rqpair->ibv_in_error_state = true;
3816 			spdk_nvmf_qpair_disconnect(&rqpair->qpair);
3817 			break;
3818 		case IBV_EVENT_QP_LAST_WQE_REACHED:
3819 			/* This event only occurs for shared receive queues. */
3820 			SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3821 			rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3822 			if (rc) {
3823 				SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3824 				rqpair->last_wqe_reached = true;
3825 			}
3826 			break;
3827 		case IBV_EVENT_QP_REQ_ERR:
3828 		case IBV_EVENT_QP_ACCESS_ERR:
3829 		case IBV_EVENT_COMM_EST:
3830 		case IBV_EVENT_PATH_MIG:
3831 		case IBV_EVENT_PATH_MIG_ERR:
3832 			SPDK_NOTICELOG("Async QP event: %s\n",
3833 				       ibv_event_type_str(event.event_type));
3834 			spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3835 					  (uintptr_t)rqpair, event.event_type);
3836 			rqpair->ibv_in_error_state = true;
3837 			break;
3838 		default:
3839 			break;
3840 		}
3841 		break;
3842 	case IBV_EVENT_DEVICE_FATAL:
3843 		SPDK_ERRLOG("Device Fatal event[%s] received on %s. device: %p\n",
3844 			    ibv_event_type_str(event.event_type), ibv_get_device_name(device->context->device), device);
3845 		device->need_destroy = true;
3846 		break;
3847 	case IBV_EVENT_CQ_ERR:
3848 	case IBV_EVENT_PORT_ACTIVE:
3849 	case IBV_EVENT_PORT_ERR:
3850 	case IBV_EVENT_LID_CHANGE:
3851 	case IBV_EVENT_PKEY_CHANGE:
3852 	case IBV_EVENT_SM_CHANGE:
3853 	case IBV_EVENT_SRQ_ERR:
3854 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3855 	case IBV_EVENT_CLIENT_REREGISTER:
3856 	case IBV_EVENT_GID_CHANGE:
3857 	case IBV_EVENT_SQ_DRAINED:
3858 	default:
3859 		SPDK_NOTICELOG("Async event: %s\n",
3860 			       ibv_event_type_str(event.event_type));
3861 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3862 		break;
3863 	}
3864 	ibv_ack_async_event(&event);
3865 
3866 	return 0;
3867 }
3868 
3869 static void
3870 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3871 {
3872 	int rc = 0;
3873 	uint32_t i = 0;
3874 
3875 	for (i = 0; i < max_events; i++) {
3876 		rc = nvmf_process_ib_event(device);
3877 		if (rc) {
3878 			break;
3879 		}
3880 	}
3881 
3882 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3883 }
3884 
3885 static int
3886 nvmf_rdma_accept(void *ctx)
3887 {
3888 	int	nfds, i = 0;
3889 	struct spdk_nvmf_transport *transport = ctx;
3890 	struct spdk_nvmf_rdma_transport *rtransport;
3891 	struct spdk_nvmf_rdma_device *device, *tmp;
3892 	uint32_t count;
3893 	short revents;
3894 	bool do_retry;
3895 
3896 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3897 	do_retry = nvmf_rdma_retry_listen_port(rtransport);
3898 
3899 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3900 
3901 	if (nfds <= 0) {
3902 		return do_retry ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3903 	}
3904 
3905 	/* The first poll descriptor is RDMA CM event */
3906 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3907 		nvmf_process_cm_events(transport, NVMF_RDMA_MAX_EVENTS_PER_POLL);
3908 		nfds--;
3909 	}
3910 
3911 	if (nfds == 0) {
3912 		return SPDK_POLLER_BUSY;
3913 	}
3914 
3915 	/* Second and subsequent poll descriptors are IB async events */
3916 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3917 		revents = rtransport->poll_fds[i++].revents;
3918 		if (revents & POLLIN) {
3919 			if (spdk_likely(!device->need_destroy)) {
3920 				nvmf_process_ib_events(device, NVMF_RDMA_MAX_EVENTS_PER_POLL);
3921 				if (spdk_unlikely(device->need_destroy)) {
3922 					nvmf_rdma_handle_device_removal(rtransport, device);
3923 				}
3924 			}
3925 			nfds--;
3926 		} else if (revents & POLLNVAL || revents & POLLHUP) {
3927 			SPDK_ERRLOG("Receive unknown revent %x on device %p\n", (int)revents, device);
3928 			nfds--;
3929 		}
3930 	}
3931 	/* check all flagged fd's have been served */
3932 	assert(nfds == 0);
3933 
3934 	return count > 0 ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3935 }
3936 
3937 static void
3938 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3939 		     struct spdk_nvmf_ctrlr_data *cdata)
3940 {
3941 	cdata->nvmf_specific.msdbd = NVMF_DEFAULT_MSDBD;
3942 
3943 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3944 	since in-capsule data only works with NVME drives that support SGL memory layout */
3945 	if (transport->opts.dif_insert_or_strip) {
3946 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3947 	}
3948 
3949 	if (cdata->nvmf_specific.ioccsz > ((sizeof(struct spdk_nvme_cmd) + 0x1000) / 16)) {
3950 		SPDK_WARNLOG("RDMA is configured to support up to 16 SGL entries while in capsule"
3951 			     " data is greater than 4KiB.\n");
3952 		SPDK_WARNLOG("When used in conjunction with the NVMe-oF initiator from the Linux "
3953 			     "kernel between versions 5.4 and 5.12 data corruption may occur for "
3954 			     "writes that are not a multiple of 4KiB in size.\n");
3955 	}
3956 }
3957 
3958 static void
3959 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3960 		   struct spdk_nvme_transport_id *trid,
3961 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3962 {
3963 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3964 	entry->adrfam = trid->adrfam;
3965 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3966 
3967 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3968 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3969 
3970 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3971 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3972 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3973 }
3974 
3975 static int
3976 nvmf_rdma_poller_create(struct spdk_nvmf_rdma_transport *rtransport,
3977 			struct spdk_nvmf_rdma_poll_group *rgroup, struct spdk_nvmf_rdma_device *device,
3978 			struct spdk_nvmf_rdma_poller **out_poller)
3979 {
3980 	struct spdk_nvmf_rdma_poller		*poller;
3981 	struct spdk_rdma_provider_srq_init_attr	srq_init_attr;
3982 	struct spdk_nvmf_rdma_resource_opts	opts;
3983 	int					num_cqe;
3984 
3985 	poller = calloc(1, sizeof(*poller));
3986 	if (!poller) {
3987 		SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3988 		return -1;
3989 	}
3990 
3991 	poller->device = device;
3992 	poller->group = rgroup;
3993 	*out_poller = poller;
3994 
3995 	RB_INIT(&poller->qpairs);
3996 	STAILQ_INIT(&poller->qpairs_pending_send);
3997 	STAILQ_INIT(&poller->qpairs_pending_recv);
3998 
3999 	TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
4000 	SPDK_DEBUGLOG(rdma, "Create poller %p on device %p in poll group %p.\n", poller, device, rgroup);
4001 	if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
4002 		if ((int)rtransport->rdma_opts.max_srq_depth > device->attr.max_srq_wr) {
4003 			SPDK_WARNLOG("Requested SRQ depth %u, max supported by dev %s is %d\n",
4004 				     rtransport->rdma_opts.max_srq_depth, device->context->device->name, device->attr.max_srq_wr);
4005 		}
4006 		poller->max_srq_depth = spdk_min((int)rtransport->rdma_opts.max_srq_depth, device->attr.max_srq_wr);
4007 
4008 		device->num_srq++;
4009 		memset(&srq_init_attr, 0, sizeof(srq_init_attr));
4010 		srq_init_attr.pd = device->pd;
4011 		srq_init_attr.stats = &poller->stat.qp_stats.recv;
4012 		srq_init_attr.srq_init_attr.attr.max_wr = poller->max_srq_depth;
4013 		srq_init_attr.srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
4014 		poller->srq = spdk_rdma_provider_srq_create(&srq_init_attr);
4015 		if (!poller->srq) {
4016 			SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
4017 			return -1;
4018 		}
4019 
4020 		opts.qp = poller->srq;
4021 		opts.map = device->map;
4022 		opts.qpair = NULL;
4023 		opts.shared = true;
4024 		opts.max_queue_depth = poller->max_srq_depth;
4025 		opts.in_capsule_data_size = rtransport->transport.opts.in_capsule_data_size;
4026 
4027 		poller->resources = nvmf_rdma_resources_create(&opts);
4028 		if (!poller->resources) {
4029 			SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
4030 			return -1;
4031 		}
4032 	}
4033 
4034 	/*
4035 	 * When using an srq, we can limit the completion queue at startup.
4036 	 * The following formula represents the calculation:
4037 	 * num_cqe = num_recv + num_data_wr + num_send_wr.
4038 	 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
4039 	 */
4040 	if (poller->srq) {
4041 		num_cqe = poller->max_srq_depth * 3;
4042 	} else {
4043 		num_cqe = rtransport->rdma_opts.num_cqe;
4044 	}
4045 
4046 	poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
4047 	if (!poller->cq) {
4048 		SPDK_ERRLOG("Unable to create completion queue\n");
4049 		return -1;
4050 	}
4051 	poller->num_cqe = num_cqe;
4052 	return 0;
4053 }
4054 
4055 static void
4056 _nvmf_rdma_register_poller_in_group(void *c)
4057 {
4058 	struct spdk_nvmf_rdma_poller	*poller;
4059 	struct poller_manage_ctx	*ctx = c;
4060 	struct spdk_nvmf_rdma_device	*device;
4061 	int				rc;
4062 
4063 	rc = nvmf_rdma_poller_create(ctx->rtransport, ctx->rgroup, ctx->device, &poller);
4064 	if (rc < 0 && poller) {
4065 		nvmf_rdma_poller_destroy(poller);
4066 	}
4067 
4068 	device = ctx->device;
4069 	if (nvmf_rdma_all_pollers_management_done(ctx)) {
4070 		device->is_ready = true;
4071 	}
4072 }
4073 
4074 static void nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
4075 
4076 static struct spdk_nvmf_transport_poll_group *
4077 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport,
4078 			    struct spdk_nvmf_poll_group *group)
4079 {
4080 	struct spdk_nvmf_rdma_transport		*rtransport;
4081 	struct spdk_nvmf_rdma_poll_group	*rgroup;
4082 	struct spdk_nvmf_rdma_poller		*poller;
4083 	struct spdk_nvmf_rdma_device		*device;
4084 	int					rc;
4085 
4086 	if (spdk_interrupt_mode_is_enabled()) {
4087 		SPDK_ERRLOG("RDMA transport does not support interrupt mode\n");
4088 		return NULL;
4089 	}
4090 
4091 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
4092 
4093 	rgroup = calloc(1, sizeof(*rgroup));
4094 	if (!rgroup) {
4095 		return NULL;
4096 	}
4097 
4098 	TAILQ_INIT(&rgroup->pollers);
4099 
4100 	TAILQ_FOREACH(device, &rtransport->devices, link) {
4101 		rc = nvmf_rdma_poller_create(rtransport, rgroup, device, &poller);
4102 		if (rc < 0) {
4103 			nvmf_rdma_poll_group_destroy(&rgroup->group);
4104 			return NULL;
4105 		}
4106 	}
4107 
4108 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
4109 	if (rtransport->conn_sched.next_admin_pg == NULL) {
4110 		rtransport->conn_sched.next_admin_pg = rgroup;
4111 		rtransport->conn_sched.next_io_pg = rgroup;
4112 	}
4113 
4114 	return &rgroup->group;
4115 }
4116 
4117 static uint32_t
4118 nvmf_poll_group_get_io_qpair_count(struct spdk_nvmf_poll_group *pg)
4119 {
4120 	uint32_t count;
4121 
4122 	/* Just assume that unassociated qpairs will eventually be io
4123 	 * qpairs.  This is close enough for the use cases for this
4124 	 * function.
4125 	 */
4126 	pthread_mutex_lock(&pg->mutex);
4127 	count = pg->stat.current_io_qpairs + pg->current_unassociated_qpairs;
4128 	pthread_mutex_unlock(&pg->mutex);
4129 
4130 	return count;
4131 }
4132 
4133 static struct spdk_nvmf_transport_poll_group *
4134 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
4135 {
4136 	struct spdk_nvmf_rdma_transport *rtransport;
4137 	struct spdk_nvmf_rdma_poll_group **pg;
4138 	struct spdk_nvmf_transport_poll_group *result;
4139 	uint32_t count;
4140 
4141 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4142 
4143 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
4144 		return NULL;
4145 	}
4146 
4147 	if (qpair->qid == 0) {
4148 		pg = &rtransport->conn_sched.next_admin_pg;
4149 	} else {
4150 		struct spdk_nvmf_rdma_poll_group *pg_min, *pg_start, *pg_current;
4151 		uint32_t min_value;
4152 
4153 		pg = &rtransport->conn_sched.next_io_pg;
4154 		pg_min = *pg;
4155 		pg_start = *pg;
4156 		pg_current = *pg;
4157 		min_value = nvmf_poll_group_get_io_qpair_count(pg_current->group.group);
4158 
4159 		while (1) {
4160 			count = nvmf_poll_group_get_io_qpair_count(pg_current->group.group);
4161 
4162 			if (count < min_value) {
4163 				min_value = count;
4164 				pg_min = pg_current;
4165 			}
4166 
4167 			pg_current = TAILQ_NEXT(pg_current, link);
4168 			if (pg_current == NULL) {
4169 				pg_current = TAILQ_FIRST(&rtransport->poll_groups);
4170 			}
4171 
4172 			if (pg_current == pg_start || min_value == 0) {
4173 				break;
4174 			}
4175 		}
4176 		*pg = pg_min;
4177 	}
4178 
4179 	assert(*pg != NULL);
4180 
4181 	result = &(*pg)->group;
4182 
4183 	*pg = TAILQ_NEXT(*pg, link);
4184 	if (*pg == NULL) {
4185 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
4186 	}
4187 
4188 	return result;
4189 }
4190 
4191 static void
4192 nvmf_rdma_poller_destroy(struct spdk_nvmf_rdma_poller *poller)
4193 {
4194 	struct spdk_nvmf_rdma_qpair	*qpair, *tmp_qpair;
4195 	int				rc;
4196 
4197 	TAILQ_REMOVE(&poller->group->pollers, poller, link);
4198 	RB_FOREACH_SAFE(qpair, qpairs_tree, &poller->qpairs, tmp_qpair) {
4199 		nvmf_rdma_qpair_destroy(qpair);
4200 	}
4201 
4202 	if (poller->srq) {
4203 		if (poller->resources) {
4204 			nvmf_rdma_resources_destroy(poller->resources);
4205 		}
4206 		spdk_rdma_provider_srq_destroy(poller->srq);
4207 		SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
4208 	}
4209 
4210 	if (poller->cq) {
4211 		rc = ibv_destroy_cq(poller->cq);
4212 		if (rc != 0) {
4213 			SPDK_ERRLOG("Destroy cq return %d, error: %s\n", rc, strerror(errno));
4214 		}
4215 	}
4216 
4217 	if (poller->destroy_cb) {
4218 		poller->destroy_cb(poller->destroy_cb_ctx);
4219 		poller->destroy_cb = NULL;
4220 	}
4221 
4222 	free(poller);
4223 }
4224 
4225 static void
4226 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
4227 {
4228 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
4229 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
4230 	struct spdk_nvmf_rdma_transport		*rtransport;
4231 
4232 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4233 	if (!rgroup) {
4234 		return;
4235 	}
4236 
4237 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
4238 		nvmf_rdma_poller_destroy(poller);
4239 	}
4240 
4241 	if (rgroup->group.transport == NULL) {
4242 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
4243 		 * calls this function directly in a failure path. */
4244 		free(rgroup);
4245 		return;
4246 	}
4247 
4248 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
4249 
4250 	next_rgroup = TAILQ_NEXT(rgroup, link);
4251 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
4252 	if (next_rgroup == NULL) {
4253 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
4254 	}
4255 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
4256 		rtransport->conn_sched.next_admin_pg = next_rgroup;
4257 	}
4258 	if (rtransport->conn_sched.next_io_pg == rgroup) {
4259 		rtransport->conn_sched.next_io_pg = next_rgroup;
4260 	}
4261 
4262 	free(rgroup);
4263 }
4264 
4265 static void
4266 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
4267 {
4268 	if (rqpair->cm_id != NULL) {
4269 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
4270 	}
4271 }
4272 
4273 static int
4274 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
4275 			 struct spdk_nvmf_qpair *qpair)
4276 {
4277 	struct spdk_nvmf_rdma_poll_group	*rgroup;
4278 	struct spdk_nvmf_rdma_qpair		*rqpair;
4279 	struct spdk_nvmf_rdma_device		*device;
4280 	struct spdk_nvmf_rdma_poller		*poller;
4281 	int					rc;
4282 
4283 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4284 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4285 
4286 	device = rqpair->device;
4287 
4288 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
4289 		if (poller->device == device) {
4290 			break;
4291 		}
4292 	}
4293 
4294 	if (!poller) {
4295 		SPDK_ERRLOG("No poller found for device.\n");
4296 		return -1;
4297 	}
4298 
4299 	if (poller->need_destroy) {
4300 		SPDK_ERRLOG("Poller is destroying.\n");
4301 		return -1;
4302 	}
4303 
4304 	rqpair->poller = poller;
4305 	rqpair->srq = rqpair->poller->srq;
4306 
4307 	rc = nvmf_rdma_qpair_initialize(qpair);
4308 	if (rc < 0) {
4309 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
4310 		rqpair->poller = NULL;
4311 		rqpair->srq = NULL;
4312 		return -1;
4313 	}
4314 
4315 	RB_INSERT(qpairs_tree, &poller->qpairs, rqpair);
4316 
4317 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
4318 	if (rc) {
4319 		/* Try to reject, but we probably can't */
4320 		nvmf_rdma_qpair_reject_connection(rqpair);
4321 		return -1;
4322 	}
4323 
4324 	return 0;
4325 }
4326 
4327 static int
4328 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
4329 			    struct spdk_nvmf_qpair *qpair)
4330 {
4331 	struct spdk_nvmf_rdma_qpair		*rqpair;
4332 
4333 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4334 	assert(group->transport->tgt != NULL);
4335 
4336 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
4337 
4338 	if (!rqpair->destruct_channel) {
4339 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
4340 		return 0;
4341 	}
4342 
4343 	/* Sanity check that we get io_channel on the correct thread */
4344 	if (qpair->group) {
4345 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
4346 	}
4347 
4348 	return 0;
4349 }
4350 
4351 static int
4352 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
4353 {
4354 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
4355 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
4356 			struct spdk_nvmf_rdma_transport, transport);
4357 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
4358 					      struct spdk_nvmf_rdma_qpair, qpair);
4359 
4360 	/*
4361 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
4362 	 * needs to be returned to the shared receive queue or the poll group will eventually be
4363 	 * starved of RECV structures.
4364 	 */
4365 	if (rqpair->srq && rdma_req->recv) {
4366 		int rc;
4367 		struct ibv_recv_wr *bad_recv_wr;
4368 
4369 		spdk_rdma_provider_srq_queue_recv_wrs(rqpair->srq, &rdma_req->recv->wr);
4370 		rc = spdk_rdma_provider_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
4371 		if (rc) {
4372 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
4373 		}
4374 	}
4375 
4376 	_nvmf_rdma_request_free(rdma_req, rtransport);
4377 	return 0;
4378 }
4379 
4380 static int
4381 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
4382 {
4383 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
4384 			struct spdk_nvmf_rdma_transport, transport);
4385 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
4386 			struct spdk_nvmf_rdma_request, req);
4387 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
4388 			struct spdk_nvmf_rdma_qpair, qpair);
4389 
4390 	if (spdk_unlikely(rqpair->ibv_in_error_state)) {
4391 		/* The connection is dead. Move the request directly to the completed state. */
4392 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4393 	} else {
4394 		/* The connection is alive, so process the request as normal */
4395 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
4396 	}
4397 
4398 	nvmf_rdma_request_process(rtransport, rdma_req);
4399 
4400 	return 0;
4401 }
4402 
4403 static void
4404 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
4405 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
4406 {
4407 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4408 
4409 	rqpair->to_close = true;
4410 
4411 	/* This happens only when the qpair is disconnected before
4412 	 * it is added to the poll group. Since there is no poll group,
4413 	 * the RDMA qp has not been initialized yet and the RDMA CM
4414 	 * event has not yet been acknowledged, so we need to reject it.
4415 	 */
4416 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
4417 		nvmf_rdma_qpair_reject_connection(rqpair);
4418 		nvmf_rdma_qpair_destroy(rqpair);
4419 		return;
4420 	}
4421 
4422 	if (rqpair->rdma_qp) {
4423 		spdk_rdma_provider_qp_disconnect(rqpair->rdma_qp);
4424 	}
4425 
4426 	nvmf_rdma_destroy_drained_qpair(rqpair);
4427 
4428 	if (cb_fn) {
4429 		cb_fn(cb_arg);
4430 	}
4431 }
4432 
4433 static struct spdk_nvmf_rdma_qpair *
4434 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
4435 {
4436 	struct spdk_nvmf_rdma_qpair find;
4437 
4438 	find.qp_num = wc->qp_num;
4439 
4440 	return RB_FIND(qpairs_tree, &rpoller->qpairs, &find);
4441 }
4442 
4443 #ifdef DEBUG
4444 static int
4445 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
4446 {
4447 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
4448 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
4449 }
4450 #endif
4451 
4452 static void
4453 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
4454 			   int rc)
4455 {
4456 	struct spdk_nvmf_rdma_recv	*rdma_recv;
4457 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
4458 
4459 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
4460 	while (bad_recv_wr != NULL) {
4461 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
4462 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
4463 
4464 		rdma_recv->qpair->current_recv_depth++;
4465 		bad_recv_wr = bad_recv_wr->next;
4466 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
4467 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair);
4468 	}
4469 }
4470 
4471 static void
4472 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
4473 {
4474 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
4475 	while (bad_recv_wr != NULL) {
4476 		bad_recv_wr = bad_recv_wr->next;
4477 		rqpair->current_recv_depth++;
4478 	}
4479 	spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4480 }
4481 
4482 static void
4483 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
4484 		     struct spdk_nvmf_rdma_poller *rpoller)
4485 {
4486 	struct spdk_nvmf_rdma_qpair	*rqpair;
4487 	struct ibv_recv_wr		*bad_recv_wr;
4488 	int				rc;
4489 
4490 	if (rpoller->srq) {
4491 		rc = spdk_rdma_provider_srq_flush_recv_wrs(rpoller->srq, &bad_recv_wr);
4492 		if (spdk_unlikely(rc)) {
4493 			_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
4494 		}
4495 	} else {
4496 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
4497 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
4498 			rc = spdk_rdma_provider_qp_flush_recv_wrs(rqpair->rdma_qp, &bad_recv_wr);
4499 			if (spdk_unlikely(rc)) {
4500 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
4501 			}
4502 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
4503 		}
4504 	}
4505 }
4506 
4507 static void
4508 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
4509 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
4510 {
4511 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
4512 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
4513 
4514 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
4515 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
4516 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
4517 		assert(rqpair->current_send_depth > 0);
4518 		rqpair->current_send_depth--;
4519 		switch (bad_rdma_wr->type) {
4520 		case RDMA_WR_TYPE_DATA:
4521 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data_wr);
4522 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
4523 				assert(rqpair->current_read_depth > 0);
4524 				rqpair->current_read_depth--;
4525 			}
4526 			break;
4527 		case RDMA_WR_TYPE_SEND:
4528 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp_wr);
4529 			break;
4530 		default:
4531 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
4532 			prev_rdma_req = cur_rdma_req;
4533 			continue;
4534 		}
4535 
4536 		if (prev_rdma_req == cur_rdma_req) {
4537 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
4538 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
4539 			continue;
4540 		}
4541 
4542 		switch (cur_rdma_req->state) {
4543 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4544 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
4545 			STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, cur_rdma_req, state_link);
4546 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
4547 			break;
4548 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
4549 		case RDMA_REQUEST_STATE_COMPLETING:
4550 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4551 			break;
4552 		default:
4553 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
4554 				    cur_rdma_req->state, rqpair);
4555 			continue;
4556 		}
4557 
4558 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
4559 		prev_rdma_req = cur_rdma_req;
4560 	}
4561 
4562 	if (spdk_nvmf_qpair_is_active(&rqpair->qpair)) {
4563 		/* Disconnect the connection. */
4564 		spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4565 	}
4566 
4567 }
4568 
4569 static void
4570 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
4571 		     struct spdk_nvmf_rdma_poller *rpoller)
4572 {
4573 	struct spdk_nvmf_rdma_qpair	*rqpair;
4574 	struct ibv_send_wr		*bad_wr = NULL;
4575 	int				rc;
4576 
4577 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
4578 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
4579 		rc = spdk_rdma_provider_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
4580 
4581 		/* bad wr always points to the first wr that failed. */
4582 		if (spdk_unlikely(rc)) {
4583 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
4584 		}
4585 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
4586 	}
4587 }
4588 
4589 static const char *
4590 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
4591 {
4592 	switch (wr_type) {
4593 	case RDMA_WR_TYPE_RECV:
4594 		return "RECV";
4595 	case RDMA_WR_TYPE_SEND:
4596 		return "SEND";
4597 	case RDMA_WR_TYPE_DATA:
4598 		return "DATA";
4599 	default:
4600 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
4601 		SPDK_UNREACHABLE();
4602 	}
4603 }
4604 
4605 static inline void
4606 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
4607 {
4608 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
4609 
4610 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
4611 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
4612 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
4613 		SPDK_DEBUGLOG(rdma,
4614 			      "Error on CQ %p, (qp state %d, in_error %d) request 0x%lu, type %s, status: (%d): %s\n",
4615 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_in_error_state, wc->wr_id,
4616 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
4617 	} else {
4618 		SPDK_ERRLOG("Error on CQ %p, (qp state %d, in_error %d) request 0x%lu, type %s, status: (%d): %s\n",
4619 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_in_error_state, wc->wr_id,
4620 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
4621 	}
4622 }
4623 
4624 static int
4625 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
4626 		      struct spdk_nvmf_rdma_poller *rpoller)
4627 {
4628 	struct ibv_wc wc[32];
4629 	struct spdk_nvmf_rdma_wr	*rdma_wr;
4630 	struct spdk_nvmf_rdma_request	*rdma_req;
4631 	struct spdk_nvmf_rdma_recv	*rdma_recv;
4632 	struct spdk_nvmf_rdma_qpair	*rqpair, *tmp_rqpair;
4633 	int reaped, i;
4634 	int count = 0;
4635 	int rc;
4636 	bool error = false;
4637 	uint64_t poll_tsc = spdk_get_ticks();
4638 
4639 	if (spdk_unlikely(rpoller->need_destroy)) {
4640 		/* If qpair is closed before poller destroy, nvmf_rdma_destroy_drained_qpair may not
4641 		 * be called because we cannot poll anything from cq. So we call that here to force
4642 		 * destroy the qpair after to_close turning true.
4643 		 */
4644 		RB_FOREACH_SAFE(rqpair, qpairs_tree, &rpoller->qpairs, tmp_rqpair) {
4645 			nvmf_rdma_destroy_drained_qpair(rqpair);
4646 		}
4647 		return 0;
4648 	}
4649 
4650 	/* Poll for completing operations. */
4651 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
4652 	if (spdk_unlikely(reaped < 0)) {
4653 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
4654 			    errno, spdk_strerror(errno));
4655 		return -1;
4656 	} else if (reaped == 0) {
4657 		rpoller->stat.idle_polls++;
4658 	}
4659 
4660 	rpoller->stat.polls++;
4661 	rpoller->stat.completions += reaped;
4662 
4663 	for (i = 0; i < reaped; i++) {
4664 
4665 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
4666 
4667 		switch (rdma_wr->type) {
4668 		case RDMA_WR_TYPE_SEND:
4669 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp_wr);
4670 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
4671 
4672 			if (spdk_likely(!wc[i].status)) {
4673 				count++;
4674 				assert(wc[i].opcode == IBV_WC_SEND);
4675 				assert(nvmf_rdma_req_is_completing(rdma_req));
4676 			}
4677 
4678 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4679 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
4680 			assert(rqpair->current_send_depth >= (uint32_t)rdma_req->num_outstanding_data_wr + 1);
4681 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
4682 			rdma_req->num_outstanding_data_wr = 0;
4683 
4684 			nvmf_rdma_request_process(rtransport, rdma_req);
4685 			break;
4686 		case RDMA_WR_TYPE_RECV:
4687 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
4688 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
4689 			if (rpoller->srq != NULL) {
4690 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
4691 				/* It is possible that there are still some completions for destroyed QP
4692 				 * associated with SRQ. We just ignore these late completions and re-post
4693 				 * receive WRs back to SRQ.
4694 				 */
4695 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
4696 					struct ibv_recv_wr *bad_wr;
4697 
4698 					rdma_recv->wr.next = NULL;
4699 					spdk_rdma_provider_srq_queue_recv_wrs(rpoller->srq, &rdma_recv->wr);
4700 					rc = spdk_rdma_provider_srq_flush_recv_wrs(rpoller->srq, &bad_wr);
4701 					if (rc) {
4702 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
4703 					}
4704 					continue;
4705 				}
4706 			}
4707 			rqpair = rdma_recv->qpair;
4708 
4709 			assert(rqpair != NULL);
4710 			if (spdk_likely(!wc[i].status)) {
4711 				assert(wc[i].opcode == IBV_WC_RECV);
4712 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
4713 					spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4714 					break;
4715 				}
4716 			}
4717 
4718 			rdma_recv->wr.next = NULL;
4719 			rqpair->current_recv_depth++;
4720 			rdma_recv->receive_tsc = poll_tsc;
4721 			rpoller->stat.requests++;
4722 			STAILQ_INSERT_HEAD(&rqpair->resources->incoming_queue, rdma_recv, link);
4723 			rqpair->qpair.queue_depth++;
4724 			break;
4725 		case RDMA_WR_TYPE_DATA:
4726 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data_wr);
4727 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
4728 
4729 			assert(rdma_req->num_outstanding_data_wr > 0);
4730 
4731 			rqpair->current_send_depth--;
4732 			rdma_req->num_outstanding_data_wr--;
4733 			if (spdk_likely(!wc[i].status)) {
4734 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
4735 				rqpair->current_read_depth--;
4736 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
4737 				if (rdma_req->num_outstanding_data_wr == 0) {
4738 					if (rdma_req->num_remaining_data_wr) {
4739 						/* Only part of RDMA_READ operations was submitted, process the rest */
4740 						nvmf_rdma_request_reset_transfer_in(rdma_req, rtransport);
4741 						rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
4742 						nvmf_rdma_request_process(rtransport, rdma_req);
4743 						break;
4744 					}
4745 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
4746 					nvmf_rdma_request_process(rtransport, rdma_req);
4747 				}
4748 			} else {
4749 				/* If the data transfer fails still force the queue into the error state,
4750 				 * if we were performing an RDMA_READ, we need to force the request into a
4751 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
4752 				 * case, we should wait for the SEND to complete. */
4753 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
4754 					rqpair->current_read_depth--;
4755 					if (rdma_req->num_outstanding_data_wr == 0) {
4756 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4757 					}
4758 				}
4759 			}
4760 			break;
4761 		default:
4762 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
4763 			continue;
4764 		}
4765 
4766 		/* Handle error conditions */
4767 		if (spdk_unlikely(wc[i].status)) {
4768 			rqpair->ibv_in_error_state = true;
4769 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
4770 
4771 			error = true;
4772 
4773 			if (spdk_nvmf_qpair_is_active(&rqpair->qpair)) {
4774 				/* Disconnect the connection. */
4775 				spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4776 			} else {
4777 				nvmf_rdma_destroy_drained_qpair(rqpair);
4778 			}
4779 			continue;
4780 		}
4781 
4782 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
4783 
4784 		if (spdk_unlikely(!spdk_nvmf_qpair_is_active(&rqpair->qpair))) {
4785 			nvmf_rdma_destroy_drained_qpair(rqpair);
4786 		}
4787 	}
4788 
4789 	if (spdk_unlikely(error == true)) {
4790 		return -1;
4791 	}
4792 
4793 	if (reaped == 0) {
4794 		/* In some cases we may not receive any CQE but we still may have pending IO requests waiting for
4795 		 * a resource (e.g. a WR from the data_wr_pool).
4796 		 * We need to start processing of such requests if no CQE reaped */
4797 		nvmf_rdma_poller_process_pending_buf_queue(rtransport, rpoller);
4798 	}
4799 
4800 	/* submit outstanding work requests. */
4801 	_poller_submit_recvs(rtransport, rpoller);
4802 	_poller_submit_sends(rtransport, rpoller);
4803 
4804 	return count;
4805 }
4806 
4807 static void
4808 _nvmf_rdma_remove_destroyed_device(void *c)
4809 {
4810 	struct spdk_nvmf_rdma_transport	*rtransport = c;
4811 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
4812 	int				rc;
4813 
4814 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
4815 		if (device->ready_to_destroy) {
4816 			destroy_ib_device(rtransport, device);
4817 		}
4818 	}
4819 
4820 	free_poll_fds(rtransport);
4821 	rc = generate_poll_fds(rtransport);
4822 	/* cannot handle fd allocation error here */
4823 	if (rc != 0) {
4824 		SPDK_ERRLOG("Failed to generate poll fds after remove ib device.\n");
4825 	}
4826 }
4827 
4828 static void
4829 _nvmf_rdma_remove_poller_in_group_cb(void *c)
4830 {
4831 	struct poller_manage_ctx	*ctx = c;
4832 	struct spdk_nvmf_rdma_transport	*rtransport = ctx->rtransport;
4833 	struct spdk_nvmf_rdma_device	*device = ctx->device;
4834 	struct spdk_thread		*thread = ctx->thread;
4835 
4836 	if (nvmf_rdma_all_pollers_management_done(c)) {
4837 		/* destroy device when last poller is destroyed */
4838 		device->ready_to_destroy = true;
4839 		spdk_thread_send_msg(thread, _nvmf_rdma_remove_destroyed_device, rtransport);
4840 	}
4841 }
4842 
4843 static void
4844 _nvmf_rdma_remove_poller_in_group(void *c)
4845 {
4846 	struct poller_manage_ctx		*ctx = c;
4847 
4848 	ctx->rpoller->need_destroy = true;
4849 	ctx->rpoller->destroy_cb_ctx = ctx;
4850 	ctx->rpoller->destroy_cb = _nvmf_rdma_remove_poller_in_group_cb;
4851 
4852 	/* qp will be disconnected after receiving a RDMA_CM_EVENT_DEVICE_REMOVAL event. */
4853 	if (RB_EMPTY(&ctx->rpoller->qpairs)) {
4854 		nvmf_rdma_poller_destroy(ctx->rpoller);
4855 	}
4856 }
4857 
4858 static int
4859 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
4860 {
4861 	struct spdk_nvmf_rdma_transport *rtransport;
4862 	struct spdk_nvmf_rdma_poll_group *rgroup;
4863 	struct spdk_nvmf_rdma_poller	*rpoller, *tmp;
4864 	int				count = 0, rc, rc2 = 0;
4865 
4866 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
4867 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4868 
4869 	TAILQ_FOREACH_SAFE(rpoller, &rgroup->pollers, link, tmp) {
4870 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
4871 		if (spdk_unlikely(rc < 0)) {
4872 			if (rc2 == 0) {
4873 				rc2 = rc;
4874 			}
4875 			continue;
4876 		}
4877 		count += rc;
4878 	}
4879 
4880 	return rc2 ? rc2 : count;
4881 }
4882 
4883 static int
4884 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
4885 			  struct spdk_nvme_transport_id *trid,
4886 			  bool peer)
4887 {
4888 	struct sockaddr *saddr;
4889 	uint16_t port;
4890 
4891 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
4892 
4893 	if (peer) {
4894 		saddr = rdma_get_peer_addr(id);
4895 	} else {
4896 		saddr = rdma_get_local_addr(id);
4897 	}
4898 	switch (saddr->sa_family) {
4899 	case AF_INET: {
4900 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
4901 
4902 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
4903 		inet_ntop(AF_INET, &saddr_in->sin_addr,
4904 			  trid->traddr, sizeof(trid->traddr));
4905 		if (peer) {
4906 			port = ntohs(rdma_get_dst_port(id));
4907 		} else {
4908 			port = ntohs(rdma_get_src_port(id));
4909 		}
4910 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4911 		break;
4912 	}
4913 	case AF_INET6: {
4914 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4915 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4916 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4917 			  trid->traddr, sizeof(trid->traddr));
4918 		if (peer) {
4919 			port = ntohs(rdma_get_dst_port(id));
4920 		} else {
4921 			port = ntohs(rdma_get_src_port(id));
4922 		}
4923 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4924 		break;
4925 	}
4926 	default:
4927 		return -1;
4928 
4929 	}
4930 
4931 	return 0;
4932 }
4933 
4934 static int
4935 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4936 			      struct spdk_nvme_transport_id *trid)
4937 {
4938 	struct spdk_nvmf_rdma_qpair	*rqpair;
4939 
4940 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4941 
4942 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4943 }
4944 
4945 static int
4946 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4947 			       struct spdk_nvme_transport_id *trid)
4948 {
4949 	struct spdk_nvmf_rdma_qpair	*rqpair;
4950 
4951 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4952 
4953 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4954 }
4955 
4956 static int
4957 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4958 				struct spdk_nvme_transport_id *trid)
4959 {
4960 	struct spdk_nvmf_rdma_qpair	*rqpair;
4961 
4962 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4963 
4964 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4965 }
4966 
4967 void
4968 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4969 {
4970 	g_nvmf_hooks = *hooks;
4971 }
4972 
4973 static void
4974 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4975 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort,
4976 				   struct spdk_nvmf_rdma_qpair *rqpair)
4977 {
4978 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4979 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4980 
4981 	STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req_to_abort, state_link);
4982 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
4983 
4984 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4985 }
4986 
4987 static int
4988 _nvmf_rdma_qpair_abort_request(void *ctx)
4989 {
4990 	struct spdk_nvmf_request *req = ctx;
4991 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4992 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4993 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4994 					      struct spdk_nvmf_rdma_qpair, qpair);
4995 	int rc;
4996 
4997 	spdk_poller_unregister(&req->poller);
4998 
4999 	switch (rdma_req_to_abort->state) {
5000 	case RDMA_REQUEST_STATE_EXECUTING:
5001 		rc = nvmf_ctrlr_abort_request(req);
5002 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
5003 			return SPDK_POLLER_BUSY;
5004 		}
5005 		break;
5006 
5007 	case RDMA_REQUEST_STATE_NEED_BUFFER:
5008 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
5009 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
5010 
5011 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5012 		break;
5013 
5014 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
5015 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
5016 			      spdk_nvmf_rdma_request, state_link);
5017 
5018 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5019 		break;
5020 
5021 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
5022 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
5023 			      spdk_nvmf_rdma_request, state_link);
5024 
5025 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5026 		break;
5027 
5028 	case RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING:
5029 		/* Remove req from the list here to re-use common function */
5030 		STAILQ_REMOVE(&rqpair->pending_rdma_send_queue, rdma_req_to_abort,
5031 			      spdk_nvmf_rdma_request, state_link);
5032 
5033 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5034 		break;
5035 
5036 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
5037 		if (spdk_get_ticks() < req->timeout_tsc) {
5038 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
5039 			return SPDK_POLLER_BUSY;
5040 		}
5041 		break;
5042 
5043 	default:
5044 		break;
5045 	}
5046 
5047 	spdk_nvmf_request_complete(req);
5048 	return SPDK_POLLER_BUSY;
5049 }
5050 
5051 static void
5052 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
5053 			      struct spdk_nvmf_request *req)
5054 {
5055 	struct spdk_nvmf_rdma_qpair *rqpair;
5056 	struct spdk_nvmf_rdma_transport *rtransport;
5057 	struct spdk_nvmf_transport *transport;
5058 	uint16_t cid;
5059 	uint32_t i, max_req_count;
5060 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL, *rdma_req;
5061 
5062 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
5063 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
5064 	transport = &rtransport->transport;
5065 
5066 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
5067 	max_req_count = rqpair->srq == NULL ? rqpair->max_queue_depth : rqpair->poller->max_srq_depth;
5068 
5069 	for (i = 0; i < max_req_count; i++) {
5070 		rdma_req = &rqpair->resources->reqs[i];
5071 		/* When SRQ == NULL, rqpair has its own requests and req.qpair pointer always points to the qpair
5072 		 * When SRQ != NULL all rqpairs share common requests and qpair pointer is assigned when we start to
5073 		 * process a request. So in both cases all requests which are not in FREE state have valid qpair ptr */
5074 		if (rdma_req->state != RDMA_REQUEST_STATE_FREE && rdma_req->req.cmd->nvme_cmd.cid == cid &&
5075 		    rdma_req->req.qpair == qpair) {
5076 			rdma_req_to_abort = rdma_req;
5077 			break;
5078 		}
5079 	}
5080 
5081 	if (rdma_req_to_abort == NULL) {
5082 		spdk_nvmf_request_complete(req);
5083 		return;
5084 	}
5085 
5086 	req->req_to_abort = &rdma_req_to_abort->req;
5087 	req->timeout_tsc = spdk_get_ticks() +
5088 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
5089 	req->poller = NULL;
5090 
5091 	_nvmf_rdma_qpair_abort_request(req);
5092 }
5093 
5094 static void
5095 nvmf_rdma_poll_group_dump_stat(struct spdk_nvmf_transport_poll_group *group,
5096 			       struct spdk_json_write_ctx *w)
5097 {
5098 	struct spdk_nvmf_rdma_poll_group *rgroup;
5099 	struct spdk_nvmf_rdma_poller *rpoller;
5100 
5101 	assert(w != NULL);
5102 
5103 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
5104 
5105 	spdk_json_write_named_uint64(w, "pending_data_buffer", rgroup->stat.pending_data_buffer);
5106 
5107 	spdk_json_write_named_array_begin(w, "devices");
5108 
5109 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
5110 		spdk_json_write_object_begin(w);
5111 		spdk_json_write_named_string(w, "name",
5112 					     ibv_get_device_name(rpoller->device->context->device));
5113 		spdk_json_write_named_uint64(w, "polls",
5114 					     rpoller->stat.polls);
5115 		spdk_json_write_named_uint64(w, "idle_polls",
5116 					     rpoller->stat.idle_polls);
5117 		spdk_json_write_named_uint64(w, "completions",
5118 					     rpoller->stat.completions);
5119 		spdk_json_write_named_uint64(w, "requests",
5120 					     rpoller->stat.requests);
5121 		spdk_json_write_named_uint64(w, "request_latency",
5122 					     rpoller->stat.request_latency);
5123 		spdk_json_write_named_uint64(w, "pending_free_request",
5124 					     rpoller->stat.pending_free_request);
5125 		spdk_json_write_named_uint64(w, "pending_rdma_read",
5126 					     rpoller->stat.pending_rdma_read);
5127 		spdk_json_write_named_uint64(w, "pending_rdma_write",
5128 					     rpoller->stat.pending_rdma_write);
5129 		spdk_json_write_named_uint64(w, "pending_rdma_send",
5130 					     rpoller->stat.pending_rdma_send);
5131 		spdk_json_write_named_uint64(w, "total_send_wrs",
5132 					     rpoller->stat.qp_stats.send.num_submitted_wrs);
5133 		spdk_json_write_named_uint64(w, "send_doorbell_updates",
5134 					     rpoller->stat.qp_stats.send.doorbell_updates);
5135 		spdk_json_write_named_uint64(w, "total_recv_wrs",
5136 					     rpoller->stat.qp_stats.recv.num_submitted_wrs);
5137 		spdk_json_write_named_uint64(w, "recv_doorbell_updates",
5138 					     rpoller->stat.qp_stats.recv.doorbell_updates);
5139 		spdk_json_write_object_end(w);
5140 	}
5141 
5142 	spdk_json_write_array_end(w);
5143 }
5144 
5145 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
5146 	.name = "RDMA",
5147 	.type = SPDK_NVME_TRANSPORT_RDMA,
5148 	.opts_init = nvmf_rdma_opts_init,
5149 	.create = nvmf_rdma_create,
5150 	.dump_opts = nvmf_rdma_dump_opts,
5151 	.destroy = nvmf_rdma_destroy,
5152 
5153 	.listen = nvmf_rdma_listen,
5154 	.stop_listen = nvmf_rdma_stop_listen,
5155 	.cdata_init = nvmf_rdma_cdata_init,
5156 
5157 	.listener_discover = nvmf_rdma_discover,
5158 
5159 	.poll_group_create = nvmf_rdma_poll_group_create,
5160 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
5161 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
5162 	.poll_group_add = nvmf_rdma_poll_group_add,
5163 	.poll_group_remove = nvmf_rdma_poll_group_remove,
5164 	.poll_group_poll = nvmf_rdma_poll_group_poll,
5165 
5166 	.req_free = nvmf_rdma_request_free,
5167 	.req_complete = nvmf_rdma_request_complete,
5168 
5169 	.qpair_fini = nvmf_rdma_close_qpair,
5170 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
5171 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
5172 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
5173 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
5174 
5175 	.poll_group_dump_stat = nvmf_rdma_poll_group_dump_stat,
5176 };
5177 
5178 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
5179 SPDK_LOG_REGISTER_COMPONENT(rdma)
5180