xref: /spdk/lib/nvmf/rdma.c (revision 5485f55dc15bde438aee60c460f09d376f93a4fb)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019-2021 Mellanox Technologies LTD. All rights reserved.
6  *   Copyright (c) 2021, 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
7  *
8  *   Redistribution and use in source and binary forms, with or without
9  *   modification, are permitted provided that the following conditions
10  *   are met:
11  *
12  *     * Redistributions of source code must retain the above copyright
13  *       notice, this list of conditions and the following disclaimer.
14  *     * Redistributions in binary form must reproduce the above copyright
15  *       notice, this list of conditions and the following disclaimer in
16  *       the documentation and/or other materials provided with the
17  *       distribution.
18  *     * Neither the name of Intel Corporation nor the names of its
19  *       contributors may be used to endorse or promote products derived
20  *       from this software without specific prior written permission.
21  *
22  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
28  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
32  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 #include "spdk/stdinc.h"
36 
37 #include "spdk/config.h"
38 #include "spdk/thread.h"
39 #include "spdk/likely.h"
40 #include "spdk/nvmf_transport.h"
41 #include "spdk/string.h"
42 #include "spdk/trace.h"
43 #include "spdk/util.h"
44 
45 #include "spdk_internal/assert.h"
46 #include "spdk/log.h"
47 #include "spdk_internal/rdma.h"
48 
49 #include "nvmf_internal.h"
50 
51 #include "spdk_internal/trace_defs.h"
52 
53 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
54 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
55 
56 /*
57  RDMA Connection Resource Defaults
58  */
59 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
60 #define NVMF_DEFAULT_RSP_SGE		1
61 #define NVMF_DEFAULT_RX_SGE		2
62 
63 /* The RDMA completion queue size */
64 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
65 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
66 
67 static int g_spdk_nvmf_ibv_query_mask =
68 	IBV_QP_STATE |
69 	IBV_QP_PKEY_INDEX |
70 	IBV_QP_PORT |
71 	IBV_QP_ACCESS_FLAGS |
72 	IBV_QP_AV |
73 	IBV_QP_PATH_MTU |
74 	IBV_QP_DEST_QPN |
75 	IBV_QP_RQ_PSN |
76 	IBV_QP_MAX_DEST_RD_ATOMIC |
77 	IBV_QP_MIN_RNR_TIMER |
78 	IBV_QP_SQ_PSN |
79 	IBV_QP_TIMEOUT |
80 	IBV_QP_RETRY_CNT |
81 	IBV_QP_RNR_RETRY |
82 	IBV_QP_MAX_QP_RD_ATOMIC;
83 
84 enum spdk_nvmf_rdma_request_state {
85 	/* The request is not currently in use */
86 	RDMA_REQUEST_STATE_FREE = 0,
87 
88 	/* Initial state when request first received */
89 	RDMA_REQUEST_STATE_NEW,
90 
91 	/* The request is queued until a data buffer is available. */
92 	RDMA_REQUEST_STATE_NEED_BUFFER,
93 
94 	/* The request is waiting on RDMA queue depth availability
95 	 * to transfer data from the host to the controller.
96 	 */
97 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
98 
99 	/* The request is currently transferring data from the host to the controller. */
100 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
101 
102 	/* The request is ready to execute at the block device */
103 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
104 
105 	/* The request is currently executing at the block device */
106 	RDMA_REQUEST_STATE_EXECUTING,
107 
108 	/* The request finished executing at the block device */
109 	RDMA_REQUEST_STATE_EXECUTED,
110 
111 	/* The request is waiting on RDMA queue depth availability
112 	 * to transfer data from the controller to the host.
113 	 */
114 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
115 
116 	/* The request is ready to send a completion */
117 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
118 
119 	/* The request is currently transferring data from the controller to the host. */
120 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
121 
122 	/* The request currently has an outstanding completion without an
123 	 * associated data transfer.
124 	 */
125 	RDMA_REQUEST_STATE_COMPLETING,
126 
127 	/* The request completed and can be marked free. */
128 	RDMA_REQUEST_STATE_COMPLETED,
129 
130 	/* Terminator */
131 	RDMA_REQUEST_NUM_STATES,
132 };
133 
134 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
135 {
136 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
137 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
138 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1,
139 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
140 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
141 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
142 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
143 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
144 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
145 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
146 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
147 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
148 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
149 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
150 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
151 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
152 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
153 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
154 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
155 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
156 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
157 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
158 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
159 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
160 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
161 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
162 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
163 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
164 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
165 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
166 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
167 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
168 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
169 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
170 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
171 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
172 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
173 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
174 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
175 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
176 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
178 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
179 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
180 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
181 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
182 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
183 
184 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
185 					OWNER_NONE, OBJECT_NONE, 0,
186 					SPDK_TRACE_ARG_TYPE_INT, "");
187 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
188 					OWNER_NONE, OBJECT_NONE, 0,
189 					SPDK_TRACE_ARG_TYPE_INT, "type");
190 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
191 					OWNER_NONE, OBJECT_NONE, 0,
192 					SPDK_TRACE_ARG_TYPE_INT, "type");
193 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
194 					OWNER_NONE, OBJECT_NONE, 0,
195 					SPDK_TRACE_ARG_TYPE_PTR, "state");
196 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
197 					OWNER_NONE, OBJECT_NONE, 0,
198 					SPDK_TRACE_ARG_TYPE_INT, "");
199 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
200 					OWNER_NONE, OBJECT_NONE, 0,
201 					SPDK_TRACE_ARG_TYPE_INT, "");
202 }
203 
204 enum spdk_nvmf_rdma_wr_type {
205 	RDMA_WR_TYPE_RECV,
206 	RDMA_WR_TYPE_SEND,
207 	RDMA_WR_TYPE_DATA,
208 };
209 
210 struct spdk_nvmf_rdma_wr {
211 	enum spdk_nvmf_rdma_wr_type	type;
212 };
213 
214 /* This structure holds commands as they are received off the wire.
215  * It must be dynamically paired with a full request object
216  * (spdk_nvmf_rdma_request) to service a request. It is separate
217  * from the request because RDMA does not appear to order
218  * completions, so occasionally we'll get a new incoming
219  * command when there aren't any free request objects.
220  */
221 struct spdk_nvmf_rdma_recv {
222 	struct ibv_recv_wr			wr;
223 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
224 
225 	struct spdk_nvmf_rdma_qpair		*qpair;
226 
227 	/* In-capsule data buffer */
228 	uint8_t					*buf;
229 
230 	struct spdk_nvmf_rdma_wr		rdma_wr;
231 	uint64_t				receive_tsc;
232 
233 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
234 };
235 
236 struct spdk_nvmf_rdma_request_data {
237 	struct spdk_nvmf_rdma_wr	rdma_wr;
238 	struct ibv_send_wr		wr;
239 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
240 };
241 
242 struct spdk_nvmf_rdma_request {
243 	struct spdk_nvmf_request		req;
244 
245 	enum spdk_nvmf_rdma_request_state	state;
246 
247 	/* Data offset in req.iov */
248 	uint32_t				offset;
249 
250 	struct spdk_nvmf_rdma_recv		*recv;
251 
252 	struct {
253 		struct spdk_nvmf_rdma_wr	rdma_wr;
254 		struct	ibv_send_wr		wr;
255 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
256 	} rsp;
257 
258 	struct spdk_nvmf_rdma_request_data	data;
259 
260 	uint32_t				iovpos;
261 
262 	uint32_t				num_outstanding_data_wr;
263 	uint64_t				receive_tsc;
264 
265 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
266 };
267 
268 struct spdk_nvmf_rdma_resource_opts {
269 	struct spdk_nvmf_rdma_qpair	*qpair;
270 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
271 	void				*qp;
272 	struct ibv_pd			*pd;
273 	uint32_t			max_queue_depth;
274 	uint32_t			in_capsule_data_size;
275 	bool				shared;
276 };
277 
278 struct spdk_nvmf_rdma_resources {
279 	/* Array of size "max_queue_depth" containing RDMA requests. */
280 	struct spdk_nvmf_rdma_request		*reqs;
281 
282 	/* Array of size "max_queue_depth" containing RDMA recvs. */
283 	struct spdk_nvmf_rdma_recv		*recvs;
284 
285 	/* Array of size "max_queue_depth" containing 64 byte capsules
286 	 * used for receive.
287 	 */
288 	union nvmf_h2c_msg			*cmds;
289 	struct ibv_mr				*cmds_mr;
290 
291 	/* Array of size "max_queue_depth" containing 16 byte completions
292 	 * to be sent back to the user.
293 	 */
294 	union nvmf_c2h_msg			*cpls;
295 	struct ibv_mr				*cpls_mr;
296 
297 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
298 	 * buffers to be used for in capsule data.
299 	 */
300 	void					*bufs;
301 	struct ibv_mr				*bufs_mr;
302 
303 	/* Receives that are waiting for a request object */
304 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
305 
306 	/* Queue to track free requests */
307 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
308 };
309 
310 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
311 
312 struct spdk_nvmf_rdma_ibv_event_ctx {
313 	struct spdk_nvmf_rdma_qpair			*rqpair;
314 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
315 	/* Link to other ibv events associated with this qpair */
316 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
317 };
318 
319 struct spdk_nvmf_rdma_qpair {
320 	struct spdk_nvmf_qpair			qpair;
321 
322 	struct spdk_nvmf_rdma_device		*device;
323 	struct spdk_nvmf_rdma_poller		*poller;
324 
325 	struct spdk_rdma_qp			*rdma_qp;
326 	struct rdma_cm_id			*cm_id;
327 	struct spdk_rdma_srq			*srq;
328 	struct rdma_cm_id			*listen_id;
329 
330 	/* The maximum number of I/O outstanding on this connection at one time */
331 	uint16_t				max_queue_depth;
332 
333 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
334 	uint16_t				max_read_depth;
335 
336 	/* The maximum number of RDMA SEND operations at one time */
337 	uint32_t				max_send_depth;
338 
339 	/* The current number of outstanding WRs from this qpair's
340 	 * recv queue. Should not exceed device->attr.max_queue_depth.
341 	 */
342 	uint16_t				current_recv_depth;
343 
344 	/* The current number of active RDMA READ operations */
345 	uint16_t				current_read_depth;
346 
347 	/* The current number of posted WRs from this qpair's
348 	 * send queue. Should not exceed max_send_depth.
349 	 */
350 	uint32_t				current_send_depth;
351 
352 	/* The maximum number of SGEs per WR on the send queue */
353 	uint32_t				max_send_sge;
354 
355 	/* The maximum number of SGEs per WR on the recv queue */
356 	uint32_t				max_recv_sge;
357 
358 	struct spdk_nvmf_rdma_resources		*resources;
359 
360 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
361 
362 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
363 
364 	/* Number of requests not in the free state */
365 	uint32_t				qd;
366 
367 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
368 
369 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
370 
371 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
372 
373 	/* IBV queue pair attributes: they are used to manage
374 	 * qp state and recover from errors.
375 	 */
376 	enum ibv_qp_state			ibv_state;
377 
378 	/*
379 	 * io_channel which is used to destroy qpair when it is removed from poll group
380 	 */
381 	struct spdk_io_channel		*destruct_channel;
382 
383 	/* List of ibv async events */
384 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
385 
386 	/* Lets us know that we have received the last_wqe event. */
387 	bool					last_wqe_reached;
388 
389 	/* Indicate that nvmf_rdma_close_qpair is called */
390 	bool					to_close;
391 };
392 
393 struct spdk_nvmf_rdma_poller_stat {
394 	uint64_t				completions;
395 	uint64_t				polls;
396 	uint64_t				idle_polls;
397 	uint64_t				requests;
398 	uint64_t				request_latency;
399 	uint64_t				pending_free_request;
400 	uint64_t				pending_rdma_read;
401 	uint64_t				pending_rdma_write;
402 	struct spdk_rdma_qp_stats		qp_stats;
403 };
404 
405 struct spdk_nvmf_rdma_poller {
406 	struct spdk_nvmf_rdma_device		*device;
407 	struct spdk_nvmf_rdma_poll_group	*group;
408 
409 	int					num_cqe;
410 	int					required_num_wr;
411 	struct ibv_cq				*cq;
412 
413 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
414 	uint16_t				max_srq_depth;
415 
416 	/* Shared receive queue */
417 	struct spdk_rdma_srq			*srq;
418 
419 	struct spdk_nvmf_rdma_resources		*resources;
420 	struct spdk_nvmf_rdma_poller_stat	stat;
421 
422 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
423 
424 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
425 
426 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
427 
428 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
429 };
430 
431 struct spdk_nvmf_rdma_poll_group_stat {
432 	uint64_t				pending_data_buffer;
433 };
434 
435 struct spdk_nvmf_rdma_poll_group {
436 	struct spdk_nvmf_transport_poll_group		group;
437 	struct spdk_nvmf_rdma_poll_group_stat		stat;
438 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
439 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
440 };
441 
442 struct spdk_nvmf_rdma_conn_sched {
443 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
444 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
445 };
446 
447 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
448 struct spdk_nvmf_rdma_device {
449 	struct ibv_device_attr			attr;
450 	struct ibv_context			*context;
451 
452 	struct spdk_rdma_mem_map		*map;
453 	struct ibv_pd				*pd;
454 
455 	int					num_srq;
456 
457 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
458 };
459 
460 struct spdk_nvmf_rdma_port {
461 	const struct spdk_nvme_transport_id	*trid;
462 	struct rdma_cm_id			*id;
463 	struct spdk_nvmf_rdma_device		*device;
464 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
465 };
466 
467 struct rdma_transport_opts {
468 	int		num_cqe;
469 	uint32_t	max_srq_depth;
470 	bool		no_srq;
471 	bool		no_wr_batching;
472 	int		acceptor_backlog;
473 };
474 
475 struct spdk_nvmf_rdma_transport {
476 	struct spdk_nvmf_transport	transport;
477 	struct rdma_transport_opts	rdma_opts;
478 
479 	struct spdk_nvmf_rdma_conn_sched conn_sched;
480 
481 	struct rdma_event_channel	*event_channel;
482 
483 	struct spdk_mempool		*data_wr_pool;
484 
485 	struct spdk_poller		*accept_poller;
486 	pthread_mutex_t			lock;
487 
488 	/* fields used to poll RDMA/IB events */
489 	nfds_t			npoll_fds;
490 	struct pollfd		*poll_fds;
491 
492 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
493 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
494 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
495 };
496 
497 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
498 	{
499 		"num_cqe", offsetof(struct rdma_transport_opts, num_cqe),
500 		spdk_json_decode_int32, true
501 	},
502 	{
503 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
504 		spdk_json_decode_uint32, true
505 	},
506 	{
507 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
508 		spdk_json_decode_bool, true
509 	},
510 	{
511 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
512 		spdk_json_decode_bool, true
513 	},
514 	{
515 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
516 		spdk_json_decode_int32, true
517 	},
518 };
519 
520 static bool
521 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
522 			  struct spdk_nvmf_rdma_request *rdma_req);
523 
524 static void
525 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
526 		     struct spdk_nvmf_rdma_poller *rpoller);
527 
528 static void
529 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
530 		     struct spdk_nvmf_rdma_poller *rpoller);
531 
532 static inline int
533 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
534 {
535 	switch (state) {
536 	case IBV_QPS_RESET:
537 	case IBV_QPS_INIT:
538 	case IBV_QPS_RTR:
539 	case IBV_QPS_RTS:
540 	case IBV_QPS_SQD:
541 	case IBV_QPS_SQE:
542 	case IBV_QPS_ERR:
543 		return 0;
544 	default:
545 		return -1;
546 	}
547 }
548 
549 static inline enum spdk_nvme_media_error_status_code
550 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
551 	enum spdk_nvme_media_error_status_code result;
552 	switch (err_type)
553 	{
554 	case SPDK_DIF_REFTAG_ERROR:
555 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
556 		break;
557 	case SPDK_DIF_APPTAG_ERROR:
558 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
559 		break;
560 	case SPDK_DIF_GUARD_ERROR:
561 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
562 		break;
563 	default:
564 		SPDK_UNREACHABLE();
565 	}
566 
567 	return result;
568 }
569 
570 static enum ibv_qp_state
571 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
572 	enum ibv_qp_state old_state, new_state;
573 	struct ibv_qp_attr qp_attr;
574 	struct ibv_qp_init_attr init_attr;
575 	int rc;
576 
577 	old_state = rqpair->ibv_state;
578 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
579 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
580 
581 	if (rc)
582 	{
583 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
584 		return IBV_QPS_ERR + 1;
585 	}
586 
587 	new_state = qp_attr.qp_state;
588 	rqpair->ibv_state = new_state;
589 	qp_attr.ah_attr.port_num = qp_attr.port_num;
590 
591 	rc = nvmf_rdma_check_ibv_state(new_state);
592 	if (rc)
593 	{
594 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
595 		/*
596 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
597 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
598 		 */
599 		return IBV_QPS_ERR + 1;
600 	}
601 
602 	if (old_state != new_state)
603 	{
604 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0, (uintptr_t)rqpair, new_state);
605 	}
606 	return new_state;
607 }
608 
609 static void
610 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
611 			    struct spdk_nvmf_rdma_transport *rtransport)
612 {
613 	struct spdk_nvmf_rdma_request_data	*data_wr;
614 	struct ibv_send_wr			*next_send_wr;
615 	uint64_t				req_wrid;
616 
617 	rdma_req->num_outstanding_data_wr = 0;
618 	data_wr = &rdma_req->data;
619 	req_wrid = data_wr->wr.wr_id;
620 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
621 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
622 		data_wr->wr.num_sge = 0;
623 		next_send_wr = data_wr->wr.next;
624 		if (data_wr != &rdma_req->data) {
625 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
626 		}
627 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
628 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
629 	}
630 }
631 
632 static void
633 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
634 {
635 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
636 	if (req->req.cmd) {
637 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
638 	}
639 	if (req->recv) {
640 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
641 	}
642 }
643 
644 static void
645 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
646 {
647 	int i;
648 
649 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
650 	for (i = 0; i < rqpair->max_queue_depth; i++) {
651 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
652 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
653 		}
654 	}
655 }
656 
657 static void
658 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
659 {
660 	if (resources->cmds_mr) {
661 		ibv_dereg_mr(resources->cmds_mr);
662 	}
663 
664 	if (resources->cpls_mr) {
665 		ibv_dereg_mr(resources->cpls_mr);
666 	}
667 
668 	if (resources->bufs_mr) {
669 		ibv_dereg_mr(resources->bufs_mr);
670 	}
671 
672 	spdk_free(resources->cmds);
673 	spdk_free(resources->cpls);
674 	spdk_free(resources->bufs);
675 	free(resources->reqs);
676 	free(resources->recvs);
677 	free(resources);
678 }
679 
680 
681 static struct spdk_nvmf_rdma_resources *
682 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
683 {
684 	struct spdk_nvmf_rdma_resources	*resources;
685 	struct spdk_nvmf_rdma_request	*rdma_req;
686 	struct spdk_nvmf_rdma_recv	*rdma_recv;
687 	struct spdk_rdma_qp		*qp = NULL;
688 	struct spdk_rdma_srq		*srq = NULL;
689 	struct ibv_recv_wr		*bad_wr = NULL;
690 	uint32_t			i;
691 	int				rc = 0;
692 
693 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
694 	if (!resources) {
695 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
696 		return NULL;
697 	}
698 
699 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
700 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
701 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
702 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
703 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
704 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
705 
706 	if (opts->in_capsule_data_size > 0) {
707 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
708 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
709 					       SPDK_MALLOC_DMA);
710 	}
711 
712 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
713 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
714 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
715 		goto cleanup;
716 	}
717 
718 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
719 					opts->max_queue_depth * sizeof(*resources->cmds),
720 					IBV_ACCESS_LOCAL_WRITE);
721 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
722 					opts->max_queue_depth * sizeof(*resources->cpls),
723 					0);
724 
725 	if (opts->in_capsule_data_size) {
726 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
727 						opts->max_queue_depth *
728 						opts->in_capsule_data_size,
729 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
730 	}
731 
732 	if (!resources->cmds_mr || !resources->cpls_mr ||
733 	    (opts->in_capsule_data_size &&
734 	     !resources->bufs_mr)) {
735 		goto cleanup;
736 	}
737 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
738 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
739 		      resources->cmds_mr->lkey);
740 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
741 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
742 		      resources->cpls_mr->lkey);
743 	if (resources->bufs && resources->bufs_mr) {
744 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
745 			      resources->bufs, opts->max_queue_depth *
746 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
747 	}
748 
749 	/* Initialize queues */
750 	STAILQ_INIT(&resources->incoming_queue);
751 	STAILQ_INIT(&resources->free_queue);
752 
753 	if (opts->shared) {
754 		srq = (struct spdk_rdma_srq *)opts->qp;
755 	} else {
756 		qp = (struct spdk_rdma_qp *)opts->qp;
757 	}
758 
759 	for (i = 0; i < opts->max_queue_depth; i++) {
760 		rdma_recv = &resources->recvs[i];
761 		rdma_recv->qpair = opts->qpair;
762 
763 		/* Set up memory to receive commands */
764 		if (resources->bufs) {
765 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
766 						  opts->in_capsule_data_size));
767 		}
768 
769 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
770 
771 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
772 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
773 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
774 		rdma_recv->wr.num_sge = 1;
775 
776 		if (rdma_recv->buf && resources->bufs_mr) {
777 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
778 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
779 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
780 			rdma_recv->wr.num_sge++;
781 		}
782 
783 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
784 		rdma_recv->wr.sg_list = rdma_recv->sgl;
785 		if (srq) {
786 			spdk_rdma_srq_queue_recv_wrs(srq, &rdma_recv->wr);
787 		} else {
788 			spdk_rdma_qp_queue_recv_wrs(qp, &rdma_recv->wr);
789 		}
790 	}
791 
792 	for (i = 0; i < opts->max_queue_depth; i++) {
793 		rdma_req = &resources->reqs[i];
794 
795 		if (opts->qpair != NULL) {
796 			rdma_req->req.qpair = &opts->qpair->qpair;
797 		} else {
798 			rdma_req->req.qpair = NULL;
799 		}
800 		rdma_req->req.cmd = NULL;
801 
802 		/* Set up memory to send responses */
803 		rdma_req->req.rsp = &resources->cpls[i];
804 
805 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
806 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
807 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
808 
809 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
810 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
811 		rdma_req->rsp.wr.next = NULL;
812 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
813 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
814 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
815 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
816 
817 		/* Set up memory for data buffers */
818 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
819 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
820 		rdma_req->data.wr.next = NULL;
821 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
822 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
823 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
824 
825 		/* Initialize request state to FREE */
826 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
827 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
828 	}
829 
830 	if (srq) {
831 		rc = spdk_rdma_srq_flush_recv_wrs(srq, &bad_wr);
832 	} else {
833 		rc = spdk_rdma_qp_flush_recv_wrs(qp, &bad_wr);
834 	}
835 
836 	if (rc) {
837 		goto cleanup;
838 	}
839 
840 	return resources;
841 
842 cleanup:
843 	nvmf_rdma_resources_destroy(resources);
844 	return NULL;
845 }
846 
847 static void
848 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
849 {
850 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
851 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
852 		ctx->rqpair = NULL;
853 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
854 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
855 	}
856 }
857 
858 static void
859 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
860 {
861 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
862 	struct ibv_recv_wr		*bad_recv_wr = NULL;
863 	int				rc;
864 
865 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair);
866 
867 	if (rqpair->qd != 0) {
868 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
869 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
870 				struct spdk_nvmf_rdma_transport, transport);
871 		struct spdk_nvmf_rdma_request *req;
872 		uint32_t i, max_req_count = 0;
873 
874 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
875 
876 		if (rqpair->srq == NULL) {
877 			nvmf_rdma_dump_qpair_contents(rqpair);
878 			max_req_count = rqpair->max_queue_depth;
879 		} else if (rqpair->poller && rqpair->resources) {
880 			max_req_count = rqpair->poller->max_srq_depth;
881 		}
882 
883 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
884 		for (i = 0; i < max_req_count; i++) {
885 			req = &rqpair->resources->reqs[i];
886 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
887 				/* nvmf_rdma_request_process checks qpair ibv and internal state
888 				 * and completes a request */
889 				nvmf_rdma_request_process(rtransport, req);
890 			}
891 		}
892 		assert(rqpair->qd == 0);
893 	}
894 
895 	if (rqpair->poller) {
896 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
897 
898 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
899 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
900 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
901 				if (rqpair == rdma_recv->qpair) {
902 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
903 					spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_recv->wr);
904 					rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
905 					if (rc) {
906 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
907 					}
908 				}
909 			}
910 		}
911 	}
912 
913 	if (rqpair->cm_id) {
914 		if (rqpair->rdma_qp != NULL) {
915 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
916 			rqpair->rdma_qp = NULL;
917 		}
918 		rdma_destroy_id(rqpair->cm_id);
919 
920 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
921 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
922 		}
923 	}
924 
925 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
926 		nvmf_rdma_resources_destroy(rqpair->resources);
927 	}
928 
929 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
930 
931 	if (rqpair->destruct_channel) {
932 		spdk_put_io_channel(rqpair->destruct_channel);
933 		rqpair->destruct_channel = NULL;
934 	}
935 
936 	free(rqpair);
937 }
938 
939 static int
940 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
941 {
942 	struct spdk_nvmf_rdma_poller	*rpoller;
943 	int				rc, num_cqe, required_num_wr;
944 
945 	/* Enlarge CQ size dynamically */
946 	rpoller = rqpair->poller;
947 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
948 	num_cqe = rpoller->num_cqe;
949 	if (num_cqe < required_num_wr) {
950 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
951 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
952 	}
953 
954 	if (rpoller->num_cqe != num_cqe) {
955 		if (device->context->device->transport_type == IBV_TRANSPORT_IWARP) {
956 			SPDK_ERRLOG("iWARP doesn't support CQ resize. Current capacity %u, required %u\n"
957 				    "Using CQ of insufficient size may lead to CQ overrun\n", rpoller->num_cqe, num_cqe);
958 			return -1;
959 		}
960 		if (required_num_wr > device->attr.max_cqe) {
961 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
962 				    required_num_wr, device->attr.max_cqe);
963 			return -1;
964 		}
965 
966 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
967 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
968 		if (rc) {
969 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
970 			return -1;
971 		}
972 
973 		rpoller->num_cqe = num_cqe;
974 	}
975 
976 	rpoller->required_num_wr = required_num_wr;
977 	return 0;
978 }
979 
980 static int
981 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
982 {
983 	struct spdk_nvmf_rdma_qpair		*rqpair;
984 	struct spdk_nvmf_rdma_transport		*rtransport;
985 	struct spdk_nvmf_transport		*transport;
986 	struct spdk_nvmf_rdma_resource_opts	opts;
987 	struct spdk_nvmf_rdma_device		*device;
988 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
989 
990 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
991 	device = rqpair->device;
992 
993 	qp_init_attr.qp_context	= rqpair;
994 	qp_init_attr.pd		= device->pd;
995 	qp_init_attr.send_cq	= rqpair->poller->cq;
996 	qp_init_attr.recv_cq	= rqpair->poller->cq;
997 
998 	if (rqpair->srq) {
999 		qp_init_attr.srq		= rqpair->srq->srq;
1000 	} else {
1001 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
1002 	}
1003 
1004 	/* SEND, READ, and WRITE operations */
1005 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
1006 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1007 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1008 	qp_init_attr.stats		= &rqpair->poller->stat.qp_stats;
1009 
1010 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1011 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1012 		goto error;
1013 	}
1014 
1015 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1016 	if (!rqpair->rdma_qp) {
1017 		goto error;
1018 	}
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.pd = rqpair->cm_id->pd;
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 
1053 	return 0;
1054 
1055 error:
1056 	rdma_destroy_id(rqpair->cm_id);
1057 	rqpair->cm_id = NULL;
1058 	return -1;
1059 }
1060 
1061 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1062 /* This function accepts either a single wr or the first wr in a linked list. */
1063 static void
1064 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1065 {
1066 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1067 			struct spdk_nvmf_rdma_transport, transport);
1068 
1069 	if (rqpair->srq != NULL) {
1070 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, first);
1071 	} else {
1072 		if (spdk_rdma_qp_queue_recv_wrs(rqpair->rdma_qp, first)) {
1073 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1074 		}
1075 	}
1076 
1077 	if (rtransport->rdma_opts.no_wr_batching) {
1078 		_poller_submit_recvs(rtransport, rqpair->poller);
1079 	}
1080 }
1081 
1082 static int
1083 request_transfer_in(struct spdk_nvmf_request *req)
1084 {
1085 	struct spdk_nvmf_rdma_request	*rdma_req;
1086 	struct spdk_nvmf_qpair		*qpair;
1087 	struct spdk_nvmf_rdma_qpair	*rqpair;
1088 	struct spdk_nvmf_rdma_transport *rtransport;
1089 
1090 	qpair = req->qpair;
1091 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1092 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1093 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1094 				      struct spdk_nvmf_rdma_transport, transport);
1095 
1096 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1097 	assert(rdma_req != NULL);
1098 
1099 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1100 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1101 	}
1102 	if (rtransport->rdma_opts.no_wr_batching) {
1103 		_poller_submit_sends(rtransport, rqpair->poller);
1104 	}
1105 
1106 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1107 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1108 	return 0;
1109 }
1110 
1111 static int
1112 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1113 {
1114 	int				num_outstanding_data_wr = 0;
1115 	struct spdk_nvmf_rdma_request	*rdma_req;
1116 	struct spdk_nvmf_qpair		*qpair;
1117 	struct spdk_nvmf_rdma_qpair	*rqpair;
1118 	struct spdk_nvme_cpl		*rsp;
1119 	struct ibv_send_wr		*first = NULL;
1120 	struct spdk_nvmf_rdma_transport *rtransport;
1121 
1122 	*data_posted = 0;
1123 	qpair = req->qpair;
1124 	rsp = &req->rsp->nvme_cpl;
1125 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1126 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1127 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1128 				      struct spdk_nvmf_rdma_transport, transport);
1129 
1130 	/* Advance our sq_head pointer */
1131 	if (qpair->sq_head == qpair->sq_head_max) {
1132 		qpair->sq_head = 0;
1133 	} else {
1134 		qpair->sq_head++;
1135 	}
1136 	rsp->sqhd = qpair->sq_head;
1137 
1138 	/* queue the capsule for the recv buffer */
1139 	assert(rdma_req->recv != NULL);
1140 
1141 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1142 
1143 	rdma_req->recv = NULL;
1144 	assert(rqpair->current_recv_depth > 0);
1145 	rqpair->current_recv_depth--;
1146 
1147 	/* Build the response which consists of optional
1148 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1149 	 * containing the response.
1150 	 */
1151 	first = &rdma_req->rsp.wr;
1152 
1153 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1154 		/* On failure, data was not read from the controller. So clear the
1155 		 * number of outstanding data WRs to zero.
1156 		 */
1157 		rdma_req->num_outstanding_data_wr = 0;
1158 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1159 		first = &rdma_req->data.wr;
1160 		*data_posted = 1;
1161 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1162 	}
1163 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1164 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1165 	}
1166 	if (rtransport->rdma_opts.no_wr_batching) {
1167 		_poller_submit_sends(rtransport, rqpair->poller);
1168 	}
1169 
1170 	/* +1 for the rsp wr */
1171 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1172 
1173 	return 0;
1174 }
1175 
1176 static int
1177 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1178 {
1179 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1180 	struct rdma_conn_param				ctrlr_event_data = {};
1181 	int						rc;
1182 
1183 	accept_data.recfmt = 0;
1184 	accept_data.crqsize = rqpair->max_queue_depth;
1185 
1186 	ctrlr_event_data.private_data = &accept_data;
1187 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1188 	if (id->ps == RDMA_PS_TCP) {
1189 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1190 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1191 	}
1192 
1193 	/* Configure infinite retries for the initiator side qpair.
1194 	 * When using a shared receive queue on the target side,
1195 	 * we need to pass this value to the initiator to prevent the
1196 	 * initiator side NIC from completing SEND requests back to the
1197 	 * initiator with status rnr_retry_count_exceeded. */
1198 	if (rqpair->srq != NULL) {
1199 		ctrlr_event_data.rnr_retry_count = 0x7;
1200 	}
1201 
1202 	/* When qpair is created without use of rdma cm API, an additional
1203 	 * information must be provided to initiator in the connection response:
1204 	 * whether qpair is using SRQ and its qp_num
1205 	 * Fields below are ignored by rdma cm if qpair has been
1206 	 * created using rdma cm API. */
1207 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1208 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1209 
1210 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1211 	if (rc) {
1212 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1213 	} else {
1214 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1215 	}
1216 
1217 	return rc;
1218 }
1219 
1220 static void
1221 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1222 {
1223 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1224 
1225 	rej_data.recfmt = 0;
1226 	rej_data.sts = error;
1227 
1228 	rdma_reject(id, &rej_data, sizeof(rej_data));
1229 }
1230 
1231 static int
1232 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1233 {
1234 	struct spdk_nvmf_rdma_transport *rtransport;
1235 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1236 	struct spdk_nvmf_rdma_port	*port;
1237 	struct rdma_conn_param		*rdma_param = NULL;
1238 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1239 	uint16_t			max_queue_depth;
1240 	uint16_t			max_read_depth;
1241 
1242 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1243 
1244 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1245 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1246 
1247 	rdma_param = &event->param.conn;
1248 	if (rdma_param->private_data == NULL ||
1249 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1250 		SPDK_ERRLOG("connect request: no private data provided\n");
1251 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1252 		return -1;
1253 	}
1254 
1255 	private_data = rdma_param->private_data;
1256 	if (private_data->recfmt != 0) {
1257 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1258 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1259 		return -1;
1260 	}
1261 
1262 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1263 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1264 
1265 	port = event->listen_id->context;
1266 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1267 		      event->listen_id, event->listen_id->verbs, port);
1268 
1269 	/* Figure out the supported queue depth. This is a multi-step process
1270 	 * that takes into account hardware maximums, host provided values,
1271 	 * and our target's internal memory limits */
1272 
1273 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1274 
1275 	/* Start with the maximum queue depth allowed by the target */
1276 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1277 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1278 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1279 		      rtransport->transport.opts.max_queue_depth);
1280 
1281 	/* Next check the local NIC's hardware limitations */
1282 	SPDK_DEBUGLOG(rdma,
1283 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1284 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1285 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1286 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1287 
1288 	/* Next check the remote NIC's hardware limitations */
1289 	SPDK_DEBUGLOG(rdma,
1290 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1291 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1292 	if (rdma_param->initiator_depth > 0) {
1293 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1294 	}
1295 
1296 	/* Finally check for the host software requested values, which are
1297 	 * optional. */
1298 	if (rdma_param->private_data != NULL &&
1299 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1300 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1301 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1302 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1303 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1304 	}
1305 
1306 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1307 		      max_queue_depth, max_read_depth);
1308 
1309 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1310 	if (rqpair == NULL) {
1311 		SPDK_ERRLOG("Could not allocate new connection.\n");
1312 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1313 		return -1;
1314 	}
1315 
1316 	rqpair->device = port->device;
1317 	rqpair->max_queue_depth = max_queue_depth;
1318 	rqpair->max_read_depth = max_read_depth;
1319 	rqpair->cm_id = event->id;
1320 	rqpair->listen_id = event->listen_id;
1321 	rqpair->qpair.transport = transport;
1322 	STAILQ_INIT(&rqpair->ibv_events);
1323 	/* use qid from the private data to determine the qpair type
1324 	   qid will be set to the appropriate value when the controller is created */
1325 	rqpair->qpair.qid = private_data->qid;
1326 
1327 	event->id->context = &rqpair->qpair;
1328 
1329 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1330 
1331 	return 0;
1332 }
1333 
1334 static inline void
1335 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1336 		   enum spdk_nvme_data_transfer xfer)
1337 {
1338 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1339 		wr->opcode = IBV_WR_RDMA_WRITE;
1340 		wr->send_flags = 0;
1341 		wr->next = next;
1342 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1343 		wr->opcode = IBV_WR_RDMA_READ;
1344 		wr->send_flags = IBV_SEND_SIGNALED;
1345 		wr->next = NULL;
1346 	} else {
1347 		assert(0);
1348 	}
1349 }
1350 
1351 static int
1352 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1353 		       struct spdk_nvmf_rdma_request *rdma_req,
1354 		       uint32_t num_sgl_descriptors)
1355 {
1356 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1357 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1358 	uint32_t				i;
1359 
1360 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1361 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1362 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1363 		return -EINVAL;
1364 	}
1365 
1366 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1367 		return -ENOMEM;
1368 	}
1369 
1370 	current_data_wr = &rdma_req->data;
1371 
1372 	for (i = 0; i < num_sgl_descriptors; i++) {
1373 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1374 		current_data_wr->wr.next = &work_requests[i]->wr;
1375 		current_data_wr = work_requests[i];
1376 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1377 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1378 	}
1379 
1380 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1381 
1382 	return 0;
1383 }
1384 
1385 static inline void
1386 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1387 {
1388 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1389 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1390 
1391 	wr->wr.rdma.rkey = sgl->keyed.key;
1392 	wr->wr.rdma.remote_addr = sgl->address;
1393 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1394 }
1395 
1396 static inline void
1397 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1398 {
1399 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1400 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1401 	uint32_t			i;
1402 	int				j;
1403 	uint64_t			remote_addr_offset = 0;
1404 
1405 	for (i = 0; i < num_wrs; ++i) {
1406 		wr->wr.rdma.rkey = sgl->keyed.key;
1407 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1408 		for (j = 0; j < wr->num_sge; ++j) {
1409 			remote_addr_offset += wr->sg_list[j].length;
1410 		}
1411 		wr = wr->next;
1412 	}
1413 }
1414 
1415 static int
1416 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1417 		      struct spdk_nvmf_rdma_device *device,
1418 		      struct spdk_nvmf_rdma_request *rdma_req,
1419 		      struct ibv_send_wr *wr,
1420 		      uint32_t total_length,
1421 		      uint32_t num_extra_wrs)
1422 {
1423 	struct spdk_rdma_memory_translation mem_translation;
1424 	struct spdk_dif_ctx *dif_ctx = NULL;
1425 	struct ibv_sge	*sg_ele;
1426 	struct iovec *iov;
1427 	uint32_t remaining_data_block = 0;
1428 	uint32_t lkey, remaining;
1429 	int rc;
1430 
1431 	if (spdk_unlikely(rdma_req->req.dif_enabled)) {
1432 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1433 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1434 	}
1435 
1436 	wr->num_sge = 0;
1437 
1438 	while (total_length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1439 		iov = &rdma_req->req.iov[rdma_req->iovpos];
1440 		rc = spdk_rdma_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1441 		if (spdk_unlikely(rc)) {
1442 			return false;
1443 		}
1444 
1445 		lkey = spdk_rdma_memory_translation_get_lkey(&mem_translation);
1446 		sg_ele = &wr->sg_list[wr->num_sge];
1447 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1448 
1449 		if (spdk_likely(!dif_ctx)) {
1450 			sg_ele->lkey = lkey;
1451 			sg_ele->addr = (uintptr_t)iov->iov_base + rdma_req->offset;
1452 			sg_ele->length = remaining;
1453 			SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele, sg_ele->addr,
1454 				      sg_ele->length);
1455 			rdma_req->offset += sg_ele->length;
1456 			total_length -= sg_ele->length;
1457 			wr->num_sge++;
1458 
1459 			if (rdma_req->offset == iov->iov_len) {
1460 				rdma_req->offset = 0;
1461 				rdma_req->iovpos++;
1462 			}
1463 		} else {
1464 			uint32_t data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1465 			uint32_t md_size = dif_ctx->md_size;
1466 			uint32_t sge_len;
1467 
1468 			while (remaining) {
1469 				if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1470 					if (num_extra_wrs > 0 && wr->next) {
1471 						wr = wr->next;
1472 						wr->num_sge = 0;
1473 						sg_ele = &wr->sg_list[wr->num_sge];
1474 						num_extra_wrs--;
1475 					} else {
1476 						break;
1477 					}
1478 				}
1479 				sg_ele->lkey = lkey;
1480 				sg_ele->addr = (uintptr_t)((char *)iov->iov_base + rdma_req->offset);
1481 				sge_len = spdk_min(remaining, remaining_data_block);
1482 				sg_ele->length = sge_len;
1483 				SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele, sg_ele->addr,
1484 					      sg_ele->length);
1485 				remaining -= sge_len;
1486 				remaining_data_block -= sge_len;
1487 				rdma_req->offset += sge_len;
1488 				total_length -= sge_len;
1489 
1490 				sg_ele++;
1491 				wr->num_sge++;
1492 
1493 				if (remaining_data_block == 0) {
1494 					/* skip metadata */
1495 					rdma_req->offset += md_size;
1496 					total_length -= md_size;
1497 					/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1498 					remaining -= spdk_min(remaining, md_size);
1499 					remaining_data_block = data_block_size;
1500 				}
1501 
1502 				if (remaining == 0) {
1503 					/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1504 					   the remaining metadata bits at the beginning of the next buffer */
1505 					rdma_req->offset -= spdk_min(iov->iov_len, rdma_req->offset);
1506 					rdma_req->iovpos++;
1507 				}
1508 			}
1509 		}
1510 	}
1511 
1512 	if (total_length) {
1513 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1514 		return -EINVAL;
1515 	}
1516 
1517 	return 0;
1518 }
1519 
1520 static inline uint32_t
1521 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1522 {
1523 	/* estimate the number of SG entries and WRs needed to process the request */
1524 	uint32_t num_sge = 0;
1525 	uint32_t i;
1526 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1527 
1528 	for (i = 0; i < num_buffers && length > 0; i++) {
1529 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1530 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1531 
1532 		if (num_sge_in_block * block_size > buffer_len) {
1533 			++num_sge_in_block;
1534 		}
1535 		num_sge += num_sge_in_block;
1536 		length -= buffer_len;
1537 	}
1538 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1539 }
1540 
1541 static int
1542 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1543 			    struct spdk_nvmf_rdma_device *device,
1544 			    struct spdk_nvmf_rdma_request *rdma_req,
1545 			    uint32_t length)
1546 {
1547 	struct spdk_nvmf_rdma_qpair		*rqpair;
1548 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1549 	struct spdk_nvmf_request		*req = &rdma_req->req;
1550 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1551 	int					rc;
1552 	uint32_t				num_wrs = 1;
1553 
1554 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1555 	rgroup = rqpair->poller->group;
1556 
1557 	/* rdma wr specifics */
1558 	nvmf_rdma_setup_request(rdma_req);
1559 
1560 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1561 					   length);
1562 	if (rc != 0) {
1563 		return rc;
1564 	}
1565 
1566 	assert(req->iovcnt <= rqpair->max_send_sge);
1567 
1568 	rdma_req->iovpos = 0;
1569 
1570 	if (spdk_unlikely(req->dif_enabled)) {
1571 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1572 						 req->dif.dif_ctx.block_size);
1573 		if (num_wrs > 1) {
1574 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1575 			if (rc != 0) {
1576 				goto err_exit;
1577 			}
1578 		}
1579 	}
1580 
1581 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1582 	if (spdk_unlikely(rc != 0)) {
1583 		goto err_exit;
1584 	}
1585 
1586 	if (spdk_unlikely(num_wrs > 1)) {
1587 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1588 	}
1589 
1590 	/* set the number of outstanding data WRs for this request. */
1591 	rdma_req->num_outstanding_data_wr = num_wrs;
1592 
1593 	return rc;
1594 
1595 err_exit:
1596 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1597 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1598 	req->iovcnt = 0;
1599 	return rc;
1600 }
1601 
1602 static int
1603 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1604 				      struct spdk_nvmf_rdma_device *device,
1605 				      struct spdk_nvmf_rdma_request *rdma_req)
1606 {
1607 	struct spdk_nvmf_rdma_qpair		*rqpair;
1608 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1609 	struct ibv_send_wr			*current_wr;
1610 	struct spdk_nvmf_request		*req = &rdma_req->req;
1611 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1612 	uint32_t				num_sgl_descriptors;
1613 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES], total_length = 0;
1614 	uint32_t				i;
1615 	int					rc;
1616 
1617 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1618 	rgroup = rqpair->poller->group;
1619 
1620 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1621 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1622 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1623 
1624 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1625 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1626 
1627 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1628 	for (i = 0; i < num_sgl_descriptors; i++) {
1629 		if (spdk_likely(!req->dif_enabled)) {
1630 			lengths[i] = desc->keyed.length;
1631 		} else {
1632 			req->dif.orig_length += desc->keyed.length;
1633 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1634 			req->dif.elba_length += lengths[i];
1635 		}
1636 		total_length += lengths[i];
1637 		desc++;
1638 	}
1639 
1640 	if (total_length > rtransport->transport.opts.max_io_size) {
1641 		SPDK_ERRLOG("Multi SGL length 0x%x exceeds max io size 0x%x\n",
1642 			    total_length, rtransport->transport.opts.max_io_size);
1643 		req->rsp->nvme_cpl.status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1644 		return -EINVAL;
1645 	}
1646 
1647 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1648 		return -ENOMEM;
1649 	}
1650 
1651 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport, total_length);
1652 	if (rc != 0) {
1653 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1654 		return rc;
1655 	}
1656 
1657 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1658 	current_wr = &rdma_req->data.wr;
1659 	assert(current_wr != NULL);
1660 
1661 	req->length = 0;
1662 	rdma_req->iovpos = 0;
1663 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1664 	for (i = 0; i < num_sgl_descriptors; i++) {
1665 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1666 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1667 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1668 			rc = -EINVAL;
1669 			goto err_exit;
1670 		}
1671 
1672 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1673 		if (rc != 0) {
1674 			rc = -ENOMEM;
1675 			goto err_exit;
1676 		}
1677 
1678 		req->length += desc->keyed.length;
1679 		current_wr->wr.rdma.rkey = desc->keyed.key;
1680 		current_wr->wr.rdma.remote_addr = desc->address;
1681 		current_wr = current_wr->next;
1682 		desc++;
1683 	}
1684 
1685 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1686 	/* Go back to the last descriptor in the list. */
1687 	desc--;
1688 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1689 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1690 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1691 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1692 		}
1693 	}
1694 #endif
1695 
1696 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1697 
1698 	return 0;
1699 
1700 err_exit:
1701 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1702 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1703 	return rc;
1704 }
1705 
1706 static int
1707 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1708 			    struct spdk_nvmf_rdma_device *device,
1709 			    struct spdk_nvmf_rdma_request *rdma_req)
1710 {
1711 	struct spdk_nvmf_request		*req = &rdma_req->req;
1712 	struct spdk_nvme_cpl			*rsp;
1713 	struct spdk_nvme_sgl_descriptor		*sgl;
1714 	int					rc;
1715 	uint32_t				length;
1716 
1717 	rsp = &req->rsp->nvme_cpl;
1718 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1719 
1720 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1721 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1722 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1723 
1724 		length = sgl->keyed.length;
1725 		if (length > rtransport->transport.opts.max_io_size) {
1726 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1727 				    length, rtransport->transport.opts.max_io_size);
1728 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1729 			return -1;
1730 		}
1731 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1732 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1733 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1734 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1735 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1736 			}
1737 		}
1738 #endif
1739 
1740 		/* fill request length and populate iovs */
1741 		req->length = length;
1742 
1743 		if (spdk_unlikely(req->dif_enabled)) {
1744 			req->dif.orig_length = length;
1745 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1746 			req->dif.elba_length = length;
1747 		}
1748 
1749 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1750 		if (spdk_unlikely(rc < 0)) {
1751 			if (rc == -EINVAL) {
1752 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1753 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1754 				return -1;
1755 			}
1756 			/* No available buffers. Queue this request up. */
1757 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1758 			return 0;
1759 		}
1760 
1761 		/* backward compatible */
1762 		req->data = req->iov[0].iov_base;
1763 
1764 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1765 			      req->iovcnt);
1766 
1767 		return 0;
1768 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1769 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1770 		uint64_t offset = sgl->address;
1771 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1772 
1773 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1774 			      offset, sgl->unkeyed.length);
1775 
1776 		if (offset > max_len) {
1777 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1778 				    offset, max_len);
1779 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1780 			return -1;
1781 		}
1782 		max_len -= (uint32_t)offset;
1783 
1784 		if (sgl->unkeyed.length > max_len) {
1785 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1786 				    sgl->unkeyed.length, max_len);
1787 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1788 			return -1;
1789 		}
1790 
1791 		rdma_req->num_outstanding_data_wr = 0;
1792 		req->data = rdma_req->recv->buf + offset;
1793 		req->data_from_pool = false;
1794 		req->length = sgl->unkeyed.length;
1795 
1796 		req->iov[0].iov_base = req->data;
1797 		req->iov[0].iov_len = req->length;
1798 		req->iovcnt = 1;
1799 
1800 		return 0;
1801 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1802 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1803 
1804 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1805 		if (rc == -ENOMEM) {
1806 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1807 			return 0;
1808 		} else if (rc == -EINVAL) {
1809 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1810 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1811 			return -1;
1812 		}
1813 
1814 		/* backward compatible */
1815 		req->data = req->iov[0].iov_base;
1816 
1817 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1818 			      req->iovcnt);
1819 
1820 		return 0;
1821 	}
1822 
1823 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1824 		    sgl->generic.type, sgl->generic.subtype);
1825 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1826 	return -1;
1827 }
1828 
1829 static void
1830 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1831 			struct spdk_nvmf_rdma_transport	*rtransport)
1832 {
1833 	struct spdk_nvmf_rdma_qpair		*rqpair;
1834 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1835 
1836 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1837 	if (rdma_req->req.data_from_pool) {
1838 		rgroup = rqpair->poller->group;
1839 
1840 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1841 	}
1842 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1843 	rdma_req->req.length = 0;
1844 	rdma_req->req.iovcnt = 0;
1845 	rdma_req->req.data = NULL;
1846 	rdma_req->rsp.wr.next = NULL;
1847 	rdma_req->data.wr.next = NULL;
1848 	rdma_req->offset = 0;
1849 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1850 	rqpair->qd--;
1851 
1852 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1853 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1854 }
1855 
1856 bool
1857 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1858 			  struct spdk_nvmf_rdma_request *rdma_req)
1859 {
1860 	struct spdk_nvmf_rdma_qpair	*rqpair;
1861 	struct spdk_nvmf_rdma_device	*device;
1862 	struct spdk_nvmf_rdma_poll_group *rgroup;
1863 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1864 	int				rc;
1865 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1866 	enum spdk_nvmf_rdma_request_state prev_state;
1867 	bool				progress = false;
1868 	int				data_posted;
1869 	uint32_t			num_blocks;
1870 
1871 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1872 	device = rqpair->device;
1873 	rgroup = rqpair->poller->group;
1874 
1875 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1876 
1877 	/* If the queue pair is in an error state, force the request to the completed state
1878 	 * to release resources. */
1879 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1880 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1881 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1882 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1883 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1884 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1885 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1886 		}
1887 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1888 	}
1889 
1890 	/* The loop here is to allow for several back-to-back state changes. */
1891 	do {
1892 		prev_state = rdma_req->state;
1893 
1894 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
1895 
1896 		switch (rdma_req->state) {
1897 		case RDMA_REQUEST_STATE_FREE:
1898 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1899 			 * to escape this state. */
1900 			break;
1901 		case RDMA_REQUEST_STATE_NEW:
1902 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1903 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
1904 			rdma_recv = rdma_req->recv;
1905 
1906 			/* The first element of the SGL is the NVMe command */
1907 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1908 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1909 
1910 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1911 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1912 				break;
1913 			}
1914 
1915 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
1916 				rdma_req->req.dif_enabled = true;
1917 			}
1918 
1919 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1920 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1921 			rdma_req->rsp.wr.imm_data = 0;
1922 #endif
1923 
1924 			/* The next state transition depends on the data transfer needs of this request. */
1925 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
1926 
1927 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
1928 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
1929 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
1930 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1931 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
1932 				break;
1933 			}
1934 
1935 			/* If no data to transfer, ready to execute. */
1936 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1937 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1938 				break;
1939 			}
1940 
1941 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1942 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
1943 			break;
1944 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1945 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1946 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
1947 
1948 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1949 
1950 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
1951 				/* This request needs to wait in line to obtain a buffer */
1952 				break;
1953 			}
1954 
1955 			/* Try to get a data buffer */
1956 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1957 			if (rc < 0) {
1958 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1959 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1960 				break;
1961 			}
1962 
1963 			if (!rdma_req->req.data) {
1964 				/* No buffers available. */
1965 				rgroup->stat.pending_data_buffer++;
1966 				break;
1967 			}
1968 
1969 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1970 
1971 			/* If data is transferring from host to controller and the data didn't
1972 			 * arrive using in capsule data, we need to do a transfer from the host.
1973 			 */
1974 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
1975 			    rdma_req->req.data_from_pool) {
1976 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1977 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1978 				break;
1979 			}
1980 
1981 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1982 			break;
1983 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1984 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1985 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
1986 
1987 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
1988 				/* This request needs to wait in line to perform RDMA */
1989 				break;
1990 			}
1991 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1992 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1993 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1994 				rqpair->poller->stat.pending_rdma_read++;
1995 				break;
1996 			}
1997 
1998 			/* We have already verified that this request is the head of the queue. */
1999 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2000 
2001 			rc = request_transfer_in(&rdma_req->req);
2002 			if (!rc) {
2003 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2004 			} else {
2005 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2006 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2007 			}
2008 			break;
2009 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2010 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2011 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2012 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2013 			 * to escape this state. */
2014 			break;
2015 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2016 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2017 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2018 
2019 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2020 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2021 					/* generate DIF for write operation */
2022 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2023 					assert(num_blocks > 0);
2024 
2025 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2026 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2027 					if (rc != 0) {
2028 						SPDK_ERRLOG("DIF generation failed\n");
2029 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2030 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2031 						break;
2032 					}
2033 				}
2034 
2035 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2036 				/* set extended length before IO operation */
2037 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2038 			}
2039 
2040 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2041 			spdk_nvmf_request_exec(&rdma_req->req);
2042 			break;
2043 		case RDMA_REQUEST_STATE_EXECUTING:
2044 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2045 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2046 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2047 			 * to escape this state. */
2048 			break;
2049 		case RDMA_REQUEST_STATE_EXECUTED:
2050 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2051 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2052 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2053 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2054 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2055 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2056 			} else {
2057 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2058 			}
2059 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2060 				/* restore the original length */
2061 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2062 
2063 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2064 					struct spdk_dif_error error_blk;
2065 
2066 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2067 
2068 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2069 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2070 					if (rc) {
2071 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2072 
2073 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2074 							    error_blk.err_offset);
2075 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2076 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2077 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2078 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2079 					}
2080 				}
2081 			}
2082 			break;
2083 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2084 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2085 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2086 
2087 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2088 				/* This request needs to wait in line to perform RDMA */
2089 				break;
2090 			}
2091 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2092 			    rqpair->max_send_depth) {
2093 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2094 				 * +1 since each request has an additional wr in the resp. */
2095 				rqpair->poller->stat.pending_rdma_write++;
2096 				break;
2097 			}
2098 
2099 			/* We have already verified that this request is the head of the queue. */
2100 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2101 
2102 			/* The data transfer will be kicked off from
2103 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2104 			 */
2105 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2106 			break;
2107 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2108 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2109 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2110 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2111 			assert(rc == 0); /* No good way to handle this currently */
2112 			if (rc) {
2113 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2114 			} else {
2115 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2116 						  RDMA_REQUEST_STATE_COMPLETING;
2117 			}
2118 			break;
2119 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2120 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2121 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2122 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2123 			 * to escape this state. */
2124 			break;
2125 		case RDMA_REQUEST_STATE_COMPLETING:
2126 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2127 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2128 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2129 			 * to escape this state. */
2130 			break;
2131 		case RDMA_REQUEST_STATE_COMPLETED:
2132 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2133 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2134 
2135 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2136 			_nvmf_rdma_request_free(rdma_req, rtransport);
2137 			break;
2138 		case RDMA_REQUEST_NUM_STATES:
2139 		default:
2140 			assert(0);
2141 			break;
2142 		}
2143 
2144 		if (rdma_req->state != prev_state) {
2145 			progress = true;
2146 		}
2147 	} while (rdma_req->state != prev_state);
2148 
2149 	return progress;
2150 }
2151 
2152 /* Public API callbacks begin here */
2153 
2154 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2155 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2156 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2157 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2158 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2159 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2160 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2161 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2162 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2163 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2164 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2165 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2166 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2167 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2168 
2169 static void
2170 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2171 {
2172 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2173 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2174 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2175 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2176 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2177 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2178 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2179 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2180 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2181 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2182 	opts->transport_specific =      NULL;
2183 }
2184 
2185 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2186 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2187 
2188 static inline bool
2189 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2190 {
2191 	return device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_OLD ||
2192 	       device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_NEW;
2193 }
2194 
2195 static int
2196 nvmf_rdma_accept(void *ctx);
2197 
2198 static struct spdk_nvmf_transport *
2199 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2200 {
2201 	int rc;
2202 	struct spdk_nvmf_rdma_transport *rtransport;
2203 	struct spdk_nvmf_rdma_device	*device, *tmp;
2204 	struct ibv_context		**contexts;
2205 	uint32_t			i;
2206 	int				flag;
2207 	uint32_t			sge_count;
2208 	uint32_t			min_shared_buffers;
2209 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2210 	pthread_mutexattr_t		attr;
2211 
2212 	rtransport = calloc(1, sizeof(*rtransport));
2213 	if (!rtransport) {
2214 		return NULL;
2215 	}
2216 
2217 	if (pthread_mutexattr_init(&attr)) {
2218 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2219 		free(rtransport);
2220 		return NULL;
2221 	}
2222 
2223 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2224 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2225 		pthread_mutexattr_destroy(&attr);
2226 		free(rtransport);
2227 		return NULL;
2228 	}
2229 
2230 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2231 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2232 		pthread_mutexattr_destroy(&attr);
2233 		free(rtransport);
2234 		return NULL;
2235 	}
2236 
2237 	pthread_mutexattr_destroy(&attr);
2238 
2239 	TAILQ_INIT(&rtransport->devices);
2240 	TAILQ_INIT(&rtransport->ports);
2241 	TAILQ_INIT(&rtransport->poll_groups);
2242 
2243 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2244 	rtransport->rdma_opts.num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2245 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2246 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2247 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2248 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2249 	if (opts->transport_specific != NULL &&
2250 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2251 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2252 					    &rtransport->rdma_opts)) {
2253 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2254 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2255 		return NULL;
2256 	}
2257 
2258 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2259 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2260 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2261 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2262 		     "  num_shared_buffers=%d, num_cqe=%d, max_srq_depth=%d, no_srq=%d,"
2263 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2264 		     opts->max_queue_depth,
2265 		     opts->max_io_size,
2266 		     opts->max_qpairs_per_ctrlr - 1,
2267 		     opts->io_unit_size,
2268 		     opts->in_capsule_data_size,
2269 		     opts->max_aq_depth,
2270 		     opts->num_shared_buffers,
2271 		     rtransport->rdma_opts.num_cqe,
2272 		     rtransport->rdma_opts.max_srq_depth,
2273 		     rtransport->rdma_opts.no_srq,
2274 		     rtransport->rdma_opts.acceptor_backlog,
2275 		     rtransport->rdma_opts.no_wr_batching,
2276 		     opts->abort_timeout_sec);
2277 
2278 	/* I/O unit size cannot be larger than max I/O size */
2279 	if (opts->io_unit_size > opts->max_io_size) {
2280 		opts->io_unit_size = opts->max_io_size;
2281 	}
2282 
2283 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2284 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2285 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2286 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2287 	}
2288 
2289 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2290 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2291 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2292 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2293 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2294 		return NULL;
2295 	}
2296 
2297 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2298 	if (min_shared_buffers > opts->num_shared_buffers) {
2299 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2300 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2301 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2302 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2303 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2304 		return NULL;
2305 	}
2306 
2307 	sge_count = opts->max_io_size / opts->io_unit_size;
2308 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2309 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2310 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2311 		return NULL;
2312 	}
2313 
2314 	rtransport->event_channel = rdma_create_event_channel();
2315 	if (rtransport->event_channel == NULL) {
2316 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2317 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2318 		return NULL;
2319 	}
2320 
2321 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2322 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2323 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2324 			    rtransport->event_channel->fd, spdk_strerror(errno));
2325 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2326 		return NULL;
2327 	}
2328 
2329 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2330 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2331 				   sizeof(struct spdk_nvmf_rdma_request_data),
2332 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2333 				   SPDK_ENV_SOCKET_ID_ANY);
2334 	if (!rtransport->data_wr_pool) {
2335 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2336 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2337 		return NULL;
2338 	}
2339 
2340 	contexts = rdma_get_devices(NULL);
2341 	if (contexts == NULL) {
2342 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2343 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2344 		return NULL;
2345 	}
2346 
2347 	i = 0;
2348 	rc = 0;
2349 	while (contexts[i] != NULL) {
2350 		device = calloc(1, sizeof(*device));
2351 		if (!device) {
2352 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2353 			rc = -ENOMEM;
2354 			break;
2355 		}
2356 		device->context = contexts[i];
2357 		rc = ibv_query_device(device->context, &device->attr);
2358 		if (rc < 0) {
2359 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2360 			free(device);
2361 			break;
2362 
2363 		}
2364 
2365 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2366 
2367 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2368 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2369 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2370 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2371 		}
2372 
2373 		/**
2374 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2375 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2376 		 * but incorrectly reports that it does. There are changes making their way
2377 		 * through the kernel now that will enable this feature. When they are merged,
2378 		 * we can conditionally enable this feature.
2379 		 *
2380 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2381 		 */
2382 		if (nvmf_rdma_is_rxe_device(device)) {
2383 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2384 		}
2385 #endif
2386 
2387 		/* set up device context async ev fd as NON_BLOCKING */
2388 		flag = fcntl(device->context->async_fd, F_GETFL);
2389 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2390 		if (rc < 0) {
2391 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2392 			free(device);
2393 			break;
2394 		}
2395 
2396 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2397 		i++;
2398 
2399 		if (g_nvmf_hooks.get_ibv_pd) {
2400 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2401 		} else {
2402 			device->pd = ibv_alloc_pd(device->context);
2403 		}
2404 
2405 		if (!device->pd) {
2406 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2407 			rc = -ENOMEM;
2408 			break;
2409 		}
2410 
2411 		assert(device->map == NULL);
2412 
2413 		device->map = spdk_rdma_create_mem_map(device->pd, &g_nvmf_hooks, SPDK_RDMA_MEMORY_MAP_ROLE_TARGET);
2414 		if (!device->map) {
2415 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2416 			rc = -ENOMEM;
2417 			break;
2418 		}
2419 
2420 		assert(device->map != NULL);
2421 		assert(device->pd != NULL);
2422 	}
2423 	rdma_free_devices(contexts);
2424 
2425 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2426 		/* divide and round up. */
2427 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2428 
2429 		/* round up to the nearest 4k. */
2430 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2431 
2432 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2433 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2434 			       opts->io_unit_size);
2435 	}
2436 
2437 	if (rc < 0) {
2438 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2439 		return NULL;
2440 	}
2441 
2442 	/* Set up poll descriptor array to monitor events from RDMA and IB
2443 	 * in a single poll syscall
2444 	 */
2445 	rtransport->npoll_fds = i + 1;
2446 	i = 0;
2447 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2448 	if (rtransport->poll_fds == NULL) {
2449 		SPDK_ERRLOG("poll_fds allocation failed\n");
2450 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2451 		return NULL;
2452 	}
2453 
2454 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2455 	rtransport->poll_fds[i++].events = POLLIN;
2456 
2457 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2458 		rtransport->poll_fds[i].fd = device->context->async_fd;
2459 		rtransport->poll_fds[i++].events = POLLIN;
2460 	}
2461 
2462 	rtransport->accept_poller = SPDK_POLLER_REGISTER(nvmf_rdma_accept, &rtransport->transport,
2463 				    opts->acceptor_poll_rate);
2464 	if (!rtransport->accept_poller) {
2465 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2466 		return NULL;
2467 	}
2468 
2469 	return &rtransport->transport;
2470 }
2471 
2472 static void
2473 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2474 {
2475 	struct spdk_nvmf_rdma_transport	*rtransport;
2476 	assert(w != NULL);
2477 
2478 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2479 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2480 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2481 	if (rtransport->rdma_opts.no_srq == true) {
2482 		spdk_json_write_named_int32(w, "num_cqe", rtransport->rdma_opts.num_cqe);
2483 	}
2484 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2485 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2486 }
2487 
2488 static int
2489 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2490 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2491 {
2492 	struct spdk_nvmf_rdma_transport	*rtransport;
2493 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2494 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2495 
2496 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2497 
2498 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2499 		TAILQ_REMOVE(&rtransport->ports, port, link);
2500 		rdma_destroy_id(port->id);
2501 		free(port);
2502 	}
2503 
2504 	if (rtransport->poll_fds != NULL) {
2505 		free(rtransport->poll_fds);
2506 	}
2507 
2508 	if (rtransport->event_channel != NULL) {
2509 		rdma_destroy_event_channel(rtransport->event_channel);
2510 	}
2511 
2512 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2513 		TAILQ_REMOVE(&rtransport->devices, device, link);
2514 		spdk_rdma_free_mem_map(&device->map);
2515 		if (device->pd) {
2516 			if (!g_nvmf_hooks.get_ibv_pd) {
2517 				ibv_dealloc_pd(device->pd);
2518 			}
2519 		}
2520 		free(device);
2521 	}
2522 
2523 	if (rtransport->data_wr_pool != NULL) {
2524 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2525 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2526 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2527 				    spdk_mempool_count(rtransport->data_wr_pool),
2528 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2529 		}
2530 	}
2531 
2532 	spdk_mempool_free(rtransport->data_wr_pool);
2533 
2534 	spdk_poller_unregister(&rtransport->accept_poller);
2535 	pthread_mutex_destroy(&rtransport->lock);
2536 	free(rtransport);
2537 
2538 	if (cb_fn) {
2539 		cb_fn(cb_arg);
2540 	}
2541 	return 0;
2542 }
2543 
2544 static int
2545 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2546 			  struct spdk_nvme_transport_id *trid,
2547 			  bool peer);
2548 
2549 static int
2550 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2551 		 struct spdk_nvmf_listen_opts *listen_opts)
2552 {
2553 	struct spdk_nvmf_rdma_transport	*rtransport;
2554 	struct spdk_nvmf_rdma_device	*device;
2555 	struct spdk_nvmf_rdma_port	*port;
2556 	struct addrinfo			*res;
2557 	struct addrinfo			hints;
2558 	int				family;
2559 	int				rc;
2560 
2561 	if (!strlen(trid->trsvcid)) {
2562 		SPDK_ERRLOG("Service id is required\n");
2563 		return -EINVAL;
2564 	}
2565 
2566 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2567 	assert(rtransport->event_channel != NULL);
2568 
2569 	pthread_mutex_lock(&rtransport->lock);
2570 	port = calloc(1, sizeof(*port));
2571 	if (!port) {
2572 		SPDK_ERRLOG("Port allocation failed\n");
2573 		pthread_mutex_unlock(&rtransport->lock);
2574 		return -ENOMEM;
2575 	}
2576 
2577 	port->trid = trid;
2578 
2579 	switch (trid->adrfam) {
2580 	case SPDK_NVMF_ADRFAM_IPV4:
2581 		family = AF_INET;
2582 		break;
2583 	case SPDK_NVMF_ADRFAM_IPV6:
2584 		family = AF_INET6;
2585 		break;
2586 	default:
2587 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2588 		free(port);
2589 		pthread_mutex_unlock(&rtransport->lock);
2590 		return -EINVAL;
2591 	}
2592 
2593 	memset(&hints, 0, sizeof(hints));
2594 	hints.ai_family = family;
2595 	hints.ai_flags = AI_NUMERICSERV;
2596 	hints.ai_socktype = SOCK_STREAM;
2597 	hints.ai_protocol = 0;
2598 
2599 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2600 	if (rc) {
2601 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2602 		free(port);
2603 		pthread_mutex_unlock(&rtransport->lock);
2604 		return -EINVAL;
2605 	}
2606 
2607 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2608 	if (rc < 0) {
2609 		SPDK_ERRLOG("rdma_create_id() failed\n");
2610 		freeaddrinfo(res);
2611 		free(port);
2612 		pthread_mutex_unlock(&rtransport->lock);
2613 		return rc;
2614 	}
2615 
2616 	rc = rdma_bind_addr(port->id, res->ai_addr);
2617 	freeaddrinfo(res);
2618 
2619 	if (rc < 0) {
2620 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2621 		rdma_destroy_id(port->id);
2622 		free(port);
2623 		pthread_mutex_unlock(&rtransport->lock);
2624 		return rc;
2625 	}
2626 
2627 	if (!port->id->verbs) {
2628 		SPDK_ERRLOG("ibv_context is null\n");
2629 		rdma_destroy_id(port->id);
2630 		free(port);
2631 		pthread_mutex_unlock(&rtransport->lock);
2632 		return -1;
2633 	}
2634 
2635 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2636 	if (rc < 0) {
2637 		SPDK_ERRLOG("rdma_listen() failed\n");
2638 		rdma_destroy_id(port->id);
2639 		free(port);
2640 		pthread_mutex_unlock(&rtransport->lock);
2641 		return rc;
2642 	}
2643 
2644 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2645 		if (device->context == port->id->verbs) {
2646 			port->device = device;
2647 			break;
2648 		}
2649 	}
2650 	if (!port->device) {
2651 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2652 			    port->id->verbs);
2653 		rdma_destroy_id(port->id);
2654 		free(port);
2655 		pthread_mutex_unlock(&rtransport->lock);
2656 		return -EINVAL;
2657 	}
2658 
2659 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2660 		       trid->traddr, trid->trsvcid);
2661 
2662 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2663 	pthread_mutex_unlock(&rtransport->lock);
2664 	return 0;
2665 }
2666 
2667 static void
2668 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2669 		      const struct spdk_nvme_transport_id *trid)
2670 {
2671 	struct spdk_nvmf_rdma_transport *rtransport;
2672 	struct spdk_nvmf_rdma_port *port, *tmp;
2673 
2674 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2675 
2676 	pthread_mutex_lock(&rtransport->lock);
2677 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2678 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2679 			TAILQ_REMOVE(&rtransport->ports, port, link);
2680 			rdma_destroy_id(port->id);
2681 			free(port);
2682 			break;
2683 		}
2684 	}
2685 
2686 	pthread_mutex_unlock(&rtransport->lock);
2687 }
2688 
2689 static void
2690 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2691 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2692 {
2693 	struct spdk_nvmf_request *req, *tmp;
2694 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2695 	struct spdk_nvmf_rdma_resources *resources;
2696 
2697 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2698 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2699 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2700 			break;
2701 		}
2702 	}
2703 
2704 	/* Then RDMA writes since reads have stronger restrictions than writes */
2705 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2706 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2707 			break;
2708 		}
2709 	}
2710 
2711 	/* Then we handle request waiting on memory buffers. */
2712 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2713 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2714 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2715 			break;
2716 		}
2717 	}
2718 
2719 	resources = rqpair->resources;
2720 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2721 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2722 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2723 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2724 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2725 
2726 		if (rqpair->srq != NULL) {
2727 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2728 			rdma_req->recv->qpair->qd++;
2729 		} else {
2730 			rqpair->qd++;
2731 		}
2732 
2733 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2734 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2735 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2736 			break;
2737 		}
2738 	}
2739 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2740 		rqpair->poller->stat.pending_free_request++;
2741 	}
2742 }
2743 
2744 static inline bool
2745 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
2746 {
2747 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
2748 	return nvmf_rdma_is_rxe_device(device) ||
2749 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
2750 }
2751 
2752 static void
2753 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2754 {
2755 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2756 			struct spdk_nvmf_rdma_transport, transport);
2757 
2758 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2759 
2760 	/* nvmr_rdma_close_qpair is not called */
2761 	if (!rqpair->to_close) {
2762 		return;
2763 	}
2764 
2765 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2766 	if (rqpair->current_send_depth != 0) {
2767 		return;
2768 	}
2769 
2770 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2771 		return;
2772 	}
2773 
2774 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
2775 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
2776 		return;
2777 	}
2778 
2779 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2780 
2781 	nvmf_rdma_qpair_destroy(rqpair);
2782 }
2783 
2784 static int
2785 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2786 {
2787 	struct spdk_nvmf_qpair		*qpair;
2788 	struct spdk_nvmf_rdma_qpair	*rqpair;
2789 
2790 	if (evt->id == NULL) {
2791 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2792 		return -1;
2793 	}
2794 
2795 	qpair = evt->id->context;
2796 	if (qpair == NULL) {
2797 		SPDK_ERRLOG("disconnect request: no active connection\n");
2798 		return -1;
2799 	}
2800 
2801 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2802 
2803 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair);
2804 
2805 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2806 
2807 	return 0;
2808 }
2809 
2810 #ifdef DEBUG
2811 static const char *CM_EVENT_STR[] = {
2812 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2813 	"RDMA_CM_EVENT_ADDR_ERROR",
2814 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2815 	"RDMA_CM_EVENT_ROUTE_ERROR",
2816 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2817 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2818 	"RDMA_CM_EVENT_CONNECT_ERROR",
2819 	"RDMA_CM_EVENT_UNREACHABLE",
2820 	"RDMA_CM_EVENT_REJECTED",
2821 	"RDMA_CM_EVENT_ESTABLISHED",
2822 	"RDMA_CM_EVENT_DISCONNECTED",
2823 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2824 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2825 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2826 	"RDMA_CM_EVENT_ADDR_CHANGE",
2827 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2828 };
2829 #endif /* DEBUG */
2830 
2831 static void
2832 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2833 				    struct spdk_nvmf_rdma_port *port)
2834 {
2835 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2836 	struct spdk_nvmf_rdma_poller		*rpoller;
2837 	struct spdk_nvmf_rdma_qpair		*rqpair;
2838 
2839 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2840 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2841 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2842 				if (rqpair->listen_id == port->id) {
2843 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2844 				}
2845 			}
2846 		}
2847 	}
2848 }
2849 
2850 static bool
2851 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2852 				      struct rdma_cm_event *event)
2853 {
2854 	const struct spdk_nvme_transport_id	*trid;
2855 	struct spdk_nvmf_rdma_port		*port;
2856 	struct spdk_nvmf_rdma_transport		*rtransport;
2857 	bool					event_acked = false;
2858 
2859 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2860 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2861 		if (port->id == event->id) {
2862 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2863 			rdma_ack_cm_event(event);
2864 			event_acked = true;
2865 			trid = port->trid;
2866 			break;
2867 		}
2868 	}
2869 
2870 	if (event_acked) {
2871 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2872 
2873 		nvmf_rdma_stop_listen(transport, trid);
2874 		nvmf_rdma_listen(transport, trid, NULL);
2875 	}
2876 
2877 	return event_acked;
2878 }
2879 
2880 static void
2881 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2882 				       struct rdma_cm_event *event)
2883 {
2884 	struct spdk_nvmf_rdma_port		*port;
2885 	struct spdk_nvmf_rdma_transport		*rtransport;
2886 
2887 	port = event->id->context;
2888 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2889 
2890 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2891 
2892 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2893 
2894 	rdma_ack_cm_event(event);
2895 
2896 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2897 		;
2898 	}
2899 }
2900 
2901 static void
2902 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2903 {
2904 	struct spdk_nvmf_rdma_transport *rtransport;
2905 	struct rdma_cm_event		*event;
2906 	int				rc;
2907 	bool				event_acked;
2908 
2909 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2910 
2911 	if (rtransport->event_channel == NULL) {
2912 		return;
2913 	}
2914 
2915 	while (1) {
2916 		event_acked = false;
2917 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2918 		if (rc) {
2919 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2920 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2921 			}
2922 			break;
2923 		}
2924 
2925 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2926 
2927 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2928 
2929 		switch (event->event) {
2930 		case RDMA_CM_EVENT_ADDR_RESOLVED:
2931 		case RDMA_CM_EVENT_ADDR_ERROR:
2932 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
2933 		case RDMA_CM_EVENT_ROUTE_ERROR:
2934 			/* No action required. The target never attempts to resolve routes. */
2935 			break;
2936 		case RDMA_CM_EVENT_CONNECT_REQUEST:
2937 			rc = nvmf_rdma_connect(transport, event);
2938 			if (rc < 0) {
2939 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2940 				break;
2941 			}
2942 			break;
2943 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
2944 			/* The target never initiates a new connection. So this will not occur. */
2945 			break;
2946 		case RDMA_CM_EVENT_CONNECT_ERROR:
2947 			/* Can this happen? The docs say it can, but not sure what causes it. */
2948 			break;
2949 		case RDMA_CM_EVENT_UNREACHABLE:
2950 		case RDMA_CM_EVENT_REJECTED:
2951 			/* These only occur on the client side. */
2952 			break;
2953 		case RDMA_CM_EVENT_ESTABLISHED:
2954 			/* TODO: Should we be waiting for this event anywhere? */
2955 			break;
2956 		case RDMA_CM_EVENT_DISCONNECTED:
2957 			rc = nvmf_rdma_disconnect(event);
2958 			if (rc < 0) {
2959 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2960 				break;
2961 			}
2962 			break;
2963 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
2964 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
2965 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
2966 			 * Once these events are sent to SPDK, we should release all IB resources and
2967 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
2968 			 * ibv_destroy* functions to release user space memory allocated by IB. All kernel
2969 			 * resources are already cleaned. */
2970 			if (event->id->qp) {
2971 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
2972 				 * corresponding qpair. Otherwise the event refers to a listening device */
2973 				rc = nvmf_rdma_disconnect(event);
2974 				if (rc < 0) {
2975 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2976 					break;
2977 				}
2978 			} else {
2979 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
2980 				event_acked = true;
2981 			}
2982 			break;
2983 		case RDMA_CM_EVENT_MULTICAST_JOIN:
2984 		case RDMA_CM_EVENT_MULTICAST_ERROR:
2985 			/* Multicast is not used */
2986 			break;
2987 		case RDMA_CM_EVENT_ADDR_CHANGE:
2988 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
2989 			break;
2990 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2991 			/* For now, do nothing. The target never re-uses queue pairs. */
2992 			break;
2993 		default:
2994 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2995 			break;
2996 		}
2997 		if (!event_acked) {
2998 			rdma_ack_cm_event(event);
2999 		}
3000 	}
3001 }
3002 
3003 static void
3004 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3005 {
3006 	rqpair->last_wqe_reached = true;
3007 	nvmf_rdma_destroy_drained_qpair(rqpair);
3008 }
3009 
3010 static void
3011 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3012 {
3013 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3014 
3015 	if (event_ctx->rqpair) {
3016 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3017 		if (event_ctx->cb_fn) {
3018 			event_ctx->cb_fn(event_ctx->rqpair);
3019 		}
3020 	}
3021 	free(event_ctx);
3022 }
3023 
3024 static int
3025 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3026 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3027 {
3028 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3029 	struct spdk_thread *thr = NULL;
3030 	int rc;
3031 
3032 	if (rqpair->qpair.group) {
3033 		thr = rqpair->qpair.group->thread;
3034 	} else if (rqpair->destruct_channel) {
3035 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3036 	}
3037 
3038 	if (!thr) {
3039 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3040 		return -EINVAL;
3041 	}
3042 
3043 	ctx = calloc(1, sizeof(*ctx));
3044 	if (!ctx) {
3045 		return -ENOMEM;
3046 	}
3047 
3048 	ctx->rqpair = rqpair;
3049 	ctx->cb_fn = fn;
3050 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3051 
3052 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3053 	if (rc) {
3054 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3055 		free(ctx);
3056 	}
3057 
3058 	return rc;
3059 }
3060 
3061 static int
3062 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3063 {
3064 	int				rc;
3065 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3066 	struct ibv_async_event		event;
3067 
3068 	rc = ibv_get_async_event(device->context, &event);
3069 
3070 	if (rc) {
3071 		/* In non-blocking mode -1 means there are no events available */
3072 		return rc;
3073 	}
3074 
3075 	switch (event.event_type) {
3076 	case IBV_EVENT_QP_FATAL:
3077 		rqpair = event.element.qp->qp_context;
3078 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3079 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3080 				  (uintptr_t)rqpair, event.event_type);
3081 		nvmf_rdma_update_ibv_state(rqpair);
3082 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3083 		break;
3084 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3085 		/* This event only occurs for shared receive queues. */
3086 		rqpair = event.element.qp->qp_context;
3087 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3088 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3089 		if (rc) {
3090 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3091 			rqpair->last_wqe_reached = true;
3092 		}
3093 		break;
3094 	case IBV_EVENT_SQ_DRAINED:
3095 		/* This event occurs frequently in both error and non-error states.
3096 		 * Check if the qpair is in an error state before sending a message. */
3097 		rqpair = event.element.qp->qp_context;
3098 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3099 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3100 				  (uintptr_t)rqpair, event.event_type);
3101 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3102 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3103 		}
3104 		break;
3105 	case IBV_EVENT_QP_REQ_ERR:
3106 	case IBV_EVENT_QP_ACCESS_ERR:
3107 	case IBV_EVENT_COMM_EST:
3108 	case IBV_EVENT_PATH_MIG:
3109 	case IBV_EVENT_PATH_MIG_ERR:
3110 		SPDK_NOTICELOG("Async event: %s\n",
3111 			       ibv_event_type_str(event.event_type));
3112 		rqpair = event.element.qp->qp_context;
3113 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3114 				  (uintptr_t)rqpair, event.event_type);
3115 		nvmf_rdma_update_ibv_state(rqpair);
3116 		break;
3117 	case IBV_EVENT_CQ_ERR:
3118 	case IBV_EVENT_DEVICE_FATAL:
3119 	case IBV_EVENT_PORT_ACTIVE:
3120 	case IBV_EVENT_PORT_ERR:
3121 	case IBV_EVENT_LID_CHANGE:
3122 	case IBV_EVENT_PKEY_CHANGE:
3123 	case IBV_EVENT_SM_CHANGE:
3124 	case IBV_EVENT_SRQ_ERR:
3125 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3126 	case IBV_EVENT_CLIENT_REREGISTER:
3127 	case IBV_EVENT_GID_CHANGE:
3128 	default:
3129 		SPDK_NOTICELOG("Async event: %s\n",
3130 			       ibv_event_type_str(event.event_type));
3131 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3132 		break;
3133 	}
3134 	ibv_ack_async_event(&event);
3135 
3136 	return 0;
3137 }
3138 
3139 static void
3140 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3141 {
3142 	int rc = 0;
3143 	uint32_t i = 0;
3144 
3145 	for (i = 0; i < max_events; i++) {
3146 		rc = nvmf_process_ib_event(device);
3147 		if (rc) {
3148 			break;
3149 		}
3150 	}
3151 
3152 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3153 }
3154 
3155 static int
3156 nvmf_rdma_accept(void *ctx)
3157 {
3158 	int	nfds, i = 0;
3159 	struct spdk_nvmf_transport *transport = ctx;
3160 	struct spdk_nvmf_rdma_transport *rtransport;
3161 	struct spdk_nvmf_rdma_device *device, *tmp;
3162 	uint32_t count;
3163 
3164 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3165 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3166 
3167 	if (nfds <= 0) {
3168 		return SPDK_POLLER_IDLE;
3169 	}
3170 
3171 	/* The first poll descriptor is RDMA CM event */
3172 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3173 		nvmf_process_cm_event(transport);
3174 		nfds--;
3175 	}
3176 
3177 	if (nfds == 0) {
3178 		return SPDK_POLLER_BUSY;
3179 	}
3180 
3181 	/* Second and subsequent poll descriptors are IB async events */
3182 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3183 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3184 			nvmf_process_ib_events(device, 32);
3185 			nfds--;
3186 		}
3187 	}
3188 	/* check all flagged fd's have been served */
3189 	assert(nfds == 0);
3190 
3191 	return count > 0 ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3192 }
3193 
3194 static void
3195 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3196 		     struct spdk_nvmf_ctrlr_data *cdata)
3197 {
3198 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3199 
3200 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3201 	since in-capsule data only works with NVME drives that support SGL memory layout */
3202 	if (transport->opts.dif_insert_or_strip) {
3203 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3204 	}
3205 
3206 	if (cdata->nvmf_specific.ioccsz > ((sizeof(struct spdk_nvme_cmd) + 0x1000) / 16)) {
3207 		SPDK_WARNLOG("RDMA is configured to support up to 16 SGL entries while in capsule"
3208 			     " data is greater than 4KiB.\n");
3209 		SPDK_WARNLOG("When used in conjunction with the NVMe-oF initiator from the Linux "
3210 			     "kernel between versions 5.4 and 5.12 data corruption may occur for "
3211 			     "writes that are not a multiple of 4KiB in size.\n");
3212 	}
3213 }
3214 
3215 static void
3216 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3217 		   struct spdk_nvme_transport_id *trid,
3218 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3219 {
3220 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3221 	entry->adrfam = trid->adrfam;
3222 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3223 
3224 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3225 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3226 
3227 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3228 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3229 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3230 }
3231 
3232 static void
3233 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3234 
3235 static struct spdk_nvmf_transport_poll_group *
3236 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3237 {
3238 	struct spdk_nvmf_rdma_transport		*rtransport;
3239 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3240 	struct spdk_nvmf_rdma_poller		*poller;
3241 	struct spdk_nvmf_rdma_device		*device;
3242 	struct spdk_rdma_srq_init_attr		srq_init_attr;
3243 	struct spdk_nvmf_rdma_resource_opts	opts;
3244 	int					num_cqe;
3245 
3246 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3247 
3248 	rgroup = calloc(1, sizeof(*rgroup));
3249 	if (!rgroup) {
3250 		return NULL;
3251 	}
3252 
3253 	TAILQ_INIT(&rgroup->pollers);
3254 
3255 	pthread_mutex_lock(&rtransport->lock);
3256 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3257 		poller = calloc(1, sizeof(*poller));
3258 		if (!poller) {
3259 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3260 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3261 			pthread_mutex_unlock(&rtransport->lock);
3262 			return NULL;
3263 		}
3264 
3265 		poller->device = device;
3266 		poller->group = rgroup;
3267 
3268 		TAILQ_INIT(&poller->qpairs);
3269 		STAILQ_INIT(&poller->qpairs_pending_send);
3270 		STAILQ_INIT(&poller->qpairs_pending_recv);
3271 
3272 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3273 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3274 			if ((int)rtransport->rdma_opts.max_srq_depth > device->attr.max_srq_wr) {
3275 				SPDK_WARNLOG("Requested SRQ depth %u, max supported by dev %s is %d\n",
3276 					     rtransport->rdma_opts.max_srq_depth, device->context->device->name, device->attr.max_srq_wr);
3277 			}
3278 			poller->max_srq_depth = spdk_min((int)rtransport->rdma_opts.max_srq_depth, device->attr.max_srq_wr);
3279 
3280 			device->num_srq++;
3281 			memset(&srq_init_attr, 0, sizeof(srq_init_attr));
3282 			srq_init_attr.pd = device->pd;
3283 			srq_init_attr.stats = &poller->stat.qp_stats.recv;
3284 			srq_init_attr.srq_init_attr.attr.max_wr = poller->max_srq_depth;
3285 			srq_init_attr.srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3286 			poller->srq = spdk_rdma_srq_create(&srq_init_attr);
3287 			if (!poller->srq) {
3288 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3289 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3290 				pthread_mutex_unlock(&rtransport->lock);
3291 				return NULL;
3292 			}
3293 
3294 			opts.qp = poller->srq;
3295 			opts.pd = device->pd;
3296 			opts.qpair = NULL;
3297 			opts.shared = true;
3298 			opts.max_queue_depth = poller->max_srq_depth;
3299 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3300 
3301 			poller->resources = nvmf_rdma_resources_create(&opts);
3302 			if (!poller->resources) {
3303 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3304 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3305 				pthread_mutex_unlock(&rtransport->lock);
3306 				return NULL;
3307 			}
3308 		}
3309 
3310 		/*
3311 		 * When using an srq, we can limit the completion queue at startup.
3312 		 * The following formula represents the calculation:
3313 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3314 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3315 		 */
3316 		if (poller->srq) {
3317 			num_cqe = poller->max_srq_depth * 3;
3318 		} else {
3319 			num_cqe = rtransport->rdma_opts.num_cqe;
3320 		}
3321 
3322 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3323 		if (!poller->cq) {
3324 			SPDK_ERRLOG("Unable to create completion queue\n");
3325 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3326 			pthread_mutex_unlock(&rtransport->lock);
3327 			return NULL;
3328 		}
3329 		poller->num_cqe = num_cqe;
3330 	}
3331 
3332 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3333 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3334 		rtransport->conn_sched.next_admin_pg = rgroup;
3335 		rtransport->conn_sched.next_io_pg = rgroup;
3336 	}
3337 
3338 	pthread_mutex_unlock(&rtransport->lock);
3339 	return &rgroup->group;
3340 }
3341 
3342 static struct spdk_nvmf_transport_poll_group *
3343 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3344 {
3345 	struct spdk_nvmf_rdma_transport *rtransport;
3346 	struct spdk_nvmf_rdma_poll_group **pg;
3347 	struct spdk_nvmf_transport_poll_group *result;
3348 
3349 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3350 
3351 	pthread_mutex_lock(&rtransport->lock);
3352 
3353 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3354 		pthread_mutex_unlock(&rtransport->lock);
3355 		return NULL;
3356 	}
3357 
3358 	if (qpair->qid == 0) {
3359 		pg = &rtransport->conn_sched.next_admin_pg;
3360 	} else {
3361 		pg = &rtransport->conn_sched.next_io_pg;
3362 	}
3363 
3364 	assert(*pg != NULL);
3365 
3366 	result = &(*pg)->group;
3367 
3368 	*pg = TAILQ_NEXT(*pg, link);
3369 	if (*pg == NULL) {
3370 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3371 	}
3372 
3373 	pthread_mutex_unlock(&rtransport->lock);
3374 
3375 	return result;
3376 }
3377 
3378 static void
3379 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3380 {
3381 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3382 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3383 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3384 	struct spdk_nvmf_rdma_transport		*rtransport;
3385 
3386 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3387 	if (!rgroup) {
3388 		return;
3389 	}
3390 
3391 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3392 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3393 
3394 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3395 			nvmf_rdma_qpair_destroy(qpair);
3396 		}
3397 
3398 		if (poller->srq) {
3399 			if (poller->resources) {
3400 				nvmf_rdma_resources_destroy(poller->resources);
3401 			}
3402 			spdk_rdma_srq_destroy(poller->srq);
3403 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3404 		}
3405 
3406 		if (poller->cq) {
3407 			ibv_destroy_cq(poller->cq);
3408 		}
3409 
3410 		free(poller);
3411 	}
3412 
3413 	if (rgroup->group.transport == NULL) {
3414 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3415 		 * calls this function directly in a failure path. */
3416 		free(rgroup);
3417 		return;
3418 	}
3419 
3420 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3421 
3422 	pthread_mutex_lock(&rtransport->lock);
3423 	next_rgroup = TAILQ_NEXT(rgroup, link);
3424 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3425 	if (next_rgroup == NULL) {
3426 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3427 	}
3428 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3429 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3430 	}
3431 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3432 		rtransport->conn_sched.next_io_pg = next_rgroup;
3433 	}
3434 	pthread_mutex_unlock(&rtransport->lock);
3435 
3436 	free(rgroup);
3437 }
3438 
3439 static void
3440 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3441 {
3442 	if (rqpair->cm_id != NULL) {
3443 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3444 	}
3445 }
3446 
3447 static int
3448 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3449 			 struct spdk_nvmf_qpair *qpair)
3450 {
3451 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3452 	struct spdk_nvmf_rdma_qpair		*rqpair;
3453 	struct spdk_nvmf_rdma_device		*device;
3454 	struct spdk_nvmf_rdma_poller		*poller;
3455 	int					rc;
3456 
3457 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3458 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3459 
3460 	device = rqpair->device;
3461 
3462 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3463 		if (poller->device == device) {
3464 			break;
3465 		}
3466 	}
3467 
3468 	if (!poller) {
3469 		SPDK_ERRLOG("No poller found for device.\n");
3470 		return -1;
3471 	}
3472 
3473 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3474 	rqpair->poller = poller;
3475 	rqpair->srq = rqpair->poller->srq;
3476 
3477 	rc = nvmf_rdma_qpair_initialize(qpair);
3478 	if (rc < 0) {
3479 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3480 		return -1;
3481 	}
3482 
3483 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3484 	if (rc) {
3485 		/* Try to reject, but we probably can't */
3486 		nvmf_rdma_qpair_reject_connection(rqpair);
3487 		return -1;
3488 	}
3489 
3490 	nvmf_rdma_update_ibv_state(rqpair);
3491 
3492 	return 0;
3493 }
3494 
3495 static int
3496 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3497 			    struct spdk_nvmf_qpair *qpair)
3498 {
3499 	struct spdk_nvmf_rdma_qpair		*rqpair;
3500 
3501 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3502 	assert(group->transport->tgt != NULL);
3503 
3504 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3505 
3506 	if (!rqpair->destruct_channel) {
3507 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3508 		return 0;
3509 	}
3510 
3511 	/* Sanity check that we get io_channel on the correct thread */
3512 	if (qpair->group) {
3513 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3514 	}
3515 
3516 	return 0;
3517 }
3518 
3519 static int
3520 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3521 {
3522 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3523 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3524 			struct spdk_nvmf_rdma_transport, transport);
3525 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3526 					      struct spdk_nvmf_rdma_qpair, qpair);
3527 
3528 	/*
3529 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3530 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3531 	 * starved of RECV structures.
3532 	 */
3533 	if (rqpair->srq && rdma_req->recv) {
3534 		int rc;
3535 		struct ibv_recv_wr *bad_recv_wr;
3536 
3537 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_req->recv->wr);
3538 		rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
3539 		if (rc) {
3540 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3541 		}
3542 	}
3543 
3544 	_nvmf_rdma_request_free(rdma_req, rtransport);
3545 	return 0;
3546 }
3547 
3548 static int
3549 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3550 {
3551 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3552 			struct spdk_nvmf_rdma_transport, transport);
3553 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3554 			struct spdk_nvmf_rdma_request, req);
3555 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3556 			struct spdk_nvmf_rdma_qpair, qpair);
3557 
3558 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3559 		/* The connection is alive, so process the request as normal */
3560 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3561 	} else {
3562 		/* The connection is dead. Move the request directly to the completed state. */
3563 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3564 	}
3565 
3566 	nvmf_rdma_request_process(rtransport, rdma_req);
3567 
3568 	return 0;
3569 }
3570 
3571 static void
3572 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
3573 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
3574 {
3575 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3576 
3577 	rqpair->to_close = true;
3578 
3579 	/* This happens only when the qpair is disconnected before
3580 	 * it is added to the poll group. Since there is no poll group,
3581 	 * the RDMA qp has not been initialized yet and the RDMA CM
3582 	 * event has not yet been acknowledged, so we need to reject it.
3583 	 */
3584 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3585 		nvmf_rdma_qpair_reject_connection(rqpair);
3586 		nvmf_rdma_qpair_destroy(rqpair);
3587 		return;
3588 	}
3589 
3590 	if (rqpair->rdma_qp) {
3591 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3592 	}
3593 
3594 	nvmf_rdma_destroy_drained_qpair(rqpair);
3595 
3596 	if (cb_fn) {
3597 		cb_fn(cb_arg);
3598 	}
3599 }
3600 
3601 static struct spdk_nvmf_rdma_qpair *
3602 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3603 {
3604 	struct spdk_nvmf_rdma_qpair *rqpair;
3605 	/* @todo: improve QP search */
3606 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3607 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3608 			return rqpair;
3609 		}
3610 	}
3611 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3612 	return NULL;
3613 }
3614 
3615 #ifdef DEBUG
3616 static int
3617 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3618 {
3619 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3620 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3621 }
3622 #endif
3623 
3624 static void
3625 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3626 			   int rc)
3627 {
3628 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3629 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3630 
3631 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3632 	while (bad_recv_wr != NULL) {
3633 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3634 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3635 
3636 		rdma_recv->qpair->current_recv_depth++;
3637 		bad_recv_wr = bad_recv_wr->next;
3638 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3639 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3640 	}
3641 }
3642 
3643 static void
3644 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3645 {
3646 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3647 	while (bad_recv_wr != NULL) {
3648 		bad_recv_wr = bad_recv_wr->next;
3649 		rqpair->current_recv_depth++;
3650 	}
3651 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3652 }
3653 
3654 static void
3655 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3656 		     struct spdk_nvmf_rdma_poller *rpoller)
3657 {
3658 	struct spdk_nvmf_rdma_qpair	*rqpair;
3659 	struct ibv_recv_wr		*bad_recv_wr;
3660 	int				rc;
3661 
3662 	if (rpoller->srq) {
3663 		rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_recv_wr);
3664 		if (rc) {
3665 			_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3666 		}
3667 	} else {
3668 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3669 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3670 			rc = spdk_rdma_qp_flush_recv_wrs(rqpair->rdma_qp, &bad_recv_wr);
3671 			if (rc) {
3672 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3673 			}
3674 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3675 		}
3676 	}
3677 }
3678 
3679 static void
3680 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3681 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3682 {
3683 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3684 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3685 
3686 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3687 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3688 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3689 		assert(rqpair->current_send_depth > 0);
3690 		rqpair->current_send_depth--;
3691 		switch (bad_rdma_wr->type) {
3692 		case RDMA_WR_TYPE_DATA:
3693 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3694 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3695 				assert(rqpair->current_read_depth > 0);
3696 				rqpair->current_read_depth--;
3697 			}
3698 			break;
3699 		case RDMA_WR_TYPE_SEND:
3700 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3701 			break;
3702 		default:
3703 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3704 			prev_rdma_req = cur_rdma_req;
3705 			continue;
3706 		}
3707 
3708 		if (prev_rdma_req == cur_rdma_req) {
3709 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3710 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3711 			continue;
3712 		}
3713 
3714 		switch (cur_rdma_req->state) {
3715 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3716 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3717 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3718 			break;
3719 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3720 		case RDMA_REQUEST_STATE_COMPLETING:
3721 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3722 			break;
3723 		default:
3724 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3725 				    cur_rdma_req->state, rqpair);
3726 			continue;
3727 		}
3728 
3729 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3730 		prev_rdma_req = cur_rdma_req;
3731 	}
3732 
3733 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3734 		/* Disconnect the connection. */
3735 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3736 	}
3737 
3738 }
3739 
3740 static void
3741 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3742 		     struct spdk_nvmf_rdma_poller *rpoller)
3743 {
3744 	struct spdk_nvmf_rdma_qpair	*rqpair;
3745 	struct ibv_send_wr		*bad_wr = NULL;
3746 	int				rc;
3747 
3748 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3749 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3750 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3751 
3752 		/* bad wr always points to the first wr that failed. */
3753 		if (rc) {
3754 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3755 		}
3756 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3757 	}
3758 }
3759 
3760 static const char *
3761 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3762 {
3763 	switch (wr_type) {
3764 	case RDMA_WR_TYPE_RECV:
3765 		return "RECV";
3766 	case RDMA_WR_TYPE_SEND:
3767 		return "SEND";
3768 	case RDMA_WR_TYPE_DATA:
3769 		return "DATA";
3770 	default:
3771 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3772 		SPDK_UNREACHABLE();
3773 	}
3774 }
3775 
3776 static inline void
3777 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3778 {
3779 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3780 
3781 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3782 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3783 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3784 		SPDK_DEBUGLOG(rdma,
3785 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3786 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3787 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3788 	} else {
3789 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3790 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3791 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3792 	}
3793 }
3794 
3795 static int
3796 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3797 		      struct spdk_nvmf_rdma_poller *rpoller)
3798 {
3799 	struct ibv_wc wc[32];
3800 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3801 	struct spdk_nvmf_rdma_request	*rdma_req;
3802 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3803 	struct spdk_nvmf_rdma_qpair	*rqpair;
3804 	int reaped, i;
3805 	int count = 0;
3806 	bool error = false;
3807 	uint64_t poll_tsc = spdk_get_ticks();
3808 
3809 	/* Poll for completing operations. */
3810 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3811 	if (reaped < 0) {
3812 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3813 			    errno, spdk_strerror(errno));
3814 		return -1;
3815 	} else if (reaped == 0) {
3816 		rpoller->stat.idle_polls++;
3817 	}
3818 
3819 	rpoller->stat.polls++;
3820 	rpoller->stat.completions += reaped;
3821 
3822 	for (i = 0; i < reaped; i++) {
3823 
3824 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3825 
3826 		switch (rdma_wr->type) {
3827 		case RDMA_WR_TYPE_SEND:
3828 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3829 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3830 
3831 			if (!wc[i].status) {
3832 				count++;
3833 				assert(wc[i].opcode == IBV_WC_SEND);
3834 				assert(nvmf_rdma_req_is_completing(rdma_req));
3835 			}
3836 
3837 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3838 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3839 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3840 			rdma_req->num_outstanding_data_wr = 0;
3841 
3842 			nvmf_rdma_request_process(rtransport, rdma_req);
3843 			break;
3844 		case RDMA_WR_TYPE_RECV:
3845 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3846 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3847 			if (rpoller->srq != NULL) {
3848 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3849 				/* It is possible that there are still some completions for destroyed QP
3850 				 * associated with SRQ. We just ignore these late completions and re-post
3851 				 * receive WRs back to SRQ.
3852 				 */
3853 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3854 					struct ibv_recv_wr *bad_wr;
3855 					int rc;
3856 
3857 					rdma_recv->wr.next = NULL;
3858 					spdk_rdma_srq_queue_recv_wrs(rpoller->srq, &rdma_recv->wr);
3859 					rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_wr);
3860 					if (rc) {
3861 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3862 					}
3863 					continue;
3864 				}
3865 			}
3866 			rqpair = rdma_recv->qpair;
3867 
3868 			assert(rqpair != NULL);
3869 			if (!wc[i].status) {
3870 				assert(wc[i].opcode == IBV_WC_RECV);
3871 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3872 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3873 					break;
3874 				}
3875 			}
3876 
3877 			rdma_recv->wr.next = NULL;
3878 			rqpair->current_recv_depth++;
3879 			rdma_recv->receive_tsc = poll_tsc;
3880 			rpoller->stat.requests++;
3881 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3882 			break;
3883 		case RDMA_WR_TYPE_DATA:
3884 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3885 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3886 
3887 			assert(rdma_req->num_outstanding_data_wr > 0);
3888 
3889 			rqpair->current_send_depth--;
3890 			rdma_req->num_outstanding_data_wr--;
3891 			if (!wc[i].status) {
3892 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3893 				rqpair->current_read_depth--;
3894 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3895 				if (rdma_req->num_outstanding_data_wr == 0) {
3896 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3897 					nvmf_rdma_request_process(rtransport, rdma_req);
3898 				}
3899 			} else {
3900 				/* If the data transfer fails still force the queue into the error state,
3901 				 * if we were performing an RDMA_READ, we need to force the request into a
3902 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3903 				 * case, we should wait for the SEND to complete. */
3904 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3905 					rqpair->current_read_depth--;
3906 					if (rdma_req->num_outstanding_data_wr == 0) {
3907 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3908 					}
3909 				}
3910 			}
3911 			break;
3912 		default:
3913 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3914 			continue;
3915 		}
3916 
3917 		/* Handle error conditions */
3918 		if (wc[i].status) {
3919 			nvmf_rdma_update_ibv_state(rqpair);
3920 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
3921 
3922 			error = true;
3923 
3924 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3925 				/* Disconnect the connection. */
3926 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3927 			} else {
3928 				nvmf_rdma_destroy_drained_qpair(rqpair);
3929 			}
3930 			continue;
3931 		}
3932 
3933 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3934 
3935 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3936 			nvmf_rdma_destroy_drained_qpair(rqpair);
3937 		}
3938 	}
3939 
3940 	if (error == true) {
3941 		return -1;
3942 	}
3943 
3944 	/* submit outstanding work requests. */
3945 	_poller_submit_recvs(rtransport, rpoller);
3946 	_poller_submit_sends(rtransport, rpoller);
3947 
3948 	return count;
3949 }
3950 
3951 static int
3952 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3953 {
3954 	struct spdk_nvmf_rdma_transport *rtransport;
3955 	struct spdk_nvmf_rdma_poll_group *rgroup;
3956 	struct spdk_nvmf_rdma_poller	*rpoller;
3957 	int				count, rc;
3958 
3959 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3960 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3961 
3962 	count = 0;
3963 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3964 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
3965 		if (rc < 0) {
3966 			return rc;
3967 		}
3968 		count += rc;
3969 	}
3970 
3971 	return count;
3972 }
3973 
3974 static int
3975 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3976 			  struct spdk_nvme_transport_id *trid,
3977 			  bool peer)
3978 {
3979 	struct sockaddr *saddr;
3980 	uint16_t port;
3981 
3982 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
3983 
3984 	if (peer) {
3985 		saddr = rdma_get_peer_addr(id);
3986 	} else {
3987 		saddr = rdma_get_local_addr(id);
3988 	}
3989 	switch (saddr->sa_family) {
3990 	case AF_INET: {
3991 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3992 
3993 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3994 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3995 			  trid->traddr, sizeof(trid->traddr));
3996 		if (peer) {
3997 			port = ntohs(rdma_get_dst_port(id));
3998 		} else {
3999 			port = ntohs(rdma_get_src_port(id));
4000 		}
4001 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4002 		break;
4003 	}
4004 	case AF_INET6: {
4005 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4006 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4007 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4008 			  trid->traddr, sizeof(trid->traddr));
4009 		if (peer) {
4010 			port = ntohs(rdma_get_dst_port(id));
4011 		} else {
4012 			port = ntohs(rdma_get_src_port(id));
4013 		}
4014 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4015 		break;
4016 	}
4017 	default:
4018 		return -1;
4019 
4020 	}
4021 
4022 	return 0;
4023 }
4024 
4025 static int
4026 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4027 			      struct spdk_nvme_transport_id *trid)
4028 {
4029 	struct spdk_nvmf_rdma_qpair	*rqpair;
4030 
4031 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4032 
4033 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4034 }
4035 
4036 static int
4037 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4038 			       struct spdk_nvme_transport_id *trid)
4039 {
4040 	struct spdk_nvmf_rdma_qpair	*rqpair;
4041 
4042 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4043 
4044 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4045 }
4046 
4047 static int
4048 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4049 				struct spdk_nvme_transport_id *trid)
4050 {
4051 	struct spdk_nvmf_rdma_qpair	*rqpair;
4052 
4053 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4054 
4055 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4056 }
4057 
4058 void
4059 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4060 {
4061 	g_nvmf_hooks = *hooks;
4062 }
4063 
4064 static void
4065 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4066 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4067 {
4068 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4069 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4070 
4071 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4072 
4073 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4074 }
4075 
4076 static int
4077 _nvmf_rdma_qpair_abort_request(void *ctx)
4078 {
4079 	struct spdk_nvmf_request *req = ctx;
4080 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4081 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4082 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4083 					      struct spdk_nvmf_rdma_qpair, qpair);
4084 	int rc;
4085 
4086 	spdk_poller_unregister(&req->poller);
4087 
4088 	switch (rdma_req_to_abort->state) {
4089 	case RDMA_REQUEST_STATE_EXECUTING:
4090 		rc = nvmf_ctrlr_abort_request(req);
4091 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4092 			return SPDK_POLLER_BUSY;
4093 		}
4094 		break;
4095 
4096 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4097 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4098 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4099 
4100 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4101 		break;
4102 
4103 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4104 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4105 			      spdk_nvmf_rdma_request, state_link);
4106 
4107 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4108 		break;
4109 
4110 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4111 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4112 			      spdk_nvmf_rdma_request, state_link);
4113 
4114 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4115 		break;
4116 
4117 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4118 		if (spdk_get_ticks() < req->timeout_tsc) {
4119 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4120 			return SPDK_POLLER_BUSY;
4121 		}
4122 		break;
4123 
4124 	default:
4125 		break;
4126 	}
4127 
4128 	spdk_nvmf_request_complete(req);
4129 	return SPDK_POLLER_BUSY;
4130 }
4131 
4132 static void
4133 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4134 			      struct spdk_nvmf_request *req)
4135 {
4136 	struct spdk_nvmf_rdma_qpair *rqpair;
4137 	struct spdk_nvmf_rdma_transport *rtransport;
4138 	struct spdk_nvmf_transport *transport;
4139 	uint16_t cid;
4140 	uint32_t i, max_req_count;
4141 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL, *rdma_req;
4142 
4143 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4144 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4145 	transport = &rtransport->transport;
4146 
4147 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4148 	max_req_count = rqpair->srq == NULL ? rqpair->max_queue_depth : rqpair->poller->max_srq_depth;
4149 
4150 	for (i = 0; i < max_req_count; i++) {
4151 		rdma_req = &rqpair->resources->reqs[i];
4152 		/* When SRQ == NULL, rqpair has its own requests and req.qpair pointer always points to the qpair
4153 		 * When SRQ != NULL all rqpairs share common requests and qpair pointer is assigned when we start to
4154 		 * process a request. So in both cases all requests which are not in FREE state have valid qpair ptr */
4155 		if (rdma_req->state != RDMA_REQUEST_STATE_FREE && rdma_req->req.cmd->nvme_cmd.cid == cid &&
4156 		    rdma_req->req.qpair == qpair) {
4157 			rdma_req_to_abort = rdma_req;
4158 			break;
4159 		}
4160 	}
4161 
4162 	if (rdma_req_to_abort == NULL) {
4163 		spdk_nvmf_request_complete(req);
4164 		return;
4165 	}
4166 
4167 	req->req_to_abort = &rdma_req_to_abort->req;
4168 	req->timeout_tsc = spdk_get_ticks() +
4169 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4170 	req->poller = NULL;
4171 
4172 	_nvmf_rdma_qpair_abort_request(req);
4173 }
4174 
4175 static void
4176 nvmf_rdma_poll_group_dump_stat(struct spdk_nvmf_transport_poll_group *group,
4177 			       struct spdk_json_write_ctx *w)
4178 {
4179 	struct spdk_nvmf_rdma_poll_group *rgroup;
4180 	struct spdk_nvmf_rdma_poller *rpoller;
4181 
4182 	assert(w != NULL);
4183 
4184 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4185 
4186 	spdk_json_write_named_uint64(w, "pending_data_buffer", rgroup->stat.pending_data_buffer);
4187 
4188 	spdk_json_write_named_array_begin(w, "devices");
4189 
4190 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4191 		spdk_json_write_object_begin(w);
4192 		spdk_json_write_named_string(w, "name",
4193 					     ibv_get_device_name(rpoller->device->context->device));
4194 		spdk_json_write_named_uint64(w, "polls",
4195 					     rpoller->stat.polls);
4196 		spdk_json_write_named_uint64(w, "idle_polls",
4197 					     rpoller->stat.idle_polls);
4198 		spdk_json_write_named_uint64(w, "completions",
4199 					     rpoller->stat.completions);
4200 		spdk_json_write_named_uint64(w, "requests",
4201 					     rpoller->stat.requests);
4202 		spdk_json_write_named_uint64(w, "request_latency",
4203 					     rpoller->stat.request_latency);
4204 		spdk_json_write_named_uint64(w, "pending_free_request",
4205 					     rpoller->stat.pending_free_request);
4206 		spdk_json_write_named_uint64(w, "pending_rdma_read",
4207 					     rpoller->stat.pending_rdma_read);
4208 		spdk_json_write_named_uint64(w, "pending_rdma_write",
4209 					     rpoller->stat.pending_rdma_write);
4210 		spdk_json_write_named_uint64(w, "total_send_wrs",
4211 					     rpoller->stat.qp_stats.send.num_submitted_wrs);
4212 		spdk_json_write_named_uint64(w, "send_doorbell_updates",
4213 					     rpoller->stat.qp_stats.send.doorbell_updates);
4214 		spdk_json_write_named_uint64(w, "total_recv_wrs",
4215 					     rpoller->stat.qp_stats.recv.num_submitted_wrs);
4216 		spdk_json_write_named_uint64(w, "recv_doorbell_updates",
4217 					     rpoller->stat.qp_stats.recv.doorbell_updates);
4218 		spdk_json_write_object_end(w);
4219 	}
4220 
4221 	spdk_json_write_array_end(w);
4222 }
4223 
4224 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4225 	.name = "RDMA",
4226 	.type = SPDK_NVME_TRANSPORT_RDMA,
4227 	.opts_init = nvmf_rdma_opts_init,
4228 	.create = nvmf_rdma_create,
4229 	.dump_opts = nvmf_rdma_dump_opts,
4230 	.destroy = nvmf_rdma_destroy,
4231 
4232 	.listen = nvmf_rdma_listen,
4233 	.stop_listen = nvmf_rdma_stop_listen,
4234 	.cdata_init = nvmf_rdma_cdata_init,
4235 
4236 	.listener_discover = nvmf_rdma_discover,
4237 
4238 	.poll_group_create = nvmf_rdma_poll_group_create,
4239 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4240 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4241 	.poll_group_add = nvmf_rdma_poll_group_add,
4242 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4243 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4244 
4245 	.req_free = nvmf_rdma_request_free,
4246 	.req_complete = nvmf_rdma_request_complete,
4247 
4248 	.qpair_fini = nvmf_rdma_close_qpair,
4249 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4250 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4251 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4252 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4253 
4254 	.poll_group_dump_stat = nvmf_rdma_poll_group_dump_stat,
4255 };
4256 
4257 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4258 SPDK_LOG_REGISTER_COMPONENT(rdma)
4259