xref: /spdk/lib/nvmf/rdma.c (revision a76bbe355313bd013960ee6874311a4af0ec46ae)
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/tree.h"
44 #include "spdk/util.h"
45 
46 #include "spdk_internal/assert.h"
47 #include "spdk/log.h"
48 #include "spdk_internal/rdma.h"
49 
50 #include "nvmf_internal.h"
51 
52 #include "spdk_internal/trace_defs.h"
53 
54 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
55 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
56 
57 /*
58  RDMA Connection Resource Defaults
59  */
60 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
61 #define NVMF_DEFAULT_RSP_SGE		1
62 #define NVMF_DEFAULT_RX_SGE		2
63 
64 /* The RDMA completion queue size */
65 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
66 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
67 
68 static int g_spdk_nvmf_ibv_query_mask =
69 	IBV_QP_STATE |
70 	IBV_QP_PKEY_INDEX |
71 	IBV_QP_PORT |
72 	IBV_QP_ACCESS_FLAGS |
73 	IBV_QP_AV |
74 	IBV_QP_PATH_MTU |
75 	IBV_QP_DEST_QPN |
76 	IBV_QP_RQ_PSN |
77 	IBV_QP_MAX_DEST_RD_ATOMIC |
78 	IBV_QP_MIN_RNR_TIMER |
79 	IBV_QP_SQ_PSN |
80 	IBV_QP_TIMEOUT |
81 	IBV_QP_RETRY_CNT |
82 	IBV_QP_RNR_RETRY |
83 	IBV_QP_MAX_QP_RD_ATOMIC;
84 
85 enum spdk_nvmf_rdma_request_state {
86 	/* The request is not currently in use */
87 	RDMA_REQUEST_STATE_FREE = 0,
88 
89 	/* Initial state when request first received */
90 	RDMA_REQUEST_STATE_NEW,
91 
92 	/* The request is queued until a data buffer is available. */
93 	RDMA_REQUEST_STATE_NEED_BUFFER,
94 
95 	/* The request is waiting on RDMA queue depth availability
96 	 * to transfer data from the host to the controller.
97 	 */
98 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
99 
100 	/* The request is currently transferring data from the host to the controller. */
101 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
102 
103 	/* The request is ready to execute at the block device */
104 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
105 
106 	/* The request is currently executing at the block device */
107 	RDMA_REQUEST_STATE_EXECUTING,
108 
109 	/* The request finished executing at the block device */
110 	RDMA_REQUEST_STATE_EXECUTED,
111 
112 	/* The request is waiting on RDMA queue depth availability
113 	 * to transfer data from the controller to the host.
114 	 */
115 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
116 
117 	/* The request is ready to send a completion */
118 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
119 
120 	/* The request is currently transferring data from the controller to the host. */
121 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
122 
123 	/* The request currently has an outstanding completion without an
124 	 * associated data transfer.
125 	 */
126 	RDMA_REQUEST_STATE_COMPLETING,
127 
128 	/* The request completed and can be marked free. */
129 	RDMA_REQUEST_STATE_COMPLETED,
130 
131 	/* Terminator */
132 	RDMA_REQUEST_NUM_STATES,
133 };
134 
135 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
136 {
137 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
138 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
139 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1,
140 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
141 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
142 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
143 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
144 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
145 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
146 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
147 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
148 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
149 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
150 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
151 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
152 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
153 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
154 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
155 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
156 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
157 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
158 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
159 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
160 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
161 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
163 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
164 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
165 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
167 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
168 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
169 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
170 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
171 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
172 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
173 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
175 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
176 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
177 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
178 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
179 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
180 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
181 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
182 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
183 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
184 
185 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
186 					OWNER_NONE, OBJECT_NONE, 0,
187 					SPDK_TRACE_ARG_TYPE_INT, "");
188 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
189 					OWNER_NONE, OBJECT_NONE, 0,
190 					SPDK_TRACE_ARG_TYPE_INT, "type");
191 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
192 					OWNER_NONE, OBJECT_NONE, 0,
193 					SPDK_TRACE_ARG_TYPE_INT, "type");
194 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
195 					OWNER_NONE, OBJECT_NONE, 0,
196 					SPDK_TRACE_ARG_TYPE_PTR, "state");
197 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
198 					OWNER_NONE, OBJECT_NONE, 0,
199 					SPDK_TRACE_ARG_TYPE_INT, "");
200 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
201 					OWNER_NONE, OBJECT_NONE, 0,
202 					SPDK_TRACE_ARG_TYPE_INT, "");
203 }
204 
205 enum spdk_nvmf_rdma_wr_type {
206 	RDMA_WR_TYPE_RECV,
207 	RDMA_WR_TYPE_SEND,
208 	RDMA_WR_TYPE_DATA,
209 };
210 
211 struct spdk_nvmf_rdma_wr {
212 	enum spdk_nvmf_rdma_wr_type	type;
213 };
214 
215 /* This structure holds commands as they are received off the wire.
216  * It must be dynamically paired with a full request object
217  * (spdk_nvmf_rdma_request) to service a request. It is separate
218  * from the request because RDMA does not appear to order
219  * completions, so occasionally we'll get a new incoming
220  * command when there aren't any free request objects.
221  */
222 struct spdk_nvmf_rdma_recv {
223 	struct ibv_recv_wr			wr;
224 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
225 
226 	struct spdk_nvmf_rdma_qpair		*qpair;
227 
228 	/* In-capsule data buffer */
229 	uint8_t					*buf;
230 
231 	struct spdk_nvmf_rdma_wr		rdma_wr;
232 	uint64_t				receive_tsc;
233 
234 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
235 };
236 
237 struct spdk_nvmf_rdma_request_data {
238 	struct spdk_nvmf_rdma_wr	rdma_wr;
239 	struct ibv_send_wr		wr;
240 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
241 };
242 
243 struct spdk_nvmf_rdma_request {
244 	struct spdk_nvmf_request		req;
245 
246 	enum spdk_nvmf_rdma_request_state	state;
247 
248 	/* Data offset in req.iov */
249 	uint32_t				offset;
250 
251 	struct spdk_nvmf_rdma_recv		*recv;
252 
253 	struct {
254 		struct spdk_nvmf_rdma_wr	rdma_wr;
255 		struct	ibv_send_wr		wr;
256 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
257 	} rsp;
258 
259 	struct spdk_nvmf_rdma_request_data	data;
260 
261 	uint32_t				iovpos;
262 
263 	uint32_t				num_outstanding_data_wr;
264 	uint64_t				receive_tsc;
265 
266 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
267 };
268 
269 struct spdk_nvmf_rdma_resource_opts {
270 	struct spdk_nvmf_rdma_qpair	*qpair;
271 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
272 	void				*qp;
273 	struct ibv_pd			*pd;
274 	uint32_t			max_queue_depth;
275 	uint32_t			in_capsule_data_size;
276 	bool				shared;
277 };
278 
279 struct spdk_nvmf_rdma_resources {
280 	/* Array of size "max_queue_depth" containing RDMA requests. */
281 	struct spdk_nvmf_rdma_request		*reqs;
282 
283 	/* Array of size "max_queue_depth" containing RDMA recvs. */
284 	struct spdk_nvmf_rdma_recv		*recvs;
285 
286 	/* Array of size "max_queue_depth" containing 64 byte capsules
287 	 * used for receive.
288 	 */
289 	union nvmf_h2c_msg			*cmds;
290 	struct ibv_mr				*cmds_mr;
291 
292 	/* Array of size "max_queue_depth" containing 16 byte completions
293 	 * to be sent back to the user.
294 	 */
295 	union nvmf_c2h_msg			*cpls;
296 	struct ibv_mr				*cpls_mr;
297 
298 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
299 	 * buffers to be used for in capsule data.
300 	 */
301 	void					*bufs;
302 	struct ibv_mr				*bufs_mr;
303 
304 	/* Receives that are waiting for a request object */
305 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
306 
307 	/* Queue to track free requests */
308 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
309 };
310 
311 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
312 
313 struct spdk_nvmf_rdma_ibv_event_ctx {
314 	struct spdk_nvmf_rdma_qpair			*rqpair;
315 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
316 	/* Link to other ibv events associated with this qpair */
317 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
318 };
319 
320 struct spdk_nvmf_rdma_qpair {
321 	struct spdk_nvmf_qpair			qpair;
322 
323 	struct spdk_nvmf_rdma_device		*device;
324 	struct spdk_nvmf_rdma_poller		*poller;
325 
326 	struct spdk_rdma_qp			*rdma_qp;
327 	struct rdma_cm_id			*cm_id;
328 	struct spdk_rdma_srq			*srq;
329 	struct rdma_cm_id			*listen_id;
330 
331 	/* Cache the QP number to improve QP search by RB tree. */
332 	uint32_t				qp_num;
333 
334 	/* The maximum number of I/O outstanding on this connection at one time */
335 	uint16_t				max_queue_depth;
336 
337 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
338 	uint16_t				max_read_depth;
339 
340 	/* The maximum number of RDMA SEND operations at one time */
341 	uint32_t				max_send_depth;
342 
343 	/* The current number of outstanding WRs from this qpair's
344 	 * recv queue. Should not exceed device->attr.max_queue_depth.
345 	 */
346 	uint16_t				current_recv_depth;
347 
348 	/* The current number of active RDMA READ operations */
349 	uint16_t				current_read_depth;
350 
351 	/* The current number of posted WRs from this qpair's
352 	 * send queue. Should not exceed max_send_depth.
353 	 */
354 	uint32_t				current_send_depth;
355 
356 	/* The maximum number of SGEs per WR on the send queue */
357 	uint32_t				max_send_sge;
358 
359 	/* The maximum number of SGEs per WR on the recv queue */
360 	uint32_t				max_recv_sge;
361 
362 	struct spdk_nvmf_rdma_resources		*resources;
363 
364 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
365 
366 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
367 
368 	/* Number of requests not in the free state */
369 	uint32_t				qd;
370 
371 	RB_ENTRY(spdk_nvmf_rdma_qpair)		node;
372 
373 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
374 
375 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
376 
377 	/* IBV queue pair attributes: they are used to manage
378 	 * qp state and recover from errors.
379 	 */
380 	enum ibv_qp_state			ibv_state;
381 
382 	/*
383 	 * io_channel which is used to destroy qpair when it is removed from poll group
384 	 */
385 	struct spdk_io_channel		*destruct_channel;
386 
387 	/* List of ibv async events */
388 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
389 
390 	/* Lets us know that we have received the last_wqe event. */
391 	bool					last_wqe_reached;
392 
393 	/* Indicate that nvmf_rdma_close_qpair is called */
394 	bool					to_close;
395 };
396 
397 struct spdk_nvmf_rdma_poller_stat {
398 	uint64_t				completions;
399 	uint64_t				polls;
400 	uint64_t				idle_polls;
401 	uint64_t				requests;
402 	uint64_t				request_latency;
403 	uint64_t				pending_free_request;
404 	uint64_t				pending_rdma_read;
405 	uint64_t				pending_rdma_write;
406 	struct spdk_rdma_qp_stats		qp_stats;
407 };
408 
409 struct spdk_nvmf_rdma_poller {
410 	struct spdk_nvmf_rdma_device		*device;
411 	struct spdk_nvmf_rdma_poll_group	*group;
412 
413 	int					num_cqe;
414 	int					required_num_wr;
415 	struct ibv_cq				*cq;
416 
417 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
418 	uint16_t				max_srq_depth;
419 
420 	/* Shared receive queue */
421 	struct spdk_rdma_srq			*srq;
422 
423 	struct spdk_nvmf_rdma_resources		*resources;
424 	struct spdk_nvmf_rdma_poller_stat	stat;
425 
426 	RB_HEAD(qpairs_tree, spdk_nvmf_rdma_qpair) qpairs;
427 
428 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
429 
430 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
431 
432 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
433 };
434 
435 struct spdk_nvmf_rdma_poll_group_stat {
436 	uint64_t				pending_data_buffer;
437 };
438 
439 struct spdk_nvmf_rdma_poll_group {
440 	struct spdk_nvmf_transport_poll_group		group;
441 	struct spdk_nvmf_rdma_poll_group_stat		stat;
442 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
443 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
444 };
445 
446 struct spdk_nvmf_rdma_conn_sched {
447 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
448 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
449 };
450 
451 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
452 struct spdk_nvmf_rdma_device {
453 	struct ibv_device_attr			attr;
454 	struct ibv_context			*context;
455 
456 	struct spdk_rdma_mem_map		*map;
457 	struct ibv_pd				*pd;
458 
459 	int					num_srq;
460 
461 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
462 };
463 
464 struct spdk_nvmf_rdma_port {
465 	const struct spdk_nvme_transport_id	*trid;
466 	struct rdma_cm_id			*id;
467 	struct spdk_nvmf_rdma_device		*device;
468 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
469 };
470 
471 struct rdma_transport_opts {
472 	int		num_cqe;
473 	uint32_t	max_srq_depth;
474 	bool		no_srq;
475 	bool		no_wr_batching;
476 	int		acceptor_backlog;
477 };
478 
479 struct spdk_nvmf_rdma_transport {
480 	struct spdk_nvmf_transport	transport;
481 	struct rdma_transport_opts	rdma_opts;
482 
483 	struct spdk_nvmf_rdma_conn_sched conn_sched;
484 
485 	struct rdma_event_channel	*event_channel;
486 
487 	struct spdk_mempool		*data_wr_pool;
488 
489 	struct spdk_poller		*accept_poller;
490 	pthread_mutex_t			lock;
491 
492 	/* fields used to poll RDMA/IB events */
493 	nfds_t			npoll_fds;
494 	struct pollfd		*poll_fds;
495 
496 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
497 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
498 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
499 };
500 
501 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
502 	{
503 		"num_cqe", offsetof(struct rdma_transport_opts, num_cqe),
504 		spdk_json_decode_int32, true
505 	},
506 	{
507 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
508 		spdk_json_decode_uint32, true
509 	},
510 	{
511 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
512 		spdk_json_decode_bool, true
513 	},
514 	{
515 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
516 		spdk_json_decode_bool, true
517 	},
518 	{
519 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
520 		spdk_json_decode_int32, true
521 	},
522 };
523 
524 static int
525 nvmf_rdma_qpair_compare(struct spdk_nvmf_rdma_qpair *rqpair1, struct spdk_nvmf_rdma_qpair *rqpair2)
526 {
527 	return rqpair1->qp_num < rqpair2->qp_num ? -1 : rqpair1->qp_num > rqpair2->qp_num;
528 }
529 
530 RB_GENERATE_STATIC(qpairs_tree, spdk_nvmf_rdma_qpair, node, nvmf_rdma_qpair_compare);
531 
532 static bool
533 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
534 			  struct spdk_nvmf_rdma_request *rdma_req);
535 
536 static void
537 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
538 		     struct spdk_nvmf_rdma_poller *rpoller);
539 
540 static void
541 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
542 		     struct spdk_nvmf_rdma_poller *rpoller);
543 
544 static inline int
545 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
546 {
547 	switch (state) {
548 	case IBV_QPS_RESET:
549 	case IBV_QPS_INIT:
550 	case IBV_QPS_RTR:
551 	case IBV_QPS_RTS:
552 	case IBV_QPS_SQD:
553 	case IBV_QPS_SQE:
554 	case IBV_QPS_ERR:
555 		return 0;
556 	default:
557 		return -1;
558 	}
559 }
560 
561 static inline enum spdk_nvme_media_error_status_code
562 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
563 	enum spdk_nvme_media_error_status_code result;
564 	switch (err_type)
565 	{
566 	case SPDK_DIF_REFTAG_ERROR:
567 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
568 		break;
569 	case SPDK_DIF_APPTAG_ERROR:
570 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
571 		break;
572 	case SPDK_DIF_GUARD_ERROR:
573 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
574 		break;
575 	default:
576 		SPDK_UNREACHABLE();
577 	}
578 
579 	return result;
580 }
581 
582 static enum ibv_qp_state
583 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
584 	enum ibv_qp_state old_state, new_state;
585 	struct ibv_qp_attr qp_attr;
586 	struct ibv_qp_init_attr init_attr;
587 	int rc;
588 
589 	old_state = rqpair->ibv_state;
590 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
591 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
592 
593 	if (rc)
594 	{
595 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
596 		return IBV_QPS_ERR + 1;
597 	}
598 
599 	new_state = qp_attr.qp_state;
600 	rqpair->ibv_state = new_state;
601 	qp_attr.ah_attr.port_num = qp_attr.port_num;
602 
603 	rc = nvmf_rdma_check_ibv_state(new_state);
604 	if (rc)
605 	{
606 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
607 		/*
608 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
609 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
610 		 */
611 		return IBV_QPS_ERR + 1;
612 	}
613 
614 	if (old_state != new_state)
615 	{
616 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0, (uintptr_t)rqpair, new_state);
617 	}
618 	return new_state;
619 }
620 
621 static void
622 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
623 			    struct spdk_nvmf_rdma_transport *rtransport)
624 {
625 	struct spdk_nvmf_rdma_request_data	*data_wr;
626 	struct ibv_send_wr			*next_send_wr;
627 	uint64_t				req_wrid;
628 
629 	rdma_req->num_outstanding_data_wr = 0;
630 	data_wr = &rdma_req->data;
631 	req_wrid = data_wr->wr.wr_id;
632 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
633 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
634 		data_wr->wr.num_sge = 0;
635 		next_send_wr = data_wr->wr.next;
636 		if (data_wr != &rdma_req->data) {
637 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
638 		}
639 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
640 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
641 	}
642 }
643 
644 static void
645 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
646 {
647 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
648 	if (req->req.cmd) {
649 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
650 	}
651 	if (req->recv) {
652 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
653 	}
654 }
655 
656 static void
657 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
658 {
659 	int i;
660 
661 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
662 	for (i = 0; i < rqpair->max_queue_depth; i++) {
663 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
664 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
665 		}
666 	}
667 }
668 
669 static void
670 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
671 {
672 	if (resources->cmds_mr) {
673 		ibv_dereg_mr(resources->cmds_mr);
674 	}
675 
676 	if (resources->cpls_mr) {
677 		ibv_dereg_mr(resources->cpls_mr);
678 	}
679 
680 	if (resources->bufs_mr) {
681 		ibv_dereg_mr(resources->bufs_mr);
682 	}
683 
684 	spdk_free(resources->cmds);
685 	spdk_free(resources->cpls);
686 	spdk_free(resources->bufs);
687 	free(resources->reqs);
688 	free(resources->recvs);
689 	free(resources);
690 }
691 
692 
693 static struct spdk_nvmf_rdma_resources *
694 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
695 {
696 	struct spdk_nvmf_rdma_resources	*resources;
697 	struct spdk_nvmf_rdma_request	*rdma_req;
698 	struct spdk_nvmf_rdma_recv	*rdma_recv;
699 	struct spdk_rdma_qp		*qp = NULL;
700 	struct spdk_rdma_srq		*srq = NULL;
701 	struct ibv_recv_wr		*bad_wr = NULL;
702 	uint32_t			i;
703 	int				rc = 0;
704 
705 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
706 	if (!resources) {
707 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
708 		return NULL;
709 	}
710 
711 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
712 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
713 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
714 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
715 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
716 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
717 
718 	if (opts->in_capsule_data_size > 0) {
719 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
720 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
721 					       SPDK_MALLOC_DMA);
722 	}
723 
724 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
725 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
726 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
727 		goto cleanup;
728 	}
729 
730 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
731 					opts->max_queue_depth * sizeof(*resources->cmds),
732 					IBV_ACCESS_LOCAL_WRITE);
733 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
734 					opts->max_queue_depth * sizeof(*resources->cpls),
735 					0);
736 
737 	if (opts->in_capsule_data_size) {
738 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
739 						opts->max_queue_depth *
740 						opts->in_capsule_data_size,
741 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
742 	}
743 
744 	if (!resources->cmds_mr || !resources->cpls_mr ||
745 	    (opts->in_capsule_data_size &&
746 	     !resources->bufs_mr)) {
747 		goto cleanup;
748 	}
749 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
750 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
751 		      resources->cmds_mr->lkey);
752 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
753 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
754 		      resources->cpls_mr->lkey);
755 	if (resources->bufs && resources->bufs_mr) {
756 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
757 			      resources->bufs, opts->max_queue_depth *
758 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
759 	}
760 
761 	/* Initialize queues */
762 	STAILQ_INIT(&resources->incoming_queue);
763 	STAILQ_INIT(&resources->free_queue);
764 
765 	if (opts->shared) {
766 		srq = (struct spdk_rdma_srq *)opts->qp;
767 	} else {
768 		qp = (struct spdk_rdma_qp *)opts->qp;
769 	}
770 
771 	for (i = 0; i < opts->max_queue_depth; i++) {
772 		rdma_recv = &resources->recvs[i];
773 		rdma_recv->qpair = opts->qpair;
774 
775 		/* Set up memory to receive commands */
776 		if (resources->bufs) {
777 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
778 						  opts->in_capsule_data_size));
779 		}
780 
781 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
782 
783 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
784 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
785 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
786 		rdma_recv->wr.num_sge = 1;
787 
788 		if (rdma_recv->buf && resources->bufs_mr) {
789 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
790 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
791 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
792 			rdma_recv->wr.num_sge++;
793 		}
794 
795 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
796 		rdma_recv->wr.sg_list = rdma_recv->sgl;
797 		if (srq) {
798 			spdk_rdma_srq_queue_recv_wrs(srq, &rdma_recv->wr);
799 		} else {
800 			spdk_rdma_qp_queue_recv_wrs(qp, &rdma_recv->wr);
801 		}
802 	}
803 
804 	for (i = 0; i < opts->max_queue_depth; i++) {
805 		rdma_req = &resources->reqs[i];
806 
807 		if (opts->qpair != NULL) {
808 			rdma_req->req.qpair = &opts->qpair->qpair;
809 		} else {
810 			rdma_req->req.qpair = NULL;
811 		}
812 		rdma_req->req.cmd = NULL;
813 
814 		/* Set up memory to send responses */
815 		rdma_req->req.rsp = &resources->cpls[i];
816 
817 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
818 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
819 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
820 
821 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
822 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
823 		rdma_req->rsp.wr.next = NULL;
824 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
825 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
826 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
827 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
828 
829 		/* Set up memory for data buffers */
830 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
831 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
832 		rdma_req->data.wr.next = NULL;
833 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
834 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
835 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
836 
837 		/* Initialize request state to FREE */
838 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
839 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
840 	}
841 
842 	if (srq) {
843 		rc = spdk_rdma_srq_flush_recv_wrs(srq, &bad_wr);
844 	} else {
845 		rc = spdk_rdma_qp_flush_recv_wrs(qp, &bad_wr);
846 	}
847 
848 	if (rc) {
849 		goto cleanup;
850 	}
851 
852 	return resources;
853 
854 cleanup:
855 	nvmf_rdma_resources_destroy(resources);
856 	return NULL;
857 }
858 
859 static void
860 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
861 {
862 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
863 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
864 		ctx->rqpair = NULL;
865 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
866 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
867 	}
868 }
869 
870 static void
871 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
872 {
873 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
874 	struct ibv_recv_wr		*bad_recv_wr = NULL;
875 	int				rc;
876 
877 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair);
878 
879 	if (rqpair->qd != 0) {
880 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
881 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
882 				struct spdk_nvmf_rdma_transport, transport);
883 		struct spdk_nvmf_rdma_request *req;
884 		uint32_t i, max_req_count = 0;
885 
886 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
887 
888 		if (rqpair->srq == NULL) {
889 			nvmf_rdma_dump_qpair_contents(rqpair);
890 			max_req_count = rqpair->max_queue_depth;
891 		} else if (rqpair->poller && rqpair->resources) {
892 			max_req_count = rqpair->poller->max_srq_depth;
893 		}
894 
895 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
896 		for (i = 0; i < max_req_count; i++) {
897 			req = &rqpair->resources->reqs[i];
898 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
899 				/* nvmf_rdma_request_process checks qpair ibv and internal state
900 				 * and completes a request */
901 				nvmf_rdma_request_process(rtransport, req);
902 			}
903 		}
904 		assert(rqpair->qd == 0);
905 	}
906 
907 	if (rqpair->poller) {
908 		RB_REMOVE(qpairs_tree, &rqpair->poller->qpairs, rqpair);
909 
910 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
911 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
912 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
913 				if (rqpair == rdma_recv->qpair) {
914 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
915 					spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_recv->wr);
916 					rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
917 					if (rc) {
918 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
919 					}
920 				}
921 			}
922 		}
923 	}
924 
925 	if (rqpair->cm_id) {
926 		if (rqpair->rdma_qp != NULL) {
927 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
928 			rqpair->rdma_qp = NULL;
929 		}
930 		rdma_destroy_id(rqpair->cm_id);
931 
932 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
933 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
934 		}
935 	}
936 
937 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
938 		nvmf_rdma_resources_destroy(rqpair->resources);
939 	}
940 
941 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
942 
943 	if (rqpair->destruct_channel) {
944 		spdk_put_io_channel(rqpair->destruct_channel);
945 		rqpair->destruct_channel = NULL;
946 	}
947 
948 	free(rqpair);
949 }
950 
951 static int
952 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
953 {
954 	struct spdk_nvmf_rdma_poller	*rpoller;
955 	int				rc, num_cqe, required_num_wr;
956 
957 	/* Enlarge CQ size dynamically */
958 	rpoller = rqpair->poller;
959 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
960 	num_cqe = rpoller->num_cqe;
961 	if (num_cqe < required_num_wr) {
962 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
963 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
964 	}
965 
966 	if (rpoller->num_cqe != num_cqe) {
967 		if (device->context->device->transport_type == IBV_TRANSPORT_IWARP) {
968 			SPDK_ERRLOG("iWARP doesn't support CQ resize. Current capacity %u, required %u\n"
969 				    "Using CQ of insufficient size may lead to CQ overrun\n", rpoller->num_cqe, num_cqe);
970 			return -1;
971 		}
972 		if (required_num_wr > device->attr.max_cqe) {
973 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
974 				    required_num_wr, device->attr.max_cqe);
975 			return -1;
976 		}
977 
978 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
979 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
980 		if (rc) {
981 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
982 			return -1;
983 		}
984 
985 		rpoller->num_cqe = num_cqe;
986 	}
987 
988 	rpoller->required_num_wr = required_num_wr;
989 	return 0;
990 }
991 
992 static int
993 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
994 {
995 	struct spdk_nvmf_rdma_qpair		*rqpair;
996 	struct spdk_nvmf_rdma_transport		*rtransport;
997 	struct spdk_nvmf_transport		*transport;
998 	struct spdk_nvmf_rdma_resource_opts	opts;
999 	struct spdk_nvmf_rdma_device		*device;
1000 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
1001 
1002 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1003 	device = rqpair->device;
1004 
1005 	qp_init_attr.qp_context	= rqpair;
1006 	qp_init_attr.pd		= device->pd;
1007 	qp_init_attr.send_cq	= rqpair->poller->cq;
1008 	qp_init_attr.recv_cq	= rqpair->poller->cq;
1009 
1010 	if (rqpair->srq) {
1011 		qp_init_attr.srq		= rqpair->srq->srq;
1012 	} else {
1013 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
1014 	}
1015 
1016 	/* SEND, READ, and WRITE operations */
1017 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
1018 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1019 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1020 	qp_init_attr.stats		= &rqpair->poller->stat.qp_stats;
1021 
1022 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1023 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1024 		goto error;
1025 	}
1026 
1027 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1028 	if (!rqpair->rdma_qp) {
1029 		goto error;
1030 	}
1031 
1032 	rqpair->qp_num = rqpair->rdma_qp->qp->qp_num;
1033 
1034 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1035 					  qp_init_attr.cap.max_send_wr);
1036 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1037 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1038 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair);
1039 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1040 
1041 	if (rqpair->poller->srq == NULL) {
1042 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1043 		transport = &rtransport->transport;
1044 
1045 		opts.qp = rqpair->rdma_qp;
1046 		opts.pd = rqpair->cm_id->pd;
1047 		opts.qpair = rqpair;
1048 		opts.shared = false;
1049 		opts.max_queue_depth = rqpair->max_queue_depth;
1050 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1051 
1052 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1053 
1054 		if (!rqpair->resources) {
1055 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1056 			rdma_destroy_qp(rqpair->cm_id);
1057 			goto error;
1058 		}
1059 	} else {
1060 		rqpair->resources = rqpair->poller->resources;
1061 	}
1062 
1063 	rqpair->current_recv_depth = 0;
1064 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1065 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1066 
1067 	return 0;
1068 
1069 error:
1070 	rdma_destroy_id(rqpair->cm_id);
1071 	rqpair->cm_id = NULL;
1072 	return -1;
1073 }
1074 
1075 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1076 /* This function accepts either a single wr or the first wr in a linked list. */
1077 static void
1078 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1079 {
1080 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1081 			struct spdk_nvmf_rdma_transport, transport);
1082 
1083 	if (rqpair->srq != NULL) {
1084 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, first);
1085 	} else {
1086 		if (spdk_rdma_qp_queue_recv_wrs(rqpair->rdma_qp, first)) {
1087 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1088 		}
1089 	}
1090 
1091 	if (rtransport->rdma_opts.no_wr_batching) {
1092 		_poller_submit_recvs(rtransport, rqpair->poller);
1093 	}
1094 }
1095 
1096 static int
1097 request_transfer_in(struct spdk_nvmf_request *req)
1098 {
1099 	struct spdk_nvmf_rdma_request	*rdma_req;
1100 	struct spdk_nvmf_qpair		*qpair;
1101 	struct spdk_nvmf_rdma_qpair	*rqpair;
1102 	struct spdk_nvmf_rdma_transport *rtransport;
1103 
1104 	qpair = req->qpair;
1105 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1106 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1107 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1108 				      struct spdk_nvmf_rdma_transport, transport);
1109 
1110 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1111 	assert(rdma_req != NULL);
1112 
1113 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1114 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1115 	}
1116 	if (rtransport->rdma_opts.no_wr_batching) {
1117 		_poller_submit_sends(rtransport, rqpair->poller);
1118 	}
1119 
1120 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1121 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1122 	return 0;
1123 }
1124 
1125 static int
1126 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1127 {
1128 	int				num_outstanding_data_wr = 0;
1129 	struct spdk_nvmf_rdma_request	*rdma_req;
1130 	struct spdk_nvmf_qpair		*qpair;
1131 	struct spdk_nvmf_rdma_qpair	*rqpair;
1132 	struct spdk_nvme_cpl		*rsp;
1133 	struct ibv_send_wr		*first = NULL;
1134 	struct spdk_nvmf_rdma_transport *rtransport;
1135 
1136 	*data_posted = 0;
1137 	qpair = req->qpair;
1138 	rsp = &req->rsp->nvme_cpl;
1139 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1140 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1141 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1142 				      struct spdk_nvmf_rdma_transport, transport);
1143 
1144 	/* Advance our sq_head pointer */
1145 	if (qpair->sq_head == qpair->sq_head_max) {
1146 		qpair->sq_head = 0;
1147 	} else {
1148 		qpair->sq_head++;
1149 	}
1150 	rsp->sqhd = qpair->sq_head;
1151 
1152 	/* queue the capsule for the recv buffer */
1153 	assert(rdma_req->recv != NULL);
1154 
1155 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1156 
1157 	rdma_req->recv = NULL;
1158 	assert(rqpair->current_recv_depth > 0);
1159 	rqpair->current_recv_depth--;
1160 
1161 	/* Build the response which consists of optional
1162 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1163 	 * containing the response.
1164 	 */
1165 	first = &rdma_req->rsp.wr;
1166 
1167 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1168 		/* On failure, data was not read from the controller. So clear the
1169 		 * number of outstanding data WRs to zero.
1170 		 */
1171 		rdma_req->num_outstanding_data_wr = 0;
1172 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1173 		first = &rdma_req->data.wr;
1174 		*data_posted = 1;
1175 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1176 	}
1177 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1178 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1179 	}
1180 	if (rtransport->rdma_opts.no_wr_batching) {
1181 		_poller_submit_sends(rtransport, rqpair->poller);
1182 	}
1183 
1184 	/* +1 for the rsp wr */
1185 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1186 
1187 	return 0;
1188 }
1189 
1190 static int
1191 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1192 {
1193 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1194 	struct rdma_conn_param				ctrlr_event_data = {};
1195 	int						rc;
1196 
1197 	accept_data.recfmt = 0;
1198 	accept_data.crqsize = rqpair->max_queue_depth;
1199 
1200 	ctrlr_event_data.private_data = &accept_data;
1201 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1202 	if (id->ps == RDMA_PS_TCP) {
1203 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1204 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1205 	}
1206 
1207 	/* Configure infinite retries for the initiator side qpair.
1208 	 * We need to pass this value to the initiator to prevent the
1209 	 * initiator side NIC from completing SEND requests back to the
1210 	 * initiator with status rnr_retry_count_exceeded. */
1211 	ctrlr_event_data.rnr_retry_count = 0x7;
1212 
1213 	/* When qpair is created without use of rdma cm API, an additional
1214 	 * information must be provided to initiator in the connection response:
1215 	 * whether qpair is using SRQ and its qp_num
1216 	 * Fields below are ignored by rdma cm if qpair has been
1217 	 * created using rdma cm API. */
1218 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1219 	ctrlr_event_data.qp_num = rqpair->qp_num;
1220 
1221 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1222 	if (rc) {
1223 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1224 	} else {
1225 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1226 	}
1227 
1228 	return rc;
1229 }
1230 
1231 static void
1232 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1233 {
1234 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1235 
1236 	rej_data.recfmt = 0;
1237 	rej_data.sts = error;
1238 
1239 	rdma_reject(id, &rej_data, sizeof(rej_data));
1240 }
1241 
1242 static int
1243 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1244 {
1245 	struct spdk_nvmf_rdma_transport *rtransport;
1246 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1247 	struct spdk_nvmf_rdma_port	*port;
1248 	struct rdma_conn_param		*rdma_param = NULL;
1249 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1250 	uint16_t			max_queue_depth;
1251 	uint16_t			max_read_depth;
1252 
1253 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1254 
1255 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1256 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1257 
1258 	rdma_param = &event->param.conn;
1259 	if (rdma_param->private_data == NULL ||
1260 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1261 		SPDK_ERRLOG("connect request: no private data provided\n");
1262 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1263 		return -1;
1264 	}
1265 
1266 	private_data = rdma_param->private_data;
1267 	if (private_data->recfmt != 0) {
1268 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1269 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1270 		return -1;
1271 	}
1272 
1273 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1274 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1275 
1276 	port = event->listen_id->context;
1277 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1278 		      event->listen_id, event->listen_id->verbs, port);
1279 
1280 	/* Figure out the supported queue depth. This is a multi-step process
1281 	 * that takes into account hardware maximums, host provided values,
1282 	 * and our target's internal memory limits */
1283 
1284 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1285 
1286 	/* Start with the maximum queue depth allowed by the target */
1287 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1288 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1289 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1290 		      rtransport->transport.opts.max_queue_depth);
1291 
1292 	/* Next check the local NIC's hardware limitations */
1293 	SPDK_DEBUGLOG(rdma,
1294 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1295 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1296 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1297 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1298 
1299 	/* Next check the remote NIC's hardware limitations */
1300 	SPDK_DEBUGLOG(rdma,
1301 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1302 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1303 	if (rdma_param->initiator_depth > 0) {
1304 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1305 	}
1306 
1307 	/* Finally check for the host software requested values, which are
1308 	 * optional. */
1309 	if (rdma_param->private_data != NULL &&
1310 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1311 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1312 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1313 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1314 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1315 	}
1316 
1317 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1318 		      max_queue_depth, max_read_depth);
1319 
1320 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1321 	if (rqpair == NULL) {
1322 		SPDK_ERRLOG("Could not allocate new connection.\n");
1323 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1324 		return -1;
1325 	}
1326 
1327 	rqpair->device = port->device;
1328 	rqpair->max_queue_depth = max_queue_depth;
1329 	rqpair->max_read_depth = max_read_depth;
1330 	rqpair->cm_id = event->id;
1331 	rqpair->listen_id = event->listen_id;
1332 	rqpair->qpair.transport = transport;
1333 	STAILQ_INIT(&rqpair->ibv_events);
1334 	/* use qid from the private data to determine the qpair type
1335 	   qid will be set to the appropriate value when the controller is created */
1336 	rqpair->qpair.qid = private_data->qid;
1337 
1338 	event->id->context = &rqpair->qpair;
1339 
1340 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1341 
1342 	return 0;
1343 }
1344 
1345 static inline void
1346 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1347 		   enum spdk_nvme_data_transfer xfer)
1348 {
1349 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1350 		wr->opcode = IBV_WR_RDMA_WRITE;
1351 		wr->send_flags = 0;
1352 		wr->next = next;
1353 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1354 		wr->opcode = IBV_WR_RDMA_READ;
1355 		wr->send_flags = IBV_SEND_SIGNALED;
1356 		wr->next = NULL;
1357 	} else {
1358 		assert(0);
1359 	}
1360 }
1361 
1362 static int
1363 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1364 		       struct spdk_nvmf_rdma_request *rdma_req,
1365 		       uint32_t num_sgl_descriptors)
1366 {
1367 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1368 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1369 	uint32_t				i;
1370 
1371 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1372 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1373 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1374 		return -EINVAL;
1375 	}
1376 
1377 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1378 		return -ENOMEM;
1379 	}
1380 
1381 	current_data_wr = &rdma_req->data;
1382 
1383 	for (i = 0; i < num_sgl_descriptors; i++) {
1384 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1385 		current_data_wr->wr.next = &work_requests[i]->wr;
1386 		current_data_wr = work_requests[i];
1387 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1388 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1389 	}
1390 
1391 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1392 
1393 	return 0;
1394 }
1395 
1396 static inline void
1397 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
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 
1402 	wr->wr.rdma.rkey = sgl->keyed.key;
1403 	wr->wr.rdma.remote_addr = sgl->address;
1404 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1405 }
1406 
1407 static inline void
1408 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1409 {
1410 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1411 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1412 	uint32_t			i;
1413 	int				j;
1414 	uint64_t			remote_addr_offset = 0;
1415 
1416 	for (i = 0; i < num_wrs; ++i) {
1417 		wr->wr.rdma.rkey = sgl->keyed.key;
1418 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1419 		for (j = 0; j < wr->num_sge; ++j) {
1420 			remote_addr_offset += wr->sg_list[j].length;
1421 		}
1422 		wr = wr->next;
1423 	}
1424 }
1425 
1426 static int
1427 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1428 		      struct spdk_nvmf_rdma_device *device,
1429 		      struct spdk_nvmf_rdma_request *rdma_req,
1430 		      struct ibv_send_wr *wr,
1431 		      uint32_t total_length,
1432 		      uint32_t num_extra_wrs)
1433 {
1434 	struct spdk_rdma_memory_translation mem_translation;
1435 	struct spdk_dif_ctx *dif_ctx = NULL;
1436 	struct ibv_sge	*sg_ele;
1437 	struct iovec *iov;
1438 	uint32_t remaining_data_block = 0;
1439 	uint32_t lkey, remaining;
1440 	int rc;
1441 
1442 	if (spdk_unlikely(rdma_req->req.dif_enabled)) {
1443 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1444 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1445 	}
1446 
1447 	wr->num_sge = 0;
1448 
1449 	while (total_length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1450 		iov = &rdma_req->req.iov[rdma_req->iovpos];
1451 		rc = spdk_rdma_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1452 		if (spdk_unlikely(rc)) {
1453 			return false;
1454 		}
1455 
1456 		lkey = spdk_rdma_memory_translation_get_lkey(&mem_translation);
1457 		sg_ele = &wr->sg_list[wr->num_sge];
1458 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1459 
1460 		if (spdk_likely(!dif_ctx)) {
1461 			sg_ele->lkey = lkey;
1462 			sg_ele->addr = (uintptr_t)iov->iov_base + rdma_req->offset;
1463 			sg_ele->length = remaining;
1464 			SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele, sg_ele->addr,
1465 				      sg_ele->length);
1466 			rdma_req->offset += sg_ele->length;
1467 			total_length -= sg_ele->length;
1468 			wr->num_sge++;
1469 
1470 			if (rdma_req->offset == iov->iov_len) {
1471 				rdma_req->offset = 0;
1472 				rdma_req->iovpos++;
1473 			}
1474 		} else {
1475 			uint32_t data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1476 			uint32_t md_size = dif_ctx->md_size;
1477 			uint32_t sge_len;
1478 
1479 			while (remaining) {
1480 				if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1481 					if (num_extra_wrs > 0 && wr->next) {
1482 						wr = wr->next;
1483 						wr->num_sge = 0;
1484 						sg_ele = &wr->sg_list[wr->num_sge];
1485 						num_extra_wrs--;
1486 					} else {
1487 						break;
1488 					}
1489 				}
1490 				sg_ele->lkey = lkey;
1491 				sg_ele->addr = (uintptr_t)((char *)iov->iov_base + rdma_req->offset);
1492 				sge_len = spdk_min(remaining, remaining_data_block);
1493 				sg_ele->length = sge_len;
1494 				SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele, sg_ele->addr,
1495 					      sg_ele->length);
1496 				remaining -= sge_len;
1497 				remaining_data_block -= sge_len;
1498 				rdma_req->offset += sge_len;
1499 				total_length -= sge_len;
1500 
1501 				sg_ele++;
1502 				wr->num_sge++;
1503 
1504 				if (remaining_data_block == 0) {
1505 					/* skip metadata */
1506 					rdma_req->offset += md_size;
1507 					total_length -= md_size;
1508 					/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1509 					remaining -= spdk_min(remaining, md_size);
1510 					remaining_data_block = data_block_size;
1511 				}
1512 
1513 				if (remaining == 0) {
1514 					/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1515 					   the remaining metadata bits at the beginning of the next buffer */
1516 					rdma_req->offset -= spdk_min(iov->iov_len, rdma_req->offset);
1517 					rdma_req->iovpos++;
1518 				}
1519 			}
1520 		}
1521 	}
1522 
1523 	if (total_length) {
1524 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1525 		return -EINVAL;
1526 	}
1527 
1528 	return 0;
1529 }
1530 
1531 static inline uint32_t
1532 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1533 {
1534 	/* estimate the number of SG entries and WRs needed to process the request */
1535 	uint32_t num_sge = 0;
1536 	uint32_t i;
1537 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1538 
1539 	for (i = 0; i < num_buffers && length > 0; i++) {
1540 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1541 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1542 
1543 		if (num_sge_in_block * block_size > buffer_len) {
1544 			++num_sge_in_block;
1545 		}
1546 		num_sge += num_sge_in_block;
1547 		length -= buffer_len;
1548 	}
1549 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1550 }
1551 
1552 static int
1553 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1554 			    struct spdk_nvmf_rdma_device *device,
1555 			    struct spdk_nvmf_rdma_request *rdma_req,
1556 			    uint32_t length)
1557 {
1558 	struct spdk_nvmf_rdma_qpair		*rqpair;
1559 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1560 	struct spdk_nvmf_request		*req = &rdma_req->req;
1561 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1562 	int					rc;
1563 	uint32_t				num_wrs = 1;
1564 
1565 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1566 	rgroup = rqpair->poller->group;
1567 
1568 	/* rdma wr specifics */
1569 	nvmf_rdma_setup_request(rdma_req);
1570 
1571 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1572 					   length);
1573 	if (rc != 0) {
1574 		return rc;
1575 	}
1576 
1577 	assert(req->iovcnt <= rqpair->max_send_sge);
1578 
1579 	rdma_req->iovpos = 0;
1580 
1581 	if (spdk_unlikely(req->dif_enabled)) {
1582 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1583 						 req->dif.dif_ctx.block_size);
1584 		if (num_wrs > 1) {
1585 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1586 			if (rc != 0) {
1587 				goto err_exit;
1588 			}
1589 		}
1590 	}
1591 
1592 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1593 	if (spdk_unlikely(rc != 0)) {
1594 		goto err_exit;
1595 	}
1596 
1597 	if (spdk_unlikely(num_wrs > 1)) {
1598 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1599 	}
1600 
1601 	/* set the number of outstanding data WRs for this request. */
1602 	rdma_req->num_outstanding_data_wr = num_wrs;
1603 
1604 	return rc;
1605 
1606 err_exit:
1607 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1608 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1609 	req->iovcnt = 0;
1610 	return rc;
1611 }
1612 
1613 static int
1614 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1615 				      struct spdk_nvmf_rdma_device *device,
1616 				      struct spdk_nvmf_rdma_request *rdma_req)
1617 {
1618 	struct spdk_nvmf_rdma_qpair		*rqpair;
1619 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1620 	struct ibv_send_wr			*current_wr;
1621 	struct spdk_nvmf_request		*req = &rdma_req->req;
1622 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1623 	uint32_t				num_sgl_descriptors;
1624 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES], total_length = 0;
1625 	uint32_t				i;
1626 	int					rc;
1627 
1628 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1629 	rgroup = rqpair->poller->group;
1630 
1631 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1632 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1633 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1634 
1635 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1636 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1637 
1638 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1639 	for (i = 0; i < num_sgl_descriptors; i++) {
1640 		if (spdk_likely(!req->dif_enabled)) {
1641 			lengths[i] = desc->keyed.length;
1642 		} else {
1643 			req->dif.orig_length += desc->keyed.length;
1644 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1645 			req->dif.elba_length += lengths[i];
1646 		}
1647 		total_length += lengths[i];
1648 		desc++;
1649 	}
1650 
1651 	if (total_length > rtransport->transport.opts.max_io_size) {
1652 		SPDK_ERRLOG("Multi SGL length 0x%x exceeds max io size 0x%x\n",
1653 			    total_length, rtransport->transport.opts.max_io_size);
1654 		req->rsp->nvme_cpl.status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1655 		return -EINVAL;
1656 	}
1657 
1658 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1659 		return -ENOMEM;
1660 	}
1661 
1662 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport, total_length);
1663 	if (rc != 0) {
1664 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1665 		return rc;
1666 	}
1667 
1668 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1669 	current_wr = &rdma_req->data.wr;
1670 	assert(current_wr != NULL);
1671 
1672 	req->length = 0;
1673 	rdma_req->iovpos = 0;
1674 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1675 	for (i = 0; i < num_sgl_descriptors; i++) {
1676 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1677 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1678 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1679 			rc = -EINVAL;
1680 			goto err_exit;
1681 		}
1682 
1683 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1684 		if (rc != 0) {
1685 			rc = -ENOMEM;
1686 			goto err_exit;
1687 		}
1688 
1689 		req->length += desc->keyed.length;
1690 		current_wr->wr.rdma.rkey = desc->keyed.key;
1691 		current_wr->wr.rdma.remote_addr = desc->address;
1692 		current_wr = current_wr->next;
1693 		desc++;
1694 	}
1695 
1696 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1697 	/* Go back to the last descriptor in the list. */
1698 	desc--;
1699 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1700 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1701 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1702 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1703 		}
1704 	}
1705 #endif
1706 
1707 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1708 
1709 	return 0;
1710 
1711 err_exit:
1712 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1713 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1714 	return rc;
1715 }
1716 
1717 static int
1718 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1719 			    struct spdk_nvmf_rdma_device *device,
1720 			    struct spdk_nvmf_rdma_request *rdma_req)
1721 {
1722 	struct spdk_nvmf_request		*req = &rdma_req->req;
1723 	struct spdk_nvme_cpl			*rsp;
1724 	struct spdk_nvme_sgl_descriptor		*sgl;
1725 	int					rc;
1726 	uint32_t				length;
1727 
1728 	rsp = &req->rsp->nvme_cpl;
1729 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1730 
1731 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1732 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1733 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1734 
1735 		length = sgl->keyed.length;
1736 		if (length > rtransport->transport.opts.max_io_size) {
1737 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1738 				    length, rtransport->transport.opts.max_io_size);
1739 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1740 			return -1;
1741 		}
1742 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1743 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1744 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1745 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1746 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1747 			}
1748 		}
1749 #endif
1750 
1751 		/* fill request length and populate iovs */
1752 		req->length = length;
1753 
1754 		if (spdk_unlikely(req->dif_enabled)) {
1755 			req->dif.orig_length = length;
1756 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1757 			req->dif.elba_length = length;
1758 		}
1759 
1760 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1761 		if (spdk_unlikely(rc < 0)) {
1762 			if (rc == -EINVAL) {
1763 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1764 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1765 				return -1;
1766 			}
1767 			/* No available buffers. Queue this request up. */
1768 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1769 			return 0;
1770 		}
1771 
1772 		/* backward compatible */
1773 		req->data = req->iov[0].iov_base;
1774 
1775 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1776 			      req->iovcnt);
1777 
1778 		return 0;
1779 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1780 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1781 		uint64_t offset = sgl->address;
1782 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1783 
1784 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1785 			      offset, sgl->unkeyed.length);
1786 
1787 		if (offset > max_len) {
1788 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1789 				    offset, max_len);
1790 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1791 			return -1;
1792 		}
1793 		max_len -= (uint32_t)offset;
1794 
1795 		if (sgl->unkeyed.length > max_len) {
1796 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1797 				    sgl->unkeyed.length, max_len);
1798 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1799 			return -1;
1800 		}
1801 
1802 		rdma_req->num_outstanding_data_wr = 0;
1803 		req->data = rdma_req->recv->buf + offset;
1804 		req->data_from_pool = false;
1805 		req->length = sgl->unkeyed.length;
1806 
1807 		req->iov[0].iov_base = req->data;
1808 		req->iov[0].iov_len = req->length;
1809 		req->iovcnt = 1;
1810 
1811 		return 0;
1812 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1813 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1814 
1815 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1816 		if (rc == -ENOMEM) {
1817 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1818 			return 0;
1819 		} else if (rc == -EINVAL) {
1820 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1821 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1822 			return -1;
1823 		}
1824 
1825 		/* backward compatible */
1826 		req->data = req->iov[0].iov_base;
1827 
1828 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1829 			      req->iovcnt);
1830 
1831 		return 0;
1832 	}
1833 
1834 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1835 		    sgl->generic.type, sgl->generic.subtype);
1836 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1837 	return -1;
1838 }
1839 
1840 static void
1841 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1842 			struct spdk_nvmf_rdma_transport	*rtransport)
1843 {
1844 	struct spdk_nvmf_rdma_qpair		*rqpair;
1845 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1846 
1847 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1848 	if (rdma_req->req.data_from_pool) {
1849 		rgroup = rqpair->poller->group;
1850 
1851 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1852 	}
1853 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1854 	rdma_req->req.length = 0;
1855 	rdma_req->req.iovcnt = 0;
1856 	rdma_req->req.data = NULL;
1857 	rdma_req->rsp.wr.next = NULL;
1858 	rdma_req->data.wr.next = NULL;
1859 	rdma_req->offset = 0;
1860 	rdma_req->req.dif_enabled = false;
1861 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1862 	rqpair->qd--;
1863 
1864 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1865 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1866 }
1867 
1868 bool
1869 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1870 			  struct spdk_nvmf_rdma_request *rdma_req)
1871 {
1872 	struct spdk_nvmf_rdma_qpair	*rqpair;
1873 	struct spdk_nvmf_rdma_device	*device;
1874 	struct spdk_nvmf_rdma_poll_group *rgroup;
1875 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1876 	int				rc;
1877 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1878 	enum spdk_nvmf_rdma_request_state prev_state;
1879 	bool				progress = false;
1880 	int				data_posted;
1881 	uint32_t			num_blocks;
1882 
1883 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1884 	device = rqpair->device;
1885 	rgroup = rqpair->poller->group;
1886 
1887 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1888 
1889 	/* If the queue pair is in an error state, force the request to the completed state
1890 	 * to release resources. */
1891 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1892 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1893 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1894 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1895 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1896 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1897 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1898 		}
1899 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1900 	}
1901 
1902 	/* The loop here is to allow for several back-to-back state changes. */
1903 	do {
1904 		prev_state = rdma_req->state;
1905 
1906 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
1907 
1908 		switch (rdma_req->state) {
1909 		case RDMA_REQUEST_STATE_FREE:
1910 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1911 			 * to escape this state. */
1912 			break;
1913 		case RDMA_REQUEST_STATE_NEW:
1914 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1915 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
1916 			rdma_recv = rdma_req->recv;
1917 
1918 			/* The first element of the SGL is the NVMe command */
1919 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1920 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1921 
1922 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1923 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1924 				break;
1925 			}
1926 
1927 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
1928 				rdma_req->req.dif_enabled = true;
1929 			}
1930 
1931 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1932 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1933 			rdma_req->rsp.wr.imm_data = 0;
1934 #endif
1935 
1936 			/* The next state transition depends on the data transfer needs of this request. */
1937 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
1938 
1939 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
1940 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
1941 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
1942 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1943 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
1944 				break;
1945 			}
1946 
1947 			/* If no data to transfer, ready to execute. */
1948 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1949 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1950 				break;
1951 			}
1952 
1953 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1954 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
1955 			break;
1956 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1957 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1958 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
1959 
1960 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1961 
1962 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
1963 				/* This request needs to wait in line to obtain a buffer */
1964 				break;
1965 			}
1966 
1967 			/* Try to get a data buffer */
1968 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1969 			if (rc < 0) {
1970 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1971 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1972 				break;
1973 			}
1974 
1975 			if (!rdma_req->req.data) {
1976 				/* No buffers available. */
1977 				rgroup->stat.pending_data_buffer++;
1978 				break;
1979 			}
1980 
1981 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1982 
1983 			/* If data is transferring from host to controller and the data didn't
1984 			 * arrive using in capsule data, we need to do a transfer from the host.
1985 			 */
1986 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
1987 			    rdma_req->req.data_from_pool) {
1988 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1989 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1990 				break;
1991 			}
1992 
1993 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1994 			break;
1995 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1996 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1997 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
1998 
1999 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2000 				/* This request needs to wait in line to perform RDMA */
2001 				break;
2002 			}
2003 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2004 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2005 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2006 				rqpair->poller->stat.pending_rdma_read++;
2007 				break;
2008 			}
2009 
2010 			/* We have already verified that this request is the head of the queue. */
2011 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2012 
2013 			rc = request_transfer_in(&rdma_req->req);
2014 			if (!rc) {
2015 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2016 			} else {
2017 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2018 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2019 			}
2020 			break;
2021 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2022 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2023 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2024 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2025 			 * to escape this state. */
2026 			break;
2027 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2028 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2029 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2030 
2031 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2032 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2033 					/* generate DIF for write operation */
2034 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2035 					assert(num_blocks > 0);
2036 
2037 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2038 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2039 					if (rc != 0) {
2040 						SPDK_ERRLOG("DIF generation failed\n");
2041 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2042 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2043 						break;
2044 					}
2045 				}
2046 
2047 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2048 				/* set extended length before IO operation */
2049 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2050 			}
2051 
2052 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2053 			spdk_nvmf_request_exec(&rdma_req->req);
2054 			break;
2055 		case RDMA_REQUEST_STATE_EXECUTING:
2056 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2057 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2058 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2059 			 * to escape this state. */
2060 			break;
2061 		case RDMA_REQUEST_STATE_EXECUTED:
2062 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2063 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2064 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2065 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2066 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2067 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2068 			} else {
2069 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2070 			}
2071 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2072 				/* restore the original length */
2073 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2074 
2075 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2076 					struct spdk_dif_error error_blk;
2077 
2078 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2079 
2080 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2081 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2082 					if (rc) {
2083 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2084 
2085 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2086 							    error_blk.err_offset);
2087 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2088 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2089 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2090 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2091 					}
2092 				}
2093 			}
2094 			break;
2095 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2096 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2097 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2098 
2099 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2100 				/* This request needs to wait in line to perform RDMA */
2101 				break;
2102 			}
2103 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2104 			    rqpair->max_send_depth) {
2105 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2106 				 * +1 since each request has an additional wr in the resp. */
2107 				rqpair->poller->stat.pending_rdma_write++;
2108 				break;
2109 			}
2110 
2111 			/* We have already verified that this request is the head of the queue. */
2112 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2113 
2114 			/* The data transfer will be kicked off from
2115 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2116 			 */
2117 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2118 			break;
2119 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2120 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2121 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2122 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2123 			assert(rc == 0); /* No good way to handle this currently */
2124 			if (rc) {
2125 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2126 			} else {
2127 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2128 						  RDMA_REQUEST_STATE_COMPLETING;
2129 			}
2130 			break;
2131 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2132 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2133 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2134 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2135 			 * to escape this state. */
2136 			break;
2137 		case RDMA_REQUEST_STATE_COMPLETING:
2138 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2139 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2140 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2141 			 * to escape this state. */
2142 			break;
2143 		case RDMA_REQUEST_STATE_COMPLETED:
2144 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2145 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2146 
2147 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2148 			_nvmf_rdma_request_free(rdma_req, rtransport);
2149 			break;
2150 		case RDMA_REQUEST_NUM_STATES:
2151 		default:
2152 			assert(0);
2153 			break;
2154 		}
2155 
2156 		if (rdma_req->state != prev_state) {
2157 			progress = true;
2158 		}
2159 	} while (rdma_req->state != prev_state);
2160 
2161 	return progress;
2162 }
2163 
2164 /* Public API callbacks begin here */
2165 
2166 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2167 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2168 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2169 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2170 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2171 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2172 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2173 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2174 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2175 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2176 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2177 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2178 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2179 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2180 
2181 static void
2182 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2183 {
2184 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2185 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2186 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2187 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2188 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2189 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2190 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2191 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2192 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2193 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2194 	opts->transport_specific =      NULL;
2195 }
2196 
2197 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2198 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2199 
2200 static inline bool
2201 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2202 {
2203 	return device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_OLD ||
2204 	       device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_NEW;
2205 }
2206 
2207 static int
2208 nvmf_rdma_accept(void *ctx);
2209 
2210 static struct spdk_nvmf_transport *
2211 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2212 {
2213 	int rc;
2214 	struct spdk_nvmf_rdma_transport *rtransport;
2215 	struct spdk_nvmf_rdma_device	*device, *tmp;
2216 	struct ibv_context		**contexts;
2217 	uint32_t			i;
2218 	int				flag;
2219 	uint32_t			sge_count;
2220 	uint32_t			min_shared_buffers;
2221 	uint32_t			min_in_capsule_data_size;
2222 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2223 	pthread_mutexattr_t		attr;
2224 
2225 	rtransport = calloc(1, sizeof(*rtransport));
2226 	if (!rtransport) {
2227 		return NULL;
2228 	}
2229 
2230 	if (pthread_mutexattr_init(&attr)) {
2231 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2232 		free(rtransport);
2233 		return NULL;
2234 	}
2235 
2236 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2237 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2238 		pthread_mutexattr_destroy(&attr);
2239 		free(rtransport);
2240 		return NULL;
2241 	}
2242 
2243 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2244 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2245 		pthread_mutexattr_destroy(&attr);
2246 		free(rtransport);
2247 		return NULL;
2248 	}
2249 
2250 	pthread_mutexattr_destroy(&attr);
2251 
2252 	TAILQ_INIT(&rtransport->devices);
2253 	TAILQ_INIT(&rtransport->ports);
2254 	TAILQ_INIT(&rtransport->poll_groups);
2255 
2256 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2257 	rtransport->rdma_opts.num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2258 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2259 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2260 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2261 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2262 	if (opts->transport_specific != NULL &&
2263 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2264 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2265 					    &rtransport->rdma_opts)) {
2266 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2267 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2268 		return NULL;
2269 	}
2270 
2271 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2272 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2273 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2274 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2275 		     "  num_shared_buffers=%d, num_cqe=%d, max_srq_depth=%d, no_srq=%d,"
2276 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2277 		     opts->max_queue_depth,
2278 		     opts->max_io_size,
2279 		     opts->max_qpairs_per_ctrlr - 1,
2280 		     opts->io_unit_size,
2281 		     opts->in_capsule_data_size,
2282 		     opts->max_aq_depth,
2283 		     opts->num_shared_buffers,
2284 		     rtransport->rdma_opts.num_cqe,
2285 		     rtransport->rdma_opts.max_srq_depth,
2286 		     rtransport->rdma_opts.no_srq,
2287 		     rtransport->rdma_opts.acceptor_backlog,
2288 		     rtransport->rdma_opts.no_wr_batching,
2289 		     opts->abort_timeout_sec);
2290 
2291 	/* I/O unit size cannot be larger than max I/O size */
2292 	if (opts->io_unit_size > opts->max_io_size) {
2293 		opts->io_unit_size = opts->max_io_size;
2294 	}
2295 
2296 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2297 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2298 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2299 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2300 	}
2301 
2302 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2303 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2304 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2305 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2306 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2307 		return NULL;
2308 	}
2309 
2310 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2311 	if (min_shared_buffers > opts->num_shared_buffers) {
2312 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2313 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2314 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2315 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2316 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2317 		return NULL;
2318 	}
2319 
2320 	sge_count = opts->max_io_size / opts->io_unit_size;
2321 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2322 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2323 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2324 		return NULL;
2325 	}
2326 
2327 	min_in_capsule_data_size = sizeof(struct spdk_nvme_sgl_descriptor) * SPDK_NVMF_MAX_SGL_ENTRIES;
2328 	if (opts->in_capsule_data_size < min_in_capsule_data_size) {
2329 		SPDK_WARNLOG("In capsule data size is set to %u, this is minimum size required to support msdbd=16\n",
2330 			     min_in_capsule_data_size);
2331 		opts->in_capsule_data_size = min_in_capsule_data_size;
2332 	}
2333 
2334 	rtransport->event_channel = rdma_create_event_channel();
2335 	if (rtransport->event_channel == NULL) {
2336 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2337 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2338 		return NULL;
2339 	}
2340 
2341 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2342 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2343 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2344 			    rtransport->event_channel->fd, spdk_strerror(errno));
2345 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2346 		return NULL;
2347 	}
2348 
2349 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2350 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2351 				   sizeof(struct spdk_nvmf_rdma_request_data),
2352 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2353 				   SPDK_ENV_SOCKET_ID_ANY);
2354 	if (!rtransport->data_wr_pool) {
2355 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2356 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2357 		return NULL;
2358 	}
2359 
2360 	contexts = rdma_get_devices(NULL);
2361 	if (contexts == NULL) {
2362 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2363 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2364 		return NULL;
2365 	}
2366 
2367 	i = 0;
2368 	rc = 0;
2369 	while (contexts[i] != NULL) {
2370 		device = calloc(1, sizeof(*device));
2371 		if (!device) {
2372 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2373 			rc = -ENOMEM;
2374 			break;
2375 		}
2376 		device->context = contexts[i];
2377 		rc = ibv_query_device(device->context, &device->attr);
2378 		if (rc < 0) {
2379 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2380 			free(device);
2381 			break;
2382 
2383 		}
2384 
2385 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2386 
2387 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2388 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2389 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2390 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2391 		}
2392 
2393 		/**
2394 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2395 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2396 		 * but incorrectly reports that it does. There are changes making their way
2397 		 * through the kernel now that will enable this feature. When they are merged,
2398 		 * we can conditionally enable this feature.
2399 		 *
2400 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2401 		 */
2402 		if (nvmf_rdma_is_rxe_device(device)) {
2403 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2404 		}
2405 #endif
2406 
2407 		/* set up device context async ev fd as NON_BLOCKING */
2408 		flag = fcntl(device->context->async_fd, F_GETFL);
2409 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2410 		if (rc < 0) {
2411 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2412 			free(device);
2413 			break;
2414 		}
2415 
2416 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2417 		i++;
2418 
2419 		if (g_nvmf_hooks.get_ibv_pd) {
2420 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2421 		} else {
2422 			device->pd = ibv_alloc_pd(device->context);
2423 		}
2424 
2425 		if (!device->pd) {
2426 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2427 			rc = -ENOMEM;
2428 			break;
2429 		}
2430 
2431 		assert(device->map == NULL);
2432 
2433 		device->map = spdk_rdma_create_mem_map(device->pd, &g_nvmf_hooks, SPDK_RDMA_MEMORY_MAP_ROLE_TARGET);
2434 		if (!device->map) {
2435 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2436 			rc = -ENOMEM;
2437 			break;
2438 		}
2439 
2440 		assert(device->map != NULL);
2441 		assert(device->pd != NULL);
2442 	}
2443 	rdma_free_devices(contexts);
2444 
2445 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2446 		/* divide and round up. */
2447 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2448 
2449 		/* round up to the nearest 4k. */
2450 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2451 
2452 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2453 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2454 			       opts->io_unit_size);
2455 	}
2456 
2457 	if (rc < 0) {
2458 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2459 		return NULL;
2460 	}
2461 
2462 	/* Set up poll descriptor array to monitor events from RDMA and IB
2463 	 * in a single poll syscall
2464 	 */
2465 	rtransport->npoll_fds = i + 1;
2466 	i = 0;
2467 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2468 	if (rtransport->poll_fds == NULL) {
2469 		SPDK_ERRLOG("poll_fds allocation failed\n");
2470 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2471 		return NULL;
2472 	}
2473 
2474 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2475 	rtransport->poll_fds[i++].events = POLLIN;
2476 
2477 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2478 		rtransport->poll_fds[i].fd = device->context->async_fd;
2479 		rtransport->poll_fds[i++].events = POLLIN;
2480 	}
2481 
2482 	rtransport->accept_poller = SPDK_POLLER_REGISTER(nvmf_rdma_accept, &rtransport->transport,
2483 				    opts->acceptor_poll_rate);
2484 	if (!rtransport->accept_poller) {
2485 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2486 		return NULL;
2487 	}
2488 
2489 	return &rtransport->transport;
2490 }
2491 
2492 static void
2493 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2494 {
2495 	struct spdk_nvmf_rdma_transport	*rtransport;
2496 	assert(w != NULL);
2497 
2498 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2499 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2500 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2501 	if (rtransport->rdma_opts.no_srq == true) {
2502 		spdk_json_write_named_int32(w, "num_cqe", rtransport->rdma_opts.num_cqe);
2503 	}
2504 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2505 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2506 }
2507 
2508 static int
2509 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2510 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2511 {
2512 	struct spdk_nvmf_rdma_transport	*rtransport;
2513 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2514 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2515 
2516 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2517 
2518 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2519 		TAILQ_REMOVE(&rtransport->ports, port, link);
2520 		rdma_destroy_id(port->id);
2521 		free(port);
2522 	}
2523 
2524 	if (rtransport->poll_fds != NULL) {
2525 		free(rtransport->poll_fds);
2526 	}
2527 
2528 	if (rtransport->event_channel != NULL) {
2529 		rdma_destroy_event_channel(rtransport->event_channel);
2530 	}
2531 
2532 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2533 		TAILQ_REMOVE(&rtransport->devices, device, link);
2534 		spdk_rdma_free_mem_map(&device->map);
2535 		if (device->pd) {
2536 			if (!g_nvmf_hooks.get_ibv_pd) {
2537 				ibv_dealloc_pd(device->pd);
2538 			}
2539 		}
2540 		free(device);
2541 	}
2542 
2543 	if (rtransport->data_wr_pool != NULL) {
2544 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2545 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2546 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2547 				    spdk_mempool_count(rtransport->data_wr_pool),
2548 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2549 		}
2550 	}
2551 
2552 	spdk_mempool_free(rtransport->data_wr_pool);
2553 
2554 	spdk_poller_unregister(&rtransport->accept_poller);
2555 	pthread_mutex_destroy(&rtransport->lock);
2556 	free(rtransport);
2557 
2558 	if (cb_fn) {
2559 		cb_fn(cb_arg);
2560 	}
2561 	return 0;
2562 }
2563 
2564 static int
2565 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2566 			  struct spdk_nvme_transport_id *trid,
2567 			  bool peer);
2568 
2569 static int
2570 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2571 		 struct spdk_nvmf_listen_opts *listen_opts)
2572 {
2573 	struct spdk_nvmf_rdma_transport	*rtransport;
2574 	struct spdk_nvmf_rdma_device	*device;
2575 	struct spdk_nvmf_rdma_port	*port;
2576 	struct addrinfo			*res;
2577 	struct addrinfo			hints;
2578 	int				family;
2579 	int				rc;
2580 
2581 	if (!strlen(trid->trsvcid)) {
2582 		SPDK_ERRLOG("Service id is required\n");
2583 		return -EINVAL;
2584 	}
2585 
2586 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2587 	assert(rtransport->event_channel != NULL);
2588 
2589 	pthread_mutex_lock(&rtransport->lock);
2590 	port = calloc(1, sizeof(*port));
2591 	if (!port) {
2592 		SPDK_ERRLOG("Port allocation failed\n");
2593 		pthread_mutex_unlock(&rtransport->lock);
2594 		return -ENOMEM;
2595 	}
2596 
2597 	port->trid = trid;
2598 
2599 	switch (trid->adrfam) {
2600 	case SPDK_NVMF_ADRFAM_IPV4:
2601 		family = AF_INET;
2602 		break;
2603 	case SPDK_NVMF_ADRFAM_IPV6:
2604 		family = AF_INET6;
2605 		break;
2606 	default:
2607 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2608 		free(port);
2609 		pthread_mutex_unlock(&rtransport->lock);
2610 		return -EINVAL;
2611 	}
2612 
2613 	memset(&hints, 0, sizeof(hints));
2614 	hints.ai_family = family;
2615 	hints.ai_flags = AI_NUMERICSERV;
2616 	hints.ai_socktype = SOCK_STREAM;
2617 	hints.ai_protocol = 0;
2618 
2619 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2620 	if (rc) {
2621 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2622 		free(port);
2623 		pthread_mutex_unlock(&rtransport->lock);
2624 		return -EINVAL;
2625 	}
2626 
2627 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2628 	if (rc < 0) {
2629 		SPDK_ERRLOG("rdma_create_id() failed\n");
2630 		freeaddrinfo(res);
2631 		free(port);
2632 		pthread_mutex_unlock(&rtransport->lock);
2633 		return rc;
2634 	}
2635 
2636 	rc = rdma_bind_addr(port->id, res->ai_addr);
2637 	freeaddrinfo(res);
2638 
2639 	if (rc < 0) {
2640 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2641 		rdma_destroy_id(port->id);
2642 		free(port);
2643 		pthread_mutex_unlock(&rtransport->lock);
2644 		return rc;
2645 	}
2646 
2647 	if (!port->id->verbs) {
2648 		SPDK_ERRLOG("ibv_context is null\n");
2649 		rdma_destroy_id(port->id);
2650 		free(port);
2651 		pthread_mutex_unlock(&rtransport->lock);
2652 		return -1;
2653 	}
2654 
2655 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2656 	if (rc < 0) {
2657 		SPDK_ERRLOG("rdma_listen() failed\n");
2658 		rdma_destroy_id(port->id);
2659 		free(port);
2660 		pthread_mutex_unlock(&rtransport->lock);
2661 		return rc;
2662 	}
2663 
2664 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2665 		if (device->context == port->id->verbs) {
2666 			port->device = device;
2667 			break;
2668 		}
2669 	}
2670 	if (!port->device) {
2671 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2672 			    port->id->verbs);
2673 		rdma_destroy_id(port->id);
2674 		free(port);
2675 		pthread_mutex_unlock(&rtransport->lock);
2676 		return -EINVAL;
2677 	}
2678 
2679 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2680 		       trid->traddr, trid->trsvcid);
2681 
2682 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2683 	pthread_mutex_unlock(&rtransport->lock);
2684 	return 0;
2685 }
2686 
2687 static void
2688 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2689 		      const struct spdk_nvme_transport_id *trid)
2690 {
2691 	struct spdk_nvmf_rdma_transport *rtransport;
2692 	struct spdk_nvmf_rdma_port *port, *tmp;
2693 
2694 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2695 
2696 	pthread_mutex_lock(&rtransport->lock);
2697 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2698 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2699 			TAILQ_REMOVE(&rtransport->ports, port, link);
2700 			rdma_destroy_id(port->id);
2701 			free(port);
2702 			break;
2703 		}
2704 	}
2705 
2706 	pthread_mutex_unlock(&rtransport->lock);
2707 }
2708 
2709 static void
2710 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2711 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2712 {
2713 	struct spdk_nvmf_request *req, *tmp;
2714 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2715 	struct spdk_nvmf_rdma_resources *resources;
2716 
2717 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2718 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2719 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2720 			break;
2721 		}
2722 	}
2723 
2724 	/* Then RDMA writes since reads have stronger restrictions than writes */
2725 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2726 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2727 			break;
2728 		}
2729 	}
2730 
2731 	/* Then we handle request waiting on memory buffers. */
2732 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2733 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2734 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2735 			break;
2736 		}
2737 	}
2738 
2739 	resources = rqpair->resources;
2740 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2741 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2742 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2743 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2744 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2745 
2746 		if (rqpair->srq != NULL) {
2747 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2748 			rdma_req->recv->qpair->qd++;
2749 		} else {
2750 			rqpair->qd++;
2751 		}
2752 
2753 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2754 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2755 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2756 			break;
2757 		}
2758 	}
2759 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2760 		rqpair->poller->stat.pending_free_request++;
2761 	}
2762 }
2763 
2764 static inline bool
2765 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
2766 {
2767 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
2768 	return nvmf_rdma_is_rxe_device(device) ||
2769 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
2770 }
2771 
2772 static void
2773 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2774 {
2775 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2776 			struct spdk_nvmf_rdma_transport, transport);
2777 
2778 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2779 
2780 	/* nvmr_rdma_close_qpair is not called */
2781 	if (!rqpair->to_close) {
2782 		return;
2783 	}
2784 
2785 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2786 	if (rqpair->current_send_depth != 0) {
2787 		return;
2788 	}
2789 
2790 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2791 		return;
2792 	}
2793 
2794 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
2795 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
2796 		return;
2797 	}
2798 
2799 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2800 
2801 	nvmf_rdma_qpair_destroy(rqpair);
2802 }
2803 
2804 static int
2805 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2806 {
2807 	struct spdk_nvmf_qpair		*qpair;
2808 	struct spdk_nvmf_rdma_qpair	*rqpair;
2809 
2810 	if (evt->id == NULL) {
2811 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2812 		return -1;
2813 	}
2814 
2815 	qpair = evt->id->context;
2816 	if (qpair == NULL) {
2817 		SPDK_ERRLOG("disconnect request: no active connection\n");
2818 		return -1;
2819 	}
2820 
2821 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2822 
2823 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair);
2824 
2825 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2826 
2827 	return 0;
2828 }
2829 
2830 #ifdef DEBUG
2831 static const char *CM_EVENT_STR[] = {
2832 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2833 	"RDMA_CM_EVENT_ADDR_ERROR",
2834 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2835 	"RDMA_CM_EVENT_ROUTE_ERROR",
2836 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2837 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2838 	"RDMA_CM_EVENT_CONNECT_ERROR",
2839 	"RDMA_CM_EVENT_UNREACHABLE",
2840 	"RDMA_CM_EVENT_REJECTED",
2841 	"RDMA_CM_EVENT_ESTABLISHED",
2842 	"RDMA_CM_EVENT_DISCONNECTED",
2843 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2844 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2845 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2846 	"RDMA_CM_EVENT_ADDR_CHANGE",
2847 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2848 };
2849 #endif /* DEBUG */
2850 
2851 static void
2852 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2853 				    struct spdk_nvmf_rdma_port *port)
2854 {
2855 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2856 	struct spdk_nvmf_rdma_poller		*rpoller;
2857 	struct spdk_nvmf_rdma_qpair		*rqpair;
2858 
2859 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2860 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2861 			RB_FOREACH(rqpair, qpairs_tree, &rpoller->qpairs) {
2862 				if (rqpair->listen_id == port->id) {
2863 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2864 				}
2865 			}
2866 		}
2867 	}
2868 }
2869 
2870 static bool
2871 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2872 				      struct rdma_cm_event *event)
2873 {
2874 	const struct spdk_nvme_transport_id	*trid;
2875 	struct spdk_nvmf_rdma_port		*port;
2876 	struct spdk_nvmf_rdma_transport		*rtransport;
2877 	bool					event_acked = false;
2878 
2879 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2880 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2881 		if (port->id == event->id) {
2882 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2883 			rdma_ack_cm_event(event);
2884 			event_acked = true;
2885 			trid = port->trid;
2886 			break;
2887 		}
2888 	}
2889 
2890 	if (event_acked) {
2891 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2892 
2893 		nvmf_rdma_stop_listen(transport, trid);
2894 		nvmf_rdma_listen(transport, trid, NULL);
2895 	}
2896 
2897 	return event_acked;
2898 }
2899 
2900 static void
2901 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2902 				       struct rdma_cm_event *event)
2903 {
2904 	struct spdk_nvmf_rdma_port		*port;
2905 	struct spdk_nvmf_rdma_transport		*rtransport;
2906 
2907 	port = event->id->context;
2908 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2909 
2910 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2911 
2912 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2913 
2914 	rdma_ack_cm_event(event);
2915 
2916 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2917 		;
2918 	}
2919 }
2920 
2921 static void
2922 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2923 {
2924 	struct spdk_nvmf_rdma_transport *rtransport;
2925 	struct rdma_cm_event		*event;
2926 	int				rc;
2927 	bool				event_acked;
2928 
2929 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2930 
2931 	if (rtransport->event_channel == NULL) {
2932 		return;
2933 	}
2934 
2935 	while (1) {
2936 		event_acked = false;
2937 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2938 		if (rc) {
2939 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2940 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2941 			}
2942 			break;
2943 		}
2944 
2945 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2946 
2947 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2948 
2949 		switch (event->event) {
2950 		case RDMA_CM_EVENT_ADDR_RESOLVED:
2951 		case RDMA_CM_EVENT_ADDR_ERROR:
2952 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
2953 		case RDMA_CM_EVENT_ROUTE_ERROR:
2954 			/* No action required. The target never attempts to resolve routes. */
2955 			break;
2956 		case RDMA_CM_EVENT_CONNECT_REQUEST:
2957 			rc = nvmf_rdma_connect(transport, event);
2958 			if (rc < 0) {
2959 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2960 				break;
2961 			}
2962 			break;
2963 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
2964 			/* The target never initiates a new connection. So this will not occur. */
2965 			break;
2966 		case RDMA_CM_EVENT_CONNECT_ERROR:
2967 			/* Can this happen? The docs say it can, but not sure what causes it. */
2968 			break;
2969 		case RDMA_CM_EVENT_UNREACHABLE:
2970 		case RDMA_CM_EVENT_REJECTED:
2971 			/* These only occur on the client side. */
2972 			break;
2973 		case RDMA_CM_EVENT_ESTABLISHED:
2974 			/* TODO: Should we be waiting for this event anywhere? */
2975 			break;
2976 		case RDMA_CM_EVENT_DISCONNECTED:
2977 			rc = nvmf_rdma_disconnect(event);
2978 			if (rc < 0) {
2979 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2980 				break;
2981 			}
2982 			break;
2983 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
2984 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
2985 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
2986 			 * Once these events are sent to SPDK, we should release all IB resources and
2987 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
2988 			 * ibv_destroy* functions to release user space memory allocated by IB. All kernel
2989 			 * resources are already cleaned. */
2990 			if (event->id->qp) {
2991 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
2992 				 * corresponding qpair. Otherwise the event refers to a listening device */
2993 				rc = nvmf_rdma_disconnect(event);
2994 				if (rc < 0) {
2995 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2996 					break;
2997 				}
2998 			} else {
2999 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3000 				event_acked = true;
3001 			}
3002 			break;
3003 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3004 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3005 			/* Multicast is not used */
3006 			break;
3007 		case RDMA_CM_EVENT_ADDR_CHANGE:
3008 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3009 			break;
3010 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3011 			/* For now, do nothing. The target never re-uses queue pairs. */
3012 			break;
3013 		default:
3014 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3015 			break;
3016 		}
3017 		if (!event_acked) {
3018 			rdma_ack_cm_event(event);
3019 		}
3020 	}
3021 }
3022 
3023 static void
3024 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3025 {
3026 	rqpair->last_wqe_reached = true;
3027 	nvmf_rdma_destroy_drained_qpair(rqpair);
3028 }
3029 
3030 static void
3031 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3032 {
3033 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3034 
3035 	if (event_ctx->rqpair) {
3036 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3037 		if (event_ctx->cb_fn) {
3038 			event_ctx->cb_fn(event_ctx->rqpair);
3039 		}
3040 	}
3041 	free(event_ctx);
3042 }
3043 
3044 static int
3045 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3046 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3047 {
3048 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3049 	struct spdk_thread *thr = NULL;
3050 	int rc;
3051 
3052 	if (rqpair->qpair.group) {
3053 		thr = rqpair->qpair.group->thread;
3054 	} else if (rqpair->destruct_channel) {
3055 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3056 	}
3057 
3058 	if (!thr) {
3059 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3060 		return -EINVAL;
3061 	}
3062 
3063 	ctx = calloc(1, sizeof(*ctx));
3064 	if (!ctx) {
3065 		return -ENOMEM;
3066 	}
3067 
3068 	ctx->rqpair = rqpair;
3069 	ctx->cb_fn = fn;
3070 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3071 
3072 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3073 	if (rc) {
3074 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3075 		free(ctx);
3076 	}
3077 
3078 	return rc;
3079 }
3080 
3081 static int
3082 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3083 {
3084 	int				rc;
3085 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3086 	struct ibv_async_event		event;
3087 
3088 	rc = ibv_get_async_event(device->context, &event);
3089 
3090 	if (rc) {
3091 		/* In non-blocking mode -1 means there are no events available */
3092 		return rc;
3093 	}
3094 
3095 	switch (event.event_type) {
3096 	case IBV_EVENT_QP_FATAL:
3097 		rqpair = event.element.qp->qp_context;
3098 		SPDK_ERRLOG("Fatal 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 		nvmf_rdma_update_ibv_state(rqpair);
3102 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3103 		break;
3104 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3105 		/* This event only occurs for shared receive queues. */
3106 		rqpair = event.element.qp->qp_context;
3107 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3108 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3109 		if (rc) {
3110 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3111 			rqpair->last_wqe_reached = true;
3112 		}
3113 		break;
3114 	case IBV_EVENT_SQ_DRAINED:
3115 		/* This event occurs frequently in both error and non-error states.
3116 		 * Check if the qpair is in an error state before sending a message. */
3117 		rqpair = event.element.qp->qp_context;
3118 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3119 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3120 				  (uintptr_t)rqpair, event.event_type);
3121 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3122 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3123 		}
3124 		break;
3125 	case IBV_EVENT_QP_REQ_ERR:
3126 	case IBV_EVENT_QP_ACCESS_ERR:
3127 	case IBV_EVENT_COMM_EST:
3128 	case IBV_EVENT_PATH_MIG:
3129 	case IBV_EVENT_PATH_MIG_ERR:
3130 		SPDK_NOTICELOG("Async event: %s\n",
3131 			       ibv_event_type_str(event.event_type));
3132 		rqpair = event.element.qp->qp_context;
3133 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3134 				  (uintptr_t)rqpair, event.event_type);
3135 		nvmf_rdma_update_ibv_state(rqpair);
3136 		break;
3137 	case IBV_EVENT_CQ_ERR:
3138 	case IBV_EVENT_DEVICE_FATAL:
3139 	case IBV_EVENT_PORT_ACTIVE:
3140 	case IBV_EVENT_PORT_ERR:
3141 	case IBV_EVENT_LID_CHANGE:
3142 	case IBV_EVENT_PKEY_CHANGE:
3143 	case IBV_EVENT_SM_CHANGE:
3144 	case IBV_EVENT_SRQ_ERR:
3145 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3146 	case IBV_EVENT_CLIENT_REREGISTER:
3147 	case IBV_EVENT_GID_CHANGE:
3148 	default:
3149 		SPDK_NOTICELOG("Async event: %s\n",
3150 			       ibv_event_type_str(event.event_type));
3151 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3152 		break;
3153 	}
3154 	ibv_ack_async_event(&event);
3155 
3156 	return 0;
3157 }
3158 
3159 static void
3160 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3161 {
3162 	int rc = 0;
3163 	uint32_t i = 0;
3164 
3165 	for (i = 0; i < max_events; i++) {
3166 		rc = nvmf_process_ib_event(device);
3167 		if (rc) {
3168 			break;
3169 		}
3170 	}
3171 
3172 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3173 }
3174 
3175 static int
3176 nvmf_rdma_accept(void *ctx)
3177 {
3178 	int	nfds, i = 0;
3179 	struct spdk_nvmf_transport *transport = ctx;
3180 	struct spdk_nvmf_rdma_transport *rtransport;
3181 	struct spdk_nvmf_rdma_device *device, *tmp;
3182 	uint32_t count;
3183 
3184 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3185 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3186 
3187 	if (nfds <= 0) {
3188 		return SPDK_POLLER_IDLE;
3189 	}
3190 
3191 	/* The first poll descriptor is RDMA CM event */
3192 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3193 		nvmf_process_cm_event(transport);
3194 		nfds--;
3195 	}
3196 
3197 	if (nfds == 0) {
3198 		return SPDK_POLLER_BUSY;
3199 	}
3200 
3201 	/* Second and subsequent poll descriptors are IB async events */
3202 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3203 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3204 			nvmf_process_ib_events(device, 32);
3205 			nfds--;
3206 		}
3207 	}
3208 	/* check all flagged fd's have been served */
3209 	assert(nfds == 0);
3210 
3211 	return count > 0 ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3212 }
3213 
3214 static void
3215 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3216 		     struct spdk_nvmf_ctrlr_data *cdata)
3217 {
3218 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3219 
3220 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3221 	since in-capsule data only works with NVME drives that support SGL memory layout */
3222 	if (transport->opts.dif_insert_or_strip) {
3223 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3224 	}
3225 
3226 	if (cdata->nvmf_specific.ioccsz > ((sizeof(struct spdk_nvme_cmd) + 0x1000) / 16)) {
3227 		SPDK_WARNLOG("RDMA is configured to support up to 16 SGL entries while in capsule"
3228 			     " data is greater than 4KiB.\n");
3229 		SPDK_WARNLOG("When used in conjunction with the NVMe-oF initiator from the Linux "
3230 			     "kernel between versions 5.4 and 5.12 data corruption may occur for "
3231 			     "writes that are not a multiple of 4KiB in size.\n");
3232 	}
3233 }
3234 
3235 static void
3236 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3237 		   struct spdk_nvme_transport_id *trid,
3238 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3239 {
3240 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3241 	entry->adrfam = trid->adrfam;
3242 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3243 
3244 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3245 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3246 
3247 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3248 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3249 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3250 }
3251 
3252 static void
3253 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3254 
3255 static struct spdk_nvmf_transport_poll_group *
3256 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport,
3257 			    struct spdk_nvmf_poll_group *group)
3258 {
3259 	struct spdk_nvmf_rdma_transport		*rtransport;
3260 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3261 	struct spdk_nvmf_rdma_poller		*poller;
3262 	struct spdk_nvmf_rdma_device		*device;
3263 	struct spdk_rdma_srq_init_attr		srq_init_attr;
3264 	struct spdk_nvmf_rdma_resource_opts	opts;
3265 	int					num_cqe;
3266 
3267 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3268 
3269 	rgroup = calloc(1, sizeof(*rgroup));
3270 	if (!rgroup) {
3271 		return NULL;
3272 	}
3273 
3274 	TAILQ_INIT(&rgroup->pollers);
3275 
3276 	pthread_mutex_lock(&rtransport->lock);
3277 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3278 		poller = calloc(1, sizeof(*poller));
3279 		if (!poller) {
3280 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3281 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3282 			pthread_mutex_unlock(&rtransport->lock);
3283 			return NULL;
3284 		}
3285 
3286 		poller->device = device;
3287 		poller->group = rgroup;
3288 
3289 		RB_INIT(&poller->qpairs);
3290 		STAILQ_INIT(&poller->qpairs_pending_send);
3291 		STAILQ_INIT(&poller->qpairs_pending_recv);
3292 
3293 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3294 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3295 			if ((int)rtransport->rdma_opts.max_srq_depth > device->attr.max_srq_wr) {
3296 				SPDK_WARNLOG("Requested SRQ depth %u, max supported by dev %s is %d\n",
3297 					     rtransport->rdma_opts.max_srq_depth, device->context->device->name, device->attr.max_srq_wr);
3298 			}
3299 			poller->max_srq_depth = spdk_min((int)rtransport->rdma_opts.max_srq_depth, device->attr.max_srq_wr);
3300 
3301 			device->num_srq++;
3302 			memset(&srq_init_attr, 0, sizeof(srq_init_attr));
3303 			srq_init_attr.pd = device->pd;
3304 			srq_init_attr.stats = &poller->stat.qp_stats.recv;
3305 			srq_init_attr.srq_init_attr.attr.max_wr = poller->max_srq_depth;
3306 			srq_init_attr.srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3307 			poller->srq = spdk_rdma_srq_create(&srq_init_attr);
3308 			if (!poller->srq) {
3309 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3310 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3311 				pthread_mutex_unlock(&rtransport->lock);
3312 				return NULL;
3313 			}
3314 
3315 			opts.qp = poller->srq;
3316 			opts.pd = device->pd;
3317 			opts.qpair = NULL;
3318 			opts.shared = true;
3319 			opts.max_queue_depth = poller->max_srq_depth;
3320 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3321 
3322 			poller->resources = nvmf_rdma_resources_create(&opts);
3323 			if (!poller->resources) {
3324 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3325 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3326 				pthread_mutex_unlock(&rtransport->lock);
3327 				return NULL;
3328 			}
3329 		}
3330 
3331 		/*
3332 		 * When using an srq, we can limit the completion queue at startup.
3333 		 * The following formula represents the calculation:
3334 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3335 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3336 		 */
3337 		if (poller->srq) {
3338 			num_cqe = poller->max_srq_depth * 3;
3339 		} else {
3340 			num_cqe = rtransport->rdma_opts.num_cqe;
3341 		}
3342 
3343 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3344 		if (!poller->cq) {
3345 			SPDK_ERRLOG("Unable to create completion queue\n");
3346 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3347 			pthread_mutex_unlock(&rtransport->lock);
3348 			return NULL;
3349 		}
3350 		poller->num_cqe = num_cqe;
3351 	}
3352 
3353 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3354 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3355 		rtransport->conn_sched.next_admin_pg = rgroup;
3356 		rtransport->conn_sched.next_io_pg = rgroup;
3357 	}
3358 
3359 	pthread_mutex_unlock(&rtransport->lock);
3360 	return &rgroup->group;
3361 }
3362 
3363 static struct spdk_nvmf_transport_poll_group *
3364 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3365 {
3366 	struct spdk_nvmf_rdma_transport *rtransport;
3367 	struct spdk_nvmf_rdma_poll_group **pg;
3368 	struct spdk_nvmf_transport_poll_group *result;
3369 
3370 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3371 
3372 	pthread_mutex_lock(&rtransport->lock);
3373 
3374 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3375 		pthread_mutex_unlock(&rtransport->lock);
3376 		return NULL;
3377 	}
3378 
3379 	if (qpair->qid == 0) {
3380 		pg = &rtransport->conn_sched.next_admin_pg;
3381 	} else {
3382 		pg = &rtransport->conn_sched.next_io_pg;
3383 	}
3384 
3385 	assert(*pg != NULL);
3386 
3387 	result = &(*pg)->group;
3388 
3389 	*pg = TAILQ_NEXT(*pg, link);
3390 	if (*pg == NULL) {
3391 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3392 	}
3393 
3394 	pthread_mutex_unlock(&rtransport->lock);
3395 
3396 	return result;
3397 }
3398 
3399 static void
3400 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3401 {
3402 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3403 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3404 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3405 	struct spdk_nvmf_rdma_transport		*rtransport;
3406 
3407 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3408 	if (!rgroup) {
3409 		return;
3410 	}
3411 
3412 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3413 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3414 
3415 		RB_FOREACH_SAFE(qpair, qpairs_tree, &poller->qpairs, tmp_qpair) {
3416 			nvmf_rdma_qpair_destroy(qpair);
3417 		}
3418 
3419 		if (poller->srq) {
3420 			if (poller->resources) {
3421 				nvmf_rdma_resources_destroy(poller->resources);
3422 			}
3423 			spdk_rdma_srq_destroy(poller->srq);
3424 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3425 		}
3426 
3427 		if (poller->cq) {
3428 			ibv_destroy_cq(poller->cq);
3429 		}
3430 
3431 		free(poller);
3432 	}
3433 
3434 	if (rgroup->group.transport == NULL) {
3435 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3436 		 * calls this function directly in a failure path. */
3437 		free(rgroup);
3438 		return;
3439 	}
3440 
3441 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3442 
3443 	pthread_mutex_lock(&rtransport->lock);
3444 	next_rgroup = TAILQ_NEXT(rgroup, link);
3445 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3446 	if (next_rgroup == NULL) {
3447 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3448 	}
3449 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3450 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3451 	}
3452 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3453 		rtransport->conn_sched.next_io_pg = next_rgroup;
3454 	}
3455 	pthread_mutex_unlock(&rtransport->lock);
3456 
3457 	free(rgroup);
3458 }
3459 
3460 static void
3461 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3462 {
3463 	if (rqpair->cm_id != NULL) {
3464 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3465 	}
3466 }
3467 
3468 static int
3469 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3470 			 struct spdk_nvmf_qpair *qpair)
3471 {
3472 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3473 	struct spdk_nvmf_rdma_qpair		*rqpair;
3474 	struct spdk_nvmf_rdma_device		*device;
3475 	struct spdk_nvmf_rdma_poller		*poller;
3476 	int					rc;
3477 
3478 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3479 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3480 
3481 	device = rqpair->device;
3482 
3483 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3484 		if (poller->device == device) {
3485 			break;
3486 		}
3487 	}
3488 
3489 	if (!poller) {
3490 		SPDK_ERRLOG("No poller found for device.\n");
3491 		return -1;
3492 	}
3493 
3494 	rqpair->poller = poller;
3495 	rqpair->srq = rqpair->poller->srq;
3496 
3497 	rc = nvmf_rdma_qpair_initialize(qpair);
3498 	if (rc < 0) {
3499 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3500 		rqpair->poller = NULL;
3501 		rqpair->srq = NULL;
3502 		return -1;
3503 	}
3504 
3505 	RB_INSERT(qpairs_tree, &poller->qpairs, rqpair);
3506 
3507 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3508 	if (rc) {
3509 		/* Try to reject, but we probably can't */
3510 		nvmf_rdma_qpair_reject_connection(rqpair);
3511 		return -1;
3512 	}
3513 
3514 	nvmf_rdma_update_ibv_state(rqpair);
3515 
3516 	return 0;
3517 }
3518 
3519 static int
3520 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3521 			    struct spdk_nvmf_qpair *qpair)
3522 {
3523 	struct spdk_nvmf_rdma_qpair		*rqpair;
3524 
3525 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3526 	assert(group->transport->tgt != NULL);
3527 
3528 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3529 
3530 	if (!rqpair->destruct_channel) {
3531 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3532 		return 0;
3533 	}
3534 
3535 	/* Sanity check that we get io_channel on the correct thread */
3536 	if (qpair->group) {
3537 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3538 	}
3539 
3540 	return 0;
3541 }
3542 
3543 static int
3544 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3545 {
3546 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3547 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3548 			struct spdk_nvmf_rdma_transport, transport);
3549 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3550 					      struct spdk_nvmf_rdma_qpair, qpair);
3551 
3552 	/*
3553 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3554 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3555 	 * starved of RECV structures.
3556 	 */
3557 	if (rqpair->srq && rdma_req->recv) {
3558 		int rc;
3559 		struct ibv_recv_wr *bad_recv_wr;
3560 
3561 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_req->recv->wr);
3562 		rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
3563 		if (rc) {
3564 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3565 		}
3566 	}
3567 
3568 	_nvmf_rdma_request_free(rdma_req, rtransport);
3569 	return 0;
3570 }
3571 
3572 static int
3573 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3574 {
3575 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3576 			struct spdk_nvmf_rdma_transport, transport);
3577 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3578 			struct spdk_nvmf_rdma_request, req);
3579 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3580 			struct spdk_nvmf_rdma_qpair, qpair);
3581 
3582 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3583 		/* The connection is alive, so process the request as normal */
3584 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3585 	} else {
3586 		/* The connection is dead. Move the request directly to the completed state. */
3587 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3588 	}
3589 
3590 	nvmf_rdma_request_process(rtransport, rdma_req);
3591 
3592 	return 0;
3593 }
3594 
3595 static void
3596 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
3597 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
3598 {
3599 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3600 
3601 	rqpair->to_close = true;
3602 
3603 	/* This happens only when the qpair is disconnected before
3604 	 * it is added to the poll group. Since there is no poll group,
3605 	 * the RDMA qp has not been initialized yet and the RDMA CM
3606 	 * event has not yet been acknowledged, so we need to reject it.
3607 	 */
3608 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3609 		nvmf_rdma_qpair_reject_connection(rqpair);
3610 		nvmf_rdma_qpair_destroy(rqpair);
3611 		return;
3612 	}
3613 
3614 	if (rqpair->rdma_qp) {
3615 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3616 	}
3617 
3618 	nvmf_rdma_destroy_drained_qpair(rqpair);
3619 
3620 	if (cb_fn) {
3621 		cb_fn(cb_arg);
3622 	}
3623 }
3624 
3625 static struct spdk_nvmf_rdma_qpair *
3626 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3627 {
3628 	struct spdk_nvmf_rdma_qpair find;
3629 
3630 	find.qp_num = wc->qp_num;
3631 
3632 	return RB_FIND(qpairs_tree, &rpoller->qpairs, &find);
3633 }
3634 
3635 #ifdef DEBUG
3636 static int
3637 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3638 {
3639 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3640 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3641 }
3642 #endif
3643 
3644 static void
3645 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3646 			   int rc)
3647 {
3648 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3649 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3650 
3651 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3652 	while (bad_recv_wr != NULL) {
3653 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3654 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3655 
3656 		rdma_recv->qpair->current_recv_depth++;
3657 		bad_recv_wr = bad_recv_wr->next;
3658 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3659 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3660 	}
3661 }
3662 
3663 static void
3664 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3665 {
3666 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3667 	while (bad_recv_wr != NULL) {
3668 		bad_recv_wr = bad_recv_wr->next;
3669 		rqpair->current_recv_depth++;
3670 	}
3671 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3672 }
3673 
3674 static void
3675 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3676 		     struct spdk_nvmf_rdma_poller *rpoller)
3677 {
3678 	struct spdk_nvmf_rdma_qpair	*rqpair;
3679 	struct ibv_recv_wr		*bad_recv_wr;
3680 	int				rc;
3681 
3682 	if (rpoller->srq) {
3683 		rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_recv_wr);
3684 		if (rc) {
3685 			_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3686 		}
3687 	} else {
3688 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3689 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3690 			rc = spdk_rdma_qp_flush_recv_wrs(rqpair->rdma_qp, &bad_recv_wr);
3691 			if (rc) {
3692 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3693 			}
3694 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3695 		}
3696 	}
3697 }
3698 
3699 static void
3700 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3701 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3702 {
3703 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3704 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3705 
3706 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3707 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3708 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3709 		assert(rqpair->current_send_depth > 0);
3710 		rqpair->current_send_depth--;
3711 		switch (bad_rdma_wr->type) {
3712 		case RDMA_WR_TYPE_DATA:
3713 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3714 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3715 				assert(rqpair->current_read_depth > 0);
3716 				rqpair->current_read_depth--;
3717 			}
3718 			break;
3719 		case RDMA_WR_TYPE_SEND:
3720 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3721 			break;
3722 		default:
3723 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3724 			prev_rdma_req = cur_rdma_req;
3725 			continue;
3726 		}
3727 
3728 		if (prev_rdma_req == cur_rdma_req) {
3729 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3730 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3731 			continue;
3732 		}
3733 
3734 		switch (cur_rdma_req->state) {
3735 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3736 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3737 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3738 			break;
3739 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3740 		case RDMA_REQUEST_STATE_COMPLETING:
3741 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3742 			break;
3743 		default:
3744 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3745 				    cur_rdma_req->state, rqpair);
3746 			continue;
3747 		}
3748 
3749 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3750 		prev_rdma_req = cur_rdma_req;
3751 	}
3752 
3753 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3754 		/* Disconnect the connection. */
3755 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3756 	}
3757 
3758 }
3759 
3760 static void
3761 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3762 		     struct spdk_nvmf_rdma_poller *rpoller)
3763 {
3764 	struct spdk_nvmf_rdma_qpair	*rqpair;
3765 	struct ibv_send_wr		*bad_wr = NULL;
3766 	int				rc;
3767 
3768 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3769 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3770 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3771 
3772 		/* bad wr always points to the first wr that failed. */
3773 		if (rc) {
3774 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3775 		}
3776 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3777 	}
3778 }
3779 
3780 static const char *
3781 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3782 {
3783 	switch (wr_type) {
3784 	case RDMA_WR_TYPE_RECV:
3785 		return "RECV";
3786 	case RDMA_WR_TYPE_SEND:
3787 		return "SEND";
3788 	case RDMA_WR_TYPE_DATA:
3789 		return "DATA";
3790 	default:
3791 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3792 		SPDK_UNREACHABLE();
3793 	}
3794 }
3795 
3796 static inline void
3797 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3798 {
3799 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3800 
3801 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3802 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3803 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3804 		SPDK_DEBUGLOG(rdma,
3805 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3806 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3807 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3808 	} else {
3809 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3810 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3811 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3812 	}
3813 }
3814 
3815 static int
3816 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3817 		      struct spdk_nvmf_rdma_poller *rpoller)
3818 {
3819 	struct ibv_wc wc[32];
3820 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3821 	struct spdk_nvmf_rdma_request	*rdma_req;
3822 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3823 	struct spdk_nvmf_rdma_qpair	*rqpair;
3824 	int reaped, i;
3825 	int count = 0;
3826 	bool error = false;
3827 	uint64_t poll_tsc = spdk_get_ticks();
3828 
3829 	/* Poll for completing operations. */
3830 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3831 	if (reaped < 0) {
3832 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3833 			    errno, spdk_strerror(errno));
3834 		return -1;
3835 	} else if (reaped == 0) {
3836 		rpoller->stat.idle_polls++;
3837 	}
3838 
3839 	rpoller->stat.polls++;
3840 	rpoller->stat.completions += reaped;
3841 
3842 	for (i = 0; i < reaped; i++) {
3843 
3844 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3845 
3846 		switch (rdma_wr->type) {
3847 		case RDMA_WR_TYPE_SEND:
3848 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3849 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3850 
3851 			if (!wc[i].status) {
3852 				count++;
3853 				assert(wc[i].opcode == IBV_WC_SEND);
3854 				assert(nvmf_rdma_req_is_completing(rdma_req));
3855 			}
3856 
3857 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3858 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3859 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3860 			rdma_req->num_outstanding_data_wr = 0;
3861 
3862 			nvmf_rdma_request_process(rtransport, rdma_req);
3863 			break;
3864 		case RDMA_WR_TYPE_RECV:
3865 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3866 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3867 			if (rpoller->srq != NULL) {
3868 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3869 				/* It is possible that there are still some completions for destroyed QP
3870 				 * associated with SRQ. We just ignore these late completions and re-post
3871 				 * receive WRs back to SRQ.
3872 				 */
3873 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3874 					struct ibv_recv_wr *bad_wr;
3875 					int rc;
3876 
3877 					rdma_recv->wr.next = NULL;
3878 					spdk_rdma_srq_queue_recv_wrs(rpoller->srq, &rdma_recv->wr);
3879 					rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_wr);
3880 					if (rc) {
3881 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3882 					}
3883 					continue;
3884 				}
3885 			}
3886 			rqpair = rdma_recv->qpair;
3887 
3888 			assert(rqpair != NULL);
3889 			if (!wc[i].status) {
3890 				assert(wc[i].opcode == IBV_WC_RECV);
3891 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3892 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3893 					break;
3894 				}
3895 			}
3896 
3897 			rdma_recv->wr.next = NULL;
3898 			rqpair->current_recv_depth++;
3899 			rdma_recv->receive_tsc = poll_tsc;
3900 			rpoller->stat.requests++;
3901 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3902 			break;
3903 		case RDMA_WR_TYPE_DATA:
3904 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3905 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3906 
3907 			assert(rdma_req->num_outstanding_data_wr > 0);
3908 
3909 			rqpair->current_send_depth--;
3910 			rdma_req->num_outstanding_data_wr--;
3911 			if (!wc[i].status) {
3912 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3913 				rqpair->current_read_depth--;
3914 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3915 				if (rdma_req->num_outstanding_data_wr == 0) {
3916 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3917 					nvmf_rdma_request_process(rtransport, rdma_req);
3918 				}
3919 			} else {
3920 				/* If the data transfer fails still force the queue into the error state,
3921 				 * if we were performing an RDMA_READ, we need to force the request into a
3922 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3923 				 * case, we should wait for the SEND to complete. */
3924 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3925 					rqpair->current_read_depth--;
3926 					if (rdma_req->num_outstanding_data_wr == 0) {
3927 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3928 					}
3929 				}
3930 			}
3931 			break;
3932 		default:
3933 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3934 			continue;
3935 		}
3936 
3937 		/* Handle error conditions */
3938 		if (wc[i].status) {
3939 			nvmf_rdma_update_ibv_state(rqpair);
3940 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
3941 
3942 			error = true;
3943 
3944 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3945 				/* Disconnect the connection. */
3946 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3947 			} else {
3948 				nvmf_rdma_destroy_drained_qpair(rqpair);
3949 			}
3950 			continue;
3951 		}
3952 
3953 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3954 
3955 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3956 			nvmf_rdma_destroy_drained_qpair(rqpair);
3957 		}
3958 	}
3959 
3960 	if (error == true) {
3961 		return -1;
3962 	}
3963 
3964 	/* submit outstanding work requests. */
3965 	_poller_submit_recvs(rtransport, rpoller);
3966 	_poller_submit_sends(rtransport, rpoller);
3967 
3968 	return count;
3969 }
3970 
3971 static int
3972 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3973 {
3974 	struct spdk_nvmf_rdma_transport *rtransport;
3975 	struct spdk_nvmf_rdma_poll_group *rgroup;
3976 	struct spdk_nvmf_rdma_poller	*rpoller;
3977 	int				count, rc;
3978 
3979 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3980 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3981 
3982 	count = 0;
3983 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3984 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
3985 		if (rc < 0) {
3986 			return rc;
3987 		}
3988 		count += rc;
3989 	}
3990 
3991 	return count;
3992 }
3993 
3994 static int
3995 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3996 			  struct spdk_nvme_transport_id *trid,
3997 			  bool peer)
3998 {
3999 	struct sockaddr *saddr;
4000 	uint16_t port;
4001 
4002 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
4003 
4004 	if (peer) {
4005 		saddr = rdma_get_peer_addr(id);
4006 	} else {
4007 		saddr = rdma_get_local_addr(id);
4008 	}
4009 	switch (saddr->sa_family) {
4010 	case AF_INET: {
4011 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
4012 
4013 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
4014 		inet_ntop(AF_INET, &saddr_in->sin_addr,
4015 			  trid->traddr, sizeof(trid->traddr));
4016 		if (peer) {
4017 			port = ntohs(rdma_get_dst_port(id));
4018 		} else {
4019 			port = ntohs(rdma_get_src_port(id));
4020 		}
4021 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4022 		break;
4023 	}
4024 	case AF_INET6: {
4025 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4026 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4027 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4028 			  trid->traddr, sizeof(trid->traddr));
4029 		if (peer) {
4030 			port = ntohs(rdma_get_dst_port(id));
4031 		} else {
4032 			port = ntohs(rdma_get_src_port(id));
4033 		}
4034 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4035 		break;
4036 	}
4037 	default:
4038 		return -1;
4039 
4040 	}
4041 
4042 	return 0;
4043 }
4044 
4045 static int
4046 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4047 			      struct spdk_nvme_transport_id *trid)
4048 {
4049 	struct spdk_nvmf_rdma_qpair	*rqpair;
4050 
4051 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4052 
4053 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4054 }
4055 
4056 static int
4057 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4058 			       struct spdk_nvme_transport_id *trid)
4059 {
4060 	struct spdk_nvmf_rdma_qpair	*rqpair;
4061 
4062 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4063 
4064 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4065 }
4066 
4067 static int
4068 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4069 				struct spdk_nvme_transport_id *trid)
4070 {
4071 	struct spdk_nvmf_rdma_qpair	*rqpair;
4072 
4073 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4074 
4075 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4076 }
4077 
4078 void
4079 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4080 {
4081 	g_nvmf_hooks = *hooks;
4082 }
4083 
4084 static void
4085 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4086 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4087 {
4088 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4089 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4090 
4091 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4092 
4093 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4094 }
4095 
4096 static int
4097 _nvmf_rdma_qpair_abort_request(void *ctx)
4098 {
4099 	struct spdk_nvmf_request *req = ctx;
4100 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4101 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4102 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4103 					      struct spdk_nvmf_rdma_qpair, qpair);
4104 	int rc;
4105 
4106 	spdk_poller_unregister(&req->poller);
4107 
4108 	switch (rdma_req_to_abort->state) {
4109 	case RDMA_REQUEST_STATE_EXECUTING:
4110 		rc = nvmf_ctrlr_abort_request(req);
4111 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4112 			return SPDK_POLLER_BUSY;
4113 		}
4114 		break;
4115 
4116 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4117 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4118 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4119 
4120 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4121 		break;
4122 
4123 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4124 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4125 			      spdk_nvmf_rdma_request, state_link);
4126 
4127 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4128 		break;
4129 
4130 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4131 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4132 			      spdk_nvmf_rdma_request, state_link);
4133 
4134 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4135 		break;
4136 
4137 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4138 		if (spdk_get_ticks() < req->timeout_tsc) {
4139 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4140 			return SPDK_POLLER_BUSY;
4141 		}
4142 		break;
4143 
4144 	default:
4145 		break;
4146 	}
4147 
4148 	spdk_nvmf_request_complete(req);
4149 	return SPDK_POLLER_BUSY;
4150 }
4151 
4152 static void
4153 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4154 			      struct spdk_nvmf_request *req)
4155 {
4156 	struct spdk_nvmf_rdma_qpair *rqpair;
4157 	struct spdk_nvmf_rdma_transport *rtransport;
4158 	struct spdk_nvmf_transport *transport;
4159 	uint16_t cid;
4160 	uint32_t i, max_req_count;
4161 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL, *rdma_req;
4162 
4163 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4164 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4165 	transport = &rtransport->transport;
4166 
4167 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4168 	max_req_count = rqpair->srq == NULL ? rqpair->max_queue_depth : rqpair->poller->max_srq_depth;
4169 
4170 	for (i = 0; i < max_req_count; i++) {
4171 		rdma_req = &rqpair->resources->reqs[i];
4172 		/* When SRQ == NULL, rqpair has its own requests and req.qpair pointer always points to the qpair
4173 		 * When SRQ != NULL all rqpairs share common requests and qpair pointer is assigned when we start to
4174 		 * process a request. So in both cases all requests which are not in FREE state have valid qpair ptr */
4175 		if (rdma_req->state != RDMA_REQUEST_STATE_FREE && rdma_req->req.cmd->nvme_cmd.cid == cid &&
4176 		    rdma_req->req.qpair == qpair) {
4177 			rdma_req_to_abort = rdma_req;
4178 			break;
4179 		}
4180 	}
4181 
4182 	if (rdma_req_to_abort == NULL) {
4183 		spdk_nvmf_request_complete(req);
4184 		return;
4185 	}
4186 
4187 	req->req_to_abort = &rdma_req_to_abort->req;
4188 	req->timeout_tsc = spdk_get_ticks() +
4189 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4190 	req->poller = NULL;
4191 
4192 	_nvmf_rdma_qpair_abort_request(req);
4193 }
4194 
4195 static void
4196 nvmf_rdma_poll_group_dump_stat(struct spdk_nvmf_transport_poll_group *group,
4197 			       struct spdk_json_write_ctx *w)
4198 {
4199 	struct spdk_nvmf_rdma_poll_group *rgroup;
4200 	struct spdk_nvmf_rdma_poller *rpoller;
4201 
4202 	assert(w != NULL);
4203 
4204 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4205 
4206 	spdk_json_write_named_uint64(w, "pending_data_buffer", rgroup->stat.pending_data_buffer);
4207 
4208 	spdk_json_write_named_array_begin(w, "devices");
4209 
4210 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4211 		spdk_json_write_object_begin(w);
4212 		spdk_json_write_named_string(w, "name",
4213 					     ibv_get_device_name(rpoller->device->context->device));
4214 		spdk_json_write_named_uint64(w, "polls",
4215 					     rpoller->stat.polls);
4216 		spdk_json_write_named_uint64(w, "idle_polls",
4217 					     rpoller->stat.idle_polls);
4218 		spdk_json_write_named_uint64(w, "completions",
4219 					     rpoller->stat.completions);
4220 		spdk_json_write_named_uint64(w, "requests",
4221 					     rpoller->stat.requests);
4222 		spdk_json_write_named_uint64(w, "request_latency",
4223 					     rpoller->stat.request_latency);
4224 		spdk_json_write_named_uint64(w, "pending_free_request",
4225 					     rpoller->stat.pending_free_request);
4226 		spdk_json_write_named_uint64(w, "pending_rdma_read",
4227 					     rpoller->stat.pending_rdma_read);
4228 		spdk_json_write_named_uint64(w, "pending_rdma_write",
4229 					     rpoller->stat.pending_rdma_write);
4230 		spdk_json_write_named_uint64(w, "total_send_wrs",
4231 					     rpoller->stat.qp_stats.send.num_submitted_wrs);
4232 		spdk_json_write_named_uint64(w, "send_doorbell_updates",
4233 					     rpoller->stat.qp_stats.send.doorbell_updates);
4234 		spdk_json_write_named_uint64(w, "total_recv_wrs",
4235 					     rpoller->stat.qp_stats.recv.num_submitted_wrs);
4236 		spdk_json_write_named_uint64(w, "recv_doorbell_updates",
4237 					     rpoller->stat.qp_stats.recv.doorbell_updates);
4238 		spdk_json_write_object_end(w);
4239 	}
4240 
4241 	spdk_json_write_array_end(w);
4242 }
4243 
4244 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4245 	.name = "RDMA",
4246 	.type = SPDK_NVME_TRANSPORT_RDMA,
4247 	.opts_init = nvmf_rdma_opts_init,
4248 	.create = nvmf_rdma_create,
4249 	.dump_opts = nvmf_rdma_dump_opts,
4250 	.destroy = nvmf_rdma_destroy,
4251 
4252 	.listen = nvmf_rdma_listen,
4253 	.stop_listen = nvmf_rdma_stop_listen,
4254 	.cdata_init = nvmf_rdma_cdata_init,
4255 
4256 	.listener_discover = nvmf_rdma_discover,
4257 
4258 	.poll_group_create = nvmf_rdma_poll_group_create,
4259 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4260 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4261 	.poll_group_add = nvmf_rdma_poll_group_add,
4262 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4263 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4264 
4265 	.req_free = nvmf_rdma_request_free,
4266 	.req_complete = nvmf_rdma_request_complete,
4267 
4268 	.qpair_fini = nvmf_rdma_close_qpair,
4269 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4270 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4271 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4272 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4273 
4274 	.poll_group_dump_stat = nvmf_rdma_poll_group_dump_stat,
4275 };
4276 
4277 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4278 SPDK_LOG_REGISTER_COMPONENT(rdma)
4279