xref: /spdk/lib/nvmf/rdma.c (revision 800b18d028b95f92738315af634b8101a4c84031)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019, 2020 Mellanox Technologies LTD. All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include "spdk/config.h"
37 #include "spdk/thread.h"
38 #include "spdk/likely.h"
39 #include "spdk/nvmf_transport.h"
40 #include "spdk/string.h"
41 #include "spdk/trace.h"
42 #include "spdk/util.h"
43 
44 #include "spdk_internal/assert.h"
45 #include "spdk_internal/log.h"
46 #include "spdk_internal/rdma.h"
47 
48 #include "nvmf_internal.h"
49 
50 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
51 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
52 
53 /*
54  RDMA Connection Resource Defaults
55  */
56 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
57 #define NVMF_DEFAULT_RSP_SGE		1
58 #define NVMF_DEFAULT_RX_SGE		2
59 
60 /* The RDMA completion queue size */
61 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
62 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
63 
64 /* Timeout for destroying defunct rqpairs */
65 #define NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US	4000000
66 
67 static int g_spdk_nvmf_ibv_query_mask =
68 	IBV_QP_STATE |
69 	IBV_QP_PKEY_INDEX |
70 	IBV_QP_PORT |
71 	IBV_QP_ACCESS_FLAGS |
72 	IBV_QP_AV |
73 	IBV_QP_PATH_MTU |
74 	IBV_QP_DEST_QPN |
75 	IBV_QP_RQ_PSN |
76 	IBV_QP_MAX_DEST_RD_ATOMIC |
77 	IBV_QP_MIN_RNR_TIMER |
78 	IBV_QP_SQ_PSN |
79 	IBV_QP_TIMEOUT |
80 	IBV_QP_RETRY_CNT |
81 	IBV_QP_RNR_RETRY |
82 	IBV_QP_MAX_QP_RD_ATOMIC;
83 
84 enum spdk_nvmf_rdma_request_state {
85 	/* The request is not currently in use */
86 	RDMA_REQUEST_STATE_FREE = 0,
87 
88 	/* Initial state when request first received */
89 	RDMA_REQUEST_STATE_NEW,
90 
91 	/* The request is queued until a data buffer is available. */
92 	RDMA_REQUEST_STATE_NEED_BUFFER,
93 
94 	/* The request is waiting on RDMA queue depth availability
95 	 * to transfer data from the host to the controller.
96 	 */
97 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
98 
99 	/* The request is currently transferring data from the host to the controller. */
100 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
101 
102 	/* The request is ready to execute at the block device */
103 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
104 
105 	/* The request is currently executing at the block device */
106 	RDMA_REQUEST_STATE_EXECUTING,
107 
108 	/* The request finished executing at the block device */
109 	RDMA_REQUEST_STATE_EXECUTED,
110 
111 	/* The request is waiting on RDMA queue depth availability
112 	 * to transfer data from the controller to the host.
113 	 */
114 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
115 
116 	/* The request is ready to send a completion */
117 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
118 
119 	/* The request is currently transferring data from the controller to the host. */
120 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
121 
122 	/* The request currently has an outstanding completion without an
123 	 * associated data transfer.
124 	 */
125 	RDMA_REQUEST_STATE_COMPLETING,
126 
127 	/* The request completed and can be marked free. */
128 	RDMA_REQUEST_STATE_COMPLETED,
129 
130 	/* Terminator */
131 	RDMA_REQUEST_NUM_STATES,
132 };
133 
134 #define OBJECT_NVMF_RDMA_IO				0x40
135 
136 #define TRACE_GROUP_NVMF_RDMA				0x4
137 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
138 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
139 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
140 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
141 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
142 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
143 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
144 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
145 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
146 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
147 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
148 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
149 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
150 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
151 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
152 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
153 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
154 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
155 
156 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
157 {
158 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
159 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
160 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
161 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
163 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
164 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
165 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
166 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
167 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
170 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
173 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
175 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
176 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
178 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
179 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
180 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
181 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
182 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
183 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
184 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
185 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
186 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
187 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
188 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
189 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
190 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
191 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
192 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
193 
194 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
195 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
196 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
197 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
198 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
199 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
200 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
201 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
202 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
203 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
204 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
205 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
206 }
207 
208 enum spdk_nvmf_rdma_wr_type {
209 	RDMA_WR_TYPE_RECV,
210 	RDMA_WR_TYPE_SEND,
211 	RDMA_WR_TYPE_DATA,
212 };
213 
214 struct spdk_nvmf_rdma_wr {
215 	enum spdk_nvmf_rdma_wr_type	type;
216 };
217 
218 /* This structure holds commands as they are received off the wire.
219  * It must be dynamically paired with a full request object
220  * (spdk_nvmf_rdma_request) to service a request. It is separate
221  * from the request because RDMA does not appear to order
222  * completions, so occasionally we'll get a new incoming
223  * command when there aren't any free request objects.
224  */
225 struct spdk_nvmf_rdma_recv {
226 	struct ibv_recv_wr			wr;
227 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
228 
229 	struct spdk_nvmf_rdma_qpair		*qpair;
230 
231 	/* In-capsule data buffer */
232 	uint8_t					*buf;
233 
234 	struct spdk_nvmf_rdma_wr		rdma_wr;
235 	uint64_t				receive_tsc;
236 
237 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
238 };
239 
240 struct spdk_nvmf_rdma_request_data {
241 	struct spdk_nvmf_rdma_wr	rdma_wr;
242 	struct ibv_send_wr		wr;
243 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
244 };
245 
246 struct spdk_nvmf_rdma_request {
247 	struct spdk_nvmf_request		req;
248 
249 	enum spdk_nvmf_rdma_request_state	state;
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 enum spdk_nvmf_rdma_qpair_disconnect_flags {
270 	RDMA_QP_DISCONNECTING		= 1,
271 	RDMA_QP_RECV_DRAINED		= 1 << 1,
272 	RDMA_QP_SEND_DRAINED		= 1 << 2
273 };
274 
275 struct spdk_nvmf_rdma_resource_opts {
276 	struct spdk_nvmf_rdma_qpair	*qpair;
277 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
278 	void				*qp;
279 	struct ibv_pd			*pd;
280 	uint32_t			max_queue_depth;
281 	uint32_t			in_capsule_data_size;
282 	bool				shared;
283 };
284 
285 struct spdk_nvmf_send_wr_list {
286 	struct ibv_send_wr	*first;
287 	struct ibv_send_wr	*last;
288 };
289 
290 struct spdk_nvmf_recv_wr_list {
291 	struct ibv_recv_wr	*first;
292 	struct ibv_recv_wr	*last;
293 };
294 
295 struct spdk_nvmf_rdma_resources {
296 	/* Array of size "max_queue_depth" containing RDMA requests. */
297 	struct spdk_nvmf_rdma_request		*reqs;
298 
299 	/* Array of size "max_queue_depth" containing RDMA recvs. */
300 	struct spdk_nvmf_rdma_recv		*recvs;
301 
302 	/* Array of size "max_queue_depth" containing 64 byte capsules
303 	 * used for receive.
304 	 */
305 	union nvmf_h2c_msg			*cmds;
306 	struct ibv_mr				*cmds_mr;
307 
308 	/* Array of size "max_queue_depth" containing 16 byte completions
309 	 * to be sent back to the user.
310 	 */
311 	union nvmf_c2h_msg			*cpls;
312 	struct ibv_mr				*cpls_mr;
313 
314 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
315 	 * buffers to be used for in capsule data.
316 	 */
317 	void					*bufs;
318 	struct ibv_mr				*bufs_mr;
319 
320 	/* The list of pending recvs to transfer */
321 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
322 
323 	/* Receives that are waiting for a request object */
324 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
325 
326 	/* Queue to track free requests */
327 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
328 };
329 
330 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
331 
332 struct spdk_nvmf_rdma_ibv_event_ctx {
333 	struct spdk_nvmf_rdma_qpair			*rqpair;
334 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
335 	/* Link to other ibv events associated with this qpair */
336 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
337 };
338 
339 struct spdk_nvmf_rdma_qpair {
340 	struct spdk_nvmf_qpair			qpair;
341 
342 	struct spdk_nvmf_rdma_device		*device;
343 	struct spdk_nvmf_rdma_poller		*poller;
344 
345 	struct spdk_rdma_qp			*rdma_qp;
346 	struct rdma_cm_id			*cm_id;
347 	struct ibv_srq				*srq;
348 	struct rdma_cm_id			*listen_id;
349 
350 	/* The maximum number of I/O outstanding on this connection at one time */
351 	uint16_t				max_queue_depth;
352 
353 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
354 	uint16_t				max_read_depth;
355 
356 	/* The maximum number of RDMA SEND operations at one time */
357 	uint32_t				max_send_depth;
358 
359 	/* The current number of outstanding WRs from this qpair's
360 	 * recv queue. Should not exceed device->attr.max_queue_depth.
361 	 */
362 	uint16_t				current_recv_depth;
363 
364 	/* The current number of active RDMA READ operations */
365 	uint16_t				current_read_depth;
366 
367 	/* The current number of posted WRs from this qpair's
368 	 * send queue. Should not exceed max_send_depth.
369 	 */
370 	uint32_t				current_send_depth;
371 
372 	/* The maximum number of SGEs per WR on the send queue */
373 	uint32_t				max_send_sge;
374 
375 	/* The maximum number of SGEs per WR on the recv queue */
376 	uint32_t				max_recv_sge;
377 
378 	struct spdk_nvmf_rdma_resources		*resources;
379 
380 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
381 
382 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
383 
384 	/* Number of requests not in the free state */
385 	uint32_t				qd;
386 
387 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
388 
389 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
390 
391 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
392 
393 	/* IBV queue pair attributes: they are used to manage
394 	 * qp state and recover from errors.
395 	 */
396 	enum ibv_qp_state			ibv_state;
397 
398 	uint32_t				disconnect_flags;
399 
400 	/* Poller registered in case the qpair doesn't properly
401 	 * complete the qpair destruct process and becomes defunct.
402 	 */
403 
404 	struct spdk_poller			*destruct_poller;
405 
406 	/* List of ibv async events */
407 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
408 
409 	/* There are several ways a disconnect can start on a qpair
410 	 * and they are not all mutually exclusive. It is important
411 	 * that we only initialize one of these paths.
412 	 */
413 	bool					disconnect_started;
414 	/* Lets us know that we have received the last_wqe event. */
415 	bool					last_wqe_reached;
416 };
417 
418 struct spdk_nvmf_rdma_poller_stat {
419 	uint64_t				completions;
420 	uint64_t				polls;
421 	uint64_t				requests;
422 	uint64_t				request_latency;
423 	uint64_t				pending_free_request;
424 	uint64_t				pending_rdma_read;
425 	uint64_t				pending_rdma_write;
426 };
427 
428 struct spdk_nvmf_rdma_poller {
429 	struct spdk_nvmf_rdma_device		*device;
430 	struct spdk_nvmf_rdma_poll_group	*group;
431 
432 	int					num_cqe;
433 	int					required_num_wr;
434 	struct ibv_cq				*cq;
435 
436 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
437 	uint16_t				max_srq_depth;
438 
439 	/* Shared receive queue */
440 	struct ibv_srq				*srq;
441 
442 	struct spdk_nvmf_rdma_resources		*resources;
443 	struct spdk_nvmf_rdma_poller_stat	stat;
444 
445 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
446 
447 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
448 
449 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
450 
451 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
452 };
453 
454 struct spdk_nvmf_rdma_poll_group_stat {
455 	uint64_t				pending_data_buffer;
456 };
457 
458 struct spdk_nvmf_rdma_poll_group {
459 	struct spdk_nvmf_transport_poll_group		group;
460 	struct spdk_nvmf_rdma_poll_group_stat		stat;
461 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
462 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
463 	/*
464 	 * buffers which are split across multiple RDMA
465 	 * memory regions cannot be used by this transport.
466 	 */
467 	STAILQ_HEAD(, spdk_nvmf_transport_pg_cache_buf)	retired_bufs;
468 };
469 
470 struct spdk_nvmf_rdma_conn_sched {
471 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
472 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
473 };
474 
475 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
476 struct spdk_nvmf_rdma_device {
477 	struct ibv_device_attr			attr;
478 	struct ibv_context			*context;
479 
480 	struct spdk_mem_map			*map;
481 	struct ibv_pd				*pd;
482 
483 	int					num_srq;
484 
485 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
486 };
487 
488 struct spdk_nvmf_rdma_port {
489 	const struct spdk_nvme_transport_id	*trid;
490 	struct rdma_cm_id			*id;
491 	struct spdk_nvmf_rdma_device		*device;
492 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
493 };
494 
495 struct spdk_nvmf_rdma_transport {
496 	struct spdk_nvmf_transport	transport;
497 
498 	struct spdk_nvmf_rdma_conn_sched conn_sched;
499 
500 	struct rdma_event_channel	*event_channel;
501 
502 	struct spdk_mempool		*data_wr_pool;
503 
504 	pthread_mutex_t			lock;
505 
506 	/* fields used to poll RDMA/IB events */
507 	nfds_t			npoll_fds;
508 	struct pollfd		*poll_fds;
509 
510 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
511 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
512 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
513 };
514 
515 static inline void
516 nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair);
517 
518 static bool
519 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
520 			  struct spdk_nvmf_rdma_request *rdma_req);
521 
522 static inline int
523 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
524 {
525 	switch (state) {
526 	case IBV_QPS_RESET:
527 	case IBV_QPS_INIT:
528 	case IBV_QPS_RTR:
529 	case IBV_QPS_RTS:
530 	case IBV_QPS_SQD:
531 	case IBV_QPS_SQE:
532 	case IBV_QPS_ERR:
533 		return 0;
534 	default:
535 		return -1;
536 	}
537 }
538 
539 static inline enum spdk_nvme_media_error_status_code
540 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
541 	enum spdk_nvme_media_error_status_code result;
542 	switch (err_type)
543 	{
544 	case SPDK_DIF_REFTAG_ERROR:
545 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
546 		break;
547 	case SPDK_DIF_APPTAG_ERROR:
548 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
549 		break;
550 	case SPDK_DIF_GUARD_ERROR:
551 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
552 		break;
553 	default:
554 		SPDK_UNREACHABLE();
555 	}
556 
557 	return result;
558 }
559 
560 static enum ibv_qp_state
561 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
562 	enum ibv_qp_state old_state, new_state;
563 	struct ibv_qp_attr qp_attr;
564 	struct ibv_qp_init_attr init_attr;
565 	int rc;
566 
567 	old_state = rqpair->ibv_state;
568 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
569 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
570 
571 	if (rc)
572 	{
573 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
574 		return IBV_QPS_ERR + 1;
575 	}
576 
577 	new_state = qp_attr.qp_state;
578 	rqpair->ibv_state = new_state;
579 	qp_attr.ah_attr.port_num = qp_attr.port_num;
580 
581 	rc = nvmf_rdma_check_ibv_state(new_state);
582 	if (rc)
583 	{
584 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
585 		/*
586 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
587 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
588 		 */
589 		return IBV_QPS_ERR + 1;
590 	}
591 
592 	if (old_state != new_state)
593 	{
594 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
595 				  (uintptr_t)rqpair->cm_id, new_state);
596 	}
597 	return new_state;
598 }
599 
600 static void
601 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
602 			    struct spdk_nvmf_rdma_transport *rtransport)
603 {
604 	struct spdk_nvmf_rdma_request_data	*data_wr;
605 	struct ibv_send_wr			*next_send_wr;
606 	uint64_t				req_wrid;
607 
608 	rdma_req->num_outstanding_data_wr = 0;
609 	data_wr = &rdma_req->data;
610 	req_wrid = data_wr->wr.wr_id;
611 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
612 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
613 		data_wr->wr.num_sge = 0;
614 		next_send_wr = data_wr->wr.next;
615 		if (data_wr != &rdma_req->data) {
616 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
617 		}
618 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
619 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
620 	}
621 }
622 
623 static void
624 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
625 {
626 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
627 	if (req->req.cmd) {
628 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
629 	}
630 	if (req->recv) {
631 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
632 	}
633 }
634 
635 static void
636 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
637 {
638 	int i;
639 
640 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
641 	for (i = 0; i < rqpair->max_queue_depth; i++) {
642 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
643 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
644 		}
645 	}
646 }
647 
648 static void
649 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
650 {
651 	if (resources->cmds_mr) {
652 		ibv_dereg_mr(resources->cmds_mr);
653 	}
654 
655 	if (resources->cpls_mr) {
656 		ibv_dereg_mr(resources->cpls_mr);
657 	}
658 
659 	if (resources->bufs_mr) {
660 		ibv_dereg_mr(resources->bufs_mr);
661 	}
662 
663 	spdk_free(resources->cmds);
664 	spdk_free(resources->cpls);
665 	spdk_free(resources->bufs);
666 	free(resources->reqs);
667 	free(resources->recvs);
668 	free(resources);
669 }
670 
671 
672 static struct spdk_nvmf_rdma_resources *
673 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
674 {
675 	struct spdk_nvmf_rdma_resources	*resources;
676 	struct spdk_nvmf_rdma_request	*rdma_req;
677 	struct spdk_nvmf_rdma_recv	*rdma_recv;
678 	struct ibv_qp			*qp;
679 	struct ibv_srq			*srq;
680 	uint32_t			i;
681 	int				rc;
682 
683 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
684 	if (!resources) {
685 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
686 		return NULL;
687 	}
688 
689 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
690 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
691 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
692 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
693 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
694 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
695 
696 	if (opts->in_capsule_data_size > 0) {
697 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
698 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
699 					       SPDK_MALLOC_DMA);
700 	}
701 
702 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
703 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
704 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
705 		goto cleanup;
706 	}
707 
708 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
709 					opts->max_queue_depth * sizeof(*resources->cmds),
710 					IBV_ACCESS_LOCAL_WRITE);
711 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
712 					opts->max_queue_depth * sizeof(*resources->cpls),
713 					0);
714 
715 	if (opts->in_capsule_data_size) {
716 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
717 						opts->max_queue_depth *
718 						opts->in_capsule_data_size,
719 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
720 	}
721 
722 	if (!resources->cmds_mr || !resources->cpls_mr ||
723 	    (opts->in_capsule_data_size &&
724 	     !resources->bufs_mr)) {
725 		goto cleanup;
726 	}
727 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
728 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
729 		      resources->cmds_mr->lkey);
730 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
731 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
732 		      resources->cpls_mr->lkey);
733 	if (resources->bufs && resources->bufs_mr) {
734 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
735 			      resources->bufs, opts->max_queue_depth *
736 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
737 	}
738 
739 	/* Initialize queues */
740 	STAILQ_INIT(&resources->incoming_queue);
741 	STAILQ_INIT(&resources->free_queue);
742 
743 	for (i = 0; i < opts->max_queue_depth; i++) {
744 		struct ibv_recv_wr *bad_wr = NULL;
745 
746 		rdma_recv = &resources->recvs[i];
747 		rdma_recv->qpair = opts->qpair;
748 
749 		/* Set up memory to receive commands */
750 		if (resources->bufs) {
751 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
752 						  opts->in_capsule_data_size));
753 		}
754 
755 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
756 
757 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
758 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
759 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
760 		rdma_recv->wr.num_sge = 1;
761 
762 		if (rdma_recv->buf && resources->bufs_mr) {
763 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
764 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
765 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
766 			rdma_recv->wr.num_sge++;
767 		}
768 
769 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
770 		rdma_recv->wr.sg_list = rdma_recv->sgl;
771 		if (opts->shared) {
772 			srq = (struct ibv_srq *)opts->qp;
773 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
774 		} else {
775 			qp = (struct ibv_qp *)opts->qp;
776 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
777 		}
778 		if (rc) {
779 			goto cleanup;
780 		}
781 	}
782 
783 	for (i = 0; i < opts->max_queue_depth; i++) {
784 		rdma_req = &resources->reqs[i];
785 
786 		if (opts->qpair != NULL) {
787 			rdma_req->req.qpair = &opts->qpair->qpair;
788 		} else {
789 			rdma_req->req.qpair = NULL;
790 		}
791 		rdma_req->req.cmd = NULL;
792 
793 		/* Set up memory to send responses */
794 		rdma_req->req.rsp = &resources->cpls[i];
795 
796 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
797 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
798 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
799 
800 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
801 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
802 		rdma_req->rsp.wr.next = NULL;
803 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
804 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
805 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
806 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
807 
808 		/* Set up memory for data buffers */
809 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
810 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
811 		rdma_req->data.wr.next = NULL;
812 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
813 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
814 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
815 
816 		/* Initialize request state to FREE */
817 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
818 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
819 	}
820 
821 	return resources;
822 
823 cleanup:
824 	nvmf_rdma_resources_destroy(resources);
825 	return NULL;
826 }
827 
828 static void
829 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
830 {
831 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
832 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
833 		ctx->rqpair = NULL;
834 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
835 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
836 	}
837 }
838 
839 static void
840 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
841 {
842 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
843 	struct ibv_recv_wr		*bad_recv_wr = NULL;
844 	int				rc;
845 
846 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
847 
848 	spdk_poller_unregister(&rqpair->destruct_poller);
849 
850 	if (rqpair->qd != 0) {
851 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
852 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
853 				struct spdk_nvmf_rdma_transport, transport);
854 		struct spdk_nvmf_rdma_request *req;
855 		uint32_t i, max_req_count = 0;
856 
857 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
858 
859 		if (rqpair->srq == NULL) {
860 			nvmf_rdma_dump_qpair_contents(rqpair);
861 			max_req_count = rqpair->max_queue_depth;
862 		} else if (rqpair->poller && rqpair->resources) {
863 			max_req_count = rqpair->poller->max_srq_depth;
864 		}
865 
866 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Release incomplete requests\n");
867 		for (i = 0; i < max_req_count; i++) {
868 			req = &rqpair->resources->reqs[i];
869 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
870 				/* nvmf_rdma_request_process checks qpair ibv and internal state
871 				 * and completes a request */
872 				nvmf_rdma_request_process(rtransport, req);
873 			}
874 		}
875 		assert(rqpair->qd == 0);
876 	}
877 
878 	if (rqpair->poller) {
879 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
880 
881 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
882 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
883 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
884 				if (rqpair == rdma_recv->qpair) {
885 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
886 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
887 					if (rc) {
888 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
889 					}
890 				}
891 			}
892 		}
893 	}
894 
895 	if (rqpair->cm_id) {
896 		if (rqpair->rdma_qp != NULL) {
897 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
898 			rqpair->rdma_qp = NULL;
899 		}
900 		rdma_destroy_id(rqpair->cm_id);
901 
902 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
903 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
904 		}
905 	}
906 
907 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
908 		nvmf_rdma_resources_destroy(rqpair->resources);
909 	}
910 
911 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
912 
913 	free(rqpair);
914 }
915 
916 static int
917 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
918 {
919 	struct spdk_nvmf_rdma_poller	*rpoller;
920 	int				rc, num_cqe, required_num_wr;
921 
922 	/* Enlarge CQ size dynamically */
923 	rpoller = rqpair->poller;
924 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
925 	num_cqe = rpoller->num_cqe;
926 	if (num_cqe < required_num_wr) {
927 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
928 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
929 	}
930 
931 	if (rpoller->num_cqe != num_cqe) {
932 		if (required_num_wr > device->attr.max_cqe) {
933 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
934 				    required_num_wr, device->attr.max_cqe);
935 			return -1;
936 		}
937 
938 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
939 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
940 		if (rc) {
941 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
942 			return -1;
943 		}
944 
945 		rpoller->num_cqe = num_cqe;
946 	}
947 
948 	rpoller->required_num_wr = required_num_wr;
949 	return 0;
950 }
951 
952 static int
953 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
954 {
955 	struct spdk_nvmf_rdma_qpair		*rqpair;
956 	struct spdk_nvmf_rdma_transport		*rtransport;
957 	struct spdk_nvmf_transport		*transport;
958 	struct spdk_nvmf_rdma_resource_opts	opts;
959 	struct spdk_nvmf_rdma_device		*device;
960 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
961 
962 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
963 	device = rqpair->device;
964 
965 	qp_init_attr.qp_context	= rqpair;
966 	qp_init_attr.pd		= device->pd;
967 	qp_init_attr.send_cq	= rqpair->poller->cq;
968 	qp_init_attr.recv_cq	= rqpair->poller->cq;
969 
970 	if (rqpair->srq) {
971 		qp_init_attr.srq		= rqpair->srq;
972 	} else {
973 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
974 	}
975 
976 	/* SEND, READ, and WRITE operations */
977 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
978 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
979 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
980 
981 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
982 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
983 		goto error;
984 	}
985 
986 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
987 	if (!rqpair->rdma_qp) {
988 		goto error;
989 	}
990 
991 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
992 					  qp_init_attr.cap.max_send_wr);
993 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
994 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
995 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
996 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
997 
998 	if (rqpair->poller->srq == NULL) {
999 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1000 		transport = &rtransport->transport;
1001 
1002 		opts.qp = rqpair->rdma_qp->qp;
1003 		opts.pd = rqpair->cm_id->pd;
1004 		opts.qpair = rqpair;
1005 		opts.shared = false;
1006 		opts.max_queue_depth = rqpair->max_queue_depth;
1007 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1008 
1009 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1010 
1011 		if (!rqpair->resources) {
1012 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1013 			rdma_destroy_qp(rqpair->cm_id);
1014 			goto error;
1015 		}
1016 	} else {
1017 		rqpair->resources = rqpair->poller->resources;
1018 	}
1019 
1020 	rqpair->current_recv_depth = 0;
1021 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1022 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1023 
1024 	return 0;
1025 
1026 error:
1027 	rdma_destroy_id(rqpair->cm_id);
1028 	rqpair->cm_id = NULL;
1029 	return -1;
1030 }
1031 
1032 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1033 /* This function accepts either a single wr or the first wr in a linked list. */
1034 static void
1035 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1036 {
1037 	struct ibv_recv_wr *last;
1038 
1039 	last = first;
1040 	while (last->next != NULL) {
1041 		last = last->next;
1042 	}
1043 
1044 	if (rqpair->resources->recvs_to_post.first == NULL) {
1045 		rqpair->resources->recvs_to_post.first = first;
1046 		rqpair->resources->recvs_to_post.last = last;
1047 		if (rqpair->srq == NULL) {
1048 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1049 		}
1050 	} else {
1051 		rqpair->resources->recvs_to_post.last->next = first;
1052 		rqpair->resources->recvs_to_post.last = last;
1053 	}
1054 }
1055 
1056 static int
1057 request_transfer_in(struct spdk_nvmf_request *req)
1058 {
1059 	struct spdk_nvmf_rdma_request	*rdma_req;
1060 	struct spdk_nvmf_qpair		*qpair;
1061 	struct spdk_nvmf_rdma_qpair	*rqpair;
1062 
1063 	qpair = req->qpair;
1064 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1065 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1066 
1067 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1068 	assert(rdma_req != NULL);
1069 
1070 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1071 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1072 	}
1073 
1074 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1075 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1076 	return 0;
1077 }
1078 
1079 static int
1080 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1081 {
1082 	int				num_outstanding_data_wr = 0;
1083 	struct spdk_nvmf_rdma_request	*rdma_req;
1084 	struct spdk_nvmf_qpair		*qpair;
1085 	struct spdk_nvmf_rdma_qpair	*rqpair;
1086 	struct spdk_nvme_cpl		*rsp;
1087 	struct ibv_send_wr		*first = NULL;
1088 
1089 	*data_posted = 0;
1090 	qpair = req->qpair;
1091 	rsp = &req->rsp->nvme_cpl;
1092 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1093 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1094 
1095 	/* Advance our sq_head pointer */
1096 	if (qpair->sq_head == qpair->sq_head_max) {
1097 		qpair->sq_head = 0;
1098 	} else {
1099 		qpair->sq_head++;
1100 	}
1101 	rsp->sqhd = qpair->sq_head;
1102 
1103 	/* queue the capsule for the recv buffer */
1104 	assert(rdma_req->recv != NULL);
1105 
1106 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1107 
1108 	rdma_req->recv = NULL;
1109 	assert(rqpair->current_recv_depth > 0);
1110 	rqpair->current_recv_depth--;
1111 
1112 	/* Build the response which consists of optional
1113 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1114 	 * containing the response.
1115 	 */
1116 	first = &rdma_req->rsp.wr;
1117 
1118 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1119 		/* On failure, data was not read from the controller. So clear the
1120 		 * number of outstanding data WRs to zero.
1121 		 */
1122 		rdma_req->num_outstanding_data_wr = 0;
1123 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1124 		first = &rdma_req->data.wr;
1125 		*data_posted = 1;
1126 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1127 	}
1128 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1129 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1130 	}
1131 
1132 	/* +1 for the rsp wr */
1133 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1134 
1135 	return 0;
1136 }
1137 
1138 static int
1139 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1140 {
1141 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1142 	struct rdma_conn_param				ctrlr_event_data = {};
1143 	int						rc;
1144 
1145 	accept_data.recfmt = 0;
1146 	accept_data.crqsize = rqpair->max_queue_depth;
1147 
1148 	ctrlr_event_data.private_data = &accept_data;
1149 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1150 	if (id->ps == RDMA_PS_TCP) {
1151 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1152 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1153 	}
1154 
1155 	/* Configure infinite retries for the initiator side qpair.
1156 	 * When using a shared receive queue on the target side,
1157 	 * we need to pass this value to the initiator to prevent the
1158 	 * initiator side NIC from completing SEND requests back to the
1159 	 * initiator with status rnr_retry_count_exceeded. */
1160 	if (rqpair->srq != NULL) {
1161 		ctrlr_event_data.rnr_retry_count = 0x7;
1162 	}
1163 
1164 	/* When qpair is created without use of rdma cm API, an additional
1165 	 * information must be provided to initiator in the connection response:
1166 	 * whether qpair is using SRQ and its qp_num
1167 	 * Fields below are ignored by rdma cm if qpair has been
1168 	 * created using rdma cm API. */
1169 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1170 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1171 
1172 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1173 	if (rc) {
1174 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1175 	} else {
1176 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
1177 	}
1178 
1179 	return rc;
1180 }
1181 
1182 static void
1183 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1184 {
1185 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1186 
1187 	rej_data.recfmt = 0;
1188 	rej_data.sts = error;
1189 
1190 	rdma_reject(id, &rej_data, sizeof(rej_data));
1191 }
1192 
1193 static int
1194 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1195 {
1196 	struct spdk_nvmf_rdma_transport *rtransport;
1197 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1198 	struct spdk_nvmf_rdma_port	*port;
1199 	struct rdma_conn_param		*rdma_param = NULL;
1200 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1201 	uint16_t			max_queue_depth;
1202 	uint16_t			max_read_depth;
1203 
1204 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1205 
1206 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1207 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1208 
1209 	rdma_param = &event->param.conn;
1210 	if (rdma_param->private_data == NULL ||
1211 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1212 		SPDK_ERRLOG("connect request: no private data provided\n");
1213 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1214 		return -1;
1215 	}
1216 
1217 	private_data = rdma_param->private_data;
1218 	if (private_data->recfmt != 0) {
1219 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1220 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1221 		return -1;
1222 	}
1223 
1224 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1225 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1226 
1227 	port = event->listen_id->context;
1228 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1229 		      event->listen_id, event->listen_id->verbs, port);
1230 
1231 	/* Figure out the supported queue depth. This is a multi-step process
1232 	 * that takes into account hardware maximums, host provided values,
1233 	 * and our target's internal memory limits */
1234 
1235 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1236 
1237 	/* Start with the maximum queue depth allowed by the target */
1238 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1239 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1240 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1241 		      rtransport->transport.opts.max_queue_depth);
1242 
1243 	/* Next check the local NIC's hardware limitations */
1244 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1245 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1246 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1247 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1248 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1249 
1250 	/* Next check the remote NIC's hardware limitations */
1251 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1252 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1253 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1254 	if (rdma_param->initiator_depth > 0) {
1255 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1256 	}
1257 
1258 	/* Finally check for the host software requested values, which are
1259 	 * optional. */
1260 	if (rdma_param->private_data != NULL &&
1261 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1262 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1263 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1264 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1265 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1266 	}
1267 
1268 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1269 		      max_queue_depth, max_read_depth);
1270 
1271 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1272 	if (rqpair == NULL) {
1273 		SPDK_ERRLOG("Could not allocate new connection.\n");
1274 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1275 		return -1;
1276 	}
1277 
1278 	rqpair->device = port->device;
1279 	rqpair->max_queue_depth = max_queue_depth;
1280 	rqpair->max_read_depth = max_read_depth;
1281 	rqpair->cm_id = event->id;
1282 	rqpair->listen_id = event->listen_id;
1283 	rqpair->qpair.transport = transport;
1284 	STAILQ_INIT(&rqpair->ibv_events);
1285 	/* use qid from the private data to determine the qpair type
1286 	   qid will be set to the appropriate value when the controller is created */
1287 	rqpair->qpair.qid = private_data->qid;
1288 
1289 	event->id->context = &rqpair->qpair;
1290 
1291 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1292 
1293 	return 0;
1294 }
1295 
1296 static int
1297 nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1298 		     enum spdk_mem_map_notify_action action,
1299 		     void *vaddr, size_t size)
1300 {
1301 	struct ibv_pd *pd = cb_ctx;
1302 	struct ibv_mr *mr;
1303 	int rc;
1304 
1305 	switch (action) {
1306 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1307 		if (!g_nvmf_hooks.get_rkey) {
1308 			mr = ibv_reg_mr(pd, vaddr, size,
1309 					IBV_ACCESS_LOCAL_WRITE |
1310 					IBV_ACCESS_REMOTE_READ |
1311 					IBV_ACCESS_REMOTE_WRITE);
1312 			if (mr == NULL) {
1313 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1314 				return -1;
1315 			} else {
1316 				rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1317 			}
1318 		} else {
1319 			rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1320 							  g_nvmf_hooks.get_rkey(pd, vaddr, size));
1321 		}
1322 		break;
1323 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1324 		if (!g_nvmf_hooks.get_rkey) {
1325 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1326 			if (mr) {
1327 				ibv_dereg_mr(mr);
1328 			}
1329 		}
1330 		rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1331 		break;
1332 	default:
1333 		SPDK_UNREACHABLE();
1334 	}
1335 
1336 	return rc;
1337 }
1338 
1339 static int
1340 nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1341 {
1342 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1343 	return addr_1 == addr_2;
1344 }
1345 
1346 static inline void
1347 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1348 		   enum spdk_nvme_data_transfer xfer)
1349 {
1350 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1351 		wr->opcode = IBV_WR_RDMA_WRITE;
1352 		wr->send_flags = 0;
1353 		wr->next = next;
1354 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1355 		wr->opcode = IBV_WR_RDMA_READ;
1356 		wr->send_flags = IBV_SEND_SIGNALED;
1357 		wr->next = NULL;
1358 	} else {
1359 		assert(0);
1360 	}
1361 }
1362 
1363 static int
1364 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1365 		       struct spdk_nvmf_rdma_request *rdma_req,
1366 		       uint32_t num_sgl_descriptors)
1367 {
1368 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1369 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1370 	uint32_t				i;
1371 
1372 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1373 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1374 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1375 		return -EINVAL;
1376 	}
1377 
1378 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1379 		return -ENOMEM;
1380 	}
1381 
1382 	current_data_wr = &rdma_req->data;
1383 
1384 	for (i = 0; i < num_sgl_descriptors; i++) {
1385 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1386 		current_data_wr->wr.next = &work_requests[i]->wr;
1387 		current_data_wr = work_requests[i];
1388 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1389 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1390 	}
1391 
1392 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1393 
1394 	return 0;
1395 }
1396 
1397 static inline void
1398 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1399 {
1400 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1401 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1402 
1403 	wr->wr.rdma.rkey = sgl->keyed.key;
1404 	wr->wr.rdma.remote_addr = sgl->address;
1405 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1406 }
1407 
1408 static inline void
1409 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1410 {
1411 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1412 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1413 	uint32_t			i;
1414 	int				j;
1415 	uint64_t			remote_addr_offset = 0;
1416 
1417 	for (i = 0; i < num_wrs; ++i) {
1418 		wr->wr.rdma.rkey = sgl->keyed.key;
1419 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1420 		for (j = 0; j < wr->num_sge; ++j) {
1421 			remote_addr_offset += wr->sg_list[j].length;
1422 		}
1423 		wr = wr->next;
1424 	}
1425 }
1426 
1427 /* This function is used in the rare case that we have a buffer split over multiple memory regions. */
1428 static int
1429 nvmf_rdma_replace_buffer(struct spdk_nvmf_rdma_poll_group *rgroup, void **buf)
1430 {
1431 	struct spdk_nvmf_transport_poll_group	*group = &rgroup->group;
1432 	struct spdk_nvmf_transport		*transport = group->transport;
1433 	struct spdk_nvmf_transport_pg_cache_buf	*old_buf;
1434 	void					*new_buf;
1435 
1436 	if (!(STAILQ_EMPTY(&group->buf_cache))) {
1437 		group->buf_cache_count--;
1438 		new_buf = STAILQ_FIRST(&group->buf_cache);
1439 		STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1440 		assert(*buf != NULL);
1441 	} else {
1442 		new_buf = spdk_mempool_get(transport->data_buf_pool);
1443 	}
1444 
1445 	if (*buf == NULL) {
1446 		return -ENOMEM;
1447 	}
1448 
1449 	old_buf = *buf;
1450 	STAILQ_INSERT_HEAD(&rgroup->retired_bufs, old_buf, link);
1451 	*buf = new_buf;
1452 	return 0;
1453 }
1454 
1455 static bool
1456 nvmf_rdma_get_lkey(struct spdk_nvmf_rdma_device *device, struct iovec *iov,
1457 		   uint32_t *_lkey)
1458 {
1459 	uint64_t	translation_len;
1460 	uint32_t	lkey;
1461 
1462 	translation_len = iov->iov_len;
1463 
1464 	if (!g_nvmf_hooks.get_rkey) {
1465 		lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1466 				(uint64_t)iov->iov_base, &translation_len))->lkey;
1467 	} else {
1468 		lkey = spdk_mem_map_translate(device->map,
1469 					      (uint64_t)iov->iov_base, &translation_len);
1470 	}
1471 
1472 	if (spdk_unlikely(translation_len < iov->iov_len)) {
1473 		return false;
1474 	}
1475 
1476 	*_lkey = lkey;
1477 	return true;
1478 }
1479 
1480 static bool
1481 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1482 		      struct iovec *iov, struct ibv_send_wr **_wr,
1483 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1484 		      uint32_t *_num_extra_wrs,
1485 		      const struct spdk_dif_ctx *dif_ctx)
1486 {
1487 	struct ibv_send_wr *wr = *_wr;
1488 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1489 	uint32_t	lkey = 0;
1490 	uint32_t	remaining, data_block_size, md_size, sge_len;
1491 
1492 	if (spdk_unlikely(!nvmf_rdma_get_lkey(device, iov, &lkey))) {
1493 		/* This is a very rare case that can occur when using DPDK version < 19.05 */
1494 		SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions. Removing it from circulation.\n");
1495 		return false;
1496 	}
1497 
1498 	if (spdk_likely(!dif_ctx)) {
1499 		sg_ele->lkey = lkey;
1500 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1501 		sg_ele->length = iov->iov_len;
1502 		wr->num_sge++;
1503 	} else {
1504 		remaining = iov->iov_len - *_offset;
1505 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1506 		md_size = dif_ctx->md_size;
1507 
1508 		while (remaining) {
1509 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1510 				if (*_num_extra_wrs > 0 && wr->next) {
1511 					*_wr = wr->next;
1512 					wr = *_wr;
1513 					wr->num_sge = 0;
1514 					sg_ele = &wr->sg_list[wr->num_sge];
1515 					(*_num_extra_wrs)--;
1516 				} else {
1517 					break;
1518 				}
1519 			}
1520 			sg_ele->lkey = lkey;
1521 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1522 			sge_len = spdk_min(remaining, *_remaining_data_block);
1523 			sg_ele->length = sge_len;
1524 			remaining -= sge_len;
1525 			*_remaining_data_block -= sge_len;
1526 			*_offset += sge_len;
1527 
1528 			sg_ele++;
1529 			wr->num_sge++;
1530 
1531 			if (*_remaining_data_block == 0) {
1532 				/* skip metadata */
1533 				*_offset += md_size;
1534 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1535 				remaining -= spdk_min(remaining, md_size);
1536 				*_remaining_data_block = data_block_size;
1537 			}
1538 
1539 			if (remaining == 0) {
1540 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1541 				   the remaining metadata bits at the beginning of the next buffer */
1542 				*_offset -= iov->iov_len;
1543 			}
1544 		}
1545 	}
1546 
1547 	return true;
1548 }
1549 
1550 static int
1551 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1552 		      struct spdk_nvmf_rdma_device *device,
1553 		      struct spdk_nvmf_rdma_request *rdma_req,
1554 		      struct ibv_send_wr *wr,
1555 		      uint32_t length,
1556 		      uint32_t num_extra_wrs)
1557 {
1558 	struct spdk_nvmf_request *req = &rdma_req->req;
1559 	struct spdk_dif_ctx *dif_ctx = NULL;
1560 	uint32_t remaining_data_block = 0;
1561 	uint32_t offset = 0;
1562 
1563 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1564 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1565 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1566 	}
1567 
1568 	wr->num_sge = 0;
1569 
1570 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1571 		while (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1572 				     &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1573 			if (nvmf_rdma_replace_buffer(rgroup, &req->buffers[rdma_req->iovpos]) == -ENOMEM) {
1574 				return -ENOMEM;
1575 			}
1576 			req->iov[rdma_req->iovpos].iov_base = (void *)((uintptr_t)(req->buffers[rdma_req->iovpos] +
1577 							      NVMF_DATA_BUFFER_MASK) &
1578 							      ~NVMF_DATA_BUFFER_MASK);
1579 		}
1580 
1581 		length -= req->iov[rdma_req->iovpos].iov_len;
1582 		rdma_req->iovpos++;
1583 	}
1584 
1585 	if (length) {
1586 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1587 		return -EINVAL;
1588 	}
1589 
1590 	return 0;
1591 }
1592 
1593 static inline uint32_t
1594 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1595 {
1596 	/* estimate the number of SG entries and WRs needed to process the request */
1597 	uint32_t num_sge = 0;
1598 	uint32_t i;
1599 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1600 
1601 	for (i = 0; i < num_buffers && length > 0; i++) {
1602 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1603 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1604 
1605 		if (num_sge_in_block * block_size > buffer_len) {
1606 			++num_sge_in_block;
1607 		}
1608 		num_sge += num_sge_in_block;
1609 		length -= buffer_len;
1610 	}
1611 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1612 }
1613 
1614 static int
1615 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1616 			    struct spdk_nvmf_rdma_device *device,
1617 			    struct spdk_nvmf_rdma_request *rdma_req,
1618 			    uint32_t length)
1619 {
1620 	struct spdk_nvmf_rdma_qpair		*rqpair;
1621 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1622 	struct spdk_nvmf_request		*req = &rdma_req->req;
1623 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1624 	int					rc;
1625 	uint32_t				num_wrs = 1;
1626 
1627 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1628 	rgroup = rqpair->poller->group;
1629 
1630 	/* rdma wr specifics */
1631 	nvmf_rdma_setup_request(rdma_req);
1632 
1633 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1634 					   length);
1635 	if (rc != 0) {
1636 		return rc;
1637 	}
1638 
1639 	assert(req->iovcnt <= rqpair->max_send_sge);
1640 
1641 	rdma_req->iovpos = 0;
1642 
1643 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1644 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1645 						 req->dif.dif_ctx.block_size);
1646 		if (num_wrs > 1) {
1647 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1648 			if (rc != 0) {
1649 				goto err_exit;
1650 			}
1651 		}
1652 	}
1653 
1654 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1655 	if (spdk_unlikely(rc != 0)) {
1656 		goto err_exit;
1657 	}
1658 
1659 	if (spdk_unlikely(num_wrs > 1)) {
1660 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1661 	}
1662 
1663 	/* set the number of outstanding data WRs for this request. */
1664 	rdma_req->num_outstanding_data_wr = num_wrs;
1665 
1666 	return rc;
1667 
1668 err_exit:
1669 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1670 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1671 	req->iovcnt = 0;
1672 	return rc;
1673 }
1674 
1675 static int
1676 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1677 				      struct spdk_nvmf_rdma_device *device,
1678 				      struct spdk_nvmf_rdma_request *rdma_req)
1679 {
1680 	struct spdk_nvmf_rdma_qpair		*rqpair;
1681 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1682 	struct ibv_send_wr			*current_wr;
1683 	struct spdk_nvmf_request		*req = &rdma_req->req;
1684 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1685 	uint32_t				num_sgl_descriptors;
1686 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1687 	uint32_t				i;
1688 	int					rc;
1689 
1690 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1691 	rgroup = rqpair->poller->group;
1692 
1693 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1694 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1695 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1696 
1697 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1698 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1699 
1700 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1701 		return -ENOMEM;
1702 	}
1703 
1704 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1705 	for (i = 0; i < num_sgl_descriptors; i++) {
1706 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1707 			lengths[i] = desc->keyed.length;
1708 		} else {
1709 			req->dif.orig_length += desc->keyed.length;
1710 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1711 			req->dif.elba_length += lengths[i];
1712 		}
1713 		desc++;
1714 	}
1715 
1716 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1717 			lengths, num_sgl_descriptors);
1718 	if (rc != 0) {
1719 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1720 		return rc;
1721 	}
1722 
1723 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1724 	current_wr = &rdma_req->data.wr;
1725 	assert(current_wr != NULL);
1726 
1727 	req->length = 0;
1728 	rdma_req->iovpos = 0;
1729 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1730 	for (i = 0; i < num_sgl_descriptors; i++) {
1731 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1732 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1733 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1734 			rc = -EINVAL;
1735 			goto err_exit;
1736 		}
1737 
1738 		current_wr->num_sge = 0;
1739 
1740 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1741 		if (rc != 0) {
1742 			rc = -ENOMEM;
1743 			goto err_exit;
1744 		}
1745 
1746 		req->length += desc->keyed.length;
1747 		current_wr->wr.rdma.rkey = desc->keyed.key;
1748 		current_wr->wr.rdma.remote_addr = desc->address;
1749 		current_wr = current_wr->next;
1750 		desc++;
1751 	}
1752 
1753 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1754 	/* Go back to the last descriptor in the list. */
1755 	desc--;
1756 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1757 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1758 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1759 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1760 		}
1761 	}
1762 #endif
1763 
1764 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1765 
1766 	return 0;
1767 
1768 err_exit:
1769 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1770 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1771 	return rc;
1772 }
1773 
1774 static int
1775 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1776 			    struct spdk_nvmf_rdma_device *device,
1777 			    struct spdk_nvmf_rdma_request *rdma_req)
1778 {
1779 	struct spdk_nvmf_request		*req = &rdma_req->req;
1780 	struct spdk_nvme_cpl			*rsp;
1781 	struct spdk_nvme_sgl_descriptor		*sgl;
1782 	int					rc;
1783 	uint32_t				length;
1784 
1785 	rsp = &req->rsp->nvme_cpl;
1786 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1787 
1788 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1789 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1790 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1791 
1792 		length = sgl->keyed.length;
1793 		if (length > rtransport->transport.opts.max_io_size) {
1794 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1795 				    length, rtransport->transport.opts.max_io_size);
1796 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1797 			return -1;
1798 		}
1799 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1800 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1801 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1802 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1803 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1804 			}
1805 		}
1806 #endif
1807 
1808 		/* fill request length and populate iovs */
1809 		req->length = length;
1810 
1811 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1812 			req->dif.orig_length = length;
1813 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1814 			req->dif.elba_length = length;
1815 		}
1816 
1817 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1818 		if (spdk_unlikely(rc < 0)) {
1819 			if (rc == -EINVAL) {
1820 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1821 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1822 				return -1;
1823 			}
1824 			/* No available buffers. Queue this request up. */
1825 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1826 			return 0;
1827 		}
1828 
1829 		/* backward compatible */
1830 		req->data = req->iov[0].iov_base;
1831 
1832 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1833 			      req->iovcnt);
1834 
1835 		return 0;
1836 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1837 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1838 		uint64_t offset = sgl->address;
1839 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1840 
1841 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1842 			      offset, sgl->unkeyed.length);
1843 
1844 		if (offset > max_len) {
1845 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1846 				    offset, max_len);
1847 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1848 			return -1;
1849 		}
1850 		max_len -= (uint32_t)offset;
1851 
1852 		if (sgl->unkeyed.length > max_len) {
1853 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1854 				    sgl->unkeyed.length, max_len);
1855 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1856 			return -1;
1857 		}
1858 
1859 		rdma_req->num_outstanding_data_wr = 0;
1860 		req->data = rdma_req->recv->buf + offset;
1861 		req->data_from_pool = false;
1862 		req->length = sgl->unkeyed.length;
1863 
1864 		req->iov[0].iov_base = req->data;
1865 		req->iov[0].iov_len = req->length;
1866 		req->iovcnt = 1;
1867 
1868 		return 0;
1869 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1870 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1871 
1872 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1873 		if (rc == -ENOMEM) {
1874 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1875 			return 0;
1876 		} else if (rc == -EINVAL) {
1877 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1878 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1879 			return -1;
1880 		}
1881 
1882 		/* backward compatible */
1883 		req->data = req->iov[0].iov_base;
1884 
1885 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1886 			      req->iovcnt);
1887 
1888 		return 0;
1889 	}
1890 
1891 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1892 		    sgl->generic.type, sgl->generic.subtype);
1893 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1894 	return -1;
1895 }
1896 
1897 static void
1898 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1899 			struct spdk_nvmf_rdma_transport	*rtransport)
1900 {
1901 	struct spdk_nvmf_rdma_qpair		*rqpair;
1902 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1903 
1904 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1905 	if (rdma_req->req.data_from_pool) {
1906 		rgroup = rqpair->poller->group;
1907 
1908 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1909 	}
1910 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1911 	rdma_req->req.length = 0;
1912 	rdma_req->req.iovcnt = 0;
1913 	rdma_req->req.data = NULL;
1914 	rdma_req->rsp.wr.next = NULL;
1915 	rdma_req->data.wr.next = NULL;
1916 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1917 	rqpair->qd--;
1918 
1919 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1920 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1921 }
1922 
1923 bool
1924 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1925 			  struct spdk_nvmf_rdma_request *rdma_req)
1926 {
1927 	struct spdk_nvmf_rdma_qpair	*rqpair;
1928 	struct spdk_nvmf_rdma_device	*device;
1929 	struct spdk_nvmf_rdma_poll_group *rgroup;
1930 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1931 	int				rc;
1932 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1933 	enum spdk_nvmf_rdma_request_state prev_state;
1934 	bool				progress = false;
1935 	int				data_posted;
1936 	uint32_t			num_blocks;
1937 
1938 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1939 	device = rqpair->device;
1940 	rgroup = rqpair->poller->group;
1941 
1942 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1943 
1944 	/* If the queue pair is in an error state, force the request to the completed state
1945 	 * to release resources. */
1946 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1947 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1948 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1949 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1950 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1951 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1952 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1953 		}
1954 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1955 	}
1956 
1957 	/* The loop here is to allow for several back-to-back state changes. */
1958 	do {
1959 		prev_state = rdma_req->state;
1960 
1961 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1962 
1963 		switch (rdma_req->state) {
1964 		case RDMA_REQUEST_STATE_FREE:
1965 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1966 			 * to escape this state. */
1967 			break;
1968 		case RDMA_REQUEST_STATE_NEW:
1969 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1970 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1971 			rdma_recv = rdma_req->recv;
1972 
1973 			/* The first element of the SGL is the NVMe command */
1974 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1975 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1976 
1977 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1978 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1979 				break;
1980 			}
1981 
1982 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
1983 				rdma_req->req.dif.dif_insert_or_strip = true;
1984 			}
1985 
1986 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1987 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1988 			rdma_req->rsp.wr.imm_data = 0;
1989 #endif
1990 
1991 			/* The next state transition depends on the data transfer needs of this request. */
1992 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
1993 
1994 			/* If no data to transfer, ready to execute. */
1995 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1996 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1997 				break;
1998 			}
1999 
2000 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2001 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2002 			break;
2003 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2004 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2005 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2006 
2007 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2008 
2009 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2010 				/* This request needs to wait in line to obtain a buffer */
2011 				break;
2012 			}
2013 
2014 			/* Try to get a data buffer */
2015 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2016 			if (rc < 0) {
2017 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2018 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2019 				break;
2020 			}
2021 
2022 			if (!rdma_req->req.data) {
2023 				/* No buffers available. */
2024 				rgroup->stat.pending_data_buffer++;
2025 				break;
2026 			}
2027 
2028 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2029 
2030 			/* If data is transferring from host to controller and the data didn't
2031 			 * arrive using in capsule data, we need to do a transfer from the host.
2032 			 */
2033 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2034 			    rdma_req->req.data_from_pool) {
2035 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2036 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2037 				break;
2038 			}
2039 
2040 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2041 			break;
2042 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2043 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2044 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2045 
2046 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2047 				/* This request needs to wait in line to perform RDMA */
2048 				break;
2049 			}
2050 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2051 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2052 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2053 				rqpair->poller->stat.pending_rdma_read++;
2054 				break;
2055 			}
2056 
2057 			/* We have already verified that this request is the head of the queue. */
2058 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2059 
2060 			rc = request_transfer_in(&rdma_req->req);
2061 			if (!rc) {
2062 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2063 			} else {
2064 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2065 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2066 			}
2067 			break;
2068 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2069 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2070 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2071 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2072 			 * to escape this state. */
2073 			break;
2074 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2075 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2076 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2077 
2078 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2079 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2080 					/* generate DIF for write operation */
2081 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2082 					assert(num_blocks > 0);
2083 
2084 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2085 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2086 					if (rc != 0) {
2087 						SPDK_ERRLOG("DIF generation failed\n");
2088 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2089 						nvmf_rdma_start_disconnect(rqpair);
2090 						break;
2091 					}
2092 				}
2093 
2094 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2095 				/* set extended length before IO operation */
2096 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2097 			}
2098 
2099 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2100 			spdk_nvmf_request_exec(&rdma_req->req);
2101 			break;
2102 		case RDMA_REQUEST_STATE_EXECUTING:
2103 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2104 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2105 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2106 			 * to escape this state. */
2107 			break;
2108 		case RDMA_REQUEST_STATE_EXECUTED:
2109 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2110 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2111 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2112 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2113 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2114 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2115 			} else {
2116 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2117 			}
2118 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2119 				/* restore the original length */
2120 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2121 
2122 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2123 					struct spdk_dif_error error_blk;
2124 
2125 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2126 
2127 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2128 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2129 					if (rc) {
2130 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2131 
2132 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2133 							    error_blk.err_offset);
2134 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2135 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2136 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2137 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2138 					}
2139 				}
2140 			}
2141 			break;
2142 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2143 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2144 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2145 
2146 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2147 				/* This request needs to wait in line to perform RDMA */
2148 				break;
2149 			}
2150 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2151 			    rqpair->max_send_depth) {
2152 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2153 				 * +1 since each request has an additional wr in the resp. */
2154 				rqpair->poller->stat.pending_rdma_write++;
2155 				break;
2156 			}
2157 
2158 			/* We have already verified that this request is the head of the queue. */
2159 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2160 
2161 			/* The data transfer will be kicked off from
2162 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2163 			 */
2164 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2165 			break;
2166 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2167 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2168 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2169 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2170 			assert(rc == 0); /* No good way to handle this currently */
2171 			if (rc) {
2172 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2173 			} else {
2174 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2175 						  RDMA_REQUEST_STATE_COMPLETING;
2176 			}
2177 			break;
2178 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2179 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2180 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2181 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2182 			 * to escape this state. */
2183 			break;
2184 		case RDMA_REQUEST_STATE_COMPLETING:
2185 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2186 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2187 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2188 			 * to escape this state. */
2189 			break;
2190 		case RDMA_REQUEST_STATE_COMPLETED:
2191 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2192 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2193 
2194 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2195 			_nvmf_rdma_request_free(rdma_req, rtransport);
2196 			break;
2197 		case RDMA_REQUEST_NUM_STATES:
2198 		default:
2199 			assert(0);
2200 			break;
2201 		}
2202 
2203 		if (rdma_req->state != prev_state) {
2204 			progress = true;
2205 		}
2206 	} while (rdma_req->state != prev_state);
2207 
2208 	return progress;
2209 }
2210 
2211 /* Public API callbacks begin here */
2212 
2213 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2214 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2215 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2216 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2217 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2218 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2219 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2220 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2221 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2222 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2223 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2224 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2225 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2226 
2227 static void
2228 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2229 {
2230 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2231 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2232 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2233 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2234 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2235 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2236 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2237 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2238 	opts->max_srq_depth =		SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2239 	opts->no_srq =			SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2240 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2241 	opts->acceptor_backlog =	SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2242 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2243 }
2244 
2245 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2246 	.notify_cb = nvmf_rdma_mem_notify,
2247 	.are_contiguous = nvmf_rdma_check_contiguous_entries
2248 };
2249 
2250 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
2251 
2252 static struct spdk_nvmf_transport *
2253 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2254 {
2255 	int rc;
2256 	struct spdk_nvmf_rdma_transport *rtransport;
2257 	struct spdk_nvmf_rdma_device	*device, *tmp;
2258 	struct ibv_context		**contexts;
2259 	uint32_t			i;
2260 	int				flag;
2261 	uint32_t			sge_count;
2262 	uint32_t			min_shared_buffers;
2263 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2264 	pthread_mutexattr_t		attr;
2265 
2266 	rtransport = calloc(1, sizeof(*rtransport));
2267 	if (!rtransport) {
2268 		return NULL;
2269 	}
2270 
2271 	if (pthread_mutexattr_init(&attr)) {
2272 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2273 		free(rtransport);
2274 		return NULL;
2275 	}
2276 
2277 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2278 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2279 		pthread_mutexattr_destroy(&attr);
2280 		free(rtransport);
2281 		return NULL;
2282 	}
2283 
2284 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2285 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2286 		pthread_mutexattr_destroy(&attr);
2287 		free(rtransport);
2288 		return NULL;
2289 	}
2290 
2291 	pthread_mutexattr_destroy(&attr);
2292 
2293 	TAILQ_INIT(&rtransport->devices);
2294 	TAILQ_INIT(&rtransport->ports);
2295 	TAILQ_INIT(&rtransport->poll_groups);
2296 
2297 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2298 
2299 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
2300 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2301 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2302 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2303 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d,"
2304 		     "  acceptor_backlog=%d, abort_timeout_sec=%d\n",
2305 		     opts->max_queue_depth,
2306 		     opts->max_io_size,
2307 		     opts->max_qpairs_per_ctrlr - 1,
2308 		     opts->io_unit_size,
2309 		     opts->in_capsule_data_size,
2310 		     opts->max_aq_depth,
2311 		     opts->num_shared_buffers,
2312 		     opts->max_srq_depth,
2313 		     opts->no_srq,
2314 		     opts->acceptor_backlog,
2315 		     opts->abort_timeout_sec);
2316 
2317 	/* I/O unit size cannot be larger than max I/O size */
2318 	if (opts->io_unit_size > opts->max_io_size) {
2319 		opts->io_unit_size = opts->max_io_size;
2320 	}
2321 
2322 	if (opts->acceptor_backlog <= 0) {
2323 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2324 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2325 		opts->acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2326 	}
2327 
2328 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2329 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2330 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2331 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2332 		nvmf_rdma_destroy(&rtransport->transport);
2333 		return NULL;
2334 	}
2335 
2336 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
2337 	if (min_shared_buffers > opts->num_shared_buffers) {
2338 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2339 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2340 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2341 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2342 		nvmf_rdma_destroy(&rtransport->transport);
2343 		return NULL;
2344 	}
2345 
2346 	sge_count = opts->max_io_size / opts->io_unit_size;
2347 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2348 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2349 		nvmf_rdma_destroy(&rtransport->transport);
2350 		return NULL;
2351 	}
2352 
2353 	rtransport->event_channel = rdma_create_event_channel();
2354 	if (rtransport->event_channel == NULL) {
2355 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2356 		nvmf_rdma_destroy(&rtransport->transport);
2357 		return NULL;
2358 	}
2359 
2360 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2361 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2362 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2363 			    rtransport->event_channel->fd, spdk_strerror(errno));
2364 		nvmf_rdma_destroy(&rtransport->transport);
2365 		return NULL;
2366 	}
2367 
2368 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2369 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2370 				   sizeof(struct spdk_nvmf_rdma_request_data),
2371 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2372 				   SPDK_ENV_SOCKET_ID_ANY);
2373 	if (!rtransport->data_wr_pool) {
2374 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2375 		nvmf_rdma_destroy(&rtransport->transport);
2376 		return NULL;
2377 	}
2378 
2379 	contexts = rdma_get_devices(NULL);
2380 	if (contexts == NULL) {
2381 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2382 		nvmf_rdma_destroy(&rtransport->transport);
2383 		return NULL;
2384 	}
2385 
2386 	i = 0;
2387 	rc = 0;
2388 	while (contexts[i] != NULL) {
2389 		device = calloc(1, sizeof(*device));
2390 		if (!device) {
2391 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2392 			rc = -ENOMEM;
2393 			break;
2394 		}
2395 		device->context = contexts[i];
2396 		rc = ibv_query_device(device->context, &device->attr);
2397 		if (rc < 0) {
2398 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2399 			free(device);
2400 			break;
2401 
2402 		}
2403 
2404 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2405 
2406 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2407 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2408 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2409 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2410 		}
2411 
2412 		/**
2413 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2414 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2415 		 * but incorrectly reports that it does. There are changes making their way
2416 		 * through the kernel now that will enable this feature. When they are merged,
2417 		 * we can conditionally enable this feature.
2418 		 *
2419 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2420 		 */
2421 		if (device->attr.vendor_id == 0) {
2422 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2423 		}
2424 #endif
2425 
2426 		/* set up device context async ev fd as NON_BLOCKING */
2427 		flag = fcntl(device->context->async_fd, F_GETFL);
2428 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2429 		if (rc < 0) {
2430 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2431 			free(device);
2432 			break;
2433 		}
2434 
2435 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2436 		i++;
2437 
2438 		if (g_nvmf_hooks.get_ibv_pd) {
2439 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2440 		} else {
2441 			device->pd = ibv_alloc_pd(device->context);
2442 		}
2443 
2444 		if (!device->pd) {
2445 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2446 			rc = -ENOMEM;
2447 			break;
2448 		}
2449 
2450 		assert(device->map == NULL);
2451 
2452 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2453 		if (!device->map) {
2454 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2455 			rc = -ENOMEM;
2456 			break;
2457 		}
2458 
2459 		assert(device->map != NULL);
2460 		assert(device->pd != NULL);
2461 	}
2462 	rdma_free_devices(contexts);
2463 
2464 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2465 		/* divide and round up. */
2466 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2467 
2468 		/* round up to the nearest 4k. */
2469 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2470 
2471 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2472 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2473 			       opts->io_unit_size);
2474 	}
2475 
2476 	if (rc < 0) {
2477 		nvmf_rdma_destroy(&rtransport->transport);
2478 		return NULL;
2479 	}
2480 
2481 	/* Set up poll descriptor array to monitor events from RDMA and IB
2482 	 * in a single poll syscall
2483 	 */
2484 	rtransport->npoll_fds = i + 1;
2485 	i = 0;
2486 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2487 	if (rtransport->poll_fds == NULL) {
2488 		SPDK_ERRLOG("poll_fds allocation failed\n");
2489 		nvmf_rdma_destroy(&rtransport->transport);
2490 		return NULL;
2491 	}
2492 
2493 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2494 	rtransport->poll_fds[i++].events = POLLIN;
2495 
2496 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2497 		rtransport->poll_fds[i].fd = device->context->async_fd;
2498 		rtransport->poll_fds[i++].events = POLLIN;
2499 	}
2500 
2501 	return &rtransport->transport;
2502 }
2503 
2504 static int
2505 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
2506 {
2507 	struct spdk_nvmf_rdma_transport	*rtransport;
2508 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2509 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2510 
2511 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2512 
2513 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2514 		TAILQ_REMOVE(&rtransport->ports, port, link);
2515 		rdma_destroy_id(port->id);
2516 		free(port);
2517 	}
2518 
2519 	if (rtransport->poll_fds != NULL) {
2520 		free(rtransport->poll_fds);
2521 	}
2522 
2523 	if (rtransport->event_channel != NULL) {
2524 		rdma_destroy_event_channel(rtransport->event_channel);
2525 	}
2526 
2527 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2528 		TAILQ_REMOVE(&rtransport->devices, device, link);
2529 		if (device->map) {
2530 			spdk_mem_map_free(&device->map);
2531 		}
2532 		if (device->pd) {
2533 			if (!g_nvmf_hooks.get_ibv_pd) {
2534 				ibv_dealloc_pd(device->pd);
2535 			}
2536 		}
2537 		free(device);
2538 	}
2539 
2540 	if (rtransport->data_wr_pool != NULL) {
2541 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2542 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2543 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2544 				    spdk_mempool_count(rtransport->data_wr_pool),
2545 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2546 		}
2547 	}
2548 
2549 	spdk_mempool_free(rtransport->data_wr_pool);
2550 
2551 	pthread_mutex_destroy(&rtransport->lock);
2552 	free(rtransport);
2553 
2554 	return 0;
2555 }
2556 
2557 static int
2558 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2559 			  struct spdk_nvme_transport_id *trid,
2560 			  bool peer);
2561 
2562 static int
2563 nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2564 		 const struct spdk_nvme_transport_id *trid)
2565 {
2566 	struct spdk_nvmf_rdma_transport	*rtransport;
2567 	struct spdk_nvmf_rdma_device	*device;
2568 	struct spdk_nvmf_rdma_port	*port;
2569 	struct addrinfo			*res;
2570 	struct addrinfo			hints;
2571 	int				family;
2572 	int				rc;
2573 
2574 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2575 	assert(rtransport->event_channel != NULL);
2576 
2577 	pthread_mutex_lock(&rtransport->lock);
2578 	port = calloc(1, sizeof(*port));
2579 	if (!port) {
2580 		SPDK_ERRLOG("Port allocation failed\n");
2581 		pthread_mutex_unlock(&rtransport->lock);
2582 		return -ENOMEM;
2583 	}
2584 
2585 	port->trid = trid;
2586 
2587 	switch (trid->adrfam) {
2588 	case SPDK_NVMF_ADRFAM_IPV4:
2589 		family = AF_INET;
2590 		break;
2591 	case SPDK_NVMF_ADRFAM_IPV6:
2592 		family = AF_INET6;
2593 		break;
2594 	default:
2595 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2596 		free(port);
2597 		pthread_mutex_unlock(&rtransport->lock);
2598 		return -EINVAL;
2599 	}
2600 
2601 	memset(&hints, 0, sizeof(hints));
2602 	hints.ai_family = family;
2603 	hints.ai_flags = AI_NUMERICSERV;
2604 	hints.ai_socktype = SOCK_STREAM;
2605 	hints.ai_protocol = 0;
2606 
2607 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2608 	if (rc) {
2609 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2610 		free(port);
2611 		pthread_mutex_unlock(&rtransport->lock);
2612 		return -EINVAL;
2613 	}
2614 
2615 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2616 	if (rc < 0) {
2617 		SPDK_ERRLOG("rdma_create_id() failed\n");
2618 		freeaddrinfo(res);
2619 		free(port);
2620 		pthread_mutex_unlock(&rtransport->lock);
2621 		return rc;
2622 	}
2623 
2624 	rc = rdma_bind_addr(port->id, res->ai_addr);
2625 	freeaddrinfo(res);
2626 
2627 	if (rc < 0) {
2628 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2629 		rdma_destroy_id(port->id);
2630 		free(port);
2631 		pthread_mutex_unlock(&rtransport->lock);
2632 		return rc;
2633 	}
2634 
2635 	if (!port->id->verbs) {
2636 		SPDK_ERRLOG("ibv_context is null\n");
2637 		rdma_destroy_id(port->id);
2638 		free(port);
2639 		pthread_mutex_unlock(&rtransport->lock);
2640 		return -1;
2641 	}
2642 
2643 	rc = rdma_listen(port->id, transport->opts.acceptor_backlog);
2644 	if (rc < 0) {
2645 		SPDK_ERRLOG("rdma_listen() failed\n");
2646 		rdma_destroy_id(port->id);
2647 		free(port);
2648 		pthread_mutex_unlock(&rtransport->lock);
2649 		return rc;
2650 	}
2651 
2652 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2653 		if (device->context == port->id->verbs) {
2654 			port->device = device;
2655 			break;
2656 		}
2657 	}
2658 	if (!port->device) {
2659 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2660 			    port->id->verbs);
2661 		rdma_destroy_id(port->id);
2662 		free(port);
2663 		pthread_mutex_unlock(&rtransport->lock);
2664 		return -EINVAL;
2665 	}
2666 
2667 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2668 		       trid->traddr, trid->trsvcid);
2669 
2670 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2671 	pthread_mutex_unlock(&rtransport->lock);
2672 	return 0;
2673 }
2674 
2675 static void
2676 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2677 		      const struct spdk_nvme_transport_id *trid)
2678 {
2679 	struct spdk_nvmf_rdma_transport *rtransport;
2680 	struct spdk_nvmf_rdma_port *port, *tmp;
2681 
2682 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2683 
2684 	pthread_mutex_lock(&rtransport->lock);
2685 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2686 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2687 			TAILQ_REMOVE(&rtransport->ports, port, link);
2688 			rdma_destroy_id(port->id);
2689 			free(port);
2690 			break;
2691 		}
2692 	}
2693 
2694 	pthread_mutex_unlock(&rtransport->lock);
2695 }
2696 
2697 static void
2698 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2699 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2700 {
2701 	struct spdk_nvmf_request *req, *tmp;
2702 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2703 	struct spdk_nvmf_rdma_resources *resources;
2704 
2705 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2706 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2707 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2708 			break;
2709 		}
2710 	}
2711 
2712 	/* Then RDMA writes since reads have stronger restrictions than writes */
2713 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2714 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2715 			break;
2716 		}
2717 	}
2718 
2719 	/* The second highest priority is I/O waiting on memory buffers. */
2720 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2721 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2722 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2723 			break;
2724 		}
2725 	}
2726 
2727 	resources = rqpair->resources;
2728 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2729 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2730 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2731 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2732 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2733 
2734 		if (rqpair->srq != NULL) {
2735 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2736 			rdma_req->recv->qpair->qd++;
2737 		} else {
2738 			rqpair->qd++;
2739 		}
2740 
2741 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2742 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2743 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2744 			break;
2745 		}
2746 	}
2747 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2748 		rqpair->poller->stat.pending_free_request++;
2749 	}
2750 }
2751 
2752 static void
2753 _nvmf_rdma_qpair_disconnect(void *ctx)
2754 {
2755 	struct spdk_nvmf_qpair *qpair = ctx;
2756 
2757 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2758 }
2759 
2760 static void
2761 _nvmf_rdma_try_disconnect(void *ctx)
2762 {
2763 	struct spdk_nvmf_qpair *qpair = ctx;
2764 	struct spdk_nvmf_poll_group *group;
2765 
2766 	/* Read the group out of the qpair. This is normally set and accessed only from
2767 	 * the thread that created the group. Here, we're not on that thread necessarily.
2768 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2769 	 * a pointer and never changes. So fortunately reading this and checking for
2770 	 * non-NULL is thread safe in the x86_64 memory model. */
2771 	group = qpair->group;
2772 
2773 	if (group == NULL) {
2774 		/* The qpair hasn't been assigned to a group yet, so we can't
2775 		 * process a disconnect. Send a message to ourself and try again. */
2776 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2777 		return;
2778 	}
2779 
2780 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2781 }
2782 
2783 static inline void
2784 nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2785 {
2786 	if (!__atomic_test_and_set(&rqpair->disconnect_started, __ATOMIC_RELAXED)) {
2787 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2788 	}
2789 }
2790 
2791 static void nvmf_rdma_destroy_drained_qpair(void *ctx)
2792 {
2793 	struct spdk_nvmf_rdma_qpair *rqpair = ctx;
2794 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2795 			struct spdk_nvmf_rdma_transport, transport);
2796 
2797 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2798 	if (rqpair->current_send_depth != 0) {
2799 		return;
2800 	}
2801 
2802 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2803 		return;
2804 	}
2805 
2806 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false) {
2807 		return;
2808 	}
2809 
2810 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2811 
2812 	/* Qpair will be destroyed after nvmf layer closes this qpair */
2813 	if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ERROR) {
2814 		return;
2815 	}
2816 
2817 	nvmf_rdma_qpair_destroy(rqpair);
2818 }
2819 
2820 
2821 static int
2822 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2823 {
2824 	struct spdk_nvmf_qpair		*qpair;
2825 	struct spdk_nvmf_rdma_qpair	*rqpair;
2826 
2827 	if (evt->id == NULL) {
2828 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2829 		return -1;
2830 	}
2831 
2832 	qpair = evt->id->context;
2833 	if (qpair == NULL) {
2834 		SPDK_ERRLOG("disconnect request: no active connection\n");
2835 		return -1;
2836 	}
2837 
2838 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2839 
2840 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2841 
2842 	nvmf_rdma_start_disconnect(rqpair);
2843 
2844 	return 0;
2845 }
2846 
2847 #ifdef DEBUG
2848 static const char *CM_EVENT_STR[] = {
2849 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2850 	"RDMA_CM_EVENT_ADDR_ERROR",
2851 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2852 	"RDMA_CM_EVENT_ROUTE_ERROR",
2853 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2854 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2855 	"RDMA_CM_EVENT_CONNECT_ERROR",
2856 	"RDMA_CM_EVENT_UNREACHABLE",
2857 	"RDMA_CM_EVENT_REJECTED",
2858 	"RDMA_CM_EVENT_ESTABLISHED",
2859 	"RDMA_CM_EVENT_DISCONNECTED",
2860 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2861 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2862 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2863 	"RDMA_CM_EVENT_ADDR_CHANGE",
2864 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2865 };
2866 #endif /* DEBUG */
2867 
2868 static void
2869 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2870 				    struct spdk_nvmf_rdma_port *port)
2871 {
2872 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2873 	struct spdk_nvmf_rdma_poller		*rpoller;
2874 	struct spdk_nvmf_rdma_qpair		*rqpair;
2875 
2876 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2877 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2878 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2879 				if (rqpair->listen_id == port->id) {
2880 					nvmf_rdma_start_disconnect(rqpair);
2881 				}
2882 			}
2883 		}
2884 	}
2885 }
2886 
2887 static bool
2888 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2889 				      struct rdma_cm_event *event)
2890 {
2891 	const struct spdk_nvme_transport_id	*trid;
2892 	struct spdk_nvmf_rdma_port		*port;
2893 	struct spdk_nvmf_rdma_transport		*rtransport;
2894 	bool					event_acked = false;
2895 
2896 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2897 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2898 		if (port->id == event->id) {
2899 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2900 			rdma_ack_cm_event(event);
2901 			event_acked = true;
2902 			trid = port->trid;
2903 			break;
2904 		}
2905 	}
2906 
2907 	if (event_acked) {
2908 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2909 
2910 		nvmf_rdma_stop_listen(transport, trid);
2911 		nvmf_rdma_listen(transport, trid);
2912 	}
2913 
2914 	return event_acked;
2915 }
2916 
2917 static void
2918 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2919 				       struct rdma_cm_event *event)
2920 {
2921 	struct spdk_nvmf_rdma_port		*port;
2922 	struct spdk_nvmf_rdma_transport		*rtransport;
2923 
2924 	port = event->id->context;
2925 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2926 
2927 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2928 
2929 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2930 
2931 	rdma_ack_cm_event(event);
2932 
2933 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2934 		;
2935 	}
2936 }
2937 
2938 static void
2939 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2940 {
2941 	struct spdk_nvmf_rdma_transport *rtransport;
2942 	struct rdma_cm_event		*event;
2943 	int				rc;
2944 	bool				event_acked;
2945 
2946 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2947 
2948 	if (rtransport->event_channel == NULL) {
2949 		return;
2950 	}
2951 
2952 	while (1) {
2953 		event_acked = false;
2954 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2955 		if (rc) {
2956 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2957 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2958 			}
2959 			break;
2960 		}
2961 
2962 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2963 
2964 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2965 
2966 		switch (event->event) {
2967 		case RDMA_CM_EVENT_ADDR_RESOLVED:
2968 		case RDMA_CM_EVENT_ADDR_ERROR:
2969 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
2970 		case RDMA_CM_EVENT_ROUTE_ERROR:
2971 			/* No action required. The target never attempts to resolve routes. */
2972 			break;
2973 		case RDMA_CM_EVENT_CONNECT_REQUEST:
2974 			rc = nvmf_rdma_connect(transport, event);
2975 			if (rc < 0) {
2976 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2977 				break;
2978 			}
2979 			break;
2980 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
2981 			/* The target never initiates a new connection. So this will not occur. */
2982 			break;
2983 		case RDMA_CM_EVENT_CONNECT_ERROR:
2984 			/* Can this happen? The docs say it can, but not sure what causes it. */
2985 			break;
2986 		case RDMA_CM_EVENT_UNREACHABLE:
2987 		case RDMA_CM_EVENT_REJECTED:
2988 			/* These only occur on the client side. */
2989 			break;
2990 		case RDMA_CM_EVENT_ESTABLISHED:
2991 			/* TODO: Should we be waiting for this event anywhere? */
2992 			break;
2993 		case RDMA_CM_EVENT_DISCONNECTED:
2994 			rc = nvmf_rdma_disconnect(event);
2995 			if (rc < 0) {
2996 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2997 				break;
2998 			}
2999 			break;
3000 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
3001 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
3002 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
3003 			 * Once these events are sent to SPDK, we should release all IB resources and
3004 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
3005 			 * ibv_destory* functions to release user space memory allocated by IB. All kernel
3006 			 * resources are already cleaned. */
3007 			if (event->id->qp) {
3008 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
3009 				 * corresponding qpair. Otherwise the event refers to a listening device */
3010 				rc = nvmf_rdma_disconnect(event);
3011 				if (rc < 0) {
3012 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3013 					break;
3014 				}
3015 			} else {
3016 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3017 				event_acked = true;
3018 			}
3019 			break;
3020 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3021 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3022 			/* Multicast is not used */
3023 			break;
3024 		case RDMA_CM_EVENT_ADDR_CHANGE:
3025 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3026 			break;
3027 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3028 			/* For now, do nothing. The target never re-uses queue pairs. */
3029 			break;
3030 		default:
3031 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3032 			break;
3033 		}
3034 		if (!event_acked) {
3035 			rdma_ack_cm_event(event);
3036 		}
3037 	}
3038 }
3039 
3040 static void
3041 nvmf_rdma_handle_qp_fatal(struct spdk_nvmf_rdma_qpair *rqpair)
3042 {
3043 	nvmf_rdma_update_ibv_state(rqpair);
3044 	nvmf_rdma_start_disconnect(rqpair);
3045 }
3046 
3047 static void
3048 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3049 {
3050 	rqpair->last_wqe_reached = true;
3051 	nvmf_rdma_destroy_drained_qpair(rqpair);
3052 }
3053 
3054 static void
3055 nvmf_rdma_handle_sq_drained(struct spdk_nvmf_rdma_qpair *rqpair)
3056 {
3057 	nvmf_rdma_start_disconnect(rqpair);
3058 }
3059 
3060 static void
3061 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3062 {
3063 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3064 
3065 	if (event_ctx->rqpair) {
3066 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3067 		if (event_ctx->cb_fn) {
3068 			event_ctx->cb_fn(event_ctx->rqpair);
3069 		}
3070 	}
3071 	free(event_ctx);
3072 }
3073 
3074 static int
3075 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3076 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3077 {
3078 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3079 
3080 	if (!rqpair->qpair.group) {
3081 		return EINVAL;
3082 	}
3083 
3084 	ctx = calloc(1, sizeof(*ctx));
3085 	if (!ctx) {
3086 		return ENOMEM;
3087 	}
3088 
3089 	ctx->rqpair = rqpair;
3090 	ctx->cb_fn = fn;
3091 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3092 
3093 	return spdk_thread_send_msg(rqpair->qpair.group->thread, nvmf_rdma_qpair_process_ibv_event,
3094 				    ctx);
3095 }
3096 
3097 static void
3098 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3099 {
3100 	int				rc;
3101 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3102 	struct ibv_async_event		event;
3103 
3104 	rc = ibv_get_async_event(device->context, &event);
3105 
3106 	if (rc) {
3107 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
3108 			    errno, spdk_strerror(errno));
3109 		return;
3110 	}
3111 
3112 	switch (event.event_type) {
3113 	case IBV_EVENT_QP_FATAL:
3114 		rqpair = event.element.qp->qp_context;
3115 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3116 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3117 				  (uintptr_t)rqpair->cm_id, event.event_type);
3118 		if (nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_qp_fatal)) {
3119 			SPDK_ERRLOG("Failed to send QP_FATAL event for rqpair %p\n", rqpair);
3120 			nvmf_rdma_handle_qp_fatal(rqpair);
3121 		}
3122 		break;
3123 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3124 		/* This event only occurs for shared receive queues. */
3125 		rqpair = event.element.qp->qp_context;
3126 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last WQE reached event received for rqpair %p\n", rqpair);
3127 		if (nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached)) {
3128 			SPDK_ERRLOG("Failed to send LAST_WQE_REACHED event for rqpair %p\n", rqpair);
3129 			rqpair->last_wqe_reached = true;
3130 		}
3131 		break;
3132 	case IBV_EVENT_SQ_DRAINED:
3133 		/* This event occurs frequently in both error and non-error states.
3134 		 * Check if the qpair is in an error state before sending a message. */
3135 		rqpair = event.element.qp->qp_context;
3136 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last sq drained event received for rqpair %p\n", rqpair);
3137 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3138 				  (uintptr_t)rqpair->cm_id, event.event_type);
3139 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3140 			if (nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_sq_drained)) {
3141 				SPDK_ERRLOG("Failed to send SQ_DRAINED event for rqpair %p\n", rqpair);
3142 				nvmf_rdma_handle_sq_drained(rqpair);
3143 			}
3144 		}
3145 		break;
3146 	case IBV_EVENT_QP_REQ_ERR:
3147 	case IBV_EVENT_QP_ACCESS_ERR:
3148 	case IBV_EVENT_COMM_EST:
3149 	case IBV_EVENT_PATH_MIG:
3150 	case IBV_EVENT_PATH_MIG_ERR:
3151 		SPDK_NOTICELOG("Async event: %s\n",
3152 			       ibv_event_type_str(event.event_type));
3153 		rqpair = event.element.qp->qp_context;
3154 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3155 				  (uintptr_t)rqpair->cm_id, event.event_type);
3156 		nvmf_rdma_update_ibv_state(rqpair);
3157 		break;
3158 	case IBV_EVENT_CQ_ERR:
3159 	case IBV_EVENT_DEVICE_FATAL:
3160 	case IBV_EVENT_PORT_ACTIVE:
3161 	case IBV_EVENT_PORT_ERR:
3162 	case IBV_EVENT_LID_CHANGE:
3163 	case IBV_EVENT_PKEY_CHANGE:
3164 	case IBV_EVENT_SM_CHANGE:
3165 	case IBV_EVENT_SRQ_ERR:
3166 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3167 	case IBV_EVENT_CLIENT_REREGISTER:
3168 	case IBV_EVENT_GID_CHANGE:
3169 	default:
3170 		SPDK_NOTICELOG("Async event: %s\n",
3171 			       ibv_event_type_str(event.event_type));
3172 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3173 		break;
3174 	}
3175 	ibv_ack_async_event(&event);
3176 }
3177 
3178 static uint32_t
3179 nvmf_rdma_accept(struct spdk_nvmf_transport *transport)
3180 {
3181 	int	nfds, i = 0;
3182 	struct spdk_nvmf_rdma_transport *rtransport;
3183 	struct spdk_nvmf_rdma_device *device, *tmp;
3184 	uint32_t count;
3185 
3186 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3187 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3188 
3189 	if (nfds <= 0) {
3190 		return 0;
3191 	}
3192 
3193 	/* The first poll descriptor is RDMA CM event */
3194 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3195 		nvmf_process_cm_event(transport);
3196 		nfds--;
3197 	}
3198 
3199 	if (nfds == 0) {
3200 		return count;
3201 	}
3202 
3203 	/* Second and subsequent poll descriptors are IB async events */
3204 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3205 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3206 			nvmf_process_ib_event(device);
3207 			nfds--;
3208 		}
3209 	}
3210 	/* check all flagged fd's have been served */
3211 	assert(nfds == 0);
3212 
3213 	return count;
3214 }
3215 
3216 static void
3217 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3218 		     struct spdk_nvmf_ctrlr_data *cdata)
3219 {
3220 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3221 
3222 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3223 	since in-capsule data only works with NVME drives that support SGL memory layout */
3224 	if (transport->opts.dif_insert_or_strip) {
3225 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3226 	}
3227 }
3228 
3229 static void
3230 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3231 		   struct spdk_nvme_transport_id *trid,
3232 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3233 {
3234 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3235 	entry->adrfam = trid->adrfam;
3236 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3237 
3238 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3239 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3240 
3241 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3242 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3243 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3244 }
3245 
3246 static void
3247 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3248 
3249 static struct spdk_nvmf_transport_poll_group *
3250 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3251 {
3252 	struct spdk_nvmf_rdma_transport		*rtransport;
3253 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3254 	struct spdk_nvmf_rdma_poller		*poller;
3255 	struct spdk_nvmf_rdma_device		*device;
3256 	struct ibv_srq_init_attr		srq_init_attr;
3257 	struct spdk_nvmf_rdma_resource_opts	opts;
3258 	int					num_cqe;
3259 
3260 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3261 
3262 	rgroup = calloc(1, sizeof(*rgroup));
3263 	if (!rgroup) {
3264 		return NULL;
3265 	}
3266 
3267 	TAILQ_INIT(&rgroup->pollers);
3268 	STAILQ_INIT(&rgroup->retired_bufs);
3269 
3270 	pthread_mutex_lock(&rtransport->lock);
3271 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3272 		poller = calloc(1, sizeof(*poller));
3273 		if (!poller) {
3274 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3275 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3276 			pthread_mutex_unlock(&rtransport->lock);
3277 			return NULL;
3278 		}
3279 
3280 		poller->device = device;
3281 		poller->group = rgroup;
3282 
3283 		TAILQ_INIT(&poller->qpairs);
3284 		STAILQ_INIT(&poller->qpairs_pending_send);
3285 		STAILQ_INIT(&poller->qpairs_pending_recv);
3286 
3287 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3288 		if (transport->opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3289 			poller->max_srq_depth = transport->opts.max_srq_depth;
3290 
3291 			device->num_srq++;
3292 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3293 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3294 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3295 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3296 			if (!poller->srq) {
3297 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3298 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3299 				pthread_mutex_unlock(&rtransport->lock);
3300 				return NULL;
3301 			}
3302 
3303 			opts.qp = poller->srq;
3304 			opts.pd = device->pd;
3305 			opts.qpair = NULL;
3306 			opts.shared = true;
3307 			opts.max_queue_depth = poller->max_srq_depth;
3308 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3309 
3310 			poller->resources = nvmf_rdma_resources_create(&opts);
3311 			if (!poller->resources) {
3312 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3313 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3314 				pthread_mutex_unlock(&rtransport->lock);
3315 				return NULL;
3316 			}
3317 		}
3318 
3319 		/*
3320 		 * When using an srq, we can limit the completion queue at startup.
3321 		 * The following formula represents the calculation:
3322 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3323 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3324 		 */
3325 		if (poller->srq) {
3326 			num_cqe = poller->max_srq_depth * 3;
3327 		} else {
3328 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3329 		}
3330 
3331 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3332 		if (!poller->cq) {
3333 			SPDK_ERRLOG("Unable to create completion queue\n");
3334 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3335 			pthread_mutex_unlock(&rtransport->lock);
3336 			return NULL;
3337 		}
3338 		poller->num_cqe = num_cqe;
3339 	}
3340 
3341 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3342 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3343 		rtransport->conn_sched.next_admin_pg = rgroup;
3344 		rtransport->conn_sched.next_io_pg = rgroup;
3345 	}
3346 
3347 	pthread_mutex_unlock(&rtransport->lock);
3348 	return &rgroup->group;
3349 }
3350 
3351 static struct spdk_nvmf_transport_poll_group *
3352 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3353 {
3354 	struct spdk_nvmf_rdma_transport *rtransport;
3355 	struct spdk_nvmf_rdma_poll_group **pg;
3356 	struct spdk_nvmf_transport_poll_group *result;
3357 
3358 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3359 
3360 	pthread_mutex_lock(&rtransport->lock);
3361 
3362 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3363 		pthread_mutex_unlock(&rtransport->lock);
3364 		return NULL;
3365 	}
3366 
3367 	if (qpair->qid == 0) {
3368 		pg = &rtransport->conn_sched.next_admin_pg;
3369 	} else {
3370 		pg = &rtransport->conn_sched.next_io_pg;
3371 	}
3372 
3373 	assert(*pg != NULL);
3374 
3375 	result = &(*pg)->group;
3376 
3377 	*pg = TAILQ_NEXT(*pg, link);
3378 	if (*pg == NULL) {
3379 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3380 	}
3381 
3382 	pthread_mutex_unlock(&rtransport->lock);
3383 
3384 	return result;
3385 }
3386 
3387 static void
3388 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3389 {
3390 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3391 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3392 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3393 	struct spdk_nvmf_transport_pg_cache_buf	*buf, *tmp_buf;
3394 	struct spdk_nvmf_rdma_transport		*rtransport;
3395 
3396 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3397 	if (!rgroup) {
3398 		return;
3399 	}
3400 
3401 	/* free all retired buffers back to the transport so we don't short the mempool. */
3402 	STAILQ_FOREACH_SAFE(buf, &rgroup->retired_bufs, link, tmp_buf) {
3403 		STAILQ_REMOVE(&rgroup->retired_bufs, buf, spdk_nvmf_transport_pg_cache_buf, link);
3404 		assert(group->transport != NULL);
3405 		spdk_mempool_put(group->transport->data_buf_pool, buf);
3406 	}
3407 
3408 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3409 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3410 
3411 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3412 			nvmf_rdma_qpair_destroy(qpair);
3413 		}
3414 
3415 		if (poller->srq) {
3416 			if (poller->resources) {
3417 				nvmf_rdma_resources_destroy(poller->resources);
3418 			}
3419 			ibv_destroy_srq(poller->srq);
3420 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Destroyed RDMA shared queue %p\n", poller->srq);
3421 		}
3422 
3423 		if (poller->cq) {
3424 			ibv_destroy_cq(poller->cq);
3425 		}
3426 
3427 		free(poller);
3428 	}
3429 
3430 	if (rgroup->group.transport == NULL) {
3431 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3432 		 * calls this function directly in a failure path. */
3433 		free(rgroup);
3434 		return;
3435 	}
3436 
3437 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3438 
3439 	pthread_mutex_lock(&rtransport->lock);
3440 	next_rgroup = TAILQ_NEXT(rgroup, link);
3441 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3442 	if (next_rgroup == NULL) {
3443 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3444 	}
3445 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3446 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3447 	}
3448 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3449 		rtransport->conn_sched.next_io_pg = next_rgroup;
3450 	}
3451 	pthread_mutex_unlock(&rtransport->lock);
3452 
3453 	free(rgroup);
3454 }
3455 
3456 static void
3457 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3458 {
3459 	if (rqpair->cm_id != NULL) {
3460 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3461 	}
3462 	nvmf_rdma_qpair_destroy(rqpair);
3463 }
3464 
3465 static int
3466 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3467 			 struct spdk_nvmf_qpair *qpair)
3468 {
3469 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3470 	struct spdk_nvmf_rdma_qpair		*rqpair;
3471 	struct spdk_nvmf_rdma_device		*device;
3472 	struct spdk_nvmf_rdma_poller		*poller;
3473 	int					rc;
3474 
3475 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3476 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3477 
3478 	device = rqpair->device;
3479 
3480 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3481 		if (poller->device == device) {
3482 			break;
3483 		}
3484 	}
3485 
3486 	if (!poller) {
3487 		SPDK_ERRLOG("No poller found for device.\n");
3488 		return -1;
3489 	}
3490 
3491 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3492 	rqpair->poller = poller;
3493 	rqpair->srq = rqpair->poller->srq;
3494 
3495 	rc = nvmf_rdma_qpair_initialize(qpair);
3496 	if (rc < 0) {
3497 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3498 		return -1;
3499 	}
3500 
3501 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3502 	if (rc) {
3503 		/* Try to reject, but we probably can't */
3504 		nvmf_rdma_qpair_reject_connection(rqpair);
3505 		return -1;
3506 	}
3507 
3508 	nvmf_rdma_update_ibv_state(rqpair);
3509 
3510 	return 0;
3511 }
3512 
3513 static int
3514 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3515 {
3516 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3517 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3518 			struct spdk_nvmf_rdma_transport, transport);
3519 
3520 	_nvmf_rdma_request_free(rdma_req, rtransport);
3521 	return 0;
3522 }
3523 
3524 static int
3525 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3526 {
3527 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3528 			struct spdk_nvmf_rdma_transport, transport);
3529 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3530 			struct spdk_nvmf_rdma_request, req);
3531 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3532 			struct spdk_nvmf_rdma_qpair, qpair);
3533 
3534 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3535 		/* The connection is alive, so process the request as normal */
3536 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3537 	} else {
3538 		/* The connection is dead. Move the request directly to the completed state. */
3539 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3540 	}
3541 
3542 	nvmf_rdma_request_process(rtransport, rdma_req);
3543 
3544 	return 0;
3545 }
3546 
3547 static int
3548 nvmf_rdma_destroy_defunct_qpair(void *ctx)
3549 {
3550 	struct spdk_nvmf_rdma_qpair	*rqpair = ctx;
3551 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3552 			struct spdk_nvmf_rdma_transport, transport);
3553 
3554 	SPDK_INFOLOG(SPDK_LOG_RDMA, "QP#%d hasn't been drained as expected, manually destroy it\n",
3555 		     rqpair->qpair.qid);
3556 
3557 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3558 	nvmf_rdma_qpair_destroy(rqpair);
3559 
3560 	return SPDK_POLLER_BUSY;
3561 }
3562 
3563 static void
3564 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
3565 {
3566 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3567 
3568 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
3569 		return;
3570 	}
3571 
3572 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
3573 
3574 	/* This happens only when the qpair is disconnected before
3575 	 * it is added to the poll group. Since there is no poll group,
3576 	 * the RDMA qp has not been initialized yet and the RDMA CM
3577 	 * event has not yet been acknowledged, so we need to reject it.
3578 	 */
3579 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3580 		nvmf_rdma_qpair_reject_connection(rqpair);
3581 		return;
3582 	}
3583 
3584 	if (rqpair->rdma_qp) {
3585 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3586 	}
3587 
3588 	rqpair->destruct_poller = SPDK_POLLER_REGISTER(nvmf_rdma_destroy_defunct_qpair, (void *)rqpair,
3589 				  NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US);
3590 }
3591 
3592 static struct spdk_nvmf_rdma_qpair *
3593 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3594 {
3595 	struct spdk_nvmf_rdma_qpair *rqpair;
3596 	/* @todo: improve QP search */
3597 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3598 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3599 			return rqpair;
3600 		}
3601 	}
3602 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3603 	return NULL;
3604 }
3605 
3606 #ifdef DEBUG
3607 static int
3608 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3609 {
3610 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3611 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3612 }
3613 #endif
3614 
3615 static void
3616 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3617 			   int rc)
3618 {
3619 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3620 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3621 
3622 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3623 	while (bad_recv_wr != NULL) {
3624 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3625 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3626 
3627 		rdma_recv->qpair->current_recv_depth++;
3628 		bad_recv_wr = bad_recv_wr->next;
3629 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3630 		nvmf_rdma_start_disconnect(rdma_recv->qpair);
3631 	}
3632 }
3633 
3634 static void
3635 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3636 {
3637 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3638 	while (bad_recv_wr != NULL) {
3639 		bad_recv_wr = bad_recv_wr->next;
3640 		rqpair->current_recv_depth++;
3641 	}
3642 	nvmf_rdma_start_disconnect(rqpair);
3643 }
3644 
3645 static void
3646 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3647 		     struct spdk_nvmf_rdma_poller *rpoller)
3648 {
3649 	struct spdk_nvmf_rdma_qpair	*rqpair;
3650 	struct ibv_recv_wr		*bad_recv_wr;
3651 	int				rc;
3652 
3653 	if (rpoller->srq) {
3654 		if (rpoller->resources->recvs_to_post.first != NULL) {
3655 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3656 			if (rc) {
3657 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3658 			}
3659 			rpoller->resources->recvs_to_post.first = NULL;
3660 			rpoller->resources->recvs_to_post.last = NULL;
3661 		}
3662 	} else {
3663 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3664 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3665 			assert(rqpair->resources->recvs_to_post.first != NULL);
3666 			rc = ibv_post_recv(rqpair->rdma_qp->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3667 			if (rc) {
3668 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3669 			}
3670 			rqpair->resources->recvs_to_post.first = NULL;
3671 			rqpair->resources->recvs_to_post.last = NULL;
3672 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3673 		}
3674 	}
3675 }
3676 
3677 static void
3678 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3679 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3680 {
3681 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3682 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3683 
3684 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3685 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3686 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3687 		assert(rqpair->current_send_depth > 0);
3688 		rqpair->current_send_depth--;
3689 		switch (bad_rdma_wr->type) {
3690 		case RDMA_WR_TYPE_DATA:
3691 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3692 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3693 				assert(rqpair->current_read_depth > 0);
3694 				rqpair->current_read_depth--;
3695 			}
3696 			break;
3697 		case RDMA_WR_TYPE_SEND:
3698 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3699 			break;
3700 		default:
3701 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3702 			prev_rdma_req = cur_rdma_req;
3703 			continue;
3704 		}
3705 
3706 		if (prev_rdma_req == cur_rdma_req) {
3707 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3708 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3709 			continue;
3710 		}
3711 
3712 		switch (cur_rdma_req->state) {
3713 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3714 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3715 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3716 			break;
3717 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3718 		case RDMA_REQUEST_STATE_COMPLETING:
3719 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3720 			break;
3721 		default:
3722 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3723 				    cur_rdma_req->state, rqpair);
3724 			continue;
3725 		}
3726 
3727 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3728 		prev_rdma_req = cur_rdma_req;
3729 	}
3730 
3731 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3732 		/* Disconnect the connection. */
3733 		nvmf_rdma_start_disconnect(rqpair);
3734 	}
3735 
3736 }
3737 
3738 static void
3739 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3740 		     struct spdk_nvmf_rdma_poller *rpoller)
3741 {
3742 	struct spdk_nvmf_rdma_qpair	*rqpair;
3743 	struct ibv_send_wr		*bad_wr = NULL;
3744 	int				rc;
3745 
3746 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3747 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3748 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3749 
3750 		/* bad wr always points to the first wr that failed. */
3751 		if (rc) {
3752 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3753 		}
3754 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3755 	}
3756 }
3757 
3758 static int
3759 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3760 		      struct spdk_nvmf_rdma_poller *rpoller)
3761 {
3762 	struct ibv_wc wc[32];
3763 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3764 	struct spdk_nvmf_rdma_request	*rdma_req;
3765 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3766 	struct spdk_nvmf_rdma_qpair	*rqpair;
3767 	int reaped, i;
3768 	int count = 0;
3769 	bool error = false;
3770 	uint64_t poll_tsc = spdk_get_ticks();
3771 
3772 	/* Poll for completing operations. */
3773 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3774 	if (reaped < 0) {
3775 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3776 			    errno, spdk_strerror(errno));
3777 		return -1;
3778 	}
3779 
3780 	rpoller->stat.polls++;
3781 	rpoller->stat.completions += reaped;
3782 
3783 	for (i = 0; i < reaped; i++) {
3784 
3785 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3786 
3787 		switch (rdma_wr->type) {
3788 		case RDMA_WR_TYPE_SEND:
3789 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3790 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3791 
3792 			if (!wc[i].status) {
3793 				count++;
3794 				assert(wc[i].opcode == IBV_WC_SEND);
3795 				assert(nvmf_rdma_req_is_completing(rdma_req));
3796 			}
3797 
3798 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3799 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3800 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3801 			rdma_req->num_outstanding_data_wr = 0;
3802 
3803 			nvmf_rdma_request_process(rtransport, rdma_req);
3804 			break;
3805 		case RDMA_WR_TYPE_RECV:
3806 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3807 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3808 			if (rpoller->srq != NULL) {
3809 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3810 				/* It is possible that there are still some completions for destroyed QP
3811 				 * associated with SRQ. We just ignore these late completions and re-post
3812 				 * receive WRs back to SRQ.
3813 				 */
3814 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3815 					struct ibv_recv_wr *bad_wr;
3816 					int rc;
3817 
3818 					rdma_recv->wr.next = NULL;
3819 					rc = ibv_post_srq_recv(rpoller->srq,
3820 							       &rdma_recv->wr,
3821 							       &bad_wr);
3822 					if (rc) {
3823 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3824 					}
3825 					continue;
3826 				}
3827 			}
3828 			rqpair = rdma_recv->qpair;
3829 
3830 			assert(rqpair != NULL);
3831 			if (!wc[i].status) {
3832 				assert(wc[i].opcode == IBV_WC_RECV);
3833 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3834 					nvmf_rdma_start_disconnect(rqpair);
3835 					break;
3836 				}
3837 			}
3838 
3839 			rdma_recv->wr.next = NULL;
3840 			rqpair->current_recv_depth++;
3841 			rdma_recv->receive_tsc = poll_tsc;
3842 			rpoller->stat.requests++;
3843 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3844 			break;
3845 		case RDMA_WR_TYPE_DATA:
3846 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3847 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3848 
3849 			assert(rdma_req->num_outstanding_data_wr > 0);
3850 
3851 			rqpair->current_send_depth--;
3852 			rdma_req->num_outstanding_data_wr--;
3853 			if (!wc[i].status) {
3854 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3855 				rqpair->current_read_depth--;
3856 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3857 				if (rdma_req->num_outstanding_data_wr == 0) {
3858 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3859 					nvmf_rdma_request_process(rtransport, rdma_req);
3860 				}
3861 			} else {
3862 				/* If the data transfer fails still force the queue into the error state,
3863 				 * if we were performing an RDMA_READ, we need to force the request into a
3864 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3865 				 * case, we should wait for the SEND to complete. */
3866 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3867 					rqpair->current_read_depth--;
3868 					if (rdma_req->num_outstanding_data_wr == 0) {
3869 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3870 					}
3871 				}
3872 			}
3873 			break;
3874 		default:
3875 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3876 			continue;
3877 		}
3878 
3879 		/* Handle error conditions */
3880 		if (wc[i].status) {
3881 			if ((rdma_wr->type == RDMA_WR_TYPE_RECV && !rpoller->srq)) {
3882 				/* When we don't use SRQ and close a qpair, we will receive completions with error
3883 				 * status for all posted ibv_recv_wrs. This is expected and we don't want to log
3884 				 * an error in that case. */
3885 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Error on CQ %p, request 0x%lu, type %d, status: (%d): %s\n",
3886 					      rpoller->cq, wc[i].wr_id, rdma_wr->type, wc[i].status, ibv_wc_status_str(wc[i].status));
3887 			} else {
3888 				SPDK_ERRLOG("Error on CQ %p, request 0x%lu, type %d, status: (%d): %s\n",
3889 					    rpoller->cq, wc[i].wr_id, rdma_wr->type, wc[i].status, ibv_wc_status_str(wc[i].status));
3890 			}
3891 
3892 			error = true;
3893 
3894 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3895 				/* Disconnect the connection. */
3896 				nvmf_rdma_start_disconnect(rqpair);
3897 			} else {
3898 				nvmf_rdma_destroy_drained_qpair(rqpair);
3899 			}
3900 			continue;
3901 		}
3902 
3903 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3904 
3905 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3906 			nvmf_rdma_destroy_drained_qpair(rqpair);
3907 		}
3908 	}
3909 
3910 	if (error == true) {
3911 		return -1;
3912 	}
3913 
3914 	/* submit outstanding work requests. */
3915 	_poller_submit_recvs(rtransport, rpoller);
3916 	_poller_submit_sends(rtransport, rpoller);
3917 
3918 	return count;
3919 }
3920 
3921 static int
3922 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3923 {
3924 	struct spdk_nvmf_rdma_transport *rtransport;
3925 	struct spdk_nvmf_rdma_poll_group *rgroup;
3926 	struct spdk_nvmf_rdma_poller	*rpoller;
3927 	int				count, rc;
3928 
3929 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3930 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3931 
3932 	count = 0;
3933 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3934 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
3935 		if (rc < 0) {
3936 			return rc;
3937 		}
3938 		count += rc;
3939 	}
3940 
3941 	return count;
3942 }
3943 
3944 static int
3945 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3946 			  struct spdk_nvme_transport_id *trid,
3947 			  bool peer)
3948 {
3949 	struct sockaddr *saddr;
3950 	uint16_t port;
3951 
3952 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
3953 
3954 	if (peer) {
3955 		saddr = rdma_get_peer_addr(id);
3956 	} else {
3957 		saddr = rdma_get_local_addr(id);
3958 	}
3959 	switch (saddr->sa_family) {
3960 	case AF_INET: {
3961 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3962 
3963 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3964 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3965 			  trid->traddr, sizeof(trid->traddr));
3966 		if (peer) {
3967 			port = ntohs(rdma_get_dst_port(id));
3968 		} else {
3969 			port = ntohs(rdma_get_src_port(id));
3970 		}
3971 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3972 		break;
3973 	}
3974 	case AF_INET6: {
3975 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
3976 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
3977 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
3978 			  trid->traddr, sizeof(trid->traddr));
3979 		if (peer) {
3980 			port = ntohs(rdma_get_dst_port(id));
3981 		} else {
3982 			port = ntohs(rdma_get_src_port(id));
3983 		}
3984 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3985 		break;
3986 	}
3987 	default:
3988 		return -1;
3989 
3990 	}
3991 
3992 	return 0;
3993 }
3994 
3995 static int
3996 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3997 			      struct spdk_nvme_transport_id *trid)
3998 {
3999 	struct spdk_nvmf_rdma_qpair	*rqpair;
4000 
4001 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4002 
4003 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4004 }
4005 
4006 static int
4007 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4008 			       struct spdk_nvme_transport_id *trid)
4009 {
4010 	struct spdk_nvmf_rdma_qpair	*rqpair;
4011 
4012 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4013 
4014 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4015 }
4016 
4017 static int
4018 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4019 				struct spdk_nvme_transport_id *trid)
4020 {
4021 	struct spdk_nvmf_rdma_qpair	*rqpair;
4022 
4023 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4024 
4025 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4026 }
4027 
4028 void
4029 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4030 {
4031 	g_nvmf_hooks = *hooks;
4032 }
4033 
4034 static void
4035 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4036 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4037 {
4038 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4039 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4040 
4041 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4042 
4043 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4044 }
4045 
4046 static int
4047 _nvmf_rdma_qpair_abort_request(void *ctx)
4048 {
4049 	struct spdk_nvmf_request *req = ctx;
4050 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4051 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4052 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4053 					      struct spdk_nvmf_rdma_qpair, qpair);
4054 	int rc;
4055 
4056 	spdk_poller_unregister(&req->poller);
4057 
4058 	switch (rdma_req_to_abort->state) {
4059 	case RDMA_REQUEST_STATE_EXECUTING:
4060 		rc = nvmf_ctrlr_abort_request(req, &rdma_req_to_abort->req);
4061 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4062 			return SPDK_POLLER_BUSY;
4063 		}
4064 		break;
4065 
4066 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4067 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4068 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4069 
4070 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4071 		break;
4072 
4073 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4074 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4075 			      spdk_nvmf_rdma_request, state_link);
4076 
4077 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4078 		break;
4079 
4080 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4081 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4082 			      spdk_nvmf_rdma_request, state_link);
4083 
4084 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4085 		break;
4086 
4087 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4088 		if (spdk_get_ticks() < req->timeout_tsc) {
4089 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4090 			return SPDK_POLLER_BUSY;
4091 		}
4092 		break;
4093 
4094 	default:
4095 		break;
4096 	}
4097 
4098 	spdk_nvmf_request_complete(req);
4099 	return SPDK_POLLER_BUSY;
4100 }
4101 
4102 static void
4103 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4104 			      struct spdk_nvmf_request *req)
4105 {
4106 	struct spdk_nvmf_rdma_qpair *rqpair;
4107 	struct spdk_nvmf_rdma_transport *rtransport;
4108 	struct spdk_nvmf_transport *transport;
4109 	uint16_t cid;
4110 	uint32_t i;
4111 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL;
4112 
4113 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4114 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4115 	transport = &rtransport->transport;
4116 
4117 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4118 
4119 	for (i = 0; i < rqpair->max_queue_depth; i++) {
4120 		rdma_req_to_abort = &rqpair->resources->reqs[i];
4121 
4122 		if (rdma_req_to_abort->state != RDMA_REQUEST_STATE_FREE &&
4123 		    rdma_req_to_abort->req.cmd->nvme_cmd.cid == cid) {
4124 			break;
4125 		}
4126 	}
4127 
4128 	if (rdma_req_to_abort == NULL) {
4129 		spdk_nvmf_request_complete(req);
4130 		return;
4131 	}
4132 
4133 	req->req_to_abort = &rdma_req_to_abort->req;
4134 	req->timeout_tsc = spdk_get_ticks() +
4135 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4136 	req->poller = NULL;
4137 
4138 	_nvmf_rdma_qpair_abort_request(req);
4139 }
4140 
4141 static int
4142 nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
4143 			      struct spdk_nvmf_transport_poll_group_stat **stat)
4144 {
4145 	struct spdk_io_channel *ch;
4146 	struct spdk_nvmf_poll_group *group;
4147 	struct spdk_nvmf_transport_poll_group *tgroup;
4148 	struct spdk_nvmf_rdma_poll_group *rgroup;
4149 	struct spdk_nvmf_rdma_poller *rpoller;
4150 	struct spdk_nvmf_rdma_device_stat *device_stat;
4151 	uint64_t num_devices = 0;
4152 
4153 	if (tgt == NULL || stat == NULL) {
4154 		return -EINVAL;
4155 	}
4156 
4157 	ch = spdk_get_io_channel(tgt);
4158 	group = spdk_io_channel_get_ctx(ch);;
4159 	spdk_put_io_channel(ch);
4160 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4161 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4162 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4163 			if (!*stat) {
4164 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4165 				return -ENOMEM;
4166 			}
4167 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4168 
4169 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4170 			/* Count devices to allocate enough memory */
4171 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4172 				++num_devices;
4173 			}
4174 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4175 			if (!(*stat)->rdma.devices) {
4176 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4177 				free(*stat);
4178 				return -ENOMEM;
4179 			}
4180 
4181 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4182 			(*stat)->rdma.num_devices = num_devices;
4183 			num_devices = 0;
4184 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4185 				device_stat = &(*stat)->rdma.devices[num_devices++];
4186 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4187 				device_stat->polls = rpoller->stat.polls;
4188 				device_stat->completions = rpoller->stat.completions;
4189 				device_stat->requests = rpoller->stat.requests;
4190 				device_stat->request_latency = rpoller->stat.request_latency;
4191 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4192 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4193 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4194 			}
4195 			return 0;
4196 		}
4197 	}
4198 	return -ENOENT;
4199 }
4200 
4201 static void
4202 nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4203 {
4204 	if (stat) {
4205 		free(stat->rdma.devices);
4206 	}
4207 	free(stat);
4208 }
4209 
4210 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4211 	.name = "RDMA",
4212 	.type = SPDK_NVME_TRANSPORT_RDMA,
4213 	.opts_init = nvmf_rdma_opts_init,
4214 	.create = nvmf_rdma_create,
4215 	.destroy = nvmf_rdma_destroy,
4216 
4217 	.listen = nvmf_rdma_listen,
4218 	.stop_listen = nvmf_rdma_stop_listen,
4219 	.accept = nvmf_rdma_accept,
4220 	.cdata_init = nvmf_rdma_cdata_init,
4221 
4222 	.listener_discover = nvmf_rdma_discover,
4223 
4224 	.poll_group_create = nvmf_rdma_poll_group_create,
4225 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4226 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4227 	.poll_group_add = nvmf_rdma_poll_group_add,
4228 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4229 
4230 	.req_free = nvmf_rdma_request_free,
4231 	.req_complete = nvmf_rdma_request_complete,
4232 
4233 	.qpair_fini = nvmf_rdma_close_qpair,
4234 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4235 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4236 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4237 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4238 
4239 	.poll_group_get_stat = nvmf_rdma_poll_group_get_stat,
4240 	.poll_group_free_stat = nvmf_rdma_poll_group_free_stat,
4241 };
4242 
4243 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4244 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
4245