xref: /spdk/lib/nvmf/rdma.c (revision 3fc824c834babab53b3188bef1d993f512b33dec)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2018 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 <infiniband/verbs.h>
37 #include <rdma/rdma_cma.h>
38 #include <rdma/rdma_verbs.h>
39 
40 #include "nvmf_internal.h"
41 #include "transport.h"
42 
43 #include "spdk/config.h"
44 #include "spdk/assert.h"
45 #include "spdk/thread.h"
46 #include "spdk/nvmf.h"
47 #include "spdk/nvmf_spec.h"
48 #include "spdk/string.h"
49 #include "spdk/trace.h"
50 #include "spdk/util.h"
51 
52 #include "spdk_internal/log.h"
53 
54 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
55 
56 /*
57  RDMA Connection Resource Defaults
58  */
59 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
60 #define NVMF_DEFAULT_RSP_SGE		1
61 #define NVMF_DEFAULT_RX_SGE		2
62 
63 /* The RDMA completion queue size */
64 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
65 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
66 
67 /* Timeout for destroying defunct rqpairs */
68 #define NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US 4000000
69 
70 enum spdk_nvmf_rdma_request_state {
71 	/* The request is not currently in use */
72 	RDMA_REQUEST_STATE_FREE = 0,
73 
74 	/* Initial state when request first received */
75 	RDMA_REQUEST_STATE_NEW,
76 
77 	/* The request is queued until a data buffer is available. */
78 	RDMA_REQUEST_STATE_NEED_BUFFER,
79 
80 	/* The request is waiting on RDMA queue depth availability
81 	 * to transfer data from the host to the controller.
82 	 */
83 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
84 
85 	/* The request is currently transferring data from the host to the controller. */
86 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
87 
88 	/* The request is ready to execute at the block device */
89 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
90 
91 	/* The request is currently executing at the block device */
92 	RDMA_REQUEST_STATE_EXECUTING,
93 
94 	/* The request finished executing at the block device */
95 	RDMA_REQUEST_STATE_EXECUTED,
96 
97 	/* The request is waiting on RDMA queue depth availability
98 	 * to transfer data from the controller to the host.
99 	 */
100 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
101 
102 	/* The request is ready to send a completion */
103 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
104 
105 	/* The request is currently transferring data from the controller to the host. */
106 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
107 
108 	/* The request currently has an outstanding completion without an
109 	 * associated data transfer.
110 	 */
111 	RDMA_REQUEST_STATE_COMPLETING,
112 
113 	/* The request completed and can be marked free. */
114 	RDMA_REQUEST_STATE_COMPLETED,
115 
116 	/* Terminator */
117 	RDMA_REQUEST_NUM_STATES,
118 };
119 
120 #define OBJECT_NVMF_RDMA_IO				0x40
121 
122 #define TRACE_GROUP_NVMF_RDMA				0x4
123 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
124 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
125 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
126 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
127 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
128 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
129 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
130 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
131 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
132 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
133 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
134 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
135 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
136 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
137 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
138 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
139 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
140 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
141 
142 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
143 {
144 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
145 	spdk_trace_register_description("RDMA_REQ_NEW", "",
146 					TRACE_RDMA_REQUEST_STATE_NEW,
147 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
148 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
149 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
150 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
151 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C_TO_H", "",
152 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
153 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
154 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
155 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
156 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
157 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
158 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
159 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
160 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
161 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
163 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
164 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
165 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
166 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
167 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
170 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 	spdk_trace_register_description("RDMA_REQ_COMPLETING_CONTROLLER_TO_HOST", "",
173 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
175 	spdk_trace_register_description("RDMA_REQ_COMPLETING_INCAPSULE", "",
176 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
178 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
179 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
180 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
181 
182 	spdk_trace_register_description("RDMA_QP_CREATE", "", TRACE_RDMA_QP_CREATE,
183 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
184 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", "", TRACE_RDMA_IBV_ASYNC_EVENT,
185 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
186 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", "", TRACE_RDMA_CM_ASYNC_EVENT,
187 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
188 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", "", TRACE_RDMA_QP_STATE_CHANGE,
189 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
190 	spdk_trace_register_description("RDMA_QP_DISCONNECT", "", TRACE_RDMA_QP_DISCONNECT,
191 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
192 	spdk_trace_register_description("RDMA_QP_DESTROY", "", TRACE_RDMA_QP_DESTROY,
193 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
194 }
195 
196 enum spdk_nvmf_rdma_wr_type {
197 	RDMA_WR_TYPE_RECV,
198 	RDMA_WR_TYPE_SEND,
199 	RDMA_WR_TYPE_DATA,
200 };
201 
202 struct spdk_nvmf_rdma_wr {
203 	enum spdk_nvmf_rdma_wr_type	type;
204 };
205 
206 /* This structure holds commands as they are received off the wire.
207  * It must be dynamically paired with a full request object
208  * (spdk_nvmf_rdma_request) to service a request. It is separate
209  * from the request because RDMA does not appear to order
210  * completions, so occasionally we'll get a new incoming
211  * command when there aren't any free request objects.
212  */
213 struct spdk_nvmf_rdma_recv {
214 	struct ibv_recv_wr			wr;
215 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
216 
217 	struct spdk_nvmf_rdma_qpair		*qpair;
218 
219 	/* In-capsule data buffer */
220 	uint8_t					*buf;
221 
222 	struct spdk_nvmf_rdma_wr		rdma_wr;
223 
224 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
225 };
226 
227 struct spdk_nvmf_rdma_request_data {
228 	struct spdk_nvmf_rdma_wr	rdma_wr;
229 	struct ibv_send_wr		wr;
230 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
231 	void				*buffers[SPDK_NVMF_MAX_SGL_ENTRIES];
232 };
233 
234 struct spdk_nvmf_rdma_request {
235 	struct spdk_nvmf_request		req;
236 	bool					data_from_pool;
237 
238 	enum spdk_nvmf_rdma_request_state	state;
239 
240 	struct spdk_nvmf_rdma_recv		*recv;
241 
242 	struct {
243 		struct spdk_nvmf_rdma_wr	rdma_wr;
244 		struct	ibv_send_wr		wr;
245 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
246 	} rsp;
247 
248 	struct spdk_nvmf_rdma_request_data	data;
249 
250 	uint32_t				num_outstanding_data_wr;
251 
252 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
253 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
254 };
255 
256 enum spdk_nvmf_rdma_qpair_disconnect_flags {
257 	RDMA_QP_DISCONNECTING		= 1,
258 	RDMA_QP_RECV_DRAINED		= 1 << 1,
259 	RDMA_QP_SEND_DRAINED		= 1 << 2
260 };
261 
262 struct spdk_nvmf_rdma_qpair {
263 	struct spdk_nvmf_qpair			qpair;
264 
265 	struct spdk_nvmf_rdma_port		*port;
266 	struct spdk_nvmf_rdma_poller		*poller;
267 
268 	struct rdma_cm_id			*cm_id;
269 	struct rdma_cm_id			*listen_id;
270 
271 	/* The maximum number of I/O outstanding on this connection at one time */
272 	uint16_t				max_queue_depth;
273 
274 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
275 	uint16_t				max_read_depth;
276 
277 	/* The maximum number of RDMA SEND operations at one time */
278 	uint32_t				max_send_depth;
279 
280 	/* The current number of outstanding WRs from this qpair's
281 	 * recv queue. Should not exceed device->attr.max_queue_depth.
282 	 */
283 	uint16_t				current_recv_depth;
284 
285 	/* The current number of posted WRs from this qpair's
286 	 * send queue. Should not exceed max_send_depth.
287 	 */
288 	uint32_t				current_send_depth;
289 
290 	/* The current number of active RDMA READ operations */
291 	uint16_t				current_read_depth;
292 
293 	/* The maximum number of SGEs per WR on the send queue */
294 	uint32_t				max_send_sge;
295 
296 	/* The maximum number of SGEs per WR on the recv queue */
297 	uint32_t				max_recv_sge;
298 
299 	/* Receives that are waiting for a request object */
300 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
301 
302 	/* Queues to track requests in critical states */
303 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
304 
305 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
306 
307 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
308 
309 	/* Number of requests not in the free state */
310 	uint32_t				qd;
311 
312 	/* Array of size "max_queue_depth" containing RDMA requests. */
313 	struct spdk_nvmf_rdma_request		*reqs;
314 
315 	/* Array of size "max_queue_depth" containing RDMA recvs. */
316 	struct spdk_nvmf_rdma_recv		*recvs;
317 
318 	/* Array of size "max_queue_depth" containing 64 byte capsules
319 	 * used for receive.
320 	 */
321 	union nvmf_h2c_msg			*cmds;
322 	struct ibv_mr				*cmds_mr;
323 
324 	/* Array of size "max_queue_depth" containing 16 byte completions
325 	 * to be sent back to the user.
326 	 */
327 	union nvmf_c2h_msg			*cpls;
328 	struct ibv_mr				*cpls_mr;
329 
330 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
331 	 * buffers to be used for in capsule data.
332 	 */
333 	void					*bufs;
334 	struct ibv_mr				*bufs_mr;
335 
336 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
337 
338 	/* IBV queue pair attributes: they are used to manage
339 	 * qp state and recover from errors.
340 	 */
341 	struct ibv_qp_attr			ibv_attr;
342 
343 	uint32_t				disconnect_flags;
344 
345 	/* Poller registered in case the qpair doesn't properly
346 	 * complete the qpair destruct process and becomes defunct.
347 	 */
348 
349 	struct spdk_poller			*destruct_poller;
350 
351 	/* There are several ways a disconnect can start on a qpair
352 	 * and they are not all mutually exclusive. It is important
353 	 * that we only initialize one of these paths.
354 	 */
355 	bool					disconnect_started;
356 };
357 
358 struct spdk_nvmf_rdma_poller {
359 	struct spdk_nvmf_rdma_device		*device;
360 	struct spdk_nvmf_rdma_poll_group	*group;
361 
362 	int					num_cqe;
363 	int					required_num_wr;
364 	struct ibv_cq				*cq;
365 
366 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
367 
368 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
369 };
370 
371 struct spdk_nvmf_rdma_poll_group {
372 	struct spdk_nvmf_transport_poll_group	group;
373 
374 	/* Requests that are waiting to obtain a data buffer */
375 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
376 
377 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
378 };
379 
380 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
381 struct spdk_nvmf_rdma_device {
382 	struct ibv_device_attr			attr;
383 	struct ibv_context			*context;
384 
385 	struct spdk_mem_map			*map;
386 	struct ibv_pd				*pd;
387 
388 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
389 };
390 
391 struct spdk_nvmf_rdma_port {
392 	struct spdk_nvme_transport_id		trid;
393 	struct rdma_cm_id			*id;
394 	struct spdk_nvmf_rdma_device		*device;
395 	uint32_t				ref;
396 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
397 };
398 
399 struct spdk_nvmf_rdma_transport {
400 	struct spdk_nvmf_transport	transport;
401 
402 	struct rdma_event_channel	*event_channel;
403 
404 	struct spdk_mempool		*data_wr_pool;
405 
406 	pthread_mutex_t			lock;
407 
408 	/* fields used to poll RDMA/IB events */
409 	nfds_t			npoll_fds;
410 	struct pollfd		*poll_fds;
411 
412 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
413 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
414 };
415 
416 static inline int
417 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
418 {
419 	switch (state) {
420 	case IBV_QPS_RESET:
421 	case IBV_QPS_INIT:
422 	case IBV_QPS_RTR:
423 	case IBV_QPS_RTS:
424 	case IBV_QPS_SQD:
425 	case IBV_QPS_SQE:
426 	case IBV_QPS_ERR:
427 		return 0;
428 	default:
429 		return -1;
430 	}
431 }
432 
433 static enum ibv_qp_state
434 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
435 	enum ibv_qp_state old_state, new_state;
436 	struct ibv_qp_init_attr init_attr;
437 	int rc;
438 
439 	/* All the attributes needed for recovery */
440 	static int spdk_nvmf_ibv_attr_mask =
441 	IBV_QP_STATE |
442 	IBV_QP_PKEY_INDEX |
443 	IBV_QP_PORT |
444 	IBV_QP_ACCESS_FLAGS |
445 	IBV_QP_AV |
446 	IBV_QP_PATH_MTU |
447 	IBV_QP_DEST_QPN |
448 	IBV_QP_RQ_PSN |
449 	IBV_QP_MAX_DEST_RD_ATOMIC |
450 	IBV_QP_MIN_RNR_TIMER |
451 	IBV_QP_SQ_PSN |
452 	IBV_QP_TIMEOUT |
453 	IBV_QP_RETRY_CNT |
454 	IBV_QP_RNR_RETRY |
455 	IBV_QP_MAX_QP_RD_ATOMIC;
456 
457 	old_state = rqpair->ibv_attr.qp_state;
458 	rc = ibv_query_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
459 			  spdk_nvmf_ibv_attr_mask, &init_attr);
460 
461 	if (rc)
462 	{
463 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
464 		assert(false);
465 	}
466 
467 	new_state = rqpair->ibv_attr.qp_state;
468 
469 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
470 	if (rc)
471 	{
472 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
473 		/*
474 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
475 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
476 		 */
477 		return IBV_QPS_ERR + 1;
478 	}
479 
480 	if (old_state != new_state)
481 	{
482 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
483 				  (uintptr_t)rqpair->cm_id, new_state);
484 	}
485 	return new_state;
486 }
487 
488 static const char *str_ibv_qp_state[] = {
489 	"IBV_QPS_RESET",
490 	"IBV_QPS_INIT",
491 	"IBV_QPS_RTR",
492 	"IBV_QPS_RTS",
493 	"IBV_QPS_SQD",
494 	"IBV_QPS_SQE",
495 	"IBV_QPS_ERR",
496 	"IBV_QPS_UNKNOWN"
497 };
498 
499 static int
500 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
501 			     enum ibv_qp_state new_state)
502 {
503 	int rc;
504 	enum ibv_qp_state state;
505 	static int attr_mask_rc[] = {
506 		[IBV_QPS_RESET] = IBV_QP_STATE,
507 		[IBV_QPS_INIT] = (IBV_QP_STATE |
508 				  IBV_QP_PKEY_INDEX |
509 				  IBV_QP_PORT |
510 				  IBV_QP_ACCESS_FLAGS),
511 		[IBV_QPS_RTR] = (IBV_QP_STATE |
512 				 IBV_QP_AV |
513 				 IBV_QP_PATH_MTU |
514 				 IBV_QP_DEST_QPN |
515 				 IBV_QP_RQ_PSN |
516 				 IBV_QP_MAX_DEST_RD_ATOMIC |
517 				 IBV_QP_MIN_RNR_TIMER),
518 		[IBV_QPS_RTS] = (IBV_QP_STATE |
519 				 IBV_QP_SQ_PSN |
520 				 IBV_QP_TIMEOUT |
521 				 IBV_QP_RETRY_CNT |
522 				 IBV_QP_RNR_RETRY |
523 				 IBV_QP_MAX_QP_RD_ATOMIC),
524 		[IBV_QPS_SQD] = IBV_QP_STATE,
525 		[IBV_QPS_SQE] = IBV_QP_STATE,
526 		[IBV_QPS_ERR] = IBV_QP_STATE,
527 	};
528 
529 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
530 	if (rc) {
531 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
532 			    rqpair->qpair.qid, new_state);
533 		return rc;
534 	}
535 
536 	rqpair->ibv_attr.cur_qp_state = rqpair->ibv_attr.qp_state;
537 	rqpair->ibv_attr.qp_state = new_state;
538 	rqpair->ibv_attr.ah_attr.port_num = rqpair->ibv_attr.port_num;
539 
540 	rc = ibv_modify_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
541 			   attr_mask_rc[new_state]);
542 
543 	if (rc) {
544 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
545 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
546 		return rc;
547 	}
548 
549 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
550 
551 	if (state != new_state) {
552 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
553 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
554 			    str_ibv_qp_state[state]);
555 		return -1;
556 	}
557 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
558 		      str_ibv_qp_state[state]);
559 	return 0;
560 }
561 
562 static void
563 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
564 {
565 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->data_from_pool);
566 	if (req->req.cmd) {
567 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
568 	}
569 	if (req->recv) {
570 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
571 	}
572 }
573 
574 static void
575 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
576 {
577 	int i;
578 
579 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
580 	for (i = 0; i < rqpair->max_queue_depth; i++) {
581 		if (rqpair->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
582 			nvmf_rdma_dump_request(&rqpair->reqs[i]);
583 		}
584 	}
585 }
586 
587 static void
588 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
589 {
590 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
591 
592 	spdk_poller_unregister(&rqpair->destruct_poller);
593 
594 	if (rqpair->qd != 0) {
595 		nvmf_rdma_dump_qpair_contents(rqpair);
596 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
597 	}
598 
599 	if (rqpair->poller) {
600 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
601 	}
602 
603 	if (rqpair->cmds_mr) {
604 		ibv_dereg_mr(rqpair->cmds_mr);
605 	}
606 
607 	if (rqpair->cpls_mr) {
608 		ibv_dereg_mr(rqpair->cpls_mr);
609 	}
610 
611 	if (rqpair->bufs_mr) {
612 		ibv_dereg_mr(rqpair->bufs_mr);
613 	}
614 
615 	if (rqpair->cm_id) {
616 		rdma_destroy_qp(rqpair->cm_id);
617 		rdma_destroy_id(rqpair->cm_id);
618 
619 		if (rqpair->poller) {
620 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
621 		}
622 	}
623 
624 	/* Free all memory */
625 	spdk_dma_free(rqpair->cmds);
626 	spdk_dma_free(rqpair->cpls);
627 	spdk_dma_free(rqpair->bufs);
628 	free(rqpair->reqs);
629 	free(rqpair->recvs);
630 	free(rqpair);
631 }
632 
633 static int
634 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
635 {
636 	struct spdk_nvmf_rdma_transport *rtransport;
637 	struct spdk_nvmf_rdma_qpair	*rqpair;
638 	struct spdk_nvmf_rdma_poller	*rpoller;
639 	int				rc, i, num_cqe, required_num_wr;;
640 	struct spdk_nvmf_rdma_recv	*rdma_recv;
641 	struct spdk_nvmf_rdma_request	*rdma_req;
642 	struct spdk_nvmf_transport	*transport;
643 	struct spdk_nvmf_rdma_device	*device;
644 	struct ibv_qp_init_attr		ibv_init_attr;
645 
646 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
647 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
648 	transport = &rtransport->transport;
649 	device = rqpair->port->device;
650 
651 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
652 	ibv_init_attr.qp_context	= rqpair;
653 	ibv_init_attr.qp_type		= IBV_QPT_RC;
654 	ibv_init_attr.send_cq		= rqpair->poller->cq;
655 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
656 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
657 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
658 	ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
659 					  1; /* RECV operations + dummy drain WR */
660 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
661 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
662 
663 	/* Enlarge CQ size dynamically */
664 	rpoller = rqpair->poller;
665 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
666 	num_cqe = rpoller->num_cqe;
667 	if (num_cqe < required_num_wr) {
668 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
669 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
670 	}
671 
672 	if (rpoller->num_cqe != num_cqe) {
673 		if (required_num_wr > device->attr.max_cqe) {
674 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
675 				    required_num_wr, device->attr.max_cqe);
676 			rdma_destroy_id(rqpair->cm_id);
677 			rqpair->cm_id = NULL;
678 			spdk_nvmf_rdma_qpair_destroy(rqpair);
679 			return -1;
680 		}
681 
682 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
683 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
684 		if (rc) {
685 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
686 			rdma_destroy_id(rqpair->cm_id);
687 			rqpair->cm_id = NULL;
688 			spdk_nvmf_rdma_qpair_destroy(rqpair);
689 			return -1;
690 		}
691 
692 		rpoller->num_cqe = num_cqe;
693 	}
694 
695 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
696 	if (rc) {
697 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
698 		rdma_destroy_id(rqpair->cm_id);
699 		rqpair->cm_id = NULL;
700 		spdk_nvmf_rdma_qpair_destroy(rqpair);
701 		return -1;
702 	}
703 
704 	rpoller->required_num_wr = required_num_wr;
705 
706 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2 + 1),
707 					  ibv_init_attr.cap.max_send_wr);
708 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
709 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
710 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
711 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
712 
713 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
714 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
715 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
716 					0x1000, NULL);
717 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
718 					0x1000, NULL);
719 
720 
721 	if (transport->opts.in_capsule_data_size > 0) {
722 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth *
723 						transport->opts.in_capsule_data_size,
724 						0x1000, NULL);
725 	}
726 
727 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
728 	    !rqpair->cpls || (transport->opts.in_capsule_data_size && !rqpair->bufs)) {
729 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
730 		spdk_nvmf_rdma_qpair_destroy(rqpair);
731 		return -1;
732 	}
733 
734 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
735 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
736 				     IBV_ACCESS_LOCAL_WRITE);
737 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
738 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
739 				     0);
740 
741 	if (transport->opts.in_capsule_data_size) {
742 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
743 					     rqpair->max_queue_depth *
744 					     transport->opts.in_capsule_data_size,
745 					     IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
746 	}
747 
748 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (transport->opts.in_capsule_data_size &&
749 			!rqpair->bufs_mr)) {
750 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
751 		spdk_nvmf_rdma_qpair_destroy(rqpair);
752 		return -1;
753 	}
754 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
755 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
756 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
757 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
758 	if (rqpair->bufs && rqpair->bufs_mr) {
759 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
760 			      rqpair->bufs, rqpair->max_queue_depth *
761 			      transport->opts.in_capsule_data_size, rqpair->bufs_mr->lkey);
762 	}
763 
764 	STAILQ_INIT(&rqpair->free_queue);
765 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
766 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
767 
768 	rqpair->current_recv_depth = rqpair->max_queue_depth;
769 	for (i = 0; i < rqpair->max_queue_depth; i++) {
770 		struct ibv_recv_wr *bad_wr = NULL;
771 
772 		rdma_recv = &rqpair->recvs[i];
773 		rdma_recv->qpair = rqpair;
774 
775 		/* Set up memory to receive commands */
776 		if (rqpair->bufs) {
777 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i *
778 						  transport->opts.in_capsule_data_size));
779 		}
780 
781 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
782 
783 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
784 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
785 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
786 		rdma_recv->wr.num_sge = 1;
787 
788 		if (rdma_recv->buf && rqpair->bufs_mr) {
789 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
790 			rdma_recv->sgl[1].length = transport->opts.in_capsule_data_size;
791 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
792 			rdma_recv->wr.num_sge++;
793 		}
794 
795 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
796 		rdma_recv->wr.sg_list = rdma_recv->sgl;
797 
798 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
799 		assert(rqpair->current_recv_depth > 0);
800 		rqpair->current_recv_depth--;
801 		if (rc) {
802 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
803 			spdk_nvmf_rdma_qpair_destroy(rqpair);
804 			return -1;
805 		}
806 	}
807 	assert(rqpair->current_recv_depth == 0);
808 
809 	for (i = 0; i < rqpair->max_queue_depth; i++) {
810 		rdma_req = &rqpair->reqs[i];
811 
812 		rdma_req->req.qpair = &rqpair->qpair;
813 		rdma_req->req.cmd = NULL;
814 
815 		/* Set up memory to send responses */
816 		rdma_req->req.rsp = &rqpair->cpls[i];
817 
818 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
819 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
820 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
821 
822 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
823 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
824 		rdma_req->rsp.wr.next = NULL;
825 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
826 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
827 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
828 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
829 
830 		/* Set up memory for data buffers */
831 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
832 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
833 		rdma_req->data.wr.next = NULL;
834 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
835 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
836 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
837 
838 		/* Initialize request state to FREE */
839 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
840 		STAILQ_INSERT_HEAD(&rqpair->free_queue, rdma_req, state_link);
841 	}
842 
843 	return 0;
844 }
845 
846 static int
847 request_transfer_in(struct spdk_nvmf_request *req)
848 {
849 	int				rc;
850 	struct spdk_nvmf_rdma_request	*rdma_req;
851 	struct spdk_nvmf_qpair		*qpair;
852 	struct spdk_nvmf_rdma_qpair	*rqpair;
853 	struct ibv_send_wr		*bad_wr = NULL;
854 
855 	qpair = req->qpair;
856 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
857 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
858 
859 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
860 	assert(rdma_req != NULL);
861 
862 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
863 
864 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
865 	if (rc) {
866 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
867 		return -1;
868 	}
869 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
870 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
871 	return 0;
872 }
873 
874 static int
875 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
876 {
877 	int				rc;
878 	struct spdk_nvmf_rdma_request	*rdma_req;
879 	struct spdk_nvmf_qpair		*qpair;
880 	struct spdk_nvmf_rdma_qpair	*rqpair;
881 	struct spdk_nvme_cpl		*rsp;
882 	struct ibv_recv_wr		*bad_recv_wr = NULL;
883 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
884 
885 	*data_posted = 0;
886 	qpair = req->qpair;
887 	rsp = &req->rsp->nvme_cpl;
888 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
889 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
890 
891 	/* Advance our sq_head pointer */
892 	if (qpair->sq_head == qpair->sq_head_max) {
893 		qpair->sq_head = 0;
894 	} else {
895 		qpair->sq_head++;
896 	}
897 	rsp->sqhd = qpair->sq_head;
898 
899 	/* Post the capsule to the recv buffer */
900 	assert(rdma_req->recv != NULL);
901 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
902 		      rqpair);
903 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
904 	if (rc) {
905 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
906 		return rc;
907 	}
908 	rdma_req->recv = NULL;
909 	assert(rqpair->current_recv_depth > 0);
910 	rqpair->current_recv_depth--;
911 
912 	/* Build the response which consists of an optional
913 	 * RDMA WRITE to transfer data, plus an RDMA SEND
914 	 * containing the response.
915 	 */
916 	send_wr = &rdma_req->rsp.wr;
917 
918 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
919 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
920 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
921 		send_wr = &rdma_req->data.wr;
922 		*data_posted = 1;
923 	}
924 
925 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
926 
927 	/* Send the completion */
928 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
929 	if (rc) {
930 		SPDK_ERRLOG("Unable to send response capsule\n");
931 		return rc;
932 	}
933 	/* +1 for the rsp wr */
934 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr + 1;
935 
936 	return 0;
937 }
938 
939 static int
940 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
941 {
942 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
943 	struct rdma_conn_param				ctrlr_event_data = {};
944 	int						rc;
945 
946 	accept_data.recfmt = 0;
947 	accept_data.crqsize = rqpair->max_queue_depth;
948 
949 	ctrlr_event_data.private_data = &accept_data;
950 	ctrlr_event_data.private_data_len = sizeof(accept_data);
951 	if (id->ps == RDMA_PS_TCP) {
952 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
953 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
954 	}
955 
956 	rc = rdma_accept(id, &ctrlr_event_data);
957 	if (rc) {
958 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
959 	} else {
960 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
961 	}
962 
963 	return rc;
964 }
965 
966 static void
967 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
968 {
969 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
970 
971 	rej_data.recfmt = 0;
972 	rej_data.sts = error;
973 
974 	rdma_reject(id, &rej_data, sizeof(rej_data));
975 }
976 
977 static int
978 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
979 		  new_qpair_fn cb_fn)
980 {
981 	struct spdk_nvmf_rdma_transport *rtransport;
982 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
983 	struct spdk_nvmf_rdma_port	*port;
984 	struct rdma_conn_param		*rdma_param = NULL;
985 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
986 	uint16_t			max_queue_depth;
987 	uint16_t			max_read_depth;
988 
989 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
990 
991 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
992 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
993 
994 	rdma_param = &event->param.conn;
995 	if (rdma_param->private_data == NULL ||
996 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
997 		SPDK_ERRLOG("connect request: no private data provided\n");
998 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
999 		return -1;
1000 	}
1001 
1002 	private_data = rdma_param->private_data;
1003 	if (private_data->recfmt != 0) {
1004 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1005 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1006 		return -1;
1007 	}
1008 
1009 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1010 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1011 
1012 	port = event->listen_id->context;
1013 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1014 		      event->listen_id, event->listen_id->verbs, port);
1015 
1016 	/* Figure out the supported queue depth. This is a multi-step process
1017 	 * that takes into account hardware maximums, host provided values,
1018 	 * and our target's internal memory limits */
1019 
1020 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1021 
1022 	/* Start with the maximum queue depth allowed by the target */
1023 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1024 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1025 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1026 		      rtransport->transport.opts.max_queue_depth);
1027 
1028 	/* Next check the local NIC's hardware limitations */
1029 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1030 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1031 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1032 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1033 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1034 
1035 	/* Next check the remote NIC's hardware limitations */
1036 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1037 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1038 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1039 	if (rdma_param->initiator_depth > 0) {
1040 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1041 	}
1042 
1043 	/* Finally check for the host software requested values, which are
1044 	 * optional. */
1045 	if (rdma_param->private_data != NULL &&
1046 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1047 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1048 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1049 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1050 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1051 	}
1052 
1053 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1054 		      max_queue_depth, max_read_depth);
1055 
1056 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1057 	if (rqpair == NULL) {
1058 		SPDK_ERRLOG("Could not allocate new connection.\n");
1059 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1060 		return -1;
1061 	}
1062 
1063 	rqpair->port = port;
1064 	rqpair->max_queue_depth = max_queue_depth;
1065 	rqpair->max_read_depth = max_read_depth;
1066 	rqpair->cm_id = event->id;
1067 	rqpair->listen_id = event->listen_id;
1068 	rqpair->qpair.transport = transport;
1069 	STAILQ_INIT(&rqpair->incoming_queue);
1070 	event->id->context = &rqpair->qpair;
1071 
1072 	cb_fn(&rqpair->qpair);
1073 
1074 	return 0;
1075 }
1076 
1077 static int
1078 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1079 			  enum spdk_mem_map_notify_action action,
1080 			  void *vaddr, size_t size)
1081 {
1082 	struct ibv_pd *pd = cb_ctx;
1083 	struct ibv_mr *mr;
1084 
1085 	switch (action) {
1086 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1087 		if (!g_nvmf_hooks.get_rkey) {
1088 			mr = ibv_reg_mr(pd, vaddr, size,
1089 					IBV_ACCESS_LOCAL_WRITE |
1090 					IBV_ACCESS_REMOTE_READ |
1091 					IBV_ACCESS_REMOTE_WRITE);
1092 			if (mr == NULL) {
1093 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1094 				return -1;
1095 			} else {
1096 				spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1097 			}
1098 		} else {
1099 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1100 						     g_nvmf_hooks.get_rkey(pd, vaddr, size));
1101 		}
1102 		break;
1103 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1104 		if (!g_nvmf_hooks.get_rkey) {
1105 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1106 			spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1107 			if (mr) {
1108 				ibv_dereg_mr(mr);
1109 			}
1110 		}
1111 		break;
1112 	}
1113 
1114 	return 0;
1115 }
1116 
1117 static int
1118 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1119 {
1120 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1121 	return addr_1 == addr_2;
1122 }
1123 
1124 static void
1125 spdk_nvmf_rdma_request_free_buffers(struct spdk_nvmf_rdma_request *rdma_req,
1126 				    struct spdk_nvmf_transport_poll_group *group, struct spdk_nvmf_transport *transport)
1127 {
1128 	for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1129 		if (group->buf_cache_count < group->buf_cache_size) {
1130 			STAILQ_INSERT_HEAD(&group->buf_cache,
1131 					   (struct spdk_nvmf_transport_pg_cache_buf *)rdma_req->data.buffers[i], link);
1132 			group->buf_cache_count++;
1133 		} else {
1134 			spdk_mempool_put(transport->data_buf_pool, rdma_req->data.buffers[i]);
1135 		}
1136 		rdma_req->req.iov[i].iov_base = NULL;
1137 		rdma_req->data.buffers[i] = NULL;
1138 		rdma_req->req.iov[i].iov_len = 0;
1139 
1140 	}
1141 	rdma_req->data_from_pool = false;
1142 }
1143 
1144 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1145 
1146 static spdk_nvme_data_transfer_t
1147 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1148 {
1149 	enum spdk_nvme_data_transfer xfer;
1150 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1151 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1152 
1153 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1154 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1155 	rdma_req->rsp.wr.imm_data = 0;
1156 #endif
1157 
1158 	/* Figure out data transfer direction */
1159 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1160 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1161 	} else {
1162 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1163 
1164 		/* Some admin commands are special cases */
1165 		if ((rdma_req->req.qpair->qid == 0) &&
1166 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1167 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1168 			switch (cmd->cdw10 & 0xff) {
1169 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1170 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1171 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1172 				break;
1173 			default:
1174 				xfer = SPDK_NVME_DATA_NONE;
1175 			}
1176 		}
1177 	}
1178 
1179 	if (xfer == SPDK_NVME_DATA_NONE) {
1180 		return xfer;
1181 	}
1182 
1183 	/* Even for commands that may transfer data, they could have specified 0 length.
1184 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1185 	 */
1186 	switch (sgl->generic.type) {
1187 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1188 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1189 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1190 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1191 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1192 		if (sgl->unkeyed.length == 0) {
1193 			xfer = SPDK_NVME_DATA_NONE;
1194 		}
1195 		break;
1196 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1197 		if (sgl->keyed.length == 0) {
1198 			xfer = SPDK_NVME_DATA_NONE;
1199 		}
1200 		break;
1201 	}
1202 
1203 	return xfer;
1204 }
1205 
1206 static int
1207 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1208 				 struct spdk_nvmf_rdma_device *device,
1209 				 struct spdk_nvmf_rdma_request *rdma_req)
1210 {
1211 	struct spdk_nvmf_rdma_qpair		*rqpair;
1212 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1213 	void					*buf = NULL;
1214 	uint32_t				length = rdma_req->req.length;
1215 	uint64_t				translation_len;
1216 	uint32_t				i = 0;
1217 	int					rc = 0;
1218 
1219 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1220 	rgroup = rqpair->poller->group;
1221 	rdma_req->req.iovcnt = 0;
1222 	while (length) {
1223 		if (!(STAILQ_EMPTY(&rgroup->group.buf_cache))) {
1224 			rgroup->group.buf_cache_count--;
1225 			buf = STAILQ_FIRST(&rgroup->group.buf_cache);
1226 			STAILQ_REMOVE_HEAD(&rgroup->group.buf_cache, link);
1227 			assert(buf != NULL);
1228 		} else {
1229 			buf = spdk_mempool_get(rtransport->transport.data_buf_pool);
1230 			if (!buf) {
1231 				rc = -ENOMEM;
1232 				goto err_exit;
1233 			}
1234 		}
1235 
1236 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
1237 						~NVMF_DATA_BUFFER_MASK);
1238 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->transport.opts.io_unit_size);
1239 		rdma_req->req.iovcnt++;
1240 		rdma_req->data.buffers[i] = buf;
1241 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
1242 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
1243 		translation_len = rdma_req->req.iov[i].iov_len;
1244 
1245 		if (!g_nvmf_hooks.get_rkey) {
1246 			rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1247 							     (uint64_t)buf, &translation_len))->lkey;
1248 		} else {
1249 			rdma_req->data.wr.sg_list[i].lkey = spdk_mem_map_translate(device->map,
1250 							    (uint64_t)buf, &translation_len);
1251 		}
1252 
1253 		length -= rdma_req->req.iov[i].iov_len;
1254 
1255 		if (translation_len < rdma_req->req.iov[i].iov_len) {
1256 			SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
1257 			rc = -EINVAL;
1258 			goto err_exit;
1259 		}
1260 		i++;
1261 	}
1262 
1263 	assert(rdma_req->req.iovcnt <= rqpair->max_send_sge);
1264 
1265 	rdma_req->data_from_pool = true;
1266 
1267 	return rc;
1268 
1269 err_exit:
1270 	spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport);
1271 	while (i) {
1272 		i--;
1273 		rdma_req->data.wr.sg_list[i].addr = 0;
1274 		rdma_req->data.wr.sg_list[i].length = 0;
1275 		rdma_req->data.wr.sg_list[i].lkey = 0;
1276 	}
1277 	rdma_req->req.iovcnt = 0;
1278 	return rc;
1279 }
1280 
1281 static int
1282 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1283 				 struct spdk_nvmf_rdma_device *device,
1284 				 struct spdk_nvmf_rdma_request *rdma_req)
1285 {
1286 	struct spdk_nvme_cmd			*cmd;
1287 	struct spdk_nvme_cpl			*rsp;
1288 	struct spdk_nvme_sgl_descriptor		*sgl;
1289 
1290 	cmd = &rdma_req->req.cmd->nvme_cmd;
1291 	rsp = &rdma_req->req.rsp->nvme_cpl;
1292 	sgl = &cmd->dptr.sgl1;
1293 
1294 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1295 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1296 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1297 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1298 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1299 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1300 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1301 			return -1;
1302 		}
1303 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1304 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1305 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1306 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1307 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1308 			}
1309 		}
1310 #endif
1311 
1312 		/* fill request length and populate iovs */
1313 		rdma_req->req.length = sgl->keyed.length;
1314 
1315 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1316 			/* No available buffers. Queue this request up. */
1317 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1318 			return 0;
1319 		}
1320 
1321 		/* backward compatible */
1322 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1323 
1324 		/* rdma wr specifics */
1325 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1326 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1327 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1328 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1329 			rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
1330 			rdma_req->data.wr.next = &rdma_req->rsp.wr;
1331 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1332 			rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
1333 			rdma_req->data.wr.next = NULL;
1334 		}
1335 
1336 		/* set the number of outstanding data WRs for this request. */
1337 		rdma_req->num_outstanding_data_wr = 1;
1338 
1339 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1340 			      rdma_req->req.iovcnt);
1341 
1342 		return 0;
1343 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1344 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1345 		uint64_t offset = sgl->address;
1346 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1347 
1348 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1349 			      offset, sgl->unkeyed.length);
1350 
1351 		if (offset > max_len) {
1352 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1353 				    offset, max_len);
1354 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1355 			return -1;
1356 		}
1357 		max_len -= (uint32_t)offset;
1358 
1359 		if (sgl->unkeyed.length > max_len) {
1360 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1361 				    sgl->unkeyed.length, max_len);
1362 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1363 			return -1;
1364 		}
1365 
1366 		rdma_req->num_outstanding_data_wr = 0;
1367 		rdma_req->req.data = rdma_req->recv->buf + offset;
1368 		rdma_req->data_from_pool = false;
1369 		rdma_req->req.length = sgl->unkeyed.length;
1370 
1371 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1372 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1373 		rdma_req->req.iovcnt = 1;
1374 
1375 		return 0;
1376 	}
1377 
1378 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1379 		    sgl->generic.type, sgl->generic.subtype);
1380 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1381 	return -1;
1382 }
1383 
1384 static void
1385 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1386 		       struct spdk_nvmf_rdma_transport	*rtransport)
1387 {
1388 	struct spdk_nvmf_rdma_qpair		*rqpair;
1389 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1390 
1391 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1392 	if (rdma_req->data_from_pool) {
1393 		rgroup = rqpair->poller->group;
1394 
1395 		spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport);
1396 	}
1397 	rdma_req->num_outstanding_data_wr = 0;
1398 	rdma_req->req.length = 0;
1399 	rdma_req->req.iovcnt = 0;
1400 	rdma_req->req.data = NULL;
1401 	rqpair->qd--;
1402 	STAILQ_INSERT_HEAD(&rqpair->free_queue, rdma_req, state_link);
1403 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1404 }
1405 
1406 static bool
1407 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1408 			       struct spdk_nvmf_rdma_request *rdma_req)
1409 {
1410 	struct spdk_nvmf_rdma_qpair	*rqpair;
1411 	struct spdk_nvmf_rdma_device	*device;
1412 	struct spdk_nvmf_rdma_poll_group *rgroup;
1413 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1414 	int				rc;
1415 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1416 	enum spdk_nvmf_rdma_request_state prev_state;
1417 	bool				progress = false;
1418 	int				data_posted;
1419 
1420 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1421 	device = rqpair->port->device;
1422 	rgroup = rqpair->poller->group;
1423 
1424 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1425 
1426 	/* If the queue pair is in an error state, force the request to the completed state
1427 	 * to release resources. */
1428 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1429 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1430 			TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1431 		}
1432 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1433 	}
1434 
1435 	/* The loop here is to allow for several back-to-back state changes. */
1436 	do {
1437 		prev_state = rdma_req->state;
1438 
1439 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1440 
1441 		switch (rdma_req->state) {
1442 		case RDMA_REQUEST_STATE_FREE:
1443 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1444 			 * to escape this state. */
1445 			break;
1446 		case RDMA_REQUEST_STATE_NEW:
1447 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1448 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1449 			rdma_recv = rdma_req->recv;
1450 
1451 			/* The first element of the SGL is the NVMe command */
1452 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1453 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1454 
1455 			if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1456 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1457 				break;
1458 			}
1459 
1460 			/* The next state transition depends on the data transfer needs of this request. */
1461 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1462 
1463 			/* If no data to transfer, ready to execute. */
1464 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1465 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1466 				break;
1467 			}
1468 
1469 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1470 			TAILQ_INSERT_TAIL(&rgroup->pending_data_buf_queue, rdma_req, link);
1471 			break;
1472 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1473 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1474 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1475 
1476 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1477 
1478 			if (rdma_req != TAILQ_FIRST(&rgroup->pending_data_buf_queue)) {
1479 				/* This request needs to wait in line to obtain a buffer */
1480 				break;
1481 			}
1482 
1483 			/* Try to get a data buffer */
1484 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1485 			if (rc < 0) {
1486 				TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1487 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1488 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1489 				break;
1490 			}
1491 
1492 			if (!rdma_req->req.data) {
1493 				/* No buffers available. */
1494 				break;
1495 			}
1496 
1497 			TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1498 
1499 			/* If data is transferring from host to controller and the data didn't
1500 			 * arrive using in capsule data, we need to do a transfer from the host.
1501 			 */
1502 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1503 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1504 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1505 				break;
1506 			}
1507 
1508 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1509 			break;
1510 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1511 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1512 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1513 
1514 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
1515 				/* This request needs to wait in line to perform RDMA */
1516 				break;
1517 			}
1518 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1519 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1520 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1521 				break;
1522 			}
1523 
1524 			/* We have already verified that this request is the head of the queue. */
1525 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
1526 
1527 			rc = request_transfer_in(&rdma_req->req);
1528 			if (!rc) {
1529 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
1530 			} else {
1531 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1532 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1533 			}
1534 			break;
1535 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1536 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1537 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1538 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1539 			 * to escape this state. */
1540 			break;
1541 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1542 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1543 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1544 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
1545 			spdk_nvmf_request_exec(&rdma_req->req);
1546 			break;
1547 		case RDMA_REQUEST_STATE_EXECUTING:
1548 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1549 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1550 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1551 			 * to escape this state. */
1552 			break;
1553 		case RDMA_REQUEST_STATE_EXECUTED:
1554 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1555 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1556 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1557 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
1558 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
1559 			} else {
1560 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1561 			}
1562 			break;
1563 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
1564 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
1565 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1566 
1567 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
1568 				/* This request needs to wait in line to perform RDMA */
1569 				break;
1570 			}
1571 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
1572 			    rqpair->max_send_depth) {
1573 				/* We can only have so many WRs outstanding. we have to wait until some finish.
1574 				 * +1 since each request has an additional wr in the resp. */
1575 				break;
1576 			}
1577 
1578 			/* We have already verified that this request is the head of the queue. */
1579 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
1580 
1581 			/* The data transfer will be kicked off from
1582 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
1583 			 */
1584 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1585 			break;
1586 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1587 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
1588 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1589 			rc = request_transfer_out(&rdma_req->req, &data_posted);
1590 			assert(rc == 0); /* No good way to handle this currently */
1591 			if (rc) {
1592 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1593 			} else {
1594 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
1595 						  RDMA_REQUEST_STATE_COMPLETING;
1596 			}
1597 			break;
1598 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
1599 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
1600 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1601 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1602 			 * to escape this state. */
1603 			break;
1604 		case RDMA_REQUEST_STATE_COMPLETING:
1605 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
1606 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1607 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1608 			 * to escape this state. */
1609 			break;
1610 		case RDMA_REQUEST_STATE_COMPLETED:
1611 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
1612 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1613 
1614 			nvmf_rdma_request_free(rdma_req, rtransport);
1615 			break;
1616 		case RDMA_REQUEST_NUM_STATES:
1617 		default:
1618 			assert(0);
1619 			break;
1620 		}
1621 
1622 		if (rdma_req->state != prev_state) {
1623 			progress = true;
1624 		}
1625 	} while (rdma_req->state != prev_state);
1626 
1627 	return progress;
1628 }
1629 
1630 /* Public API callbacks begin here */
1631 
1632 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
1633 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
1634 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
1635 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
1636 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
1637 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
1638 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4096
1639 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
1640 
1641 static void
1642 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
1643 {
1644 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
1645 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
1646 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
1647 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
1648 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
1649 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
1650 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
1651 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
1652 }
1653 
1654 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
1655 
1656 static struct spdk_nvmf_transport *
1657 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
1658 {
1659 	int rc;
1660 	struct spdk_nvmf_rdma_transport *rtransport;
1661 	struct spdk_nvmf_rdma_device	*device, *tmp;
1662 	struct ibv_context		**contexts;
1663 	uint32_t			i;
1664 	int				flag;
1665 	uint32_t			sge_count;
1666 	uint32_t			min_shared_buffers;
1667 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
1668 
1669 	rtransport = calloc(1, sizeof(*rtransport));
1670 	if (!rtransport) {
1671 		return NULL;
1672 	}
1673 
1674 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
1675 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
1676 		free(rtransport);
1677 		return NULL;
1678 	}
1679 
1680 	TAILQ_INIT(&rtransport->devices);
1681 	TAILQ_INIT(&rtransport->ports);
1682 
1683 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1684 
1685 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
1686 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
1687 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
1688 		     "  in_capsule_data_size=%d, max_aq_depth=%d\n"
1689 		     "  num_shared_buffers=%d\n",
1690 		     opts->max_queue_depth,
1691 		     opts->max_io_size,
1692 		     opts->max_qpairs_per_ctrlr,
1693 		     opts->io_unit_size,
1694 		     opts->in_capsule_data_size,
1695 		     opts->max_aq_depth,
1696 		     opts->num_shared_buffers);
1697 
1698 	/* I/O unit size cannot be larger than max I/O size */
1699 	if (opts->io_unit_size > opts->max_io_size) {
1700 		opts->io_unit_size = opts->max_io_size;
1701 	}
1702 
1703 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
1704 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
1705 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
1706 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
1707 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1708 		return NULL;
1709 	}
1710 
1711 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
1712 	if (min_shared_buffers > opts->num_shared_buffers) {
1713 		SPDK_ERRLOG("There are not enough buffers to satisfy"
1714 			    "per-poll group caches for each thread. (%" PRIu32 ")"
1715 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
1716 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
1717 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1718 		return NULL;
1719 	}
1720 
1721 	sge_count = opts->max_io_size / opts->io_unit_size;
1722 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
1723 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
1724 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1725 		return NULL;
1726 	}
1727 
1728 	rtransport->event_channel = rdma_create_event_channel();
1729 	if (rtransport->event_channel == NULL) {
1730 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1731 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1732 		return NULL;
1733 	}
1734 
1735 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1736 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1737 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1738 			    rtransport->event_channel->fd, spdk_strerror(errno));
1739 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1740 		return NULL;
1741 	}
1742 
1743 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
1744 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
1745 				   sizeof(struct spdk_nvmf_rdma_request_data),
1746 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1747 				   SPDK_ENV_SOCKET_ID_ANY);
1748 	if (!rtransport->data_wr_pool) {
1749 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
1750 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1751 		return NULL;
1752 	}
1753 
1754 	contexts = rdma_get_devices(NULL);
1755 	if (contexts == NULL) {
1756 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
1757 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1758 		return NULL;
1759 	}
1760 
1761 	i = 0;
1762 	rc = 0;
1763 	while (contexts[i] != NULL) {
1764 		device = calloc(1, sizeof(*device));
1765 		if (!device) {
1766 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1767 			rc = -ENOMEM;
1768 			break;
1769 		}
1770 		device->context = contexts[i];
1771 		rc = ibv_query_device(device->context, &device->attr);
1772 		if (rc < 0) {
1773 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1774 			free(device);
1775 			break;
1776 
1777 		}
1778 
1779 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
1780 
1781 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1782 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
1783 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
1784 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
1785 		}
1786 
1787 		/**
1788 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
1789 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
1790 		 * but incorrectly reports that it does. There are changes making their way
1791 		 * through the kernel now that will enable this feature. When they are merged,
1792 		 * we can conditionally enable this feature.
1793 		 *
1794 		 * TODO: enable this for versions of the kernel rxe driver that support it.
1795 		 */
1796 		if (device->attr.vendor_id == 0) {
1797 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
1798 		}
1799 #endif
1800 
1801 		/* set up device context async ev fd as NON_BLOCKING */
1802 		flag = fcntl(device->context->async_fd, F_GETFL);
1803 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1804 		if (rc < 0) {
1805 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1806 			free(device);
1807 			break;
1808 		}
1809 
1810 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1811 		i++;
1812 	}
1813 	rdma_free_devices(contexts);
1814 
1815 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
1816 		/* divide and round up. */
1817 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
1818 
1819 		/* round up to the nearest 4k. */
1820 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
1821 
1822 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
1823 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
1824 			       opts->io_unit_size);
1825 	}
1826 
1827 	if (rc < 0) {
1828 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1829 		return NULL;
1830 	}
1831 
1832 	/* Set up poll descriptor array to monitor events from RDMA and IB
1833 	 * in a single poll syscall
1834 	 */
1835 	rtransport->npoll_fds = i + 1;
1836 	i = 0;
1837 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1838 	if (rtransport->poll_fds == NULL) {
1839 		SPDK_ERRLOG("poll_fds allocation failed\n");
1840 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1841 		return NULL;
1842 	}
1843 
1844 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1845 	rtransport->poll_fds[i++].events = POLLIN;
1846 
1847 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1848 		rtransport->poll_fds[i].fd = device->context->async_fd;
1849 		rtransport->poll_fds[i++].events = POLLIN;
1850 	}
1851 
1852 	return &rtransport->transport;
1853 }
1854 
1855 static int
1856 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1857 {
1858 	struct spdk_nvmf_rdma_transport	*rtransport;
1859 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1860 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1861 
1862 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1863 
1864 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1865 		TAILQ_REMOVE(&rtransport->ports, port, link);
1866 		rdma_destroy_id(port->id);
1867 		free(port);
1868 	}
1869 
1870 	if (rtransport->poll_fds != NULL) {
1871 		free(rtransport->poll_fds);
1872 	}
1873 
1874 	if (rtransport->event_channel != NULL) {
1875 		rdma_destroy_event_channel(rtransport->event_channel);
1876 	}
1877 
1878 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1879 		TAILQ_REMOVE(&rtransport->devices, device, link);
1880 		if (device->map) {
1881 			spdk_mem_map_free(&device->map);
1882 		}
1883 		if (device->pd) {
1884 			if (!g_nvmf_hooks.get_ibv_pd) {
1885 				ibv_dealloc_pd(device->pd);
1886 			}
1887 		}
1888 		free(device);
1889 	}
1890 
1891 	if (rtransport->data_wr_pool != NULL) {
1892 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
1893 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
1894 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
1895 				    spdk_mempool_count(rtransport->data_wr_pool),
1896 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
1897 		}
1898 	}
1899 
1900 	spdk_mempool_free(rtransport->data_wr_pool);
1901 	pthread_mutex_destroy(&rtransport->lock);
1902 	free(rtransport);
1903 
1904 	return 0;
1905 }
1906 
1907 static int
1908 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
1909 			       struct spdk_nvme_transport_id *trid,
1910 			       bool peer);
1911 
1912 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
1913 	.notify_cb = spdk_nvmf_rdma_mem_notify,
1914 	.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
1915 };
1916 
1917 static int
1918 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1919 		      const struct spdk_nvme_transport_id *trid)
1920 {
1921 	struct spdk_nvmf_rdma_transport	*rtransport;
1922 	struct spdk_nvmf_rdma_device	*device;
1923 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1924 	struct ibv_pd			*pd;
1925 	struct addrinfo			*res;
1926 	struct addrinfo			hints;
1927 	int				family;
1928 	int				rc;
1929 
1930 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1931 
1932 	port = calloc(1, sizeof(*port));
1933 	if (!port) {
1934 		return -ENOMEM;
1935 	}
1936 
1937 	/* Selectively copy the trid. Things like NQN don't matter here - that
1938 	 * mapping is enforced elsewhere.
1939 	 */
1940 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1941 	port->trid.adrfam = trid->adrfam;
1942 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1943 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1944 
1945 	pthread_mutex_lock(&rtransport->lock);
1946 	assert(rtransport->event_channel != NULL);
1947 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1948 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1949 			port_tmp->ref++;
1950 			free(port);
1951 			/* Already listening at this address */
1952 			pthread_mutex_unlock(&rtransport->lock);
1953 			return 0;
1954 		}
1955 	}
1956 
1957 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1958 	if (rc < 0) {
1959 		SPDK_ERRLOG("rdma_create_id() failed\n");
1960 		free(port);
1961 		pthread_mutex_unlock(&rtransport->lock);
1962 		return rc;
1963 	}
1964 
1965 	switch (port->trid.adrfam) {
1966 	case SPDK_NVMF_ADRFAM_IPV4:
1967 		family = AF_INET;
1968 		break;
1969 	case SPDK_NVMF_ADRFAM_IPV6:
1970 		family = AF_INET6;
1971 		break;
1972 	default:
1973 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1974 		free(port);
1975 		pthread_mutex_unlock(&rtransport->lock);
1976 		return -EINVAL;
1977 	}
1978 
1979 	memset(&hints, 0, sizeof(hints));
1980 	hints.ai_family = family;
1981 	hints.ai_flags = AI_NUMERICSERV;
1982 	hints.ai_socktype = SOCK_STREAM;
1983 	hints.ai_protocol = 0;
1984 
1985 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1986 	if (rc) {
1987 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1988 		free(port);
1989 		pthread_mutex_unlock(&rtransport->lock);
1990 		return -EINVAL;
1991 	}
1992 
1993 	rc = rdma_bind_addr(port->id, res->ai_addr);
1994 	freeaddrinfo(res);
1995 
1996 	if (rc < 0) {
1997 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1998 		rdma_destroy_id(port->id);
1999 		free(port);
2000 		pthread_mutex_unlock(&rtransport->lock);
2001 		return rc;
2002 	}
2003 
2004 	if (!port->id->verbs) {
2005 		SPDK_ERRLOG("ibv_context is null\n");
2006 		rdma_destroy_id(port->id);
2007 		free(port);
2008 		pthread_mutex_unlock(&rtransport->lock);
2009 		return -1;
2010 	}
2011 
2012 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
2013 	if (rc < 0) {
2014 		SPDK_ERRLOG("rdma_listen() failed\n");
2015 		rdma_destroy_id(port->id);
2016 		free(port);
2017 		pthread_mutex_unlock(&rtransport->lock);
2018 		return rc;
2019 	}
2020 
2021 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2022 		if (device->context == port->id->verbs) {
2023 			port->device = device;
2024 			break;
2025 		}
2026 	}
2027 	if (!port->device) {
2028 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2029 			    port->id->verbs);
2030 		rdma_destroy_id(port->id);
2031 		free(port);
2032 		pthread_mutex_unlock(&rtransport->lock);
2033 		return -EINVAL;
2034 	}
2035 
2036 	pd = NULL;
2037 	if (g_nvmf_hooks.get_ibv_pd) {
2038 		if (spdk_nvmf_rdma_trid_from_cm_id(port->id, &port->trid, 1) < 0) {
2039 			rdma_destroy_id(port->id);
2040 			free(port);
2041 			pthread_mutex_unlock(&rtransport->lock);
2042 			return -EINVAL;
2043 		}
2044 
2045 		pd = g_nvmf_hooks.get_ibv_pd(&port->trid, port->id->verbs);
2046 	}
2047 
2048 	if (device->pd == NULL) {
2049 		/* Haven't created a protection domain yet. */
2050 
2051 		if (!g_nvmf_hooks.get_ibv_pd) {
2052 			device->pd = ibv_alloc_pd(device->context);
2053 			if (!device->pd) {
2054 				SPDK_ERRLOG("Unable to allocate protection domain.\n");
2055 				rdma_destroy_id(port->id);
2056 				free(port);
2057 				pthread_mutex_unlock(&rtransport->lock);
2058 				return -ENOMEM;
2059 			}
2060 		} else {
2061 			device->pd = pd;
2062 		}
2063 
2064 		assert(device->map == NULL);
2065 
2066 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2067 		if (!device->map) {
2068 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2069 			if (!g_nvmf_hooks.get_ibv_pd) {
2070 				ibv_dealloc_pd(device->pd);
2071 			}
2072 			rdma_destroy_id(port->id);
2073 			free(port);
2074 			pthread_mutex_unlock(&rtransport->lock);
2075 			return -ENOMEM;
2076 		}
2077 	} else if (g_nvmf_hooks.get_ibv_pd) {
2078 		/* A protection domain exists for this device, but the user has
2079 		 * enabled hooks. Verify that they only supply one pd per device. */
2080 		if (device->pd != pd) {
2081 			SPDK_ERRLOG("The NVMe-oF target only supports one protection domain per device.\n");
2082 			rdma_destroy_id(port->id);
2083 			free(port);
2084 			pthread_mutex_unlock(&rtransport->lock);
2085 			return -EINVAL;
2086 		}
2087 	}
2088 
2089 	assert(device->map != NULL);
2090 	assert(device->pd != NULL);
2091 
2092 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
2093 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
2094 
2095 	port->ref = 1;
2096 
2097 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2098 	pthread_mutex_unlock(&rtransport->lock);
2099 
2100 	return 0;
2101 }
2102 
2103 static int
2104 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2105 			   const struct spdk_nvme_transport_id *_trid)
2106 {
2107 	struct spdk_nvmf_rdma_transport *rtransport;
2108 	struct spdk_nvmf_rdma_port *port, *tmp;
2109 	struct spdk_nvme_transport_id trid = {};
2110 
2111 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2112 
2113 	/* Selectively copy the trid. Things like NQN don't matter here - that
2114 	 * mapping is enforced elsewhere.
2115 	 */
2116 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2117 	trid.adrfam = _trid->adrfam;
2118 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2119 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2120 
2121 	pthread_mutex_lock(&rtransport->lock);
2122 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2123 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2124 			assert(port->ref > 0);
2125 			port->ref--;
2126 			if (port->ref == 0) {
2127 				TAILQ_REMOVE(&rtransport->ports, port, link);
2128 				rdma_destroy_id(port->id);
2129 				free(port);
2130 			}
2131 			break;
2132 		}
2133 	}
2134 
2135 	pthread_mutex_unlock(&rtransport->lock);
2136 	return 0;
2137 }
2138 
2139 static bool
2140 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
2141 {
2142 	struct spdk_nvmf_rdma_qpair *rqpair;
2143 
2144 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2145 
2146 	if (rqpair->qd == 0) {
2147 		return true;
2148 	}
2149 	return false;
2150 }
2151 
2152 static void
2153 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2154 				     struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2155 {
2156 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2157 
2158 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2159 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2160 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2161 			break;
2162 		}
2163 	}
2164 
2165 	/* Then RDMA writes since reads have stronger restrictions than writes */
2166 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2167 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2168 			break;
2169 		}
2170 	}
2171 
2172 	/* The second highest priority is I/O waiting on memory buffers. */
2173 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->poller->group->pending_data_buf_queue, link,
2174 			   req_tmp) {
2175 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2176 			break;
2177 		}
2178 	}
2179 
2180 	while (!STAILQ_EMPTY(&rqpair->free_queue) && !STAILQ_EMPTY(&rqpair->incoming_queue)) {
2181 
2182 		rdma_req = STAILQ_FIRST(&rqpair->free_queue);
2183 		STAILQ_REMOVE_HEAD(&rqpair->free_queue, state_link);
2184 		rdma_req->recv = STAILQ_FIRST(&rqpair->incoming_queue);
2185 		STAILQ_REMOVE_HEAD(&rqpair->incoming_queue, link);
2186 
2187 		rqpair->qd++;
2188 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2189 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2190 			break;
2191 		}
2192 	}
2193 }
2194 
2195 static void
2196 _nvmf_rdma_qpair_disconnect(void *ctx)
2197 {
2198 	struct spdk_nvmf_qpair *qpair = ctx;
2199 
2200 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2201 }
2202 
2203 static void
2204 _nvmf_rdma_try_disconnect(void *ctx)
2205 {
2206 	struct spdk_nvmf_qpair *qpair = ctx;
2207 	struct spdk_nvmf_poll_group *group;
2208 
2209 	/* Read the group out of the qpair. This is normally set and accessed only from
2210 	 * the thread that created the group. Here, we're not on that thread necessarily.
2211 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2212 	 * a pointer and never changes. So fortunately reading this and checking for
2213 	 * non-NULL is thread safe in the x86_64 memory model. */
2214 	group = qpair->group;
2215 
2216 	if (group == NULL) {
2217 		/* The qpair hasn't been assigned to a group yet, so we can't
2218 		 * process a disconnect. Send a message to ourself and try again. */
2219 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2220 		return;
2221 	}
2222 
2223 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2224 }
2225 
2226 static inline void
2227 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2228 {
2229 	if (__sync_bool_compare_and_swap(&rqpair->disconnect_started, false, true)) {
2230 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2231 	}
2232 }
2233 
2234 static void spdk_nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair,
2235 		struct spdk_nvmf_rdma_transport *rtransport)
2236 {
2237 	if (rqpair->current_send_depth == 0 && rqpair->current_recv_depth == rqpair->max_queue_depth) {
2238 		/* The qpair has been drained. Free the resources. */
2239 		spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2240 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2241 	}
2242 }
2243 
2244 
2245 static int
2246 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2247 {
2248 	struct spdk_nvmf_qpair		*qpair;
2249 	struct spdk_nvmf_rdma_qpair	*rqpair;
2250 
2251 	if (evt->id == NULL) {
2252 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2253 		return -1;
2254 	}
2255 
2256 	qpair = evt->id->context;
2257 	if (qpair == NULL) {
2258 		SPDK_ERRLOG("disconnect request: no active connection\n");
2259 		return -1;
2260 	}
2261 
2262 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2263 
2264 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2265 
2266 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2267 
2268 	spdk_nvmf_rdma_start_disconnect(rqpair);
2269 
2270 	return 0;
2271 }
2272 
2273 #ifdef DEBUG
2274 static const char *CM_EVENT_STR[] = {
2275 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2276 	"RDMA_CM_EVENT_ADDR_ERROR",
2277 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2278 	"RDMA_CM_EVENT_ROUTE_ERROR",
2279 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2280 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2281 	"RDMA_CM_EVENT_CONNECT_ERROR",
2282 	"RDMA_CM_EVENT_UNREACHABLE",
2283 	"RDMA_CM_EVENT_REJECTED",
2284 	"RDMA_CM_EVENT_ESTABLISHED",
2285 	"RDMA_CM_EVENT_DISCONNECTED",
2286 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2287 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2288 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2289 	"RDMA_CM_EVENT_ADDR_CHANGE",
2290 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2291 };
2292 #endif /* DEBUG */
2293 
2294 static void
2295 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2296 {
2297 	struct spdk_nvmf_rdma_transport *rtransport;
2298 	struct rdma_cm_event		*event;
2299 	int				rc;
2300 
2301 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2302 
2303 	if (rtransport->event_channel == NULL) {
2304 		return;
2305 	}
2306 
2307 	while (1) {
2308 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2309 		if (rc == 0) {
2310 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2311 
2312 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2313 
2314 			switch (event->event) {
2315 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2316 			case RDMA_CM_EVENT_ADDR_ERROR:
2317 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2318 			case RDMA_CM_EVENT_ROUTE_ERROR:
2319 				/* No action required. The target never attempts to resolve routes. */
2320 				break;
2321 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2322 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2323 				if (rc < 0) {
2324 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2325 					break;
2326 				}
2327 				break;
2328 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2329 				/* The target never initiates a new connection. So this will not occur. */
2330 				break;
2331 			case RDMA_CM_EVENT_CONNECT_ERROR:
2332 				/* Can this happen? The docs say it can, but not sure what causes it. */
2333 				break;
2334 			case RDMA_CM_EVENT_UNREACHABLE:
2335 			case RDMA_CM_EVENT_REJECTED:
2336 				/* These only occur on the client side. */
2337 				break;
2338 			case RDMA_CM_EVENT_ESTABLISHED:
2339 				/* TODO: Should we be waiting for this event anywhere? */
2340 				break;
2341 			case RDMA_CM_EVENT_DISCONNECTED:
2342 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2343 				rc = nvmf_rdma_disconnect(event);
2344 				if (rc < 0) {
2345 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2346 					break;
2347 				}
2348 				break;
2349 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2350 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2351 				/* Multicast is not used */
2352 				break;
2353 			case RDMA_CM_EVENT_ADDR_CHANGE:
2354 				/* Not utilizing this event */
2355 				break;
2356 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2357 				/* For now, do nothing. The target never re-uses queue pairs. */
2358 				break;
2359 			default:
2360 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2361 				break;
2362 			}
2363 
2364 			rdma_ack_cm_event(event);
2365 		} else {
2366 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2367 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2368 			}
2369 			break;
2370 		}
2371 	}
2372 }
2373 
2374 static void
2375 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2376 {
2377 	int				rc;
2378 	struct spdk_nvmf_rdma_qpair	*rqpair;
2379 	struct ibv_async_event		event;
2380 	enum ibv_qp_state		state;
2381 
2382 	rc = ibv_get_async_event(device->context, &event);
2383 
2384 	if (rc) {
2385 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2386 			    errno, spdk_strerror(errno));
2387 		return;
2388 	}
2389 
2390 	SPDK_NOTICELOG("Async event: %s\n",
2391 		       ibv_event_type_str(event.event_type));
2392 
2393 	switch (event.event_type) {
2394 	case IBV_EVENT_QP_FATAL:
2395 		rqpair = event.element.qp->qp_context;
2396 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2397 				  (uintptr_t)rqpair->cm_id, event.event_type);
2398 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2399 		spdk_nvmf_rdma_start_disconnect(rqpair);
2400 		break;
2401 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2402 		/* This event only occurs for shared receive queues, which are not currently supported. */
2403 		break;
2404 	case IBV_EVENT_SQ_DRAINED:
2405 		/* This event occurs frequently in both error and non-error states.
2406 		 * Check if the qpair is in an error state before sending a message.
2407 		 * Note that we're not on the correct thread to access the qpair, but
2408 		 * the operations that the below calls make all happen to be thread
2409 		 * safe. */
2410 		rqpair = event.element.qp->qp_context;
2411 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2412 				  (uintptr_t)rqpair->cm_id, event.event_type);
2413 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2414 		if (state == IBV_QPS_ERR) {
2415 			spdk_nvmf_rdma_start_disconnect(rqpair);
2416 		}
2417 		break;
2418 	case IBV_EVENT_QP_REQ_ERR:
2419 	case IBV_EVENT_QP_ACCESS_ERR:
2420 	case IBV_EVENT_COMM_EST:
2421 	case IBV_EVENT_PATH_MIG:
2422 	case IBV_EVENT_PATH_MIG_ERR:
2423 		rqpair = event.element.qp->qp_context;
2424 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2425 				  (uintptr_t)rqpair->cm_id, event.event_type);
2426 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2427 		break;
2428 	case IBV_EVENT_CQ_ERR:
2429 	case IBV_EVENT_DEVICE_FATAL:
2430 	case IBV_EVENT_PORT_ACTIVE:
2431 	case IBV_EVENT_PORT_ERR:
2432 	case IBV_EVENT_LID_CHANGE:
2433 	case IBV_EVENT_PKEY_CHANGE:
2434 	case IBV_EVENT_SM_CHANGE:
2435 	case IBV_EVENT_SRQ_ERR:
2436 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2437 	case IBV_EVENT_CLIENT_REREGISTER:
2438 	case IBV_EVENT_GID_CHANGE:
2439 	default:
2440 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2441 		break;
2442 	}
2443 	ibv_ack_async_event(&event);
2444 }
2445 
2446 static void
2447 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2448 {
2449 	int	nfds, i = 0;
2450 	struct spdk_nvmf_rdma_transport *rtransport;
2451 	struct spdk_nvmf_rdma_device *device, *tmp;
2452 
2453 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2454 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2455 
2456 	if (nfds <= 0) {
2457 		return;
2458 	}
2459 
2460 	/* The first poll descriptor is RDMA CM event */
2461 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2462 		spdk_nvmf_process_cm_event(transport, cb_fn);
2463 		nfds--;
2464 	}
2465 
2466 	if (nfds == 0) {
2467 		return;
2468 	}
2469 
2470 	/* Second and subsequent poll descriptors are IB async events */
2471 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2472 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2473 			spdk_nvmf_process_ib_event(device);
2474 			nfds--;
2475 		}
2476 	}
2477 	/* check all flagged fd's have been served */
2478 	assert(nfds == 0);
2479 }
2480 
2481 static void
2482 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2483 			struct spdk_nvme_transport_id *trid,
2484 			struct spdk_nvmf_discovery_log_page_entry *entry)
2485 {
2486 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2487 	entry->adrfam = trid->adrfam;
2488 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2489 
2490 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2491 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2492 
2493 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2494 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2495 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2496 }
2497 
2498 static struct spdk_nvmf_transport_poll_group *
2499 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2500 {
2501 	struct spdk_nvmf_rdma_transport		*rtransport;
2502 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2503 	struct spdk_nvmf_rdma_poller		*poller, *tpoller;
2504 	struct spdk_nvmf_rdma_device		*device;
2505 
2506 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2507 
2508 	rgroup = calloc(1, sizeof(*rgroup));
2509 	if (!rgroup) {
2510 		return NULL;
2511 	}
2512 
2513 	TAILQ_INIT(&rgroup->pollers);
2514 	TAILQ_INIT(&rgroup->pending_data_buf_queue);
2515 
2516 	pthread_mutex_lock(&rtransport->lock);
2517 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2518 		poller = calloc(1, sizeof(*poller));
2519 		if (!poller) {
2520 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2521 			goto err_exit;
2522 		}
2523 
2524 		poller->device = device;
2525 		poller->group = rgroup;
2526 
2527 		TAILQ_INIT(&poller->qpairs);
2528 
2529 		poller->cq = ibv_create_cq(device->context, DEFAULT_NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
2530 		if (!poller->cq) {
2531 			SPDK_ERRLOG("Unable to create completion queue\n");
2532 			free(poller);
2533 			goto err_exit;
2534 		}
2535 		poller->num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2536 
2537 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2538 	}
2539 
2540 	pthread_mutex_unlock(&rtransport->lock);
2541 	return &rgroup->group;
2542 
2543 err_exit:
2544 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tpoller) {
2545 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2546 		if (poller->cq) {
2547 			ibv_destroy_cq(poller->cq);
2548 		}
2549 		free(poller);
2550 	}
2551 
2552 	free(rgroup);
2553 	pthread_mutex_unlock(&rtransport->lock);
2554 	return NULL;
2555 }
2556 
2557 static void
2558 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
2559 {
2560 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2561 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
2562 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
2563 
2564 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2565 
2566 	if (!rgroup) {
2567 		return;
2568 	}
2569 
2570 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
2571 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2572 
2573 		if (poller->cq) {
2574 			ibv_destroy_cq(poller->cq);
2575 		}
2576 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
2577 			spdk_nvmf_rdma_qpair_destroy(qpair);
2578 		}
2579 
2580 		free(poller);
2581 	}
2582 
2583 	if (!TAILQ_EMPTY(&rgroup->pending_data_buf_queue)) {
2584 		SPDK_ERRLOG("Pending I/O list wasn't empty on poll group destruction\n");
2585 	}
2586 
2587 	free(rgroup);
2588 }
2589 
2590 static void
2591 spdk_nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
2592 {
2593 	spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2594 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2595 }
2596 
2597 static int
2598 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
2599 			      struct spdk_nvmf_qpair *qpair)
2600 {
2601 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2602 	struct spdk_nvmf_rdma_qpair		*rqpair;
2603 	struct spdk_nvmf_rdma_device		*device;
2604 	struct spdk_nvmf_rdma_poller		*poller;
2605 	int					rc;
2606 
2607 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2608 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2609 
2610 	device = rqpair->port->device;
2611 
2612 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
2613 		if (poller->device == device) {
2614 			break;
2615 		}
2616 	}
2617 
2618 	if (!poller) {
2619 		SPDK_ERRLOG("No poller found for device.\n");
2620 		return -1;
2621 	}
2622 
2623 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
2624 	rqpair->poller = poller;
2625 
2626 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
2627 	if (rc < 0) {
2628 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
2629 		return -1;
2630 	}
2631 
2632 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
2633 	if (rc) {
2634 		/* Try to reject, but we probably can't */
2635 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
2636 		return -1;
2637 	}
2638 
2639 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2640 
2641 	return 0;
2642 }
2643 
2644 static int
2645 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
2646 {
2647 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2648 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2649 			struct spdk_nvmf_rdma_transport, transport);
2650 
2651 	nvmf_rdma_request_free(rdma_req, rtransport);
2652 	return 0;
2653 }
2654 
2655 static int
2656 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
2657 {
2658 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2659 			struct spdk_nvmf_rdma_transport, transport);
2660 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
2661 			struct spdk_nvmf_rdma_request, req);
2662 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
2663 			struct spdk_nvmf_rdma_qpair, qpair);
2664 
2665 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2666 		/* The connection is alive, so process the request as normal */
2667 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
2668 	} else {
2669 		/* The connection is dead. Move the request directly to the completed state. */
2670 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2671 	}
2672 
2673 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2674 
2675 	return 0;
2676 }
2677 
2678 static int
2679 spdk_nvmf_rdma_destroy_defunct_qpair(void *ctx)
2680 {
2681 	struct spdk_nvmf_rdma_qpair	*rqpair = ctx;
2682 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2683 			struct spdk_nvmf_rdma_transport, transport);
2684 
2685 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2686 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2687 
2688 	return 0;
2689 }
2690 
2691 static void
2692 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
2693 {
2694 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2695 
2696 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
2697 		return;
2698 	}
2699 
2700 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
2701 
2702 	/* This happens only when the qpair is disconnected before
2703 	 * it is added to the poll group. Since there is no poll group,
2704 	 * the RDMA qp has not been initialized yet and the RDMA CM
2705 	 * event has not yet been acknowledged, so we need to reject it.
2706 	 */
2707 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
2708 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
2709 		return;
2710 	}
2711 
2712 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2713 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
2714 	}
2715 
2716 	rqpair->destruct_poller = spdk_poller_register(spdk_nvmf_rdma_destroy_defunct_qpair, (void *)rqpair,
2717 				  NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US);
2718 }
2719 
2720 #ifdef DEBUG
2721 static int
2722 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
2723 {
2724 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
2725 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
2726 }
2727 #endif
2728 
2729 static int
2730 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2731 			   struct spdk_nvmf_rdma_poller *rpoller)
2732 {
2733 	struct ibv_wc wc[32];
2734 	struct spdk_nvmf_rdma_wr	*rdma_wr;
2735 	struct spdk_nvmf_rdma_request	*rdma_req;
2736 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2737 	struct spdk_nvmf_rdma_qpair	*rqpair;
2738 	int reaped, i;
2739 	int count = 0;
2740 	bool error = false;
2741 
2742 	/* Poll for completing operations. */
2743 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2744 	if (reaped < 0) {
2745 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2746 			    errno, spdk_strerror(errno));
2747 		return -1;
2748 	}
2749 
2750 	for (i = 0; i < reaped; i++) {
2751 
2752 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
2753 
2754 		/* Handle error conditions */
2755 		if (wc[i].status) {
2756 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2757 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2758 
2759 			error = true;
2760 
2761 			switch (rdma_wr->type) {
2762 			case RDMA_WR_TYPE_SEND:
2763 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2764 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2765 
2766 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2767 				/* We're going to attempt an error recovery, so force the request into
2768 				 * the completed state. */
2769 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2770 				rqpair->current_send_depth--;
2771 
2772 				assert(rdma_req->num_outstanding_data_wr == 0);
2773 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2774 				break;
2775 			case RDMA_WR_TYPE_RECV:
2776 				rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2777 				rqpair = rdma_recv->qpair;
2778 
2779 				/* Dump this into the incoming queue. This gets cleaned up when
2780 				 * the queue pair disconnects or recovers. */
2781 				STAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2782 				rqpair->current_recv_depth++;
2783 
2784 				/* Don't worry about responding to recv overflow, we are disconnecting anyways */
2785 				break;
2786 			case RDMA_WR_TYPE_DATA:
2787 				/* If the data transfer fails still force the queue into the error state,
2788 				 * if we were performing an RDMA_READ, we need to force the request into a
2789 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
2790 				 * case, we should wait for the SEND to complete. */
2791 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2792 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2793 
2794 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2795 				assert(rdma_req->num_outstanding_data_wr > 0);
2796 				rdma_req->num_outstanding_data_wr--;
2797 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
2798 					rqpair->current_read_depth--;
2799 					if (rdma_req->num_outstanding_data_wr == 0) {
2800 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2801 					}
2802 				}
2803 				rqpair->current_send_depth--;
2804 				break;
2805 			default:
2806 				SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2807 				continue;
2808 			}
2809 
2810 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
2811 				/* Disconnect the connection. */
2812 				spdk_nvmf_rdma_start_disconnect(rqpair);
2813 			} else {
2814 				spdk_nvmf_rdma_destroy_drained_qpair(rqpair, rtransport);
2815 			}
2816 			continue;
2817 		}
2818 
2819 		switch (wc[i].opcode) {
2820 		case IBV_WC_SEND:
2821 			assert(rdma_wr->type == RDMA_WR_TYPE_SEND);
2822 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2823 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2824 
2825 			assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
2826 
2827 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2828 			rqpair->current_send_depth--;
2829 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2830 
2831 			count++;
2832 
2833 			assert(rdma_req->num_outstanding_data_wr == 0);
2834 			/* Try to process other queued requests */
2835 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2836 			break;
2837 
2838 		case IBV_WC_RDMA_WRITE:
2839 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2840 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2841 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2842 			rqpair->current_send_depth--;
2843 			rdma_req->num_outstanding_data_wr--;
2844 
2845 			/* Try to process other queued requests */
2846 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2847 			break;
2848 
2849 		case IBV_WC_RDMA_READ:
2850 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2851 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2852 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2853 			rqpair->current_send_depth--;
2854 
2855 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2856 			/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
2857 			assert(rdma_req->num_outstanding_data_wr > 0);
2858 			rqpair->current_read_depth--;
2859 			rdma_req->num_outstanding_data_wr--;
2860 			if (rdma_req->num_outstanding_data_wr == 0) {
2861 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2862 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2863 			}
2864 
2865 			/* Try to process other queued requests */
2866 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2867 			break;
2868 
2869 		case IBV_WC_RECV:
2870 			assert(rdma_wr->type == RDMA_WR_TYPE_RECV);
2871 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2872 			rqpair = rdma_recv->qpair;
2873 			/* The qpair should not send more requests than are allowed per qpair. */
2874 			if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
2875 				spdk_nvmf_rdma_start_disconnect(rqpair);
2876 			} else {
2877 				rqpair->current_recv_depth++;
2878 			}
2879 			STAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2880 			/* Try to process other queued requests */
2881 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2882 			break;
2883 
2884 		default:
2885 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2886 			continue;
2887 		}
2888 
2889 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2890 			spdk_nvmf_rdma_destroy_drained_qpair(rqpair, rtransport);
2891 		}
2892 	}
2893 
2894 	if (error == true) {
2895 		return -1;
2896 	}
2897 
2898 	return count;
2899 }
2900 
2901 static int
2902 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2903 {
2904 	struct spdk_nvmf_rdma_transport *rtransport;
2905 	struct spdk_nvmf_rdma_poll_group *rgroup;
2906 	struct spdk_nvmf_rdma_poller	*rpoller;
2907 	int				count, rc;
2908 
2909 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2910 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2911 
2912 	count = 0;
2913 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2914 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2915 		if (rc < 0) {
2916 			return rc;
2917 		}
2918 		count += rc;
2919 	}
2920 
2921 	return count;
2922 }
2923 
2924 static int
2925 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2926 			       struct spdk_nvme_transport_id *trid,
2927 			       bool peer)
2928 {
2929 	struct sockaddr *saddr;
2930 	uint16_t port;
2931 
2932 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
2933 
2934 	if (peer) {
2935 		saddr = rdma_get_peer_addr(id);
2936 	} else {
2937 		saddr = rdma_get_local_addr(id);
2938 	}
2939 	switch (saddr->sa_family) {
2940 	case AF_INET: {
2941 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
2942 
2943 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
2944 		inet_ntop(AF_INET, &saddr_in->sin_addr,
2945 			  trid->traddr, sizeof(trid->traddr));
2946 		if (peer) {
2947 			port = ntohs(rdma_get_dst_port(id));
2948 		} else {
2949 			port = ntohs(rdma_get_src_port(id));
2950 		}
2951 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2952 		break;
2953 	}
2954 	case AF_INET6: {
2955 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
2956 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
2957 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
2958 			  trid->traddr, sizeof(trid->traddr));
2959 		if (peer) {
2960 			port = ntohs(rdma_get_dst_port(id));
2961 		} else {
2962 			port = ntohs(rdma_get_src_port(id));
2963 		}
2964 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2965 		break;
2966 	}
2967 	default:
2968 		return -1;
2969 
2970 	}
2971 
2972 	return 0;
2973 }
2974 
2975 static int
2976 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
2977 				   struct spdk_nvme_transport_id *trid)
2978 {
2979 	struct spdk_nvmf_rdma_qpair	*rqpair;
2980 
2981 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2982 
2983 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
2984 }
2985 
2986 static int
2987 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
2988 				    struct spdk_nvme_transport_id *trid)
2989 {
2990 	struct spdk_nvmf_rdma_qpair	*rqpair;
2991 
2992 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2993 
2994 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
2995 }
2996 
2997 static int
2998 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
2999 				     struct spdk_nvme_transport_id *trid)
3000 {
3001 	struct spdk_nvmf_rdma_qpair	*rqpair;
3002 
3003 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3004 
3005 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
3006 }
3007 
3008 void
3009 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
3010 {
3011 	g_nvmf_hooks = *hooks;
3012 }
3013 
3014 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
3015 	.type = SPDK_NVME_TRANSPORT_RDMA,
3016 	.opts_init = spdk_nvmf_rdma_opts_init,
3017 	.create = spdk_nvmf_rdma_create,
3018 	.destroy = spdk_nvmf_rdma_destroy,
3019 
3020 	.listen = spdk_nvmf_rdma_listen,
3021 	.stop_listen = spdk_nvmf_rdma_stop_listen,
3022 	.accept = spdk_nvmf_rdma_accept,
3023 
3024 	.listener_discover = spdk_nvmf_rdma_discover,
3025 
3026 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
3027 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
3028 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
3029 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
3030 
3031 	.req_free = spdk_nvmf_rdma_request_free,
3032 	.req_complete = spdk_nvmf_rdma_request_complete,
3033 
3034 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
3035 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
3036 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
3037 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
3038 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
3039 
3040 };
3041 
3042 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
3043