xref: /spdk/lib/nvmf/rdma.c (revision 1fc4165fe9bf8512483356ad8e6d27f793f2e3db)
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 	RDMA_WR_TYPE_DRAIN_SEND,
201 	RDMA_WR_TYPE_DRAIN_RECV
202 };
203 
204 struct spdk_nvmf_rdma_wr {
205 	enum spdk_nvmf_rdma_wr_type	type;
206 };
207 
208 /* This structure holds commands as they are received off the wire.
209  * It must be dynamically paired with a full request object
210  * (spdk_nvmf_rdma_request) to service a request. It is separate
211  * from the request because RDMA does not appear to order
212  * completions, so occasionally we'll get a new incoming
213  * command when there aren't any free request objects.
214  */
215 struct spdk_nvmf_rdma_recv {
216 	struct ibv_recv_wr			wr;
217 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
218 
219 	struct spdk_nvmf_rdma_qpair		*qpair;
220 
221 	/* In-capsule data buffer */
222 	uint8_t					*buf;
223 
224 	struct spdk_nvmf_rdma_wr		rdma_wr;
225 
226 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
227 };
228 
229 struct spdk_nvmf_rdma_request_data {
230 	struct spdk_nvmf_rdma_wr	rdma_wr;
231 	struct ibv_send_wr		wr;
232 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
233 	void				*buffers[SPDK_NVMF_MAX_SGL_ENTRIES];
234 };
235 
236 struct spdk_nvmf_rdma_request {
237 	struct spdk_nvmf_request		req;
238 	bool					data_from_pool;
239 
240 	enum spdk_nvmf_rdma_request_state	state;
241 
242 	struct spdk_nvmf_rdma_recv		*recv;
243 
244 	struct {
245 		struct spdk_nvmf_rdma_wr	rdma_wr;
246 		struct	ibv_send_wr		wr;
247 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
248 	} rsp;
249 
250 	struct spdk_nvmf_rdma_request_data	data;
251 
252 	uint32_t				num_outstanding_data_wr;
253 
254 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
255 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
256 };
257 
258 enum spdk_nvmf_rdma_qpair_disconnect_flags {
259 	RDMA_QP_DISCONNECTING		= 1,
260 	RDMA_QP_RECV_DRAINED		= 1 << 1,
261 	RDMA_QP_SEND_DRAINED		= 1 << 2
262 };
263 
264 struct spdk_nvmf_rdma_qpair {
265 	struct spdk_nvmf_qpair			qpair;
266 
267 	struct spdk_nvmf_rdma_port		*port;
268 	struct spdk_nvmf_rdma_poller		*poller;
269 
270 	struct rdma_cm_id			*cm_id;
271 	struct rdma_cm_id			*listen_id;
272 
273 	/* The maximum number of I/O outstanding on this connection at one time */
274 	uint16_t				max_queue_depth;
275 
276 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
277 	uint16_t				max_read_depth;
278 
279 	/* The maximum number of RDMA SEND operations at one time */
280 	uint32_t				max_send_depth;
281 
282 	/* The current number of outstanding WRs from this qpair's
283 	 * recv queue. Should not exceed device->attr.max_queue_depth.
284 	 */
285 	uint16_t				current_recv_depth;
286 
287 	/* The current number of posted WRs from this qpair's
288 	 * send queue. Should not exceed max_send_depth.
289 	 */
290 	uint32_t				current_send_depth;
291 
292 	/* The current number of active RDMA READ operations */
293 	uint16_t				current_read_depth;
294 
295 	/* The maximum number of SGEs per WR on the send queue */
296 	uint32_t				max_send_sge;
297 
298 	/* The maximum number of SGEs per WR on the recv queue */
299 	uint32_t				max_recv_sge;
300 
301 	/* Receives that are waiting for a request object */
302 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
303 
304 	/* Queues to track requests in critical states */
305 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
306 
307 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
308 
309 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
310 
311 	/* Number of requests not in the free state */
312 	uint32_t				qd;
313 
314 	/* Array of size "max_queue_depth" containing RDMA requests. */
315 	struct spdk_nvmf_rdma_request		*reqs;
316 
317 	/* Array of size "max_queue_depth" containing RDMA recvs. */
318 	struct spdk_nvmf_rdma_recv		*recvs;
319 
320 	/* Array of size "max_queue_depth" containing 64 byte capsules
321 	 * used for receive.
322 	 */
323 	union nvmf_h2c_msg			*cmds;
324 	struct ibv_mr				*cmds_mr;
325 
326 	/* Array of size "max_queue_depth" containing 16 byte completions
327 	 * to be sent back to the user.
328 	 */
329 	union nvmf_c2h_msg			*cpls;
330 	struct ibv_mr				*cpls_mr;
331 
332 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
333 	 * buffers to be used for in capsule data.
334 	 */
335 	void					*bufs;
336 	struct ibv_mr				*bufs_mr;
337 
338 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
339 
340 	/* IBV queue pair attributes: they are used to manage
341 	 * qp state and recover from errors.
342 	 */
343 	struct ibv_qp_attr			ibv_attr;
344 
345 	uint32_t				disconnect_flags;
346 	struct spdk_nvmf_rdma_wr		drain_send_wr;
347 	struct spdk_nvmf_rdma_wr		drain_recv_wr;
348 
349 	/* Poller registered in case the qpair doesn't properly
350 	 * complete the qpair destruct process and becomes defunct.
351 	 */
352 
353 	struct spdk_poller			*destruct_poller;
354 
355 	/* There are several ways a disconnect can start on a qpair
356 	 * and they are not all mutually exclusive. It is important
357 	 * that we only initialize one of these paths.
358 	 */
359 	bool					disconnect_started;
360 };
361 
362 struct spdk_nvmf_rdma_poller {
363 	struct spdk_nvmf_rdma_device		*device;
364 	struct spdk_nvmf_rdma_poll_group	*group;
365 
366 	int					num_cqe;
367 	int					required_num_wr;
368 	struct ibv_cq				*cq;
369 
370 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
371 
372 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
373 };
374 
375 struct spdk_nvmf_rdma_poll_group {
376 	struct spdk_nvmf_transport_poll_group	group;
377 
378 	/* Requests that are waiting to obtain a data buffer */
379 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
380 
381 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
382 };
383 
384 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
385 struct spdk_nvmf_rdma_device {
386 	struct ibv_device_attr			attr;
387 	struct ibv_context			*context;
388 
389 	struct spdk_mem_map			*map;
390 	struct ibv_pd				*pd;
391 
392 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
393 };
394 
395 struct spdk_nvmf_rdma_port {
396 	struct spdk_nvme_transport_id		trid;
397 	struct rdma_cm_id			*id;
398 	struct spdk_nvmf_rdma_device		*device;
399 	uint32_t				ref;
400 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
401 };
402 
403 struct spdk_nvmf_rdma_transport {
404 	struct spdk_nvmf_transport	transport;
405 
406 	struct rdma_event_channel	*event_channel;
407 
408 	struct spdk_mempool		*data_wr_pool;
409 
410 	pthread_mutex_t			lock;
411 
412 	/* fields used to poll RDMA/IB events */
413 	nfds_t			npoll_fds;
414 	struct pollfd		*poll_fds;
415 
416 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
417 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
418 };
419 
420 static inline int
421 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
422 {
423 	switch (state) {
424 	case IBV_QPS_RESET:
425 	case IBV_QPS_INIT:
426 	case IBV_QPS_RTR:
427 	case IBV_QPS_RTS:
428 	case IBV_QPS_SQD:
429 	case IBV_QPS_SQE:
430 	case IBV_QPS_ERR:
431 		return 0;
432 	default:
433 		return -1;
434 	}
435 }
436 
437 static enum ibv_qp_state
438 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
439 	enum ibv_qp_state old_state, new_state;
440 	struct ibv_qp_init_attr init_attr;
441 	int rc;
442 
443 	/* All the attributes needed for recovery */
444 	static int spdk_nvmf_ibv_attr_mask =
445 	IBV_QP_STATE |
446 	IBV_QP_PKEY_INDEX |
447 	IBV_QP_PORT |
448 	IBV_QP_ACCESS_FLAGS |
449 	IBV_QP_AV |
450 	IBV_QP_PATH_MTU |
451 	IBV_QP_DEST_QPN |
452 	IBV_QP_RQ_PSN |
453 	IBV_QP_MAX_DEST_RD_ATOMIC |
454 	IBV_QP_MIN_RNR_TIMER |
455 	IBV_QP_SQ_PSN |
456 	IBV_QP_TIMEOUT |
457 	IBV_QP_RETRY_CNT |
458 	IBV_QP_RNR_RETRY |
459 	IBV_QP_MAX_QP_RD_ATOMIC;
460 
461 	old_state = rqpair->ibv_attr.qp_state;
462 	rc = ibv_query_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
463 			  spdk_nvmf_ibv_attr_mask, &init_attr);
464 
465 	if (rc)
466 	{
467 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
468 		assert(false);
469 	}
470 
471 	new_state = rqpair->ibv_attr.qp_state;
472 
473 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
474 	if (rc)
475 	{
476 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
477 		/*
478 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
479 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
480 		 */
481 		return IBV_QPS_ERR + 1;
482 	}
483 
484 	if (old_state != new_state)
485 	{
486 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
487 				  (uintptr_t)rqpair->cm_id, new_state);
488 	}
489 	return new_state;
490 }
491 
492 static const char *str_ibv_qp_state[] = {
493 	"IBV_QPS_RESET",
494 	"IBV_QPS_INIT",
495 	"IBV_QPS_RTR",
496 	"IBV_QPS_RTS",
497 	"IBV_QPS_SQD",
498 	"IBV_QPS_SQE",
499 	"IBV_QPS_ERR",
500 	"IBV_QPS_UNKNOWN"
501 };
502 
503 static int
504 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
505 			     enum ibv_qp_state new_state)
506 {
507 	int rc;
508 	enum ibv_qp_state state;
509 	static int attr_mask_rc[] = {
510 		[IBV_QPS_RESET] = IBV_QP_STATE,
511 		[IBV_QPS_INIT] = (IBV_QP_STATE |
512 				  IBV_QP_PKEY_INDEX |
513 				  IBV_QP_PORT |
514 				  IBV_QP_ACCESS_FLAGS),
515 		[IBV_QPS_RTR] = (IBV_QP_STATE |
516 				 IBV_QP_AV |
517 				 IBV_QP_PATH_MTU |
518 				 IBV_QP_DEST_QPN |
519 				 IBV_QP_RQ_PSN |
520 				 IBV_QP_MAX_DEST_RD_ATOMIC |
521 				 IBV_QP_MIN_RNR_TIMER),
522 		[IBV_QPS_RTS] = (IBV_QP_STATE |
523 				 IBV_QP_SQ_PSN |
524 				 IBV_QP_TIMEOUT |
525 				 IBV_QP_RETRY_CNT |
526 				 IBV_QP_RNR_RETRY |
527 				 IBV_QP_MAX_QP_RD_ATOMIC),
528 		[IBV_QPS_SQD] = IBV_QP_STATE,
529 		[IBV_QPS_SQE] = IBV_QP_STATE,
530 		[IBV_QPS_ERR] = IBV_QP_STATE,
531 	};
532 
533 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
534 	if (rc) {
535 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
536 			    rqpair->qpair.qid, new_state);
537 		return rc;
538 	}
539 
540 	rqpair->ibv_attr.cur_qp_state = rqpair->ibv_attr.qp_state;
541 	rqpair->ibv_attr.qp_state = new_state;
542 	rqpair->ibv_attr.ah_attr.port_num = rqpair->ibv_attr.port_num;
543 
544 	rc = ibv_modify_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
545 			   attr_mask_rc[new_state]);
546 
547 	if (rc) {
548 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
549 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
550 		return rc;
551 	}
552 
553 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
554 
555 	if (state != new_state) {
556 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
557 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
558 			    str_ibv_qp_state[state]);
559 		return -1;
560 	}
561 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
562 		      str_ibv_qp_state[state]);
563 	return 0;
564 }
565 
566 static void
567 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
568 {
569 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->data_from_pool);
570 	if (req->req.cmd) {
571 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
572 	}
573 	if (req->recv) {
574 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
575 	}
576 }
577 
578 static void
579 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
580 {
581 	int i;
582 
583 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
584 	for (i = 0; i < rqpair->max_queue_depth; i++) {
585 		if (rqpair->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
586 			nvmf_rdma_dump_request(&rqpair->reqs[i]);
587 		}
588 	}
589 }
590 
591 static void
592 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
593 {
594 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
595 
596 	spdk_poller_unregister(&rqpair->destruct_poller);
597 
598 	if (rqpair->qd != 0) {
599 		nvmf_rdma_dump_qpair_contents(rqpair);
600 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
601 	}
602 
603 	if (rqpair->poller) {
604 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
605 	}
606 
607 	if (rqpair->cmds_mr) {
608 		ibv_dereg_mr(rqpair->cmds_mr);
609 	}
610 
611 	if (rqpair->cpls_mr) {
612 		ibv_dereg_mr(rqpair->cpls_mr);
613 	}
614 
615 	if (rqpair->bufs_mr) {
616 		ibv_dereg_mr(rqpair->bufs_mr);
617 	}
618 
619 	if (rqpair->cm_id) {
620 		rdma_destroy_qp(rqpair->cm_id);
621 		rdma_destroy_id(rqpair->cm_id);
622 
623 		if (rqpair->poller) {
624 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
625 		}
626 	}
627 
628 	/* Free all memory */
629 	spdk_dma_free(rqpair->cmds);
630 	spdk_dma_free(rqpair->cpls);
631 	spdk_dma_free(rqpair->bufs);
632 	free(rqpair->reqs);
633 	free(rqpair->recvs);
634 	free(rqpair);
635 }
636 
637 static int
638 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
639 {
640 	struct spdk_nvmf_rdma_transport *rtransport;
641 	struct spdk_nvmf_rdma_qpair	*rqpair;
642 	struct spdk_nvmf_rdma_poller	*rpoller;
643 	int				rc, i, num_cqe, required_num_wr;;
644 	struct spdk_nvmf_rdma_recv	*rdma_recv;
645 	struct spdk_nvmf_rdma_request	*rdma_req;
646 	struct spdk_nvmf_transport	*transport;
647 	struct spdk_nvmf_rdma_device	*device;
648 	struct ibv_qp_init_attr		ibv_init_attr;
649 
650 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
651 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
652 	transport = &rtransport->transport;
653 	device = rqpair->port->device;
654 
655 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
656 	ibv_init_attr.qp_context	= rqpair;
657 	ibv_init_attr.qp_type		= IBV_QPT_RC;
658 	ibv_init_attr.send_cq		= rqpair->poller->cq;
659 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
660 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
661 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
662 	ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
663 					  1; /* RECV operations + dummy drain WR */
664 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
665 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
666 
667 	/* Enlarge CQ size dynamically */
668 	rpoller = rqpair->poller;
669 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
670 	num_cqe = rpoller->num_cqe;
671 	if (num_cqe < required_num_wr) {
672 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
673 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
674 	}
675 
676 	if (rpoller->num_cqe != num_cqe) {
677 		if (required_num_wr > device->attr.max_cqe) {
678 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
679 				    required_num_wr, device->attr.max_cqe);
680 			rdma_destroy_id(rqpair->cm_id);
681 			rqpair->cm_id = NULL;
682 			spdk_nvmf_rdma_qpair_destroy(rqpair);
683 			return -1;
684 		}
685 
686 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
687 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
688 		if (rc) {
689 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
690 			rdma_destroy_id(rqpair->cm_id);
691 			rqpair->cm_id = NULL;
692 			spdk_nvmf_rdma_qpair_destroy(rqpair);
693 			return -1;
694 		}
695 
696 		rpoller->num_cqe = num_cqe;
697 	}
698 
699 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
700 	if (rc) {
701 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
702 		rdma_destroy_id(rqpair->cm_id);
703 		rqpair->cm_id = NULL;
704 		spdk_nvmf_rdma_qpair_destroy(rqpair);
705 		return -1;
706 	}
707 
708 	rpoller->required_num_wr = required_num_wr;
709 
710 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2 + 1),
711 					  ibv_init_attr.cap.max_send_wr);
712 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
713 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
714 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
715 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
716 
717 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
718 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
719 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
720 					0x1000, NULL);
721 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
722 					0x1000, NULL);
723 
724 
725 	if (transport->opts.in_capsule_data_size > 0) {
726 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth *
727 						transport->opts.in_capsule_data_size,
728 						0x1000, NULL);
729 	}
730 
731 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
732 	    !rqpair->cpls || (transport->opts.in_capsule_data_size && !rqpair->bufs)) {
733 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
734 		spdk_nvmf_rdma_qpair_destroy(rqpair);
735 		return -1;
736 	}
737 
738 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
739 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
740 				     IBV_ACCESS_LOCAL_WRITE);
741 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
742 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
743 				     0);
744 
745 	if (transport->opts.in_capsule_data_size) {
746 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
747 					     rqpair->max_queue_depth *
748 					     transport->opts.in_capsule_data_size,
749 					     IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
750 	}
751 
752 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (transport->opts.in_capsule_data_size &&
753 			!rqpair->bufs_mr)) {
754 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
755 		spdk_nvmf_rdma_qpair_destroy(rqpair);
756 		return -1;
757 	}
758 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
759 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
760 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
761 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
762 	if (rqpair->bufs && rqpair->bufs_mr) {
763 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
764 			      rqpair->bufs, rqpair->max_queue_depth *
765 			      transport->opts.in_capsule_data_size, rqpair->bufs_mr->lkey);
766 	}
767 
768 	STAILQ_INIT(&rqpair->free_queue);
769 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
770 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
771 
772 	rqpair->current_recv_depth = rqpair->max_queue_depth;
773 	for (i = 0; i < rqpair->max_queue_depth; i++) {
774 		struct ibv_recv_wr *bad_wr = NULL;
775 
776 		rdma_recv = &rqpair->recvs[i];
777 		rdma_recv->qpair = rqpair;
778 
779 		/* Set up memory to receive commands */
780 		if (rqpair->bufs) {
781 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i *
782 						  transport->opts.in_capsule_data_size));
783 		}
784 
785 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
786 
787 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
788 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
789 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
790 		rdma_recv->wr.num_sge = 1;
791 
792 		if (rdma_recv->buf && rqpair->bufs_mr) {
793 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
794 			rdma_recv->sgl[1].length = transport->opts.in_capsule_data_size;
795 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
796 			rdma_recv->wr.num_sge++;
797 		}
798 
799 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
800 		rdma_recv->wr.sg_list = rdma_recv->sgl;
801 
802 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
803 		assert(rqpair->current_recv_depth > 0);
804 		rqpair->current_recv_depth--;
805 		if (rc) {
806 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
807 			spdk_nvmf_rdma_qpair_destroy(rqpair);
808 			return -1;
809 		}
810 	}
811 	assert(rqpair->current_recv_depth == 0);
812 
813 	for (i = 0; i < rqpair->max_queue_depth; i++) {
814 		rdma_req = &rqpair->reqs[i];
815 
816 		rdma_req->req.qpair = &rqpair->qpair;
817 		rdma_req->req.cmd = NULL;
818 
819 		/* Set up memory to send responses */
820 		rdma_req->req.rsp = &rqpair->cpls[i];
821 
822 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
823 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
824 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
825 
826 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
827 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
828 		rdma_req->rsp.wr.next = NULL;
829 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
830 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
831 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
832 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
833 
834 		/* Set up memory for data buffers */
835 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
836 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
837 		rdma_req->data.wr.next = NULL;
838 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
839 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
840 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
841 
842 		/* Initialize request state to FREE */
843 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
844 		STAILQ_INSERT_HEAD(&rqpair->free_queue, rdma_req, state_link);
845 	}
846 
847 	return 0;
848 }
849 
850 static int
851 request_transfer_in(struct spdk_nvmf_request *req)
852 {
853 	int				rc;
854 	struct spdk_nvmf_rdma_request	*rdma_req;
855 	struct spdk_nvmf_qpair		*qpair;
856 	struct spdk_nvmf_rdma_qpair	*rqpair;
857 	struct ibv_send_wr		*bad_wr = NULL;
858 
859 	qpair = req->qpair;
860 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
861 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
862 
863 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
864 	assert(rdma_req != NULL);
865 
866 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
867 
868 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
869 	if (rc) {
870 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
871 		return -1;
872 	}
873 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
874 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
875 	return 0;
876 }
877 
878 static int
879 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
880 {
881 	int				rc;
882 	struct spdk_nvmf_rdma_request	*rdma_req;
883 	struct spdk_nvmf_qpair		*qpair;
884 	struct spdk_nvmf_rdma_qpair	*rqpair;
885 	struct spdk_nvme_cpl		*rsp;
886 	struct ibv_recv_wr		*bad_recv_wr = NULL;
887 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
888 
889 	*data_posted = 0;
890 	qpair = req->qpair;
891 	rsp = &req->rsp->nvme_cpl;
892 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
893 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
894 
895 	/* Advance our sq_head pointer */
896 	if (qpair->sq_head == qpair->sq_head_max) {
897 		qpair->sq_head = 0;
898 	} else {
899 		qpair->sq_head++;
900 	}
901 	rsp->sqhd = qpair->sq_head;
902 
903 	/* Post the capsule to the recv buffer */
904 	assert(rdma_req->recv != NULL);
905 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
906 		      rqpair);
907 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
908 	if (rc) {
909 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
910 		return rc;
911 	}
912 	rdma_req->recv = NULL;
913 	assert(rqpair->current_recv_depth > 0);
914 	rqpair->current_recv_depth--;
915 
916 	/* Build the response which consists of an optional
917 	 * RDMA WRITE to transfer data, plus an RDMA SEND
918 	 * containing the response.
919 	 */
920 	send_wr = &rdma_req->rsp.wr;
921 
922 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
923 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
924 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
925 		send_wr = &rdma_req->data.wr;
926 		*data_posted = 1;
927 	}
928 
929 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
930 
931 	/* Send the completion */
932 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
933 	if (rc) {
934 		SPDK_ERRLOG("Unable to send response capsule\n");
935 		return rc;
936 	}
937 	/* +1 for the rsp wr */
938 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr + 1;
939 
940 	return 0;
941 }
942 
943 static int
944 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
945 {
946 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
947 	struct rdma_conn_param				ctrlr_event_data = {};
948 	int						rc;
949 
950 	accept_data.recfmt = 0;
951 	accept_data.crqsize = rqpair->max_queue_depth;
952 
953 	ctrlr_event_data.private_data = &accept_data;
954 	ctrlr_event_data.private_data_len = sizeof(accept_data);
955 	if (id->ps == RDMA_PS_TCP) {
956 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
957 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
958 	}
959 
960 	rc = rdma_accept(id, &ctrlr_event_data);
961 	if (rc) {
962 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
963 	} else {
964 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
965 	}
966 
967 	return rc;
968 }
969 
970 static void
971 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
972 {
973 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
974 
975 	rej_data.recfmt = 0;
976 	rej_data.sts = error;
977 
978 	rdma_reject(id, &rej_data, sizeof(rej_data));
979 }
980 
981 static int
982 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
983 		  new_qpair_fn cb_fn)
984 {
985 	struct spdk_nvmf_rdma_transport *rtransport;
986 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
987 	struct spdk_nvmf_rdma_port	*port;
988 	struct rdma_conn_param		*rdma_param = NULL;
989 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
990 	uint16_t			max_queue_depth;
991 	uint16_t			max_read_depth;
992 
993 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
994 
995 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
996 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
997 
998 	rdma_param = &event->param.conn;
999 	if (rdma_param->private_data == NULL ||
1000 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1001 		SPDK_ERRLOG("connect request: no private data provided\n");
1002 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1003 		return -1;
1004 	}
1005 
1006 	private_data = rdma_param->private_data;
1007 	if (private_data->recfmt != 0) {
1008 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1009 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1010 		return -1;
1011 	}
1012 
1013 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1014 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1015 
1016 	port = event->listen_id->context;
1017 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1018 		      event->listen_id, event->listen_id->verbs, port);
1019 
1020 	/* Figure out the supported queue depth. This is a multi-step process
1021 	 * that takes into account hardware maximums, host provided values,
1022 	 * and our target's internal memory limits */
1023 
1024 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1025 
1026 	/* Start with the maximum queue depth allowed by the target */
1027 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1028 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1029 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1030 		      rtransport->transport.opts.max_queue_depth);
1031 
1032 	/* Next check the local NIC's hardware limitations */
1033 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1034 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1035 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1036 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1037 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1038 
1039 	/* Next check the remote NIC's hardware limitations */
1040 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1041 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1042 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1043 	if (rdma_param->initiator_depth > 0) {
1044 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1045 	}
1046 
1047 	/* Finally check for the host software requested values, which are
1048 	 * optional. */
1049 	if (rdma_param->private_data != NULL &&
1050 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1051 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1052 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1053 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1054 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1055 	}
1056 
1057 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1058 		      max_queue_depth, max_read_depth);
1059 
1060 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1061 	if (rqpair == NULL) {
1062 		SPDK_ERRLOG("Could not allocate new connection.\n");
1063 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1064 		return -1;
1065 	}
1066 
1067 	rqpair->port = port;
1068 	rqpair->max_queue_depth = max_queue_depth;
1069 	rqpair->max_read_depth = max_read_depth;
1070 	rqpair->cm_id = event->id;
1071 	rqpair->listen_id = event->listen_id;
1072 	rqpair->qpair.transport = transport;
1073 	STAILQ_INIT(&rqpair->incoming_queue);
1074 	event->id->context = &rqpair->qpair;
1075 
1076 	cb_fn(&rqpair->qpair);
1077 
1078 	return 0;
1079 }
1080 
1081 static int
1082 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1083 			  enum spdk_mem_map_notify_action action,
1084 			  void *vaddr, size_t size)
1085 {
1086 	struct ibv_pd *pd = cb_ctx;
1087 	struct ibv_mr *mr;
1088 
1089 	switch (action) {
1090 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1091 		if (!g_nvmf_hooks.get_rkey) {
1092 			mr = ibv_reg_mr(pd, vaddr, size,
1093 					IBV_ACCESS_LOCAL_WRITE |
1094 					IBV_ACCESS_REMOTE_READ |
1095 					IBV_ACCESS_REMOTE_WRITE);
1096 			if (mr == NULL) {
1097 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1098 				return -1;
1099 			} else {
1100 				spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1101 			}
1102 		} else {
1103 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1104 						     g_nvmf_hooks.get_rkey(pd, vaddr, size));
1105 		}
1106 		break;
1107 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1108 		if (!g_nvmf_hooks.get_rkey) {
1109 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1110 			spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1111 			if (mr) {
1112 				ibv_dereg_mr(mr);
1113 			}
1114 		}
1115 		break;
1116 	}
1117 
1118 	return 0;
1119 }
1120 
1121 static int
1122 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1123 {
1124 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1125 	return addr_1 == addr_2;
1126 }
1127 
1128 static void
1129 spdk_nvmf_rdma_request_free_buffers(struct spdk_nvmf_rdma_request *rdma_req,
1130 				    struct spdk_nvmf_transport_poll_group *group, struct spdk_nvmf_transport *transport)
1131 {
1132 	for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1133 		if (group->buf_cache_count < group->buf_cache_size) {
1134 			STAILQ_INSERT_HEAD(&group->buf_cache,
1135 					   (struct spdk_nvmf_transport_pg_cache_buf *)rdma_req->data.buffers[i], link);
1136 			group->buf_cache_count++;
1137 		} else {
1138 			spdk_mempool_put(transport->data_buf_pool, rdma_req->data.buffers[i]);
1139 		}
1140 		rdma_req->req.iov[i].iov_base = NULL;
1141 		rdma_req->data.buffers[i] = NULL;
1142 		rdma_req->req.iov[i].iov_len = 0;
1143 
1144 	}
1145 	rdma_req->data_from_pool = false;
1146 }
1147 
1148 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1149 
1150 static spdk_nvme_data_transfer_t
1151 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1152 {
1153 	enum spdk_nvme_data_transfer xfer;
1154 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1155 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1156 
1157 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1158 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1159 	rdma_req->rsp.wr.imm_data = 0;
1160 #endif
1161 
1162 	/* Figure out data transfer direction */
1163 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1164 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1165 	} else {
1166 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1167 
1168 		/* Some admin commands are special cases */
1169 		if ((rdma_req->req.qpair->qid == 0) &&
1170 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1171 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1172 			switch (cmd->cdw10 & 0xff) {
1173 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1174 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1175 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1176 				break;
1177 			default:
1178 				xfer = SPDK_NVME_DATA_NONE;
1179 			}
1180 		}
1181 	}
1182 
1183 	if (xfer == SPDK_NVME_DATA_NONE) {
1184 		return xfer;
1185 	}
1186 
1187 	/* Even for commands that may transfer data, they could have specified 0 length.
1188 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1189 	 */
1190 	switch (sgl->generic.type) {
1191 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1192 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1193 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1194 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1195 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1196 		if (sgl->unkeyed.length == 0) {
1197 			xfer = SPDK_NVME_DATA_NONE;
1198 		}
1199 		break;
1200 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1201 		if (sgl->keyed.length == 0) {
1202 			xfer = SPDK_NVME_DATA_NONE;
1203 		}
1204 		break;
1205 	}
1206 
1207 	return xfer;
1208 }
1209 
1210 static int
1211 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1212 				 struct spdk_nvmf_rdma_device *device,
1213 				 struct spdk_nvmf_rdma_request *rdma_req)
1214 {
1215 	struct spdk_nvmf_rdma_qpair		*rqpair;
1216 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1217 	void					*buf = NULL;
1218 	uint32_t				length = rdma_req->req.length;
1219 	uint64_t				translation_len;
1220 	uint32_t				i = 0;
1221 	int					rc = 0;
1222 
1223 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1224 	rgroup = rqpair->poller->group;
1225 	rdma_req->req.iovcnt = 0;
1226 	while (length) {
1227 		if (!(STAILQ_EMPTY(&rgroup->group.buf_cache))) {
1228 			rgroup->group.buf_cache_count--;
1229 			buf = STAILQ_FIRST(&rgroup->group.buf_cache);
1230 			STAILQ_REMOVE_HEAD(&rgroup->group.buf_cache, link);
1231 			assert(buf != NULL);
1232 		} else {
1233 			buf = spdk_mempool_get(rtransport->transport.data_buf_pool);
1234 			if (!buf) {
1235 				rc = -ENOMEM;
1236 				goto err_exit;
1237 			}
1238 		}
1239 
1240 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
1241 						~NVMF_DATA_BUFFER_MASK);
1242 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->transport.opts.io_unit_size);
1243 		rdma_req->req.iovcnt++;
1244 		rdma_req->data.buffers[i] = buf;
1245 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
1246 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
1247 		translation_len = rdma_req->req.iov[i].iov_len;
1248 
1249 		if (!g_nvmf_hooks.get_rkey) {
1250 			rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1251 							     (uint64_t)buf, &translation_len))->lkey;
1252 		} else {
1253 			rdma_req->data.wr.sg_list[i].lkey = spdk_mem_map_translate(device->map,
1254 							    (uint64_t)buf, &translation_len);
1255 		}
1256 
1257 		length -= rdma_req->req.iov[i].iov_len;
1258 
1259 		if (translation_len < rdma_req->req.iov[i].iov_len) {
1260 			SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
1261 			rc = -EINVAL;
1262 			goto err_exit;
1263 		}
1264 		i++;
1265 	}
1266 
1267 	assert(rdma_req->req.iovcnt <= rqpair->max_send_sge);
1268 
1269 	rdma_req->data_from_pool = true;
1270 
1271 	return rc;
1272 
1273 err_exit:
1274 	spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport);
1275 	while (i) {
1276 		i--;
1277 		rdma_req->data.wr.sg_list[i].addr = 0;
1278 		rdma_req->data.wr.sg_list[i].length = 0;
1279 		rdma_req->data.wr.sg_list[i].lkey = 0;
1280 	}
1281 	rdma_req->req.iovcnt = 0;
1282 	return rc;
1283 }
1284 
1285 static int
1286 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1287 				 struct spdk_nvmf_rdma_device *device,
1288 				 struct spdk_nvmf_rdma_request *rdma_req)
1289 {
1290 	struct spdk_nvme_cmd			*cmd;
1291 	struct spdk_nvme_cpl			*rsp;
1292 	struct spdk_nvme_sgl_descriptor		*sgl;
1293 
1294 	cmd = &rdma_req->req.cmd->nvme_cmd;
1295 	rsp = &rdma_req->req.rsp->nvme_cpl;
1296 	sgl = &cmd->dptr.sgl1;
1297 
1298 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1299 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1300 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1301 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1302 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1303 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1304 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1305 			return -1;
1306 		}
1307 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1308 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1309 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1310 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1311 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1312 			}
1313 		}
1314 #endif
1315 
1316 		/* fill request length and populate iovs */
1317 		rdma_req->req.length = sgl->keyed.length;
1318 
1319 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1320 			/* No available buffers. Queue this request up. */
1321 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1322 			return 0;
1323 		}
1324 
1325 		/* backward compatible */
1326 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1327 
1328 		/* rdma wr specifics */
1329 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1330 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1331 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1332 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1333 			rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
1334 			rdma_req->data.wr.next = &rdma_req->rsp.wr;
1335 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1336 			rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
1337 			rdma_req->data.wr.next = NULL;
1338 		}
1339 
1340 		/* set the number of outstanding data WRs for this request. */
1341 		rdma_req->num_outstanding_data_wr = 1;
1342 
1343 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1344 			      rdma_req->req.iovcnt);
1345 
1346 		return 0;
1347 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1348 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1349 		uint64_t offset = sgl->address;
1350 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1351 
1352 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1353 			      offset, sgl->unkeyed.length);
1354 
1355 		if (offset > max_len) {
1356 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1357 				    offset, max_len);
1358 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1359 			return -1;
1360 		}
1361 		max_len -= (uint32_t)offset;
1362 
1363 		if (sgl->unkeyed.length > max_len) {
1364 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1365 				    sgl->unkeyed.length, max_len);
1366 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1367 			return -1;
1368 		}
1369 
1370 		rdma_req->num_outstanding_data_wr = 0;
1371 		rdma_req->req.data = rdma_req->recv->buf + offset;
1372 		rdma_req->data_from_pool = false;
1373 		rdma_req->req.length = sgl->unkeyed.length;
1374 
1375 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1376 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1377 		rdma_req->req.iovcnt = 1;
1378 
1379 		return 0;
1380 	}
1381 
1382 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1383 		    sgl->generic.type, sgl->generic.subtype);
1384 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1385 	return -1;
1386 }
1387 
1388 static void
1389 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1390 		       struct spdk_nvmf_rdma_transport	*rtransport)
1391 {
1392 	struct spdk_nvmf_rdma_qpair		*rqpair;
1393 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1394 
1395 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1396 	if (rdma_req->data_from_pool) {
1397 		rgroup = rqpair->poller->group;
1398 
1399 		spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport);
1400 	}
1401 	rdma_req->num_outstanding_data_wr = 0;
1402 	rdma_req->req.length = 0;
1403 	rdma_req->req.iovcnt = 0;
1404 	rdma_req->req.data = NULL;
1405 	rqpair->qd--;
1406 	STAILQ_INSERT_HEAD(&rqpair->free_queue, rdma_req, state_link);
1407 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1408 }
1409 
1410 static bool
1411 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1412 			       struct spdk_nvmf_rdma_request *rdma_req)
1413 {
1414 	struct spdk_nvmf_rdma_qpair	*rqpair;
1415 	struct spdk_nvmf_rdma_device	*device;
1416 	struct spdk_nvmf_rdma_poll_group *rgroup;
1417 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1418 	int				rc;
1419 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1420 	enum spdk_nvmf_rdma_request_state prev_state;
1421 	bool				progress = false;
1422 	int				data_posted;
1423 
1424 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1425 	device = rqpair->port->device;
1426 	rgroup = rqpair->poller->group;
1427 
1428 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1429 
1430 	/* If the queue pair is in an error state, force the request to the completed state
1431 	 * to release resources. */
1432 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1433 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1434 			TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1435 		}
1436 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1437 	}
1438 
1439 	/* The loop here is to allow for several back-to-back state changes. */
1440 	do {
1441 		prev_state = rdma_req->state;
1442 
1443 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1444 
1445 		switch (rdma_req->state) {
1446 		case RDMA_REQUEST_STATE_FREE:
1447 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1448 			 * to escape this state. */
1449 			break;
1450 		case RDMA_REQUEST_STATE_NEW:
1451 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1452 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1453 			rdma_recv = rdma_req->recv;
1454 
1455 			/* The first element of the SGL is the NVMe command */
1456 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1457 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1458 
1459 			if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1460 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1461 				break;
1462 			}
1463 
1464 			/* The next state transition depends on the data transfer needs of this request. */
1465 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1466 
1467 			/* If no data to transfer, ready to execute. */
1468 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1469 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1470 				break;
1471 			}
1472 
1473 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1474 			TAILQ_INSERT_TAIL(&rgroup->pending_data_buf_queue, rdma_req, link);
1475 			break;
1476 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1477 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1478 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1479 
1480 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1481 
1482 			if (rdma_req != TAILQ_FIRST(&rgroup->pending_data_buf_queue)) {
1483 				/* This request needs to wait in line to obtain a buffer */
1484 				break;
1485 			}
1486 
1487 			/* Try to get a data buffer */
1488 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1489 			if (rc < 0) {
1490 				TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1491 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1492 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1493 				break;
1494 			}
1495 
1496 			if (!rdma_req->req.data) {
1497 				/* No buffers available. */
1498 				break;
1499 			}
1500 
1501 			TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1502 
1503 			/* If data is transferring from host to controller and the data didn't
1504 			 * arrive using in capsule data, we need to do a transfer from the host.
1505 			 */
1506 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1507 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1508 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1509 				break;
1510 			}
1511 
1512 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1513 			break;
1514 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1515 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1516 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1517 
1518 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
1519 				/* This request needs to wait in line to perform RDMA */
1520 				break;
1521 			}
1522 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1523 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1524 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1525 				break;
1526 			}
1527 
1528 			/* We have already verified that this request is the head of the queue. */
1529 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
1530 
1531 			rc = request_transfer_in(&rdma_req->req);
1532 			if (!rc) {
1533 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
1534 			} else {
1535 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1536 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1537 			}
1538 			break;
1539 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1540 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1541 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1542 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1543 			 * to escape this state. */
1544 			break;
1545 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1546 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1547 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1548 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
1549 			spdk_nvmf_request_exec(&rdma_req->req);
1550 			break;
1551 		case RDMA_REQUEST_STATE_EXECUTING:
1552 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1553 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1554 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1555 			 * to escape this state. */
1556 			break;
1557 		case RDMA_REQUEST_STATE_EXECUTED:
1558 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1559 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1560 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1561 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
1562 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
1563 			} else {
1564 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1565 			}
1566 			break;
1567 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
1568 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
1569 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1570 
1571 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
1572 				/* This request needs to wait in line to perform RDMA */
1573 				break;
1574 			}
1575 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
1576 			    rqpair->max_send_depth) {
1577 				/* We can only have so many WRs outstanding. we have to wait until some finish.
1578 				 * +1 since each request has an additional wr in the resp. */
1579 				break;
1580 			}
1581 
1582 			/* We have already verified that this request is the head of the queue. */
1583 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
1584 
1585 			/* The data transfer will be kicked off from
1586 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
1587 			 */
1588 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1589 			break;
1590 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1591 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
1592 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1593 			rc = request_transfer_out(&rdma_req->req, &data_posted);
1594 			assert(rc == 0); /* No good way to handle this currently */
1595 			if (rc) {
1596 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1597 			} else {
1598 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
1599 						  RDMA_REQUEST_STATE_COMPLETING;
1600 			}
1601 			break;
1602 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
1603 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
1604 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1605 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1606 			 * to escape this state. */
1607 			break;
1608 		case RDMA_REQUEST_STATE_COMPLETING:
1609 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
1610 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1611 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1612 			 * to escape this state. */
1613 			break;
1614 		case RDMA_REQUEST_STATE_COMPLETED:
1615 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
1616 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1617 
1618 			nvmf_rdma_request_free(rdma_req, rtransport);
1619 			break;
1620 		case RDMA_REQUEST_NUM_STATES:
1621 		default:
1622 			assert(0);
1623 			break;
1624 		}
1625 
1626 		if (rdma_req->state != prev_state) {
1627 			progress = true;
1628 		}
1629 	} while (rdma_req->state != prev_state);
1630 
1631 	return progress;
1632 }
1633 
1634 /* Public API callbacks begin here */
1635 
1636 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
1637 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
1638 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
1639 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
1640 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
1641 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
1642 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4096
1643 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
1644 
1645 static void
1646 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
1647 {
1648 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
1649 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
1650 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
1651 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
1652 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
1653 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
1654 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
1655 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
1656 }
1657 
1658 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
1659 
1660 static struct spdk_nvmf_transport *
1661 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
1662 {
1663 	int rc;
1664 	struct spdk_nvmf_rdma_transport *rtransport;
1665 	struct spdk_nvmf_rdma_device	*device, *tmp;
1666 	struct ibv_context		**contexts;
1667 	uint32_t			i;
1668 	int				flag;
1669 	uint32_t			sge_count;
1670 	uint32_t			min_shared_buffers;
1671 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
1672 
1673 	rtransport = calloc(1, sizeof(*rtransport));
1674 	if (!rtransport) {
1675 		return NULL;
1676 	}
1677 
1678 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
1679 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
1680 		free(rtransport);
1681 		return NULL;
1682 	}
1683 
1684 	TAILQ_INIT(&rtransport->devices);
1685 	TAILQ_INIT(&rtransport->ports);
1686 
1687 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1688 
1689 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
1690 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
1691 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
1692 		     "  in_capsule_data_size=%d, max_aq_depth=%d\n"
1693 		     "  num_shared_buffers=%d\n",
1694 		     opts->max_queue_depth,
1695 		     opts->max_io_size,
1696 		     opts->max_qpairs_per_ctrlr,
1697 		     opts->io_unit_size,
1698 		     opts->in_capsule_data_size,
1699 		     opts->max_aq_depth,
1700 		     opts->num_shared_buffers);
1701 
1702 	/* I/O unit size cannot be larger than max I/O size */
1703 	if (opts->io_unit_size > opts->max_io_size) {
1704 		opts->io_unit_size = opts->max_io_size;
1705 	}
1706 
1707 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
1708 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
1709 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
1710 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
1711 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1712 		return NULL;
1713 	}
1714 
1715 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
1716 	if (min_shared_buffers > opts->num_shared_buffers) {
1717 		SPDK_ERRLOG("There are not enough buffers to satisfy"
1718 			    "per-poll group caches for each thread. (%" PRIu32 ")"
1719 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
1720 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
1721 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1722 		return NULL;
1723 	}
1724 
1725 	sge_count = opts->max_io_size / opts->io_unit_size;
1726 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
1727 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
1728 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1729 		return NULL;
1730 	}
1731 
1732 	rtransport->event_channel = rdma_create_event_channel();
1733 	if (rtransport->event_channel == NULL) {
1734 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1735 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1736 		return NULL;
1737 	}
1738 
1739 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1740 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1741 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1742 			    rtransport->event_channel->fd, spdk_strerror(errno));
1743 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1744 		return NULL;
1745 	}
1746 
1747 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
1748 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
1749 				   sizeof(struct spdk_nvmf_rdma_request_data),
1750 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1751 				   SPDK_ENV_SOCKET_ID_ANY);
1752 	if (!rtransport->data_wr_pool) {
1753 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
1754 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1755 		return NULL;
1756 	}
1757 
1758 	contexts = rdma_get_devices(NULL);
1759 	if (contexts == NULL) {
1760 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
1761 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1762 		return NULL;
1763 	}
1764 
1765 	i = 0;
1766 	rc = 0;
1767 	while (contexts[i] != NULL) {
1768 		device = calloc(1, sizeof(*device));
1769 		if (!device) {
1770 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1771 			rc = -ENOMEM;
1772 			break;
1773 		}
1774 		device->context = contexts[i];
1775 		rc = ibv_query_device(device->context, &device->attr);
1776 		if (rc < 0) {
1777 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1778 			free(device);
1779 			break;
1780 
1781 		}
1782 
1783 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
1784 
1785 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1786 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
1787 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
1788 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
1789 		}
1790 
1791 		/**
1792 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
1793 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
1794 		 * but incorrectly reports that it does. There are changes making their way
1795 		 * through the kernel now that will enable this feature. When they are merged,
1796 		 * we can conditionally enable this feature.
1797 		 *
1798 		 * TODO: enable this for versions of the kernel rxe driver that support it.
1799 		 */
1800 		if (device->attr.vendor_id == 0) {
1801 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
1802 		}
1803 #endif
1804 
1805 		/* set up device context async ev fd as NON_BLOCKING */
1806 		flag = fcntl(device->context->async_fd, F_GETFL);
1807 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1808 		if (rc < 0) {
1809 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1810 			free(device);
1811 			break;
1812 		}
1813 
1814 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1815 		i++;
1816 	}
1817 	rdma_free_devices(contexts);
1818 
1819 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
1820 		/* divide and round up. */
1821 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
1822 
1823 		/* round up to the nearest 4k. */
1824 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
1825 
1826 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
1827 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
1828 			       opts->io_unit_size);
1829 	}
1830 
1831 	if (rc < 0) {
1832 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1833 		return NULL;
1834 	}
1835 
1836 	/* Set up poll descriptor array to monitor events from RDMA and IB
1837 	 * in a single poll syscall
1838 	 */
1839 	rtransport->npoll_fds = i + 1;
1840 	i = 0;
1841 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1842 	if (rtransport->poll_fds == NULL) {
1843 		SPDK_ERRLOG("poll_fds allocation failed\n");
1844 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1845 		return NULL;
1846 	}
1847 
1848 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1849 	rtransport->poll_fds[i++].events = POLLIN;
1850 
1851 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1852 		rtransport->poll_fds[i].fd = device->context->async_fd;
1853 		rtransport->poll_fds[i++].events = POLLIN;
1854 	}
1855 
1856 	return &rtransport->transport;
1857 }
1858 
1859 static int
1860 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1861 {
1862 	struct spdk_nvmf_rdma_transport	*rtransport;
1863 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1864 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1865 
1866 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1867 
1868 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1869 		TAILQ_REMOVE(&rtransport->ports, port, link);
1870 		rdma_destroy_id(port->id);
1871 		free(port);
1872 	}
1873 
1874 	if (rtransport->poll_fds != NULL) {
1875 		free(rtransport->poll_fds);
1876 	}
1877 
1878 	if (rtransport->event_channel != NULL) {
1879 		rdma_destroy_event_channel(rtransport->event_channel);
1880 	}
1881 
1882 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1883 		TAILQ_REMOVE(&rtransport->devices, device, link);
1884 		if (device->map) {
1885 			spdk_mem_map_free(&device->map);
1886 		}
1887 		if (device->pd) {
1888 			if (!g_nvmf_hooks.get_ibv_pd) {
1889 				ibv_dealloc_pd(device->pd);
1890 			}
1891 		}
1892 		free(device);
1893 	}
1894 
1895 	if (rtransport->data_wr_pool != NULL) {
1896 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
1897 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
1898 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
1899 				    spdk_mempool_count(rtransport->data_wr_pool),
1900 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
1901 		}
1902 	}
1903 
1904 	spdk_mempool_free(rtransport->data_wr_pool);
1905 	pthread_mutex_destroy(&rtransport->lock);
1906 	free(rtransport);
1907 
1908 	return 0;
1909 }
1910 
1911 static int
1912 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
1913 			       struct spdk_nvme_transport_id *trid,
1914 			       bool peer);
1915 
1916 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
1917 	.notify_cb = spdk_nvmf_rdma_mem_notify,
1918 	.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
1919 };
1920 
1921 static int
1922 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1923 		      const struct spdk_nvme_transport_id *trid)
1924 {
1925 	struct spdk_nvmf_rdma_transport	*rtransport;
1926 	struct spdk_nvmf_rdma_device	*device;
1927 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1928 	struct ibv_pd			*pd;
1929 	struct addrinfo			*res;
1930 	struct addrinfo			hints;
1931 	int				family;
1932 	int				rc;
1933 
1934 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1935 
1936 	port = calloc(1, sizeof(*port));
1937 	if (!port) {
1938 		return -ENOMEM;
1939 	}
1940 
1941 	/* Selectively copy the trid. Things like NQN don't matter here - that
1942 	 * mapping is enforced elsewhere.
1943 	 */
1944 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1945 	port->trid.adrfam = trid->adrfam;
1946 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1947 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1948 
1949 	pthread_mutex_lock(&rtransport->lock);
1950 	assert(rtransport->event_channel != NULL);
1951 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1952 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1953 			port_tmp->ref++;
1954 			free(port);
1955 			/* Already listening at this address */
1956 			pthread_mutex_unlock(&rtransport->lock);
1957 			return 0;
1958 		}
1959 	}
1960 
1961 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1962 	if (rc < 0) {
1963 		SPDK_ERRLOG("rdma_create_id() failed\n");
1964 		free(port);
1965 		pthread_mutex_unlock(&rtransport->lock);
1966 		return rc;
1967 	}
1968 
1969 	switch (port->trid.adrfam) {
1970 	case SPDK_NVMF_ADRFAM_IPV4:
1971 		family = AF_INET;
1972 		break;
1973 	case SPDK_NVMF_ADRFAM_IPV6:
1974 		family = AF_INET6;
1975 		break;
1976 	default:
1977 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1978 		free(port);
1979 		pthread_mutex_unlock(&rtransport->lock);
1980 		return -EINVAL;
1981 	}
1982 
1983 	memset(&hints, 0, sizeof(hints));
1984 	hints.ai_family = family;
1985 	hints.ai_flags = AI_NUMERICSERV;
1986 	hints.ai_socktype = SOCK_STREAM;
1987 	hints.ai_protocol = 0;
1988 
1989 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1990 	if (rc) {
1991 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1992 		free(port);
1993 		pthread_mutex_unlock(&rtransport->lock);
1994 		return -EINVAL;
1995 	}
1996 
1997 	rc = rdma_bind_addr(port->id, res->ai_addr);
1998 	freeaddrinfo(res);
1999 
2000 	if (rc < 0) {
2001 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2002 		rdma_destroy_id(port->id);
2003 		free(port);
2004 		pthread_mutex_unlock(&rtransport->lock);
2005 		return rc;
2006 	}
2007 
2008 	if (!port->id->verbs) {
2009 		SPDK_ERRLOG("ibv_context is null\n");
2010 		rdma_destroy_id(port->id);
2011 		free(port);
2012 		pthread_mutex_unlock(&rtransport->lock);
2013 		return -1;
2014 	}
2015 
2016 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
2017 	if (rc < 0) {
2018 		SPDK_ERRLOG("rdma_listen() failed\n");
2019 		rdma_destroy_id(port->id);
2020 		free(port);
2021 		pthread_mutex_unlock(&rtransport->lock);
2022 		return rc;
2023 	}
2024 
2025 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2026 		if (device->context == port->id->verbs) {
2027 			port->device = device;
2028 			break;
2029 		}
2030 	}
2031 	if (!port->device) {
2032 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2033 			    port->id->verbs);
2034 		rdma_destroy_id(port->id);
2035 		free(port);
2036 		pthread_mutex_unlock(&rtransport->lock);
2037 		return -EINVAL;
2038 	}
2039 
2040 	pd = NULL;
2041 	if (g_nvmf_hooks.get_ibv_pd) {
2042 		if (spdk_nvmf_rdma_trid_from_cm_id(port->id, &port->trid, 1) < 0) {
2043 			rdma_destroy_id(port->id);
2044 			free(port);
2045 			pthread_mutex_unlock(&rtransport->lock);
2046 			return -EINVAL;
2047 		}
2048 
2049 		pd = g_nvmf_hooks.get_ibv_pd(&port->trid, port->id->verbs);
2050 	}
2051 
2052 	if (device->pd == NULL) {
2053 		/* Haven't created a protection domain yet. */
2054 
2055 		if (!g_nvmf_hooks.get_ibv_pd) {
2056 			device->pd = ibv_alloc_pd(device->context);
2057 			if (!device->pd) {
2058 				SPDK_ERRLOG("Unable to allocate protection domain.\n");
2059 				rdma_destroy_id(port->id);
2060 				free(port);
2061 				pthread_mutex_unlock(&rtransport->lock);
2062 				return -ENOMEM;
2063 			}
2064 		} else {
2065 			device->pd = pd;
2066 		}
2067 
2068 		assert(device->map == NULL);
2069 
2070 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2071 		if (!device->map) {
2072 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2073 			if (!g_nvmf_hooks.get_ibv_pd) {
2074 				ibv_dealloc_pd(device->pd);
2075 			}
2076 			rdma_destroy_id(port->id);
2077 			free(port);
2078 			pthread_mutex_unlock(&rtransport->lock);
2079 			return -ENOMEM;
2080 		}
2081 	} else if (g_nvmf_hooks.get_ibv_pd) {
2082 		/* A protection domain exists for this device, but the user has
2083 		 * enabled hooks. Verify that they only supply one pd per device. */
2084 		if (device->pd != pd) {
2085 			SPDK_ERRLOG("The NVMe-oF target only supports one protection domain per device.\n");
2086 			rdma_destroy_id(port->id);
2087 			free(port);
2088 			pthread_mutex_unlock(&rtransport->lock);
2089 			return -EINVAL;
2090 		}
2091 	}
2092 
2093 	assert(device->map != NULL);
2094 	assert(device->pd != NULL);
2095 
2096 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
2097 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
2098 
2099 	port->ref = 1;
2100 
2101 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2102 	pthread_mutex_unlock(&rtransport->lock);
2103 
2104 	return 0;
2105 }
2106 
2107 static int
2108 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2109 			   const struct spdk_nvme_transport_id *_trid)
2110 {
2111 	struct spdk_nvmf_rdma_transport *rtransport;
2112 	struct spdk_nvmf_rdma_port *port, *tmp;
2113 	struct spdk_nvme_transport_id trid = {};
2114 
2115 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2116 
2117 	/* Selectively copy the trid. Things like NQN don't matter here - that
2118 	 * mapping is enforced elsewhere.
2119 	 */
2120 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2121 	trid.adrfam = _trid->adrfam;
2122 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2123 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2124 
2125 	pthread_mutex_lock(&rtransport->lock);
2126 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2127 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2128 			assert(port->ref > 0);
2129 			port->ref--;
2130 			if (port->ref == 0) {
2131 				TAILQ_REMOVE(&rtransport->ports, port, link);
2132 				rdma_destroy_id(port->id);
2133 				free(port);
2134 			}
2135 			break;
2136 		}
2137 	}
2138 
2139 	pthread_mutex_unlock(&rtransport->lock);
2140 	return 0;
2141 }
2142 
2143 static bool
2144 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
2145 {
2146 	struct spdk_nvmf_rdma_qpair *rqpair;
2147 
2148 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2149 
2150 	if (rqpair->qd == 0) {
2151 		return true;
2152 	}
2153 	return false;
2154 }
2155 
2156 static void
2157 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2158 				     struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2159 {
2160 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2161 
2162 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2163 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2164 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2165 			break;
2166 		}
2167 	}
2168 
2169 	/* Then RDMA writes since reads have stronger restrictions than writes */
2170 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2171 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2172 			break;
2173 		}
2174 	}
2175 
2176 	/* The second highest priority is I/O waiting on memory buffers. */
2177 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->poller->group->pending_data_buf_queue, link,
2178 			   req_tmp) {
2179 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2180 			break;
2181 		}
2182 	}
2183 
2184 	while (!STAILQ_EMPTY(&rqpair->free_queue) && !STAILQ_EMPTY(&rqpair->incoming_queue)) {
2185 
2186 		rdma_req = STAILQ_FIRST(&rqpair->free_queue);
2187 		STAILQ_REMOVE_HEAD(&rqpair->free_queue, state_link);
2188 		rdma_req->recv = STAILQ_FIRST(&rqpair->incoming_queue);
2189 		STAILQ_REMOVE_HEAD(&rqpair->incoming_queue, link);
2190 
2191 		rqpair->qd++;
2192 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2193 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2194 			break;
2195 		}
2196 	}
2197 }
2198 
2199 static void
2200 _nvmf_rdma_qpair_disconnect(void *ctx)
2201 {
2202 	struct spdk_nvmf_qpair *qpair = ctx;
2203 
2204 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2205 }
2206 
2207 static void
2208 _nvmf_rdma_try_disconnect(void *ctx)
2209 {
2210 	struct spdk_nvmf_qpair *qpair = ctx;
2211 	struct spdk_nvmf_poll_group *group;
2212 
2213 	/* Read the group out of the qpair. This is normally set and accessed only from
2214 	 * the thread that created the group. Here, we're not on that thread necessarily.
2215 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2216 	 * a pointer and never changes. So fortunately reading this and checking for
2217 	 * non-NULL is thread safe in the x86_64 memory model. */
2218 	group = qpair->group;
2219 
2220 	if (group == NULL) {
2221 		/* The qpair hasn't been assigned to a group yet, so we can't
2222 		 * process a disconnect. Send a message to ourself and try again. */
2223 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2224 		return;
2225 	}
2226 
2227 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2228 }
2229 
2230 static inline void
2231 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2232 {
2233 	if (__sync_bool_compare_and_swap(&rqpair->disconnect_started, false, true)) {
2234 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2235 	}
2236 }
2237 
2238 
2239 static int
2240 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2241 {
2242 	struct spdk_nvmf_qpair		*qpair;
2243 	struct spdk_nvmf_rdma_qpair	*rqpair;
2244 
2245 	if (evt->id == NULL) {
2246 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2247 		return -1;
2248 	}
2249 
2250 	qpair = evt->id->context;
2251 	if (qpair == NULL) {
2252 		SPDK_ERRLOG("disconnect request: no active connection\n");
2253 		return -1;
2254 	}
2255 
2256 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2257 
2258 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2259 
2260 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2261 
2262 	spdk_nvmf_rdma_start_disconnect(rqpair);
2263 
2264 	return 0;
2265 }
2266 
2267 #ifdef DEBUG
2268 static const char *CM_EVENT_STR[] = {
2269 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2270 	"RDMA_CM_EVENT_ADDR_ERROR",
2271 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2272 	"RDMA_CM_EVENT_ROUTE_ERROR",
2273 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2274 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2275 	"RDMA_CM_EVENT_CONNECT_ERROR",
2276 	"RDMA_CM_EVENT_UNREACHABLE",
2277 	"RDMA_CM_EVENT_REJECTED",
2278 	"RDMA_CM_EVENT_ESTABLISHED",
2279 	"RDMA_CM_EVENT_DISCONNECTED",
2280 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2281 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2282 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2283 	"RDMA_CM_EVENT_ADDR_CHANGE",
2284 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2285 };
2286 #endif /* DEBUG */
2287 
2288 static void
2289 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2290 {
2291 	struct spdk_nvmf_rdma_transport *rtransport;
2292 	struct rdma_cm_event		*event;
2293 	int				rc;
2294 
2295 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2296 
2297 	if (rtransport->event_channel == NULL) {
2298 		return;
2299 	}
2300 
2301 	while (1) {
2302 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2303 		if (rc == 0) {
2304 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2305 
2306 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2307 
2308 			switch (event->event) {
2309 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2310 			case RDMA_CM_EVENT_ADDR_ERROR:
2311 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2312 			case RDMA_CM_EVENT_ROUTE_ERROR:
2313 				/* No action required. The target never attempts to resolve routes. */
2314 				break;
2315 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2316 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2317 				if (rc < 0) {
2318 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2319 					break;
2320 				}
2321 				break;
2322 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2323 				/* The target never initiates a new connection. So this will not occur. */
2324 				break;
2325 			case RDMA_CM_EVENT_CONNECT_ERROR:
2326 				/* Can this happen? The docs say it can, but not sure what causes it. */
2327 				break;
2328 			case RDMA_CM_EVENT_UNREACHABLE:
2329 			case RDMA_CM_EVENT_REJECTED:
2330 				/* These only occur on the client side. */
2331 				break;
2332 			case RDMA_CM_EVENT_ESTABLISHED:
2333 				/* TODO: Should we be waiting for this event anywhere? */
2334 				break;
2335 			case RDMA_CM_EVENT_DISCONNECTED:
2336 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2337 				rc = nvmf_rdma_disconnect(event);
2338 				if (rc < 0) {
2339 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2340 					break;
2341 				}
2342 				break;
2343 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2344 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2345 				/* Multicast is not used */
2346 				break;
2347 			case RDMA_CM_EVENT_ADDR_CHANGE:
2348 				/* Not utilizing this event */
2349 				break;
2350 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2351 				/* For now, do nothing. The target never re-uses queue pairs. */
2352 				break;
2353 			default:
2354 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2355 				break;
2356 			}
2357 
2358 			rdma_ack_cm_event(event);
2359 		} else {
2360 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2361 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2362 			}
2363 			break;
2364 		}
2365 	}
2366 }
2367 
2368 static void
2369 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2370 {
2371 	int				rc;
2372 	struct spdk_nvmf_rdma_qpair	*rqpair;
2373 	struct ibv_async_event		event;
2374 	enum ibv_qp_state		state;
2375 
2376 	rc = ibv_get_async_event(device->context, &event);
2377 
2378 	if (rc) {
2379 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2380 			    errno, spdk_strerror(errno));
2381 		return;
2382 	}
2383 
2384 	SPDK_NOTICELOG("Async event: %s\n",
2385 		       ibv_event_type_str(event.event_type));
2386 
2387 	switch (event.event_type) {
2388 	case IBV_EVENT_QP_FATAL:
2389 		rqpair = event.element.qp->qp_context;
2390 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2391 				  (uintptr_t)rqpair->cm_id, event.event_type);
2392 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2393 		spdk_nvmf_rdma_start_disconnect(rqpair);
2394 		break;
2395 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2396 		/* This event only occurs for shared receive queues, which are not currently supported. */
2397 		break;
2398 	case IBV_EVENT_SQ_DRAINED:
2399 		/* This event occurs frequently in both error and non-error states.
2400 		 * Check if the qpair is in an error state before sending a message.
2401 		 * Note that we're not on the correct thread to access the qpair, but
2402 		 * the operations that the below calls make all happen to be thread
2403 		 * safe. */
2404 		rqpair = event.element.qp->qp_context;
2405 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2406 				  (uintptr_t)rqpair->cm_id, event.event_type);
2407 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2408 		if (state == IBV_QPS_ERR) {
2409 			spdk_nvmf_rdma_start_disconnect(rqpair);
2410 		}
2411 		break;
2412 	case IBV_EVENT_QP_REQ_ERR:
2413 	case IBV_EVENT_QP_ACCESS_ERR:
2414 	case IBV_EVENT_COMM_EST:
2415 	case IBV_EVENT_PATH_MIG:
2416 	case IBV_EVENT_PATH_MIG_ERR:
2417 		rqpair = event.element.qp->qp_context;
2418 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2419 				  (uintptr_t)rqpair->cm_id, event.event_type);
2420 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2421 		break;
2422 	case IBV_EVENT_CQ_ERR:
2423 	case IBV_EVENT_DEVICE_FATAL:
2424 	case IBV_EVENT_PORT_ACTIVE:
2425 	case IBV_EVENT_PORT_ERR:
2426 	case IBV_EVENT_LID_CHANGE:
2427 	case IBV_EVENT_PKEY_CHANGE:
2428 	case IBV_EVENT_SM_CHANGE:
2429 	case IBV_EVENT_SRQ_ERR:
2430 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2431 	case IBV_EVENT_CLIENT_REREGISTER:
2432 	case IBV_EVENT_GID_CHANGE:
2433 	default:
2434 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2435 		break;
2436 	}
2437 	ibv_ack_async_event(&event);
2438 }
2439 
2440 static void
2441 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2442 {
2443 	int	nfds, i = 0;
2444 	struct spdk_nvmf_rdma_transport *rtransport;
2445 	struct spdk_nvmf_rdma_device *device, *tmp;
2446 
2447 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2448 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2449 
2450 	if (nfds <= 0) {
2451 		return;
2452 	}
2453 
2454 	/* The first poll descriptor is RDMA CM event */
2455 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2456 		spdk_nvmf_process_cm_event(transport, cb_fn);
2457 		nfds--;
2458 	}
2459 
2460 	if (nfds == 0) {
2461 		return;
2462 	}
2463 
2464 	/* Second and subsequent poll descriptors are IB async events */
2465 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2466 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2467 			spdk_nvmf_process_ib_event(device);
2468 			nfds--;
2469 		}
2470 	}
2471 	/* check all flagged fd's have been served */
2472 	assert(nfds == 0);
2473 }
2474 
2475 static void
2476 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2477 			struct spdk_nvme_transport_id *trid,
2478 			struct spdk_nvmf_discovery_log_page_entry *entry)
2479 {
2480 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2481 	entry->adrfam = trid->adrfam;
2482 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2483 
2484 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2485 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2486 
2487 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2488 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2489 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2490 }
2491 
2492 static struct spdk_nvmf_transport_poll_group *
2493 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2494 {
2495 	struct spdk_nvmf_rdma_transport		*rtransport;
2496 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2497 	struct spdk_nvmf_rdma_poller		*poller, *tpoller;
2498 	struct spdk_nvmf_rdma_device		*device;
2499 
2500 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2501 
2502 	rgroup = calloc(1, sizeof(*rgroup));
2503 	if (!rgroup) {
2504 		return NULL;
2505 	}
2506 
2507 	TAILQ_INIT(&rgroup->pollers);
2508 	TAILQ_INIT(&rgroup->pending_data_buf_queue);
2509 
2510 	pthread_mutex_lock(&rtransport->lock);
2511 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2512 		poller = calloc(1, sizeof(*poller));
2513 		if (!poller) {
2514 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2515 			goto err_exit;
2516 		}
2517 
2518 		poller->device = device;
2519 		poller->group = rgroup;
2520 
2521 		TAILQ_INIT(&poller->qpairs);
2522 
2523 		poller->cq = ibv_create_cq(device->context, DEFAULT_NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
2524 		if (!poller->cq) {
2525 			SPDK_ERRLOG("Unable to create completion queue\n");
2526 			free(poller);
2527 			goto err_exit;
2528 		}
2529 		poller->num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2530 
2531 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2532 	}
2533 
2534 	pthread_mutex_unlock(&rtransport->lock);
2535 	return &rgroup->group;
2536 
2537 err_exit:
2538 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tpoller) {
2539 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2540 		if (poller->cq) {
2541 			ibv_destroy_cq(poller->cq);
2542 		}
2543 		free(poller);
2544 	}
2545 
2546 	free(rgroup);
2547 	pthread_mutex_unlock(&rtransport->lock);
2548 	return NULL;
2549 }
2550 
2551 static void
2552 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
2553 {
2554 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2555 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
2556 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
2557 
2558 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2559 
2560 	if (!rgroup) {
2561 		return;
2562 	}
2563 
2564 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
2565 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2566 
2567 		if (poller->cq) {
2568 			ibv_destroy_cq(poller->cq);
2569 		}
2570 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
2571 			spdk_nvmf_rdma_qpair_destroy(qpair);
2572 		}
2573 
2574 		free(poller);
2575 	}
2576 
2577 	if (!TAILQ_EMPTY(&rgroup->pending_data_buf_queue)) {
2578 		SPDK_ERRLOG("Pending I/O list wasn't empty on poll group destruction\n");
2579 	}
2580 
2581 	free(rgroup);
2582 }
2583 
2584 static void
2585 spdk_nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
2586 {
2587 	spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2588 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2589 }
2590 
2591 static int
2592 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
2593 			      struct spdk_nvmf_qpair *qpair)
2594 {
2595 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2596 	struct spdk_nvmf_rdma_qpair		*rqpair;
2597 	struct spdk_nvmf_rdma_device		*device;
2598 	struct spdk_nvmf_rdma_poller		*poller;
2599 	int					rc;
2600 
2601 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2602 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2603 
2604 	device = rqpair->port->device;
2605 
2606 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
2607 		if (poller->device == device) {
2608 			break;
2609 		}
2610 	}
2611 
2612 	if (!poller) {
2613 		SPDK_ERRLOG("No poller found for device.\n");
2614 		return -1;
2615 	}
2616 
2617 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
2618 	rqpair->poller = poller;
2619 
2620 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
2621 	if (rc < 0) {
2622 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
2623 		return -1;
2624 	}
2625 
2626 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
2627 	if (rc) {
2628 		/* Try to reject, but we probably can't */
2629 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
2630 		return -1;
2631 	}
2632 
2633 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2634 
2635 	return 0;
2636 }
2637 
2638 static int
2639 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
2640 {
2641 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2642 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2643 			struct spdk_nvmf_rdma_transport, transport);
2644 
2645 	nvmf_rdma_request_free(rdma_req, rtransport);
2646 	return 0;
2647 }
2648 
2649 static int
2650 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
2651 {
2652 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2653 			struct spdk_nvmf_rdma_transport, transport);
2654 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
2655 			struct spdk_nvmf_rdma_request, req);
2656 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
2657 			struct spdk_nvmf_rdma_qpair, qpair);
2658 
2659 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2660 		/* The connection is alive, so process the request as normal */
2661 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
2662 	} else {
2663 		/* The connection is dead. Move the request directly to the completed state. */
2664 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2665 	}
2666 
2667 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2668 
2669 	return 0;
2670 }
2671 
2672 static int
2673 spdk_nvmf_rdma_destroy_defunct_qpair(void *ctx)
2674 {
2675 	struct spdk_nvmf_rdma_qpair	*rqpair = ctx;
2676 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2677 			struct spdk_nvmf_rdma_transport, transport);
2678 
2679 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2680 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2681 
2682 	return 0;
2683 }
2684 
2685 static void
2686 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
2687 {
2688 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2689 	struct ibv_recv_wr recv_wr = {};
2690 	struct ibv_recv_wr *bad_recv_wr;
2691 	struct ibv_send_wr send_wr = {};
2692 	struct ibv_send_wr *bad_send_wr;
2693 	int rc;
2694 
2695 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
2696 		return;
2697 	}
2698 
2699 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
2700 
2701 	/* This happens only when the qpair is disconnected before
2702 	 * it is added to the poll group. Since there is no poll group,
2703 	 * the RDMA qp has not been initialized yet and the RDMA CM
2704 	 * event has not yet been acknowledged, so we need to reject it.
2705 	 */
2706 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
2707 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
2708 		return;
2709 	}
2710 
2711 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2712 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
2713 	}
2714 
2715 	rqpair->drain_recv_wr.type = RDMA_WR_TYPE_DRAIN_RECV;
2716 	recv_wr.wr_id = (uintptr_t)&rqpair->drain_recv_wr;
2717 	rc = ibv_post_recv(rqpair->cm_id->qp, &recv_wr, &bad_recv_wr);
2718 	if (rc) {
2719 		SPDK_ERRLOG("Failed to post dummy receive WR, errno %d\n", errno);
2720 		assert(false);
2721 		return;
2722 	}
2723 
2724 	rqpair->drain_send_wr.type = RDMA_WR_TYPE_DRAIN_SEND;
2725 	send_wr.wr_id = (uintptr_t)&rqpair->drain_send_wr;
2726 	send_wr.opcode = IBV_WR_SEND;
2727 	rc = ibv_post_send(rqpair->cm_id->qp, &send_wr, &bad_send_wr);
2728 	if (rc) {
2729 		SPDK_ERRLOG("Failed to post dummy send WR, errno %d\n", errno);
2730 		assert(false);
2731 		return;
2732 	}
2733 	rqpair->current_send_depth++;
2734 
2735 	rqpair->destruct_poller = spdk_poller_register(spdk_nvmf_rdma_destroy_defunct_qpair, (void *)rqpair,
2736 				  NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US);
2737 }
2738 
2739 #ifdef DEBUG
2740 static int
2741 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
2742 {
2743 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
2744 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
2745 }
2746 #endif
2747 
2748 static int
2749 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2750 			   struct spdk_nvmf_rdma_poller *rpoller)
2751 {
2752 	struct ibv_wc wc[32];
2753 	struct spdk_nvmf_rdma_wr	*rdma_wr;
2754 	struct spdk_nvmf_rdma_request	*rdma_req;
2755 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2756 	struct spdk_nvmf_rdma_qpair	*rqpair;
2757 	int reaped, i;
2758 	int count = 0;
2759 	bool error = false;
2760 
2761 	/* Poll for completing operations. */
2762 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2763 	if (reaped < 0) {
2764 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2765 			    errno, spdk_strerror(errno));
2766 		return -1;
2767 	}
2768 
2769 	for (i = 0; i < reaped; i++) {
2770 
2771 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
2772 
2773 		/* Handle error conditions */
2774 		if (wc[i].status) {
2775 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2776 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2777 
2778 			error = true;
2779 
2780 			switch (rdma_wr->type) {
2781 			case RDMA_WR_TYPE_SEND:
2782 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2783 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2784 
2785 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2786 				/* We're going to attempt an error recovery, so force the request into
2787 				 * the completed state. */
2788 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2789 				rqpair->current_send_depth--;
2790 
2791 				assert(rdma_req->num_outstanding_data_wr == 0);
2792 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2793 				break;
2794 			case RDMA_WR_TYPE_RECV:
2795 				rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2796 				rqpair = rdma_recv->qpair;
2797 
2798 				/* Dump this into the incoming queue. This gets cleaned up when
2799 				 * the queue pair disconnects or recovers. */
2800 				STAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2801 				rqpair->current_recv_depth++;
2802 
2803 				/* Don't worry about responding to recv overflow, we are disconnecting anyways */
2804 				break;
2805 			case RDMA_WR_TYPE_DATA:
2806 				/* If the data transfer fails still force the queue into the error state,
2807 				 * if we were performing an RDMA_READ, we need to force the request into a
2808 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
2809 				 * case, we should wait for the SEND to complete. */
2810 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2811 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2812 
2813 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2814 				assert(rdma_req->num_outstanding_data_wr > 0);
2815 				rdma_req->num_outstanding_data_wr--;
2816 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
2817 					rqpair->current_read_depth--;
2818 					if (rdma_req->num_outstanding_data_wr == 0) {
2819 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2820 					}
2821 				}
2822 				rqpair->current_send_depth--;
2823 				break;
2824 			case RDMA_WR_TYPE_DRAIN_RECV:
2825 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_recv_wr);
2826 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2827 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP RECV %u (%p)\n", rqpair->qpair.qid, rqpair);
2828 				rqpair->disconnect_flags |= RDMA_QP_RECV_DRAINED;
2829 				assert(rqpair->current_recv_depth == rqpair->max_queue_depth);
2830 				/* Don't worry about responding to recv overflow, we are disconnecting anyways */
2831 				if (rqpair->disconnect_flags & RDMA_QP_SEND_DRAINED) {
2832 					spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2833 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2834 				}
2835 				/* Continue so that this does not trigger the disconnect path below. */
2836 				continue;
2837 			case RDMA_WR_TYPE_DRAIN_SEND:
2838 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_send_wr);
2839 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2840 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP SEND %u (%p)\n", rqpair->qpair.qid, rqpair);
2841 				rqpair->disconnect_flags |= RDMA_QP_SEND_DRAINED;
2842 				rqpair->current_send_depth--;
2843 				if (rqpair->disconnect_flags & RDMA_QP_RECV_DRAINED) {
2844 					spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2845 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2846 				}
2847 				/* Continue so that this does not trigger the disconnect path below. */
2848 				continue;
2849 			default:
2850 				SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2851 				continue;
2852 			}
2853 
2854 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
2855 				/* Disconnect the connection. */
2856 				spdk_nvmf_rdma_start_disconnect(rqpair);
2857 			}
2858 			continue;
2859 		}
2860 
2861 		switch (wc[i].opcode) {
2862 		case IBV_WC_SEND:
2863 			assert(rdma_wr->type == RDMA_WR_TYPE_SEND);
2864 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2865 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2866 
2867 			assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
2868 
2869 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2870 			rqpair->current_send_depth--;
2871 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2872 
2873 			count++;
2874 
2875 			assert(rdma_req->num_outstanding_data_wr == 0);
2876 			/* Try to process other queued requests */
2877 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2878 			break;
2879 
2880 		case IBV_WC_RDMA_WRITE:
2881 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2882 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2883 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2884 			rqpair->current_send_depth--;
2885 			rdma_req->num_outstanding_data_wr--;
2886 
2887 			/* Try to process other queued requests */
2888 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2889 			break;
2890 
2891 		case IBV_WC_RDMA_READ:
2892 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2893 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2894 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2895 			rqpair->current_send_depth--;
2896 
2897 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2898 			/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
2899 			assert(rdma_req->num_outstanding_data_wr > 0);
2900 			rqpair->current_read_depth--;
2901 			rdma_req->num_outstanding_data_wr--;
2902 			if (rdma_req->num_outstanding_data_wr == 0) {
2903 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2904 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2905 			}
2906 
2907 			/* Try to process other queued requests */
2908 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2909 			break;
2910 
2911 		case IBV_WC_RECV:
2912 			assert(rdma_wr->type == RDMA_WR_TYPE_RECV);
2913 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2914 			rqpair = rdma_recv->qpair;
2915 			/* The qpair should not send more requests than are allowed per qpair. */
2916 			if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
2917 				spdk_nvmf_rdma_start_disconnect(rqpair);
2918 			} else {
2919 				rqpair->current_recv_depth++;
2920 			}
2921 			STAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2922 			/* Try to process other queued requests */
2923 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2924 			break;
2925 
2926 		default:
2927 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2928 			continue;
2929 		}
2930 	}
2931 
2932 	if (error == true) {
2933 		return -1;
2934 	}
2935 
2936 	return count;
2937 }
2938 
2939 static int
2940 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2941 {
2942 	struct spdk_nvmf_rdma_transport *rtransport;
2943 	struct spdk_nvmf_rdma_poll_group *rgroup;
2944 	struct spdk_nvmf_rdma_poller	*rpoller;
2945 	int				count, rc;
2946 
2947 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2948 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2949 
2950 	count = 0;
2951 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2952 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2953 		if (rc < 0) {
2954 			return rc;
2955 		}
2956 		count += rc;
2957 	}
2958 
2959 	return count;
2960 }
2961 
2962 static int
2963 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2964 			       struct spdk_nvme_transport_id *trid,
2965 			       bool peer)
2966 {
2967 	struct sockaddr *saddr;
2968 	uint16_t port;
2969 
2970 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
2971 
2972 	if (peer) {
2973 		saddr = rdma_get_peer_addr(id);
2974 	} else {
2975 		saddr = rdma_get_local_addr(id);
2976 	}
2977 	switch (saddr->sa_family) {
2978 	case AF_INET: {
2979 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
2980 
2981 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
2982 		inet_ntop(AF_INET, &saddr_in->sin_addr,
2983 			  trid->traddr, sizeof(trid->traddr));
2984 		if (peer) {
2985 			port = ntohs(rdma_get_dst_port(id));
2986 		} else {
2987 			port = ntohs(rdma_get_src_port(id));
2988 		}
2989 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2990 		break;
2991 	}
2992 	case AF_INET6: {
2993 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
2994 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
2995 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
2996 			  trid->traddr, sizeof(trid->traddr));
2997 		if (peer) {
2998 			port = ntohs(rdma_get_dst_port(id));
2999 		} else {
3000 			port = ntohs(rdma_get_src_port(id));
3001 		}
3002 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3003 		break;
3004 	}
3005 	default:
3006 		return -1;
3007 
3008 	}
3009 
3010 	return 0;
3011 }
3012 
3013 static int
3014 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3015 				   struct spdk_nvme_transport_id *trid)
3016 {
3017 	struct spdk_nvmf_rdma_qpair	*rqpair;
3018 
3019 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3020 
3021 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
3022 }
3023 
3024 static int
3025 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
3026 				    struct spdk_nvme_transport_id *trid)
3027 {
3028 	struct spdk_nvmf_rdma_qpair	*rqpair;
3029 
3030 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3031 
3032 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
3033 }
3034 
3035 static int
3036 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
3037 				     struct spdk_nvme_transport_id *trid)
3038 {
3039 	struct spdk_nvmf_rdma_qpair	*rqpair;
3040 
3041 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3042 
3043 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
3044 }
3045 
3046 void
3047 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
3048 {
3049 	g_nvmf_hooks = *hooks;
3050 }
3051 
3052 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
3053 	.type = SPDK_NVME_TRANSPORT_RDMA,
3054 	.opts_init = spdk_nvmf_rdma_opts_init,
3055 	.create = spdk_nvmf_rdma_create,
3056 	.destroy = spdk_nvmf_rdma_destroy,
3057 
3058 	.listen = spdk_nvmf_rdma_listen,
3059 	.stop_listen = spdk_nvmf_rdma_stop_listen,
3060 	.accept = spdk_nvmf_rdma_accept,
3061 
3062 	.listener_discover = spdk_nvmf_rdma_discover,
3063 
3064 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
3065 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
3066 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
3067 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
3068 
3069 	.req_free = spdk_nvmf_rdma_request_free,
3070 	.req_complete = spdk_nvmf_rdma_request_complete,
3071 
3072 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
3073 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
3074 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
3075 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
3076 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
3077 
3078 };
3079 
3080 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
3081