xref: /spdk/lib/nvmf/rdma.c (revision b961d9cc12de49251d135307eaa05ec0fc9dd2fa)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   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 "request.h"
42 #include "session.h"
43 #include "subsystem.h"
44 #include "transport.h"
45 
46 #include "spdk/assert.h"
47 #include "spdk/nvmf.h"
48 #include "spdk/nvmf_spec.h"
49 #include "spdk/string.h"
50 #include "spdk/trace.h"
51 #include "spdk/util.h"
52 #include "spdk/likely.h"
53 
54 #include "spdk_internal/log.h"
55 
56 /*
57  RDMA Connection Resouce Defaults
58  */
59 #define NVMF_DEFAULT_TX_SGE		1
60 #define NVMF_DEFAULT_RX_SGE		2
61 
62 struct spdk_nvmf_rdma_buf {
63 	SLIST_ENTRY(spdk_nvmf_rdma_buf) link;
64 };
65 
66 /* This structure holds commands as they are received off the wire.
67  * It must be dynamically paired with a full request object
68  * (spdk_nvmf_rdma_request) to service a request. It is separate
69  * from the request because RDMA does not appear to order
70  * completions, so occasionally we'll get a new incoming
71  * command when there aren't any free request objects.
72  */
73 struct spdk_nvmf_rdma_recv {
74 	struct ibv_recv_wr		wr;
75 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
76 
77 	/* In-capsule data buffer */
78 	uint8_t				*buf;
79 
80 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
81 
82 #ifdef DEBUG
83 	bool				in_use;
84 #endif
85 };
86 
87 struct spdk_nvmf_rdma_request {
88 	struct spdk_nvmf_request		req;
89 	bool					data_from_pool;
90 
91 	struct spdk_nvmf_rdma_recv		*recv;
92 
93 	struct {
94 		struct	ibv_send_wr		wr;
95 		struct	ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
96 	} rsp;
97 
98 	struct {
99 		struct ibv_send_wr		wr;
100 		struct ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
101 	} data;
102 
103 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
104 };
105 
106 struct spdk_nvmf_rdma_conn {
107 	struct spdk_nvmf_conn			conn;
108 
109 	struct rdma_cm_id			*cm_id;
110 	struct ibv_cq				*cq;
111 
112 	/* The maximum number of I/O outstanding on this connection at one time */
113 	uint16_t				max_queue_depth;
114 
115 	/* The maximum number of active RDMA READ and WRITE operations at one time */
116 	uint16_t				max_rw_depth;
117 
118 	/* The current number of I/O outstanding on this connection. This number
119 	 * includes all I/O from the time the capsule is first received until it is
120 	 * completed.
121 	 */
122 	uint16_t				cur_queue_depth;
123 
124 	/* The number of RDMA READ and WRITE requests that are outstanding */
125 	uint16_t				cur_rdma_rw_depth;
126 
127 	/* Receives that are waiting for a request object */
128 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
129 
130 	/* Requests that are not in use */
131 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
132 
133 	/* Requests that are waiting to obtain a data buffer */
134 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
135 
136 	/* Requests that are waiting to perform an RDMA READ or WRITE */
137 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_rw_queue;
138 
139 	/* Array of size "max_queue_depth" containing RDMA requests. */
140 	struct spdk_nvmf_rdma_request		*reqs;
141 
142 	/* Array of size "max_queue_depth" containing RDMA recvs. */
143 	struct spdk_nvmf_rdma_recv		*recvs;
144 
145 	/* Array of size "max_queue_depth" containing 64 byte capsules
146 	 * used for receive.
147 	 */
148 	union nvmf_h2c_msg			*cmds;
149 	struct ibv_mr				*cmds_mr;
150 
151 	/* Array of size "max_queue_depth" containing 16 byte completions
152 	 * to be sent back to the user.
153 	 */
154 	union nvmf_c2h_msg			*cpls;
155 	struct ibv_mr				*cpls_mr;
156 
157 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
158 	 * buffers to be used for in capsule data.
159 	 */
160 	void					*bufs;
161 	struct ibv_mr				*bufs_mr;
162 
163 	TAILQ_ENTRY(spdk_nvmf_rdma_conn)	link;
164 };
165 
166 /* List of RDMA connections that have not yet received a CONNECT capsule */
167 static TAILQ_HEAD(, spdk_nvmf_rdma_conn) g_pending_conns = TAILQ_HEAD_INITIALIZER(g_pending_conns);
168 
169 struct spdk_nvmf_rdma_session {
170 	struct spdk_nvmf_session		session;
171 
172 	SLIST_HEAD(, spdk_nvmf_rdma_buf)	data_buf_pool;
173 
174 	struct ibv_context			*verbs;
175 
176 	uint8_t					*buf;
177 	struct ibv_mr				*buf_mr;
178 };
179 
180 struct spdk_nvmf_rdma_listen_addr {
181 	char					*traddr;
182 	char					*trsvcid;
183 	struct rdma_cm_id			*id;
184 	struct ibv_device_attr 			attr;
185 	struct ibv_comp_channel			*comp_channel;
186 	uint32_t				ref;
187 	bool					is_listened;
188 	TAILQ_ENTRY(spdk_nvmf_rdma_listen_addr)	link;
189 };
190 
191 struct spdk_nvmf_rdma {
192 	struct rdma_event_channel	*event_channel;
193 
194 	pthread_mutex_t 		lock;
195 
196 	uint16_t 			max_queue_depth;
197 	uint32_t 			max_io_size;
198 	uint32_t 			in_capsule_data_size;
199 
200 	TAILQ_HEAD(, spdk_nvmf_rdma_listen_addr)	listen_addrs;
201 };
202 
203 static struct spdk_nvmf_rdma g_rdma = {
204 	.lock = PTHREAD_MUTEX_INITIALIZER,
205 	.listen_addrs = TAILQ_HEAD_INITIALIZER(g_rdma.listen_addrs),
206 };
207 
208 static inline struct spdk_nvmf_rdma_conn *
209 get_rdma_conn(struct spdk_nvmf_conn *conn)
210 {
211 	return (struct spdk_nvmf_rdma_conn *)((uintptr_t)conn - offsetof(struct spdk_nvmf_rdma_conn, conn));
212 }
213 
214 static inline struct spdk_nvmf_rdma_request *
215 get_rdma_req(struct spdk_nvmf_request *req)
216 {
217 	return (struct spdk_nvmf_rdma_request *)((uintptr_t)req - offsetof(struct spdk_nvmf_rdma_request,
218 			req));
219 }
220 
221 static inline struct spdk_nvmf_rdma_session *
222 get_rdma_sess(struct spdk_nvmf_session *sess)
223 {
224 	return (struct spdk_nvmf_rdma_session *)((uintptr_t)sess - offsetof(struct spdk_nvmf_rdma_session,
225 			session));
226 }
227 
228 static void
229 spdk_nvmf_rdma_conn_destroy(struct spdk_nvmf_rdma_conn *rdma_conn)
230 {
231 	if (rdma_conn->cmds_mr) {
232 		ibv_dereg_mr(rdma_conn->cmds_mr);
233 	}
234 
235 	if (rdma_conn->cpls_mr) {
236 		ibv_dereg_mr(rdma_conn->cpls_mr);
237 	}
238 
239 	if (rdma_conn->bufs_mr) {
240 		ibv_dereg_mr(rdma_conn->bufs_mr);
241 	}
242 
243 	if (rdma_conn->cm_id) {
244 		rdma_destroy_qp(rdma_conn->cm_id);
245 		rdma_destroy_id(rdma_conn->cm_id);
246 	}
247 
248 	if (rdma_conn->cq) {
249 		ibv_destroy_cq(rdma_conn->cq);
250 	}
251 
252 	/* Free all memory */
253 	spdk_free(rdma_conn->cmds);
254 	spdk_free(rdma_conn->cpls);
255 	spdk_free(rdma_conn->bufs);
256 	free(rdma_conn->reqs);
257 	free(rdma_conn);
258 }
259 
260 static struct spdk_nvmf_rdma_conn *
261 spdk_nvmf_rdma_conn_create(struct rdma_cm_id *id, struct ibv_comp_channel *channel,
262 			   uint16_t max_queue_depth, uint16_t max_rw_depth, uint32_t subsystem_id)
263 {
264 	struct spdk_nvmf_rdma_conn	*rdma_conn;
265 	struct spdk_nvmf_conn		*conn;
266 	int				rc, i;
267 	struct ibv_qp_init_attr		attr;
268 	struct spdk_nvmf_rdma_recv	*rdma_recv;
269 	struct spdk_nvmf_rdma_request	*rdma_req;
270 
271 	rdma_conn = calloc(1, sizeof(struct spdk_nvmf_rdma_conn));
272 	if (rdma_conn == NULL) {
273 		SPDK_ERRLOG("Could not allocate new connection.\n");
274 		return NULL;
275 	}
276 
277 	rdma_conn->max_queue_depth = max_queue_depth;
278 	rdma_conn->max_rw_depth = max_rw_depth;
279 	TAILQ_INIT(&rdma_conn->incoming_queue);
280 	TAILQ_INIT(&rdma_conn->free_queue);
281 	TAILQ_INIT(&rdma_conn->pending_data_buf_queue);
282 	TAILQ_INIT(&rdma_conn->pending_rdma_rw_queue);
283 
284 	rdma_conn->cq = ibv_create_cq(id->verbs, max_queue_depth * 3, rdma_conn, channel, 0);
285 	if (!rdma_conn->cq) {
286 		SPDK_ERRLOG("Unable to create completion queue\n");
287 		SPDK_ERRLOG("Completion Channel: %p Id: %p Verbs: %p\n", channel, id, id->verbs);
288 		SPDK_ERRLOG("Errno %d: %s\n", errno, strerror(errno));
289 		rdma_destroy_id(id);
290 		spdk_nvmf_rdma_conn_destroy(rdma_conn);
291 		return NULL;
292 	}
293 
294 	memset(&attr, 0, sizeof(struct ibv_qp_init_attr));
295 	attr.qp_type		= IBV_QPT_RC;
296 	attr.send_cq		= rdma_conn->cq;
297 	attr.recv_cq		= rdma_conn->cq;
298 	attr.cap.max_send_wr	= max_queue_depth * 2; /* SEND, READ, and WRITE operations */
299 	attr.cap.max_recv_wr	= max_queue_depth; /* RECV operations */
300 	attr.cap.max_send_sge	= NVMF_DEFAULT_TX_SGE;
301 	attr.cap.max_recv_sge	= NVMF_DEFAULT_RX_SGE;
302 
303 	rc = rdma_create_qp(id, NULL, &attr);
304 	if (rc) {
305 		SPDK_ERRLOG("rdma_create_qp failed\n");
306 		SPDK_ERRLOG("Errno %d: %s\n", errno, strerror(errno));
307 		rdma_destroy_id(id);
308 		spdk_nvmf_rdma_conn_destroy(rdma_conn);
309 		return NULL;
310 	}
311 
312 	conn = &rdma_conn->conn;
313 	conn->transport = &spdk_nvmf_transport_rdma;
314 	id->context = conn;
315 	rdma_conn->cm_id = id;
316 
317 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "New RDMA Connection: %p\n", conn);
318 
319 	rdma_conn->reqs = calloc(max_queue_depth, sizeof(*rdma_conn->reqs));
320 	rdma_conn->recvs = calloc(max_queue_depth, sizeof(*rdma_conn->recvs));
321 	rdma_conn->cmds = spdk_zmalloc(max_queue_depth * sizeof(*rdma_conn->cmds),
322 				       0x1000, NULL);
323 	rdma_conn->cpls = spdk_zmalloc(max_queue_depth * sizeof(*rdma_conn->cpls),
324 				       0x1000, NULL);
325 	rdma_conn->bufs = spdk_zmalloc(max_queue_depth * g_rdma.in_capsule_data_size,
326 				       0x1000, NULL);
327 	if (!rdma_conn->reqs || !rdma_conn->recvs || !rdma_conn->cmds ||
328 	    !rdma_conn->cpls || !rdma_conn->bufs) {
329 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
330 		spdk_nvmf_rdma_conn_destroy(rdma_conn);
331 		return NULL;
332 	}
333 
334 	rdma_conn->cmds_mr = ibv_reg_mr(id->pd, rdma_conn->cmds,
335 					max_queue_depth * sizeof(*rdma_conn->cmds),
336 					IBV_ACCESS_LOCAL_WRITE);
337 	rdma_conn->cpls_mr = ibv_reg_mr(id->pd, rdma_conn->cpls,
338 					max_queue_depth * sizeof(*rdma_conn->cpls),
339 					0);
340 	rdma_conn->bufs_mr = ibv_reg_mr(id->pd, rdma_conn->bufs,
341 					max_queue_depth * g_rdma.in_capsule_data_size,
342 					IBV_ACCESS_LOCAL_WRITE |
343 					IBV_ACCESS_REMOTE_WRITE);
344 	if (!rdma_conn->cmds_mr || !rdma_conn->cpls_mr || !rdma_conn->bufs_mr) {
345 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
346 		spdk_nvmf_rdma_conn_destroy(rdma_conn);
347 		return NULL;
348 	}
349 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
350 		      rdma_conn->cmds, max_queue_depth * sizeof(*rdma_conn->cmds), rdma_conn->cmds_mr->lkey);
351 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
352 		      rdma_conn->cpls, max_queue_depth * sizeof(*rdma_conn->cpls), rdma_conn->cpls_mr->lkey);
353 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
354 		      rdma_conn->bufs, max_queue_depth * g_rdma.in_capsule_data_size, rdma_conn->bufs_mr->lkey);
355 
356 	for (i = 0; i < max_queue_depth; i++) {
357 		struct ibv_recv_wr *bad_wr = NULL;
358 
359 		rdma_recv = &rdma_conn->recvs[i];
360 
361 		/* Set up memory to receive commands */
362 		rdma_recv->buf = (void *)((uintptr_t)rdma_conn->bufs + (i * g_rdma.in_capsule_data_size));
363 
364 		rdma_recv->sgl[0].addr = (uintptr_t)&rdma_conn->cmds[i];
365 		rdma_recv->sgl[0].length = sizeof(rdma_conn->cmds[i]);
366 		rdma_recv->sgl[0].lkey = rdma_conn->cmds_mr->lkey;
367 
368 		rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
369 		rdma_recv->sgl[1].length = g_rdma.in_capsule_data_size;
370 		rdma_recv->sgl[1].lkey = rdma_conn->bufs_mr->lkey;
371 
372 		rdma_recv->wr.wr_id = (uintptr_t)rdma_recv;
373 		rdma_recv->wr.sg_list = rdma_recv->sgl;
374 		rdma_recv->wr.num_sge = SPDK_COUNTOF(rdma_recv->sgl);
375 #ifdef DEBUG
376 		rdma_recv->in_use = false;
377 #endif
378 
379 		rc = ibv_post_recv(rdma_conn->cm_id->qp, &rdma_recv->wr, &bad_wr);
380 		if (rc) {
381 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
382 			spdk_nvmf_rdma_conn_destroy(rdma_conn);
383 			return NULL;
384 		}
385 	}
386 
387 	for (i = 0; i < max_queue_depth; i++) {
388 		rdma_req = &rdma_conn->reqs[i];
389 
390 		rdma_req->req.conn = &rdma_conn->conn;
391 		rdma_req->req.cmd = NULL;
392 
393 		/* Set up memory to send responses */
394 		rdma_req->req.rsp = &rdma_conn->cpls[i];
395 
396 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rdma_conn->cpls[i];
397 		rdma_req->rsp.sgl[0].length = sizeof(rdma_conn->cpls[i]);
398 		rdma_req->rsp.sgl[0].lkey = rdma_conn->cpls_mr->lkey;
399 
400 		rdma_req->rsp.wr.wr_id = (uintptr_t)rdma_req;
401 		rdma_req->rsp.wr.next = NULL;
402 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
403 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
404 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
405 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
406 
407 		/* Set up memory for data buffers */
408 		rdma_req->data.wr.wr_id = (uint64_t)rdma_req;
409 		rdma_req->data.wr.next = NULL;
410 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
411 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
412 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
413 
414 		TAILQ_INSERT_TAIL(&rdma_conn->free_queue, rdma_req, link);
415 	}
416 
417 	return rdma_conn;
418 }
419 
420 static int
421 request_transfer_in(struct spdk_nvmf_request *req)
422 {
423 	int				rc;
424 	struct spdk_nvmf_rdma_request	*rdma_req = get_rdma_req(req);
425 	struct spdk_nvmf_conn 		*conn = req->conn;
426 	struct spdk_nvmf_rdma_conn 	*rdma_conn = get_rdma_conn(conn);
427 	struct ibv_send_wr		*bad_wr = NULL;
428 
429 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
430 
431 	rdma_conn->cur_rdma_rw_depth++;
432 
433 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, conn);
434 	spdk_trace_record(TRACE_RDMA_READ_START, 0, 0, (uintptr_t)req, 0);
435 
436 	rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
437 	rdma_req->data.wr.next = NULL;
438 	rc = ibv_post_send(rdma_conn->cm_id->qp, &rdma_req->data.wr, &bad_wr);
439 	if (rc) {
440 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
441 		return -1;
442 	}
443 
444 	return 0;
445 }
446 
447 static int
448 request_transfer_out(struct spdk_nvmf_request *req)
449 {
450 	int 				rc;
451 	struct spdk_nvmf_rdma_request	*rdma_req = get_rdma_req(req);
452 	struct spdk_nvmf_conn		*conn = req->conn;
453 	struct spdk_nvmf_rdma_conn 	*rdma_conn = get_rdma_conn(conn);
454 	struct spdk_nvme_cpl		*rsp = &req->rsp->nvme_cpl;
455 	struct ibv_recv_wr		*bad_recv_wr = NULL;
456 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
457 
458 	/* Advance our sq_head pointer */
459 	if (conn->sq_head == conn->sq_head_max) {
460 		conn->sq_head = 0;
461 	} else {
462 		conn->sq_head++;
463 	}
464 	rsp->sqhd = conn->sq_head;
465 
466 	/* Post the capsule to the recv buffer */
467 	assert(rdma_req->recv != NULL);
468 #ifdef DEBUG
469 	assert(rdma_req->recv->in_use == true);
470 	rdma_req->recv->in_use = false;
471 #endif
472 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
473 		      rdma_conn);
474 	rc = ibv_post_recv(rdma_conn->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
475 	if (rc) {
476 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
477 		return rc;
478 	}
479 	rdma_req->recv = NULL;
480 
481 	/* Build the response which consists of an optional
482 	 * RDMA WRITE to transfer data, plus an RDMA SEND
483 	 * containing the response.
484 	 */
485 	send_wr = &rdma_req->rsp.wr;
486 
487 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
488 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
489 		SPDK_TRACELOG(SPDK_TRACE_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, conn);
490 		spdk_trace_record(TRACE_RDMA_WRITE_START, 0, 0, (uintptr_t)req, 0);
491 
492 		rdma_conn->cur_rdma_rw_depth++;
493 		rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
494 
495 		rdma_req->data.wr.next = send_wr;
496 		send_wr = &rdma_req->data.wr;
497 	}
498 
499 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, conn);
500 	spdk_trace_record(TRACE_NVMF_IO_COMPLETE, 0, 0, (uintptr_t)req, 0);
501 
502 	/* Send the completion */
503 	rc = ibv_post_send(rdma_conn->cm_id->qp, send_wr, &bad_send_wr);
504 	if (rc) {
505 		SPDK_ERRLOG("Unable to send response capsule\n");
506 	}
507 
508 	return rc;
509 }
510 
511 static int
512 spdk_nvmf_rdma_request_transfer_data(struct spdk_nvmf_request *req)
513 {
514 	struct spdk_nvmf_rdma_request *rdma_req = get_rdma_req(req);
515 	struct spdk_nvmf_conn *conn = req->conn;
516 	struct spdk_nvmf_rdma_conn *rdma_conn = get_rdma_conn(conn);
517 
518 	if (req->xfer == SPDK_NVME_DATA_NONE) {
519 		/* If no data transfer, this can bypass the queue */
520 		return request_transfer_out(req);
521 	}
522 
523 	if (rdma_conn->cur_rdma_rw_depth < rdma_conn->max_rw_depth) {
524 		if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
525 			return request_transfer_out(req);
526 		} else if (req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
527 			return request_transfer_in(req);
528 		}
529 	} else {
530 		TAILQ_INSERT_TAIL(&rdma_conn->pending_rdma_rw_queue, rdma_req, link);
531 	}
532 
533 	return 0;
534 }
535 
536 static int
537 nvmf_rdma_connect(struct rdma_cm_event *event)
538 {
539 	struct spdk_nvmf_rdma_conn	*rdma_conn = NULL;
540 	struct spdk_nvmf_rdma_listen_addr *addr;
541 	struct rdma_conn_param		*rdma_param = NULL;
542 	struct rdma_conn_param		ctrlr_event_data;
543 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
544 	struct spdk_nvmf_rdma_accept_private_data accept_data;
545 	uint16_t			sts = 0;
546 	uint16_t			max_queue_depth;
547 	uint16_t			max_rw_depth;
548 	uint32_t			subsystem_id = 0;
549 	int 				rc;
550 
551 	if (event->id == NULL) {
552 		SPDK_ERRLOG("connect request: missing cm_id\n");
553 		goto err0;
554 	}
555 
556 	if (event->id->verbs == NULL) {
557 		SPDK_ERRLOG("connect request: missing cm_id ibv_context\n");
558 		goto err0;
559 	}
560 
561 	rdma_param = &event->param.conn;
562 	if (rdma_param->private_data == NULL ||
563 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
564 		SPDK_ERRLOG("connect request: no private data provided\n");
565 		goto err0;
566 	}
567 	private_data = rdma_param->private_data;
568 
569 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
570 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
571 
572 	addr = event->listen_id->context;
573 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
574 		      event->listen_id, event->listen_id->verbs, addr);
575 
576 	/* Figure out the supported queue depth. This is a multi-step process
577 	 * that takes into account hardware maximums, host provided values,
578 	 * and our target's internal memory limits */
579 
580 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Calculating Queue Depth\n");
581 
582 	/* Start with the maximum queue depth allowed by the target */
583 	max_queue_depth = g_rdma.max_queue_depth;
584 	max_rw_depth = g_rdma.max_queue_depth;
585 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Target Max Queue Depth: %d\n", g_rdma.max_queue_depth);
586 
587 	/* Next check the local NIC's hardware limitations */
588 	SPDK_TRACELOG(SPDK_TRACE_RDMA,
589 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
590 		      addr->attr.max_qp_wr, addr->attr.max_qp_rd_atom);
591 	max_queue_depth = spdk_min(max_queue_depth, addr->attr.max_qp_wr);
592 	max_rw_depth = spdk_min(max_rw_depth, addr->attr.max_qp_rd_atom);
593 
594 	/* Next check the remote NIC's hardware limitations */
595 	SPDK_TRACELOG(SPDK_TRACE_RDMA,
596 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
597 		      rdma_param->initiator_depth, rdma_param->responder_resources);
598 	if (rdma_param->initiator_depth > 0) {
599 		max_rw_depth = spdk_min(max_rw_depth, rdma_param->initiator_depth);
600 	}
601 
602 	/* Finally check for the host software requested values, which are
603 	 * optional. */
604 	if (rdma_param->private_data != NULL &&
605 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
606 		SPDK_TRACELOG(SPDK_TRACE_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
607 		SPDK_TRACELOG(SPDK_TRACE_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
608 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
609 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
610 	}
611 
612 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
613 		      max_queue_depth, max_rw_depth);
614 
615 	/* Init the NVMf rdma transport connection */
616 	rdma_conn = spdk_nvmf_rdma_conn_create(event->id, addr->comp_channel, max_queue_depth,
617 					       max_rw_depth, subsystem_id);
618 	if (rdma_conn == NULL) {
619 		SPDK_ERRLOG("Error on nvmf connection creation\n");
620 		goto err1;
621 	}
622 
623 	accept_data.recfmt = 0;
624 	accept_data.crqsize = max_queue_depth;
625 	ctrlr_event_data = *rdma_param;
626 	ctrlr_event_data.private_data = &accept_data;
627 	ctrlr_event_data.private_data_len = sizeof(accept_data);
628 	if (event->id->ps == RDMA_PS_TCP) {
629 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
630 		ctrlr_event_data.initiator_depth = max_rw_depth;
631 	}
632 
633 	rc = rdma_accept(event->id, &ctrlr_event_data);
634 	if (rc) {
635 		SPDK_ERRLOG("Error on rdma_accept\n");
636 		goto err2;
637 	}
638 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Sent back the accept\n");
639 
640 	/* Add this RDMA connection to the global list until a CONNECT capsule
641 	 * is received. */
642 	TAILQ_INSERT_TAIL(&g_pending_conns, rdma_conn, link);
643 
644 	return 0;
645 
646 err2:
647 	spdk_nvmf_rdma_conn_destroy(rdma_conn);
648 
649 err1: {
650 		struct spdk_nvmf_rdma_reject_private_data rej_data;
651 
652 		rej_data.status.sc = sts;
653 		rdma_reject(event->id, &ctrlr_event_data, sizeof(rej_data));
654 	}
655 err0:
656 	return -1;
657 }
658 
659 static int
660 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
661 {
662 	struct spdk_nvmf_conn		*conn;
663 	struct spdk_nvmf_session	*session;
664 	struct spdk_nvmf_subsystem	*subsystem;
665 	struct spdk_nvmf_rdma_conn 	*rdma_conn;
666 
667 	if (evt->id == NULL) {
668 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
669 		return -1;
670 	}
671 
672 	conn = evt->id->context;
673 	if (conn == NULL) {
674 		SPDK_ERRLOG("disconnect request: no active connection\n");
675 		return -1;
676 	}
677 	/* ack the disconnect event before rdma_destroy_id */
678 	rdma_ack_cm_event(evt);
679 
680 	rdma_conn = get_rdma_conn(conn);
681 
682 	session = conn->sess;
683 	if (session == NULL) {
684 		/* No session has been established yet. That means the conn
685 		 * must be in the pending connections list. Remove it. */
686 		TAILQ_REMOVE(&g_pending_conns, rdma_conn, link);
687 		spdk_nvmf_rdma_conn_destroy(rdma_conn);
688 		return 0;
689 	}
690 
691 	subsystem = session->subsys;
692 
693 	subsystem->disconnect_cb(subsystem->cb_ctx, conn);
694 
695 	return 0;
696 }
697 
698 #ifdef DEBUG
699 static const char *CM_EVENT_STR[] = {
700 	"RDMA_CM_EVENT_ADDR_RESOLVED",
701 	"RDMA_CM_EVENT_ADDR_ERROR",
702 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
703 	"RDMA_CM_EVENT_ROUTE_ERROR",
704 	"RDMA_CM_EVENT_CONNECT_REQUEST",
705 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
706 	"RDMA_CM_EVENT_CONNECT_ERROR",
707 	"RDMA_CM_EVENT_UNREACHABLE",
708 	"RDMA_CM_EVENT_REJECTED",
709 	"RDMA_CM_EVENT_ESTABLISHED",
710 	"RDMA_CM_EVENT_DISCONNECTED",
711 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
712 	"RDMA_CM_EVENT_MULTICAST_JOIN",
713 	"RDMA_CM_EVENT_MULTICAST_ERROR",
714 	"RDMA_CM_EVENT_ADDR_CHANGE",
715 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
716 };
717 #endif /* DEBUG */
718 
719 typedef enum _spdk_nvmf_request_prep_type {
720 	SPDK_NVMF_REQUEST_PREP_ERROR = -1,
721 	SPDK_NVMF_REQUEST_PREP_READY = 0,
722 	SPDK_NVMF_REQUEST_PREP_PENDING_BUFFER = 1,
723 	SPDK_NVMF_REQUEST_PREP_PENDING_DATA = 2,
724 } spdk_nvmf_request_prep_type;
725 
726 static spdk_nvmf_request_prep_type
727 spdk_nvmf_request_prep_data(struct spdk_nvmf_request *req)
728 {
729 	struct spdk_nvme_cmd		*cmd = &req->cmd->nvme_cmd;
730 	struct spdk_nvme_cpl		*rsp = &req->rsp->nvme_cpl;
731 	struct spdk_nvmf_rdma_request	*rdma_req = get_rdma_req(req);
732 	struct spdk_nvmf_rdma_session	*rdma_sess;
733 	struct spdk_nvme_sgl_descriptor *sgl;
734 
735 	req->length = 0;
736 	req->data = NULL;
737 
738 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
739 		req->xfer = spdk_nvme_opc_get_data_transfer(req->cmd->nvmf_cmd.fctype);
740 	} else {
741 		req->xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
742 		if ((req->conn->type == CONN_TYPE_AQ) &&
743 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
744 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
745 			switch (cmd->cdw10 & 0xff) {
746 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
747 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
748 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
749 				break;
750 			default:
751 				req->xfer = SPDK_NVME_DATA_NONE;
752 				break;
753 			}
754 		}
755 	}
756 
757 	if (req->xfer == SPDK_NVME_DATA_NONE) {
758 		return SPDK_NVMF_REQUEST_PREP_READY;
759 	}
760 
761 	sgl = &cmd->dptr.sgl1;
762 
763 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
764 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
765 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
766 		if (sgl->keyed.length > g_rdma.max_io_size) {
767 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
768 				    sgl->keyed.length, g_rdma.max_io_size);
769 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
770 			return SPDK_NVMF_REQUEST_PREP_ERROR;
771 		}
772 
773 		if (sgl->keyed.length == 0) {
774 			req->xfer = SPDK_NVME_DATA_NONE;
775 			return SPDK_NVMF_REQUEST_PREP_READY;
776 		}
777 
778 		req->length = sgl->keyed.length;
779 		rdma_req->data.sgl[0].length = sgl->keyed.length;
780 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
781 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
782 
783 		rdma_sess = get_rdma_sess(req->conn->sess);
784 		if (!rdma_sess) {
785 			/* The only time a connection won't have a session
786 			 * is when this is the CONNECT request.
787 			 */
788 			assert(cmd->opc == SPDK_NVME_OPC_FABRIC);
789 			assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
790 			assert(req->length <= g_rdma.in_capsule_data_size);
791 
792 			/* Use the in capsule data buffer, even though this isn't in capsule data. */
793 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "Request using in capsule buffer for non-capsule data\n");
794 			req->data = rdma_req->recv->buf;
795 			rdma_req->data.sgl[0].lkey = get_rdma_conn(req->conn)->bufs_mr->lkey;
796 			rdma_req->data_from_pool = false;
797 		} else {
798 			req->data = SLIST_FIRST(&rdma_sess->data_buf_pool);
799 			rdma_req->data.sgl[0].lkey = rdma_sess->buf_mr->lkey;
800 			rdma_req->data_from_pool = true;
801 			if (!req->data) {
802 				/* No available buffers. Queue this request up. */
803 				SPDK_TRACELOG(SPDK_TRACE_RDMA, "No available large data buffers. Queueing request %p\n", req);
804 				/* This will get assigned when we actually obtain a buffer */
805 				rdma_req->data.sgl[0].addr = (uintptr_t)NULL;
806 				return SPDK_NVMF_REQUEST_PREP_PENDING_BUFFER;
807 			}
808 
809 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "Request %p took buffer from central pool\n", req);
810 			SLIST_REMOVE_HEAD(&rdma_sess->data_buf_pool, link);
811 		}
812 
813 		rdma_req->data.sgl[0].addr = (uintptr_t)req->data;
814 
815 		if (req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
816 			return SPDK_NVMF_REQUEST_PREP_PENDING_DATA;
817 		} else {
818 			return SPDK_NVMF_REQUEST_PREP_READY;
819 		}
820 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
821 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
822 		uint64_t offset = sgl->address;
823 		uint32_t max_len = g_rdma.in_capsule_data_size;
824 
825 		SPDK_TRACELOG(SPDK_TRACE_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
826 			      offset, sgl->unkeyed.length);
827 
828 		if (offset > max_len) {
829 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
830 				    offset, max_len);
831 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
832 			return SPDK_NVMF_REQUEST_PREP_ERROR;
833 		}
834 		max_len -= (uint32_t)offset;
835 
836 		if (sgl->unkeyed.length > max_len) {
837 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
838 				    sgl->unkeyed.length, max_len);
839 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
840 			return SPDK_NVMF_REQUEST_PREP_ERROR;
841 		}
842 
843 		if (sgl->unkeyed.length == 0) {
844 			req->xfer = SPDK_NVME_DATA_NONE;
845 			return SPDK_NVMF_REQUEST_PREP_READY;
846 		}
847 
848 		req->data = rdma_req->recv->buf + offset;
849 		rdma_req->data_from_pool = false;
850 		req->length = sgl->unkeyed.length;
851 		return SPDK_NVMF_REQUEST_PREP_READY;
852 	}
853 
854 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
855 		    sgl->generic.type, sgl->generic.subtype);
856 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
857 	return SPDK_NVMF_REQUEST_PREP_ERROR;
858 }
859 
860 static int
861 spdk_nvmf_rdma_handle_pending_rdma_rw(struct spdk_nvmf_conn *conn)
862 {
863 	struct spdk_nvmf_rdma_conn	*rdma_conn = get_rdma_conn(conn);
864 	struct spdk_nvmf_rdma_session	*rdma_sess;
865 	struct spdk_nvmf_rdma_request	*rdma_req, *tmp;
866 	int rc;
867 	int count = 0;
868 
869 	/* First, try to assign free data buffers to requests that need one */
870 	if (conn->sess) {
871 		rdma_sess = get_rdma_sess(conn->sess);
872 		TAILQ_FOREACH_SAFE(rdma_req, &rdma_conn->pending_data_buf_queue, link, tmp) {
873 			assert(rdma_req->req.data == NULL);
874 			rdma_req->req.data = SLIST_FIRST(&rdma_sess->data_buf_pool);
875 			if (!rdma_req->req.data) {
876 				break;
877 			}
878 			SLIST_REMOVE_HEAD(&rdma_sess->data_buf_pool, link);
879 			rdma_req->data.sgl[0].addr = (uintptr_t)rdma_req->req.data;
880 			TAILQ_REMOVE(&rdma_conn->pending_data_buf_queue, rdma_req, link);
881 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
882 				TAILQ_INSERT_TAIL(&rdma_conn->pending_rdma_rw_queue, rdma_req, link);
883 			} else {
884 				rc = spdk_nvmf_request_exec(&rdma_req->req);
885 				if (rc < 0) {
886 					return -1;
887 				}
888 				count++;
889 			}
890 		}
891 	}
892 
893 	/* Try to initiate RDMA Reads or Writes on requests that have data buffers */
894 	while (rdma_conn->cur_rdma_rw_depth < rdma_conn->max_rw_depth) {
895 		rdma_req = TAILQ_FIRST(&rdma_conn->pending_rdma_rw_queue);
896 		if (spdk_unlikely(!rdma_req)) {
897 			break;
898 		}
899 
900 		TAILQ_REMOVE(&rdma_conn->pending_rdma_rw_queue, rdma_req, link);
901 
902 		SPDK_TRACELOG(SPDK_TRACE_RDMA, "Submitting previously queued for RDMA R/W request %p\n", rdma_req);
903 
904 		rc = spdk_nvmf_rdma_request_transfer_data(&rdma_req->req);
905 		if (rc) {
906 			return -1;
907 		}
908 	}
909 
910 	return count;
911 }
912 
913 /* Public API callbacks begin here */
914 
915 static int
916 spdk_nvmf_rdma_init(uint16_t max_queue_depth, uint32_t max_io_size,
917 		    uint32_t in_capsule_data_size)
918 {
919 	int rc;
920 
921 	SPDK_NOTICELOG("*** RDMA Transport Init ***\n");
922 
923 	pthread_mutex_lock(&g_rdma.lock);
924 	g_rdma.max_queue_depth = max_queue_depth;
925 	g_rdma.max_io_size = max_io_size;
926 	g_rdma.in_capsule_data_size = in_capsule_data_size;
927 
928 	g_rdma.event_channel = rdma_create_event_channel();
929 	if (g_rdma.event_channel == NULL) {
930 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", strerror(errno));
931 		pthread_mutex_unlock(&g_rdma.lock);
932 		return -1;
933 	}
934 
935 	rc = fcntl(g_rdma.event_channel->fd, F_SETFL, O_NONBLOCK);
936 	if (rc < 0) {
937 		SPDK_ERRLOG("fcntl to set fd to non-blocking failed\n");
938 		pthread_mutex_unlock(&g_rdma.lock);
939 		return -1;
940 	}
941 
942 	pthread_mutex_unlock(&g_rdma.lock);
943 	return 0;
944 }
945 
946 static void
947 spdk_nvmf_rdma_listen_addr_free(struct spdk_nvmf_rdma_listen_addr *addr)
948 {
949 	if (!addr) {
950 		return;
951 	}
952 
953 	free(addr->traddr);
954 	free(addr->trsvcid);
955 	free(addr);
956 }
957 static int
958 spdk_nvmf_rdma_fini(void)
959 {
960 	pthread_mutex_lock(&g_rdma.lock);
961 
962 	assert(TAILQ_EMPTY(&g_rdma.listen_addrs));
963 	if (g_rdma.event_channel != NULL) {
964 		rdma_destroy_event_channel(g_rdma.event_channel);
965 	}
966 	pthread_mutex_unlock(&g_rdma.lock);
967 
968 	return 0;
969 }
970 
971 static int
972 spdk_nvmf_rdma_listen_remove(struct spdk_nvmf_listen_addr *listen_addr)
973 {
974 	struct spdk_nvmf_rdma_listen_addr *addr, *tmp;
975 
976 	pthread_mutex_lock(&g_rdma.lock);
977 	TAILQ_FOREACH_SAFE(addr, &g_rdma.listen_addrs, link, tmp) {
978 		if ((!strcasecmp(addr->traddr, listen_addr->traddr)) &&
979 		    (!strcasecmp(addr->trsvcid, listen_addr->trsvcid))) {
980 			assert(addr->ref > 0);
981 			addr->ref--;
982 			if (!addr->ref) {
983 				TAILQ_REMOVE(&g_rdma.listen_addrs, addr, link);
984 				ibv_destroy_comp_channel(addr->comp_channel);
985 				rdma_destroy_id(addr->id);
986 				spdk_nvmf_rdma_listen_addr_free(addr);
987 			}
988 			break;
989 		}
990 	}
991 
992 	pthread_mutex_unlock(&g_rdma.lock);
993 	return 0;
994 }
995 
996 static int
997 spdk_nvmf_rdma_poll(struct spdk_nvmf_conn *conn);
998 
999 static void
1000 spdk_nvmf_rdma_addr_listen_init(struct spdk_nvmf_rdma_listen_addr *addr)
1001 {
1002 	int rc;
1003 
1004 	rc = rdma_listen(addr->id, 10); /* 10 = backlog */
1005 	if (rc < 0) {
1006 		SPDK_ERRLOG("rdma_listen() failed\n");
1007 		addr->ref--;
1008 		assert(addr->ref == 0);
1009 		TAILQ_REMOVE(&g_rdma.listen_addrs, addr, link);
1010 		ibv_destroy_comp_channel(addr->comp_channel);
1011 		rdma_destroy_id(addr->id);
1012 		spdk_nvmf_rdma_listen_addr_free(addr);
1013 		return;
1014 	}
1015 
1016 	addr->is_listened = true;
1017 
1018 	SPDK_NOTICELOG("*** NVMf Target Listening on %s port %d ***\n",
1019 		       addr->traddr, ntohs(rdma_get_src_port(addr->id)));
1020 }
1021 
1022 static void
1023 spdk_nvmf_rdma_acceptor_poll(void)
1024 {
1025 	struct rdma_cm_event		*event;
1026 	int				rc;
1027 	struct spdk_nvmf_rdma_conn	*rdma_conn, *tmp;
1028 	struct spdk_nvmf_rdma_listen_addr *addr = NULL, *addr_tmp;
1029 
1030 	if (g_rdma.event_channel == NULL) {
1031 		return;
1032 	}
1033 
1034 	pthread_mutex_lock(&g_rdma.lock);
1035 	TAILQ_FOREACH_SAFE(addr, &g_rdma.listen_addrs, link, addr_tmp) {
1036 		if (!addr->is_listened) {
1037 			spdk_nvmf_rdma_addr_listen_init(addr);
1038 		}
1039 	}
1040 	pthread_mutex_unlock(&g_rdma.lock);
1041 
1042 	/* Process pending connections for incoming capsules. The only capsule
1043 	 * this should ever find is a CONNECT request. */
1044 	TAILQ_FOREACH_SAFE(rdma_conn, &g_pending_conns, link, tmp) {
1045 		rc = spdk_nvmf_rdma_poll(&rdma_conn->conn);
1046 		if (rc < 0) {
1047 			TAILQ_REMOVE(&g_pending_conns, rdma_conn, link);
1048 			spdk_nvmf_rdma_conn_destroy(rdma_conn);
1049 		} else if (rc > 0) {
1050 			/* At least one request was processed which is assumed to be
1051 			 * a CONNECT. Remove this connection from our list. */
1052 			TAILQ_REMOVE(&g_pending_conns, rdma_conn, link);
1053 		}
1054 	}
1055 
1056 	while (1) {
1057 		rc = rdma_get_cm_event(g_rdma.event_channel, &event);
1058 		if (rc == 0) {
1059 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
1060 
1061 			switch (event->event) {
1062 			case RDMA_CM_EVENT_CONNECT_REQUEST:
1063 				rc = nvmf_rdma_connect(event);
1064 				if (rc < 0) {
1065 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
1066 					break;
1067 				}
1068 				break;
1069 			case RDMA_CM_EVENT_ESTABLISHED:
1070 				break;
1071 			case RDMA_CM_EVENT_ADDR_CHANGE:
1072 			case RDMA_CM_EVENT_DISCONNECTED:
1073 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
1074 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1075 				rc = nvmf_rdma_disconnect(event);
1076 				if (rc < 0) {
1077 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
1078 					break;
1079 				}
1080 				continue;
1081 			default:
1082 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
1083 				break;
1084 			}
1085 
1086 			rdma_ack_cm_event(event);
1087 		} else {
1088 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
1089 				SPDK_ERRLOG("Acceptor Event Error: %s\n", strerror(errno));
1090 			}
1091 			break;
1092 		}
1093 	}
1094 }
1095 
1096 static int
1097 spdk_nvmf_rdma_listen(struct spdk_nvmf_listen_addr *listen_addr)
1098 {
1099 	struct spdk_nvmf_rdma_listen_addr *addr;
1100 	struct sockaddr_in saddr;
1101 	int rc;
1102 
1103 	pthread_mutex_lock(&g_rdma.lock);
1104 	assert(g_rdma.event_channel != NULL);
1105 	TAILQ_FOREACH(addr, &g_rdma.listen_addrs, link) {
1106 		if ((!strcasecmp(addr->traddr, listen_addr->traddr)) &&
1107 		    (!strcasecmp(addr->trsvcid, listen_addr->trsvcid))) {
1108 			addr->ref++;
1109 			/* Already listening at this address */
1110 			pthread_mutex_unlock(&g_rdma.lock);
1111 			return 0;
1112 		}
1113 	}
1114 
1115 	addr = calloc(1, sizeof(*addr));
1116 	if (!addr) {
1117 		pthread_mutex_unlock(&g_rdma.lock);
1118 		return -1;
1119 	}
1120 
1121 	addr->traddr = strdup(listen_addr->traddr);
1122 	if (!addr->traddr) {
1123 		spdk_nvmf_rdma_listen_addr_free(addr);
1124 		pthread_mutex_unlock(&g_rdma.lock);
1125 		return -1;
1126 	}
1127 
1128 	addr->trsvcid = strdup(listen_addr->trsvcid);
1129 	if (!addr->trsvcid) {
1130 		spdk_nvmf_rdma_listen_addr_free(addr);
1131 		pthread_mutex_unlock(&g_rdma.lock);
1132 		return -1;
1133 	}
1134 
1135 	rc = rdma_create_id(g_rdma.event_channel, &addr->id, addr, RDMA_PS_TCP);
1136 	if (rc < 0) {
1137 		SPDK_ERRLOG("rdma_create_id() failed\n");
1138 		spdk_nvmf_rdma_listen_addr_free(addr);
1139 		pthread_mutex_unlock(&g_rdma.lock);
1140 		return -1;
1141 	}
1142 
1143 	memset(&saddr, 0, sizeof(saddr));
1144 	saddr.sin_family = AF_INET;
1145 	saddr.sin_addr.s_addr = inet_addr(addr->traddr);
1146 	saddr.sin_port = htons((uint16_t)strtoul(addr->trsvcid, NULL, 10));
1147 	rc = rdma_bind_addr(addr->id, (struct sockaddr *)&saddr);
1148 	if (rc < 0) {
1149 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1150 		rdma_destroy_id(addr->id);
1151 		spdk_nvmf_rdma_listen_addr_free(addr);
1152 		pthread_mutex_unlock(&g_rdma.lock);
1153 		return -1;
1154 	}
1155 
1156 	rc = ibv_query_device(addr->id->verbs, &addr->attr);
1157 	if (rc < 0) {
1158 		SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1159 		rdma_destroy_id(addr->id);
1160 		spdk_nvmf_rdma_listen_addr_free(addr);
1161 		pthread_mutex_unlock(&g_rdma.lock);
1162 		return -1;
1163 	}
1164 
1165 	addr->comp_channel = ibv_create_comp_channel(addr->id->verbs);
1166 	if (!addr->comp_channel) {
1167 		SPDK_ERRLOG("Failed to create completion channel\n");
1168 		rdma_destroy_id(addr->id);
1169 		spdk_nvmf_rdma_listen_addr_free(addr);
1170 		pthread_mutex_unlock(&g_rdma.lock);
1171 		return -1;
1172 	}
1173 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "For listen id %p with context %p, created completion channel %p\n",
1174 		      addr->id, addr->id->verbs, addr->comp_channel);
1175 
1176 	rc = fcntl(addr->comp_channel->fd, F_SETFL, O_NONBLOCK);
1177 	if (rc < 0) {
1178 		SPDK_ERRLOG("fcntl to set comp channel to non-blocking failed\n");
1179 		rdma_destroy_id(addr->id);
1180 		ibv_destroy_comp_channel(addr->comp_channel);
1181 		spdk_nvmf_rdma_listen_addr_free(addr);
1182 		pthread_mutex_unlock(&g_rdma.lock);
1183 		return -1;
1184 	}
1185 
1186 
1187 	addr->ref = 1;
1188 	TAILQ_INSERT_TAIL(&g_rdma.listen_addrs, addr, link);
1189 	pthread_mutex_unlock(&g_rdma.lock);
1190 
1191 
1192 	return 0;
1193 }
1194 
1195 static void
1196 spdk_nvmf_rdma_discover(struct spdk_nvmf_listen_addr *listen_addr,
1197 			struct spdk_nvmf_discovery_log_page_entry *entry)
1198 {
1199 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
1200 	entry->adrfam = SPDK_NVMF_ADRFAM_IPV4;
1201 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
1202 
1203 	spdk_strcpy_pad(entry->trsvcid, listen_addr->trsvcid, sizeof(entry->trsvcid), ' ');
1204 	spdk_strcpy_pad(entry->traddr, listen_addr->traddr, sizeof(entry->traddr), ' ');
1205 
1206 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
1207 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
1208 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
1209 }
1210 
1211 static struct spdk_nvmf_session *
1212 spdk_nvmf_rdma_session_init(void)
1213 {
1214 	struct spdk_nvmf_rdma_session	*rdma_sess;
1215 	int				i;
1216 	struct spdk_nvmf_rdma_buf	*buf;
1217 
1218 	rdma_sess = calloc(1, sizeof(*rdma_sess));
1219 	if (!rdma_sess) {
1220 		return NULL;
1221 	}
1222 
1223 	/* TODO: Make the number of elements in this pool configurable. For now, one full queue
1224 	 *       worth seems reasonable.
1225 	 */
1226 	rdma_sess->buf = spdk_zmalloc(g_rdma.max_queue_depth * g_rdma.max_io_size,
1227 				      0x20000, NULL);
1228 	if (!rdma_sess->buf) {
1229 		SPDK_ERRLOG("Large buffer pool allocation failed (%d x %d)\n",
1230 			    g_rdma.max_queue_depth, g_rdma.max_io_size);
1231 		free(rdma_sess);
1232 		return NULL;
1233 	}
1234 
1235 	SLIST_INIT(&rdma_sess->data_buf_pool);
1236 	for (i = 0; i < g_rdma.max_queue_depth; i++) {
1237 		buf = (struct spdk_nvmf_rdma_buf *)(rdma_sess->buf + (i * g_rdma.max_io_size));
1238 		SLIST_INSERT_HEAD(&rdma_sess->data_buf_pool, buf, link);
1239 	}
1240 
1241 	rdma_sess->session.transport = &spdk_nvmf_transport_rdma;
1242 
1243 	return &rdma_sess->session;
1244 }
1245 
1246 static void
1247 spdk_nvmf_rdma_session_fini(struct spdk_nvmf_session *session)
1248 {
1249 	struct spdk_nvmf_rdma_session *rdma_sess = get_rdma_sess(session);
1250 
1251 	if (!rdma_sess) {
1252 		return;
1253 	}
1254 
1255 	ibv_dereg_mr(rdma_sess->buf_mr);
1256 	spdk_free(rdma_sess->buf);
1257 	free(rdma_sess);
1258 }
1259 
1260 static int
1261 spdk_nvmf_rdma_session_add_conn(struct spdk_nvmf_session *session,
1262 				struct spdk_nvmf_conn *conn)
1263 {
1264 	struct spdk_nvmf_rdma_session	*rdma_sess = get_rdma_sess(session);
1265 	struct spdk_nvmf_rdma_conn	*rdma_conn = get_rdma_conn(conn);
1266 
1267 	if (rdma_sess->verbs != NULL) {
1268 		if (rdma_sess->verbs != rdma_conn->cm_id->verbs) {
1269 			SPDK_ERRLOG("Two connections belonging to the same session cannot connect using different RDMA devices.\n");
1270 			return -1;
1271 		}
1272 
1273 		/* Nothing else to do. */
1274 		return 0;
1275 	}
1276 
1277 	rdma_sess->verbs = rdma_conn->cm_id->verbs;
1278 	rdma_sess->buf_mr = ibv_reg_mr(rdma_conn->cm_id->pd, rdma_sess->buf,
1279 				       g_rdma.max_queue_depth * g_rdma.max_io_size,
1280 				       IBV_ACCESS_LOCAL_WRITE |
1281 				       IBV_ACCESS_REMOTE_WRITE);
1282 	if (!rdma_sess->buf_mr) {
1283 		SPDK_ERRLOG("Large buffer pool registration failed (%d x %d)\n",
1284 			    g_rdma.max_queue_depth, g_rdma.max_io_size);
1285 		spdk_free(rdma_sess->buf);
1286 		free(rdma_sess);
1287 		return -1;
1288 	}
1289 
1290 	SPDK_TRACELOG(SPDK_TRACE_RDMA, "Session Shared Data Pool: %p Length: %x LKey: %x\n",
1291 		      rdma_sess->buf,  g_rdma.max_queue_depth * g_rdma.max_io_size, rdma_sess->buf_mr->lkey);
1292 
1293 	return 0;
1294 }
1295 
1296 static int
1297 spdk_nvmf_rdma_session_remove_conn(struct spdk_nvmf_session *session,
1298 				   struct spdk_nvmf_conn *conn)
1299 {
1300 	return 0;
1301 }
1302 
1303 static int
1304 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
1305 {
1306 	struct spdk_nvme_cpl *rsp = &req->rsp->nvme_cpl;
1307 	int rc;
1308 
1309 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
1310 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1311 		rc = spdk_nvmf_rdma_request_transfer_data(req);
1312 	} else {
1313 		rc = request_transfer_out(req);
1314 	}
1315 
1316 	return rc;
1317 }
1318 
1319 static void
1320 request_release_buffer(struct spdk_nvmf_request *req)
1321 {
1322 	struct spdk_nvmf_rdma_request	*rdma_req = get_rdma_req(req);
1323 	struct spdk_nvmf_conn		*conn = req->conn;
1324 	struct spdk_nvmf_rdma_session	*rdma_sess;
1325 	struct spdk_nvmf_rdma_buf	*buf;
1326 
1327 	if (rdma_req->data_from_pool) {
1328 		/* Put the buffer back in the pool */
1329 		rdma_sess = get_rdma_sess(conn->sess);
1330 		buf = req->data;
1331 
1332 		SLIST_INSERT_HEAD(&rdma_sess->data_buf_pool, buf, link);
1333 		req->data = NULL;
1334 		req->length = 0;
1335 		rdma_req->data_from_pool = false;
1336 	}
1337 }
1338 
1339 static void
1340 spdk_nvmf_rdma_close_conn(struct spdk_nvmf_conn *conn)
1341 {
1342 	spdk_nvmf_rdma_conn_destroy(get_rdma_conn(conn));
1343 }
1344 
1345 static int
1346 process_incoming_queue(struct spdk_nvmf_rdma_conn *rdma_conn)
1347 {
1348 	struct spdk_nvmf_rdma_recv	*rdma_recv, *tmp;
1349 	struct spdk_nvmf_rdma_request	*rdma_req;
1350 	struct spdk_nvmf_request	*req;
1351 	int rc, count;
1352 	bool error = false;
1353 
1354 	count = 0;
1355 	TAILQ_FOREACH_SAFE(rdma_recv, &rdma_conn->incoming_queue, link, tmp) {
1356 		rdma_req = TAILQ_FIRST(&rdma_conn->free_queue);
1357 		if (rdma_req == NULL) {
1358 			/* Need to wait for more SEND completions */
1359 			break;
1360 		}
1361 		TAILQ_REMOVE(&rdma_conn->free_queue, rdma_req, link);
1362 		TAILQ_REMOVE(&rdma_conn->incoming_queue, rdma_recv, link);
1363 		rdma_req->recv = rdma_recv;
1364 		req = &rdma_req->req;
1365 
1366 		/* The first element of the SGL is the NVMe command */
1367 		req->cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1368 
1369 		spdk_trace_record(TRACE_NVMF_IO_START, 0, 0, (uint64_t)req, 0);
1370 
1371 		memset(req->rsp, 0, sizeof(*req->rsp));
1372 		rc = spdk_nvmf_request_prep_data(req);
1373 		switch (rc) {
1374 		case SPDK_NVMF_REQUEST_PREP_READY:
1375 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "Request %p is ready for execution\n", req);
1376 			/* Data is immediately available */
1377 			rc = spdk_nvmf_request_exec(req);
1378 			if (rc < 0) {
1379 				error = true;
1380 				continue;
1381 			}
1382 			count++;
1383 			break;
1384 		case SPDK_NVMF_REQUEST_PREP_PENDING_BUFFER:
1385 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "Request %p needs data buffer\n", req);
1386 			TAILQ_INSERT_TAIL(&rdma_conn->pending_data_buf_queue, rdma_req, link);
1387 			break;
1388 		case SPDK_NVMF_REQUEST_PREP_PENDING_DATA:
1389 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "Request %p needs data transfer\n", req);
1390 			rc = spdk_nvmf_rdma_request_transfer_data(req);
1391 			if (rc < 0) {
1392 				error = true;
1393 				continue;
1394 			}
1395 			break;
1396 		case SPDK_NVMF_REQUEST_PREP_ERROR:
1397 			spdk_nvmf_request_complete(req);
1398 			break;
1399 		}
1400 	}
1401 
1402 	if (error) {
1403 		return -1;
1404 	}
1405 
1406 	return count;
1407 }
1408 
1409 static struct spdk_nvmf_rdma_request *
1410 get_rdma_req_from_wc(struct spdk_nvmf_rdma_conn *rdma_conn,
1411 		     struct ibv_wc *wc)
1412 {
1413 	struct spdk_nvmf_rdma_request *rdma_req;
1414 
1415 	rdma_req = (struct spdk_nvmf_rdma_request *)wc->wr_id;
1416 	assert(rdma_req != NULL);
1417 	assert(rdma_req - rdma_conn->reqs >= 0);
1418 	assert(rdma_req - rdma_conn->reqs < (ptrdiff_t)rdma_conn->max_queue_depth);
1419 
1420 	return rdma_req;
1421 }
1422 
1423 static struct spdk_nvmf_rdma_recv *
1424 get_rdma_recv_from_wc(struct spdk_nvmf_rdma_conn *rdma_conn,
1425 		      struct ibv_wc *wc)
1426 {
1427 	struct spdk_nvmf_rdma_recv *rdma_recv;
1428 
1429 	assert(wc->byte_len >= sizeof(struct spdk_nvmf_capsule_cmd));
1430 
1431 	rdma_recv = (struct spdk_nvmf_rdma_recv *)wc->wr_id;
1432 	assert(rdma_recv != NULL);
1433 	assert(rdma_recv - rdma_conn->recvs >= 0);
1434 	assert(rdma_recv - rdma_conn->recvs < (ptrdiff_t)rdma_conn->max_queue_depth);
1435 #ifdef DEBUG
1436 	assert(rdma_recv->in_use == false);
1437 	rdma_recv->in_use = true;
1438 #endif
1439 
1440 	return rdma_recv;
1441 }
1442 
1443 /* Returns the number of times that spdk_nvmf_request_exec was called,
1444  * or -1 on error.
1445  */
1446 static int
1447 spdk_nvmf_rdma_poll(struct spdk_nvmf_conn *conn)
1448 {
1449 	struct ibv_wc wc[32];
1450 	struct spdk_nvmf_rdma_conn *rdma_conn = get_rdma_conn(conn);
1451 	struct spdk_nvmf_rdma_request *rdma_req;
1452 	struct spdk_nvmf_rdma_recv    *rdma_recv;
1453 	struct spdk_nvmf_request *req;
1454 	int reaped, i, rc;
1455 	int count = 0;
1456 	bool error = false;
1457 
1458 	/* Poll for completing operations. */
1459 	rc = ibv_poll_cq(rdma_conn->cq, 32, wc);
1460 	if (rc < 0) {
1461 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
1462 			    errno, strerror(errno));
1463 		return -1;
1464 	}
1465 
1466 	reaped = rc;
1467 	for (i = 0; i < reaped; i++) {
1468 		if (wc[i].status) {
1469 			SPDK_ERRLOG("CQ error on Connection %p, Request 0x%lu (%d): %s\n",
1470 				    conn, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
1471 			error = true;
1472 			continue;
1473 		}
1474 
1475 		switch (wc[i].opcode) {
1476 		case IBV_WC_SEND:
1477 			rdma_req = get_rdma_req_from_wc(rdma_conn, &wc[i]);
1478 			req = &rdma_req->req;
1479 
1480 			assert(rdma_conn->cur_queue_depth > 0);
1481 			SPDK_TRACELOG(SPDK_TRACE_RDMA,
1482 				      "RDMA SEND Complete. Request: %p Connection: %p Outstanding I/O: %d\n",
1483 				      req, conn, rdma_conn->cur_queue_depth - 1);
1484 			rdma_conn->cur_queue_depth--;
1485 
1486 			/* The request may still own a data buffer. Release it */
1487 			request_release_buffer(req);
1488 
1489 			/* Put the request back on the free list */
1490 			TAILQ_INSERT_TAIL(&rdma_conn->free_queue, rdma_req, link);
1491 
1492 			/* Try to process queued incoming requests */
1493 			rc = process_incoming_queue(rdma_conn);
1494 			if (rc < 0) {
1495 				error = true;
1496 				continue;
1497 			}
1498 			count += rc;
1499 			break;
1500 
1501 		case IBV_WC_RDMA_WRITE:
1502 			rdma_req = get_rdma_req_from_wc(rdma_conn, &wc[i]);
1503 			req = &rdma_req->req;
1504 
1505 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "RDMA WRITE Complete. Request: %p Connection: %p\n",
1506 				      req, conn);
1507 			spdk_trace_record(TRACE_RDMA_WRITE_COMPLETE, 0, 0, (uint64_t)req, 0);
1508 
1509 			/* Now that the write has completed, the data buffer can be released */
1510 			request_release_buffer(req);
1511 
1512 			rdma_conn->cur_rdma_rw_depth--;
1513 
1514 			/* Since an RDMA R/W operation completed, try to submit from the pending list. */
1515 			rc = spdk_nvmf_rdma_handle_pending_rdma_rw(conn);
1516 			if (rc < 0) {
1517 				error = true;
1518 				continue;
1519 			}
1520 			count += rc;
1521 			break;
1522 
1523 		case IBV_WC_RDMA_READ:
1524 			rdma_req = get_rdma_req_from_wc(rdma_conn, &wc[i]);
1525 			req = &rdma_req->req;
1526 
1527 			SPDK_TRACELOG(SPDK_TRACE_RDMA, "RDMA READ Complete. Request: %p Connection: %p\n",
1528 				      req, conn);
1529 			spdk_trace_record(TRACE_RDMA_READ_COMPLETE, 0, 0, (uint64_t)req, 0);
1530 			rc = spdk_nvmf_request_exec(req);
1531 			if (rc) {
1532 				error = true;
1533 				continue;
1534 			}
1535 			count++;
1536 
1537 			/* Since an RDMA R/W operation completed, try to submit from the pending list. */
1538 			rdma_conn->cur_rdma_rw_depth--;
1539 			rc = spdk_nvmf_rdma_handle_pending_rdma_rw(conn);
1540 			if (rc < 0) {
1541 				error = true;
1542 				continue;
1543 			}
1544 			count += rc;
1545 			break;
1546 
1547 		case IBV_WC_RECV:
1548 			rdma_recv = get_rdma_recv_from_wc(rdma_conn, &wc[i]);
1549 
1550 			rdma_conn->cur_queue_depth++;
1551 			if (rdma_conn->cur_queue_depth > rdma_conn->max_queue_depth) {
1552 				SPDK_TRACELOG(SPDK_TRACE_RDMA,
1553 					      "Temporarily exceeded maximum queue depth (%u). Queueing.\n",
1554 					      rdma_conn->cur_queue_depth);
1555 			}
1556 			SPDK_TRACELOG(SPDK_TRACE_RDMA,
1557 				      "RDMA RECV Complete. Recv: %p Connection: %p Outstanding I/O: %d\n",
1558 				      rdma_recv, conn, rdma_conn->cur_queue_depth);
1559 
1560 			TAILQ_INSERT_TAIL(&rdma_conn->incoming_queue, rdma_recv, link);
1561 			rc = process_incoming_queue(rdma_conn);
1562 			if (rc < 0) {
1563 				error = true;
1564 				continue;
1565 			}
1566 			count += rc;
1567 			break;
1568 
1569 		default:
1570 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
1571 			error = true;
1572 			continue;
1573 		}
1574 	}
1575 
1576 	if (error == true) {
1577 		return -1;
1578 	}
1579 
1580 	return count;
1581 }
1582 
1583 static bool
1584 spdk_nvmf_rdma_conn_is_idle(struct spdk_nvmf_conn *conn)
1585 {
1586 	struct spdk_nvmf_rdma_conn *rdma_conn = get_rdma_conn(conn);
1587 
1588 	if (rdma_conn->cur_queue_depth == 0 && rdma_conn->cur_rdma_rw_depth == 0) {
1589 		return true;
1590 	}
1591 	return false;
1592 }
1593 
1594 const struct spdk_nvmf_transport spdk_nvmf_transport_rdma = {
1595 	.name = "rdma",
1596 	.transport_init = spdk_nvmf_rdma_init,
1597 	.transport_fini = spdk_nvmf_rdma_fini,
1598 
1599 	.acceptor_poll = spdk_nvmf_rdma_acceptor_poll,
1600 
1601 	.listen_addr_add = spdk_nvmf_rdma_listen,
1602 	.listen_addr_remove = spdk_nvmf_rdma_listen_remove,
1603 	.listen_addr_discover = spdk_nvmf_rdma_discover,
1604 
1605 	.session_init = spdk_nvmf_rdma_session_init,
1606 	.session_fini = spdk_nvmf_rdma_session_fini,
1607 	.session_add_conn = spdk_nvmf_rdma_session_add_conn,
1608 	.session_remove_conn = spdk_nvmf_rdma_session_remove_conn,
1609 
1610 	.req_complete = spdk_nvmf_rdma_request_complete,
1611 
1612 	.conn_fini = spdk_nvmf_rdma_close_conn,
1613 	.conn_poll = spdk_nvmf_rdma_poll,
1614 	.conn_is_idle = spdk_nvmf_rdma_conn_is_idle,
1615 
1616 };
1617 
1618 SPDK_LOG_REGISTER_TRACE_FLAG("rdma", SPDK_TRACE_RDMA)
1619