xref: /spdk/lib/nvmf/rdma.c (revision 8a0a98d35e21f282088edf28b9e8da66ec390e3a)
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 "transport.h"
42 
43 #include "spdk/assert.h"
44 #include "spdk/thread.h"
45 #include "spdk/nvmf.h"
46 #include "spdk/nvmf_spec.h"
47 #include "spdk/string.h"
48 #include "spdk/trace.h"
49 #include "spdk/util.h"
50 
51 #include "spdk_internal/log.h"
52 
53 /*
54  RDMA Connection Resouce Defaults
55  */
56 #define NVMF_DEFAULT_TX_SGE		1
57 #define NVMF_DEFAULT_RX_SGE		2
58 #define NVMF_DEFAULT_DATA_SGE		16
59 
60 /* The RDMA completion queue size */
61 #define NVMF_RDMA_CQ_SIZE	4096
62 
63 /* AIO backend requires block size aligned data buffers,
64  * extra 4KiB aligned data buffer should work for most devices.
65  */
66 #define SHIFT_4KB			12
67 #define NVMF_DATA_BUFFER_ALIGNMENT	(1 << SHIFT_4KB)
68 #define NVMF_DATA_BUFFER_MASK		(NVMF_DATA_BUFFER_ALIGNMENT - 1)
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_TRANSFER_PENDING_HOST_TO_CONTROLLER,
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_TRANSFER_PENDING_CONTROLLER_TO_HOST,
101 
102 	/* The request is ready to send a completion */
103 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
104 
105 	/* The request currently has a completion outstanding */
106 	RDMA_REQUEST_STATE_COMPLETING,
107 
108 	/* The request completed and can be marked free. */
109 	RDMA_REQUEST_STATE_COMPLETED,
110 };
111 
112 #define OBJECT_NVMF_RDMA_IO				0x40
113 
114 #define									TRACE_GROUP_NVMF_RDMA 0x4
115 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
116 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
117 #define TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
118 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
119 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
120 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
121 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
122 #define TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
123 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
124 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
125 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
126 
127 SPDK_TRACE_REGISTER_FN(nvmf_trace)
128 {
129 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
130 	spdk_trace_register_description("RDMA_REQ_NEW", "",
131 					TRACE_RDMA_REQUEST_STATE_NEW,
132 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 0, 0, "");
133 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
134 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
135 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
136 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
137 					TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER,
138 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
139 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
140 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
141 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
142 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
143 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
144 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
145 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
146 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
147 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
148 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
149 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
150 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
151 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C_TO_H", "",
152 					TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST,
153 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
154 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
155 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
156 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
157 	spdk_trace_register_description("RDMA_REQ_COMPLETING", "",
158 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
159 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
160 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
161 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
163 }
164 
165 /* This structure holds commands as they are received off the wire.
166  * It must be dynamically paired with a full request object
167  * (spdk_nvmf_rdma_request) to service a request. It is separate
168  * from the request because RDMA does not appear to order
169  * completions, so occasionally we'll get a new incoming
170  * command when there aren't any free request objects.
171  */
172 struct spdk_nvmf_rdma_recv {
173 	struct ibv_recv_wr		wr;
174 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
175 
176 	struct spdk_nvmf_rdma_qpair	*qpair;
177 
178 	/* In-capsule data buffer */
179 	uint8_t				*buf;
180 
181 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
182 };
183 
184 struct spdk_nvmf_rdma_request {
185 	struct spdk_nvmf_request		req;
186 	bool					data_from_pool;
187 
188 	enum spdk_nvmf_rdma_request_state	state;
189 
190 	struct spdk_nvmf_rdma_recv		*recv;
191 
192 	struct {
193 		struct	ibv_send_wr		wr;
194 		struct	ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
195 	} rsp;
196 
197 	struct {
198 		struct ibv_send_wr		wr;
199 		struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
200 		void				*buffers[SPDK_NVMF_MAX_SGL_ENTRIES];
201 	} data;
202 
203 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
204 };
205 
206 struct spdk_nvmf_rdma_qpair {
207 	struct spdk_nvmf_qpair			qpair;
208 
209 	struct spdk_nvmf_rdma_port		*port;
210 	struct spdk_nvmf_rdma_poller		*poller;
211 
212 	struct rdma_cm_id			*cm_id;
213 
214 	/* The maximum number of I/O outstanding on this connection at one time */
215 	uint16_t				max_queue_depth;
216 
217 	/* The maximum number of active RDMA READ and WRITE operations at one time */
218 	uint16_t				max_rw_depth;
219 
220 	/* The current number of I/O outstanding on this connection. This number
221 	 * includes all I/O from the time the capsule is first received until it is
222 	 * completed.
223 	 */
224 	uint16_t				cur_queue_depth;
225 
226 	/* The number of RDMA READ and WRITE requests that are outstanding */
227 	uint16_t				cur_rdma_rw_depth;
228 
229 	/* Receives that are waiting for a request object */
230 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
231 
232 	/* Requests that are not in use */
233 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
234 
235 	/* Requests that are waiting to perform an RDMA READ or WRITE */
236 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_rw_queue;
237 
238 	/* Array of size "max_queue_depth" containing RDMA requests. */
239 	struct spdk_nvmf_rdma_request		*reqs;
240 
241 	/* Array of size "max_queue_depth" containing RDMA recvs. */
242 	struct spdk_nvmf_rdma_recv		*recvs;
243 
244 	/* Array of size "max_queue_depth" containing 64 byte capsules
245 	 * used for receive.
246 	 */
247 	union nvmf_h2c_msg			*cmds;
248 	struct ibv_mr				*cmds_mr;
249 
250 	/* Array of size "max_queue_depth" containing 16 byte completions
251 	 * to be sent back to the user.
252 	 */
253 	union nvmf_c2h_msg			*cpls;
254 	struct ibv_mr				*cpls_mr;
255 
256 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
257 	 * buffers to be used for in capsule data.
258 	 */
259 	void					*bufs;
260 	struct ibv_mr				*bufs_mr;
261 
262 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
263 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	pending_link;
264 
265 	/* Mgmt channel */
266 	struct spdk_io_channel			*mgmt_channel;
267 	struct spdk_nvmf_rdma_mgmt_channel	*ch;
268 };
269 
270 struct spdk_nvmf_rdma_poller {
271 	struct spdk_nvmf_rdma_device		*device;
272 	struct spdk_nvmf_rdma_poll_group	*group;
273 
274 	struct ibv_cq				*cq;
275 
276 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
277 
278 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
279 };
280 
281 struct spdk_nvmf_rdma_poll_group {
282 	struct spdk_nvmf_transport_poll_group	group;
283 
284 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
285 };
286 
287 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
288 struct spdk_nvmf_rdma_device {
289 	struct ibv_device_attr			attr;
290 	struct ibv_context			*context;
291 
292 	struct spdk_mem_map			*map;
293 	struct ibv_pd				*pd;
294 
295 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
296 };
297 
298 struct spdk_nvmf_rdma_port {
299 	struct spdk_nvme_transport_id		trid;
300 	struct rdma_cm_id			*id;
301 	struct spdk_nvmf_rdma_device		*device;
302 	uint32_t				ref;
303 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
304 };
305 
306 struct spdk_nvmf_rdma_transport {
307 	struct spdk_nvmf_transport	transport;
308 
309 	struct rdma_event_channel	*event_channel;
310 
311 	struct spdk_mempool		*data_buf_pool;
312 
313 	pthread_mutex_t			lock;
314 
315 	uint16_t			max_queue_depth;
316 	uint32_t			max_io_size;
317 	uint32_t			io_unit_size;
318 	uint32_t			in_capsule_data_size;
319 
320 	/* fields used to poll RDMA/IB events */
321 	nfds_t			npoll_fds;
322 	struct pollfd		*poll_fds;
323 
324 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
325 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
326 };
327 
328 struct spdk_nvmf_rdma_mgmt_channel {
329 	/* Requests that are waiting to obtain a data buffer */
330 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
331 };
332 
333 static int
334 spdk_nvmf_rdma_mgmt_channel_create(void *io_device, void *ctx_buf)
335 {
336 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
337 
338 	TAILQ_INIT(&ch->pending_data_buf_queue);
339 	return 0;
340 }
341 
342 static void
343 spdk_nvmf_rdma_mgmt_channel_destroy(void *io_device, void *ctx_buf)
344 {
345 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
346 
347 	if (!TAILQ_EMPTY(&ch->pending_data_buf_queue)) {
348 		SPDK_ERRLOG("Pending I/O list wasn't empty on channel destruction\n");
349 	}
350 }
351 
352 static void
353 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
354 {
355 	if (rqpair->poller) {
356 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
357 	}
358 
359 	if (rqpair->cmds_mr) {
360 		ibv_dereg_mr(rqpair->cmds_mr);
361 	}
362 
363 	if (rqpair->cpls_mr) {
364 		ibv_dereg_mr(rqpair->cpls_mr);
365 	}
366 
367 	if (rqpair->bufs_mr) {
368 		ibv_dereg_mr(rqpair->bufs_mr);
369 	}
370 
371 	if (rqpair->cm_id) {
372 		rdma_destroy_qp(rqpair->cm_id);
373 		rdma_destroy_id(rqpair->cm_id);
374 	}
375 
376 	if (rqpair->mgmt_channel) {
377 		spdk_put_io_channel(rqpair->mgmt_channel);
378 	}
379 
380 	/* Free all memory */
381 	spdk_dma_free(rqpair->cmds);
382 	spdk_dma_free(rqpair->cpls);
383 	spdk_dma_free(rqpair->bufs);
384 	free(rqpair->reqs);
385 	free(rqpair->recvs);
386 	free(rqpair);
387 }
388 
389 static int
390 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
391 {
392 	struct spdk_nvmf_rdma_transport *rtransport;
393 	struct spdk_nvmf_rdma_qpair	*rqpair;
394 	int				rc, i;
395 	struct ibv_qp_init_attr		attr;
396 	struct spdk_nvmf_rdma_recv	*rdma_recv;
397 	struct spdk_nvmf_rdma_request	*rdma_req;
398 
399 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
400 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
401 
402 	memset(&attr, 0, sizeof(struct ibv_qp_init_attr));
403 	attr.qp_type		= IBV_QPT_RC;
404 	attr.send_cq		= rqpair->poller->cq;
405 	attr.recv_cq		= rqpair->poller->cq;
406 	attr.cap.max_send_wr	= rqpair->max_queue_depth * 2; /* SEND, READ, and WRITE operations */
407 	attr.cap.max_recv_wr	= rqpair->max_queue_depth; /* RECV operations */
408 	attr.cap.max_send_sge	= SPDK_NVMF_MAX_SGL_ENTRIES;
409 	attr.cap.max_recv_sge	= NVMF_DEFAULT_RX_SGE;
410 
411 	rc = rdma_create_qp(rqpair->cm_id, NULL, &attr);
412 	if (rc) {
413 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
414 		rdma_destroy_id(rqpair->cm_id);
415 		rqpair->cm_id = NULL;
416 		spdk_nvmf_rdma_qpair_destroy(rqpair);
417 		return -1;
418 	}
419 
420 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
421 
422 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
423 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
424 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
425 					0x1000, NULL);
426 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
427 					0x1000, NULL);
428 	rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth * rtransport->in_capsule_data_size,
429 					0x1000, NULL);
430 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
431 	    !rqpair->cpls || !rqpair->bufs) {
432 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
433 		spdk_nvmf_rdma_qpair_destroy(rqpair);
434 		return -1;
435 	}
436 
437 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
438 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
439 				     IBV_ACCESS_LOCAL_WRITE);
440 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
441 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
442 				     0);
443 	rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
444 				     rqpair->max_queue_depth * rtransport->in_capsule_data_size,
445 				     IBV_ACCESS_LOCAL_WRITE |
446 				     IBV_ACCESS_REMOTE_WRITE);
447 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || !rqpair->bufs_mr) {
448 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
449 		spdk_nvmf_rdma_qpair_destroy(rqpair);
450 		return -1;
451 	}
452 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
453 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
454 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
455 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
456 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
457 		      rqpair->bufs, rqpair->max_queue_depth * rtransport->in_capsule_data_size, rqpair->bufs_mr->lkey);
458 
459 	for (i = 0; i < rqpair->max_queue_depth; i++) {
460 		struct ibv_recv_wr *bad_wr = NULL;
461 
462 		rdma_recv = &rqpair->recvs[i];
463 		rdma_recv->qpair = rqpair;
464 
465 		/* Set up memory to receive commands */
466 		rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i * rtransport->in_capsule_data_size));
467 
468 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
469 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
470 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
471 
472 		rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
473 		rdma_recv->sgl[1].length = rtransport->in_capsule_data_size;
474 		rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
475 
476 		rdma_recv->wr.wr_id = (uintptr_t)rdma_recv;
477 		rdma_recv->wr.sg_list = rdma_recv->sgl;
478 		rdma_recv->wr.num_sge = SPDK_COUNTOF(rdma_recv->sgl);
479 
480 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
481 		if (rc) {
482 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
483 			spdk_nvmf_rdma_qpair_destroy(rqpair);
484 			return -1;
485 		}
486 	}
487 
488 	for (i = 0; i < rqpair->max_queue_depth; i++) {
489 		rdma_req = &rqpair->reqs[i];
490 
491 		rdma_req->req.qpair = &rqpair->qpair;
492 		rdma_req->req.cmd = NULL;
493 
494 		/* Set up memory to send responses */
495 		rdma_req->req.rsp = &rqpair->cpls[i];
496 
497 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
498 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
499 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
500 
501 		rdma_req->rsp.wr.wr_id = (uintptr_t)rdma_req;
502 		rdma_req->rsp.wr.next = NULL;
503 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
504 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
505 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
506 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
507 
508 		/* Set up memory for data buffers */
509 		rdma_req->data.wr.wr_id = (uint64_t)rdma_req;
510 		rdma_req->data.wr.next = NULL;
511 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
512 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
513 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
514 
515 		TAILQ_INSERT_TAIL(&rqpair->free_queue, rdma_req, link);
516 	}
517 
518 	return 0;
519 }
520 
521 static int
522 request_transfer_in(struct spdk_nvmf_request *req)
523 {
524 	int				rc;
525 	struct spdk_nvmf_rdma_request	*rdma_req;
526 	struct spdk_nvmf_qpair		*qpair;
527 	struct spdk_nvmf_rdma_qpair	*rqpair;
528 	struct ibv_send_wr		*bad_wr = NULL;
529 
530 	qpair = req->qpair;
531 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
532 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
533 
534 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
535 
536 	rqpair->cur_rdma_rw_depth++;
537 
538 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
539 
540 	rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
541 	rdma_req->data.wr.next = NULL;
542 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
543 	if (rc) {
544 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
545 
546 		/* Decrement r/w counter back since data transfer
547 		 * has not started.
548 		 */
549 		rqpair->cur_rdma_rw_depth--;
550 		return -1;
551 	}
552 
553 	return 0;
554 }
555 
556 static int
557 request_transfer_out(struct spdk_nvmf_request *req)
558 {
559 	int				rc;
560 	struct spdk_nvmf_rdma_request	*rdma_req;
561 	struct spdk_nvmf_qpair		*qpair;
562 	struct spdk_nvmf_rdma_qpair	*rqpair;
563 	struct spdk_nvme_cpl		*rsp;
564 	struct ibv_recv_wr		*bad_recv_wr = NULL;
565 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
566 
567 	qpair = req->qpair;
568 	rsp = &req->rsp->nvme_cpl;
569 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
570 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
571 
572 	/* Advance our sq_head pointer */
573 	if (qpair->sq_head == qpair->sq_head_max) {
574 		qpair->sq_head = 0;
575 	} else {
576 		qpair->sq_head++;
577 	}
578 	rsp->sqhd = qpair->sq_head;
579 
580 	/* Post the capsule to the recv buffer */
581 	assert(rdma_req->recv != NULL);
582 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
583 		      rqpair);
584 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
585 	if (rc) {
586 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
587 		return rc;
588 	}
589 	rdma_req->recv = NULL;
590 
591 	/* Build the response which consists of an optional
592 	 * RDMA WRITE to transfer data, plus an RDMA SEND
593 	 * containing the response.
594 	 */
595 	send_wr = &rdma_req->rsp.wr;
596 
597 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
598 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
599 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
600 
601 		rqpair->cur_rdma_rw_depth++;
602 		rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
603 
604 		rdma_req->data.wr.next = send_wr;
605 		send_wr = &rdma_req->data.wr;
606 	}
607 
608 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
609 
610 	/* Send the completion */
611 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
612 	if (rc) {
613 		SPDK_ERRLOG("Unable to send response capsule\n");
614 
615 		if (rdma_req->data.wr.opcode == IBV_WR_RDMA_WRITE) {
616 			/* Decrement r/w counter back since data transfer
617 			 * has not started.
618 			 */
619 			rqpair->cur_rdma_rw_depth--;
620 		}
621 	}
622 
623 	return rc;
624 }
625 
626 static int
627 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
628 {
629 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
630 	struct rdma_conn_param				ctrlr_event_data = {};
631 	int						rc;
632 
633 	accept_data.recfmt = 0;
634 	accept_data.crqsize = rqpair->max_queue_depth;
635 
636 	ctrlr_event_data.private_data = &accept_data;
637 	ctrlr_event_data.private_data_len = sizeof(accept_data);
638 	if (id->ps == RDMA_PS_TCP) {
639 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
640 		ctrlr_event_data.initiator_depth = rqpair->max_rw_depth;
641 	}
642 
643 	rc = rdma_accept(id, &ctrlr_event_data);
644 	if (rc) {
645 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
646 	} else {
647 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
648 	}
649 
650 	return rc;
651 }
652 
653 static void
654 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
655 {
656 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
657 
658 	rej_data.recfmt = 0;
659 	rej_data.sts = error;
660 
661 	rdma_reject(id, &rej_data, sizeof(rej_data));
662 }
663 
664 static int
665 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
666 		  new_qpair_fn cb_fn)
667 {
668 	struct spdk_nvmf_rdma_transport *rtransport;
669 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
670 	struct spdk_nvmf_rdma_port	*port;
671 	struct rdma_conn_param		*rdma_param = NULL;
672 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
673 	uint16_t			max_queue_depth;
674 	uint16_t			max_rw_depth;
675 
676 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
677 
678 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
679 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
680 
681 	rdma_param = &event->param.conn;
682 	if (rdma_param->private_data == NULL ||
683 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
684 		SPDK_ERRLOG("connect request: no private data provided\n");
685 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
686 		return -1;
687 	}
688 
689 	private_data = rdma_param->private_data;
690 	if (private_data->recfmt != 0) {
691 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
692 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
693 		return -1;
694 	}
695 
696 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
697 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
698 
699 	port = event->listen_id->context;
700 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
701 		      event->listen_id, event->listen_id->verbs, port);
702 
703 	/* Figure out the supported queue depth. This is a multi-step process
704 	 * that takes into account hardware maximums, host provided values,
705 	 * and our target's internal memory limits */
706 
707 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
708 
709 	/* Start with the maximum queue depth allowed by the target */
710 	max_queue_depth = rtransport->max_queue_depth;
711 	max_rw_depth = rtransport->max_queue_depth;
712 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n", rtransport->max_queue_depth);
713 
714 	/* Next check the local NIC's hardware limitations */
715 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
716 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
717 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
718 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
719 	max_rw_depth = spdk_min(max_rw_depth, port->device->attr.max_qp_rd_atom);
720 
721 	/* Next check the remote NIC's hardware limitations */
722 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
723 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
724 		      rdma_param->initiator_depth, rdma_param->responder_resources);
725 	if (rdma_param->initiator_depth > 0) {
726 		max_rw_depth = spdk_min(max_rw_depth, rdma_param->initiator_depth);
727 	}
728 
729 	/* Finally check for the host software requested values, which are
730 	 * optional. */
731 	if (rdma_param->private_data != NULL &&
732 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
733 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
734 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
735 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
736 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
737 	}
738 
739 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
740 		      max_queue_depth, max_rw_depth);
741 
742 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
743 	if (rqpair == NULL) {
744 		SPDK_ERRLOG("Could not allocate new connection.\n");
745 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
746 		return -1;
747 	}
748 
749 	rqpair->port = port;
750 	rqpair->max_queue_depth = max_queue_depth;
751 	rqpair->max_rw_depth = max_rw_depth;
752 	rqpair->cm_id = event->id;
753 	rqpair->qpair.transport = transport;
754 	TAILQ_INIT(&rqpair->incoming_queue);
755 	TAILQ_INIT(&rqpair->free_queue);
756 	TAILQ_INIT(&rqpair->pending_rdma_rw_queue);
757 
758 	event->id->context = &rqpair->qpair;
759 
760 	cb_fn(&rqpair->qpair);
761 
762 	return 0;
763 }
764 
765 static int
766 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
767 {
768 	struct spdk_nvmf_qpair		*qpair;
769 
770 	if (evt->id == NULL) {
771 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
772 		return -1;
773 	}
774 
775 	qpair = evt->id->context;
776 	if (qpair == NULL) {
777 		SPDK_ERRLOG("disconnect request: no active connection\n");
778 		return -1;
779 	}
780 	/* ack the disconnect event before rdma_destroy_id */
781 	rdma_ack_cm_event(evt);
782 
783 	spdk_nvmf_qpair_disconnect(qpair);
784 
785 	return 0;
786 }
787 
788 #ifdef DEBUG
789 static const char *CM_EVENT_STR[] = {
790 	"RDMA_CM_EVENT_ADDR_RESOLVED",
791 	"RDMA_CM_EVENT_ADDR_ERROR",
792 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
793 	"RDMA_CM_EVENT_ROUTE_ERROR",
794 	"RDMA_CM_EVENT_CONNECT_REQUEST",
795 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
796 	"RDMA_CM_EVENT_CONNECT_ERROR",
797 	"RDMA_CM_EVENT_UNREACHABLE",
798 	"RDMA_CM_EVENT_REJECTED",
799 	"RDMA_CM_EVENT_ESTABLISHED",
800 	"RDMA_CM_EVENT_DISCONNECTED",
801 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
802 	"RDMA_CM_EVENT_MULTICAST_JOIN",
803 	"RDMA_CM_EVENT_MULTICAST_ERROR",
804 	"RDMA_CM_EVENT_ADDR_CHANGE",
805 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
806 };
807 #endif /* DEBUG */
808 
809 static int
810 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
811 			  enum spdk_mem_map_notify_action action,
812 			  void *vaddr, size_t size)
813 {
814 	struct spdk_nvmf_rdma_device *device = cb_ctx;
815 	struct ibv_pd *pd = device->pd;
816 	struct ibv_mr *mr;
817 
818 	switch (action) {
819 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
820 		mr = ibv_reg_mr(pd, vaddr, size,
821 				IBV_ACCESS_LOCAL_WRITE |
822 				IBV_ACCESS_REMOTE_READ |
823 				IBV_ACCESS_REMOTE_WRITE);
824 		if (mr == NULL) {
825 			SPDK_ERRLOG("ibv_reg_mr() failed\n");
826 			return -1;
827 		} else {
828 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
829 		}
830 		break;
831 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
832 		mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, size);
833 		spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
834 		if (mr) {
835 			ibv_dereg_mr(mr);
836 		}
837 		break;
838 	}
839 
840 	return 0;
841 }
842 
843 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
844 
845 static spdk_nvme_data_transfer_t
846 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
847 {
848 	enum spdk_nvme_data_transfer xfer;
849 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
850 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
851 
852 	/* Figure out data transfer direction */
853 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
854 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
855 	} else {
856 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
857 
858 		/* Some admin commands are special cases */
859 		if ((rdma_req->req.qpair->qid == 0) &&
860 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
861 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
862 			switch (cmd->cdw10 & 0xff) {
863 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
864 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
865 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
866 				break;
867 			default:
868 				xfer = SPDK_NVME_DATA_NONE;
869 			}
870 		}
871 	}
872 
873 	if (xfer == SPDK_NVME_DATA_NONE) {
874 		return xfer;
875 	}
876 
877 	/* Even for commands that may transfer data, they could have specified 0 length.
878 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
879 	 */
880 	switch (sgl->generic.type) {
881 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
882 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
883 	case SPDK_NVME_SGL_TYPE_SEGMENT:
884 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
885 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
886 		if (sgl->unkeyed.length == 0) {
887 			xfer = SPDK_NVME_DATA_NONE;
888 		}
889 		break;
890 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
891 		if (sgl->keyed.length == 0) {
892 			xfer = SPDK_NVME_DATA_NONE;
893 		}
894 		break;
895 	}
896 
897 	return xfer;
898 }
899 
900 static int
901 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
902 				 struct spdk_nvmf_rdma_device *device,
903 				 struct spdk_nvmf_rdma_request *rdma_req)
904 {
905 	void		*buf = NULL;
906 	uint32_t	length = rdma_req->req.length;
907 	uint32_t	i = 0;
908 
909 	rdma_req->req.iovcnt = 0;
910 	while (length) {
911 		buf = spdk_mempool_get(rtransport->data_buf_pool);
912 		if (!buf) {
913 			goto nomem;
914 		}
915 
916 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
917 						~NVMF_DATA_BUFFER_MASK);
918 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->io_unit_size);
919 		rdma_req->req.iovcnt++;
920 		rdma_req->data.buffers[i] = buf;
921 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
922 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
923 		rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
924 						     (uint64_t)buf, rdma_req->req.iov[i].iov_len))->lkey;
925 
926 		length -= rdma_req->req.iov[i].iov_len;
927 		i++;
928 	}
929 
930 	rdma_req->data_from_pool = true;
931 
932 	return 0;
933 
934 nomem:
935 	while (i) {
936 		i--;
937 		spdk_mempool_put(rtransport->data_buf_pool, rdma_req->req.iov[i].iov_base);
938 		rdma_req->req.iov[i].iov_base = NULL;
939 		rdma_req->req.iov[i].iov_len = 0;
940 
941 		rdma_req->data.wr.sg_list[i].addr = 0;
942 		rdma_req->data.wr.sg_list[i].length = 0;
943 		rdma_req->data.wr.sg_list[i].lkey = 0;
944 	}
945 	rdma_req->req.iovcnt = 0;
946 	return -ENOMEM;
947 }
948 
949 static int
950 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
951 				 struct spdk_nvmf_rdma_device *device,
952 				 struct spdk_nvmf_rdma_request *rdma_req)
953 {
954 	struct spdk_nvme_cmd			*cmd;
955 	struct spdk_nvme_cpl			*rsp;
956 	struct spdk_nvme_sgl_descriptor		*sgl;
957 
958 	cmd = &rdma_req->req.cmd->nvme_cmd;
959 	rsp = &rdma_req->req.rsp->nvme_cpl;
960 	sgl = &cmd->dptr.sgl1;
961 
962 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
963 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
964 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
965 		if (sgl->keyed.length > rtransport->max_io_size) {
966 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
967 				    sgl->keyed.length, rtransport->max_io_size);
968 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
969 			return -1;
970 		}
971 
972 		/* fill request length and populate iovs */
973 		rdma_req->req.length = sgl->keyed.length;
974 
975 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
976 			/* No available buffers. Queue this request up. */
977 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
978 			return 0;
979 		}
980 
981 		/* backward compatible */
982 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
983 
984 		/* rdma wr specifics */
985 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
986 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
987 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
988 
989 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
990 			      rdma_req->req.iovcnt);
991 
992 		return 0;
993 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
994 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
995 		uint64_t offset = sgl->address;
996 		uint32_t max_len = rtransport->in_capsule_data_size;
997 
998 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
999 			      offset, sgl->unkeyed.length);
1000 
1001 		if (offset > max_len) {
1002 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1003 				    offset, max_len);
1004 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1005 			return -1;
1006 		}
1007 		max_len -= (uint32_t)offset;
1008 
1009 		if (sgl->unkeyed.length > max_len) {
1010 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1011 				    sgl->unkeyed.length, max_len);
1012 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1013 			return -1;
1014 		}
1015 
1016 		rdma_req->req.data = rdma_req->recv->buf + offset;
1017 		rdma_req->data_from_pool = false;
1018 		rdma_req->req.length = sgl->unkeyed.length;
1019 
1020 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1021 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1022 		rdma_req->req.iovcnt = 1;
1023 
1024 		return 0;
1025 	}
1026 
1027 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1028 		    sgl->generic.type, sgl->generic.subtype);
1029 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1030 	return -1;
1031 }
1032 
1033 static bool
1034 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1035 			       struct spdk_nvmf_rdma_request *rdma_req)
1036 {
1037 	struct spdk_nvmf_rdma_qpair	*rqpair;
1038 	struct spdk_nvmf_rdma_device	*device;
1039 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1040 	int				rc;
1041 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1042 	enum spdk_nvmf_rdma_request_state prev_state;
1043 	bool				progress = false;
1044 
1045 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1046 	device = rqpair->port->device;
1047 
1048 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1049 
1050 	/* The loop here is to allow for several back-to-back state changes. */
1051 	do {
1052 		prev_state = rdma_req->state;
1053 
1054 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1055 
1056 		switch (rdma_req->state) {
1057 		case RDMA_REQUEST_STATE_FREE:
1058 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1059 			 * to escape this state. */
1060 			break;
1061 		case RDMA_REQUEST_STATE_NEW:
1062 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0, (uintptr_t)rdma_req, 0);
1063 
1064 			rqpair->cur_queue_depth++;
1065 			rdma_recv = rdma_req->recv;
1066 
1067 			/* The first element of the SGL is the NVMe command */
1068 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1069 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1070 
1071 			TAILQ_REMOVE(&rqpair->incoming_queue, rdma_recv, link);
1072 			TAILQ_REMOVE(&rqpair->free_queue, rdma_req, link);
1073 
1074 			/* The next state transition depends on the data transfer needs of this request. */
1075 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1076 
1077 			/* If no data to transfer, ready to execute. */
1078 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1079 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1080 				break;
1081 			}
1082 
1083 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1084 			TAILQ_INSERT_TAIL(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1085 			break;
1086 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1087 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0, (uintptr_t)rdma_req, 0);
1088 
1089 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1090 
1091 			if (rdma_req != TAILQ_FIRST(&rqpair->ch->pending_data_buf_queue)) {
1092 				/* This request needs to wait in line to obtain a buffer */
1093 				break;
1094 			}
1095 
1096 			/* Try to get a data buffer */
1097 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1098 			if (rc < 0) {
1099 				TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1100 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1101 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1102 				break;
1103 			}
1104 
1105 			if (!rdma_req->req.data) {
1106 				/* No buffers available. */
1107 				break;
1108 			}
1109 
1110 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1111 
1112 			/* If data is transferring from host to controller and the data didn't
1113 			 * arrive using in capsule data, we need to do a transfer from the host.
1114 			 */
1115 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1116 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER;
1117 				TAILQ_INSERT_TAIL(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1118 				break;
1119 			}
1120 
1121 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1122 			break;
1123 		case RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER:
1124 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER, 0, 0,
1125 					  (uintptr_t)rdma_req, 0);
1126 
1127 			if (rdma_req != TAILQ_FIRST(&rqpair->pending_rdma_rw_queue)) {
1128 				/* This request needs to wait in line to perform RDMA */
1129 				break;
1130 			}
1131 
1132 			if (rqpair->cur_rdma_rw_depth < rqpair->max_rw_depth) {
1133 				TAILQ_REMOVE(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1134 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
1135 				rc = request_transfer_in(&rdma_req->req);
1136 				if (rc) {
1137 					rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1138 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1139 				}
1140 			}
1141 			break;
1142 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1143 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1144 					  (uintptr_t)rdma_req, 0);
1145 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1146 			 * to escape this state. */
1147 			break;
1148 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1149 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0, (uintptr_t)rdma_req, 0);
1150 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
1151 			spdk_nvmf_request_exec(&rdma_req->req);
1152 			break;
1153 		case RDMA_REQUEST_STATE_EXECUTING:
1154 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0, (uintptr_t)rdma_req, 0);
1155 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1156 			 * to escape this state. */
1157 			break;
1158 		case RDMA_REQUEST_STATE_EXECUTED:
1159 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0, (uintptr_t)rdma_req, 0);
1160 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1161 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST;
1162 				TAILQ_INSERT_TAIL(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1163 			} else {
1164 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1165 			}
1166 			break;
1167 		case RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST:
1168 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST, 0, 0,
1169 					  (uintptr_t)rdma_req, 0);
1170 			if (rdma_req != TAILQ_FIRST(&rqpair->pending_rdma_rw_queue)) {
1171 				/* This request needs to wait in line to perform RDMA */
1172 				break;
1173 			}
1174 
1175 			if (rqpair->cur_rdma_rw_depth < rqpair->max_rw_depth) {
1176 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1177 				TAILQ_REMOVE(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1178 			}
1179 			break;
1180 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1181 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0, (uintptr_t)rdma_req, 0);
1182 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETING;
1183 
1184 			rc = request_transfer_out(&rdma_req->req);
1185 			assert(rc == 0); /* No good way to handle this currently */
1186 			break;
1187 		case RDMA_REQUEST_STATE_COMPLETING:
1188 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0, (uintptr_t)rdma_req, 0);
1189 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1190 			 * to escape this state. */
1191 			break;
1192 		case RDMA_REQUEST_STATE_COMPLETED:
1193 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0, (uintptr_t)rdma_req, 0);
1194 			assert(rqpair->cur_queue_depth > 0);
1195 			rqpair->cur_queue_depth--;
1196 
1197 			if (rdma_req->data_from_pool) {
1198 				/* Put the buffer/s back in the pool */
1199 				for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1200 					spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1201 					rdma_req->req.iov[i].iov_base = NULL;
1202 					rdma_req->data.buffers[i] = NULL;
1203 				}
1204 				rdma_req->data_from_pool = false;
1205 			}
1206 			rdma_req->req.length = 0;
1207 			rdma_req->req.iovcnt = 0;
1208 			rdma_req->req.data = NULL;
1209 			rdma_req->state = RDMA_REQUEST_STATE_FREE;
1210 			TAILQ_INSERT_TAIL(&rqpair->free_queue, rdma_req, link);
1211 			break;
1212 		}
1213 
1214 		if (rdma_req->state != prev_state) {
1215 			progress = true;
1216 		}
1217 	} while (rdma_req->state != prev_state);
1218 
1219 	return progress;
1220 }
1221 
1222 /* Public API callbacks begin here */
1223 
1224 static struct spdk_nvmf_transport *
1225 spdk_nvmf_rdma_create(struct spdk_nvmf_tgt *tgt)
1226 {
1227 	int rc;
1228 	struct spdk_nvmf_rdma_transport *rtransport;
1229 	struct spdk_nvmf_rdma_device	*device, *tmp;
1230 	struct ibv_context		**contexts;
1231 	uint32_t			i;
1232 	int				flag;
1233 	uint32_t			sge_count;
1234 
1235 	rtransport = calloc(1, sizeof(*rtransport));
1236 	if (!rtransport) {
1237 		return NULL;
1238 	}
1239 
1240 	pthread_mutex_init(&rtransport->lock, NULL);
1241 	TAILQ_INIT(&rtransport->devices);
1242 	TAILQ_INIT(&rtransport->ports);
1243 
1244 	rtransport->transport.tgt = tgt;
1245 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1246 
1247 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n");
1248 
1249 	rtransport->max_queue_depth = tgt->opts.max_queue_depth;
1250 	rtransport->max_io_size = tgt->opts.max_io_size;
1251 	rtransport->io_unit_size = tgt->opts.io_unit_size;
1252 	rtransport->in_capsule_data_size = tgt->opts.in_capsule_data_size;
1253 
1254 	/* I/O unit size cannot be larger than max I/O size */
1255 	if (rtransport->io_unit_size > rtransport->max_io_size) {
1256 		rtransport->io_unit_size = rtransport->max_io_size;
1257 	}
1258 
1259 	sge_count = rtransport->max_io_size / rtransport->io_unit_size;
1260 	if (sge_count > SPDK_NVMF_MAX_SGL_ENTRIES) {
1261 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", rtransport->io_unit_size);
1262 		free(rtransport);
1263 		return NULL;
1264 	}
1265 
1266 	rtransport->event_channel = rdma_create_event_channel();
1267 	if (rtransport->event_channel == NULL) {
1268 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1269 		free(rtransport);
1270 		return NULL;
1271 	}
1272 
1273 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1274 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1275 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1276 			    rtransport->event_channel->fd, spdk_strerror(errno));
1277 		free(rtransport);
1278 		return NULL;
1279 	}
1280 
1281 	rtransport->data_buf_pool = spdk_mempool_create("spdk_nvmf_rdma",
1282 				    rtransport->max_queue_depth * 4, /* The 4 is arbitrarily chosen. Needs to be configurable. */
1283 				    rtransport->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT,
1284 				    SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1285 				    SPDK_ENV_SOCKET_ID_ANY);
1286 	if (!rtransport->data_buf_pool) {
1287 		SPDK_ERRLOG("Unable to allocate buffer pool for poll group\n");
1288 		free(rtransport);
1289 		return NULL;
1290 	}
1291 
1292 	spdk_io_device_register(rtransport, spdk_nvmf_rdma_mgmt_channel_create,
1293 				spdk_nvmf_rdma_mgmt_channel_destroy,
1294 				sizeof(struct spdk_nvmf_rdma_mgmt_channel));
1295 
1296 	contexts = rdma_get_devices(NULL);
1297 	i = 0;
1298 	rc = 0;
1299 	while (contexts[i] != NULL) {
1300 		device = calloc(1, sizeof(*device));
1301 		if (!device) {
1302 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1303 			rc = -ENOMEM;
1304 			break;
1305 		}
1306 		device->context = contexts[i];
1307 		rc = ibv_query_device(device->context, &device->attr);
1308 		if (rc < 0) {
1309 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1310 			free(device);
1311 			break;
1312 
1313 		}
1314 		/* set up device context async ev fd as NON_BLOCKING */
1315 		flag = fcntl(device->context->async_fd, F_GETFL);
1316 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1317 		if (rc < 0) {
1318 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1319 			free(device);
1320 			break;
1321 		}
1322 
1323 		device->pd = NULL;
1324 		device->map = NULL;
1325 
1326 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1327 		i++;
1328 	}
1329 
1330 	if (rc < 0) {
1331 		TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1332 			TAILQ_REMOVE(&rtransport->devices, device, link);
1333 			free(device);
1334 		}
1335 		spdk_mempool_free(rtransport->data_buf_pool);
1336 		rdma_destroy_event_channel(rtransport->event_channel);
1337 		free(rtransport);
1338 		rdma_free_devices(contexts);
1339 		return NULL;
1340 	} else {
1341 		/* Set up poll descriptor array to monitor events from RDMA and IB
1342 		 * in a single poll syscall
1343 		 */
1344 		rtransport->npoll_fds = i + 1;
1345 		i = 0;
1346 		rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1347 		rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1348 		rtransport->poll_fds[i++].events = POLLIN;
1349 
1350 		TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1351 			rtransport->poll_fds[i].fd = device->context->async_fd;
1352 			rtransport->poll_fds[i++].events = POLLIN;
1353 		}
1354 	}
1355 
1356 	rdma_free_devices(contexts);
1357 
1358 	return &rtransport->transport;
1359 }
1360 
1361 static int
1362 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1363 {
1364 	struct spdk_nvmf_rdma_transport	*rtransport;
1365 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1366 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1367 
1368 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1369 
1370 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1371 		TAILQ_REMOVE(&rtransport->ports, port, link);
1372 		rdma_destroy_id(port->id);
1373 		free(port);
1374 	}
1375 
1376 	if (rtransport->poll_fds != NULL) {
1377 		free(rtransport->poll_fds);
1378 	}
1379 
1380 	if (rtransport->event_channel != NULL) {
1381 		rdma_destroy_event_channel(rtransport->event_channel);
1382 	}
1383 
1384 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1385 		TAILQ_REMOVE(&rtransport->devices, device, link);
1386 		if (device->map) {
1387 			spdk_mem_map_free(&device->map);
1388 		}
1389 		free(device);
1390 	}
1391 
1392 	if (spdk_mempool_count(rtransport->data_buf_pool) != (rtransport->max_queue_depth * 4)) {
1393 		SPDK_ERRLOG("transport buffer pool count is %zu but should be %u\n",
1394 			    spdk_mempool_count(rtransport->data_buf_pool),
1395 			    rtransport->max_queue_depth * 4);
1396 	}
1397 
1398 	spdk_mempool_free(rtransport->data_buf_pool);
1399 	spdk_io_device_unregister(rtransport, NULL);
1400 	free(rtransport);
1401 
1402 	return 0;
1403 }
1404 
1405 static int
1406 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1407 		      const struct spdk_nvme_transport_id *trid)
1408 {
1409 	struct spdk_nvmf_rdma_transport	*rtransport;
1410 	struct spdk_nvmf_rdma_device	*device;
1411 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1412 	struct addrinfo			*res;
1413 	struct addrinfo			hints;
1414 	int				family;
1415 	int				rc;
1416 
1417 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1418 
1419 	port = calloc(1, sizeof(*port));
1420 	if (!port) {
1421 		return -ENOMEM;
1422 	}
1423 
1424 	/* Selectively copy the trid. Things like NQN don't matter here - that
1425 	 * mapping is enforced elsewhere.
1426 	 */
1427 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1428 	port->trid.adrfam = trid->adrfam;
1429 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1430 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1431 
1432 	pthread_mutex_lock(&rtransport->lock);
1433 	assert(rtransport->event_channel != NULL);
1434 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1435 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1436 			port_tmp->ref++;
1437 			free(port);
1438 			/* Already listening at this address */
1439 			pthread_mutex_unlock(&rtransport->lock);
1440 			return 0;
1441 		}
1442 	}
1443 
1444 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1445 	if (rc < 0) {
1446 		SPDK_ERRLOG("rdma_create_id() failed\n");
1447 		free(port);
1448 		pthread_mutex_unlock(&rtransport->lock);
1449 		return rc;
1450 	}
1451 
1452 	switch (port->trid.adrfam) {
1453 	case SPDK_NVMF_ADRFAM_IPV4:
1454 		family = AF_INET;
1455 		break;
1456 	case SPDK_NVMF_ADRFAM_IPV6:
1457 		family = AF_INET6;
1458 		break;
1459 	default:
1460 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1461 		free(port);
1462 		pthread_mutex_unlock(&rtransport->lock);
1463 		return -EINVAL;
1464 	}
1465 
1466 	memset(&hints, 0, sizeof(hints));
1467 	hints.ai_family = family;
1468 	hints.ai_socktype = SOCK_STREAM;
1469 	hints.ai_protocol = 0;
1470 
1471 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1472 	if (rc) {
1473 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1474 		free(port);
1475 		pthread_mutex_unlock(&rtransport->lock);
1476 		return -EINVAL;
1477 	}
1478 
1479 	rc = rdma_bind_addr(port->id, res->ai_addr);
1480 	freeaddrinfo(res);
1481 
1482 	if (rc < 0) {
1483 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1484 		rdma_destroy_id(port->id);
1485 		free(port);
1486 		pthread_mutex_unlock(&rtransport->lock);
1487 		return rc;
1488 	}
1489 
1490 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
1491 	if (rc < 0) {
1492 		SPDK_ERRLOG("rdma_listen() failed\n");
1493 		rdma_destroy_id(port->id);
1494 		free(port);
1495 		pthread_mutex_unlock(&rtransport->lock);
1496 		return rc;
1497 	}
1498 
1499 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1500 		if (device->context == port->id->verbs) {
1501 			port->device = device;
1502 			break;
1503 		}
1504 	}
1505 	if (!port->device) {
1506 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
1507 			    port->id->verbs);
1508 		rdma_destroy_id(port->id);
1509 		free(port);
1510 		pthread_mutex_unlock(&rtransport->lock);
1511 		return -EINVAL;
1512 	}
1513 
1514 	if (!device->map) {
1515 		device->pd = port->id->pd;
1516 		device->map = spdk_mem_map_alloc(0, spdk_nvmf_rdma_mem_notify, device);
1517 		if (!device->map) {
1518 			SPDK_ERRLOG("Unable to allocate memory map for new poll group\n");
1519 			return -1;
1520 		}
1521 	} else {
1522 		assert(device->pd == port->id->pd);
1523 	}
1524 
1525 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
1526 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
1527 
1528 	port->ref = 1;
1529 
1530 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
1531 	pthread_mutex_unlock(&rtransport->lock);
1532 
1533 	return 0;
1534 }
1535 
1536 static int
1537 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
1538 			   const struct spdk_nvme_transport_id *_trid)
1539 {
1540 	struct spdk_nvmf_rdma_transport *rtransport;
1541 	struct spdk_nvmf_rdma_port *port, *tmp;
1542 	struct spdk_nvme_transport_id trid = {};
1543 
1544 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1545 
1546 	/* Selectively copy the trid. Things like NQN don't matter here - that
1547 	 * mapping is enforced elsewhere.
1548 	 */
1549 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1550 	trid.adrfam = _trid->adrfam;
1551 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
1552 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
1553 
1554 	pthread_mutex_lock(&rtransport->lock);
1555 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
1556 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
1557 			assert(port->ref > 0);
1558 			port->ref--;
1559 			if (port->ref == 0) {
1560 				TAILQ_REMOVE(&rtransport->ports, port, link);
1561 				rdma_destroy_id(port->id);
1562 				free(port);
1563 			}
1564 			break;
1565 		}
1566 	}
1567 
1568 	pthread_mutex_unlock(&rtransport->lock);
1569 	return 0;
1570 }
1571 
1572 static void
1573 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
1574 {
1575 	struct spdk_nvmf_rdma_transport *rtransport;
1576 	struct rdma_cm_event		*event;
1577 	int				rc;
1578 
1579 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1580 
1581 	if (rtransport->event_channel == NULL) {
1582 		return;
1583 	}
1584 
1585 	while (1) {
1586 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
1587 		if (rc == 0) {
1588 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
1589 
1590 			switch (event->event) {
1591 			case RDMA_CM_EVENT_ADDR_RESOLVED:
1592 			case RDMA_CM_EVENT_ADDR_ERROR:
1593 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
1594 			case RDMA_CM_EVENT_ROUTE_ERROR:
1595 				/* No action required. The target never attempts to resolve routes. */
1596 				break;
1597 			case RDMA_CM_EVENT_CONNECT_REQUEST:
1598 				rc = nvmf_rdma_connect(transport, event, cb_fn);
1599 				if (rc < 0) {
1600 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
1601 					break;
1602 				}
1603 				break;
1604 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
1605 				/* The target never initiates a new connection. So this will not occur. */
1606 				break;
1607 			case RDMA_CM_EVENT_CONNECT_ERROR:
1608 				/* Can this happen? The docs say it can, but not sure what causes it. */
1609 				break;
1610 			case RDMA_CM_EVENT_UNREACHABLE:
1611 			case RDMA_CM_EVENT_REJECTED:
1612 				/* These only occur on the client side. */
1613 				break;
1614 			case RDMA_CM_EVENT_ESTABLISHED:
1615 				/* TODO: Should we be waiting for this event anywhere? */
1616 				break;
1617 			case RDMA_CM_EVENT_DISCONNECTED:
1618 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
1619 				rc = nvmf_rdma_disconnect(event);
1620 				if (rc < 0) {
1621 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
1622 					break;
1623 				}
1624 				continue;
1625 			case RDMA_CM_EVENT_MULTICAST_JOIN:
1626 			case RDMA_CM_EVENT_MULTICAST_ERROR:
1627 				/* Multicast is not used */
1628 				break;
1629 			case RDMA_CM_EVENT_ADDR_CHANGE:
1630 				/* Not utilizing this event */
1631 				break;
1632 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1633 				/* For now, do nothing. The target never re-uses queue pairs. */
1634 				break;
1635 			default:
1636 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
1637 				break;
1638 			}
1639 
1640 			rdma_ack_cm_event(event);
1641 		} else {
1642 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
1643 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
1644 			}
1645 			break;
1646 		}
1647 	}
1648 }
1649 
1650 static void
1651 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
1652 {
1653 	int rc;
1654 	struct ibv_async_event event;
1655 
1656 	rc = ibv_get_async_event(device->context, &event);
1657 
1658 	if (rc) {
1659 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
1660 			    errno, spdk_strerror(errno));
1661 		return;
1662 	}
1663 
1664 	SPDK_NOTICELOG("Async event: %s\n",
1665 		       ibv_event_type_str(event.event_type));
1666 	ibv_ack_async_event(&event);
1667 }
1668 
1669 static void
1670 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
1671 {
1672 	int	nfds, i = 0;
1673 	struct spdk_nvmf_rdma_transport *rtransport;
1674 	struct spdk_nvmf_rdma_device *device, *tmp;
1675 
1676 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1677 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
1678 
1679 	if (nfds <= 0) {
1680 		return;
1681 	}
1682 
1683 	/* The first poll descriptor is RDMA CM event */
1684 	if (rtransport->poll_fds[i++].revents & POLLIN) {
1685 		spdk_nvmf_process_cm_event(transport, cb_fn);
1686 		nfds--;
1687 	}
1688 
1689 	if (nfds == 0) {
1690 		return;
1691 	}
1692 
1693 	/* Second and subsequent poll descriptors are IB async events */
1694 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1695 		if (rtransport->poll_fds[i++].revents & POLLIN) {
1696 			spdk_nvmf_process_ib_event(device);
1697 			nfds--;
1698 		}
1699 	}
1700 	/* check all flagged fd's have been served */
1701 	assert(nfds == 0);
1702 }
1703 
1704 static void
1705 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
1706 			struct spdk_nvme_transport_id *trid,
1707 			struct spdk_nvmf_discovery_log_page_entry *entry)
1708 {
1709 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
1710 	entry->adrfam = trid->adrfam;
1711 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
1712 
1713 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
1714 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
1715 
1716 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
1717 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
1718 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
1719 }
1720 
1721 static struct spdk_nvmf_transport_poll_group *
1722 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
1723 {
1724 	struct spdk_nvmf_rdma_transport		*rtransport;
1725 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1726 	struct spdk_nvmf_rdma_poller		*poller;
1727 	struct spdk_nvmf_rdma_device		*device;
1728 
1729 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1730 
1731 	rgroup = calloc(1, sizeof(*rgroup));
1732 	if (!rgroup) {
1733 		return NULL;
1734 	}
1735 
1736 	TAILQ_INIT(&rgroup->pollers);
1737 
1738 	pthread_mutex_lock(&rtransport->lock);
1739 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1740 		if (device->map == NULL) {
1741 			/*
1742 			 * The device is not in use (no listeners),
1743 			 * so no protection domain has been constructed.
1744 			 * Skip it.
1745 			 */
1746 			SPDK_NOTICELOG("Skipping unused RDMA device when creating poll group.\n");
1747 			continue;
1748 		}
1749 
1750 		poller = calloc(1, sizeof(*poller));
1751 		if (!poller) {
1752 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
1753 			free(rgroup);
1754 			pthread_mutex_unlock(&rtransport->lock);
1755 			return NULL;
1756 		}
1757 
1758 		poller->device = device;
1759 		poller->group = rgroup;
1760 
1761 		TAILQ_INIT(&poller->qpairs);
1762 
1763 		poller->cq = ibv_create_cq(device->context, NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
1764 		if (!poller->cq) {
1765 			SPDK_ERRLOG("Unable to create completion queue\n");
1766 			free(poller);
1767 			free(rgroup);
1768 			pthread_mutex_unlock(&rtransport->lock);
1769 			return NULL;
1770 		}
1771 
1772 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
1773 	}
1774 
1775 	pthread_mutex_unlock(&rtransport->lock);
1776 	return &rgroup->group;
1777 }
1778 
1779 static void
1780 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
1781 {
1782 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1783 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
1784 
1785 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
1786 
1787 	if (!rgroup) {
1788 		return;
1789 	}
1790 
1791 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
1792 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
1793 
1794 		if (poller->cq) {
1795 			ibv_destroy_cq(poller->cq);
1796 		}
1797 
1798 		free(poller);
1799 	}
1800 
1801 	free(rgroup);
1802 }
1803 
1804 static int
1805 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
1806 			      struct spdk_nvmf_qpair *qpair)
1807 {
1808 	struct spdk_nvmf_rdma_transport		*rtransport;
1809 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1810 	struct spdk_nvmf_rdma_qpair		*rqpair;
1811 	struct spdk_nvmf_rdma_device		*device;
1812 	struct spdk_nvmf_rdma_poller		*poller;
1813 	int					rc;
1814 
1815 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1816 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
1817 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1818 
1819 	device = rqpair->port->device;
1820 
1821 	if (device->pd != rqpair->cm_id->pd) {
1822 		SPDK_ERRLOG("Mismatched protection domains\n");
1823 		return -1;
1824 	}
1825 
1826 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
1827 		if (poller->device == device) {
1828 			break;
1829 		}
1830 	}
1831 
1832 	if (!poller) {
1833 		SPDK_ERRLOG("No poller found for device.\n");
1834 		return -1;
1835 	}
1836 
1837 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
1838 	rqpair->poller = poller;
1839 
1840 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
1841 	if (rc < 0) {
1842 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
1843 		return -1;
1844 	}
1845 
1846 	rqpair->mgmt_channel = spdk_get_io_channel(rtransport);
1847 	if (!rqpair->mgmt_channel) {
1848 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1849 		spdk_nvmf_rdma_qpair_destroy(rqpair);
1850 		return -1;
1851 	}
1852 
1853 	rqpair->ch = spdk_io_channel_get_ctx(rqpair->mgmt_channel);
1854 	assert(rqpair->ch != NULL);
1855 
1856 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
1857 	if (rc) {
1858 		/* Try to reject, but we probably can't */
1859 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1860 		spdk_nvmf_rdma_qpair_destroy(rqpair);
1861 		return -1;
1862 	}
1863 
1864 	return 0;
1865 }
1866 
1867 static int
1868 spdk_nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
1869 				 struct spdk_nvmf_qpair *qpair)
1870 {
1871 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1872 	struct spdk_nvmf_rdma_qpair		*rqpair;
1873 	struct spdk_nvmf_rdma_device		*device;
1874 	struct spdk_nvmf_rdma_poller		*poller;
1875 	struct spdk_nvmf_rdma_qpair		*rq, *trq;
1876 
1877 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
1878 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1879 
1880 	device = rqpair->port->device;
1881 
1882 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
1883 		if (poller->device == device) {
1884 			break;
1885 		}
1886 	}
1887 
1888 	if (!poller) {
1889 		SPDK_ERRLOG("No poller found for device.\n");
1890 		return -1;
1891 	}
1892 
1893 	TAILQ_FOREACH_SAFE(rq, &poller->qpairs, link, trq) {
1894 		if (rq == rqpair) {
1895 			TAILQ_REMOVE(&poller->qpairs, rqpair, link);
1896 			rqpair->poller = NULL;
1897 			break;
1898 		}
1899 	}
1900 
1901 	if (rq == NULL) {
1902 		SPDK_ERRLOG("RDMA qpair cannot be removed from group (not in group).\n");
1903 		return -1;
1904 	}
1905 
1906 	return 0;
1907 }
1908 
1909 static int
1910 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
1911 {
1912 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
1913 			struct spdk_nvmf_rdma_transport, transport);
1914 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1915 
1916 	rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
1917 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
1918 
1919 	return 0;
1920 }
1921 
1922 static void
1923 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
1924 {
1925 	spdk_nvmf_rdma_qpair_destroy(SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair));
1926 }
1927 
1928 static void
1929 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
1930 				     struct spdk_nvmf_rdma_qpair *rqpair)
1931 {
1932 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
1933 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
1934 
1935 	/* We process I/O in the pending_rdma_rw queue at the highest priority. */
1936 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_rw_queue, link, req_tmp) {
1937 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1938 			break;
1939 		}
1940 	}
1941 
1942 	/* The second highest priority is I/O waiting on memory buffers. */
1943 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->ch->pending_data_buf_queue, link, req_tmp) {
1944 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1945 			break;
1946 		}
1947 	}
1948 
1949 	/* The lowest priority is processing newly received commands */
1950 	TAILQ_FOREACH_SAFE(rdma_recv, &rqpair->incoming_queue, link, recv_tmp) {
1951 		rdma_req = TAILQ_FIRST(&rqpair->free_queue);
1952 		if (rdma_req == NULL) {
1953 			/* Need to wait for more SEND completions */
1954 			break;
1955 		}
1956 
1957 		rdma_req->recv = rdma_recv;
1958 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
1959 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1960 			break;
1961 		}
1962 	}
1963 }
1964 
1965 static struct spdk_nvmf_rdma_request *
1966 get_rdma_req_from_wc(struct ibv_wc *wc)
1967 {
1968 	struct spdk_nvmf_rdma_request *rdma_req;
1969 
1970 	rdma_req = (struct spdk_nvmf_rdma_request *)wc->wr_id;
1971 	assert(rdma_req != NULL);
1972 
1973 #ifdef DEBUG
1974 	struct spdk_nvmf_rdma_qpair *rqpair;
1975 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1976 
1977 	assert(rdma_req - rqpair->reqs >= 0);
1978 	assert(rdma_req - rqpair->reqs < (ptrdiff_t)rqpair->max_queue_depth);
1979 #endif
1980 
1981 	return rdma_req;
1982 }
1983 
1984 static struct spdk_nvmf_rdma_recv *
1985 get_rdma_recv_from_wc(struct ibv_wc *wc)
1986 {
1987 	struct spdk_nvmf_rdma_recv *rdma_recv;
1988 
1989 	assert(wc->byte_len >= sizeof(struct spdk_nvmf_capsule_cmd));
1990 
1991 	rdma_recv = (struct spdk_nvmf_rdma_recv *)wc->wr_id;
1992 	assert(rdma_recv != NULL);
1993 
1994 #ifdef DEBUG
1995 	struct spdk_nvmf_rdma_qpair *rqpair = rdma_recv->qpair;
1996 
1997 	assert(rdma_recv - rqpair->recvs >= 0);
1998 	assert(rdma_recv - rqpair->recvs < (ptrdiff_t)rqpair->max_queue_depth);
1999 #endif
2000 
2001 	return rdma_recv;
2002 }
2003 
2004 static int
2005 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2006 			   struct spdk_nvmf_rdma_poller *rpoller)
2007 {
2008 	struct ibv_wc wc[32];
2009 	struct spdk_nvmf_rdma_request	*rdma_req;
2010 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2011 	struct spdk_nvmf_rdma_qpair	*rqpair;
2012 	int reaped, i;
2013 	int count = 0;
2014 	bool error = false;
2015 
2016 	/* Poll for completing operations. */
2017 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2018 	if (reaped < 0) {
2019 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2020 			    errno, spdk_strerror(errno));
2021 		return -1;
2022 	}
2023 
2024 	for (i = 0; i < reaped; i++) {
2025 		if (wc[i].status) {
2026 			SPDK_ERRLOG("CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2027 				    rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2028 			error = true;
2029 			continue;
2030 		}
2031 
2032 		switch (wc[i].opcode) {
2033 		case IBV_WC_SEND:
2034 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2035 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2036 
2037 			assert(rdma_req->state == RDMA_REQUEST_STATE_COMPLETING);
2038 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2039 
2040 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2041 
2042 			count++;
2043 
2044 			/* Try to process other queued requests */
2045 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2046 			break;
2047 
2048 		case IBV_WC_RDMA_WRITE:
2049 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2050 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2051 
2052 			rqpair->cur_rdma_rw_depth--;
2053 
2054 			/* Try to process other queued requests */
2055 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2056 			break;
2057 
2058 		case IBV_WC_RDMA_READ:
2059 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2060 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2061 
2062 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2063 			rqpair->cur_rdma_rw_depth--;
2064 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2065 
2066 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2067 
2068 			/* Try to process other queued requests */
2069 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2070 			break;
2071 
2072 		case IBV_WC_RECV:
2073 			rdma_recv = get_rdma_recv_from_wc(&wc[i]);
2074 			rqpair = rdma_recv->qpair;
2075 
2076 			TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2077 
2078 			/* Try to process other queued requests */
2079 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2080 			break;
2081 
2082 		default:
2083 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2084 			continue;
2085 		}
2086 	}
2087 
2088 	if (error == true) {
2089 		return -1;
2090 	}
2091 
2092 	return count;
2093 }
2094 
2095 static int
2096 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2097 {
2098 	struct spdk_nvmf_rdma_transport *rtransport;
2099 	struct spdk_nvmf_rdma_poll_group *rgroup;
2100 	struct spdk_nvmf_rdma_poller	*rpoller;
2101 	int				count, rc;
2102 
2103 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2104 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2105 
2106 	count = 0;
2107 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2108 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2109 		if (rc < 0) {
2110 			return rc;
2111 		}
2112 		count += rc;
2113 	}
2114 
2115 	return count;
2116 }
2117 
2118 static bool
2119 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
2120 {
2121 	struct spdk_nvmf_rdma_qpair *rqpair;
2122 
2123 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2124 
2125 	if (rqpair->cur_queue_depth == 0 && rqpair->cur_rdma_rw_depth == 0) {
2126 		return true;
2127 	}
2128 	return false;
2129 }
2130 
2131 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
2132 	.type = SPDK_NVME_TRANSPORT_RDMA,
2133 	.create = spdk_nvmf_rdma_create,
2134 	.destroy = spdk_nvmf_rdma_destroy,
2135 
2136 	.listen = spdk_nvmf_rdma_listen,
2137 	.stop_listen = spdk_nvmf_rdma_stop_listen,
2138 	.accept = spdk_nvmf_rdma_accept,
2139 
2140 	.listener_discover = spdk_nvmf_rdma_discover,
2141 
2142 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
2143 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
2144 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
2145 	.poll_group_remove = spdk_nvmf_rdma_poll_group_remove,
2146 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
2147 
2148 	.req_complete = spdk_nvmf_rdma_request_complete,
2149 
2150 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
2151 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
2152 
2153 };
2154 
2155 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
2156