xref: /spdk/lib/nvmf/rdma.c (revision 65e5bbdc059f740cbbe8271ddec0929ea9b9624e)
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/config.h"
44 #include "spdk/assert.h"
45 #include "spdk/thread.h"
46 #include "spdk/nvmf.h"
47 #include "spdk/nvmf_spec.h"
48 #include "spdk/string.h"
49 #include "spdk/trace.h"
50 #include "spdk/util.h"
51 
52 #include "spdk_internal/log.h"
53 
54 /*
55  RDMA Connection Resource Defaults
56  */
57 #define NVMF_DEFAULT_TX_SGE		1
58 #define NVMF_DEFAULT_RX_SGE		2
59 #define NVMF_DEFAULT_DATA_SGE		16
60 
61 /* The RDMA completion queue size */
62 #define NVMF_RDMA_CQ_SIZE	4096
63 
64 /* AIO backend requires block size aligned data buffers,
65  * extra 4KiB aligned data buffer should work for most devices.
66  */
67 #define SHIFT_4KB			12
68 #define NVMF_DATA_BUFFER_ALIGNMENT	(1 << SHIFT_4KB)
69 #define NVMF_DATA_BUFFER_MASK		(NVMF_DATA_BUFFER_ALIGNMENT - 1)
70 
71 enum spdk_nvmf_rdma_request_state {
72 	/* The request is not currently in use */
73 	RDMA_REQUEST_STATE_FREE = 0,
74 
75 	/* Initial state when request first received */
76 	RDMA_REQUEST_STATE_NEW,
77 
78 	/* The request is queued until a data buffer is available. */
79 	RDMA_REQUEST_STATE_NEED_BUFFER,
80 
81 	/* The request is waiting on RDMA queue depth availability
82 	 * to transfer data between the host and the controller.
83 	 */
84 	RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
85 
86 	/* The request is currently transferring data from the host to the controller. */
87 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
88 
89 	/* The request is ready to execute at the block device */
90 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
91 
92 	/* The request is currently executing at the block device */
93 	RDMA_REQUEST_STATE_EXECUTING,
94 
95 	/* The request finished executing at the block device */
96 	RDMA_REQUEST_STATE_EXECUTED,
97 
98 	/* The request is ready to send a completion */
99 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
100 
101 	/* The request is currently transferring data from the controller to the host. */
102 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
103 
104 	/* The request currently has an outstanding completion without an
105 	 * associated data transfer.
106 	 */
107 	RDMA_REQUEST_STATE_COMPLETING,
108 
109 	/* The request completed and can be marked free. */
110 	RDMA_REQUEST_STATE_COMPLETED,
111 
112 	/* Terminator */
113 	RDMA_REQUEST_NUM_STATES,
114 };
115 
116 #define OBJECT_NVMF_RDMA_IO				0x40
117 
118 #define									TRACE_GROUP_NVMF_RDMA 0x4
119 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
120 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
121 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
122 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
123 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
124 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
125 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
126 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
127 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
128 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
129 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
130 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
131 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
132 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
133 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
134 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
135 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
136 
137 SPDK_TRACE_REGISTER_FN(nvmf_trace)
138 {
139 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
140 	spdk_trace_register_description("RDMA_REQ_NEW", "",
141 					TRACE_RDMA_REQUEST_STATE_NEW,
142 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
143 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
144 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
145 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
146 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
147 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
148 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
149 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
150 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
151 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
152 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
153 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
154 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
155 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
156 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
157 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
158 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
159 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
160 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
161 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
162 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
163 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
164 	spdk_trace_register_description("RDMA_REQ_COMPLETING_CONTROLLER_TO_HOST", "",
165 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_COMPLETING_INCAPSULE", "",
168 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
169 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
170 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
171 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
172 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
173 
174 	spdk_trace_register_description("RDMA_QP_CREATE", "", TRACE_RDMA_QP_CREATE,
175 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
176 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", "", TRACE_RDMA_IBV_ASYNC_EVENT,
177 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
178 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", "", TRACE_RDMA_CM_ASYNC_EVENT,
179 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
180 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", "", TRACE_RDMA_QP_STATE_CHANGE,
181 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
182 	spdk_trace_register_description("RDMA_QP_DISCONNECT", "", TRACE_RDMA_QP_DISCONNECT,
183 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
184 	spdk_trace_register_description("RDMA_QP_DESTROY", "", TRACE_RDMA_QP_DESTROY,
185 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
186 }
187 
188 /* This structure holds commands as they are received off the wire.
189  * It must be dynamically paired with a full request object
190  * (spdk_nvmf_rdma_request) to service a request. It is separate
191  * from the request because RDMA does not appear to order
192  * completions, so occasionally we'll get a new incoming
193  * command when there aren't any free request objects.
194  */
195 struct spdk_nvmf_rdma_recv {
196 	struct ibv_recv_wr		wr;
197 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
198 
199 	struct spdk_nvmf_rdma_qpair	*qpair;
200 
201 	/* In-capsule data buffer */
202 	uint8_t				*buf;
203 
204 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
205 };
206 
207 struct spdk_nvmf_rdma_request {
208 	struct spdk_nvmf_request		req;
209 	bool					data_from_pool;
210 
211 	enum spdk_nvmf_rdma_request_state	state;
212 
213 	struct spdk_nvmf_rdma_recv		*recv;
214 
215 	struct {
216 		struct	ibv_send_wr		wr;
217 		struct	ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
218 	} rsp;
219 
220 	struct {
221 		struct ibv_send_wr		wr;
222 		struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
223 		void				*buffers[SPDK_NVMF_MAX_SGL_ENTRIES];
224 	} data;
225 
226 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
227 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
228 };
229 
230 struct spdk_nvmf_rdma_qpair {
231 	struct spdk_nvmf_qpair			qpair;
232 
233 	struct spdk_nvmf_rdma_port		*port;
234 	struct spdk_nvmf_rdma_poller		*poller;
235 
236 	struct rdma_cm_id			*cm_id;
237 	struct rdma_cm_id			*listen_id;
238 
239 	/* The maximum number of I/O outstanding on this connection at one time */
240 	uint16_t				max_queue_depth;
241 
242 	/* The maximum number of active RDMA READ and WRITE operations at one time */
243 	uint16_t				max_rw_depth;
244 
245 	/* Receives that are waiting for a request object */
246 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
247 
248 	/* Queues to track the requests in all states */
249 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	state_queue[RDMA_REQUEST_NUM_STATES];
250 
251 	/* Number of requests in each state */
252 	uint32_t				state_cntr[RDMA_REQUEST_NUM_STATES];
253 
254 	int                                     max_sge;
255 
256 	/* Array of size "max_queue_depth" containing RDMA requests. */
257 	struct spdk_nvmf_rdma_request		*reqs;
258 
259 	/* Array of size "max_queue_depth" containing RDMA recvs. */
260 	struct spdk_nvmf_rdma_recv		*recvs;
261 
262 	/* Array of size "max_queue_depth" containing 64 byte capsules
263 	 * used for receive.
264 	 */
265 	union nvmf_h2c_msg			*cmds;
266 	struct ibv_mr				*cmds_mr;
267 
268 	/* Array of size "max_queue_depth" containing 16 byte completions
269 	 * to be sent back to the user.
270 	 */
271 	union nvmf_c2h_msg			*cpls;
272 	struct ibv_mr				*cpls_mr;
273 
274 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
275 	 * buffers to be used for in capsule data.
276 	 */
277 	void					*bufs;
278 	struct ibv_mr				*bufs_mr;
279 
280 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
281 
282 	/* Mgmt channel */
283 	struct spdk_io_channel			*mgmt_channel;
284 	struct spdk_nvmf_rdma_mgmt_channel	*ch;
285 
286 	/* IBV queue pair attributes: they are used to manage
287 	 * qp state and recover from errors.
288 	 */
289 	struct ibv_qp_init_attr			ibv_init_attr;
290 	struct ibv_qp_attr			ibv_attr;
291 
292 	bool					qpair_disconnected;
293 
294 	/* Reference counter for how many unprocessed messages
295 	 * from other threads are currently outstanding. The
296 	 * qpair cannot be destroyed until this is 0. This is
297 	 * atomically incremented from any thread, but only
298 	 * decremented and read from the thread that owns this
299 	 * qpair.
300 	 */
301 	uint32_t				refcnt;
302 };
303 
304 struct spdk_nvmf_rdma_poller {
305 	struct spdk_nvmf_rdma_device		*device;
306 	struct spdk_nvmf_rdma_poll_group	*group;
307 
308 	struct ibv_cq				*cq;
309 
310 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
311 
312 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
313 };
314 
315 struct spdk_nvmf_rdma_poll_group {
316 	struct spdk_nvmf_transport_poll_group	group;
317 
318 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
319 };
320 
321 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
322 struct spdk_nvmf_rdma_device {
323 	struct ibv_device_attr			attr;
324 	struct ibv_context			*context;
325 
326 	struct spdk_mem_map			*map;
327 	struct ibv_pd				*pd;
328 
329 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
330 };
331 
332 struct spdk_nvmf_rdma_port {
333 	struct spdk_nvme_transport_id		trid;
334 	struct rdma_cm_id			*id;
335 	struct spdk_nvmf_rdma_device		*device;
336 	uint32_t				ref;
337 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
338 };
339 
340 struct spdk_nvmf_rdma_transport {
341 	struct spdk_nvmf_transport	transport;
342 
343 	struct rdma_event_channel	*event_channel;
344 
345 	struct spdk_mempool		*data_buf_pool;
346 
347 	pthread_mutex_t			lock;
348 
349 	/* fields used to poll RDMA/IB events */
350 	nfds_t			npoll_fds;
351 	struct pollfd		*poll_fds;
352 
353 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
354 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
355 };
356 
357 struct spdk_nvmf_rdma_mgmt_channel {
358 	/* Requests that are waiting to obtain a data buffer */
359 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
360 };
361 
362 static inline void
363 spdk_nvmf_rdma_qpair_inc_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
364 {
365 	__sync_fetch_and_add(&rqpair->refcnt, 1);
366 }
367 
368 static inline uint32_t
369 spdk_nvmf_rdma_qpair_dec_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
370 {
371 	uint32_t old_refcnt, new_refcnt;
372 
373 	do {
374 		old_refcnt = rqpair->refcnt;
375 		assert(old_refcnt > 0);
376 		new_refcnt = old_refcnt - 1;
377 	} while (__sync_bool_compare_and_swap(&rqpair->refcnt, old_refcnt, new_refcnt) == false);
378 
379 	return new_refcnt;
380 }
381 
382 /* API to IBV QueuePair */
383 static const char *str_ibv_qp_state[] = {
384 	"IBV_QPS_RESET",
385 	"IBV_QPS_INIT",
386 	"IBV_QPS_RTR",
387 	"IBV_QPS_RTS",
388 	"IBV_QPS_SQD",
389 	"IBV_QPS_SQE",
390 	"IBV_QPS_ERR"
391 };
392 
393 static enum ibv_qp_state
394 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
395 	enum ibv_qp_state old_state, new_state;
396 	int rc;
397 
398 	/* All the attributes needed for recovery */
399 	static int spdk_nvmf_ibv_attr_mask =
400 	IBV_QP_STATE |
401 	IBV_QP_PKEY_INDEX |
402 	IBV_QP_PORT |
403 	IBV_QP_ACCESS_FLAGS |
404 	IBV_QP_AV |
405 	IBV_QP_PATH_MTU |
406 	IBV_QP_DEST_QPN |
407 	IBV_QP_RQ_PSN |
408 	IBV_QP_MAX_DEST_RD_ATOMIC |
409 	IBV_QP_MIN_RNR_TIMER |
410 	IBV_QP_SQ_PSN |
411 	IBV_QP_TIMEOUT |
412 	IBV_QP_RETRY_CNT |
413 	IBV_QP_RNR_RETRY |
414 	IBV_QP_MAX_QP_RD_ATOMIC;
415 
416 	old_state = rqpair->ibv_attr.qp_state;
417 	rc = ibv_query_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
418 			  spdk_nvmf_ibv_attr_mask, &rqpair->ibv_init_attr);
419 
420 	if (rc)
421 	{
422 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
423 		assert(false);
424 	}
425 
426 	new_state = rqpair->ibv_attr.qp_state;
427 	if (old_state != new_state)
428 	{
429 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
430 				  (uintptr_t)rqpair->cm_id, new_state);
431 	}
432 	return new_state;
433 }
434 
435 static int
436 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
437 			     enum ibv_qp_state new_state)
438 {
439 	int rc;
440 	enum ibv_qp_state state;
441 	static int attr_mask_rc[] = {
442 		[IBV_QPS_RESET] = IBV_QP_STATE,
443 		[IBV_QPS_INIT] = (IBV_QP_STATE |
444 				  IBV_QP_PKEY_INDEX |
445 				  IBV_QP_PORT |
446 				  IBV_QP_ACCESS_FLAGS),
447 		[IBV_QPS_RTR] = (IBV_QP_STATE |
448 				 IBV_QP_AV |
449 				 IBV_QP_PATH_MTU |
450 				 IBV_QP_DEST_QPN |
451 				 IBV_QP_RQ_PSN |
452 				 IBV_QP_MAX_DEST_RD_ATOMIC |
453 				 IBV_QP_MIN_RNR_TIMER),
454 		[IBV_QPS_RTS] = (IBV_QP_STATE |
455 				 IBV_QP_SQ_PSN |
456 				 IBV_QP_TIMEOUT |
457 				 IBV_QP_RETRY_CNT |
458 				 IBV_QP_RNR_RETRY |
459 				 IBV_QP_MAX_QP_RD_ATOMIC),
460 		[IBV_QPS_SQD] = IBV_QP_STATE,
461 		[IBV_QPS_SQE] = IBV_QP_STATE,
462 		[IBV_QPS_ERR] = IBV_QP_STATE,
463 	};
464 
465 	switch (new_state) {
466 	case IBV_QPS_RESET:
467 	case IBV_QPS_INIT:
468 	case IBV_QPS_RTR:
469 	case IBV_QPS_RTS:
470 	case IBV_QPS_SQD:
471 	case IBV_QPS_SQE:
472 	case IBV_QPS_ERR:
473 		break;
474 	default:
475 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
476 			    rqpair->qpair.qid, new_state);
477 		return -1;
478 	}
479 	rqpair->ibv_attr.cur_qp_state = rqpair->ibv_attr.qp_state;
480 	rqpair->ibv_attr.qp_state = new_state;
481 	rqpair->ibv_attr.ah_attr.port_num = rqpair->ibv_attr.port_num;
482 
483 	rc = ibv_modify_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
484 			   attr_mask_rc[new_state]);
485 
486 	if (rc) {
487 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
488 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
489 		return rc;
490 	}
491 
492 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
493 
494 	if (state != new_state) {
495 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
496 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
497 			    str_ibv_qp_state[state]);
498 		return -1;
499 	}
500 	SPDK_NOTICELOG("IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
501 		       str_ibv_qp_state[state]);
502 	return 0;
503 }
504 
505 static void
506 spdk_nvmf_rdma_request_set_state(struct spdk_nvmf_rdma_request *rdma_req,
507 				 enum spdk_nvmf_rdma_request_state state)
508 {
509 	struct spdk_nvmf_qpair		*qpair;
510 	struct spdk_nvmf_rdma_qpair	*rqpair;
511 
512 	qpair = rdma_req->req.qpair;
513 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
514 
515 	TAILQ_REMOVE(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
516 	rqpair->state_cntr[rdma_req->state]--;
517 
518 	rdma_req->state = state;
519 
520 	TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
521 	rqpair->state_cntr[rdma_req->state]++;
522 }
523 
524 static int
525 spdk_nvmf_rdma_mgmt_channel_create(void *io_device, void *ctx_buf)
526 {
527 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
528 
529 	TAILQ_INIT(&ch->pending_data_buf_queue);
530 	return 0;
531 }
532 
533 static void
534 spdk_nvmf_rdma_mgmt_channel_destroy(void *io_device, void *ctx_buf)
535 {
536 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
537 
538 	if (!TAILQ_EMPTY(&ch->pending_data_buf_queue)) {
539 		SPDK_ERRLOG("Pending I/O list wasn't empty on channel destruction\n");
540 	}
541 }
542 
543 static int
544 spdk_nvmf_rdma_cur_rw_depth(struct spdk_nvmf_rdma_qpair *rqpair)
545 {
546 	return rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER] +
547 	       rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST];
548 }
549 
550 static int
551 spdk_nvmf_rdma_cur_queue_depth(struct spdk_nvmf_rdma_qpair *rqpair)
552 {
553 	return rqpair->max_queue_depth -
554 	       rqpair->state_cntr[RDMA_REQUEST_STATE_FREE];
555 }
556 
557 static void
558 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
559 {
560 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
561 
562 	if (spdk_nvmf_rdma_cur_queue_depth(rqpair)) {
563 		rqpair->qpair_disconnected = true;
564 		return;
565 	}
566 
567 	if (rqpair->refcnt > 0) {
568 		return;
569 	}
570 
571 	if (rqpair->poller) {
572 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
573 	}
574 
575 	if (rqpair->cmds_mr) {
576 		ibv_dereg_mr(rqpair->cmds_mr);
577 	}
578 
579 	if (rqpair->cpls_mr) {
580 		ibv_dereg_mr(rqpair->cpls_mr);
581 	}
582 
583 	if (rqpair->bufs_mr) {
584 		ibv_dereg_mr(rqpair->bufs_mr);
585 	}
586 
587 	if (rqpair->cm_id) {
588 		rdma_destroy_qp(rqpair->cm_id);
589 		rdma_destroy_id(rqpair->cm_id);
590 	}
591 
592 	if (rqpair->mgmt_channel) {
593 		spdk_put_io_channel(rqpair->mgmt_channel);
594 	}
595 
596 	/* Free all memory */
597 	spdk_dma_free(rqpair->cmds);
598 	spdk_dma_free(rqpair->cpls);
599 	spdk_dma_free(rqpair->bufs);
600 	free(rqpair->reqs);
601 	free(rqpair->recvs);
602 	free(rqpair);
603 }
604 
605 static int
606 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
607 {
608 	struct spdk_nvmf_rdma_transport *rtransport;
609 	struct spdk_nvmf_rdma_qpair	*rqpair;
610 	int				rc, i;
611 	struct spdk_nvmf_rdma_recv	*rdma_recv;
612 	struct spdk_nvmf_rdma_request	*rdma_req;
613 	struct spdk_nvmf_transport      *transport;
614 
615 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
616 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
617 	transport = &rtransport->transport;
618 
619 	memset(&rqpair->ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
620 	rqpair->ibv_init_attr.qp_context	= rqpair;
621 	rqpair->ibv_init_attr.qp_type		= IBV_QPT_RC;
622 	rqpair->ibv_init_attr.send_cq		= rqpair->poller->cq;
623 	rqpair->ibv_init_attr.recv_cq		= rqpair->poller->cq;
624 	rqpair->ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
625 			2; /* SEND, READ, and WRITE operations */
626 	rqpair->ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth; /* RECV operations */
627 	rqpair->ibv_init_attr.cap.max_send_sge	= rqpair->max_sge;
628 	rqpair->ibv_init_attr.cap.max_recv_sge	= NVMF_DEFAULT_RX_SGE;
629 
630 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &rqpair->ibv_init_attr);
631 	if (rc) {
632 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
633 		rdma_destroy_id(rqpair->cm_id);
634 		rqpair->cm_id = NULL;
635 		spdk_nvmf_rdma_qpair_destroy(rqpair);
636 		return -1;
637 	}
638 
639 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
640 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
641 
642 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
643 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
644 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
645 					0x1000, NULL);
646 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
647 					0x1000, NULL);
648 
649 
650 	if (transport->opts.in_capsule_data_size > 0) {
651 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth *
652 						transport->opts.in_capsule_data_size,
653 						0x1000, NULL);
654 	}
655 
656 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
657 	    !rqpair->cpls || (transport->opts.in_capsule_data_size && !rqpair->bufs)) {
658 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
659 		spdk_nvmf_rdma_qpair_destroy(rqpair);
660 		return -1;
661 	}
662 
663 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
664 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
665 				     IBV_ACCESS_LOCAL_WRITE);
666 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
667 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
668 				     0);
669 
670 	if (transport->opts.in_capsule_data_size) {
671 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
672 					     rqpair->max_queue_depth *
673 					     transport->opts.in_capsule_data_size,
674 					     IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
675 	}
676 
677 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (transport->opts.in_capsule_data_size &&
678 			!rqpair->bufs_mr)) {
679 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
680 		spdk_nvmf_rdma_qpair_destroy(rqpair);
681 		return -1;
682 	}
683 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
684 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
685 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
686 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
687 	if (rqpair->bufs && rqpair->bufs_mr) {
688 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
689 			      rqpair->bufs, rqpair->max_queue_depth *
690 			      transport->opts.in_capsule_data_size, rqpair->bufs_mr->lkey);
691 	}
692 
693 	/* Initialise request state queues and counters of the queue pair */
694 	for (i = RDMA_REQUEST_STATE_FREE; i < RDMA_REQUEST_NUM_STATES; i++) {
695 		TAILQ_INIT(&rqpair->state_queue[i]);
696 		rqpair->state_cntr[i] = 0;
697 	}
698 
699 	for (i = 0; i < rqpair->max_queue_depth; i++) {
700 		struct ibv_recv_wr *bad_wr = NULL;
701 
702 		rdma_recv = &rqpair->recvs[i];
703 		rdma_recv->qpair = rqpair;
704 
705 		/* Set up memory to receive commands */
706 		if (rqpair->bufs) {
707 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i *
708 						  transport->opts.in_capsule_data_size));
709 		}
710 
711 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
712 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
713 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
714 		rdma_recv->wr.num_sge = 1;
715 
716 		if (rdma_recv->buf && rqpair->bufs_mr) {
717 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
718 			rdma_recv->sgl[1].length = transport->opts.in_capsule_data_size;
719 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
720 			rdma_recv->wr.num_sge++;
721 		}
722 
723 		rdma_recv->wr.wr_id = (uintptr_t)rdma_recv;
724 		rdma_recv->wr.sg_list = rdma_recv->sgl;
725 
726 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
727 		if (rc) {
728 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
729 			spdk_nvmf_rdma_qpair_destroy(rqpair);
730 			return -1;
731 		}
732 	}
733 
734 	for (i = 0; i < rqpair->max_queue_depth; i++) {
735 		rdma_req = &rqpair->reqs[i];
736 
737 		rdma_req->req.qpair = &rqpair->qpair;
738 		rdma_req->req.cmd = NULL;
739 
740 		/* Set up memory to send responses */
741 		rdma_req->req.rsp = &rqpair->cpls[i];
742 
743 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
744 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
745 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
746 
747 		rdma_req->rsp.wr.wr_id = (uintptr_t)rdma_req;
748 		rdma_req->rsp.wr.next = NULL;
749 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
750 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
751 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
752 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
753 
754 		/* Set up memory for data buffers */
755 		rdma_req->data.wr.wr_id = (uint64_t)rdma_req;
756 		rdma_req->data.wr.next = NULL;
757 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
758 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
759 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
760 
761 		/* Initialize request state to FREE */
762 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
763 		TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
764 		rqpair->state_cntr[rdma_req->state]++;
765 	}
766 
767 	return 0;
768 }
769 
770 static int
771 request_transfer_in(struct spdk_nvmf_request *req)
772 {
773 	int				rc;
774 	struct spdk_nvmf_rdma_request	*rdma_req;
775 	struct spdk_nvmf_qpair		*qpair;
776 	struct spdk_nvmf_rdma_qpair	*rqpair;
777 	struct ibv_send_wr		*bad_wr = NULL;
778 
779 	qpair = req->qpair;
780 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
781 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
782 
783 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
784 
785 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
786 
787 	rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
788 	rdma_req->data.wr.next = NULL;
789 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
790 	if (rc) {
791 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
792 		return -1;
793 	}
794 	return 0;
795 }
796 
797 static int
798 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
799 {
800 	int				rc;
801 	struct spdk_nvmf_rdma_request	*rdma_req;
802 	struct spdk_nvmf_qpair		*qpair;
803 	struct spdk_nvmf_rdma_qpair	*rqpair;
804 	struct spdk_nvme_cpl		*rsp;
805 	struct ibv_recv_wr		*bad_recv_wr = NULL;
806 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
807 
808 	*data_posted = 0;
809 	qpair = req->qpair;
810 	rsp = &req->rsp->nvme_cpl;
811 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
812 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
813 
814 	/* Advance our sq_head pointer */
815 	if (qpair->sq_head == qpair->sq_head_max) {
816 		qpair->sq_head = 0;
817 	} else {
818 		qpair->sq_head++;
819 	}
820 	rsp->sqhd = qpair->sq_head;
821 
822 	/* Post the capsule to the recv buffer */
823 	assert(rdma_req->recv != NULL);
824 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
825 		      rqpair);
826 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
827 	if (rc) {
828 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
829 		return rc;
830 	}
831 	rdma_req->recv = NULL;
832 
833 	/* Build the response which consists of an optional
834 	 * RDMA WRITE to transfer data, plus an RDMA SEND
835 	 * containing the response.
836 	 */
837 	send_wr = &rdma_req->rsp.wr;
838 
839 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
840 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
841 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
842 
843 		rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
844 
845 		rdma_req->data.wr.next = send_wr;
846 		*data_posted = 1;
847 		send_wr = &rdma_req->data.wr;
848 	}
849 
850 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
851 
852 	/* Send the completion */
853 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
854 	if (rc) {
855 		SPDK_ERRLOG("Unable to send response capsule\n");
856 	}
857 
858 	return rc;
859 }
860 
861 static int
862 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
863 {
864 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
865 	struct rdma_conn_param				ctrlr_event_data = {};
866 	int						rc;
867 
868 	accept_data.recfmt = 0;
869 	accept_data.crqsize = rqpair->max_queue_depth;
870 
871 	ctrlr_event_data.private_data = &accept_data;
872 	ctrlr_event_data.private_data_len = sizeof(accept_data);
873 	if (id->ps == RDMA_PS_TCP) {
874 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
875 		ctrlr_event_data.initiator_depth = rqpair->max_rw_depth;
876 	}
877 
878 	rc = rdma_accept(id, &ctrlr_event_data);
879 	if (rc) {
880 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
881 	} else {
882 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
883 	}
884 
885 	return rc;
886 }
887 
888 static void
889 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
890 {
891 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
892 
893 	rej_data.recfmt = 0;
894 	rej_data.sts = error;
895 
896 	rdma_reject(id, &rej_data, sizeof(rej_data));
897 }
898 
899 static int
900 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
901 		  new_qpair_fn cb_fn)
902 {
903 	struct spdk_nvmf_rdma_transport *rtransport;
904 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
905 	struct spdk_nvmf_rdma_port	*port;
906 	struct rdma_conn_param		*rdma_param = NULL;
907 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
908 	uint16_t			max_queue_depth;
909 	uint16_t			max_rw_depth;
910 
911 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
912 
913 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
914 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
915 
916 	rdma_param = &event->param.conn;
917 	if (rdma_param->private_data == NULL ||
918 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
919 		SPDK_ERRLOG("connect request: no private data provided\n");
920 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
921 		return -1;
922 	}
923 
924 	private_data = rdma_param->private_data;
925 	if (private_data->recfmt != 0) {
926 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
927 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
928 		return -1;
929 	}
930 
931 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
932 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
933 
934 	port = event->listen_id->context;
935 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
936 		      event->listen_id, event->listen_id->verbs, port);
937 
938 	/* Figure out the supported queue depth. This is a multi-step process
939 	 * that takes into account hardware maximums, host provided values,
940 	 * and our target's internal memory limits */
941 
942 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
943 
944 	/* Start with the maximum queue depth allowed by the target */
945 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
946 	max_rw_depth = rtransport->transport.opts.max_queue_depth;
947 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
948 		      rtransport->transport.opts.max_queue_depth);
949 
950 	/* Next check the local NIC's hardware limitations */
951 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
952 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
953 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
954 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
955 	max_rw_depth = spdk_min(max_rw_depth, port->device->attr.max_qp_rd_atom);
956 
957 	/* Next check the remote NIC's hardware limitations */
958 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
959 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
960 		      rdma_param->initiator_depth, rdma_param->responder_resources);
961 	if (rdma_param->initiator_depth > 0) {
962 		max_rw_depth = spdk_min(max_rw_depth, rdma_param->initiator_depth);
963 	}
964 
965 	/* Finally check for the host software requested values, which are
966 	 * optional. */
967 	if (rdma_param->private_data != NULL &&
968 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
969 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
970 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
971 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
972 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
973 	}
974 
975 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
976 		      max_queue_depth, max_rw_depth);
977 
978 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
979 	if (rqpair == NULL) {
980 		SPDK_ERRLOG("Could not allocate new connection.\n");
981 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
982 		return -1;
983 	}
984 
985 	rqpair->port = port;
986 	rqpair->max_queue_depth = max_queue_depth;
987 	rqpair->max_rw_depth = max_rw_depth;
988 	rqpair->cm_id = event->id;
989 	rqpair->listen_id = event->listen_id;
990 	rqpair->qpair.transport = transport;
991 	rqpair->max_sge = spdk_min(port->device->attr.max_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
992 	TAILQ_INIT(&rqpair->incoming_queue);
993 	event->id->context = &rqpair->qpair;
994 
995 	cb_fn(&rqpair->qpair);
996 
997 	return 0;
998 }
999 
1000 static int
1001 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1002 			  enum spdk_mem_map_notify_action action,
1003 			  void *vaddr, size_t size)
1004 {
1005 	struct spdk_nvmf_rdma_device *device = cb_ctx;
1006 	struct ibv_pd *pd = device->pd;
1007 	struct ibv_mr *mr;
1008 
1009 	switch (action) {
1010 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1011 		mr = ibv_reg_mr(pd, vaddr, size,
1012 				IBV_ACCESS_LOCAL_WRITE |
1013 				IBV_ACCESS_REMOTE_READ |
1014 				IBV_ACCESS_REMOTE_WRITE);
1015 		if (mr == NULL) {
1016 			SPDK_ERRLOG("ibv_reg_mr() failed\n");
1017 			return -1;
1018 		} else {
1019 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1020 		}
1021 		break;
1022 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1023 		mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1024 		spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1025 		if (mr) {
1026 			ibv_dereg_mr(mr);
1027 		}
1028 		break;
1029 	}
1030 
1031 	return 0;
1032 }
1033 
1034 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1035 
1036 static spdk_nvme_data_transfer_t
1037 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1038 {
1039 	enum spdk_nvme_data_transfer xfer;
1040 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1041 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1042 
1043 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1044 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1045 	rdma_req->rsp.wr.imm_data = 0;
1046 #endif
1047 
1048 	/* Figure out data transfer direction */
1049 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1050 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1051 	} else {
1052 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1053 
1054 		/* Some admin commands are special cases */
1055 		if ((rdma_req->req.qpair->qid == 0) &&
1056 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1057 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1058 			switch (cmd->cdw10 & 0xff) {
1059 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1060 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1061 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1062 				break;
1063 			default:
1064 				xfer = SPDK_NVME_DATA_NONE;
1065 			}
1066 		}
1067 	}
1068 
1069 	if (xfer == SPDK_NVME_DATA_NONE) {
1070 		return xfer;
1071 	}
1072 
1073 	/* Even for commands that may transfer data, they could have specified 0 length.
1074 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1075 	 */
1076 	switch (sgl->generic.type) {
1077 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1078 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1079 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1080 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1081 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1082 		if (sgl->unkeyed.length == 0) {
1083 			xfer = SPDK_NVME_DATA_NONE;
1084 		}
1085 		break;
1086 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1087 		if (sgl->keyed.length == 0) {
1088 			xfer = SPDK_NVME_DATA_NONE;
1089 		}
1090 		break;
1091 	}
1092 
1093 	return xfer;
1094 }
1095 
1096 static int
1097 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1098 				 struct spdk_nvmf_rdma_device *device,
1099 				 struct spdk_nvmf_rdma_request *rdma_req)
1100 {
1101 	void		*buf = NULL;
1102 	uint32_t	length = rdma_req->req.length;
1103 	uint32_t	i = 0;
1104 
1105 	rdma_req->req.iovcnt = 0;
1106 	while (length) {
1107 		buf = spdk_mempool_get(rtransport->data_buf_pool);
1108 		if (!buf) {
1109 			goto nomem;
1110 		}
1111 
1112 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
1113 						~NVMF_DATA_BUFFER_MASK);
1114 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->transport.opts.io_unit_size);
1115 		rdma_req->req.iovcnt++;
1116 		rdma_req->data.buffers[i] = buf;
1117 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
1118 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
1119 		rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1120 						     (uint64_t)buf, NULL))->lkey;
1121 
1122 		length -= rdma_req->req.iov[i].iov_len;
1123 		i++;
1124 	}
1125 
1126 	rdma_req->data_from_pool = true;
1127 
1128 	return 0;
1129 
1130 nomem:
1131 	while (i) {
1132 		i--;
1133 		spdk_mempool_put(rtransport->data_buf_pool, rdma_req->req.iov[i].iov_base);
1134 		rdma_req->req.iov[i].iov_base = NULL;
1135 		rdma_req->req.iov[i].iov_len = 0;
1136 
1137 		rdma_req->data.wr.sg_list[i].addr = 0;
1138 		rdma_req->data.wr.sg_list[i].length = 0;
1139 		rdma_req->data.wr.sg_list[i].lkey = 0;
1140 	}
1141 	rdma_req->req.iovcnt = 0;
1142 	return -ENOMEM;
1143 }
1144 
1145 static int
1146 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1147 				 struct spdk_nvmf_rdma_device *device,
1148 				 struct spdk_nvmf_rdma_request *rdma_req)
1149 {
1150 	struct spdk_nvme_cmd			*cmd;
1151 	struct spdk_nvme_cpl			*rsp;
1152 	struct spdk_nvme_sgl_descriptor		*sgl;
1153 
1154 	cmd = &rdma_req->req.cmd->nvme_cmd;
1155 	rsp = &rdma_req->req.rsp->nvme_cpl;
1156 	sgl = &cmd->dptr.sgl1;
1157 
1158 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1159 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1160 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1161 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1162 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1163 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1164 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1165 			return -1;
1166 		}
1167 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1168 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1169 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1170 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1171 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1172 			}
1173 		}
1174 #endif
1175 
1176 		/* fill request length and populate iovs */
1177 		rdma_req->req.length = sgl->keyed.length;
1178 
1179 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1180 			/* No available buffers. Queue this request up. */
1181 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1182 			return 0;
1183 		}
1184 
1185 		/* backward compatible */
1186 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1187 
1188 		/* rdma wr specifics */
1189 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1190 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1191 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1192 
1193 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1194 			      rdma_req->req.iovcnt);
1195 
1196 		return 0;
1197 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1198 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1199 		uint64_t offset = sgl->address;
1200 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1201 
1202 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1203 			      offset, sgl->unkeyed.length);
1204 
1205 		if (offset > max_len) {
1206 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1207 				    offset, max_len);
1208 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1209 			return -1;
1210 		}
1211 		max_len -= (uint32_t)offset;
1212 
1213 		if (sgl->unkeyed.length > max_len) {
1214 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1215 				    sgl->unkeyed.length, max_len);
1216 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1217 			return -1;
1218 		}
1219 
1220 		rdma_req->req.data = rdma_req->recv->buf + offset;
1221 		rdma_req->data_from_pool = false;
1222 		rdma_req->req.length = sgl->unkeyed.length;
1223 
1224 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1225 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1226 		rdma_req->req.iovcnt = 1;
1227 
1228 		return 0;
1229 	}
1230 
1231 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1232 		    sgl->generic.type, sgl->generic.subtype);
1233 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1234 	return -1;
1235 }
1236 
1237 static bool
1238 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1239 			       struct spdk_nvmf_rdma_request *rdma_req)
1240 {
1241 	struct spdk_nvmf_rdma_qpair	*rqpair;
1242 	struct spdk_nvmf_rdma_device	*device;
1243 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1244 	int				rc;
1245 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1246 	enum spdk_nvmf_rdma_request_state prev_state;
1247 	bool				progress = false;
1248 	int				data_posted;
1249 	int				cur_rdma_rw_depth;
1250 
1251 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1252 	device = rqpair->port->device;
1253 
1254 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1255 
1256 	/* If the queue pair is in an error state, force the request to the completed state
1257 	 * to release resources. */
1258 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1259 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1260 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1261 		}
1262 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1263 	}
1264 
1265 	/* The loop here is to allow for several back-to-back state changes. */
1266 	do {
1267 		prev_state = rdma_req->state;
1268 
1269 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1270 
1271 		switch (rdma_req->state) {
1272 		case RDMA_REQUEST_STATE_FREE:
1273 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1274 			 * to escape this state. */
1275 			break;
1276 		case RDMA_REQUEST_STATE_NEW:
1277 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1278 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1279 			rdma_recv = rdma_req->recv;
1280 
1281 			/* The first element of the SGL is the NVMe command */
1282 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1283 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1284 
1285 			TAILQ_REMOVE(&rqpair->incoming_queue, rdma_recv, link);
1286 
1287 			if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR) {
1288 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1289 				break;
1290 			}
1291 
1292 			/* The next state transition depends on the data transfer needs of this request. */
1293 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1294 
1295 			/* If no data to transfer, ready to execute. */
1296 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1297 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1298 				break;
1299 			}
1300 
1301 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEED_BUFFER);
1302 			TAILQ_INSERT_TAIL(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1303 			break;
1304 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1305 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1306 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1307 
1308 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1309 
1310 			if (rdma_req != TAILQ_FIRST(&rqpair->ch->pending_data_buf_queue)) {
1311 				/* This request needs to wait in line to obtain a buffer */
1312 				break;
1313 			}
1314 
1315 			/* Try to get a data buffer */
1316 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1317 			if (rc < 0) {
1318 				TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1319 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1320 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1321 				break;
1322 			}
1323 
1324 			if (!rdma_req->req.data) {
1325 				/* No buffers available. */
1326 				break;
1327 			}
1328 
1329 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1330 
1331 			/* If data is transferring from host to controller and the data didn't
1332 			 * arrive using in capsule data, we need to do a transfer from the host.
1333 			 */
1334 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1335 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1336 				break;
1337 			}
1338 
1339 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1340 			break;
1341 		case RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING:
1342 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING, 0, 0,
1343 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1344 
1345 			if (rdma_req != TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING])) {
1346 				/* This request needs to wait in line to perform RDMA */
1347 				break;
1348 			}
1349 			cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
1350 
1351 			if (cur_rdma_rw_depth >= rqpair->max_rw_depth) {
1352 				/* R/W queue is full, need to wait */
1353 				break;
1354 			}
1355 
1356 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1357 				rc = request_transfer_in(&rdma_req->req);
1358 				if (!rc) {
1359 					spdk_nvmf_rdma_request_set_state(rdma_req,
1360 									 RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
1361 				} else {
1362 					rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1363 					spdk_nvmf_rdma_request_set_state(rdma_req,
1364 									 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1365 				}
1366 			} else if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1367 				/* The data transfer will be kicked off from
1368 				 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
1369 				 */
1370 				spdk_nvmf_rdma_request_set_state(rdma_req,
1371 								 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1372 			} else {
1373 				SPDK_ERRLOG("Cannot perform data transfer, unknown state: %u\n",
1374 					    rdma_req->req.xfer);
1375 				assert(0);
1376 			}
1377 			break;
1378 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1379 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1380 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1381 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1382 			 * to escape this state. */
1383 			break;
1384 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1385 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1386 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1387 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTING);
1388 			spdk_nvmf_request_exec(&rdma_req->req);
1389 			break;
1390 		case RDMA_REQUEST_STATE_EXECUTING:
1391 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1392 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1393 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1394 			 * to escape this state. */
1395 			break;
1396 		case RDMA_REQUEST_STATE_EXECUTED:
1397 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1398 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1399 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1400 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1401 			} else {
1402 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1403 			}
1404 			break;
1405 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1406 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
1407 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1408 			rc = request_transfer_out(&rdma_req->req, &data_posted);
1409 			assert(rc == 0); /* No good way to handle this currently */
1410 			if (rc) {
1411 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1412 			} else {
1413 				spdk_nvmf_rdma_request_set_state(rdma_req,
1414 								 data_posted ?
1415 								 RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
1416 								 RDMA_REQUEST_STATE_COMPLETING);
1417 			}
1418 			break;
1419 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
1420 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
1421 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1422 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1423 			 * to escape this state. */
1424 			break;
1425 		case RDMA_REQUEST_STATE_COMPLETING:
1426 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
1427 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1428 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1429 			 * to escape this state. */
1430 			break;
1431 		case RDMA_REQUEST_STATE_COMPLETED:
1432 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
1433 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1434 
1435 			if (rdma_req->data_from_pool) {
1436 				/* Put the buffer/s back in the pool */
1437 				for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1438 					spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1439 					rdma_req->req.iov[i].iov_base = NULL;
1440 					rdma_req->data.buffers[i] = NULL;
1441 				}
1442 				rdma_req->data_from_pool = false;
1443 			}
1444 			rdma_req->req.length = 0;
1445 			rdma_req->req.iovcnt = 0;
1446 			rdma_req->req.data = NULL;
1447 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
1448 			break;
1449 		case RDMA_REQUEST_NUM_STATES:
1450 		default:
1451 			assert(0);
1452 			break;
1453 		}
1454 
1455 		if (rdma_req->state != prev_state) {
1456 			progress = true;
1457 		}
1458 	} while (rdma_req->state != prev_state);
1459 
1460 	return progress;
1461 }
1462 
1463 /* Public API callbacks begin here */
1464 
1465 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
1466 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
1467 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
1468 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
1469 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
1470 #define SPDK_NVMF_RDMA_DEFAULT_IO_BUFFER_SIZE 131072
1471 
1472 static void
1473 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
1474 {
1475 	opts->max_queue_depth =      SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
1476 	opts->max_qpairs_per_ctrlr = SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
1477 	opts->in_capsule_data_size = SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
1478 	opts->max_io_size =          SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
1479 	opts->io_unit_size =         SPDK_NVMF_RDMA_DEFAULT_IO_BUFFER_SIZE;
1480 	opts->max_aq_depth =         SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
1481 }
1482 
1483 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
1484 
1485 static struct spdk_nvmf_transport *
1486 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
1487 {
1488 	int rc;
1489 	struct spdk_nvmf_rdma_transport *rtransport;
1490 	struct spdk_nvmf_rdma_device	*device, *tmp;
1491 	struct ibv_context		**contexts;
1492 	uint32_t			i;
1493 	int				flag;
1494 	uint32_t			sge_count;
1495 
1496 	const struct spdk_mem_map_ops nvmf_rdma_map_ops = {
1497 		.notify_cb = spdk_nvmf_rdma_mem_notify,
1498 		.are_contiguous = NULL
1499 	};
1500 
1501 	rtransport = calloc(1, sizeof(*rtransport));
1502 	if (!rtransport) {
1503 		return NULL;
1504 	}
1505 
1506 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
1507 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
1508 		free(rtransport);
1509 		return NULL;
1510 	}
1511 
1512 	spdk_io_device_register(rtransport, spdk_nvmf_rdma_mgmt_channel_create,
1513 				spdk_nvmf_rdma_mgmt_channel_destroy,
1514 				sizeof(struct spdk_nvmf_rdma_mgmt_channel),
1515 				"rdma_transport");
1516 
1517 	TAILQ_INIT(&rtransport->devices);
1518 	TAILQ_INIT(&rtransport->ports);
1519 
1520 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1521 
1522 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
1523 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
1524 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
1525 		     "  in_capsule_data_size=%d, max_aq_depth=%d\n",
1526 		     opts->max_queue_depth,
1527 		     opts->max_io_size,
1528 		     opts->max_qpairs_per_ctrlr,
1529 		     opts->io_unit_size,
1530 		     opts->in_capsule_data_size,
1531 		     opts->max_aq_depth);
1532 
1533 	/* I/O unit size cannot be larger than max I/O size */
1534 	if (opts->io_unit_size > opts->max_io_size) {
1535 		opts->io_unit_size = opts->max_io_size;
1536 	}
1537 
1538 	sge_count = opts->max_io_size / opts->io_unit_size;
1539 	if (sge_count > SPDK_NVMF_MAX_SGL_ENTRIES) {
1540 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
1541 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1542 		return NULL;
1543 	}
1544 
1545 	rtransport->event_channel = rdma_create_event_channel();
1546 	if (rtransport->event_channel == NULL) {
1547 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1548 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1549 		return NULL;
1550 	}
1551 
1552 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1553 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1554 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1555 			    rtransport->event_channel->fd, spdk_strerror(errno));
1556 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1557 		return NULL;
1558 	}
1559 
1560 	rtransport->data_buf_pool = spdk_mempool_create("spdk_nvmf_rdma",
1561 				    opts->max_queue_depth * 4, /* The 4 is arbitrarily chosen. Needs to be configurable. */
1562 				    opts->max_io_size + NVMF_DATA_BUFFER_ALIGNMENT,
1563 				    SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1564 				    SPDK_ENV_SOCKET_ID_ANY);
1565 	if (!rtransport->data_buf_pool) {
1566 		SPDK_ERRLOG("Unable to allocate buffer pool for poll group\n");
1567 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1568 		return NULL;
1569 	}
1570 
1571 	contexts = rdma_get_devices(NULL);
1572 	if (contexts == NULL) {
1573 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
1574 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1575 		return NULL;
1576 	}
1577 
1578 	i = 0;
1579 	rc = 0;
1580 	while (contexts[i] != NULL) {
1581 		device = calloc(1, sizeof(*device));
1582 		if (!device) {
1583 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1584 			rc = -ENOMEM;
1585 			break;
1586 		}
1587 		device->context = contexts[i];
1588 		rc = ibv_query_device(device->context, &device->attr);
1589 		if (rc < 0) {
1590 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1591 			free(device);
1592 			break;
1593 
1594 		}
1595 
1596 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1597 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
1598 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
1599 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
1600 		}
1601 
1602 		/**
1603 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
1604 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
1605 		 * but incorrectly reports that it does. There are changes making their way
1606 		 * through the kernel now that will enable this feature. When they are merged,
1607 		 * we can conditionally enable this feature.
1608 		 *
1609 		 * TODO: enable this for versions of the kernel rxe driver that support it.
1610 		 */
1611 		if (device->attr.vendor_id == 0) {
1612 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
1613 		}
1614 #endif
1615 
1616 		/* set up device context async ev fd as NON_BLOCKING */
1617 		flag = fcntl(device->context->async_fd, F_GETFL);
1618 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1619 		if (rc < 0) {
1620 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1621 			free(device);
1622 			break;
1623 		}
1624 
1625 		device->pd = ibv_alloc_pd(device->context);
1626 		if (!device->pd) {
1627 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
1628 			free(device);
1629 			rc = -1;
1630 			break;
1631 		}
1632 
1633 		device->map = spdk_mem_map_alloc(0, &nvmf_rdma_map_ops, device);
1634 		if (!device->map) {
1635 			SPDK_ERRLOG("Unable to allocate memory map for new poll group\n");
1636 			ibv_dealloc_pd(device->pd);
1637 			free(device);
1638 			rc = -1;
1639 			break;
1640 		}
1641 
1642 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1643 		i++;
1644 	}
1645 	rdma_free_devices(contexts);
1646 
1647 	if (rc < 0) {
1648 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1649 		return NULL;
1650 	}
1651 
1652 	/* Set up poll descriptor array to monitor events from RDMA and IB
1653 	 * in a single poll syscall
1654 	 */
1655 	rtransport->npoll_fds = i + 1;
1656 	i = 0;
1657 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1658 	if (rtransport->poll_fds == NULL) {
1659 		SPDK_ERRLOG("poll_fds allocation failed\n");
1660 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1661 		return NULL;
1662 	}
1663 
1664 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1665 	rtransport->poll_fds[i++].events = POLLIN;
1666 
1667 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1668 		rtransport->poll_fds[i].fd = device->context->async_fd;
1669 		rtransport->poll_fds[i++].events = POLLIN;
1670 	}
1671 
1672 	return &rtransport->transport;
1673 }
1674 
1675 static int
1676 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1677 {
1678 	struct spdk_nvmf_rdma_transport	*rtransport;
1679 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1680 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1681 
1682 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1683 
1684 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1685 		TAILQ_REMOVE(&rtransport->ports, port, link);
1686 		rdma_destroy_id(port->id);
1687 		free(port);
1688 	}
1689 
1690 	if (rtransport->poll_fds != NULL) {
1691 		free(rtransport->poll_fds);
1692 	}
1693 
1694 	if (rtransport->event_channel != NULL) {
1695 		rdma_destroy_event_channel(rtransport->event_channel);
1696 	}
1697 
1698 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1699 		TAILQ_REMOVE(&rtransport->devices, device, link);
1700 		if (device->map) {
1701 			spdk_mem_map_free(&device->map);
1702 		}
1703 		if (device->pd) {
1704 			ibv_dealloc_pd(device->pd);
1705 		}
1706 		free(device);
1707 	}
1708 
1709 	if (rtransport->data_buf_pool != NULL) {
1710 		if (spdk_mempool_count(rtransport->data_buf_pool) !=
1711 		    (transport->opts.max_queue_depth * 4)) {
1712 			SPDK_ERRLOG("transport buffer pool count is %zu but should be %u\n",
1713 				    spdk_mempool_count(rtransport->data_buf_pool),
1714 				    transport->opts.max_queue_depth * 4);
1715 		}
1716 	}
1717 
1718 	spdk_mempool_free(rtransport->data_buf_pool);
1719 	spdk_io_device_unregister(rtransport, NULL);
1720 	pthread_mutex_destroy(&rtransport->lock);
1721 	free(rtransport);
1722 
1723 	return 0;
1724 }
1725 
1726 static int
1727 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1728 		      const struct spdk_nvme_transport_id *trid)
1729 {
1730 	struct spdk_nvmf_rdma_transport	*rtransport;
1731 	struct spdk_nvmf_rdma_device	*device;
1732 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1733 	struct addrinfo			*res;
1734 	struct addrinfo			hints;
1735 	int				family;
1736 	int				rc;
1737 
1738 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1739 
1740 	port = calloc(1, sizeof(*port));
1741 	if (!port) {
1742 		return -ENOMEM;
1743 	}
1744 
1745 	/* Selectively copy the trid. Things like NQN don't matter here - that
1746 	 * mapping is enforced elsewhere.
1747 	 */
1748 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1749 	port->trid.adrfam = trid->adrfam;
1750 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1751 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1752 
1753 	pthread_mutex_lock(&rtransport->lock);
1754 	assert(rtransport->event_channel != NULL);
1755 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1756 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1757 			port_tmp->ref++;
1758 			free(port);
1759 			/* Already listening at this address */
1760 			pthread_mutex_unlock(&rtransport->lock);
1761 			return 0;
1762 		}
1763 	}
1764 
1765 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1766 	if (rc < 0) {
1767 		SPDK_ERRLOG("rdma_create_id() failed\n");
1768 		free(port);
1769 		pthread_mutex_unlock(&rtransport->lock);
1770 		return rc;
1771 	}
1772 
1773 	switch (port->trid.adrfam) {
1774 	case SPDK_NVMF_ADRFAM_IPV4:
1775 		family = AF_INET;
1776 		break;
1777 	case SPDK_NVMF_ADRFAM_IPV6:
1778 		family = AF_INET6;
1779 		break;
1780 	default:
1781 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1782 		free(port);
1783 		pthread_mutex_unlock(&rtransport->lock);
1784 		return -EINVAL;
1785 	}
1786 
1787 	memset(&hints, 0, sizeof(hints));
1788 	hints.ai_family = family;
1789 	hints.ai_flags = AI_NUMERICSERV;
1790 	hints.ai_socktype = SOCK_STREAM;
1791 	hints.ai_protocol = 0;
1792 
1793 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1794 	if (rc) {
1795 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1796 		free(port);
1797 		pthread_mutex_unlock(&rtransport->lock);
1798 		return -EINVAL;
1799 	}
1800 
1801 	rc = rdma_bind_addr(port->id, res->ai_addr);
1802 	freeaddrinfo(res);
1803 
1804 	if (rc < 0) {
1805 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1806 		rdma_destroy_id(port->id);
1807 		free(port);
1808 		pthread_mutex_unlock(&rtransport->lock);
1809 		return rc;
1810 	}
1811 
1812 	if (!port->id->verbs) {
1813 		SPDK_ERRLOG("ibv_context is null\n");
1814 		rdma_destroy_id(port->id);
1815 		free(port);
1816 		pthread_mutex_unlock(&rtransport->lock);
1817 		return -1;
1818 	}
1819 
1820 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
1821 	if (rc < 0) {
1822 		SPDK_ERRLOG("rdma_listen() failed\n");
1823 		rdma_destroy_id(port->id);
1824 		free(port);
1825 		pthread_mutex_unlock(&rtransport->lock);
1826 		return rc;
1827 	}
1828 
1829 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1830 		if (device->context == port->id->verbs) {
1831 			port->device = device;
1832 			break;
1833 		}
1834 	}
1835 	if (!port->device) {
1836 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
1837 			    port->id->verbs);
1838 		rdma_destroy_id(port->id);
1839 		free(port);
1840 		pthread_mutex_unlock(&rtransport->lock);
1841 		return -EINVAL;
1842 	}
1843 
1844 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
1845 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
1846 
1847 	port->ref = 1;
1848 
1849 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
1850 	pthread_mutex_unlock(&rtransport->lock);
1851 
1852 	return 0;
1853 }
1854 
1855 static int
1856 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
1857 			   const struct spdk_nvme_transport_id *_trid)
1858 {
1859 	struct spdk_nvmf_rdma_transport *rtransport;
1860 	struct spdk_nvmf_rdma_port *port, *tmp;
1861 	struct spdk_nvme_transport_id trid = {};
1862 
1863 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1864 
1865 	/* Selectively copy the trid. Things like NQN don't matter here - that
1866 	 * mapping is enforced elsewhere.
1867 	 */
1868 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1869 	trid.adrfam = _trid->adrfam;
1870 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
1871 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
1872 
1873 	pthread_mutex_lock(&rtransport->lock);
1874 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
1875 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
1876 			assert(port->ref > 0);
1877 			port->ref--;
1878 			if (port->ref == 0) {
1879 				TAILQ_REMOVE(&rtransport->ports, port, link);
1880 				rdma_destroy_id(port->id);
1881 				free(port);
1882 			}
1883 			break;
1884 		}
1885 	}
1886 
1887 	pthread_mutex_unlock(&rtransport->lock);
1888 	return 0;
1889 }
1890 
1891 static bool
1892 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
1893 {
1894 	int cur_queue_depth, cur_rdma_rw_depth;
1895 	struct spdk_nvmf_rdma_qpair *rqpair;
1896 
1897 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1898 	cur_queue_depth = spdk_nvmf_rdma_cur_queue_depth(rqpair);
1899 	cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
1900 
1901 	if (cur_queue_depth == 0 && cur_rdma_rw_depth == 0) {
1902 		return true;
1903 	}
1904 	return false;
1905 }
1906 
1907 static void
1908 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
1909 				     struct spdk_nvmf_rdma_qpair *rqpair)
1910 {
1911 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
1912 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
1913 
1914 	/* We process I/O in the data transfer pending queue at the highest priority. */
1915 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING],
1916 			   state_link, req_tmp) {
1917 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1918 			break;
1919 		}
1920 	}
1921 
1922 	/* The second highest priority is I/O waiting on memory buffers. */
1923 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->ch->pending_data_buf_queue, link,
1924 			   req_tmp) {
1925 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1926 			break;
1927 		}
1928 	}
1929 
1930 	if (rqpair->qpair_disconnected) {
1931 		spdk_nvmf_rdma_qpair_destroy(rqpair);
1932 		return;
1933 	}
1934 
1935 	/* Do not process newly received commands if qp is in ERROR state,
1936 	 * wait till the recovery is complete.
1937 	 */
1938 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR) {
1939 		return;
1940 	}
1941 
1942 	/* The lowest priority is processing newly received commands */
1943 	TAILQ_FOREACH_SAFE(rdma_recv, &rqpair->incoming_queue, link, recv_tmp) {
1944 		if (TAILQ_EMPTY(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE])) {
1945 			break;
1946 		}
1947 
1948 		rdma_req = TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE]);
1949 		rdma_req->recv = rdma_recv;
1950 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEW);
1951 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1952 			break;
1953 		}
1954 	}
1955 }
1956 
1957 static void
1958 _nvmf_rdma_disconnect(void *ctx)
1959 {
1960 	struct spdk_nvmf_qpair *qpair = ctx;
1961 	struct spdk_nvmf_rdma_qpair *rqpair;
1962 
1963 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1964 
1965 	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);
1966 
1967 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
1968 }
1969 
1970 static void
1971 _nvmf_rdma_disconnect_retry(void *ctx)
1972 {
1973 	struct spdk_nvmf_qpair *qpair = ctx;
1974 	struct spdk_nvmf_poll_group *group;
1975 
1976 	/* Read the group out of the qpair. This is normally set and accessed only from
1977 	 * the thread that created the group. Here, we're not on that thread necessarily.
1978 	 * The data member qpair->group begins it's life as NULL and then is assigned to
1979 	 * a pointer and never changes. So fortunately reading this and checking for
1980 	 * non-NULL is thread safe in the x86_64 memory model. */
1981 	group = qpair->group;
1982 
1983 	if (group == NULL) {
1984 		/* The qpair hasn't been assigned to a group yet, so we can't
1985 		 * process a disconnect. Send a message to ourself and try again. */
1986 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_disconnect_retry, qpair);
1987 		return;
1988 	}
1989 
1990 	spdk_thread_send_msg(group->thread, _nvmf_rdma_disconnect, qpair);
1991 }
1992 
1993 static int
1994 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
1995 {
1996 	struct spdk_nvmf_qpair		*qpair;
1997 	struct spdk_nvmf_rdma_qpair	*rqpair;
1998 
1999 	if (evt->id == NULL) {
2000 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2001 		return -1;
2002 	}
2003 
2004 	qpair = evt->id->context;
2005 	if (qpair == NULL) {
2006 		SPDK_ERRLOG("disconnect request: no active connection\n");
2007 		return -1;
2008 	}
2009 
2010 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2011 
2012 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2013 
2014 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2015 	spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2016 
2017 	_nvmf_rdma_disconnect_retry(qpair);
2018 
2019 	return 0;
2020 }
2021 
2022 #ifdef DEBUG
2023 static const char *CM_EVENT_STR[] = {
2024 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2025 	"RDMA_CM_EVENT_ADDR_ERROR",
2026 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2027 	"RDMA_CM_EVENT_ROUTE_ERROR",
2028 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2029 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2030 	"RDMA_CM_EVENT_CONNECT_ERROR",
2031 	"RDMA_CM_EVENT_UNREACHABLE",
2032 	"RDMA_CM_EVENT_REJECTED",
2033 	"RDMA_CM_EVENT_ESTABLISHED",
2034 	"RDMA_CM_EVENT_DISCONNECTED",
2035 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2036 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2037 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2038 	"RDMA_CM_EVENT_ADDR_CHANGE",
2039 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2040 };
2041 #endif /* DEBUG */
2042 
2043 static void
2044 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2045 {
2046 	struct spdk_nvmf_rdma_transport *rtransport;
2047 	struct rdma_cm_event		*event;
2048 	int				rc;
2049 
2050 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2051 
2052 	if (rtransport->event_channel == NULL) {
2053 		return;
2054 	}
2055 
2056 	while (1) {
2057 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2058 		if (rc == 0) {
2059 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2060 
2061 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2062 
2063 			switch (event->event) {
2064 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2065 			case RDMA_CM_EVENT_ADDR_ERROR:
2066 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2067 			case RDMA_CM_EVENT_ROUTE_ERROR:
2068 				/* No action required. The target never attempts to resolve routes. */
2069 				break;
2070 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2071 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2072 				if (rc < 0) {
2073 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2074 					break;
2075 				}
2076 				break;
2077 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2078 				/* The target never initiates a new connection. So this will not occur. */
2079 				break;
2080 			case RDMA_CM_EVENT_CONNECT_ERROR:
2081 				/* Can this happen? The docs say it can, but not sure what causes it. */
2082 				break;
2083 			case RDMA_CM_EVENT_UNREACHABLE:
2084 			case RDMA_CM_EVENT_REJECTED:
2085 				/* These only occur on the client side. */
2086 				break;
2087 			case RDMA_CM_EVENT_ESTABLISHED:
2088 				/* TODO: Should we be waiting for this event anywhere? */
2089 				break;
2090 			case RDMA_CM_EVENT_DISCONNECTED:
2091 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2092 				rc = nvmf_rdma_disconnect(event);
2093 				if (rc < 0) {
2094 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2095 					break;
2096 				}
2097 				break;
2098 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2099 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2100 				/* Multicast is not used */
2101 				break;
2102 			case RDMA_CM_EVENT_ADDR_CHANGE:
2103 				/* Not utilizing this event */
2104 				break;
2105 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2106 				/* For now, do nothing. The target never re-uses queue pairs. */
2107 				break;
2108 			default:
2109 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2110 				break;
2111 			}
2112 
2113 			rdma_ack_cm_event(event);
2114 		} else {
2115 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2116 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2117 			}
2118 			break;
2119 		}
2120 	}
2121 }
2122 
2123 static void
2124 spdk_nvmf_rdma_drain_state_queue(struct spdk_nvmf_rdma_qpair *rqpair,
2125 				 enum spdk_nvmf_rdma_request_state state)
2126 {
2127 	struct spdk_nvmf_rdma_request *rdma_req, *req_tmp;
2128 	struct spdk_nvmf_rdma_transport *rtransport;
2129 
2130 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[state], state_link, req_tmp) {
2131 		rtransport = SPDK_CONTAINEROF(rdma_req->req.qpair->transport,
2132 					      struct spdk_nvmf_rdma_transport, transport);
2133 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2134 		spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2135 	}
2136 }
2137 
2138 static void
2139 spdk_nvmf_rdma_qpair_recover(struct spdk_nvmf_rdma_qpair *rqpair)
2140 {
2141 	enum ibv_qp_state state, next_state;
2142 	int recovered;
2143 	struct spdk_nvmf_rdma_transport *rtransport;
2144 
2145 	if (!spdk_nvmf_rdma_qpair_is_idle(&rqpair->qpair)) {
2146 		/* There must be outstanding requests down to media.
2147 		 * If so, wait till they're complete.
2148 		 */
2149 		assert(!TAILQ_EMPTY(&rqpair->qpair.outstanding));
2150 		return;
2151 	}
2152 
2153 	state = rqpair->ibv_attr.qp_state;
2154 	next_state = state;
2155 
2156 	SPDK_NOTICELOG("RDMA qpair %u is in state: %s\n",
2157 		       rqpair->qpair.qid,
2158 		       str_ibv_qp_state[state]);
2159 
2160 	if (!(state == IBV_QPS_ERR || state == IBV_QPS_RESET)) {
2161 		SPDK_ERRLOG("Can't recover RDMA qpair %u from the state: %s\n",
2162 			    rqpair->qpair.qid,
2163 			    str_ibv_qp_state[state]);
2164 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2165 		return;
2166 	}
2167 
2168 	recovered = 0;
2169 	while (!recovered) {
2170 		switch (state) {
2171 		case IBV_QPS_ERR:
2172 			next_state = IBV_QPS_RESET;
2173 			break;
2174 		case IBV_QPS_RESET:
2175 			next_state = IBV_QPS_INIT;
2176 			break;
2177 		case IBV_QPS_INIT:
2178 			next_state = IBV_QPS_RTR;
2179 			break;
2180 		case IBV_QPS_RTR:
2181 			next_state = IBV_QPS_RTS;
2182 			break;
2183 		case IBV_QPS_RTS:
2184 			recovered = 1;
2185 			break;
2186 		default:
2187 			SPDK_ERRLOG("RDMA qpair %u unexpected state for recovery: %u\n",
2188 				    rqpair->qpair.qid, state);
2189 			goto error;
2190 		}
2191 		/* Do not transition into same state */
2192 		if (next_state == state) {
2193 			break;
2194 		}
2195 
2196 		if (spdk_nvmf_rdma_set_ibv_state(rqpair, next_state)) {
2197 			goto error;
2198 		}
2199 
2200 		state = next_state;
2201 	}
2202 
2203 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2204 				      struct spdk_nvmf_rdma_transport,
2205 				      transport);
2206 
2207 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2208 
2209 	return;
2210 error:
2211 	SPDK_NOTICELOG("RDMA qpair %u: recovery failed, disconnecting...\n",
2212 		       rqpair->qpair.qid);
2213 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2214 }
2215 
2216 /* Clean up only the states that can be aborted at any time */
2217 static void
2218 _spdk_nvmf_rdma_qp_cleanup_safe_states(struct spdk_nvmf_rdma_qpair *rqpair)
2219 {
2220 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2221 
2222 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_NEW);
2223 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[RDMA_REQUEST_STATE_NEED_BUFFER], link, req_tmp) {
2224 		TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
2225 	}
2226 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_NEED_BUFFER);
2227 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
2228 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
2229 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_EXECUTED);
2230 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
2231 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_COMPLETED);
2232 }
2233 
2234 /* This cleans up all memory. It is only safe to use if the rest of the software stack
2235  * has been shut down */
2236 static void
2237 _spdk_nvmf_rdma_qp_cleanup_all_states(struct spdk_nvmf_rdma_qpair *rqpair)
2238 {
2239 	_spdk_nvmf_rdma_qp_cleanup_safe_states(rqpair);
2240 
2241 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_EXECUTING);
2242 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2243 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST);
2244 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_COMPLETING);
2245 }
2246 
2247 static void
2248 _spdk_nvmf_rdma_qp_error(void *arg)
2249 {
2250 	struct spdk_nvmf_rdma_qpair	*rqpair = arg;
2251 	enum ibv_qp_state		state;
2252 
2253 	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);
2254 
2255 	state = rqpair->ibv_attr.qp_state;
2256 	if (state != IBV_QPS_ERR) {
2257 		/* Error was already recovered */
2258 		return;
2259 	}
2260 
2261 	if (spdk_nvmf_qpair_is_admin_queue(&rqpair->qpair)) {
2262 		spdk_nvmf_ctrlr_abort_aer(rqpair->qpair.ctrlr);
2263 	}
2264 
2265 	_spdk_nvmf_rdma_qp_cleanup_safe_states(rqpair);
2266 
2267 	/* Attempt recovery. This will exit without recovering if I/O requests
2268 	 * are still outstanding */
2269 	spdk_nvmf_rdma_qpair_recover(rqpair);
2270 }
2271 
2272 static void
2273 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2274 {
2275 	int				rc;
2276 	struct spdk_nvmf_rdma_qpair	*rqpair;
2277 	struct ibv_async_event		event;
2278 	enum ibv_qp_state		state;
2279 
2280 	rc = ibv_get_async_event(device->context, &event);
2281 
2282 	if (rc) {
2283 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2284 			    errno, spdk_strerror(errno));
2285 		return;
2286 	}
2287 
2288 	SPDK_NOTICELOG("Async event: %s\n",
2289 		       ibv_event_type_str(event.event_type));
2290 
2291 	switch (event.event_type) {
2292 	case IBV_EVENT_QP_FATAL:
2293 		rqpair = event.element.qp->qp_context;
2294 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2295 				  (uintptr_t)rqpair->cm_id, event.event_type);
2296 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2297 		spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2298 		spdk_thread_send_msg(rqpair->qpair.group->thread, _spdk_nvmf_rdma_qp_error, rqpair);
2299 		break;
2300 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2301 		/* This event only occurs for shared receive queues, which are not currently supported. */
2302 		break;
2303 	case IBV_EVENT_SQ_DRAINED:
2304 		/* This event occurs frequently in both error and non-error states.
2305 		 * Check if the qpair is in an error state before sending a message.
2306 		 * Note that we're not on the correct thread to access the qpair, but
2307 		 * the operations that the below calls make all happen to be thread
2308 		 * safe. */
2309 		rqpair = event.element.qp->qp_context;
2310 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2311 				  (uintptr_t)rqpair->cm_id, event.event_type);
2312 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2313 		if (state == IBV_QPS_ERR) {
2314 			spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2315 			spdk_thread_send_msg(rqpair->qpair.group->thread, _spdk_nvmf_rdma_qp_error, rqpair);
2316 		}
2317 		break;
2318 	case IBV_EVENT_QP_REQ_ERR:
2319 	case IBV_EVENT_QP_ACCESS_ERR:
2320 	case IBV_EVENT_COMM_EST:
2321 	case IBV_EVENT_PATH_MIG:
2322 	case IBV_EVENT_PATH_MIG_ERR:
2323 		rqpair = event.element.qp->qp_context;
2324 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2325 				  (uintptr_t)rqpair->cm_id, event.event_type);
2326 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2327 		break;
2328 	case IBV_EVENT_CQ_ERR:
2329 	case IBV_EVENT_DEVICE_FATAL:
2330 	case IBV_EVENT_PORT_ACTIVE:
2331 	case IBV_EVENT_PORT_ERR:
2332 	case IBV_EVENT_LID_CHANGE:
2333 	case IBV_EVENT_PKEY_CHANGE:
2334 	case IBV_EVENT_SM_CHANGE:
2335 	case IBV_EVENT_SRQ_ERR:
2336 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2337 	case IBV_EVENT_CLIENT_REREGISTER:
2338 	case IBV_EVENT_GID_CHANGE:
2339 	default:
2340 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2341 		break;
2342 	}
2343 	ibv_ack_async_event(&event);
2344 }
2345 
2346 static void
2347 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2348 {
2349 	int	nfds, i = 0;
2350 	struct spdk_nvmf_rdma_transport *rtransport;
2351 	struct spdk_nvmf_rdma_device *device, *tmp;
2352 
2353 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2354 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2355 
2356 	if (nfds <= 0) {
2357 		return;
2358 	}
2359 
2360 	/* The first poll descriptor is RDMA CM event */
2361 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2362 		spdk_nvmf_process_cm_event(transport, cb_fn);
2363 		nfds--;
2364 	}
2365 
2366 	if (nfds == 0) {
2367 		return;
2368 	}
2369 
2370 	/* Second and subsequent poll descriptors are IB async events */
2371 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2372 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2373 			spdk_nvmf_process_ib_event(device);
2374 			nfds--;
2375 		}
2376 	}
2377 	/* check all flagged fd's have been served */
2378 	assert(nfds == 0);
2379 }
2380 
2381 static void
2382 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2383 			struct spdk_nvme_transport_id *trid,
2384 			struct spdk_nvmf_discovery_log_page_entry *entry)
2385 {
2386 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2387 	entry->adrfam = trid->adrfam;
2388 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2389 
2390 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2391 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2392 
2393 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2394 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2395 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2396 }
2397 
2398 static struct spdk_nvmf_transport_poll_group *
2399 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2400 {
2401 	struct spdk_nvmf_rdma_transport		*rtransport;
2402 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2403 	struct spdk_nvmf_rdma_poller		*poller;
2404 	struct spdk_nvmf_rdma_device		*device;
2405 
2406 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2407 
2408 	rgroup = calloc(1, sizeof(*rgroup));
2409 	if (!rgroup) {
2410 		return NULL;
2411 	}
2412 
2413 	TAILQ_INIT(&rgroup->pollers);
2414 
2415 	pthread_mutex_lock(&rtransport->lock);
2416 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2417 		poller = calloc(1, sizeof(*poller));
2418 		if (!poller) {
2419 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2420 			free(rgroup);
2421 			pthread_mutex_unlock(&rtransport->lock);
2422 			return NULL;
2423 		}
2424 
2425 		poller->device = device;
2426 		poller->group = rgroup;
2427 
2428 		TAILQ_INIT(&poller->qpairs);
2429 
2430 		poller->cq = ibv_create_cq(device->context, NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
2431 		if (!poller->cq) {
2432 			SPDK_ERRLOG("Unable to create completion queue\n");
2433 			free(poller);
2434 			free(rgroup);
2435 			pthread_mutex_unlock(&rtransport->lock);
2436 			return NULL;
2437 		}
2438 
2439 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2440 	}
2441 
2442 	pthread_mutex_unlock(&rtransport->lock);
2443 	return &rgroup->group;
2444 }
2445 
2446 static void
2447 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
2448 {
2449 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2450 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
2451 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
2452 
2453 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2454 
2455 	if (!rgroup) {
2456 		return;
2457 	}
2458 
2459 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
2460 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2461 
2462 		if (poller->cq) {
2463 			ibv_destroy_cq(poller->cq);
2464 		}
2465 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
2466 			_spdk_nvmf_rdma_qp_cleanup_all_states(qpair);
2467 			spdk_nvmf_rdma_qpair_destroy(qpair);
2468 		}
2469 
2470 		free(poller);
2471 	}
2472 
2473 	free(rgroup);
2474 }
2475 
2476 static int
2477 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
2478 			      struct spdk_nvmf_qpair *qpair)
2479 {
2480 	struct spdk_nvmf_rdma_transport		*rtransport;
2481 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2482 	struct spdk_nvmf_rdma_qpair		*rqpair;
2483 	struct spdk_nvmf_rdma_device		*device;
2484 	struct spdk_nvmf_rdma_poller		*poller;
2485 	int					rc;
2486 
2487 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
2488 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2489 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2490 
2491 	device = rqpair->port->device;
2492 
2493 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
2494 		if (poller->device == device) {
2495 			break;
2496 		}
2497 	}
2498 
2499 	if (!poller) {
2500 		SPDK_ERRLOG("No poller found for device.\n");
2501 		return -1;
2502 	}
2503 
2504 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
2505 	rqpair->poller = poller;
2506 
2507 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
2508 	if (rc < 0) {
2509 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
2510 		return -1;
2511 	}
2512 
2513 	rqpair->mgmt_channel = spdk_get_io_channel(rtransport);
2514 	if (!rqpair->mgmt_channel) {
2515 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2516 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2517 		return -1;
2518 	}
2519 
2520 	rqpair->ch = spdk_io_channel_get_ctx(rqpair->mgmt_channel);
2521 	assert(rqpair->ch != NULL);
2522 
2523 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
2524 	if (rc) {
2525 		/* Try to reject, but we probably can't */
2526 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2527 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2528 		return -1;
2529 	}
2530 
2531 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2532 
2533 	return 0;
2534 }
2535 
2536 static int
2537 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
2538 {
2539 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2540 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2541 			struct spdk_nvmf_rdma_transport, transport);
2542 
2543 	if (rdma_req->data_from_pool) {
2544 		/* Put the buffer/s back in the pool */
2545 		for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
2546 			spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
2547 			rdma_req->req.iov[i].iov_base = NULL;
2548 			rdma_req->data.buffers[i] = NULL;
2549 		}
2550 		rdma_req->data_from_pool = false;
2551 	}
2552 	rdma_req->req.length = 0;
2553 	rdma_req->req.iovcnt = 0;
2554 	rdma_req->req.data = NULL;
2555 	spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
2556 	return 0;
2557 }
2558 
2559 static int
2560 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
2561 {
2562 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2563 			struct spdk_nvmf_rdma_transport, transport);
2564 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
2565 			struct spdk_nvmf_rdma_request, req);
2566 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
2567 			struct spdk_nvmf_rdma_qpair, qpair);
2568 
2569 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2570 		/* The connection is alive, so process the request as normal */
2571 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTED);
2572 	} else {
2573 		/* The connection is dead. Move the request directly to the completed state. */
2574 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2575 	}
2576 
2577 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2578 
2579 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE && rqpair->ibv_attr.qp_state == IBV_QPS_ERR) {
2580 		/* If the NVMe-oF layer thinks the connection is active, but the RDMA layer thinks
2581 		 * the connection is dead, perform error recovery. */
2582 		spdk_nvmf_rdma_qpair_recover(rqpair);
2583 	}
2584 
2585 	return 0;
2586 }
2587 
2588 static void
2589 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
2590 {
2591 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2592 
2593 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2594 }
2595 
2596 static struct spdk_nvmf_rdma_request *
2597 get_rdma_req_from_wc(struct ibv_wc *wc)
2598 {
2599 	struct spdk_nvmf_rdma_request *rdma_req;
2600 
2601 	rdma_req = (struct spdk_nvmf_rdma_request *)wc->wr_id;
2602 	assert(rdma_req != NULL);
2603 
2604 #ifdef DEBUG
2605 	struct spdk_nvmf_rdma_qpair *rqpair;
2606 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2607 
2608 	assert(rdma_req - rqpair->reqs >= 0);
2609 	assert(rdma_req - rqpair->reqs < (ptrdiff_t)rqpair->max_queue_depth);
2610 #endif
2611 
2612 	return rdma_req;
2613 }
2614 
2615 static struct spdk_nvmf_rdma_recv *
2616 get_rdma_recv_from_wc(struct ibv_wc *wc)
2617 {
2618 	struct spdk_nvmf_rdma_recv *rdma_recv;
2619 
2620 	assert(wc->byte_len >= sizeof(struct spdk_nvmf_capsule_cmd));
2621 
2622 	rdma_recv = (struct spdk_nvmf_rdma_recv *)wc->wr_id;
2623 	assert(rdma_recv != NULL);
2624 
2625 #ifdef DEBUG
2626 	struct spdk_nvmf_rdma_qpair *rqpair = rdma_recv->qpair;
2627 
2628 	assert(rdma_recv - rqpair->recvs >= 0);
2629 	assert(rdma_recv - rqpair->recvs < (ptrdiff_t)rqpair->max_queue_depth);
2630 #endif
2631 
2632 	return rdma_recv;
2633 }
2634 
2635 #ifdef DEBUG
2636 static int
2637 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
2638 {
2639 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
2640 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
2641 }
2642 #endif
2643 
2644 static int
2645 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2646 			   struct spdk_nvmf_rdma_poller *rpoller)
2647 {
2648 	struct ibv_wc wc[32];
2649 	struct spdk_nvmf_rdma_request	*rdma_req;
2650 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2651 	struct spdk_nvmf_rdma_qpair	*rqpair;
2652 	int reaped, i;
2653 	int count = 0;
2654 	bool error = false;
2655 
2656 	/* Poll for completing operations. */
2657 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2658 	if (reaped < 0) {
2659 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2660 			    errno, spdk_strerror(errno));
2661 		return -1;
2662 	}
2663 
2664 	for (i = 0; i < reaped; i++) {
2665 		/* Handle error conditions */
2666 		if (wc[i].status) {
2667 			SPDK_WARNLOG("CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2668 				     rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2669 			error = true;
2670 
2671 			switch (wc[i].opcode) {
2672 			case IBV_WC_SEND:
2673 				rdma_req = get_rdma_req_from_wc(&wc[i]);
2674 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2675 
2676 				/* We're going to attempt an error recovery, so force the request into
2677 				 * the completed state. */
2678 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2679 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2680 				break;
2681 			case IBV_WC_RECV:
2682 				rdma_recv = get_rdma_recv_from_wc(&wc[i]);
2683 				rqpair = rdma_recv->qpair;
2684 
2685 				/* Dump this into the incoming queue. This gets cleaned up when
2686 				 * the queue pair disconnects or recovers. */
2687 				TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2688 				break;
2689 			case IBV_WC_RDMA_WRITE:
2690 			case IBV_WC_RDMA_READ:
2691 				/* If the data transfer fails still force the queue into the error state,
2692 				 * but the rdma_req objects should only be manipulated in response to
2693 				 * SEND and RECV operations. */
2694 				rdma_req = get_rdma_req_from_wc(&wc[i]);
2695 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2696 				break;
2697 			default:
2698 				SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2699 				continue;
2700 			}
2701 
2702 			/* Set the qpair to the error state. This will initiate a recovery. */
2703 			spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
2704 			continue;
2705 		}
2706 
2707 		switch (wc[i].opcode) {
2708 		case IBV_WC_SEND:
2709 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2710 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2711 
2712 			assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
2713 
2714 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2715 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2716 
2717 			count++;
2718 
2719 			/* Try to process other queued requests */
2720 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2721 			break;
2722 
2723 		case IBV_WC_RDMA_WRITE:
2724 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2725 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2726 
2727 			/* Try to process other queued requests */
2728 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2729 			break;
2730 
2731 		case IBV_WC_RDMA_READ:
2732 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2733 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2734 
2735 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2736 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
2737 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2738 
2739 			/* Try to process other queued requests */
2740 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2741 			break;
2742 
2743 		case IBV_WC_RECV:
2744 			rdma_recv = get_rdma_recv_from_wc(&wc[i]);
2745 			rqpair = rdma_recv->qpair;
2746 
2747 			TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2748 			/* Try to process other queued requests */
2749 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2750 			break;
2751 
2752 		default:
2753 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2754 			continue;
2755 		}
2756 	}
2757 
2758 	if (error == true) {
2759 		return -1;
2760 	}
2761 
2762 	return count;
2763 }
2764 
2765 static int
2766 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2767 {
2768 	struct spdk_nvmf_rdma_transport *rtransport;
2769 	struct spdk_nvmf_rdma_poll_group *rgroup;
2770 	struct spdk_nvmf_rdma_poller	*rpoller;
2771 	int				count, rc;
2772 
2773 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2774 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2775 
2776 	count = 0;
2777 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2778 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2779 		if (rc < 0) {
2780 			return rc;
2781 		}
2782 		count += rc;
2783 	}
2784 
2785 	return count;
2786 }
2787 
2788 static int
2789 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2790 			       struct spdk_nvme_transport_id *trid,
2791 			       bool peer)
2792 {
2793 	struct sockaddr *saddr;
2794 	uint16_t port;
2795 
2796 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
2797 
2798 	if (peer) {
2799 		saddr = rdma_get_peer_addr(id);
2800 	} else {
2801 		saddr = rdma_get_local_addr(id);
2802 	}
2803 	switch (saddr->sa_family) {
2804 	case AF_INET: {
2805 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
2806 
2807 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
2808 		inet_ntop(AF_INET, &saddr_in->sin_addr,
2809 			  trid->traddr, sizeof(trid->traddr));
2810 		if (peer) {
2811 			port = ntohs(rdma_get_dst_port(id));
2812 		} else {
2813 			port = ntohs(rdma_get_src_port(id));
2814 		}
2815 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2816 		break;
2817 	}
2818 	case AF_INET6: {
2819 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
2820 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
2821 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
2822 			  trid->traddr, sizeof(trid->traddr));
2823 		if (peer) {
2824 			port = ntohs(rdma_get_dst_port(id));
2825 		} else {
2826 			port = ntohs(rdma_get_src_port(id));
2827 		}
2828 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2829 		break;
2830 	}
2831 	default:
2832 		return -1;
2833 
2834 	}
2835 
2836 	return 0;
2837 }
2838 
2839 static int
2840 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
2841 				   struct spdk_nvme_transport_id *trid)
2842 {
2843 	struct spdk_nvmf_rdma_qpair	*rqpair;
2844 
2845 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2846 
2847 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
2848 }
2849 
2850 static int
2851 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
2852 				    struct spdk_nvme_transport_id *trid)
2853 {
2854 	struct spdk_nvmf_rdma_qpair	*rqpair;
2855 
2856 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2857 
2858 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
2859 }
2860 
2861 static int
2862 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
2863 				     struct spdk_nvme_transport_id *trid)
2864 {
2865 	struct spdk_nvmf_rdma_qpair	*rqpair;
2866 
2867 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2868 
2869 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
2870 }
2871 
2872 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
2873 	.type = SPDK_NVME_TRANSPORT_RDMA,
2874 	.opts_init = spdk_nvmf_rdma_opts_init,
2875 	.create = spdk_nvmf_rdma_create,
2876 	.destroy = spdk_nvmf_rdma_destroy,
2877 
2878 	.listen = spdk_nvmf_rdma_listen,
2879 	.stop_listen = spdk_nvmf_rdma_stop_listen,
2880 	.accept = spdk_nvmf_rdma_accept,
2881 
2882 	.listener_discover = spdk_nvmf_rdma_discover,
2883 
2884 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
2885 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
2886 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
2887 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
2888 
2889 	.req_free = spdk_nvmf_rdma_request_free,
2890 	.req_complete = spdk_nvmf_rdma_request_complete,
2891 
2892 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
2893 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
2894 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
2895 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
2896 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
2897 
2898 };
2899 
2900 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
2901