xref: /spdk/lib/nvmf/rdma.c (revision c34d149139a5b1b351a9ab1948df3a9958848159)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include <infiniband/verbs.h>
37 #include <rdma/rdma_cma.h>
38 #include <rdma/rdma_verbs.h>
39 
40 #include "nvmf_internal.h"
41 #include "transport.h"
42 
43 #include "spdk/assert.h"
44 #include "spdk/thread.h"
45 #include "spdk/nvmf.h"
46 #include "spdk/nvmf_spec.h"
47 #include "spdk/string.h"
48 #include "spdk/trace.h"
49 #include "spdk/util.h"
50 
51 #include "spdk_internal/log.h"
52 
53 /*
54  RDMA Connection Resource Defaults
55  */
56 #define NVMF_DEFAULT_TX_SGE		1
57 #define NVMF_DEFAULT_RX_SGE		2
58 #define NVMF_DEFAULT_DATA_SGE		16
59 
60 /* The RDMA completion queue size */
61 #define NVMF_RDMA_CQ_SIZE	4096
62 
63 /* AIO backend requires block size aligned data buffers,
64  * extra 4KiB aligned data buffer should work for most devices.
65  */
66 #define SHIFT_4KB			12
67 #define NVMF_DATA_BUFFER_ALIGNMENT	(1 << SHIFT_4KB)
68 #define NVMF_DATA_BUFFER_MASK		(NVMF_DATA_BUFFER_ALIGNMENT - 1)
69 
70 enum spdk_nvmf_rdma_request_state {
71 	/* The request is not currently in use */
72 	RDMA_REQUEST_STATE_FREE = 0,
73 
74 	/* Initial state when request first received */
75 	RDMA_REQUEST_STATE_NEW,
76 
77 	/* The request is queued until a data buffer is available. */
78 	RDMA_REQUEST_STATE_NEED_BUFFER,
79 
80 	/* The request is waiting on RDMA queue depth availability
81 	 * to transfer data between the host and the controller.
82 	 */
83 	RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
84 
85 	/* The request is currently transferring data from the host to the controller. */
86 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
87 
88 	/* The request is ready to execute at the block device */
89 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
90 
91 	/* The request is currently executing at the block device */
92 	RDMA_REQUEST_STATE_EXECUTING,
93 
94 	/* The request finished executing at the block device */
95 	RDMA_REQUEST_STATE_EXECUTED,
96 
97 	/* The request is ready to send a completion */
98 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
99 
100 	/* The request is currently transferring data from the controller to the host. */
101 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
102 
103 	/* The request currently has an outstanding completion without an
104 	 * associated data transfer.
105 	 */
106 	RDMA_REQUEST_STATE_COMPLETING,
107 
108 	/* The request completed and can be marked free. */
109 	RDMA_REQUEST_STATE_COMPLETED,
110 
111 	/* Terminator */
112 	RDMA_REQUEST_NUM_STATES,
113 };
114 
115 #define OBJECT_NVMF_RDMA_IO				0x40
116 
117 #define									TRACE_GROUP_NVMF_RDMA 0x4
118 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
119 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
120 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
121 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
122 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
123 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
124 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
125 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
126 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
127 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
128 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
129 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
130 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
131 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
132 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
133 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
134 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
135 
136 SPDK_TRACE_REGISTER_FN(nvmf_trace)
137 {
138 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
139 	spdk_trace_register_description("RDMA_REQ_NEW", "",
140 					TRACE_RDMA_REQUEST_STATE_NEW,
141 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
142 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
143 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
144 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
145 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
146 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
147 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
148 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
149 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
150 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
151 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
152 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
153 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
154 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
155 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
156 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
157 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
158 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
159 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
160 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
161 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
163 	spdk_trace_register_description("RDMA_REQ_COMPLETING_CONTROLLER_TO_HOST", "",
164 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
165 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
166 	spdk_trace_register_description("RDMA_REQ_COMPLETING_INCAPSULE", "",
167 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
170 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 
173 	spdk_trace_register_description("RDMA_QP_CREATE", "", TRACE_RDMA_QP_CREATE,
174 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
175 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", "", TRACE_RDMA_IBV_ASYNC_EVENT,
176 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
177 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", "", TRACE_RDMA_CM_ASYNC_EVENT,
178 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
179 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", "", TRACE_RDMA_QP_STATE_CHANGE,
180 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
181 	spdk_trace_register_description("RDMA_QP_DISCONNECT", "", TRACE_RDMA_QP_DISCONNECT,
182 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
183 	spdk_trace_register_description("RDMA_QP_DESTROY", "", TRACE_RDMA_QP_DESTROY,
184 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
185 }
186 
187 /* This structure holds commands as they are received off the wire.
188  * It must be dynamically paired with a full request object
189  * (spdk_nvmf_rdma_request) to service a request. It is separate
190  * from the request because RDMA does not appear to order
191  * completions, so occasionally we'll get a new incoming
192  * command when there aren't any free request objects.
193  */
194 struct spdk_nvmf_rdma_recv {
195 	struct ibv_recv_wr		wr;
196 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
197 
198 	struct spdk_nvmf_rdma_qpair	*qpair;
199 
200 	/* In-capsule data buffer */
201 	uint8_t				*buf;
202 
203 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
204 };
205 
206 struct spdk_nvmf_rdma_request {
207 	struct spdk_nvmf_request		req;
208 	bool					data_from_pool;
209 
210 	enum spdk_nvmf_rdma_request_state	state;
211 
212 	struct spdk_nvmf_rdma_recv		*recv;
213 
214 	struct {
215 		struct	ibv_send_wr		wr;
216 		struct	ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
217 	} rsp;
218 
219 	struct {
220 		struct ibv_send_wr		wr;
221 		struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
222 		void				*buffers[SPDK_NVMF_MAX_SGL_ENTRIES];
223 	} data;
224 
225 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
226 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
227 };
228 
229 struct spdk_nvmf_rdma_qpair {
230 	struct spdk_nvmf_qpair			qpair;
231 
232 	struct spdk_nvmf_rdma_port		*port;
233 	struct spdk_nvmf_rdma_poller		*poller;
234 
235 	struct rdma_cm_id			*cm_id;
236 	struct rdma_cm_id			*listen_id;
237 
238 	/* The maximum number of I/O outstanding on this connection at one time */
239 	uint16_t				max_queue_depth;
240 
241 	/* The maximum number of active RDMA READ and WRITE operations at one time */
242 	uint16_t				max_rw_depth;
243 
244 	/* Receives that are waiting for a request object */
245 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
246 
247 	/* Queues to track the requests in all states */
248 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	state_queue[RDMA_REQUEST_NUM_STATES];
249 
250 	/* Number of requests in each state */
251 	uint32_t				state_cntr[RDMA_REQUEST_NUM_STATES];
252 
253 	int                                     max_sge;
254 
255 	/* Array of size "max_queue_depth" containing RDMA requests. */
256 	struct spdk_nvmf_rdma_request		*reqs;
257 
258 	/* Array of size "max_queue_depth" containing RDMA recvs. */
259 	struct spdk_nvmf_rdma_recv		*recvs;
260 
261 	/* Array of size "max_queue_depth" containing 64 byte capsules
262 	 * used for receive.
263 	 */
264 	union nvmf_h2c_msg			*cmds;
265 	struct ibv_mr				*cmds_mr;
266 
267 	/* Array of size "max_queue_depth" containing 16 byte completions
268 	 * to be sent back to the user.
269 	 */
270 	union nvmf_c2h_msg			*cpls;
271 	struct ibv_mr				*cpls_mr;
272 
273 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
274 	 * buffers to be used for in capsule data.
275 	 */
276 	void					*bufs;
277 	struct ibv_mr				*bufs_mr;
278 
279 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
280 
281 	/* Mgmt channel */
282 	struct spdk_io_channel			*mgmt_channel;
283 	struct spdk_nvmf_rdma_mgmt_channel	*ch;
284 
285 	/* IBV queue pair attributes: they are used to manage
286 	 * qp state and recover from errors.
287 	 */
288 	struct ibv_qp_init_attr			ibv_init_attr;
289 	struct ibv_qp_attr			ibv_attr;
290 
291 	bool					qpair_disconnected;
292 
293 	/* Reference counter for how many unprocessed messages
294 	 * from other threads are currently outstanding. The
295 	 * qpair cannot be destroyed until this is 0. This is
296 	 * atomically incremented from any thread, but only
297 	 * decremented and read from the thread that owns this
298 	 * qpair.
299 	 */
300 	uint32_t				refcnt;
301 };
302 
303 struct spdk_nvmf_rdma_poller {
304 	struct spdk_nvmf_rdma_device		*device;
305 	struct spdk_nvmf_rdma_poll_group	*group;
306 
307 	struct ibv_cq				*cq;
308 
309 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
310 
311 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
312 };
313 
314 struct spdk_nvmf_rdma_poll_group {
315 	struct spdk_nvmf_transport_poll_group	group;
316 
317 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
318 };
319 
320 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
321 struct spdk_nvmf_rdma_device {
322 	struct ibv_device_attr			attr;
323 	struct ibv_context			*context;
324 
325 	struct spdk_mem_map			*map;
326 	struct ibv_pd				*pd;
327 
328 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
329 };
330 
331 struct spdk_nvmf_rdma_port {
332 	struct spdk_nvme_transport_id		trid;
333 	struct rdma_cm_id			*id;
334 	struct spdk_nvmf_rdma_device		*device;
335 	uint32_t				ref;
336 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
337 };
338 
339 struct spdk_nvmf_rdma_transport {
340 	struct spdk_nvmf_transport	transport;
341 
342 	struct rdma_event_channel	*event_channel;
343 
344 	struct spdk_mempool		*data_buf_pool;
345 
346 	pthread_mutex_t			lock;
347 
348 	/* fields used to poll RDMA/IB events */
349 	nfds_t			npoll_fds;
350 	struct pollfd		*poll_fds;
351 
352 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
353 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
354 };
355 
356 struct spdk_nvmf_rdma_mgmt_channel {
357 	/* Requests that are waiting to obtain a data buffer */
358 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
359 };
360 
361 static inline void
362 spdk_nvmf_rdma_qpair_inc_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
363 {
364 	__sync_fetch_and_add(&rqpair->refcnt, 1);
365 }
366 
367 static inline uint32_t
368 spdk_nvmf_rdma_qpair_dec_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
369 {
370 	uint32_t old_refcnt, new_refcnt;
371 
372 	do {
373 		old_refcnt = rqpair->refcnt;
374 		assert(old_refcnt > 0);
375 		new_refcnt = old_refcnt - 1;
376 	} while (__sync_bool_compare_and_swap(&rqpair->refcnt, old_refcnt, new_refcnt) == false);
377 
378 	return new_refcnt;
379 }
380 
381 /* API to IBV QueuePair */
382 static const char *str_ibv_qp_state[] = {
383 	"IBV_QPS_RESET",
384 	"IBV_QPS_INIT",
385 	"IBV_QPS_RTR",
386 	"IBV_QPS_RTS",
387 	"IBV_QPS_SQD",
388 	"IBV_QPS_SQE",
389 	"IBV_QPS_ERR"
390 };
391 
392 static enum ibv_qp_state
393 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
394 	enum ibv_qp_state old_state, new_state;
395 	int rc;
396 
397 	/* All the attributes needed for recovery */
398 	static int spdk_nvmf_ibv_attr_mask =
399 	IBV_QP_STATE |
400 	IBV_QP_PKEY_INDEX |
401 	IBV_QP_PORT |
402 	IBV_QP_ACCESS_FLAGS |
403 	IBV_QP_AV |
404 	IBV_QP_PATH_MTU |
405 	IBV_QP_DEST_QPN |
406 	IBV_QP_RQ_PSN |
407 	IBV_QP_MAX_DEST_RD_ATOMIC |
408 	IBV_QP_MIN_RNR_TIMER |
409 	IBV_QP_SQ_PSN |
410 	IBV_QP_TIMEOUT |
411 	IBV_QP_RETRY_CNT |
412 	IBV_QP_RNR_RETRY |
413 	IBV_QP_MAX_QP_RD_ATOMIC;
414 
415 	old_state = rqpair->ibv_attr.qp_state;
416 	rc = ibv_query_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
417 			  spdk_nvmf_ibv_attr_mask, &rqpair->ibv_init_attr);
418 
419 	if (rc)
420 	{
421 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
422 		assert(false);
423 	}
424 
425 	new_state = rqpair->ibv_attr.qp_state;
426 	if (old_state != new_state)
427 	{
428 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
429 				  (uintptr_t)rqpair->cm_id, new_state);
430 	}
431 	return new_state;
432 }
433 
434 static int
435 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
436 			     enum ibv_qp_state new_state)
437 {
438 	int rc;
439 	enum ibv_qp_state state;
440 	static int attr_mask_rc[] = {
441 		[IBV_QPS_RESET] = IBV_QP_STATE,
442 		[IBV_QPS_INIT] = (IBV_QP_STATE |
443 				  IBV_QP_PKEY_INDEX |
444 				  IBV_QP_PORT |
445 				  IBV_QP_ACCESS_FLAGS),
446 		[IBV_QPS_RTR] = (IBV_QP_STATE |
447 				 IBV_QP_AV |
448 				 IBV_QP_PATH_MTU |
449 				 IBV_QP_DEST_QPN |
450 				 IBV_QP_RQ_PSN |
451 				 IBV_QP_MAX_DEST_RD_ATOMIC |
452 				 IBV_QP_MIN_RNR_TIMER),
453 		[IBV_QPS_RTS] = (IBV_QP_STATE |
454 				 IBV_QP_SQ_PSN |
455 				 IBV_QP_TIMEOUT |
456 				 IBV_QP_RETRY_CNT |
457 				 IBV_QP_RNR_RETRY |
458 				 IBV_QP_MAX_QP_RD_ATOMIC),
459 		[IBV_QPS_SQD] = IBV_QP_STATE,
460 		[IBV_QPS_SQE] = IBV_QP_STATE,
461 		[IBV_QPS_ERR] = IBV_QP_STATE,
462 	};
463 
464 	switch (new_state) {
465 	case IBV_QPS_RESET:
466 	case IBV_QPS_INIT:
467 	case IBV_QPS_RTR:
468 	case IBV_QPS_RTS:
469 	case IBV_QPS_SQD:
470 	case IBV_QPS_SQE:
471 	case IBV_QPS_ERR:
472 		break;
473 	default:
474 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
475 			    rqpair->qpair.qid, new_state);
476 		return -1;
477 	}
478 	rqpair->ibv_attr.cur_qp_state = rqpair->ibv_attr.qp_state;
479 	rqpair->ibv_attr.qp_state = new_state;
480 	rqpair->ibv_attr.ah_attr.port_num = rqpair->ibv_attr.port_num;
481 
482 	rc = ibv_modify_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
483 			   attr_mask_rc[new_state]);
484 
485 	if (rc) {
486 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
487 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
488 		return rc;
489 	}
490 
491 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
492 
493 	if (state != new_state) {
494 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
495 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
496 			    str_ibv_qp_state[state]);
497 		return -1;
498 	}
499 	SPDK_NOTICELOG("IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
500 		       str_ibv_qp_state[state]);
501 	return 0;
502 }
503 
504 static void
505 spdk_nvmf_rdma_request_set_state(struct spdk_nvmf_rdma_request *rdma_req,
506 				 enum spdk_nvmf_rdma_request_state state)
507 {
508 	struct spdk_nvmf_qpair		*qpair;
509 	struct spdk_nvmf_rdma_qpair	*rqpair;
510 
511 	qpair = rdma_req->req.qpair;
512 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
513 
514 	TAILQ_REMOVE(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
515 	rqpair->state_cntr[rdma_req->state]--;
516 
517 	rdma_req->state = state;
518 
519 	TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
520 	rqpair->state_cntr[rdma_req->state]++;
521 }
522 
523 static int
524 spdk_nvmf_rdma_mgmt_channel_create(void *io_device, void *ctx_buf)
525 {
526 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
527 
528 	TAILQ_INIT(&ch->pending_data_buf_queue);
529 	return 0;
530 }
531 
532 static void
533 spdk_nvmf_rdma_mgmt_channel_destroy(void *io_device, void *ctx_buf)
534 {
535 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
536 
537 	if (!TAILQ_EMPTY(&ch->pending_data_buf_queue)) {
538 		SPDK_ERRLOG("Pending I/O list wasn't empty on channel destruction\n");
539 	}
540 }
541 
542 static int
543 spdk_nvmf_rdma_cur_rw_depth(struct spdk_nvmf_rdma_qpair *rqpair)
544 {
545 	return rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER] +
546 	       rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST];
547 }
548 
549 static int
550 spdk_nvmf_rdma_cur_queue_depth(struct spdk_nvmf_rdma_qpair *rqpair)
551 {
552 	return rqpair->max_queue_depth -
553 	       rqpair->state_cntr[RDMA_REQUEST_STATE_FREE];
554 }
555 
556 static void
557 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
558 {
559 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
560 
561 	if (spdk_nvmf_rdma_cur_queue_depth(rqpair)) {
562 		rqpair->qpair_disconnected = true;
563 		return;
564 	}
565 
566 	if (rqpair->refcnt > 0) {
567 		return;
568 	}
569 
570 	if (rqpair->poller) {
571 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
572 	}
573 
574 	if (rqpair->cmds_mr) {
575 		ibv_dereg_mr(rqpair->cmds_mr);
576 	}
577 
578 	if (rqpair->cpls_mr) {
579 		ibv_dereg_mr(rqpair->cpls_mr);
580 	}
581 
582 	if (rqpair->bufs_mr) {
583 		ibv_dereg_mr(rqpair->bufs_mr);
584 	}
585 
586 	if (rqpair->cm_id) {
587 		rdma_destroy_qp(rqpair->cm_id);
588 		rdma_destroy_id(rqpair->cm_id);
589 	}
590 
591 	if (rqpair->mgmt_channel) {
592 		spdk_put_io_channel(rqpair->mgmt_channel);
593 	}
594 
595 	/* Free all memory */
596 	spdk_dma_free(rqpair->cmds);
597 	spdk_dma_free(rqpair->cpls);
598 	spdk_dma_free(rqpair->bufs);
599 	free(rqpair->reqs);
600 	free(rqpair->recvs);
601 	free(rqpair);
602 }
603 
604 static int
605 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
606 {
607 	struct spdk_nvmf_rdma_transport *rtransport;
608 	struct spdk_nvmf_rdma_qpair	*rqpair;
609 	int				rc, i;
610 	struct spdk_nvmf_rdma_recv	*rdma_recv;
611 	struct spdk_nvmf_rdma_request	*rdma_req;
612 	struct spdk_nvmf_transport      *transport;
613 
614 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
615 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
616 	transport = &rtransport->transport;
617 
618 	memset(&rqpair->ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
619 	rqpair->ibv_init_attr.qp_context	= rqpair;
620 	rqpair->ibv_init_attr.qp_type		= IBV_QPT_RC;
621 	rqpair->ibv_init_attr.send_cq		= rqpair->poller->cq;
622 	rqpair->ibv_init_attr.recv_cq		= rqpair->poller->cq;
623 	rqpair->ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
624 			2; /* SEND, READ, and WRITE operations */
625 	rqpair->ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth; /* RECV operations */
626 	rqpair->ibv_init_attr.cap.max_send_sge	= rqpair->max_sge;
627 	rqpair->ibv_init_attr.cap.max_recv_sge	= NVMF_DEFAULT_RX_SGE;
628 
629 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &rqpair->ibv_init_attr);
630 	if (rc) {
631 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
632 		rdma_destroy_id(rqpair->cm_id);
633 		rqpair->cm_id = NULL;
634 		spdk_nvmf_rdma_qpair_destroy(rqpair);
635 		return -1;
636 	}
637 
638 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
639 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
640 
641 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
642 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
643 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
644 					0x1000, NULL);
645 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
646 					0x1000, NULL);
647 
648 
649 	if (transport->opts.in_capsule_data_size > 0) {
650 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth *
651 						transport->opts.in_capsule_data_size,
652 						0x1000, NULL);
653 	}
654 
655 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
656 	    !rqpair->cpls || (transport->opts.in_capsule_data_size && !rqpair->bufs)) {
657 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
658 		spdk_nvmf_rdma_qpair_destroy(rqpair);
659 		return -1;
660 	}
661 
662 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
663 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
664 				     IBV_ACCESS_LOCAL_WRITE);
665 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
666 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
667 				     0);
668 
669 	if (transport->opts.in_capsule_data_size) {
670 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
671 					     rqpair->max_queue_depth *
672 					     transport->opts.in_capsule_data_size,
673 					     IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
674 	}
675 
676 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (transport->opts.in_capsule_data_size &&
677 			!rqpair->bufs_mr)) {
678 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
679 		spdk_nvmf_rdma_qpair_destroy(rqpair);
680 		return -1;
681 	}
682 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
683 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
684 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
685 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
686 	if (rqpair->bufs && rqpair->bufs_mr) {
687 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
688 			      rqpair->bufs, rqpair->max_queue_depth *
689 			      transport->opts.in_capsule_data_size, rqpair->bufs_mr->lkey);
690 	}
691 
692 	/* Initialise request state queues and counters of the queue pair */
693 	for (i = RDMA_REQUEST_STATE_FREE; i < RDMA_REQUEST_NUM_STATES; i++) {
694 		TAILQ_INIT(&rqpair->state_queue[i]);
695 		rqpair->state_cntr[i] = 0;
696 	}
697 
698 	for (i = 0; i < rqpair->max_queue_depth; i++) {
699 		struct ibv_recv_wr *bad_wr = NULL;
700 
701 		rdma_recv = &rqpair->recvs[i];
702 		rdma_recv->qpair = rqpair;
703 
704 		/* Set up memory to receive commands */
705 		if (rqpair->bufs) {
706 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i *
707 						  transport->opts.in_capsule_data_size));
708 		}
709 
710 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
711 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
712 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
713 		rdma_recv->wr.num_sge = 1;
714 
715 		if (rdma_recv->buf && rqpair->bufs_mr) {
716 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
717 			rdma_recv->sgl[1].length = transport->opts.in_capsule_data_size;
718 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
719 			rdma_recv->wr.num_sge++;
720 		}
721 
722 		rdma_recv->wr.wr_id = (uintptr_t)rdma_recv;
723 		rdma_recv->wr.sg_list = rdma_recv->sgl;
724 
725 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
726 		if (rc) {
727 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
728 			spdk_nvmf_rdma_qpair_destroy(rqpair);
729 			return -1;
730 		}
731 	}
732 
733 	for (i = 0; i < rqpair->max_queue_depth; i++) {
734 		rdma_req = &rqpair->reqs[i];
735 
736 		rdma_req->req.qpair = &rqpair->qpair;
737 		rdma_req->req.cmd = NULL;
738 
739 		/* Set up memory to send responses */
740 		rdma_req->req.rsp = &rqpair->cpls[i];
741 
742 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
743 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
744 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
745 
746 		rdma_req->rsp.wr.wr_id = (uintptr_t)rdma_req;
747 		rdma_req->rsp.wr.next = NULL;
748 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
749 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
750 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
751 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
752 
753 		/* Set up memory for data buffers */
754 		rdma_req->data.wr.wr_id = (uint64_t)rdma_req;
755 		rdma_req->data.wr.next = NULL;
756 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
757 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
758 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
759 
760 		/* Initialize request state to FREE */
761 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
762 		TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
763 		rqpair->state_cntr[rdma_req->state]++;
764 	}
765 
766 	return 0;
767 }
768 
769 static int
770 request_transfer_in(struct spdk_nvmf_request *req)
771 {
772 	int				rc;
773 	struct spdk_nvmf_rdma_request	*rdma_req;
774 	struct spdk_nvmf_qpair		*qpair;
775 	struct spdk_nvmf_rdma_qpair	*rqpair;
776 	struct ibv_send_wr		*bad_wr = NULL;
777 
778 	qpair = req->qpair;
779 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
780 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
781 
782 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
783 
784 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
785 
786 	rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
787 	rdma_req->data.wr.next = NULL;
788 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
789 	if (rc) {
790 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
791 		return -1;
792 	}
793 	return 0;
794 }
795 
796 static int
797 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
798 {
799 	int				rc;
800 	struct spdk_nvmf_rdma_request	*rdma_req;
801 	struct spdk_nvmf_qpair		*qpair;
802 	struct spdk_nvmf_rdma_qpair	*rqpair;
803 	struct spdk_nvme_cpl		*rsp;
804 	struct ibv_recv_wr		*bad_recv_wr = NULL;
805 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
806 
807 	*data_posted = 0;
808 	qpair = req->qpair;
809 	rsp = &req->rsp->nvme_cpl;
810 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
811 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
812 
813 	/* Advance our sq_head pointer */
814 	if (qpair->sq_head == qpair->sq_head_max) {
815 		qpair->sq_head = 0;
816 	} else {
817 		qpair->sq_head++;
818 	}
819 	rsp->sqhd = qpair->sq_head;
820 
821 	/* Post the capsule to the recv buffer */
822 	assert(rdma_req->recv != NULL);
823 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
824 		      rqpair);
825 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
826 	if (rc) {
827 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
828 		return rc;
829 	}
830 	rdma_req->recv = NULL;
831 
832 	/* Build the response which consists of an optional
833 	 * RDMA WRITE to transfer data, plus an RDMA SEND
834 	 * containing the response.
835 	 */
836 	send_wr = &rdma_req->rsp.wr;
837 
838 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
839 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
840 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
841 
842 		rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
843 
844 		rdma_req->data.wr.next = send_wr;
845 		*data_posted = 1;
846 		send_wr = &rdma_req->data.wr;
847 	}
848 
849 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
850 
851 	/* Send the completion */
852 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
853 	if (rc) {
854 		SPDK_ERRLOG("Unable to send response capsule\n");
855 	}
856 
857 	return rc;
858 }
859 
860 static int
861 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
862 {
863 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
864 	struct rdma_conn_param				ctrlr_event_data = {};
865 	int						rc;
866 
867 	accept_data.recfmt = 0;
868 	accept_data.crqsize = rqpair->max_queue_depth;
869 
870 	ctrlr_event_data.private_data = &accept_data;
871 	ctrlr_event_data.private_data_len = sizeof(accept_data);
872 	if (id->ps == RDMA_PS_TCP) {
873 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
874 		ctrlr_event_data.initiator_depth = rqpair->max_rw_depth;
875 	}
876 
877 	rc = rdma_accept(id, &ctrlr_event_data);
878 	if (rc) {
879 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
880 	} else {
881 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
882 	}
883 
884 	return rc;
885 }
886 
887 static void
888 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
889 {
890 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
891 
892 	rej_data.recfmt = 0;
893 	rej_data.sts = error;
894 
895 	rdma_reject(id, &rej_data, sizeof(rej_data));
896 }
897 
898 static int
899 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
900 		  new_qpair_fn cb_fn)
901 {
902 	struct spdk_nvmf_rdma_transport *rtransport;
903 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
904 	struct spdk_nvmf_rdma_port	*port;
905 	struct rdma_conn_param		*rdma_param = NULL;
906 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
907 	uint16_t			max_queue_depth;
908 	uint16_t			max_rw_depth;
909 
910 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
911 
912 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
913 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
914 
915 	rdma_param = &event->param.conn;
916 	if (rdma_param->private_data == NULL ||
917 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
918 		SPDK_ERRLOG("connect request: no private data provided\n");
919 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
920 		return -1;
921 	}
922 
923 	private_data = rdma_param->private_data;
924 	if (private_data->recfmt != 0) {
925 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
926 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
927 		return -1;
928 	}
929 
930 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
931 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
932 
933 	port = event->listen_id->context;
934 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
935 		      event->listen_id, event->listen_id->verbs, port);
936 
937 	/* Figure out the supported queue depth. This is a multi-step process
938 	 * that takes into account hardware maximums, host provided values,
939 	 * and our target's internal memory limits */
940 
941 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
942 
943 	/* Start with the maximum queue depth allowed by the target */
944 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
945 	max_rw_depth = rtransport->transport.opts.max_queue_depth;
946 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
947 		      rtransport->transport.opts.max_queue_depth);
948 
949 	/* Next check the local NIC's hardware limitations */
950 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
951 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
952 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
953 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
954 	max_rw_depth = spdk_min(max_rw_depth, port->device->attr.max_qp_rd_atom);
955 
956 	/* Next check the remote NIC's hardware limitations */
957 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
958 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
959 		      rdma_param->initiator_depth, rdma_param->responder_resources);
960 	if (rdma_param->initiator_depth > 0) {
961 		max_rw_depth = spdk_min(max_rw_depth, rdma_param->initiator_depth);
962 	}
963 
964 	/* Finally check for the host software requested values, which are
965 	 * optional. */
966 	if (rdma_param->private_data != NULL &&
967 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
968 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
969 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
970 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
971 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
972 	}
973 
974 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
975 		      max_queue_depth, max_rw_depth);
976 
977 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
978 	if (rqpair == NULL) {
979 		SPDK_ERRLOG("Could not allocate new connection.\n");
980 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
981 		return -1;
982 	}
983 
984 	rqpair->port = port;
985 	rqpair->max_queue_depth = max_queue_depth;
986 	rqpair->max_rw_depth = max_rw_depth;
987 	rqpair->cm_id = event->id;
988 	rqpair->listen_id = event->listen_id;
989 	rqpair->qpair.transport = transport;
990 	rqpair->max_sge = spdk_min(port->device->attr.max_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
991 	TAILQ_INIT(&rqpair->incoming_queue);
992 	event->id->context = &rqpair->qpair;
993 
994 	cb_fn(&rqpair->qpair);
995 
996 	return 0;
997 }
998 
999 static void
1000 _nvmf_rdma_disconnect(void *ctx)
1001 {
1002 	struct spdk_nvmf_qpair *qpair = ctx;
1003 	struct spdk_nvmf_rdma_qpair *rqpair;
1004 
1005 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1006 
1007 	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);
1008 
1009 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
1010 }
1011 
1012 static int
1013 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
1014 {
1015 	struct spdk_nvmf_qpair		*qpair;
1016 	struct spdk_nvmf_rdma_qpair	*rqpair;
1017 
1018 	if (evt->id == NULL) {
1019 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
1020 		return -1;
1021 	}
1022 
1023 	qpair = evt->id->context;
1024 	if (qpair == NULL) {
1025 		SPDK_ERRLOG("disconnect request: no active connection\n");
1026 		return -1;
1027 	}
1028 
1029 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1030 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1031 	spdk_nvmf_rdma_update_ibv_state(rqpair);
1032 
1033 	spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
1034 
1035 	spdk_thread_send_msg(qpair->group->thread, _nvmf_rdma_disconnect, qpair);
1036 
1037 	return 0;
1038 }
1039 
1040 #ifdef DEBUG
1041 static const char *CM_EVENT_STR[] = {
1042 	"RDMA_CM_EVENT_ADDR_RESOLVED",
1043 	"RDMA_CM_EVENT_ADDR_ERROR",
1044 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
1045 	"RDMA_CM_EVENT_ROUTE_ERROR",
1046 	"RDMA_CM_EVENT_CONNECT_REQUEST",
1047 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
1048 	"RDMA_CM_EVENT_CONNECT_ERROR",
1049 	"RDMA_CM_EVENT_UNREACHABLE",
1050 	"RDMA_CM_EVENT_REJECTED",
1051 	"RDMA_CM_EVENT_ESTABLISHED",
1052 	"RDMA_CM_EVENT_DISCONNECTED",
1053 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
1054 	"RDMA_CM_EVENT_MULTICAST_JOIN",
1055 	"RDMA_CM_EVENT_MULTICAST_ERROR",
1056 	"RDMA_CM_EVENT_ADDR_CHANGE",
1057 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
1058 };
1059 #endif /* DEBUG */
1060 
1061 static void
1062 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
1063 {
1064 	struct spdk_nvmf_rdma_transport *rtransport;
1065 	struct rdma_cm_event		*event;
1066 	int				rc;
1067 
1068 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1069 
1070 	if (rtransport->event_channel == NULL) {
1071 		return;
1072 	}
1073 
1074 	while (1) {
1075 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
1076 		if (rc == 0) {
1077 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
1078 
1079 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
1080 
1081 			switch (event->event) {
1082 			case RDMA_CM_EVENT_ADDR_RESOLVED:
1083 			case RDMA_CM_EVENT_ADDR_ERROR:
1084 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
1085 			case RDMA_CM_EVENT_ROUTE_ERROR:
1086 				/* No action required. The target never attempts to resolve routes. */
1087 				break;
1088 			case RDMA_CM_EVENT_CONNECT_REQUEST:
1089 				rc = nvmf_rdma_connect(transport, event, cb_fn);
1090 				if (rc < 0) {
1091 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
1092 					break;
1093 				}
1094 				break;
1095 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
1096 				/* The target never initiates a new connection. So this will not occur. */
1097 				break;
1098 			case RDMA_CM_EVENT_CONNECT_ERROR:
1099 				/* Can this happen? The docs say it can, but not sure what causes it. */
1100 				break;
1101 			case RDMA_CM_EVENT_UNREACHABLE:
1102 			case RDMA_CM_EVENT_REJECTED:
1103 				/* These only occur on the client side. */
1104 				break;
1105 			case RDMA_CM_EVENT_ESTABLISHED:
1106 				/* TODO: Should we be waiting for this event anywhere? */
1107 				break;
1108 			case RDMA_CM_EVENT_DISCONNECTED:
1109 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
1110 				rc = nvmf_rdma_disconnect(event);
1111 				if (rc < 0) {
1112 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
1113 					break;
1114 				}
1115 				break;
1116 			case RDMA_CM_EVENT_MULTICAST_JOIN:
1117 			case RDMA_CM_EVENT_MULTICAST_ERROR:
1118 				/* Multicast is not used */
1119 				break;
1120 			case RDMA_CM_EVENT_ADDR_CHANGE:
1121 				/* Not utilizing this event */
1122 				break;
1123 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1124 				/* For now, do nothing. The target never re-uses queue pairs. */
1125 				break;
1126 			default:
1127 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
1128 				break;
1129 			}
1130 
1131 			rdma_ack_cm_event(event);
1132 		} else {
1133 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
1134 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
1135 			}
1136 			break;
1137 		}
1138 	}
1139 }
1140 
1141 static int
1142 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1143 			  enum spdk_mem_map_notify_action action,
1144 			  void *vaddr, size_t size)
1145 {
1146 	struct spdk_nvmf_rdma_device *device = cb_ctx;
1147 	struct ibv_pd *pd = device->pd;
1148 	struct ibv_mr *mr;
1149 
1150 	switch (action) {
1151 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1152 		mr = ibv_reg_mr(pd, vaddr, size,
1153 				IBV_ACCESS_LOCAL_WRITE |
1154 				IBV_ACCESS_REMOTE_READ |
1155 				IBV_ACCESS_REMOTE_WRITE);
1156 		if (mr == NULL) {
1157 			SPDK_ERRLOG("ibv_reg_mr() failed\n");
1158 			return -1;
1159 		} else {
1160 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1161 		}
1162 		break;
1163 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1164 		mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1165 		spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1166 		if (mr) {
1167 			ibv_dereg_mr(mr);
1168 		}
1169 		break;
1170 	}
1171 
1172 	return 0;
1173 }
1174 
1175 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1176 
1177 static spdk_nvme_data_transfer_t
1178 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1179 {
1180 	enum spdk_nvme_data_transfer xfer;
1181 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1182 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1183 
1184 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1185 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1186 	rdma_req->rsp.wr.imm_data = 0;
1187 #endif
1188 
1189 	/* Figure out data transfer direction */
1190 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1191 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1192 	} else {
1193 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1194 
1195 		/* Some admin commands are special cases */
1196 		if ((rdma_req->req.qpair->qid == 0) &&
1197 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1198 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1199 			switch (cmd->cdw10 & 0xff) {
1200 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1201 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1202 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1203 				break;
1204 			default:
1205 				xfer = SPDK_NVME_DATA_NONE;
1206 			}
1207 		}
1208 	}
1209 
1210 	if (xfer == SPDK_NVME_DATA_NONE) {
1211 		return xfer;
1212 	}
1213 
1214 	/* Even for commands that may transfer data, they could have specified 0 length.
1215 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1216 	 */
1217 	switch (sgl->generic.type) {
1218 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1219 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1220 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1221 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1222 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1223 		if (sgl->unkeyed.length == 0) {
1224 			xfer = SPDK_NVME_DATA_NONE;
1225 		}
1226 		break;
1227 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1228 		if (sgl->keyed.length == 0) {
1229 			xfer = SPDK_NVME_DATA_NONE;
1230 		}
1231 		break;
1232 	}
1233 
1234 	return xfer;
1235 }
1236 
1237 static int
1238 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1239 				 struct spdk_nvmf_rdma_device *device,
1240 				 struct spdk_nvmf_rdma_request *rdma_req)
1241 {
1242 	void		*buf = NULL;
1243 	uint32_t	length = rdma_req->req.length;
1244 	uint32_t	i = 0;
1245 
1246 	rdma_req->req.iovcnt = 0;
1247 	while (length) {
1248 		buf = spdk_mempool_get(rtransport->data_buf_pool);
1249 		if (!buf) {
1250 			goto nomem;
1251 		}
1252 
1253 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
1254 						~NVMF_DATA_BUFFER_MASK);
1255 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->transport.opts.io_unit_size);
1256 		rdma_req->req.iovcnt++;
1257 		rdma_req->data.buffers[i] = buf;
1258 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
1259 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
1260 		rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1261 						     (uint64_t)buf, NULL))->lkey;
1262 
1263 		length -= rdma_req->req.iov[i].iov_len;
1264 		i++;
1265 	}
1266 
1267 	rdma_req->data_from_pool = true;
1268 
1269 	return 0;
1270 
1271 nomem:
1272 	while (i) {
1273 		i--;
1274 		spdk_mempool_put(rtransport->data_buf_pool, rdma_req->req.iov[i].iov_base);
1275 		rdma_req->req.iov[i].iov_base = NULL;
1276 		rdma_req->req.iov[i].iov_len = 0;
1277 
1278 		rdma_req->data.wr.sg_list[i].addr = 0;
1279 		rdma_req->data.wr.sg_list[i].length = 0;
1280 		rdma_req->data.wr.sg_list[i].lkey = 0;
1281 	}
1282 	rdma_req->req.iovcnt = 0;
1283 	return -ENOMEM;
1284 }
1285 
1286 static int
1287 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1288 				 struct spdk_nvmf_rdma_device *device,
1289 				 struct spdk_nvmf_rdma_request *rdma_req)
1290 {
1291 	struct spdk_nvme_cmd			*cmd;
1292 	struct spdk_nvme_cpl			*rsp;
1293 	struct spdk_nvme_sgl_descriptor		*sgl;
1294 
1295 	cmd = &rdma_req->req.cmd->nvme_cmd;
1296 	rsp = &rdma_req->req.rsp->nvme_cpl;
1297 	sgl = &cmd->dptr.sgl1;
1298 
1299 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1300 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1301 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1302 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1303 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1304 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1305 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1306 			return -1;
1307 		}
1308 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1309 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1310 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1311 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1312 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1313 			}
1314 		}
1315 #endif
1316 
1317 		/* fill request length and populate iovs */
1318 		rdma_req->req.length = sgl->keyed.length;
1319 
1320 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1321 			/* No available buffers. Queue this request up. */
1322 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1323 			return 0;
1324 		}
1325 
1326 		/* backward compatible */
1327 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1328 
1329 		/* rdma wr specifics */
1330 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1331 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1332 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1333 
1334 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1335 			      rdma_req->req.iovcnt);
1336 
1337 		return 0;
1338 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1339 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1340 		uint64_t offset = sgl->address;
1341 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1342 
1343 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1344 			      offset, sgl->unkeyed.length);
1345 
1346 		if (offset > max_len) {
1347 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1348 				    offset, max_len);
1349 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1350 			return -1;
1351 		}
1352 		max_len -= (uint32_t)offset;
1353 
1354 		if (sgl->unkeyed.length > max_len) {
1355 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1356 				    sgl->unkeyed.length, max_len);
1357 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1358 			return -1;
1359 		}
1360 
1361 		rdma_req->req.data = rdma_req->recv->buf + offset;
1362 		rdma_req->data_from_pool = false;
1363 		rdma_req->req.length = sgl->unkeyed.length;
1364 
1365 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1366 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1367 		rdma_req->req.iovcnt = 1;
1368 
1369 		return 0;
1370 	}
1371 
1372 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1373 		    sgl->generic.type, sgl->generic.subtype);
1374 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1375 	return -1;
1376 }
1377 
1378 static bool
1379 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1380 			       struct spdk_nvmf_rdma_request *rdma_req)
1381 {
1382 	struct spdk_nvmf_rdma_qpair	*rqpair;
1383 	struct spdk_nvmf_rdma_device	*device;
1384 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1385 	int				rc;
1386 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1387 	enum spdk_nvmf_rdma_request_state prev_state;
1388 	bool				progress = false;
1389 	int				data_posted;
1390 	int				cur_rdma_rw_depth;
1391 
1392 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1393 	device = rqpair->port->device;
1394 
1395 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1396 
1397 	/* If the queue pair is in an error state, force the request to the completed state
1398 	 * to release resources. */
1399 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1400 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1401 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1402 		}
1403 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1404 	}
1405 
1406 	/* The loop here is to allow for several back-to-back state changes. */
1407 	do {
1408 		prev_state = rdma_req->state;
1409 
1410 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1411 
1412 		switch (rdma_req->state) {
1413 		case RDMA_REQUEST_STATE_FREE:
1414 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1415 			 * to escape this state. */
1416 			break;
1417 		case RDMA_REQUEST_STATE_NEW:
1418 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1419 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1420 			rdma_recv = rdma_req->recv;
1421 
1422 			/* The first element of the SGL is the NVMe command */
1423 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1424 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1425 
1426 			TAILQ_REMOVE(&rqpair->incoming_queue, rdma_recv, link);
1427 
1428 			if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR) {
1429 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1430 				break;
1431 			}
1432 
1433 			/* The next state transition depends on the data transfer needs of this request. */
1434 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1435 
1436 			/* If no data to transfer, ready to execute. */
1437 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1438 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1439 				break;
1440 			}
1441 
1442 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEED_BUFFER);
1443 			TAILQ_INSERT_TAIL(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1444 			break;
1445 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1446 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1447 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1448 
1449 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1450 
1451 			if (rdma_req != TAILQ_FIRST(&rqpair->ch->pending_data_buf_queue)) {
1452 				/* This request needs to wait in line to obtain a buffer */
1453 				break;
1454 			}
1455 
1456 			/* Try to get a data buffer */
1457 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1458 			if (rc < 0) {
1459 				TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1460 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1461 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1462 				break;
1463 			}
1464 
1465 			if (!rdma_req->req.data) {
1466 				/* No buffers available. */
1467 				break;
1468 			}
1469 
1470 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1471 
1472 			/* If data is transferring from host to controller and the data didn't
1473 			 * arrive using in capsule data, we need to do a transfer from the host.
1474 			 */
1475 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1476 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1477 				break;
1478 			}
1479 
1480 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1481 			break;
1482 		case RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING:
1483 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING, 0, 0,
1484 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1485 
1486 			if (rdma_req != TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING])) {
1487 				/* This request needs to wait in line to perform RDMA */
1488 				break;
1489 			}
1490 			cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
1491 
1492 			if (cur_rdma_rw_depth >= rqpair->max_rw_depth) {
1493 				/* R/W queue is full, need to wait */
1494 				break;
1495 			}
1496 
1497 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1498 				rc = request_transfer_in(&rdma_req->req);
1499 				if (!rc) {
1500 					spdk_nvmf_rdma_request_set_state(rdma_req,
1501 									 RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
1502 				} else {
1503 					rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1504 					spdk_nvmf_rdma_request_set_state(rdma_req,
1505 									 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1506 				}
1507 			} else if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1508 				/* The data transfer will be kicked off from
1509 				 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
1510 				 */
1511 				spdk_nvmf_rdma_request_set_state(rdma_req,
1512 								 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1513 			} else {
1514 				SPDK_ERRLOG("Cannot perform data transfer, unknown state: %u\n",
1515 					    rdma_req->req.xfer);
1516 				assert(0);
1517 			}
1518 			break;
1519 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1520 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1521 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1522 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1523 			 * to escape this state. */
1524 			break;
1525 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1526 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1527 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1528 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTING);
1529 			spdk_nvmf_request_exec(&rdma_req->req);
1530 			break;
1531 		case RDMA_REQUEST_STATE_EXECUTING:
1532 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1533 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1534 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1535 			 * to escape this state. */
1536 			break;
1537 		case RDMA_REQUEST_STATE_EXECUTED:
1538 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1539 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1540 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1541 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1542 			} else {
1543 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1544 			}
1545 			break;
1546 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1547 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
1548 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1549 			rc = request_transfer_out(&rdma_req->req, &data_posted);
1550 			assert(rc == 0); /* No good way to handle this currently */
1551 			if (rc) {
1552 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1553 			} else {
1554 				spdk_nvmf_rdma_request_set_state(rdma_req,
1555 								 data_posted ?
1556 								 RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
1557 								 RDMA_REQUEST_STATE_COMPLETING);
1558 			}
1559 			break;
1560 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
1561 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
1562 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1563 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1564 			 * to escape this state. */
1565 			break;
1566 		case RDMA_REQUEST_STATE_COMPLETING:
1567 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
1568 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1569 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1570 			 * to escape this state. */
1571 			break;
1572 		case RDMA_REQUEST_STATE_COMPLETED:
1573 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
1574 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1575 
1576 			if (rdma_req->data_from_pool) {
1577 				/* Put the buffer/s back in the pool */
1578 				for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1579 					spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1580 					rdma_req->req.iov[i].iov_base = NULL;
1581 					rdma_req->data.buffers[i] = NULL;
1582 				}
1583 				rdma_req->data_from_pool = false;
1584 			}
1585 			rdma_req->req.length = 0;
1586 			rdma_req->req.iovcnt = 0;
1587 			rdma_req->req.data = NULL;
1588 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
1589 			break;
1590 		case RDMA_REQUEST_NUM_STATES:
1591 		default:
1592 			assert(0);
1593 			break;
1594 		}
1595 
1596 		if (rdma_req->state != prev_state) {
1597 			progress = true;
1598 		}
1599 	} while (rdma_req->state != prev_state);
1600 
1601 	return progress;
1602 }
1603 
1604 /* Public API callbacks begin here */
1605 
1606 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
1607 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
1608 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
1609 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
1610 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
1611 #define SPDK_NVMF_RDMA_DEFAULT_IO_UNIT_SIZE 131072
1612 
1613 static void
1614 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
1615 {
1616 	opts->max_queue_depth =      SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
1617 	opts->max_qpairs_per_ctrlr = SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
1618 	opts->in_capsule_data_size = SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
1619 	opts->max_io_size =          SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
1620 	opts->io_unit_size =         SPDK_NVMF_RDMA_DEFAULT_IO_UNIT_SIZE;
1621 	opts->max_aq_depth =         SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
1622 }
1623 
1624 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
1625 
1626 static struct spdk_nvmf_transport *
1627 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
1628 {
1629 	int rc;
1630 	struct spdk_nvmf_rdma_transport *rtransport;
1631 	struct spdk_nvmf_rdma_device	*device, *tmp;
1632 	struct ibv_context		**contexts;
1633 	uint32_t			i;
1634 	int				flag;
1635 	uint32_t			sge_count;
1636 
1637 	rtransport = calloc(1, sizeof(*rtransport));
1638 	if (!rtransport) {
1639 		return NULL;
1640 	}
1641 
1642 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
1643 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
1644 		free(rtransport);
1645 		return NULL;
1646 	}
1647 
1648 	spdk_io_device_register(rtransport, spdk_nvmf_rdma_mgmt_channel_create,
1649 				spdk_nvmf_rdma_mgmt_channel_destroy,
1650 				sizeof(struct spdk_nvmf_rdma_mgmt_channel),
1651 				"rdma_transport");
1652 
1653 	TAILQ_INIT(&rtransport->devices);
1654 	TAILQ_INIT(&rtransport->ports);
1655 
1656 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1657 
1658 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
1659 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
1660 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
1661 		     "  in_capsule_data_size=%d, max_aq_depth=%d\n",
1662 		     opts->max_queue_depth,
1663 		     opts->max_io_size,
1664 		     opts->max_qpairs_per_ctrlr,
1665 		     opts->io_unit_size,
1666 		     opts->in_capsule_data_size,
1667 		     opts->max_aq_depth);
1668 
1669 	/* I/O unit size cannot be larger than max I/O size */
1670 	if (opts->io_unit_size > opts->max_io_size) {
1671 		opts->io_unit_size = opts->max_io_size;
1672 	}
1673 
1674 	sge_count = opts->max_io_size / opts->io_unit_size;
1675 	if (sge_count > SPDK_NVMF_MAX_SGL_ENTRIES) {
1676 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
1677 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1678 		return NULL;
1679 	}
1680 
1681 	rtransport->event_channel = rdma_create_event_channel();
1682 	if (rtransport->event_channel == NULL) {
1683 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1684 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1685 		return NULL;
1686 	}
1687 
1688 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1689 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1690 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1691 			    rtransport->event_channel->fd, spdk_strerror(errno));
1692 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1693 		return NULL;
1694 	}
1695 
1696 	rtransport->data_buf_pool = spdk_mempool_create("spdk_nvmf_rdma",
1697 				    opts->max_queue_depth * 4, /* The 4 is arbitrarily chosen. Needs to be configurable. */
1698 				    opts->max_io_size + NVMF_DATA_BUFFER_ALIGNMENT,
1699 				    SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1700 				    SPDK_ENV_SOCKET_ID_ANY);
1701 	if (!rtransport->data_buf_pool) {
1702 		SPDK_ERRLOG("Unable to allocate buffer pool for poll group\n");
1703 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1704 		return NULL;
1705 	}
1706 
1707 	contexts = rdma_get_devices(NULL);
1708 	if (contexts == NULL) {
1709 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
1710 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1711 		return NULL;
1712 	}
1713 
1714 	i = 0;
1715 	rc = 0;
1716 	while (contexts[i] != NULL) {
1717 		device = calloc(1, sizeof(*device));
1718 		if (!device) {
1719 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1720 			rc = -ENOMEM;
1721 			break;
1722 		}
1723 		device->context = contexts[i];
1724 		rc = ibv_query_device(device->context, &device->attr);
1725 		if (rc < 0) {
1726 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1727 			free(device);
1728 			break;
1729 
1730 		}
1731 
1732 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1733 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
1734 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
1735 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
1736 		}
1737 
1738 		/**
1739 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
1740 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
1741 		 * but incorrectly reports that it does. There are changes making their way
1742 		 * through the kernel now that will enable this feature. When they are merged,
1743 		 * we can conditionally enable this feature.
1744 		 *
1745 		 * TODO: enable this for versions of the kernel rxe driver that support it.
1746 		 */
1747 		if (device->attr.vendor_id == 0) {
1748 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
1749 		}
1750 #endif
1751 
1752 		/* set up device context async ev fd as NON_BLOCKING */
1753 		flag = fcntl(device->context->async_fd, F_GETFL);
1754 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1755 		if (rc < 0) {
1756 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1757 			free(device);
1758 			break;
1759 		}
1760 
1761 		device->pd = ibv_alloc_pd(device->context);
1762 		if (!device->pd) {
1763 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
1764 			free(device);
1765 			rc = -1;
1766 			break;
1767 		}
1768 
1769 		device->map = spdk_mem_map_alloc(0, spdk_nvmf_rdma_mem_notify, device);
1770 		if (!device->map) {
1771 			SPDK_ERRLOG("Unable to allocate memory map for new poll group\n");
1772 			ibv_dealloc_pd(device->pd);
1773 			free(device);
1774 			rc = -1;
1775 			break;
1776 		}
1777 
1778 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1779 		i++;
1780 	}
1781 	rdma_free_devices(contexts);
1782 
1783 	if (rc < 0) {
1784 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1785 		return NULL;
1786 	}
1787 
1788 	/* Set up poll descriptor array to monitor events from RDMA and IB
1789 	 * in a single poll syscall
1790 	 */
1791 	rtransport->npoll_fds = i + 1;
1792 	i = 0;
1793 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1794 	if (rtransport->poll_fds == NULL) {
1795 		SPDK_ERRLOG("poll_fds allocation failed\n");
1796 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1797 		return NULL;
1798 	}
1799 
1800 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1801 	rtransport->poll_fds[i++].events = POLLIN;
1802 
1803 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1804 		rtransport->poll_fds[i].fd = device->context->async_fd;
1805 		rtransport->poll_fds[i++].events = POLLIN;
1806 	}
1807 
1808 	return &rtransport->transport;
1809 }
1810 
1811 static int
1812 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1813 {
1814 	struct spdk_nvmf_rdma_transport	*rtransport;
1815 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1816 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1817 
1818 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1819 
1820 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1821 		TAILQ_REMOVE(&rtransport->ports, port, link);
1822 		rdma_destroy_id(port->id);
1823 		free(port);
1824 	}
1825 
1826 	if (rtransport->poll_fds != NULL) {
1827 		free(rtransport->poll_fds);
1828 	}
1829 
1830 	if (rtransport->event_channel != NULL) {
1831 		rdma_destroy_event_channel(rtransport->event_channel);
1832 	}
1833 
1834 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1835 		TAILQ_REMOVE(&rtransport->devices, device, link);
1836 		if (device->map) {
1837 			spdk_mem_map_free(&device->map);
1838 		}
1839 		if (device->pd) {
1840 			ibv_dealloc_pd(device->pd);
1841 		}
1842 		free(device);
1843 	}
1844 
1845 	if (rtransport->data_buf_pool != NULL) {
1846 		if (spdk_mempool_count(rtransport->data_buf_pool) !=
1847 		    (transport->opts.max_queue_depth * 4)) {
1848 			SPDK_ERRLOG("transport buffer pool count is %zu but should be %u\n",
1849 				    spdk_mempool_count(rtransport->data_buf_pool),
1850 				    transport->opts.max_queue_depth * 4);
1851 		}
1852 	}
1853 
1854 	spdk_mempool_free(rtransport->data_buf_pool);
1855 	spdk_io_device_unregister(rtransport, NULL);
1856 	pthread_mutex_destroy(&rtransport->lock);
1857 	free(rtransport);
1858 
1859 	return 0;
1860 }
1861 
1862 static int
1863 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1864 		      const struct spdk_nvme_transport_id *trid)
1865 {
1866 	struct spdk_nvmf_rdma_transport	*rtransport;
1867 	struct spdk_nvmf_rdma_device	*device;
1868 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1869 	struct addrinfo			*res;
1870 	struct addrinfo			hints;
1871 	int				family;
1872 	int				rc;
1873 
1874 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1875 
1876 	port = calloc(1, sizeof(*port));
1877 	if (!port) {
1878 		return -ENOMEM;
1879 	}
1880 
1881 	/* Selectively copy the trid. Things like NQN don't matter here - that
1882 	 * mapping is enforced elsewhere.
1883 	 */
1884 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1885 	port->trid.adrfam = trid->adrfam;
1886 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1887 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1888 
1889 	pthread_mutex_lock(&rtransport->lock);
1890 	assert(rtransport->event_channel != NULL);
1891 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1892 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1893 			port_tmp->ref++;
1894 			free(port);
1895 			/* Already listening at this address */
1896 			pthread_mutex_unlock(&rtransport->lock);
1897 			return 0;
1898 		}
1899 	}
1900 
1901 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1902 	if (rc < 0) {
1903 		SPDK_ERRLOG("rdma_create_id() failed\n");
1904 		free(port);
1905 		pthread_mutex_unlock(&rtransport->lock);
1906 		return rc;
1907 	}
1908 
1909 	switch (port->trid.adrfam) {
1910 	case SPDK_NVMF_ADRFAM_IPV4:
1911 		family = AF_INET;
1912 		break;
1913 	case SPDK_NVMF_ADRFAM_IPV6:
1914 		family = AF_INET6;
1915 		break;
1916 	default:
1917 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1918 		free(port);
1919 		pthread_mutex_unlock(&rtransport->lock);
1920 		return -EINVAL;
1921 	}
1922 
1923 	memset(&hints, 0, sizeof(hints));
1924 	hints.ai_family = family;
1925 	hints.ai_flags = AI_NUMERICSERV;
1926 	hints.ai_socktype = SOCK_STREAM;
1927 	hints.ai_protocol = 0;
1928 
1929 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1930 	if (rc) {
1931 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1932 		free(port);
1933 		pthread_mutex_unlock(&rtransport->lock);
1934 		return -EINVAL;
1935 	}
1936 
1937 	rc = rdma_bind_addr(port->id, res->ai_addr);
1938 	freeaddrinfo(res);
1939 
1940 	if (rc < 0) {
1941 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1942 		rdma_destroy_id(port->id);
1943 		free(port);
1944 		pthread_mutex_unlock(&rtransport->lock);
1945 		return rc;
1946 	}
1947 
1948 	if (!port->id->verbs) {
1949 		SPDK_ERRLOG("ibv_context is null\n");
1950 		rdma_destroy_id(port->id);
1951 		free(port);
1952 		pthread_mutex_unlock(&rtransport->lock);
1953 		return -1;
1954 	}
1955 
1956 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
1957 	if (rc < 0) {
1958 		SPDK_ERRLOG("rdma_listen() failed\n");
1959 		rdma_destroy_id(port->id);
1960 		free(port);
1961 		pthread_mutex_unlock(&rtransport->lock);
1962 		return rc;
1963 	}
1964 
1965 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1966 		if (device->context == port->id->verbs) {
1967 			port->device = device;
1968 			break;
1969 		}
1970 	}
1971 	if (!port->device) {
1972 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
1973 			    port->id->verbs);
1974 		rdma_destroy_id(port->id);
1975 		free(port);
1976 		pthread_mutex_unlock(&rtransport->lock);
1977 		return -EINVAL;
1978 	}
1979 
1980 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
1981 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
1982 
1983 	port->ref = 1;
1984 
1985 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
1986 	pthread_mutex_unlock(&rtransport->lock);
1987 
1988 	return 0;
1989 }
1990 
1991 static int
1992 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
1993 			   const struct spdk_nvme_transport_id *_trid)
1994 {
1995 	struct spdk_nvmf_rdma_transport *rtransport;
1996 	struct spdk_nvmf_rdma_port *port, *tmp;
1997 	struct spdk_nvme_transport_id trid = {};
1998 
1999 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2000 
2001 	/* Selectively copy the trid. Things like NQN don't matter here - that
2002 	 * mapping is enforced elsewhere.
2003 	 */
2004 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2005 	trid.adrfam = _trid->adrfam;
2006 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2007 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2008 
2009 	pthread_mutex_lock(&rtransport->lock);
2010 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2011 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2012 			assert(port->ref > 0);
2013 			port->ref--;
2014 			if (port->ref == 0) {
2015 				TAILQ_REMOVE(&rtransport->ports, port, link);
2016 				rdma_destroy_id(port->id);
2017 				free(port);
2018 			}
2019 			break;
2020 		}
2021 	}
2022 
2023 	pthread_mutex_unlock(&rtransport->lock);
2024 	return 0;
2025 }
2026 
2027 static bool
2028 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
2029 {
2030 	int cur_queue_depth, cur_rdma_rw_depth;
2031 	struct spdk_nvmf_rdma_qpair *rqpair;
2032 
2033 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2034 	cur_queue_depth = spdk_nvmf_rdma_cur_queue_depth(rqpair);
2035 	cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
2036 
2037 	if (cur_queue_depth == 0 && cur_rdma_rw_depth == 0) {
2038 		return true;
2039 	}
2040 	return false;
2041 }
2042 
2043 static void
2044 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2045 				     struct spdk_nvmf_rdma_qpair *rqpair)
2046 {
2047 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
2048 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2049 
2050 	/* We process I/O in the data transfer pending queue at the highest priority. */
2051 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING],
2052 			   state_link, req_tmp) {
2053 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2054 			break;
2055 		}
2056 	}
2057 
2058 	/* The second highest priority is I/O waiting on memory buffers. */
2059 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->ch->pending_data_buf_queue, link,
2060 			   req_tmp) {
2061 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2062 			break;
2063 		}
2064 	}
2065 
2066 	if (rqpair->qpair_disconnected) {
2067 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2068 		return;
2069 	}
2070 
2071 	/* Do not process newly received commands if qp is in ERROR state,
2072 	 * wait till the recovery is complete.
2073 	 */
2074 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR) {
2075 		return;
2076 	}
2077 
2078 	/* The lowest priority is processing newly received commands */
2079 	TAILQ_FOREACH_SAFE(rdma_recv, &rqpair->incoming_queue, link, recv_tmp) {
2080 		if (TAILQ_EMPTY(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE])) {
2081 			break;
2082 		}
2083 
2084 		rdma_req = TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE]);
2085 		rdma_req->recv = rdma_recv;
2086 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEW);
2087 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2088 			break;
2089 		}
2090 	}
2091 }
2092 
2093 static void
2094 spdk_nvmf_rdma_drain_state_queue(struct spdk_nvmf_rdma_qpair *rqpair,
2095 				 enum spdk_nvmf_rdma_request_state state)
2096 {
2097 	struct spdk_nvmf_rdma_request *rdma_req, *req_tmp;
2098 	struct spdk_nvmf_rdma_transport *rtransport;
2099 
2100 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[state], state_link, req_tmp) {
2101 		rtransport = SPDK_CONTAINEROF(rdma_req->req.qpair->transport,
2102 					      struct spdk_nvmf_rdma_transport, transport);
2103 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2104 		spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2105 	}
2106 }
2107 
2108 static void
2109 spdk_nvmf_rdma_qpair_recover(struct spdk_nvmf_rdma_qpair *rqpair)
2110 {
2111 	enum ibv_qp_state state, next_state;
2112 	int recovered;
2113 	struct spdk_nvmf_rdma_transport *rtransport;
2114 
2115 	if (!spdk_nvmf_rdma_qpair_is_idle(&rqpair->qpair)) {
2116 		/* There must be outstanding requests down to media.
2117 		 * If so, wait till they're complete.
2118 		 */
2119 		assert(!TAILQ_EMPTY(&rqpair->qpair.outstanding));
2120 		return;
2121 	}
2122 
2123 	state = rqpair->ibv_attr.qp_state;
2124 	next_state = state;
2125 
2126 	SPDK_NOTICELOG("RDMA qpair %u is in state: %s\n",
2127 		       rqpair->qpair.qid,
2128 		       str_ibv_qp_state[state]);
2129 
2130 	if (!(state == IBV_QPS_ERR || state == IBV_QPS_RESET)) {
2131 		SPDK_ERRLOG("Can't recover RDMA qpair %u from the state: %s\n",
2132 			    rqpair->qpair.qid,
2133 			    str_ibv_qp_state[state]);
2134 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2135 		return;
2136 	}
2137 
2138 	recovered = 0;
2139 	while (!recovered) {
2140 		switch (state) {
2141 		case IBV_QPS_ERR:
2142 			next_state = IBV_QPS_RESET;
2143 			break;
2144 		case IBV_QPS_RESET:
2145 			next_state = IBV_QPS_INIT;
2146 			break;
2147 		case IBV_QPS_INIT:
2148 			next_state = IBV_QPS_RTR;
2149 			break;
2150 		case IBV_QPS_RTR:
2151 			next_state = IBV_QPS_RTS;
2152 			break;
2153 		case IBV_QPS_RTS:
2154 			recovered = 1;
2155 			break;
2156 		default:
2157 			SPDK_ERRLOG("RDMA qpair %u unexpected state for recovery: %u\n",
2158 				    rqpair->qpair.qid, state);
2159 			goto error;
2160 		}
2161 		/* Do not transition into same state */
2162 		if (next_state == state) {
2163 			break;
2164 		}
2165 
2166 		if (spdk_nvmf_rdma_set_ibv_state(rqpair, next_state)) {
2167 			goto error;
2168 		}
2169 
2170 		state = next_state;
2171 	}
2172 
2173 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2174 				      struct spdk_nvmf_rdma_transport,
2175 				      transport);
2176 
2177 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2178 
2179 	return;
2180 error:
2181 	SPDK_NOTICELOG("RDMA qpair %u: recovery failed, disconnecting...\n",
2182 		       rqpair->qpair.qid);
2183 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2184 }
2185 
2186 /* Clean up only the states that can be aborted at any time */
2187 static void
2188 _spdk_nvmf_rdma_qp_cleanup_safe_states(struct spdk_nvmf_rdma_qpair *rqpair)
2189 {
2190 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2191 
2192 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_NEW);
2193 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[RDMA_REQUEST_STATE_NEED_BUFFER], link, req_tmp) {
2194 		TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
2195 	}
2196 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_NEED_BUFFER);
2197 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
2198 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
2199 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_EXECUTED);
2200 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
2201 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_COMPLETED);
2202 }
2203 
2204 /* This cleans up all memory. It is only safe to use if the rest of the software stack
2205  * has been shut down */
2206 static void
2207 _spdk_nvmf_rdma_qp_cleanup_all_states(struct spdk_nvmf_rdma_qpair *rqpair)
2208 {
2209 	_spdk_nvmf_rdma_qp_cleanup_safe_states(rqpair);
2210 
2211 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_EXECUTING);
2212 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2213 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST);
2214 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_COMPLETING);
2215 }
2216 
2217 static void
2218 _spdk_nvmf_rdma_qp_error(void *arg)
2219 {
2220 	struct spdk_nvmf_rdma_qpair	*rqpair = arg;
2221 	enum ibv_qp_state		state;
2222 
2223 	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);
2224 
2225 	state = rqpair->ibv_attr.qp_state;
2226 	if (state != IBV_QPS_ERR) {
2227 		/* Error was already recovered */
2228 		return;
2229 	}
2230 
2231 	if (spdk_nvmf_qpair_is_admin_queue(&rqpair->qpair)) {
2232 		spdk_nvmf_ctrlr_abort_aer(rqpair->qpair.ctrlr);
2233 	}
2234 
2235 	_spdk_nvmf_rdma_qp_cleanup_safe_states(rqpair);
2236 
2237 	/* Attempt recovery. This will exit without recovering if I/O requests
2238 	 * are still outstanding */
2239 	spdk_nvmf_rdma_qpair_recover(rqpair);
2240 }
2241 
2242 static void
2243 _spdk_nvmf_rdma_qp_last_wqe(void *arg)
2244 {
2245 	struct spdk_nvmf_rdma_qpair	*rqpair = arg;
2246 	enum ibv_qp_state		state;
2247 
2248 	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);
2249 
2250 	state = rqpair->ibv_attr.qp_state;
2251 	if (state != IBV_QPS_ERR) {
2252 		/* Error was already recovered */
2253 		return;
2254 	}
2255 
2256 	/* Clear out the states that are safe to clear any time, plus the
2257 	 * RDMA data transfer states. */
2258 	_spdk_nvmf_rdma_qp_cleanup_safe_states(rqpair);
2259 
2260 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2261 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST);
2262 	spdk_nvmf_rdma_drain_state_queue(rqpair, RDMA_REQUEST_STATE_COMPLETING);
2263 
2264 	spdk_nvmf_rdma_qpair_recover(rqpair);
2265 }
2266 
2267 static void
2268 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2269 {
2270 	int				rc;
2271 	struct spdk_nvmf_rdma_qpair	*rqpair;
2272 	struct ibv_async_event		event;
2273 	enum ibv_qp_state		state;
2274 
2275 	rc = ibv_get_async_event(device->context, &event);
2276 
2277 	if (rc) {
2278 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2279 			    errno, spdk_strerror(errno));
2280 		return;
2281 	}
2282 
2283 	SPDK_NOTICELOG("Async event: %s\n",
2284 		       ibv_event_type_str(event.event_type));
2285 
2286 	switch (event.event_type) {
2287 	case IBV_EVENT_QP_FATAL:
2288 		rqpair = event.element.qp->qp_context;
2289 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2290 				  (uintptr_t)rqpair->cm_id, event.event_type);
2291 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2292 		spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2293 		spdk_thread_send_msg(rqpair->qpair.group->thread, _spdk_nvmf_rdma_qp_error, rqpair);
2294 		break;
2295 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2296 		rqpair = event.element.qp->qp_context;
2297 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2298 				  (uintptr_t)rqpair->cm_id, event.event_type);
2299 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2300 		spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2301 		spdk_thread_send_msg(rqpair->qpair.group->thread, _spdk_nvmf_rdma_qp_last_wqe, rqpair);
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