xref: /spdk/lib/nvmf/rdma.c (revision 5977aad8f7486552c94c5cc93ea9bb110e1cb5d0)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2018 Mellanox Technologies LTD. All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include <infiniband/verbs.h>
37 #include <rdma/rdma_cma.h>
38 #include <rdma/rdma_verbs.h>
39 
40 #include "nvmf_internal.h"
41 #include "transport.h"
42 
43 #include "spdk/config.h"
44 #include "spdk/assert.h"
45 #include "spdk/thread.h"
46 #include "spdk/nvmf.h"
47 #include "spdk/nvmf_spec.h"
48 #include "spdk/string.h"
49 #include "spdk/trace.h"
50 #include "spdk/util.h"
51 
52 #include "spdk_internal/log.h"
53 
54 /*
55  RDMA Connection Resource Defaults
56  */
57 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
58 #define NVMF_DEFAULT_RSP_SGE		1
59 #define NVMF_DEFAULT_RX_SGE		2
60 
61 /* The RDMA completion queue size */
62 #define NVMF_RDMA_CQ_SIZE	4096
63 
64 /* AIO backend requires block size aligned data buffers,
65  * extra 4KiB aligned data buffer should work for most devices.
66  */
67 #define SHIFT_4KB			12
68 #define NVMF_DATA_BUFFER_ALIGNMENT	(1 << SHIFT_4KB)
69 #define NVMF_DATA_BUFFER_MASK		(NVMF_DATA_BUFFER_ALIGNMENT - 1)
70 
71 enum spdk_nvmf_rdma_request_state {
72 	/* The request is not currently in use */
73 	RDMA_REQUEST_STATE_FREE = 0,
74 
75 	/* Initial state when request first received */
76 	RDMA_REQUEST_STATE_NEW,
77 
78 	/* The request is queued until a data buffer is available. */
79 	RDMA_REQUEST_STATE_NEED_BUFFER,
80 
81 	/* The request is waiting on RDMA queue depth availability
82 	 * to transfer data between the host and the controller.
83 	 */
84 	RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
85 
86 	/* The request is currently transferring data from the host to the controller. */
87 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
88 
89 	/* The request is ready to execute at the block device */
90 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
91 
92 	/* The request is currently executing at the block device */
93 	RDMA_REQUEST_STATE_EXECUTING,
94 
95 	/* The request finished executing at the block device */
96 	RDMA_REQUEST_STATE_EXECUTED,
97 
98 	/* The request is ready to send a completion */
99 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
100 
101 	/* The request is currently transferring data from the controller to the host. */
102 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
103 
104 	/* The request currently has an outstanding completion without an
105 	 * associated data transfer.
106 	 */
107 	RDMA_REQUEST_STATE_COMPLETING,
108 
109 	/* The request completed and can be marked free. */
110 	RDMA_REQUEST_STATE_COMPLETED,
111 
112 	/* Terminator */
113 	RDMA_REQUEST_NUM_STATES,
114 };
115 
116 #define OBJECT_NVMF_RDMA_IO				0x40
117 
118 #define TRACE_GROUP_NVMF_RDMA				0x4
119 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
120 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
121 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
122 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
123 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
124 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
125 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
126 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
127 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
128 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
129 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
130 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
131 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
132 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
133 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
134 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
135 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
136 
137 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
138 {
139 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
140 	spdk_trace_register_description("RDMA_REQ_NEW", "",
141 					TRACE_RDMA_REQUEST_STATE_NEW,
142 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
143 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
144 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
145 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
146 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
147 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
148 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
149 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
150 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
151 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
152 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
153 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
154 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
155 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
156 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
157 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
158 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
159 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
160 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
161 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
162 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
163 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
164 	spdk_trace_register_description("RDMA_REQ_COMPLETING_CONTROLLER_TO_HOST", "",
165 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_COMPLETING_INCAPSULE", "",
168 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
169 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
170 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
171 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
172 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
173 
174 	spdk_trace_register_description("RDMA_QP_CREATE", "", TRACE_RDMA_QP_CREATE,
175 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
176 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", "", TRACE_RDMA_IBV_ASYNC_EVENT,
177 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
178 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", "", TRACE_RDMA_CM_ASYNC_EVENT,
179 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
180 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", "", TRACE_RDMA_QP_STATE_CHANGE,
181 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
182 	spdk_trace_register_description("RDMA_QP_DISCONNECT", "", TRACE_RDMA_QP_DISCONNECT,
183 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
184 	spdk_trace_register_description("RDMA_QP_DESTROY", "", TRACE_RDMA_QP_DESTROY,
185 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
186 }
187 
188 enum spdk_nvmf_rdma_wr_type {
189 	RDMA_WR_TYPE_RECV,
190 	RDMA_WR_TYPE_SEND,
191 	RDMA_WR_TYPE_DATA,
192 	RDMA_WR_TYPE_DRAIN_SEND,
193 	RDMA_WR_TYPE_DRAIN_RECV
194 };
195 
196 struct spdk_nvmf_rdma_wr {
197 	enum spdk_nvmf_rdma_wr_type	type;
198 };
199 
200 /* This structure holds commands as they are received off the wire.
201  * It must be dynamically paired with a full request object
202  * (spdk_nvmf_rdma_request) to service a request. It is separate
203  * from the request because RDMA does not appear to order
204  * completions, so occasionally we'll get a new incoming
205  * command when there aren't any free request objects.
206  */
207 struct spdk_nvmf_rdma_recv {
208 	struct ibv_recv_wr		wr;
209 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
210 
211 	struct spdk_nvmf_rdma_qpair	*qpair;
212 
213 	/* In-capsule data buffer */
214 	uint8_t				*buf;
215 
216 	struct spdk_nvmf_rdma_wr	rdma_wr;
217 
218 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
219 };
220 
221 struct spdk_nvmf_rdma_request {
222 	struct spdk_nvmf_request		req;
223 	bool					data_from_pool;
224 
225 	enum spdk_nvmf_rdma_request_state	state;
226 
227 	struct spdk_nvmf_rdma_recv		*recv;
228 
229 	struct {
230 		struct spdk_nvmf_rdma_wr	rdma_wr;
231 		struct	ibv_send_wr		wr;
232 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
233 	} rsp;
234 
235 	struct {
236 		struct spdk_nvmf_rdma_wr	rdma_wr;
237 		struct ibv_send_wr		wr;
238 		struct ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
239 		void				*buffers[NVMF_DEFAULT_TX_SGE];
240 	} data;
241 
242 	struct spdk_nvmf_rdma_wr		rdma_wr;
243 
244 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
245 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
246 };
247 
248 enum spdk_nvmf_rdma_qpair_disconnect_flags {
249 	RDMA_QP_DISCONNECTING		= 1,
250 	RDMA_QP_RECV_DRAINED		= 1 << 1,
251 	RDMA_QP_SEND_DRAINED		= 1 << 2
252 };
253 
254 struct spdk_nvmf_rdma_qpair {
255 	struct spdk_nvmf_qpair			qpair;
256 
257 	struct spdk_nvmf_rdma_port		*port;
258 	struct spdk_nvmf_rdma_poller		*poller;
259 
260 	struct rdma_cm_id			*cm_id;
261 	struct rdma_cm_id			*listen_id;
262 
263 	/* The maximum number of I/O outstanding on this connection at one time */
264 	uint16_t				max_queue_depth;
265 
266 	/* The maximum number of active RDMA READ and WRITE operations at one time */
267 	uint16_t				max_rw_depth;
268 
269 	/* The maximum number of SGEs per WR on the send queue */
270 	uint32_t				max_send_sge;
271 
272 	/* The maximum number of SGEs per WR on the recv queue */
273 	uint32_t				max_recv_sge;
274 
275 	/* Receives that are waiting for a request object */
276 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
277 
278 	/* Queues to track the requests in all states */
279 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	state_queue[RDMA_REQUEST_NUM_STATES];
280 
281 	/* Number of requests in each state */
282 	uint32_t				state_cntr[RDMA_REQUEST_NUM_STATES];
283 
284 	/* Array of size "max_queue_depth" containing RDMA requests. */
285 	struct spdk_nvmf_rdma_request		*reqs;
286 
287 	/* Array of size "max_queue_depth" containing RDMA recvs. */
288 	struct spdk_nvmf_rdma_recv		*recvs;
289 
290 	/* Array of size "max_queue_depth" containing 64 byte capsules
291 	 * used for receive.
292 	 */
293 	union nvmf_h2c_msg			*cmds;
294 	struct ibv_mr				*cmds_mr;
295 
296 	/* Array of size "max_queue_depth" containing 16 byte completions
297 	 * to be sent back to the user.
298 	 */
299 	union nvmf_c2h_msg			*cpls;
300 	struct ibv_mr				*cpls_mr;
301 
302 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
303 	 * buffers to be used for in capsule data.
304 	 */
305 	void					*bufs;
306 	struct ibv_mr				*bufs_mr;
307 
308 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
309 
310 	/* Mgmt channel */
311 	struct spdk_io_channel			*mgmt_channel;
312 	struct spdk_nvmf_rdma_mgmt_channel	*ch;
313 
314 	/* IBV queue pair attributes: they are used to manage
315 	 * qp state and recover from errors.
316 	 */
317 	struct ibv_qp_attr			ibv_attr;
318 
319 	uint32_t				disconnect_flags;
320 	struct spdk_nvmf_rdma_wr		drain_send_wr;
321 	struct spdk_nvmf_rdma_wr		drain_recv_wr;
322 
323 	/* Reference counter for how many unprocessed messages
324 	 * from other threads are currently outstanding. The
325 	 * qpair cannot be destroyed until this is 0. This is
326 	 * atomically incremented from any thread, but only
327 	 * decremented and read from the thread that owns this
328 	 * qpair.
329 	 */
330 	uint32_t				refcnt;
331 };
332 
333 struct spdk_nvmf_rdma_poller {
334 	struct spdk_nvmf_rdma_device		*device;
335 	struct spdk_nvmf_rdma_poll_group	*group;
336 
337 	struct ibv_cq				*cq;
338 
339 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
340 
341 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
342 };
343 
344 struct spdk_nvmf_rdma_poll_group {
345 	struct spdk_nvmf_transport_poll_group	group;
346 
347 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
348 };
349 
350 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
351 struct spdk_nvmf_rdma_device {
352 	struct ibv_device_attr			attr;
353 	struct ibv_context			*context;
354 
355 	struct spdk_mem_map			*map;
356 	struct ibv_pd				*pd;
357 
358 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
359 };
360 
361 struct spdk_nvmf_rdma_port {
362 	struct spdk_nvme_transport_id		trid;
363 	struct rdma_cm_id			*id;
364 	struct spdk_nvmf_rdma_device		*device;
365 	uint32_t				ref;
366 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
367 };
368 
369 struct spdk_nvmf_rdma_transport {
370 	struct spdk_nvmf_transport	transport;
371 
372 	struct rdma_event_channel	*event_channel;
373 
374 	struct spdk_mempool		*data_buf_pool;
375 
376 	pthread_mutex_t			lock;
377 
378 	/* fields used to poll RDMA/IB events */
379 	nfds_t			npoll_fds;
380 	struct pollfd		*poll_fds;
381 
382 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
383 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
384 };
385 
386 struct spdk_nvmf_rdma_mgmt_channel {
387 	/* Requests that are waiting to obtain a data buffer */
388 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
389 };
390 
391 static inline void
392 spdk_nvmf_rdma_qpair_inc_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
393 {
394 	__sync_fetch_and_add(&rqpair->refcnt, 1);
395 }
396 
397 static inline uint32_t
398 spdk_nvmf_rdma_qpair_dec_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
399 {
400 	uint32_t old_refcnt, new_refcnt;
401 
402 	do {
403 		old_refcnt = rqpair->refcnt;
404 		assert(old_refcnt > 0);
405 		new_refcnt = old_refcnt - 1;
406 	} while (__sync_bool_compare_and_swap(&rqpair->refcnt, old_refcnt, new_refcnt) == false);
407 
408 	return new_refcnt;
409 }
410 
411 static inline int
412 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
413 {
414 	switch (state) {
415 	case IBV_QPS_RESET:
416 	case IBV_QPS_INIT:
417 	case IBV_QPS_RTR:
418 	case IBV_QPS_RTS:
419 	case IBV_QPS_SQD:
420 	case IBV_QPS_SQE:
421 	case IBV_QPS_ERR:
422 		return 0;
423 	default:
424 		return -1;
425 	}
426 }
427 
428 static enum ibv_qp_state
429 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
430 	enum ibv_qp_state old_state, new_state;
431 	struct ibv_qp_init_attr init_attr;
432 	int rc;
433 
434 	/* All the attributes needed for recovery */
435 	static int spdk_nvmf_ibv_attr_mask =
436 	IBV_QP_STATE |
437 	IBV_QP_PKEY_INDEX |
438 	IBV_QP_PORT |
439 	IBV_QP_ACCESS_FLAGS |
440 	IBV_QP_AV |
441 	IBV_QP_PATH_MTU |
442 	IBV_QP_DEST_QPN |
443 	IBV_QP_RQ_PSN |
444 	IBV_QP_MAX_DEST_RD_ATOMIC |
445 	IBV_QP_MIN_RNR_TIMER |
446 	IBV_QP_SQ_PSN |
447 	IBV_QP_TIMEOUT |
448 	IBV_QP_RETRY_CNT |
449 	IBV_QP_RNR_RETRY |
450 	IBV_QP_MAX_QP_RD_ATOMIC;
451 
452 	old_state = rqpair->ibv_attr.qp_state;
453 	rc = ibv_query_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
454 			  spdk_nvmf_ibv_attr_mask, &init_attr);
455 
456 	if (rc)
457 	{
458 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
459 		assert(false);
460 	}
461 
462 	new_state = rqpair->ibv_attr.qp_state;
463 
464 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
465 	if (rc)
466 	{
467 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
468 		/*
469 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
470 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
471 		 */
472 		return IBV_QPS_ERR + 1;
473 	}
474 
475 	if (old_state != new_state)
476 	{
477 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
478 				  (uintptr_t)rqpair->cm_id, new_state);
479 	}
480 	return new_state;
481 }
482 
483 static const char *str_ibv_qp_state[] = {
484 	"IBV_QPS_RESET",
485 	"IBV_QPS_INIT",
486 	"IBV_QPS_RTR",
487 	"IBV_QPS_RTS",
488 	"IBV_QPS_SQD",
489 	"IBV_QPS_SQE",
490 	"IBV_QPS_ERR",
491 	"IBV_QPS_UNKNOWN"
492 };
493 
494 static int
495 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
496 			     enum ibv_qp_state new_state)
497 {
498 	int rc;
499 	enum ibv_qp_state state;
500 	static int attr_mask_rc[] = {
501 		[IBV_QPS_RESET] = IBV_QP_STATE,
502 		[IBV_QPS_INIT] = (IBV_QP_STATE |
503 				  IBV_QP_PKEY_INDEX |
504 				  IBV_QP_PORT |
505 				  IBV_QP_ACCESS_FLAGS),
506 		[IBV_QPS_RTR] = (IBV_QP_STATE |
507 				 IBV_QP_AV |
508 				 IBV_QP_PATH_MTU |
509 				 IBV_QP_DEST_QPN |
510 				 IBV_QP_RQ_PSN |
511 				 IBV_QP_MAX_DEST_RD_ATOMIC |
512 				 IBV_QP_MIN_RNR_TIMER),
513 		[IBV_QPS_RTS] = (IBV_QP_STATE |
514 				 IBV_QP_SQ_PSN |
515 				 IBV_QP_TIMEOUT |
516 				 IBV_QP_RETRY_CNT |
517 				 IBV_QP_RNR_RETRY |
518 				 IBV_QP_MAX_QP_RD_ATOMIC),
519 		[IBV_QPS_SQD] = IBV_QP_STATE,
520 		[IBV_QPS_SQE] = IBV_QP_STATE,
521 		[IBV_QPS_ERR] = IBV_QP_STATE,
522 	};
523 
524 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
525 	if (rc) {
526 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
527 			    rqpair->qpair.qid, new_state);
528 		return rc;
529 	}
530 
531 	rqpair->ibv_attr.cur_qp_state = rqpair->ibv_attr.qp_state;
532 	rqpair->ibv_attr.qp_state = new_state;
533 	rqpair->ibv_attr.ah_attr.port_num = rqpair->ibv_attr.port_num;
534 
535 	rc = ibv_modify_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
536 			   attr_mask_rc[new_state]);
537 
538 	if (rc) {
539 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
540 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
541 		return rc;
542 	}
543 
544 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
545 
546 	if (state != new_state) {
547 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
548 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
549 			    str_ibv_qp_state[state]);
550 		return -1;
551 	}
552 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
553 		      str_ibv_qp_state[state]);
554 	return 0;
555 }
556 
557 static void
558 spdk_nvmf_rdma_request_set_state(struct spdk_nvmf_rdma_request *rdma_req,
559 				 enum spdk_nvmf_rdma_request_state state)
560 {
561 	struct spdk_nvmf_qpair		*qpair;
562 	struct spdk_nvmf_rdma_qpair	*rqpair;
563 
564 	qpair = rdma_req->req.qpair;
565 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
566 
567 	TAILQ_REMOVE(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
568 	rqpair->state_cntr[rdma_req->state]--;
569 
570 	rdma_req->state = state;
571 
572 	TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
573 	rqpair->state_cntr[rdma_req->state]++;
574 }
575 
576 static int
577 spdk_nvmf_rdma_mgmt_channel_create(void *io_device, void *ctx_buf)
578 {
579 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
580 
581 	TAILQ_INIT(&ch->pending_data_buf_queue);
582 	return 0;
583 }
584 
585 static void
586 spdk_nvmf_rdma_mgmt_channel_destroy(void *io_device, void *ctx_buf)
587 {
588 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
589 
590 	if (!TAILQ_EMPTY(&ch->pending_data_buf_queue)) {
591 		SPDK_ERRLOG("Pending I/O list wasn't empty on channel destruction\n");
592 	}
593 }
594 
595 static int
596 spdk_nvmf_rdma_cur_rw_depth(struct spdk_nvmf_rdma_qpair *rqpair)
597 {
598 	return rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER] +
599 	       rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST];
600 }
601 
602 static int
603 spdk_nvmf_rdma_cur_queue_depth(struct spdk_nvmf_rdma_qpair *rqpair)
604 {
605 	return rqpair->max_queue_depth -
606 	       rqpair->state_cntr[RDMA_REQUEST_STATE_FREE];
607 }
608 
609 static void
610 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
611 {
612 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->data_from_pool);
613 	SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
614 	SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
615 }
616 
617 static void
618 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
619 {
620 	int i;
621 	struct spdk_nvmf_rdma_request *req;
622 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
623 	for (i = 1; i < RDMA_REQUEST_NUM_STATES; i++) {
624 		SPDK_ERRLOG("\tdumping requests in state %d\n", i);
625 		TAILQ_FOREACH(req, &rqpair->state_queue[i], state_link) {
626 			nvmf_rdma_dump_request(req);
627 		}
628 	}
629 }
630 
631 static void
632 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
633 {
634 	int qd;
635 
636 	if (rqpair->refcnt != 0) {
637 		return;
638 	}
639 
640 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
641 
642 	qd = spdk_nvmf_rdma_cur_queue_depth(rqpair);
643 	if (qd != 0) {
644 		nvmf_rdma_dump_qpair_contents(rqpair);
645 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", qd);
646 	}
647 
648 	if (rqpair->poller) {
649 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
650 	}
651 
652 	if (rqpair->cmds_mr) {
653 		ibv_dereg_mr(rqpair->cmds_mr);
654 	}
655 
656 	if (rqpair->cpls_mr) {
657 		ibv_dereg_mr(rqpair->cpls_mr);
658 	}
659 
660 	if (rqpair->bufs_mr) {
661 		ibv_dereg_mr(rqpair->bufs_mr);
662 	}
663 
664 	if (rqpair->cm_id) {
665 		rdma_destroy_qp(rqpair->cm_id);
666 		rdma_destroy_id(rqpair->cm_id);
667 	}
668 
669 	if (rqpair->mgmt_channel) {
670 		spdk_put_io_channel(rqpair->mgmt_channel);
671 	}
672 
673 	/* Free all memory */
674 	spdk_dma_free(rqpair->cmds);
675 	spdk_dma_free(rqpair->cpls);
676 	spdk_dma_free(rqpair->bufs);
677 	free(rqpair->reqs);
678 	free(rqpair->recvs);
679 	free(rqpair);
680 }
681 
682 static int
683 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
684 {
685 	struct spdk_nvmf_rdma_transport *rtransport;
686 	struct spdk_nvmf_rdma_qpair	*rqpair;
687 	int				rc, i;
688 	struct spdk_nvmf_rdma_recv	*rdma_recv;
689 	struct spdk_nvmf_rdma_request	*rdma_req;
690 	struct spdk_nvmf_transport	*transport;
691 	struct spdk_nvmf_rdma_device	*device;
692 	struct ibv_qp_init_attr		ibv_init_attr;
693 
694 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
695 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
696 	transport = &rtransport->transport;
697 	device = rqpair->port->device;
698 
699 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
700 	ibv_init_attr.qp_context	= rqpair;
701 	ibv_init_attr.qp_type		= IBV_QPT_RC;
702 	ibv_init_attr.send_cq		= rqpair->poller->cq;
703 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
704 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
705 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
706 	ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
707 					  1; /* RECV operations + dummy drain WR */
708 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
709 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
710 
711 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
712 	if (rc) {
713 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
714 		rdma_destroy_id(rqpair->cm_id);
715 		rqpair->cm_id = NULL;
716 		spdk_nvmf_rdma_qpair_destroy(rqpair);
717 		return -1;
718 	}
719 
720 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
721 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
722 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
723 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
724 
725 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
726 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
727 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
728 					0x1000, NULL);
729 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
730 					0x1000, NULL);
731 
732 
733 	if (transport->opts.in_capsule_data_size > 0) {
734 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth *
735 						transport->opts.in_capsule_data_size,
736 						0x1000, NULL);
737 	}
738 
739 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
740 	    !rqpair->cpls || (transport->opts.in_capsule_data_size && !rqpair->bufs)) {
741 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
742 		spdk_nvmf_rdma_qpair_destroy(rqpair);
743 		return -1;
744 	}
745 
746 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
747 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
748 				     IBV_ACCESS_LOCAL_WRITE);
749 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
750 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
751 				     0);
752 
753 	if (transport->opts.in_capsule_data_size) {
754 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
755 					     rqpair->max_queue_depth *
756 					     transport->opts.in_capsule_data_size,
757 					     IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
758 	}
759 
760 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (transport->opts.in_capsule_data_size &&
761 			!rqpair->bufs_mr)) {
762 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
763 		spdk_nvmf_rdma_qpair_destroy(rqpair);
764 		return -1;
765 	}
766 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
767 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
768 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
769 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
770 	if (rqpair->bufs && rqpair->bufs_mr) {
771 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
772 			      rqpair->bufs, rqpair->max_queue_depth *
773 			      transport->opts.in_capsule_data_size, rqpair->bufs_mr->lkey);
774 	}
775 
776 	/* Initialise request state queues and counters of the queue pair */
777 	for (i = RDMA_REQUEST_STATE_FREE; i < RDMA_REQUEST_NUM_STATES; i++) {
778 		TAILQ_INIT(&rqpair->state_queue[i]);
779 		rqpair->state_cntr[i] = 0;
780 	}
781 
782 	for (i = 0; i < rqpair->max_queue_depth; i++) {
783 		struct ibv_recv_wr *bad_wr = NULL;
784 
785 		rdma_recv = &rqpair->recvs[i];
786 		rdma_recv->qpair = rqpair;
787 
788 		/* Set up memory to receive commands */
789 		if (rqpair->bufs) {
790 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i *
791 						  transport->opts.in_capsule_data_size));
792 		}
793 
794 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
795 
796 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
797 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
798 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
799 		rdma_recv->wr.num_sge = 1;
800 
801 		if (rdma_recv->buf && rqpair->bufs_mr) {
802 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
803 			rdma_recv->sgl[1].length = transport->opts.in_capsule_data_size;
804 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
805 			rdma_recv->wr.num_sge++;
806 		}
807 
808 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
809 		rdma_recv->wr.sg_list = rdma_recv->sgl;
810 
811 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
812 		if (rc) {
813 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
814 			spdk_nvmf_rdma_qpair_destroy(rqpair);
815 			return -1;
816 		}
817 	}
818 
819 	for (i = 0; i < rqpair->max_queue_depth; i++) {
820 		rdma_req = &rqpair->reqs[i];
821 
822 		rdma_req->req.qpair = &rqpair->qpair;
823 		rdma_req->req.cmd = NULL;
824 
825 		/* Set up memory to send responses */
826 		rdma_req->req.rsp = &rqpair->cpls[i];
827 
828 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
829 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
830 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
831 
832 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
833 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
834 		rdma_req->rsp.wr.next = NULL;
835 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
836 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
837 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
838 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
839 
840 		/* Set up memory for data buffers */
841 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
842 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
843 		rdma_req->data.wr.next = NULL;
844 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
845 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
846 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
847 
848 		/* Initialize request state to FREE */
849 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
850 		TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
851 		rqpair->state_cntr[rdma_req->state]++;
852 	}
853 
854 	return 0;
855 }
856 
857 static int
858 request_transfer_in(struct spdk_nvmf_request *req)
859 {
860 	int				rc;
861 	struct spdk_nvmf_rdma_request	*rdma_req;
862 	struct spdk_nvmf_qpair		*qpair;
863 	struct spdk_nvmf_rdma_qpair	*rqpair;
864 	struct ibv_send_wr		*bad_wr = NULL;
865 
866 	qpair = req->qpair;
867 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
868 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
869 
870 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
871 
872 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
873 
874 	rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
875 	rdma_req->data.wr.next = NULL;
876 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
877 	if (rc) {
878 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
879 		return -1;
880 	}
881 	return 0;
882 }
883 
884 static int
885 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
886 {
887 	int				rc;
888 	struct spdk_nvmf_rdma_request	*rdma_req;
889 	struct spdk_nvmf_qpair		*qpair;
890 	struct spdk_nvmf_rdma_qpair	*rqpair;
891 	struct spdk_nvme_cpl		*rsp;
892 	struct ibv_recv_wr		*bad_recv_wr = NULL;
893 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
894 
895 	*data_posted = 0;
896 	qpair = req->qpair;
897 	rsp = &req->rsp->nvme_cpl;
898 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
899 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
900 
901 	/* Advance our sq_head pointer */
902 	if (qpair->sq_head == qpair->sq_head_max) {
903 		qpair->sq_head = 0;
904 	} else {
905 		qpair->sq_head++;
906 	}
907 	rsp->sqhd = qpair->sq_head;
908 
909 	/* Post the capsule to the recv buffer */
910 	assert(rdma_req->recv != NULL);
911 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
912 		      rqpair);
913 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
914 	if (rc) {
915 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
916 		return rc;
917 	}
918 	rdma_req->recv = NULL;
919 
920 	/* Build the response which consists of an optional
921 	 * RDMA WRITE to transfer data, plus an RDMA SEND
922 	 * containing the response.
923 	 */
924 	send_wr = &rdma_req->rsp.wr;
925 
926 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
927 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
928 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
929 
930 		rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
931 
932 		rdma_req->data.wr.next = send_wr;
933 		*data_posted = 1;
934 		send_wr = &rdma_req->data.wr;
935 	}
936 
937 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
938 
939 	/* Send the completion */
940 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
941 	if (rc) {
942 		SPDK_ERRLOG("Unable to send response capsule\n");
943 	}
944 
945 	return rc;
946 }
947 
948 static int
949 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
950 {
951 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
952 	struct rdma_conn_param				ctrlr_event_data = {};
953 	int						rc;
954 
955 	accept_data.recfmt = 0;
956 	accept_data.crqsize = rqpair->max_queue_depth;
957 
958 	ctrlr_event_data.private_data = &accept_data;
959 	ctrlr_event_data.private_data_len = sizeof(accept_data);
960 	if (id->ps == RDMA_PS_TCP) {
961 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
962 		ctrlr_event_data.initiator_depth = rqpair->max_rw_depth;
963 	}
964 
965 	rc = rdma_accept(id, &ctrlr_event_data);
966 	if (rc) {
967 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
968 	} else {
969 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
970 	}
971 
972 	return rc;
973 }
974 
975 static void
976 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
977 {
978 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
979 
980 	rej_data.recfmt = 0;
981 	rej_data.sts = error;
982 
983 	rdma_reject(id, &rej_data, sizeof(rej_data));
984 }
985 
986 static int
987 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
988 		  new_qpair_fn cb_fn)
989 {
990 	struct spdk_nvmf_rdma_transport *rtransport;
991 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
992 	struct spdk_nvmf_rdma_port	*port;
993 	struct rdma_conn_param		*rdma_param = NULL;
994 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
995 	uint16_t			max_queue_depth;
996 	uint16_t			max_rw_depth;
997 
998 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
999 
1000 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1001 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1002 
1003 	rdma_param = &event->param.conn;
1004 	if (rdma_param->private_data == NULL ||
1005 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1006 		SPDK_ERRLOG("connect request: no private data provided\n");
1007 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1008 		return -1;
1009 	}
1010 
1011 	private_data = rdma_param->private_data;
1012 	if (private_data->recfmt != 0) {
1013 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1014 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1015 		return -1;
1016 	}
1017 
1018 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1019 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1020 
1021 	port = event->listen_id->context;
1022 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1023 		      event->listen_id, event->listen_id->verbs, port);
1024 
1025 	/* Figure out the supported queue depth. This is a multi-step process
1026 	 * that takes into account hardware maximums, host provided values,
1027 	 * and our target's internal memory limits */
1028 
1029 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1030 
1031 	/* Start with the maximum queue depth allowed by the target */
1032 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1033 	max_rw_depth = rtransport->transport.opts.max_queue_depth;
1034 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1035 		      rtransport->transport.opts.max_queue_depth);
1036 
1037 	/* Next check the local NIC's hardware limitations */
1038 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1039 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1040 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1041 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1042 	max_rw_depth = spdk_min(max_rw_depth, port->device->attr.max_qp_rd_atom);
1043 
1044 	/* Next check the remote NIC's hardware limitations */
1045 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1046 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1047 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1048 	if (rdma_param->initiator_depth > 0) {
1049 		max_rw_depth = spdk_min(max_rw_depth, rdma_param->initiator_depth);
1050 	}
1051 
1052 	/* Finally check for the host software requested values, which are
1053 	 * optional. */
1054 	if (rdma_param->private_data != NULL &&
1055 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1056 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1057 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1058 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1059 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1060 	}
1061 
1062 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1063 		      max_queue_depth, max_rw_depth);
1064 
1065 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1066 	if (rqpair == NULL) {
1067 		SPDK_ERRLOG("Could not allocate new connection.\n");
1068 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1069 		return -1;
1070 	}
1071 
1072 	rqpair->port = port;
1073 	rqpair->max_queue_depth = max_queue_depth;
1074 	rqpair->max_rw_depth = max_rw_depth;
1075 	rqpair->cm_id = event->id;
1076 	rqpair->listen_id = event->listen_id;
1077 	rqpair->qpair.transport = transport;
1078 	TAILQ_INIT(&rqpair->incoming_queue);
1079 	event->id->context = &rqpair->qpair;
1080 
1081 	cb_fn(&rqpair->qpair);
1082 
1083 	return 0;
1084 }
1085 
1086 static int
1087 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1088 			  enum spdk_mem_map_notify_action action,
1089 			  void *vaddr, size_t size)
1090 {
1091 	struct spdk_nvmf_rdma_device *device = cb_ctx;
1092 	struct ibv_pd *pd = device->pd;
1093 	struct ibv_mr *mr;
1094 
1095 	switch (action) {
1096 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1097 		mr = ibv_reg_mr(pd, vaddr, size,
1098 				IBV_ACCESS_LOCAL_WRITE |
1099 				IBV_ACCESS_REMOTE_READ |
1100 				IBV_ACCESS_REMOTE_WRITE);
1101 		if (mr == NULL) {
1102 			SPDK_ERRLOG("ibv_reg_mr() failed\n");
1103 			return -1;
1104 		} else {
1105 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1106 		}
1107 		break;
1108 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1109 		mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1110 		spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1111 		if (mr) {
1112 			ibv_dereg_mr(mr);
1113 		}
1114 		break;
1115 	}
1116 
1117 	return 0;
1118 }
1119 
1120 static int
1121 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1122 {
1123 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1124 	return addr_1 == addr_2;
1125 }
1126 
1127 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1128 
1129 static spdk_nvme_data_transfer_t
1130 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1131 {
1132 	enum spdk_nvme_data_transfer xfer;
1133 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1134 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1135 
1136 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1137 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1138 	rdma_req->rsp.wr.imm_data = 0;
1139 #endif
1140 
1141 	/* Figure out data transfer direction */
1142 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1143 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1144 	} else {
1145 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1146 
1147 		/* Some admin commands are special cases */
1148 		if ((rdma_req->req.qpair->qid == 0) &&
1149 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1150 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1151 			switch (cmd->cdw10 & 0xff) {
1152 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1153 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1154 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1155 				break;
1156 			default:
1157 				xfer = SPDK_NVME_DATA_NONE;
1158 			}
1159 		}
1160 	}
1161 
1162 	if (xfer == SPDK_NVME_DATA_NONE) {
1163 		return xfer;
1164 	}
1165 
1166 	/* Even for commands that may transfer data, they could have specified 0 length.
1167 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1168 	 */
1169 	switch (sgl->generic.type) {
1170 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1171 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1172 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1173 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1174 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1175 		if (sgl->unkeyed.length == 0) {
1176 			xfer = SPDK_NVME_DATA_NONE;
1177 		}
1178 		break;
1179 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1180 		if (sgl->keyed.length == 0) {
1181 			xfer = SPDK_NVME_DATA_NONE;
1182 		}
1183 		break;
1184 	}
1185 
1186 	return xfer;
1187 }
1188 
1189 static int
1190 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1191 				 struct spdk_nvmf_rdma_device *device,
1192 				 struct spdk_nvmf_rdma_request *rdma_req)
1193 {
1194 	void		*buf = NULL;
1195 	uint32_t	length = rdma_req->req.length;
1196 	uint64_t	translation_len;
1197 	uint32_t	i = 0;
1198 	int		rc = 0;
1199 
1200 	rdma_req->req.iovcnt = 0;
1201 	while (length) {
1202 		buf = spdk_mempool_get(rtransport->data_buf_pool);
1203 		if (!buf) {
1204 			rc = -ENOMEM;
1205 			goto err_exit;
1206 		}
1207 
1208 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
1209 						~NVMF_DATA_BUFFER_MASK);
1210 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->transport.opts.io_unit_size);
1211 		rdma_req->req.iovcnt++;
1212 		rdma_req->data.buffers[i] = buf;
1213 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
1214 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
1215 		translation_len = rdma_req->req.iov[i].iov_len;
1216 		rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1217 						     (uint64_t)buf, &translation_len))->lkey;
1218 		length -= rdma_req->req.iov[i].iov_len;
1219 
1220 		if (translation_len < rdma_req->req.iov[i].iov_len) {
1221 			SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
1222 			rc = -EINVAL;
1223 			goto err_exit;
1224 		}
1225 		i++;
1226 	}
1227 
1228 	rdma_req->data_from_pool = true;
1229 
1230 	return rc;
1231 
1232 err_exit:
1233 	while (i) {
1234 		i--;
1235 		spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1236 		rdma_req->req.iov[i].iov_base = NULL;
1237 		rdma_req->req.iov[i].iov_len = 0;
1238 
1239 		rdma_req->data.wr.sg_list[i].addr = 0;
1240 		rdma_req->data.wr.sg_list[i].length = 0;
1241 		rdma_req->data.wr.sg_list[i].lkey = 0;
1242 	}
1243 	rdma_req->req.iovcnt = 0;
1244 	return rc;
1245 }
1246 
1247 static int
1248 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1249 				 struct spdk_nvmf_rdma_device *device,
1250 				 struct spdk_nvmf_rdma_request *rdma_req)
1251 {
1252 	struct spdk_nvme_cmd			*cmd;
1253 	struct spdk_nvme_cpl			*rsp;
1254 	struct spdk_nvme_sgl_descriptor		*sgl;
1255 
1256 	cmd = &rdma_req->req.cmd->nvme_cmd;
1257 	rsp = &rdma_req->req.rsp->nvme_cpl;
1258 	sgl = &cmd->dptr.sgl1;
1259 
1260 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1261 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1262 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1263 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1264 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1265 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1266 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1267 			return -1;
1268 		}
1269 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1270 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1271 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1272 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1273 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1274 			}
1275 		}
1276 #endif
1277 
1278 		/* fill request length and populate iovs */
1279 		rdma_req->req.length = sgl->keyed.length;
1280 
1281 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1282 			/* No available buffers. Queue this request up. */
1283 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1284 			return 0;
1285 		}
1286 
1287 		/* backward compatible */
1288 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1289 
1290 		/* rdma wr specifics */
1291 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1292 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1293 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1294 
1295 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1296 			      rdma_req->req.iovcnt);
1297 
1298 		return 0;
1299 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1300 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1301 		uint64_t offset = sgl->address;
1302 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1303 
1304 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1305 			      offset, sgl->unkeyed.length);
1306 
1307 		if (offset > max_len) {
1308 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1309 				    offset, max_len);
1310 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1311 			return -1;
1312 		}
1313 		max_len -= (uint32_t)offset;
1314 
1315 		if (sgl->unkeyed.length > max_len) {
1316 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1317 				    sgl->unkeyed.length, max_len);
1318 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1319 			return -1;
1320 		}
1321 
1322 		rdma_req->req.data = rdma_req->recv->buf + offset;
1323 		rdma_req->data_from_pool = false;
1324 		rdma_req->req.length = sgl->unkeyed.length;
1325 
1326 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1327 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1328 		rdma_req->req.iovcnt = 1;
1329 
1330 		return 0;
1331 	}
1332 
1333 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1334 		    sgl->generic.type, sgl->generic.subtype);
1335 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1336 	return -1;
1337 }
1338 
1339 static void
1340 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1341 		       struct spdk_nvmf_rdma_transport	*rtransport)
1342 {
1343 	if (rdma_req->data_from_pool) {
1344 		/* Put the buffer/s back in the pool */
1345 		for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1346 			spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1347 			rdma_req->req.iov[i].iov_base = NULL;
1348 			rdma_req->data.buffers[i] = NULL;
1349 		}
1350 		rdma_req->data_from_pool = false;
1351 	}
1352 	rdma_req->req.length = 0;
1353 	rdma_req->req.iovcnt = 0;
1354 	rdma_req->req.data = NULL;
1355 	spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
1356 }
1357 
1358 static bool
1359 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1360 			       struct spdk_nvmf_rdma_request *rdma_req)
1361 {
1362 	struct spdk_nvmf_rdma_qpair	*rqpair;
1363 	struct spdk_nvmf_rdma_device	*device;
1364 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1365 	int				rc;
1366 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1367 	enum spdk_nvmf_rdma_request_state prev_state;
1368 	bool				progress = false;
1369 	int				data_posted;
1370 	int				cur_rdma_rw_depth;
1371 
1372 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1373 	device = rqpair->port->device;
1374 
1375 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1376 
1377 	/* If the queue pair is in an error state, force the request to the completed state
1378 	 * to release resources. */
1379 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1380 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1381 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1382 		}
1383 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1384 	}
1385 
1386 	/* The loop here is to allow for several back-to-back state changes. */
1387 	do {
1388 		prev_state = rdma_req->state;
1389 
1390 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1391 
1392 		switch (rdma_req->state) {
1393 		case RDMA_REQUEST_STATE_FREE:
1394 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1395 			 * to escape this state. */
1396 			break;
1397 		case RDMA_REQUEST_STATE_NEW:
1398 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1399 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1400 			rdma_recv = rdma_req->recv;
1401 
1402 			/* The first element of the SGL is the NVMe command */
1403 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1404 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1405 
1406 			TAILQ_REMOVE(&rqpair->incoming_queue, rdma_recv, link);
1407 
1408 			if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR) {
1409 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1410 				break;
1411 			}
1412 
1413 			/* The next state transition depends on the data transfer needs of this request. */
1414 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1415 
1416 			/* If no data to transfer, ready to execute. */
1417 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1418 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1419 				break;
1420 			}
1421 
1422 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEED_BUFFER);
1423 			TAILQ_INSERT_TAIL(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1424 			break;
1425 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1426 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1427 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1428 
1429 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1430 
1431 			if (rdma_req != TAILQ_FIRST(&rqpair->ch->pending_data_buf_queue)) {
1432 				/* This request needs to wait in line to obtain a buffer */
1433 				break;
1434 			}
1435 
1436 			/* Try to get a data buffer */
1437 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1438 			if (rc < 0) {
1439 				TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1440 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1441 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1442 				break;
1443 			}
1444 
1445 			if (!rdma_req->req.data) {
1446 				/* No buffers available. */
1447 				break;
1448 			}
1449 
1450 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1451 
1452 			/* If data is transferring from host to controller and the data didn't
1453 			 * arrive using in capsule data, we need to do a transfer from the host.
1454 			 */
1455 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1456 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1457 				break;
1458 			}
1459 
1460 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1461 			break;
1462 		case RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING:
1463 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING, 0, 0,
1464 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1465 
1466 			if (rdma_req != TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING])) {
1467 				/* This request needs to wait in line to perform RDMA */
1468 				break;
1469 			}
1470 			cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
1471 
1472 			if (cur_rdma_rw_depth >= rqpair->max_rw_depth) {
1473 				/* R/W queue is full, need to wait */
1474 				break;
1475 			}
1476 
1477 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1478 				rc = request_transfer_in(&rdma_req->req);
1479 				if (!rc) {
1480 					spdk_nvmf_rdma_request_set_state(rdma_req,
1481 									 RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
1482 				} else {
1483 					rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1484 					spdk_nvmf_rdma_request_set_state(rdma_req,
1485 									 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1486 				}
1487 			} else if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1488 				/* The data transfer will be kicked off from
1489 				 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
1490 				 */
1491 				spdk_nvmf_rdma_request_set_state(rdma_req,
1492 								 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1493 			} else {
1494 				SPDK_ERRLOG("Cannot perform data transfer, unknown state: %u\n",
1495 					    rdma_req->req.xfer);
1496 				assert(0);
1497 			}
1498 			break;
1499 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1500 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1501 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1502 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1503 			 * to escape this state. */
1504 			break;
1505 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1506 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1507 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1508 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTING);
1509 			spdk_nvmf_request_exec(&rdma_req->req);
1510 			break;
1511 		case RDMA_REQUEST_STATE_EXECUTING:
1512 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1513 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1514 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1515 			 * to escape this state. */
1516 			break;
1517 		case RDMA_REQUEST_STATE_EXECUTED:
1518 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1519 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1520 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1521 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1522 			} else {
1523 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1524 			}
1525 			break;
1526 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1527 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
1528 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1529 			rc = request_transfer_out(&rdma_req->req, &data_posted);
1530 			assert(rc == 0); /* No good way to handle this currently */
1531 			if (rc) {
1532 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1533 			} else {
1534 				spdk_nvmf_rdma_request_set_state(rdma_req,
1535 								 data_posted ?
1536 								 RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
1537 								 RDMA_REQUEST_STATE_COMPLETING);
1538 			}
1539 			break;
1540 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
1541 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
1542 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1543 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1544 			 * to escape this state. */
1545 			break;
1546 		case RDMA_REQUEST_STATE_COMPLETING:
1547 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
1548 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1549 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1550 			 * to escape this state. */
1551 			break;
1552 		case RDMA_REQUEST_STATE_COMPLETED:
1553 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
1554 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1555 
1556 			nvmf_rdma_request_free(rdma_req, rtransport);
1557 			break;
1558 		case RDMA_REQUEST_NUM_STATES:
1559 		default:
1560 			assert(0);
1561 			break;
1562 		}
1563 
1564 		if (rdma_req->state != prev_state) {
1565 			progress = true;
1566 		}
1567 	} while (rdma_req->state != prev_state);
1568 
1569 	return progress;
1570 }
1571 
1572 /* Public API callbacks begin here */
1573 
1574 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
1575 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
1576 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
1577 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
1578 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
1579 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE 4096
1580 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 512
1581 #define SPDK_NVMF_RDMA_DEFAULT_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
1582 
1583 static void
1584 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
1585 {
1586 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
1587 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
1588 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
1589 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
1590 	opts->io_unit_size =		spdk_max(SPDK_NVMF_RDMA_DEFAULT_IO_BUFFER_SIZE,
1591 					SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
1592 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
1593 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
1594 }
1595 
1596 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
1597 
1598 static struct spdk_nvmf_transport *
1599 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
1600 {
1601 	int rc;
1602 	struct spdk_nvmf_rdma_transport *rtransport;
1603 	struct spdk_nvmf_rdma_device	*device, *tmp;
1604 	struct ibv_context		**contexts;
1605 	uint32_t			i;
1606 	int				flag;
1607 	uint32_t			sge_count;
1608 
1609 	const struct spdk_mem_map_ops nvmf_rdma_map_ops = {
1610 		.notify_cb = spdk_nvmf_rdma_mem_notify,
1611 		.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
1612 	};
1613 
1614 	rtransport = calloc(1, sizeof(*rtransport));
1615 	if (!rtransport) {
1616 		return NULL;
1617 	}
1618 
1619 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
1620 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
1621 		free(rtransport);
1622 		return NULL;
1623 	}
1624 
1625 	spdk_io_device_register(rtransport, spdk_nvmf_rdma_mgmt_channel_create,
1626 				spdk_nvmf_rdma_mgmt_channel_destroy,
1627 				sizeof(struct spdk_nvmf_rdma_mgmt_channel),
1628 				"rdma_transport");
1629 
1630 	TAILQ_INIT(&rtransport->devices);
1631 	TAILQ_INIT(&rtransport->ports);
1632 
1633 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1634 
1635 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
1636 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
1637 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
1638 		     "  in_capsule_data_size=%d, max_aq_depth=%d\n"
1639 		     "  num_shared_buffers=%d\n",
1640 		     opts->max_queue_depth,
1641 		     opts->max_io_size,
1642 		     opts->max_qpairs_per_ctrlr,
1643 		     opts->io_unit_size,
1644 		     opts->in_capsule_data_size,
1645 		     opts->max_aq_depth,
1646 		     opts->num_shared_buffers);
1647 
1648 	/* I/O unit size cannot be larger than max I/O size */
1649 	if (opts->io_unit_size > opts->max_io_size) {
1650 		opts->io_unit_size = opts->max_io_size;
1651 	}
1652 
1653 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
1654 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
1655 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
1656 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
1657 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1658 		return NULL;
1659 	}
1660 
1661 	sge_count = opts->max_io_size / opts->io_unit_size;
1662 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
1663 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
1664 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1665 		return NULL;
1666 	}
1667 
1668 	rtransport->event_channel = rdma_create_event_channel();
1669 	if (rtransport->event_channel == NULL) {
1670 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1671 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1672 		return NULL;
1673 	}
1674 
1675 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1676 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1677 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1678 			    rtransport->event_channel->fd, spdk_strerror(errno));
1679 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1680 		return NULL;
1681 	}
1682 
1683 	rtransport->data_buf_pool = spdk_mempool_create("spdk_nvmf_rdma",
1684 				    opts->num_shared_buffers,
1685 				    opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT,
1686 				    SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1687 				    SPDK_ENV_SOCKET_ID_ANY);
1688 	if (!rtransport->data_buf_pool) {
1689 		SPDK_ERRLOG("Unable to allocate buffer pool for poll group\n");
1690 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1691 		return NULL;
1692 	}
1693 
1694 	contexts = rdma_get_devices(NULL);
1695 	if (contexts == NULL) {
1696 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
1697 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1698 		return NULL;
1699 	}
1700 
1701 	i = 0;
1702 	rc = 0;
1703 	while (contexts[i] != NULL) {
1704 		device = calloc(1, sizeof(*device));
1705 		if (!device) {
1706 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1707 			rc = -ENOMEM;
1708 			break;
1709 		}
1710 		device->context = contexts[i];
1711 		rc = ibv_query_device(device->context, &device->attr);
1712 		if (rc < 0) {
1713 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1714 			free(device);
1715 			break;
1716 
1717 		}
1718 
1719 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1720 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
1721 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
1722 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
1723 		}
1724 
1725 		/**
1726 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
1727 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
1728 		 * but incorrectly reports that it does. There are changes making their way
1729 		 * through the kernel now that will enable this feature. When they are merged,
1730 		 * we can conditionally enable this feature.
1731 		 *
1732 		 * TODO: enable this for versions of the kernel rxe driver that support it.
1733 		 */
1734 		if (device->attr.vendor_id == 0) {
1735 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
1736 		}
1737 #endif
1738 
1739 		/* set up device context async ev fd as NON_BLOCKING */
1740 		flag = fcntl(device->context->async_fd, F_GETFL);
1741 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1742 		if (rc < 0) {
1743 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1744 			free(device);
1745 			break;
1746 		}
1747 
1748 		device->pd = ibv_alloc_pd(device->context);
1749 		if (!device->pd) {
1750 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
1751 			free(device);
1752 			rc = -1;
1753 			break;
1754 		}
1755 
1756 		device->map = spdk_mem_map_alloc(0, &nvmf_rdma_map_ops, device);
1757 		if (!device->map) {
1758 			SPDK_ERRLOG("Unable to allocate memory map for new poll group\n");
1759 			ibv_dealloc_pd(device->pd);
1760 			free(device);
1761 			rc = -1;
1762 			break;
1763 		}
1764 
1765 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1766 		i++;
1767 	}
1768 	rdma_free_devices(contexts);
1769 
1770 	if (rc < 0) {
1771 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1772 		return NULL;
1773 	}
1774 
1775 	/* Set up poll descriptor array to monitor events from RDMA and IB
1776 	 * in a single poll syscall
1777 	 */
1778 	rtransport->npoll_fds = i + 1;
1779 	i = 0;
1780 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1781 	if (rtransport->poll_fds == NULL) {
1782 		SPDK_ERRLOG("poll_fds allocation failed\n");
1783 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1784 		return NULL;
1785 	}
1786 
1787 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1788 	rtransport->poll_fds[i++].events = POLLIN;
1789 
1790 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1791 		rtransport->poll_fds[i].fd = device->context->async_fd;
1792 		rtransport->poll_fds[i++].events = POLLIN;
1793 	}
1794 
1795 	return &rtransport->transport;
1796 }
1797 
1798 static int
1799 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1800 {
1801 	struct spdk_nvmf_rdma_transport	*rtransport;
1802 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1803 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1804 
1805 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1806 
1807 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1808 		TAILQ_REMOVE(&rtransport->ports, port, link);
1809 		rdma_destroy_id(port->id);
1810 		free(port);
1811 	}
1812 
1813 	if (rtransport->poll_fds != NULL) {
1814 		free(rtransport->poll_fds);
1815 	}
1816 
1817 	if (rtransport->event_channel != NULL) {
1818 		rdma_destroy_event_channel(rtransport->event_channel);
1819 	}
1820 
1821 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1822 		TAILQ_REMOVE(&rtransport->devices, device, link);
1823 		if (device->map) {
1824 			spdk_mem_map_free(&device->map);
1825 		}
1826 		if (device->pd) {
1827 			ibv_dealloc_pd(device->pd);
1828 		}
1829 		free(device);
1830 	}
1831 
1832 	if (rtransport->data_buf_pool != NULL) {
1833 		if (spdk_mempool_count(rtransport->data_buf_pool) !=
1834 		    transport->opts.num_shared_buffers) {
1835 			SPDK_ERRLOG("transport buffer pool count is %zu but should be %u\n",
1836 				    spdk_mempool_count(rtransport->data_buf_pool),
1837 				    transport->opts.num_shared_buffers);
1838 		}
1839 	}
1840 
1841 	spdk_mempool_free(rtransport->data_buf_pool);
1842 	spdk_io_device_unregister(rtransport, NULL);
1843 	pthread_mutex_destroy(&rtransport->lock);
1844 	free(rtransport);
1845 
1846 	return 0;
1847 }
1848 
1849 static int
1850 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1851 		      const struct spdk_nvme_transport_id *trid)
1852 {
1853 	struct spdk_nvmf_rdma_transport	*rtransport;
1854 	struct spdk_nvmf_rdma_device	*device;
1855 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1856 	struct addrinfo			*res;
1857 	struct addrinfo			hints;
1858 	int				family;
1859 	int				rc;
1860 
1861 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1862 
1863 	port = calloc(1, sizeof(*port));
1864 	if (!port) {
1865 		return -ENOMEM;
1866 	}
1867 
1868 	/* Selectively copy the trid. Things like NQN don't matter here - that
1869 	 * mapping is enforced elsewhere.
1870 	 */
1871 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1872 	port->trid.adrfam = trid->adrfam;
1873 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1874 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1875 
1876 	pthread_mutex_lock(&rtransport->lock);
1877 	assert(rtransport->event_channel != NULL);
1878 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1879 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1880 			port_tmp->ref++;
1881 			free(port);
1882 			/* Already listening at this address */
1883 			pthread_mutex_unlock(&rtransport->lock);
1884 			return 0;
1885 		}
1886 	}
1887 
1888 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1889 	if (rc < 0) {
1890 		SPDK_ERRLOG("rdma_create_id() failed\n");
1891 		free(port);
1892 		pthread_mutex_unlock(&rtransport->lock);
1893 		return rc;
1894 	}
1895 
1896 	switch (port->trid.adrfam) {
1897 	case SPDK_NVMF_ADRFAM_IPV4:
1898 		family = AF_INET;
1899 		break;
1900 	case SPDK_NVMF_ADRFAM_IPV6:
1901 		family = AF_INET6;
1902 		break;
1903 	default:
1904 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1905 		free(port);
1906 		pthread_mutex_unlock(&rtransport->lock);
1907 		return -EINVAL;
1908 	}
1909 
1910 	memset(&hints, 0, sizeof(hints));
1911 	hints.ai_family = family;
1912 	hints.ai_flags = AI_NUMERICSERV;
1913 	hints.ai_socktype = SOCK_STREAM;
1914 	hints.ai_protocol = 0;
1915 
1916 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1917 	if (rc) {
1918 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1919 		free(port);
1920 		pthread_mutex_unlock(&rtransport->lock);
1921 		return -EINVAL;
1922 	}
1923 
1924 	rc = rdma_bind_addr(port->id, res->ai_addr);
1925 	freeaddrinfo(res);
1926 
1927 	if (rc < 0) {
1928 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1929 		rdma_destroy_id(port->id);
1930 		free(port);
1931 		pthread_mutex_unlock(&rtransport->lock);
1932 		return rc;
1933 	}
1934 
1935 	if (!port->id->verbs) {
1936 		SPDK_ERRLOG("ibv_context is null\n");
1937 		rdma_destroy_id(port->id);
1938 		free(port);
1939 		pthread_mutex_unlock(&rtransport->lock);
1940 		return -1;
1941 	}
1942 
1943 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
1944 	if (rc < 0) {
1945 		SPDK_ERRLOG("rdma_listen() failed\n");
1946 		rdma_destroy_id(port->id);
1947 		free(port);
1948 		pthread_mutex_unlock(&rtransport->lock);
1949 		return rc;
1950 	}
1951 
1952 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1953 		if (device->context == port->id->verbs) {
1954 			port->device = device;
1955 			break;
1956 		}
1957 	}
1958 	if (!port->device) {
1959 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
1960 			    port->id->verbs);
1961 		rdma_destroy_id(port->id);
1962 		free(port);
1963 		pthread_mutex_unlock(&rtransport->lock);
1964 		return -EINVAL;
1965 	}
1966 
1967 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
1968 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
1969 
1970 	port->ref = 1;
1971 
1972 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
1973 	pthread_mutex_unlock(&rtransport->lock);
1974 
1975 	return 0;
1976 }
1977 
1978 static int
1979 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
1980 			   const struct spdk_nvme_transport_id *_trid)
1981 {
1982 	struct spdk_nvmf_rdma_transport *rtransport;
1983 	struct spdk_nvmf_rdma_port *port, *tmp;
1984 	struct spdk_nvme_transport_id trid = {};
1985 
1986 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1987 
1988 	/* Selectively copy the trid. Things like NQN don't matter here - that
1989 	 * mapping is enforced elsewhere.
1990 	 */
1991 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1992 	trid.adrfam = _trid->adrfam;
1993 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
1994 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
1995 
1996 	pthread_mutex_lock(&rtransport->lock);
1997 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
1998 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
1999 			assert(port->ref > 0);
2000 			port->ref--;
2001 			if (port->ref == 0) {
2002 				TAILQ_REMOVE(&rtransport->ports, port, link);
2003 				rdma_destroy_id(port->id);
2004 				free(port);
2005 			}
2006 			break;
2007 		}
2008 	}
2009 
2010 	pthread_mutex_unlock(&rtransport->lock);
2011 	return 0;
2012 }
2013 
2014 static bool
2015 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
2016 {
2017 	int cur_queue_depth, cur_rdma_rw_depth;
2018 	struct spdk_nvmf_rdma_qpair *rqpair;
2019 
2020 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2021 	cur_queue_depth = spdk_nvmf_rdma_cur_queue_depth(rqpair);
2022 	cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
2023 
2024 	if (cur_queue_depth == 0 && cur_rdma_rw_depth == 0) {
2025 		return true;
2026 	}
2027 	return false;
2028 }
2029 
2030 static void
2031 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2032 				     struct spdk_nvmf_rdma_qpair *rqpair)
2033 {
2034 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
2035 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2036 
2037 	/* We process I/O in the data transfer pending queue at the highest priority. */
2038 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING],
2039 			   state_link, req_tmp) {
2040 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2041 			break;
2042 		}
2043 	}
2044 
2045 	/* The second highest priority is I/O waiting on memory buffers. */
2046 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->ch->pending_data_buf_queue, link,
2047 			   req_tmp) {
2048 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2049 			break;
2050 		}
2051 	}
2052 
2053 	/* The lowest priority is processing newly received commands */
2054 	TAILQ_FOREACH_SAFE(rdma_recv, &rqpair->incoming_queue, link, recv_tmp) {
2055 		if (TAILQ_EMPTY(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE])) {
2056 			break;
2057 		}
2058 
2059 		rdma_req = TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE]);
2060 		rdma_req->recv = rdma_recv;
2061 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEW);
2062 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2063 			break;
2064 		}
2065 	}
2066 }
2067 
2068 static void
2069 _nvmf_rdma_qpair_disconnect(void *ctx)
2070 {
2071 	struct spdk_nvmf_qpair *qpair = ctx;
2072 	struct spdk_nvmf_rdma_qpair *rqpair;
2073 
2074 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2075 
2076 	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);
2077 
2078 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2079 }
2080 
2081 static void
2082 _nvmf_rdma_disconnect_retry(void *ctx)
2083 {
2084 	struct spdk_nvmf_qpair *qpair = ctx;
2085 	struct spdk_nvmf_poll_group *group;
2086 
2087 	/* Read the group out of the qpair. This is normally set and accessed only from
2088 	 * the thread that created the group. Here, we're not on that thread necessarily.
2089 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2090 	 * a pointer and never changes. So fortunately reading this and checking for
2091 	 * non-NULL is thread safe in the x86_64 memory model. */
2092 	group = qpair->group;
2093 
2094 	if (group == NULL) {
2095 		/* The qpair hasn't been assigned to a group yet, so we can't
2096 		 * process a disconnect. Send a message to ourself and try again. */
2097 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_disconnect_retry, qpair);
2098 		return;
2099 	}
2100 
2101 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2102 }
2103 
2104 static int
2105 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2106 {
2107 	struct spdk_nvmf_qpair		*qpair;
2108 	struct spdk_nvmf_rdma_qpair	*rqpair;
2109 
2110 	if (evt->id == NULL) {
2111 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2112 		return -1;
2113 	}
2114 
2115 	qpair = evt->id->context;
2116 	if (qpair == NULL) {
2117 		SPDK_ERRLOG("disconnect request: no active connection\n");
2118 		return -1;
2119 	}
2120 
2121 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2122 
2123 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2124 
2125 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2126 	spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2127 
2128 	_nvmf_rdma_disconnect_retry(qpair);
2129 
2130 	return 0;
2131 }
2132 
2133 #ifdef DEBUG
2134 static const char *CM_EVENT_STR[] = {
2135 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2136 	"RDMA_CM_EVENT_ADDR_ERROR",
2137 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2138 	"RDMA_CM_EVENT_ROUTE_ERROR",
2139 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2140 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2141 	"RDMA_CM_EVENT_CONNECT_ERROR",
2142 	"RDMA_CM_EVENT_UNREACHABLE",
2143 	"RDMA_CM_EVENT_REJECTED",
2144 	"RDMA_CM_EVENT_ESTABLISHED",
2145 	"RDMA_CM_EVENT_DISCONNECTED",
2146 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2147 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2148 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2149 	"RDMA_CM_EVENT_ADDR_CHANGE",
2150 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2151 };
2152 #endif /* DEBUG */
2153 
2154 static void
2155 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2156 {
2157 	struct spdk_nvmf_rdma_transport *rtransport;
2158 	struct rdma_cm_event		*event;
2159 	int				rc;
2160 
2161 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2162 
2163 	if (rtransport->event_channel == NULL) {
2164 		return;
2165 	}
2166 
2167 	while (1) {
2168 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2169 		if (rc == 0) {
2170 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2171 
2172 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2173 
2174 			switch (event->event) {
2175 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2176 			case RDMA_CM_EVENT_ADDR_ERROR:
2177 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2178 			case RDMA_CM_EVENT_ROUTE_ERROR:
2179 				/* No action required. The target never attempts to resolve routes. */
2180 				break;
2181 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2182 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2183 				if (rc < 0) {
2184 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2185 					break;
2186 				}
2187 				break;
2188 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2189 				/* The target never initiates a new connection. So this will not occur. */
2190 				break;
2191 			case RDMA_CM_EVENT_CONNECT_ERROR:
2192 				/* Can this happen? The docs say it can, but not sure what causes it. */
2193 				break;
2194 			case RDMA_CM_EVENT_UNREACHABLE:
2195 			case RDMA_CM_EVENT_REJECTED:
2196 				/* These only occur on the client side. */
2197 				break;
2198 			case RDMA_CM_EVENT_ESTABLISHED:
2199 				/* TODO: Should we be waiting for this event anywhere? */
2200 				break;
2201 			case RDMA_CM_EVENT_DISCONNECTED:
2202 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2203 				rc = nvmf_rdma_disconnect(event);
2204 				if (rc < 0) {
2205 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2206 					break;
2207 				}
2208 				break;
2209 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2210 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2211 				/* Multicast is not used */
2212 				break;
2213 			case RDMA_CM_EVENT_ADDR_CHANGE:
2214 				/* Not utilizing this event */
2215 				break;
2216 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2217 				/* For now, do nothing. The target never re-uses queue pairs. */
2218 				break;
2219 			default:
2220 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2221 				break;
2222 			}
2223 
2224 			rdma_ack_cm_event(event);
2225 		} else {
2226 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2227 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2228 			}
2229 			break;
2230 		}
2231 	}
2232 }
2233 
2234 static void
2235 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2236 {
2237 	int				rc;
2238 	struct spdk_nvmf_rdma_qpair	*rqpair;
2239 	struct ibv_async_event		event;
2240 	enum ibv_qp_state		state;
2241 
2242 	rc = ibv_get_async_event(device->context, &event);
2243 
2244 	if (rc) {
2245 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2246 			    errno, spdk_strerror(errno));
2247 		return;
2248 	}
2249 
2250 	SPDK_NOTICELOG("Async event: %s\n",
2251 		       ibv_event_type_str(event.event_type));
2252 
2253 	switch (event.event_type) {
2254 	case IBV_EVENT_QP_FATAL:
2255 		rqpair = event.element.qp->qp_context;
2256 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2257 				  (uintptr_t)rqpair->cm_id, event.event_type);
2258 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2259 		spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2260 		_nvmf_rdma_disconnect_retry(&rqpair->qpair);
2261 		break;
2262 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2263 		/* This event only occurs for shared receive queues, which are not currently supported. */
2264 		break;
2265 	case IBV_EVENT_SQ_DRAINED:
2266 		/* This event occurs frequently in both error and non-error states.
2267 		 * Check if the qpair is in an error state before sending a message.
2268 		 * Note that we're not on the correct thread to access the qpair, but
2269 		 * the operations that the below calls make all happen to be thread
2270 		 * safe. */
2271 		rqpair = event.element.qp->qp_context;
2272 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2273 				  (uintptr_t)rqpair->cm_id, event.event_type);
2274 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2275 		if (state == IBV_QPS_ERR) {
2276 			spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2277 			_nvmf_rdma_disconnect_retry(&rqpair->qpair);
2278 		}
2279 		break;
2280 	case IBV_EVENT_QP_REQ_ERR:
2281 	case IBV_EVENT_QP_ACCESS_ERR:
2282 	case IBV_EVENT_COMM_EST:
2283 	case IBV_EVENT_PATH_MIG:
2284 	case IBV_EVENT_PATH_MIG_ERR:
2285 		rqpair = event.element.qp->qp_context;
2286 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2287 				  (uintptr_t)rqpair->cm_id, event.event_type);
2288 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2289 		break;
2290 	case IBV_EVENT_CQ_ERR:
2291 	case IBV_EVENT_DEVICE_FATAL:
2292 	case IBV_EVENT_PORT_ACTIVE:
2293 	case IBV_EVENT_PORT_ERR:
2294 	case IBV_EVENT_LID_CHANGE:
2295 	case IBV_EVENT_PKEY_CHANGE:
2296 	case IBV_EVENT_SM_CHANGE:
2297 	case IBV_EVENT_SRQ_ERR:
2298 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2299 	case IBV_EVENT_CLIENT_REREGISTER:
2300 	case IBV_EVENT_GID_CHANGE:
2301 	default:
2302 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2303 		break;
2304 	}
2305 	ibv_ack_async_event(&event);
2306 }
2307 
2308 static void
2309 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2310 {
2311 	int	nfds, i = 0;
2312 	struct spdk_nvmf_rdma_transport *rtransport;
2313 	struct spdk_nvmf_rdma_device *device, *tmp;
2314 
2315 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2316 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2317 
2318 	if (nfds <= 0) {
2319 		return;
2320 	}
2321 
2322 	/* The first poll descriptor is RDMA CM event */
2323 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2324 		spdk_nvmf_process_cm_event(transport, cb_fn);
2325 		nfds--;
2326 	}
2327 
2328 	if (nfds == 0) {
2329 		return;
2330 	}
2331 
2332 	/* Second and subsequent poll descriptors are IB async events */
2333 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2334 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2335 			spdk_nvmf_process_ib_event(device);
2336 			nfds--;
2337 		}
2338 	}
2339 	/* check all flagged fd's have been served */
2340 	assert(nfds == 0);
2341 }
2342 
2343 static void
2344 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2345 			struct spdk_nvme_transport_id *trid,
2346 			struct spdk_nvmf_discovery_log_page_entry *entry)
2347 {
2348 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2349 	entry->adrfam = trid->adrfam;
2350 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2351 
2352 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2353 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2354 
2355 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2356 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2357 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2358 }
2359 
2360 static struct spdk_nvmf_transport_poll_group *
2361 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2362 {
2363 	struct spdk_nvmf_rdma_transport		*rtransport;
2364 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2365 	struct spdk_nvmf_rdma_poller		*poller;
2366 	struct spdk_nvmf_rdma_device		*device;
2367 
2368 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2369 
2370 	rgroup = calloc(1, sizeof(*rgroup));
2371 	if (!rgroup) {
2372 		return NULL;
2373 	}
2374 
2375 	TAILQ_INIT(&rgroup->pollers);
2376 
2377 	pthread_mutex_lock(&rtransport->lock);
2378 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2379 		poller = calloc(1, sizeof(*poller));
2380 		if (!poller) {
2381 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2382 			free(rgroup);
2383 			pthread_mutex_unlock(&rtransport->lock);
2384 			return NULL;
2385 		}
2386 
2387 		poller->device = device;
2388 		poller->group = rgroup;
2389 
2390 		TAILQ_INIT(&poller->qpairs);
2391 
2392 		poller->cq = ibv_create_cq(device->context, NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
2393 		if (!poller->cq) {
2394 			SPDK_ERRLOG("Unable to create completion queue\n");
2395 			free(poller);
2396 			free(rgroup);
2397 			pthread_mutex_unlock(&rtransport->lock);
2398 			return NULL;
2399 		}
2400 
2401 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2402 	}
2403 
2404 	pthread_mutex_unlock(&rtransport->lock);
2405 	return &rgroup->group;
2406 }
2407 
2408 static void
2409 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
2410 {
2411 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2412 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
2413 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
2414 
2415 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2416 
2417 	if (!rgroup) {
2418 		return;
2419 	}
2420 
2421 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
2422 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2423 
2424 		if (poller->cq) {
2425 			ibv_destroy_cq(poller->cq);
2426 		}
2427 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
2428 			spdk_nvmf_rdma_qpair_destroy(qpair);
2429 		}
2430 
2431 		free(poller);
2432 	}
2433 
2434 	free(rgroup);
2435 }
2436 
2437 static int
2438 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
2439 			      struct spdk_nvmf_qpair *qpair)
2440 {
2441 	struct spdk_nvmf_rdma_transport		*rtransport;
2442 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2443 	struct spdk_nvmf_rdma_qpair		*rqpair;
2444 	struct spdk_nvmf_rdma_device		*device;
2445 	struct spdk_nvmf_rdma_poller		*poller;
2446 	int					rc;
2447 
2448 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
2449 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2450 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2451 
2452 	device = rqpair->port->device;
2453 
2454 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
2455 		if (poller->device == device) {
2456 			break;
2457 		}
2458 	}
2459 
2460 	if (!poller) {
2461 		SPDK_ERRLOG("No poller found for device.\n");
2462 		return -1;
2463 	}
2464 
2465 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
2466 	rqpair->poller = poller;
2467 
2468 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
2469 	if (rc < 0) {
2470 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
2471 		return -1;
2472 	}
2473 
2474 	rqpair->mgmt_channel = spdk_get_io_channel(rtransport);
2475 	if (!rqpair->mgmt_channel) {
2476 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2477 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2478 		return -1;
2479 	}
2480 
2481 	rqpair->ch = spdk_io_channel_get_ctx(rqpair->mgmt_channel);
2482 	assert(rqpair->ch != NULL);
2483 
2484 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
2485 	if (rc) {
2486 		/* Try to reject, but we probably can't */
2487 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2488 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2489 		return -1;
2490 	}
2491 
2492 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2493 
2494 	return 0;
2495 }
2496 
2497 static int
2498 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
2499 {
2500 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2501 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2502 			struct spdk_nvmf_rdma_transport, transport);
2503 
2504 	nvmf_rdma_request_free(rdma_req, rtransport);
2505 	return 0;
2506 }
2507 
2508 static int
2509 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
2510 {
2511 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2512 			struct spdk_nvmf_rdma_transport, transport);
2513 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
2514 			struct spdk_nvmf_rdma_request, req);
2515 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
2516 			struct spdk_nvmf_rdma_qpair, qpair);
2517 
2518 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2519 		/* The connection is alive, so process the request as normal */
2520 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTED);
2521 	} else {
2522 		/* The connection is dead. Move the request directly to the completed state. */
2523 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2524 	}
2525 
2526 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2527 
2528 	return 0;
2529 }
2530 
2531 static void
2532 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
2533 {
2534 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2535 	struct ibv_recv_wr recv_wr = {};
2536 	struct ibv_recv_wr *bad_recv_wr;
2537 	struct ibv_send_wr send_wr = {};
2538 	struct ibv_send_wr *bad_send_wr;
2539 	int rc;
2540 
2541 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
2542 		return;
2543 	}
2544 
2545 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
2546 
2547 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2548 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
2549 	}
2550 
2551 	rqpair->drain_recv_wr.type = RDMA_WR_TYPE_DRAIN_RECV;
2552 	recv_wr.wr_id = (uintptr_t)&rqpair->drain_recv_wr;
2553 	rc = ibv_post_recv(rqpair->cm_id->qp, &recv_wr, &bad_recv_wr);
2554 	if (rc) {
2555 		SPDK_ERRLOG("Failed to post dummy receive WR, errno %d\n", errno);
2556 		assert(false);
2557 		return;
2558 	}
2559 
2560 	rqpair->drain_send_wr.type = RDMA_WR_TYPE_DRAIN_SEND;
2561 	send_wr.wr_id = (uintptr_t)&rqpair->drain_send_wr;
2562 	send_wr.opcode = IBV_WR_SEND;
2563 	rc = ibv_post_send(rqpair->cm_id->qp, &send_wr, &bad_send_wr);
2564 	if (rc) {
2565 		SPDK_ERRLOG("Failed to post dummy send WR, errno %d\n", errno);
2566 		assert(false);
2567 		return;
2568 	}
2569 }
2570 
2571 #ifdef DEBUG
2572 static int
2573 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
2574 {
2575 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
2576 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
2577 }
2578 #endif
2579 
2580 static int
2581 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2582 			   struct spdk_nvmf_rdma_poller *rpoller)
2583 {
2584 	struct ibv_wc wc[32];
2585 	struct spdk_nvmf_rdma_wr	*rdma_wr;
2586 	struct spdk_nvmf_rdma_request	*rdma_req;
2587 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2588 	struct spdk_nvmf_rdma_qpair	*rqpair;
2589 	int reaped, i;
2590 	int count = 0;
2591 	bool error = false;
2592 
2593 	/* Poll for completing operations. */
2594 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2595 	if (reaped < 0) {
2596 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2597 			    errno, spdk_strerror(errno));
2598 		return -1;
2599 	}
2600 
2601 	for (i = 0; i < reaped; i++) {
2602 
2603 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
2604 
2605 		/* Handle error conditions */
2606 		if (wc[i].status) {
2607 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2608 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2609 
2610 			error = true;
2611 
2612 			switch (rdma_wr->type) {
2613 			case RDMA_WR_TYPE_SEND:
2614 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2615 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2616 
2617 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2618 				/* We're going to attempt an error recovery, so force the request into
2619 				 * the completed state. */
2620 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2621 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2622 				break;
2623 			case RDMA_WR_TYPE_RECV:
2624 				rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2625 				rqpair = rdma_recv->qpair;
2626 
2627 				/* Dump this into the incoming queue. This gets cleaned up when
2628 				 * the queue pair disconnects or recovers. */
2629 				TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2630 				break;
2631 			case RDMA_WR_TYPE_DATA:
2632 				/* If the data transfer fails still force the queue into the error state,
2633 				 * if we were performing an RDMA_READ, we need to force the request into a
2634 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
2635 				 * case, we should wait for the SEND to complete. */
2636 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2637 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2638 
2639 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2640 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
2641 					spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2642 				}
2643 				break;
2644 			case RDMA_WR_TYPE_DRAIN_RECV:
2645 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_recv_wr);
2646 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2647 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP RECV %u (%p)\n", rqpair->qpair.qid, rqpair);
2648 				rqpair->disconnect_flags |= RDMA_QP_RECV_DRAINED;
2649 				if (rqpair->disconnect_flags & RDMA_QP_SEND_DRAINED) {
2650 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2651 				}
2652 				/* Continue so that this does not trigger the disconnect path below. */
2653 				continue;
2654 			case RDMA_WR_TYPE_DRAIN_SEND:
2655 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_send_wr);
2656 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2657 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP SEND %u (%p)\n", rqpair->qpair.qid, rqpair);
2658 				rqpair->disconnect_flags |= RDMA_QP_SEND_DRAINED;
2659 				if (rqpair->disconnect_flags & RDMA_QP_RECV_DRAINED) {
2660 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2661 				}
2662 				/* Continue so that this does not trigger the disconnect path below. */
2663 				continue;
2664 			default:
2665 				SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2666 				continue;
2667 			}
2668 
2669 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
2670 				/* Disconnect the connection. */
2671 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2672 			}
2673 			continue;
2674 		}
2675 
2676 		switch (wc[i].opcode) {
2677 		case IBV_WC_SEND:
2678 			assert(rdma_wr->type == RDMA_WR_TYPE_SEND);
2679 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2680 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2681 
2682 			assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
2683 
2684 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2685 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2686 
2687 			count++;
2688 
2689 			/* Try to process other queued requests */
2690 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2691 			break;
2692 
2693 		case IBV_WC_RDMA_WRITE:
2694 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2695 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2696 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2697 
2698 			/* Try to process other queued requests */
2699 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2700 			break;
2701 
2702 		case IBV_WC_RDMA_READ:
2703 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2704 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2705 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2706 
2707 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2708 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
2709 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2710 
2711 			/* Try to process other queued requests */
2712 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2713 			break;
2714 
2715 		case IBV_WC_RECV:
2716 			assert(rdma_wr->type == RDMA_WR_TYPE_RECV);
2717 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2718 			rqpair = rdma_recv->qpair;
2719 
2720 			TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2721 			/* Try to process other queued requests */
2722 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2723 			break;
2724 
2725 		default:
2726 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2727 			continue;
2728 		}
2729 	}
2730 
2731 	if (error == true) {
2732 		return -1;
2733 	}
2734 
2735 	return count;
2736 }
2737 
2738 static int
2739 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2740 {
2741 	struct spdk_nvmf_rdma_transport *rtransport;
2742 	struct spdk_nvmf_rdma_poll_group *rgroup;
2743 	struct spdk_nvmf_rdma_poller	*rpoller;
2744 	int				count, rc;
2745 
2746 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2747 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2748 
2749 	count = 0;
2750 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2751 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2752 		if (rc < 0) {
2753 			return rc;
2754 		}
2755 		count += rc;
2756 	}
2757 
2758 	return count;
2759 }
2760 
2761 static int
2762 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2763 			       struct spdk_nvme_transport_id *trid,
2764 			       bool peer)
2765 {
2766 	struct sockaddr *saddr;
2767 	uint16_t port;
2768 
2769 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
2770 
2771 	if (peer) {
2772 		saddr = rdma_get_peer_addr(id);
2773 	} else {
2774 		saddr = rdma_get_local_addr(id);
2775 	}
2776 	switch (saddr->sa_family) {
2777 	case AF_INET: {
2778 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
2779 
2780 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
2781 		inet_ntop(AF_INET, &saddr_in->sin_addr,
2782 			  trid->traddr, sizeof(trid->traddr));
2783 		if (peer) {
2784 			port = ntohs(rdma_get_dst_port(id));
2785 		} else {
2786 			port = ntohs(rdma_get_src_port(id));
2787 		}
2788 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2789 		break;
2790 	}
2791 	case AF_INET6: {
2792 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
2793 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
2794 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
2795 			  trid->traddr, sizeof(trid->traddr));
2796 		if (peer) {
2797 			port = ntohs(rdma_get_dst_port(id));
2798 		} else {
2799 			port = ntohs(rdma_get_src_port(id));
2800 		}
2801 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2802 		break;
2803 	}
2804 	default:
2805 		return -1;
2806 
2807 	}
2808 
2809 	return 0;
2810 }
2811 
2812 static int
2813 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
2814 				   struct spdk_nvme_transport_id *trid)
2815 {
2816 	struct spdk_nvmf_rdma_qpair	*rqpair;
2817 
2818 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2819 
2820 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
2821 }
2822 
2823 static int
2824 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
2825 				    struct spdk_nvme_transport_id *trid)
2826 {
2827 	struct spdk_nvmf_rdma_qpair	*rqpair;
2828 
2829 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2830 
2831 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
2832 }
2833 
2834 static int
2835 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
2836 				     struct spdk_nvme_transport_id *trid)
2837 {
2838 	struct spdk_nvmf_rdma_qpair	*rqpair;
2839 
2840 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2841 
2842 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
2843 }
2844 
2845 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
2846 	.type = SPDK_NVME_TRANSPORT_RDMA,
2847 	.opts_init = spdk_nvmf_rdma_opts_init,
2848 	.create = spdk_nvmf_rdma_create,
2849 	.destroy = spdk_nvmf_rdma_destroy,
2850 
2851 	.listen = spdk_nvmf_rdma_listen,
2852 	.stop_listen = spdk_nvmf_rdma_stop_listen,
2853 	.accept = spdk_nvmf_rdma_accept,
2854 
2855 	.listener_discover = spdk_nvmf_rdma_discover,
2856 
2857 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
2858 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
2859 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
2860 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
2861 
2862 	.req_free = spdk_nvmf_rdma_request_free,
2863 	.req_complete = spdk_nvmf_rdma_request_complete,
2864 
2865 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
2866 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
2867 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
2868 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
2869 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
2870 
2871 };
2872 
2873 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
2874