xref: /spdk/lib/nvmf/rdma.c (revision 56e12b00711b40d1e2ff45d4147193f45fdd9af0)
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 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
55 
56 /*
57  RDMA Connection Resource Defaults
58  */
59 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
60 #define NVMF_DEFAULT_RSP_SGE		1
61 #define NVMF_DEFAULT_RX_SGE		2
62 
63 /* The RDMA completion queue size */
64 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
65 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
66 
67 enum spdk_nvmf_rdma_request_state {
68 	/* The request is not currently in use */
69 	RDMA_REQUEST_STATE_FREE = 0,
70 
71 	/* Initial state when request first received */
72 	RDMA_REQUEST_STATE_NEW,
73 
74 	/* The request is queued until a data buffer is available. */
75 	RDMA_REQUEST_STATE_NEED_BUFFER,
76 
77 	/* The request is waiting on RDMA queue depth availability
78 	 * to transfer data from the host to the controller.
79 	 */
80 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
81 
82 	/* The request is currently transferring data from the host to the controller. */
83 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
84 
85 	/* The request is ready to execute at the block device */
86 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
87 
88 	/* The request is currently executing at the block device */
89 	RDMA_REQUEST_STATE_EXECUTING,
90 
91 	/* The request finished executing at the block device */
92 	RDMA_REQUEST_STATE_EXECUTED,
93 
94 	/* The request is waiting on RDMA queue depth availability
95 	 * to transfer data from the controller to the host.
96 	 */
97 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
98 
99 	/* The request is ready to send a completion */
100 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
101 
102 	/* The request is currently transferring data from the controller to the host. */
103 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
104 
105 	/* The request currently has an outstanding completion without an
106 	 * associated data transfer.
107 	 */
108 	RDMA_REQUEST_STATE_COMPLETING,
109 
110 	/* The request completed and can be marked free. */
111 	RDMA_REQUEST_STATE_COMPLETED,
112 
113 	/* Terminator */
114 	RDMA_REQUEST_NUM_STATES,
115 };
116 
117 #define OBJECT_NVMF_RDMA_IO				0x40
118 
119 #define TRACE_GROUP_NVMF_RDMA				0x4
120 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
121 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
122 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
123 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
124 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
125 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
126 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
127 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
128 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
129 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
130 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
131 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
132 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
133 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
134 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
135 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
136 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
137 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
138 
139 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
140 {
141 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
142 	spdk_trace_register_description("RDMA_REQ_NEW", "",
143 					TRACE_RDMA_REQUEST_STATE_NEW,
144 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
145 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
146 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
147 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
148 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C_TO_H", "",
149 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
150 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
151 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
152 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
153 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
154 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
155 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
156 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
157 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
158 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
159 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
160 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
161 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
163 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
164 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
165 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
166 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
167 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_COMPLETING_CONTROLLER_TO_HOST", "",
170 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 	spdk_trace_register_description("RDMA_REQ_COMPLETING_INCAPSULE", "",
173 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
175 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
176 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
178 
179 	spdk_trace_register_description("RDMA_QP_CREATE", "", TRACE_RDMA_QP_CREATE,
180 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
181 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", "", TRACE_RDMA_IBV_ASYNC_EVENT,
182 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
183 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", "", TRACE_RDMA_CM_ASYNC_EVENT,
184 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
185 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", "", TRACE_RDMA_QP_STATE_CHANGE,
186 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
187 	spdk_trace_register_description("RDMA_QP_DISCONNECT", "", TRACE_RDMA_QP_DISCONNECT,
188 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
189 	spdk_trace_register_description("RDMA_QP_DESTROY", "", TRACE_RDMA_QP_DESTROY,
190 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
191 }
192 
193 enum spdk_nvmf_rdma_wr_type {
194 	RDMA_WR_TYPE_RECV,
195 	RDMA_WR_TYPE_SEND,
196 	RDMA_WR_TYPE_DATA,
197 	RDMA_WR_TYPE_DRAIN_SEND,
198 	RDMA_WR_TYPE_DRAIN_RECV
199 };
200 
201 struct spdk_nvmf_rdma_wr {
202 	enum spdk_nvmf_rdma_wr_type	type;
203 };
204 
205 /* This structure holds commands as they are received off the wire.
206  * It must be dynamically paired with a full request object
207  * (spdk_nvmf_rdma_request) to service a request. It is separate
208  * from the request because RDMA does not appear to order
209  * completions, so occasionally we'll get a new incoming
210  * command when there aren't any free request objects.
211  */
212 struct spdk_nvmf_rdma_recv {
213 	struct ibv_recv_wr		wr;
214 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
215 
216 	struct spdk_nvmf_rdma_qpair	*qpair;
217 
218 	/* In-capsule data buffer */
219 	uint8_t				*buf;
220 
221 	struct spdk_nvmf_rdma_wr	rdma_wr;
222 
223 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
224 };
225 
226 struct spdk_nvmf_rdma_request_data {
227 	struct spdk_nvmf_rdma_wr	rdma_wr;
228 	struct ibv_send_wr		wr;
229 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
230 	void				*buffers[SPDK_NVMF_MAX_SGL_ENTRIES];
231 };
232 
233 struct spdk_nvmf_rdma_request {
234 	struct spdk_nvmf_request		req;
235 	bool					data_from_pool;
236 
237 	enum spdk_nvmf_rdma_request_state	state;
238 
239 	struct spdk_nvmf_rdma_recv		*recv;
240 
241 	struct {
242 		struct spdk_nvmf_rdma_wr	rdma_wr;
243 		struct	ibv_send_wr		wr;
244 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
245 	} rsp;
246 
247 	struct spdk_nvmf_rdma_request_data	data;
248 
249 	uint32_t				num_outstanding_data_wr;
250 
251 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
252 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
253 };
254 
255 enum spdk_nvmf_rdma_qpair_disconnect_flags {
256 	RDMA_QP_DISCONNECTING		= 1,
257 	RDMA_QP_RECV_DRAINED		= 1 << 1,
258 	RDMA_QP_SEND_DRAINED		= 1 << 2
259 };
260 
261 struct spdk_nvmf_rdma_qpair {
262 	struct spdk_nvmf_qpair			qpair;
263 
264 	struct spdk_nvmf_rdma_port		*port;
265 	struct spdk_nvmf_rdma_poller		*poller;
266 
267 	struct rdma_cm_id			*cm_id;
268 	struct rdma_cm_id			*listen_id;
269 
270 	/* The maximum number of I/O outstanding on this connection at one time */
271 	uint16_t				max_queue_depth;
272 
273 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
274 	uint16_t				max_read_depth;
275 
276 	/* The maximum number of RDMA SEND operations at one time */
277 	uint32_t				max_send_depth;
278 
279 	/* The current number of outstanding WRs from this qpair's
280 	 * recv queue. Should not exceed device->attr.max_queue_depth.
281 	 */
282 	uint16_t				current_recv_depth;
283 
284 	/* The current number of posted WRs from this qpair's
285 	 * send queue. Should not exceed max_send_depth.
286 	 */
287 	uint32_t				current_send_depth;
288 
289 	/* The current number of active RDMA READ operations */
290 	uint16_t				current_read_depth;
291 
292 	/* The maximum number of SGEs per WR on the send queue */
293 	uint32_t				max_send_sge;
294 
295 	/* The maximum number of SGEs per WR on the recv queue */
296 	uint32_t				max_recv_sge;
297 
298 	/* Receives that are waiting for a request object */
299 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
300 
301 	/* Queues to track the requests in all states */
302 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	state_queue[RDMA_REQUEST_NUM_STATES];
303 
304 	/* Number of requests in each state */
305 	uint32_t				state_cntr[RDMA_REQUEST_NUM_STATES];
306 
307 	/* Array of size "max_queue_depth" containing RDMA requests. */
308 	struct spdk_nvmf_rdma_request		*reqs;
309 
310 	/* Array of size "max_queue_depth" containing RDMA recvs. */
311 	struct spdk_nvmf_rdma_recv		*recvs;
312 
313 	/* Array of size "max_queue_depth" containing 64 byte capsules
314 	 * used for receive.
315 	 */
316 	union nvmf_h2c_msg			*cmds;
317 	struct ibv_mr				*cmds_mr;
318 
319 	/* Array of size "max_queue_depth" containing 16 byte completions
320 	 * to be sent back to the user.
321 	 */
322 	union nvmf_c2h_msg			*cpls;
323 	struct ibv_mr				*cpls_mr;
324 
325 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
326 	 * buffers to be used for in capsule data.
327 	 */
328 	void					*bufs;
329 	struct ibv_mr				*bufs_mr;
330 
331 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
332 
333 	/* IBV queue pair attributes: they are used to manage
334 	 * qp state and recover from errors.
335 	 */
336 	struct ibv_qp_attr			ibv_attr;
337 
338 	uint32_t				disconnect_flags;
339 	struct spdk_nvmf_rdma_wr		drain_send_wr;
340 	struct spdk_nvmf_rdma_wr		drain_recv_wr;
341 
342 	/* There are several ways a disconnect can start on a qpair
343 	 * and they are not all mutually exclusive. It is important
344 	 * that we only initialize one of these paths.
345 	 */
346 	bool					disconnect_started;
347 };
348 
349 struct spdk_nvmf_rdma_poller {
350 	struct spdk_nvmf_rdma_device		*device;
351 	struct spdk_nvmf_rdma_poll_group	*group;
352 
353 	int					num_cqe;
354 	int					required_num_wr;
355 	struct ibv_cq				*cq;
356 
357 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
358 
359 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
360 };
361 
362 struct spdk_nvmf_rdma_poll_group {
363 	struct spdk_nvmf_transport_poll_group	group;
364 
365 	/* Requests that are waiting to obtain a data buffer */
366 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
367 
368 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
369 };
370 
371 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
372 struct spdk_nvmf_rdma_device {
373 	struct ibv_device_attr			attr;
374 	struct ibv_context			*context;
375 
376 	struct spdk_mem_map			*map;
377 	struct ibv_pd				*pd;
378 
379 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
380 };
381 
382 struct spdk_nvmf_rdma_port {
383 	struct spdk_nvme_transport_id		trid;
384 	struct rdma_cm_id			*id;
385 	struct spdk_nvmf_rdma_device		*device;
386 	uint32_t				ref;
387 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
388 };
389 
390 struct spdk_nvmf_rdma_transport {
391 	struct spdk_nvmf_transport	transport;
392 
393 	struct rdma_event_channel	*event_channel;
394 
395 	struct spdk_mempool		*data_wr_pool;
396 
397 	pthread_mutex_t			lock;
398 
399 	/* fields used to poll RDMA/IB events */
400 	nfds_t			npoll_fds;
401 	struct pollfd		*poll_fds;
402 
403 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
404 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
405 };
406 
407 static inline int
408 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
409 {
410 	switch (state) {
411 	case IBV_QPS_RESET:
412 	case IBV_QPS_INIT:
413 	case IBV_QPS_RTR:
414 	case IBV_QPS_RTS:
415 	case IBV_QPS_SQD:
416 	case IBV_QPS_SQE:
417 	case IBV_QPS_ERR:
418 		return 0;
419 	default:
420 		return -1;
421 	}
422 }
423 
424 static enum ibv_qp_state
425 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
426 	enum ibv_qp_state old_state, new_state;
427 	struct ibv_qp_init_attr init_attr;
428 	int rc;
429 
430 	/* All the attributes needed for recovery */
431 	static int spdk_nvmf_ibv_attr_mask =
432 	IBV_QP_STATE |
433 	IBV_QP_PKEY_INDEX |
434 	IBV_QP_PORT |
435 	IBV_QP_ACCESS_FLAGS |
436 	IBV_QP_AV |
437 	IBV_QP_PATH_MTU |
438 	IBV_QP_DEST_QPN |
439 	IBV_QP_RQ_PSN |
440 	IBV_QP_MAX_DEST_RD_ATOMIC |
441 	IBV_QP_MIN_RNR_TIMER |
442 	IBV_QP_SQ_PSN |
443 	IBV_QP_TIMEOUT |
444 	IBV_QP_RETRY_CNT |
445 	IBV_QP_RNR_RETRY |
446 	IBV_QP_MAX_QP_RD_ATOMIC;
447 
448 	old_state = rqpair->ibv_attr.qp_state;
449 	rc = ibv_query_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
450 			  spdk_nvmf_ibv_attr_mask, &init_attr);
451 
452 	if (rc)
453 	{
454 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
455 		assert(false);
456 	}
457 
458 	new_state = rqpair->ibv_attr.qp_state;
459 
460 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
461 	if (rc)
462 	{
463 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
464 		/*
465 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
466 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
467 		 */
468 		return IBV_QPS_ERR + 1;
469 	}
470 
471 	if (old_state != new_state)
472 	{
473 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
474 				  (uintptr_t)rqpair->cm_id, new_state);
475 	}
476 	return new_state;
477 }
478 
479 static const char *str_ibv_qp_state[] = {
480 	"IBV_QPS_RESET",
481 	"IBV_QPS_INIT",
482 	"IBV_QPS_RTR",
483 	"IBV_QPS_RTS",
484 	"IBV_QPS_SQD",
485 	"IBV_QPS_SQE",
486 	"IBV_QPS_ERR",
487 	"IBV_QPS_UNKNOWN"
488 };
489 
490 static int
491 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
492 			     enum ibv_qp_state new_state)
493 {
494 	int rc;
495 	enum ibv_qp_state state;
496 	static int attr_mask_rc[] = {
497 		[IBV_QPS_RESET] = IBV_QP_STATE,
498 		[IBV_QPS_INIT] = (IBV_QP_STATE |
499 				  IBV_QP_PKEY_INDEX |
500 				  IBV_QP_PORT |
501 				  IBV_QP_ACCESS_FLAGS),
502 		[IBV_QPS_RTR] = (IBV_QP_STATE |
503 				 IBV_QP_AV |
504 				 IBV_QP_PATH_MTU |
505 				 IBV_QP_DEST_QPN |
506 				 IBV_QP_RQ_PSN |
507 				 IBV_QP_MAX_DEST_RD_ATOMIC |
508 				 IBV_QP_MIN_RNR_TIMER),
509 		[IBV_QPS_RTS] = (IBV_QP_STATE |
510 				 IBV_QP_SQ_PSN |
511 				 IBV_QP_TIMEOUT |
512 				 IBV_QP_RETRY_CNT |
513 				 IBV_QP_RNR_RETRY |
514 				 IBV_QP_MAX_QP_RD_ATOMIC),
515 		[IBV_QPS_SQD] = IBV_QP_STATE,
516 		[IBV_QPS_SQE] = IBV_QP_STATE,
517 		[IBV_QPS_ERR] = IBV_QP_STATE,
518 	};
519 
520 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
521 	if (rc) {
522 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
523 			    rqpair->qpair.qid, new_state);
524 		return rc;
525 	}
526 
527 	rqpair->ibv_attr.cur_qp_state = rqpair->ibv_attr.qp_state;
528 	rqpair->ibv_attr.qp_state = new_state;
529 	rqpair->ibv_attr.ah_attr.port_num = rqpair->ibv_attr.port_num;
530 
531 	rc = ibv_modify_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
532 			   attr_mask_rc[new_state]);
533 
534 	if (rc) {
535 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
536 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
537 		return rc;
538 	}
539 
540 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
541 
542 	if (state != new_state) {
543 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
544 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
545 			    str_ibv_qp_state[state]);
546 		return -1;
547 	}
548 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
549 		      str_ibv_qp_state[state]);
550 	return 0;
551 }
552 
553 static void
554 spdk_nvmf_rdma_request_set_state(struct spdk_nvmf_rdma_request *rdma_req,
555 				 enum spdk_nvmf_rdma_request_state state)
556 {
557 	struct spdk_nvmf_qpair		*qpair;
558 	struct spdk_nvmf_rdma_qpair	*rqpair;
559 
560 	qpair = rdma_req->req.qpair;
561 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
562 
563 	TAILQ_REMOVE(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
564 	rqpair->state_cntr[rdma_req->state]--;
565 
566 	rdma_req->state = state;
567 
568 	TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
569 	rqpair->state_cntr[rdma_req->state]++;
570 }
571 
572 static int
573 spdk_nvmf_rdma_cur_queue_depth(struct spdk_nvmf_rdma_qpair *rqpair)
574 {
575 	return rqpair->max_queue_depth -
576 	       rqpair->state_cntr[RDMA_REQUEST_STATE_FREE];
577 }
578 
579 static void
580 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
581 {
582 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->data_from_pool);
583 	if (req->req.cmd) {
584 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
585 	}
586 	if (req->recv) {
587 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
588 	}
589 }
590 
591 static void
592 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
593 {
594 	int i;
595 	struct spdk_nvmf_rdma_request *req;
596 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
597 	for (i = 1; i < RDMA_REQUEST_NUM_STATES; i++) {
598 		SPDK_ERRLOG("\tdumping requests in state %d\n", i);
599 		TAILQ_FOREACH(req, &rqpair->state_queue[i], state_link) {
600 			nvmf_rdma_dump_request(req);
601 		}
602 	}
603 }
604 
605 static void
606 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
607 {
608 	int qd;
609 
610 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
611 
612 	qd = spdk_nvmf_rdma_cur_queue_depth(rqpair);
613 	if (qd != 0) {
614 		nvmf_rdma_dump_qpair_contents(rqpair);
615 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", qd);
616 	}
617 
618 	if (rqpair->poller) {
619 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
620 	}
621 
622 	if (rqpair->cmds_mr) {
623 		ibv_dereg_mr(rqpair->cmds_mr);
624 	}
625 
626 	if (rqpair->cpls_mr) {
627 		ibv_dereg_mr(rqpair->cpls_mr);
628 	}
629 
630 	if (rqpair->bufs_mr) {
631 		ibv_dereg_mr(rqpair->bufs_mr);
632 	}
633 
634 	if (rqpair->cm_id) {
635 		rdma_destroy_qp(rqpair->cm_id);
636 		rdma_destroy_id(rqpair->cm_id);
637 
638 		if (rqpair->poller) {
639 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
640 		}
641 	}
642 
643 	/* Free all memory */
644 	spdk_dma_free(rqpair->cmds);
645 	spdk_dma_free(rqpair->cpls);
646 	spdk_dma_free(rqpair->bufs);
647 	free(rqpair->reqs);
648 	free(rqpair->recvs);
649 	free(rqpair);
650 }
651 
652 static int
653 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
654 {
655 	struct spdk_nvmf_rdma_transport *rtransport;
656 	struct spdk_nvmf_rdma_qpair	*rqpair;
657 	struct spdk_nvmf_rdma_poller	*rpoller;
658 	int				rc, i, num_cqe, required_num_wr;;
659 	struct spdk_nvmf_rdma_recv	*rdma_recv;
660 	struct spdk_nvmf_rdma_request	*rdma_req;
661 	struct spdk_nvmf_transport	*transport;
662 	struct spdk_nvmf_rdma_device	*device;
663 	struct ibv_qp_init_attr		ibv_init_attr;
664 
665 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
666 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
667 	transport = &rtransport->transport;
668 	device = rqpair->port->device;
669 
670 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
671 	ibv_init_attr.qp_context	= rqpair;
672 	ibv_init_attr.qp_type		= IBV_QPT_RC;
673 	ibv_init_attr.send_cq		= rqpair->poller->cq;
674 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
675 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
676 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
677 	ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
678 					  1; /* RECV operations + dummy drain WR */
679 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
680 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
681 
682 	/* Enlarge CQ size dynamically */
683 	rpoller = rqpair->poller;
684 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
685 	num_cqe = rpoller->num_cqe;
686 	if (num_cqe < required_num_wr) {
687 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
688 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
689 	}
690 
691 	if (rpoller->num_cqe != num_cqe) {
692 		if (required_num_wr > device->attr.max_cqe) {
693 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
694 				    required_num_wr, device->attr.max_cqe);
695 			rdma_destroy_id(rqpair->cm_id);
696 			rqpair->cm_id = NULL;
697 			spdk_nvmf_rdma_qpair_destroy(rqpair);
698 			return -1;
699 		}
700 
701 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
702 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
703 		if (rc) {
704 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
705 			rdma_destroy_id(rqpair->cm_id);
706 			rqpair->cm_id = NULL;
707 			spdk_nvmf_rdma_qpair_destroy(rqpair);
708 			return -1;
709 		}
710 
711 		rpoller->num_cqe = num_cqe;
712 	}
713 
714 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
715 	if (rc) {
716 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
717 		rdma_destroy_id(rqpair->cm_id);
718 		rqpair->cm_id = NULL;
719 		spdk_nvmf_rdma_qpair_destroy(rqpair);
720 		return -1;
721 	}
722 
723 	rpoller->required_num_wr = required_num_wr;
724 
725 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2 + 1),
726 					  ibv_init_attr.cap.max_send_wr);
727 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
728 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
729 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
730 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
731 
732 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
733 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
734 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
735 					0x1000, NULL);
736 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
737 					0x1000, NULL);
738 
739 
740 	if (transport->opts.in_capsule_data_size > 0) {
741 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth *
742 						transport->opts.in_capsule_data_size,
743 						0x1000, NULL);
744 	}
745 
746 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
747 	    !rqpair->cpls || (transport->opts.in_capsule_data_size && !rqpair->bufs)) {
748 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
749 		spdk_nvmf_rdma_qpair_destroy(rqpair);
750 		return -1;
751 	}
752 
753 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
754 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
755 				     IBV_ACCESS_LOCAL_WRITE);
756 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
757 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
758 				     0);
759 
760 	if (transport->opts.in_capsule_data_size) {
761 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
762 					     rqpair->max_queue_depth *
763 					     transport->opts.in_capsule_data_size,
764 					     IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
765 	}
766 
767 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (transport->opts.in_capsule_data_size &&
768 			!rqpair->bufs_mr)) {
769 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
770 		spdk_nvmf_rdma_qpair_destroy(rqpair);
771 		return -1;
772 	}
773 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
774 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
775 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
776 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
777 	if (rqpair->bufs && rqpair->bufs_mr) {
778 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
779 			      rqpair->bufs, rqpair->max_queue_depth *
780 			      transport->opts.in_capsule_data_size, rqpair->bufs_mr->lkey);
781 	}
782 
783 	/* Initialise request state queues and counters of the queue pair */
784 	for (i = RDMA_REQUEST_STATE_FREE; i < RDMA_REQUEST_NUM_STATES; i++) {
785 		TAILQ_INIT(&rqpair->state_queue[i]);
786 		rqpair->state_cntr[i] = 0;
787 	}
788 
789 	rqpair->current_recv_depth = rqpair->max_queue_depth;
790 	for (i = 0; i < rqpair->max_queue_depth; i++) {
791 		struct ibv_recv_wr *bad_wr = NULL;
792 
793 		rdma_recv = &rqpair->recvs[i];
794 		rdma_recv->qpair = rqpair;
795 
796 		/* Set up memory to receive commands */
797 		if (rqpair->bufs) {
798 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i *
799 						  transport->opts.in_capsule_data_size));
800 		}
801 
802 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
803 
804 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
805 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
806 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
807 		rdma_recv->wr.num_sge = 1;
808 
809 		if (rdma_recv->buf && rqpair->bufs_mr) {
810 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
811 			rdma_recv->sgl[1].length = transport->opts.in_capsule_data_size;
812 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
813 			rdma_recv->wr.num_sge++;
814 		}
815 
816 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
817 		rdma_recv->wr.sg_list = rdma_recv->sgl;
818 
819 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
820 		assert(rqpair->current_recv_depth > 0);
821 		rqpair->current_recv_depth--;
822 		if (rc) {
823 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
824 			spdk_nvmf_rdma_qpair_destroy(rqpair);
825 			return -1;
826 		}
827 	}
828 	assert(rqpair->current_recv_depth == 0);
829 
830 	for (i = 0; i < rqpair->max_queue_depth; i++) {
831 		rdma_req = &rqpair->reqs[i];
832 
833 		rdma_req->req.qpair = &rqpair->qpair;
834 		rdma_req->req.cmd = NULL;
835 
836 		/* Set up memory to send responses */
837 		rdma_req->req.rsp = &rqpair->cpls[i];
838 
839 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
840 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
841 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
842 
843 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
844 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
845 		rdma_req->rsp.wr.next = NULL;
846 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
847 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
848 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
849 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
850 
851 		/* Set up memory for data buffers */
852 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
853 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
854 		rdma_req->data.wr.next = NULL;
855 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
856 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
857 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
858 
859 		/* Initialize request state to FREE */
860 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
861 		TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
862 		rqpair->state_cntr[rdma_req->state]++;
863 	}
864 
865 	return 0;
866 }
867 
868 static int
869 request_transfer_in(struct spdk_nvmf_request *req)
870 {
871 	int				rc;
872 	struct spdk_nvmf_rdma_request	*rdma_req;
873 	struct spdk_nvmf_qpair		*qpair;
874 	struct spdk_nvmf_rdma_qpair	*rqpair;
875 	struct ibv_send_wr		*bad_wr = NULL;
876 
877 	qpair = req->qpair;
878 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
879 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
880 
881 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
882 	assert(rdma_req != NULL);
883 
884 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
885 
886 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
887 	if (rc) {
888 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
889 		return -1;
890 	}
891 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
892 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
893 	return 0;
894 }
895 
896 static int
897 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
898 {
899 	int				rc;
900 	struct spdk_nvmf_rdma_request	*rdma_req;
901 	struct spdk_nvmf_qpair		*qpair;
902 	struct spdk_nvmf_rdma_qpair	*rqpair;
903 	struct spdk_nvme_cpl		*rsp;
904 	struct ibv_recv_wr		*bad_recv_wr = NULL;
905 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
906 
907 	*data_posted = 0;
908 	qpair = req->qpair;
909 	rsp = &req->rsp->nvme_cpl;
910 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
911 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
912 
913 	/* Advance our sq_head pointer */
914 	if (qpair->sq_head == qpair->sq_head_max) {
915 		qpair->sq_head = 0;
916 	} else {
917 		qpair->sq_head++;
918 	}
919 	rsp->sqhd = qpair->sq_head;
920 
921 	/* Post the capsule to the recv buffer */
922 	assert(rdma_req->recv != NULL);
923 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
924 		      rqpair);
925 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
926 	if (rc) {
927 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
928 		return rc;
929 	}
930 	rdma_req->recv = NULL;
931 	assert(rqpair->current_recv_depth > 0);
932 	rqpair->current_recv_depth--;
933 
934 	/* Build the response which consists of an optional
935 	 * RDMA WRITE to transfer data, plus an RDMA SEND
936 	 * containing the response.
937 	 */
938 	send_wr = &rdma_req->rsp.wr;
939 
940 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
941 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
942 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
943 		send_wr = &rdma_req->data.wr;
944 		*data_posted = 1;
945 	}
946 
947 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
948 
949 	/* Send the completion */
950 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
951 	if (rc) {
952 		SPDK_ERRLOG("Unable to send response capsule\n");
953 		return rc;
954 	}
955 	/* +1 for the rsp wr */
956 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr + 1;
957 
958 	return 0;
959 }
960 
961 static int
962 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
963 {
964 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
965 	struct rdma_conn_param				ctrlr_event_data = {};
966 	int						rc;
967 
968 	accept_data.recfmt = 0;
969 	accept_data.crqsize = rqpair->max_queue_depth;
970 
971 	ctrlr_event_data.private_data = &accept_data;
972 	ctrlr_event_data.private_data_len = sizeof(accept_data);
973 	if (id->ps == RDMA_PS_TCP) {
974 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
975 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
976 	}
977 
978 	rc = rdma_accept(id, &ctrlr_event_data);
979 	if (rc) {
980 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
981 	} else {
982 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
983 	}
984 
985 	return rc;
986 }
987 
988 static void
989 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
990 {
991 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
992 
993 	rej_data.recfmt = 0;
994 	rej_data.sts = error;
995 
996 	rdma_reject(id, &rej_data, sizeof(rej_data));
997 }
998 
999 static int
1000 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
1001 		  new_qpair_fn cb_fn)
1002 {
1003 	struct spdk_nvmf_rdma_transport *rtransport;
1004 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1005 	struct spdk_nvmf_rdma_port	*port;
1006 	struct rdma_conn_param		*rdma_param = NULL;
1007 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1008 	uint16_t			max_queue_depth;
1009 	uint16_t			max_read_depth;
1010 
1011 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1012 
1013 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1014 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1015 
1016 	rdma_param = &event->param.conn;
1017 	if (rdma_param->private_data == NULL ||
1018 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1019 		SPDK_ERRLOG("connect request: no private data provided\n");
1020 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1021 		return -1;
1022 	}
1023 
1024 	private_data = rdma_param->private_data;
1025 	if (private_data->recfmt != 0) {
1026 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1027 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1028 		return -1;
1029 	}
1030 
1031 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1032 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1033 
1034 	port = event->listen_id->context;
1035 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1036 		      event->listen_id, event->listen_id->verbs, port);
1037 
1038 	/* Figure out the supported queue depth. This is a multi-step process
1039 	 * that takes into account hardware maximums, host provided values,
1040 	 * and our target's internal memory limits */
1041 
1042 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1043 
1044 	/* Start with the maximum queue depth allowed by the target */
1045 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1046 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1047 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1048 		      rtransport->transport.opts.max_queue_depth);
1049 
1050 	/* Next check the local NIC's hardware limitations */
1051 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1052 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1053 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1054 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1055 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1056 
1057 	/* Next check the remote NIC's hardware limitations */
1058 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1059 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1060 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1061 	if (rdma_param->initiator_depth > 0) {
1062 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1063 	}
1064 
1065 	/* Finally check for the host software requested values, which are
1066 	 * optional. */
1067 	if (rdma_param->private_data != NULL &&
1068 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1069 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1070 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1071 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1072 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1073 	}
1074 
1075 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1076 		      max_queue_depth, max_read_depth);
1077 
1078 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1079 	if (rqpair == NULL) {
1080 		SPDK_ERRLOG("Could not allocate new connection.\n");
1081 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1082 		return -1;
1083 	}
1084 
1085 	rqpair->port = port;
1086 	rqpair->max_queue_depth = max_queue_depth;
1087 	rqpair->max_read_depth = max_read_depth;
1088 	rqpair->cm_id = event->id;
1089 	rqpair->listen_id = event->listen_id;
1090 	rqpair->qpair.transport = transport;
1091 	TAILQ_INIT(&rqpair->incoming_queue);
1092 	event->id->context = &rqpair->qpair;
1093 
1094 	cb_fn(&rqpair->qpair);
1095 
1096 	return 0;
1097 }
1098 
1099 static int
1100 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1101 			  enum spdk_mem_map_notify_action action,
1102 			  void *vaddr, size_t size)
1103 {
1104 	struct ibv_pd *pd = cb_ctx;
1105 	struct ibv_mr *mr;
1106 
1107 	switch (action) {
1108 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1109 		if (!g_nvmf_hooks.get_rkey) {
1110 			mr = ibv_reg_mr(pd, vaddr, size,
1111 					IBV_ACCESS_LOCAL_WRITE |
1112 					IBV_ACCESS_REMOTE_READ |
1113 					IBV_ACCESS_REMOTE_WRITE);
1114 			if (mr == NULL) {
1115 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1116 				return -1;
1117 			} else {
1118 				spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1119 			}
1120 		} else {
1121 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1122 						     g_nvmf_hooks.get_rkey(pd, vaddr, size));
1123 		}
1124 		break;
1125 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1126 		if (!g_nvmf_hooks.get_rkey) {
1127 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1128 			spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1129 			if (mr) {
1130 				ibv_dereg_mr(mr);
1131 			}
1132 		}
1133 		break;
1134 	}
1135 
1136 	return 0;
1137 }
1138 
1139 static int
1140 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1141 {
1142 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1143 	return addr_1 == addr_2;
1144 }
1145 
1146 static void
1147 spdk_nvmf_rdma_request_free_buffers(struct spdk_nvmf_rdma_request *rdma_req,
1148 				    struct spdk_nvmf_transport_poll_group *group, struct spdk_nvmf_transport *transport)
1149 {
1150 	for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1151 		if (group->buf_cache_count < group->buf_cache_size) {
1152 			STAILQ_INSERT_HEAD(&group->buf_cache,
1153 					   (struct spdk_nvmf_transport_pg_cache_buf *)rdma_req->data.buffers[i], link);
1154 			group->buf_cache_count++;
1155 		} else {
1156 			spdk_mempool_put(transport->data_buf_pool, rdma_req->data.buffers[i]);
1157 		}
1158 		rdma_req->req.iov[i].iov_base = NULL;
1159 		rdma_req->data.buffers[i] = NULL;
1160 		rdma_req->req.iov[i].iov_len = 0;
1161 
1162 	}
1163 	rdma_req->data_from_pool = false;
1164 }
1165 
1166 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1167 
1168 static spdk_nvme_data_transfer_t
1169 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1170 {
1171 	enum spdk_nvme_data_transfer xfer;
1172 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1173 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1174 
1175 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1176 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1177 	rdma_req->rsp.wr.imm_data = 0;
1178 #endif
1179 
1180 	/* Figure out data transfer direction */
1181 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1182 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1183 	} else {
1184 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1185 
1186 		/* Some admin commands are special cases */
1187 		if ((rdma_req->req.qpair->qid == 0) &&
1188 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1189 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1190 			switch (cmd->cdw10 & 0xff) {
1191 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1192 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1193 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1194 				break;
1195 			default:
1196 				xfer = SPDK_NVME_DATA_NONE;
1197 			}
1198 		}
1199 	}
1200 
1201 	if (xfer == SPDK_NVME_DATA_NONE) {
1202 		return xfer;
1203 	}
1204 
1205 	/* Even for commands that may transfer data, they could have specified 0 length.
1206 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1207 	 */
1208 	switch (sgl->generic.type) {
1209 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1210 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1211 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1212 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1213 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1214 		if (sgl->unkeyed.length == 0) {
1215 			xfer = SPDK_NVME_DATA_NONE;
1216 		}
1217 		break;
1218 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1219 		if (sgl->keyed.length == 0) {
1220 			xfer = SPDK_NVME_DATA_NONE;
1221 		}
1222 		break;
1223 	}
1224 
1225 	return xfer;
1226 }
1227 
1228 static int
1229 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1230 				 struct spdk_nvmf_rdma_device *device,
1231 				 struct spdk_nvmf_rdma_request *rdma_req)
1232 {
1233 	struct spdk_nvmf_rdma_qpair		*rqpair;
1234 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1235 	void					*buf = NULL;
1236 	uint32_t				length = rdma_req->req.length;
1237 	uint64_t				translation_len;
1238 	uint32_t				i = 0;
1239 	int					rc = 0;
1240 
1241 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1242 	rgroup = rqpair->poller->group;
1243 	rdma_req->req.iovcnt = 0;
1244 	while (length) {
1245 		if (!(STAILQ_EMPTY(&rgroup->group.buf_cache))) {
1246 			rgroup->group.buf_cache_count--;
1247 			buf = STAILQ_FIRST(&rgroup->group.buf_cache);
1248 			STAILQ_REMOVE_HEAD(&rgroup->group.buf_cache, link);
1249 			assert(buf != NULL);
1250 		} else {
1251 			buf = spdk_mempool_get(rtransport->transport.data_buf_pool);
1252 			if (!buf) {
1253 				rc = -ENOMEM;
1254 				goto err_exit;
1255 			}
1256 		}
1257 
1258 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
1259 						~NVMF_DATA_BUFFER_MASK);
1260 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->transport.opts.io_unit_size);
1261 		rdma_req->req.iovcnt++;
1262 		rdma_req->data.buffers[i] = buf;
1263 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
1264 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
1265 		translation_len = rdma_req->req.iov[i].iov_len;
1266 
1267 		if (!g_nvmf_hooks.get_rkey) {
1268 			rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1269 							     (uint64_t)buf, &translation_len))->lkey;
1270 		} else {
1271 			rdma_req->data.wr.sg_list[i].lkey = *((uint64_t *)spdk_mem_map_translate(device->map,
1272 							      (uint64_t)buf, &translation_len));
1273 		}
1274 
1275 		length -= rdma_req->req.iov[i].iov_len;
1276 
1277 		if (translation_len < rdma_req->req.iov[i].iov_len) {
1278 			SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
1279 			rc = -EINVAL;
1280 			goto err_exit;
1281 		}
1282 		i++;
1283 	}
1284 
1285 	assert(rdma_req->req.iovcnt <= rqpair->max_send_sge);
1286 
1287 	rdma_req->data_from_pool = true;
1288 
1289 	return rc;
1290 
1291 err_exit:
1292 	spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport);
1293 	while (i) {
1294 		i--;
1295 		rdma_req->data.wr.sg_list[i].addr = 0;
1296 		rdma_req->data.wr.sg_list[i].length = 0;
1297 		rdma_req->data.wr.sg_list[i].lkey = 0;
1298 	}
1299 	rdma_req->req.iovcnt = 0;
1300 	return rc;
1301 }
1302 
1303 static int
1304 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1305 				 struct spdk_nvmf_rdma_device *device,
1306 				 struct spdk_nvmf_rdma_request *rdma_req)
1307 {
1308 	struct spdk_nvme_cmd			*cmd;
1309 	struct spdk_nvme_cpl			*rsp;
1310 	struct spdk_nvme_sgl_descriptor		*sgl;
1311 
1312 	cmd = &rdma_req->req.cmd->nvme_cmd;
1313 	rsp = &rdma_req->req.rsp->nvme_cpl;
1314 	sgl = &cmd->dptr.sgl1;
1315 
1316 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1317 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1318 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1319 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1320 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1321 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1322 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1323 			return -1;
1324 		}
1325 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1326 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1327 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1328 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1329 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1330 			}
1331 		}
1332 #endif
1333 
1334 		/* fill request length and populate iovs */
1335 		rdma_req->req.length = sgl->keyed.length;
1336 
1337 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1338 			/* No available buffers. Queue this request up. */
1339 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1340 			return 0;
1341 		}
1342 
1343 		/* backward compatible */
1344 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1345 
1346 		/* rdma wr specifics */
1347 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1348 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1349 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1350 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1351 			rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
1352 			rdma_req->data.wr.next = &rdma_req->rsp.wr;
1353 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1354 			rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
1355 			rdma_req->data.wr.next = NULL;
1356 		}
1357 
1358 		/* set the number of outstanding data WRs for this request. */
1359 		rdma_req->num_outstanding_data_wr = 1;
1360 
1361 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1362 			      rdma_req->req.iovcnt);
1363 
1364 		return 0;
1365 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1366 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1367 		uint64_t offset = sgl->address;
1368 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1369 
1370 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1371 			      offset, sgl->unkeyed.length);
1372 
1373 		if (offset > max_len) {
1374 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1375 				    offset, max_len);
1376 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1377 			return -1;
1378 		}
1379 		max_len -= (uint32_t)offset;
1380 
1381 		if (sgl->unkeyed.length > max_len) {
1382 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1383 				    sgl->unkeyed.length, max_len);
1384 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1385 			return -1;
1386 		}
1387 
1388 		rdma_req->num_outstanding_data_wr = 0;
1389 		rdma_req->req.data = rdma_req->recv->buf + offset;
1390 		rdma_req->data_from_pool = false;
1391 		rdma_req->req.length = sgl->unkeyed.length;
1392 
1393 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1394 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1395 		rdma_req->req.iovcnt = 1;
1396 
1397 		return 0;
1398 	}
1399 
1400 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1401 		    sgl->generic.type, sgl->generic.subtype);
1402 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1403 	return -1;
1404 }
1405 
1406 static void
1407 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1408 		       struct spdk_nvmf_rdma_transport	*rtransport)
1409 {
1410 	struct spdk_nvmf_rdma_qpair		*rqpair;
1411 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1412 
1413 	if (rdma_req->data_from_pool) {
1414 		rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1415 		rgroup = rqpair->poller->group;
1416 
1417 		spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport);
1418 	}
1419 	rdma_req->num_outstanding_data_wr = 0;
1420 	rdma_req->req.length = 0;
1421 	rdma_req->req.iovcnt = 0;
1422 	rdma_req->req.data = NULL;
1423 	spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
1424 }
1425 
1426 static bool
1427 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1428 			       struct spdk_nvmf_rdma_request *rdma_req)
1429 {
1430 	struct spdk_nvmf_rdma_qpair	*rqpair;
1431 	struct spdk_nvmf_rdma_device	*device;
1432 	struct spdk_nvmf_rdma_poll_group *rgroup;
1433 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1434 	int				rc;
1435 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1436 	enum spdk_nvmf_rdma_request_state prev_state;
1437 	bool				progress = false;
1438 	int				data_posted;
1439 
1440 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1441 	device = rqpair->port->device;
1442 	rgroup = rqpair->poller->group;
1443 
1444 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1445 
1446 	/* If the queue pair is in an error state, force the request to the completed state
1447 	 * to release resources. */
1448 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1449 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1450 			TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1451 		}
1452 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1453 	}
1454 
1455 	/* The loop here is to allow for several back-to-back state changes. */
1456 	do {
1457 		prev_state = rdma_req->state;
1458 
1459 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1460 
1461 		switch (rdma_req->state) {
1462 		case RDMA_REQUEST_STATE_FREE:
1463 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1464 			 * to escape this state. */
1465 			break;
1466 		case RDMA_REQUEST_STATE_NEW:
1467 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1468 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1469 			rdma_recv = rdma_req->recv;
1470 
1471 			/* The first element of the SGL is the NVMe command */
1472 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1473 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1474 
1475 			TAILQ_REMOVE(&rqpair->incoming_queue, rdma_recv, link);
1476 
1477 			if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1478 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1479 				break;
1480 			}
1481 
1482 			/* The next state transition depends on the data transfer needs of this request. */
1483 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1484 
1485 			/* If no data to transfer, ready to execute. */
1486 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1487 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1488 				break;
1489 			}
1490 
1491 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEED_BUFFER);
1492 			TAILQ_INSERT_TAIL(&rgroup->pending_data_buf_queue, rdma_req, link);
1493 			break;
1494 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1495 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1496 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1497 
1498 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1499 
1500 			if (rdma_req != TAILQ_FIRST(&rgroup->pending_data_buf_queue)) {
1501 				/* This request needs to wait in line to obtain a buffer */
1502 				break;
1503 			}
1504 
1505 			/* Try to get a data buffer */
1506 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1507 			if (rc < 0) {
1508 				TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1509 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1510 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1511 				break;
1512 			}
1513 
1514 			if (!rdma_req->req.data) {
1515 				/* No buffers available. */
1516 				break;
1517 			}
1518 
1519 			TAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, link);
1520 
1521 			/* If data is transferring from host to controller and the data didn't
1522 			 * arrive using in capsule data, we need to do a transfer from the host.
1523 			 */
1524 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1525 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING);
1526 				break;
1527 			}
1528 
1529 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1530 			break;
1531 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1532 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1533 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1534 
1535 			if (rdma_req != TAILQ_FIRST(
1536 				    &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING])) {
1537 				/* This request needs to wait in line to perform RDMA */
1538 				break;
1539 			}
1540 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1541 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1542 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1543 				break;
1544 			}
1545 			rc = request_transfer_in(&rdma_req->req);
1546 			if (!rc) {
1547 				spdk_nvmf_rdma_request_set_state(rdma_req,
1548 								 RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
1549 			} else {
1550 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1551 				spdk_nvmf_rdma_request_set_state(rdma_req,
1552 								 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1553 			}
1554 			break;
1555 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1556 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1557 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1558 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1559 			 * to escape this state. */
1560 			break;
1561 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1562 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1563 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1564 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTING);
1565 			spdk_nvmf_request_exec(&rdma_req->req);
1566 			break;
1567 		case RDMA_REQUEST_STATE_EXECUTING:
1568 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1569 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1570 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1571 			 * to escape this state. */
1572 			break;
1573 		case RDMA_REQUEST_STATE_EXECUTED:
1574 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1575 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1576 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1577 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING);
1578 			} else {
1579 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1580 			}
1581 			break;
1582 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
1583 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
1584 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1585 
1586 			if (rdma_req != TAILQ_FIRST(
1587 				    &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING])) {
1588 				/* This request needs to wait in line to perform RDMA */
1589 				break;
1590 			}
1591 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
1592 			    rqpair->max_send_depth) {
1593 				/* We can only have so many WRs outstanding. we have to wait until some finish.
1594 				 * +1 since each request has an additional wr in the resp. */
1595 				break;
1596 			}
1597 			/* The data transfer will be kicked off from
1598 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
1599 			 */
1600 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1601 			break;
1602 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1603 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
1604 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1605 			rc = request_transfer_out(&rdma_req->req, &data_posted);
1606 			assert(rc == 0); /* No good way to handle this currently */
1607 			if (rc) {
1608 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1609 			} else {
1610 				spdk_nvmf_rdma_request_set_state(rdma_req,
1611 								 data_posted ?
1612 								 RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
1613 								 RDMA_REQUEST_STATE_COMPLETING);
1614 			}
1615 			break;
1616 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
1617 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
1618 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1619 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1620 			 * to escape this state. */
1621 			break;
1622 		case RDMA_REQUEST_STATE_COMPLETING:
1623 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
1624 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1625 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1626 			 * to escape this state. */
1627 			break;
1628 		case RDMA_REQUEST_STATE_COMPLETED:
1629 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
1630 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1631 
1632 			nvmf_rdma_request_free(rdma_req, rtransport);
1633 			break;
1634 		case RDMA_REQUEST_NUM_STATES:
1635 		default:
1636 			assert(0);
1637 			break;
1638 		}
1639 
1640 		if (rdma_req->state != prev_state) {
1641 			progress = true;
1642 		}
1643 	} while (rdma_req->state != prev_state);
1644 
1645 	return progress;
1646 }
1647 
1648 /* Public API callbacks begin here */
1649 
1650 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
1651 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
1652 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
1653 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
1654 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
1655 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
1656 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 512
1657 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
1658 
1659 static void
1660 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
1661 {
1662 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
1663 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
1664 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
1665 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
1666 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
1667 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
1668 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
1669 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
1670 }
1671 
1672 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
1673 
1674 static struct spdk_nvmf_transport *
1675 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
1676 {
1677 	int rc;
1678 	struct spdk_nvmf_rdma_transport *rtransport;
1679 	struct spdk_nvmf_rdma_device	*device, *tmp;
1680 	struct ibv_context		**contexts;
1681 	uint32_t			i;
1682 	int				flag;
1683 	uint32_t			sge_count;
1684 	uint32_t			min_shared_buffers;
1685 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
1686 
1687 	rtransport = calloc(1, sizeof(*rtransport));
1688 	if (!rtransport) {
1689 		return NULL;
1690 	}
1691 
1692 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
1693 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
1694 		free(rtransport);
1695 		return NULL;
1696 	}
1697 
1698 	TAILQ_INIT(&rtransport->devices);
1699 	TAILQ_INIT(&rtransport->ports);
1700 
1701 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1702 
1703 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
1704 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
1705 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
1706 		     "  in_capsule_data_size=%d, max_aq_depth=%d\n"
1707 		     "  num_shared_buffers=%d\n",
1708 		     opts->max_queue_depth,
1709 		     opts->max_io_size,
1710 		     opts->max_qpairs_per_ctrlr,
1711 		     opts->io_unit_size,
1712 		     opts->in_capsule_data_size,
1713 		     opts->max_aq_depth,
1714 		     opts->num_shared_buffers);
1715 
1716 	/* I/O unit size cannot be larger than max I/O size */
1717 	if (opts->io_unit_size > opts->max_io_size) {
1718 		opts->io_unit_size = opts->max_io_size;
1719 	}
1720 
1721 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
1722 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
1723 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
1724 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
1725 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1726 		return NULL;
1727 	}
1728 
1729 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
1730 	if (min_shared_buffers > opts->num_shared_buffers) {
1731 		SPDK_ERRLOG("There are not enough buffers to satisfy"
1732 			    "per-poll group caches for each thread. (%" PRIu32 ")"
1733 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
1734 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
1735 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1736 		return NULL;
1737 	}
1738 
1739 	sge_count = opts->max_io_size / opts->io_unit_size;
1740 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
1741 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
1742 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1743 		return NULL;
1744 	}
1745 
1746 	rtransport->event_channel = rdma_create_event_channel();
1747 	if (rtransport->event_channel == NULL) {
1748 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1749 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1750 		return NULL;
1751 	}
1752 
1753 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1754 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1755 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1756 			    rtransport->event_channel->fd, spdk_strerror(errno));
1757 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1758 		return NULL;
1759 	}
1760 
1761 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
1762 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
1763 				   sizeof(struct spdk_nvmf_rdma_request_data),
1764 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1765 				   SPDK_ENV_SOCKET_ID_ANY);
1766 	if (!rtransport->data_wr_pool) {
1767 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
1768 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1769 		return NULL;
1770 	}
1771 
1772 	contexts = rdma_get_devices(NULL);
1773 	if (contexts == NULL) {
1774 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
1775 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1776 		return NULL;
1777 	}
1778 
1779 	i = 0;
1780 	rc = 0;
1781 	while (contexts[i] != NULL) {
1782 		device = calloc(1, sizeof(*device));
1783 		if (!device) {
1784 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1785 			rc = -ENOMEM;
1786 			break;
1787 		}
1788 		device->context = contexts[i];
1789 		rc = ibv_query_device(device->context, &device->attr);
1790 		if (rc < 0) {
1791 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1792 			free(device);
1793 			break;
1794 
1795 		}
1796 
1797 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
1798 
1799 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1800 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
1801 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
1802 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
1803 		}
1804 
1805 		/**
1806 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
1807 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
1808 		 * but incorrectly reports that it does. There are changes making their way
1809 		 * through the kernel now that will enable this feature. When they are merged,
1810 		 * we can conditionally enable this feature.
1811 		 *
1812 		 * TODO: enable this for versions of the kernel rxe driver that support it.
1813 		 */
1814 		if (device->attr.vendor_id == 0) {
1815 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
1816 		}
1817 #endif
1818 
1819 		/* set up device context async ev fd as NON_BLOCKING */
1820 		flag = fcntl(device->context->async_fd, F_GETFL);
1821 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1822 		if (rc < 0) {
1823 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1824 			free(device);
1825 			break;
1826 		}
1827 
1828 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1829 		i++;
1830 	}
1831 	rdma_free_devices(contexts);
1832 
1833 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
1834 		/* divide and round up. */
1835 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
1836 
1837 		/* round up to the nearest 4k. */
1838 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
1839 
1840 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
1841 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
1842 			       opts->io_unit_size);
1843 	}
1844 
1845 	if (rc < 0) {
1846 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1847 		return NULL;
1848 	}
1849 
1850 	/* Set up poll descriptor array to monitor events from RDMA and IB
1851 	 * in a single poll syscall
1852 	 */
1853 	rtransport->npoll_fds = i + 1;
1854 	i = 0;
1855 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1856 	if (rtransport->poll_fds == NULL) {
1857 		SPDK_ERRLOG("poll_fds allocation failed\n");
1858 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1859 		return NULL;
1860 	}
1861 
1862 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1863 	rtransport->poll_fds[i++].events = POLLIN;
1864 
1865 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1866 		rtransport->poll_fds[i].fd = device->context->async_fd;
1867 		rtransport->poll_fds[i++].events = POLLIN;
1868 	}
1869 
1870 	return &rtransport->transport;
1871 }
1872 
1873 static int
1874 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1875 {
1876 	struct spdk_nvmf_rdma_transport	*rtransport;
1877 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1878 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1879 
1880 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1881 
1882 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1883 		TAILQ_REMOVE(&rtransport->ports, port, link);
1884 		rdma_destroy_id(port->id);
1885 		free(port);
1886 	}
1887 
1888 	if (rtransport->poll_fds != NULL) {
1889 		free(rtransport->poll_fds);
1890 	}
1891 
1892 	if (rtransport->event_channel != NULL) {
1893 		rdma_destroy_event_channel(rtransport->event_channel);
1894 	}
1895 
1896 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1897 		TAILQ_REMOVE(&rtransport->devices, device, link);
1898 		if (device->map) {
1899 			spdk_mem_map_free(&device->map);
1900 		}
1901 		if (device->pd) {
1902 			if (!g_nvmf_hooks.get_ibv_pd) {
1903 				ibv_dealloc_pd(device->pd);
1904 			}
1905 		}
1906 		free(device);
1907 	}
1908 
1909 	if (rtransport->data_wr_pool != NULL) {
1910 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
1911 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
1912 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
1913 				    spdk_mempool_count(rtransport->data_wr_pool),
1914 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
1915 		}
1916 	}
1917 
1918 	spdk_mempool_free(rtransport->data_wr_pool);
1919 	pthread_mutex_destroy(&rtransport->lock);
1920 	free(rtransport);
1921 
1922 	return 0;
1923 }
1924 
1925 static int
1926 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
1927 			       struct spdk_nvme_transport_id *trid,
1928 			       bool peer);
1929 
1930 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
1931 	.notify_cb = spdk_nvmf_rdma_mem_notify,
1932 	.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
1933 };
1934 
1935 static int
1936 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1937 		      const struct spdk_nvme_transport_id *trid)
1938 {
1939 	struct spdk_nvmf_rdma_transport	*rtransport;
1940 	struct spdk_nvmf_rdma_device	*device;
1941 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1942 	struct ibv_pd			*pd;
1943 	struct addrinfo			*res;
1944 	struct addrinfo			hints;
1945 	int				family;
1946 	int				rc;
1947 
1948 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1949 
1950 	port = calloc(1, sizeof(*port));
1951 	if (!port) {
1952 		return -ENOMEM;
1953 	}
1954 
1955 	/* Selectively copy the trid. Things like NQN don't matter here - that
1956 	 * mapping is enforced elsewhere.
1957 	 */
1958 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1959 	port->trid.adrfam = trid->adrfam;
1960 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1961 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1962 
1963 	pthread_mutex_lock(&rtransport->lock);
1964 	assert(rtransport->event_channel != NULL);
1965 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1966 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1967 			port_tmp->ref++;
1968 			free(port);
1969 			/* Already listening at this address */
1970 			pthread_mutex_unlock(&rtransport->lock);
1971 			return 0;
1972 		}
1973 	}
1974 
1975 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1976 	if (rc < 0) {
1977 		SPDK_ERRLOG("rdma_create_id() failed\n");
1978 		free(port);
1979 		pthread_mutex_unlock(&rtransport->lock);
1980 		return rc;
1981 	}
1982 
1983 	switch (port->trid.adrfam) {
1984 	case SPDK_NVMF_ADRFAM_IPV4:
1985 		family = AF_INET;
1986 		break;
1987 	case SPDK_NVMF_ADRFAM_IPV6:
1988 		family = AF_INET6;
1989 		break;
1990 	default:
1991 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1992 		free(port);
1993 		pthread_mutex_unlock(&rtransport->lock);
1994 		return -EINVAL;
1995 	}
1996 
1997 	memset(&hints, 0, sizeof(hints));
1998 	hints.ai_family = family;
1999 	hints.ai_flags = AI_NUMERICSERV;
2000 	hints.ai_socktype = SOCK_STREAM;
2001 	hints.ai_protocol = 0;
2002 
2003 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
2004 	if (rc) {
2005 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2006 		free(port);
2007 		pthread_mutex_unlock(&rtransport->lock);
2008 		return -EINVAL;
2009 	}
2010 
2011 	rc = rdma_bind_addr(port->id, res->ai_addr);
2012 	freeaddrinfo(res);
2013 
2014 	if (rc < 0) {
2015 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2016 		rdma_destroy_id(port->id);
2017 		free(port);
2018 		pthread_mutex_unlock(&rtransport->lock);
2019 		return rc;
2020 	}
2021 
2022 	if (!port->id->verbs) {
2023 		SPDK_ERRLOG("ibv_context is null\n");
2024 		rdma_destroy_id(port->id);
2025 		free(port);
2026 		pthread_mutex_unlock(&rtransport->lock);
2027 		return -1;
2028 	}
2029 
2030 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
2031 	if (rc < 0) {
2032 		SPDK_ERRLOG("rdma_listen() failed\n");
2033 		rdma_destroy_id(port->id);
2034 		free(port);
2035 		pthread_mutex_unlock(&rtransport->lock);
2036 		return rc;
2037 	}
2038 
2039 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2040 		if (device->context == port->id->verbs) {
2041 			port->device = device;
2042 			break;
2043 		}
2044 	}
2045 	if (!port->device) {
2046 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2047 			    port->id->verbs);
2048 		rdma_destroy_id(port->id);
2049 		free(port);
2050 		pthread_mutex_unlock(&rtransport->lock);
2051 		return -EINVAL;
2052 	}
2053 
2054 	pd = NULL;
2055 	if (g_nvmf_hooks.get_ibv_pd) {
2056 		if (spdk_nvmf_rdma_trid_from_cm_id(port->id, &port->trid, 1) < 0) {
2057 			rdma_destroy_id(port->id);
2058 			free(port);
2059 			pthread_mutex_unlock(&rtransport->lock);
2060 			return -EINVAL;
2061 		}
2062 
2063 		pd = g_nvmf_hooks.get_ibv_pd(&port->trid, port->id->verbs);
2064 	}
2065 
2066 	if (device->pd == NULL) {
2067 		/* Haven't created a protection domain yet. */
2068 
2069 		if (!g_nvmf_hooks.get_ibv_pd) {
2070 			device->pd = ibv_alloc_pd(device->context);
2071 			if (!device->pd) {
2072 				SPDK_ERRLOG("Unable to allocate protection domain.\n");
2073 				rdma_destroy_id(port->id);
2074 				free(port);
2075 				pthread_mutex_unlock(&rtransport->lock);
2076 				return -ENOMEM;
2077 			}
2078 		} else {
2079 			device->pd = pd;
2080 		}
2081 
2082 		assert(device->map == NULL);
2083 
2084 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2085 		if (!device->map) {
2086 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2087 			if (!g_nvmf_hooks.get_ibv_pd) {
2088 				ibv_dealloc_pd(device->pd);
2089 			}
2090 			rdma_destroy_id(port->id);
2091 			free(port);
2092 			pthread_mutex_unlock(&rtransport->lock);
2093 			return -ENOMEM;
2094 		}
2095 	} else if (g_nvmf_hooks.get_ibv_pd) {
2096 		/* A protection domain exists for this device, but the user has
2097 		 * enabled hooks. Verify that they only supply one pd per device. */
2098 		if (device->pd != pd) {
2099 			SPDK_ERRLOG("The NVMe-oF target only supports one protection domain per device.\n");
2100 			rdma_destroy_id(port->id);
2101 			free(port);
2102 			pthread_mutex_unlock(&rtransport->lock);
2103 			return -EINVAL;
2104 		}
2105 	}
2106 
2107 	assert(device->map != NULL);
2108 	assert(device->pd != NULL);
2109 
2110 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
2111 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
2112 
2113 	port->ref = 1;
2114 
2115 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2116 	pthread_mutex_unlock(&rtransport->lock);
2117 
2118 	return 0;
2119 }
2120 
2121 static int
2122 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2123 			   const struct spdk_nvme_transport_id *_trid)
2124 {
2125 	struct spdk_nvmf_rdma_transport *rtransport;
2126 	struct spdk_nvmf_rdma_port *port, *tmp;
2127 	struct spdk_nvme_transport_id trid = {};
2128 
2129 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2130 
2131 	/* Selectively copy the trid. Things like NQN don't matter here - that
2132 	 * mapping is enforced elsewhere.
2133 	 */
2134 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2135 	trid.adrfam = _trid->adrfam;
2136 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2137 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2138 
2139 	pthread_mutex_lock(&rtransport->lock);
2140 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2141 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2142 			assert(port->ref > 0);
2143 			port->ref--;
2144 			if (port->ref == 0) {
2145 				TAILQ_REMOVE(&rtransport->ports, port, link);
2146 				rdma_destroy_id(port->id);
2147 				free(port);
2148 			}
2149 			break;
2150 		}
2151 	}
2152 
2153 	pthread_mutex_unlock(&rtransport->lock);
2154 	return 0;
2155 }
2156 
2157 static bool
2158 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
2159 {
2160 	struct spdk_nvmf_rdma_qpair *rqpair;
2161 
2162 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2163 
2164 	if (spdk_nvmf_rdma_cur_queue_depth(rqpair) == 0) {
2165 		return true;
2166 	}
2167 	return false;
2168 }
2169 
2170 static void
2171 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2172 				     struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2173 {
2174 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
2175 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2176 
2177 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2178 	TAILQ_FOREACH_SAFE(rdma_req,
2179 			   &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING],
2180 			   state_link, req_tmp) {
2181 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2182 			break;
2183 		}
2184 	}
2185 
2186 	/* Then RDMA writes sincereads have stronger restrictions than writes */
2187 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING],
2188 			   state_link, req_tmp) {
2189 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2190 			break;
2191 		}
2192 	}
2193 
2194 	/* The second highest priority is I/O waiting on memory buffers. */
2195 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->poller->group->pending_data_buf_queue, link,
2196 			   req_tmp) {
2197 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2198 			break;
2199 		}
2200 	}
2201 
2202 	/* The lowest priority is processing newly received commands */
2203 	TAILQ_FOREACH_SAFE(rdma_recv, &rqpair->incoming_queue, link, recv_tmp) {
2204 		if (TAILQ_EMPTY(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE])) {
2205 			break;
2206 		}
2207 
2208 		rdma_req = TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE]);
2209 		rdma_req->recv = rdma_recv;
2210 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEW);
2211 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2212 			break;
2213 		}
2214 	}
2215 }
2216 
2217 static void
2218 _nvmf_rdma_qpair_disconnect(void *ctx)
2219 {
2220 	struct spdk_nvmf_qpair *qpair = ctx;
2221 
2222 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2223 }
2224 
2225 static void
2226 _nvmf_rdma_try_disconnect(void *ctx)
2227 {
2228 	struct spdk_nvmf_qpair *qpair = ctx;
2229 	struct spdk_nvmf_poll_group *group;
2230 
2231 	/* Read the group out of the qpair. This is normally set and accessed only from
2232 	 * the thread that created the group. Here, we're not on that thread necessarily.
2233 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2234 	 * a pointer and never changes. So fortunately reading this and checking for
2235 	 * non-NULL is thread safe in the x86_64 memory model. */
2236 	group = qpair->group;
2237 
2238 	if (group == NULL) {
2239 		/* The qpair hasn't been assigned to a group yet, so we can't
2240 		 * process a disconnect. Send a message to ourself and try again. */
2241 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2242 		return;
2243 	}
2244 
2245 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2246 }
2247 
2248 static inline void
2249 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2250 {
2251 	if (__sync_bool_compare_and_swap(&rqpair->disconnect_started, false, true)) {
2252 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2253 	}
2254 }
2255 
2256 
2257 static int
2258 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2259 {
2260 	struct spdk_nvmf_qpair		*qpair;
2261 	struct spdk_nvmf_rdma_qpair	*rqpair;
2262 
2263 	if (evt->id == NULL) {
2264 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2265 		return -1;
2266 	}
2267 
2268 	qpair = evt->id->context;
2269 	if (qpair == NULL) {
2270 		SPDK_ERRLOG("disconnect request: no active connection\n");
2271 		return -1;
2272 	}
2273 
2274 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2275 
2276 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2277 
2278 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2279 
2280 	spdk_nvmf_rdma_start_disconnect(rqpair);
2281 
2282 	return 0;
2283 }
2284 
2285 #ifdef DEBUG
2286 static const char *CM_EVENT_STR[] = {
2287 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2288 	"RDMA_CM_EVENT_ADDR_ERROR",
2289 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2290 	"RDMA_CM_EVENT_ROUTE_ERROR",
2291 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2292 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2293 	"RDMA_CM_EVENT_CONNECT_ERROR",
2294 	"RDMA_CM_EVENT_UNREACHABLE",
2295 	"RDMA_CM_EVENT_REJECTED",
2296 	"RDMA_CM_EVENT_ESTABLISHED",
2297 	"RDMA_CM_EVENT_DISCONNECTED",
2298 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2299 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2300 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2301 	"RDMA_CM_EVENT_ADDR_CHANGE",
2302 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2303 };
2304 #endif /* DEBUG */
2305 
2306 static void
2307 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2308 {
2309 	struct spdk_nvmf_rdma_transport *rtransport;
2310 	struct rdma_cm_event		*event;
2311 	int				rc;
2312 
2313 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2314 
2315 	if (rtransport->event_channel == NULL) {
2316 		return;
2317 	}
2318 
2319 	while (1) {
2320 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2321 		if (rc == 0) {
2322 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2323 
2324 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2325 
2326 			switch (event->event) {
2327 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2328 			case RDMA_CM_EVENT_ADDR_ERROR:
2329 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2330 			case RDMA_CM_EVENT_ROUTE_ERROR:
2331 				/* No action required. The target never attempts to resolve routes. */
2332 				break;
2333 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2334 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2335 				if (rc < 0) {
2336 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2337 					break;
2338 				}
2339 				break;
2340 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2341 				/* The target never initiates a new connection. So this will not occur. */
2342 				break;
2343 			case RDMA_CM_EVENT_CONNECT_ERROR:
2344 				/* Can this happen? The docs say it can, but not sure what causes it. */
2345 				break;
2346 			case RDMA_CM_EVENT_UNREACHABLE:
2347 			case RDMA_CM_EVENT_REJECTED:
2348 				/* These only occur on the client side. */
2349 				break;
2350 			case RDMA_CM_EVENT_ESTABLISHED:
2351 				/* TODO: Should we be waiting for this event anywhere? */
2352 				break;
2353 			case RDMA_CM_EVENT_DISCONNECTED:
2354 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2355 				rc = nvmf_rdma_disconnect(event);
2356 				if (rc < 0) {
2357 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2358 					break;
2359 				}
2360 				break;
2361 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2362 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2363 				/* Multicast is not used */
2364 				break;
2365 			case RDMA_CM_EVENT_ADDR_CHANGE:
2366 				/* Not utilizing this event */
2367 				break;
2368 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2369 				/* For now, do nothing. The target never re-uses queue pairs. */
2370 				break;
2371 			default:
2372 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2373 				break;
2374 			}
2375 
2376 			rdma_ack_cm_event(event);
2377 		} else {
2378 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2379 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2380 			}
2381 			break;
2382 		}
2383 	}
2384 }
2385 
2386 static void
2387 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2388 {
2389 	int				rc;
2390 	struct spdk_nvmf_rdma_qpair	*rqpair;
2391 	struct ibv_async_event		event;
2392 	enum ibv_qp_state		state;
2393 
2394 	rc = ibv_get_async_event(device->context, &event);
2395 
2396 	if (rc) {
2397 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2398 			    errno, spdk_strerror(errno));
2399 		return;
2400 	}
2401 
2402 	SPDK_NOTICELOG("Async event: %s\n",
2403 		       ibv_event_type_str(event.event_type));
2404 
2405 	switch (event.event_type) {
2406 	case IBV_EVENT_QP_FATAL:
2407 		rqpair = event.element.qp->qp_context;
2408 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2409 				  (uintptr_t)rqpair->cm_id, event.event_type);
2410 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2411 		spdk_nvmf_rdma_start_disconnect(rqpair);
2412 		break;
2413 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2414 		/* This event only occurs for shared receive queues, which are not currently supported. */
2415 		break;
2416 	case IBV_EVENT_SQ_DRAINED:
2417 		/* This event occurs frequently in both error and non-error states.
2418 		 * Check if the qpair is in an error state before sending a message.
2419 		 * Note that we're not on the correct thread to access the qpair, but
2420 		 * the operations that the below calls make all happen to be thread
2421 		 * safe. */
2422 		rqpair = event.element.qp->qp_context;
2423 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2424 				  (uintptr_t)rqpair->cm_id, event.event_type);
2425 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2426 		if (state == IBV_QPS_ERR) {
2427 			spdk_nvmf_rdma_start_disconnect(rqpair);
2428 		}
2429 		break;
2430 	case IBV_EVENT_QP_REQ_ERR:
2431 	case IBV_EVENT_QP_ACCESS_ERR:
2432 	case IBV_EVENT_COMM_EST:
2433 	case IBV_EVENT_PATH_MIG:
2434 	case IBV_EVENT_PATH_MIG_ERR:
2435 		rqpair = event.element.qp->qp_context;
2436 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2437 				  (uintptr_t)rqpair->cm_id, event.event_type);
2438 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2439 		break;
2440 	case IBV_EVENT_CQ_ERR:
2441 	case IBV_EVENT_DEVICE_FATAL:
2442 	case IBV_EVENT_PORT_ACTIVE:
2443 	case IBV_EVENT_PORT_ERR:
2444 	case IBV_EVENT_LID_CHANGE:
2445 	case IBV_EVENT_PKEY_CHANGE:
2446 	case IBV_EVENT_SM_CHANGE:
2447 	case IBV_EVENT_SRQ_ERR:
2448 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2449 	case IBV_EVENT_CLIENT_REREGISTER:
2450 	case IBV_EVENT_GID_CHANGE:
2451 	default:
2452 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2453 		break;
2454 	}
2455 	ibv_ack_async_event(&event);
2456 }
2457 
2458 static void
2459 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2460 {
2461 	int	nfds, i = 0;
2462 	struct spdk_nvmf_rdma_transport *rtransport;
2463 	struct spdk_nvmf_rdma_device *device, *tmp;
2464 
2465 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2466 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2467 
2468 	if (nfds <= 0) {
2469 		return;
2470 	}
2471 
2472 	/* The first poll descriptor is RDMA CM event */
2473 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2474 		spdk_nvmf_process_cm_event(transport, cb_fn);
2475 		nfds--;
2476 	}
2477 
2478 	if (nfds == 0) {
2479 		return;
2480 	}
2481 
2482 	/* Second and subsequent poll descriptors are IB async events */
2483 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2484 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2485 			spdk_nvmf_process_ib_event(device);
2486 			nfds--;
2487 		}
2488 	}
2489 	/* check all flagged fd's have been served */
2490 	assert(nfds == 0);
2491 }
2492 
2493 static void
2494 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2495 			struct spdk_nvme_transport_id *trid,
2496 			struct spdk_nvmf_discovery_log_page_entry *entry)
2497 {
2498 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2499 	entry->adrfam = trid->adrfam;
2500 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2501 
2502 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2503 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2504 
2505 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2506 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2507 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2508 }
2509 
2510 static struct spdk_nvmf_transport_poll_group *
2511 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2512 {
2513 	struct spdk_nvmf_rdma_transport		*rtransport;
2514 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2515 	struct spdk_nvmf_rdma_poller		*poller, *tpoller;
2516 	struct spdk_nvmf_rdma_device		*device;
2517 
2518 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2519 
2520 	rgroup = calloc(1, sizeof(*rgroup));
2521 	if (!rgroup) {
2522 		return NULL;
2523 	}
2524 
2525 	TAILQ_INIT(&rgroup->pollers);
2526 	TAILQ_INIT(&rgroup->pending_data_buf_queue);
2527 
2528 	pthread_mutex_lock(&rtransport->lock);
2529 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2530 		poller = calloc(1, sizeof(*poller));
2531 		if (!poller) {
2532 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2533 			goto err_exit;
2534 		}
2535 
2536 		poller->device = device;
2537 		poller->group = rgroup;
2538 
2539 		TAILQ_INIT(&poller->qpairs);
2540 
2541 		poller->cq = ibv_create_cq(device->context, DEFAULT_NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
2542 		if (!poller->cq) {
2543 			SPDK_ERRLOG("Unable to create completion queue\n");
2544 			free(poller);
2545 			goto err_exit;
2546 		}
2547 		poller->num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2548 
2549 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2550 	}
2551 
2552 	pthread_mutex_unlock(&rtransport->lock);
2553 	return &rgroup->group;
2554 
2555 err_exit:
2556 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tpoller) {
2557 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2558 		if (poller->cq) {
2559 			ibv_destroy_cq(poller->cq);
2560 		}
2561 		free(poller);
2562 	}
2563 
2564 	free(rgroup);
2565 	pthread_mutex_unlock(&rtransport->lock);
2566 	return NULL;
2567 }
2568 
2569 static void
2570 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
2571 {
2572 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2573 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
2574 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
2575 
2576 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2577 
2578 	if (!rgroup) {
2579 		return;
2580 	}
2581 
2582 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
2583 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2584 
2585 		if (poller->cq) {
2586 			ibv_destroy_cq(poller->cq);
2587 		}
2588 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
2589 			spdk_nvmf_rdma_qpair_destroy(qpair);
2590 		}
2591 
2592 		free(poller);
2593 	}
2594 
2595 	if (!TAILQ_EMPTY(&rgroup->pending_data_buf_queue)) {
2596 		SPDK_ERRLOG("Pending I/O list wasn't empty on poll group destruction\n");
2597 	}
2598 
2599 	free(rgroup);
2600 }
2601 
2602 static void
2603 spdk_nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
2604 {
2605 	spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2606 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2607 }
2608 
2609 static int
2610 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
2611 			      struct spdk_nvmf_qpair *qpair)
2612 {
2613 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2614 	struct spdk_nvmf_rdma_qpair		*rqpair;
2615 	struct spdk_nvmf_rdma_device		*device;
2616 	struct spdk_nvmf_rdma_poller		*poller;
2617 	int					rc;
2618 
2619 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2620 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2621 
2622 	device = rqpair->port->device;
2623 
2624 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
2625 		if (poller->device == device) {
2626 			break;
2627 		}
2628 	}
2629 
2630 	if (!poller) {
2631 		SPDK_ERRLOG("No poller found for device.\n");
2632 		return -1;
2633 	}
2634 
2635 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
2636 	rqpair->poller = poller;
2637 
2638 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
2639 	if (rc < 0) {
2640 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
2641 		return -1;
2642 	}
2643 
2644 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
2645 	if (rc) {
2646 		/* Try to reject, but we probably can't */
2647 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
2648 		return -1;
2649 	}
2650 
2651 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2652 
2653 	return 0;
2654 }
2655 
2656 static int
2657 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
2658 {
2659 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2660 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2661 			struct spdk_nvmf_rdma_transport, transport);
2662 
2663 	nvmf_rdma_request_free(rdma_req, rtransport);
2664 	return 0;
2665 }
2666 
2667 static int
2668 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
2669 {
2670 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2671 			struct spdk_nvmf_rdma_transport, transport);
2672 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
2673 			struct spdk_nvmf_rdma_request, req);
2674 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
2675 			struct spdk_nvmf_rdma_qpair, qpair);
2676 
2677 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2678 		/* The connection is alive, so process the request as normal */
2679 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTED);
2680 	} else {
2681 		/* The connection is dead. Move the request directly to the completed state. */
2682 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2683 	}
2684 
2685 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2686 
2687 	return 0;
2688 }
2689 
2690 static void
2691 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
2692 {
2693 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2694 	struct ibv_recv_wr recv_wr = {};
2695 	struct ibv_recv_wr *bad_recv_wr;
2696 	struct ibv_send_wr send_wr = {};
2697 	struct ibv_send_wr *bad_send_wr;
2698 	int rc;
2699 
2700 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
2701 		return;
2702 	}
2703 
2704 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
2705 
2706 	/* This happens only when the qpair is disconnected before
2707 	 * it is added to the poll group. Since there is no poll group,
2708 	 * the RDMA qp has not been initialized yet and the RDMA CM
2709 	 * event has not yet been acknowledged, so we need to reject it.
2710 	 */
2711 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
2712 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
2713 		return;
2714 	}
2715 
2716 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2717 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
2718 	}
2719 
2720 	rqpair->drain_recv_wr.type = RDMA_WR_TYPE_DRAIN_RECV;
2721 	recv_wr.wr_id = (uintptr_t)&rqpair->drain_recv_wr;
2722 	rc = ibv_post_recv(rqpair->cm_id->qp, &recv_wr, &bad_recv_wr);
2723 	if (rc) {
2724 		SPDK_ERRLOG("Failed to post dummy receive WR, errno %d\n", errno);
2725 		assert(false);
2726 		return;
2727 	}
2728 
2729 	rqpair->drain_send_wr.type = RDMA_WR_TYPE_DRAIN_SEND;
2730 	send_wr.wr_id = (uintptr_t)&rqpair->drain_send_wr;
2731 	send_wr.opcode = IBV_WR_SEND;
2732 	rc = ibv_post_send(rqpair->cm_id->qp, &send_wr, &bad_send_wr);
2733 	if (rc) {
2734 		SPDK_ERRLOG("Failed to post dummy send WR, errno %d\n", errno);
2735 		assert(false);
2736 		return;
2737 	}
2738 	rqpair->current_send_depth++;
2739 }
2740 
2741 #ifdef DEBUG
2742 static int
2743 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
2744 {
2745 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
2746 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
2747 }
2748 #endif
2749 
2750 static int
2751 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2752 			   struct spdk_nvmf_rdma_poller *rpoller)
2753 {
2754 	struct ibv_wc wc[32];
2755 	struct spdk_nvmf_rdma_wr	*rdma_wr;
2756 	struct spdk_nvmf_rdma_request	*rdma_req;
2757 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2758 	struct spdk_nvmf_rdma_qpair	*rqpair;
2759 	int reaped, i;
2760 	int count = 0;
2761 	bool error = false;
2762 
2763 	/* Poll for completing operations. */
2764 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2765 	if (reaped < 0) {
2766 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2767 			    errno, spdk_strerror(errno));
2768 		return -1;
2769 	}
2770 
2771 	for (i = 0; i < reaped; i++) {
2772 
2773 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
2774 
2775 		/* Handle error conditions */
2776 		if (wc[i].status) {
2777 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2778 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2779 
2780 			error = true;
2781 
2782 			switch (rdma_wr->type) {
2783 			case RDMA_WR_TYPE_SEND:
2784 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2785 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2786 
2787 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2788 				/* We're going to attempt an error recovery, so force the request into
2789 				 * the completed state. */
2790 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2791 				rqpair->current_send_depth--;
2792 
2793 				assert(rdma_req->num_outstanding_data_wr == 0);
2794 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2795 				break;
2796 			case RDMA_WR_TYPE_RECV:
2797 				rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2798 				rqpair = rdma_recv->qpair;
2799 
2800 				/* Dump this into the incoming queue. This gets cleaned up when
2801 				 * the queue pair disconnects or recovers. */
2802 				TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2803 				rqpair->current_recv_depth++;
2804 
2805 				/* Don't worry about responding to recv overflow, we are disconnecting anyways */
2806 				break;
2807 			case RDMA_WR_TYPE_DATA:
2808 				/* If the data transfer fails still force the queue into the error state,
2809 				 * if we were performing an RDMA_READ, we need to force the request into a
2810 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
2811 				 * case, we should wait for the SEND to complete. */
2812 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2813 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2814 
2815 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2816 				rdma_req->num_outstanding_data_wr--;
2817 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
2818 					assert(rdma_req->num_outstanding_data_wr > 0);
2819 					rqpair->current_read_depth--;
2820 					if (rdma_req->num_outstanding_data_wr == 0) {
2821 						spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2822 					}
2823 				}
2824 				rqpair->current_send_depth--;
2825 				break;
2826 			case RDMA_WR_TYPE_DRAIN_RECV:
2827 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_recv_wr);
2828 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2829 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP RECV %u (%p)\n", rqpair->qpair.qid, rqpair);
2830 				rqpair->disconnect_flags |= RDMA_QP_RECV_DRAINED;
2831 				assert(rqpair->current_recv_depth == rqpair->max_queue_depth);
2832 				/* Don't worry about responding to recv overflow, we are disconnecting anyways */
2833 				if (rqpair->disconnect_flags & RDMA_QP_SEND_DRAINED) {
2834 					spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2835 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2836 				}
2837 				/* Continue so that this does not trigger the disconnect path below. */
2838 				continue;
2839 			case RDMA_WR_TYPE_DRAIN_SEND:
2840 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_send_wr);
2841 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2842 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP SEND %u (%p)\n", rqpair->qpair.qid, rqpair);
2843 				rqpair->disconnect_flags |= RDMA_QP_SEND_DRAINED;
2844 				rqpair->current_send_depth--;
2845 				if (rqpair->disconnect_flags & RDMA_QP_RECV_DRAINED) {
2846 					spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2847 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2848 				}
2849 				/* Continue so that this does not trigger the disconnect path below. */
2850 				continue;
2851 			default:
2852 				SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2853 				continue;
2854 			}
2855 
2856 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
2857 				/* Disconnect the connection. */
2858 				spdk_nvmf_rdma_start_disconnect(rqpair);
2859 			}
2860 			continue;
2861 		}
2862 
2863 		switch (wc[i].opcode) {
2864 		case IBV_WC_SEND:
2865 			assert(rdma_wr->type == RDMA_WR_TYPE_SEND);
2866 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2867 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2868 
2869 			assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
2870 
2871 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2872 			rqpair->current_send_depth--;
2873 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2874 
2875 			count++;
2876 
2877 			assert(rdma_req->num_outstanding_data_wr == 0);
2878 			/* Try to process other queued requests */
2879 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2880 			break;
2881 
2882 		case IBV_WC_RDMA_WRITE:
2883 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2884 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2885 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2886 			rqpair->current_send_depth--;
2887 			rdma_req->num_outstanding_data_wr--;
2888 
2889 			/* Try to process other queued requests */
2890 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2891 			break;
2892 
2893 		case IBV_WC_RDMA_READ:
2894 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2895 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2896 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2897 			rqpair->current_send_depth--;
2898 
2899 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2900 			/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
2901 			assert(rdma_req->num_outstanding_data_wr > 0);
2902 			rqpair->current_read_depth--;
2903 			rdma_req->num_outstanding_data_wr--;
2904 			if (rdma_req->num_outstanding_data_wr == 0) {
2905 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
2906 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2907 			}
2908 
2909 			/* Try to process other queued requests */
2910 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2911 			break;
2912 
2913 		case IBV_WC_RECV:
2914 			assert(rdma_wr->type == RDMA_WR_TYPE_RECV);
2915 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2916 			rqpair = rdma_recv->qpair;
2917 			/* The qpair should not send more requests than are allowed per qpair. */
2918 			if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
2919 				spdk_nvmf_rdma_start_disconnect(rqpair);
2920 			} else {
2921 				rqpair->current_recv_depth++;
2922 			}
2923 			TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2924 			/* Try to process other queued requests */
2925 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
2926 			break;
2927 
2928 		default:
2929 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2930 			continue;
2931 		}
2932 	}
2933 
2934 	if (error == true) {
2935 		return -1;
2936 	}
2937 
2938 	return count;
2939 }
2940 
2941 static int
2942 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2943 {
2944 	struct spdk_nvmf_rdma_transport *rtransport;
2945 	struct spdk_nvmf_rdma_poll_group *rgroup;
2946 	struct spdk_nvmf_rdma_poller	*rpoller;
2947 	int				count, rc;
2948 
2949 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2950 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2951 
2952 	count = 0;
2953 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2954 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2955 		if (rc < 0) {
2956 			return rc;
2957 		}
2958 		count += rc;
2959 	}
2960 
2961 	return count;
2962 }
2963 
2964 static int
2965 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2966 			       struct spdk_nvme_transport_id *trid,
2967 			       bool peer)
2968 {
2969 	struct sockaddr *saddr;
2970 	uint16_t port;
2971 
2972 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
2973 
2974 	if (peer) {
2975 		saddr = rdma_get_peer_addr(id);
2976 	} else {
2977 		saddr = rdma_get_local_addr(id);
2978 	}
2979 	switch (saddr->sa_family) {
2980 	case AF_INET: {
2981 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
2982 
2983 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
2984 		inet_ntop(AF_INET, &saddr_in->sin_addr,
2985 			  trid->traddr, sizeof(trid->traddr));
2986 		if (peer) {
2987 			port = ntohs(rdma_get_dst_port(id));
2988 		} else {
2989 			port = ntohs(rdma_get_src_port(id));
2990 		}
2991 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2992 		break;
2993 	}
2994 	case AF_INET6: {
2995 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
2996 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
2997 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
2998 			  trid->traddr, sizeof(trid->traddr));
2999 		if (peer) {
3000 			port = ntohs(rdma_get_dst_port(id));
3001 		} else {
3002 			port = ntohs(rdma_get_src_port(id));
3003 		}
3004 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3005 		break;
3006 	}
3007 	default:
3008 		return -1;
3009 
3010 	}
3011 
3012 	return 0;
3013 }
3014 
3015 static int
3016 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3017 				   struct spdk_nvme_transport_id *trid)
3018 {
3019 	struct spdk_nvmf_rdma_qpair	*rqpair;
3020 
3021 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3022 
3023 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
3024 }
3025 
3026 static int
3027 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
3028 				    struct spdk_nvme_transport_id *trid)
3029 {
3030 	struct spdk_nvmf_rdma_qpair	*rqpair;
3031 
3032 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3033 
3034 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
3035 }
3036 
3037 static int
3038 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
3039 				     struct spdk_nvme_transport_id *trid)
3040 {
3041 	struct spdk_nvmf_rdma_qpair	*rqpair;
3042 
3043 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3044 
3045 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
3046 }
3047 
3048 void
3049 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
3050 {
3051 	g_nvmf_hooks = *hooks;
3052 }
3053 
3054 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
3055 	.type = SPDK_NVME_TRANSPORT_RDMA,
3056 	.opts_init = spdk_nvmf_rdma_opts_init,
3057 	.create = spdk_nvmf_rdma_create,
3058 	.destroy = spdk_nvmf_rdma_destroy,
3059 
3060 	.listen = spdk_nvmf_rdma_listen,
3061 	.stop_listen = spdk_nvmf_rdma_stop_listen,
3062 	.accept = spdk_nvmf_rdma_accept,
3063 
3064 	.listener_discover = spdk_nvmf_rdma_discover,
3065 
3066 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
3067 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
3068 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
3069 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
3070 
3071 	.req_free = spdk_nvmf_rdma_request_free,
3072 	.req_complete = spdk_nvmf_rdma_request_complete,
3073 
3074 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
3075 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
3076 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
3077 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
3078 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
3079 
3080 };
3081 
3082 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
3083