xref: /spdk/lib/nvmf/rdma.c (revision 310fc0b5d56fa43b80af869270fcf2758df9c92d)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019 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 /* Timeout for destroying defunct rqpairs */
68 #define NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US	4000000
69 
70 /* The maximum number of buffers per request */
71 #define NVMF_REQ_MAX_BUFFERS	(SPDK_NVMF_MAX_SGL_ENTRIES * 2)
72 
73 static int g_spdk_nvmf_ibv_query_mask =
74 	IBV_QP_STATE |
75 	IBV_QP_PKEY_INDEX |
76 	IBV_QP_PORT |
77 	IBV_QP_ACCESS_FLAGS |
78 	IBV_QP_AV |
79 	IBV_QP_PATH_MTU |
80 	IBV_QP_DEST_QPN |
81 	IBV_QP_RQ_PSN |
82 	IBV_QP_MAX_DEST_RD_ATOMIC |
83 	IBV_QP_MIN_RNR_TIMER |
84 	IBV_QP_SQ_PSN |
85 	IBV_QP_TIMEOUT |
86 	IBV_QP_RETRY_CNT |
87 	IBV_QP_RNR_RETRY |
88 	IBV_QP_MAX_QP_RD_ATOMIC;
89 
90 enum spdk_nvmf_rdma_request_state {
91 	/* The request is not currently in use */
92 	RDMA_REQUEST_STATE_FREE = 0,
93 
94 	/* Initial state when request first received */
95 	RDMA_REQUEST_STATE_NEW,
96 
97 	/* The request is queued until a data buffer is available. */
98 	RDMA_REQUEST_STATE_NEED_BUFFER,
99 
100 	/* The request is waiting on RDMA queue depth availability
101 	 * to transfer data from the host to the controller.
102 	 */
103 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
104 
105 	/* The request is currently transferring data from the host to the controller. */
106 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
107 
108 	/* The request is ready to execute at the block device */
109 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
110 
111 	/* The request is currently executing at the block device */
112 	RDMA_REQUEST_STATE_EXECUTING,
113 
114 	/* The request finished executing at the block device */
115 	RDMA_REQUEST_STATE_EXECUTED,
116 
117 	/* The request is waiting on RDMA queue depth availability
118 	 * to transfer data from the controller to the host.
119 	 */
120 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
121 
122 	/* The request is ready to send a completion */
123 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
124 
125 	/* The request is currently transferring data from the controller to the host. */
126 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
127 
128 	/* The request currently has an outstanding completion without an
129 	 * associated data transfer.
130 	 */
131 	RDMA_REQUEST_STATE_COMPLETING,
132 
133 	/* The request completed and can be marked free. */
134 	RDMA_REQUEST_STATE_COMPLETED,
135 
136 	/* Terminator */
137 	RDMA_REQUEST_NUM_STATES,
138 };
139 
140 #define OBJECT_NVMF_RDMA_IO				0x40
141 
142 #define TRACE_GROUP_NVMF_RDMA				0x4
143 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
144 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
145 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
146 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
147 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
148 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
149 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
150 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
151 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
152 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
153 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
154 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
155 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
156 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
157 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
158 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
159 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
160 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
161 
162 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
163 {
164 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
165 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
170 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
173 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
175 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
176 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
178 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
179 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
180 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
181 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
182 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
183 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
184 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
185 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
186 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
187 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
188 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
189 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
190 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
191 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
192 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
193 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
194 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
195 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
196 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
197 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
198 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
199 
200 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
201 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
202 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
203 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
204 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
205 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
206 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
207 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
208 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
209 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
210 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
211 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
212 }
213 
214 enum spdk_nvmf_rdma_wr_type {
215 	RDMA_WR_TYPE_RECV,
216 	RDMA_WR_TYPE_SEND,
217 	RDMA_WR_TYPE_DATA,
218 };
219 
220 struct spdk_nvmf_rdma_wr {
221 	enum spdk_nvmf_rdma_wr_type	type;
222 };
223 
224 /* This structure holds commands as they are received off the wire.
225  * It must be dynamically paired with a full request object
226  * (spdk_nvmf_rdma_request) to service a request. It is separate
227  * from the request because RDMA does not appear to order
228  * completions, so occasionally we'll get a new incoming
229  * command when there aren't any free request objects.
230  */
231 struct spdk_nvmf_rdma_recv {
232 	struct ibv_recv_wr			wr;
233 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
234 
235 	struct spdk_nvmf_rdma_qpair		*qpair;
236 
237 	/* In-capsule data buffer */
238 	uint8_t					*buf;
239 
240 	struct spdk_nvmf_rdma_wr		rdma_wr;
241 
242 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
243 };
244 
245 struct spdk_nvmf_rdma_request_data {
246 	struct spdk_nvmf_rdma_wr	rdma_wr;
247 	struct ibv_send_wr		wr;
248 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
249 };
250 
251 struct spdk_nvmf_rdma_request {
252 	struct spdk_nvmf_request		req;
253 	bool					data_from_pool;
254 
255 	enum spdk_nvmf_rdma_request_state	state;
256 
257 	struct spdk_nvmf_rdma_recv		*recv;
258 
259 	struct {
260 		struct spdk_nvmf_rdma_wr	rdma_wr;
261 		struct	ibv_send_wr		wr;
262 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
263 	} rsp;
264 
265 	struct spdk_nvmf_rdma_request_data	data;
266 	void					*buffers[NVMF_REQ_MAX_BUFFERS];
267 
268 	uint32_t				num_outstanding_data_wr;
269 
270 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
271 };
272 
273 enum spdk_nvmf_rdma_qpair_disconnect_flags {
274 	RDMA_QP_DISCONNECTING		= 1,
275 	RDMA_QP_RECV_DRAINED		= 1 << 1,
276 	RDMA_QP_SEND_DRAINED		= 1 << 2
277 };
278 
279 struct spdk_nvmf_rdma_resource_opts {
280 	struct spdk_nvmf_rdma_qpair	*qpair;
281 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
282 	void				*qp;
283 	struct ibv_pd			*pd;
284 	uint32_t			max_queue_depth;
285 	uint32_t			in_capsule_data_size;
286 	bool				shared;
287 };
288 
289 struct spdk_nvmf_send_wr_list {
290 	struct ibv_send_wr	*first;
291 	struct ibv_send_wr	*last;
292 };
293 
294 struct spdk_nvmf_recv_wr_list {
295 	struct ibv_recv_wr	*first;
296 	struct ibv_recv_wr	*last;
297 };
298 
299 struct spdk_nvmf_rdma_resources {
300 	/* Array of size "max_queue_depth" containing RDMA requests. */
301 	struct spdk_nvmf_rdma_request		*reqs;
302 
303 	/* Array of size "max_queue_depth" containing RDMA recvs. */
304 	struct spdk_nvmf_rdma_recv		*recvs;
305 
306 	/* Array of size "max_queue_depth" containing 64 byte capsules
307 	 * used for receive.
308 	 */
309 	union nvmf_h2c_msg			*cmds;
310 	struct ibv_mr				*cmds_mr;
311 
312 	/* Array of size "max_queue_depth" containing 16 byte completions
313 	 * to be sent back to the user.
314 	 */
315 	union nvmf_c2h_msg			*cpls;
316 	struct ibv_mr				*cpls_mr;
317 
318 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
319 	 * buffers to be used for in capsule data.
320 	 */
321 	void					*bufs;
322 	struct ibv_mr				*bufs_mr;
323 
324 	/* The list of pending recvs to transfer */
325 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
326 
327 	/* Receives that are waiting for a request object */
328 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
329 
330 	/* Queue to track free requests */
331 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
332 };
333 
334 struct spdk_nvmf_rdma_qpair {
335 	struct spdk_nvmf_qpair			qpair;
336 
337 	struct spdk_nvmf_rdma_port		*port;
338 	struct spdk_nvmf_rdma_poller		*poller;
339 
340 	struct rdma_cm_id			*cm_id;
341 	struct ibv_srq				*srq;
342 	struct rdma_cm_id			*listen_id;
343 
344 	/* The maximum number of I/O outstanding on this connection at one time */
345 	uint16_t				max_queue_depth;
346 
347 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
348 	uint16_t				max_read_depth;
349 
350 	/* The maximum number of RDMA SEND operations at one time */
351 	uint32_t				max_send_depth;
352 
353 	/* The current number of outstanding WRs from this qpair's
354 	 * recv queue. Should not exceed device->attr.max_queue_depth.
355 	 */
356 	uint16_t				current_recv_depth;
357 
358 	/* The current number of active RDMA READ operations */
359 	uint16_t				current_read_depth;
360 
361 	/* The current number of posted WRs from this qpair's
362 	 * send queue. Should not exceed max_send_depth.
363 	 */
364 	uint32_t				current_send_depth;
365 
366 	/* The maximum number of SGEs per WR on the send queue */
367 	uint32_t				max_send_sge;
368 
369 	/* The maximum number of SGEs per WR on the recv queue */
370 	uint32_t				max_recv_sge;
371 
372 	/* The list of pending send requests for a transfer */
373 	struct spdk_nvmf_send_wr_list		sends_to_post;
374 
375 	struct spdk_nvmf_rdma_resources		*resources;
376 
377 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
378 
379 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
380 
381 	/* Number of requests not in the free state */
382 	uint32_t				qd;
383 
384 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
385 
386 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
387 
388 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
389 
390 	/* IBV queue pair attributes: they are used to manage
391 	 * qp state and recover from errors.
392 	 */
393 	enum ibv_qp_state			ibv_state;
394 
395 	uint32_t				disconnect_flags;
396 
397 	/* Poller registered in case the qpair doesn't properly
398 	 * complete the qpair destruct process and becomes defunct.
399 	 */
400 
401 	struct spdk_poller			*destruct_poller;
402 
403 	/* There are several ways a disconnect can start on a qpair
404 	 * and they are not all mutually exclusive. It is important
405 	 * that we only initialize one of these paths.
406 	 */
407 	bool					disconnect_started;
408 	/* Lets us know that we have received the last_wqe event. */
409 	bool					last_wqe_reached;
410 };
411 
412 struct spdk_nvmf_rdma_poller {
413 	struct spdk_nvmf_rdma_device		*device;
414 	struct spdk_nvmf_rdma_poll_group	*group;
415 
416 	int					num_cqe;
417 	int					required_num_wr;
418 	struct ibv_cq				*cq;
419 
420 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
421 	uint16_t				max_srq_depth;
422 
423 	/* Shared receive queue */
424 	struct ibv_srq				*srq;
425 
426 	struct spdk_nvmf_rdma_resources		*resources;
427 
428 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
429 
430 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
431 
432 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
433 
434 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
435 };
436 
437 struct spdk_nvmf_rdma_poll_group {
438 	struct spdk_nvmf_transport_poll_group	group;
439 
440 	/* Requests that are waiting to obtain a data buffer */
441 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
442 
443 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
444 };
445 
446 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
447 struct spdk_nvmf_rdma_device {
448 	struct ibv_device_attr			attr;
449 	struct ibv_context			*context;
450 
451 	struct spdk_mem_map			*map;
452 	struct ibv_pd				*pd;
453 
454 	int					num_srq;
455 
456 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
457 };
458 
459 struct spdk_nvmf_rdma_port {
460 	struct spdk_nvme_transport_id		trid;
461 	struct rdma_cm_id			*id;
462 	struct spdk_nvmf_rdma_device		*device;
463 	uint32_t				ref;
464 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
465 };
466 
467 struct spdk_nvmf_rdma_transport {
468 	struct spdk_nvmf_transport	transport;
469 
470 	struct rdma_event_channel	*event_channel;
471 
472 	struct spdk_mempool		*data_wr_pool;
473 
474 	pthread_mutex_t			lock;
475 
476 	/* fields used to poll RDMA/IB events */
477 	nfds_t			npoll_fds;
478 	struct pollfd		*poll_fds;
479 
480 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
481 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
482 };
483 
484 static inline int
485 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
486 {
487 	switch (state) {
488 	case IBV_QPS_RESET:
489 	case IBV_QPS_INIT:
490 	case IBV_QPS_RTR:
491 	case IBV_QPS_RTS:
492 	case IBV_QPS_SQD:
493 	case IBV_QPS_SQE:
494 	case IBV_QPS_ERR:
495 		return 0;
496 	default:
497 		return -1;
498 	}
499 }
500 
501 static enum ibv_qp_state
502 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
503 	enum ibv_qp_state old_state, new_state;
504 	struct ibv_qp_attr qp_attr;
505 	struct ibv_qp_init_attr init_attr;
506 	int rc;
507 
508 	old_state = rqpair->ibv_state;
509 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
510 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
511 
512 	if (rc)
513 	{
514 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
515 		return IBV_QPS_ERR + 1;
516 	}
517 
518 	new_state = qp_attr.qp_state;
519 	rqpair->ibv_state = new_state;
520 	qp_attr.ah_attr.port_num = qp_attr.port_num;
521 
522 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
523 	if (rc)
524 	{
525 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
526 		/*
527 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
528 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
529 		 */
530 		return IBV_QPS_ERR + 1;
531 	}
532 
533 	if (old_state != new_state)
534 	{
535 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
536 				  (uintptr_t)rqpair->cm_id, new_state);
537 	}
538 	return new_state;
539 }
540 
541 static const char *str_ibv_qp_state[] = {
542 	"IBV_QPS_RESET",
543 	"IBV_QPS_INIT",
544 	"IBV_QPS_RTR",
545 	"IBV_QPS_RTS",
546 	"IBV_QPS_SQD",
547 	"IBV_QPS_SQE",
548 	"IBV_QPS_ERR",
549 	"IBV_QPS_UNKNOWN"
550 };
551 
552 static int
553 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
554 			     enum ibv_qp_state new_state)
555 {
556 	struct ibv_qp_attr qp_attr;
557 	struct ibv_qp_init_attr init_attr;
558 	int rc;
559 	enum ibv_qp_state state;
560 	static int attr_mask_rc[] = {
561 		[IBV_QPS_RESET] = IBV_QP_STATE,
562 		[IBV_QPS_INIT] = (IBV_QP_STATE |
563 				  IBV_QP_PKEY_INDEX |
564 				  IBV_QP_PORT |
565 				  IBV_QP_ACCESS_FLAGS),
566 		[IBV_QPS_RTR] = (IBV_QP_STATE |
567 				 IBV_QP_AV |
568 				 IBV_QP_PATH_MTU |
569 				 IBV_QP_DEST_QPN |
570 				 IBV_QP_RQ_PSN |
571 				 IBV_QP_MAX_DEST_RD_ATOMIC |
572 				 IBV_QP_MIN_RNR_TIMER),
573 		[IBV_QPS_RTS] = (IBV_QP_STATE |
574 				 IBV_QP_SQ_PSN |
575 				 IBV_QP_TIMEOUT |
576 				 IBV_QP_RETRY_CNT |
577 				 IBV_QP_RNR_RETRY |
578 				 IBV_QP_MAX_QP_RD_ATOMIC),
579 		[IBV_QPS_SQD] = IBV_QP_STATE,
580 		[IBV_QPS_SQE] = IBV_QP_STATE,
581 		[IBV_QPS_ERR] = IBV_QP_STATE,
582 	};
583 
584 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
585 	if (rc) {
586 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
587 			    rqpair->qpair.qid, new_state);
588 		return rc;
589 	}
590 
591 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
592 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
593 
594 	if (rc) {
595 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
596 		assert(false);
597 	}
598 
599 	qp_attr.cur_qp_state = rqpair->ibv_state;
600 	qp_attr.qp_state = new_state;
601 
602 	rc = ibv_modify_qp(rqpair->cm_id->qp, &qp_attr,
603 			   attr_mask_rc[new_state]);
604 
605 	if (rc) {
606 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
607 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
608 		return rc;
609 	}
610 
611 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
612 
613 	if (state != new_state) {
614 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
615 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
616 			    str_ibv_qp_state[state]);
617 		return -1;
618 	}
619 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
620 		      str_ibv_qp_state[state]);
621 	return 0;
622 }
623 
624 static void
625 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
626 			    struct spdk_nvmf_rdma_transport *rtransport)
627 {
628 	struct spdk_nvmf_rdma_request_data	*current_data_wr = NULL, *next_data_wr = NULL;
629 	struct ibv_send_wr			*send_wr;
630 	int					i;
631 
632 	rdma_req->num_outstanding_data_wr = 0;
633 	current_data_wr = &rdma_req->data;
634 	for (i = 0; i < current_data_wr->wr.num_sge; i++) {
635 		current_data_wr->wr.sg_list[i].addr = 0;
636 		current_data_wr->wr.sg_list[i].length = 0;
637 		current_data_wr->wr.sg_list[i].lkey = 0;
638 	}
639 	current_data_wr->wr.num_sge = 0;
640 
641 	send_wr = current_data_wr->wr.next;
642 	if (send_wr != NULL && send_wr != &rdma_req->rsp.wr) {
643 		next_data_wr = SPDK_CONTAINEROF(send_wr, struct spdk_nvmf_rdma_request_data, wr);
644 	}
645 	while (next_data_wr) {
646 		current_data_wr = next_data_wr;
647 		send_wr = current_data_wr->wr.next;
648 		if (send_wr != NULL && send_wr != &rdma_req->rsp.wr &&
649 		    send_wr->wr_id == current_data_wr->wr.wr_id) {
650 			next_data_wr = SPDK_CONTAINEROF(send_wr, struct spdk_nvmf_rdma_request_data, wr);
651 		} else {
652 			next_data_wr = NULL;
653 		}
654 
655 		for (i = 0; i < current_data_wr->wr.num_sge; i++) {
656 			current_data_wr->wr.sg_list[i].addr = 0;
657 			current_data_wr->wr.sg_list[i].length = 0;
658 			current_data_wr->wr.sg_list[i].lkey = 0;
659 		}
660 		current_data_wr->wr.num_sge = 0;
661 		spdk_mempool_put(rtransport->data_wr_pool, current_data_wr);
662 	}
663 }
664 
665 static void
666 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
667 {
668 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->data_from_pool);
669 	if (req->req.cmd) {
670 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
671 	}
672 	if (req->recv) {
673 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
674 	}
675 }
676 
677 static void
678 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
679 {
680 	int i;
681 
682 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
683 	for (i = 0; i < rqpair->max_queue_depth; i++) {
684 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
685 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
686 		}
687 	}
688 }
689 
690 static void
691 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
692 {
693 	if (resources->cmds_mr) {
694 		ibv_dereg_mr(resources->cmds_mr);
695 	}
696 
697 	if (resources->cpls_mr) {
698 		ibv_dereg_mr(resources->cpls_mr);
699 	}
700 
701 	if (resources->bufs_mr) {
702 		ibv_dereg_mr(resources->bufs_mr);
703 	}
704 
705 	spdk_dma_free(resources->cmds);
706 	spdk_dma_free(resources->cpls);
707 	spdk_dma_free(resources->bufs);
708 	free(resources->reqs);
709 	free(resources->recvs);
710 	free(resources);
711 }
712 
713 
714 static struct spdk_nvmf_rdma_resources *
715 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
716 {
717 	struct spdk_nvmf_rdma_resources	*resources;
718 	struct spdk_nvmf_rdma_request	*rdma_req;
719 	struct spdk_nvmf_rdma_recv	*rdma_recv;
720 	struct ibv_qp			*qp;
721 	struct ibv_srq			*srq;
722 	uint32_t			i;
723 	int				rc;
724 
725 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
726 	if (!resources) {
727 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
728 		return NULL;
729 	}
730 
731 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
732 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
733 	resources->cmds = spdk_dma_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
734 					   0x1000, NULL);
735 	resources->cpls = spdk_dma_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
736 					   0x1000, NULL);
737 
738 	if (opts->in_capsule_data_size > 0) {
739 		resources->bufs = spdk_dma_zmalloc(opts->max_queue_depth *
740 						   opts->in_capsule_data_size,
741 						   0x1000, NULL);
742 	}
743 
744 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
745 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
746 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
747 		goto cleanup;
748 	}
749 
750 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
751 					opts->max_queue_depth * sizeof(*resources->cmds),
752 					IBV_ACCESS_LOCAL_WRITE);
753 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
754 					opts->max_queue_depth * sizeof(*resources->cpls),
755 					0);
756 
757 	if (opts->in_capsule_data_size) {
758 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
759 						opts->max_queue_depth *
760 						opts->in_capsule_data_size,
761 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
762 	}
763 
764 	if (!resources->cmds_mr || !resources->cpls_mr ||
765 	    (opts->in_capsule_data_size &&
766 	     !resources->bufs_mr)) {
767 		goto cleanup;
768 	}
769 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
770 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
771 		      resources->cmds_mr->lkey);
772 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
773 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
774 		      resources->cpls_mr->lkey);
775 	if (resources->bufs && resources->bufs_mr) {
776 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
777 			      resources->bufs, opts->max_queue_depth *
778 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
779 	}
780 
781 	/* Initialize queues */
782 	STAILQ_INIT(&resources->incoming_queue);
783 	STAILQ_INIT(&resources->free_queue);
784 
785 	for (i = 0; i < opts->max_queue_depth; i++) {
786 		struct ibv_recv_wr *bad_wr = NULL;
787 
788 		rdma_recv = &resources->recvs[i];
789 		rdma_recv->qpair = opts->qpair;
790 
791 		/* Set up memory to receive commands */
792 		if (resources->bufs) {
793 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
794 						  opts->in_capsule_data_size));
795 		}
796 
797 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
798 
799 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
800 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
801 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
802 		rdma_recv->wr.num_sge = 1;
803 
804 		if (rdma_recv->buf && resources->bufs_mr) {
805 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
806 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
807 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
808 			rdma_recv->wr.num_sge++;
809 		}
810 
811 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
812 		rdma_recv->wr.sg_list = rdma_recv->sgl;
813 		if (opts->shared) {
814 			srq = (struct ibv_srq *)opts->qp;
815 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
816 		} else {
817 			qp = (struct ibv_qp *)opts->qp;
818 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
819 		}
820 		if (rc) {
821 			goto cleanup;
822 		}
823 	}
824 
825 	for (i = 0; i < opts->max_queue_depth; i++) {
826 		rdma_req = &resources->reqs[i];
827 
828 		if (opts->qpair != NULL) {
829 			rdma_req->req.qpair = &opts->qpair->qpair;
830 		} else {
831 			rdma_req->req.qpair = NULL;
832 		}
833 		rdma_req->req.cmd = NULL;
834 
835 		/* Set up memory to send responses */
836 		rdma_req->req.rsp = &resources->cpls[i];
837 
838 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
839 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
840 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
841 
842 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
843 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
844 		rdma_req->rsp.wr.next = NULL;
845 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
846 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
847 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
848 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
849 
850 		/* Set up memory for data buffers */
851 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
852 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
853 		rdma_req->data.wr.next = NULL;
854 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
855 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
856 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
857 
858 		/* Initialize request state to FREE */
859 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
860 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
861 	}
862 
863 	return resources;
864 
865 cleanup:
866 	nvmf_rdma_resources_destroy(resources);
867 	return NULL;
868 }
869 
870 static void
871 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
872 {
873 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
874 	struct ibv_recv_wr		*bad_recv_wr = NULL;
875 	int				rc;
876 
877 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
878 
879 	spdk_poller_unregister(&rqpair->destruct_poller);
880 
881 	if (rqpair->qd != 0) {
882 		if (rqpair->srq == NULL) {
883 			nvmf_rdma_dump_qpair_contents(rqpair);
884 		}
885 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
886 	}
887 
888 	if (rqpair->poller) {
889 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
890 
891 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
892 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
893 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
894 				if (rqpair == rdma_recv->qpair) {
895 					STAILQ_REMOVE_HEAD(&rqpair->resources->incoming_queue, link);
896 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
897 					if (rc) {
898 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
899 					}
900 				}
901 			}
902 		}
903 	}
904 
905 	if (rqpair->cm_id) {
906 		if (rqpair->cm_id->qp != NULL) {
907 			rdma_destroy_qp(rqpair->cm_id);
908 		}
909 		rdma_destroy_id(rqpair->cm_id);
910 
911 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
912 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
913 		}
914 	}
915 
916 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
917 		nvmf_rdma_resources_destroy(rqpair->resources);
918 	}
919 
920 	free(rqpair);
921 }
922 
923 static int
924 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
925 {
926 	struct spdk_nvmf_rdma_poller	*rpoller;
927 	int				rc, num_cqe, required_num_wr;
928 
929 	/* Enlarge CQ size dynamically */
930 	rpoller = rqpair->poller;
931 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
932 	num_cqe = rpoller->num_cqe;
933 	if (num_cqe < required_num_wr) {
934 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
935 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
936 	}
937 
938 	if (rpoller->num_cqe != num_cqe) {
939 		if (required_num_wr > device->attr.max_cqe) {
940 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
941 				    required_num_wr, device->attr.max_cqe);
942 			return -1;
943 		}
944 
945 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
946 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
947 		if (rc) {
948 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
949 			return -1;
950 		}
951 
952 		rpoller->num_cqe = num_cqe;
953 	}
954 
955 	rpoller->required_num_wr = required_num_wr;
956 	return 0;
957 }
958 
959 static int
960 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
961 {
962 	struct spdk_nvmf_rdma_qpair		*rqpair;
963 	int					rc;
964 	struct spdk_nvmf_rdma_transport		*rtransport;
965 	struct spdk_nvmf_transport		*transport;
966 	struct spdk_nvmf_rdma_resource_opts	opts;
967 	struct spdk_nvmf_rdma_device		*device;
968 	struct ibv_qp_init_attr			ibv_init_attr;
969 
970 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
971 	device = rqpair->port->device;
972 
973 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
974 	ibv_init_attr.qp_context	= rqpair;
975 	ibv_init_attr.qp_type		= IBV_QPT_RC;
976 	ibv_init_attr.send_cq		= rqpair->poller->cq;
977 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
978 
979 	if (rqpair->srq) {
980 		ibv_init_attr.srq		= rqpair->srq;
981 	} else {
982 		ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
983 						  1; /* RECV operations + dummy drain WR */
984 	}
985 
986 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
987 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
988 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
989 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
990 
991 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
992 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
993 		goto error;
994 	}
995 
996 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
997 	if (rc) {
998 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
999 		goto error;
1000 	}
1001 
1002 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2 + 1),
1003 					  ibv_init_attr.cap.max_send_wr);
1004 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
1005 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
1006 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1007 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
1008 
1009 	rqpair->sends_to_post.first = NULL;
1010 	rqpair->sends_to_post.last = NULL;
1011 
1012 	if (rqpair->poller->srq == NULL) {
1013 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1014 		transport = &rtransport->transport;
1015 
1016 		opts.qp = rqpair->cm_id->qp;
1017 		opts.pd = rqpair->cm_id->pd;
1018 		opts.qpair = rqpair;
1019 		opts.shared = false;
1020 		opts.max_queue_depth = rqpair->max_queue_depth;
1021 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1022 
1023 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1024 
1025 		if (!rqpair->resources) {
1026 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1027 			goto error;
1028 		}
1029 	} else {
1030 		rqpair->resources = rqpair->poller->resources;
1031 	}
1032 
1033 	rqpair->current_recv_depth = 0;
1034 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1035 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1036 
1037 	return 0;
1038 
1039 error:
1040 	rdma_destroy_id(rqpair->cm_id);
1041 	rqpair->cm_id = NULL;
1042 	spdk_nvmf_rdma_qpair_destroy(rqpair);
1043 	return -1;
1044 }
1045 
1046 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1047 /* This function accepts either a single wr or the first wr in a linked list. */
1048 static void
1049 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1050 {
1051 	struct ibv_recv_wr *last;
1052 
1053 	last = first;
1054 	while (last->next != NULL) {
1055 		last = last->next;
1056 	}
1057 
1058 	if (rqpair->resources->recvs_to_post.first == NULL) {
1059 		rqpair->resources->recvs_to_post.first = first;
1060 		rqpair->resources->recvs_to_post.last = last;
1061 		if (rqpair->srq == NULL) {
1062 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1063 		}
1064 	} else {
1065 		rqpair->resources->recvs_to_post.last->next = first;
1066 		rqpair->resources->recvs_to_post.last = last;
1067 	}
1068 }
1069 
1070 /* Append the given send wr structure to the qpair's outstanding sends list. */
1071 /* This function accepts either a single wr or the first wr in a linked list. */
1072 static void
1073 nvmf_rdma_qpair_queue_send_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *first)
1074 {
1075 	struct ibv_send_wr *last;
1076 
1077 	last = first;
1078 	while (last->next != NULL) {
1079 		last = last->next;
1080 	}
1081 
1082 	if (rqpair->sends_to_post.first == NULL) {
1083 		rqpair->sends_to_post.first = first;
1084 		rqpair->sends_to_post.last = last;
1085 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1086 	} else {
1087 		rqpair->sends_to_post.last->next = first;
1088 		rqpair->sends_to_post.last = last;
1089 	}
1090 }
1091 
1092 static int
1093 request_transfer_in(struct spdk_nvmf_request *req)
1094 {
1095 	struct spdk_nvmf_rdma_request	*rdma_req;
1096 	struct spdk_nvmf_qpair		*qpair;
1097 	struct spdk_nvmf_rdma_qpair	*rqpair;
1098 
1099 	qpair = req->qpair;
1100 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1101 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1102 
1103 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1104 	assert(rdma_req != NULL);
1105 
1106 	nvmf_rdma_qpair_queue_send_wrs(rqpair, &rdma_req->data.wr);
1107 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1108 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1109 	return 0;
1110 }
1111 
1112 static int
1113 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1114 {
1115 	int				num_outstanding_data_wr = 0;
1116 	struct spdk_nvmf_rdma_request	*rdma_req;
1117 	struct spdk_nvmf_qpair		*qpair;
1118 	struct spdk_nvmf_rdma_qpair	*rqpair;
1119 	struct spdk_nvme_cpl		*rsp;
1120 	struct ibv_send_wr		*first = NULL;
1121 
1122 	*data_posted = 0;
1123 	qpair = req->qpair;
1124 	rsp = &req->rsp->nvme_cpl;
1125 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1126 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1127 
1128 	/* Advance our sq_head pointer */
1129 	if (qpair->sq_head == qpair->sq_head_max) {
1130 		qpair->sq_head = 0;
1131 	} else {
1132 		qpair->sq_head++;
1133 	}
1134 	rsp->sqhd = qpair->sq_head;
1135 
1136 	/* queue the capsule for the recv buffer */
1137 	assert(rdma_req->recv != NULL);
1138 
1139 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1140 
1141 	rdma_req->recv = NULL;
1142 	assert(rqpair->current_recv_depth > 0);
1143 	rqpair->current_recv_depth--;
1144 
1145 	/* Build the response which consists of optional
1146 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1147 	 * containing the response.
1148 	 */
1149 	first = &rdma_req->rsp.wr;
1150 
1151 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
1152 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1153 		first = &rdma_req->data.wr;
1154 		*data_posted = 1;
1155 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1156 	}
1157 	nvmf_rdma_qpair_queue_send_wrs(rqpair, first);
1158 	/* +1 for the rsp wr */
1159 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1160 
1161 	return 0;
1162 }
1163 
1164 static int
1165 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1166 {
1167 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1168 	struct rdma_conn_param				ctrlr_event_data = {};
1169 	int						rc;
1170 
1171 	accept_data.recfmt = 0;
1172 	accept_data.crqsize = rqpair->max_queue_depth;
1173 
1174 	ctrlr_event_data.private_data = &accept_data;
1175 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1176 	if (id->ps == RDMA_PS_TCP) {
1177 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1178 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1179 	}
1180 
1181 	/* Configure infinite retries for the initiator side qpair.
1182 	 * When using a shared receive queue on the target side,
1183 	 * we need to pass this value to the initiator to prevent the
1184 	 * initiator side NIC from completing SEND requests back to the
1185 	 * initiator with status rnr_retry_count_exceeded. */
1186 	if (rqpair->srq != NULL) {
1187 		ctrlr_event_data.rnr_retry_count = 0x7;
1188 	}
1189 
1190 	rc = rdma_accept(id, &ctrlr_event_data);
1191 	if (rc) {
1192 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
1193 	} else {
1194 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
1195 	}
1196 
1197 	return rc;
1198 }
1199 
1200 static void
1201 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1202 {
1203 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1204 
1205 	rej_data.recfmt = 0;
1206 	rej_data.sts = error;
1207 
1208 	rdma_reject(id, &rej_data, sizeof(rej_data));
1209 }
1210 
1211 static int
1212 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
1213 		  new_qpair_fn cb_fn)
1214 {
1215 	struct spdk_nvmf_rdma_transport *rtransport;
1216 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1217 	struct spdk_nvmf_rdma_port	*port;
1218 	struct rdma_conn_param		*rdma_param = NULL;
1219 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1220 	uint16_t			max_queue_depth;
1221 	uint16_t			max_read_depth;
1222 
1223 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1224 
1225 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1226 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1227 
1228 	rdma_param = &event->param.conn;
1229 	if (rdma_param->private_data == NULL ||
1230 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1231 		SPDK_ERRLOG("connect request: no private data provided\n");
1232 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1233 		return -1;
1234 	}
1235 
1236 	private_data = rdma_param->private_data;
1237 	if (private_data->recfmt != 0) {
1238 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1239 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1240 		return -1;
1241 	}
1242 
1243 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1244 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1245 
1246 	port = event->listen_id->context;
1247 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1248 		      event->listen_id, event->listen_id->verbs, port);
1249 
1250 	/* Figure out the supported queue depth. This is a multi-step process
1251 	 * that takes into account hardware maximums, host provided values,
1252 	 * and our target's internal memory limits */
1253 
1254 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1255 
1256 	/* Start with the maximum queue depth allowed by the target */
1257 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1258 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1259 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1260 		      rtransport->transport.opts.max_queue_depth);
1261 
1262 	/* Next check the local NIC's hardware limitations */
1263 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1264 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1265 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1266 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1267 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1268 
1269 	/* Next check the remote NIC's hardware limitations */
1270 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1271 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1272 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1273 	if (rdma_param->initiator_depth > 0) {
1274 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1275 	}
1276 
1277 	/* Finally check for the host software requested values, which are
1278 	 * optional. */
1279 	if (rdma_param->private_data != NULL &&
1280 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1281 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1282 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1283 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1284 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1285 	}
1286 
1287 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1288 		      max_queue_depth, max_read_depth);
1289 
1290 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1291 	if (rqpair == NULL) {
1292 		SPDK_ERRLOG("Could not allocate new connection.\n");
1293 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1294 		return -1;
1295 	}
1296 
1297 	rqpair->port = port;
1298 	rqpair->max_queue_depth = max_queue_depth;
1299 	rqpair->max_read_depth = max_read_depth;
1300 	rqpair->cm_id = event->id;
1301 	rqpair->listen_id = event->listen_id;
1302 	rqpair->qpair.transport = transport;
1303 
1304 	event->id->context = &rqpair->qpair;
1305 
1306 	cb_fn(&rqpair->qpair);
1307 
1308 	return 0;
1309 }
1310 
1311 static int
1312 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1313 			  enum spdk_mem_map_notify_action action,
1314 			  void *vaddr, size_t size)
1315 {
1316 	struct ibv_pd *pd = cb_ctx;
1317 	struct ibv_mr *mr;
1318 
1319 	switch (action) {
1320 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1321 		if (!g_nvmf_hooks.get_rkey) {
1322 			mr = ibv_reg_mr(pd, vaddr, size,
1323 					IBV_ACCESS_LOCAL_WRITE |
1324 					IBV_ACCESS_REMOTE_READ |
1325 					IBV_ACCESS_REMOTE_WRITE);
1326 			if (mr == NULL) {
1327 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1328 				return -1;
1329 			} else {
1330 				spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1331 			}
1332 		} else {
1333 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1334 						     g_nvmf_hooks.get_rkey(pd, vaddr, size));
1335 		}
1336 		break;
1337 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1338 		if (!g_nvmf_hooks.get_rkey) {
1339 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1340 			spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1341 			if (mr) {
1342 				ibv_dereg_mr(mr);
1343 			}
1344 		}
1345 		break;
1346 	}
1347 
1348 	return 0;
1349 }
1350 
1351 static int
1352 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1353 {
1354 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1355 	return addr_1 == addr_2;
1356 }
1357 
1358 static void
1359 spdk_nvmf_rdma_request_free_buffers(struct spdk_nvmf_rdma_request *rdma_req,
1360 				    struct spdk_nvmf_transport_poll_group *group, struct spdk_nvmf_transport *transport,
1361 				    uint32_t num_buffers)
1362 {
1363 	uint32_t i;
1364 
1365 	for (i = 0; i < num_buffers; i++) {
1366 		if (group->buf_cache_count < group->buf_cache_size) {
1367 			STAILQ_INSERT_HEAD(&group->buf_cache,
1368 					   (struct spdk_nvmf_transport_pg_cache_buf *)rdma_req->buffers[i], link);
1369 			group->buf_cache_count++;
1370 		} else {
1371 			spdk_mempool_put(transport->data_buf_pool, rdma_req->buffers[i]);
1372 		}
1373 		rdma_req->req.iov[i].iov_base = NULL;
1374 		rdma_req->buffers[i] = NULL;
1375 		rdma_req->req.iov[i].iov_len = 0;
1376 
1377 	}
1378 	rdma_req->data_from_pool = false;
1379 }
1380 
1381 static int
1382 nvmf_rdma_request_get_buffers(struct spdk_nvmf_rdma_request *rdma_req,
1383 			      struct spdk_nvmf_transport_poll_group *group, struct spdk_nvmf_transport *transport,
1384 			      uint32_t num_buffers)
1385 {
1386 	uint32_t i = 0;
1387 
1388 	while (i < num_buffers) {
1389 		if (!(STAILQ_EMPTY(&group->buf_cache))) {
1390 			group->buf_cache_count--;
1391 			rdma_req->buffers[i] = STAILQ_FIRST(&group->buf_cache);
1392 			STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1393 			assert(rdma_req->buffers[i] != NULL);
1394 			i++;
1395 		} else {
1396 			if (spdk_mempool_get_bulk(transport->data_buf_pool, &rdma_req->buffers[i], num_buffers - i)) {
1397 				goto err_exit;
1398 			}
1399 			i += num_buffers - i;
1400 		}
1401 	}
1402 
1403 	return 0;
1404 
1405 err_exit:
1406 	spdk_nvmf_rdma_request_free_buffers(rdma_req, group, transport, i);
1407 	return -ENOMEM;
1408 }
1409 
1410 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1411 
1412 static spdk_nvme_data_transfer_t
1413 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1414 {
1415 	enum spdk_nvme_data_transfer xfer;
1416 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1417 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1418 
1419 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1420 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1421 	rdma_req->rsp.wr.imm_data = 0;
1422 #endif
1423 
1424 	/* Figure out data transfer direction */
1425 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1426 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1427 	} else {
1428 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1429 
1430 		/* Some admin commands are special cases */
1431 		if ((rdma_req->req.qpair->qid == 0) &&
1432 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1433 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1434 			switch (cmd->cdw10 & 0xff) {
1435 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1436 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1437 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1438 				break;
1439 			default:
1440 				xfer = SPDK_NVME_DATA_NONE;
1441 			}
1442 		}
1443 	}
1444 
1445 	if (xfer == SPDK_NVME_DATA_NONE) {
1446 		return xfer;
1447 	}
1448 
1449 	/* Even for commands that may transfer data, they could have specified 0 length.
1450 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1451 	 */
1452 	switch (sgl->generic.type) {
1453 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1454 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1455 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1456 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1457 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1458 		if (sgl->unkeyed.length == 0) {
1459 			xfer = SPDK_NVME_DATA_NONE;
1460 		}
1461 		break;
1462 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1463 		if (sgl->keyed.length == 0) {
1464 			xfer = SPDK_NVME_DATA_NONE;
1465 		}
1466 		break;
1467 	}
1468 
1469 	return xfer;
1470 }
1471 
1472 static int
1473 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1474 		       struct spdk_nvmf_rdma_request *rdma_req,
1475 		       uint32_t num_sgl_descriptors)
1476 {
1477 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1478 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1479 	uint32_t				i;
1480 
1481 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1482 		return -ENOMEM;
1483 	}
1484 
1485 	current_data_wr = &rdma_req->data;
1486 
1487 	for (i = 0; i < num_sgl_descriptors; i++) {
1488 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1489 			current_data_wr->wr.opcode = IBV_WR_RDMA_WRITE;
1490 			current_data_wr->wr.send_flags = 0;
1491 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1492 			current_data_wr->wr.opcode = IBV_WR_RDMA_READ;
1493 			current_data_wr->wr.send_flags = IBV_SEND_SIGNALED;
1494 		} else {
1495 			assert(false);
1496 		}
1497 		work_requests[i]->wr.sg_list = work_requests[i]->sgl;
1498 		work_requests[i]->wr.wr_id = rdma_req->data.wr.wr_id;
1499 		current_data_wr->wr.next = &work_requests[i]->wr;
1500 		current_data_wr = work_requests[i];
1501 	}
1502 
1503 	if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1504 		current_data_wr->wr.opcode = IBV_WR_RDMA_WRITE;
1505 		current_data_wr->wr.next = &rdma_req->rsp.wr;
1506 		current_data_wr->wr.send_flags = 0;
1507 	} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1508 		current_data_wr->wr.opcode = IBV_WR_RDMA_READ;
1509 		current_data_wr->wr.next = NULL;
1510 		current_data_wr->wr.send_flags = IBV_SEND_SIGNALED;
1511 	}
1512 	return 0;
1513 }
1514 
1515 static int
1516 nvmf_rdma_fill_buffers(struct spdk_nvmf_rdma_transport *rtransport,
1517 		       struct spdk_nvmf_rdma_poll_group *rgroup,
1518 		       struct spdk_nvmf_rdma_device *device,
1519 		       struct spdk_nvmf_rdma_request *rdma_req,
1520 		       struct ibv_send_wr *wr,
1521 		       uint32_t length)
1522 {
1523 	uint64_t	translation_len;
1524 	uint32_t	remaining_length = length;
1525 	uint32_t	iovcnt;
1526 	uint32_t	i = 0;
1527 
1528 
1529 	while (remaining_length) {
1530 		iovcnt = rdma_req->req.iovcnt;
1531 		rdma_req->req.iov[iovcnt].iov_base = (void *)((uintptr_t)(rdma_req->buffers[iovcnt] +
1532 						     NVMF_DATA_BUFFER_MASK) &
1533 						     ~NVMF_DATA_BUFFER_MASK);
1534 		rdma_req->req.iov[iovcnt].iov_len  = spdk_min(remaining_length,
1535 						     rtransport->transport.opts.io_unit_size);
1536 		rdma_req->req.iovcnt++;
1537 		wr->sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[iovcnt].iov_base);
1538 		wr->sg_list[i].length = rdma_req->req.iov[iovcnt].iov_len;
1539 		translation_len = rdma_req->req.iov[iovcnt].iov_len;
1540 
1541 		if (!g_nvmf_hooks.get_rkey) {
1542 			wr->sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1543 					       (uint64_t)rdma_req->buffers[iovcnt], &translation_len))->lkey;
1544 		} else {
1545 			wr->sg_list[i].lkey = spdk_mem_map_translate(device->map,
1546 					      (uint64_t)rdma_req->buffers[iovcnt], &translation_len);
1547 		}
1548 
1549 		remaining_length -= rdma_req->req.iov[iovcnt].iov_len;
1550 
1551 		if (translation_len < rdma_req->req.iov[iovcnt].iov_len) {
1552 			SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
1553 			return -EINVAL;
1554 		}
1555 		i++;
1556 	}
1557 	wr->num_sge = i;
1558 
1559 	return 0;
1560 }
1561 
1562 static int
1563 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1564 				 struct spdk_nvmf_rdma_device *device,
1565 				 struct spdk_nvmf_rdma_request *rdma_req)
1566 {
1567 	struct spdk_nvmf_rdma_qpair		*rqpair;
1568 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1569 	uint32_t				num_buffers;
1570 	uint32_t				i = 0;
1571 	int					rc = 0;
1572 
1573 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1574 	rgroup = rqpair->poller->group;
1575 	rdma_req->req.iovcnt = 0;
1576 
1577 	num_buffers = rdma_req->req.length / rtransport->transport.opts.io_unit_size;
1578 	if (rdma_req->req.length % rtransport->transport.opts.io_unit_size) {
1579 		num_buffers++;
1580 	}
1581 
1582 	if (nvmf_rdma_request_get_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers)) {
1583 		return -ENOMEM;
1584 	}
1585 
1586 	rdma_req->req.iovcnt = 0;
1587 
1588 	rc = nvmf_rdma_fill_buffers(rtransport, rgroup, device, rdma_req, &rdma_req->data.wr,
1589 				    rdma_req->req.length);
1590 	if (rc != 0) {
1591 		goto err_exit;
1592 	}
1593 
1594 	assert(rdma_req->req.iovcnt <= rqpair->max_send_sge);
1595 
1596 	rdma_req->data_from_pool = true;
1597 
1598 	return rc;
1599 
1600 err_exit:
1601 	spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers);
1602 	while (i) {
1603 		i--;
1604 		rdma_req->data.wr.sg_list[i].addr = 0;
1605 		rdma_req->data.wr.sg_list[i].length = 0;
1606 		rdma_req->data.wr.sg_list[i].lkey = 0;
1607 	}
1608 	rdma_req->req.iovcnt = 0;
1609 	return rc;
1610 }
1611 
1612 static int
1613 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1614 				      struct spdk_nvmf_rdma_device *device,
1615 				      struct spdk_nvmf_rdma_request *rdma_req)
1616 {
1617 	struct spdk_nvmf_rdma_qpair		*rqpair;
1618 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1619 	struct ibv_send_wr			*current_wr;
1620 	struct spdk_nvmf_request		*req = &rdma_req->req;
1621 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1622 	uint32_t				num_sgl_descriptors;
1623 	uint32_t				num_buffers = 0;
1624 	uint32_t				i;
1625 	int					rc;
1626 
1627 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1628 	rgroup = rqpair->poller->group;
1629 
1630 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1631 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1632 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1633 
1634 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1635 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1636 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1637 
1638 	for (i = 0; i < num_sgl_descriptors; i++) {
1639 		num_buffers += desc->keyed.length / rtransport->transport.opts.io_unit_size;
1640 		if (desc->keyed.length % rtransport->transport.opts.io_unit_size) {
1641 			num_buffers++;
1642 		}
1643 		desc++;
1644 	}
1645 	/* If the number of buffers is too large, then we know the I/O is larger than allowed. Fail it. */
1646 	if (num_buffers > NVMF_REQ_MAX_BUFFERS) {
1647 		return -EINVAL;
1648 	}
1649 	if (nvmf_rdma_request_get_buffers(rdma_req, &rgroup->group, &rtransport->transport,
1650 					  num_buffers) != 0) {
1651 		return -ENOMEM;
1652 	}
1653 
1654 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1655 		spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers);
1656 		return -ENOMEM;
1657 	}
1658 
1659 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1660 	current_wr = &rdma_req->data.wr;
1661 	assert(current_wr != NULL);
1662 
1663 	req->iovcnt = 0;
1664 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1665 	for (i = 0; i < num_sgl_descriptors; i++) {
1666 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1667 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1668 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1669 			rc = -EINVAL;
1670 			goto err_exit;
1671 		}
1672 
1673 		current_wr->num_sge = 0;
1674 		req->length += desc->keyed.length;
1675 
1676 		rc = nvmf_rdma_fill_buffers(rtransport, rgroup, device, rdma_req, current_wr,
1677 					    desc->keyed.length);
1678 		if (rc != 0) {
1679 			rc = -ENOMEM;
1680 			goto err_exit;
1681 		}
1682 
1683 		current_wr->wr.rdma.rkey = desc->keyed.key;
1684 		current_wr->wr.rdma.remote_addr = desc->address;
1685 		current_wr = current_wr->next;
1686 		desc++;
1687 	}
1688 
1689 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1690 	/* Go back to the last descriptor in the list. */
1691 	desc--;
1692 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1693 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1694 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1695 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1696 		}
1697 	}
1698 #endif
1699 
1700 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1701 	rdma_req->data_from_pool = true;
1702 
1703 	return 0;
1704 
1705 err_exit:
1706 	spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers);
1707 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1708 	return rc;
1709 }
1710 
1711 static int
1712 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1713 				 struct spdk_nvmf_rdma_device *device,
1714 				 struct spdk_nvmf_rdma_request *rdma_req)
1715 {
1716 	struct spdk_nvme_cmd			*cmd;
1717 	struct spdk_nvme_cpl			*rsp;
1718 	struct spdk_nvme_sgl_descriptor		*sgl;
1719 	int					rc;
1720 
1721 	cmd = &rdma_req->req.cmd->nvme_cmd;
1722 	rsp = &rdma_req->req.rsp->nvme_cpl;
1723 	sgl = &cmd->dptr.sgl1;
1724 
1725 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1726 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1727 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1728 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1729 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1730 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1731 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1732 			return -1;
1733 		}
1734 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1735 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1736 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1737 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1738 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1739 			}
1740 		}
1741 #endif
1742 
1743 		/* fill request length and populate iovs */
1744 		rdma_req->req.length = sgl->keyed.length;
1745 
1746 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1747 			/* No available buffers. Queue this request up. */
1748 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1749 			return 0;
1750 		}
1751 
1752 		/* backward compatible */
1753 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1754 
1755 		/* rdma wr specifics */
1756 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1757 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1758 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1759 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1760 			rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
1761 			rdma_req->data.wr.next = &rdma_req->rsp.wr;
1762 			rdma_req->data.wr.send_flags &= ~IBV_SEND_SIGNALED;
1763 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1764 			rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
1765 			rdma_req->data.wr.next = NULL;
1766 			rdma_req->data.wr.send_flags |= IBV_SEND_SIGNALED;
1767 		}
1768 
1769 		/* set the number of outstanding data WRs for this request. */
1770 		rdma_req->num_outstanding_data_wr = 1;
1771 
1772 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1773 			      rdma_req->req.iovcnt);
1774 
1775 		return 0;
1776 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1777 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1778 		uint64_t offset = sgl->address;
1779 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1780 
1781 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1782 			      offset, sgl->unkeyed.length);
1783 
1784 		if (offset > max_len) {
1785 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1786 				    offset, max_len);
1787 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1788 			return -1;
1789 		}
1790 		max_len -= (uint32_t)offset;
1791 
1792 		if (sgl->unkeyed.length > max_len) {
1793 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1794 				    sgl->unkeyed.length, max_len);
1795 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1796 			return -1;
1797 		}
1798 
1799 		rdma_req->num_outstanding_data_wr = 0;
1800 		rdma_req->req.data = rdma_req->recv->buf + offset;
1801 		rdma_req->data_from_pool = false;
1802 		rdma_req->req.length = sgl->unkeyed.length;
1803 
1804 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1805 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1806 		rdma_req->req.iovcnt = 1;
1807 
1808 		return 0;
1809 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1810 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1811 
1812 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1813 		if (rc == -ENOMEM) {
1814 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1815 			return 0;
1816 		} else if (rc == -EINVAL) {
1817 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1818 			return -1;
1819 		}
1820 
1821 		/* backward compatible */
1822 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1823 
1824 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1825 			      rdma_req->req.iovcnt);
1826 
1827 		return 0;
1828 	}
1829 
1830 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1831 		    sgl->generic.type, sgl->generic.subtype);
1832 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1833 	return -1;
1834 }
1835 
1836 static void
1837 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1838 		       struct spdk_nvmf_rdma_transport	*rtransport)
1839 {
1840 	struct spdk_nvmf_rdma_qpair		*rqpair;
1841 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1842 
1843 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1844 	if (rdma_req->data_from_pool) {
1845 		rgroup = rqpair->poller->group;
1846 
1847 		spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport,
1848 						    rdma_req->req.iovcnt);
1849 	}
1850 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1851 	rdma_req->req.length = 0;
1852 	rdma_req->req.iovcnt = 0;
1853 	rdma_req->req.data = NULL;
1854 	rdma_req->rsp.wr.next = NULL;
1855 	rdma_req->data.wr.next = NULL;
1856 	rqpair->qd--;
1857 
1858 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1859 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1860 }
1861 
1862 static bool
1863 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1864 			       struct spdk_nvmf_rdma_request *rdma_req)
1865 {
1866 	struct spdk_nvmf_rdma_qpair	*rqpair;
1867 	struct spdk_nvmf_rdma_device	*device;
1868 	struct spdk_nvmf_rdma_poll_group *rgroup;
1869 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1870 	int				rc;
1871 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1872 	enum spdk_nvmf_rdma_request_state prev_state;
1873 	bool				progress = false;
1874 	int				data_posted;
1875 
1876 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1877 	device = rqpair->port->device;
1878 	rgroup = rqpair->poller->group;
1879 
1880 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1881 
1882 	/* If the queue pair is in an error state, force the request to the completed state
1883 	 * to release resources. */
1884 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1885 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1886 			STAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1887 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1888 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1889 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1890 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1891 		}
1892 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1893 	}
1894 
1895 	/* The loop here is to allow for several back-to-back state changes. */
1896 	do {
1897 		prev_state = rdma_req->state;
1898 
1899 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1900 
1901 		switch (rdma_req->state) {
1902 		case RDMA_REQUEST_STATE_FREE:
1903 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1904 			 * to escape this state. */
1905 			break;
1906 		case RDMA_REQUEST_STATE_NEW:
1907 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1908 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1909 			rdma_recv = rdma_req->recv;
1910 
1911 			/* The first element of the SGL is the NVMe command */
1912 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1913 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1914 
1915 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1916 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1917 				break;
1918 			}
1919 
1920 			/* The next state transition depends on the data transfer needs of this request. */
1921 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1922 
1923 			/* If no data to transfer, ready to execute. */
1924 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1925 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1926 				break;
1927 			}
1928 
1929 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1930 			STAILQ_INSERT_TAIL(&rgroup->pending_data_buf_queue, rdma_req, state_link);
1931 			break;
1932 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1933 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1934 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1935 
1936 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1937 
1938 			if (rdma_req != STAILQ_FIRST(&rgroup->pending_data_buf_queue)) {
1939 				/* This request needs to wait in line to obtain a buffer */
1940 				break;
1941 			}
1942 
1943 			/* Try to get a data buffer */
1944 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1945 			if (rc < 0) {
1946 				STAILQ_REMOVE_HEAD(&rgroup->pending_data_buf_queue, state_link);
1947 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1948 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1949 				break;
1950 			}
1951 
1952 			if (!rdma_req->req.data) {
1953 				/* No buffers available. */
1954 				break;
1955 			}
1956 
1957 			STAILQ_REMOVE_HEAD(&rgroup->pending_data_buf_queue, state_link);
1958 
1959 			/* If data is transferring from host to controller and the data didn't
1960 			 * arrive using in capsule data, we need to do a transfer from the host.
1961 			 */
1962 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1963 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1964 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1965 				break;
1966 			}
1967 
1968 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1969 			break;
1970 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1971 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1972 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1973 
1974 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
1975 				/* This request needs to wait in line to perform RDMA */
1976 				break;
1977 			}
1978 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1979 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1980 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1981 				break;
1982 			}
1983 
1984 			/* We have already verified that this request is the head of the queue. */
1985 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
1986 
1987 			rc = request_transfer_in(&rdma_req->req);
1988 			if (!rc) {
1989 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
1990 			} else {
1991 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1992 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1993 			}
1994 			break;
1995 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1996 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1997 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1998 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1999 			 * to escape this state. */
2000 			break;
2001 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2002 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2003 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2004 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2005 			spdk_nvmf_request_exec(&rdma_req->req);
2006 			break;
2007 		case RDMA_REQUEST_STATE_EXECUTING:
2008 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2009 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2010 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2011 			 * to escape this state. */
2012 			break;
2013 		case RDMA_REQUEST_STATE_EXECUTED:
2014 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2015 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2016 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2017 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2018 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2019 			} else {
2020 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2021 			}
2022 			break;
2023 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2024 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2025 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2026 
2027 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2028 				/* This request needs to wait in line to perform RDMA */
2029 				break;
2030 			}
2031 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2032 			    rqpair->max_send_depth) {
2033 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2034 				 * +1 since each request has an additional wr in the resp. */
2035 				break;
2036 			}
2037 
2038 			/* We have already verified that this request is the head of the queue. */
2039 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2040 
2041 			/* The data transfer will be kicked off from
2042 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2043 			 */
2044 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2045 			break;
2046 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2047 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2048 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2049 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2050 			assert(rc == 0); /* No good way to handle this currently */
2051 			if (rc) {
2052 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2053 			} else {
2054 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2055 						  RDMA_REQUEST_STATE_COMPLETING;
2056 			}
2057 			break;
2058 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2059 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2060 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2061 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2062 			 * to escape this state. */
2063 			break;
2064 		case RDMA_REQUEST_STATE_COMPLETING:
2065 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2066 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2067 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2068 			 * to escape this state. */
2069 			break;
2070 		case RDMA_REQUEST_STATE_COMPLETED:
2071 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2072 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2073 
2074 			nvmf_rdma_request_free(rdma_req, rtransport);
2075 			break;
2076 		case RDMA_REQUEST_NUM_STATES:
2077 		default:
2078 			assert(0);
2079 			break;
2080 		}
2081 
2082 		if (rdma_req->state != prev_state) {
2083 			progress = true;
2084 		}
2085 	} while (rdma_req->state != prev_state);
2086 
2087 	return progress;
2088 }
2089 
2090 /* Public API callbacks begin here */
2091 
2092 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2093 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2094 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2095 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2096 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2097 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2098 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2099 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2100 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2101 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false;
2102 
2103 static void
2104 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2105 {
2106 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2107 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2108 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2109 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2110 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2111 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2112 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2113 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2114 	opts->max_srq_depth =		SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2115 	opts->no_srq =			SPDK_NVMF_RDMA_DEFAULT_NO_SRQ
2116 }
2117 
2118 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2119 	.notify_cb = spdk_nvmf_rdma_mem_notify,
2120 	.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
2121 };
2122 
2123 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
2124 
2125 static struct spdk_nvmf_transport *
2126 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2127 {
2128 	int rc;
2129 	struct spdk_nvmf_rdma_transport *rtransport;
2130 	struct spdk_nvmf_rdma_device	*device, *tmp;
2131 	struct ibv_pd			*pd;
2132 	struct ibv_context		**contexts;
2133 	uint32_t			i;
2134 	int				flag;
2135 	uint32_t			sge_count;
2136 	uint32_t			min_shared_buffers;
2137 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2138 
2139 	rtransport = calloc(1, sizeof(*rtransport));
2140 	if (!rtransport) {
2141 		return NULL;
2142 	}
2143 
2144 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
2145 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2146 		free(rtransport);
2147 		return NULL;
2148 	}
2149 
2150 	TAILQ_INIT(&rtransport->devices);
2151 	TAILQ_INIT(&rtransport->ports);
2152 
2153 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2154 
2155 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
2156 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2157 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2158 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2159 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d\n",
2160 		     opts->max_queue_depth,
2161 		     opts->max_io_size,
2162 		     opts->max_qpairs_per_ctrlr,
2163 		     opts->io_unit_size,
2164 		     opts->in_capsule_data_size,
2165 		     opts->max_aq_depth,
2166 		     opts->num_shared_buffers,
2167 		     opts->max_srq_depth,
2168 		     opts->no_srq);
2169 
2170 	/* I/O unit size cannot be larger than max I/O size */
2171 	if (opts->io_unit_size > opts->max_io_size) {
2172 		opts->io_unit_size = opts->max_io_size;
2173 	}
2174 
2175 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2176 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2177 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2178 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2179 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2180 		return NULL;
2181 	}
2182 
2183 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
2184 	if (min_shared_buffers > opts->num_shared_buffers) {
2185 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2186 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2187 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2188 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2189 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2190 		return NULL;
2191 	}
2192 
2193 	sge_count = opts->max_io_size / opts->io_unit_size;
2194 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2195 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2196 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2197 		return NULL;
2198 	}
2199 
2200 	rtransport->event_channel = rdma_create_event_channel();
2201 	if (rtransport->event_channel == NULL) {
2202 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2203 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2204 		return NULL;
2205 	}
2206 
2207 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2208 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2209 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2210 			    rtransport->event_channel->fd, spdk_strerror(errno));
2211 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2212 		return NULL;
2213 	}
2214 
2215 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2216 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2217 				   sizeof(struct spdk_nvmf_rdma_request_data),
2218 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2219 				   SPDK_ENV_SOCKET_ID_ANY);
2220 	if (!rtransport->data_wr_pool) {
2221 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2222 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2223 		return NULL;
2224 	}
2225 
2226 	contexts = rdma_get_devices(NULL);
2227 	if (contexts == NULL) {
2228 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2229 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2230 		return NULL;
2231 	}
2232 
2233 	i = 0;
2234 	rc = 0;
2235 	while (contexts[i] != NULL) {
2236 		device = calloc(1, sizeof(*device));
2237 		if (!device) {
2238 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2239 			rc = -ENOMEM;
2240 			break;
2241 		}
2242 		device->context = contexts[i];
2243 		rc = ibv_query_device(device->context, &device->attr);
2244 		if (rc < 0) {
2245 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2246 			free(device);
2247 			break;
2248 
2249 		}
2250 
2251 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2252 
2253 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2254 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2255 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2256 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2257 		}
2258 
2259 		/**
2260 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2261 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2262 		 * but incorrectly reports that it does. There are changes making their way
2263 		 * through the kernel now that will enable this feature. When they are merged,
2264 		 * we can conditionally enable this feature.
2265 		 *
2266 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2267 		 */
2268 		if (device->attr.vendor_id == 0) {
2269 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2270 		}
2271 #endif
2272 
2273 		/* set up device context async ev fd as NON_BLOCKING */
2274 		flag = fcntl(device->context->async_fd, F_GETFL);
2275 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2276 		if (rc < 0) {
2277 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2278 			free(device);
2279 			break;
2280 		}
2281 
2282 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2283 		i++;
2284 
2285 		pd = NULL;
2286 		if (g_nvmf_hooks.get_ibv_pd) {
2287 			pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2288 		}
2289 
2290 		if (!g_nvmf_hooks.get_ibv_pd) {
2291 			device->pd = ibv_alloc_pd(device->context);
2292 			if (!device->pd) {
2293 				SPDK_ERRLOG("Unable to allocate protection domain.\n");
2294 				spdk_nvmf_rdma_destroy(&rtransport->transport);
2295 				return NULL;
2296 			}
2297 		} else {
2298 			device->pd = pd;
2299 		}
2300 
2301 		assert(device->map == NULL);
2302 
2303 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2304 		if (!device->map) {
2305 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2306 			spdk_nvmf_rdma_destroy(&rtransport->transport);
2307 			return NULL;
2308 		}
2309 
2310 		assert(device->map != NULL);
2311 		assert(device->pd != NULL);
2312 	}
2313 	rdma_free_devices(contexts);
2314 
2315 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2316 		/* divide and round up. */
2317 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2318 
2319 		/* round up to the nearest 4k. */
2320 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2321 
2322 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2323 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2324 			       opts->io_unit_size);
2325 	}
2326 
2327 	if (rc < 0) {
2328 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2329 		return NULL;
2330 	}
2331 
2332 	/* Set up poll descriptor array to monitor events from RDMA and IB
2333 	 * in a single poll syscall
2334 	 */
2335 	rtransport->npoll_fds = i + 1;
2336 	i = 0;
2337 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2338 	if (rtransport->poll_fds == NULL) {
2339 		SPDK_ERRLOG("poll_fds allocation failed\n");
2340 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2341 		return NULL;
2342 	}
2343 
2344 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2345 	rtransport->poll_fds[i++].events = POLLIN;
2346 
2347 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2348 		rtransport->poll_fds[i].fd = device->context->async_fd;
2349 		rtransport->poll_fds[i++].events = POLLIN;
2350 	}
2351 
2352 	return &rtransport->transport;
2353 }
2354 
2355 static int
2356 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
2357 {
2358 	struct spdk_nvmf_rdma_transport	*rtransport;
2359 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2360 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2361 
2362 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2363 
2364 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2365 		TAILQ_REMOVE(&rtransport->ports, port, link);
2366 		rdma_destroy_id(port->id);
2367 		free(port);
2368 	}
2369 
2370 	if (rtransport->poll_fds != NULL) {
2371 		free(rtransport->poll_fds);
2372 	}
2373 
2374 	if (rtransport->event_channel != NULL) {
2375 		rdma_destroy_event_channel(rtransport->event_channel);
2376 	}
2377 
2378 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2379 		TAILQ_REMOVE(&rtransport->devices, device, link);
2380 		if (device->map) {
2381 			spdk_mem_map_free(&device->map);
2382 		}
2383 		if (device->pd) {
2384 			if (!g_nvmf_hooks.get_ibv_pd) {
2385 				ibv_dealloc_pd(device->pd);
2386 			}
2387 		}
2388 		free(device);
2389 	}
2390 
2391 	if (rtransport->data_wr_pool != NULL) {
2392 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2393 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2394 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2395 				    spdk_mempool_count(rtransport->data_wr_pool),
2396 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2397 		}
2398 	}
2399 
2400 	spdk_mempool_free(rtransport->data_wr_pool);
2401 	pthread_mutex_destroy(&rtransport->lock);
2402 	free(rtransport);
2403 
2404 	return 0;
2405 }
2406 
2407 static int
2408 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2409 			       struct spdk_nvme_transport_id *trid,
2410 			       bool peer);
2411 
2412 static int
2413 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2414 		      const struct spdk_nvme_transport_id *trid)
2415 {
2416 	struct spdk_nvmf_rdma_transport	*rtransport;
2417 	struct spdk_nvmf_rdma_device	*device;
2418 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
2419 	struct addrinfo			*res;
2420 	struct addrinfo			hints;
2421 	int				family;
2422 	int				rc;
2423 
2424 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2425 
2426 	port = calloc(1, sizeof(*port));
2427 	if (!port) {
2428 		return -ENOMEM;
2429 	}
2430 
2431 	/* Selectively copy the trid. Things like NQN don't matter here - that
2432 	 * mapping is enforced elsewhere.
2433 	 */
2434 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2435 	port->trid.adrfam = trid->adrfam;
2436 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
2437 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
2438 
2439 	pthread_mutex_lock(&rtransport->lock);
2440 	assert(rtransport->event_channel != NULL);
2441 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
2442 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
2443 			port_tmp->ref++;
2444 			free(port);
2445 			/* Already listening at this address */
2446 			pthread_mutex_unlock(&rtransport->lock);
2447 			return 0;
2448 		}
2449 	}
2450 
2451 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2452 	if (rc < 0) {
2453 		SPDK_ERRLOG("rdma_create_id() failed\n");
2454 		free(port);
2455 		pthread_mutex_unlock(&rtransport->lock);
2456 		return rc;
2457 	}
2458 
2459 	switch (port->trid.adrfam) {
2460 	case SPDK_NVMF_ADRFAM_IPV4:
2461 		family = AF_INET;
2462 		break;
2463 	case SPDK_NVMF_ADRFAM_IPV6:
2464 		family = AF_INET6;
2465 		break;
2466 	default:
2467 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
2468 		free(port);
2469 		pthread_mutex_unlock(&rtransport->lock);
2470 		return -EINVAL;
2471 	}
2472 
2473 	memset(&hints, 0, sizeof(hints));
2474 	hints.ai_family = family;
2475 	hints.ai_flags = AI_NUMERICSERV;
2476 	hints.ai_socktype = SOCK_STREAM;
2477 	hints.ai_protocol = 0;
2478 
2479 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
2480 	if (rc) {
2481 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2482 		free(port);
2483 		pthread_mutex_unlock(&rtransport->lock);
2484 		return -EINVAL;
2485 	}
2486 
2487 	rc = rdma_bind_addr(port->id, res->ai_addr);
2488 	freeaddrinfo(res);
2489 
2490 	if (rc < 0) {
2491 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2492 		rdma_destroy_id(port->id);
2493 		free(port);
2494 		pthread_mutex_unlock(&rtransport->lock);
2495 		return rc;
2496 	}
2497 
2498 	if (!port->id->verbs) {
2499 		SPDK_ERRLOG("ibv_context is null\n");
2500 		rdma_destroy_id(port->id);
2501 		free(port);
2502 		pthread_mutex_unlock(&rtransport->lock);
2503 		return -1;
2504 	}
2505 
2506 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
2507 	if (rc < 0) {
2508 		SPDK_ERRLOG("rdma_listen() failed\n");
2509 		rdma_destroy_id(port->id);
2510 		free(port);
2511 		pthread_mutex_unlock(&rtransport->lock);
2512 		return rc;
2513 	}
2514 
2515 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2516 		if (device->context == port->id->verbs) {
2517 			port->device = device;
2518 			break;
2519 		}
2520 	}
2521 	if (!port->device) {
2522 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2523 			    port->id->verbs);
2524 		rdma_destroy_id(port->id);
2525 		free(port);
2526 		pthread_mutex_unlock(&rtransport->lock);
2527 		return -EINVAL;
2528 	}
2529 
2530 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
2531 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
2532 
2533 	port->ref = 1;
2534 
2535 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2536 	pthread_mutex_unlock(&rtransport->lock);
2537 
2538 	return 0;
2539 }
2540 
2541 static int
2542 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2543 			   const struct spdk_nvme_transport_id *_trid)
2544 {
2545 	struct spdk_nvmf_rdma_transport *rtransport;
2546 	struct spdk_nvmf_rdma_port *port, *tmp;
2547 	struct spdk_nvme_transport_id trid = {};
2548 
2549 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2550 
2551 	/* Selectively copy the trid. Things like NQN don't matter here - that
2552 	 * mapping is enforced elsewhere.
2553 	 */
2554 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2555 	trid.adrfam = _trid->adrfam;
2556 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2557 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2558 
2559 	pthread_mutex_lock(&rtransport->lock);
2560 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2561 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2562 			assert(port->ref > 0);
2563 			port->ref--;
2564 			if (port->ref == 0) {
2565 				TAILQ_REMOVE(&rtransport->ports, port, link);
2566 				rdma_destroy_id(port->id);
2567 				free(port);
2568 			}
2569 			break;
2570 		}
2571 	}
2572 
2573 	pthread_mutex_unlock(&rtransport->lock);
2574 	return 0;
2575 }
2576 
2577 static void
2578 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2579 				     struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2580 {
2581 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2582 	struct spdk_nvmf_rdma_resources *resources;
2583 
2584 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2585 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2586 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2587 			break;
2588 		}
2589 	}
2590 
2591 	/* Then RDMA writes since reads have stronger restrictions than writes */
2592 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2593 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2594 			break;
2595 		}
2596 	}
2597 
2598 	/* The second highest priority is I/O waiting on memory buffers. */
2599 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->poller->group->pending_data_buf_queue, state_link,
2600 			    req_tmp) {
2601 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2602 			break;
2603 		}
2604 	}
2605 
2606 	resources = rqpair->resources;
2607 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2608 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2609 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2610 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2611 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2612 
2613 		if (rqpair->srq != NULL) {
2614 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2615 			rdma_req->recv->qpair->qd++;
2616 		} else {
2617 			rqpair->qd++;
2618 		}
2619 
2620 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2621 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2622 			break;
2623 		}
2624 	}
2625 }
2626 
2627 static void
2628 _nvmf_rdma_qpair_disconnect(void *ctx)
2629 {
2630 	struct spdk_nvmf_qpair *qpair = ctx;
2631 
2632 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2633 }
2634 
2635 static void
2636 _nvmf_rdma_try_disconnect(void *ctx)
2637 {
2638 	struct spdk_nvmf_qpair *qpair = ctx;
2639 	struct spdk_nvmf_poll_group *group;
2640 
2641 	/* Read the group out of the qpair. This is normally set and accessed only from
2642 	 * the thread that created the group. Here, we're not on that thread necessarily.
2643 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2644 	 * a pointer and never changes. So fortunately reading this and checking for
2645 	 * non-NULL is thread safe in the x86_64 memory model. */
2646 	group = qpair->group;
2647 
2648 	if (group == NULL) {
2649 		/* The qpair hasn't been assigned to a group yet, so we can't
2650 		 * process a disconnect. Send a message to ourself and try again. */
2651 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2652 		return;
2653 	}
2654 
2655 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2656 }
2657 
2658 static inline void
2659 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2660 {
2661 	if (__sync_bool_compare_and_swap(&rqpair->disconnect_started, false, true)) {
2662 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2663 	}
2664 }
2665 
2666 static void nvmf_rdma_destroy_drained_qpair(void *ctx)
2667 {
2668 	struct spdk_nvmf_rdma_qpair *rqpair = ctx;
2669 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2670 			struct spdk_nvmf_rdma_transport, transport);
2671 
2672 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2673 	if (rqpair->current_send_depth != 0) {
2674 		return;
2675 	}
2676 
2677 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2678 		return;
2679 	}
2680 
2681 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false) {
2682 		return;
2683 	}
2684 
2685 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2686 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2687 }
2688 
2689 
2690 static int
2691 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2692 {
2693 	struct spdk_nvmf_qpair		*qpair;
2694 	struct spdk_nvmf_rdma_qpair	*rqpair;
2695 
2696 	if (evt->id == NULL) {
2697 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2698 		return -1;
2699 	}
2700 
2701 	qpair = evt->id->context;
2702 	if (qpair == NULL) {
2703 		SPDK_ERRLOG("disconnect request: no active connection\n");
2704 		return -1;
2705 	}
2706 
2707 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2708 
2709 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2710 
2711 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2712 
2713 	spdk_nvmf_rdma_start_disconnect(rqpair);
2714 
2715 	return 0;
2716 }
2717 
2718 #ifdef DEBUG
2719 static const char *CM_EVENT_STR[] = {
2720 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2721 	"RDMA_CM_EVENT_ADDR_ERROR",
2722 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2723 	"RDMA_CM_EVENT_ROUTE_ERROR",
2724 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2725 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2726 	"RDMA_CM_EVENT_CONNECT_ERROR",
2727 	"RDMA_CM_EVENT_UNREACHABLE",
2728 	"RDMA_CM_EVENT_REJECTED",
2729 	"RDMA_CM_EVENT_ESTABLISHED",
2730 	"RDMA_CM_EVENT_DISCONNECTED",
2731 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2732 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2733 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2734 	"RDMA_CM_EVENT_ADDR_CHANGE",
2735 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2736 };
2737 #endif /* DEBUG */
2738 
2739 static void
2740 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2741 {
2742 	struct spdk_nvmf_rdma_transport *rtransport;
2743 	struct rdma_cm_event		*event;
2744 	int				rc;
2745 
2746 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2747 
2748 	if (rtransport->event_channel == NULL) {
2749 		return;
2750 	}
2751 
2752 	while (1) {
2753 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2754 		if (rc == 0) {
2755 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2756 
2757 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2758 
2759 			switch (event->event) {
2760 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2761 			case RDMA_CM_EVENT_ADDR_ERROR:
2762 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2763 			case RDMA_CM_EVENT_ROUTE_ERROR:
2764 				/* No action required. The target never attempts to resolve routes. */
2765 				break;
2766 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2767 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2768 				if (rc < 0) {
2769 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2770 					break;
2771 				}
2772 				break;
2773 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2774 				/* The target never initiates a new connection. So this will not occur. */
2775 				break;
2776 			case RDMA_CM_EVENT_CONNECT_ERROR:
2777 				/* Can this happen? The docs say it can, but not sure what causes it. */
2778 				break;
2779 			case RDMA_CM_EVENT_UNREACHABLE:
2780 			case RDMA_CM_EVENT_REJECTED:
2781 				/* These only occur on the client side. */
2782 				break;
2783 			case RDMA_CM_EVENT_ESTABLISHED:
2784 				/* TODO: Should we be waiting for this event anywhere? */
2785 				break;
2786 			case RDMA_CM_EVENT_DISCONNECTED:
2787 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2788 				rc = nvmf_rdma_disconnect(event);
2789 				if (rc < 0) {
2790 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2791 					break;
2792 				}
2793 				break;
2794 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2795 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2796 				/* Multicast is not used */
2797 				break;
2798 			case RDMA_CM_EVENT_ADDR_CHANGE:
2799 				/* Not utilizing this event */
2800 				break;
2801 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2802 				/* For now, do nothing. The target never re-uses queue pairs. */
2803 				break;
2804 			default:
2805 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2806 				break;
2807 			}
2808 
2809 			rdma_ack_cm_event(event);
2810 		} else {
2811 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2812 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2813 			}
2814 			break;
2815 		}
2816 	}
2817 }
2818 
2819 static void
2820 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2821 {
2822 	int				rc;
2823 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
2824 	struct ibv_async_event		event;
2825 	enum ibv_qp_state		state;
2826 
2827 	rc = ibv_get_async_event(device->context, &event);
2828 
2829 	if (rc) {
2830 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2831 			    errno, spdk_strerror(errno));
2832 		return;
2833 	}
2834 
2835 	switch (event.event_type) {
2836 	case IBV_EVENT_QP_FATAL:
2837 		rqpair = event.element.qp->qp_context;
2838 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
2839 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2840 				  (uintptr_t)rqpair->cm_id, event.event_type);
2841 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2842 		spdk_nvmf_rdma_start_disconnect(rqpair);
2843 		break;
2844 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2845 		/* This event only occurs for shared receive queues. */
2846 		rqpair = event.element.qp->qp_context;
2847 		rqpair->last_wqe_reached = true;
2848 
2849 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last WQE reached event received for rqpair %p\n", rqpair);
2850 		/* This must be handled on the polling thread if it exists. Otherwise the timeout will catch it. */
2851 		if (rqpair->qpair.group) {
2852 			spdk_thread_send_msg(rqpair->qpair.group->thread, nvmf_rdma_destroy_drained_qpair, rqpair);
2853 		} else {
2854 			SPDK_ERRLOG("Unable to destroy the qpair %p since it does not have a poll group.\n", rqpair);
2855 		}
2856 
2857 		break;
2858 	case IBV_EVENT_SQ_DRAINED:
2859 		/* This event occurs frequently in both error and non-error states.
2860 		 * Check if the qpair is in an error state before sending a message.
2861 		 * Note that we're not on the correct thread to access the qpair, but
2862 		 * the operations that the below calls make all happen to be thread
2863 		 * safe. */
2864 		rqpair = event.element.qp->qp_context;
2865 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last sq drained event received for rqpair %p\n", rqpair);
2866 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2867 				  (uintptr_t)rqpair->cm_id, event.event_type);
2868 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2869 		if (state == IBV_QPS_ERR) {
2870 			spdk_nvmf_rdma_start_disconnect(rqpair);
2871 		}
2872 		break;
2873 	case IBV_EVENT_QP_REQ_ERR:
2874 	case IBV_EVENT_QP_ACCESS_ERR:
2875 	case IBV_EVENT_COMM_EST:
2876 	case IBV_EVENT_PATH_MIG:
2877 	case IBV_EVENT_PATH_MIG_ERR:
2878 		SPDK_NOTICELOG("Async event: %s\n",
2879 			       ibv_event_type_str(event.event_type));
2880 		rqpair = event.element.qp->qp_context;
2881 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2882 				  (uintptr_t)rqpair->cm_id, event.event_type);
2883 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2884 		break;
2885 	case IBV_EVENT_CQ_ERR:
2886 	case IBV_EVENT_DEVICE_FATAL:
2887 	case IBV_EVENT_PORT_ACTIVE:
2888 	case IBV_EVENT_PORT_ERR:
2889 	case IBV_EVENT_LID_CHANGE:
2890 	case IBV_EVENT_PKEY_CHANGE:
2891 	case IBV_EVENT_SM_CHANGE:
2892 	case IBV_EVENT_SRQ_ERR:
2893 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2894 	case IBV_EVENT_CLIENT_REREGISTER:
2895 	case IBV_EVENT_GID_CHANGE:
2896 	default:
2897 		SPDK_NOTICELOG("Async event: %s\n",
2898 			       ibv_event_type_str(event.event_type));
2899 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2900 		break;
2901 	}
2902 	ibv_ack_async_event(&event);
2903 }
2904 
2905 static void
2906 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2907 {
2908 	int	nfds, i = 0;
2909 	struct spdk_nvmf_rdma_transport *rtransport;
2910 	struct spdk_nvmf_rdma_device *device, *tmp;
2911 
2912 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2913 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2914 
2915 	if (nfds <= 0) {
2916 		return;
2917 	}
2918 
2919 	/* The first poll descriptor is RDMA CM event */
2920 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2921 		spdk_nvmf_process_cm_event(transport, cb_fn);
2922 		nfds--;
2923 	}
2924 
2925 	if (nfds == 0) {
2926 		return;
2927 	}
2928 
2929 	/* Second and subsequent poll descriptors are IB async events */
2930 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2931 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2932 			spdk_nvmf_process_ib_event(device);
2933 			nfds--;
2934 		}
2935 	}
2936 	/* check all flagged fd's have been served */
2937 	assert(nfds == 0);
2938 }
2939 
2940 static void
2941 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2942 			struct spdk_nvme_transport_id *trid,
2943 			struct spdk_nvmf_discovery_log_page_entry *entry)
2944 {
2945 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2946 	entry->adrfam = trid->adrfam;
2947 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2948 
2949 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2950 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2951 
2952 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2953 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2954 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2955 }
2956 
2957 static void
2958 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
2959 
2960 static struct spdk_nvmf_transport_poll_group *
2961 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2962 {
2963 	struct spdk_nvmf_rdma_transport		*rtransport;
2964 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2965 	struct spdk_nvmf_rdma_poller		*poller;
2966 	struct spdk_nvmf_rdma_device		*device;
2967 	struct ibv_srq_init_attr		srq_init_attr;
2968 	struct spdk_nvmf_rdma_resource_opts	opts;
2969 	int					num_cqe;
2970 
2971 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2972 
2973 	rgroup = calloc(1, sizeof(*rgroup));
2974 	if (!rgroup) {
2975 		return NULL;
2976 	}
2977 
2978 	TAILQ_INIT(&rgroup->pollers);
2979 	STAILQ_INIT(&rgroup->pending_data_buf_queue);
2980 
2981 	pthread_mutex_lock(&rtransport->lock);
2982 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2983 		poller = calloc(1, sizeof(*poller));
2984 		if (!poller) {
2985 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2986 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
2987 			pthread_mutex_unlock(&rtransport->lock);
2988 			return NULL;
2989 		}
2990 
2991 		poller->device = device;
2992 		poller->group = rgroup;
2993 
2994 		TAILQ_INIT(&poller->qpairs);
2995 		STAILQ_INIT(&poller->qpairs_pending_send);
2996 		STAILQ_INIT(&poller->qpairs_pending_recv);
2997 
2998 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2999 		if (transport->opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3000 			poller->max_srq_depth = transport->opts.max_srq_depth;
3001 
3002 			device->num_srq++;
3003 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3004 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3005 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3006 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3007 			if (!poller->srq) {
3008 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3009 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3010 				pthread_mutex_unlock(&rtransport->lock);
3011 				return NULL;
3012 			}
3013 
3014 			opts.qp = poller->srq;
3015 			opts.pd = device->pd;
3016 			opts.qpair = NULL;
3017 			opts.shared = true;
3018 			opts.max_queue_depth = poller->max_srq_depth;
3019 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3020 
3021 			poller->resources = nvmf_rdma_resources_create(&opts);
3022 			if (!poller->resources) {
3023 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3024 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3025 				pthread_mutex_unlock(&rtransport->lock);
3026 			}
3027 		}
3028 
3029 		/*
3030 		 * When using an srq, we can limit the completion queue at startup.
3031 		 * The following formula represents the calculation:
3032 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3033 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3034 		 */
3035 		if (poller->srq) {
3036 			num_cqe = poller->max_srq_depth * 3;
3037 		} else {
3038 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3039 		}
3040 
3041 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3042 		if (!poller->cq) {
3043 			SPDK_ERRLOG("Unable to create completion queue\n");
3044 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3045 			pthread_mutex_unlock(&rtransport->lock);
3046 			return NULL;
3047 		}
3048 		poller->num_cqe = num_cqe;
3049 	}
3050 
3051 	pthread_mutex_unlock(&rtransport->lock);
3052 	return &rgroup->group;
3053 }
3054 
3055 static void
3056 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3057 {
3058 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3059 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3060 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3061 
3062 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3063 
3064 	if (!rgroup) {
3065 		return;
3066 	}
3067 
3068 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3069 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3070 
3071 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3072 			spdk_nvmf_rdma_qpair_destroy(qpair);
3073 		}
3074 
3075 		if (poller->srq) {
3076 			nvmf_rdma_resources_destroy(poller->resources);
3077 			ibv_destroy_srq(poller->srq);
3078 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Destroyed RDMA shared queue %p\n", poller->srq);
3079 		}
3080 
3081 		if (poller->cq) {
3082 			ibv_destroy_cq(poller->cq);
3083 		}
3084 
3085 		free(poller);
3086 	}
3087 
3088 	if (!STAILQ_EMPTY(&rgroup->pending_data_buf_queue)) {
3089 		SPDK_ERRLOG("Pending I/O list wasn't empty on poll group destruction\n");
3090 	}
3091 
3092 	free(rgroup);
3093 }
3094 
3095 static void
3096 spdk_nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3097 {
3098 	if (rqpair->cm_id != NULL) {
3099 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3100 	}
3101 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3102 }
3103 
3104 static int
3105 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3106 			      struct spdk_nvmf_qpair *qpair)
3107 {
3108 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3109 	struct spdk_nvmf_rdma_qpair		*rqpair;
3110 	struct spdk_nvmf_rdma_device		*device;
3111 	struct spdk_nvmf_rdma_poller		*poller;
3112 	int					rc;
3113 
3114 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3115 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3116 
3117 	device = rqpair->port->device;
3118 
3119 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3120 		if (poller->device == device) {
3121 			break;
3122 		}
3123 	}
3124 
3125 	if (!poller) {
3126 		SPDK_ERRLOG("No poller found for device.\n");
3127 		return -1;
3128 	}
3129 
3130 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3131 	rqpair->poller = poller;
3132 	rqpair->srq = rqpair->poller->srq;
3133 
3134 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
3135 	if (rc < 0) {
3136 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3137 		return -1;
3138 	}
3139 
3140 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3141 	if (rc) {
3142 		/* Try to reject, but we probably can't */
3143 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3144 		return -1;
3145 	}
3146 
3147 	spdk_nvmf_rdma_update_ibv_state(rqpair);
3148 
3149 	return 0;
3150 }
3151 
3152 static int
3153 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3154 {
3155 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3156 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3157 			struct spdk_nvmf_rdma_transport, transport);
3158 
3159 	nvmf_rdma_request_free(rdma_req, rtransport);
3160 	return 0;
3161 }
3162 
3163 static int
3164 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3165 {
3166 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3167 			struct spdk_nvmf_rdma_transport, transport);
3168 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3169 			struct spdk_nvmf_rdma_request, req);
3170 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3171 			struct spdk_nvmf_rdma_qpair, qpair);
3172 
3173 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3174 		/* The connection is alive, so process the request as normal */
3175 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3176 	} else {
3177 		/* The connection is dead. Move the request directly to the completed state. */
3178 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3179 	}
3180 
3181 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3182 
3183 	return 0;
3184 }
3185 
3186 static int
3187 spdk_nvmf_rdma_destroy_defunct_qpair(void *ctx)
3188 {
3189 	struct spdk_nvmf_rdma_qpair	*rqpair = ctx;
3190 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3191 			struct spdk_nvmf_rdma_transport, transport);
3192 
3193 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3194 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3195 
3196 	return 0;
3197 }
3198 
3199 static void
3200 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
3201 {
3202 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3203 
3204 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
3205 		return;
3206 	}
3207 
3208 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
3209 
3210 	/* This happens only when the qpair is disconnected before
3211 	 * it is added to the poll group. Since there is no poll group,
3212 	 * the RDMA qp has not been initialized yet and the RDMA CM
3213 	 * event has not yet been acknowledged, so we need to reject it.
3214 	 */
3215 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3216 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3217 		return;
3218 	}
3219 
3220 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3221 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
3222 	}
3223 
3224 	rqpair->destruct_poller = spdk_poller_register(spdk_nvmf_rdma_destroy_defunct_qpair, (void *)rqpair,
3225 				  NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US);
3226 }
3227 
3228 static struct spdk_nvmf_rdma_qpair *
3229 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3230 {
3231 	struct spdk_nvmf_rdma_qpair *rqpair;
3232 	/* @todo: improve QP search */
3233 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3234 		if (wc->qp_num == rqpair->cm_id->qp->qp_num) {
3235 			return rqpair;
3236 		}
3237 	}
3238 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3239 	return NULL;
3240 }
3241 
3242 #ifdef DEBUG
3243 static int
3244 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3245 {
3246 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3247 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3248 }
3249 #endif
3250 
3251 static void
3252 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3253 			   int rc)
3254 {
3255 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3256 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3257 
3258 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3259 	while (bad_recv_wr != NULL) {
3260 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3261 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3262 
3263 		rdma_recv->qpair->current_recv_depth++;
3264 		bad_recv_wr = bad_recv_wr->next;
3265 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3266 		spdk_nvmf_rdma_start_disconnect(rdma_recv->qpair);
3267 	}
3268 }
3269 
3270 static void
3271 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3272 {
3273 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3274 	while (bad_recv_wr != NULL) {
3275 		bad_recv_wr = bad_recv_wr->next;
3276 		rqpair->current_recv_depth++;
3277 	}
3278 	spdk_nvmf_rdma_start_disconnect(rqpair);
3279 }
3280 
3281 static void
3282 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3283 		     struct spdk_nvmf_rdma_poller *rpoller)
3284 {
3285 	struct spdk_nvmf_rdma_qpair	*rqpair;
3286 	struct ibv_recv_wr		*bad_recv_wr;
3287 	int				rc;
3288 
3289 	if (rpoller->srq) {
3290 		if (rpoller->resources->recvs_to_post.first != NULL) {
3291 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3292 			if (rc) {
3293 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3294 			}
3295 			rpoller->resources->recvs_to_post.first = NULL;
3296 			rpoller->resources->recvs_to_post.last = NULL;
3297 		}
3298 	} else {
3299 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3300 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3301 			assert(rqpair->resources->recvs_to_post.first != NULL);
3302 			rc = ibv_post_recv(rqpair->cm_id->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3303 			if (rc) {
3304 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3305 			}
3306 			rqpair->resources->recvs_to_post.first = NULL;
3307 			rqpair->resources->recvs_to_post.last = NULL;
3308 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3309 		}
3310 	}
3311 }
3312 
3313 static void
3314 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3315 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3316 {
3317 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3318 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3319 
3320 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3321 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3322 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3323 		assert(rqpair->current_send_depth > 0);
3324 		rqpair->current_send_depth--;
3325 		switch (bad_rdma_wr->type) {
3326 		case RDMA_WR_TYPE_DATA:
3327 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3328 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3329 				assert(rqpair->current_read_depth > 0);
3330 				rqpair->current_read_depth--;
3331 			}
3332 			break;
3333 		case RDMA_WR_TYPE_SEND:
3334 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3335 			break;
3336 		default:
3337 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3338 			prev_rdma_req = cur_rdma_req;
3339 			continue;
3340 		}
3341 
3342 		if (prev_rdma_req == cur_rdma_req) {
3343 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3344 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3345 			continue;
3346 		}
3347 
3348 		switch (cur_rdma_req->state) {
3349 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3350 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3351 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3352 			break;
3353 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3354 		case RDMA_REQUEST_STATE_COMPLETING:
3355 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3356 			break;
3357 		default:
3358 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3359 				    cur_rdma_req->state, rqpair);
3360 			continue;
3361 		}
3362 
3363 		spdk_nvmf_rdma_request_process(rtransport, cur_rdma_req);
3364 		prev_rdma_req = cur_rdma_req;
3365 	}
3366 
3367 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3368 		/* Disconnect the connection. */
3369 		spdk_nvmf_rdma_start_disconnect(rqpair);
3370 	}
3371 
3372 }
3373 
3374 static void
3375 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3376 		     struct spdk_nvmf_rdma_poller *rpoller)
3377 {
3378 	struct spdk_nvmf_rdma_qpair	*rqpair;
3379 	struct ibv_send_wr		*bad_wr = NULL;
3380 	int				rc;
3381 
3382 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3383 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3384 		assert(rqpair->sends_to_post.first != NULL);
3385 		rc = ibv_post_send(rqpair->cm_id->qp, rqpair->sends_to_post.first, &bad_wr);
3386 
3387 		/* bad wr always points to the first wr that failed. */
3388 		if (rc) {
3389 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3390 		}
3391 		rqpair->sends_to_post.first = NULL;
3392 		rqpair->sends_to_post.last = NULL;
3393 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3394 	}
3395 }
3396 
3397 static int
3398 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3399 			   struct spdk_nvmf_rdma_poller *rpoller)
3400 {
3401 	struct ibv_wc wc[32];
3402 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3403 	struct spdk_nvmf_rdma_request	*rdma_req;
3404 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3405 	struct spdk_nvmf_rdma_qpair	*rqpair;
3406 	int reaped, i;
3407 	int count = 0;
3408 	bool error = false;
3409 
3410 	/* Poll for completing operations. */
3411 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3412 	if (reaped < 0) {
3413 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3414 			    errno, spdk_strerror(errno));
3415 		return -1;
3416 	}
3417 
3418 	for (i = 0; i < reaped; i++) {
3419 
3420 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3421 
3422 		switch (rdma_wr->type) {
3423 		case RDMA_WR_TYPE_SEND:
3424 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3425 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3426 
3427 			if (!wc[i].status) {
3428 				count++;
3429 				assert(wc[i].opcode == IBV_WC_SEND);
3430 				assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
3431 			} else {
3432 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3433 			}
3434 
3435 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3436 			/* +1 for the response wr */
3437 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3438 			rdma_req->num_outstanding_data_wr = 0;
3439 
3440 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3441 			break;
3442 		case RDMA_WR_TYPE_RECV:
3443 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3444 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3445 			if (rpoller->srq != NULL) {
3446 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3447 			}
3448 			rqpair = rdma_recv->qpair;
3449 
3450 			assert(rqpair != NULL);
3451 			if (!wc[i].status) {
3452 				assert(wc[i].opcode == IBV_WC_RECV);
3453 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3454 					spdk_nvmf_rdma_start_disconnect(rqpair);
3455 					break;
3456 				}
3457 			}
3458 
3459 			rdma_recv->wr.next = NULL;
3460 			rqpair->current_recv_depth++;
3461 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3462 			break;
3463 		case RDMA_WR_TYPE_DATA:
3464 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3465 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3466 
3467 			assert(rdma_req->num_outstanding_data_wr > 0);
3468 
3469 			rqpair->current_send_depth--;
3470 			rdma_req->num_outstanding_data_wr--;
3471 			if (!wc[i].status) {
3472 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3473 				rqpair->current_read_depth--;
3474 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3475 				if (rdma_req->num_outstanding_data_wr == 0) {
3476 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3477 					spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3478 				}
3479 			} else {
3480 				/* If the data transfer fails still force the queue into the error state,
3481 				 * if we were performing an RDMA_READ, we need to force the request into a
3482 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3483 				 * case, we should wait for the SEND to complete. */
3484 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3485 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3486 					rqpair->current_read_depth--;
3487 					if (rdma_req->num_outstanding_data_wr == 0) {
3488 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3489 					}
3490 				}
3491 			}
3492 			break;
3493 		default:
3494 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3495 			continue;
3496 		}
3497 
3498 		/* Handle error conditions */
3499 		if (wc[i].status) {
3500 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
3501 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
3502 
3503 			error = true;
3504 
3505 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3506 				/* Disconnect the connection. */
3507 				spdk_nvmf_rdma_start_disconnect(rqpair);
3508 			} else {
3509 				nvmf_rdma_destroy_drained_qpair(rqpair);
3510 			}
3511 			continue;
3512 		}
3513 
3514 		spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3515 
3516 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3517 			nvmf_rdma_destroy_drained_qpair(rqpair);
3518 		}
3519 	}
3520 
3521 	if (error == true) {
3522 		return -1;
3523 	}
3524 
3525 	/* submit outstanding work requests. */
3526 	_poller_submit_recvs(rtransport, rpoller);
3527 	_poller_submit_sends(rtransport, rpoller);
3528 
3529 	return count;
3530 }
3531 
3532 static int
3533 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3534 {
3535 	struct spdk_nvmf_rdma_transport *rtransport;
3536 	struct spdk_nvmf_rdma_poll_group *rgroup;
3537 	struct spdk_nvmf_rdma_poller	*rpoller;
3538 	int				count, rc;
3539 
3540 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3541 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3542 
3543 	count = 0;
3544 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3545 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
3546 		if (rc < 0) {
3547 			return rc;
3548 		}
3549 		count += rc;
3550 	}
3551 
3552 	return count;
3553 }
3554 
3555 static int
3556 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3557 			       struct spdk_nvme_transport_id *trid,
3558 			       bool peer)
3559 {
3560 	struct sockaddr *saddr;
3561 	uint16_t port;
3562 
3563 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
3564 
3565 	if (peer) {
3566 		saddr = rdma_get_peer_addr(id);
3567 	} else {
3568 		saddr = rdma_get_local_addr(id);
3569 	}
3570 	switch (saddr->sa_family) {
3571 	case AF_INET: {
3572 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3573 
3574 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3575 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3576 			  trid->traddr, sizeof(trid->traddr));
3577 		if (peer) {
3578 			port = ntohs(rdma_get_dst_port(id));
3579 		} else {
3580 			port = ntohs(rdma_get_src_port(id));
3581 		}
3582 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3583 		break;
3584 	}
3585 	case AF_INET6: {
3586 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
3587 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
3588 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
3589 			  trid->traddr, sizeof(trid->traddr));
3590 		if (peer) {
3591 			port = ntohs(rdma_get_dst_port(id));
3592 		} else {
3593 			port = ntohs(rdma_get_src_port(id));
3594 		}
3595 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3596 		break;
3597 	}
3598 	default:
3599 		return -1;
3600 
3601 	}
3602 
3603 	return 0;
3604 }
3605 
3606 static int
3607 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3608 				   struct spdk_nvme_transport_id *trid)
3609 {
3610 	struct spdk_nvmf_rdma_qpair	*rqpair;
3611 
3612 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3613 
3614 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
3615 }
3616 
3617 static int
3618 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
3619 				    struct spdk_nvme_transport_id *trid)
3620 {
3621 	struct spdk_nvmf_rdma_qpair	*rqpair;
3622 
3623 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3624 
3625 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
3626 }
3627 
3628 static int
3629 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
3630 				     struct spdk_nvme_transport_id *trid)
3631 {
3632 	struct spdk_nvmf_rdma_qpair	*rqpair;
3633 
3634 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3635 
3636 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
3637 }
3638 
3639 void
3640 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
3641 {
3642 	g_nvmf_hooks = *hooks;
3643 }
3644 
3645 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
3646 	.type = SPDK_NVME_TRANSPORT_RDMA,
3647 	.opts_init = spdk_nvmf_rdma_opts_init,
3648 	.create = spdk_nvmf_rdma_create,
3649 	.destroy = spdk_nvmf_rdma_destroy,
3650 
3651 	.listen = spdk_nvmf_rdma_listen,
3652 	.stop_listen = spdk_nvmf_rdma_stop_listen,
3653 	.accept = spdk_nvmf_rdma_accept,
3654 
3655 	.listener_discover = spdk_nvmf_rdma_discover,
3656 
3657 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
3658 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
3659 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
3660 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
3661 
3662 	.req_free = spdk_nvmf_rdma_request_free,
3663 	.req_complete = spdk_nvmf_rdma_request_complete,
3664 
3665 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
3666 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
3667 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
3668 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
3669 
3670 };
3671 
3672 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
3673