xref: /spdk/lib/nvmf/rdma.c (revision 4237d2d8cb14e5e52ede3ed9718019488b445afe)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019, 2020 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 "spdk/config.h"
37 #include "spdk/thread.h"
38 #include "spdk/likely.h"
39 #include "spdk/nvmf_transport.h"
40 #include "spdk/string.h"
41 #include "spdk/trace.h"
42 #include "spdk/util.h"
43 
44 #include "spdk_internal/assert.h"
45 #include "spdk/log.h"
46 #include "spdk_internal/rdma.h"
47 
48 #include "nvmf_internal.h"
49 
50 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
51 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
52 
53 /*
54  RDMA Connection Resource Defaults
55  */
56 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
57 #define NVMF_DEFAULT_RSP_SGE		1
58 #define NVMF_DEFAULT_RX_SGE		2
59 
60 /* The RDMA completion queue size */
61 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
62 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
63 
64 static int g_spdk_nvmf_ibv_query_mask =
65 	IBV_QP_STATE |
66 	IBV_QP_PKEY_INDEX |
67 	IBV_QP_PORT |
68 	IBV_QP_ACCESS_FLAGS |
69 	IBV_QP_AV |
70 	IBV_QP_PATH_MTU |
71 	IBV_QP_DEST_QPN |
72 	IBV_QP_RQ_PSN |
73 	IBV_QP_MAX_DEST_RD_ATOMIC |
74 	IBV_QP_MIN_RNR_TIMER |
75 	IBV_QP_SQ_PSN |
76 	IBV_QP_TIMEOUT |
77 	IBV_QP_RETRY_CNT |
78 	IBV_QP_RNR_RETRY |
79 	IBV_QP_MAX_QP_RD_ATOMIC;
80 
81 enum spdk_nvmf_rdma_request_state {
82 	/* The request is not currently in use */
83 	RDMA_REQUEST_STATE_FREE = 0,
84 
85 	/* Initial state when request first received */
86 	RDMA_REQUEST_STATE_NEW,
87 
88 	/* The request is queued until a data buffer is available. */
89 	RDMA_REQUEST_STATE_NEED_BUFFER,
90 
91 	/* The request is waiting on RDMA queue depth availability
92 	 * to transfer data from the host to the controller.
93 	 */
94 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
95 
96 	/* The request is currently transferring data from the host to the controller. */
97 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
98 
99 	/* The request is ready to execute at the block device */
100 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
101 
102 	/* The request is currently executing at the block device */
103 	RDMA_REQUEST_STATE_EXECUTING,
104 
105 	/* The request finished executing at the block device */
106 	RDMA_REQUEST_STATE_EXECUTED,
107 
108 	/* The request is waiting on RDMA queue depth availability
109 	 * to transfer data from the controller to the host.
110 	 */
111 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
112 
113 	/* The request is ready to send a completion */
114 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
115 
116 	/* The request is currently transferring data from the controller to the host. */
117 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
118 
119 	/* The request currently has an outstanding completion without an
120 	 * associated data transfer.
121 	 */
122 	RDMA_REQUEST_STATE_COMPLETING,
123 
124 	/* The request completed and can be marked free. */
125 	RDMA_REQUEST_STATE_COMPLETED,
126 
127 	/* Terminator */
128 	RDMA_REQUEST_NUM_STATES,
129 };
130 
131 #define OBJECT_NVMF_RDMA_IO				0x40
132 
133 #define TRACE_GROUP_NVMF_RDMA				0x4
134 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
135 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
136 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
137 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
138 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
139 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
140 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
141 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
142 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
143 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
144 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
145 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
146 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
147 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
148 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
149 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
150 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
151 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
152 
153 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
154 {
155 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
156 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
157 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
158 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
159 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
160 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
161 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
163 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
164 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
165 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
166 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
167 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
170 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
173 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
175 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
176 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
178 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
179 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
180 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
181 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
182 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
183 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
184 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
185 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
186 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
187 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
188 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
189 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
190 
191 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
192 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
193 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
194 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
195 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
196 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
197 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
198 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
199 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
200 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
201 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
202 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
203 }
204 
205 enum spdk_nvmf_rdma_wr_type {
206 	RDMA_WR_TYPE_RECV,
207 	RDMA_WR_TYPE_SEND,
208 	RDMA_WR_TYPE_DATA,
209 };
210 
211 struct spdk_nvmf_rdma_wr {
212 	enum spdk_nvmf_rdma_wr_type	type;
213 };
214 
215 /* This structure holds commands as they are received off the wire.
216  * It must be dynamically paired with a full request object
217  * (spdk_nvmf_rdma_request) to service a request. It is separate
218  * from the request because RDMA does not appear to order
219  * completions, so occasionally we'll get a new incoming
220  * command when there aren't any free request objects.
221  */
222 struct spdk_nvmf_rdma_recv {
223 	struct ibv_recv_wr			wr;
224 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
225 
226 	struct spdk_nvmf_rdma_qpair		*qpair;
227 
228 	/* In-capsule data buffer */
229 	uint8_t					*buf;
230 
231 	struct spdk_nvmf_rdma_wr		rdma_wr;
232 	uint64_t				receive_tsc;
233 
234 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
235 };
236 
237 struct spdk_nvmf_rdma_request_data {
238 	struct spdk_nvmf_rdma_wr	rdma_wr;
239 	struct ibv_send_wr		wr;
240 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
241 };
242 
243 struct spdk_nvmf_rdma_request {
244 	struct spdk_nvmf_request		req;
245 
246 	enum spdk_nvmf_rdma_request_state	state;
247 
248 	struct spdk_nvmf_rdma_recv		*recv;
249 
250 	struct {
251 		struct spdk_nvmf_rdma_wr	rdma_wr;
252 		struct	ibv_send_wr		wr;
253 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
254 	} rsp;
255 
256 	struct spdk_nvmf_rdma_request_data	data;
257 
258 	uint32_t				iovpos;
259 
260 	uint32_t				num_outstanding_data_wr;
261 	uint64_t				receive_tsc;
262 
263 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
264 };
265 
266 struct spdk_nvmf_rdma_resource_opts {
267 	struct spdk_nvmf_rdma_qpair	*qpair;
268 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
269 	void				*qp;
270 	struct ibv_pd			*pd;
271 	uint32_t			max_queue_depth;
272 	uint32_t			in_capsule_data_size;
273 	bool				shared;
274 };
275 
276 struct spdk_nvmf_recv_wr_list {
277 	struct ibv_recv_wr	*first;
278 	struct ibv_recv_wr	*last;
279 };
280 
281 struct spdk_nvmf_rdma_resources {
282 	/* Array of size "max_queue_depth" containing RDMA requests. */
283 	struct spdk_nvmf_rdma_request		*reqs;
284 
285 	/* Array of size "max_queue_depth" containing RDMA recvs. */
286 	struct spdk_nvmf_rdma_recv		*recvs;
287 
288 	/* Array of size "max_queue_depth" containing 64 byte capsules
289 	 * used for receive.
290 	 */
291 	union nvmf_h2c_msg			*cmds;
292 	struct ibv_mr				*cmds_mr;
293 
294 	/* Array of size "max_queue_depth" containing 16 byte completions
295 	 * to be sent back to the user.
296 	 */
297 	union nvmf_c2h_msg			*cpls;
298 	struct ibv_mr				*cpls_mr;
299 
300 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
301 	 * buffers to be used for in capsule data.
302 	 */
303 	void					*bufs;
304 	struct ibv_mr				*bufs_mr;
305 
306 	/* The list of pending recvs to transfer */
307 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
308 
309 	/* Receives that are waiting for a request object */
310 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
311 
312 	/* Queue to track free requests */
313 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
314 };
315 
316 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
317 
318 struct spdk_nvmf_rdma_ibv_event_ctx {
319 	struct spdk_nvmf_rdma_qpair			*rqpair;
320 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
321 	/* Link to other ibv events associated with this qpair */
322 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
323 };
324 
325 struct spdk_nvmf_rdma_qpair {
326 	struct spdk_nvmf_qpair			qpair;
327 
328 	struct spdk_nvmf_rdma_device		*device;
329 	struct spdk_nvmf_rdma_poller		*poller;
330 
331 	struct spdk_rdma_qp			*rdma_qp;
332 	struct rdma_cm_id			*cm_id;
333 	struct ibv_srq				*srq;
334 	struct rdma_cm_id			*listen_id;
335 
336 	/* The maximum number of I/O outstanding on this connection at one time */
337 	uint16_t				max_queue_depth;
338 
339 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
340 	uint16_t				max_read_depth;
341 
342 	/* The maximum number of RDMA SEND operations at one time */
343 	uint32_t				max_send_depth;
344 
345 	/* The current number of outstanding WRs from this qpair's
346 	 * recv queue. Should not exceed device->attr.max_queue_depth.
347 	 */
348 	uint16_t				current_recv_depth;
349 
350 	/* The current number of active RDMA READ operations */
351 	uint16_t				current_read_depth;
352 
353 	/* The current number of posted WRs from this qpair's
354 	 * send queue. Should not exceed max_send_depth.
355 	 */
356 	uint32_t				current_send_depth;
357 
358 	/* The maximum number of SGEs per WR on the send queue */
359 	uint32_t				max_send_sge;
360 
361 	/* The maximum number of SGEs per WR on the recv queue */
362 	uint32_t				max_recv_sge;
363 
364 	struct spdk_nvmf_rdma_resources		*resources;
365 
366 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
367 
368 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
369 
370 	/* Number of requests not in the free state */
371 	uint32_t				qd;
372 
373 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
374 
375 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
376 
377 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
378 
379 	/* IBV queue pair attributes: they are used to manage
380 	 * qp state and recover from errors.
381 	 */
382 	enum ibv_qp_state			ibv_state;
383 
384 	/*
385 	 * io_channel which is used to destroy qpair when it is removed from poll group
386 	 */
387 	struct spdk_io_channel		*destruct_channel;
388 
389 	/* List of ibv async events */
390 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
391 
392 	/* Lets us know that we have received the last_wqe event. */
393 	bool					last_wqe_reached;
394 
395 	/* Indicate that nvmf_rdma_close_qpair is called */
396 	bool					to_close;
397 };
398 
399 struct spdk_nvmf_rdma_poller_stat {
400 	uint64_t				completions;
401 	uint64_t				polls;
402 	uint64_t				requests;
403 	uint64_t				request_latency;
404 	uint64_t				pending_free_request;
405 	uint64_t				pending_rdma_read;
406 	uint64_t				pending_rdma_write;
407 };
408 
409 struct spdk_nvmf_rdma_poller {
410 	struct spdk_nvmf_rdma_device		*device;
411 	struct spdk_nvmf_rdma_poll_group	*group;
412 
413 	int					num_cqe;
414 	int					required_num_wr;
415 	struct ibv_cq				*cq;
416 
417 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
418 	uint16_t				max_srq_depth;
419 
420 	/* Shared receive queue */
421 	struct ibv_srq				*srq;
422 
423 	struct spdk_nvmf_rdma_resources		*resources;
424 	struct spdk_nvmf_rdma_poller_stat	stat;
425 
426 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
427 
428 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
429 
430 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
431 
432 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
433 };
434 
435 struct spdk_nvmf_rdma_poll_group_stat {
436 	uint64_t				pending_data_buffer;
437 };
438 
439 struct spdk_nvmf_rdma_poll_group {
440 	struct spdk_nvmf_transport_poll_group		group;
441 	struct spdk_nvmf_rdma_poll_group_stat		stat;
442 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
443 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
444 	/*
445 	 * buffers which are split across multiple RDMA
446 	 * memory regions cannot be used by this transport.
447 	 */
448 	STAILQ_HEAD(, spdk_nvmf_transport_pg_cache_buf)	retired_bufs;
449 };
450 
451 struct spdk_nvmf_rdma_conn_sched {
452 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
453 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
454 };
455 
456 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
457 struct spdk_nvmf_rdma_device {
458 	struct ibv_device_attr			attr;
459 	struct ibv_context			*context;
460 
461 	struct spdk_mem_map			*map;
462 	struct ibv_pd				*pd;
463 
464 	int					num_srq;
465 
466 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
467 };
468 
469 struct spdk_nvmf_rdma_port {
470 	const struct spdk_nvme_transport_id	*trid;
471 	struct rdma_cm_id			*id;
472 	struct spdk_nvmf_rdma_device		*device;
473 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
474 };
475 
476 struct rdma_transport_opts {
477 	uint32_t	max_srq_depth;
478 	bool		no_srq;
479 	bool		no_wr_batching;
480 	int		acceptor_backlog;
481 };
482 
483 struct spdk_nvmf_rdma_transport {
484 	struct spdk_nvmf_transport	transport;
485 	struct rdma_transport_opts	rdma_opts;
486 
487 	struct spdk_nvmf_rdma_conn_sched conn_sched;
488 
489 	struct rdma_event_channel	*event_channel;
490 
491 	struct spdk_mempool		*data_wr_pool;
492 
493 	pthread_mutex_t			lock;
494 
495 	/* fields used to poll RDMA/IB events */
496 	nfds_t			npoll_fds;
497 	struct pollfd		*poll_fds;
498 
499 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
500 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
501 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
502 };
503 
504 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
505 	{
506 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
507 		spdk_json_decode_uint32, true
508 	},
509 	{
510 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
511 		spdk_json_decode_bool, true
512 	},
513 	{
514 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
515 		spdk_json_decode_bool, true
516 	},
517 	{
518 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
519 		spdk_json_decode_int32, true
520 	},
521 };
522 
523 static bool
524 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
525 			  struct spdk_nvmf_rdma_request *rdma_req);
526 
527 static void
528 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
529 		     struct spdk_nvmf_rdma_poller *rpoller);
530 
531 static void
532 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
533 		     struct spdk_nvmf_rdma_poller *rpoller);
534 
535 static inline int
536 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
537 {
538 	switch (state) {
539 	case IBV_QPS_RESET:
540 	case IBV_QPS_INIT:
541 	case IBV_QPS_RTR:
542 	case IBV_QPS_RTS:
543 	case IBV_QPS_SQD:
544 	case IBV_QPS_SQE:
545 	case IBV_QPS_ERR:
546 		return 0;
547 	default:
548 		return -1;
549 	}
550 }
551 
552 static inline enum spdk_nvme_media_error_status_code
553 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
554 	enum spdk_nvme_media_error_status_code result;
555 	switch (err_type)
556 	{
557 	case SPDK_DIF_REFTAG_ERROR:
558 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
559 		break;
560 	case SPDK_DIF_APPTAG_ERROR:
561 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
562 		break;
563 	case SPDK_DIF_GUARD_ERROR:
564 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
565 		break;
566 	default:
567 		SPDK_UNREACHABLE();
568 	}
569 
570 	return result;
571 }
572 
573 static enum ibv_qp_state
574 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
575 	enum ibv_qp_state old_state, new_state;
576 	struct ibv_qp_attr qp_attr;
577 	struct ibv_qp_init_attr init_attr;
578 	int rc;
579 
580 	old_state = rqpair->ibv_state;
581 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
582 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
583 
584 	if (rc)
585 	{
586 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
587 		return IBV_QPS_ERR + 1;
588 	}
589 
590 	new_state = qp_attr.qp_state;
591 	rqpair->ibv_state = new_state;
592 	qp_attr.ah_attr.port_num = qp_attr.port_num;
593 
594 	rc = nvmf_rdma_check_ibv_state(new_state);
595 	if (rc)
596 	{
597 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
598 		/*
599 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
600 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
601 		 */
602 		return IBV_QPS_ERR + 1;
603 	}
604 
605 	if (old_state != new_state)
606 	{
607 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
608 				  (uintptr_t)rqpair->cm_id, new_state);
609 	}
610 	return new_state;
611 }
612 
613 static void
614 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
615 			    struct spdk_nvmf_rdma_transport *rtransport)
616 {
617 	struct spdk_nvmf_rdma_request_data	*data_wr;
618 	struct ibv_send_wr			*next_send_wr;
619 	uint64_t				req_wrid;
620 
621 	rdma_req->num_outstanding_data_wr = 0;
622 	data_wr = &rdma_req->data;
623 	req_wrid = data_wr->wr.wr_id;
624 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
625 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
626 		data_wr->wr.num_sge = 0;
627 		next_send_wr = data_wr->wr.next;
628 		if (data_wr != &rdma_req->data) {
629 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
630 		}
631 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
632 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
633 	}
634 }
635 
636 static void
637 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
638 {
639 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
640 	if (req->req.cmd) {
641 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
642 	}
643 	if (req->recv) {
644 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
645 	}
646 }
647 
648 static void
649 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
650 {
651 	int i;
652 
653 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
654 	for (i = 0; i < rqpair->max_queue_depth; i++) {
655 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
656 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
657 		}
658 	}
659 }
660 
661 static void
662 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
663 {
664 	if (resources->cmds_mr) {
665 		ibv_dereg_mr(resources->cmds_mr);
666 	}
667 
668 	if (resources->cpls_mr) {
669 		ibv_dereg_mr(resources->cpls_mr);
670 	}
671 
672 	if (resources->bufs_mr) {
673 		ibv_dereg_mr(resources->bufs_mr);
674 	}
675 
676 	spdk_free(resources->cmds);
677 	spdk_free(resources->cpls);
678 	spdk_free(resources->bufs);
679 	free(resources->reqs);
680 	free(resources->recvs);
681 	free(resources);
682 }
683 
684 
685 static struct spdk_nvmf_rdma_resources *
686 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
687 {
688 	struct spdk_nvmf_rdma_resources	*resources;
689 	struct spdk_nvmf_rdma_request	*rdma_req;
690 	struct spdk_nvmf_rdma_recv	*rdma_recv;
691 	struct ibv_qp			*qp;
692 	struct ibv_srq			*srq;
693 	uint32_t			i;
694 	int				rc;
695 
696 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
697 	if (!resources) {
698 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
699 		return NULL;
700 	}
701 
702 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
703 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
704 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
705 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
706 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
707 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
708 
709 	if (opts->in_capsule_data_size > 0) {
710 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
711 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
712 					       SPDK_MALLOC_DMA);
713 	}
714 
715 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
716 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
717 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
718 		goto cleanup;
719 	}
720 
721 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
722 					opts->max_queue_depth * sizeof(*resources->cmds),
723 					IBV_ACCESS_LOCAL_WRITE);
724 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
725 					opts->max_queue_depth * sizeof(*resources->cpls),
726 					0);
727 
728 	if (opts->in_capsule_data_size) {
729 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
730 						opts->max_queue_depth *
731 						opts->in_capsule_data_size,
732 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
733 	}
734 
735 	if (!resources->cmds_mr || !resources->cpls_mr ||
736 	    (opts->in_capsule_data_size &&
737 	     !resources->bufs_mr)) {
738 		goto cleanup;
739 	}
740 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
741 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
742 		      resources->cmds_mr->lkey);
743 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
744 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
745 		      resources->cpls_mr->lkey);
746 	if (resources->bufs && resources->bufs_mr) {
747 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
748 			      resources->bufs, opts->max_queue_depth *
749 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
750 	}
751 
752 	/* Initialize queues */
753 	STAILQ_INIT(&resources->incoming_queue);
754 	STAILQ_INIT(&resources->free_queue);
755 
756 	for (i = 0; i < opts->max_queue_depth; i++) {
757 		struct ibv_recv_wr *bad_wr = NULL;
758 
759 		rdma_recv = &resources->recvs[i];
760 		rdma_recv->qpair = opts->qpair;
761 
762 		/* Set up memory to receive commands */
763 		if (resources->bufs) {
764 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
765 						  opts->in_capsule_data_size));
766 		}
767 
768 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
769 
770 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
771 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
772 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
773 		rdma_recv->wr.num_sge = 1;
774 
775 		if (rdma_recv->buf && resources->bufs_mr) {
776 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
777 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
778 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
779 			rdma_recv->wr.num_sge++;
780 		}
781 
782 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
783 		rdma_recv->wr.sg_list = rdma_recv->sgl;
784 		if (opts->shared) {
785 			srq = (struct ibv_srq *)opts->qp;
786 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
787 		} else {
788 			qp = (struct ibv_qp *)opts->qp;
789 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
790 		}
791 		if (rc) {
792 			goto cleanup;
793 		}
794 	}
795 
796 	for (i = 0; i < opts->max_queue_depth; i++) {
797 		rdma_req = &resources->reqs[i];
798 
799 		if (opts->qpair != NULL) {
800 			rdma_req->req.qpair = &opts->qpair->qpair;
801 		} else {
802 			rdma_req->req.qpair = NULL;
803 		}
804 		rdma_req->req.cmd = NULL;
805 
806 		/* Set up memory to send responses */
807 		rdma_req->req.rsp = &resources->cpls[i];
808 
809 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
810 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
811 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
812 
813 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
814 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
815 		rdma_req->rsp.wr.next = NULL;
816 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
817 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
818 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
819 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
820 
821 		/* Set up memory for data buffers */
822 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
823 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
824 		rdma_req->data.wr.next = NULL;
825 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
826 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
827 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
828 
829 		/* Initialize request state to FREE */
830 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
831 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
832 	}
833 
834 	return resources;
835 
836 cleanup:
837 	nvmf_rdma_resources_destroy(resources);
838 	return NULL;
839 }
840 
841 static void
842 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
843 {
844 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
845 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
846 		ctx->rqpair = NULL;
847 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
848 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
849 	}
850 }
851 
852 static void
853 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
854 {
855 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
856 	struct ibv_recv_wr		*bad_recv_wr = NULL;
857 	int				rc;
858 
859 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
860 
861 	if (rqpair->qd != 0) {
862 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
863 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
864 				struct spdk_nvmf_rdma_transport, transport);
865 		struct spdk_nvmf_rdma_request *req;
866 		uint32_t i, max_req_count = 0;
867 
868 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
869 
870 		if (rqpair->srq == NULL) {
871 			nvmf_rdma_dump_qpair_contents(rqpair);
872 			max_req_count = rqpair->max_queue_depth;
873 		} else if (rqpair->poller && rqpair->resources) {
874 			max_req_count = rqpair->poller->max_srq_depth;
875 		}
876 
877 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
878 		for (i = 0; i < max_req_count; i++) {
879 			req = &rqpair->resources->reqs[i];
880 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
881 				/* nvmf_rdma_request_process checks qpair ibv and internal state
882 				 * and completes a request */
883 				nvmf_rdma_request_process(rtransport, req);
884 			}
885 		}
886 		assert(rqpair->qd == 0);
887 	}
888 
889 	if (rqpair->poller) {
890 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
891 
892 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
893 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
894 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
895 				if (rqpair == rdma_recv->qpair) {
896 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
897 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
898 					if (rc) {
899 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
900 					}
901 				}
902 			}
903 		}
904 	}
905 
906 	if (rqpair->cm_id) {
907 		if (rqpair->rdma_qp != NULL) {
908 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
909 			rqpair->rdma_qp = NULL;
910 		}
911 		rdma_destroy_id(rqpair->cm_id);
912 
913 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
914 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
915 		}
916 	}
917 
918 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
919 		nvmf_rdma_resources_destroy(rqpair->resources);
920 	}
921 
922 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
923 
924 	if (rqpair->destruct_channel) {
925 		spdk_put_io_channel(rqpair->destruct_channel);
926 		rqpair->destruct_channel = NULL;
927 	}
928 
929 	free(rqpair);
930 }
931 
932 static int
933 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
934 {
935 	struct spdk_nvmf_rdma_poller	*rpoller;
936 	int				rc, num_cqe, required_num_wr;
937 
938 	/* Enlarge CQ size dynamically */
939 	rpoller = rqpair->poller;
940 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
941 	num_cqe = rpoller->num_cqe;
942 	if (num_cqe < required_num_wr) {
943 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
944 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
945 	}
946 
947 	if (rpoller->num_cqe != num_cqe) {
948 		if (required_num_wr > device->attr.max_cqe) {
949 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
950 				    required_num_wr, device->attr.max_cqe);
951 			return -1;
952 		}
953 
954 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
955 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
956 		if (rc) {
957 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
958 			return -1;
959 		}
960 
961 		rpoller->num_cqe = num_cqe;
962 	}
963 
964 	rpoller->required_num_wr = required_num_wr;
965 	return 0;
966 }
967 
968 static int
969 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
970 {
971 	struct spdk_nvmf_rdma_qpair		*rqpair;
972 	struct spdk_nvmf_rdma_transport		*rtransport;
973 	struct spdk_nvmf_transport		*transport;
974 	struct spdk_nvmf_rdma_resource_opts	opts;
975 	struct spdk_nvmf_rdma_device		*device;
976 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
977 
978 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
979 	device = rqpair->device;
980 
981 	qp_init_attr.qp_context	= rqpair;
982 	qp_init_attr.pd		= device->pd;
983 	qp_init_attr.send_cq	= rqpair->poller->cq;
984 	qp_init_attr.recv_cq	= rqpair->poller->cq;
985 
986 	if (rqpair->srq) {
987 		qp_init_attr.srq		= rqpair->srq;
988 	} else {
989 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
990 	}
991 
992 	/* SEND, READ, and WRITE operations */
993 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
994 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
995 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
996 
997 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
998 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
999 		goto error;
1000 	}
1001 
1002 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1003 	if (!rqpair->rdma_qp) {
1004 		goto error;
1005 	}
1006 
1007 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1008 					  qp_init_attr.cap.max_send_wr);
1009 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1010 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1011 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1012 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1013 
1014 	if (rqpair->poller->srq == NULL) {
1015 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1016 		transport = &rtransport->transport;
1017 
1018 		opts.qp = rqpair->rdma_qp->qp;
1019 		opts.pd = rqpair->cm_id->pd;
1020 		opts.qpair = rqpair;
1021 		opts.shared = false;
1022 		opts.max_queue_depth = rqpair->max_queue_depth;
1023 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1024 
1025 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1026 
1027 		if (!rqpair->resources) {
1028 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1029 			rdma_destroy_qp(rqpair->cm_id);
1030 			goto error;
1031 		}
1032 	} else {
1033 		rqpair->resources = rqpair->poller->resources;
1034 	}
1035 
1036 	rqpair->current_recv_depth = 0;
1037 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1038 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1039 
1040 	return 0;
1041 
1042 error:
1043 	rdma_destroy_id(rqpair->cm_id);
1044 	rqpair->cm_id = NULL;
1045 	return -1;
1046 }
1047 
1048 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1049 /* This function accepts either a single wr or the first wr in a linked list. */
1050 static void
1051 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1052 {
1053 	struct ibv_recv_wr *last;
1054 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1055 			struct spdk_nvmf_rdma_transport, transport);
1056 
1057 	last = first;
1058 	while (last->next != NULL) {
1059 		last = last->next;
1060 	}
1061 
1062 	if (rqpair->resources->recvs_to_post.first == NULL) {
1063 		rqpair->resources->recvs_to_post.first = first;
1064 		rqpair->resources->recvs_to_post.last = last;
1065 		if (rqpair->srq == NULL) {
1066 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1067 		}
1068 	} else {
1069 		rqpair->resources->recvs_to_post.last->next = first;
1070 		rqpair->resources->recvs_to_post.last = last;
1071 	}
1072 
1073 	if (rtransport->rdma_opts.no_wr_batching) {
1074 		_poller_submit_recvs(rtransport, rqpair->poller);
1075 	}
1076 }
1077 
1078 static int
1079 request_transfer_in(struct spdk_nvmf_request *req)
1080 {
1081 	struct spdk_nvmf_rdma_request	*rdma_req;
1082 	struct spdk_nvmf_qpair		*qpair;
1083 	struct spdk_nvmf_rdma_qpair	*rqpair;
1084 	struct spdk_nvmf_rdma_transport *rtransport;
1085 
1086 	qpair = req->qpair;
1087 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1088 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1089 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1090 				      struct spdk_nvmf_rdma_transport, transport);
1091 
1092 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1093 	assert(rdma_req != NULL);
1094 
1095 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1096 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1097 	}
1098 	if (rtransport->rdma_opts.no_wr_batching) {
1099 		_poller_submit_sends(rtransport, rqpair->poller);
1100 	}
1101 
1102 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1103 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1104 	return 0;
1105 }
1106 
1107 static int
1108 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1109 {
1110 	int				num_outstanding_data_wr = 0;
1111 	struct spdk_nvmf_rdma_request	*rdma_req;
1112 	struct spdk_nvmf_qpair		*qpair;
1113 	struct spdk_nvmf_rdma_qpair	*rqpair;
1114 	struct spdk_nvme_cpl		*rsp;
1115 	struct ibv_send_wr		*first = NULL;
1116 	struct spdk_nvmf_rdma_transport *rtransport;
1117 
1118 	*data_posted = 0;
1119 	qpair = req->qpair;
1120 	rsp = &req->rsp->nvme_cpl;
1121 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1122 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1123 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1124 				      struct spdk_nvmf_rdma_transport, transport);
1125 
1126 	/* Advance our sq_head pointer */
1127 	if (qpair->sq_head == qpair->sq_head_max) {
1128 		qpair->sq_head = 0;
1129 	} else {
1130 		qpair->sq_head++;
1131 	}
1132 	rsp->sqhd = qpair->sq_head;
1133 
1134 	/* queue the capsule for the recv buffer */
1135 	assert(rdma_req->recv != NULL);
1136 
1137 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1138 
1139 	rdma_req->recv = NULL;
1140 	assert(rqpair->current_recv_depth > 0);
1141 	rqpair->current_recv_depth--;
1142 
1143 	/* Build the response which consists of optional
1144 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1145 	 * containing the response.
1146 	 */
1147 	first = &rdma_req->rsp.wr;
1148 
1149 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1150 		/* On failure, data was not read from the controller. So clear the
1151 		 * number of outstanding data WRs to zero.
1152 		 */
1153 		rdma_req->num_outstanding_data_wr = 0;
1154 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1155 		first = &rdma_req->data.wr;
1156 		*data_posted = 1;
1157 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1158 	}
1159 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1160 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1161 	}
1162 	if (rtransport->rdma_opts.no_wr_batching) {
1163 		_poller_submit_sends(rtransport, rqpair->poller);
1164 	}
1165 
1166 	/* +1 for the rsp wr */
1167 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1168 
1169 	return 0;
1170 }
1171 
1172 static int
1173 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1174 {
1175 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1176 	struct rdma_conn_param				ctrlr_event_data = {};
1177 	int						rc;
1178 
1179 	accept_data.recfmt = 0;
1180 	accept_data.crqsize = rqpair->max_queue_depth;
1181 
1182 	ctrlr_event_data.private_data = &accept_data;
1183 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1184 	if (id->ps == RDMA_PS_TCP) {
1185 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1186 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1187 	}
1188 
1189 	/* Configure infinite retries for the initiator side qpair.
1190 	 * When using a shared receive queue on the target side,
1191 	 * we need to pass this value to the initiator to prevent the
1192 	 * initiator side NIC from completing SEND requests back to the
1193 	 * initiator with status rnr_retry_count_exceeded. */
1194 	if (rqpair->srq != NULL) {
1195 		ctrlr_event_data.rnr_retry_count = 0x7;
1196 	}
1197 
1198 	/* When qpair is created without use of rdma cm API, an additional
1199 	 * information must be provided to initiator in the connection response:
1200 	 * whether qpair is using SRQ and its qp_num
1201 	 * Fields below are ignored by rdma cm if qpair has been
1202 	 * created using rdma cm API. */
1203 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1204 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1205 
1206 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1207 	if (rc) {
1208 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1209 	} else {
1210 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1211 	}
1212 
1213 	return rc;
1214 }
1215 
1216 static void
1217 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1218 {
1219 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1220 
1221 	rej_data.recfmt = 0;
1222 	rej_data.sts = error;
1223 
1224 	rdma_reject(id, &rej_data, sizeof(rej_data));
1225 }
1226 
1227 static int
1228 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1229 {
1230 	struct spdk_nvmf_rdma_transport *rtransport;
1231 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1232 	struct spdk_nvmf_rdma_port	*port;
1233 	struct rdma_conn_param		*rdma_param = NULL;
1234 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1235 	uint16_t			max_queue_depth;
1236 	uint16_t			max_read_depth;
1237 
1238 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1239 
1240 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1241 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1242 
1243 	rdma_param = &event->param.conn;
1244 	if (rdma_param->private_data == NULL ||
1245 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1246 		SPDK_ERRLOG("connect request: no private data provided\n");
1247 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1248 		return -1;
1249 	}
1250 
1251 	private_data = rdma_param->private_data;
1252 	if (private_data->recfmt != 0) {
1253 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1254 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1255 		return -1;
1256 	}
1257 
1258 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1259 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1260 
1261 	port = event->listen_id->context;
1262 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1263 		      event->listen_id, event->listen_id->verbs, port);
1264 
1265 	/* Figure out the supported queue depth. This is a multi-step process
1266 	 * that takes into account hardware maximums, host provided values,
1267 	 * and our target's internal memory limits */
1268 
1269 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1270 
1271 	/* Start with the maximum queue depth allowed by the target */
1272 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1273 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1274 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1275 		      rtransport->transport.opts.max_queue_depth);
1276 
1277 	/* Next check the local NIC's hardware limitations */
1278 	SPDK_DEBUGLOG(rdma,
1279 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1280 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1281 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1282 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1283 
1284 	/* Next check the remote NIC's hardware limitations */
1285 	SPDK_DEBUGLOG(rdma,
1286 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1287 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1288 	if (rdma_param->initiator_depth > 0) {
1289 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1290 	}
1291 
1292 	/* Finally check for the host software requested values, which are
1293 	 * optional. */
1294 	if (rdma_param->private_data != NULL &&
1295 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1296 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1297 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1298 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1299 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1300 	}
1301 
1302 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1303 		      max_queue_depth, max_read_depth);
1304 
1305 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1306 	if (rqpair == NULL) {
1307 		SPDK_ERRLOG("Could not allocate new connection.\n");
1308 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1309 		return -1;
1310 	}
1311 
1312 	rqpair->device = port->device;
1313 	rqpair->max_queue_depth = max_queue_depth;
1314 	rqpair->max_read_depth = max_read_depth;
1315 	rqpair->cm_id = event->id;
1316 	rqpair->listen_id = event->listen_id;
1317 	rqpair->qpair.transport = transport;
1318 	rqpair->qpair.trid = port->trid;
1319 	STAILQ_INIT(&rqpair->ibv_events);
1320 	/* use qid from the private data to determine the qpair type
1321 	   qid will be set to the appropriate value when the controller is created */
1322 	rqpair->qpair.qid = private_data->qid;
1323 
1324 	event->id->context = &rqpair->qpair;
1325 
1326 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1327 
1328 	return 0;
1329 }
1330 
1331 static int
1332 nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1333 		     enum spdk_mem_map_notify_action action,
1334 		     void *vaddr, size_t size)
1335 {
1336 	struct ibv_pd *pd = cb_ctx;
1337 	struct ibv_mr *mr;
1338 	int rc;
1339 
1340 	switch (action) {
1341 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1342 		if (!g_nvmf_hooks.get_rkey) {
1343 			mr = ibv_reg_mr(pd, vaddr, size,
1344 					IBV_ACCESS_LOCAL_WRITE |
1345 					IBV_ACCESS_REMOTE_READ |
1346 					IBV_ACCESS_REMOTE_WRITE);
1347 			if (mr == NULL) {
1348 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1349 				return -1;
1350 			} else {
1351 				rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1352 			}
1353 		} else {
1354 			rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1355 							  g_nvmf_hooks.get_rkey(pd, vaddr, size));
1356 		}
1357 		break;
1358 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1359 		if (!g_nvmf_hooks.get_rkey) {
1360 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1361 			if (mr) {
1362 				ibv_dereg_mr(mr);
1363 			}
1364 		}
1365 		rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1366 		break;
1367 	default:
1368 		SPDK_UNREACHABLE();
1369 	}
1370 
1371 	return rc;
1372 }
1373 
1374 static int
1375 nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1376 {
1377 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1378 	return addr_1 == addr_2;
1379 }
1380 
1381 static inline void
1382 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1383 		   enum spdk_nvme_data_transfer xfer)
1384 {
1385 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1386 		wr->opcode = IBV_WR_RDMA_WRITE;
1387 		wr->send_flags = 0;
1388 		wr->next = next;
1389 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1390 		wr->opcode = IBV_WR_RDMA_READ;
1391 		wr->send_flags = IBV_SEND_SIGNALED;
1392 		wr->next = NULL;
1393 	} else {
1394 		assert(0);
1395 	}
1396 }
1397 
1398 static int
1399 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1400 		       struct spdk_nvmf_rdma_request *rdma_req,
1401 		       uint32_t num_sgl_descriptors)
1402 {
1403 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1404 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1405 	uint32_t				i;
1406 
1407 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1408 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1409 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1410 		return -EINVAL;
1411 	}
1412 
1413 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1414 		return -ENOMEM;
1415 	}
1416 
1417 	current_data_wr = &rdma_req->data;
1418 
1419 	for (i = 0; i < num_sgl_descriptors; i++) {
1420 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1421 		current_data_wr->wr.next = &work_requests[i]->wr;
1422 		current_data_wr = work_requests[i];
1423 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1424 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1425 	}
1426 
1427 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1428 
1429 	return 0;
1430 }
1431 
1432 static inline void
1433 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1434 {
1435 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1436 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1437 
1438 	wr->wr.rdma.rkey = sgl->keyed.key;
1439 	wr->wr.rdma.remote_addr = sgl->address;
1440 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1441 }
1442 
1443 static inline void
1444 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1445 {
1446 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1447 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1448 	uint32_t			i;
1449 	int				j;
1450 	uint64_t			remote_addr_offset = 0;
1451 
1452 	for (i = 0; i < num_wrs; ++i) {
1453 		wr->wr.rdma.rkey = sgl->keyed.key;
1454 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1455 		for (j = 0; j < wr->num_sge; ++j) {
1456 			remote_addr_offset += wr->sg_list[j].length;
1457 		}
1458 		wr = wr->next;
1459 	}
1460 }
1461 
1462 /* This function is used in the rare case that we have a buffer split over multiple memory regions. */
1463 static int
1464 nvmf_rdma_replace_buffer(struct spdk_nvmf_rdma_poll_group *rgroup, void **buf)
1465 {
1466 	struct spdk_nvmf_transport_poll_group	*group = &rgroup->group;
1467 	struct spdk_nvmf_transport		*transport = group->transport;
1468 	struct spdk_nvmf_transport_pg_cache_buf	*old_buf;
1469 	void					*new_buf;
1470 
1471 	if (!(STAILQ_EMPTY(&group->buf_cache))) {
1472 		group->buf_cache_count--;
1473 		new_buf = STAILQ_FIRST(&group->buf_cache);
1474 		STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1475 		assert(*buf != NULL);
1476 	} else {
1477 		new_buf = spdk_mempool_get(transport->data_buf_pool);
1478 	}
1479 
1480 	if (*buf == NULL) {
1481 		return -ENOMEM;
1482 	}
1483 
1484 	old_buf = *buf;
1485 	STAILQ_INSERT_HEAD(&rgroup->retired_bufs, old_buf, link);
1486 	*buf = new_buf;
1487 	return 0;
1488 }
1489 
1490 static bool
1491 nvmf_rdma_get_lkey(struct spdk_nvmf_rdma_device *device, struct iovec *iov,
1492 		   uint32_t *_lkey)
1493 {
1494 	uint64_t	translation_len;
1495 	uint32_t	lkey;
1496 
1497 	translation_len = iov->iov_len;
1498 
1499 	if (!g_nvmf_hooks.get_rkey) {
1500 		lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1501 				(uint64_t)iov->iov_base, &translation_len))->lkey;
1502 	} else {
1503 		lkey = spdk_mem_map_translate(device->map,
1504 					      (uint64_t)iov->iov_base, &translation_len);
1505 	}
1506 
1507 	if (spdk_unlikely(translation_len < iov->iov_len)) {
1508 		return false;
1509 	}
1510 
1511 	*_lkey = lkey;
1512 	return true;
1513 }
1514 
1515 static bool
1516 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1517 		      struct iovec *iov, struct ibv_send_wr **_wr,
1518 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1519 		      uint32_t *_num_extra_wrs,
1520 		      const struct spdk_dif_ctx *dif_ctx)
1521 {
1522 	struct ibv_send_wr *wr = *_wr;
1523 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1524 	uint32_t	lkey = 0;
1525 	uint32_t	remaining, data_block_size, md_size, sge_len;
1526 
1527 	if (spdk_unlikely(!nvmf_rdma_get_lkey(device, iov, &lkey))) {
1528 		/* This is a very rare case that can occur when using DPDK version < 19.05 */
1529 		SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions. Removing it from circulation.\n");
1530 		return false;
1531 	}
1532 
1533 	if (spdk_likely(!dif_ctx)) {
1534 		sg_ele->lkey = lkey;
1535 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1536 		sg_ele->length = iov->iov_len;
1537 		wr->num_sge++;
1538 	} else {
1539 		remaining = iov->iov_len - *_offset;
1540 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1541 		md_size = dif_ctx->md_size;
1542 
1543 		while (remaining) {
1544 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1545 				if (*_num_extra_wrs > 0 && wr->next) {
1546 					*_wr = wr->next;
1547 					wr = *_wr;
1548 					wr->num_sge = 0;
1549 					sg_ele = &wr->sg_list[wr->num_sge];
1550 					(*_num_extra_wrs)--;
1551 				} else {
1552 					break;
1553 				}
1554 			}
1555 			sg_ele->lkey = lkey;
1556 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1557 			sge_len = spdk_min(remaining, *_remaining_data_block);
1558 			sg_ele->length = sge_len;
1559 			remaining -= sge_len;
1560 			*_remaining_data_block -= sge_len;
1561 			*_offset += sge_len;
1562 
1563 			sg_ele++;
1564 			wr->num_sge++;
1565 
1566 			if (*_remaining_data_block == 0) {
1567 				/* skip metadata */
1568 				*_offset += md_size;
1569 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1570 				remaining -= spdk_min(remaining, md_size);
1571 				*_remaining_data_block = data_block_size;
1572 			}
1573 
1574 			if (remaining == 0) {
1575 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1576 				   the remaining metadata bits at the beginning of the next buffer */
1577 				*_offset -= iov->iov_len;
1578 			}
1579 		}
1580 	}
1581 
1582 	return true;
1583 }
1584 
1585 static int
1586 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1587 		      struct spdk_nvmf_rdma_device *device,
1588 		      struct spdk_nvmf_rdma_request *rdma_req,
1589 		      struct ibv_send_wr *wr,
1590 		      uint32_t length,
1591 		      uint32_t num_extra_wrs)
1592 {
1593 	struct spdk_nvmf_request *req = &rdma_req->req;
1594 	struct spdk_dif_ctx *dif_ctx = NULL;
1595 	uint32_t remaining_data_block = 0;
1596 	uint32_t offset = 0;
1597 
1598 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1599 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1600 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1601 	}
1602 
1603 	wr->num_sge = 0;
1604 
1605 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1606 		while (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1607 				     &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1608 			if (nvmf_rdma_replace_buffer(rgroup, &req->buffers[rdma_req->iovpos]) == -ENOMEM) {
1609 				return -ENOMEM;
1610 			}
1611 			req->iov[rdma_req->iovpos].iov_base = (void *)((uintptr_t)(req->buffers[rdma_req->iovpos] +
1612 							      NVMF_DATA_BUFFER_MASK) &
1613 							      ~NVMF_DATA_BUFFER_MASK);
1614 		}
1615 
1616 		length -= req->iov[rdma_req->iovpos].iov_len;
1617 		rdma_req->iovpos++;
1618 	}
1619 
1620 	if (length) {
1621 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1622 		return -EINVAL;
1623 	}
1624 
1625 	return 0;
1626 }
1627 
1628 static inline uint32_t
1629 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1630 {
1631 	/* estimate the number of SG entries and WRs needed to process the request */
1632 	uint32_t num_sge = 0;
1633 	uint32_t i;
1634 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1635 
1636 	for (i = 0; i < num_buffers && length > 0; i++) {
1637 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1638 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1639 
1640 		if (num_sge_in_block * block_size > buffer_len) {
1641 			++num_sge_in_block;
1642 		}
1643 		num_sge += num_sge_in_block;
1644 		length -= buffer_len;
1645 	}
1646 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1647 }
1648 
1649 static int
1650 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1651 			    struct spdk_nvmf_rdma_device *device,
1652 			    struct spdk_nvmf_rdma_request *rdma_req,
1653 			    uint32_t length)
1654 {
1655 	struct spdk_nvmf_rdma_qpair		*rqpair;
1656 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1657 	struct spdk_nvmf_request		*req = &rdma_req->req;
1658 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1659 	int					rc;
1660 	uint32_t				num_wrs = 1;
1661 
1662 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1663 	rgroup = rqpair->poller->group;
1664 
1665 	/* rdma wr specifics */
1666 	nvmf_rdma_setup_request(rdma_req);
1667 
1668 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1669 					   length);
1670 	if (rc != 0) {
1671 		return rc;
1672 	}
1673 
1674 	assert(req->iovcnt <= rqpair->max_send_sge);
1675 
1676 	rdma_req->iovpos = 0;
1677 
1678 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1679 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1680 						 req->dif.dif_ctx.block_size);
1681 		if (num_wrs > 1) {
1682 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1683 			if (rc != 0) {
1684 				goto err_exit;
1685 			}
1686 		}
1687 	}
1688 
1689 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1690 	if (spdk_unlikely(rc != 0)) {
1691 		goto err_exit;
1692 	}
1693 
1694 	if (spdk_unlikely(num_wrs > 1)) {
1695 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1696 	}
1697 
1698 	/* set the number of outstanding data WRs for this request. */
1699 	rdma_req->num_outstanding_data_wr = num_wrs;
1700 
1701 	return rc;
1702 
1703 err_exit:
1704 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1705 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1706 	req->iovcnt = 0;
1707 	return rc;
1708 }
1709 
1710 static int
1711 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1712 				      struct spdk_nvmf_rdma_device *device,
1713 				      struct spdk_nvmf_rdma_request *rdma_req)
1714 {
1715 	struct spdk_nvmf_rdma_qpair		*rqpair;
1716 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1717 	struct ibv_send_wr			*current_wr;
1718 	struct spdk_nvmf_request		*req = &rdma_req->req;
1719 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1720 	uint32_t				num_sgl_descriptors;
1721 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1722 	uint32_t				i;
1723 	int					rc;
1724 
1725 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1726 	rgroup = rqpair->poller->group;
1727 
1728 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1729 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1730 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1731 
1732 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1733 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1734 
1735 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1736 		return -ENOMEM;
1737 	}
1738 
1739 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1740 	for (i = 0; i < num_sgl_descriptors; i++) {
1741 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1742 			lengths[i] = desc->keyed.length;
1743 		} else {
1744 			req->dif.orig_length += desc->keyed.length;
1745 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1746 			req->dif.elba_length += lengths[i];
1747 		}
1748 		desc++;
1749 	}
1750 
1751 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1752 			lengths, num_sgl_descriptors);
1753 	if (rc != 0) {
1754 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1755 		return rc;
1756 	}
1757 
1758 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1759 	current_wr = &rdma_req->data.wr;
1760 	assert(current_wr != NULL);
1761 
1762 	req->length = 0;
1763 	rdma_req->iovpos = 0;
1764 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1765 	for (i = 0; i < num_sgl_descriptors; i++) {
1766 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1767 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1768 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1769 			rc = -EINVAL;
1770 			goto err_exit;
1771 		}
1772 
1773 		current_wr->num_sge = 0;
1774 
1775 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1776 		if (rc != 0) {
1777 			rc = -ENOMEM;
1778 			goto err_exit;
1779 		}
1780 
1781 		req->length += desc->keyed.length;
1782 		current_wr->wr.rdma.rkey = desc->keyed.key;
1783 		current_wr->wr.rdma.remote_addr = desc->address;
1784 		current_wr = current_wr->next;
1785 		desc++;
1786 	}
1787 
1788 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1789 	/* Go back to the last descriptor in the list. */
1790 	desc--;
1791 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1792 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1793 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1794 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1795 		}
1796 	}
1797 #endif
1798 
1799 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1800 
1801 	return 0;
1802 
1803 err_exit:
1804 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1805 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1806 	return rc;
1807 }
1808 
1809 static int
1810 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1811 			    struct spdk_nvmf_rdma_device *device,
1812 			    struct spdk_nvmf_rdma_request *rdma_req)
1813 {
1814 	struct spdk_nvmf_request		*req = &rdma_req->req;
1815 	struct spdk_nvme_cpl			*rsp;
1816 	struct spdk_nvme_sgl_descriptor		*sgl;
1817 	int					rc;
1818 	uint32_t				length;
1819 
1820 	rsp = &req->rsp->nvme_cpl;
1821 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1822 
1823 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1824 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1825 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1826 
1827 		length = sgl->keyed.length;
1828 		if (length > rtransport->transport.opts.max_io_size) {
1829 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1830 				    length, rtransport->transport.opts.max_io_size);
1831 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1832 			return -1;
1833 		}
1834 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1835 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1836 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1837 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1838 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1839 			}
1840 		}
1841 #endif
1842 
1843 		/* fill request length and populate iovs */
1844 		req->length = length;
1845 
1846 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1847 			req->dif.orig_length = length;
1848 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1849 			req->dif.elba_length = length;
1850 		}
1851 
1852 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1853 		if (spdk_unlikely(rc < 0)) {
1854 			if (rc == -EINVAL) {
1855 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1856 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1857 				return -1;
1858 			}
1859 			/* No available buffers. Queue this request up. */
1860 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1861 			return 0;
1862 		}
1863 
1864 		/* backward compatible */
1865 		req->data = req->iov[0].iov_base;
1866 
1867 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1868 			      req->iovcnt);
1869 
1870 		return 0;
1871 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1872 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1873 		uint64_t offset = sgl->address;
1874 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1875 
1876 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1877 			      offset, sgl->unkeyed.length);
1878 
1879 		if (offset > max_len) {
1880 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1881 				    offset, max_len);
1882 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1883 			return -1;
1884 		}
1885 		max_len -= (uint32_t)offset;
1886 
1887 		if (sgl->unkeyed.length > max_len) {
1888 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1889 				    sgl->unkeyed.length, max_len);
1890 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1891 			return -1;
1892 		}
1893 
1894 		rdma_req->num_outstanding_data_wr = 0;
1895 		req->data = rdma_req->recv->buf + offset;
1896 		req->data_from_pool = false;
1897 		req->length = sgl->unkeyed.length;
1898 
1899 		req->iov[0].iov_base = req->data;
1900 		req->iov[0].iov_len = req->length;
1901 		req->iovcnt = 1;
1902 
1903 		return 0;
1904 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1905 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1906 
1907 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1908 		if (rc == -ENOMEM) {
1909 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1910 			return 0;
1911 		} else if (rc == -EINVAL) {
1912 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1913 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1914 			return -1;
1915 		}
1916 
1917 		/* backward compatible */
1918 		req->data = req->iov[0].iov_base;
1919 
1920 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1921 			      req->iovcnt);
1922 
1923 		return 0;
1924 	}
1925 
1926 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1927 		    sgl->generic.type, sgl->generic.subtype);
1928 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1929 	return -1;
1930 }
1931 
1932 static void
1933 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1934 			struct spdk_nvmf_rdma_transport	*rtransport)
1935 {
1936 	struct spdk_nvmf_rdma_qpair		*rqpair;
1937 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1938 
1939 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1940 	if (rdma_req->req.data_from_pool) {
1941 		rgroup = rqpair->poller->group;
1942 
1943 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1944 	}
1945 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1946 	rdma_req->req.length = 0;
1947 	rdma_req->req.iovcnt = 0;
1948 	rdma_req->req.data = NULL;
1949 	rdma_req->rsp.wr.next = NULL;
1950 	rdma_req->data.wr.next = NULL;
1951 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1952 	rqpair->qd--;
1953 
1954 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1955 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1956 }
1957 
1958 bool
1959 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1960 			  struct spdk_nvmf_rdma_request *rdma_req)
1961 {
1962 	struct spdk_nvmf_rdma_qpair	*rqpair;
1963 	struct spdk_nvmf_rdma_device	*device;
1964 	struct spdk_nvmf_rdma_poll_group *rgroup;
1965 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1966 	int				rc;
1967 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1968 	enum spdk_nvmf_rdma_request_state prev_state;
1969 	bool				progress = false;
1970 	int				data_posted;
1971 	uint32_t			num_blocks;
1972 
1973 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1974 	device = rqpair->device;
1975 	rgroup = rqpair->poller->group;
1976 
1977 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1978 
1979 	/* If the queue pair is in an error state, force the request to the completed state
1980 	 * to release resources. */
1981 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1982 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1983 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1984 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1985 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1986 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1987 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1988 		}
1989 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1990 	}
1991 
1992 	/* The loop here is to allow for several back-to-back state changes. */
1993 	do {
1994 		prev_state = rdma_req->state;
1995 
1996 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
1997 
1998 		switch (rdma_req->state) {
1999 		case RDMA_REQUEST_STATE_FREE:
2000 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
2001 			 * to escape this state. */
2002 			break;
2003 		case RDMA_REQUEST_STATE_NEW:
2004 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
2005 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2006 			rdma_recv = rdma_req->recv;
2007 
2008 			/* The first element of the SGL is the NVMe command */
2009 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
2010 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
2011 
2012 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2013 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2014 				break;
2015 			}
2016 
2017 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
2018 				rdma_req->req.dif.dif_insert_or_strip = true;
2019 			}
2020 
2021 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2022 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
2023 			rdma_req->rsp.wr.imm_data = 0;
2024 #endif
2025 
2026 			/* The next state transition depends on the data transfer needs of this request. */
2027 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
2028 
2029 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
2030 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2031 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
2032 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2033 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
2034 				break;
2035 			}
2036 
2037 			/* If no data to transfer, ready to execute. */
2038 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2039 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2040 				break;
2041 			}
2042 
2043 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2044 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2045 			break;
2046 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2047 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2048 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2049 
2050 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2051 
2052 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2053 				/* This request needs to wait in line to obtain a buffer */
2054 				break;
2055 			}
2056 
2057 			/* Try to get a data buffer */
2058 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2059 			if (rc < 0) {
2060 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2061 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2062 				break;
2063 			}
2064 
2065 			if (!rdma_req->req.data) {
2066 				/* No buffers available. */
2067 				rgroup->stat.pending_data_buffer++;
2068 				break;
2069 			}
2070 
2071 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2072 
2073 			/* If data is transferring from host to controller and the data didn't
2074 			 * arrive using in capsule data, we need to do a transfer from the host.
2075 			 */
2076 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2077 			    rdma_req->req.data_from_pool) {
2078 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2079 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2080 				break;
2081 			}
2082 
2083 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2084 			break;
2085 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2086 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2087 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2088 
2089 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2090 				/* This request needs to wait in line to perform RDMA */
2091 				break;
2092 			}
2093 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2094 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2095 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2096 				rqpair->poller->stat.pending_rdma_read++;
2097 				break;
2098 			}
2099 
2100 			/* We have already verified that this request is the head of the queue. */
2101 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2102 
2103 			rc = request_transfer_in(&rdma_req->req);
2104 			if (!rc) {
2105 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2106 			} else {
2107 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2108 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2109 			}
2110 			break;
2111 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2112 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2113 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2114 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2115 			 * to escape this state. */
2116 			break;
2117 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2118 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2119 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2120 
2121 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2122 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2123 					/* generate DIF for write operation */
2124 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2125 					assert(num_blocks > 0);
2126 
2127 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2128 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2129 					if (rc != 0) {
2130 						SPDK_ERRLOG("DIF generation failed\n");
2131 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2132 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2133 						break;
2134 					}
2135 				}
2136 
2137 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2138 				/* set extended length before IO operation */
2139 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2140 			}
2141 
2142 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2143 			spdk_nvmf_request_exec(&rdma_req->req);
2144 			break;
2145 		case RDMA_REQUEST_STATE_EXECUTING:
2146 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2147 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2148 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2149 			 * to escape this state. */
2150 			break;
2151 		case RDMA_REQUEST_STATE_EXECUTED:
2152 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2153 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2154 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2155 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2156 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2157 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2158 			} else {
2159 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2160 			}
2161 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2162 				/* restore the original length */
2163 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2164 
2165 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2166 					struct spdk_dif_error error_blk;
2167 
2168 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2169 
2170 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2171 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2172 					if (rc) {
2173 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2174 
2175 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2176 							    error_blk.err_offset);
2177 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2178 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2179 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2180 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2181 					}
2182 				}
2183 			}
2184 			break;
2185 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2186 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2187 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2188 
2189 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2190 				/* This request needs to wait in line to perform RDMA */
2191 				break;
2192 			}
2193 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2194 			    rqpair->max_send_depth) {
2195 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2196 				 * +1 since each request has an additional wr in the resp. */
2197 				rqpair->poller->stat.pending_rdma_write++;
2198 				break;
2199 			}
2200 
2201 			/* We have already verified that this request is the head of the queue. */
2202 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2203 
2204 			/* The data transfer will be kicked off from
2205 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2206 			 */
2207 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2208 			break;
2209 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2210 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2211 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2212 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2213 			assert(rc == 0); /* No good way to handle this currently */
2214 			if (rc) {
2215 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2216 			} else {
2217 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2218 						  RDMA_REQUEST_STATE_COMPLETING;
2219 			}
2220 			break;
2221 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2222 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2223 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2224 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2225 			 * to escape this state. */
2226 			break;
2227 		case RDMA_REQUEST_STATE_COMPLETING:
2228 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2229 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2230 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2231 			 * to escape this state. */
2232 			break;
2233 		case RDMA_REQUEST_STATE_COMPLETED:
2234 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2235 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2236 
2237 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2238 			_nvmf_rdma_request_free(rdma_req, rtransport);
2239 			break;
2240 		case RDMA_REQUEST_NUM_STATES:
2241 		default:
2242 			assert(0);
2243 			break;
2244 		}
2245 
2246 		if (rdma_req->state != prev_state) {
2247 			progress = true;
2248 		}
2249 	} while (rdma_req->state != prev_state);
2250 
2251 	return progress;
2252 }
2253 
2254 /* Public API callbacks begin here */
2255 
2256 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2257 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2258 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2259 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2260 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2261 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2262 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2263 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2264 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2265 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2266 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2267 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2268 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2269 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2270 
2271 static void
2272 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2273 {
2274 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2275 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2276 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2277 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2278 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2279 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2280 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2281 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2282 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2283 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2284 	opts->transport_specific =      NULL;
2285 }
2286 
2287 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2288 	.notify_cb = nvmf_rdma_mem_notify,
2289 	.are_contiguous = nvmf_rdma_check_contiguous_entries
2290 };
2291 
2292 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
2293 
2294 static struct spdk_nvmf_transport *
2295 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2296 {
2297 	int rc;
2298 	struct spdk_nvmf_rdma_transport *rtransport;
2299 	struct spdk_nvmf_rdma_device	*device, *tmp;
2300 	struct ibv_context		**contexts;
2301 	uint32_t			i;
2302 	int				flag;
2303 	uint32_t			sge_count;
2304 	uint32_t			min_shared_buffers;
2305 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2306 	pthread_mutexattr_t		attr;
2307 
2308 	rtransport = calloc(1, sizeof(*rtransport));
2309 	if (!rtransport) {
2310 		return NULL;
2311 	}
2312 
2313 	if (pthread_mutexattr_init(&attr)) {
2314 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2315 		free(rtransport);
2316 		return NULL;
2317 	}
2318 
2319 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2320 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2321 		pthread_mutexattr_destroy(&attr);
2322 		free(rtransport);
2323 		return NULL;
2324 	}
2325 
2326 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2327 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2328 		pthread_mutexattr_destroy(&attr);
2329 		free(rtransport);
2330 		return NULL;
2331 	}
2332 
2333 	pthread_mutexattr_destroy(&attr);
2334 
2335 	TAILQ_INIT(&rtransport->devices);
2336 	TAILQ_INIT(&rtransport->ports);
2337 	TAILQ_INIT(&rtransport->poll_groups);
2338 
2339 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2340 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2341 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2342 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2343 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2344 	if (opts->transport_specific != NULL &&
2345 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2346 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2347 					    &rtransport->rdma_opts)) {
2348 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2349 		nvmf_rdma_destroy(&rtransport->transport);
2350 		return NULL;
2351 	}
2352 
2353 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2354 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2355 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2356 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2357 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d,"
2358 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2359 		     opts->max_queue_depth,
2360 		     opts->max_io_size,
2361 		     opts->max_qpairs_per_ctrlr - 1,
2362 		     opts->io_unit_size,
2363 		     opts->in_capsule_data_size,
2364 		     opts->max_aq_depth,
2365 		     opts->num_shared_buffers,
2366 		     rtransport->rdma_opts.max_srq_depth,
2367 		     rtransport->rdma_opts.no_srq,
2368 		     rtransport->rdma_opts.acceptor_backlog,
2369 		     rtransport->rdma_opts.no_wr_batching,
2370 		     opts->abort_timeout_sec);
2371 
2372 	/* I/O unit size cannot be larger than max I/O size */
2373 	if (opts->io_unit_size > opts->max_io_size) {
2374 		opts->io_unit_size = opts->max_io_size;
2375 	}
2376 
2377 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2378 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2379 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2380 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2381 	}
2382 
2383 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2384 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2385 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2386 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2387 		nvmf_rdma_destroy(&rtransport->transport);
2388 		return NULL;
2389 	}
2390 
2391 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2392 	if (min_shared_buffers > opts->num_shared_buffers) {
2393 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2394 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2395 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2396 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2397 		nvmf_rdma_destroy(&rtransport->transport);
2398 		return NULL;
2399 	}
2400 
2401 	sge_count = opts->max_io_size / opts->io_unit_size;
2402 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2403 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2404 		nvmf_rdma_destroy(&rtransport->transport);
2405 		return NULL;
2406 	}
2407 
2408 	rtransport->event_channel = rdma_create_event_channel();
2409 	if (rtransport->event_channel == NULL) {
2410 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2411 		nvmf_rdma_destroy(&rtransport->transport);
2412 		return NULL;
2413 	}
2414 
2415 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2416 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2417 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2418 			    rtransport->event_channel->fd, spdk_strerror(errno));
2419 		nvmf_rdma_destroy(&rtransport->transport);
2420 		return NULL;
2421 	}
2422 
2423 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2424 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2425 				   sizeof(struct spdk_nvmf_rdma_request_data),
2426 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2427 				   SPDK_ENV_SOCKET_ID_ANY);
2428 	if (!rtransport->data_wr_pool) {
2429 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2430 		nvmf_rdma_destroy(&rtransport->transport);
2431 		return NULL;
2432 	}
2433 
2434 	contexts = rdma_get_devices(NULL);
2435 	if (contexts == NULL) {
2436 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2437 		nvmf_rdma_destroy(&rtransport->transport);
2438 		return NULL;
2439 	}
2440 
2441 	i = 0;
2442 	rc = 0;
2443 	while (contexts[i] != NULL) {
2444 		device = calloc(1, sizeof(*device));
2445 		if (!device) {
2446 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2447 			rc = -ENOMEM;
2448 			break;
2449 		}
2450 		device->context = contexts[i];
2451 		rc = ibv_query_device(device->context, &device->attr);
2452 		if (rc < 0) {
2453 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2454 			free(device);
2455 			break;
2456 
2457 		}
2458 
2459 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2460 
2461 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2462 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2463 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2464 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2465 		}
2466 
2467 		/**
2468 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2469 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2470 		 * but incorrectly reports that it does. There are changes making their way
2471 		 * through the kernel now that will enable this feature. When they are merged,
2472 		 * we can conditionally enable this feature.
2473 		 *
2474 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2475 		 */
2476 		if (device->attr.vendor_id == 0) {
2477 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2478 		}
2479 #endif
2480 
2481 		/* set up device context async ev fd as NON_BLOCKING */
2482 		flag = fcntl(device->context->async_fd, F_GETFL);
2483 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2484 		if (rc < 0) {
2485 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2486 			free(device);
2487 			break;
2488 		}
2489 
2490 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2491 		i++;
2492 
2493 		if (g_nvmf_hooks.get_ibv_pd) {
2494 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2495 		} else {
2496 			device->pd = ibv_alloc_pd(device->context);
2497 		}
2498 
2499 		if (!device->pd) {
2500 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2501 			rc = -ENOMEM;
2502 			break;
2503 		}
2504 
2505 		assert(device->map == NULL);
2506 
2507 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2508 		if (!device->map) {
2509 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2510 			rc = -ENOMEM;
2511 			break;
2512 		}
2513 
2514 		assert(device->map != NULL);
2515 		assert(device->pd != NULL);
2516 	}
2517 	rdma_free_devices(contexts);
2518 
2519 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2520 		/* divide and round up. */
2521 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2522 
2523 		/* round up to the nearest 4k. */
2524 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2525 
2526 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2527 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2528 			       opts->io_unit_size);
2529 	}
2530 
2531 	if (rc < 0) {
2532 		nvmf_rdma_destroy(&rtransport->transport);
2533 		return NULL;
2534 	}
2535 
2536 	/* Set up poll descriptor array to monitor events from RDMA and IB
2537 	 * in a single poll syscall
2538 	 */
2539 	rtransport->npoll_fds = i + 1;
2540 	i = 0;
2541 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2542 	if (rtransport->poll_fds == NULL) {
2543 		SPDK_ERRLOG("poll_fds allocation failed\n");
2544 		nvmf_rdma_destroy(&rtransport->transport);
2545 		return NULL;
2546 	}
2547 
2548 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2549 	rtransport->poll_fds[i++].events = POLLIN;
2550 
2551 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2552 		rtransport->poll_fds[i].fd = device->context->async_fd;
2553 		rtransport->poll_fds[i++].events = POLLIN;
2554 	}
2555 
2556 	return &rtransport->transport;
2557 }
2558 
2559 static void
2560 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2561 {
2562 	struct spdk_nvmf_rdma_transport	*rtransport;
2563 	assert(w != NULL);
2564 
2565 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2566 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2567 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2568 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2569 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2570 }
2571 
2572 static int
2573 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
2574 {
2575 	struct spdk_nvmf_rdma_transport	*rtransport;
2576 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2577 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2578 
2579 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2580 
2581 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2582 		TAILQ_REMOVE(&rtransport->ports, port, link);
2583 		rdma_destroy_id(port->id);
2584 		free(port);
2585 	}
2586 
2587 	if (rtransport->poll_fds != NULL) {
2588 		free(rtransport->poll_fds);
2589 	}
2590 
2591 	if (rtransport->event_channel != NULL) {
2592 		rdma_destroy_event_channel(rtransport->event_channel);
2593 	}
2594 
2595 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2596 		TAILQ_REMOVE(&rtransport->devices, device, link);
2597 		if (device->map) {
2598 			spdk_mem_map_free(&device->map);
2599 		}
2600 		if (device->pd) {
2601 			if (!g_nvmf_hooks.get_ibv_pd) {
2602 				ibv_dealloc_pd(device->pd);
2603 			}
2604 		}
2605 		free(device);
2606 	}
2607 
2608 	if (rtransport->data_wr_pool != NULL) {
2609 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2610 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2611 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2612 				    spdk_mempool_count(rtransport->data_wr_pool),
2613 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2614 		}
2615 	}
2616 
2617 	spdk_mempool_free(rtransport->data_wr_pool);
2618 
2619 	pthread_mutex_destroy(&rtransport->lock);
2620 	free(rtransport);
2621 
2622 	return 0;
2623 }
2624 
2625 static int
2626 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2627 			  struct spdk_nvme_transport_id *trid,
2628 			  bool peer);
2629 
2630 static int
2631 nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2632 		 const struct spdk_nvme_transport_id *trid)
2633 {
2634 	struct spdk_nvmf_rdma_transport	*rtransport;
2635 	struct spdk_nvmf_rdma_device	*device;
2636 	struct spdk_nvmf_rdma_port	*port;
2637 	struct addrinfo			*res;
2638 	struct addrinfo			hints;
2639 	int				family;
2640 	int				rc;
2641 
2642 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2643 	assert(rtransport->event_channel != NULL);
2644 
2645 	pthread_mutex_lock(&rtransport->lock);
2646 	port = calloc(1, sizeof(*port));
2647 	if (!port) {
2648 		SPDK_ERRLOG("Port allocation failed\n");
2649 		pthread_mutex_unlock(&rtransport->lock);
2650 		return -ENOMEM;
2651 	}
2652 
2653 	port->trid = trid;
2654 
2655 	switch (trid->adrfam) {
2656 	case SPDK_NVMF_ADRFAM_IPV4:
2657 		family = AF_INET;
2658 		break;
2659 	case SPDK_NVMF_ADRFAM_IPV6:
2660 		family = AF_INET6;
2661 		break;
2662 	default:
2663 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2664 		free(port);
2665 		pthread_mutex_unlock(&rtransport->lock);
2666 		return -EINVAL;
2667 	}
2668 
2669 	memset(&hints, 0, sizeof(hints));
2670 	hints.ai_family = family;
2671 	hints.ai_flags = AI_NUMERICSERV;
2672 	hints.ai_socktype = SOCK_STREAM;
2673 	hints.ai_protocol = 0;
2674 
2675 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2676 	if (rc) {
2677 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2678 		free(port);
2679 		pthread_mutex_unlock(&rtransport->lock);
2680 		return -EINVAL;
2681 	}
2682 
2683 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2684 	if (rc < 0) {
2685 		SPDK_ERRLOG("rdma_create_id() failed\n");
2686 		freeaddrinfo(res);
2687 		free(port);
2688 		pthread_mutex_unlock(&rtransport->lock);
2689 		return rc;
2690 	}
2691 
2692 	rc = rdma_bind_addr(port->id, res->ai_addr);
2693 	freeaddrinfo(res);
2694 
2695 	if (rc < 0) {
2696 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2697 		rdma_destroy_id(port->id);
2698 		free(port);
2699 		pthread_mutex_unlock(&rtransport->lock);
2700 		return rc;
2701 	}
2702 
2703 	if (!port->id->verbs) {
2704 		SPDK_ERRLOG("ibv_context is null\n");
2705 		rdma_destroy_id(port->id);
2706 		free(port);
2707 		pthread_mutex_unlock(&rtransport->lock);
2708 		return -1;
2709 	}
2710 
2711 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2712 	if (rc < 0) {
2713 		SPDK_ERRLOG("rdma_listen() failed\n");
2714 		rdma_destroy_id(port->id);
2715 		free(port);
2716 		pthread_mutex_unlock(&rtransport->lock);
2717 		return rc;
2718 	}
2719 
2720 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2721 		if (device->context == port->id->verbs) {
2722 			port->device = device;
2723 			break;
2724 		}
2725 	}
2726 	if (!port->device) {
2727 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2728 			    port->id->verbs);
2729 		rdma_destroy_id(port->id);
2730 		free(port);
2731 		pthread_mutex_unlock(&rtransport->lock);
2732 		return -EINVAL;
2733 	}
2734 
2735 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2736 		       trid->traddr, trid->trsvcid);
2737 
2738 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2739 	pthread_mutex_unlock(&rtransport->lock);
2740 	return 0;
2741 }
2742 
2743 static void
2744 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2745 		      const struct spdk_nvme_transport_id *trid)
2746 {
2747 	struct spdk_nvmf_rdma_transport *rtransport;
2748 	struct spdk_nvmf_rdma_port *port, *tmp;
2749 
2750 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2751 
2752 	pthread_mutex_lock(&rtransport->lock);
2753 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2754 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2755 			TAILQ_REMOVE(&rtransport->ports, port, link);
2756 			rdma_destroy_id(port->id);
2757 			free(port);
2758 			break;
2759 		}
2760 	}
2761 
2762 	pthread_mutex_unlock(&rtransport->lock);
2763 }
2764 
2765 static void
2766 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2767 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2768 {
2769 	struct spdk_nvmf_request *req, *tmp;
2770 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2771 	struct spdk_nvmf_rdma_resources *resources;
2772 
2773 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2774 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2775 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2776 			break;
2777 		}
2778 	}
2779 
2780 	/* Then RDMA writes since reads have stronger restrictions than writes */
2781 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2782 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2783 			break;
2784 		}
2785 	}
2786 
2787 	/* The second highest priority is I/O waiting on memory buffers. */
2788 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2789 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2790 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2791 			break;
2792 		}
2793 	}
2794 
2795 	resources = rqpair->resources;
2796 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2797 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2798 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2799 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2800 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2801 
2802 		if (rqpair->srq != NULL) {
2803 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2804 			rdma_req->recv->qpair->qd++;
2805 		} else {
2806 			rqpair->qd++;
2807 		}
2808 
2809 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2810 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2811 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2812 			break;
2813 		}
2814 	}
2815 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2816 		rqpair->poller->stat.pending_free_request++;
2817 	}
2818 }
2819 
2820 static void
2821 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2822 {
2823 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2824 			struct spdk_nvmf_rdma_transport, transport);
2825 
2826 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2827 
2828 	/* nvmr_rdma_close_qpair is not called */
2829 	if (!rqpair->to_close) {
2830 		return;
2831 	}
2832 
2833 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2834 	if (rqpair->current_send_depth != 0) {
2835 		return;
2836 	}
2837 
2838 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2839 		return;
2840 	}
2841 
2842 	/* Judge whether the device is emulated by Software RoCE.
2843 	 * And it will not send last_wqe event
2844 	 */
2845 	if (rqpair->srq != NULL && rqpair->device->attr.vendor_id != 0 &&
2846 	    rqpair->last_wqe_reached == false) {
2847 		return;
2848 	}
2849 
2850 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2851 
2852 	nvmf_rdma_qpair_destroy(rqpair);
2853 }
2854 
2855 static int
2856 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2857 {
2858 	struct spdk_nvmf_qpair		*qpair;
2859 	struct spdk_nvmf_rdma_qpair	*rqpair;
2860 
2861 	if (evt->id == NULL) {
2862 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2863 		return -1;
2864 	}
2865 
2866 	qpair = evt->id->context;
2867 	if (qpair == NULL) {
2868 		SPDK_ERRLOG("disconnect request: no active connection\n");
2869 		return -1;
2870 	}
2871 
2872 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2873 
2874 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2875 
2876 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2877 
2878 	return 0;
2879 }
2880 
2881 #ifdef DEBUG
2882 static const char *CM_EVENT_STR[] = {
2883 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2884 	"RDMA_CM_EVENT_ADDR_ERROR",
2885 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2886 	"RDMA_CM_EVENT_ROUTE_ERROR",
2887 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2888 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2889 	"RDMA_CM_EVENT_CONNECT_ERROR",
2890 	"RDMA_CM_EVENT_UNREACHABLE",
2891 	"RDMA_CM_EVENT_REJECTED",
2892 	"RDMA_CM_EVENT_ESTABLISHED",
2893 	"RDMA_CM_EVENT_DISCONNECTED",
2894 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2895 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2896 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2897 	"RDMA_CM_EVENT_ADDR_CHANGE",
2898 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2899 };
2900 #endif /* DEBUG */
2901 
2902 static void
2903 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2904 				    struct spdk_nvmf_rdma_port *port)
2905 {
2906 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2907 	struct spdk_nvmf_rdma_poller		*rpoller;
2908 	struct spdk_nvmf_rdma_qpair		*rqpair;
2909 
2910 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2911 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2912 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2913 				if (rqpair->listen_id == port->id) {
2914 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2915 				}
2916 			}
2917 		}
2918 	}
2919 }
2920 
2921 static bool
2922 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2923 				      struct rdma_cm_event *event)
2924 {
2925 	const struct spdk_nvme_transport_id	*trid;
2926 	struct spdk_nvmf_rdma_port		*port;
2927 	struct spdk_nvmf_rdma_transport		*rtransport;
2928 	bool					event_acked = false;
2929 
2930 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2931 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2932 		if (port->id == event->id) {
2933 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2934 			rdma_ack_cm_event(event);
2935 			event_acked = true;
2936 			trid = port->trid;
2937 			break;
2938 		}
2939 	}
2940 
2941 	if (event_acked) {
2942 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2943 
2944 		nvmf_rdma_stop_listen(transport, trid);
2945 		nvmf_rdma_listen(transport, trid);
2946 	}
2947 
2948 	return event_acked;
2949 }
2950 
2951 static void
2952 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2953 				       struct rdma_cm_event *event)
2954 {
2955 	struct spdk_nvmf_rdma_port		*port;
2956 	struct spdk_nvmf_rdma_transport		*rtransport;
2957 
2958 	port = event->id->context;
2959 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2960 
2961 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2962 
2963 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2964 
2965 	rdma_ack_cm_event(event);
2966 
2967 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2968 		;
2969 	}
2970 }
2971 
2972 static void
2973 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2974 {
2975 	struct spdk_nvmf_rdma_transport *rtransport;
2976 	struct rdma_cm_event		*event;
2977 	int				rc;
2978 	bool				event_acked;
2979 
2980 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2981 
2982 	if (rtransport->event_channel == NULL) {
2983 		return;
2984 	}
2985 
2986 	while (1) {
2987 		event_acked = false;
2988 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2989 		if (rc) {
2990 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2991 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2992 			}
2993 			break;
2994 		}
2995 
2996 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2997 
2998 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2999 
3000 		switch (event->event) {
3001 		case RDMA_CM_EVENT_ADDR_RESOLVED:
3002 		case RDMA_CM_EVENT_ADDR_ERROR:
3003 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
3004 		case RDMA_CM_EVENT_ROUTE_ERROR:
3005 			/* No action required. The target never attempts to resolve routes. */
3006 			break;
3007 		case RDMA_CM_EVENT_CONNECT_REQUEST:
3008 			rc = nvmf_rdma_connect(transport, event);
3009 			if (rc < 0) {
3010 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
3011 				break;
3012 			}
3013 			break;
3014 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
3015 			/* The target never initiates a new connection. So this will not occur. */
3016 			break;
3017 		case RDMA_CM_EVENT_CONNECT_ERROR:
3018 			/* Can this happen? The docs say it can, but not sure what causes it. */
3019 			break;
3020 		case RDMA_CM_EVENT_UNREACHABLE:
3021 		case RDMA_CM_EVENT_REJECTED:
3022 			/* These only occur on the client side. */
3023 			break;
3024 		case RDMA_CM_EVENT_ESTABLISHED:
3025 			/* TODO: Should we be waiting for this event anywhere? */
3026 			break;
3027 		case RDMA_CM_EVENT_DISCONNECTED:
3028 			rc = nvmf_rdma_disconnect(event);
3029 			if (rc < 0) {
3030 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3031 				break;
3032 			}
3033 			break;
3034 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
3035 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
3036 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
3037 			 * Once these events are sent to SPDK, we should release all IB resources and
3038 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
3039 			 * ibv_destory* functions to release user space memory allocated by IB. All kernel
3040 			 * resources are already cleaned. */
3041 			if (event->id->qp) {
3042 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
3043 				 * corresponding qpair. Otherwise the event refers to a listening device */
3044 				rc = nvmf_rdma_disconnect(event);
3045 				if (rc < 0) {
3046 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3047 					break;
3048 				}
3049 			} else {
3050 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3051 				event_acked = true;
3052 			}
3053 			break;
3054 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3055 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3056 			/* Multicast is not used */
3057 			break;
3058 		case RDMA_CM_EVENT_ADDR_CHANGE:
3059 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3060 			break;
3061 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3062 			/* For now, do nothing. The target never re-uses queue pairs. */
3063 			break;
3064 		default:
3065 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3066 			break;
3067 		}
3068 		if (!event_acked) {
3069 			rdma_ack_cm_event(event);
3070 		}
3071 	}
3072 }
3073 
3074 static void
3075 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3076 {
3077 	rqpair->last_wqe_reached = true;
3078 	nvmf_rdma_destroy_drained_qpair(rqpair);
3079 }
3080 
3081 static void
3082 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3083 {
3084 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3085 
3086 	if (event_ctx->rqpair) {
3087 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3088 		if (event_ctx->cb_fn) {
3089 			event_ctx->cb_fn(event_ctx->rqpair);
3090 		}
3091 	}
3092 	free(event_ctx);
3093 }
3094 
3095 static int
3096 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3097 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3098 {
3099 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3100 	struct spdk_thread *thr = NULL;
3101 	int rc;
3102 
3103 	if (rqpair->qpair.group) {
3104 		thr = rqpair->qpair.group->thread;
3105 	} else if (rqpair->destruct_channel) {
3106 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3107 	}
3108 
3109 	if (!thr) {
3110 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3111 		return -EINVAL;
3112 	}
3113 
3114 	ctx = calloc(1, sizeof(*ctx));
3115 	if (!ctx) {
3116 		return -ENOMEM;
3117 	}
3118 
3119 	ctx->rqpair = rqpair;
3120 	ctx->cb_fn = fn;
3121 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3122 
3123 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3124 	if (rc) {
3125 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3126 		free(ctx);
3127 	}
3128 
3129 	return rc;
3130 }
3131 
3132 static int
3133 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3134 {
3135 	int				rc;
3136 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3137 	struct ibv_async_event		event;
3138 
3139 	rc = ibv_get_async_event(device->context, &event);
3140 
3141 	if (rc) {
3142 		/* In non-blocking mode -1 means there are no events available */
3143 		return rc;
3144 	}
3145 
3146 	switch (event.event_type) {
3147 	case IBV_EVENT_QP_FATAL:
3148 		rqpair = event.element.qp->qp_context;
3149 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3150 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3151 				  (uintptr_t)rqpair->cm_id, event.event_type);
3152 		nvmf_rdma_update_ibv_state(rqpair);
3153 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3154 		break;
3155 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3156 		/* This event only occurs for shared receive queues. */
3157 		rqpair = event.element.qp->qp_context;
3158 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3159 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3160 		if (rc) {
3161 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3162 			rqpair->last_wqe_reached = true;
3163 		}
3164 		break;
3165 	case IBV_EVENT_SQ_DRAINED:
3166 		/* This event occurs frequently in both error and non-error states.
3167 		 * Check if the qpair is in an error state before sending a message. */
3168 		rqpair = event.element.qp->qp_context;
3169 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3170 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3171 				  (uintptr_t)rqpair->cm_id, event.event_type);
3172 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3173 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3174 		}
3175 		break;
3176 	case IBV_EVENT_QP_REQ_ERR:
3177 	case IBV_EVENT_QP_ACCESS_ERR:
3178 	case IBV_EVENT_COMM_EST:
3179 	case IBV_EVENT_PATH_MIG:
3180 	case IBV_EVENT_PATH_MIG_ERR:
3181 		SPDK_NOTICELOG("Async event: %s\n",
3182 			       ibv_event_type_str(event.event_type));
3183 		rqpair = event.element.qp->qp_context;
3184 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3185 				  (uintptr_t)rqpair->cm_id, event.event_type);
3186 		nvmf_rdma_update_ibv_state(rqpair);
3187 		break;
3188 	case IBV_EVENT_CQ_ERR:
3189 	case IBV_EVENT_DEVICE_FATAL:
3190 	case IBV_EVENT_PORT_ACTIVE:
3191 	case IBV_EVENT_PORT_ERR:
3192 	case IBV_EVENT_LID_CHANGE:
3193 	case IBV_EVENT_PKEY_CHANGE:
3194 	case IBV_EVENT_SM_CHANGE:
3195 	case IBV_EVENT_SRQ_ERR:
3196 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3197 	case IBV_EVENT_CLIENT_REREGISTER:
3198 	case IBV_EVENT_GID_CHANGE:
3199 	default:
3200 		SPDK_NOTICELOG("Async event: %s\n",
3201 			       ibv_event_type_str(event.event_type));
3202 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3203 		break;
3204 	}
3205 	ibv_ack_async_event(&event);
3206 
3207 	return 0;
3208 }
3209 
3210 static void
3211 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3212 {
3213 	int rc = 0;
3214 	uint32_t i = 0;
3215 
3216 	for (i = 0; i < max_events; i++) {
3217 		rc = nvmf_process_ib_event(device);
3218 		if (rc) {
3219 			break;
3220 		}
3221 	}
3222 
3223 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3224 }
3225 
3226 static uint32_t
3227 nvmf_rdma_accept(struct spdk_nvmf_transport *transport)
3228 {
3229 	int	nfds, i = 0;
3230 	struct spdk_nvmf_rdma_transport *rtransport;
3231 	struct spdk_nvmf_rdma_device *device, *tmp;
3232 	uint32_t count;
3233 
3234 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3235 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3236 
3237 	if (nfds <= 0) {
3238 		return 0;
3239 	}
3240 
3241 	/* The first poll descriptor is RDMA CM event */
3242 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3243 		nvmf_process_cm_event(transport);
3244 		nfds--;
3245 	}
3246 
3247 	if (nfds == 0) {
3248 		return count;
3249 	}
3250 
3251 	/* Second and subsequent poll descriptors are IB async events */
3252 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3253 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3254 			nvmf_process_ib_events(device, 32);
3255 			nfds--;
3256 		}
3257 	}
3258 	/* check all flagged fd's have been served */
3259 	assert(nfds == 0);
3260 
3261 	return count;
3262 }
3263 
3264 static void
3265 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3266 		     struct spdk_nvmf_ctrlr_data *cdata)
3267 {
3268 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3269 
3270 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3271 	since in-capsule data only works with NVME drives that support SGL memory layout */
3272 	if (transport->opts.dif_insert_or_strip) {
3273 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3274 	}
3275 }
3276 
3277 static void
3278 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3279 		   struct spdk_nvme_transport_id *trid,
3280 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3281 {
3282 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3283 	entry->adrfam = trid->adrfam;
3284 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3285 
3286 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3287 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3288 
3289 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3290 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3291 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3292 }
3293 
3294 static void
3295 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3296 
3297 static struct spdk_nvmf_transport_poll_group *
3298 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3299 {
3300 	struct spdk_nvmf_rdma_transport		*rtransport;
3301 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3302 	struct spdk_nvmf_rdma_poller		*poller;
3303 	struct spdk_nvmf_rdma_device		*device;
3304 	struct ibv_srq_init_attr		srq_init_attr;
3305 	struct spdk_nvmf_rdma_resource_opts	opts;
3306 	int					num_cqe;
3307 
3308 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3309 
3310 	rgroup = calloc(1, sizeof(*rgroup));
3311 	if (!rgroup) {
3312 		return NULL;
3313 	}
3314 
3315 	TAILQ_INIT(&rgroup->pollers);
3316 	STAILQ_INIT(&rgroup->retired_bufs);
3317 
3318 	pthread_mutex_lock(&rtransport->lock);
3319 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3320 		poller = calloc(1, sizeof(*poller));
3321 		if (!poller) {
3322 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3323 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3324 			pthread_mutex_unlock(&rtransport->lock);
3325 			return NULL;
3326 		}
3327 
3328 		poller->device = device;
3329 		poller->group = rgroup;
3330 
3331 		TAILQ_INIT(&poller->qpairs);
3332 		STAILQ_INIT(&poller->qpairs_pending_send);
3333 		STAILQ_INIT(&poller->qpairs_pending_recv);
3334 
3335 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3336 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3337 			poller->max_srq_depth = rtransport->rdma_opts.max_srq_depth;
3338 
3339 			device->num_srq++;
3340 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3341 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3342 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3343 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3344 			if (!poller->srq) {
3345 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3346 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3347 				pthread_mutex_unlock(&rtransport->lock);
3348 				return NULL;
3349 			}
3350 
3351 			opts.qp = poller->srq;
3352 			opts.pd = device->pd;
3353 			opts.qpair = NULL;
3354 			opts.shared = true;
3355 			opts.max_queue_depth = poller->max_srq_depth;
3356 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3357 
3358 			poller->resources = nvmf_rdma_resources_create(&opts);
3359 			if (!poller->resources) {
3360 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3361 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3362 				pthread_mutex_unlock(&rtransport->lock);
3363 				return NULL;
3364 			}
3365 		}
3366 
3367 		/*
3368 		 * When using an srq, we can limit the completion queue at startup.
3369 		 * The following formula represents the calculation:
3370 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3371 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3372 		 */
3373 		if (poller->srq) {
3374 			num_cqe = poller->max_srq_depth * 3;
3375 		} else {
3376 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3377 		}
3378 
3379 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3380 		if (!poller->cq) {
3381 			SPDK_ERRLOG("Unable to create completion queue\n");
3382 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3383 			pthread_mutex_unlock(&rtransport->lock);
3384 			return NULL;
3385 		}
3386 		poller->num_cqe = num_cqe;
3387 	}
3388 
3389 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3390 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3391 		rtransport->conn_sched.next_admin_pg = rgroup;
3392 		rtransport->conn_sched.next_io_pg = rgroup;
3393 	}
3394 
3395 	pthread_mutex_unlock(&rtransport->lock);
3396 	return &rgroup->group;
3397 }
3398 
3399 static struct spdk_nvmf_transport_poll_group *
3400 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3401 {
3402 	struct spdk_nvmf_rdma_transport *rtransport;
3403 	struct spdk_nvmf_rdma_poll_group **pg;
3404 	struct spdk_nvmf_transport_poll_group *result;
3405 
3406 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3407 
3408 	pthread_mutex_lock(&rtransport->lock);
3409 
3410 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3411 		pthread_mutex_unlock(&rtransport->lock);
3412 		return NULL;
3413 	}
3414 
3415 	if (qpair->qid == 0) {
3416 		pg = &rtransport->conn_sched.next_admin_pg;
3417 	} else {
3418 		pg = &rtransport->conn_sched.next_io_pg;
3419 	}
3420 
3421 	assert(*pg != NULL);
3422 
3423 	result = &(*pg)->group;
3424 
3425 	*pg = TAILQ_NEXT(*pg, link);
3426 	if (*pg == NULL) {
3427 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3428 	}
3429 
3430 	pthread_mutex_unlock(&rtransport->lock);
3431 
3432 	return result;
3433 }
3434 
3435 static void
3436 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3437 {
3438 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3439 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3440 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3441 	struct spdk_nvmf_transport_pg_cache_buf	*buf, *tmp_buf;
3442 	struct spdk_nvmf_rdma_transport		*rtransport;
3443 
3444 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3445 	if (!rgroup) {
3446 		return;
3447 	}
3448 
3449 	/* free all retired buffers back to the transport so we don't short the mempool. */
3450 	STAILQ_FOREACH_SAFE(buf, &rgroup->retired_bufs, link, tmp_buf) {
3451 		STAILQ_REMOVE(&rgroup->retired_bufs, buf, spdk_nvmf_transport_pg_cache_buf, link);
3452 		assert(group->transport != NULL);
3453 		spdk_mempool_put(group->transport->data_buf_pool, buf);
3454 	}
3455 
3456 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3457 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3458 
3459 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3460 			nvmf_rdma_qpair_destroy(qpair);
3461 		}
3462 
3463 		if (poller->srq) {
3464 			if (poller->resources) {
3465 				nvmf_rdma_resources_destroy(poller->resources);
3466 			}
3467 			ibv_destroy_srq(poller->srq);
3468 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3469 		}
3470 
3471 		if (poller->cq) {
3472 			ibv_destroy_cq(poller->cq);
3473 		}
3474 
3475 		free(poller);
3476 	}
3477 
3478 	if (rgroup->group.transport == NULL) {
3479 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3480 		 * calls this function directly in a failure path. */
3481 		free(rgroup);
3482 		return;
3483 	}
3484 
3485 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3486 
3487 	pthread_mutex_lock(&rtransport->lock);
3488 	next_rgroup = TAILQ_NEXT(rgroup, link);
3489 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3490 	if (next_rgroup == NULL) {
3491 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3492 	}
3493 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3494 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3495 	}
3496 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3497 		rtransport->conn_sched.next_io_pg = next_rgroup;
3498 	}
3499 	pthread_mutex_unlock(&rtransport->lock);
3500 
3501 	free(rgroup);
3502 }
3503 
3504 static void
3505 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3506 {
3507 	if (rqpair->cm_id != NULL) {
3508 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3509 	}
3510 }
3511 
3512 static int
3513 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3514 			 struct spdk_nvmf_qpair *qpair)
3515 {
3516 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3517 	struct spdk_nvmf_rdma_qpair		*rqpair;
3518 	struct spdk_nvmf_rdma_device		*device;
3519 	struct spdk_nvmf_rdma_poller		*poller;
3520 	int					rc;
3521 
3522 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3523 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3524 
3525 	device = rqpair->device;
3526 
3527 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3528 		if (poller->device == device) {
3529 			break;
3530 		}
3531 	}
3532 
3533 	if (!poller) {
3534 		SPDK_ERRLOG("No poller found for device.\n");
3535 		return -1;
3536 	}
3537 
3538 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3539 	rqpair->poller = poller;
3540 	rqpair->srq = rqpair->poller->srq;
3541 
3542 	rc = nvmf_rdma_qpair_initialize(qpair);
3543 	if (rc < 0) {
3544 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3545 		return -1;
3546 	}
3547 
3548 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3549 	if (rc) {
3550 		/* Try to reject, but we probably can't */
3551 		nvmf_rdma_qpair_reject_connection(rqpair);
3552 		return -1;
3553 	}
3554 
3555 	nvmf_rdma_update_ibv_state(rqpair);
3556 
3557 	return 0;
3558 }
3559 
3560 static int
3561 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3562 			    struct spdk_nvmf_qpair *qpair)
3563 {
3564 	struct spdk_nvmf_rdma_qpair		*rqpair;
3565 
3566 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3567 	assert(group->transport->tgt != NULL);
3568 
3569 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3570 
3571 	if (!rqpair->destruct_channel) {
3572 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3573 		return 0;
3574 	}
3575 
3576 	/* Sanity check that we get io_channel on the correct thread */
3577 	if (qpair->group) {
3578 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3579 	}
3580 
3581 	return 0;
3582 }
3583 
3584 static int
3585 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3586 {
3587 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3588 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3589 			struct spdk_nvmf_rdma_transport, transport);
3590 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3591 					      struct spdk_nvmf_rdma_qpair, qpair);
3592 
3593 	/*
3594 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3595 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3596 	 * starved of RECV structures.
3597 	 */
3598 	if (rqpair->srq && rdma_req->recv) {
3599 		int rc;
3600 		struct ibv_recv_wr *bad_recv_wr;
3601 
3602 		rc = ibv_post_srq_recv(rqpair->srq, &rdma_req->recv->wr, &bad_recv_wr);
3603 		if (rc) {
3604 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3605 		}
3606 	}
3607 
3608 	_nvmf_rdma_request_free(rdma_req, rtransport);
3609 	return 0;
3610 }
3611 
3612 static int
3613 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3614 {
3615 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3616 			struct spdk_nvmf_rdma_transport, transport);
3617 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3618 			struct spdk_nvmf_rdma_request, req);
3619 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3620 			struct spdk_nvmf_rdma_qpair, qpair);
3621 
3622 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3623 		/* The connection is alive, so process the request as normal */
3624 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3625 	} else {
3626 		/* The connection is dead. Move the request directly to the completed state. */
3627 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3628 	}
3629 
3630 	nvmf_rdma_request_process(rtransport, rdma_req);
3631 
3632 	return 0;
3633 }
3634 
3635 static void
3636 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
3637 {
3638 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3639 
3640 	rqpair->to_close = true;
3641 
3642 	/* This happens only when the qpair is disconnected before
3643 	 * it is added to the poll group. Since there is no poll group,
3644 	 * the RDMA qp has not been initialized yet and the RDMA CM
3645 	 * event has not yet been acknowledged, so we need to reject it.
3646 	 */
3647 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3648 		nvmf_rdma_qpair_reject_connection(rqpair);
3649 		nvmf_rdma_qpair_destroy(rqpair);
3650 		return;
3651 	}
3652 
3653 	if (rqpair->rdma_qp) {
3654 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3655 	}
3656 
3657 	nvmf_rdma_destroy_drained_qpair(rqpair);
3658 }
3659 
3660 static struct spdk_nvmf_rdma_qpair *
3661 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3662 {
3663 	struct spdk_nvmf_rdma_qpair *rqpair;
3664 	/* @todo: improve QP search */
3665 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3666 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3667 			return rqpair;
3668 		}
3669 	}
3670 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3671 	return NULL;
3672 }
3673 
3674 #ifdef DEBUG
3675 static int
3676 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3677 {
3678 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3679 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3680 }
3681 #endif
3682 
3683 static void
3684 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3685 			   int rc)
3686 {
3687 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3688 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3689 
3690 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3691 	while (bad_recv_wr != NULL) {
3692 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3693 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3694 
3695 		rdma_recv->qpair->current_recv_depth++;
3696 		bad_recv_wr = bad_recv_wr->next;
3697 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3698 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3699 	}
3700 }
3701 
3702 static void
3703 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3704 {
3705 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3706 	while (bad_recv_wr != NULL) {
3707 		bad_recv_wr = bad_recv_wr->next;
3708 		rqpair->current_recv_depth++;
3709 	}
3710 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3711 }
3712 
3713 static void
3714 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3715 		     struct spdk_nvmf_rdma_poller *rpoller)
3716 {
3717 	struct spdk_nvmf_rdma_qpair	*rqpair;
3718 	struct ibv_recv_wr		*bad_recv_wr;
3719 	int				rc;
3720 
3721 	if (rpoller->srq) {
3722 		if (rpoller->resources->recvs_to_post.first != NULL) {
3723 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3724 			if (rc) {
3725 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3726 			}
3727 			rpoller->resources->recvs_to_post.first = NULL;
3728 			rpoller->resources->recvs_to_post.last = NULL;
3729 		}
3730 	} else {
3731 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3732 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3733 			assert(rqpair->resources->recvs_to_post.first != NULL);
3734 			rc = ibv_post_recv(rqpair->rdma_qp->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3735 			if (rc) {
3736 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3737 			}
3738 			rqpair->resources->recvs_to_post.first = NULL;
3739 			rqpair->resources->recvs_to_post.last = NULL;
3740 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3741 		}
3742 	}
3743 }
3744 
3745 static void
3746 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3747 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3748 {
3749 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3750 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3751 
3752 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3753 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3754 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3755 		assert(rqpair->current_send_depth > 0);
3756 		rqpair->current_send_depth--;
3757 		switch (bad_rdma_wr->type) {
3758 		case RDMA_WR_TYPE_DATA:
3759 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3760 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3761 				assert(rqpair->current_read_depth > 0);
3762 				rqpair->current_read_depth--;
3763 			}
3764 			break;
3765 		case RDMA_WR_TYPE_SEND:
3766 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3767 			break;
3768 		default:
3769 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3770 			prev_rdma_req = cur_rdma_req;
3771 			continue;
3772 		}
3773 
3774 		if (prev_rdma_req == cur_rdma_req) {
3775 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3776 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3777 			continue;
3778 		}
3779 
3780 		switch (cur_rdma_req->state) {
3781 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3782 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3783 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3784 			break;
3785 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3786 		case RDMA_REQUEST_STATE_COMPLETING:
3787 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3788 			break;
3789 		default:
3790 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3791 				    cur_rdma_req->state, rqpair);
3792 			continue;
3793 		}
3794 
3795 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3796 		prev_rdma_req = cur_rdma_req;
3797 	}
3798 
3799 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3800 		/* Disconnect the connection. */
3801 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3802 	}
3803 
3804 }
3805 
3806 static void
3807 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3808 		     struct spdk_nvmf_rdma_poller *rpoller)
3809 {
3810 	struct spdk_nvmf_rdma_qpair	*rqpair;
3811 	struct ibv_send_wr		*bad_wr = NULL;
3812 	int				rc;
3813 
3814 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3815 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3816 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3817 
3818 		/* bad wr always points to the first wr that failed. */
3819 		if (rc) {
3820 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3821 		}
3822 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3823 	}
3824 }
3825 
3826 static const char *
3827 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3828 {
3829 	switch (wr_type) {
3830 	case RDMA_WR_TYPE_RECV:
3831 		return "RECV";
3832 	case RDMA_WR_TYPE_SEND:
3833 		return "SEND";
3834 	case RDMA_WR_TYPE_DATA:
3835 		return "DATA";
3836 	default:
3837 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3838 		SPDK_UNREACHABLE();
3839 	}
3840 }
3841 
3842 static inline void
3843 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3844 {
3845 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3846 
3847 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3848 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3849 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3850 		SPDK_DEBUGLOG(rdma,
3851 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3852 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3853 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3854 	} else {
3855 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3856 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3857 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3858 	}
3859 }
3860 
3861 static int
3862 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3863 		      struct spdk_nvmf_rdma_poller *rpoller)
3864 {
3865 	struct ibv_wc wc[32];
3866 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3867 	struct spdk_nvmf_rdma_request	*rdma_req;
3868 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3869 	struct spdk_nvmf_rdma_qpair	*rqpair;
3870 	int reaped, i;
3871 	int count = 0;
3872 	bool error = false;
3873 	uint64_t poll_tsc = spdk_get_ticks();
3874 
3875 	/* Poll for completing operations. */
3876 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3877 	if (reaped < 0) {
3878 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3879 			    errno, spdk_strerror(errno));
3880 		return -1;
3881 	}
3882 
3883 	rpoller->stat.polls++;
3884 	rpoller->stat.completions += reaped;
3885 
3886 	for (i = 0; i < reaped; i++) {
3887 
3888 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3889 
3890 		switch (rdma_wr->type) {
3891 		case RDMA_WR_TYPE_SEND:
3892 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3893 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3894 
3895 			if (!wc[i].status) {
3896 				count++;
3897 				assert(wc[i].opcode == IBV_WC_SEND);
3898 				assert(nvmf_rdma_req_is_completing(rdma_req));
3899 			}
3900 
3901 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3902 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3903 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3904 			rdma_req->num_outstanding_data_wr = 0;
3905 
3906 			nvmf_rdma_request_process(rtransport, rdma_req);
3907 			break;
3908 		case RDMA_WR_TYPE_RECV:
3909 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3910 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3911 			if (rpoller->srq != NULL) {
3912 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3913 				/* It is possible that there are still some completions for destroyed QP
3914 				 * associated with SRQ. We just ignore these late completions and re-post
3915 				 * receive WRs back to SRQ.
3916 				 */
3917 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3918 					struct ibv_recv_wr *bad_wr;
3919 					int rc;
3920 
3921 					rdma_recv->wr.next = NULL;
3922 					rc = ibv_post_srq_recv(rpoller->srq,
3923 							       &rdma_recv->wr,
3924 							       &bad_wr);
3925 					if (rc) {
3926 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3927 					}
3928 					continue;
3929 				}
3930 			}
3931 			rqpair = rdma_recv->qpair;
3932 
3933 			assert(rqpair != NULL);
3934 			if (!wc[i].status) {
3935 				assert(wc[i].opcode == IBV_WC_RECV);
3936 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3937 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3938 					break;
3939 				}
3940 			}
3941 
3942 			rdma_recv->wr.next = NULL;
3943 			rqpair->current_recv_depth++;
3944 			rdma_recv->receive_tsc = poll_tsc;
3945 			rpoller->stat.requests++;
3946 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3947 			break;
3948 		case RDMA_WR_TYPE_DATA:
3949 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3950 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3951 
3952 			assert(rdma_req->num_outstanding_data_wr > 0);
3953 
3954 			rqpair->current_send_depth--;
3955 			rdma_req->num_outstanding_data_wr--;
3956 			if (!wc[i].status) {
3957 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3958 				rqpair->current_read_depth--;
3959 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3960 				if (rdma_req->num_outstanding_data_wr == 0) {
3961 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3962 					nvmf_rdma_request_process(rtransport, rdma_req);
3963 				}
3964 			} else {
3965 				/* If the data transfer fails still force the queue into the error state,
3966 				 * if we were performing an RDMA_READ, we need to force the request into a
3967 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3968 				 * case, we should wait for the SEND to complete. */
3969 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3970 					rqpair->current_read_depth--;
3971 					if (rdma_req->num_outstanding_data_wr == 0) {
3972 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3973 					}
3974 				}
3975 			}
3976 			break;
3977 		default:
3978 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3979 			continue;
3980 		}
3981 
3982 		/* Handle error conditions */
3983 		if (wc[i].status) {
3984 			nvmf_rdma_update_ibv_state(rqpair);
3985 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
3986 
3987 			error = true;
3988 
3989 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3990 				/* Disconnect the connection. */
3991 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3992 			} else {
3993 				nvmf_rdma_destroy_drained_qpair(rqpair);
3994 			}
3995 			continue;
3996 		}
3997 
3998 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3999 
4000 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
4001 			nvmf_rdma_destroy_drained_qpair(rqpair);
4002 		}
4003 	}
4004 
4005 	if (error == true) {
4006 		return -1;
4007 	}
4008 
4009 	/* submit outstanding work requests. */
4010 	_poller_submit_recvs(rtransport, rpoller);
4011 	_poller_submit_sends(rtransport, rpoller);
4012 
4013 	return count;
4014 }
4015 
4016 static int
4017 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
4018 {
4019 	struct spdk_nvmf_rdma_transport *rtransport;
4020 	struct spdk_nvmf_rdma_poll_group *rgroup;
4021 	struct spdk_nvmf_rdma_poller	*rpoller;
4022 	int				count, rc;
4023 
4024 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
4025 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4026 
4027 	count = 0;
4028 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4029 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
4030 		if (rc < 0) {
4031 			return rc;
4032 		}
4033 		count += rc;
4034 	}
4035 
4036 	return count;
4037 }
4038 
4039 static int
4040 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
4041 			  struct spdk_nvme_transport_id *trid,
4042 			  bool peer)
4043 {
4044 	struct sockaddr *saddr;
4045 	uint16_t port;
4046 
4047 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
4048 
4049 	if (peer) {
4050 		saddr = rdma_get_peer_addr(id);
4051 	} else {
4052 		saddr = rdma_get_local_addr(id);
4053 	}
4054 	switch (saddr->sa_family) {
4055 	case AF_INET: {
4056 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
4057 
4058 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
4059 		inet_ntop(AF_INET, &saddr_in->sin_addr,
4060 			  trid->traddr, sizeof(trid->traddr));
4061 		if (peer) {
4062 			port = ntohs(rdma_get_dst_port(id));
4063 		} else {
4064 			port = ntohs(rdma_get_src_port(id));
4065 		}
4066 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4067 		break;
4068 	}
4069 	case AF_INET6: {
4070 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4071 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4072 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4073 			  trid->traddr, sizeof(trid->traddr));
4074 		if (peer) {
4075 			port = ntohs(rdma_get_dst_port(id));
4076 		} else {
4077 			port = ntohs(rdma_get_src_port(id));
4078 		}
4079 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4080 		break;
4081 	}
4082 	default:
4083 		return -1;
4084 
4085 	}
4086 
4087 	return 0;
4088 }
4089 
4090 static int
4091 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4092 			      struct spdk_nvme_transport_id *trid)
4093 {
4094 	struct spdk_nvmf_rdma_qpair	*rqpair;
4095 
4096 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4097 
4098 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4099 }
4100 
4101 static int
4102 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4103 			       struct spdk_nvme_transport_id *trid)
4104 {
4105 	struct spdk_nvmf_rdma_qpair	*rqpair;
4106 
4107 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4108 
4109 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4110 }
4111 
4112 static int
4113 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4114 				struct spdk_nvme_transport_id *trid)
4115 {
4116 	struct spdk_nvmf_rdma_qpair	*rqpair;
4117 
4118 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4119 
4120 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4121 }
4122 
4123 void
4124 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4125 {
4126 	g_nvmf_hooks = *hooks;
4127 }
4128 
4129 static void
4130 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4131 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4132 {
4133 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4134 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4135 
4136 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4137 
4138 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4139 }
4140 
4141 static int
4142 _nvmf_rdma_qpair_abort_request(void *ctx)
4143 {
4144 	struct spdk_nvmf_request *req = ctx;
4145 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4146 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4147 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4148 					      struct spdk_nvmf_rdma_qpair, qpair);
4149 	int rc;
4150 
4151 	spdk_poller_unregister(&req->poller);
4152 
4153 	switch (rdma_req_to_abort->state) {
4154 	case RDMA_REQUEST_STATE_EXECUTING:
4155 		rc = nvmf_ctrlr_abort_request(req);
4156 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4157 			return SPDK_POLLER_BUSY;
4158 		}
4159 		break;
4160 
4161 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4162 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4163 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4164 
4165 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4166 		break;
4167 
4168 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4169 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4170 			      spdk_nvmf_rdma_request, state_link);
4171 
4172 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4173 		break;
4174 
4175 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4176 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4177 			      spdk_nvmf_rdma_request, state_link);
4178 
4179 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4180 		break;
4181 
4182 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4183 		if (spdk_get_ticks() < req->timeout_tsc) {
4184 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4185 			return SPDK_POLLER_BUSY;
4186 		}
4187 		break;
4188 
4189 	default:
4190 		break;
4191 	}
4192 
4193 	spdk_nvmf_request_complete(req);
4194 	return SPDK_POLLER_BUSY;
4195 }
4196 
4197 static void
4198 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4199 			      struct spdk_nvmf_request *req)
4200 {
4201 	struct spdk_nvmf_rdma_qpair *rqpair;
4202 	struct spdk_nvmf_rdma_transport *rtransport;
4203 	struct spdk_nvmf_transport *transport;
4204 	uint16_t cid;
4205 	uint32_t i;
4206 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL;
4207 
4208 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4209 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4210 	transport = &rtransport->transport;
4211 
4212 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4213 
4214 	for (i = 0; i < rqpair->max_queue_depth; i++) {
4215 		rdma_req_to_abort = &rqpair->resources->reqs[i];
4216 
4217 		if (rdma_req_to_abort->state != RDMA_REQUEST_STATE_FREE &&
4218 		    rdma_req_to_abort->req.cmd->nvme_cmd.cid == cid) {
4219 			break;
4220 		}
4221 	}
4222 
4223 	if (rdma_req_to_abort == NULL) {
4224 		spdk_nvmf_request_complete(req);
4225 		return;
4226 	}
4227 
4228 	req->req_to_abort = &rdma_req_to_abort->req;
4229 	req->timeout_tsc = spdk_get_ticks() +
4230 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4231 	req->poller = NULL;
4232 
4233 	_nvmf_rdma_qpair_abort_request(req);
4234 }
4235 
4236 static int
4237 nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
4238 			      struct spdk_nvmf_transport_poll_group_stat **stat)
4239 {
4240 	struct spdk_io_channel *ch;
4241 	struct spdk_nvmf_poll_group *group;
4242 	struct spdk_nvmf_transport_poll_group *tgroup;
4243 	struct spdk_nvmf_rdma_poll_group *rgroup;
4244 	struct spdk_nvmf_rdma_poller *rpoller;
4245 	struct spdk_nvmf_rdma_device_stat *device_stat;
4246 	uint64_t num_devices = 0;
4247 
4248 	if (tgt == NULL || stat == NULL) {
4249 		return -EINVAL;
4250 	}
4251 
4252 	ch = spdk_get_io_channel(tgt);
4253 	group = spdk_io_channel_get_ctx(ch);;
4254 	spdk_put_io_channel(ch);
4255 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4256 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4257 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4258 			if (!*stat) {
4259 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4260 				return -ENOMEM;
4261 			}
4262 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4263 
4264 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4265 			/* Count devices to allocate enough memory */
4266 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4267 				++num_devices;
4268 			}
4269 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4270 			if (!(*stat)->rdma.devices) {
4271 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4272 				free(*stat);
4273 				return -ENOMEM;
4274 			}
4275 
4276 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4277 			(*stat)->rdma.num_devices = num_devices;
4278 			num_devices = 0;
4279 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4280 				device_stat = &(*stat)->rdma.devices[num_devices++];
4281 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4282 				device_stat->polls = rpoller->stat.polls;
4283 				device_stat->completions = rpoller->stat.completions;
4284 				device_stat->requests = rpoller->stat.requests;
4285 				device_stat->request_latency = rpoller->stat.request_latency;
4286 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4287 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4288 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4289 			}
4290 			return 0;
4291 		}
4292 	}
4293 	return -ENOENT;
4294 }
4295 
4296 static void
4297 nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4298 {
4299 	if (stat) {
4300 		free(stat->rdma.devices);
4301 	}
4302 	free(stat);
4303 }
4304 
4305 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4306 	.name = "RDMA",
4307 	.type = SPDK_NVME_TRANSPORT_RDMA,
4308 	.opts_init = nvmf_rdma_opts_init,
4309 	.create = nvmf_rdma_create,
4310 	.dump_opts = nvmf_rdma_dump_opts,
4311 	.destroy = nvmf_rdma_destroy,
4312 
4313 	.listen = nvmf_rdma_listen,
4314 	.stop_listen = nvmf_rdma_stop_listen,
4315 	.accept = nvmf_rdma_accept,
4316 	.cdata_init = nvmf_rdma_cdata_init,
4317 
4318 	.listener_discover = nvmf_rdma_discover,
4319 
4320 	.poll_group_create = nvmf_rdma_poll_group_create,
4321 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4322 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4323 	.poll_group_add = nvmf_rdma_poll_group_add,
4324 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4325 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4326 
4327 	.req_free = nvmf_rdma_request_free,
4328 	.req_complete = nvmf_rdma_request_complete,
4329 
4330 	.qpair_fini = nvmf_rdma_close_qpair,
4331 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4332 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4333 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4334 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4335 
4336 	.poll_group_get_stat = nvmf_rdma_poll_group_get_stat,
4337 	.poll_group_free_stat = nvmf_rdma_poll_group_free_stat,
4338 };
4339 
4340 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4341 SPDK_LOG_REGISTER_COMPONENT(rdma)
4342