xref: /spdk/lib/nvmf/rdma.c (revision 8a12e2e715a13d30a8c921c48e7ce67704c37044)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019-2021 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 /* rxe driver vendor_id has been changed from 0 to 0XFFFFFF in 0184afd15a141d7ce24c32c0d86a1e3ba6bc0eb3 */
65 #define NVMF_RXE_VENDOR_ID_OLD 0
66 #define NVMF_RXE_VENDOR_ID_NEW 0XFFFFFF
67 
68 static int g_spdk_nvmf_ibv_query_mask =
69 	IBV_QP_STATE |
70 	IBV_QP_PKEY_INDEX |
71 	IBV_QP_PORT |
72 	IBV_QP_ACCESS_FLAGS |
73 	IBV_QP_AV |
74 	IBV_QP_PATH_MTU |
75 	IBV_QP_DEST_QPN |
76 	IBV_QP_RQ_PSN |
77 	IBV_QP_MAX_DEST_RD_ATOMIC |
78 	IBV_QP_MIN_RNR_TIMER |
79 	IBV_QP_SQ_PSN |
80 	IBV_QP_TIMEOUT |
81 	IBV_QP_RETRY_CNT |
82 	IBV_QP_RNR_RETRY |
83 	IBV_QP_MAX_QP_RD_ATOMIC;
84 
85 enum spdk_nvmf_rdma_request_state {
86 	/* The request is not currently in use */
87 	RDMA_REQUEST_STATE_FREE = 0,
88 
89 	/* Initial state when request first received */
90 	RDMA_REQUEST_STATE_NEW,
91 
92 	/* The request is queued until a data buffer is available. */
93 	RDMA_REQUEST_STATE_NEED_BUFFER,
94 
95 	/* The request is waiting on RDMA queue depth availability
96 	 * to transfer data from the host to the controller.
97 	 */
98 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
99 
100 	/* The request is currently transferring data from the host to the controller. */
101 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
102 
103 	/* The request is ready to execute at the block device */
104 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
105 
106 	/* The request is currently executing at the block device */
107 	RDMA_REQUEST_STATE_EXECUTING,
108 
109 	/* The request finished executing at the block device */
110 	RDMA_REQUEST_STATE_EXECUTED,
111 
112 	/* The request is waiting on RDMA queue depth availability
113 	 * to transfer data from the controller to the host.
114 	 */
115 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
116 
117 	/* The request is ready to send a completion */
118 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
119 
120 	/* The request is currently transferring data from the controller to the host. */
121 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
122 
123 	/* The request currently has an outstanding completion without an
124 	 * associated data transfer.
125 	 */
126 	RDMA_REQUEST_STATE_COMPLETING,
127 
128 	/* The request completed and can be marked free. */
129 	RDMA_REQUEST_STATE_COMPLETED,
130 
131 	/* Terminator */
132 	RDMA_REQUEST_NUM_STATES,
133 };
134 
135 #define OBJECT_NVMF_RDMA_IO				0x40
136 
137 #define TRACE_GROUP_NVMF_RDMA				0x4
138 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
139 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
140 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
141 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
142 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
143 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
144 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
145 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
146 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
147 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
148 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
149 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
150 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
151 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
152 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
153 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
154 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
155 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
156 
157 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
158 {
159 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
160 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
161 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1,
162 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
163 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
164 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
165 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
166 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
167 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
169 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
170 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
171 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
172 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
173 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
174 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
175 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
176 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
177 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
178 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
179 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
180 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
181 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
182 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
183 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
184 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
185 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
186 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
187 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
188 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
189 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
190 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
191 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
192 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
193 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
194 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
195 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
196 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
197 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
198 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
199 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
200 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
201 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
202 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
203 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
204 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
205 					SPDK_TRACE_ARG_TYPE_PTR, "cmid:   ");
206 
207 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
208 					OWNER_NONE, OBJECT_NONE, 0,
209 					SPDK_TRACE_ARG_TYPE_INT, "");
210 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
211 					OWNER_NONE, OBJECT_NONE, 0,
212 					SPDK_TRACE_ARG_TYPE_INT, "type:   ");
213 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
214 					OWNER_NONE, OBJECT_NONE, 0,
215 					SPDK_TRACE_ARG_TYPE_INT, "type:   ");
216 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
217 					OWNER_NONE, OBJECT_NONE, 0,
218 					SPDK_TRACE_ARG_TYPE_PTR, "state:  ");
219 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
220 					OWNER_NONE, OBJECT_NONE, 0,
221 					SPDK_TRACE_ARG_TYPE_INT, "");
222 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
223 					OWNER_NONE, OBJECT_NONE, 0,
224 					SPDK_TRACE_ARG_TYPE_INT, "");
225 }
226 
227 enum spdk_nvmf_rdma_wr_type {
228 	RDMA_WR_TYPE_RECV,
229 	RDMA_WR_TYPE_SEND,
230 	RDMA_WR_TYPE_DATA,
231 };
232 
233 struct spdk_nvmf_rdma_wr {
234 	enum spdk_nvmf_rdma_wr_type	type;
235 };
236 
237 /* This structure holds commands as they are received off the wire.
238  * It must be dynamically paired with a full request object
239  * (spdk_nvmf_rdma_request) to service a request. It is separate
240  * from the request because RDMA does not appear to order
241  * completions, so occasionally we'll get a new incoming
242  * command when there aren't any free request objects.
243  */
244 struct spdk_nvmf_rdma_recv {
245 	struct ibv_recv_wr			wr;
246 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
247 
248 	struct spdk_nvmf_rdma_qpair		*qpair;
249 
250 	/* In-capsule data buffer */
251 	uint8_t					*buf;
252 
253 	struct spdk_nvmf_rdma_wr		rdma_wr;
254 	uint64_t				receive_tsc;
255 
256 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
257 };
258 
259 struct spdk_nvmf_rdma_request_data {
260 	struct spdk_nvmf_rdma_wr	rdma_wr;
261 	struct ibv_send_wr		wr;
262 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
263 };
264 
265 struct spdk_nvmf_rdma_request {
266 	struct spdk_nvmf_request		req;
267 
268 	enum spdk_nvmf_rdma_request_state	state;
269 
270 	struct spdk_nvmf_rdma_recv		*recv;
271 
272 	struct {
273 		struct spdk_nvmf_rdma_wr	rdma_wr;
274 		struct	ibv_send_wr		wr;
275 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
276 	} rsp;
277 
278 	struct spdk_nvmf_rdma_request_data	data;
279 
280 	uint32_t				iovpos;
281 
282 	uint32_t				num_outstanding_data_wr;
283 	uint64_t				receive_tsc;
284 
285 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
286 };
287 
288 struct spdk_nvmf_rdma_resource_opts {
289 	struct spdk_nvmf_rdma_qpair	*qpair;
290 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
291 	void				*qp;
292 	struct ibv_pd			*pd;
293 	uint32_t			max_queue_depth;
294 	uint32_t			in_capsule_data_size;
295 	bool				shared;
296 };
297 
298 struct spdk_nvmf_rdma_resources {
299 	/* Array of size "max_queue_depth" containing RDMA requests. */
300 	struct spdk_nvmf_rdma_request		*reqs;
301 
302 	/* Array of size "max_queue_depth" containing RDMA recvs. */
303 	struct spdk_nvmf_rdma_recv		*recvs;
304 
305 	/* Array of size "max_queue_depth" containing 64 byte capsules
306 	 * used for receive.
307 	 */
308 	union nvmf_h2c_msg			*cmds;
309 	struct ibv_mr				*cmds_mr;
310 
311 	/* Array of size "max_queue_depth" containing 16 byte completions
312 	 * to be sent back to the user.
313 	 */
314 	union nvmf_c2h_msg			*cpls;
315 	struct ibv_mr				*cpls_mr;
316 
317 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
318 	 * buffers to be used for in capsule data.
319 	 */
320 	void					*bufs;
321 	struct ibv_mr				*bufs_mr;
322 
323 	/* Receives that are waiting for a request object */
324 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
325 
326 	/* Queue to track free requests */
327 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
328 };
329 
330 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
331 
332 struct spdk_nvmf_rdma_ibv_event_ctx {
333 	struct spdk_nvmf_rdma_qpair			*rqpair;
334 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
335 	/* Link to other ibv events associated with this qpair */
336 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
337 };
338 
339 struct spdk_nvmf_rdma_qpair {
340 	struct spdk_nvmf_qpair			qpair;
341 
342 	struct spdk_nvmf_rdma_device		*device;
343 	struct spdk_nvmf_rdma_poller		*poller;
344 
345 	struct spdk_rdma_qp			*rdma_qp;
346 	struct rdma_cm_id			*cm_id;
347 	struct spdk_rdma_srq			*srq;
348 	struct rdma_cm_id			*listen_id;
349 
350 	/* The maximum number of I/O outstanding on this connection at one time */
351 	uint16_t				max_queue_depth;
352 
353 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
354 	uint16_t				max_read_depth;
355 
356 	/* The maximum number of RDMA SEND operations at one time */
357 	uint32_t				max_send_depth;
358 
359 	/* The current number of outstanding WRs from this qpair's
360 	 * recv queue. Should not exceed device->attr.max_queue_depth.
361 	 */
362 	uint16_t				current_recv_depth;
363 
364 	/* The current number of active RDMA READ operations */
365 	uint16_t				current_read_depth;
366 
367 	/* The current number of posted WRs from this qpair's
368 	 * send queue. Should not exceed max_send_depth.
369 	 */
370 	uint32_t				current_send_depth;
371 
372 	/* The maximum number of SGEs per WR on the send queue */
373 	uint32_t				max_send_sge;
374 
375 	/* The maximum number of SGEs per WR on the recv queue */
376 	uint32_t				max_recv_sge;
377 
378 	struct spdk_nvmf_rdma_resources		*resources;
379 
380 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
381 
382 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
383 
384 	/* Number of requests not in the free state */
385 	uint32_t				qd;
386 
387 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
388 
389 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
390 
391 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
392 
393 	/* IBV queue pair attributes: they are used to manage
394 	 * qp state and recover from errors.
395 	 */
396 	enum ibv_qp_state			ibv_state;
397 
398 	/*
399 	 * io_channel which is used to destroy qpair when it is removed from poll group
400 	 */
401 	struct spdk_io_channel		*destruct_channel;
402 
403 	/* List of ibv async events */
404 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
405 
406 	/* Lets us know that we have received the last_wqe event. */
407 	bool					last_wqe_reached;
408 
409 	/* Indicate that nvmf_rdma_close_qpair is called */
410 	bool					to_close;
411 };
412 
413 struct spdk_nvmf_rdma_poller_stat {
414 	uint64_t				completions;
415 	uint64_t				polls;
416 	uint64_t				idle_polls;
417 	uint64_t				requests;
418 	uint64_t				request_latency;
419 	uint64_t				pending_free_request;
420 	uint64_t				pending_rdma_read;
421 	uint64_t				pending_rdma_write;
422 	struct spdk_rdma_qp_stats		qp_stats;
423 };
424 
425 struct spdk_nvmf_rdma_poller {
426 	struct spdk_nvmf_rdma_device		*device;
427 	struct spdk_nvmf_rdma_poll_group	*group;
428 
429 	int					num_cqe;
430 	int					required_num_wr;
431 	struct ibv_cq				*cq;
432 
433 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
434 	uint16_t				max_srq_depth;
435 
436 	/* Shared receive queue */
437 	struct spdk_rdma_srq			*srq;
438 
439 	struct spdk_nvmf_rdma_resources		*resources;
440 	struct spdk_nvmf_rdma_poller_stat	stat;
441 
442 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
443 
444 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
445 
446 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
447 
448 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
449 };
450 
451 struct spdk_nvmf_rdma_poll_group_stat {
452 	uint64_t				pending_data_buffer;
453 };
454 
455 struct spdk_nvmf_rdma_poll_group {
456 	struct spdk_nvmf_transport_poll_group		group;
457 	struct spdk_nvmf_rdma_poll_group_stat		stat;
458 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
459 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
460 };
461 
462 struct spdk_nvmf_rdma_conn_sched {
463 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
464 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
465 };
466 
467 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
468 struct spdk_nvmf_rdma_device {
469 	struct ibv_device_attr			attr;
470 	struct ibv_context			*context;
471 
472 	struct spdk_rdma_mem_map		*map;
473 	struct ibv_pd				*pd;
474 
475 	int					num_srq;
476 
477 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
478 };
479 
480 struct spdk_nvmf_rdma_port {
481 	const struct spdk_nvme_transport_id	*trid;
482 	struct rdma_cm_id			*id;
483 	struct spdk_nvmf_rdma_device		*device;
484 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
485 };
486 
487 struct rdma_transport_opts {
488 	int		num_cqe;
489 	uint32_t	max_srq_depth;
490 	bool		no_srq;
491 	bool		no_wr_batching;
492 	int		acceptor_backlog;
493 };
494 
495 struct spdk_nvmf_rdma_transport {
496 	struct spdk_nvmf_transport	transport;
497 	struct rdma_transport_opts	rdma_opts;
498 
499 	struct spdk_nvmf_rdma_conn_sched conn_sched;
500 
501 	struct rdma_event_channel	*event_channel;
502 
503 	struct spdk_mempool		*data_wr_pool;
504 
505 	pthread_mutex_t			lock;
506 
507 	/* fields used to poll RDMA/IB events */
508 	nfds_t			npoll_fds;
509 	struct pollfd		*poll_fds;
510 
511 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
512 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
513 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
514 };
515 
516 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
517 	{
518 		"num_cqe", offsetof(struct rdma_transport_opts, num_cqe),
519 		spdk_json_decode_int32, true
520 	},
521 	{
522 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
523 		spdk_json_decode_uint32, true
524 	},
525 	{
526 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
527 		spdk_json_decode_bool, true
528 	},
529 	{
530 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
531 		spdk_json_decode_bool, true
532 	},
533 	{
534 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
535 		spdk_json_decode_int32, true
536 	},
537 };
538 
539 static bool
540 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
541 			  struct spdk_nvmf_rdma_request *rdma_req);
542 
543 static void
544 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
545 		     struct spdk_nvmf_rdma_poller *rpoller);
546 
547 static void
548 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
549 		     struct spdk_nvmf_rdma_poller *rpoller);
550 
551 static inline int
552 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
553 {
554 	switch (state) {
555 	case IBV_QPS_RESET:
556 	case IBV_QPS_INIT:
557 	case IBV_QPS_RTR:
558 	case IBV_QPS_RTS:
559 	case IBV_QPS_SQD:
560 	case IBV_QPS_SQE:
561 	case IBV_QPS_ERR:
562 		return 0;
563 	default:
564 		return -1;
565 	}
566 }
567 
568 static inline enum spdk_nvme_media_error_status_code
569 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
570 	enum spdk_nvme_media_error_status_code result;
571 	switch (err_type)
572 	{
573 	case SPDK_DIF_REFTAG_ERROR:
574 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
575 		break;
576 	case SPDK_DIF_APPTAG_ERROR:
577 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
578 		break;
579 	case SPDK_DIF_GUARD_ERROR:
580 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
581 		break;
582 	default:
583 		SPDK_UNREACHABLE();
584 	}
585 
586 	return result;
587 }
588 
589 static enum ibv_qp_state
590 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
591 	enum ibv_qp_state old_state, new_state;
592 	struct ibv_qp_attr qp_attr;
593 	struct ibv_qp_init_attr init_attr;
594 	int rc;
595 
596 	old_state = rqpair->ibv_state;
597 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
598 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
599 
600 	if (rc)
601 	{
602 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
603 		return IBV_QPS_ERR + 1;
604 	}
605 
606 	new_state = qp_attr.qp_state;
607 	rqpair->ibv_state = new_state;
608 	qp_attr.ah_attr.port_num = qp_attr.port_num;
609 
610 	rc = nvmf_rdma_check_ibv_state(new_state);
611 	if (rc)
612 	{
613 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
614 		/*
615 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
616 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
617 		 */
618 		return IBV_QPS_ERR + 1;
619 	}
620 
621 	if (old_state != new_state)
622 	{
623 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
624 				  (uintptr_t)rqpair->cm_id, new_state);
625 	}
626 	return new_state;
627 }
628 
629 static void
630 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
631 			    struct spdk_nvmf_rdma_transport *rtransport)
632 {
633 	struct spdk_nvmf_rdma_request_data	*data_wr;
634 	struct ibv_send_wr			*next_send_wr;
635 	uint64_t				req_wrid;
636 
637 	rdma_req->num_outstanding_data_wr = 0;
638 	data_wr = &rdma_req->data;
639 	req_wrid = data_wr->wr.wr_id;
640 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
641 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
642 		data_wr->wr.num_sge = 0;
643 		next_send_wr = data_wr->wr.next;
644 		if (data_wr != &rdma_req->data) {
645 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
646 		}
647 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
648 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
649 	}
650 }
651 
652 static void
653 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
654 {
655 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
656 	if (req->req.cmd) {
657 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
658 	}
659 	if (req->recv) {
660 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
661 	}
662 }
663 
664 static void
665 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
666 {
667 	int i;
668 
669 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
670 	for (i = 0; i < rqpair->max_queue_depth; i++) {
671 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
672 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
673 		}
674 	}
675 }
676 
677 static void
678 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
679 {
680 	if (resources->cmds_mr) {
681 		ibv_dereg_mr(resources->cmds_mr);
682 	}
683 
684 	if (resources->cpls_mr) {
685 		ibv_dereg_mr(resources->cpls_mr);
686 	}
687 
688 	if (resources->bufs_mr) {
689 		ibv_dereg_mr(resources->bufs_mr);
690 	}
691 
692 	spdk_free(resources->cmds);
693 	spdk_free(resources->cpls);
694 	spdk_free(resources->bufs);
695 	free(resources->reqs);
696 	free(resources->recvs);
697 	free(resources);
698 }
699 
700 
701 static struct spdk_nvmf_rdma_resources *
702 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
703 {
704 	struct spdk_nvmf_rdma_resources	*resources;
705 	struct spdk_nvmf_rdma_request	*rdma_req;
706 	struct spdk_nvmf_rdma_recv	*rdma_recv;
707 	struct spdk_rdma_qp		*qp = NULL;
708 	struct spdk_rdma_srq		*srq = NULL;
709 	struct ibv_recv_wr		*bad_wr = NULL;
710 	uint32_t			i;
711 	int				rc = 0;
712 
713 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
714 	if (!resources) {
715 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
716 		return NULL;
717 	}
718 
719 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
720 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
721 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
722 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
723 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
724 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
725 
726 	if (opts->in_capsule_data_size > 0) {
727 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
728 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
729 					       SPDK_MALLOC_DMA);
730 	}
731 
732 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
733 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
734 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
735 		goto cleanup;
736 	}
737 
738 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
739 					opts->max_queue_depth * sizeof(*resources->cmds),
740 					IBV_ACCESS_LOCAL_WRITE);
741 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
742 					opts->max_queue_depth * sizeof(*resources->cpls),
743 					0);
744 
745 	if (opts->in_capsule_data_size) {
746 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
747 						opts->max_queue_depth *
748 						opts->in_capsule_data_size,
749 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
750 	}
751 
752 	if (!resources->cmds_mr || !resources->cpls_mr ||
753 	    (opts->in_capsule_data_size &&
754 	     !resources->bufs_mr)) {
755 		goto cleanup;
756 	}
757 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
758 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
759 		      resources->cmds_mr->lkey);
760 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
761 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
762 		      resources->cpls_mr->lkey);
763 	if (resources->bufs && resources->bufs_mr) {
764 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
765 			      resources->bufs, opts->max_queue_depth *
766 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
767 	}
768 
769 	/* Initialize queues */
770 	STAILQ_INIT(&resources->incoming_queue);
771 	STAILQ_INIT(&resources->free_queue);
772 
773 	if (opts->shared) {
774 		srq = (struct spdk_rdma_srq *)opts->qp;
775 	} else {
776 		qp = (struct spdk_rdma_qp *)opts->qp;
777 	}
778 
779 	for (i = 0; i < opts->max_queue_depth; i++) {
780 		rdma_recv = &resources->recvs[i];
781 		rdma_recv->qpair = opts->qpair;
782 
783 		/* Set up memory to receive commands */
784 		if (resources->bufs) {
785 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
786 						  opts->in_capsule_data_size));
787 		}
788 
789 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
790 
791 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
792 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
793 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
794 		rdma_recv->wr.num_sge = 1;
795 
796 		if (rdma_recv->buf && resources->bufs_mr) {
797 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
798 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
799 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
800 			rdma_recv->wr.num_sge++;
801 		}
802 
803 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
804 		rdma_recv->wr.sg_list = rdma_recv->sgl;
805 		if (srq) {
806 			spdk_rdma_srq_queue_recv_wrs(srq, &rdma_recv->wr);
807 		} else {
808 			spdk_rdma_qp_queue_recv_wrs(qp, &rdma_recv->wr);
809 		}
810 	}
811 
812 	for (i = 0; i < opts->max_queue_depth; i++) {
813 		rdma_req = &resources->reqs[i];
814 
815 		if (opts->qpair != NULL) {
816 			rdma_req->req.qpair = &opts->qpair->qpair;
817 		} else {
818 			rdma_req->req.qpair = NULL;
819 		}
820 		rdma_req->req.cmd = NULL;
821 
822 		/* Set up memory to send responses */
823 		rdma_req->req.rsp = &resources->cpls[i];
824 
825 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
826 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
827 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
828 
829 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
830 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
831 		rdma_req->rsp.wr.next = NULL;
832 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
833 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
834 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
835 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
836 
837 		/* Set up memory for data buffers */
838 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
839 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
840 		rdma_req->data.wr.next = NULL;
841 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
842 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
843 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
844 
845 		/* Initialize request state to FREE */
846 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
847 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
848 	}
849 
850 	if (srq) {
851 		rc = spdk_rdma_srq_flush_recv_wrs(srq, &bad_wr);
852 	} else {
853 		rc = spdk_rdma_qp_flush_recv_wrs(qp, &bad_wr);
854 	}
855 
856 	if (rc) {
857 		goto cleanup;
858 	}
859 
860 	return resources;
861 
862 cleanup:
863 	nvmf_rdma_resources_destroy(resources);
864 	return NULL;
865 }
866 
867 static void
868 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
869 {
870 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
871 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
872 		ctx->rqpair = NULL;
873 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
874 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
875 	}
876 }
877 
878 static void
879 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
880 {
881 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
882 	struct ibv_recv_wr		*bad_recv_wr = NULL;
883 	int				rc;
884 
885 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
886 
887 	if (rqpair->qd != 0) {
888 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
889 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
890 				struct spdk_nvmf_rdma_transport, transport);
891 		struct spdk_nvmf_rdma_request *req;
892 		uint32_t i, max_req_count = 0;
893 
894 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
895 
896 		if (rqpair->srq == NULL) {
897 			nvmf_rdma_dump_qpair_contents(rqpair);
898 			max_req_count = rqpair->max_queue_depth;
899 		} else if (rqpair->poller && rqpair->resources) {
900 			max_req_count = rqpair->poller->max_srq_depth;
901 		}
902 
903 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
904 		for (i = 0; i < max_req_count; i++) {
905 			req = &rqpair->resources->reqs[i];
906 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
907 				/* nvmf_rdma_request_process checks qpair ibv and internal state
908 				 * and completes a request */
909 				nvmf_rdma_request_process(rtransport, req);
910 			}
911 		}
912 		assert(rqpair->qd == 0);
913 	}
914 
915 	if (rqpair->poller) {
916 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
917 
918 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
919 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
920 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
921 				if (rqpair == rdma_recv->qpair) {
922 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
923 					spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_recv->wr);
924 					rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
925 					if (rc) {
926 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
927 					}
928 				}
929 			}
930 		}
931 	}
932 
933 	if (rqpair->cm_id) {
934 		if (rqpair->rdma_qp != NULL) {
935 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
936 			rqpair->rdma_qp = NULL;
937 		}
938 		rdma_destroy_id(rqpair->cm_id);
939 
940 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
941 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
942 		}
943 	}
944 
945 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
946 		nvmf_rdma_resources_destroy(rqpair->resources);
947 	}
948 
949 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
950 
951 	if (rqpair->destruct_channel) {
952 		spdk_put_io_channel(rqpair->destruct_channel);
953 		rqpair->destruct_channel = NULL;
954 	}
955 
956 	free(rqpair);
957 }
958 
959 static int
960 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
961 {
962 	struct spdk_nvmf_rdma_poller	*rpoller;
963 	int				rc, num_cqe, required_num_wr;
964 
965 	/* Enlarge CQ size dynamically */
966 	rpoller = rqpair->poller;
967 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
968 	num_cqe = rpoller->num_cqe;
969 	if (num_cqe < required_num_wr) {
970 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
971 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
972 	}
973 
974 	if (rpoller->num_cqe != num_cqe) {
975 		if (device->context->device->transport_type == IBV_TRANSPORT_IWARP) {
976 			SPDK_ERRLOG("iWARP doesn't support CQ resize. Current capacity %u, required %u\n"
977 				    "Using CQ of insufficient size may lead to CQ overrun\n", rpoller->num_cqe, num_cqe);
978 			return -1;
979 		}
980 		if (required_num_wr > device->attr.max_cqe) {
981 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
982 				    required_num_wr, device->attr.max_cqe);
983 			return -1;
984 		}
985 
986 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
987 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
988 		if (rc) {
989 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
990 			return -1;
991 		}
992 
993 		rpoller->num_cqe = num_cqe;
994 	}
995 
996 	rpoller->required_num_wr = required_num_wr;
997 	return 0;
998 }
999 
1000 static int
1001 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
1002 {
1003 	struct spdk_nvmf_rdma_qpair		*rqpair;
1004 	struct spdk_nvmf_rdma_transport		*rtransport;
1005 	struct spdk_nvmf_transport		*transport;
1006 	struct spdk_nvmf_rdma_resource_opts	opts;
1007 	struct spdk_nvmf_rdma_device		*device;
1008 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
1009 
1010 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1011 	device = rqpair->device;
1012 
1013 	qp_init_attr.qp_context	= rqpair;
1014 	qp_init_attr.pd		= device->pd;
1015 	qp_init_attr.send_cq	= rqpair->poller->cq;
1016 	qp_init_attr.recv_cq	= rqpair->poller->cq;
1017 
1018 	if (rqpair->srq) {
1019 		qp_init_attr.srq		= rqpair->srq->srq;
1020 	} else {
1021 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
1022 	}
1023 
1024 	/* SEND, READ, and WRITE operations */
1025 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
1026 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1027 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1028 	qp_init_attr.stats		= &rqpair->poller->stat.qp_stats;
1029 
1030 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1031 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1032 		goto error;
1033 	}
1034 
1035 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1036 	if (!rqpair->rdma_qp) {
1037 		goto error;
1038 	}
1039 
1040 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1041 					  qp_init_attr.cap.max_send_wr);
1042 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1043 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1044 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1045 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1046 
1047 	if (rqpair->poller->srq == NULL) {
1048 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1049 		transport = &rtransport->transport;
1050 
1051 		opts.qp = rqpair->rdma_qp;
1052 		opts.pd = rqpair->cm_id->pd;
1053 		opts.qpair = rqpair;
1054 		opts.shared = false;
1055 		opts.max_queue_depth = rqpair->max_queue_depth;
1056 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1057 
1058 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1059 
1060 		if (!rqpair->resources) {
1061 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1062 			rdma_destroy_qp(rqpair->cm_id);
1063 			goto error;
1064 		}
1065 	} else {
1066 		rqpair->resources = rqpair->poller->resources;
1067 	}
1068 
1069 	rqpair->current_recv_depth = 0;
1070 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1071 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1072 
1073 	return 0;
1074 
1075 error:
1076 	rdma_destroy_id(rqpair->cm_id);
1077 	rqpair->cm_id = NULL;
1078 	return -1;
1079 }
1080 
1081 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1082 /* This function accepts either a single wr or the first wr in a linked list. */
1083 static void
1084 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1085 {
1086 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1087 			struct spdk_nvmf_rdma_transport, transport);
1088 
1089 	if (rqpair->srq != NULL) {
1090 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, first);
1091 	} else {
1092 		if (spdk_rdma_qp_queue_recv_wrs(rqpair->rdma_qp, first)) {
1093 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1094 		}
1095 	}
1096 
1097 	if (rtransport->rdma_opts.no_wr_batching) {
1098 		_poller_submit_recvs(rtransport, rqpair->poller);
1099 	}
1100 }
1101 
1102 static int
1103 request_transfer_in(struct spdk_nvmf_request *req)
1104 {
1105 	struct spdk_nvmf_rdma_request	*rdma_req;
1106 	struct spdk_nvmf_qpair		*qpair;
1107 	struct spdk_nvmf_rdma_qpair	*rqpair;
1108 	struct spdk_nvmf_rdma_transport *rtransport;
1109 
1110 	qpair = req->qpair;
1111 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1112 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1113 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1114 				      struct spdk_nvmf_rdma_transport, transport);
1115 
1116 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1117 	assert(rdma_req != NULL);
1118 
1119 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1120 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1121 	}
1122 	if (rtransport->rdma_opts.no_wr_batching) {
1123 		_poller_submit_sends(rtransport, rqpair->poller);
1124 	}
1125 
1126 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1127 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1128 	return 0;
1129 }
1130 
1131 static int
1132 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1133 {
1134 	int				num_outstanding_data_wr = 0;
1135 	struct spdk_nvmf_rdma_request	*rdma_req;
1136 	struct spdk_nvmf_qpair		*qpair;
1137 	struct spdk_nvmf_rdma_qpair	*rqpair;
1138 	struct spdk_nvme_cpl		*rsp;
1139 	struct ibv_send_wr		*first = NULL;
1140 	struct spdk_nvmf_rdma_transport *rtransport;
1141 
1142 	*data_posted = 0;
1143 	qpair = req->qpair;
1144 	rsp = &req->rsp->nvme_cpl;
1145 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1146 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1147 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1148 				      struct spdk_nvmf_rdma_transport, transport);
1149 
1150 	/* Advance our sq_head pointer */
1151 	if (qpair->sq_head == qpair->sq_head_max) {
1152 		qpair->sq_head = 0;
1153 	} else {
1154 		qpair->sq_head++;
1155 	}
1156 	rsp->sqhd = qpair->sq_head;
1157 
1158 	/* queue the capsule for the recv buffer */
1159 	assert(rdma_req->recv != NULL);
1160 
1161 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1162 
1163 	rdma_req->recv = NULL;
1164 	assert(rqpair->current_recv_depth > 0);
1165 	rqpair->current_recv_depth--;
1166 
1167 	/* Build the response which consists of optional
1168 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1169 	 * containing the response.
1170 	 */
1171 	first = &rdma_req->rsp.wr;
1172 
1173 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1174 		/* On failure, data was not read from the controller. So clear the
1175 		 * number of outstanding data WRs to zero.
1176 		 */
1177 		rdma_req->num_outstanding_data_wr = 0;
1178 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1179 		first = &rdma_req->data.wr;
1180 		*data_posted = 1;
1181 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1182 	}
1183 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1184 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1185 	}
1186 	if (rtransport->rdma_opts.no_wr_batching) {
1187 		_poller_submit_sends(rtransport, rqpair->poller);
1188 	}
1189 
1190 	/* +1 for the rsp wr */
1191 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1192 
1193 	return 0;
1194 }
1195 
1196 static int
1197 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1198 {
1199 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1200 	struct rdma_conn_param				ctrlr_event_data = {};
1201 	int						rc;
1202 
1203 	accept_data.recfmt = 0;
1204 	accept_data.crqsize = rqpair->max_queue_depth;
1205 
1206 	ctrlr_event_data.private_data = &accept_data;
1207 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1208 	if (id->ps == RDMA_PS_TCP) {
1209 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1210 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1211 	}
1212 
1213 	/* Configure infinite retries for the initiator side qpair.
1214 	 * When using a shared receive queue on the target side,
1215 	 * we need to pass this value to the initiator to prevent the
1216 	 * initiator side NIC from completing SEND requests back to the
1217 	 * initiator with status rnr_retry_count_exceeded. */
1218 	if (rqpair->srq != NULL) {
1219 		ctrlr_event_data.rnr_retry_count = 0x7;
1220 	}
1221 
1222 	/* When qpair is created without use of rdma cm API, an additional
1223 	 * information must be provided to initiator in the connection response:
1224 	 * whether qpair is using SRQ and its qp_num
1225 	 * Fields below are ignored by rdma cm if qpair has been
1226 	 * created using rdma cm API. */
1227 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1228 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1229 
1230 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1231 	if (rc) {
1232 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1233 	} else {
1234 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1235 	}
1236 
1237 	return rc;
1238 }
1239 
1240 static void
1241 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1242 {
1243 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1244 
1245 	rej_data.recfmt = 0;
1246 	rej_data.sts = error;
1247 
1248 	rdma_reject(id, &rej_data, sizeof(rej_data));
1249 }
1250 
1251 static int
1252 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1253 {
1254 	struct spdk_nvmf_rdma_transport *rtransport;
1255 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1256 	struct spdk_nvmf_rdma_port	*port;
1257 	struct rdma_conn_param		*rdma_param = NULL;
1258 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1259 	uint16_t			max_queue_depth;
1260 	uint16_t			max_read_depth;
1261 
1262 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1263 
1264 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1265 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1266 
1267 	rdma_param = &event->param.conn;
1268 	if (rdma_param->private_data == NULL ||
1269 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1270 		SPDK_ERRLOG("connect request: no private data provided\n");
1271 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1272 		return -1;
1273 	}
1274 
1275 	private_data = rdma_param->private_data;
1276 	if (private_data->recfmt != 0) {
1277 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1278 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1279 		return -1;
1280 	}
1281 
1282 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1283 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1284 
1285 	port = event->listen_id->context;
1286 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1287 		      event->listen_id, event->listen_id->verbs, port);
1288 
1289 	/* Figure out the supported queue depth. This is a multi-step process
1290 	 * that takes into account hardware maximums, host provided values,
1291 	 * and our target's internal memory limits */
1292 
1293 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1294 
1295 	/* Start with the maximum queue depth allowed by the target */
1296 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1297 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1298 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1299 		      rtransport->transport.opts.max_queue_depth);
1300 
1301 	/* Next check the local NIC's hardware limitations */
1302 	SPDK_DEBUGLOG(rdma,
1303 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1304 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1305 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1306 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1307 
1308 	/* Next check the remote NIC's hardware limitations */
1309 	SPDK_DEBUGLOG(rdma,
1310 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1311 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1312 	if (rdma_param->initiator_depth > 0) {
1313 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1314 	}
1315 
1316 	/* Finally check for the host software requested values, which are
1317 	 * optional. */
1318 	if (rdma_param->private_data != NULL &&
1319 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1320 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1321 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1322 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1323 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1324 	}
1325 
1326 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1327 		      max_queue_depth, max_read_depth);
1328 
1329 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1330 	if (rqpair == NULL) {
1331 		SPDK_ERRLOG("Could not allocate new connection.\n");
1332 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1333 		return -1;
1334 	}
1335 
1336 	rqpair->device = port->device;
1337 	rqpair->max_queue_depth = max_queue_depth;
1338 	rqpair->max_read_depth = max_read_depth;
1339 	rqpair->cm_id = event->id;
1340 	rqpair->listen_id = event->listen_id;
1341 	rqpair->qpair.transport = transport;
1342 	STAILQ_INIT(&rqpair->ibv_events);
1343 	/* use qid from the private data to determine the qpair type
1344 	   qid will be set to the appropriate value when the controller is created */
1345 	rqpair->qpair.qid = private_data->qid;
1346 
1347 	event->id->context = &rqpair->qpair;
1348 
1349 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1350 
1351 	return 0;
1352 }
1353 
1354 static inline void
1355 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1356 		   enum spdk_nvme_data_transfer xfer)
1357 {
1358 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1359 		wr->opcode = IBV_WR_RDMA_WRITE;
1360 		wr->send_flags = 0;
1361 		wr->next = next;
1362 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1363 		wr->opcode = IBV_WR_RDMA_READ;
1364 		wr->send_flags = IBV_SEND_SIGNALED;
1365 		wr->next = NULL;
1366 	} else {
1367 		assert(0);
1368 	}
1369 }
1370 
1371 static int
1372 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1373 		       struct spdk_nvmf_rdma_request *rdma_req,
1374 		       uint32_t num_sgl_descriptors)
1375 {
1376 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1377 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1378 	uint32_t				i;
1379 
1380 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1381 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1382 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1383 		return -EINVAL;
1384 	}
1385 
1386 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1387 		return -ENOMEM;
1388 	}
1389 
1390 	current_data_wr = &rdma_req->data;
1391 
1392 	for (i = 0; i < num_sgl_descriptors; i++) {
1393 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1394 		current_data_wr->wr.next = &work_requests[i]->wr;
1395 		current_data_wr = work_requests[i];
1396 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1397 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1398 	}
1399 
1400 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1401 
1402 	return 0;
1403 }
1404 
1405 static inline void
1406 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1407 {
1408 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1409 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1410 
1411 	wr->wr.rdma.rkey = sgl->keyed.key;
1412 	wr->wr.rdma.remote_addr = sgl->address;
1413 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1414 }
1415 
1416 static inline void
1417 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1418 {
1419 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1420 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1421 	uint32_t			i;
1422 	int				j;
1423 	uint64_t			remote_addr_offset = 0;
1424 
1425 	for (i = 0; i < num_wrs; ++i) {
1426 		wr->wr.rdma.rkey = sgl->keyed.key;
1427 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1428 		for (j = 0; j < wr->num_sge; ++j) {
1429 			remote_addr_offset += wr->sg_list[j].length;
1430 		}
1431 		wr = wr->next;
1432 	}
1433 }
1434 
1435 static bool
1436 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1437 		      struct iovec *iov, struct ibv_send_wr **_wr,
1438 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1439 		      uint32_t *_num_extra_wrs,
1440 		      const struct spdk_dif_ctx *dif_ctx)
1441 {
1442 	struct ibv_send_wr *wr = *_wr;
1443 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1444 	struct spdk_rdma_memory_translation mem_translation;
1445 	int		rc;
1446 	uint32_t	lkey = 0;
1447 	uint32_t	remaining, data_block_size, md_size, sge_len;
1448 
1449 	rc = spdk_rdma_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1450 	if (spdk_unlikely(rc)) {
1451 		return false;
1452 	}
1453 
1454 	lkey = spdk_rdma_memory_translation_get_lkey(&mem_translation);
1455 
1456 	if (spdk_likely(!dif_ctx)) {
1457 		sg_ele->lkey = lkey;
1458 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1459 		sg_ele->length = iov->iov_len;
1460 		wr->num_sge++;
1461 	} else {
1462 		remaining = iov->iov_len - *_offset;
1463 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1464 		md_size = dif_ctx->md_size;
1465 
1466 		while (remaining) {
1467 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1468 				if (*_num_extra_wrs > 0 && wr->next) {
1469 					*_wr = wr->next;
1470 					wr = *_wr;
1471 					wr->num_sge = 0;
1472 					sg_ele = &wr->sg_list[wr->num_sge];
1473 					(*_num_extra_wrs)--;
1474 				} else {
1475 					break;
1476 				}
1477 			}
1478 			sg_ele->lkey = lkey;
1479 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1480 			sge_len = spdk_min(remaining, *_remaining_data_block);
1481 			sg_ele->length = sge_len;
1482 			remaining -= sge_len;
1483 			*_remaining_data_block -= sge_len;
1484 			*_offset += sge_len;
1485 
1486 			sg_ele++;
1487 			wr->num_sge++;
1488 
1489 			if (*_remaining_data_block == 0) {
1490 				/* skip metadata */
1491 				*_offset += md_size;
1492 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1493 				remaining -= spdk_min(remaining, md_size);
1494 				*_remaining_data_block = data_block_size;
1495 			}
1496 
1497 			if (remaining == 0) {
1498 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1499 				   the remaining metadata bits at the beginning of the next buffer */
1500 				*_offset -= iov->iov_len;
1501 			}
1502 		}
1503 	}
1504 
1505 	return true;
1506 }
1507 
1508 static int
1509 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1510 		      struct spdk_nvmf_rdma_device *device,
1511 		      struct spdk_nvmf_rdma_request *rdma_req,
1512 		      struct ibv_send_wr *wr,
1513 		      uint32_t length,
1514 		      uint32_t num_extra_wrs)
1515 {
1516 	struct spdk_nvmf_request *req = &rdma_req->req;
1517 	struct spdk_dif_ctx *dif_ctx = NULL;
1518 	uint32_t remaining_data_block = 0;
1519 	uint32_t offset = 0;
1520 
1521 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1522 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1523 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1524 	}
1525 
1526 	wr->num_sge = 0;
1527 
1528 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1529 		if (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1530 				  &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1531 			return -EINVAL;
1532 		}
1533 
1534 		length -= req->iov[rdma_req->iovpos].iov_len;
1535 		rdma_req->iovpos++;
1536 	}
1537 
1538 	if (length) {
1539 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1540 		return -EINVAL;
1541 	}
1542 
1543 	return 0;
1544 }
1545 
1546 static inline uint32_t
1547 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1548 {
1549 	/* estimate the number of SG entries and WRs needed to process the request */
1550 	uint32_t num_sge = 0;
1551 	uint32_t i;
1552 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1553 
1554 	for (i = 0; i < num_buffers && length > 0; i++) {
1555 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1556 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1557 
1558 		if (num_sge_in_block * block_size > buffer_len) {
1559 			++num_sge_in_block;
1560 		}
1561 		num_sge += num_sge_in_block;
1562 		length -= buffer_len;
1563 	}
1564 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1565 }
1566 
1567 static int
1568 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1569 			    struct spdk_nvmf_rdma_device *device,
1570 			    struct spdk_nvmf_rdma_request *rdma_req,
1571 			    uint32_t length)
1572 {
1573 	struct spdk_nvmf_rdma_qpair		*rqpair;
1574 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1575 	struct spdk_nvmf_request		*req = &rdma_req->req;
1576 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1577 	int					rc;
1578 	uint32_t				num_wrs = 1;
1579 
1580 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1581 	rgroup = rqpair->poller->group;
1582 
1583 	/* rdma wr specifics */
1584 	nvmf_rdma_setup_request(rdma_req);
1585 
1586 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1587 					   length);
1588 	if (rc != 0) {
1589 		return rc;
1590 	}
1591 
1592 	assert(req->iovcnt <= rqpair->max_send_sge);
1593 
1594 	rdma_req->iovpos = 0;
1595 
1596 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1597 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1598 						 req->dif.dif_ctx.block_size);
1599 		if (num_wrs > 1) {
1600 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1601 			if (rc != 0) {
1602 				goto err_exit;
1603 			}
1604 		}
1605 	}
1606 
1607 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1608 	if (spdk_unlikely(rc != 0)) {
1609 		goto err_exit;
1610 	}
1611 
1612 	if (spdk_unlikely(num_wrs > 1)) {
1613 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1614 	}
1615 
1616 	/* set the number of outstanding data WRs for this request. */
1617 	rdma_req->num_outstanding_data_wr = num_wrs;
1618 
1619 	return rc;
1620 
1621 err_exit:
1622 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1623 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1624 	req->iovcnt = 0;
1625 	return rc;
1626 }
1627 
1628 static int
1629 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1630 				      struct spdk_nvmf_rdma_device *device,
1631 				      struct spdk_nvmf_rdma_request *rdma_req)
1632 {
1633 	struct spdk_nvmf_rdma_qpair		*rqpair;
1634 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1635 	struct ibv_send_wr			*current_wr;
1636 	struct spdk_nvmf_request		*req = &rdma_req->req;
1637 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1638 	uint32_t				num_sgl_descriptors;
1639 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1640 	uint32_t				i;
1641 	int					rc;
1642 
1643 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1644 	rgroup = rqpair->poller->group;
1645 
1646 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1647 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1648 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1649 
1650 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1651 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1652 
1653 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1654 		return -ENOMEM;
1655 	}
1656 
1657 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1658 	for (i = 0; i < num_sgl_descriptors; i++) {
1659 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1660 			lengths[i] = desc->keyed.length;
1661 		} else {
1662 			req->dif.orig_length += desc->keyed.length;
1663 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1664 			req->dif.elba_length += lengths[i];
1665 		}
1666 		desc++;
1667 	}
1668 
1669 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1670 			lengths, num_sgl_descriptors);
1671 	if (rc != 0) {
1672 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1673 		return rc;
1674 	}
1675 
1676 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1677 	current_wr = &rdma_req->data.wr;
1678 	assert(current_wr != NULL);
1679 
1680 	req->length = 0;
1681 	rdma_req->iovpos = 0;
1682 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1683 	for (i = 0; i < num_sgl_descriptors; i++) {
1684 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1685 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1686 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1687 			rc = -EINVAL;
1688 			goto err_exit;
1689 		}
1690 
1691 		current_wr->num_sge = 0;
1692 
1693 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1694 		if (rc != 0) {
1695 			rc = -ENOMEM;
1696 			goto err_exit;
1697 		}
1698 
1699 		req->length += desc->keyed.length;
1700 		current_wr->wr.rdma.rkey = desc->keyed.key;
1701 		current_wr->wr.rdma.remote_addr = desc->address;
1702 		current_wr = current_wr->next;
1703 		desc++;
1704 	}
1705 
1706 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1707 	/* Go back to the last descriptor in the list. */
1708 	desc--;
1709 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1710 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1711 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1712 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1713 		}
1714 	}
1715 #endif
1716 
1717 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1718 
1719 	return 0;
1720 
1721 err_exit:
1722 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1723 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1724 	return rc;
1725 }
1726 
1727 static int
1728 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1729 			    struct spdk_nvmf_rdma_device *device,
1730 			    struct spdk_nvmf_rdma_request *rdma_req)
1731 {
1732 	struct spdk_nvmf_request		*req = &rdma_req->req;
1733 	struct spdk_nvme_cpl			*rsp;
1734 	struct spdk_nvme_sgl_descriptor		*sgl;
1735 	int					rc;
1736 	uint32_t				length;
1737 
1738 	rsp = &req->rsp->nvme_cpl;
1739 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1740 
1741 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1742 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1743 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1744 
1745 		length = sgl->keyed.length;
1746 		if (length > rtransport->transport.opts.max_io_size) {
1747 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1748 				    length, rtransport->transport.opts.max_io_size);
1749 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1750 			return -1;
1751 		}
1752 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1753 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1754 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1755 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1756 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1757 			}
1758 		}
1759 #endif
1760 
1761 		/* fill request length and populate iovs */
1762 		req->length = length;
1763 
1764 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1765 			req->dif.orig_length = length;
1766 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1767 			req->dif.elba_length = length;
1768 		}
1769 
1770 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1771 		if (spdk_unlikely(rc < 0)) {
1772 			if (rc == -EINVAL) {
1773 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1774 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1775 				return -1;
1776 			}
1777 			/* No available buffers. Queue this request up. */
1778 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1779 			return 0;
1780 		}
1781 
1782 		/* backward compatible */
1783 		req->data = req->iov[0].iov_base;
1784 
1785 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1786 			      req->iovcnt);
1787 
1788 		return 0;
1789 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1790 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1791 		uint64_t offset = sgl->address;
1792 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1793 
1794 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1795 			      offset, sgl->unkeyed.length);
1796 
1797 		if (offset > max_len) {
1798 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1799 				    offset, max_len);
1800 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1801 			return -1;
1802 		}
1803 		max_len -= (uint32_t)offset;
1804 
1805 		if (sgl->unkeyed.length > max_len) {
1806 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1807 				    sgl->unkeyed.length, max_len);
1808 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1809 			return -1;
1810 		}
1811 
1812 		rdma_req->num_outstanding_data_wr = 0;
1813 		req->data = rdma_req->recv->buf + offset;
1814 		req->data_from_pool = false;
1815 		req->length = sgl->unkeyed.length;
1816 
1817 		req->iov[0].iov_base = req->data;
1818 		req->iov[0].iov_len = req->length;
1819 		req->iovcnt = 1;
1820 
1821 		return 0;
1822 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1823 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1824 
1825 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1826 		if (rc == -ENOMEM) {
1827 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1828 			return 0;
1829 		} else if (rc == -EINVAL) {
1830 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1831 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1832 			return -1;
1833 		}
1834 
1835 		/* backward compatible */
1836 		req->data = req->iov[0].iov_base;
1837 
1838 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1839 			      req->iovcnt);
1840 
1841 		return 0;
1842 	}
1843 
1844 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1845 		    sgl->generic.type, sgl->generic.subtype);
1846 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1847 	return -1;
1848 }
1849 
1850 static void
1851 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1852 			struct spdk_nvmf_rdma_transport	*rtransport)
1853 {
1854 	struct spdk_nvmf_rdma_qpair		*rqpair;
1855 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1856 
1857 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1858 	if (rdma_req->req.data_from_pool) {
1859 		rgroup = rqpair->poller->group;
1860 
1861 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1862 	}
1863 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1864 	rdma_req->req.length = 0;
1865 	rdma_req->req.iovcnt = 0;
1866 	rdma_req->req.data = NULL;
1867 	rdma_req->rsp.wr.next = NULL;
1868 	rdma_req->data.wr.next = NULL;
1869 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1870 	rqpair->qd--;
1871 
1872 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1873 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1874 }
1875 
1876 bool
1877 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1878 			  struct spdk_nvmf_rdma_request *rdma_req)
1879 {
1880 	struct spdk_nvmf_rdma_qpair	*rqpair;
1881 	struct spdk_nvmf_rdma_device	*device;
1882 	struct spdk_nvmf_rdma_poll_group *rgroup;
1883 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1884 	int				rc;
1885 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1886 	enum spdk_nvmf_rdma_request_state prev_state;
1887 	bool				progress = false;
1888 	int				data_posted;
1889 	uint32_t			num_blocks;
1890 
1891 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1892 	device = rqpair->device;
1893 	rgroup = rqpair->poller->group;
1894 
1895 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1896 
1897 	/* If the queue pair is in an error state, force the request to the completed state
1898 	 * to release resources. */
1899 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1900 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1901 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1902 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1903 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1904 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1905 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1906 		}
1907 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1908 	}
1909 
1910 	/* The loop here is to allow for several back-to-back state changes. */
1911 	do {
1912 		prev_state = rdma_req->state;
1913 
1914 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
1915 
1916 		switch (rdma_req->state) {
1917 		case RDMA_REQUEST_STATE_FREE:
1918 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1919 			 * to escape this state. */
1920 			break;
1921 		case RDMA_REQUEST_STATE_NEW:
1922 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1923 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1924 			rdma_recv = rdma_req->recv;
1925 
1926 			/* The first element of the SGL is the NVMe command */
1927 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1928 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1929 
1930 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1931 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1932 				break;
1933 			}
1934 
1935 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
1936 				rdma_req->req.dif.dif_insert_or_strip = true;
1937 			}
1938 
1939 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1940 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1941 			rdma_req->rsp.wr.imm_data = 0;
1942 #endif
1943 
1944 			/* The next state transition depends on the data transfer needs of this request. */
1945 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
1946 
1947 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
1948 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
1949 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
1950 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1951 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
1952 				break;
1953 			}
1954 
1955 			/* If no data to transfer, ready to execute. */
1956 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1957 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1958 				break;
1959 			}
1960 
1961 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1962 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
1963 			break;
1964 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1965 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1966 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1967 
1968 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1969 
1970 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
1971 				/* This request needs to wait in line to obtain a buffer */
1972 				break;
1973 			}
1974 
1975 			/* Try to get a data buffer */
1976 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1977 			if (rc < 0) {
1978 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1979 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1980 				break;
1981 			}
1982 
1983 			if (!rdma_req->req.data) {
1984 				/* No buffers available. */
1985 				rgroup->stat.pending_data_buffer++;
1986 				break;
1987 			}
1988 
1989 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1990 
1991 			/* If data is transferring from host to controller and the data didn't
1992 			 * arrive using in capsule data, we need to do a transfer from the host.
1993 			 */
1994 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
1995 			    rdma_req->req.data_from_pool) {
1996 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1997 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1998 				break;
1999 			}
2000 
2001 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2002 			break;
2003 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2004 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2005 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2006 
2007 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2008 				/* This request needs to wait in line to perform RDMA */
2009 				break;
2010 			}
2011 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2012 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2013 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2014 				rqpair->poller->stat.pending_rdma_read++;
2015 				break;
2016 			}
2017 
2018 			/* We have already verified that this request is the head of the queue. */
2019 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2020 
2021 			rc = request_transfer_in(&rdma_req->req);
2022 			if (!rc) {
2023 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2024 			} else {
2025 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2026 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2027 			}
2028 			break;
2029 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2030 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2031 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2032 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2033 			 * to escape this state. */
2034 			break;
2035 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2036 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2037 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2038 
2039 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2040 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2041 					/* generate DIF for write operation */
2042 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2043 					assert(num_blocks > 0);
2044 
2045 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2046 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2047 					if (rc != 0) {
2048 						SPDK_ERRLOG("DIF generation failed\n");
2049 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2050 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2051 						break;
2052 					}
2053 				}
2054 
2055 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2056 				/* set extended length before IO operation */
2057 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2058 			}
2059 
2060 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2061 			spdk_nvmf_request_exec(&rdma_req->req);
2062 			break;
2063 		case RDMA_REQUEST_STATE_EXECUTING:
2064 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2065 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2066 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2067 			 * to escape this state. */
2068 			break;
2069 		case RDMA_REQUEST_STATE_EXECUTED:
2070 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2071 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2072 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2073 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2074 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2075 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2076 			} else {
2077 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2078 			}
2079 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2080 				/* restore the original length */
2081 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2082 
2083 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2084 					struct spdk_dif_error error_blk;
2085 
2086 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2087 
2088 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2089 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2090 					if (rc) {
2091 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2092 
2093 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2094 							    error_blk.err_offset);
2095 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2096 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2097 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2098 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2099 					}
2100 				}
2101 			}
2102 			break;
2103 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2104 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2105 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2106 
2107 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2108 				/* This request needs to wait in line to perform RDMA */
2109 				break;
2110 			}
2111 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2112 			    rqpair->max_send_depth) {
2113 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2114 				 * +1 since each request has an additional wr in the resp. */
2115 				rqpair->poller->stat.pending_rdma_write++;
2116 				break;
2117 			}
2118 
2119 			/* We have already verified that this request is the head of the queue. */
2120 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2121 
2122 			/* The data transfer will be kicked off from
2123 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2124 			 */
2125 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2126 			break;
2127 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2128 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2129 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2130 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2131 			assert(rc == 0); /* No good way to handle this currently */
2132 			if (rc) {
2133 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2134 			} else {
2135 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2136 						  RDMA_REQUEST_STATE_COMPLETING;
2137 			}
2138 			break;
2139 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2140 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2141 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2142 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2143 			 * to escape this state. */
2144 			break;
2145 		case RDMA_REQUEST_STATE_COMPLETING:
2146 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2147 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2148 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2149 			 * to escape this state. */
2150 			break;
2151 		case RDMA_REQUEST_STATE_COMPLETED:
2152 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2153 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2154 
2155 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2156 			_nvmf_rdma_request_free(rdma_req, rtransport);
2157 			break;
2158 		case RDMA_REQUEST_NUM_STATES:
2159 		default:
2160 			assert(0);
2161 			break;
2162 		}
2163 
2164 		if (rdma_req->state != prev_state) {
2165 			progress = true;
2166 		}
2167 	} while (rdma_req->state != prev_state);
2168 
2169 	return progress;
2170 }
2171 
2172 /* Public API callbacks begin here */
2173 
2174 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2175 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2176 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2177 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2178 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2179 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2180 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2181 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2182 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2183 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2184 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2185 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2186 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2187 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2188 
2189 static void
2190 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2191 {
2192 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2193 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2194 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2195 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2196 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2197 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2198 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2199 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2200 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2201 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2202 	opts->transport_specific =      NULL;
2203 }
2204 
2205 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2206 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2207 
2208 static inline bool
2209 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2210 {
2211 	return device->attr.vendor_id == NVMF_RXE_VENDOR_ID_OLD ||
2212 	       device->attr.vendor_id == NVMF_RXE_VENDOR_ID_NEW;
2213 }
2214 
2215 static struct spdk_nvmf_transport *
2216 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2217 {
2218 	int rc;
2219 	struct spdk_nvmf_rdma_transport *rtransport;
2220 	struct spdk_nvmf_rdma_device	*device, *tmp;
2221 	struct ibv_context		**contexts;
2222 	uint32_t			i;
2223 	int				flag;
2224 	uint32_t			sge_count;
2225 	uint32_t			min_shared_buffers;
2226 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2227 	pthread_mutexattr_t		attr;
2228 
2229 	rtransport = calloc(1, sizeof(*rtransport));
2230 	if (!rtransport) {
2231 		return NULL;
2232 	}
2233 
2234 	if (pthread_mutexattr_init(&attr)) {
2235 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2236 		free(rtransport);
2237 		return NULL;
2238 	}
2239 
2240 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2241 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2242 		pthread_mutexattr_destroy(&attr);
2243 		free(rtransport);
2244 		return NULL;
2245 	}
2246 
2247 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2248 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2249 		pthread_mutexattr_destroy(&attr);
2250 		free(rtransport);
2251 		return NULL;
2252 	}
2253 
2254 	pthread_mutexattr_destroy(&attr);
2255 
2256 	TAILQ_INIT(&rtransport->devices);
2257 	TAILQ_INIT(&rtransport->ports);
2258 	TAILQ_INIT(&rtransport->poll_groups);
2259 
2260 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2261 	rtransport->rdma_opts.num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2262 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2263 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2264 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2265 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2266 	if (opts->transport_specific != NULL &&
2267 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2268 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2269 					    &rtransport->rdma_opts)) {
2270 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2271 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2272 		return NULL;
2273 	}
2274 
2275 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2276 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2277 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2278 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2279 		     "  num_shared_buffers=%d, num_cqe=%d, max_srq_depth=%d, no_srq=%d,"
2280 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2281 		     opts->max_queue_depth,
2282 		     opts->max_io_size,
2283 		     opts->max_qpairs_per_ctrlr - 1,
2284 		     opts->io_unit_size,
2285 		     opts->in_capsule_data_size,
2286 		     opts->max_aq_depth,
2287 		     opts->num_shared_buffers,
2288 		     rtransport->rdma_opts.num_cqe,
2289 		     rtransport->rdma_opts.max_srq_depth,
2290 		     rtransport->rdma_opts.no_srq,
2291 		     rtransport->rdma_opts.acceptor_backlog,
2292 		     rtransport->rdma_opts.no_wr_batching,
2293 		     opts->abort_timeout_sec);
2294 
2295 	/* I/O unit size cannot be larger than max I/O size */
2296 	if (opts->io_unit_size > opts->max_io_size) {
2297 		opts->io_unit_size = opts->max_io_size;
2298 	}
2299 
2300 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2301 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2302 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2303 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2304 	}
2305 
2306 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2307 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2308 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2309 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2310 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2311 		return NULL;
2312 	}
2313 
2314 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2315 	if (min_shared_buffers > opts->num_shared_buffers) {
2316 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2317 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2318 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2319 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2320 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2321 		return NULL;
2322 	}
2323 
2324 	sge_count = opts->max_io_size / opts->io_unit_size;
2325 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2326 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2327 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2328 		return NULL;
2329 	}
2330 
2331 	rtransport->event_channel = rdma_create_event_channel();
2332 	if (rtransport->event_channel == NULL) {
2333 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2334 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2335 		return NULL;
2336 	}
2337 
2338 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2339 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2340 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2341 			    rtransport->event_channel->fd, spdk_strerror(errno));
2342 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2343 		return NULL;
2344 	}
2345 
2346 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2347 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2348 				   sizeof(struct spdk_nvmf_rdma_request_data),
2349 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2350 				   SPDK_ENV_SOCKET_ID_ANY);
2351 	if (!rtransport->data_wr_pool) {
2352 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2353 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2354 		return NULL;
2355 	}
2356 
2357 	contexts = rdma_get_devices(NULL);
2358 	if (contexts == NULL) {
2359 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2360 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2361 		return NULL;
2362 	}
2363 
2364 	i = 0;
2365 	rc = 0;
2366 	while (contexts[i] != NULL) {
2367 		device = calloc(1, sizeof(*device));
2368 		if (!device) {
2369 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2370 			rc = -ENOMEM;
2371 			break;
2372 		}
2373 		device->context = contexts[i];
2374 		rc = ibv_query_device(device->context, &device->attr);
2375 		if (rc < 0) {
2376 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2377 			free(device);
2378 			break;
2379 
2380 		}
2381 
2382 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2383 
2384 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2385 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2386 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2387 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2388 		}
2389 
2390 		/**
2391 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2392 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2393 		 * but incorrectly reports that it does. There are changes making their way
2394 		 * through the kernel now that will enable this feature. When they are merged,
2395 		 * we can conditionally enable this feature.
2396 		 *
2397 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2398 		 */
2399 		if (nvmf_rdma_is_rxe_device(device)) {
2400 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2401 		}
2402 #endif
2403 
2404 		/* set up device context async ev fd as NON_BLOCKING */
2405 		flag = fcntl(device->context->async_fd, F_GETFL);
2406 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2407 		if (rc < 0) {
2408 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2409 			free(device);
2410 			break;
2411 		}
2412 
2413 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2414 		i++;
2415 
2416 		if (g_nvmf_hooks.get_ibv_pd) {
2417 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2418 		} else {
2419 			device->pd = ibv_alloc_pd(device->context);
2420 		}
2421 
2422 		if (!device->pd) {
2423 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2424 			rc = -ENOMEM;
2425 			break;
2426 		}
2427 
2428 		assert(device->map == NULL);
2429 
2430 		device->map = spdk_rdma_create_mem_map(device->pd, &g_nvmf_hooks);
2431 		if (!device->map) {
2432 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2433 			rc = -ENOMEM;
2434 			break;
2435 		}
2436 
2437 		assert(device->map != NULL);
2438 		assert(device->pd != NULL);
2439 	}
2440 	rdma_free_devices(contexts);
2441 
2442 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2443 		/* divide and round up. */
2444 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2445 
2446 		/* round up to the nearest 4k. */
2447 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2448 
2449 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2450 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2451 			       opts->io_unit_size);
2452 	}
2453 
2454 	if (rc < 0) {
2455 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2456 		return NULL;
2457 	}
2458 
2459 	/* Set up poll descriptor array to monitor events from RDMA and IB
2460 	 * in a single poll syscall
2461 	 */
2462 	rtransport->npoll_fds = i + 1;
2463 	i = 0;
2464 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2465 	if (rtransport->poll_fds == NULL) {
2466 		SPDK_ERRLOG("poll_fds allocation failed\n");
2467 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2468 		return NULL;
2469 	}
2470 
2471 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2472 	rtransport->poll_fds[i++].events = POLLIN;
2473 
2474 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2475 		rtransport->poll_fds[i].fd = device->context->async_fd;
2476 		rtransport->poll_fds[i++].events = POLLIN;
2477 	}
2478 
2479 	return &rtransport->transport;
2480 }
2481 
2482 static void
2483 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2484 {
2485 	struct spdk_nvmf_rdma_transport	*rtransport;
2486 	assert(w != NULL);
2487 
2488 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2489 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2490 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2491 	if (rtransport->rdma_opts.no_srq == true) {
2492 		spdk_json_write_named_int32(w, "num_cqe", rtransport->rdma_opts.num_cqe);
2493 	}
2494 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2495 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2496 }
2497 
2498 static int
2499 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2500 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2501 {
2502 	struct spdk_nvmf_rdma_transport	*rtransport;
2503 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2504 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2505 
2506 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2507 
2508 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2509 		TAILQ_REMOVE(&rtransport->ports, port, link);
2510 		rdma_destroy_id(port->id);
2511 		free(port);
2512 	}
2513 
2514 	if (rtransport->poll_fds != NULL) {
2515 		free(rtransport->poll_fds);
2516 	}
2517 
2518 	if (rtransport->event_channel != NULL) {
2519 		rdma_destroy_event_channel(rtransport->event_channel);
2520 	}
2521 
2522 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2523 		TAILQ_REMOVE(&rtransport->devices, device, link);
2524 		spdk_rdma_free_mem_map(&device->map);
2525 		if (device->pd) {
2526 			if (!g_nvmf_hooks.get_ibv_pd) {
2527 				ibv_dealloc_pd(device->pd);
2528 			}
2529 		}
2530 		free(device);
2531 	}
2532 
2533 	if (rtransport->data_wr_pool != NULL) {
2534 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2535 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2536 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2537 				    spdk_mempool_count(rtransport->data_wr_pool),
2538 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2539 		}
2540 	}
2541 
2542 	spdk_mempool_free(rtransport->data_wr_pool);
2543 
2544 	pthread_mutex_destroy(&rtransport->lock);
2545 	free(rtransport);
2546 
2547 	if (cb_fn) {
2548 		cb_fn(cb_arg);
2549 	}
2550 	return 0;
2551 }
2552 
2553 static int
2554 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2555 			  struct spdk_nvme_transport_id *trid,
2556 			  bool peer);
2557 
2558 static int
2559 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2560 		 struct spdk_nvmf_listen_opts *listen_opts)
2561 {
2562 	struct spdk_nvmf_rdma_transport	*rtransport;
2563 	struct spdk_nvmf_rdma_device	*device;
2564 	struct spdk_nvmf_rdma_port	*port;
2565 	struct addrinfo			*res;
2566 	struct addrinfo			hints;
2567 	int				family;
2568 	int				rc;
2569 
2570 	if (!strlen(trid->trsvcid)) {
2571 		SPDK_ERRLOG("Service id is required\n");
2572 		return -EINVAL;
2573 	}
2574 
2575 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2576 	assert(rtransport->event_channel != NULL);
2577 
2578 	pthread_mutex_lock(&rtransport->lock);
2579 	port = calloc(1, sizeof(*port));
2580 	if (!port) {
2581 		SPDK_ERRLOG("Port allocation failed\n");
2582 		pthread_mutex_unlock(&rtransport->lock);
2583 		return -ENOMEM;
2584 	}
2585 
2586 	port->trid = trid;
2587 
2588 	switch (trid->adrfam) {
2589 	case SPDK_NVMF_ADRFAM_IPV4:
2590 		family = AF_INET;
2591 		break;
2592 	case SPDK_NVMF_ADRFAM_IPV6:
2593 		family = AF_INET6;
2594 		break;
2595 	default:
2596 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2597 		free(port);
2598 		pthread_mutex_unlock(&rtransport->lock);
2599 		return -EINVAL;
2600 	}
2601 
2602 	memset(&hints, 0, sizeof(hints));
2603 	hints.ai_family = family;
2604 	hints.ai_flags = AI_NUMERICSERV;
2605 	hints.ai_socktype = SOCK_STREAM;
2606 	hints.ai_protocol = 0;
2607 
2608 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2609 	if (rc) {
2610 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2611 		free(port);
2612 		pthread_mutex_unlock(&rtransport->lock);
2613 		return -EINVAL;
2614 	}
2615 
2616 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2617 	if (rc < 0) {
2618 		SPDK_ERRLOG("rdma_create_id() failed\n");
2619 		freeaddrinfo(res);
2620 		free(port);
2621 		pthread_mutex_unlock(&rtransport->lock);
2622 		return rc;
2623 	}
2624 
2625 	rc = rdma_bind_addr(port->id, res->ai_addr);
2626 	freeaddrinfo(res);
2627 
2628 	if (rc < 0) {
2629 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2630 		rdma_destroy_id(port->id);
2631 		free(port);
2632 		pthread_mutex_unlock(&rtransport->lock);
2633 		return rc;
2634 	}
2635 
2636 	if (!port->id->verbs) {
2637 		SPDK_ERRLOG("ibv_context is null\n");
2638 		rdma_destroy_id(port->id);
2639 		free(port);
2640 		pthread_mutex_unlock(&rtransport->lock);
2641 		return -1;
2642 	}
2643 
2644 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2645 	if (rc < 0) {
2646 		SPDK_ERRLOG("rdma_listen() failed\n");
2647 		rdma_destroy_id(port->id);
2648 		free(port);
2649 		pthread_mutex_unlock(&rtransport->lock);
2650 		return rc;
2651 	}
2652 
2653 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2654 		if (device->context == port->id->verbs) {
2655 			port->device = device;
2656 			break;
2657 		}
2658 	}
2659 	if (!port->device) {
2660 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2661 			    port->id->verbs);
2662 		rdma_destroy_id(port->id);
2663 		free(port);
2664 		pthread_mutex_unlock(&rtransport->lock);
2665 		return -EINVAL;
2666 	}
2667 
2668 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2669 		       trid->traddr, trid->trsvcid);
2670 
2671 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2672 	pthread_mutex_unlock(&rtransport->lock);
2673 	return 0;
2674 }
2675 
2676 static void
2677 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2678 		      const struct spdk_nvme_transport_id *trid)
2679 {
2680 	struct spdk_nvmf_rdma_transport *rtransport;
2681 	struct spdk_nvmf_rdma_port *port, *tmp;
2682 
2683 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2684 
2685 	pthread_mutex_lock(&rtransport->lock);
2686 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2687 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2688 			TAILQ_REMOVE(&rtransport->ports, port, link);
2689 			rdma_destroy_id(port->id);
2690 			free(port);
2691 			break;
2692 		}
2693 	}
2694 
2695 	pthread_mutex_unlock(&rtransport->lock);
2696 }
2697 
2698 static void
2699 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2700 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2701 {
2702 	struct spdk_nvmf_request *req, *tmp;
2703 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2704 	struct spdk_nvmf_rdma_resources *resources;
2705 
2706 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2707 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2708 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2709 			break;
2710 		}
2711 	}
2712 
2713 	/* Then RDMA writes since reads have stronger restrictions than writes */
2714 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2715 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2716 			break;
2717 		}
2718 	}
2719 
2720 	/* Then we handle request waiting on memory buffers. */
2721 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2722 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2723 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2724 			break;
2725 		}
2726 	}
2727 
2728 	resources = rqpair->resources;
2729 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2730 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2731 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2732 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2733 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2734 
2735 		if (rqpair->srq != NULL) {
2736 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2737 			rdma_req->recv->qpair->qd++;
2738 		} else {
2739 			rqpair->qd++;
2740 		}
2741 
2742 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2743 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2744 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2745 			break;
2746 		}
2747 	}
2748 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2749 		rqpair->poller->stat.pending_free_request++;
2750 	}
2751 }
2752 
2753 static inline bool
2754 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
2755 {
2756 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
2757 	return nvmf_rdma_is_rxe_device(device) ||
2758 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
2759 }
2760 
2761 static void
2762 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2763 {
2764 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2765 			struct spdk_nvmf_rdma_transport, transport);
2766 
2767 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2768 
2769 	/* nvmr_rdma_close_qpair is not called */
2770 	if (!rqpair->to_close) {
2771 		return;
2772 	}
2773 
2774 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2775 	if (rqpair->current_send_depth != 0) {
2776 		return;
2777 	}
2778 
2779 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2780 		return;
2781 	}
2782 
2783 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
2784 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
2785 		return;
2786 	}
2787 
2788 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2789 
2790 	nvmf_rdma_qpair_destroy(rqpair);
2791 }
2792 
2793 static int
2794 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2795 {
2796 	struct spdk_nvmf_qpair		*qpair;
2797 	struct spdk_nvmf_rdma_qpair	*rqpair;
2798 
2799 	if (evt->id == NULL) {
2800 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2801 		return -1;
2802 	}
2803 
2804 	qpair = evt->id->context;
2805 	if (qpair == NULL) {
2806 		SPDK_ERRLOG("disconnect request: no active connection\n");
2807 		return -1;
2808 	}
2809 
2810 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2811 
2812 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2813 
2814 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2815 
2816 	return 0;
2817 }
2818 
2819 #ifdef DEBUG
2820 static const char *CM_EVENT_STR[] = {
2821 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2822 	"RDMA_CM_EVENT_ADDR_ERROR",
2823 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2824 	"RDMA_CM_EVENT_ROUTE_ERROR",
2825 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2826 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2827 	"RDMA_CM_EVENT_CONNECT_ERROR",
2828 	"RDMA_CM_EVENT_UNREACHABLE",
2829 	"RDMA_CM_EVENT_REJECTED",
2830 	"RDMA_CM_EVENT_ESTABLISHED",
2831 	"RDMA_CM_EVENT_DISCONNECTED",
2832 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2833 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2834 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2835 	"RDMA_CM_EVENT_ADDR_CHANGE",
2836 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2837 };
2838 #endif /* DEBUG */
2839 
2840 static void
2841 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2842 				    struct spdk_nvmf_rdma_port *port)
2843 {
2844 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2845 	struct spdk_nvmf_rdma_poller		*rpoller;
2846 	struct spdk_nvmf_rdma_qpair		*rqpair;
2847 
2848 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2849 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2850 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2851 				if (rqpair->listen_id == port->id) {
2852 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2853 				}
2854 			}
2855 		}
2856 	}
2857 }
2858 
2859 static bool
2860 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2861 				      struct rdma_cm_event *event)
2862 {
2863 	const struct spdk_nvme_transport_id	*trid;
2864 	struct spdk_nvmf_rdma_port		*port;
2865 	struct spdk_nvmf_rdma_transport		*rtransport;
2866 	bool					event_acked = false;
2867 
2868 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2869 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2870 		if (port->id == event->id) {
2871 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2872 			rdma_ack_cm_event(event);
2873 			event_acked = true;
2874 			trid = port->trid;
2875 			break;
2876 		}
2877 	}
2878 
2879 	if (event_acked) {
2880 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2881 
2882 		nvmf_rdma_stop_listen(transport, trid);
2883 		nvmf_rdma_listen(transport, trid, NULL);
2884 	}
2885 
2886 	return event_acked;
2887 }
2888 
2889 static void
2890 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2891 				       struct rdma_cm_event *event)
2892 {
2893 	struct spdk_nvmf_rdma_port		*port;
2894 	struct spdk_nvmf_rdma_transport		*rtransport;
2895 
2896 	port = event->id->context;
2897 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2898 
2899 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2900 
2901 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2902 
2903 	rdma_ack_cm_event(event);
2904 
2905 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2906 		;
2907 	}
2908 }
2909 
2910 static void
2911 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2912 {
2913 	struct spdk_nvmf_rdma_transport *rtransport;
2914 	struct rdma_cm_event		*event;
2915 	int				rc;
2916 	bool				event_acked;
2917 
2918 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2919 
2920 	if (rtransport->event_channel == NULL) {
2921 		return;
2922 	}
2923 
2924 	while (1) {
2925 		event_acked = false;
2926 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2927 		if (rc) {
2928 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2929 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2930 			}
2931 			break;
2932 		}
2933 
2934 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2935 
2936 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2937 
2938 		switch (event->event) {
2939 		case RDMA_CM_EVENT_ADDR_RESOLVED:
2940 		case RDMA_CM_EVENT_ADDR_ERROR:
2941 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
2942 		case RDMA_CM_EVENT_ROUTE_ERROR:
2943 			/* No action required. The target never attempts to resolve routes. */
2944 			break;
2945 		case RDMA_CM_EVENT_CONNECT_REQUEST:
2946 			rc = nvmf_rdma_connect(transport, event);
2947 			if (rc < 0) {
2948 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2949 				break;
2950 			}
2951 			break;
2952 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
2953 			/* The target never initiates a new connection. So this will not occur. */
2954 			break;
2955 		case RDMA_CM_EVENT_CONNECT_ERROR:
2956 			/* Can this happen? The docs say it can, but not sure what causes it. */
2957 			break;
2958 		case RDMA_CM_EVENT_UNREACHABLE:
2959 		case RDMA_CM_EVENT_REJECTED:
2960 			/* These only occur on the client side. */
2961 			break;
2962 		case RDMA_CM_EVENT_ESTABLISHED:
2963 			/* TODO: Should we be waiting for this event anywhere? */
2964 			break;
2965 		case RDMA_CM_EVENT_DISCONNECTED:
2966 			rc = nvmf_rdma_disconnect(event);
2967 			if (rc < 0) {
2968 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2969 				break;
2970 			}
2971 			break;
2972 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
2973 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
2974 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
2975 			 * Once these events are sent to SPDK, we should release all IB resources and
2976 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
2977 			 * ibv_destory* functions to release user space memory allocated by IB. All kernel
2978 			 * resources are already cleaned. */
2979 			if (event->id->qp) {
2980 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
2981 				 * corresponding qpair. Otherwise the event refers to a listening device */
2982 				rc = nvmf_rdma_disconnect(event);
2983 				if (rc < 0) {
2984 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2985 					break;
2986 				}
2987 			} else {
2988 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
2989 				event_acked = true;
2990 			}
2991 			break;
2992 		case RDMA_CM_EVENT_MULTICAST_JOIN:
2993 		case RDMA_CM_EVENT_MULTICAST_ERROR:
2994 			/* Multicast is not used */
2995 			break;
2996 		case RDMA_CM_EVENT_ADDR_CHANGE:
2997 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
2998 			break;
2999 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3000 			/* For now, do nothing. The target never re-uses queue pairs. */
3001 			break;
3002 		default:
3003 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3004 			break;
3005 		}
3006 		if (!event_acked) {
3007 			rdma_ack_cm_event(event);
3008 		}
3009 	}
3010 }
3011 
3012 static void
3013 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3014 {
3015 	rqpair->last_wqe_reached = true;
3016 	nvmf_rdma_destroy_drained_qpair(rqpair);
3017 }
3018 
3019 static void
3020 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3021 {
3022 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3023 
3024 	if (event_ctx->rqpair) {
3025 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3026 		if (event_ctx->cb_fn) {
3027 			event_ctx->cb_fn(event_ctx->rqpair);
3028 		}
3029 	}
3030 	free(event_ctx);
3031 }
3032 
3033 static int
3034 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3035 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3036 {
3037 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3038 	struct spdk_thread *thr = NULL;
3039 	int rc;
3040 
3041 	if (rqpair->qpair.group) {
3042 		thr = rqpair->qpair.group->thread;
3043 	} else if (rqpair->destruct_channel) {
3044 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3045 	}
3046 
3047 	if (!thr) {
3048 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3049 		return -EINVAL;
3050 	}
3051 
3052 	ctx = calloc(1, sizeof(*ctx));
3053 	if (!ctx) {
3054 		return -ENOMEM;
3055 	}
3056 
3057 	ctx->rqpair = rqpair;
3058 	ctx->cb_fn = fn;
3059 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3060 
3061 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3062 	if (rc) {
3063 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3064 		free(ctx);
3065 	}
3066 
3067 	return rc;
3068 }
3069 
3070 static int
3071 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3072 {
3073 	int				rc;
3074 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3075 	struct ibv_async_event		event;
3076 
3077 	rc = ibv_get_async_event(device->context, &event);
3078 
3079 	if (rc) {
3080 		/* In non-blocking mode -1 means there are no events available */
3081 		return rc;
3082 	}
3083 
3084 	switch (event.event_type) {
3085 	case IBV_EVENT_QP_FATAL:
3086 		rqpair = event.element.qp->qp_context;
3087 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3088 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3089 				  (uintptr_t)rqpair->cm_id, event.event_type);
3090 		nvmf_rdma_update_ibv_state(rqpair);
3091 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3092 		break;
3093 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3094 		/* This event only occurs for shared receive queues. */
3095 		rqpair = event.element.qp->qp_context;
3096 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3097 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3098 		if (rc) {
3099 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3100 			rqpair->last_wqe_reached = true;
3101 		}
3102 		break;
3103 	case IBV_EVENT_SQ_DRAINED:
3104 		/* This event occurs frequently in both error and non-error states.
3105 		 * Check if the qpair is in an error state before sending a message. */
3106 		rqpair = event.element.qp->qp_context;
3107 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3108 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3109 				  (uintptr_t)rqpair->cm_id, event.event_type);
3110 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3111 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3112 		}
3113 		break;
3114 	case IBV_EVENT_QP_REQ_ERR:
3115 	case IBV_EVENT_QP_ACCESS_ERR:
3116 	case IBV_EVENT_COMM_EST:
3117 	case IBV_EVENT_PATH_MIG:
3118 	case IBV_EVENT_PATH_MIG_ERR:
3119 		SPDK_NOTICELOG("Async event: %s\n",
3120 			       ibv_event_type_str(event.event_type));
3121 		rqpair = event.element.qp->qp_context;
3122 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3123 				  (uintptr_t)rqpair->cm_id, event.event_type);
3124 		nvmf_rdma_update_ibv_state(rqpair);
3125 		break;
3126 	case IBV_EVENT_CQ_ERR:
3127 	case IBV_EVENT_DEVICE_FATAL:
3128 	case IBV_EVENT_PORT_ACTIVE:
3129 	case IBV_EVENT_PORT_ERR:
3130 	case IBV_EVENT_LID_CHANGE:
3131 	case IBV_EVENT_PKEY_CHANGE:
3132 	case IBV_EVENT_SM_CHANGE:
3133 	case IBV_EVENT_SRQ_ERR:
3134 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3135 	case IBV_EVENT_CLIENT_REREGISTER:
3136 	case IBV_EVENT_GID_CHANGE:
3137 	default:
3138 		SPDK_NOTICELOG("Async event: %s\n",
3139 			       ibv_event_type_str(event.event_type));
3140 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3141 		break;
3142 	}
3143 	ibv_ack_async_event(&event);
3144 
3145 	return 0;
3146 }
3147 
3148 static void
3149 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3150 {
3151 	int rc = 0;
3152 	uint32_t i = 0;
3153 
3154 	for (i = 0; i < max_events; i++) {
3155 		rc = nvmf_process_ib_event(device);
3156 		if (rc) {
3157 			break;
3158 		}
3159 	}
3160 
3161 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3162 }
3163 
3164 static uint32_t
3165 nvmf_rdma_accept(struct spdk_nvmf_transport *transport)
3166 {
3167 	int	nfds, i = 0;
3168 	struct spdk_nvmf_rdma_transport *rtransport;
3169 	struct spdk_nvmf_rdma_device *device, *tmp;
3170 	uint32_t count;
3171 
3172 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3173 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3174 
3175 	if (nfds <= 0) {
3176 		return 0;
3177 	}
3178 
3179 	/* The first poll descriptor is RDMA CM event */
3180 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3181 		nvmf_process_cm_event(transport);
3182 		nfds--;
3183 	}
3184 
3185 	if (nfds == 0) {
3186 		return count;
3187 	}
3188 
3189 	/* Second and subsequent poll descriptors are IB async events */
3190 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3191 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3192 			nvmf_process_ib_events(device, 32);
3193 			nfds--;
3194 		}
3195 	}
3196 	/* check all flagged fd's have been served */
3197 	assert(nfds == 0);
3198 
3199 	return count;
3200 }
3201 
3202 static void
3203 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3204 		     struct spdk_nvmf_ctrlr_data *cdata)
3205 {
3206 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3207 
3208 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3209 	since in-capsule data only works with NVME drives that support SGL memory layout */
3210 	if (transport->opts.dif_insert_or_strip) {
3211 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3212 	}
3213 }
3214 
3215 static void
3216 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3217 		   struct spdk_nvme_transport_id *trid,
3218 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3219 {
3220 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3221 	entry->adrfam = trid->adrfam;
3222 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3223 
3224 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3225 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3226 
3227 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3228 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3229 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3230 }
3231 
3232 static void
3233 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3234 
3235 static struct spdk_nvmf_transport_poll_group *
3236 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3237 {
3238 	struct spdk_nvmf_rdma_transport		*rtransport;
3239 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3240 	struct spdk_nvmf_rdma_poller		*poller;
3241 	struct spdk_nvmf_rdma_device		*device;
3242 	struct spdk_rdma_srq_init_attr		srq_init_attr;
3243 	struct spdk_nvmf_rdma_resource_opts	opts;
3244 	int					num_cqe;
3245 
3246 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3247 
3248 	rgroup = calloc(1, sizeof(*rgroup));
3249 	if (!rgroup) {
3250 		return NULL;
3251 	}
3252 
3253 	TAILQ_INIT(&rgroup->pollers);
3254 
3255 	pthread_mutex_lock(&rtransport->lock);
3256 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3257 		poller = calloc(1, sizeof(*poller));
3258 		if (!poller) {
3259 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3260 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3261 			pthread_mutex_unlock(&rtransport->lock);
3262 			return NULL;
3263 		}
3264 
3265 		poller->device = device;
3266 		poller->group = rgroup;
3267 
3268 		TAILQ_INIT(&poller->qpairs);
3269 		STAILQ_INIT(&poller->qpairs_pending_send);
3270 		STAILQ_INIT(&poller->qpairs_pending_recv);
3271 
3272 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3273 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3274 			poller->max_srq_depth = rtransport->rdma_opts.max_srq_depth;
3275 
3276 			device->num_srq++;
3277 			memset(&srq_init_attr, 0, sizeof(srq_init_attr));
3278 			srq_init_attr.pd = device->pd;
3279 			srq_init_attr.stats = &poller->stat.qp_stats.recv;
3280 			srq_init_attr.srq_init_attr.attr.max_wr = poller->max_srq_depth;
3281 			srq_init_attr.srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3282 			poller->srq = spdk_rdma_srq_create(&srq_init_attr);
3283 			if (!poller->srq) {
3284 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3285 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3286 				pthread_mutex_unlock(&rtransport->lock);
3287 				return NULL;
3288 			}
3289 
3290 			opts.qp = poller->srq;
3291 			opts.pd = device->pd;
3292 			opts.qpair = NULL;
3293 			opts.shared = true;
3294 			opts.max_queue_depth = poller->max_srq_depth;
3295 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3296 
3297 			poller->resources = nvmf_rdma_resources_create(&opts);
3298 			if (!poller->resources) {
3299 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3300 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3301 				pthread_mutex_unlock(&rtransport->lock);
3302 				return NULL;
3303 			}
3304 		}
3305 
3306 		/*
3307 		 * When using an srq, we can limit the completion queue at startup.
3308 		 * The following formula represents the calculation:
3309 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3310 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3311 		 */
3312 		if (poller->srq) {
3313 			num_cqe = poller->max_srq_depth * 3;
3314 		} else {
3315 			num_cqe = rtransport->rdma_opts.num_cqe;
3316 		}
3317 
3318 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3319 		if (!poller->cq) {
3320 			SPDK_ERRLOG("Unable to create completion queue\n");
3321 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3322 			pthread_mutex_unlock(&rtransport->lock);
3323 			return NULL;
3324 		}
3325 		poller->num_cqe = num_cqe;
3326 	}
3327 
3328 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3329 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3330 		rtransport->conn_sched.next_admin_pg = rgroup;
3331 		rtransport->conn_sched.next_io_pg = rgroup;
3332 	}
3333 
3334 	pthread_mutex_unlock(&rtransport->lock);
3335 	return &rgroup->group;
3336 }
3337 
3338 static struct spdk_nvmf_transport_poll_group *
3339 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3340 {
3341 	struct spdk_nvmf_rdma_transport *rtransport;
3342 	struct spdk_nvmf_rdma_poll_group **pg;
3343 	struct spdk_nvmf_transport_poll_group *result;
3344 
3345 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3346 
3347 	pthread_mutex_lock(&rtransport->lock);
3348 
3349 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3350 		pthread_mutex_unlock(&rtransport->lock);
3351 		return NULL;
3352 	}
3353 
3354 	if (qpair->qid == 0) {
3355 		pg = &rtransport->conn_sched.next_admin_pg;
3356 	} else {
3357 		pg = &rtransport->conn_sched.next_io_pg;
3358 	}
3359 
3360 	assert(*pg != NULL);
3361 
3362 	result = &(*pg)->group;
3363 
3364 	*pg = TAILQ_NEXT(*pg, link);
3365 	if (*pg == NULL) {
3366 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3367 	}
3368 
3369 	pthread_mutex_unlock(&rtransport->lock);
3370 
3371 	return result;
3372 }
3373 
3374 static void
3375 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3376 {
3377 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3378 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3379 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3380 	struct spdk_nvmf_rdma_transport		*rtransport;
3381 
3382 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3383 	if (!rgroup) {
3384 		return;
3385 	}
3386 
3387 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3388 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3389 
3390 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3391 			nvmf_rdma_qpair_destroy(qpair);
3392 		}
3393 
3394 		if (poller->srq) {
3395 			if (poller->resources) {
3396 				nvmf_rdma_resources_destroy(poller->resources);
3397 			}
3398 			spdk_rdma_srq_destroy(poller->srq);
3399 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3400 		}
3401 
3402 		if (poller->cq) {
3403 			ibv_destroy_cq(poller->cq);
3404 		}
3405 
3406 		free(poller);
3407 	}
3408 
3409 	if (rgroup->group.transport == NULL) {
3410 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3411 		 * calls this function directly in a failure path. */
3412 		free(rgroup);
3413 		return;
3414 	}
3415 
3416 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3417 
3418 	pthread_mutex_lock(&rtransport->lock);
3419 	next_rgroup = TAILQ_NEXT(rgroup, link);
3420 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3421 	if (next_rgroup == NULL) {
3422 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3423 	}
3424 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3425 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3426 	}
3427 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3428 		rtransport->conn_sched.next_io_pg = next_rgroup;
3429 	}
3430 	pthread_mutex_unlock(&rtransport->lock);
3431 
3432 	free(rgroup);
3433 }
3434 
3435 static void
3436 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3437 {
3438 	if (rqpair->cm_id != NULL) {
3439 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3440 	}
3441 }
3442 
3443 static int
3444 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3445 			 struct spdk_nvmf_qpair *qpair)
3446 {
3447 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3448 	struct spdk_nvmf_rdma_qpair		*rqpair;
3449 	struct spdk_nvmf_rdma_device		*device;
3450 	struct spdk_nvmf_rdma_poller		*poller;
3451 	int					rc;
3452 
3453 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3454 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3455 
3456 	device = rqpair->device;
3457 
3458 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3459 		if (poller->device == device) {
3460 			break;
3461 		}
3462 	}
3463 
3464 	if (!poller) {
3465 		SPDK_ERRLOG("No poller found for device.\n");
3466 		return -1;
3467 	}
3468 
3469 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3470 	rqpair->poller = poller;
3471 	rqpair->srq = rqpair->poller->srq;
3472 
3473 	rc = nvmf_rdma_qpair_initialize(qpair);
3474 	if (rc < 0) {
3475 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3476 		return -1;
3477 	}
3478 
3479 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3480 	if (rc) {
3481 		/* Try to reject, but we probably can't */
3482 		nvmf_rdma_qpair_reject_connection(rqpair);
3483 		return -1;
3484 	}
3485 
3486 	nvmf_rdma_update_ibv_state(rqpair);
3487 
3488 	return 0;
3489 }
3490 
3491 static int
3492 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3493 			    struct spdk_nvmf_qpair *qpair)
3494 {
3495 	struct spdk_nvmf_rdma_qpair		*rqpair;
3496 
3497 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3498 	assert(group->transport->tgt != NULL);
3499 
3500 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3501 
3502 	if (!rqpair->destruct_channel) {
3503 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3504 		return 0;
3505 	}
3506 
3507 	/* Sanity check that we get io_channel on the correct thread */
3508 	if (qpair->group) {
3509 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3510 	}
3511 
3512 	return 0;
3513 }
3514 
3515 static int
3516 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3517 {
3518 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3519 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3520 			struct spdk_nvmf_rdma_transport, transport);
3521 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3522 					      struct spdk_nvmf_rdma_qpair, qpair);
3523 
3524 	/*
3525 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3526 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3527 	 * starved of RECV structures.
3528 	 */
3529 	if (rqpair->srq && rdma_req->recv) {
3530 		int rc;
3531 		struct ibv_recv_wr *bad_recv_wr;
3532 
3533 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_req->recv->wr);
3534 		rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
3535 		if (rc) {
3536 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3537 		}
3538 	}
3539 
3540 	_nvmf_rdma_request_free(rdma_req, rtransport);
3541 	return 0;
3542 }
3543 
3544 static int
3545 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3546 {
3547 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3548 			struct spdk_nvmf_rdma_transport, transport);
3549 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3550 			struct spdk_nvmf_rdma_request, req);
3551 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3552 			struct spdk_nvmf_rdma_qpair, qpair);
3553 
3554 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3555 		/* The connection is alive, so process the request as normal */
3556 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3557 	} else {
3558 		/* The connection is dead. Move the request directly to the completed state. */
3559 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3560 	}
3561 
3562 	nvmf_rdma_request_process(rtransport, rdma_req);
3563 
3564 	return 0;
3565 }
3566 
3567 static void
3568 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
3569 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
3570 {
3571 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3572 
3573 	rqpair->to_close = true;
3574 
3575 	/* This happens only when the qpair is disconnected before
3576 	 * it is added to the poll group. Since there is no poll group,
3577 	 * the RDMA qp has not been initialized yet and the RDMA CM
3578 	 * event has not yet been acknowledged, so we need to reject it.
3579 	 */
3580 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3581 		nvmf_rdma_qpair_reject_connection(rqpair);
3582 		nvmf_rdma_qpair_destroy(rqpair);
3583 		return;
3584 	}
3585 
3586 	if (rqpair->rdma_qp) {
3587 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3588 	}
3589 
3590 	nvmf_rdma_destroy_drained_qpair(rqpair);
3591 
3592 	if (cb_fn) {
3593 		cb_fn(cb_arg);
3594 	}
3595 }
3596 
3597 static struct spdk_nvmf_rdma_qpair *
3598 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3599 {
3600 	struct spdk_nvmf_rdma_qpair *rqpair;
3601 	/* @todo: improve QP search */
3602 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3603 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3604 			return rqpair;
3605 		}
3606 	}
3607 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3608 	return NULL;
3609 }
3610 
3611 #ifdef DEBUG
3612 static int
3613 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3614 {
3615 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3616 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3617 }
3618 #endif
3619 
3620 static void
3621 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3622 			   int rc)
3623 {
3624 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3625 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3626 
3627 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3628 	while (bad_recv_wr != NULL) {
3629 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3630 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3631 
3632 		rdma_recv->qpair->current_recv_depth++;
3633 		bad_recv_wr = bad_recv_wr->next;
3634 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3635 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3636 	}
3637 }
3638 
3639 static void
3640 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3641 {
3642 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3643 	while (bad_recv_wr != NULL) {
3644 		bad_recv_wr = bad_recv_wr->next;
3645 		rqpair->current_recv_depth++;
3646 	}
3647 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3648 }
3649 
3650 static void
3651 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3652 		     struct spdk_nvmf_rdma_poller *rpoller)
3653 {
3654 	struct spdk_nvmf_rdma_qpair	*rqpair;
3655 	struct ibv_recv_wr		*bad_recv_wr;
3656 	int				rc;
3657 
3658 	if (rpoller->srq) {
3659 		rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_recv_wr);
3660 		if (rc) {
3661 			_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3662 		}
3663 	} else {
3664 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3665 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3666 			rc = spdk_rdma_qp_flush_recv_wrs(rqpair->rdma_qp, &bad_recv_wr);
3667 			if (rc) {
3668 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3669 			}
3670 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3671 		}
3672 	}
3673 }
3674 
3675 static void
3676 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3677 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3678 {
3679 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3680 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3681 
3682 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3683 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3684 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3685 		assert(rqpair->current_send_depth > 0);
3686 		rqpair->current_send_depth--;
3687 		switch (bad_rdma_wr->type) {
3688 		case RDMA_WR_TYPE_DATA:
3689 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3690 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3691 				assert(rqpair->current_read_depth > 0);
3692 				rqpair->current_read_depth--;
3693 			}
3694 			break;
3695 		case RDMA_WR_TYPE_SEND:
3696 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3697 			break;
3698 		default:
3699 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3700 			prev_rdma_req = cur_rdma_req;
3701 			continue;
3702 		}
3703 
3704 		if (prev_rdma_req == cur_rdma_req) {
3705 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3706 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3707 			continue;
3708 		}
3709 
3710 		switch (cur_rdma_req->state) {
3711 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3712 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3713 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3714 			break;
3715 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3716 		case RDMA_REQUEST_STATE_COMPLETING:
3717 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3718 			break;
3719 		default:
3720 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3721 				    cur_rdma_req->state, rqpair);
3722 			continue;
3723 		}
3724 
3725 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3726 		prev_rdma_req = cur_rdma_req;
3727 	}
3728 
3729 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3730 		/* Disconnect the connection. */
3731 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3732 	}
3733 
3734 }
3735 
3736 static void
3737 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3738 		     struct spdk_nvmf_rdma_poller *rpoller)
3739 {
3740 	struct spdk_nvmf_rdma_qpair	*rqpair;
3741 	struct ibv_send_wr		*bad_wr = NULL;
3742 	int				rc;
3743 
3744 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3745 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3746 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3747 
3748 		/* bad wr always points to the first wr that failed. */
3749 		if (rc) {
3750 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3751 		}
3752 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3753 	}
3754 }
3755 
3756 static const char *
3757 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3758 {
3759 	switch (wr_type) {
3760 	case RDMA_WR_TYPE_RECV:
3761 		return "RECV";
3762 	case RDMA_WR_TYPE_SEND:
3763 		return "SEND";
3764 	case RDMA_WR_TYPE_DATA:
3765 		return "DATA";
3766 	default:
3767 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3768 		SPDK_UNREACHABLE();
3769 	}
3770 }
3771 
3772 static inline void
3773 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3774 {
3775 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3776 
3777 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3778 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3779 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3780 		SPDK_DEBUGLOG(rdma,
3781 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3782 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3783 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3784 	} else {
3785 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3786 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3787 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3788 	}
3789 }
3790 
3791 static int
3792 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3793 		      struct spdk_nvmf_rdma_poller *rpoller)
3794 {
3795 	struct ibv_wc wc[32];
3796 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3797 	struct spdk_nvmf_rdma_request	*rdma_req;
3798 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3799 	struct spdk_nvmf_rdma_qpair	*rqpair;
3800 	int reaped, i;
3801 	int count = 0;
3802 	bool error = false;
3803 	uint64_t poll_tsc = spdk_get_ticks();
3804 
3805 	/* Poll for completing operations. */
3806 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3807 	if (reaped < 0) {
3808 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3809 			    errno, spdk_strerror(errno));
3810 		return -1;
3811 	} else if (reaped == 0) {
3812 		rpoller->stat.idle_polls++;
3813 	}
3814 
3815 	rpoller->stat.polls++;
3816 	rpoller->stat.completions += reaped;
3817 
3818 	for (i = 0; i < reaped; i++) {
3819 
3820 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3821 
3822 		switch (rdma_wr->type) {
3823 		case RDMA_WR_TYPE_SEND:
3824 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3825 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3826 
3827 			if (!wc[i].status) {
3828 				count++;
3829 				assert(wc[i].opcode == IBV_WC_SEND);
3830 				assert(nvmf_rdma_req_is_completing(rdma_req));
3831 			}
3832 
3833 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3834 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3835 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3836 			rdma_req->num_outstanding_data_wr = 0;
3837 
3838 			nvmf_rdma_request_process(rtransport, rdma_req);
3839 			break;
3840 		case RDMA_WR_TYPE_RECV:
3841 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3842 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3843 			if (rpoller->srq != NULL) {
3844 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3845 				/* It is possible that there are still some completions for destroyed QP
3846 				 * associated with SRQ. We just ignore these late completions and re-post
3847 				 * receive WRs back to SRQ.
3848 				 */
3849 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3850 					struct ibv_recv_wr *bad_wr;
3851 					int rc;
3852 
3853 					rdma_recv->wr.next = NULL;
3854 					spdk_rdma_srq_queue_recv_wrs(rpoller->srq, &rdma_recv->wr);
3855 					rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_wr);
3856 					if (rc) {
3857 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3858 					}
3859 					continue;
3860 				}
3861 			}
3862 			rqpair = rdma_recv->qpair;
3863 
3864 			assert(rqpair != NULL);
3865 			if (!wc[i].status) {
3866 				assert(wc[i].opcode == IBV_WC_RECV);
3867 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3868 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3869 					break;
3870 				}
3871 			}
3872 
3873 			rdma_recv->wr.next = NULL;
3874 			rqpair->current_recv_depth++;
3875 			rdma_recv->receive_tsc = poll_tsc;
3876 			rpoller->stat.requests++;
3877 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3878 			break;
3879 		case RDMA_WR_TYPE_DATA:
3880 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3881 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3882 
3883 			assert(rdma_req->num_outstanding_data_wr > 0);
3884 
3885 			rqpair->current_send_depth--;
3886 			rdma_req->num_outstanding_data_wr--;
3887 			if (!wc[i].status) {
3888 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3889 				rqpair->current_read_depth--;
3890 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3891 				if (rdma_req->num_outstanding_data_wr == 0) {
3892 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3893 					nvmf_rdma_request_process(rtransport, rdma_req);
3894 				}
3895 			} else {
3896 				/* If the data transfer fails still force the queue into the error state,
3897 				 * if we were performing an RDMA_READ, we need to force the request into a
3898 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3899 				 * case, we should wait for the SEND to complete. */
3900 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3901 					rqpair->current_read_depth--;
3902 					if (rdma_req->num_outstanding_data_wr == 0) {
3903 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3904 					}
3905 				}
3906 			}
3907 			break;
3908 		default:
3909 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3910 			continue;
3911 		}
3912 
3913 		/* Handle error conditions */
3914 		if (wc[i].status) {
3915 			nvmf_rdma_update_ibv_state(rqpair);
3916 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
3917 
3918 			error = true;
3919 
3920 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3921 				/* Disconnect the connection. */
3922 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3923 			} else {
3924 				nvmf_rdma_destroy_drained_qpair(rqpair);
3925 			}
3926 			continue;
3927 		}
3928 
3929 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3930 
3931 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3932 			nvmf_rdma_destroy_drained_qpair(rqpair);
3933 		}
3934 	}
3935 
3936 	if (error == true) {
3937 		return -1;
3938 	}
3939 
3940 	/* submit outstanding work requests. */
3941 	_poller_submit_recvs(rtransport, rpoller);
3942 	_poller_submit_sends(rtransport, rpoller);
3943 
3944 	return count;
3945 }
3946 
3947 static int
3948 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3949 {
3950 	struct spdk_nvmf_rdma_transport *rtransport;
3951 	struct spdk_nvmf_rdma_poll_group *rgroup;
3952 	struct spdk_nvmf_rdma_poller	*rpoller;
3953 	int				count, rc;
3954 
3955 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3956 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3957 
3958 	count = 0;
3959 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3960 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
3961 		if (rc < 0) {
3962 			return rc;
3963 		}
3964 		count += rc;
3965 	}
3966 
3967 	return count;
3968 }
3969 
3970 static int
3971 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3972 			  struct spdk_nvme_transport_id *trid,
3973 			  bool peer)
3974 {
3975 	struct sockaddr *saddr;
3976 	uint16_t port;
3977 
3978 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
3979 
3980 	if (peer) {
3981 		saddr = rdma_get_peer_addr(id);
3982 	} else {
3983 		saddr = rdma_get_local_addr(id);
3984 	}
3985 	switch (saddr->sa_family) {
3986 	case AF_INET: {
3987 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3988 
3989 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3990 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3991 			  trid->traddr, sizeof(trid->traddr));
3992 		if (peer) {
3993 			port = ntohs(rdma_get_dst_port(id));
3994 		} else {
3995 			port = ntohs(rdma_get_src_port(id));
3996 		}
3997 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3998 		break;
3999 	}
4000 	case AF_INET6: {
4001 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4002 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4003 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4004 			  trid->traddr, sizeof(trid->traddr));
4005 		if (peer) {
4006 			port = ntohs(rdma_get_dst_port(id));
4007 		} else {
4008 			port = ntohs(rdma_get_src_port(id));
4009 		}
4010 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4011 		break;
4012 	}
4013 	default:
4014 		return -1;
4015 
4016 	}
4017 
4018 	return 0;
4019 }
4020 
4021 static int
4022 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4023 			      struct spdk_nvme_transport_id *trid)
4024 {
4025 	struct spdk_nvmf_rdma_qpair	*rqpair;
4026 
4027 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4028 
4029 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4030 }
4031 
4032 static int
4033 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4034 			       struct spdk_nvme_transport_id *trid)
4035 {
4036 	struct spdk_nvmf_rdma_qpair	*rqpair;
4037 
4038 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4039 
4040 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4041 }
4042 
4043 static int
4044 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4045 				struct spdk_nvme_transport_id *trid)
4046 {
4047 	struct spdk_nvmf_rdma_qpair	*rqpair;
4048 
4049 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4050 
4051 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4052 }
4053 
4054 void
4055 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4056 {
4057 	g_nvmf_hooks = *hooks;
4058 }
4059 
4060 static void
4061 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4062 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4063 {
4064 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4065 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4066 
4067 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4068 
4069 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4070 }
4071 
4072 static int
4073 _nvmf_rdma_qpair_abort_request(void *ctx)
4074 {
4075 	struct spdk_nvmf_request *req = ctx;
4076 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4077 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4078 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4079 					      struct spdk_nvmf_rdma_qpair, qpair);
4080 	int rc;
4081 
4082 	spdk_poller_unregister(&req->poller);
4083 
4084 	switch (rdma_req_to_abort->state) {
4085 	case RDMA_REQUEST_STATE_EXECUTING:
4086 		rc = nvmf_ctrlr_abort_request(req);
4087 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4088 			return SPDK_POLLER_BUSY;
4089 		}
4090 		break;
4091 
4092 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4093 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4094 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4095 
4096 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4097 		break;
4098 
4099 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4100 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4101 			      spdk_nvmf_rdma_request, state_link);
4102 
4103 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4104 		break;
4105 
4106 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4107 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4108 			      spdk_nvmf_rdma_request, state_link);
4109 
4110 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4111 		break;
4112 
4113 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4114 		if (spdk_get_ticks() < req->timeout_tsc) {
4115 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4116 			return SPDK_POLLER_BUSY;
4117 		}
4118 		break;
4119 
4120 	default:
4121 		break;
4122 	}
4123 
4124 	spdk_nvmf_request_complete(req);
4125 	return SPDK_POLLER_BUSY;
4126 }
4127 
4128 static void
4129 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4130 			      struct spdk_nvmf_request *req)
4131 {
4132 	struct spdk_nvmf_rdma_qpair *rqpair;
4133 	struct spdk_nvmf_rdma_transport *rtransport;
4134 	struct spdk_nvmf_transport *transport;
4135 	uint16_t cid;
4136 	uint32_t i, max_req_count;
4137 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL, *rdma_req;
4138 
4139 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4140 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4141 	transport = &rtransport->transport;
4142 
4143 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4144 	max_req_count = rqpair->srq == NULL ? rqpair->max_queue_depth : rqpair->poller->max_srq_depth;
4145 
4146 	for (i = 0; i < max_req_count; i++) {
4147 		rdma_req = &rqpair->resources->reqs[i];
4148 		/* When SRQ == NULL, rqpair has its own requests and req.qpair pointer always points to the qpair
4149 		 * When SRQ != NULL all rqpairs share common requests and qpair pointer is assigned when we start to
4150 		 * process a request. So in both cases all requests which are not in FREE state have valid qpair ptr */
4151 		if (rdma_req->state != RDMA_REQUEST_STATE_FREE && rdma_req->req.cmd->nvme_cmd.cid == cid &&
4152 		    rdma_req->req.qpair == qpair) {
4153 			rdma_req_to_abort = rdma_req;
4154 			break;
4155 		}
4156 	}
4157 
4158 	if (rdma_req_to_abort == NULL) {
4159 		spdk_nvmf_request_complete(req);
4160 		return;
4161 	}
4162 
4163 	req->req_to_abort = &rdma_req_to_abort->req;
4164 	req->timeout_tsc = spdk_get_ticks() +
4165 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4166 	req->poller = NULL;
4167 
4168 	_nvmf_rdma_qpair_abort_request(req);
4169 }
4170 
4171 /* Deprecated, please use the flow with nvmf_rdma_poll_group_dump_stat. */
4172 static int
4173 nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
4174 			      struct spdk_nvmf_transport_poll_group_stat **stat)
4175 {
4176 	struct spdk_io_channel *ch;
4177 	struct spdk_nvmf_poll_group *group;
4178 	struct spdk_nvmf_transport_poll_group *tgroup;
4179 	struct spdk_nvmf_rdma_poll_group *rgroup;
4180 	struct spdk_nvmf_rdma_poller *rpoller;
4181 	struct spdk_nvmf_rdma_device_stat *device_stat;
4182 	uint64_t num_devices = 0;
4183 
4184 	SPDK_ERRLOG("nvmf_rdma_poll_group_get_stat is deprecated and will be removed\n");
4185 
4186 	if (tgt == NULL || stat == NULL) {
4187 		return -EINVAL;
4188 	}
4189 
4190 	ch = spdk_get_io_channel(tgt);
4191 	group = spdk_io_channel_get_ctx(ch);;
4192 	spdk_put_io_channel(ch);
4193 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4194 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4195 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4196 			if (!*stat) {
4197 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4198 				return -ENOMEM;
4199 			}
4200 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4201 
4202 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4203 			/* Count devices to allocate enough memory */
4204 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4205 				++num_devices;
4206 			}
4207 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4208 			if (!(*stat)->rdma.devices) {
4209 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4210 				free(*stat);
4211 				return -ENOMEM;
4212 			}
4213 
4214 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4215 			(*stat)->rdma.num_devices = num_devices;
4216 			num_devices = 0;
4217 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4218 				device_stat = &(*stat)->rdma.devices[num_devices++];
4219 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4220 				device_stat->polls = rpoller->stat.polls;
4221 				device_stat->idle_polls = rpoller->stat.idle_polls;
4222 				device_stat->completions = rpoller->stat.completions;
4223 				device_stat->requests = rpoller->stat.requests;
4224 				device_stat->request_latency = rpoller->stat.request_latency;
4225 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4226 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4227 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4228 				device_stat->total_send_wrs = rpoller->stat.qp_stats.send.num_submitted_wrs;
4229 				device_stat->send_doorbell_updates = rpoller->stat.qp_stats.send.doorbell_updates;
4230 				device_stat->total_recv_wrs = rpoller->stat.qp_stats.recv.num_submitted_wrs;
4231 				device_stat->recv_doorbell_updates = rpoller->stat.qp_stats.recv.doorbell_updates;
4232 			}
4233 			return 0;
4234 		}
4235 	}
4236 	return -ENOENT;
4237 }
4238 
4239 /* Deprecated, please use the flow with nvmf_rdma_poll_group_dump_stat. */
4240 static void
4241 nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4242 {
4243 	SPDK_ERRLOG("nvmf_rdma_poll_group_free_stat is deprecated and will be removed\n");
4244 
4245 	if (stat) {
4246 		free(stat->rdma.devices);
4247 	}
4248 	free(stat);
4249 }
4250 
4251 static void
4252 nvmf_rdma_poll_group_dump_stat(struct spdk_nvmf_transport_poll_group *group,
4253 			       struct spdk_json_write_ctx *w)
4254 {
4255 	struct spdk_nvmf_rdma_poll_group *rgroup;
4256 	struct spdk_nvmf_rdma_poller *rpoller;
4257 
4258 	assert(w != NULL);
4259 
4260 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4261 
4262 	spdk_json_write_named_uint64(w, "pending_data_buffer", rgroup->stat.pending_data_buffer);
4263 
4264 	spdk_json_write_named_array_begin(w, "devices");
4265 
4266 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4267 		spdk_json_write_object_begin(w);
4268 		spdk_json_write_named_string(w, "name",
4269 					     ibv_get_device_name(rpoller->device->context->device));
4270 		spdk_json_write_named_uint64(w, "polls",
4271 					     rpoller->stat.polls);
4272 		spdk_json_write_named_uint64(w, "idle_polls",
4273 					     rpoller->stat.idle_polls);
4274 		spdk_json_write_named_uint64(w, "completions",
4275 					     rpoller->stat.completions);
4276 		spdk_json_write_named_uint64(w, "requests",
4277 					     rpoller->stat.requests);
4278 		spdk_json_write_named_uint64(w, "request_latency",
4279 					     rpoller->stat.request_latency);
4280 		spdk_json_write_named_uint64(w, "pending_free_request",
4281 					     rpoller->stat.pending_free_request);
4282 		spdk_json_write_named_uint64(w, "pending_rdma_read",
4283 					     rpoller->stat.pending_rdma_read);
4284 		spdk_json_write_named_uint64(w, "pending_rdma_write",
4285 					     rpoller->stat.pending_rdma_write);
4286 		spdk_json_write_named_uint64(w, "total_send_wrs",
4287 					     rpoller->stat.qp_stats.send.num_submitted_wrs);
4288 		spdk_json_write_named_uint64(w, "send_doorbell_updates",
4289 					     rpoller->stat.qp_stats.send.doorbell_updates);
4290 		spdk_json_write_named_uint64(w, "total_recv_wrs",
4291 					     rpoller->stat.qp_stats.recv.num_submitted_wrs);
4292 		spdk_json_write_named_uint64(w, "recv_doorbell_updates",
4293 					     rpoller->stat.qp_stats.recv.doorbell_updates);
4294 		spdk_json_write_object_end(w);
4295 	}
4296 
4297 	spdk_json_write_array_end(w);
4298 }
4299 
4300 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4301 	.name = "RDMA",
4302 	.type = SPDK_NVME_TRANSPORT_RDMA,
4303 	.opts_init = nvmf_rdma_opts_init,
4304 	.create = nvmf_rdma_create,
4305 	.dump_opts = nvmf_rdma_dump_opts,
4306 	.destroy = nvmf_rdma_destroy,
4307 
4308 	.listen = nvmf_rdma_listen,
4309 	.stop_listen = nvmf_rdma_stop_listen,
4310 	.accept = nvmf_rdma_accept,
4311 	.cdata_init = nvmf_rdma_cdata_init,
4312 
4313 	.listener_discover = nvmf_rdma_discover,
4314 
4315 	.poll_group_create = nvmf_rdma_poll_group_create,
4316 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4317 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4318 	.poll_group_add = nvmf_rdma_poll_group_add,
4319 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4320 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4321 
4322 	.req_free = nvmf_rdma_request_free,
4323 	.req_complete = nvmf_rdma_request_complete,
4324 
4325 	.qpair_fini = nvmf_rdma_close_qpair,
4326 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4327 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4328 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4329 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4330 
4331 	.poll_group_get_stat = nvmf_rdma_poll_group_get_stat,
4332 	.poll_group_free_stat = nvmf_rdma_poll_group_free_stat,
4333 	.poll_group_dump_stat = nvmf_rdma_poll_group_dump_stat,
4334 };
4335 
4336 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4337 SPDK_LOG_REGISTER_COMPONENT(rdma)
4338