xref: /spdk/lib/nvmf/rdma.c (revision 32999ab917f67af61872f868585fd3d78ad6fb8a)
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, 1, "cmid:   ");
162 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
163 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
164 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
165 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
168 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
169 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
170 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
171 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
172 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
173 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
174 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
175 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
176 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
177 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
178 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
179 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
180 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
181 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
182 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
183 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
184 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
185 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
186 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
187 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
188 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
189 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
190 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
191 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
192 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
193 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
194 
195 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
196 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
197 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
198 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
199 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
200 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
201 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
202 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
203 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
204 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
205 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
206 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
207 }
208 
209 enum spdk_nvmf_rdma_wr_type {
210 	RDMA_WR_TYPE_RECV,
211 	RDMA_WR_TYPE_SEND,
212 	RDMA_WR_TYPE_DATA,
213 };
214 
215 struct spdk_nvmf_rdma_wr {
216 	enum spdk_nvmf_rdma_wr_type	type;
217 };
218 
219 /* This structure holds commands as they are received off the wire.
220  * It must be dynamically paired with a full request object
221  * (spdk_nvmf_rdma_request) to service a request. It is separate
222  * from the request because RDMA does not appear to order
223  * completions, so occasionally we'll get a new incoming
224  * command when there aren't any free request objects.
225  */
226 struct spdk_nvmf_rdma_recv {
227 	struct ibv_recv_wr			wr;
228 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
229 
230 	struct spdk_nvmf_rdma_qpair		*qpair;
231 
232 	/* In-capsule data buffer */
233 	uint8_t					*buf;
234 
235 	struct spdk_nvmf_rdma_wr		rdma_wr;
236 	uint64_t				receive_tsc;
237 
238 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
239 };
240 
241 struct spdk_nvmf_rdma_request_data {
242 	struct spdk_nvmf_rdma_wr	rdma_wr;
243 	struct ibv_send_wr		wr;
244 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
245 };
246 
247 struct spdk_nvmf_rdma_request {
248 	struct spdk_nvmf_request		req;
249 
250 	enum spdk_nvmf_rdma_request_state	state;
251 
252 	struct spdk_nvmf_rdma_recv		*recv;
253 
254 	struct {
255 		struct spdk_nvmf_rdma_wr	rdma_wr;
256 		struct	ibv_send_wr		wr;
257 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
258 	} rsp;
259 
260 	struct spdk_nvmf_rdma_request_data	data;
261 
262 	uint32_t				iovpos;
263 
264 	uint32_t				num_outstanding_data_wr;
265 	uint64_t				receive_tsc;
266 
267 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
268 };
269 
270 struct spdk_nvmf_rdma_resource_opts {
271 	struct spdk_nvmf_rdma_qpair	*qpair;
272 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
273 	void				*qp;
274 	struct ibv_pd			*pd;
275 	uint32_t			max_queue_depth;
276 	uint32_t			in_capsule_data_size;
277 	bool				shared;
278 };
279 
280 struct spdk_nvmf_rdma_resources {
281 	/* Array of size "max_queue_depth" containing RDMA requests. */
282 	struct spdk_nvmf_rdma_request		*reqs;
283 
284 	/* Array of size "max_queue_depth" containing RDMA recvs. */
285 	struct spdk_nvmf_rdma_recv		*recvs;
286 
287 	/* Array of size "max_queue_depth" containing 64 byte capsules
288 	 * used for receive.
289 	 */
290 	union nvmf_h2c_msg			*cmds;
291 	struct ibv_mr				*cmds_mr;
292 
293 	/* Array of size "max_queue_depth" containing 16 byte completions
294 	 * to be sent back to the user.
295 	 */
296 	union nvmf_c2h_msg			*cpls;
297 	struct ibv_mr				*cpls_mr;
298 
299 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
300 	 * buffers to be used for in capsule data.
301 	 */
302 	void					*bufs;
303 	struct ibv_mr				*bufs_mr;
304 
305 	/* Receives that are waiting for a request object */
306 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
307 
308 	/* Queue to track free requests */
309 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
310 };
311 
312 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
313 
314 struct spdk_nvmf_rdma_ibv_event_ctx {
315 	struct spdk_nvmf_rdma_qpair			*rqpair;
316 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
317 	/* Link to other ibv events associated with this qpair */
318 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
319 };
320 
321 struct spdk_nvmf_rdma_qpair {
322 	struct spdk_nvmf_qpair			qpair;
323 
324 	struct spdk_nvmf_rdma_device		*device;
325 	struct spdk_nvmf_rdma_poller		*poller;
326 
327 	struct spdk_rdma_qp			*rdma_qp;
328 	struct rdma_cm_id			*cm_id;
329 	struct spdk_rdma_srq			*srq;
330 	struct rdma_cm_id			*listen_id;
331 
332 	/* The maximum number of I/O outstanding on this connection at one time */
333 	uint16_t				max_queue_depth;
334 
335 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
336 	uint16_t				max_read_depth;
337 
338 	/* The maximum number of RDMA SEND operations at one time */
339 	uint32_t				max_send_depth;
340 
341 	/* The current number of outstanding WRs from this qpair's
342 	 * recv queue. Should not exceed device->attr.max_queue_depth.
343 	 */
344 	uint16_t				current_recv_depth;
345 
346 	/* The current number of active RDMA READ operations */
347 	uint16_t				current_read_depth;
348 
349 	/* The current number of posted WRs from this qpair's
350 	 * send queue. Should not exceed max_send_depth.
351 	 */
352 	uint32_t				current_send_depth;
353 
354 	/* The maximum number of SGEs per WR on the send queue */
355 	uint32_t				max_send_sge;
356 
357 	/* The maximum number of SGEs per WR on the recv queue */
358 	uint32_t				max_recv_sge;
359 
360 	struct spdk_nvmf_rdma_resources		*resources;
361 
362 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
363 
364 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
365 
366 	/* Number of requests not in the free state */
367 	uint32_t				qd;
368 
369 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
370 
371 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
372 
373 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
374 
375 	/* IBV queue pair attributes: they are used to manage
376 	 * qp state and recover from errors.
377 	 */
378 	enum ibv_qp_state			ibv_state;
379 
380 	/*
381 	 * io_channel which is used to destroy qpair when it is removed from poll group
382 	 */
383 	struct spdk_io_channel		*destruct_channel;
384 
385 	/* List of ibv async events */
386 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
387 
388 	/* Lets us know that we have received the last_wqe event. */
389 	bool					last_wqe_reached;
390 
391 	/* Indicate that nvmf_rdma_close_qpair is called */
392 	bool					to_close;
393 };
394 
395 struct spdk_nvmf_rdma_poller_stat {
396 	uint64_t				completions;
397 	uint64_t				polls;
398 	uint64_t				idle_polls;
399 	uint64_t				requests;
400 	uint64_t				request_latency;
401 	uint64_t				pending_free_request;
402 	uint64_t				pending_rdma_read;
403 	uint64_t				pending_rdma_write;
404 	struct spdk_rdma_qp_stats		qp_stats;
405 };
406 
407 struct spdk_nvmf_rdma_poller {
408 	struct spdk_nvmf_rdma_device		*device;
409 	struct spdk_nvmf_rdma_poll_group	*group;
410 
411 	int					num_cqe;
412 	int					required_num_wr;
413 	struct ibv_cq				*cq;
414 
415 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
416 	uint16_t				max_srq_depth;
417 
418 	/* Shared receive queue */
419 	struct spdk_rdma_srq			*srq;
420 
421 	struct spdk_nvmf_rdma_resources		*resources;
422 	struct spdk_nvmf_rdma_poller_stat	stat;
423 
424 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
425 
426 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
427 
428 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
429 
430 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
431 };
432 
433 struct spdk_nvmf_rdma_poll_group_stat {
434 	uint64_t				pending_data_buffer;
435 };
436 
437 struct spdk_nvmf_rdma_poll_group {
438 	struct spdk_nvmf_transport_poll_group		group;
439 	struct spdk_nvmf_rdma_poll_group_stat		stat;
440 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
441 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
442 };
443 
444 struct spdk_nvmf_rdma_conn_sched {
445 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
446 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
447 };
448 
449 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
450 struct spdk_nvmf_rdma_device {
451 	struct ibv_device_attr			attr;
452 	struct ibv_context			*context;
453 
454 	struct spdk_rdma_mem_map		*map;
455 	struct ibv_pd				*pd;
456 
457 	int					num_srq;
458 
459 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
460 };
461 
462 struct spdk_nvmf_rdma_port {
463 	const struct spdk_nvme_transport_id	*trid;
464 	struct rdma_cm_id			*id;
465 	struct spdk_nvmf_rdma_device		*device;
466 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
467 };
468 
469 struct rdma_transport_opts {
470 	int		num_cqe;
471 	uint32_t	max_srq_depth;
472 	bool		no_srq;
473 	bool		no_wr_batching;
474 	int		acceptor_backlog;
475 };
476 
477 struct spdk_nvmf_rdma_transport {
478 	struct spdk_nvmf_transport	transport;
479 	struct rdma_transport_opts	rdma_opts;
480 
481 	struct spdk_nvmf_rdma_conn_sched conn_sched;
482 
483 	struct rdma_event_channel	*event_channel;
484 
485 	struct spdk_mempool		*data_wr_pool;
486 
487 	pthread_mutex_t			lock;
488 
489 	/* fields used to poll RDMA/IB events */
490 	nfds_t			npoll_fds;
491 	struct pollfd		*poll_fds;
492 
493 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
494 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
495 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
496 };
497 
498 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
499 	{
500 		"num_cqe", offsetof(struct rdma_transport_opts, num_cqe),
501 		spdk_json_decode_int32, true
502 	},
503 	{
504 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
505 		spdk_json_decode_uint32, true
506 	},
507 	{
508 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
509 		spdk_json_decode_bool, true
510 	},
511 	{
512 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
513 		spdk_json_decode_bool, true
514 	},
515 	{
516 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
517 		spdk_json_decode_int32, true
518 	},
519 };
520 
521 static bool
522 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
523 			  struct spdk_nvmf_rdma_request *rdma_req);
524 
525 static void
526 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
527 		     struct spdk_nvmf_rdma_poller *rpoller);
528 
529 static void
530 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
531 		     struct spdk_nvmf_rdma_poller *rpoller);
532 
533 static inline int
534 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
535 {
536 	switch (state) {
537 	case IBV_QPS_RESET:
538 	case IBV_QPS_INIT:
539 	case IBV_QPS_RTR:
540 	case IBV_QPS_RTS:
541 	case IBV_QPS_SQD:
542 	case IBV_QPS_SQE:
543 	case IBV_QPS_ERR:
544 		return 0;
545 	default:
546 		return -1;
547 	}
548 }
549 
550 static inline enum spdk_nvme_media_error_status_code
551 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
552 	enum spdk_nvme_media_error_status_code result;
553 	switch (err_type)
554 	{
555 	case SPDK_DIF_REFTAG_ERROR:
556 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
557 		break;
558 	case SPDK_DIF_APPTAG_ERROR:
559 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
560 		break;
561 	case SPDK_DIF_GUARD_ERROR:
562 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
563 		break;
564 	default:
565 		SPDK_UNREACHABLE();
566 	}
567 
568 	return result;
569 }
570 
571 static enum ibv_qp_state
572 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
573 	enum ibv_qp_state old_state, new_state;
574 	struct ibv_qp_attr qp_attr;
575 	struct ibv_qp_init_attr init_attr;
576 	int rc;
577 
578 	old_state = rqpair->ibv_state;
579 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
580 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
581 
582 	if (rc)
583 	{
584 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
585 		return IBV_QPS_ERR + 1;
586 	}
587 
588 	new_state = qp_attr.qp_state;
589 	rqpair->ibv_state = new_state;
590 	qp_attr.ah_attr.port_num = qp_attr.port_num;
591 
592 	rc = nvmf_rdma_check_ibv_state(new_state);
593 	if (rc)
594 	{
595 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
596 		/*
597 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
598 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
599 		 */
600 		return IBV_QPS_ERR + 1;
601 	}
602 
603 	if (old_state != new_state)
604 	{
605 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
606 				  (uintptr_t)rqpair->cm_id, new_state);
607 	}
608 	return new_state;
609 }
610 
611 static void
612 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
613 			    struct spdk_nvmf_rdma_transport *rtransport)
614 {
615 	struct spdk_nvmf_rdma_request_data	*data_wr;
616 	struct ibv_send_wr			*next_send_wr;
617 	uint64_t				req_wrid;
618 
619 	rdma_req->num_outstanding_data_wr = 0;
620 	data_wr = &rdma_req->data;
621 	req_wrid = data_wr->wr.wr_id;
622 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
623 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
624 		data_wr->wr.num_sge = 0;
625 		next_send_wr = data_wr->wr.next;
626 		if (data_wr != &rdma_req->data) {
627 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
628 		}
629 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
630 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
631 	}
632 }
633 
634 static void
635 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
636 {
637 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
638 	if (req->req.cmd) {
639 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
640 	}
641 	if (req->recv) {
642 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
643 	}
644 }
645 
646 static void
647 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
648 {
649 	int i;
650 
651 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
652 	for (i = 0; i < rqpair->max_queue_depth; i++) {
653 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
654 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
655 		}
656 	}
657 }
658 
659 static void
660 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
661 {
662 	if (resources->cmds_mr) {
663 		ibv_dereg_mr(resources->cmds_mr);
664 	}
665 
666 	if (resources->cpls_mr) {
667 		ibv_dereg_mr(resources->cpls_mr);
668 	}
669 
670 	if (resources->bufs_mr) {
671 		ibv_dereg_mr(resources->bufs_mr);
672 	}
673 
674 	spdk_free(resources->cmds);
675 	spdk_free(resources->cpls);
676 	spdk_free(resources->bufs);
677 	free(resources->reqs);
678 	free(resources->recvs);
679 	free(resources);
680 }
681 
682 
683 static struct spdk_nvmf_rdma_resources *
684 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
685 {
686 	struct spdk_nvmf_rdma_resources	*resources;
687 	struct spdk_nvmf_rdma_request	*rdma_req;
688 	struct spdk_nvmf_rdma_recv	*rdma_recv;
689 	struct spdk_rdma_qp		*qp = NULL;
690 	struct spdk_rdma_srq		*srq = NULL;
691 	struct ibv_recv_wr		*bad_wr = NULL;
692 	uint32_t			i;
693 	int				rc = 0;
694 
695 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
696 	if (!resources) {
697 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
698 		return NULL;
699 	}
700 
701 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
702 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
703 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
704 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
705 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
706 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
707 
708 	if (opts->in_capsule_data_size > 0) {
709 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
710 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
711 					       SPDK_MALLOC_DMA);
712 	}
713 
714 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
715 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
716 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
717 		goto cleanup;
718 	}
719 
720 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
721 					opts->max_queue_depth * sizeof(*resources->cmds),
722 					IBV_ACCESS_LOCAL_WRITE);
723 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
724 					opts->max_queue_depth * sizeof(*resources->cpls),
725 					0);
726 
727 	if (opts->in_capsule_data_size) {
728 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
729 						opts->max_queue_depth *
730 						opts->in_capsule_data_size,
731 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
732 	}
733 
734 	if (!resources->cmds_mr || !resources->cpls_mr ||
735 	    (opts->in_capsule_data_size &&
736 	     !resources->bufs_mr)) {
737 		goto cleanup;
738 	}
739 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
740 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
741 		      resources->cmds_mr->lkey);
742 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
743 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
744 		      resources->cpls_mr->lkey);
745 	if (resources->bufs && resources->bufs_mr) {
746 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
747 			      resources->bufs, opts->max_queue_depth *
748 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
749 	}
750 
751 	/* Initialize queues */
752 	STAILQ_INIT(&resources->incoming_queue);
753 	STAILQ_INIT(&resources->free_queue);
754 
755 	if (opts->shared) {
756 		srq = (struct spdk_rdma_srq *)opts->qp;
757 	} else {
758 		qp = (struct spdk_rdma_qp *)opts->qp;
759 	}
760 
761 	for (i = 0; i < opts->max_queue_depth; i++) {
762 		rdma_recv = &resources->recvs[i];
763 		rdma_recv->qpair = opts->qpair;
764 
765 		/* Set up memory to receive commands */
766 		if (resources->bufs) {
767 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
768 						  opts->in_capsule_data_size));
769 		}
770 
771 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
772 
773 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
774 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
775 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
776 		rdma_recv->wr.num_sge = 1;
777 
778 		if (rdma_recv->buf && resources->bufs_mr) {
779 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
780 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
781 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
782 			rdma_recv->wr.num_sge++;
783 		}
784 
785 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
786 		rdma_recv->wr.sg_list = rdma_recv->sgl;
787 		if (srq) {
788 			spdk_rdma_srq_queue_recv_wrs(srq, &rdma_recv->wr);
789 		} else {
790 			spdk_rdma_qp_queue_recv_wrs(qp, &rdma_recv->wr);
791 		}
792 	}
793 
794 	for (i = 0; i < opts->max_queue_depth; i++) {
795 		rdma_req = &resources->reqs[i];
796 
797 		if (opts->qpair != NULL) {
798 			rdma_req->req.qpair = &opts->qpair->qpair;
799 		} else {
800 			rdma_req->req.qpair = NULL;
801 		}
802 		rdma_req->req.cmd = NULL;
803 
804 		/* Set up memory to send responses */
805 		rdma_req->req.rsp = &resources->cpls[i];
806 
807 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
808 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
809 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
810 
811 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
812 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
813 		rdma_req->rsp.wr.next = NULL;
814 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
815 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
816 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
817 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
818 
819 		/* Set up memory for data buffers */
820 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
821 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
822 		rdma_req->data.wr.next = NULL;
823 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
824 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
825 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
826 
827 		/* Initialize request state to FREE */
828 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
829 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
830 	}
831 
832 	if (srq) {
833 		rc = spdk_rdma_srq_flush_recv_wrs(srq, &bad_wr);
834 	} else {
835 		rc = spdk_rdma_qp_flush_recv_wrs(qp, &bad_wr);
836 	}
837 
838 	if (rc) {
839 		goto cleanup;
840 	}
841 
842 	return resources;
843 
844 cleanup:
845 	nvmf_rdma_resources_destroy(resources);
846 	return NULL;
847 }
848 
849 static void
850 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
851 {
852 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
853 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
854 		ctx->rqpair = NULL;
855 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
856 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
857 	}
858 }
859 
860 static void
861 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
862 {
863 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
864 	struct ibv_recv_wr		*bad_recv_wr = NULL;
865 	int				rc;
866 
867 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
868 
869 	if (rqpair->qd != 0) {
870 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
871 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
872 				struct spdk_nvmf_rdma_transport, transport);
873 		struct spdk_nvmf_rdma_request *req;
874 		uint32_t i, max_req_count = 0;
875 
876 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
877 
878 		if (rqpair->srq == NULL) {
879 			nvmf_rdma_dump_qpair_contents(rqpair);
880 			max_req_count = rqpair->max_queue_depth;
881 		} else if (rqpair->poller && rqpair->resources) {
882 			max_req_count = rqpair->poller->max_srq_depth;
883 		}
884 
885 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
886 		for (i = 0; i < max_req_count; i++) {
887 			req = &rqpair->resources->reqs[i];
888 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
889 				/* nvmf_rdma_request_process checks qpair ibv and internal state
890 				 * and completes a request */
891 				nvmf_rdma_request_process(rtransport, req);
892 			}
893 		}
894 		assert(rqpair->qd == 0);
895 	}
896 
897 	if (rqpair->poller) {
898 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
899 
900 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
901 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
902 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
903 				if (rqpair == rdma_recv->qpair) {
904 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
905 					spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_recv->wr);
906 					rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
907 					if (rc) {
908 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
909 					}
910 				}
911 			}
912 		}
913 	}
914 
915 	if (rqpair->cm_id) {
916 		if (rqpair->rdma_qp != NULL) {
917 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
918 			rqpair->rdma_qp = NULL;
919 		}
920 		rdma_destroy_id(rqpair->cm_id);
921 
922 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
923 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
924 		}
925 	}
926 
927 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
928 		nvmf_rdma_resources_destroy(rqpair->resources);
929 	}
930 
931 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
932 
933 	if (rqpair->destruct_channel) {
934 		spdk_put_io_channel(rqpair->destruct_channel);
935 		rqpair->destruct_channel = NULL;
936 	}
937 
938 	free(rqpair);
939 }
940 
941 static int
942 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
943 {
944 	struct spdk_nvmf_rdma_poller	*rpoller;
945 	int				rc, num_cqe, required_num_wr;
946 
947 	/* Enlarge CQ size dynamically */
948 	rpoller = rqpair->poller;
949 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
950 	num_cqe = rpoller->num_cqe;
951 	if (num_cqe < required_num_wr) {
952 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
953 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
954 	}
955 
956 	if (rpoller->num_cqe != num_cqe) {
957 		if (device->context->device->transport_type == IBV_TRANSPORT_IWARP) {
958 			SPDK_ERRLOG("iWARP doesn't support CQ resize. Current capacity %u, required %u\n"
959 				    "Using CQ of insufficient size may lead to CQ overrun\n", rpoller->num_cqe, num_cqe);
960 			return -1;
961 		}
962 		if (required_num_wr > device->attr.max_cqe) {
963 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
964 				    required_num_wr, device->attr.max_cqe);
965 			return -1;
966 		}
967 
968 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
969 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
970 		if (rc) {
971 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
972 			return -1;
973 		}
974 
975 		rpoller->num_cqe = num_cqe;
976 	}
977 
978 	rpoller->required_num_wr = required_num_wr;
979 	return 0;
980 }
981 
982 static int
983 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
984 {
985 	struct spdk_nvmf_rdma_qpair		*rqpair;
986 	struct spdk_nvmf_rdma_transport		*rtransport;
987 	struct spdk_nvmf_transport		*transport;
988 	struct spdk_nvmf_rdma_resource_opts	opts;
989 	struct spdk_nvmf_rdma_device		*device;
990 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
991 
992 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
993 	device = rqpair->device;
994 
995 	qp_init_attr.qp_context	= rqpair;
996 	qp_init_attr.pd		= device->pd;
997 	qp_init_attr.send_cq	= rqpair->poller->cq;
998 	qp_init_attr.recv_cq	= rqpair->poller->cq;
999 
1000 	if (rqpair->srq) {
1001 		qp_init_attr.srq		= rqpair->srq->srq;
1002 	} else {
1003 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
1004 	}
1005 
1006 	/* SEND, READ, and WRITE operations */
1007 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
1008 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1009 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1010 	qp_init_attr.stats		= &rqpair->poller->stat.qp_stats;
1011 
1012 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1013 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1014 		goto error;
1015 	}
1016 
1017 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1018 	if (!rqpair->rdma_qp) {
1019 		goto error;
1020 	}
1021 
1022 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1023 					  qp_init_attr.cap.max_send_wr);
1024 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1025 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1026 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1027 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1028 
1029 	if (rqpair->poller->srq == NULL) {
1030 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1031 		transport = &rtransport->transport;
1032 
1033 		opts.qp = rqpair->rdma_qp;
1034 		opts.pd = rqpair->cm_id->pd;
1035 		opts.qpair = rqpair;
1036 		opts.shared = false;
1037 		opts.max_queue_depth = rqpair->max_queue_depth;
1038 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1039 
1040 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1041 
1042 		if (!rqpair->resources) {
1043 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1044 			rdma_destroy_qp(rqpair->cm_id);
1045 			goto error;
1046 		}
1047 	} else {
1048 		rqpair->resources = rqpair->poller->resources;
1049 	}
1050 
1051 	rqpair->current_recv_depth = 0;
1052 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1053 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1054 
1055 	return 0;
1056 
1057 error:
1058 	rdma_destroy_id(rqpair->cm_id);
1059 	rqpair->cm_id = NULL;
1060 	return -1;
1061 }
1062 
1063 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1064 /* This function accepts either a single wr or the first wr in a linked list. */
1065 static void
1066 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1067 {
1068 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1069 			struct spdk_nvmf_rdma_transport, transport);
1070 
1071 	if (rqpair->srq != NULL) {
1072 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, first);
1073 	} else {
1074 		if (spdk_rdma_qp_queue_recv_wrs(rqpair->rdma_qp, first)) {
1075 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1076 		}
1077 	}
1078 
1079 	if (rtransport->rdma_opts.no_wr_batching) {
1080 		_poller_submit_recvs(rtransport, rqpair->poller);
1081 	}
1082 }
1083 
1084 static int
1085 request_transfer_in(struct spdk_nvmf_request *req)
1086 {
1087 	struct spdk_nvmf_rdma_request	*rdma_req;
1088 	struct spdk_nvmf_qpair		*qpair;
1089 	struct spdk_nvmf_rdma_qpair	*rqpair;
1090 	struct spdk_nvmf_rdma_transport *rtransport;
1091 
1092 	qpair = req->qpair;
1093 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1094 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1095 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1096 				      struct spdk_nvmf_rdma_transport, transport);
1097 
1098 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1099 	assert(rdma_req != NULL);
1100 
1101 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1102 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1103 	}
1104 	if (rtransport->rdma_opts.no_wr_batching) {
1105 		_poller_submit_sends(rtransport, rqpair->poller);
1106 	}
1107 
1108 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1109 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1110 	return 0;
1111 }
1112 
1113 static int
1114 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1115 {
1116 	int				num_outstanding_data_wr = 0;
1117 	struct spdk_nvmf_rdma_request	*rdma_req;
1118 	struct spdk_nvmf_qpair		*qpair;
1119 	struct spdk_nvmf_rdma_qpair	*rqpair;
1120 	struct spdk_nvme_cpl		*rsp;
1121 	struct ibv_send_wr		*first = NULL;
1122 	struct spdk_nvmf_rdma_transport *rtransport;
1123 
1124 	*data_posted = 0;
1125 	qpair = req->qpair;
1126 	rsp = &req->rsp->nvme_cpl;
1127 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1128 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1129 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1130 				      struct spdk_nvmf_rdma_transport, transport);
1131 
1132 	/* Advance our sq_head pointer */
1133 	if (qpair->sq_head == qpair->sq_head_max) {
1134 		qpair->sq_head = 0;
1135 	} else {
1136 		qpair->sq_head++;
1137 	}
1138 	rsp->sqhd = qpair->sq_head;
1139 
1140 	/* queue the capsule for the recv buffer */
1141 	assert(rdma_req->recv != NULL);
1142 
1143 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1144 
1145 	rdma_req->recv = NULL;
1146 	assert(rqpair->current_recv_depth > 0);
1147 	rqpair->current_recv_depth--;
1148 
1149 	/* Build the response which consists of optional
1150 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1151 	 * containing the response.
1152 	 */
1153 	first = &rdma_req->rsp.wr;
1154 
1155 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1156 		/* On failure, data was not read from the controller. So clear the
1157 		 * number of outstanding data WRs to zero.
1158 		 */
1159 		rdma_req->num_outstanding_data_wr = 0;
1160 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1161 		first = &rdma_req->data.wr;
1162 		*data_posted = 1;
1163 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1164 	}
1165 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1166 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1167 	}
1168 	if (rtransport->rdma_opts.no_wr_batching) {
1169 		_poller_submit_sends(rtransport, rqpair->poller);
1170 	}
1171 
1172 	/* +1 for the rsp wr */
1173 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1174 
1175 	return 0;
1176 }
1177 
1178 static int
1179 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1180 {
1181 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1182 	struct rdma_conn_param				ctrlr_event_data = {};
1183 	int						rc;
1184 
1185 	accept_data.recfmt = 0;
1186 	accept_data.crqsize = rqpair->max_queue_depth;
1187 
1188 	ctrlr_event_data.private_data = &accept_data;
1189 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1190 	if (id->ps == RDMA_PS_TCP) {
1191 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1192 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1193 	}
1194 
1195 	/* Configure infinite retries for the initiator side qpair.
1196 	 * When using a shared receive queue on the target side,
1197 	 * we need to pass this value to the initiator to prevent the
1198 	 * initiator side NIC from completing SEND requests back to the
1199 	 * initiator with status rnr_retry_count_exceeded. */
1200 	if (rqpair->srq != NULL) {
1201 		ctrlr_event_data.rnr_retry_count = 0x7;
1202 	}
1203 
1204 	/* When qpair is created without use of rdma cm API, an additional
1205 	 * information must be provided to initiator in the connection response:
1206 	 * whether qpair is using SRQ and its qp_num
1207 	 * Fields below are ignored by rdma cm if qpair has been
1208 	 * created using rdma cm API. */
1209 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1210 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1211 
1212 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1213 	if (rc) {
1214 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1215 	} else {
1216 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1217 	}
1218 
1219 	return rc;
1220 }
1221 
1222 static void
1223 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1224 {
1225 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1226 
1227 	rej_data.recfmt = 0;
1228 	rej_data.sts = error;
1229 
1230 	rdma_reject(id, &rej_data, sizeof(rej_data));
1231 }
1232 
1233 static int
1234 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1235 {
1236 	struct spdk_nvmf_rdma_transport *rtransport;
1237 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1238 	struct spdk_nvmf_rdma_port	*port;
1239 	struct rdma_conn_param		*rdma_param = NULL;
1240 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1241 	uint16_t			max_queue_depth;
1242 	uint16_t			max_read_depth;
1243 
1244 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1245 
1246 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1247 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1248 
1249 	rdma_param = &event->param.conn;
1250 	if (rdma_param->private_data == NULL ||
1251 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1252 		SPDK_ERRLOG("connect request: no private data provided\n");
1253 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1254 		return -1;
1255 	}
1256 
1257 	private_data = rdma_param->private_data;
1258 	if (private_data->recfmt != 0) {
1259 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1260 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1261 		return -1;
1262 	}
1263 
1264 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1265 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1266 
1267 	port = event->listen_id->context;
1268 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1269 		      event->listen_id, event->listen_id->verbs, port);
1270 
1271 	/* Figure out the supported queue depth. This is a multi-step process
1272 	 * that takes into account hardware maximums, host provided values,
1273 	 * and our target's internal memory limits */
1274 
1275 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1276 
1277 	/* Start with the maximum queue depth allowed by the target */
1278 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1279 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1280 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1281 		      rtransport->transport.opts.max_queue_depth);
1282 
1283 	/* Next check the local NIC's hardware limitations */
1284 	SPDK_DEBUGLOG(rdma,
1285 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1286 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1287 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1288 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1289 
1290 	/* Next check the remote NIC's hardware limitations */
1291 	SPDK_DEBUGLOG(rdma,
1292 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1293 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1294 	if (rdma_param->initiator_depth > 0) {
1295 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1296 	}
1297 
1298 	/* Finally check for the host software requested values, which are
1299 	 * optional. */
1300 	if (rdma_param->private_data != NULL &&
1301 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1302 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1303 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1304 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1305 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1306 	}
1307 
1308 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1309 		      max_queue_depth, max_read_depth);
1310 
1311 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1312 	if (rqpair == NULL) {
1313 		SPDK_ERRLOG("Could not allocate new connection.\n");
1314 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1315 		return -1;
1316 	}
1317 
1318 	rqpair->device = port->device;
1319 	rqpair->max_queue_depth = max_queue_depth;
1320 	rqpair->max_read_depth = max_read_depth;
1321 	rqpair->cm_id = event->id;
1322 	rqpair->listen_id = event->listen_id;
1323 	rqpair->qpair.transport = transport;
1324 	STAILQ_INIT(&rqpair->ibv_events);
1325 	/* use qid from the private data to determine the qpair type
1326 	   qid will be set to the appropriate value when the controller is created */
1327 	rqpair->qpair.qid = private_data->qid;
1328 
1329 	event->id->context = &rqpair->qpair;
1330 
1331 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1332 
1333 	return 0;
1334 }
1335 
1336 static inline void
1337 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1338 		   enum spdk_nvme_data_transfer xfer)
1339 {
1340 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1341 		wr->opcode = IBV_WR_RDMA_WRITE;
1342 		wr->send_flags = 0;
1343 		wr->next = next;
1344 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1345 		wr->opcode = IBV_WR_RDMA_READ;
1346 		wr->send_flags = IBV_SEND_SIGNALED;
1347 		wr->next = NULL;
1348 	} else {
1349 		assert(0);
1350 	}
1351 }
1352 
1353 static int
1354 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1355 		       struct spdk_nvmf_rdma_request *rdma_req,
1356 		       uint32_t num_sgl_descriptors)
1357 {
1358 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1359 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1360 	uint32_t				i;
1361 
1362 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1363 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1364 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1365 		return -EINVAL;
1366 	}
1367 
1368 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1369 		return -ENOMEM;
1370 	}
1371 
1372 	current_data_wr = &rdma_req->data;
1373 
1374 	for (i = 0; i < num_sgl_descriptors; i++) {
1375 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1376 		current_data_wr->wr.next = &work_requests[i]->wr;
1377 		current_data_wr = work_requests[i];
1378 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1379 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1380 	}
1381 
1382 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1383 
1384 	return 0;
1385 }
1386 
1387 static inline void
1388 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1389 {
1390 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1391 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1392 
1393 	wr->wr.rdma.rkey = sgl->keyed.key;
1394 	wr->wr.rdma.remote_addr = sgl->address;
1395 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1396 }
1397 
1398 static inline void
1399 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1400 {
1401 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1402 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1403 	uint32_t			i;
1404 	int				j;
1405 	uint64_t			remote_addr_offset = 0;
1406 
1407 	for (i = 0; i < num_wrs; ++i) {
1408 		wr->wr.rdma.rkey = sgl->keyed.key;
1409 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1410 		for (j = 0; j < wr->num_sge; ++j) {
1411 			remote_addr_offset += wr->sg_list[j].length;
1412 		}
1413 		wr = wr->next;
1414 	}
1415 }
1416 
1417 static bool
1418 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1419 		      struct iovec *iov, struct ibv_send_wr **_wr,
1420 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1421 		      uint32_t *_num_extra_wrs,
1422 		      const struct spdk_dif_ctx *dif_ctx)
1423 {
1424 	struct ibv_send_wr *wr = *_wr;
1425 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1426 	struct spdk_rdma_memory_translation mem_translation;
1427 	int		rc;
1428 	uint32_t	lkey = 0;
1429 	uint32_t	remaining, data_block_size, md_size, sge_len;
1430 
1431 	rc = spdk_rdma_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1432 	if (spdk_unlikely(rc)) {
1433 		return false;
1434 	}
1435 
1436 	lkey = spdk_rdma_memory_translation_get_lkey(&mem_translation);
1437 
1438 	if (spdk_likely(!dif_ctx)) {
1439 		sg_ele->lkey = lkey;
1440 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1441 		sg_ele->length = iov->iov_len;
1442 		wr->num_sge++;
1443 	} else {
1444 		remaining = iov->iov_len - *_offset;
1445 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1446 		md_size = dif_ctx->md_size;
1447 
1448 		while (remaining) {
1449 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1450 				if (*_num_extra_wrs > 0 && wr->next) {
1451 					*_wr = wr->next;
1452 					wr = *_wr;
1453 					wr->num_sge = 0;
1454 					sg_ele = &wr->sg_list[wr->num_sge];
1455 					(*_num_extra_wrs)--;
1456 				} else {
1457 					break;
1458 				}
1459 			}
1460 			sg_ele->lkey = lkey;
1461 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1462 			sge_len = spdk_min(remaining, *_remaining_data_block);
1463 			sg_ele->length = sge_len;
1464 			remaining -= sge_len;
1465 			*_remaining_data_block -= sge_len;
1466 			*_offset += sge_len;
1467 
1468 			sg_ele++;
1469 			wr->num_sge++;
1470 
1471 			if (*_remaining_data_block == 0) {
1472 				/* skip metadata */
1473 				*_offset += md_size;
1474 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1475 				remaining -= spdk_min(remaining, md_size);
1476 				*_remaining_data_block = data_block_size;
1477 			}
1478 
1479 			if (remaining == 0) {
1480 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1481 				   the remaining metadata bits at the beginning of the next buffer */
1482 				*_offset -= iov->iov_len;
1483 			}
1484 		}
1485 	}
1486 
1487 	return true;
1488 }
1489 
1490 static int
1491 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1492 		      struct spdk_nvmf_rdma_device *device,
1493 		      struct spdk_nvmf_rdma_request *rdma_req,
1494 		      struct ibv_send_wr *wr,
1495 		      uint32_t length,
1496 		      uint32_t num_extra_wrs)
1497 {
1498 	struct spdk_nvmf_request *req = &rdma_req->req;
1499 	struct spdk_dif_ctx *dif_ctx = NULL;
1500 	uint32_t remaining_data_block = 0;
1501 	uint32_t offset = 0;
1502 
1503 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1504 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1505 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1506 	}
1507 
1508 	wr->num_sge = 0;
1509 
1510 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1511 		if (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1512 				  &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1513 			return -EINVAL;
1514 		}
1515 
1516 		length -= req->iov[rdma_req->iovpos].iov_len;
1517 		rdma_req->iovpos++;
1518 	}
1519 
1520 	if (length) {
1521 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1522 		return -EINVAL;
1523 	}
1524 
1525 	return 0;
1526 }
1527 
1528 static inline uint32_t
1529 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1530 {
1531 	/* estimate the number of SG entries and WRs needed to process the request */
1532 	uint32_t num_sge = 0;
1533 	uint32_t i;
1534 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1535 
1536 	for (i = 0; i < num_buffers && length > 0; i++) {
1537 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1538 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1539 
1540 		if (num_sge_in_block * block_size > buffer_len) {
1541 			++num_sge_in_block;
1542 		}
1543 		num_sge += num_sge_in_block;
1544 		length -= buffer_len;
1545 	}
1546 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1547 }
1548 
1549 static int
1550 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1551 			    struct spdk_nvmf_rdma_device *device,
1552 			    struct spdk_nvmf_rdma_request *rdma_req,
1553 			    uint32_t length)
1554 {
1555 	struct spdk_nvmf_rdma_qpair		*rqpair;
1556 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1557 	struct spdk_nvmf_request		*req = &rdma_req->req;
1558 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1559 	int					rc;
1560 	uint32_t				num_wrs = 1;
1561 
1562 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1563 	rgroup = rqpair->poller->group;
1564 
1565 	/* rdma wr specifics */
1566 	nvmf_rdma_setup_request(rdma_req);
1567 
1568 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1569 					   length);
1570 	if (rc != 0) {
1571 		return rc;
1572 	}
1573 
1574 	assert(req->iovcnt <= rqpair->max_send_sge);
1575 
1576 	rdma_req->iovpos = 0;
1577 
1578 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1579 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1580 						 req->dif.dif_ctx.block_size);
1581 		if (num_wrs > 1) {
1582 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1583 			if (rc != 0) {
1584 				goto err_exit;
1585 			}
1586 		}
1587 	}
1588 
1589 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1590 	if (spdk_unlikely(rc != 0)) {
1591 		goto err_exit;
1592 	}
1593 
1594 	if (spdk_unlikely(num_wrs > 1)) {
1595 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1596 	}
1597 
1598 	/* set the number of outstanding data WRs for this request. */
1599 	rdma_req->num_outstanding_data_wr = num_wrs;
1600 
1601 	return rc;
1602 
1603 err_exit:
1604 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1605 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1606 	req->iovcnt = 0;
1607 	return rc;
1608 }
1609 
1610 static int
1611 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1612 				      struct spdk_nvmf_rdma_device *device,
1613 				      struct spdk_nvmf_rdma_request *rdma_req)
1614 {
1615 	struct spdk_nvmf_rdma_qpair		*rqpair;
1616 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1617 	struct ibv_send_wr			*current_wr;
1618 	struct spdk_nvmf_request		*req = &rdma_req->req;
1619 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1620 	uint32_t				num_sgl_descriptors;
1621 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1622 	uint32_t				i;
1623 	int					rc;
1624 
1625 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1626 	rgroup = rqpair->poller->group;
1627 
1628 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1629 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1630 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1631 
1632 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1633 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1634 
1635 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1636 		return -ENOMEM;
1637 	}
1638 
1639 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1640 	for (i = 0; i < num_sgl_descriptors; i++) {
1641 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1642 			lengths[i] = desc->keyed.length;
1643 		} else {
1644 			req->dif.orig_length += desc->keyed.length;
1645 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1646 			req->dif.elba_length += lengths[i];
1647 		}
1648 		desc++;
1649 	}
1650 
1651 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1652 			lengths, num_sgl_descriptors);
1653 	if (rc != 0) {
1654 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1655 		return rc;
1656 	}
1657 
1658 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1659 	current_wr = &rdma_req->data.wr;
1660 	assert(current_wr != NULL);
1661 
1662 	req->length = 0;
1663 	rdma_req->iovpos = 0;
1664 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1665 	for (i = 0; i < num_sgl_descriptors; i++) {
1666 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1667 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1668 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1669 			rc = -EINVAL;
1670 			goto err_exit;
1671 		}
1672 
1673 		current_wr->num_sge = 0;
1674 
1675 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1676 		if (rc != 0) {
1677 			rc = -ENOMEM;
1678 			goto err_exit;
1679 		}
1680 
1681 		req->length += desc->keyed.length;
1682 		current_wr->wr.rdma.rkey = desc->keyed.key;
1683 		current_wr->wr.rdma.remote_addr = desc->address;
1684 		current_wr = current_wr->next;
1685 		desc++;
1686 	}
1687 
1688 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1689 	/* Go back to the last descriptor in the list. */
1690 	desc--;
1691 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1692 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1693 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1694 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1695 		}
1696 	}
1697 #endif
1698 
1699 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1700 
1701 	return 0;
1702 
1703 err_exit:
1704 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1705 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1706 	return rc;
1707 }
1708 
1709 static int
1710 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1711 			    struct spdk_nvmf_rdma_device *device,
1712 			    struct spdk_nvmf_rdma_request *rdma_req)
1713 {
1714 	struct spdk_nvmf_request		*req = &rdma_req->req;
1715 	struct spdk_nvme_cpl			*rsp;
1716 	struct spdk_nvme_sgl_descriptor		*sgl;
1717 	int					rc;
1718 	uint32_t				length;
1719 
1720 	rsp = &req->rsp->nvme_cpl;
1721 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1722 
1723 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1724 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1725 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1726 
1727 		length = sgl->keyed.length;
1728 		if (length > rtransport->transport.opts.max_io_size) {
1729 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1730 				    length, rtransport->transport.opts.max_io_size);
1731 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1732 			return -1;
1733 		}
1734 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1735 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1736 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1737 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1738 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1739 			}
1740 		}
1741 #endif
1742 
1743 		/* fill request length and populate iovs */
1744 		req->length = length;
1745 
1746 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1747 			req->dif.orig_length = length;
1748 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1749 			req->dif.elba_length = length;
1750 		}
1751 
1752 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1753 		if (spdk_unlikely(rc < 0)) {
1754 			if (rc == -EINVAL) {
1755 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1756 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1757 				return -1;
1758 			}
1759 			/* No available buffers. Queue this request up. */
1760 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1761 			return 0;
1762 		}
1763 
1764 		/* backward compatible */
1765 		req->data = req->iov[0].iov_base;
1766 
1767 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1768 			      req->iovcnt);
1769 
1770 		return 0;
1771 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1772 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1773 		uint64_t offset = sgl->address;
1774 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1775 
1776 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1777 			      offset, sgl->unkeyed.length);
1778 
1779 		if (offset > max_len) {
1780 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1781 				    offset, max_len);
1782 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1783 			return -1;
1784 		}
1785 		max_len -= (uint32_t)offset;
1786 
1787 		if (sgl->unkeyed.length > max_len) {
1788 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1789 				    sgl->unkeyed.length, max_len);
1790 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1791 			return -1;
1792 		}
1793 
1794 		rdma_req->num_outstanding_data_wr = 0;
1795 		req->data = rdma_req->recv->buf + offset;
1796 		req->data_from_pool = false;
1797 		req->length = sgl->unkeyed.length;
1798 
1799 		req->iov[0].iov_base = req->data;
1800 		req->iov[0].iov_len = req->length;
1801 		req->iovcnt = 1;
1802 
1803 		return 0;
1804 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1805 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1806 
1807 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1808 		if (rc == -ENOMEM) {
1809 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1810 			return 0;
1811 		} else if (rc == -EINVAL) {
1812 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1813 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1814 			return -1;
1815 		}
1816 
1817 		/* backward compatible */
1818 		req->data = req->iov[0].iov_base;
1819 
1820 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1821 			      req->iovcnt);
1822 
1823 		return 0;
1824 	}
1825 
1826 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1827 		    sgl->generic.type, sgl->generic.subtype);
1828 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1829 	return -1;
1830 }
1831 
1832 static void
1833 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1834 			struct spdk_nvmf_rdma_transport	*rtransport)
1835 {
1836 	struct spdk_nvmf_rdma_qpair		*rqpair;
1837 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1838 
1839 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1840 	if (rdma_req->req.data_from_pool) {
1841 		rgroup = rqpair->poller->group;
1842 
1843 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1844 	}
1845 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1846 	rdma_req->req.length = 0;
1847 	rdma_req->req.iovcnt = 0;
1848 	rdma_req->req.data = NULL;
1849 	rdma_req->rsp.wr.next = NULL;
1850 	rdma_req->data.wr.next = NULL;
1851 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1852 	rqpair->qd--;
1853 
1854 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1855 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1856 }
1857 
1858 bool
1859 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1860 			  struct spdk_nvmf_rdma_request *rdma_req)
1861 {
1862 	struct spdk_nvmf_rdma_qpair	*rqpair;
1863 	struct spdk_nvmf_rdma_device	*device;
1864 	struct spdk_nvmf_rdma_poll_group *rgroup;
1865 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1866 	int				rc;
1867 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1868 	enum spdk_nvmf_rdma_request_state prev_state;
1869 	bool				progress = false;
1870 	int				data_posted;
1871 	uint32_t			num_blocks;
1872 
1873 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1874 	device = rqpair->device;
1875 	rgroup = rqpair->poller->group;
1876 
1877 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1878 
1879 	/* If the queue pair is in an error state, force the request to the completed state
1880 	 * to release resources. */
1881 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1882 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1883 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1884 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1885 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1886 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1887 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1888 		}
1889 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1890 	}
1891 
1892 	/* The loop here is to allow for several back-to-back state changes. */
1893 	do {
1894 		prev_state = rdma_req->state;
1895 
1896 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
1897 
1898 		switch (rdma_req->state) {
1899 		case RDMA_REQUEST_STATE_FREE:
1900 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1901 			 * to escape this state. */
1902 			break;
1903 		case RDMA_REQUEST_STATE_NEW:
1904 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1905 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1906 			rdma_recv = rdma_req->recv;
1907 
1908 			/* The first element of the SGL is the NVMe command */
1909 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1910 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1911 
1912 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1913 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1914 				break;
1915 			}
1916 
1917 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
1918 				rdma_req->req.dif.dif_insert_or_strip = true;
1919 			}
1920 
1921 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1922 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1923 			rdma_req->rsp.wr.imm_data = 0;
1924 #endif
1925 
1926 			/* The next state transition depends on the data transfer needs of this request. */
1927 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
1928 
1929 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
1930 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
1931 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
1932 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1933 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
1934 				break;
1935 			}
1936 
1937 			/* If no data to transfer, ready to execute. */
1938 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1939 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1940 				break;
1941 			}
1942 
1943 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1944 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
1945 			break;
1946 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1947 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1948 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1949 
1950 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1951 
1952 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
1953 				/* This request needs to wait in line to obtain a buffer */
1954 				break;
1955 			}
1956 
1957 			/* Try to get a data buffer */
1958 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1959 			if (rc < 0) {
1960 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1961 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1962 				break;
1963 			}
1964 
1965 			if (!rdma_req->req.data) {
1966 				/* No buffers available. */
1967 				rgroup->stat.pending_data_buffer++;
1968 				break;
1969 			}
1970 
1971 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1972 
1973 			/* If data is transferring from host to controller and the data didn't
1974 			 * arrive using in capsule data, we need to do a transfer from the host.
1975 			 */
1976 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
1977 			    rdma_req->req.data_from_pool) {
1978 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1979 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1980 				break;
1981 			}
1982 
1983 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1984 			break;
1985 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1986 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1987 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1988 
1989 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
1990 				/* This request needs to wait in line to perform RDMA */
1991 				break;
1992 			}
1993 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1994 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1995 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1996 				rqpair->poller->stat.pending_rdma_read++;
1997 				break;
1998 			}
1999 
2000 			/* We have already verified that this request is the head of the queue. */
2001 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2002 
2003 			rc = request_transfer_in(&rdma_req->req);
2004 			if (!rc) {
2005 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2006 			} else {
2007 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2008 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2009 			}
2010 			break;
2011 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2012 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2013 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2014 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2015 			 * to escape this state. */
2016 			break;
2017 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2018 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2019 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2020 
2021 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2022 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2023 					/* generate DIF for write operation */
2024 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2025 					assert(num_blocks > 0);
2026 
2027 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2028 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2029 					if (rc != 0) {
2030 						SPDK_ERRLOG("DIF generation failed\n");
2031 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2032 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2033 						break;
2034 					}
2035 				}
2036 
2037 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2038 				/* set extended length before IO operation */
2039 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2040 			}
2041 
2042 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2043 			spdk_nvmf_request_exec(&rdma_req->req);
2044 			break;
2045 		case RDMA_REQUEST_STATE_EXECUTING:
2046 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2047 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2048 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2049 			 * to escape this state. */
2050 			break;
2051 		case RDMA_REQUEST_STATE_EXECUTED:
2052 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2053 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2054 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2055 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2056 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2057 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2058 			} else {
2059 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2060 			}
2061 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2062 				/* restore the original length */
2063 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2064 
2065 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2066 					struct spdk_dif_error error_blk;
2067 
2068 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2069 
2070 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2071 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2072 					if (rc) {
2073 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2074 
2075 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2076 							    error_blk.err_offset);
2077 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2078 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2079 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2080 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2081 					}
2082 				}
2083 			}
2084 			break;
2085 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2086 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2087 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2088 
2089 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2090 				/* This request needs to wait in line to perform RDMA */
2091 				break;
2092 			}
2093 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2094 			    rqpair->max_send_depth) {
2095 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2096 				 * +1 since each request has an additional wr in the resp. */
2097 				rqpair->poller->stat.pending_rdma_write++;
2098 				break;
2099 			}
2100 
2101 			/* We have already verified that this request is the head of the queue. */
2102 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2103 
2104 			/* The data transfer will be kicked off from
2105 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2106 			 */
2107 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2108 			break;
2109 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2110 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2111 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2112 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2113 			assert(rc == 0); /* No good way to handle this currently */
2114 			if (rc) {
2115 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2116 			} else {
2117 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2118 						  RDMA_REQUEST_STATE_COMPLETING;
2119 			}
2120 			break;
2121 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2122 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2123 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2124 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2125 			 * to escape this state. */
2126 			break;
2127 		case RDMA_REQUEST_STATE_COMPLETING:
2128 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2129 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2130 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2131 			 * to escape this state. */
2132 			break;
2133 		case RDMA_REQUEST_STATE_COMPLETED:
2134 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2135 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2136 
2137 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2138 			_nvmf_rdma_request_free(rdma_req, rtransport);
2139 			break;
2140 		case RDMA_REQUEST_NUM_STATES:
2141 		default:
2142 			assert(0);
2143 			break;
2144 		}
2145 
2146 		if (rdma_req->state != prev_state) {
2147 			progress = true;
2148 		}
2149 	} while (rdma_req->state != prev_state);
2150 
2151 	return progress;
2152 }
2153 
2154 /* Public API callbacks begin here */
2155 
2156 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2157 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2158 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2159 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2160 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2161 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2162 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2163 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2164 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2165 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2166 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2167 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2168 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2169 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2170 
2171 static void
2172 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2173 {
2174 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2175 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2176 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2177 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2178 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2179 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2180 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2181 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2182 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2183 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2184 	opts->transport_specific =      NULL;
2185 }
2186 
2187 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2188 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2189 
2190 static inline bool
2191 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2192 {
2193 	return device->attr.vendor_id == NVMF_RXE_VENDOR_ID_OLD ||
2194 	       device->attr.vendor_id == NVMF_RXE_VENDOR_ID_NEW;
2195 }
2196 
2197 static struct spdk_nvmf_transport *
2198 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2199 {
2200 	int rc;
2201 	struct spdk_nvmf_rdma_transport *rtransport;
2202 	struct spdk_nvmf_rdma_device	*device, *tmp;
2203 	struct ibv_context		**contexts;
2204 	uint32_t			i;
2205 	int				flag;
2206 	uint32_t			sge_count;
2207 	uint32_t			min_shared_buffers;
2208 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2209 	pthread_mutexattr_t		attr;
2210 
2211 	rtransport = calloc(1, sizeof(*rtransport));
2212 	if (!rtransport) {
2213 		return NULL;
2214 	}
2215 
2216 	if (pthread_mutexattr_init(&attr)) {
2217 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2218 		free(rtransport);
2219 		return NULL;
2220 	}
2221 
2222 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2223 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2224 		pthread_mutexattr_destroy(&attr);
2225 		free(rtransport);
2226 		return NULL;
2227 	}
2228 
2229 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2230 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2231 		pthread_mutexattr_destroy(&attr);
2232 		free(rtransport);
2233 		return NULL;
2234 	}
2235 
2236 	pthread_mutexattr_destroy(&attr);
2237 
2238 	TAILQ_INIT(&rtransport->devices);
2239 	TAILQ_INIT(&rtransport->ports);
2240 	TAILQ_INIT(&rtransport->poll_groups);
2241 
2242 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2243 	rtransport->rdma_opts.num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2244 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2245 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2246 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2247 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2248 	if (opts->transport_specific != NULL &&
2249 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2250 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2251 					    &rtransport->rdma_opts)) {
2252 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2253 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2254 		return NULL;
2255 	}
2256 
2257 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2258 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2259 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2260 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2261 		     "  num_shared_buffers=%d, num_cqe=%d, max_srq_depth=%d, no_srq=%d,"
2262 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2263 		     opts->max_queue_depth,
2264 		     opts->max_io_size,
2265 		     opts->max_qpairs_per_ctrlr - 1,
2266 		     opts->io_unit_size,
2267 		     opts->in_capsule_data_size,
2268 		     opts->max_aq_depth,
2269 		     opts->num_shared_buffers,
2270 		     rtransport->rdma_opts.num_cqe,
2271 		     rtransport->rdma_opts.max_srq_depth,
2272 		     rtransport->rdma_opts.no_srq,
2273 		     rtransport->rdma_opts.acceptor_backlog,
2274 		     rtransport->rdma_opts.no_wr_batching,
2275 		     opts->abort_timeout_sec);
2276 
2277 	/* I/O unit size cannot be larger than max I/O size */
2278 	if (opts->io_unit_size > opts->max_io_size) {
2279 		opts->io_unit_size = opts->max_io_size;
2280 	}
2281 
2282 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2283 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2284 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2285 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2286 	}
2287 
2288 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2289 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2290 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2291 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2292 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2293 		return NULL;
2294 	}
2295 
2296 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2297 	if (min_shared_buffers > opts->num_shared_buffers) {
2298 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2299 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2300 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2301 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2302 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2303 		return NULL;
2304 	}
2305 
2306 	sge_count = opts->max_io_size / opts->io_unit_size;
2307 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2308 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2309 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2310 		return NULL;
2311 	}
2312 
2313 	rtransport->event_channel = rdma_create_event_channel();
2314 	if (rtransport->event_channel == NULL) {
2315 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2316 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2317 		return NULL;
2318 	}
2319 
2320 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2321 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2322 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2323 			    rtransport->event_channel->fd, spdk_strerror(errno));
2324 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2325 		return NULL;
2326 	}
2327 
2328 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2329 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2330 				   sizeof(struct spdk_nvmf_rdma_request_data),
2331 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2332 				   SPDK_ENV_SOCKET_ID_ANY);
2333 	if (!rtransport->data_wr_pool) {
2334 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2335 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2336 		return NULL;
2337 	}
2338 
2339 	contexts = rdma_get_devices(NULL);
2340 	if (contexts == NULL) {
2341 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2342 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2343 		return NULL;
2344 	}
2345 
2346 	i = 0;
2347 	rc = 0;
2348 	while (contexts[i] != NULL) {
2349 		device = calloc(1, sizeof(*device));
2350 		if (!device) {
2351 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2352 			rc = -ENOMEM;
2353 			break;
2354 		}
2355 		device->context = contexts[i];
2356 		rc = ibv_query_device(device->context, &device->attr);
2357 		if (rc < 0) {
2358 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2359 			free(device);
2360 			break;
2361 
2362 		}
2363 
2364 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2365 
2366 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2367 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2368 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2369 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2370 		}
2371 
2372 		/**
2373 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2374 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2375 		 * but incorrectly reports that it does. There are changes making their way
2376 		 * through the kernel now that will enable this feature. When they are merged,
2377 		 * we can conditionally enable this feature.
2378 		 *
2379 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2380 		 */
2381 		if (nvmf_rdma_is_rxe_device(device)) {
2382 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2383 		}
2384 #endif
2385 
2386 		/* set up device context async ev fd as NON_BLOCKING */
2387 		flag = fcntl(device->context->async_fd, F_GETFL);
2388 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2389 		if (rc < 0) {
2390 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2391 			free(device);
2392 			break;
2393 		}
2394 
2395 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2396 		i++;
2397 
2398 		if (g_nvmf_hooks.get_ibv_pd) {
2399 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2400 		} else {
2401 			device->pd = ibv_alloc_pd(device->context);
2402 		}
2403 
2404 		if (!device->pd) {
2405 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2406 			rc = -ENOMEM;
2407 			break;
2408 		}
2409 
2410 		assert(device->map == NULL);
2411 
2412 		device->map = spdk_rdma_create_mem_map(device->pd, &g_nvmf_hooks);
2413 		if (!device->map) {
2414 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2415 			rc = -ENOMEM;
2416 			break;
2417 		}
2418 
2419 		assert(device->map != NULL);
2420 		assert(device->pd != NULL);
2421 	}
2422 	rdma_free_devices(contexts);
2423 
2424 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2425 		/* divide and round up. */
2426 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2427 
2428 		/* round up to the nearest 4k. */
2429 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2430 
2431 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2432 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2433 			       opts->io_unit_size);
2434 	}
2435 
2436 	if (rc < 0) {
2437 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2438 		return NULL;
2439 	}
2440 
2441 	/* Set up poll descriptor array to monitor events from RDMA and IB
2442 	 * in a single poll syscall
2443 	 */
2444 	rtransport->npoll_fds = i + 1;
2445 	i = 0;
2446 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2447 	if (rtransport->poll_fds == NULL) {
2448 		SPDK_ERRLOG("poll_fds allocation failed\n");
2449 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2450 		return NULL;
2451 	}
2452 
2453 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2454 	rtransport->poll_fds[i++].events = POLLIN;
2455 
2456 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2457 		rtransport->poll_fds[i].fd = device->context->async_fd;
2458 		rtransport->poll_fds[i++].events = POLLIN;
2459 	}
2460 
2461 	return &rtransport->transport;
2462 }
2463 
2464 static void
2465 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2466 {
2467 	struct spdk_nvmf_rdma_transport	*rtransport;
2468 	assert(w != NULL);
2469 
2470 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2471 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2472 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2473 	if (rtransport->rdma_opts.no_srq == true) {
2474 		spdk_json_write_named_int32(w, "num_cqe", rtransport->rdma_opts.num_cqe);
2475 	}
2476 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2477 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2478 }
2479 
2480 static int
2481 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2482 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2483 {
2484 	struct spdk_nvmf_rdma_transport	*rtransport;
2485 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2486 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2487 
2488 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2489 
2490 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2491 		TAILQ_REMOVE(&rtransport->ports, port, link);
2492 		rdma_destroy_id(port->id);
2493 		free(port);
2494 	}
2495 
2496 	if (rtransport->poll_fds != NULL) {
2497 		free(rtransport->poll_fds);
2498 	}
2499 
2500 	if (rtransport->event_channel != NULL) {
2501 		rdma_destroy_event_channel(rtransport->event_channel);
2502 	}
2503 
2504 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2505 		TAILQ_REMOVE(&rtransport->devices, device, link);
2506 		spdk_rdma_free_mem_map(&device->map);
2507 		if (device->pd) {
2508 			if (!g_nvmf_hooks.get_ibv_pd) {
2509 				ibv_dealloc_pd(device->pd);
2510 			}
2511 		}
2512 		free(device);
2513 	}
2514 
2515 	if (rtransport->data_wr_pool != NULL) {
2516 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2517 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2518 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2519 				    spdk_mempool_count(rtransport->data_wr_pool),
2520 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2521 		}
2522 	}
2523 
2524 	spdk_mempool_free(rtransport->data_wr_pool);
2525 
2526 	pthread_mutex_destroy(&rtransport->lock);
2527 	free(rtransport);
2528 
2529 	if (cb_fn) {
2530 		cb_fn(cb_arg);
2531 	}
2532 	return 0;
2533 }
2534 
2535 static int
2536 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2537 			  struct spdk_nvme_transport_id *trid,
2538 			  bool peer);
2539 
2540 static int
2541 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2542 		 struct spdk_nvmf_listen_opts *listen_opts)
2543 {
2544 	struct spdk_nvmf_rdma_transport	*rtransport;
2545 	struct spdk_nvmf_rdma_device	*device;
2546 	struct spdk_nvmf_rdma_port	*port;
2547 	struct addrinfo			*res;
2548 	struct addrinfo			hints;
2549 	int				family;
2550 	int				rc;
2551 
2552 	if (!strlen(trid->trsvcid)) {
2553 		SPDK_ERRLOG("Service id is required\n");
2554 		return -EINVAL;
2555 	}
2556 
2557 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2558 	assert(rtransport->event_channel != NULL);
2559 
2560 	pthread_mutex_lock(&rtransport->lock);
2561 	port = calloc(1, sizeof(*port));
2562 	if (!port) {
2563 		SPDK_ERRLOG("Port allocation failed\n");
2564 		pthread_mutex_unlock(&rtransport->lock);
2565 		return -ENOMEM;
2566 	}
2567 
2568 	port->trid = trid;
2569 
2570 	switch (trid->adrfam) {
2571 	case SPDK_NVMF_ADRFAM_IPV4:
2572 		family = AF_INET;
2573 		break;
2574 	case SPDK_NVMF_ADRFAM_IPV6:
2575 		family = AF_INET6;
2576 		break;
2577 	default:
2578 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2579 		free(port);
2580 		pthread_mutex_unlock(&rtransport->lock);
2581 		return -EINVAL;
2582 	}
2583 
2584 	memset(&hints, 0, sizeof(hints));
2585 	hints.ai_family = family;
2586 	hints.ai_flags = AI_NUMERICSERV;
2587 	hints.ai_socktype = SOCK_STREAM;
2588 	hints.ai_protocol = 0;
2589 
2590 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2591 	if (rc) {
2592 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2593 		free(port);
2594 		pthread_mutex_unlock(&rtransport->lock);
2595 		return -EINVAL;
2596 	}
2597 
2598 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2599 	if (rc < 0) {
2600 		SPDK_ERRLOG("rdma_create_id() failed\n");
2601 		freeaddrinfo(res);
2602 		free(port);
2603 		pthread_mutex_unlock(&rtransport->lock);
2604 		return rc;
2605 	}
2606 
2607 	rc = rdma_bind_addr(port->id, res->ai_addr);
2608 	freeaddrinfo(res);
2609 
2610 	if (rc < 0) {
2611 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2612 		rdma_destroy_id(port->id);
2613 		free(port);
2614 		pthread_mutex_unlock(&rtransport->lock);
2615 		return rc;
2616 	}
2617 
2618 	if (!port->id->verbs) {
2619 		SPDK_ERRLOG("ibv_context is null\n");
2620 		rdma_destroy_id(port->id);
2621 		free(port);
2622 		pthread_mutex_unlock(&rtransport->lock);
2623 		return -1;
2624 	}
2625 
2626 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2627 	if (rc < 0) {
2628 		SPDK_ERRLOG("rdma_listen() failed\n");
2629 		rdma_destroy_id(port->id);
2630 		free(port);
2631 		pthread_mutex_unlock(&rtransport->lock);
2632 		return rc;
2633 	}
2634 
2635 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2636 		if (device->context == port->id->verbs) {
2637 			port->device = device;
2638 			break;
2639 		}
2640 	}
2641 	if (!port->device) {
2642 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2643 			    port->id->verbs);
2644 		rdma_destroy_id(port->id);
2645 		free(port);
2646 		pthread_mutex_unlock(&rtransport->lock);
2647 		return -EINVAL;
2648 	}
2649 
2650 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2651 		       trid->traddr, trid->trsvcid);
2652 
2653 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2654 	pthread_mutex_unlock(&rtransport->lock);
2655 	return 0;
2656 }
2657 
2658 static void
2659 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2660 		      const struct spdk_nvme_transport_id *trid)
2661 {
2662 	struct spdk_nvmf_rdma_transport *rtransport;
2663 	struct spdk_nvmf_rdma_port *port, *tmp;
2664 
2665 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2666 
2667 	pthread_mutex_lock(&rtransport->lock);
2668 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2669 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2670 			TAILQ_REMOVE(&rtransport->ports, port, link);
2671 			rdma_destroy_id(port->id);
2672 			free(port);
2673 			break;
2674 		}
2675 	}
2676 
2677 	pthread_mutex_unlock(&rtransport->lock);
2678 }
2679 
2680 static void
2681 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2682 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2683 {
2684 	struct spdk_nvmf_request *req, *tmp;
2685 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2686 	struct spdk_nvmf_rdma_resources *resources;
2687 
2688 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2689 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2690 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2691 			break;
2692 		}
2693 	}
2694 
2695 	/* Then RDMA writes since reads have stronger restrictions than writes */
2696 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2697 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2698 			break;
2699 		}
2700 	}
2701 
2702 	/* Then we handle request waiting on memory buffers. */
2703 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2704 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2705 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2706 			break;
2707 		}
2708 	}
2709 
2710 	resources = rqpair->resources;
2711 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2712 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2713 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2714 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2715 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2716 
2717 		if (rqpair->srq != NULL) {
2718 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2719 			rdma_req->recv->qpair->qd++;
2720 		} else {
2721 			rqpair->qd++;
2722 		}
2723 
2724 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2725 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2726 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2727 			break;
2728 		}
2729 	}
2730 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2731 		rqpair->poller->stat.pending_free_request++;
2732 	}
2733 }
2734 
2735 static inline bool
2736 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
2737 {
2738 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
2739 	return nvmf_rdma_is_rxe_device(device) ||
2740 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
2741 }
2742 
2743 static void
2744 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2745 {
2746 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2747 			struct spdk_nvmf_rdma_transport, transport);
2748 
2749 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2750 
2751 	/* nvmr_rdma_close_qpair is not called */
2752 	if (!rqpair->to_close) {
2753 		return;
2754 	}
2755 
2756 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2757 	if (rqpair->current_send_depth != 0) {
2758 		return;
2759 	}
2760 
2761 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2762 		return;
2763 	}
2764 
2765 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
2766 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
2767 		return;
2768 	}
2769 
2770 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2771 
2772 	nvmf_rdma_qpair_destroy(rqpair);
2773 }
2774 
2775 static int
2776 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2777 {
2778 	struct spdk_nvmf_qpair		*qpair;
2779 	struct spdk_nvmf_rdma_qpair	*rqpair;
2780 
2781 	if (evt->id == NULL) {
2782 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2783 		return -1;
2784 	}
2785 
2786 	qpair = evt->id->context;
2787 	if (qpair == NULL) {
2788 		SPDK_ERRLOG("disconnect request: no active connection\n");
2789 		return -1;
2790 	}
2791 
2792 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2793 
2794 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2795 
2796 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2797 
2798 	return 0;
2799 }
2800 
2801 #ifdef DEBUG
2802 static const char *CM_EVENT_STR[] = {
2803 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2804 	"RDMA_CM_EVENT_ADDR_ERROR",
2805 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2806 	"RDMA_CM_EVENT_ROUTE_ERROR",
2807 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2808 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2809 	"RDMA_CM_EVENT_CONNECT_ERROR",
2810 	"RDMA_CM_EVENT_UNREACHABLE",
2811 	"RDMA_CM_EVENT_REJECTED",
2812 	"RDMA_CM_EVENT_ESTABLISHED",
2813 	"RDMA_CM_EVENT_DISCONNECTED",
2814 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2815 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2816 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2817 	"RDMA_CM_EVENT_ADDR_CHANGE",
2818 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2819 };
2820 #endif /* DEBUG */
2821 
2822 static void
2823 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2824 				    struct spdk_nvmf_rdma_port *port)
2825 {
2826 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2827 	struct spdk_nvmf_rdma_poller		*rpoller;
2828 	struct spdk_nvmf_rdma_qpair		*rqpair;
2829 
2830 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2831 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2832 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2833 				if (rqpair->listen_id == port->id) {
2834 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2835 				}
2836 			}
2837 		}
2838 	}
2839 }
2840 
2841 static bool
2842 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2843 				      struct rdma_cm_event *event)
2844 {
2845 	const struct spdk_nvme_transport_id	*trid;
2846 	struct spdk_nvmf_rdma_port		*port;
2847 	struct spdk_nvmf_rdma_transport		*rtransport;
2848 	bool					event_acked = false;
2849 
2850 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2851 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2852 		if (port->id == event->id) {
2853 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2854 			rdma_ack_cm_event(event);
2855 			event_acked = true;
2856 			trid = port->trid;
2857 			break;
2858 		}
2859 	}
2860 
2861 	if (event_acked) {
2862 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2863 
2864 		nvmf_rdma_stop_listen(transport, trid);
2865 		nvmf_rdma_listen(transport, trid, NULL);
2866 	}
2867 
2868 	return event_acked;
2869 }
2870 
2871 static void
2872 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2873 				       struct rdma_cm_event *event)
2874 {
2875 	struct spdk_nvmf_rdma_port		*port;
2876 	struct spdk_nvmf_rdma_transport		*rtransport;
2877 
2878 	port = event->id->context;
2879 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2880 
2881 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2882 
2883 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2884 
2885 	rdma_ack_cm_event(event);
2886 
2887 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2888 		;
2889 	}
2890 }
2891 
2892 static void
2893 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2894 {
2895 	struct spdk_nvmf_rdma_transport *rtransport;
2896 	struct rdma_cm_event		*event;
2897 	int				rc;
2898 	bool				event_acked;
2899 
2900 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2901 
2902 	if (rtransport->event_channel == NULL) {
2903 		return;
2904 	}
2905 
2906 	while (1) {
2907 		event_acked = false;
2908 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2909 		if (rc) {
2910 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2911 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2912 			}
2913 			break;
2914 		}
2915 
2916 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2917 
2918 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2919 
2920 		switch (event->event) {
2921 		case RDMA_CM_EVENT_ADDR_RESOLVED:
2922 		case RDMA_CM_EVENT_ADDR_ERROR:
2923 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
2924 		case RDMA_CM_EVENT_ROUTE_ERROR:
2925 			/* No action required. The target never attempts to resolve routes. */
2926 			break;
2927 		case RDMA_CM_EVENT_CONNECT_REQUEST:
2928 			rc = nvmf_rdma_connect(transport, event);
2929 			if (rc < 0) {
2930 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2931 				break;
2932 			}
2933 			break;
2934 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
2935 			/* The target never initiates a new connection. So this will not occur. */
2936 			break;
2937 		case RDMA_CM_EVENT_CONNECT_ERROR:
2938 			/* Can this happen? The docs say it can, but not sure what causes it. */
2939 			break;
2940 		case RDMA_CM_EVENT_UNREACHABLE:
2941 		case RDMA_CM_EVENT_REJECTED:
2942 			/* These only occur on the client side. */
2943 			break;
2944 		case RDMA_CM_EVENT_ESTABLISHED:
2945 			/* TODO: Should we be waiting for this event anywhere? */
2946 			break;
2947 		case RDMA_CM_EVENT_DISCONNECTED:
2948 			rc = nvmf_rdma_disconnect(event);
2949 			if (rc < 0) {
2950 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2951 				break;
2952 			}
2953 			break;
2954 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
2955 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
2956 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
2957 			 * Once these events are sent to SPDK, we should release all IB resources and
2958 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
2959 			 * ibv_destory* functions to release user space memory allocated by IB. All kernel
2960 			 * resources are already cleaned. */
2961 			if (event->id->qp) {
2962 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
2963 				 * corresponding qpair. Otherwise the event refers to a listening device */
2964 				rc = nvmf_rdma_disconnect(event);
2965 				if (rc < 0) {
2966 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2967 					break;
2968 				}
2969 			} else {
2970 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
2971 				event_acked = true;
2972 			}
2973 			break;
2974 		case RDMA_CM_EVENT_MULTICAST_JOIN:
2975 		case RDMA_CM_EVENT_MULTICAST_ERROR:
2976 			/* Multicast is not used */
2977 			break;
2978 		case RDMA_CM_EVENT_ADDR_CHANGE:
2979 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
2980 			break;
2981 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2982 			/* For now, do nothing. The target never re-uses queue pairs. */
2983 			break;
2984 		default:
2985 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2986 			break;
2987 		}
2988 		if (!event_acked) {
2989 			rdma_ack_cm_event(event);
2990 		}
2991 	}
2992 }
2993 
2994 static void
2995 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
2996 {
2997 	rqpair->last_wqe_reached = true;
2998 	nvmf_rdma_destroy_drained_qpair(rqpair);
2999 }
3000 
3001 static void
3002 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3003 {
3004 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3005 
3006 	if (event_ctx->rqpair) {
3007 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3008 		if (event_ctx->cb_fn) {
3009 			event_ctx->cb_fn(event_ctx->rqpair);
3010 		}
3011 	}
3012 	free(event_ctx);
3013 }
3014 
3015 static int
3016 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3017 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3018 {
3019 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3020 	struct spdk_thread *thr = NULL;
3021 	int rc;
3022 
3023 	if (rqpair->qpair.group) {
3024 		thr = rqpair->qpair.group->thread;
3025 	} else if (rqpair->destruct_channel) {
3026 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3027 	}
3028 
3029 	if (!thr) {
3030 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3031 		return -EINVAL;
3032 	}
3033 
3034 	ctx = calloc(1, sizeof(*ctx));
3035 	if (!ctx) {
3036 		return -ENOMEM;
3037 	}
3038 
3039 	ctx->rqpair = rqpair;
3040 	ctx->cb_fn = fn;
3041 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3042 
3043 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3044 	if (rc) {
3045 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3046 		free(ctx);
3047 	}
3048 
3049 	return rc;
3050 }
3051 
3052 static int
3053 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3054 {
3055 	int				rc;
3056 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3057 	struct ibv_async_event		event;
3058 
3059 	rc = ibv_get_async_event(device->context, &event);
3060 
3061 	if (rc) {
3062 		/* In non-blocking mode -1 means there are no events available */
3063 		return rc;
3064 	}
3065 
3066 	switch (event.event_type) {
3067 	case IBV_EVENT_QP_FATAL:
3068 		rqpair = event.element.qp->qp_context;
3069 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3070 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3071 				  (uintptr_t)rqpair->cm_id, event.event_type);
3072 		nvmf_rdma_update_ibv_state(rqpair);
3073 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3074 		break;
3075 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3076 		/* This event only occurs for shared receive queues. */
3077 		rqpair = event.element.qp->qp_context;
3078 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3079 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3080 		if (rc) {
3081 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3082 			rqpair->last_wqe_reached = true;
3083 		}
3084 		break;
3085 	case IBV_EVENT_SQ_DRAINED:
3086 		/* This event occurs frequently in both error and non-error states.
3087 		 * Check if the qpair is in an error state before sending a message. */
3088 		rqpair = event.element.qp->qp_context;
3089 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3090 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3091 				  (uintptr_t)rqpair->cm_id, event.event_type);
3092 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3093 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3094 		}
3095 		break;
3096 	case IBV_EVENT_QP_REQ_ERR:
3097 	case IBV_EVENT_QP_ACCESS_ERR:
3098 	case IBV_EVENT_COMM_EST:
3099 	case IBV_EVENT_PATH_MIG:
3100 	case IBV_EVENT_PATH_MIG_ERR:
3101 		SPDK_NOTICELOG("Async event: %s\n",
3102 			       ibv_event_type_str(event.event_type));
3103 		rqpair = event.element.qp->qp_context;
3104 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3105 				  (uintptr_t)rqpair->cm_id, event.event_type);
3106 		nvmf_rdma_update_ibv_state(rqpair);
3107 		break;
3108 	case IBV_EVENT_CQ_ERR:
3109 	case IBV_EVENT_DEVICE_FATAL:
3110 	case IBV_EVENT_PORT_ACTIVE:
3111 	case IBV_EVENT_PORT_ERR:
3112 	case IBV_EVENT_LID_CHANGE:
3113 	case IBV_EVENT_PKEY_CHANGE:
3114 	case IBV_EVENT_SM_CHANGE:
3115 	case IBV_EVENT_SRQ_ERR:
3116 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3117 	case IBV_EVENT_CLIENT_REREGISTER:
3118 	case IBV_EVENT_GID_CHANGE:
3119 	default:
3120 		SPDK_NOTICELOG("Async event: %s\n",
3121 			       ibv_event_type_str(event.event_type));
3122 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3123 		break;
3124 	}
3125 	ibv_ack_async_event(&event);
3126 
3127 	return 0;
3128 }
3129 
3130 static void
3131 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3132 {
3133 	int rc = 0;
3134 	uint32_t i = 0;
3135 
3136 	for (i = 0; i < max_events; i++) {
3137 		rc = nvmf_process_ib_event(device);
3138 		if (rc) {
3139 			break;
3140 		}
3141 	}
3142 
3143 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3144 }
3145 
3146 static uint32_t
3147 nvmf_rdma_accept(struct spdk_nvmf_transport *transport)
3148 {
3149 	int	nfds, i = 0;
3150 	struct spdk_nvmf_rdma_transport *rtransport;
3151 	struct spdk_nvmf_rdma_device *device, *tmp;
3152 	uint32_t count;
3153 
3154 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3155 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3156 
3157 	if (nfds <= 0) {
3158 		return 0;
3159 	}
3160 
3161 	/* The first poll descriptor is RDMA CM event */
3162 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3163 		nvmf_process_cm_event(transport);
3164 		nfds--;
3165 	}
3166 
3167 	if (nfds == 0) {
3168 		return count;
3169 	}
3170 
3171 	/* Second and subsequent poll descriptors are IB async events */
3172 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3173 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3174 			nvmf_process_ib_events(device, 32);
3175 			nfds--;
3176 		}
3177 	}
3178 	/* check all flagged fd's have been served */
3179 	assert(nfds == 0);
3180 
3181 	return count;
3182 }
3183 
3184 static void
3185 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3186 		     struct spdk_nvmf_ctrlr_data *cdata)
3187 {
3188 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3189 
3190 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3191 	since in-capsule data only works with NVME drives that support SGL memory layout */
3192 	if (transport->opts.dif_insert_or_strip) {
3193 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3194 	}
3195 }
3196 
3197 static void
3198 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3199 		   struct spdk_nvme_transport_id *trid,
3200 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3201 {
3202 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3203 	entry->adrfam = trid->adrfam;
3204 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3205 
3206 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3207 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3208 
3209 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3210 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3211 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3212 }
3213 
3214 static void
3215 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3216 
3217 static struct spdk_nvmf_transport_poll_group *
3218 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3219 {
3220 	struct spdk_nvmf_rdma_transport		*rtransport;
3221 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3222 	struct spdk_nvmf_rdma_poller		*poller;
3223 	struct spdk_nvmf_rdma_device		*device;
3224 	struct spdk_rdma_srq_init_attr		srq_init_attr;
3225 	struct spdk_nvmf_rdma_resource_opts	opts;
3226 	int					num_cqe;
3227 
3228 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3229 
3230 	rgroup = calloc(1, sizeof(*rgroup));
3231 	if (!rgroup) {
3232 		return NULL;
3233 	}
3234 
3235 	TAILQ_INIT(&rgroup->pollers);
3236 
3237 	pthread_mutex_lock(&rtransport->lock);
3238 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3239 		poller = calloc(1, sizeof(*poller));
3240 		if (!poller) {
3241 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3242 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3243 			pthread_mutex_unlock(&rtransport->lock);
3244 			return NULL;
3245 		}
3246 
3247 		poller->device = device;
3248 		poller->group = rgroup;
3249 
3250 		TAILQ_INIT(&poller->qpairs);
3251 		STAILQ_INIT(&poller->qpairs_pending_send);
3252 		STAILQ_INIT(&poller->qpairs_pending_recv);
3253 
3254 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3255 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3256 			poller->max_srq_depth = rtransport->rdma_opts.max_srq_depth;
3257 
3258 			device->num_srq++;
3259 			memset(&srq_init_attr, 0, sizeof(srq_init_attr));
3260 			srq_init_attr.pd = device->pd;
3261 			srq_init_attr.stats = &poller->stat.qp_stats.recv;
3262 			srq_init_attr.srq_init_attr.attr.max_wr = poller->max_srq_depth;
3263 			srq_init_attr.srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3264 			poller->srq = spdk_rdma_srq_create(&srq_init_attr);
3265 			if (!poller->srq) {
3266 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3267 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3268 				pthread_mutex_unlock(&rtransport->lock);
3269 				return NULL;
3270 			}
3271 
3272 			opts.qp = poller->srq;
3273 			opts.pd = device->pd;
3274 			opts.qpair = NULL;
3275 			opts.shared = true;
3276 			opts.max_queue_depth = poller->max_srq_depth;
3277 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3278 
3279 			poller->resources = nvmf_rdma_resources_create(&opts);
3280 			if (!poller->resources) {
3281 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3282 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3283 				pthread_mutex_unlock(&rtransport->lock);
3284 				return NULL;
3285 			}
3286 		}
3287 
3288 		/*
3289 		 * When using an srq, we can limit the completion queue at startup.
3290 		 * The following formula represents the calculation:
3291 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3292 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3293 		 */
3294 		if (poller->srq) {
3295 			num_cqe = poller->max_srq_depth * 3;
3296 		} else {
3297 			num_cqe = rtransport->rdma_opts.num_cqe;
3298 		}
3299 
3300 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3301 		if (!poller->cq) {
3302 			SPDK_ERRLOG("Unable to create completion queue\n");
3303 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3304 			pthread_mutex_unlock(&rtransport->lock);
3305 			return NULL;
3306 		}
3307 		poller->num_cqe = num_cqe;
3308 	}
3309 
3310 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3311 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3312 		rtransport->conn_sched.next_admin_pg = rgroup;
3313 		rtransport->conn_sched.next_io_pg = rgroup;
3314 	}
3315 
3316 	pthread_mutex_unlock(&rtransport->lock);
3317 	return &rgroup->group;
3318 }
3319 
3320 static struct spdk_nvmf_transport_poll_group *
3321 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3322 {
3323 	struct spdk_nvmf_rdma_transport *rtransport;
3324 	struct spdk_nvmf_rdma_poll_group **pg;
3325 	struct spdk_nvmf_transport_poll_group *result;
3326 
3327 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3328 
3329 	pthread_mutex_lock(&rtransport->lock);
3330 
3331 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3332 		pthread_mutex_unlock(&rtransport->lock);
3333 		return NULL;
3334 	}
3335 
3336 	if (qpair->qid == 0) {
3337 		pg = &rtransport->conn_sched.next_admin_pg;
3338 	} else {
3339 		pg = &rtransport->conn_sched.next_io_pg;
3340 	}
3341 
3342 	assert(*pg != NULL);
3343 
3344 	result = &(*pg)->group;
3345 
3346 	*pg = TAILQ_NEXT(*pg, link);
3347 	if (*pg == NULL) {
3348 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3349 	}
3350 
3351 	pthread_mutex_unlock(&rtransport->lock);
3352 
3353 	return result;
3354 }
3355 
3356 static void
3357 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3358 {
3359 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3360 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3361 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3362 	struct spdk_nvmf_rdma_transport		*rtransport;
3363 
3364 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3365 	if (!rgroup) {
3366 		return;
3367 	}
3368 
3369 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3370 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3371 
3372 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3373 			nvmf_rdma_qpair_destroy(qpair);
3374 		}
3375 
3376 		if (poller->srq) {
3377 			if (poller->resources) {
3378 				nvmf_rdma_resources_destroy(poller->resources);
3379 			}
3380 			spdk_rdma_srq_destroy(poller->srq);
3381 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3382 		}
3383 
3384 		if (poller->cq) {
3385 			ibv_destroy_cq(poller->cq);
3386 		}
3387 
3388 		free(poller);
3389 	}
3390 
3391 	if (rgroup->group.transport == NULL) {
3392 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3393 		 * calls this function directly in a failure path. */
3394 		free(rgroup);
3395 		return;
3396 	}
3397 
3398 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3399 
3400 	pthread_mutex_lock(&rtransport->lock);
3401 	next_rgroup = TAILQ_NEXT(rgroup, link);
3402 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3403 	if (next_rgroup == NULL) {
3404 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3405 	}
3406 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3407 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3408 	}
3409 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3410 		rtransport->conn_sched.next_io_pg = next_rgroup;
3411 	}
3412 	pthread_mutex_unlock(&rtransport->lock);
3413 
3414 	free(rgroup);
3415 }
3416 
3417 static void
3418 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3419 {
3420 	if (rqpair->cm_id != NULL) {
3421 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3422 	}
3423 }
3424 
3425 static int
3426 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3427 			 struct spdk_nvmf_qpair *qpair)
3428 {
3429 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3430 	struct spdk_nvmf_rdma_qpair		*rqpair;
3431 	struct spdk_nvmf_rdma_device		*device;
3432 	struct spdk_nvmf_rdma_poller		*poller;
3433 	int					rc;
3434 
3435 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3436 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3437 
3438 	device = rqpair->device;
3439 
3440 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3441 		if (poller->device == device) {
3442 			break;
3443 		}
3444 	}
3445 
3446 	if (!poller) {
3447 		SPDK_ERRLOG("No poller found for device.\n");
3448 		return -1;
3449 	}
3450 
3451 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3452 	rqpair->poller = poller;
3453 	rqpair->srq = rqpair->poller->srq;
3454 
3455 	rc = nvmf_rdma_qpair_initialize(qpair);
3456 	if (rc < 0) {
3457 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3458 		return -1;
3459 	}
3460 
3461 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3462 	if (rc) {
3463 		/* Try to reject, but we probably can't */
3464 		nvmf_rdma_qpair_reject_connection(rqpair);
3465 		return -1;
3466 	}
3467 
3468 	nvmf_rdma_update_ibv_state(rqpair);
3469 
3470 	return 0;
3471 }
3472 
3473 static int
3474 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3475 			    struct spdk_nvmf_qpair *qpair)
3476 {
3477 	struct spdk_nvmf_rdma_qpair		*rqpair;
3478 
3479 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3480 	assert(group->transport->tgt != NULL);
3481 
3482 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3483 
3484 	if (!rqpair->destruct_channel) {
3485 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3486 		return 0;
3487 	}
3488 
3489 	/* Sanity check that we get io_channel on the correct thread */
3490 	if (qpair->group) {
3491 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3492 	}
3493 
3494 	return 0;
3495 }
3496 
3497 static int
3498 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3499 {
3500 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3501 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3502 			struct spdk_nvmf_rdma_transport, transport);
3503 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3504 					      struct spdk_nvmf_rdma_qpair, qpair);
3505 
3506 	/*
3507 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3508 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3509 	 * starved of RECV structures.
3510 	 */
3511 	if (rqpair->srq && rdma_req->recv) {
3512 		int rc;
3513 		struct ibv_recv_wr *bad_recv_wr;
3514 
3515 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_req->recv->wr);
3516 		rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
3517 		if (rc) {
3518 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3519 		}
3520 	}
3521 
3522 	_nvmf_rdma_request_free(rdma_req, rtransport);
3523 	return 0;
3524 }
3525 
3526 static int
3527 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3528 {
3529 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3530 			struct spdk_nvmf_rdma_transport, transport);
3531 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3532 			struct spdk_nvmf_rdma_request, req);
3533 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3534 			struct spdk_nvmf_rdma_qpair, qpair);
3535 
3536 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3537 		/* The connection is alive, so process the request as normal */
3538 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3539 	} else {
3540 		/* The connection is dead. Move the request directly to the completed state. */
3541 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3542 	}
3543 
3544 	nvmf_rdma_request_process(rtransport, rdma_req);
3545 
3546 	return 0;
3547 }
3548 
3549 static void
3550 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
3551 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
3552 {
3553 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3554 
3555 	rqpair->to_close = true;
3556 
3557 	/* This happens only when the qpair is disconnected before
3558 	 * it is added to the poll group. Since there is no poll group,
3559 	 * the RDMA qp has not been initialized yet and the RDMA CM
3560 	 * event has not yet been acknowledged, so we need to reject it.
3561 	 */
3562 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3563 		nvmf_rdma_qpair_reject_connection(rqpair);
3564 		nvmf_rdma_qpair_destroy(rqpair);
3565 		return;
3566 	}
3567 
3568 	if (rqpair->rdma_qp) {
3569 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3570 	}
3571 
3572 	nvmf_rdma_destroy_drained_qpair(rqpair);
3573 
3574 	if (cb_fn) {
3575 		cb_fn(cb_arg);
3576 	}
3577 }
3578 
3579 static struct spdk_nvmf_rdma_qpair *
3580 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3581 {
3582 	struct spdk_nvmf_rdma_qpair *rqpair;
3583 	/* @todo: improve QP search */
3584 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3585 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3586 			return rqpair;
3587 		}
3588 	}
3589 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3590 	return NULL;
3591 }
3592 
3593 #ifdef DEBUG
3594 static int
3595 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3596 {
3597 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3598 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3599 }
3600 #endif
3601 
3602 static void
3603 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3604 			   int rc)
3605 {
3606 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3607 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3608 
3609 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3610 	while (bad_recv_wr != NULL) {
3611 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3612 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3613 
3614 		rdma_recv->qpair->current_recv_depth++;
3615 		bad_recv_wr = bad_recv_wr->next;
3616 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3617 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3618 	}
3619 }
3620 
3621 static void
3622 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3623 {
3624 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3625 	while (bad_recv_wr != NULL) {
3626 		bad_recv_wr = bad_recv_wr->next;
3627 		rqpair->current_recv_depth++;
3628 	}
3629 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3630 }
3631 
3632 static void
3633 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3634 		     struct spdk_nvmf_rdma_poller *rpoller)
3635 {
3636 	struct spdk_nvmf_rdma_qpair	*rqpair;
3637 	struct ibv_recv_wr		*bad_recv_wr;
3638 	int				rc;
3639 
3640 	if (rpoller->srq) {
3641 		rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_recv_wr);
3642 		if (rc) {
3643 			_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3644 		}
3645 	} else {
3646 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3647 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3648 			rc = spdk_rdma_qp_flush_recv_wrs(rqpair->rdma_qp, &bad_recv_wr);
3649 			if (rc) {
3650 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3651 			}
3652 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3653 		}
3654 	}
3655 }
3656 
3657 static void
3658 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3659 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3660 {
3661 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3662 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3663 
3664 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3665 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3666 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3667 		assert(rqpair->current_send_depth > 0);
3668 		rqpair->current_send_depth--;
3669 		switch (bad_rdma_wr->type) {
3670 		case RDMA_WR_TYPE_DATA:
3671 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3672 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3673 				assert(rqpair->current_read_depth > 0);
3674 				rqpair->current_read_depth--;
3675 			}
3676 			break;
3677 		case RDMA_WR_TYPE_SEND:
3678 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3679 			break;
3680 		default:
3681 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3682 			prev_rdma_req = cur_rdma_req;
3683 			continue;
3684 		}
3685 
3686 		if (prev_rdma_req == cur_rdma_req) {
3687 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3688 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3689 			continue;
3690 		}
3691 
3692 		switch (cur_rdma_req->state) {
3693 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3694 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3695 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3696 			break;
3697 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3698 		case RDMA_REQUEST_STATE_COMPLETING:
3699 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3700 			break;
3701 		default:
3702 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3703 				    cur_rdma_req->state, rqpair);
3704 			continue;
3705 		}
3706 
3707 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3708 		prev_rdma_req = cur_rdma_req;
3709 	}
3710 
3711 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3712 		/* Disconnect the connection. */
3713 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3714 	}
3715 
3716 }
3717 
3718 static void
3719 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3720 		     struct spdk_nvmf_rdma_poller *rpoller)
3721 {
3722 	struct spdk_nvmf_rdma_qpair	*rqpair;
3723 	struct ibv_send_wr		*bad_wr = NULL;
3724 	int				rc;
3725 
3726 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3727 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3728 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3729 
3730 		/* bad wr always points to the first wr that failed. */
3731 		if (rc) {
3732 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3733 		}
3734 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3735 	}
3736 }
3737 
3738 static const char *
3739 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3740 {
3741 	switch (wr_type) {
3742 	case RDMA_WR_TYPE_RECV:
3743 		return "RECV";
3744 	case RDMA_WR_TYPE_SEND:
3745 		return "SEND";
3746 	case RDMA_WR_TYPE_DATA:
3747 		return "DATA";
3748 	default:
3749 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3750 		SPDK_UNREACHABLE();
3751 	}
3752 }
3753 
3754 static inline void
3755 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3756 {
3757 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3758 
3759 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3760 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3761 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3762 		SPDK_DEBUGLOG(rdma,
3763 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3764 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3765 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3766 	} else {
3767 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3768 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3769 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3770 	}
3771 }
3772 
3773 static int
3774 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3775 		      struct spdk_nvmf_rdma_poller *rpoller)
3776 {
3777 	struct ibv_wc wc[32];
3778 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3779 	struct spdk_nvmf_rdma_request	*rdma_req;
3780 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3781 	struct spdk_nvmf_rdma_qpair	*rqpair;
3782 	int reaped, i;
3783 	int count = 0;
3784 	bool error = false;
3785 	uint64_t poll_tsc = spdk_get_ticks();
3786 
3787 	/* Poll for completing operations. */
3788 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3789 	if (reaped < 0) {
3790 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3791 			    errno, spdk_strerror(errno));
3792 		return -1;
3793 	} else if (reaped == 0) {
3794 		rpoller->stat.idle_polls++;
3795 	}
3796 
3797 	rpoller->stat.polls++;
3798 	rpoller->stat.completions += reaped;
3799 
3800 	for (i = 0; i < reaped; i++) {
3801 
3802 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3803 
3804 		switch (rdma_wr->type) {
3805 		case RDMA_WR_TYPE_SEND:
3806 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3807 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3808 
3809 			if (!wc[i].status) {
3810 				count++;
3811 				assert(wc[i].opcode == IBV_WC_SEND);
3812 				assert(nvmf_rdma_req_is_completing(rdma_req));
3813 			}
3814 
3815 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3816 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3817 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3818 			rdma_req->num_outstanding_data_wr = 0;
3819 
3820 			nvmf_rdma_request_process(rtransport, rdma_req);
3821 			break;
3822 		case RDMA_WR_TYPE_RECV:
3823 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3824 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3825 			if (rpoller->srq != NULL) {
3826 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3827 				/* It is possible that there are still some completions for destroyed QP
3828 				 * associated with SRQ. We just ignore these late completions and re-post
3829 				 * receive WRs back to SRQ.
3830 				 */
3831 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3832 					struct ibv_recv_wr *bad_wr;
3833 					int rc;
3834 
3835 					rdma_recv->wr.next = NULL;
3836 					spdk_rdma_srq_queue_recv_wrs(rpoller->srq, &rdma_recv->wr);
3837 					rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_wr);
3838 					if (rc) {
3839 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3840 					}
3841 					continue;
3842 				}
3843 			}
3844 			rqpair = rdma_recv->qpair;
3845 
3846 			assert(rqpair != NULL);
3847 			if (!wc[i].status) {
3848 				assert(wc[i].opcode == IBV_WC_RECV);
3849 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3850 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3851 					break;
3852 				}
3853 			}
3854 
3855 			rdma_recv->wr.next = NULL;
3856 			rqpair->current_recv_depth++;
3857 			rdma_recv->receive_tsc = poll_tsc;
3858 			rpoller->stat.requests++;
3859 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3860 			break;
3861 		case RDMA_WR_TYPE_DATA:
3862 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3863 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3864 
3865 			assert(rdma_req->num_outstanding_data_wr > 0);
3866 
3867 			rqpair->current_send_depth--;
3868 			rdma_req->num_outstanding_data_wr--;
3869 			if (!wc[i].status) {
3870 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3871 				rqpair->current_read_depth--;
3872 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3873 				if (rdma_req->num_outstanding_data_wr == 0) {
3874 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3875 					nvmf_rdma_request_process(rtransport, rdma_req);
3876 				}
3877 			} else {
3878 				/* If the data transfer fails still force the queue into the error state,
3879 				 * if we were performing an RDMA_READ, we need to force the request into a
3880 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3881 				 * case, we should wait for the SEND to complete. */
3882 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3883 					rqpair->current_read_depth--;
3884 					if (rdma_req->num_outstanding_data_wr == 0) {
3885 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3886 					}
3887 				}
3888 			}
3889 			break;
3890 		default:
3891 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3892 			continue;
3893 		}
3894 
3895 		/* Handle error conditions */
3896 		if (wc[i].status) {
3897 			nvmf_rdma_update_ibv_state(rqpair);
3898 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
3899 
3900 			error = true;
3901 
3902 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3903 				/* Disconnect the connection. */
3904 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3905 			} else {
3906 				nvmf_rdma_destroy_drained_qpair(rqpair);
3907 			}
3908 			continue;
3909 		}
3910 
3911 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3912 
3913 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3914 			nvmf_rdma_destroy_drained_qpair(rqpair);
3915 		}
3916 	}
3917 
3918 	if (error == true) {
3919 		return -1;
3920 	}
3921 
3922 	/* submit outstanding work requests. */
3923 	_poller_submit_recvs(rtransport, rpoller);
3924 	_poller_submit_sends(rtransport, rpoller);
3925 
3926 	return count;
3927 }
3928 
3929 static int
3930 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3931 {
3932 	struct spdk_nvmf_rdma_transport *rtransport;
3933 	struct spdk_nvmf_rdma_poll_group *rgroup;
3934 	struct spdk_nvmf_rdma_poller	*rpoller;
3935 	int				count, rc;
3936 
3937 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3938 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3939 
3940 	count = 0;
3941 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3942 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
3943 		if (rc < 0) {
3944 			return rc;
3945 		}
3946 		count += rc;
3947 	}
3948 
3949 	return count;
3950 }
3951 
3952 static int
3953 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3954 			  struct spdk_nvme_transport_id *trid,
3955 			  bool peer)
3956 {
3957 	struct sockaddr *saddr;
3958 	uint16_t port;
3959 
3960 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
3961 
3962 	if (peer) {
3963 		saddr = rdma_get_peer_addr(id);
3964 	} else {
3965 		saddr = rdma_get_local_addr(id);
3966 	}
3967 	switch (saddr->sa_family) {
3968 	case AF_INET: {
3969 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3970 
3971 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3972 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3973 			  trid->traddr, sizeof(trid->traddr));
3974 		if (peer) {
3975 			port = ntohs(rdma_get_dst_port(id));
3976 		} else {
3977 			port = ntohs(rdma_get_src_port(id));
3978 		}
3979 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3980 		break;
3981 	}
3982 	case AF_INET6: {
3983 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
3984 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
3985 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
3986 			  trid->traddr, sizeof(trid->traddr));
3987 		if (peer) {
3988 			port = ntohs(rdma_get_dst_port(id));
3989 		} else {
3990 			port = ntohs(rdma_get_src_port(id));
3991 		}
3992 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3993 		break;
3994 	}
3995 	default:
3996 		return -1;
3997 
3998 	}
3999 
4000 	return 0;
4001 }
4002 
4003 static int
4004 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4005 			      struct spdk_nvme_transport_id *trid)
4006 {
4007 	struct spdk_nvmf_rdma_qpair	*rqpair;
4008 
4009 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4010 
4011 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4012 }
4013 
4014 static int
4015 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4016 			       struct spdk_nvme_transport_id *trid)
4017 {
4018 	struct spdk_nvmf_rdma_qpair	*rqpair;
4019 
4020 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4021 
4022 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4023 }
4024 
4025 static int
4026 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4027 				struct spdk_nvme_transport_id *trid)
4028 {
4029 	struct spdk_nvmf_rdma_qpair	*rqpair;
4030 
4031 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4032 
4033 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4034 }
4035 
4036 void
4037 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4038 {
4039 	g_nvmf_hooks = *hooks;
4040 }
4041 
4042 static void
4043 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4044 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4045 {
4046 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4047 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4048 
4049 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4050 
4051 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4052 }
4053 
4054 static int
4055 _nvmf_rdma_qpair_abort_request(void *ctx)
4056 {
4057 	struct spdk_nvmf_request *req = ctx;
4058 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4059 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4060 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4061 					      struct spdk_nvmf_rdma_qpair, qpair);
4062 	int rc;
4063 
4064 	spdk_poller_unregister(&req->poller);
4065 
4066 	switch (rdma_req_to_abort->state) {
4067 	case RDMA_REQUEST_STATE_EXECUTING:
4068 		rc = nvmf_ctrlr_abort_request(req);
4069 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4070 			return SPDK_POLLER_BUSY;
4071 		}
4072 		break;
4073 
4074 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4075 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4076 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4077 
4078 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4079 		break;
4080 
4081 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4082 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4083 			      spdk_nvmf_rdma_request, state_link);
4084 
4085 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4086 		break;
4087 
4088 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4089 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4090 			      spdk_nvmf_rdma_request, state_link);
4091 
4092 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4093 		break;
4094 
4095 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4096 		if (spdk_get_ticks() < req->timeout_tsc) {
4097 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4098 			return SPDK_POLLER_BUSY;
4099 		}
4100 		break;
4101 
4102 	default:
4103 		break;
4104 	}
4105 
4106 	spdk_nvmf_request_complete(req);
4107 	return SPDK_POLLER_BUSY;
4108 }
4109 
4110 static void
4111 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4112 			      struct spdk_nvmf_request *req)
4113 {
4114 	struct spdk_nvmf_rdma_qpair *rqpair;
4115 	struct spdk_nvmf_rdma_transport *rtransport;
4116 	struct spdk_nvmf_transport *transport;
4117 	uint16_t cid;
4118 	uint32_t i, max_req_count;
4119 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL, *rdma_req;
4120 
4121 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4122 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4123 	transport = &rtransport->transport;
4124 
4125 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4126 	max_req_count = rqpair->srq == NULL ? rqpair->max_queue_depth : rqpair->poller->max_srq_depth;
4127 
4128 	for (i = 0; i < max_req_count; i++) {
4129 		rdma_req = &rqpair->resources->reqs[i];
4130 		/* When SRQ == NULL, rqpair has its own requests and req.qpair pointer always points to the qpair
4131 		 * When SRQ != NULL all rqpairs share common requests and qpair pointer is assigned when we start to
4132 		 * process a request. So in both cases all requests which are not in FREE state have valid qpair ptr */
4133 		if (rdma_req->state != RDMA_REQUEST_STATE_FREE && rdma_req->req.cmd->nvme_cmd.cid == cid &&
4134 		    rdma_req->req.qpair == qpair) {
4135 			rdma_req_to_abort = rdma_req;
4136 			break;
4137 		}
4138 	}
4139 
4140 	if (rdma_req_to_abort == NULL) {
4141 		spdk_nvmf_request_complete(req);
4142 		return;
4143 	}
4144 
4145 	req->req_to_abort = &rdma_req_to_abort->req;
4146 	req->timeout_tsc = spdk_get_ticks() +
4147 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4148 	req->poller = NULL;
4149 
4150 	_nvmf_rdma_qpair_abort_request(req);
4151 }
4152 
4153 /* Deprecated, please use the flow with nvmf_rdma_poll_group_dump_stat. */
4154 static int
4155 nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
4156 			      struct spdk_nvmf_transport_poll_group_stat **stat)
4157 {
4158 	struct spdk_io_channel *ch;
4159 	struct spdk_nvmf_poll_group *group;
4160 	struct spdk_nvmf_transport_poll_group *tgroup;
4161 	struct spdk_nvmf_rdma_poll_group *rgroup;
4162 	struct spdk_nvmf_rdma_poller *rpoller;
4163 	struct spdk_nvmf_rdma_device_stat *device_stat;
4164 	uint64_t num_devices = 0;
4165 
4166 	SPDK_ERRLOG("nvmf_rdma_poll_group_get_stat is deprecated and will be removed\n");
4167 
4168 	if (tgt == NULL || stat == NULL) {
4169 		return -EINVAL;
4170 	}
4171 
4172 	ch = spdk_get_io_channel(tgt);
4173 	group = spdk_io_channel_get_ctx(ch);;
4174 	spdk_put_io_channel(ch);
4175 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4176 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4177 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4178 			if (!*stat) {
4179 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4180 				return -ENOMEM;
4181 			}
4182 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4183 
4184 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4185 			/* Count devices to allocate enough memory */
4186 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4187 				++num_devices;
4188 			}
4189 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4190 			if (!(*stat)->rdma.devices) {
4191 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4192 				free(*stat);
4193 				return -ENOMEM;
4194 			}
4195 
4196 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4197 			(*stat)->rdma.num_devices = num_devices;
4198 			num_devices = 0;
4199 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4200 				device_stat = &(*stat)->rdma.devices[num_devices++];
4201 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4202 				device_stat->polls = rpoller->stat.polls;
4203 				device_stat->idle_polls = rpoller->stat.idle_polls;
4204 				device_stat->completions = rpoller->stat.completions;
4205 				device_stat->requests = rpoller->stat.requests;
4206 				device_stat->request_latency = rpoller->stat.request_latency;
4207 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4208 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4209 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4210 				device_stat->total_send_wrs = rpoller->stat.qp_stats.send.num_submitted_wrs;
4211 				device_stat->send_doorbell_updates = rpoller->stat.qp_stats.send.doorbell_updates;
4212 				device_stat->total_recv_wrs = rpoller->stat.qp_stats.recv.num_submitted_wrs;
4213 				device_stat->recv_doorbell_updates = rpoller->stat.qp_stats.recv.doorbell_updates;
4214 			}
4215 			return 0;
4216 		}
4217 	}
4218 	return -ENOENT;
4219 }
4220 
4221 /* Deprecated, please use the flow with nvmf_rdma_poll_group_dump_stat. */
4222 static void
4223 nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4224 {
4225 	SPDK_ERRLOG("nvmf_rdma_poll_group_free_stat is deprecated and will be removed\n");
4226 
4227 	if (stat) {
4228 		free(stat->rdma.devices);
4229 	}
4230 	free(stat);
4231 }
4232 
4233 static void
4234 nvmf_rdma_poll_group_dump_stat(struct spdk_nvmf_transport_poll_group *group,
4235 			       struct spdk_json_write_ctx *w)
4236 {
4237 	struct spdk_nvmf_rdma_poll_group *rgroup;
4238 	struct spdk_nvmf_rdma_poller *rpoller;
4239 
4240 	assert(w != NULL);
4241 
4242 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4243 
4244 	spdk_json_write_named_uint64(w, "pending_data_buffer", rgroup->stat.pending_data_buffer);
4245 
4246 	spdk_json_write_named_array_begin(w, "devices");
4247 
4248 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4249 		spdk_json_write_object_begin(w);
4250 		spdk_json_write_named_string(w, "name",
4251 					     ibv_get_device_name(rpoller->device->context->device));
4252 		spdk_json_write_named_uint64(w, "polls",
4253 					     rpoller->stat.polls);
4254 		spdk_json_write_named_uint64(w, "idle_polls",
4255 					     rpoller->stat.idle_polls);
4256 		spdk_json_write_named_uint64(w, "completions",
4257 					     rpoller->stat.completions);
4258 		spdk_json_write_named_uint64(w, "requests",
4259 					     rpoller->stat.requests);
4260 		spdk_json_write_named_uint64(w, "request_latency",
4261 					     rpoller->stat.request_latency);
4262 		spdk_json_write_named_uint64(w, "pending_free_request",
4263 					     rpoller->stat.pending_free_request);
4264 		spdk_json_write_named_uint64(w, "pending_rdma_read",
4265 					     rpoller->stat.pending_rdma_read);
4266 		spdk_json_write_named_uint64(w, "pending_rdma_write",
4267 					     rpoller->stat.pending_rdma_write);
4268 		spdk_json_write_named_uint64(w, "total_send_wrs",
4269 					     rpoller->stat.qp_stats.send.num_submitted_wrs);
4270 		spdk_json_write_named_uint64(w, "send_doorbell_updates",
4271 					     rpoller->stat.qp_stats.send.doorbell_updates);
4272 		spdk_json_write_named_uint64(w, "total_recv_wrs",
4273 					     rpoller->stat.qp_stats.recv.num_submitted_wrs);
4274 		spdk_json_write_named_uint64(w, "recv_doorbell_updates",
4275 					     rpoller->stat.qp_stats.recv.doorbell_updates);
4276 		spdk_json_write_object_end(w);
4277 	}
4278 
4279 	spdk_json_write_array_end(w);
4280 }
4281 
4282 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4283 	.name = "RDMA",
4284 	.type = SPDK_NVME_TRANSPORT_RDMA,
4285 	.opts_init = nvmf_rdma_opts_init,
4286 	.create = nvmf_rdma_create,
4287 	.dump_opts = nvmf_rdma_dump_opts,
4288 	.destroy = nvmf_rdma_destroy,
4289 
4290 	.listen = nvmf_rdma_listen,
4291 	.stop_listen = nvmf_rdma_stop_listen,
4292 	.accept = nvmf_rdma_accept,
4293 	.cdata_init = nvmf_rdma_cdata_init,
4294 
4295 	.listener_discover = nvmf_rdma_discover,
4296 
4297 	.poll_group_create = nvmf_rdma_poll_group_create,
4298 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4299 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4300 	.poll_group_add = nvmf_rdma_poll_group_add,
4301 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4302 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4303 
4304 	.req_free = nvmf_rdma_request_free,
4305 	.req_complete = nvmf_rdma_request_complete,
4306 
4307 	.qpair_fini = nvmf_rdma_close_qpair,
4308 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4309 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4310 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4311 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4312 
4313 	.poll_group_get_stat = nvmf_rdma_poll_group_get_stat,
4314 	.poll_group_free_stat = nvmf_rdma_poll_group_free_stat,
4315 	.poll_group_dump_stat = nvmf_rdma_poll_group_dump_stat,
4316 };
4317 
4318 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4319 SPDK_LOG_REGISTER_COMPONENT(rdma)
4320