xref: /spdk/lib/nvmf/rdma.c (revision ceea3088870a3919d6bdfe61d7adba11b9733fb7)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019, 2020 Mellanox Technologies LTD. All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include "spdk/config.h"
37 #include "spdk/thread.h"
38 #include "spdk/likely.h"
39 #include "spdk/nvmf_transport.h"
40 #include "spdk/string.h"
41 #include "spdk/trace.h"
42 #include "spdk/util.h"
43 
44 #include "spdk_internal/assert.h"
45 #include "spdk/log.h"
46 #include "spdk_internal/rdma.h"
47 
48 #include "nvmf_internal.h"
49 
50 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
51 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
52 
53 /*
54  RDMA Connection Resource Defaults
55  */
56 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
57 #define NVMF_DEFAULT_RSP_SGE		1
58 #define NVMF_DEFAULT_RX_SGE		2
59 
60 /* The RDMA completion queue size */
61 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
62 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
63 
64 static int g_spdk_nvmf_ibv_query_mask =
65 	IBV_QP_STATE |
66 	IBV_QP_PKEY_INDEX |
67 	IBV_QP_PORT |
68 	IBV_QP_ACCESS_FLAGS |
69 	IBV_QP_AV |
70 	IBV_QP_PATH_MTU |
71 	IBV_QP_DEST_QPN |
72 	IBV_QP_RQ_PSN |
73 	IBV_QP_MAX_DEST_RD_ATOMIC |
74 	IBV_QP_MIN_RNR_TIMER |
75 	IBV_QP_SQ_PSN |
76 	IBV_QP_TIMEOUT |
77 	IBV_QP_RETRY_CNT |
78 	IBV_QP_RNR_RETRY |
79 	IBV_QP_MAX_QP_RD_ATOMIC;
80 
81 enum spdk_nvmf_rdma_request_state {
82 	/* The request is not currently in use */
83 	RDMA_REQUEST_STATE_FREE = 0,
84 
85 	/* Initial state when request first received */
86 	RDMA_REQUEST_STATE_NEW,
87 
88 	/* The request is queued until a data buffer is available. */
89 	RDMA_REQUEST_STATE_NEED_BUFFER,
90 
91 	/* The request is waiting on RDMA queue depth availability
92 	 * to transfer data from the host to the controller.
93 	 */
94 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
95 
96 	/* The request is currently transferring data from the host to the controller. */
97 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
98 
99 	/* The request is ready to execute at the block device */
100 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
101 
102 	/* The request is currently executing at the block device */
103 	RDMA_REQUEST_STATE_EXECUTING,
104 
105 	/* The request finished executing at the block device */
106 	RDMA_REQUEST_STATE_EXECUTED,
107 
108 	/* The request is waiting on RDMA queue depth availability
109 	 * to transfer data from the controller to the host.
110 	 */
111 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
112 
113 	/* The request is ready to send a completion */
114 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
115 
116 	/* The request is currently transferring data from the controller to the host. */
117 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
118 
119 	/* The request currently has an outstanding completion without an
120 	 * associated data transfer.
121 	 */
122 	RDMA_REQUEST_STATE_COMPLETING,
123 
124 	/* The request completed and can be marked free. */
125 	RDMA_REQUEST_STATE_COMPLETED,
126 
127 	/* Terminator */
128 	RDMA_REQUEST_NUM_STATES,
129 };
130 
131 #define OBJECT_NVMF_RDMA_IO				0x40
132 
133 #define TRACE_GROUP_NVMF_RDMA				0x4
134 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
135 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
136 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
137 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
138 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
139 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
140 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
141 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
142 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
143 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
144 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
145 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
146 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
147 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
148 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
149 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
150 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
151 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
152 
153 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
154 {
155 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
156 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
157 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
158 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
159 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
160 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
161 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
163 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
164 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
165 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
166 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
167 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
170 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
173 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
175 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
176 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
178 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
179 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
180 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
181 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
182 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
183 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
184 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
185 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
186 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
187 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
188 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
189 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
190 
191 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
192 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
193 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
194 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
195 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
196 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
197 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
198 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
199 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
200 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
201 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
202 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
203 }
204 
205 enum spdk_nvmf_rdma_wr_type {
206 	RDMA_WR_TYPE_RECV,
207 	RDMA_WR_TYPE_SEND,
208 	RDMA_WR_TYPE_DATA,
209 };
210 
211 struct spdk_nvmf_rdma_wr {
212 	enum spdk_nvmf_rdma_wr_type	type;
213 };
214 
215 /* This structure holds commands as they are received off the wire.
216  * It must be dynamically paired with a full request object
217  * (spdk_nvmf_rdma_request) to service a request. It is separate
218  * from the request because RDMA does not appear to order
219  * completions, so occasionally we'll get a new incoming
220  * command when there aren't any free request objects.
221  */
222 struct spdk_nvmf_rdma_recv {
223 	struct ibv_recv_wr			wr;
224 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
225 
226 	struct spdk_nvmf_rdma_qpair		*qpair;
227 
228 	/* In-capsule data buffer */
229 	uint8_t					*buf;
230 
231 	struct spdk_nvmf_rdma_wr		rdma_wr;
232 	uint64_t				receive_tsc;
233 
234 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
235 };
236 
237 struct spdk_nvmf_rdma_request_data {
238 	struct spdk_nvmf_rdma_wr	rdma_wr;
239 	struct ibv_send_wr		wr;
240 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
241 };
242 
243 struct spdk_nvmf_rdma_request {
244 	struct spdk_nvmf_request		req;
245 
246 	enum spdk_nvmf_rdma_request_state	state;
247 
248 	struct spdk_nvmf_rdma_recv		*recv;
249 
250 	struct {
251 		struct spdk_nvmf_rdma_wr	rdma_wr;
252 		struct	ibv_send_wr		wr;
253 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
254 	} rsp;
255 
256 	struct spdk_nvmf_rdma_request_data	data;
257 
258 	uint32_t				iovpos;
259 
260 	uint32_t				num_outstanding_data_wr;
261 	uint64_t				receive_tsc;
262 
263 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
264 };
265 
266 struct spdk_nvmf_rdma_resource_opts {
267 	struct spdk_nvmf_rdma_qpair	*qpair;
268 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
269 	void				*qp;
270 	struct ibv_pd			*pd;
271 	uint32_t			max_queue_depth;
272 	uint32_t			in_capsule_data_size;
273 	bool				shared;
274 };
275 
276 struct spdk_nvmf_recv_wr_list {
277 	struct ibv_recv_wr	*first;
278 	struct ibv_recv_wr	*last;
279 };
280 
281 struct spdk_nvmf_rdma_resources {
282 	/* Array of size "max_queue_depth" containing RDMA requests. */
283 	struct spdk_nvmf_rdma_request		*reqs;
284 
285 	/* Array of size "max_queue_depth" containing RDMA recvs. */
286 	struct spdk_nvmf_rdma_recv		*recvs;
287 
288 	/* Array of size "max_queue_depth" containing 64 byte capsules
289 	 * used for receive.
290 	 */
291 	union nvmf_h2c_msg			*cmds;
292 	struct ibv_mr				*cmds_mr;
293 
294 	/* Array of size "max_queue_depth" containing 16 byte completions
295 	 * to be sent back to the user.
296 	 */
297 	union nvmf_c2h_msg			*cpls;
298 	struct ibv_mr				*cpls_mr;
299 
300 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
301 	 * buffers to be used for in capsule data.
302 	 */
303 	void					*bufs;
304 	struct ibv_mr				*bufs_mr;
305 
306 	/* The list of pending recvs to transfer */
307 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
308 
309 	/* Receives that are waiting for a request object */
310 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
311 
312 	/* Queue to track free requests */
313 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
314 };
315 
316 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
317 
318 struct spdk_nvmf_rdma_ibv_event_ctx {
319 	struct spdk_nvmf_rdma_qpair			*rqpair;
320 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
321 	/* Link to other ibv events associated with this qpair */
322 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
323 };
324 
325 struct spdk_nvmf_rdma_qpair {
326 	struct spdk_nvmf_qpair			qpair;
327 
328 	struct spdk_nvmf_rdma_device		*device;
329 	struct spdk_nvmf_rdma_poller		*poller;
330 
331 	struct spdk_rdma_qp			*rdma_qp;
332 	struct rdma_cm_id			*cm_id;
333 	struct ibv_srq				*srq;
334 	struct rdma_cm_id			*listen_id;
335 
336 	/* The maximum number of I/O outstanding on this connection at one time */
337 	uint16_t				max_queue_depth;
338 
339 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
340 	uint16_t				max_read_depth;
341 
342 	/* The maximum number of RDMA SEND operations at one time */
343 	uint32_t				max_send_depth;
344 
345 	/* The current number of outstanding WRs from this qpair's
346 	 * recv queue. Should not exceed device->attr.max_queue_depth.
347 	 */
348 	uint16_t				current_recv_depth;
349 
350 	/* The current number of active RDMA READ operations */
351 	uint16_t				current_read_depth;
352 
353 	/* The current number of posted WRs from this qpair's
354 	 * send queue. Should not exceed max_send_depth.
355 	 */
356 	uint32_t				current_send_depth;
357 
358 	/* The maximum number of SGEs per WR on the send queue */
359 	uint32_t				max_send_sge;
360 
361 	/* The maximum number of SGEs per WR on the recv queue */
362 	uint32_t				max_recv_sge;
363 
364 	struct spdk_nvmf_rdma_resources		*resources;
365 
366 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
367 
368 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
369 
370 	/* Number of requests not in the free state */
371 	uint32_t				qd;
372 
373 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
374 
375 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
376 
377 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
378 
379 	/* IBV queue pair attributes: they are used to manage
380 	 * qp state and recover from errors.
381 	 */
382 	enum ibv_qp_state			ibv_state;
383 
384 	/*
385 	 * io_channel which is used to destroy qpair when it is removed from poll group
386 	 */
387 	struct spdk_io_channel		*destruct_channel;
388 
389 	/* List of ibv async events */
390 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
391 
392 	/* Lets us know that we have received the last_wqe event. */
393 	bool					last_wqe_reached;
394 
395 	/* Indicate that nvmf_rdma_close_qpair is called */
396 	bool					to_close;
397 };
398 
399 struct spdk_nvmf_rdma_poller_stat {
400 	uint64_t				completions;
401 	uint64_t				polls;
402 	uint64_t				requests;
403 	uint64_t				request_latency;
404 	uint64_t				pending_free_request;
405 	uint64_t				pending_rdma_read;
406 	uint64_t				pending_rdma_write;
407 };
408 
409 struct spdk_nvmf_rdma_poller {
410 	struct spdk_nvmf_rdma_device		*device;
411 	struct spdk_nvmf_rdma_poll_group	*group;
412 
413 	int					num_cqe;
414 	int					required_num_wr;
415 	struct ibv_cq				*cq;
416 
417 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
418 	uint16_t				max_srq_depth;
419 
420 	/* Shared receive queue */
421 	struct ibv_srq				*srq;
422 
423 	struct spdk_nvmf_rdma_resources		*resources;
424 	struct spdk_nvmf_rdma_poller_stat	stat;
425 
426 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
427 
428 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
429 
430 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
431 
432 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
433 };
434 
435 struct spdk_nvmf_rdma_poll_group_stat {
436 	uint64_t				pending_data_buffer;
437 };
438 
439 struct spdk_nvmf_rdma_poll_group {
440 	struct spdk_nvmf_transport_poll_group		group;
441 	struct spdk_nvmf_rdma_poll_group_stat		stat;
442 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
443 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
444 	/*
445 	 * buffers which are split across multiple RDMA
446 	 * memory regions cannot be used by this transport.
447 	 */
448 	STAILQ_HEAD(, spdk_nvmf_transport_pg_cache_buf)	retired_bufs;
449 };
450 
451 struct spdk_nvmf_rdma_conn_sched {
452 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
453 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
454 };
455 
456 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
457 struct spdk_nvmf_rdma_device {
458 	struct ibv_device_attr			attr;
459 	struct ibv_context			*context;
460 
461 	struct spdk_mem_map			*map;
462 	struct ibv_pd				*pd;
463 
464 	int					num_srq;
465 
466 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
467 };
468 
469 struct spdk_nvmf_rdma_port {
470 	const struct spdk_nvme_transport_id	*trid;
471 	struct rdma_cm_id			*id;
472 	struct spdk_nvmf_rdma_device		*device;
473 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
474 };
475 
476 struct rdma_transport_opts {
477 	uint32_t	max_srq_depth;
478 	bool		no_srq;
479 	int		acceptor_backlog;
480 };
481 
482 struct spdk_nvmf_rdma_transport {
483 	struct spdk_nvmf_transport	transport;
484 	struct rdma_transport_opts	rdma_opts;
485 
486 	struct spdk_nvmf_rdma_conn_sched conn_sched;
487 
488 	struct rdma_event_channel	*event_channel;
489 
490 	struct spdk_mempool		*data_wr_pool;
491 
492 	pthread_mutex_t			lock;
493 
494 	/* fields used to poll RDMA/IB events */
495 	nfds_t			npoll_fds;
496 	struct pollfd		*poll_fds;
497 
498 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
499 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
500 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
501 };
502 
503 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
504 	{
505 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
506 		spdk_json_decode_uint32, true
507 	},
508 	{
509 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
510 		spdk_json_decode_bool, true
511 	},
512 	{
513 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
514 		spdk_json_decode_int32, true
515 	},
516 };
517 
518 static bool
519 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
520 			  struct spdk_nvmf_rdma_request *rdma_req);
521 
522 static inline int
523 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
524 {
525 	switch (state) {
526 	case IBV_QPS_RESET:
527 	case IBV_QPS_INIT:
528 	case IBV_QPS_RTR:
529 	case IBV_QPS_RTS:
530 	case IBV_QPS_SQD:
531 	case IBV_QPS_SQE:
532 	case IBV_QPS_ERR:
533 		return 0;
534 	default:
535 		return -1;
536 	}
537 }
538 
539 static inline enum spdk_nvme_media_error_status_code
540 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
541 	enum spdk_nvme_media_error_status_code result;
542 	switch (err_type)
543 	{
544 	case SPDK_DIF_REFTAG_ERROR:
545 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
546 		break;
547 	case SPDK_DIF_APPTAG_ERROR:
548 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
549 		break;
550 	case SPDK_DIF_GUARD_ERROR:
551 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
552 		break;
553 	default:
554 		SPDK_UNREACHABLE();
555 	}
556 
557 	return result;
558 }
559 
560 static enum ibv_qp_state
561 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
562 	enum ibv_qp_state old_state, new_state;
563 	struct ibv_qp_attr qp_attr;
564 	struct ibv_qp_init_attr init_attr;
565 	int rc;
566 
567 	old_state = rqpair->ibv_state;
568 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
569 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
570 
571 	if (rc)
572 	{
573 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
574 		return IBV_QPS_ERR + 1;
575 	}
576 
577 	new_state = qp_attr.qp_state;
578 	rqpair->ibv_state = new_state;
579 	qp_attr.ah_attr.port_num = qp_attr.port_num;
580 
581 	rc = nvmf_rdma_check_ibv_state(new_state);
582 	if (rc)
583 	{
584 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
585 		/*
586 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
587 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
588 		 */
589 		return IBV_QPS_ERR + 1;
590 	}
591 
592 	if (old_state != new_state)
593 	{
594 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
595 				  (uintptr_t)rqpair->cm_id, new_state);
596 	}
597 	return new_state;
598 }
599 
600 static void
601 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
602 			    struct spdk_nvmf_rdma_transport *rtransport)
603 {
604 	struct spdk_nvmf_rdma_request_data	*data_wr;
605 	struct ibv_send_wr			*next_send_wr;
606 	uint64_t				req_wrid;
607 
608 	rdma_req->num_outstanding_data_wr = 0;
609 	data_wr = &rdma_req->data;
610 	req_wrid = data_wr->wr.wr_id;
611 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
612 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
613 		data_wr->wr.num_sge = 0;
614 		next_send_wr = data_wr->wr.next;
615 		if (data_wr != &rdma_req->data) {
616 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
617 		}
618 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
619 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
620 	}
621 }
622 
623 static void
624 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
625 {
626 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
627 	if (req->req.cmd) {
628 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
629 	}
630 	if (req->recv) {
631 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
632 	}
633 }
634 
635 static void
636 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
637 {
638 	int i;
639 
640 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
641 	for (i = 0; i < rqpair->max_queue_depth; i++) {
642 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
643 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
644 		}
645 	}
646 }
647 
648 static void
649 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
650 {
651 	if (resources->cmds_mr) {
652 		ibv_dereg_mr(resources->cmds_mr);
653 	}
654 
655 	if (resources->cpls_mr) {
656 		ibv_dereg_mr(resources->cpls_mr);
657 	}
658 
659 	if (resources->bufs_mr) {
660 		ibv_dereg_mr(resources->bufs_mr);
661 	}
662 
663 	spdk_free(resources->cmds);
664 	spdk_free(resources->cpls);
665 	spdk_free(resources->bufs);
666 	free(resources->reqs);
667 	free(resources->recvs);
668 	free(resources);
669 }
670 
671 
672 static struct spdk_nvmf_rdma_resources *
673 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
674 {
675 	struct spdk_nvmf_rdma_resources	*resources;
676 	struct spdk_nvmf_rdma_request	*rdma_req;
677 	struct spdk_nvmf_rdma_recv	*rdma_recv;
678 	struct ibv_qp			*qp;
679 	struct ibv_srq			*srq;
680 	uint32_t			i;
681 	int				rc;
682 
683 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
684 	if (!resources) {
685 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
686 		return NULL;
687 	}
688 
689 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
690 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
691 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
692 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
693 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
694 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
695 
696 	if (opts->in_capsule_data_size > 0) {
697 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
698 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
699 					       SPDK_MALLOC_DMA);
700 	}
701 
702 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
703 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
704 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
705 		goto cleanup;
706 	}
707 
708 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
709 					opts->max_queue_depth * sizeof(*resources->cmds),
710 					IBV_ACCESS_LOCAL_WRITE);
711 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
712 					opts->max_queue_depth * sizeof(*resources->cpls),
713 					0);
714 
715 	if (opts->in_capsule_data_size) {
716 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
717 						opts->max_queue_depth *
718 						opts->in_capsule_data_size,
719 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
720 	}
721 
722 	if (!resources->cmds_mr || !resources->cpls_mr ||
723 	    (opts->in_capsule_data_size &&
724 	     !resources->bufs_mr)) {
725 		goto cleanup;
726 	}
727 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
728 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
729 		      resources->cmds_mr->lkey);
730 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
731 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
732 		      resources->cpls_mr->lkey);
733 	if (resources->bufs && resources->bufs_mr) {
734 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
735 			      resources->bufs, opts->max_queue_depth *
736 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
737 	}
738 
739 	/* Initialize queues */
740 	STAILQ_INIT(&resources->incoming_queue);
741 	STAILQ_INIT(&resources->free_queue);
742 
743 	for (i = 0; i < opts->max_queue_depth; i++) {
744 		struct ibv_recv_wr *bad_wr = NULL;
745 
746 		rdma_recv = &resources->recvs[i];
747 		rdma_recv->qpair = opts->qpair;
748 
749 		/* Set up memory to receive commands */
750 		if (resources->bufs) {
751 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
752 						  opts->in_capsule_data_size));
753 		}
754 
755 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
756 
757 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
758 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
759 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
760 		rdma_recv->wr.num_sge = 1;
761 
762 		if (rdma_recv->buf && resources->bufs_mr) {
763 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
764 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
765 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
766 			rdma_recv->wr.num_sge++;
767 		}
768 
769 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
770 		rdma_recv->wr.sg_list = rdma_recv->sgl;
771 		if (opts->shared) {
772 			srq = (struct ibv_srq *)opts->qp;
773 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
774 		} else {
775 			qp = (struct ibv_qp *)opts->qp;
776 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
777 		}
778 		if (rc) {
779 			goto cleanup;
780 		}
781 	}
782 
783 	for (i = 0; i < opts->max_queue_depth; i++) {
784 		rdma_req = &resources->reqs[i];
785 
786 		if (opts->qpair != NULL) {
787 			rdma_req->req.qpair = &opts->qpair->qpair;
788 		} else {
789 			rdma_req->req.qpair = NULL;
790 		}
791 		rdma_req->req.cmd = NULL;
792 
793 		/* Set up memory to send responses */
794 		rdma_req->req.rsp = &resources->cpls[i];
795 
796 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
797 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
798 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
799 
800 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
801 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
802 		rdma_req->rsp.wr.next = NULL;
803 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
804 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
805 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
806 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
807 
808 		/* Set up memory for data buffers */
809 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
810 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
811 		rdma_req->data.wr.next = NULL;
812 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
813 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
814 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
815 
816 		/* Initialize request state to FREE */
817 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
818 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
819 	}
820 
821 	return resources;
822 
823 cleanup:
824 	nvmf_rdma_resources_destroy(resources);
825 	return NULL;
826 }
827 
828 static void
829 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
830 {
831 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
832 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
833 		ctx->rqpair = NULL;
834 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
835 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
836 	}
837 }
838 
839 static void
840 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
841 {
842 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
843 	struct ibv_recv_wr		*bad_recv_wr = NULL;
844 	int				rc;
845 
846 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
847 
848 	if (rqpair->qd != 0) {
849 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
850 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
851 				struct spdk_nvmf_rdma_transport, transport);
852 		struct spdk_nvmf_rdma_request *req;
853 		uint32_t i, max_req_count = 0;
854 
855 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
856 
857 		if (rqpair->srq == NULL) {
858 			nvmf_rdma_dump_qpair_contents(rqpair);
859 			max_req_count = rqpair->max_queue_depth;
860 		} else if (rqpair->poller && rqpair->resources) {
861 			max_req_count = rqpair->poller->max_srq_depth;
862 		}
863 
864 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
865 		for (i = 0; i < max_req_count; i++) {
866 			req = &rqpair->resources->reqs[i];
867 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
868 				/* nvmf_rdma_request_process checks qpair ibv and internal state
869 				 * and completes a request */
870 				nvmf_rdma_request_process(rtransport, req);
871 			}
872 		}
873 		assert(rqpair->qd == 0);
874 	}
875 
876 	if (rqpair->poller) {
877 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
878 
879 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
880 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
881 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
882 				if (rqpair == rdma_recv->qpair) {
883 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
884 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
885 					if (rc) {
886 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
887 					}
888 				}
889 			}
890 		}
891 	}
892 
893 	if (rqpair->cm_id) {
894 		if (rqpair->rdma_qp != NULL) {
895 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
896 			rqpair->rdma_qp = NULL;
897 		}
898 		rdma_destroy_id(rqpair->cm_id);
899 
900 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
901 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
902 		}
903 	}
904 
905 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
906 		nvmf_rdma_resources_destroy(rqpair->resources);
907 	}
908 
909 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
910 
911 	if (rqpair->destruct_channel) {
912 		spdk_put_io_channel(rqpair->destruct_channel);
913 		rqpair->destruct_channel = NULL;
914 	}
915 
916 	free(rqpair);
917 }
918 
919 static int
920 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
921 {
922 	struct spdk_nvmf_rdma_poller	*rpoller;
923 	int				rc, num_cqe, required_num_wr;
924 
925 	/* Enlarge CQ size dynamically */
926 	rpoller = rqpair->poller;
927 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
928 	num_cqe = rpoller->num_cqe;
929 	if (num_cqe < required_num_wr) {
930 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
931 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
932 	}
933 
934 	if (rpoller->num_cqe != num_cqe) {
935 		if (required_num_wr > device->attr.max_cqe) {
936 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
937 				    required_num_wr, device->attr.max_cqe);
938 			return -1;
939 		}
940 
941 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
942 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
943 		if (rc) {
944 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
945 			return -1;
946 		}
947 
948 		rpoller->num_cqe = num_cqe;
949 	}
950 
951 	rpoller->required_num_wr = required_num_wr;
952 	return 0;
953 }
954 
955 static int
956 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
957 {
958 	struct spdk_nvmf_rdma_qpair		*rqpair;
959 	struct spdk_nvmf_rdma_transport		*rtransport;
960 	struct spdk_nvmf_transport		*transport;
961 	struct spdk_nvmf_rdma_resource_opts	opts;
962 	struct spdk_nvmf_rdma_device		*device;
963 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
964 
965 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
966 	device = rqpair->device;
967 
968 	qp_init_attr.qp_context	= rqpair;
969 	qp_init_attr.pd		= device->pd;
970 	qp_init_attr.send_cq	= rqpair->poller->cq;
971 	qp_init_attr.recv_cq	= rqpair->poller->cq;
972 
973 	if (rqpair->srq) {
974 		qp_init_attr.srq		= rqpair->srq;
975 	} else {
976 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
977 	}
978 
979 	/* SEND, READ, and WRITE operations */
980 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
981 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
982 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
983 
984 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
985 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
986 		goto error;
987 	}
988 
989 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
990 	if (!rqpair->rdma_qp) {
991 		goto error;
992 	}
993 
994 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
995 					  qp_init_attr.cap.max_send_wr);
996 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
997 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
998 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
999 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1000 
1001 	if (rqpair->poller->srq == NULL) {
1002 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1003 		transport = &rtransport->transport;
1004 
1005 		opts.qp = rqpair->rdma_qp->qp;
1006 		opts.pd = rqpair->cm_id->pd;
1007 		opts.qpair = rqpair;
1008 		opts.shared = false;
1009 		opts.max_queue_depth = rqpair->max_queue_depth;
1010 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1011 
1012 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1013 
1014 		if (!rqpair->resources) {
1015 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1016 			rdma_destroy_qp(rqpair->cm_id);
1017 			goto error;
1018 		}
1019 	} else {
1020 		rqpair->resources = rqpair->poller->resources;
1021 	}
1022 
1023 	rqpair->current_recv_depth = 0;
1024 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1025 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1026 
1027 	return 0;
1028 
1029 error:
1030 	rdma_destroy_id(rqpair->cm_id);
1031 	rqpair->cm_id = NULL;
1032 	return -1;
1033 }
1034 
1035 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1036 /* This function accepts either a single wr or the first wr in a linked list. */
1037 static void
1038 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1039 {
1040 	struct ibv_recv_wr *last;
1041 
1042 	last = first;
1043 	while (last->next != NULL) {
1044 		last = last->next;
1045 	}
1046 
1047 	if (rqpair->resources->recvs_to_post.first == NULL) {
1048 		rqpair->resources->recvs_to_post.first = first;
1049 		rqpair->resources->recvs_to_post.last = last;
1050 		if (rqpair->srq == NULL) {
1051 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1052 		}
1053 	} else {
1054 		rqpair->resources->recvs_to_post.last->next = first;
1055 		rqpair->resources->recvs_to_post.last = last;
1056 	}
1057 }
1058 
1059 static int
1060 request_transfer_in(struct spdk_nvmf_request *req)
1061 {
1062 	struct spdk_nvmf_rdma_request	*rdma_req;
1063 	struct spdk_nvmf_qpair		*qpair;
1064 	struct spdk_nvmf_rdma_qpair	*rqpair;
1065 
1066 	qpair = req->qpair;
1067 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1068 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1069 
1070 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1071 	assert(rdma_req != NULL);
1072 
1073 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1074 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1075 	}
1076 
1077 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1078 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1079 	return 0;
1080 }
1081 
1082 static int
1083 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1084 {
1085 	int				num_outstanding_data_wr = 0;
1086 	struct spdk_nvmf_rdma_request	*rdma_req;
1087 	struct spdk_nvmf_qpair		*qpair;
1088 	struct spdk_nvmf_rdma_qpair	*rqpair;
1089 	struct spdk_nvme_cpl		*rsp;
1090 	struct ibv_send_wr		*first = NULL;
1091 
1092 	*data_posted = 0;
1093 	qpair = req->qpair;
1094 	rsp = &req->rsp->nvme_cpl;
1095 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1096 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1097 
1098 	/* Advance our sq_head pointer */
1099 	if (qpair->sq_head == qpair->sq_head_max) {
1100 		qpair->sq_head = 0;
1101 	} else {
1102 		qpair->sq_head++;
1103 	}
1104 	rsp->sqhd = qpair->sq_head;
1105 
1106 	/* queue the capsule for the recv buffer */
1107 	assert(rdma_req->recv != NULL);
1108 
1109 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1110 
1111 	rdma_req->recv = NULL;
1112 	assert(rqpair->current_recv_depth > 0);
1113 	rqpair->current_recv_depth--;
1114 
1115 	/* Build the response which consists of optional
1116 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1117 	 * containing the response.
1118 	 */
1119 	first = &rdma_req->rsp.wr;
1120 
1121 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1122 		/* On failure, data was not read from the controller. So clear the
1123 		 * number of outstanding data WRs to zero.
1124 		 */
1125 		rdma_req->num_outstanding_data_wr = 0;
1126 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1127 		first = &rdma_req->data.wr;
1128 		*data_posted = 1;
1129 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1130 	}
1131 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1132 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1133 	}
1134 
1135 	/* +1 for the rsp wr */
1136 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1137 
1138 	return 0;
1139 }
1140 
1141 static int
1142 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1143 {
1144 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1145 	struct rdma_conn_param				ctrlr_event_data = {};
1146 	int						rc;
1147 
1148 	accept_data.recfmt = 0;
1149 	accept_data.crqsize = rqpair->max_queue_depth;
1150 
1151 	ctrlr_event_data.private_data = &accept_data;
1152 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1153 	if (id->ps == RDMA_PS_TCP) {
1154 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1155 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1156 	}
1157 
1158 	/* Configure infinite retries for the initiator side qpair.
1159 	 * When using a shared receive queue on the target side,
1160 	 * we need to pass this value to the initiator to prevent the
1161 	 * initiator side NIC from completing SEND requests back to the
1162 	 * initiator with status rnr_retry_count_exceeded. */
1163 	if (rqpair->srq != NULL) {
1164 		ctrlr_event_data.rnr_retry_count = 0x7;
1165 	}
1166 
1167 	/* When qpair is created without use of rdma cm API, an additional
1168 	 * information must be provided to initiator in the connection response:
1169 	 * whether qpair is using SRQ and its qp_num
1170 	 * Fields below are ignored by rdma cm if qpair has been
1171 	 * created using rdma cm API. */
1172 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1173 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1174 
1175 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1176 	if (rc) {
1177 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1178 	} else {
1179 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1180 	}
1181 
1182 	return rc;
1183 }
1184 
1185 static void
1186 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1187 {
1188 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1189 
1190 	rej_data.recfmt = 0;
1191 	rej_data.sts = error;
1192 
1193 	rdma_reject(id, &rej_data, sizeof(rej_data));
1194 }
1195 
1196 static int
1197 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1198 {
1199 	struct spdk_nvmf_rdma_transport *rtransport;
1200 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1201 	struct spdk_nvmf_rdma_port	*port;
1202 	struct rdma_conn_param		*rdma_param = NULL;
1203 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1204 	uint16_t			max_queue_depth;
1205 	uint16_t			max_read_depth;
1206 
1207 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1208 
1209 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1210 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1211 
1212 	rdma_param = &event->param.conn;
1213 	if (rdma_param->private_data == NULL ||
1214 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1215 		SPDK_ERRLOG("connect request: no private data provided\n");
1216 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1217 		return -1;
1218 	}
1219 
1220 	private_data = rdma_param->private_data;
1221 	if (private_data->recfmt != 0) {
1222 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1223 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1224 		return -1;
1225 	}
1226 
1227 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1228 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1229 
1230 	port = event->listen_id->context;
1231 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1232 		      event->listen_id, event->listen_id->verbs, port);
1233 
1234 	/* Figure out the supported queue depth. This is a multi-step process
1235 	 * that takes into account hardware maximums, host provided values,
1236 	 * and our target's internal memory limits */
1237 
1238 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1239 
1240 	/* Start with the maximum queue depth allowed by the target */
1241 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1242 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1243 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1244 		      rtransport->transport.opts.max_queue_depth);
1245 
1246 	/* Next check the local NIC's hardware limitations */
1247 	SPDK_DEBUGLOG(rdma,
1248 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1249 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1250 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1251 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1252 
1253 	/* Next check the remote NIC's hardware limitations */
1254 	SPDK_DEBUGLOG(rdma,
1255 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1256 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1257 	if (rdma_param->initiator_depth > 0) {
1258 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1259 	}
1260 
1261 	/* Finally check for the host software requested values, which are
1262 	 * optional. */
1263 	if (rdma_param->private_data != NULL &&
1264 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1265 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1266 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1267 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1268 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1269 	}
1270 
1271 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1272 		      max_queue_depth, max_read_depth);
1273 
1274 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1275 	if (rqpair == NULL) {
1276 		SPDK_ERRLOG("Could not allocate new connection.\n");
1277 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1278 		return -1;
1279 	}
1280 
1281 	rqpair->device = port->device;
1282 	rqpair->max_queue_depth = max_queue_depth;
1283 	rqpair->max_read_depth = max_read_depth;
1284 	rqpair->cm_id = event->id;
1285 	rqpair->listen_id = event->listen_id;
1286 	rqpair->qpair.transport = transport;
1287 	rqpair->qpair.trid = port->trid;
1288 	STAILQ_INIT(&rqpair->ibv_events);
1289 	/* use qid from the private data to determine the qpair type
1290 	   qid will be set to the appropriate value when the controller is created */
1291 	rqpair->qpair.qid = private_data->qid;
1292 
1293 	event->id->context = &rqpair->qpair;
1294 
1295 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1296 
1297 	return 0;
1298 }
1299 
1300 static int
1301 nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1302 		     enum spdk_mem_map_notify_action action,
1303 		     void *vaddr, size_t size)
1304 {
1305 	struct ibv_pd *pd = cb_ctx;
1306 	struct ibv_mr *mr;
1307 	int rc;
1308 
1309 	switch (action) {
1310 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1311 		if (!g_nvmf_hooks.get_rkey) {
1312 			mr = ibv_reg_mr(pd, vaddr, size,
1313 					IBV_ACCESS_LOCAL_WRITE |
1314 					IBV_ACCESS_REMOTE_READ |
1315 					IBV_ACCESS_REMOTE_WRITE);
1316 			if (mr == NULL) {
1317 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1318 				return -1;
1319 			} else {
1320 				rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1321 			}
1322 		} else {
1323 			rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1324 							  g_nvmf_hooks.get_rkey(pd, vaddr, size));
1325 		}
1326 		break;
1327 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1328 		if (!g_nvmf_hooks.get_rkey) {
1329 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1330 			if (mr) {
1331 				ibv_dereg_mr(mr);
1332 			}
1333 		}
1334 		rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1335 		break;
1336 	default:
1337 		SPDK_UNREACHABLE();
1338 	}
1339 
1340 	return rc;
1341 }
1342 
1343 static int
1344 nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1345 {
1346 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1347 	return addr_1 == addr_2;
1348 }
1349 
1350 static inline void
1351 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1352 		   enum spdk_nvme_data_transfer xfer)
1353 {
1354 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1355 		wr->opcode = IBV_WR_RDMA_WRITE;
1356 		wr->send_flags = 0;
1357 		wr->next = next;
1358 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1359 		wr->opcode = IBV_WR_RDMA_READ;
1360 		wr->send_flags = IBV_SEND_SIGNALED;
1361 		wr->next = NULL;
1362 	} else {
1363 		assert(0);
1364 	}
1365 }
1366 
1367 static int
1368 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1369 		       struct spdk_nvmf_rdma_request *rdma_req,
1370 		       uint32_t num_sgl_descriptors)
1371 {
1372 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1373 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1374 	uint32_t				i;
1375 
1376 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1377 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1378 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1379 		return -EINVAL;
1380 	}
1381 
1382 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1383 		return -ENOMEM;
1384 	}
1385 
1386 	current_data_wr = &rdma_req->data;
1387 
1388 	for (i = 0; i < num_sgl_descriptors; i++) {
1389 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1390 		current_data_wr->wr.next = &work_requests[i]->wr;
1391 		current_data_wr = work_requests[i];
1392 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1393 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1394 	}
1395 
1396 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1397 
1398 	return 0;
1399 }
1400 
1401 static inline void
1402 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1403 {
1404 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1405 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1406 
1407 	wr->wr.rdma.rkey = sgl->keyed.key;
1408 	wr->wr.rdma.remote_addr = sgl->address;
1409 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1410 }
1411 
1412 static inline void
1413 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1414 {
1415 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1416 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1417 	uint32_t			i;
1418 	int				j;
1419 	uint64_t			remote_addr_offset = 0;
1420 
1421 	for (i = 0; i < num_wrs; ++i) {
1422 		wr->wr.rdma.rkey = sgl->keyed.key;
1423 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1424 		for (j = 0; j < wr->num_sge; ++j) {
1425 			remote_addr_offset += wr->sg_list[j].length;
1426 		}
1427 		wr = wr->next;
1428 	}
1429 }
1430 
1431 /* This function is used in the rare case that we have a buffer split over multiple memory regions. */
1432 static int
1433 nvmf_rdma_replace_buffer(struct spdk_nvmf_rdma_poll_group *rgroup, void **buf)
1434 {
1435 	struct spdk_nvmf_transport_poll_group	*group = &rgroup->group;
1436 	struct spdk_nvmf_transport		*transport = group->transport;
1437 	struct spdk_nvmf_transport_pg_cache_buf	*old_buf;
1438 	void					*new_buf;
1439 
1440 	if (!(STAILQ_EMPTY(&group->buf_cache))) {
1441 		group->buf_cache_count--;
1442 		new_buf = STAILQ_FIRST(&group->buf_cache);
1443 		STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1444 		assert(*buf != NULL);
1445 	} else {
1446 		new_buf = spdk_mempool_get(transport->data_buf_pool);
1447 	}
1448 
1449 	if (*buf == NULL) {
1450 		return -ENOMEM;
1451 	}
1452 
1453 	old_buf = *buf;
1454 	STAILQ_INSERT_HEAD(&rgroup->retired_bufs, old_buf, link);
1455 	*buf = new_buf;
1456 	return 0;
1457 }
1458 
1459 static bool
1460 nvmf_rdma_get_lkey(struct spdk_nvmf_rdma_device *device, struct iovec *iov,
1461 		   uint32_t *_lkey)
1462 {
1463 	uint64_t	translation_len;
1464 	uint32_t	lkey;
1465 
1466 	translation_len = iov->iov_len;
1467 
1468 	if (!g_nvmf_hooks.get_rkey) {
1469 		lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1470 				(uint64_t)iov->iov_base, &translation_len))->lkey;
1471 	} else {
1472 		lkey = spdk_mem_map_translate(device->map,
1473 					      (uint64_t)iov->iov_base, &translation_len);
1474 	}
1475 
1476 	if (spdk_unlikely(translation_len < iov->iov_len)) {
1477 		return false;
1478 	}
1479 
1480 	*_lkey = lkey;
1481 	return true;
1482 }
1483 
1484 static bool
1485 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1486 		      struct iovec *iov, struct ibv_send_wr **_wr,
1487 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1488 		      uint32_t *_num_extra_wrs,
1489 		      const struct spdk_dif_ctx *dif_ctx)
1490 {
1491 	struct ibv_send_wr *wr = *_wr;
1492 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1493 	uint32_t	lkey = 0;
1494 	uint32_t	remaining, data_block_size, md_size, sge_len;
1495 
1496 	if (spdk_unlikely(!nvmf_rdma_get_lkey(device, iov, &lkey))) {
1497 		/* This is a very rare case that can occur when using DPDK version < 19.05 */
1498 		SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions. Removing it from circulation.\n");
1499 		return false;
1500 	}
1501 
1502 	if (spdk_likely(!dif_ctx)) {
1503 		sg_ele->lkey = lkey;
1504 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1505 		sg_ele->length = iov->iov_len;
1506 		wr->num_sge++;
1507 	} else {
1508 		remaining = iov->iov_len - *_offset;
1509 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1510 		md_size = dif_ctx->md_size;
1511 
1512 		while (remaining) {
1513 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1514 				if (*_num_extra_wrs > 0 && wr->next) {
1515 					*_wr = wr->next;
1516 					wr = *_wr;
1517 					wr->num_sge = 0;
1518 					sg_ele = &wr->sg_list[wr->num_sge];
1519 					(*_num_extra_wrs)--;
1520 				} else {
1521 					break;
1522 				}
1523 			}
1524 			sg_ele->lkey = lkey;
1525 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1526 			sge_len = spdk_min(remaining, *_remaining_data_block);
1527 			sg_ele->length = sge_len;
1528 			remaining -= sge_len;
1529 			*_remaining_data_block -= sge_len;
1530 			*_offset += sge_len;
1531 
1532 			sg_ele++;
1533 			wr->num_sge++;
1534 
1535 			if (*_remaining_data_block == 0) {
1536 				/* skip metadata */
1537 				*_offset += md_size;
1538 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1539 				remaining -= spdk_min(remaining, md_size);
1540 				*_remaining_data_block = data_block_size;
1541 			}
1542 
1543 			if (remaining == 0) {
1544 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1545 				   the remaining metadata bits at the beginning of the next buffer */
1546 				*_offset -= iov->iov_len;
1547 			}
1548 		}
1549 	}
1550 
1551 	return true;
1552 }
1553 
1554 static int
1555 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1556 		      struct spdk_nvmf_rdma_device *device,
1557 		      struct spdk_nvmf_rdma_request *rdma_req,
1558 		      struct ibv_send_wr *wr,
1559 		      uint32_t length,
1560 		      uint32_t num_extra_wrs)
1561 {
1562 	struct spdk_nvmf_request *req = &rdma_req->req;
1563 	struct spdk_dif_ctx *dif_ctx = NULL;
1564 	uint32_t remaining_data_block = 0;
1565 	uint32_t offset = 0;
1566 
1567 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1568 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1569 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1570 	}
1571 
1572 	wr->num_sge = 0;
1573 
1574 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1575 		while (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1576 				     &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1577 			if (nvmf_rdma_replace_buffer(rgroup, &req->buffers[rdma_req->iovpos]) == -ENOMEM) {
1578 				return -ENOMEM;
1579 			}
1580 			req->iov[rdma_req->iovpos].iov_base = (void *)((uintptr_t)(req->buffers[rdma_req->iovpos] +
1581 							      NVMF_DATA_BUFFER_MASK) &
1582 							      ~NVMF_DATA_BUFFER_MASK);
1583 		}
1584 
1585 		length -= req->iov[rdma_req->iovpos].iov_len;
1586 		rdma_req->iovpos++;
1587 	}
1588 
1589 	if (length) {
1590 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1591 		return -EINVAL;
1592 	}
1593 
1594 	return 0;
1595 }
1596 
1597 static inline uint32_t
1598 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1599 {
1600 	/* estimate the number of SG entries and WRs needed to process the request */
1601 	uint32_t num_sge = 0;
1602 	uint32_t i;
1603 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1604 
1605 	for (i = 0; i < num_buffers && length > 0; i++) {
1606 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1607 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1608 
1609 		if (num_sge_in_block * block_size > buffer_len) {
1610 			++num_sge_in_block;
1611 		}
1612 		num_sge += num_sge_in_block;
1613 		length -= buffer_len;
1614 	}
1615 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1616 }
1617 
1618 static int
1619 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1620 			    struct spdk_nvmf_rdma_device *device,
1621 			    struct spdk_nvmf_rdma_request *rdma_req,
1622 			    uint32_t length)
1623 {
1624 	struct spdk_nvmf_rdma_qpair		*rqpair;
1625 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1626 	struct spdk_nvmf_request		*req = &rdma_req->req;
1627 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1628 	int					rc;
1629 	uint32_t				num_wrs = 1;
1630 
1631 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1632 	rgroup = rqpair->poller->group;
1633 
1634 	/* rdma wr specifics */
1635 	nvmf_rdma_setup_request(rdma_req);
1636 
1637 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1638 					   length);
1639 	if (rc != 0) {
1640 		return rc;
1641 	}
1642 
1643 	assert(req->iovcnt <= rqpair->max_send_sge);
1644 
1645 	rdma_req->iovpos = 0;
1646 
1647 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1648 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1649 						 req->dif.dif_ctx.block_size);
1650 		if (num_wrs > 1) {
1651 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1652 			if (rc != 0) {
1653 				goto err_exit;
1654 			}
1655 		}
1656 	}
1657 
1658 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1659 	if (spdk_unlikely(rc != 0)) {
1660 		goto err_exit;
1661 	}
1662 
1663 	if (spdk_unlikely(num_wrs > 1)) {
1664 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1665 	}
1666 
1667 	/* set the number of outstanding data WRs for this request. */
1668 	rdma_req->num_outstanding_data_wr = num_wrs;
1669 
1670 	return rc;
1671 
1672 err_exit:
1673 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1674 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1675 	req->iovcnt = 0;
1676 	return rc;
1677 }
1678 
1679 static int
1680 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1681 				      struct spdk_nvmf_rdma_device *device,
1682 				      struct spdk_nvmf_rdma_request *rdma_req)
1683 {
1684 	struct spdk_nvmf_rdma_qpair		*rqpair;
1685 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1686 	struct ibv_send_wr			*current_wr;
1687 	struct spdk_nvmf_request		*req = &rdma_req->req;
1688 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1689 	uint32_t				num_sgl_descriptors;
1690 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1691 	uint32_t				i;
1692 	int					rc;
1693 
1694 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1695 	rgroup = rqpair->poller->group;
1696 
1697 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1698 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1699 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1700 
1701 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1702 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1703 
1704 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1705 		return -ENOMEM;
1706 	}
1707 
1708 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1709 	for (i = 0; i < num_sgl_descriptors; i++) {
1710 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1711 			lengths[i] = desc->keyed.length;
1712 		} else {
1713 			req->dif.orig_length += desc->keyed.length;
1714 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1715 			req->dif.elba_length += lengths[i];
1716 		}
1717 		desc++;
1718 	}
1719 
1720 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1721 			lengths, num_sgl_descriptors);
1722 	if (rc != 0) {
1723 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1724 		return rc;
1725 	}
1726 
1727 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1728 	current_wr = &rdma_req->data.wr;
1729 	assert(current_wr != NULL);
1730 
1731 	req->length = 0;
1732 	rdma_req->iovpos = 0;
1733 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1734 	for (i = 0; i < num_sgl_descriptors; i++) {
1735 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1736 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1737 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1738 			rc = -EINVAL;
1739 			goto err_exit;
1740 		}
1741 
1742 		current_wr->num_sge = 0;
1743 
1744 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1745 		if (rc != 0) {
1746 			rc = -ENOMEM;
1747 			goto err_exit;
1748 		}
1749 
1750 		req->length += desc->keyed.length;
1751 		current_wr->wr.rdma.rkey = desc->keyed.key;
1752 		current_wr->wr.rdma.remote_addr = desc->address;
1753 		current_wr = current_wr->next;
1754 		desc++;
1755 	}
1756 
1757 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1758 	/* Go back to the last descriptor in the list. */
1759 	desc--;
1760 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1761 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1762 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1763 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1764 		}
1765 	}
1766 #endif
1767 
1768 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1769 
1770 	return 0;
1771 
1772 err_exit:
1773 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1774 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1775 	return rc;
1776 }
1777 
1778 static int
1779 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1780 			    struct spdk_nvmf_rdma_device *device,
1781 			    struct spdk_nvmf_rdma_request *rdma_req)
1782 {
1783 	struct spdk_nvmf_request		*req = &rdma_req->req;
1784 	struct spdk_nvme_cpl			*rsp;
1785 	struct spdk_nvme_sgl_descriptor		*sgl;
1786 	int					rc;
1787 	uint32_t				length;
1788 
1789 	rsp = &req->rsp->nvme_cpl;
1790 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1791 
1792 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1793 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1794 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1795 
1796 		length = sgl->keyed.length;
1797 		if (length > rtransport->transport.opts.max_io_size) {
1798 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1799 				    length, rtransport->transport.opts.max_io_size);
1800 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1801 			return -1;
1802 		}
1803 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1804 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1805 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1806 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1807 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1808 			}
1809 		}
1810 #endif
1811 
1812 		/* fill request length and populate iovs */
1813 		req->length = length;
1814 
1815 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1816 			req->dif.orig_length = length;
1817 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1818 			req->dif.elba_length = length;
1819 		}
1820 
1821 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1822 		if (spdk_unlikely(rc < 0)) {
1823 			if (rc == -EINVAL) {
1824 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1825 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1826 				return -1;
1827 			}
1828 			/* No available buffers. Queue this request up. */
1829 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1830 			return 0;
1831 		}
1832 
1833 		/* backward compatible */
1834 		req->data = req->iov[0].iov_base;
1835 
1836 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1837 			      req->iovcnt);
1838 
1839 		return 0;
1840 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1841 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1842 		uint64_t offset = sgl->address;
1843 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1844 
1845 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1846 			      offset, sgl->unkeyed.length);
1847 
1848 		if (offset > max_len) {
1849 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1850 				    offset, max_len);
1851 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1852 			return -1;
1853 		}
1854 		max_len -= (uint32_t)offset;
1855 
1856 		if (sgl->unkeyed.length > max_len) {
1857 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1858 				    sgl->unkeyed.length, max_len);
1859 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1860 			return -1;
1861 		}
1862 
1863 		rdma_req->num_outstanding_data_wr = 0;
1864 		req->data = rdma_req->recv->buf + offset;
1865 		req->data_from_pool = false;
1866 		req->length = sgl->unkeyed.length;
1867 
1868 		req->iov[0].iov_base = req->data;
1869 		req->iov[0].iov_len = req->length;
1870 		req->iovcnt = 1;
1871 
1872 		return 0;
1873 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1874 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1875 
1876 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1877 		if (rc == -ENOMEM) {
1878 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1879 			return 0;
1880 		} else if (rc == -EINVAL) {
1881 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1882 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1883 			return -1;
1884 		}
1885 
1886 		/* backward compatible */
1887 		req->data = req->iov[0].iov_base;
1888 
1889 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1890 			      req->iovcnt);
1891 
1892 		return 0;
1893 	}
1894 
1895 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1896 		    sgl->generic.type, sgl->generic.subtype);
1897 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1898 	return -1;
1899 }
1900 
1901 static void
1902 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1903 			struct spdk_nvmf_rdma_transport	*rtransport)
1904 {
1905 	struct spdk_nvmf_rdma_qpair		*rqpair;
1906 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1907 
1908 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1909 	if (rdma_req->req.data_from_pool) {
1910 		rgroup = rqpair->poller->group;
1911 
1912 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1913 	}
1914 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1915 	rdma_req->req.length = 0;
1916 	rdma_req->req.iovcnt = 0;
1917 	rdma_req->req.data = NULL;
1918 	rdma_req->rsp.wr.next = NULL;
1919 	rdma_req->data.wr.next = NULL;
1920 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1921 	rqpair->qd--;
1922 
1923 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1924 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1925 }
1926 
1927 bool
1928 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1929 			  struct spdk_nvmf_rdma_request *rdma_req)
1930 {
1931 	struct spdk_nvmf_rdma_qpair	*rqpair;
1932 	struct spdk_nvmf_rdma_device	*device;
1933 	struct spdk_nvmf_rdma_poll_group *rgroup;
1934 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1935 	int				rc;
1936 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1937 	enum spdk_nvmf_rdma_request_state prev_state;
1938 	bool				progress = false;
1939 	int				data_posted;
1940 	uint32_t			num_blocks;
1941 
1942 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1943 	device = rqpair->device;
1944 	rgroup = rqpair->poller->group;
1945 
1946 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1947 
1948 	/* If the queue pair is in an error state, force the request to the completed state
1949 	 * to release resources. */
1950 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1951 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1952 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1953 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1954 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1955 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1956 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1957 		}
1958 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1959 	}
1960 
1961 	/* The loop here is to allow for several back-to-back state changes. */
1962 	do {
1963 		prev_state = rdma_req->state;
1964 
1965 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
1966 
1967 		switch (rdma_req->state) {
1968 		case RDMA_REQUEST_STATE_FREE:
1969 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1970 			 * to escape this state. */
1971 			break;
1972 		case RDMA_REQUEST_STATE_NEW:
1973 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1974 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1975 			rdma_recv = rdma_req->recv;
1976 
1977 			/* The first element of the SGL is the NVMe command */
1978 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1979 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1980 
1981 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1982 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1983 				break;
1984 			}
1985 
1986 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
1987 				rdma_req->req.dif.dif_insert_or_strip = true;
1988 			}
1989 
1990 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1991 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1992 			rdma_req->rsp.wr.imm_data = 0;
1993 #endif
1994 
1995 			/* The next state transition depends on the data transfer needs of this request. */
1996 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
1997 
1998 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
1999 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2000 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
2001 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2002 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
2003 				break;
2004 			}
2005 
2006 			/* If no data to transfer, ready to execute. */
2007 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2008 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2009 				break;
2010 			}
2011 
2012 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2013 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2014 			break;
2015 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2016 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2017 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2018 
2019 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2020 
2021 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2022 				/* This request needs to wait in line to obtain a buffer */
2023 				break;
2024 			}
2025 
2026 			/* Try to get a data buffer */
2027 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2028 			if (rc < 0) {
2029 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2030 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2031 				break;
2032 			}
2033 
2034 			if (!rdma_req->req.data) {
2035 				/* No buffers available. */
2036 				rgroup->stat.pending_data_buffer++;
2037 				break;
2038 			}
2039 
2040 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2041 
2042 			/* If data is transferring from host to controller and the data didn't
2043 			 * arrive using in capsule data, we need to do a transfer from the host.
2044 			 */
2045 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2046 			    rdma_req->req.data_from_pool) {
2047 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2048 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2049 				break;
2050 			}
2051 
2052 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2053 			break;
2054 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2055 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2056 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2057 
2058 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2059 				/* This request needs to wait in line to perform RDMA */
2060 				break;
2061 			}
2062 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2063 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2064 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2065 				rqpair->poller->stat.pending_rdma_read++;
2066 				break;
2067 			}
2068 
2069 			/* We have already verified that this request is the head of the queue. */
2070 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2071 
2072 			rc = request_transfer_in(&rdma_req->req);
2073 			if (!rc) {
2074 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2075 			} else {
2076 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2077 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2078 			}
2079 			break;
2080 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2081 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2082 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2083 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2084 			 * to escape this state. */
2085 			break;
2086 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2087 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2088 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2089 
2090 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2091 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2092 					/* generate DIF for write operation */
2093 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2094 					assert(num_blocks > 0);
2095 
2096 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2097 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2098 					if (rc != 0) {
2099 						SPDK_ERRLOG("DIF generation failed\n");
2100 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2101 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2102 						break;
2103 					}
2104 				}
2105 
2106 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2107 				/* set extended length before IO operation */
2108 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2109 			}
2110 
2111 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2112 			spdk_nvmf_request_exec(&rdma_req->req);
2113 			break;
2114 		case RDMA_REQUEST_STATE_EXECUTING:
2115 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2116 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2117 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2118 			 * to escape this state. */
2119 			break;
2120 		case RDMA_REQUEST_STATE_EXECUTED:
2121 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2122 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2123 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2124 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2125 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2126 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2127 			} else {
2128 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2129 			}
2130 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2131 				/* restore the original length */
2132 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2133 
2134 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2135 					struct spdk_dif_error error_blk;
2136 
2137 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2138 
2139 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2140 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2141 					if (rc) {
2142 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2143 
2144 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2145 							    error_blk.err_offset);
2146 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2147 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2148 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2149 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2150 					}
2151 				}
2152 			}
2153 			break;
2154 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2155 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2156 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2157 
2158 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2159 				/* This request needs to wait in line to perform RDMA */
2160 				break;
2161 			}
2162 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2163 			    rqpair->max_send_depth) {
2164 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2165 				 * +1 since each request has an additional wr in the resp. */
2166 				rqpair->poller->stat.pending_rdma_write++;
2167 				break;
2168 			}
2169 
2170 			/* We have already verified that this request is the head of the queue. */
2171 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2172 
2173 			/* The data transfer will be kicked off from
2174 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2175 			 */
2176 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2177 			break;
2178 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2179 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2180 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2181 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2182 			assert(rc == 0); /* No good way to handle this currently */
2183 			if (rc) {
2184 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2185 			} else {
2186 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2187 						  RDMA_REQUEST_STATE_COMPLETING;
2188 			}
2189 			break;
2190 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2191 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2192 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2193 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2194 			 * to escape this state. */
2195 			break;
2196 		case RDMA_REQUEST_STATE_COMPLETING:
2197 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2198 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2199 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2200 			 * to escape this state. */
2201 			break;
2202 		case RDMA_REQUEST_STATE_COMPLETED:
2203 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2204 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2205 
2206 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2207 			_nvmf_rdma_request_free(rdma_req, rtransport);
2208 			break;
2209 		case RDMA_REQUEST_NUM_STATES:
2210 		default:
2211 			assert(0);
2212 			break;
2213 		}
2214 
2215 		if (rdma_req->state != prev_state) {
2216 			progress = true;
2217 		}
2218 	} while (rdma_req->state != prev_state);
2219 
2220 	return progress;
2221 }
2222 
2223 /* Public API callbacks begin here */
2224 
2225 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2226 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2227 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2228 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2229 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2230 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2231 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2232 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2233 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2234 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2235 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2236 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2237 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2238 
2239 static void
2240 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2241 {
2242 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2243 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2244 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2245 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2246 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2247 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2248 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2249 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2250 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2251 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2252 	opts->transport_specific =      NULL;
2253 }
2254 
2255 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2256 	.notify_cb = nvmf_rdma_mem_notify,
2257 	.are_contiguous = nvmf_rdma_check_contiguous_entries
2258 };
2259 
2260 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
2261 
2262 static struct spdk_nvmf_transport *
2263 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2264 {
2265 	int rc;
2266 	struct spdk_nvmf_rdma_transport *rtransport;
2267 	struct spdk_nvmf_rdma_device	*device, *tmp;
2268 	struct ibv_context		**contexts;
2269 	uint32_t			i;
2270 	int				flag;
2271 	uint32_t			sge_count;
2272 	uint32_t			min_shared_buffers;
2273 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2274 	pthread_mutexattr_t		attr;
2275 
2276 	rtransport = calloc(1, sizeof(*rtransport));
2277 	if (!rtransport) {
2278 		return NULL;
2279 	}
2280 
2281 	if (pthread_mutexattr_init(&attr)) {
2282 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2283 		free(rtransport);
2284 		return NULL;
2285 	}
2286 
2287 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2288 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2289 		pthread_mutexattr_destroy(&attr);
2290 		free(rtransport);
2291 		return NULL;
2292 	}
2293 
2294 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2295 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2296 		pthread_mutexattr_destroy(&attr);
2297 		free(rtransport);
2298 		return NULL;
2299 	}
2300 
2301 	pthread_mutexattr_destroy(&attr);
2302 
2303 	TAILQ_INIT(&rtransport->devices);
2304 	TAILQ_INIT(&rtransport->ports);
2305 	TAILQ_INIT(&rtransport->poll_groups);
2306 
2307 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2308 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2309 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2310 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2311 	if (opts->transport_specific != NULL &&
2312 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2313 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2314 					    &rtransport->rdma_opts)) {
2315 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2316 		nvmf_rdma_destroy(&rtransport->transport);
2317 		return NULL;
2318 	}
2319 
2320 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2321 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2322 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2323 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2324 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d,"
2325 		     "  acceptor_backlog=%d, abort_timeout_sec=%d\n",
2326 		     opts->max_queue_depth,
2327 		     opts->max_io_size,
2328 		     opts->max_qpairs_per_ctrlr - 1,
2329 		     opts->io_unit_size,
2330 		     opts->in_capsule_data_size,
2331 		     opts->max_aq_depth,
2332 		     opts->num_shared_buffers,
2333 		     rtransport->rdma_opts.max_srq_depth,
2334 		     rtransport->rdma_opts.no_srq,
2335 		     rtransport->rdma_opts.acceptor_backlog,
2336 		     opts->abort_timeout_sec);
2337 
2338 	/* I/O unit size cannot be larger than max I/O size */
2339 	if (opts->io_unit_size > opts->max_io_size) {
2340 		opts->io_unit_size = opts->max_io_size;
2341 	}
2342 
2343 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2344 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2345 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2346 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2347 	}
2348 
2349 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2350 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2351 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2352 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2353 		nvmf_rdma_destroy(&rtransport->transport);
2354 		return NULL;
2355 	}
2356 
2357 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2358 	if (min_shared_buffers > opts->num_shared_buffers) {
2359 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2360 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2361 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2362 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2363 		nvmf_rdma_destroy(&rtransport->transport);
2364 		return NULL;
2365 	}
2366 
2367 	sge_count = opts->max_io_size / opts->io_unit_size;
2368 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2369 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2370 		nvmf_rdma_destroy(&rtransport->transport);
2371 		return NULL;
2372 	}
2373 
2374 	rtransport->event_channel = rdma_create_event_channel();
2375 	if (rtransport->event_channel == NULL) {
2376 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2377 		nvmf_rdma_destroy(&rtransport->transport);
2378 		return NULL;
2379 	}
2380 
2381 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2382 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2383 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2384 			    rtransport->event_channel->fd, spdk_strerror(errno));
2385 		nvmf_rdma_destroy(&rtransport->transport);
2386 		return NULL;
2387 	}
2388 
2389 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2390 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2391 				   sizeof(struct spdk_nvmf_rdma_request_data),
2392 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2393 				   SPDK_ENV_SOCKET_ID_ANY);
2394 	if (!rtransport->data_wr_pool) {
2395 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2396 		nvmf_rdma_destroy(&rtransport->transport);
2397 		return NULL;
2398 	}
2399 
2400 	contexts = rdma_get_devices(NULL);
2401 	if (contexts == NULL) {
2402 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2403 		nvmf_rdma_destroy(&rtransport->transport);
2404 		return NULL;
2405 	}
2406 
2407 	i = 0;
2408 	rc = 0;
2409 	while (contexts[i] != NULL) {
2410 		device = calloc(1, sizeof(*device));
2411 		if (!device) {
2412 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2413 			rc = -ENOMEM;
2414 			break;
2415 		}
2416 		device->context = contexts[i];
2417 		rc = ibv_query_device(device->context, &device->attr);
2418 		if (rc < 0) {
2419 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2420 			free(device);
2421 			break;
2422 
2423 		}
2424 
2425 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2426 
2427 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2428 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2429 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2430 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2431 		}
2432 
2433 		/**
2434 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2435 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2436 		 * but incorrectly reports that it does. There are changes making their way
2437 		 * through the kernel now that will enable this feature. When they are merged,
2438 		 * we can conditionally enable this feature.
2439 		 *
2440 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2441 		 */
2442 		if (device->attr.vendor_id == 0) {
2443 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2444 		}
2445 #endif
2446 
2447 		/* set up device context async ev fd as NON_BLOCKING */
2448 		flag = fcntl(device->context->async_fd, F_GETFL);
2449 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2450 		if (rc < 0) {
2451 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2452 			free(device);
2453 			break;
2454 		}
2455 
2456 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2457 		i++;
2458 
2459 		if (g_nvmf_hooks.get_ibv_pd) {
2460 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2461 		} else {
2462 			device->pd = ibv_alloc_pd(device->context);
2463 		}
2464 
2465 		if (!device->pd) {
2466 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2467 			rc = -ENOMEM;
2468 			break;
2469 		}
2470 
2471 		assert(device->map == NULL);
2472 
2473 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2474 		if (!device->map) {
2475 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2476 			rc = -ENOMEM;
2477 			break;
2478 		}
2479 
2480 		assert(device->map != NULL);
2481 		assert(device->pd != NULL);
2482 	}
2483 	rdma_free_devices(contexts);
2484 
2485 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2486 		/* divide and round up. */
2487 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2488 
2489 		/* round up to the nearest 4k. */
2490 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2491 
2492 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2493 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2494 			       opts->io_unit_size);
2495 	}
2496 
2497 	if (rc < 0) {
2498 		nvmf_rdma_destroy(&rtransport->transport);
2499 		return NULL;
2500 	}
2501 
2502 	/* Set up poll descriptor array to monitor events from RDMA and IB
2503 	 * in a single poll syscall
2504 	 */
2505 	rtransport->npoll_fds = i + 1;
2506 	i = 0;
2507 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2508 	if (rtransport->poll_fds == NULL) {
2509 		SPDK_ERRLOG("poll_fds allocation failed\n");
2510 		nvmf_rdma_destroy(&rtransport->transport);
2511 		return NULL;
2512 	}
2513 
2514 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2515 	rtransport->poll_fds[i++].events = POLLIN;
2516 
2517 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2518 		rtransport->poll_fds[i].fd = device->context->async_fd;
2519 		rtransport->poll_fds[i++].events = POLLIN;
2520 	}
2521 
2522 	return &rtransport->transport;
2523 }
2524 
2525 static void
2526 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2527 {
2528 	struct spdk_nvmf_rdma_transport	*rtransport;
2529 	assert(w != NULL);
2530 
2531 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2532 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2533 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2534 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2535 }
2536 
2537 static int
2538 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
2539 {
2540 	struct spdk_nvmf_rdma_transport	*rtransport;
2541 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2542 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2543 
2544 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2545 
2546 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2547 		TAILQ_REMOVE(&rtransport->ports, port, link);
2548 		rdma_destroy_id(port->id);
2549 		free(port);
2550 	}
2551 
2552 	if (rtransport->poll_fds != NULL) {
2553 		free(rtransport->poll_fds);
2554 	}
2555 
2556 	if (rtransport->event_channel != NULL) {
2557 		rdma_destroy_event_channel(rtransport->event_channel);
2558 	}
2559 
2560 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2561 		TAILQ_REMOVE(&rtransport->devices, device, link);
2562 		if (device->map) {
2563 			spdk_mem_map_free(&device->map);
2564 		}
2565 		if (device->pd) {
2566 			if (!g_nvmf_hooks.get_ibv_pd) {
2567 				ibv_dealloc_pd(device->pd);
2568 			}
2569 		}
2570 		free(device);
2571 	}
2572 
2573 	if (rtransport->data_wr_pool != NULL) {
2574 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2575 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2576 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2577 				    spdk_mempool_count(rtransport->data_wr_pool),
2578 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2579 		}
2580 	}
2581 
2582 	spdk_mempool_free(rtransport->data_wr_pool);
2583 
2584 	pthread_mutex_destroy(&rtransport->lock);
2585 	free(rtransport);
2586 
2587 	return 0;
2588 }
2589 
2590 static int
2591 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2592 			  struct spdk_nvme_transport_id *trid,
2593 			  bool peer);
2594 
2595 static int
2596 nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2597 		 const struct spdk_nvme_transport_id *trid)
2598 {
2599 	struct spdk_nvmf_rdma_transport	*rtransport;
2600 	struct spdk_nvmf_rdma_device	*device;
2601 	struct spdk_nvmf_rdma_port	*port;
2602 	struct addrinfo			*res;
2603 	struct addrinfo			hints;
2604 	int				family;
2605 	int				rc;
2606 
2607 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2608 	assert(rtransport->event_channel != NULL);
2609 
2610 	pthread_mutex_lock(&rtransport->lock);
2611 	port = calloc(1, sizeof(*port));
2612 	if (!port) {
2613 		SPDK_ERRLOG("Port allocation failed\n");
2614 		pthread_mutex_unlock(&rtransport->lock);
2615 		return -ENOMEM;
2616 	}
2617 
2618 	port->trid = trid;
2619 
2620 	switch (trid->adrfam) {
2621 	case SPDK_NVMF_ADRFAM_IPV4:
2622 		family = AF_INET;
2623 		break;
2624 	case SPDK_NVMF_ADRFAM_IPV6:
2625 		family = AF_INET6;
2626 		break;
2627 	default:
2628 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2629 		free(port);
2630 		pthread_mutex_unlock(&rtransport->lock);
2631 		return -EINVAL;
2632 	}
2633 
2634 	memset(&hints, 0, sizeof(hints));
2635 	hints.ai_family = family;
2636 	hints.ai_flags = AI_NUMERICSERV;
2637 	hints.ai_socktype = SOCK_STREAM;
2638 	hints.ai_protocol = 0;
2639 
2640 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2641 	if (rc) {
2642 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2643 		free(port);
2644 		pthread_mutex_unlock(&rtransport->lock);
2645 		return -EINVAL;
2646 	}
2647 
2648 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2649 	if (rc < 0) {
2650 		SPDK_ERRLOG("rdma_create_id() failed\n");
2651 		freeaddrinfo(res);
2652 		free(port);
2653 		pthread_mutex_unlock(&rtransport->lock);
2654 		return rc;
2655 	}
2656 
2657 	rc = rdma_bind_addr(port->id, res->ai_addr);
2658 	freeaddrinfo(res);
2659 
2660 	if (rc < 0) {
2661 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2662 		rdma_destroy_id(port->id);
2663 		free(port);
2664 		pthread_mutex_unlock(&rtransport->lock);
2665 		return rc;
2666 	}
2667 
2668 	if (!port->id->verbs) {
2669 		SPDK_ERRLOG("ibv_context is null\n");
2670 		rdma_destroy_id(port->id);
2671 		free(port);
2672 		pthread_mutex_unlock(&rtransport->lock);
2673 		return -1;
2674 	}
2675 
2676 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2677 	if (rc < 0) {
2678 		SPDK_ERRLOG("rdma_listen() failed\n");
2679 		rdma_destroy_id(port->id);
2680 		free(port);
2681 		pthread_mutex_unlock(&rtransport->lock);
2682 		return rc;
2683 	}
2684 
2685 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2686 		if (device->context == port->id->verbs) {
2687 			port->device = device;
2688 			break;
2689 		}
2690 	}
2691 	if (!port->device) {
2692 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2693 			    port->id->verbs);
2694 		rdma_destroy_id(port->id);
2695 		free(port);
2696 		pthread_mutex_unlock(&rtransport->lock);
2697 		return -EINVAL;
2698 	}
2699 
2700 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2701 		       trid->traddr, trid->trsvcid);
2702 
2703 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2704 	pthread_mutex_unlock(&rtransport->lock);
2705 	return 0;
2706 }
2707 
2708 static void
2709 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2710 		      const struct spdk_nvme_transport_id *trid)
2711 {
2712 	struct spdk_nvmf_rdma_transport *rtransport;
2713 	struct spdk_nvmf_rdma_port *port, *tmp;
2714 
2715 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2716 
2717 	pthread_mutex_lock(&rtransport->lock);
2718 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2719 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2720 			TAILQ_REMOVE(&rtransport->ports, port, link);
2721 			rdma_destroy_id(port->id);
2722 			free(port);
2723 			break;
2724 		}
2725 	}
2726 
2727 	pthread_mutex_unlock(&rtransport->lock);
2728 }
2729 
2730 static void
2731 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2732 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2733 {
2734 	struct spdk_nvmf_request *req, *tmp;
2735 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2736 	struct spdk_nvmf_rdma_resources *resources;
2737 
2738 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2739 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2740 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2741 			break;
2742 		}
2743 	}
2744 
2745 	/* Then RDMA writes since reads have stronger restrictions than writes */
2746 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2747 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2748 			break;
2749 		}
2750 	}
2751 
2752 	/* The second highest priority is I/O waiting on memory buffers. */
2753 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2754 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2755 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2756 			break;
2757 		}
2758 	}
2759 
2760 	resources = rqpair->resources;
2761 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2762 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2763 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2764 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2765 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2766 
2767 		if (rqpair->srq != NULL) {
2768 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2769 			rdma_req->recv->qpair->qd++;
2770 		} else {
2771 			rqpair->qd++;
2772 		}
2773 
2774 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2775 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2776 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2777 			break;
2778 		}
2779 	}
2780 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2781 		rqpair->poller->stat.pending_free_request++;
2782 	}
2783 }
2784 
2785 static void
2786 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2787 {
2788 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2789 			struct spdk_nvmf_rdma_transport, transport);
2790 
2791 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2792 
2793 	/* nvmr_rdma_close_qpair is not called */
2794 	if (!rqpair->to_close) {
2795 		return;
2796 	}
2797 
2798 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2799 	if (rqpair->current_send_depth != 0) {
2800 		return;
2801 	}
2802 
2803 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2804 		return;
2805 	}
2806 
2807 	/* Judge whether the device is emulated by Software RoCE.
2808 	 * And it will not send last_wqe event
2809 	 */
2810 	if (rqpair->srq != NULL && rqpair->device->attr.vendor_id != 0 &&
2811 	    rqpair->last_wqe_reached == false) {
2812 		return;
2813 	}
2814 
2815 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2816 
2817 	nvmf_rdma_qpair_destroy(rqpair);
2818 }
2819 
2820 static int
2821 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2822 {
2823 	struct spdk_nvmf_qpair		*qpair;
2824 	struct spdk_nvmf_rdma_qpair	*rqpair;
2825 
2826 	if (evt->id == NULL) {
2827 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2828 		return -1;
2829 	}
2830 
2831 	qpair = evt->id->context;
2832 	if (qpair == NULL) {
2833 		SPDK_ERRLOG("disconnect request: no active connection\n");
2834 		return -1;
2835 	}
2836 
2837 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2838 
2839 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2840 
2841 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2842 
2843 	return 0;
2844 }
2845 
2846 #ifdef DEBUG
2847 static const char *CM_EVENT_STR[] = {
2848 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2849 	"RDMA_CM_EVENT_ADDR_ERROR",
2850 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2851 	"RDMA_CM_EVENT_ROUTE_ERROR",
2852 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2853 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2854 	"RDMA_CM_EVENT_CONNECT_ERROR",
2855 	"RDMA_CM_EVENT_UNREACHABLE",
2856 	"RDMA_CM_EVENT_REJECTED",
2857 	"RDMA_CM_EVENT_ESTABLISHED",
2858 	"RDMA_CM_EVENT_DISCONNECTED",
2859 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2860 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2861 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2862 	"RDMA_CM_EVENT_ADDR_CHANGE",
2863 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2864 };
2865 #endif /* DEBUG */
2866 
2867 static void
2868 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2869 				    struct spdk_nvmf_rdma_port *port)
2870 {
2871 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2872 	struct spdk_nvmf_rdma_poller		*rpoller;
2873 	struct spdk_nvmf_rdma_qpair		*rqpair;
2874 
2875 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2876 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2877 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2878 				if (rqpair->listen_id == port->id) {
2879 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2880 				}
2881 			}
2882 		}
2883 	}
2884 }
2885 
2886 static bool
2887 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2888 				      struct rdma_cm_event *event)
2889 {
2890 	const struct spdk_nvme_transport_id	*trid;
2891 	struct spdk_nvmf_rdma_port		*port;
2892 	struct spdk_nvmf_rdma_transport		*rtransport;
2893 	bool					event_acked = false;
2894 
2895 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2896 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2897 		if (port->id == event->id) {
2898 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2899 			rdma_ack_cm_event(event);
2900 			event_acked = true;
2901 			trid = port->trid;
2902 			break;
2903 		}
2904 	}
2905 
2906 	if (event_acked) {
2907 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2908 
2909 		nvmf_rdma_stop_listen(transport, trid);
2910 		nvmf_rdma_listen(transport, trid);
2911 	}
2912 
2913 	return event_acked;
2914 }
2915 
2916 static void
2917 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2918 				       struct rdma_cm_event *event)
2919 {
2920 	struct spdk_nvmf_rdma_port		*port;
2921 	struct spdk_nvmf_rdma_transport		*rtransport;
2922 
2923 	port = event->id->context;
2924 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2925 
2926 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2927 
2928 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2929 
2930 	rdma_ack_cm_event(event);
2931 
2932 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2933 		;
2934 	}
2935 }
2936 
2937 static void
2938 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2939 {
2940 	struct spdk_nvmf_rdma_transport *rtransport;
2941 	struct rdma_cm_event		*event;
2942 	int				rc;
2943 	bool				event_acked;
2944 
2945 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2946 
2947 	if (rtransport->event_channel == NULL) {
2948 		return;
2949 	}
2950 
2951 	while (1) {
2952 		event_acked = false;
2953 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2954 		if (rc) {
2955 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2956 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2957 			}
2958 			break;
2959 		}
2960 
2961 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2962 
2963 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2964 
2965 		switch (event->event) {
2966 		case RDMA_CM_EVENT_ADDR_RESOLVED:
2967 		case RDMA_CM_EVENT_ADDR_ERROR:
2968 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
2969 		case RDMA_CM_EVENT_ROUTE_ERROR:
2970 			/* No action required. The target never attempts to resolve routes. */
2971 			break;
2972 		case RDMA_CM_EVENT_CONNECT_REQUEST:
2973 			rc = nvmf_rdma_connect(transport, event);
2974 			if (rc < 0) {
2975 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2976 				break;
2977 			}
2978 			break;
2979 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
2980 			/* The target never initiates a new connection. So this will not occur. */
2981 			break;
2982 		case RDMA_CM_EVENT_CONNECT_ERROR:
2983 			/* Can this happen? The docs say it can, but not sure what causes it. */
2984 			break;
2985 		case RDMA_CM_EVENT_UNREACHABLE:
2986 		case RDMA_CM_EVENT_REJECTED:
2987 			/* These only occur on the client side. */
2988 			break;
2989 		case RDMA_CM_EVENT_ESTABLISHED:
2990 			/* TODO: Should we be waiting for this event anywhere? */
2991 			break;
2992 		case RDMA_CM_EVENT_DISCONNECTED:
2993 			rc = nvmf_rdma_disconnect(event);
2994 			if (rc < 0) {
2995 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2996 				break;
2997 			}
2998 			break;
2999 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
3000 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
3001 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
3002 			 * Once these events are sent to SPDK, we should release all IB resources and
3003 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
3004 			 * ibv_destory* functions to release user space memory allocated by IB. All kernel
3005 			 * resources are already cleaned. */
3006 			if (event->id->qp) {
3007 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
3008 				 * corresponding qpair. Otherwise the event refers to a listening device */
3009 				rc = nvmf_rdma_disconnect(event);
3010 				if (rc < 0) {
3011 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3012 					break;
3013 				}
3014 			} else {
3015 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3016 				event_acked = true;
3017 			}
3018 			break;
3019 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3020 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3021 			/* Multicast is not used */
3022 			break;
3023 		case RDMA_CM_EVENT_ADDR_CHANGE:
3024 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3025 			break;
3026 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3027 			/* For now, do nothing. The target never re-uses queue pairs. */
3028 			break;
3029 		default:
3030 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3031 			break;
3032 		}
3033 		if (!event_acked) {
3034 			rdma_ack_cm_event(event);
3035 		}
3036 	}
3037 }
3038 
3039 static void
3040 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3041 {
3042 	rqpair->last_wqe_reached = true;
3043 	nvmf_rdma_destroy_drained_qpair(rqpair);
3044 }
3045 
3046 static void
3047 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3048 {
3049 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3050 
3051 	if (event_ctx->rqpair) {
3052 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3053 		if (event_ctx->cb_fn) {
3054 			event_ctx->cb_fn(event_ctx->rqpair);
3055 		}
3056 	}
3057 	free(event_ctx);
3058 }
3059 
3060 static int
3061 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3062 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3063 {
3064 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3065 	struct spdk_thread *thr = NULL;
3066 	int rc;
3067 
3068 	if (rqpair->qpair.group) {
3069 		thr = rqpair->qpair.group->thread;
3070 	} else if (rqpair->destruct_channel) {
3071 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3072 	}
3073 
3074 	if (!thr) {
3075 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3076 		return -EINVAL;
3077 	}
3078 
3079 	ctx = calloc(1, sizeof(*ctx));
3080 	if (!ctx) {
3081 		return -ENOMEM;
3082 	}
3083 
3084 	ctx->rqpair = rqpair;
3085 	ctx->cb_fn = fn;
3086 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3087 
3088 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3089 	if (rc) {
3090 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3091 		free(ctx);
3092 	}
3093 
3094 	return rc;
3095 }
3096 
3097 static int
3098 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3099 {
3100 	int				rc;
3101 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3102 	struct ibv_async_event		event;
3103 
3104 	rc = ibv_get_async_event(device->context, &event);
3105 
3106 	if (rc) {
3107 		/* In non-blocking mode -1 means there are no events available */
3108 		return rc;
3109 	}
3110 
3111 	switch (event.event_type) {
3112 	case IBV_EVENT_QP_FATAL:
3113 		rqpair = event.element.qp->qp_context;
3114 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3115 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3116 				  (uintptr_t)rqpair->cm_id, event.event_type);
3117 		nvmf_rdma_update_ibv_state(rqpair);
3118 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3119 		break;
3120 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3121 		/* This event only occurs for shared receive queues. */
3122 		rqpair = event.element.qp->qp_context;
3123 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3124 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3125 		if (rc) {
3126 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3127 			rqpair->last_wqe_reached = true;
3128 		}
3129 		break;
3130 	case IBV_EVENT_SQ_DRAINED:
3131 		/* This event occurs frequently in both error and non-error states.
3132 		 * Check if the qpair is in an error state before sending a message. */
3133 		rqpair = event.element.qp->qp_context;
3134 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3135 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3136 				  (uintptr_t)rqpair->cm_id, event.event_type);
3137 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3138 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3139 		}
3140 		break;
3141 	case IBV_EVENT_QP_REQ_ERR:
3142 	case IBV_EVENT_QP_ACCESS_ERR:
3143 	case IBV_EVENT_COMM_EST:
3144 	case IBV_EVENT_PATH_MIG:
3145 	case IBV_EVENT_PATH_MIG_ERR:
3146 		SPDK_NOTICELOG("Async event: %s\n",
3147 			       ibv_event_type_str(event.event_type));
3148 		rqpair = event.element.qp->qp_context;
3149 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3150 				  (uintptr_t)rqpair->cm_id, event.event_type);
3151 		nvmf_rdma_update_ibv_state(rqpair);
3152 		break;
3153 	case IBV_EVENT_CQ_ERR:
3154 	case IBV_EVENT_DEVICE_FATAL:
3155 	case IBV_EVENT_PORT_ACTIVE:
3156 	case IBV_EVENT_PORT_ERR:
3157 	case IBV_EVENT_LID_CHANGE:
3158 	case IBV_EVENT_PKEY_CHANGE:
3159 	case IBV_EVENT_SM_CHANGE:
3160 	case IBV_EVENT_SRQ_ERR:
3161 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3162 	case IBV_EVENT_CLIENT_REREGISTER:
3163 	case IBV_EVENT_GID_CHANGE:
3164 	default:
3165 		SPDK_NOTICELOG("Async event: %s\n",
3166 			       ibv_event_type_str(event.event_type));
3167 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3168 		break;
3169 	}
3170 	ibv_ack_async_event(&event);
3171 
3172 	return 0;
3173 }
3174 
3175 static void
3176 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3177 {
3178 	int rc = 0;
3179 	uint32_t i = 0;
3180 
3181 	for (i = 0; i < max_events; i++) {
3182 		rc = nvmf_process_ib_event(device);
3183 		if (rc) {
3184 			break;
3185 		}
3186 	}
3187 
3188 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3189 }
3190 
3191 static uint32_t
3192 nvmf_rdma_accept(struct spdk_nvmf_transport *transport)
3193 {
3194 	int	nfds, i = 0;
3195 	struct spdk_nvmf_rdma_transport *rtransport;
3196 	struct spdk_nvmf_rdma_device *device, *tmp;
3197 	uint32_t count;
3198 
3199 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3200 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3201 
3202 	if (nfds <= 0) {
3203 		return 0;
3204 	}
3205 
3206 	/* The first poll descriptor is RDMA CM event */
3207 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3208 		nvmf_process_cm_event(transport);
3209 		nfds--;
3210 	}
3211 
3212 	if (nfds == 0) {
3213 		return count;
3214 	}
3215 
3216 	/* Second and subsequent poll descriptors are IB async events */
3217 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3218 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3219 			nvmf_process_ib_events(device, 32);
3220 			nfds--;
3221 		}
3222 	}
3223 	/* check all flagged fd's have been served */
3224 	assert(nfds == 0);
3225 
3226 	return count;
3227 }
3228 
3229 static void
3230 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3231 		     struct spdk_nvmf_ctrlr_data *cdata)
3232 {
3233 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3234 
3235 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3236 	since in-capsule data only works with NVME drives that support SGL memory layout */
3237 	if (transport->opts.dif_insert_or_strip) {
3238 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3239 	}
3240 }
3241 
3242 static void
3243 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3244 		   struct spdk_nvme_transport_id *trid,
3245 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3246 {
3247 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3248 	entry->adrfam = trid->adrfam;
3249 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3250 
3251 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3252 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3253 
3254 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3255 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3256 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3257 }
3258 
3259 static void
3260 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3261 
3262 static struct spdk_nvmf_transport_poll_group *
3263 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3264 {
3265 	struct spdk_nvmf_rdma_transport		*rtransport;
3266 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3267 	struct spdk_nvmf_rdma_poller		*poller;
3268 	struct spdk_nvmf_rdma_device		*device;
3269 	struct ibv_srq_init_attr		srq_init_attr;
3270 	struct spdk_nvmf_rdma_resource_opts	opts;
3271 	int					num_cqe;
3272 
3273 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3274 
3275 	rgroup = calloc(1, sizeof(*rgroup));
3276 	if (!rgroup) {
3277 		return NULL;
3278 	}
3279 
3280 	TAILQ_INIT(&rgroup->pollers);
3281 	STAILQ_INIT(&rgroup->retired_bufs);
3282 
3283 	pthread_mutex_lock(&rtransport->lock);
3284 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3285 		poller = calloc(1, sizeof(*poller));
3286 		if (!poller) {
3287 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3288 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3289 			pthread_mutex_unlock(&rtransport->lock);
3290 			return NULL;
3291 		}
3292 
3293 		poller->device = device;
3294 		poller->group = rgroup;
3295 
3296 		TAILQ_INIT(&poller->qpairs);
3297 		STAILQ_INIT(&poller->qpairs_pending_send);
3298 		STAILQ_INIT(&poller->qpairs_pending_recv);
3299 
3300 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3301 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3302 			poller->max_srq_depth = rtransport->rdma_opts.max_srq_depth;
3303 
3304 			device->num_srq++;
3305 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3306 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3307 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3308 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3309 			if (!poller->srq) {
3310 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3311 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3312 				pthread_mutex_unlock(&rtransport->lock);
3313 				return NULL;
3314 			}
3315 
3316 			opts.qp = poller->srq;
3317 			opts.pd = device->pd;
3318 			opts.qpair = NULL;
3319 			opts.shared = true;
3320 			opts.max_queue_depth = poller->max_srq_depth;
3321 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3322 
3323 			poller->resources = nvmf_rdma_resources_create(&opts);
3324 			if (!poller->resources) {
3325 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3326 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3327 				pthread_mutex_unlock(&rtransport->lock);
3328 				return NULL;
3329 			}
3330 		}
3331 
3332 		/*
3333 		 * When using an srq, we can limit the completion queue at startup.
3334 		 * The following formula represents the calculation:
3335 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3336 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3337 		 */
3338 		if (poller->srq) {
3339 			num_cqe = poller->max_srq_depth * 3;
3340 		} else {
3341 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3342 		}
3343 
3344 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3345 		if (!poller->cq) {
3346 			SPDK_ERRLOG("Unable to create completion queue\n");
3347 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3348 			pthread_mutex_unlock(&rtransport->lock);
3349 			return NULL;
3350 		}
3351 		poller->num_cqe = num_cqe;
3352 	}
3353 
3354 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3355 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3356 		rtransport->conn_sched.next_admin_pg = rgroup;
3357 		rtransport->conn_sched.next_io_pg = rgroup;
3358 	}
3359 
3360 	pthread_mutex_unlock(&rtransport->lock);
3361 	return &rgroup->group;
3362 }
3363 
3364 static struct spdk_nvmf_transport_poll_group *
3365 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3366 {
3367 	struct spdk_nvmf_rdma_transport *rtransport;
3368 	struct spdk_nvmf_rdma_poll_group **pg;
3369 	struct spdk_nvmf_transport_poll_group *result;
3370 
3371 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3372 
3373 	pthread_mutex_lock(&rtransport->lock);
3374 
3375 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3376 		pthread_mutex_unlock(&rtransport->lock);
3377 		return NULL;
3378 	}
3379 
3380 	if (qpair->qid == 0) {
3381 		pg = &rtransport->conn_sched.next_admin_pg;
3382 	} else {
3383 		pg = &rtransport->conn_sched.next_io_pg;
3384 	}
3385 
3386 	assert(*pg != NULL);
3387 
3388 	result = &(*pg)->group;
3389 
3390 	*pg = TAILQ_NEXT(*pg, link);
3391 	if (*pg == NULL) {
3392 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3393 	}
3394 
3395 	pthread_mutex_unlock(&rtransport->lock);
3396 
3397 	return result;
3398 }
3399 
3400 static void
3401 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3402 {
3403 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3404 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3405 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3406 	struct spdk_nvmf_transport_pg_cache_buf	*buf, *tmp_buf;
3407 	struct spdk_nvmf_rdma_transport		*rtransport;
3408 
3409 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3410 	if (!rgroup) {
3411 		return;
3412 	}
3413 
3414 	/* free all retired buffers back to the transport so we don't short the mempool. */
3415 	STAILQ_FOREACH_SAFE(buf, &rgroup->retired_bufs, link, tmp_buf) {
3416 		STAILQ_REMOVE(&rgroup->retired_bufs, buf, spdk_nvmf_transport_pg_cache_buf, link);
3417 		assert(group->transport != NULL);
3418 		spdk_mempool_put(group->transport->data_buf_pool, buf);
3419 	}
3420 
3421 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3422 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3423 
3424 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3425 			nvmf_rdma_qpair_destroy(qpair);
3426 		}
3427 
3428 		if (poller->srq) {
3429 			if (poller->resources) {
3430 				nvmf_rdma_resources_destroy(poller->resources);
3431 			}
3432 			ibv_destroy_srq(poller->srq);
3433 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3434 		}
3435 
3436 		if (poller->cq) {
3437 			ibv_destroy_cq(poller->cq);
3438 		}
3439 
3440 		free(poller);
3441 	}
3442 
3443 	if (rgroup->group.transport == NULL) {
3444 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3445 		 * calls this function directly in a failure path. */
3446 		free(rgroup);
3447 		return;
3448 	}
3449 
3450 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3451 
3452 	pthread_mutex_lock(&rtransport->lock);
3453 	next_rgroup = TAILQ_NEXT(rgroup, link);
3454 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3455 	if (next_rgroup == NULL) {
3456 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3457 	}
3458 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3459 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3460 	}
3461 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3462 		rtransport->conn_sched.next_io_pg = next_rgroup;
3463 	}
3464 	pthread_mutex_unlock(&rtransport->lock);
3465 
3466 	free(rgroup);
3467 }
3468 
3469 static void
3470 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3471 {
3472 	if (rqpair->cm_id != NULL) {
3473 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3474 	}
3475 }
3476 
3477 static int
3478 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3479 			 struct spdk_nvmf_qpair *qpair)
3480 {
3481 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3482 	struct spdk_nvmf_rdma_qpair		*rqpair;
3483 	struct spdk_nvmf_rdma_device		*device;
3484 	struct spdk_nvmf_rdma_poller		*poller;
3485 	int					rc;
3486 
3487 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3488 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3489 
3490 	device = rqpair->device;
3491 
3492 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3493 		if (poller->device == device) {
3494 			break;
3495 		}
3496 	}
3497 
3498 	if (!poller) {
3499 		SPDK_ERRLOG("No poller found for device.\n");
3500 		return -1;
3501 	}
3502 
3503 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3504 	rqpair->poller = poller;
3505 	rqpair->srq = rqpair->poller->srq;
3506 
3507 	rc = nvmf_rdma_qpair_initialize(qpair);
3508 	if (rc < 0) {
3509 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3510 		return -1;
3511 	}
3512 
3513 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3514 	if (rc) {
3515 		/* Try to reject, but we probably can't */
3516 		nvmf_rdma_qpair_reject_connection(rqpair);
3517 		return -1;
3518 	}
3519 
3520 	nvmf_rdma_update_ibv_state(rqpair);
3521 
3522 	return 0;
3523 }
3524 
3525 static int
3526 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3527 			    struct spdk_nvmf_qpair *qpair)
3528 {
3529 	struct spdk_nvmf_rdma_qpair		*rqpair;
3530 
3531 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3532 	assert(group->transport->tgt != NULL);
3533 
3534 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3535 
3536 	if (!rqpair->destruct_channel) {
3537 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3538 		return 0;
3539 	}
3540 
3541 	/* Sanity check that we get io_channel on the correct thread */
3542 	if (qpair->group) {
3543 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3544 	}
3545 
3546 	return 0;
3547 }
3548 
3549 static int
3550 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3551 {
3552 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3553 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3554 			struct spdk_nvmf_rdma_transport, transport);
3555 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3556 					      struct spdk_nvmf_rdma_qpair, qpair);
3557 
3558 	/*
3559 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3560 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3561 	 * starved of RECV structures.
3562 	 */
3563 	if (rqpair->srq && rdma_req->recv) {
3564 		int rc;
3565 		struct ibv_recv_wr *bad_recv_wr;
3566 
3567 		rc = ibv_post_srq_recv(rqpair->srq, &rdma_req->recv->wr, &bad_recv_wr);
3568 		if (rc) {
3569 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3570 		}
3571 	}
3572 
3573 	_nvmf_rdma_request_free(rdma_req, rtransport);
3574 	return 0;
3575 }
3576 
3577 static int
3578 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3579 {
3580 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3581 			struct spdk_nvmf_rdma_transport, transport);
3582 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3583 			struct spdk_nvmf_rdma_request, req);
3584 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3585 			struct spdk_nvmf_rdma_qpair, qpair);
3586 
3587 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3588 		/* The connection is alive, so process the request as normal */
3589 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3590 	} else {
3591 		/* The connection is dead. Move the request directly to the completed state. */
3592 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3593 	}
3594 
3595 	nvmf_rdma_request_process(rtransport, rdma_req);
3596 
3597 	return 0;
3598 }
3599 
3600 static void
3601 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
3602 {
3603 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3604 
3605 	rqpair->to_close = true;
3606 
3607 	/* This happens only when the qpair is disconnected before
3608 	 * it is added to the poll group. Since there is no poll group,
3609 	 * the RDMA qp has not been initialized yet and the RDMA CM
3610 	 * event has not yet been acknowledged, so we need to reject it.
3611 	 */
3612 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3613 		nvmf_rdma_qpair_reject_connection(rqpair);
3614 		nvmf_rdma_qpair_destroy(rqpair);
3615 		return;
3616 	}
3617 
3618 	if (rqpair->rdma_qp) {
3619 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3620 	}
3621 
3622 	nvmf_rdma_destroy_drained_qpair(rqpair);
3623 }
3624 
3625 static struct spdk_nvmf_rdma_qpair *
3626 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3627 {
3628 	struct spdk_nvmf_rdma_qpair *rqpair;
3629 	/* @todo: improve QP search */
3630 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3631 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3632 			return rqpair;
3633 		}
3634 	}
3635 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3636 	return NULL;
3637 }
3638 
3639 #ifdef DEBUG
3640 static int
3641 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3642 {
3643 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3644 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3645 }
3646 #endif
3647 
3648 static void
3649 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3650 			   int rc)
3651 {
3652 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3653 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3654 
3655 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3656 	while (bad_recv_wr != NULL) {
3657 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3658 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3659 
3660 		rdma_recv->qpair->current_recv_depth++;
3661 		bad_recv_wr = bad_recv_wr->next;
3662 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3663 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3664 	}
3665 }
3666 
3667 static void
3668 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3669 {
3670 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3671 	while (bad_recv_wr != NULL) {
3672 		bad_recv_wr = bad_recv_wr->next;
3673 		rqpair->current_recv_depth++;
3674 	}
3675 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3676 }
3677 
3678 static void
3679 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3680 		     struct spdk_nvmf_rdma_poller *rpoller)
3681 {
3682 	struct spdk_nvmf_rdma_qpair	*rqpair;
3683 	struct ibv_recv_wr		*bad_recv_wr;
3684 	int				rc;
3685 
3686 	if (rpoller->srq) {
3687 		if (rpoller->resources->recvs_to_post.first != NULL) {
3688 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3689 			if (rc) {
3690 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3691 			}
3692 			rpoller->resources->recvs_to_post.first = NULL;
3693 			rpoller->resources->recvs_to_post.last = NULL;
3694 		}
3695 	} else {
3696 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3697 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3698 			assert(rqpair->resources->recvs_to_post.first != NULL);
3699 			rc = ibv_post_recv(rqpair->rdma_qp->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3700 			if (rc) {
3701 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3702 			}
3703 			rqpair->resources->recvs_to_post.first = NULL;
3704 			rqpair->resources->recvs_to_post.last = NULL;
3705 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3706 		}
3707 	}
3708 }
3709 
3710 static void
3711 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3712 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3713 {
3714 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3715 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3716 
3717 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3718 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3719 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3720 		assert(rqpair->current_send_depth > 0);
3721 		rqpair->current_send_depth--;
3722 		switch (bad_rdma_wr->type) {
3723 		case RDMA_WR_TYPE_DATA:
3724 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3725 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3726 				assert(rqpair->current_read_depth > 0);
3727 				rqpair->current_read_depth--;
3728 			}
3729 			break;
3730 		case RDMA_WR_TYPE_SEND:
3731 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3732 			break;
3733 		default:
3734 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3735 			prev_rdma_req = cur_rdma_req;
3736 			continue;
3737 		}
3738 
3739 		if (prev_rdma_req == cur_rdma_req) {
3740 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3741 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3742 			continue;
3743 		}
3744 
3745 		switch (cur_rdma_req->state) {
3746 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3747 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3748 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3749 			break;
3750 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3751 		case RDMA_REQUEST_STATE_COMPLETING:
3752 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3753 			break;
3754 		default:
3755 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3756 				    cur_rdma_req->state, rqpair);
3757 			continue;
3758 		}
3759 
3760 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3761 		prev_rdma_req = cur_rdma_req;
3762 	}
3763 
3764 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3765 		/* Disconnect the connection. */
3766 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3767 	}
3768 
3769 }
3770 
3771 static void
3772 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3773 		     struct spdk_nvmf_rdma_poller *rpoller)
3774 {
3775 	struct spdk_nvmf_rdma_qpair	*rqpair;
3776 	struct ibv_send_wr		*bad_wr = NULL;
3777 	int				rc;
3778 
3779 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3780 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3781 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3782 
3783 		/* bad wr always points to the first wr that failed. */
3784 		if (rc) {
3785 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3786 		}
3787 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3788 	}
3789 }
3790 
3791 static const char *
3792 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3793 {
3794 	switch (wr_type) {
3795 	case RDMA_WR_TYPE_RECV:
3796 		return "RECV";
3797 	case RDMA_WR_TYPE_SEND:
3798 		return "SEND";
3799 	case RDMA_WR_TYPE_DATA:
3800 		return "DATA";
3801 	default:
3802 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3803 		SPDK_UNREACHABLE();
3804 	}
3805 }
3806 
3807 static inline void
3808 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3809 {
3810 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3811 
3812 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3813 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3814 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3815 		SPDK_DEBUGLOG(rdma,
3816 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3817 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3818 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3819 	} else {
3820 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3821 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3822 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3823 	}
3824 }
3825 
3826 static int
3827 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3828 		      struct spdk_nvmf_rdma_poller *rpoller)
3829 {
3830 	struct ibv_wc wc[32];
3831 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3832 	struct spdk_nvmf_rdma_request	*rdma_req;
3833 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3834 	struct spdk_nvmf_rdma_qpair	*rqpair;
3835 	int reaped, i;
3836 	int count = 0;
3837 	bool error = false;
3838 	uint64_t poll_tsc = spdk_get_ticks();
3839 
3840 	/* Poll for completing operations. */
3841 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3842 	if (reaped < 0) {
3843 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3844 			    errno, spdk_strerror(errno));
3845 		return -1;
3846 	}
3847 
3848 	rpoller->stat.polls++;
3849 	rpoller->stat.completions += reaped;
3850 
3851 	for (i = 0; i < reaped; i++) {
3852 
3853 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3854 
3855 		switch (rdma_wr->type) {
3856 		case RDMA_WR_TYPE_SEND:
3857 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3858 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3859 
3860 			if (!wc[i].status) {
3861 				count++;
3862 				assert(wc[i].opcode == IBV_WC_SEND);
3863 				assert(nvmf_rdma_req_is_completing(rdma_req));
3864 			}
3865 
3866 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3867 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3868 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3869 			rdma_req->num_outstanding_data_wr = 0;
3870 
3871 			nvmf_rdma_request_process(rtransport, rdma_req);
3872 			break;
3873 		case RDMA_WR_TYPE_RECV:
3874 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3875 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3876 			if (rpoller->srq != NULL) {
3877 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3878 				/* It is possible that there are still some completions for destroyed QP
3879 				 * associated with SRQ. We just ignore these late completions and re-post
3880 				 * receive WRs back to SRQ.
3881 				 */
3882 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3883 					struct ibv_recv_wr *bad_wr;
3884 					int rc;
3885 
3886 					rdma_recv->wr.next = NULL;
3887 					rc = ibv_post_srq_recv(rpoller->srq,
3888 							       &rdma_recv->wr,
3889 							       &bad_wr);
3890 					if (rc) {
3891 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3892 					}
3893 					continue;
3894 				}
3895 			}
3896 			rqpair = rdma_recv->qpair;
3897 
3898 			assert(rqpair != NULL);
3899 			if (!wc[i].status) {
3900 				assert(wc[i].opcode == IBV_WC_RECV);
3901 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3902 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3903 					break;
3904 				}
3905 			}
3906 
3907 			rdma_recv->wr.next = NULL;
3908 			rqpair->current_recv_depth++;
3909 			rdma_recv->receive_tsc = poll_tsc;
3910 			rpoller->stat.requests++;
3911 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3912 			break;
3913 		case RDMA_WR_TYPE_DATA:
3914 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3915 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3916 
3917 			assert(rdma_req->num_outstanding_data_wr > 0);
3918 
3919 			rqpair->current_send_depth--;
3920 			rdma_req->num_outstanding_data_wr--;
3921 			if (!wc[i].status) {
3922 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3923 				rqpair->current_read_depth--;
3924 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3925 				if (rdma_req->num_outstanding_data_wr == 0) {
3926 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3927 					nvmf_rdma_request_process(rtransport, rdma_req);
3928 				}
3929 			} else {
3930 				/* If the data transfer fails still force the queue into the error state,
3931 				 * if we were performing an RDMA_READ, we need to force the request into a
3932 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3933 				 * case, we should wait for the SEND to complete. */
3934 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3935 					rqpair->current_read_depth--;
3936 					if (rdma_req->num_outstanding_data_wr == 0) {
3937 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3938 					}
3939 				}
3940 			}
3941 			break;
3942 		default:
3943 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3944 			continue;
3945 		}
3946 
3947 		/* Handle error conditions */
3948 		if (wc[i].status) {
3949 			nvmf_rdma_update_ibv_state(rqpair);
3950 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
3951 
3952 			error = true;
3953 
3954 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3955 				/* Disconnect the connection. */
3956 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3957 			} else {
3958 				nvmf_rdma_destroy_drained_qpair(rqpair);
3959 			}
3960 			continue;
3961 		}
3962 
3963 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3964 
3965 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3966 			nvmf_rdma_destroy_drained_qpair(rqpair);
3967 		}
3968 	}
3969 
3970 	if (error == true) {
3971 		return -1;
3972 	}
3973 
3974 	/* submit outstanding work requests. */
3975 	_poller_submit_recvs(rtransport, rpoller);
3976 	_poller_submit_sends(rtransport, rpoller);
3977 
3978 	return count;
3979 }
3980 
3981 static int
3982 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3983 {
3984 	struct spdk_nvmf_rdma_transport *rtransport;
3985 	struct spdk_nvmf_rdma_poll_group *rgroup;
3986 	struct spdk_nvmf_rdma_poller	*rpoller;
3987 	int				count, rc;
3988 
3989 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3990 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3991 
3992 	count = 0;
3993 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3994 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
3995 		if (rc < 0) {
3996 			return rc;
3997 		}
3998 		count += rc;
3999 	}
4000 
4001 	return count;
4002 }
4003 
4004 static int
4005 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
4006 			  struct spdk_nvme_transport_id *trid,
4007 			  bool peer)
4008 {
4009 	struct sockaddr *saddr;
4010 	uint16_t port;
4011 
4012 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
4013 
4014 	if (peer) {
4015 		saddr = rdma_get_peer_addr(id);
4016 	} else {
4017 		saddr = rdma_get_local_addr(id);
4018 	}
4019 	switch (saddr->sa_family) {
4020 	case AF_INET: {
4021 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
4022 
4023 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
4024 		inet_ntop(AF_INET, &saddr_in->sin_addr,
4025 			  trid->traddr, sizeof(trid->traddr));
4026 		if (peer) {
4027 			port = ntohs(rdma_get_dst_port(id));
4028 		} else {
4029 			port = ntohs(rdma_get_src_port(id));
4030 		}
4031 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4032 		break;
4033 	}
4034 	case AF_INET6: {
4035 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4036 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4037 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4038 			  trid->traddr, sizeof(trid->traddr));
4039 		if (peer) {
4040 			port = ntohs(rdma_get_dst_port(id));
4041 		} else {
4042 			port = ntohs(rdma_get_src_port(id));
4043 		}
4044 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4045 		break;
4046 	}
4047 	default:
4048 		return -1;
4049 
4050 	}
4051 
4052 	return 0;
4053 }
4054 
4055 static int
4056 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4057 			      struct spdk_nvme_transport_id *trid)
4058 {
4059 	struct spdk_nvmf_rdma_qpair	*rqpair;
4060 
4061 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4062 
4063 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4064 }
4065 
4066 static int
4067 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4068 			       struct spdk_nvme_transport_id *trid)
4069 {
4070 	struct spdk_nvmf_rdma_qpair	*rqpair;
4071 
4072 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4073 
4074 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4075 }
4076 
4077 static int
4078 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4079 				struct spdk_nvme_transport_id *trid)
4080 {
4081 	struct spdk_nvmf_rdma_qpair	*rqpair;
4082 
4083 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4084 
4085 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4086 }
4087 
4088 void
4089 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4090 {
4091 	g_nvmf_hooks = *hooks;
4092 }
4093 
4094 static void
4095 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4096 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4097 {
4098 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4099 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4100 
4101 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4102 
4103 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4104 }
4105 
4106 static int
4107 _nvmf_rdma_qpair_abort_request(void *ctx)
4108 {
4109 	struct spdk_nvmf_request *req = ctx;
4110 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4111 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4112 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4113 					      struct spdk_nvmf_rdma_qpair, qpair);
4114 	int rc;
4115 
4116 	spdk_poller_unregister(&req->poller);
4117 
4118 	switch (rdma_req_to_abort->state) {
4119 	case RDMA_REQUEST_STATE_EXECUTING:
4120 		rc = nvmf_ctrlr_abort_request(req);
4121 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4122 			return SPDK_POLLER_BUSY;
4123 		}
4124 		break;
4125 
4126 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4127 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4128 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4129 
4130 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4131 		break;
4132 
4133 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4134 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4135 			      spdk_nvmf_rdma_request, state_link);
4136 
4137 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4138 		break;
4139 
4140 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4141 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4142 			      spdk_nvmf_rdma_request, state_link);
4143 
4144 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4145 		break;
4146 
4147 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4148 		if (spdk_get_ticks() < req->timeout_tsc) {
4149 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4150 			return SPDK_POLLER_BUSY;
4151 		}
4152 		break;
4153 
4154 	default:
4155 		break;
4156 	}
4157 
4158 	spdk_nvmf_request_complete(req);
4159 	return SPDK_POLLER_BUSY;
4160 }
4161 
4162 static void
4163 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4164 			      struct spdk_nvmf_request *req)
4165 {
4166 	struct spdk_nvmf_rdma_qpair *rqpair;
4167 	struct spdk_nvmf_rdma_transport *rtransport;
4168 	struct spdk_nvmf_transport *transport;
4169 	uint16_t cid;
4170 	uint32_t i;
4171 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL;
4172 
4173 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4174 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4175 	transport = &rtransport->transport;
4176 
4177 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4178 
4179 	for (i = 0; i < rqpair->max_queue_depth; i++) {
4180 		rdma_req_to_abort = &rqpair->resources->reqs[i];
4181 
4182 		if (rdma_req_to_abort->state != RDMA_REQUEST_STATE_FREE &&
4183 		    rdma_req_to_abort->req.cmd->nvme_cmd.cid == cid) {
4184 			break;
4185 		}
4186 	}
4187 
4188 	if (rdma_req_to_abort == NULL) {
4189 		spdk_nvmf_request_complete(req);
4190 		return;
4191 	}
4192 
4193 	req->req_to_abort = &rdma_req_to_abort->req;
4194 	req->timeout_tsc = spdk_get_ticks() +
4195 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4196 	req->poller = NULL;
4197 
4198 	_nvmf_rdma_qpair_abort_request(req);
4199 }
4200 
4201 static int
4202 nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
4203 			      struct spdk_nvmf_transport_poll_group_stat **stat)
4204 {
4205 	struct spdk_io_channel *ch;
4206 	struct spdk_nvmf_poll_group *group;
4207 	struct spdk_nvmf_transport_poll_group *tgroup;
4208 	struct spdk_nvmf_rdma_poll_group *rgroup;
4209 	struct spdk_nvmf_rdma_poller *rpoller;
4210 	struct spdk_nvmf_rdma_device_stat *device_stat;
4211 	uint64_t num_devices = 0;
4212 
4213 	if (tgt == NULL || stat == NULL) {
4214 		return -EINVAL;
4215 	}
4216 
4217 	ch = spdk_get_io_channel(tgt);
4218 	group = spdk_io_channel_get_ctx(ch);;
4219 	spdk_put_io_channel(ch);
4220 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4221 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4222 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4223 			if (!*stat) {
4224 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4225 				return -ENOMEM;
4226 			}
4227 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4228 
4229 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4230 			/* Count devices to allocate enough memory */
4231 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4232 				++num_devices;
4233 			}
4234 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4235 			if (!(*stat)->rdma.devices) {
4236 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4237 				free(*stat);
4238 				return -ENOMEM;
4239 			}
4240 
4241 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4242 			(*stat)->rdma.num_devices = num_devices;
4243 			num_devices = 0;
4244 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4245 				device_stat = &(*stat)->rdma.devices[num_devices++];
4246 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4247 				device_stat->polls = rpoller->stat.polls;
4248 				device_stat->completions = rpoller->stat.completions;
4249 				device_stat->requests = rpoller->stat.requests;
4250 				device_stat->request_latency = rpoller->stat.request_latency;
4251 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4252 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4253 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4254 			}
4255 			return 0;
4256 		}
4257 	}
4258 	return -ENOENT;
4259 }
4260 
4261 static void
4262 nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4263 {
4264 	if (stat) {
4265 		free(stat->rdma.devices);
4266 	}
4267 	free(stat);
4268 }
4269 
4270 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4271 	.name = "RDMA",
4272 	.type = SPDK_NVME_TRANSPORT_RDMA,
4273 	.opts_init = nvmf_rdma_opts_init,
4274 	.create = nvmf_rdma_create,
4275 	.dump_opts = nvmf_rdma_dump_opts,
4276 	.destroy = nvmf_rdma_destroy,
4277 
4278 	.listen = nvmf_rdma_listen,
4279 	.stop_listen = nvmf_rdma_stop_listen,
4280 	.accept = nvmf_rdma_accept,
4281 	.cdata_init = nvmf_rdma_cdata_init,
4282 
4283 	.listener_discover = nvmf_rdma_discover,
4284 
4285 	.poll_group_create = nvmf_rdma_poll_group_create,
4286 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4287 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4288 	.poll_group_add = nvmf_rdma_poll_group_add,
4289 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4290 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4291 
4292 	.req_free = nvmf_rdma_request_free,
4293 	.req_complete = nvmf_rdma_request_complete,
4294 
4295 	.qpair_fini = nvmf_rdma_close_qpair,
4296 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4297 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4298 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4299 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4300 
4301 	.poll_group_get_stat = nvmf_rdma_poll_group_get_stat,
4302 	.poll_group_free_stat = nvmf_rdma_poll_group_free_stat,
4303 };
4304 
4305 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4306 SPDK_LOG_REGISTER_COMPONENT(rdma)
4307