xref: /spdk/lib/nvmf/rdma.c (revision 88e3ffd7b6c5ec1ea1a660354d25f02c766092e1)
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 /* rxe driver vendor_id has been changed from 0 to 0XFFFFFF in 0184afd15a141d7ce24c32c0d86a1e3ba6bc0eb3 */
65 #define NVMF_RXE_VENDOR_ID_OLD 0
66 #define NVMF_RXE_VENDOR_ID_NEW 0XFFFFFF
67 
68 static int g_spdk_nvmf_ibv_query_mask =
69 	IBV_QP_STATE |
70 	IBV_QP_PKEY_INDEX |
71 	IBV_QP_PORT |
72 	IBV_QP_ACCESS_FLAGS |
73 	IBV_QP_AV |
74 	IBV_QP_PATH_MTU |
75 	IBV_QP_DEST_QPN |
76 	IBV_QP_RQ_PSN |
77 	IBV_QP_MAX_DEST_RD_ATOMIC |
78 	IBV_QP_MIN_RNR_TIMER |
79 	IBV_QP_SQ_PSN |
80 	IBV_QP_TIMEOUT |
81 	IBV_QP_RETRY_CNT |
82 	IBV_QP_RNR_RETRY |
83 	IBV_QP_MAX_QP_RD_ATOMIC;
84 
85 enum spdk_nvmf_rdma_request_state {
86 	/* The request is not currently in use */
87 	RDMA_REQUEST_STATE_FREE = 0,
88 
89 	/* Initial state when request first received */
90 	RDMA_REQUEST_STATE_NEW,
91 
92 	/* The request is queued until a data buffer is available. */
93 	RDMA_REQUEST_STATE_NEED_BUFFER,
94 
95 	/* The request is waiting on RDMA queue depth availability
96 	 * to transfer data from the host to the controller.
97 	 */
98 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
99 
100 	/* The request is currently transferring data from the host to the controller. */
101 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
102 
103 	/* The request is ready to execute at the block device */
104 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
105 
106 	/* The request is currently executing at the block device */
107 	RDMA_REQUEST_STATE_EXECUTING,
108 
109 	/* The request finished executing at the block device */
110 	RDMA_REQUEST_STATE_EXECUTED,
111 
112 	/* The request is waiting on RDMA queue depth availability
113 	 * to transfer data from the controller to the host.
114 	 */
115 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
116 
117 	/* The request is ready to send a completion */
118 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
119 
120 	/* The request is currently transferring data from the controller to the host. */
121 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
122 
123 	/* The request currently has an outstanding completion without an
124 	 * associated data transfer.
125 	 */
126 	RDMA_REQUEST_STATE_COMPLETING,
127 
128 	/* The request completed and can be marked free. */
129 	RDMA_REQUEST_STATE_COMPLETED,
130 
131 	/* Terminator */
132 	RDMA_REQUEST_NUM_STATES,
133 };
134 
135 #define OBJECT_NVMF_RDMA_IO				0x40
136 
137 #define TRACE_GROUP_NVMF_RDMA				0x4
138 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
139 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
140 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
141 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
142 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
143 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
144 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
145 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
146 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
147 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
148 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
149 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
150 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
151 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
152 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
153 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
154 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
155 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
156 
157 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
158 {
159 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
160 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
161 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
162 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
163 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
164 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
165 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
168 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
169 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
170 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
171 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
172 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
173 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
174 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
175 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
176 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
177 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
178 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
179 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
180 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
181 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
182 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
183 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
184 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
185 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
186 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
187 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
188 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
189 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
190 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
191 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
192 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
193 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
194 
195 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
196 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
197 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
198 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
199 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
200 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
201 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
202 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
203 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
204 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
205 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
206 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
207 }
208 
209 enum spdk_nvmf_rdma_wr_type {
210 	RDMA_WR_TYPE_RECV,
211 	RDMA_WR_TYPE_SEND,
212 	RDMA_WR_TYPE_DATA,
213 };
214 
215 struct spdk_nvmf_rdma_wr {
216 	enum spdk_nvmf_rdma_wr_type	type;
217 };
218 
219 /* This structure holds commands as they are received off the wire.
220  * It must be dynamically paired with a full request object
221  * (spdk_nvmf_rdma_request) to service a request. It is separate
222  * from the request because RDMA does not appear to order
223  * completions, so occasionally we'll get a new incoming
224  * command when there aren't any free request objects.
225  */
226 struct spdk_nvmf_rdma_recv {
227 	struct ibv_recv_wr			wr;
228 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
229 
230 	struct spdk_nvmf_rdma_qpair		*qpair;
231 
232 	/* In-capsule data buffer */
233 	uint8_t					*buf;
234 
235 	struct spdk_nvmf_rdma_wr		rdma_wr;
236 	uint64_t				receive_tsc;
237 
238 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
239 };
240 
241 struct spdk_nvmf_rdma_request_data {
242 	struct spdk_nvmf_rdma_wr	rdma_wr;
243 	struct ibv_send_wr		wr;
244 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
245 };
246 
247 struct spdk_nvmf_rdma_request {
248 	struct spdk_nvmf_request		req;
249 
250 	enum spdk_nvmf_rdma_request_state	state;
251 
252 	struct spdk_nvmf_rdma_recv		*recv;
253 
254 	struct {
255 		struct spdk_nvmf_rdma_wr	rdma_wr;
256 		struct	ibv_send_wr		wr;
257 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
258 	} rsp;
259 
260 	struct spdk_nvmf_rdma_request_data	data;
261 
262 	uint32_t				iovpos;
263 
264 	uint32_t				num_outstanding_data_wr;
265 	uint64_t				receive_tsc;
266 
267 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
268 };
269 
270 struct spdk_nvmf_rdma_resource_opts {
271 	struct spdk_nvmf_rdma_qpair	*qpair;
272 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
273 	void				*qp;
274 	struct ibv_pd			*pd;
275 	uint32_t			max_queue_depth;
276 	uint32_t			in_capsule_data_size;
277 	bool				shared;
278 };
279 
280 struct spdk_nvmf_recv_wr_list {
281 	struct ibv_recv_wr	*first;
282 	struct ibv_recv_wr	*last;
283 };
284 
285 struct spdk_nvmf_rdma_resources {
286 	/* Array of size "max_queue_depth" containing RDMA requests. */
287 	struct spdk_nvmf_rdma_request		*reqs;
288 
289 	/* Array of size "max_queue_depth" containing RDMA recvs. */
290 	struct spdk_nvmf_rdma_recv		*recvs;
291 
292 	/* Array of size "max_queue_depth" containing 64 byte capsules
293 	 * used for receive.
294 	 */
295 	union nvmf_h2c_msg			*cmds;
296 	struct ibv_mr				*cmds_mr;
297 
298 	/* Array of size "max_queue_depth" containing 16 byte completions
299 	 * to be sent back to the user.
300 	 */
301 	union nvmf_c2h_msg			*cpls;
302 	struct ibv_mr				*cpls_mr;
303 
304 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
305 	 * buffers to be used for in capsule data.
306 	 */
307 	void					*bufs;
308 	struct ibv_mr				*bufs_mr;
309 
310 	/* The list of pending recvs to transfer */
311 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
312 
313 	/* Receives that are waiting for a request object */
314 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
315 
316 	/* Queue to track free requests */
317 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
318 };
319 
320 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
321 
322 struct spdk_nvmf_rdma_ibv_event_ctx {
323 	struct spdk_nvmf_rdma_qpair			*rqpair;
324 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
325 	/* Link to other ibv events associated with this qpair */
326 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
327 };
328 
329 struct spdk_nvmf_rdma_qpair {
330 	struct spdk_nvmf_qpair			qpair;
331 
332 	struct spdk_nvmf_rdma_device		*device;
333 	struct spdk_nvmf_rdma_poller		*poller;
334 
335 	struct spdk_rdma_qp			*rdma_qp;
336 	struct rdma_cm_id			*cm_id;
337 	struct ibv_srq				*srq;
338 	struct rdma_cm_id			*listen_id;
339 
340 	/* The maximum number of I/O outstanding on this connection at one time */
341 	uint16_t				max_queue_depth;
342 
343 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
344 	uint16_t				max_read_depth;
345 
346 	/* The maximum number of RDMA SEND operations at one time */
347 	uint32_t				max_send_depth;
348 
349 	/* The current number of outstanding WRs from this qpair's
350 	 * recv queue. Should not exceed device->attr.max_queue_depth.
351 	 */
352 	uint16_t				current_recv_depth;
353 
354 	/* The current number of active RDMA READ operations */
355 	uint16_t				current_read_depth;
356 
357 	/* The current number of posted WRs from this qpair's
358 	 * send queue. Should not exceed max_send_depth.
359 	 */
360 	uint32_t				current_send_depth;
361 
362 	/* The maximum number of SGEs per WR on the send queue */
363 	uint32_t				max_send_sge;
364 
365 	/* The maximum number of SGEs per WR on the recv queue */
366 	uint32_t				max_recv_sge;
367 
368 	struct spdk_nvmf_rdma_resources		*resources;
369 
370 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
371 
372 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
373 
374 	/* Number of requests not in the free state */
375 	uint32_t				qd;
376 
377 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
378 
379 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
380 
381 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
382 
383 	/* IBV queue pair attributes: they are used to manage
384 	 * qp state and recover from errors.
385 	 */
386 	enum ibv_qp_state			ibv_state;
387 
388 	/*
389 	 * io_channel which is used to destroy qpair when it is removed from poll group
390 	 */
391 	struct spdk_io_channel		*destruct_channel;
392 
393 	/* List of ibv async events */
394 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
395 
396 	/* Lets us know that we have received the last_wqe event. */
397 	bool					last_wqe_reached;
398 
399 	/* Indicate that nvmf_rdma_close_qpair is called */
400 	bool					to_close;
401 };
402 
403 struct spdk_nvmf_rdma_poller_stat {
404 	uint64_t				completions;
405 	uint64_t				polls;
406 	uint64_t				requests;
407 	uint64_t				request_latency;
408 	uint64_t				pending_free_request;
409 	uint64_t				pending_rdma_read;
410 	uint64_t				pending_rdma_write;
411 };
412 
413 struct spdk_nvmf_rdma_poller {
414 	struct spdk_nvmf_rdma_device		*device;
415 	struct spdk_nvmf_rdma_poll_group	*group;
416 
417 	int					num_cqe;
418 	int					required_num_wr;
419 	struct ibv_cq				*cq;
420 
421 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
422 	uint16_t				max_srq_depth;
423 
424 	/* Shared receive queue */
425 	struct ibv_srq				*srq;
426 
427 	struct spdk_nvmf_rdma_resources		*resources;
428 	struct spdk_nvmf_rdma_poller_stat	stat;
429 
430 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
431 
432 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
433 
434 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
435 
436 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
437 };
438 
439 struct spdk_nvmf_rdma_poll_group_stat {
440 	uint64_t				pending_data_buffer;
441 };
442 
443 struct spdk_nvmf_rdma_poll_group {
444 	struct spdk_nvmf_transport_poll_group		group;
445 	struct spdk_nvmf_rdma_poll_group_stat		stat;
446 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
447 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
448 };
449 
450 struct spdk_nvmf_rdma_conn_sched {
451 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
452 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
453 };
454 
455 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
456 struct spdk_nvmf_rdma_device {
457 	struct ibv_device_attr			attr;
458 	struct ibv_context			*context;
459 
460 	struct spdk_rdma_mem_map		*map;
461 	struct ibv_pd				*pd;
462 
463 	int					num_srq;
464 
465 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
466 };
467 
468 struct spdk_nvmf_rdma_port {
469 	const struct spdk_nvme_transport_id	*trid;
470 	struct rdma_cm_id			*id;
471 	struct spdk_nvmf_rdma_device		*device;
472 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
473 };
474 
475 struct rdma_transport_opts {
476 	uint32_t	max_srq_depth;
477 	bool		no_srq;
478 	bool		no_wr_batching;
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 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
514 		spdk_json_decode_bool, true
515 	},
516 	{
517 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
518 		spdk_json_decode_int32, true
519 	},
520 };
521 
522 static bool
523 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
524 			  struct spdk_nvmf_rdma_request *rdma_req);
525 
526 static void
527 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
528 		     struct spdk_nvmf_rdma_poller *rpoller);
529 
530 static void
531 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
532 		     struct spdk_nvmf_rdma_poller *rpoller);
533 
534 static inline int
535 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
536 {
537 	switch (state) {
538 	case IBV_QPS_RESET:
539 	case IBV_QPS_INIT:
540 	case IBV_QPS_RTR:
541 	case IBV_QPS_RTS:
542 	case IBV_QPS_SQD:
543 	case IBV_QPS_SQE:
544 	case IBV_QPS_ERR:
545 		return 0;
546 	default:
547 		return -1;
548 	}
549 }
550 
551 static inline enum spdk_nvme_media_error_status_code
552 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
553 	enum spdk_nvme_media_error_status_code result;
554 	switch (err_type)
555 	{
556 	case SPDK_DIF_REFTAG_ERROR:
557 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
558 		break;
559 	case SPDK_DIF_APPTAG_ERROR:
560 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
561 		break;
562 	case SPDK_DIF_GUARD_ERROR:
563 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
564 		break;
565 	default:
566 		SPDK_UNREACHABLE();
567 	}
568 
569 	return result;
570 }
571 
572 static enum ibv_qp_state
573 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
574 	enum ibv_qp_state old_state, new_state;
575 	struct ibv_qp_attr qp_attr;
576 	struct ibv_qp_init_attr init_attr;
577 	int rc;
578 
579 	old_state = rqpair->ibv_state;
580 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
581 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
582 
583 	if (rc)
584 	{
585 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
586 		return IBV_QPS_ERR + 1;
587 	}
588 
589 	new_state = qp_attr.qp_state;
590 	rqpair->ibv_state = new_state;
591 	qp_attr.ah_attr.port_num = qp_attr.port_num;
592 
593 	rc = nvmf_rdma_check_ibv_state(new_state);
594 	if (rc)
595 	{
596 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
597 		/*
598 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
599 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
600 		 */
601 		return IBV_QPS_ERR + 1;
602 	}
603 
604 	if (old_state != new_state)
605 	{
606 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
607 				  (uintptr_t)rqpair->cm_id, new_state);
608 	}
609 	return new_state;
610 }
611 
612 static void
613 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
614 			    struct spdk_nvmf_rdma_transport *rtransport)
615 {
616 	struct spdk_nvmf_rdma_request_data	*data_wr;
617 	struct ibv_send_wr			*next_send_wr;
618 	uint64_t				req_wrid;
619 
620 	rdma_req->num_outstanding_data_wr = 0;
621 	data_wr = &rdma_req->data;
622 	req_wrid = data_wr->wr.wr_id;
623 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
624 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
625 		data_wr->wr.num_sge = 0;
626 		next_send_wr = data_wr->wr.next;
627 		if (data_wr != &rdma_req->data) {
628 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
629 		}
630 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
631 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
632 	}
633 }
634 
635 static void
636 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
637 {
638 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
639 	if (req->req.cmd) {
640 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
641 	}
642 	if (req->recv) {
643 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
644 	}
645 }
646 
647 static void
648 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
649 {
650 	int i;
651 
652 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
653 	for (i = 0; i < rqpair->max_queue_depth; i++) {
654 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
655 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
656 		}
657 	}
658 }
659 
660 static void
661 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
662 {
663 	if (resources->cmds_mr) {
664 		ibv_dereg_mr(resources->cmds_mr);
665 	}
666 
667 	if (resources->cpls_mr) {
668 		ibv_dereg_mr(resources->cpls_mr);
669 	}
670 
671 	if (resources->bufs_mr) {
672 		ibv_dereg_mr(resources->bufs_mr);
673 	}
674 
675 	spdk_free(resources->cmds);
676 	spdk_free(resources->cpls);
677 	spdk_free(resources->bufs);
678 	free(resources->reqs);
679 	free(resources->recvs);
680 	free(resources);
681 }
682 
683 
684 static struct spdk_nvmf_rdma_resources *
685 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
686 {
687 	struct spdk_nvmf_rdma_resources	*resources;
688 	struct spdk_nvmf_rdma_request	*rdma_req;
689 	struct spdk_nvmf_rdma_recv	*rdma_recv;
690 	struct ibv_qp			*qp;
691 	struct ibv_srq			*srq;
692 	uint32_t			i;
693 	int				rc;
694 
695 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
696 	if (!resources) {
697 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
698 		return NULL;
699 	}
700 
701 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
702 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
703 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
704 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
705 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
706 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
707 
708 	if (opts->in_capsule_data_size > 0) {
709 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
710 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
711 					       SPDK_MALLOC_DMA);
712 	}
713 
714 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
715 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
716 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
717 		goto cleanup;
718 	}
719 
720 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
721 					opts->max_queue_depth * sizeof(*resources->cmds),
722 					IBV_ACCESS_LOCAL_WRITE);
723 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
724 					opts->max_queue_depth * sizeof(*resources->cpls),
725 					0);
726 
727 	if (opts->in_capsule_data_size) {
728 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
729 						opts->max_queue_depth *
730 						opts->in_capsule_data_size,
731 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
732 	}
733 
734 	if (!resources->cmds_mr || !resources->cpls_mr ||
735 	    (opts->in_capsule_data_size &&
736 	     !resources->bufs_mr)) {
737 		goto cleanup;
738 	}
739 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
740 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
741 		      resources->cmds_mr->lkey);
742 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
743 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
744 		      resources->cpls_mr->lkey);
745 	if (resources->bufs && resources->bufs_mr) {
746 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
747 			      resources->bufs, opts->max_queue_depth *
748 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
749 	}
750 
751 	/* Initialize queues */
752 	STAILQ_INIT(&resources->incoming_queue);
753 	STAILQ_INIT(&resources->free_queue);
754 
755 	for (i = 0; i < opts->max_queue_depth; i++) {
756 		struct ibv_recv_wr *bad_wr = NULL;
757 
758 		rdma_recv = &resources->recvs[i];
759 		rdma_recv->qpair = opts->qpair;
760 
761 		/* Set up memory to receive commands */
762 		if (resources->bufs) {
763 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
764 						  opts->in_capsule_data_size));
765 		}
766 
767 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
768 
769 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
770 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
771 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
772 		rdma_recv->wr.num_sge = 1;
773 
774 		if (rdma_recv->buf && resources->bufs_mr) {
775 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
776 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
777 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
778 			rdma_recv->wr.num_sge++;
779 		}
780 
781 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
782 		rdma_recv->wr.sg_list = rdma_recv->sgl;
783 		if (opts->shared) {
784 			srq = (struct ibv_srq *)opts->qp;
785 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
786 		} else {
787 			qp = (struct ibv_qp *)opts->qp;
788 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
789 		}
790 		if (rc) {
791 			goto cleanup;
792 		}
793 	}
794 
795 	for (i = 0; i < opts->max_queue_depth; i++) {
796 		rdma_req = &resources->reqs[i];
797 
798 		if (opts->qpair != NULL) {
799 			rdma_req->req.qpair = &opts->qpair->qpair;
800 		} else {
801 			rdma_req->req.qpair = NULL;
802 		}
803 		rdma_req->req.cmd = NULL;
804 
805 		/* Set up memory to send responses */
806 		rdma_req->req.rsp = &resources->cpls[i];
807 
808 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
809 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
810 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
811 
812 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
813 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
814 		rdma_req->rsp.wr.next = NULL;
815 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
816 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
817 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
818 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
819 
820 		/* Set up memory for data buffers */
821 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
822 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
823 		rdma_req->data.wr.next = NULL;
824 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
825 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
826 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
827 
828 		/* Initialize request state to FREE */
829 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
830 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
831 	}
832 
833 	return resources;
834 
835 cleanup:
836 	nvmf_rdma_resources_destroy(resources);
837 	return NULL;
838 }
839 
840 static void
841 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
842 {
843 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
844 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
845 		ctx->rqpair = NULL;
846 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
847 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
848 	}
849 }
850 
851 static void
852 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
853 {
854 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
855 	struct ibv_recv_wr		*bad_recv_wr = NULL;
856 	int				rc;
857 
858 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
859 
860 	if (rqpair->qd != 0) {
861 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
862 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
863 				struct spdk_nvmf_rdma_transport, transport);
864 		struct spdk_nvmf_rdma_request *req;
865 		uint32_t i, max_req_count = 0;
866 
867 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
868 
869 		if (rqpair->srq == NULL) {
870 			nvmf_rdma_dump_qpair_contents(rqpair);
871 			max_req_count = rqpair->max_queue_depth;
872 		} else if (rqpair->poller && rqpair->resources) {
873 			max_req_count = rqpair->poller->max_srq_depth;
874 		}
875 
876 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
877 		for (i = 0; i < max_req_count; i++) {
878 			req = &rqpair->resources->reqs[i];
879 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
880 				/* nvmf_rdma_request_process checks qpair ibv and internal state
881 				 * and completes a request */
882 				nvmf_rdma_request_process(rtransport, req);
883 			}
884 		}
885 		assert(rqpair->qd == 0);
886 	}
887 
888 	if (rqpair->poller) {
889 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
890 
891 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
892 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
893 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
894 				if (rqpair == rdma_recv->qpair) {
895 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
896 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
897 					if (rc) {
898 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
899 					}
900 				}
901 			}
902 		}
903 	}
904 
905 	if (rqpair->cm_id) {
906 		if (rqpair->rdma_qp != NULL) {
907 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
908 			rqpair->rdma_qp = NULL;
909 		}
910 		rdma_destroy_id(rqpair->cm_id);
911 
912 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
913 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
914 		}
915 	}
916 
917 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
918 		nvmf_rdma_resources_destroy(rqpair->resources);
919 	}
920 
921 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
922 
923 	if (rqpair->destruct_channel) {
924 		spdk_put_io_channel(rqpair->destruct_channel);
925 		rqpair->destruct_channel = NULL;
926 	}
927 
928 	free(rqpair);
929 }
930 
931 static int
932 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
933 {
934 	struct spdk_nvmf_rdma_poller	*rpoller;
935 	int				rc, num_cqe, required_num_wr;
936 
937 	/* Enlarge CQ size dynamically */
938 	rpoller = rqpair->poller;
939 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
940 	num_cqe = rpoller->num_cqe;
941 	if (num_cqe < required_num_wr) {
942 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
943 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
944 	}
945 
946 	if (rpoller->num_cqe != num_cqe) {
947 		if (required_num_wr > device->attr.max_cqe) {
948 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
949 				    required_num_wr, device->attr.max_cqe);
950 			return -1;
951 		}
952 
953 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
954 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
955 		if (rc) {
956 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
957 			return -1;
958 		}
959 
960 		rpoller->num_cqe = num_cqe;
961 	}
962 
963 	rpoller->required_num_wr = required_num_wr;
964 	return 0;
965 }
966 
967 static int
968 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
969 {
970 	struct spdk_nvmf_rdma_qpair		*rqpair;
971 	struct spdk_nvmf_rdma_transport		*rtransport;
972 	struct spdk_nvmf_transport		*transport;
973 	struct spdk_nvmf_rdma_resource_opts	opts;
974 	struct spdk_nvmf_rdma_device		*device;
975 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
976 
977 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
978 	device = rqpair->device;
979 
980 	qp_init_attr.qp_context	= rqpair;
981 	qp_init_attr.pd		= device->pd;
982 	qp_init_attr.send_cq	= rqpair->poller->cq;
983 	qp_init_attr.recv_cq	= rqpair->poller->cq;
984 
985 	if (rqpair->srq) {
986 		qp_init_attr.srq		= rqpair->srq;
987 	} else {
988 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
989 	}
990 
991 	/* SEND, READ, and WRITE operations */
992 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
993 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
994 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
995 
996 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
997 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
998 		goto error;
999 	}
1000 
1001 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1002 	if (!rqpair->rdma_qp) {
1003 		goto error;
1004 	}
1005 
1006 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1007 					  qp_init_attr.cap.max_send_wr);
1008 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1009 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1010 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1011 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1012 
1013 	if (rqpair->poller->srq == NULL) {
1014 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1015 		transport = &rtransport->transport;
1016 
1017 		opts.qp = rqpair->rdma_qp->qp;
1018 		opts.pd = rqpair->cm_id->pd;
1019 		opts.qpair = rqpair;
1020 		opts.shared = false;
1021 		opts.max_queue_depth = rqpair->max_queue_depth;
1022 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1023 
1024 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1025 
1026 		if (!rqpair->resources) {
1027 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1028 			rdma_destroy_qp(rqpair->cm_id);
1029 			goto error;
1030 		}
1031 	} else {
1032 		rqpair->resources = rqpair->poller->resources;
1033 	}
1034 
1035 	rqpair->current_recv_depth = 0;
1036 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1037 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1038 
1039 	return 0;
1040 
1041 error:
1042 	rdma_destroy_id(rqpair->cm_id);
1043 	rqpair->cm_id = NULL;
1044 	return -1;
1045 }
1046 
1047 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1048 /* This function accepts either a single wr or the first wr in a linked list. */
1049 static void
1050 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1051 {
1052 	struct ibv_recv_wr *last;
1053 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1054 			struct spdk_nvmf_rdma_transport, transport);
1055 
1056 	last = first;
1057 	while (last->next != NULL) {
1058 		last = last->next;
1059 	}
1060 
1061 	if (rqpair->resources->recvs_to_post.first == NULL) {
1062 		rqpair->resources->recvs_to_post.first = first;
1063 		rqpair->resources->recvs_to_post.last = last;
1064 		if (rqpair->srq == NULL) {
1065 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1066 		}
1067 	} else {
1068 		rqpair->resources->recvs_to_post.last->next = first;
1069 		rqpair->resources->recvs_to_post.last = last;
1070 	}
1071 
1072 	if (rtransport->rdma_opts.no_wr_batching) {
1073 		_poller_submit_recvs(rtransport, rqpair->poller);
1074 	}
1075 }
1076 
1077 static int
1078 request_transfer_in(struct spdk_nvmf_request *req)
1079 {
1080 	struct spdk_nvmf_rdma_request	*rdma_req;
1081 	struct spdk_nvmf_qpair		*qpair;
1082 	struct spdk_nvmf_rdma_qpair	*rqpair;
1083 	struct spdk_nvmf_rdma_transport *rtransport;
1084 
1085 	qpair = req->qpair;
1086 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1087 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1088 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1089 				      struct spdk_nvmf_rdma_transport, transport);
1090 
1091 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1092 	assert(rdma_req != NULL);
1093 
1094 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1095 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1096 	}
1097 	if (rtransport->rdma_opts.no_wr_batching) {
1098 		_poller_submit_sends(rtransport, rqpair->poller);
1099 	}
1100 
1101 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1102 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1103 	return 0;
1104 }
1105 
1106 static int
1107 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1108 {
1109 	int				num_outstanding_data_wr = 0;
1110 	struct spdk_nvmf_rdma_request	*rdma_req;
1111 	struct spdk_nvmf_qpair		*qpair;
1112 	struct spdk_nvmf_rdma_qpair	*rqpair;
1113 	struct spdk_nvme_cpl		*rsp;
1114 	struct ibv_send_wr		*first = NULL;
1115 	struct spdk_nvmf_rdma_transport *rtransport;
1116 
1117 	*data_posted = 0;
1118 	qpair = req->qpair;
1119 	rsp = &req->rsp->nvme_cpl;
1120 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1121 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1122 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1123 				      struct spdk_nvmf_rdma_transport, transport);
1124 
1125 	/* Advance our sq_head pointer */
1126 	if (qpair->sq_head == qpair->sq_head_max) {
1127 		qpair->sq_head = 0;
1128 	} else {
1129 		qpair->sq_head++;
1130 	}
1131 	rsp->sqhd = qpair->sq_head;
1132 
1133 	/* queue the capsule for the recv buffer */
1134 	assert(rdma_req->recv != NULL);
1135 
1136 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1137 
1138 	rdma_req->recv = NULL;
1139 	assert(rqpair->current_recv_depth > 0);
1140 	rqpair->current_recv_depth--;
1141 
1142 	/* Build the response which consists of optional
1143 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1144 	 * containing the response.
1145 	 */
1146 	first = &rdma_req->rsp.wr;
1147 
1148 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1149 		/* On failure, data was not read from the controller. So clear the
1150 		 * number of outstanding data WRs to zero.
1151 		 */
1152 		rdma_req->num_outstanding_data_wr = 0;
1153 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1154 		first = &rdma_req->data.wr;
1155 		*data_posted = 1;
1156 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1157 	}
1158 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1159 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1160 	}
1161 	if (rtransport->rdma_opts.no_wr_batching) {
1162 		_poller_submit_sends(rtransport, rqpair->poller);
1163 	}
1164 
1165 	/* +1 for the rsp wr */
1166 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1167 
1168 	return 0;
1169 }
1170 
1171 static int
1172 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1173 {
1174 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1175 	struct rdma_conn_param				ctrlr_event_data = {};
1176 	int						rc;
1177 
1178 	accept_data.recfmt = 0;
1179 	accept_data.crqsize = rqpair->max_queue_depth;
1180 
1181 	ctrlr_event_data.private_data = &accept_data;
1182 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1183 	if (id->ps == RDMA_PS_TCP) {
1184 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1185 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1186 	}
1187 
1188 	/* Configure infinite retries for the initiator side qpair.
1189 	 * When using a shared receive queue on the target side,
1190 	 * we need to pass this value to the initiator to prevent the
1191 	 * initiator side NIC from completing SEND requests back to the
1192 	 * initiator with status rnr_retry_count_exceeded. */
1193 	if (rqpair->srq != NULL) {
1194 		ctrlr_event_data.rnr_retry_count = 0x7;
1195 	}
1196 
1197 	/* When qpair is created without use of rdma cm API, an additional
1198 	 * information must be provided to initiator in the connection response:
1199 	 * whether qpair is using SRQ and its qp_num
1200 	 * Fields below are ignored by rdma cm if qpair has been
1201 	 * created using rdma cm API. */
1202 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1203 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1204 
1205 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1206 	if (rc) {
1207 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1208 	} else {
1209 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1210 	}
1211 
1212 	return rc;
1213 }
1214 
1215 static void
1216 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1217 {
1218 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1219 
1220 	rej_data.recfmt = 0;
1221 	rej_data.sts = error;
1222 
1223 	rdma_reject(id, &rej_data, sizeof(rej_data));
1224 }
1225 
1226 static int
1227 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1228 {
1229 	struct spdk_nvmf_rdma_transport *rtransport;
1230 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1231 	struct spdk_nvmf_rdma_port	*port;
1232 	struct rdma_conn_param		*rdma_param = NULL;
1233 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1234 	uint16_t			max_queue_depth;
1235 	uint16_t			max_read_depth;
1236 
1237 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1238 
1239 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1240 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1241 
1242 	rdma_param = &event->param.conn;
1243 	if (rdma_param->private_data == NULL ||
1244 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1245 		SPDK_ERRLOG("connect request: no private data provided\n");
1246 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1247 		return -1;
1248 	}
1249 
1250 	private_data = rdma_param->private_data;
1251 	if (private_data->recfmt != 0) {
1252 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1253 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1254 		return -1;
1255 	}
1256 
1257 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1258 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1259 
1260 	port = event->listen_id->context;
1261 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1262 		      event->listen_id, event->listen_id->verbs, port);
1263 
1264 	/* Figure out the supported queue depth. This is a multi-step process
1265 	 * that takes into account hardware maximums, host provided values,
1266 	 * and our target's internal memory limits */
1267 
1268 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1269 
1270 	/* Start with the maximum queue depth allowed by the target */
1271 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1272 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1273 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1274 		      rtransport->transport.opts.max_queue_depth);
1275 
1276 	/* Next check the local NIC's hardware limitations */
1277 	SPDK_DEBUGLOG(rdma,
1278 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1279 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1280 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1281 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1282 
1283 	/* Next check the remote NIC's hardware limitations */
1284 	SPDK_DEBUGLOG(rdma,
1285 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1286 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1287 	if (rdma_param->initiator_depth > 0) {
1288 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1289 	}
1290 
1291 	/* Finally check for the host software requested values, which are
1292 	 * optional. */
1293 	if (rdma_param->private_data != NULL &&
1294 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1295 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1296 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1297 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1298 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1299 	}
1300 
1301 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1302 		      max_queue_depth, max_read_depth);
1303 
1304 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1305 	if (rqpair == NULL) {
1306 		SPDK_ERRLOG("Could not allocate new connection.\n");
1307 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1308 		return -1;
1309 	}
1310 
1311 	rqpair->device = port->device;
1312 	rqpair->max_queue_depth = max_queue_depth;
1313 	rqpair->max_read_depth = max_read_depth;
1314 	rqpair->cm_id = event->id;
1315 	rqpair->listen_id = event->listen_id;
1316 	rqpair->qpair.transport = transport;
1317 	STAILQ_INIT(&rqpair->ibv_events);
1318 	/* use qid from the private data to determine the qpair type
1319 	   qid will be set to the appropriate value when the controller is created */
1320 	rqpair->qpair.qid = private_data->qid;
1321 
1322 	event->id->context = &rqpair->qpair;
1323 
1324 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1325 
1326 	return 0;
1327 }
1328 
1329 static inline void
1330 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1331 		   enum spdk_nvme_data_transfer xfer)
1332 {
1333 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1334 		wr->opcode = IBV_WR_RDMA_WRITE;
1335 		wr->send_flags = 0;
1336 		wr->next = next;
1337 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1338 		wr->opcode = IBV_WR_RDMA_READ;
1339 		wr->send_flags = IBV_SEND_SIGNALED;
1340 		wr->next = NULL;
1341 	} else {
1342 		assert(0);
1343 	}
1344 }
1345 
1346 static int
1347 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1348 		       struct spdk_nvmf_rdma_request *rdma_req,
1349 		       uint32_t num_sgl_descriptors)
1350 {
1351 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1352 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1353 	uint32_t				i;
1354 
1355 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1356 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1357 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1358 		return -EINVAL;
1359 	}
1360 
1361 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1362 		return -ENOMEM;
1363 	}
1364 
1365 	current_data_wr = &rdma_req->data;
1366 
1367 	for (i = 0; i < num_sgl_descriptors; i++) {
1368 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1369 		current_data_wr->wr.next = &work_requests[i]->wr;
1370 		current_data_wr = work_requests[i];
1371 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1372 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1373 	}
1374 
1375 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1376 
1377 	return 0;
1378 }
1379 
1380 static inline void
1381 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1382 {
1383 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1384 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1385 
1386 	wr->wr.rdma.rkey = sgl->keyed.key;
1387 	wr->wr.rdma.remote_addr = sgl->address;
1388 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1389 }
1390 
1391 static inline void
1392 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1393 {
1394 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1395 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1396 	uint32_t			i;
1397 	int				j;
1398 	uint64_t			remote_addr_offset = 0;
1399 
1400 	for (i = 0; i < num_wrs; ++i) {
1401 		wr->wr.rdma.rkey = sgl->keyed.key;
1402 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1403 		for (j = 0; j < wr->num_sge; ++j) {
1404 			remote_addr_offset += wr->sg_list[j].length;
1405 		}
1406 		wr = wr->next;
1407 	}
1408 }
1409 
1410 static bool
1411 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1412 		      struct iovec *iov, struct ibv_send_wr **_wr,
1413 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1414 		      uint32_t *_num_extra_wrs,
1415 		      const struct spdk_dif_ctx *dif_ctx)
1416 {
1417 	struct ibv_send_wr *wr = *_wr;
1418 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1419 	struct spdk_rdma_memory_translation mem_translation;
1420 	int		rc;
1421 	uint32_t	lkey = 0;
1422 	uint32_t	remaining, data_block_size, md_size, sge_len;
1423 
1424 	rc = spdk_rdma_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1425 	if (spdk_unlikely(rc)) {
1426 		return false;
1427 	}
1428 
1429 	lkey = spdk_rdma_memory_translation_get_lkey(&mem_translation);
1430 
1431 	if (spdk_likely(!dif_ctx)) {
1432 		sg_ele->lkey = lkey;
1433 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1434 		sg_ele->length = iov->iov_len;
1435 		wr->num_sge++;
1436 	} else {
1437 		remaining = iov->iov_len - *_offset;
1438 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1439 		md_size = dif_ctx->md_size;
1440 
1441 		while (remaining) {
1442 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1443 				if (*_num_extra_wrs > 0 && wr->next) {
1444 					*_wr = wr->next;
1445 					wr = *_wr;
1446 					wr->num_sge = 0;
1447 					sg_ele = &wr->sg_list[wr->num_sge];
1448 					(*_num_extra_wrs)--;
1449 				} else {
1450 					break;
1451 				}
1452 			}
1453 			sg_ele->lkey = lkey;
1454 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1455 			sge_len = spdk_min(remaining, *_remaining_data_block);
1456 			sg_ele->length = sge_len;
1457 			remaining -= sge_len;
1458 			*_remaining_data_block -= sge_len;
1459 			*_offset += sge_len;
1460 
1461 			sg_ele++;
1462 			wr->num_sge++;
1463 
1464 			if (*_remaining_data_block == 0) {
1465 				/* skip metadata */
1466 				*_offset += md_size;
1467 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1468 				remaining -= spdk_min(remaining, md_size);
1469 				*_remaining_data_block = data_block_size;
1470 			}
1471 
1472 			if (remaining == 0) {
1473 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1474 				   the remaining metadata bits at the beginning of the next buffer */
1475 				*_offset -= iov->iov_len;
1476 			}
1477 		}
1478 	}
1479 
1480 	return true;
1481 }
1482 
1483 static int
1484 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1485 		      struct spdk_nvmf_rdma_device *device,
1486 		      struct spdk_nvmf_rdma_request *rdma_req,
1487 		      struct ibv_send_wr *wr,
1488 		      uint32_t length,
1489 		      uint32_t num_extra_wrs)
1490 {
1491 	struct spdk_nvmf_request *req = &rdma_req->req;
1492 	struct spdk_dif_ctx *dif_ctx = NULL;
1493 	uint32_t remaining_data_block = 0;
1494 	uint32_t offset = 0;
1495 
1496 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1497 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1498 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1499 	}
1500 
1501 	wr->num_sge = 0;
1502 
1503 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1504 		if (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1505 				  &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1506 			return -EINVAL;
1507 		}
1508 
1509 		length -= req->iov[rdma_req->iovpos].iov_len;
1510 		rdma_req->iovpos++;
1511 	}
1512 
1513 	if (length) {
1514 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1515 		return -EINVAL;
1516 	}
1517 
1518 	return 0;
1519 }
1520 
1521 static inline uint32_t
1522 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1523 {
1524 	/* estimate the number of SG entries and WRs needed to process the request */
1525 	uint32_t num_sge = 0;
1526 	uint32_t i;
1527 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1528 
1529 	for (i = 0; i < num_buffers && length > 0; i++) {
1530 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1531 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1532 
1533 		if (num_sge_in_block * block_size > buffer_len) {
1534 			++num_sge_in_block;
1535 		}
1536 		num_sge += num_sge_in_block;
1537 		length -= buffer_len;
1538 	}
1539 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1540 }
1541 
1542 static int
1543 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1544 			    struct spdk_nvmf_rdma_device *device,
1545 			    struct spdk_nvmf_rdma_request *rdma_req,
1546 			    uint32_t length)
1547 {
1548 	struct spdk_nvmf_rdma_qpair		*rqpair;
1549 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1550 	struct spdk_nvmf_request		*req = &rdma_req->req;
1551 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1552 	int					rc;
1553 	uint32_t				num_wrs = 1;
1554 
1555 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1556 	rgroup = rqpair->poller->group;
1557 
1558 	/* rdma wr specifics */
1559 	nvmf_rdma_setup_request(rdma_req);
1560 
1561 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1562 					   length);
1563 	if (rc != 0) {
1564 		return rc;
1565 	}
1566 
1567 	assert(req->iovcnt <= rqpair->max_send_sge);
1568 
1569 	rdma_req->iovpos = 0;
1570 
1571 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1572 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1573 						 req->dif.dif_ctx.block_size);
1574 		if (num_wrs > 1) {
1575 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1576 			if (rc != 0) {
1577 				goto err_exit;
1578 			}
1579 		}
1580 	}
1581 
1582 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1583 	if (spdk_unlikely(rc != 0)) {
1584 		goto err_exit;
1585 	}
1586 
1587 	if (spdk_unlikely(num_wrs > 1)) {
1588 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1589 	}
1590 
1591 	/* set the number of outstanding data WRs for this request. */
1592 	rdma_req->num_outstanding_data_wr = num_wrs;
1593 
1594 	return rc;
1595 
1596 err_exit:
1597 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1598 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1599 	req->iovcnt = 0;
1600 	return rc;
1601 }
1602 
1603 static int
1604 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1605 				      struct spdk_nvmf_rdma_device *device,
1606 				      struct spdk_nvmf_rdma_request *rdma_req)
1607 {
1608 	struct spdk_nvmf_rdma_qpair		*rqpair;
1609 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1610 	struct ibv_send_wr			*current_wr;
1611 	struct spdk_nvmf_request		*req = &rdma_req->req;
1612 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1613 	uint32_t				num_sgl_descriptors;
1614 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1615 	uint32_t				i;
1616 	int					rc;
1617 
1618 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1619 	rgroup = rqpair->poller->group;
1620 
1621 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1622 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1623 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1624 
1625 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1626 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1627 
1628 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1629 		return -ENOMEM;
1630 	}
1631 
1632 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1633 	for (i = 0; i < num_sgl_descriptors; i++) {
1634 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1635 			lengths[i] = desc->keyed.length;
1636 		} else {
1637 			req->dif.orig_length += desc->keyed.length;
1638 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1639 			req->dif.elba_length += lengths[i];
1640 		}
1641 		desc++;
1642 	}
1643 
1644 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1645 			lengths, num_sgl_descriptors);
1646 	if (rc != 0) {
1647 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1648 		return rc;
1649 	}
1650 
1651 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1652 	current_wr = &rdma_req->data.wr;
1653 	assert(current_wr != NULL);
1654 
1655 	req->length = 0;
1656 	rdma_req->iovpos = 0;
1657 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1658 	for (i = 0; i < num_sgl_descriptors; i++) {
1659 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1660 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1661 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1662 			rc = -EINVAL;
1663 			goto err_exit;
1664 		}
1665 
1666 		current_wr->num_sge = 0;
1667 
1668 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1669 		if (rc != 0) {
1670 			rc = -ENOMEM;
1671 			goto err_exit;
1672 		}
1673 
1674 		req->length += desc->keyed.length;
1675 		current_wr->wr.rdma.rkey = desc->keyed.key;
1676 		current_wr->wr.rdma.remote_addr = desc->address;
1677 		current_wr = current_wr->next;
1678 		desc++;
1679 	}
1680 
1681 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1682 	/* Go back to the last descriptor in the list. */
1683 	desc--;
1684 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1685 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1686 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1687 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1688 		}
1689 	}
1690 #endif
1691 
1692 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1693 
1694 	return 0;
1695 
1696 err_exit:
1697 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1698 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1699 	return rc;
1700 }
1701 
1702 static int
1703 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1704 			    struct spdk_nvmf_rdma_device *device,
1705 			    struct spdk_nvmf_rdma_request *rdma_req)
1706 {
1707 	struct spdk_nvmf_request		*req = &rdma_req->req;
1708 	struct spdk_nvme_cpl			*rsp;
1709 	struct spdk_nvme_sgl_descriptor		*sgl;
1710 	int					rc;
1711 	uint32_t				length;
1712 
1713 	rsp = &req->rsp->nvme_cpl;
1714 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1715 
1716 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1717 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1718 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1719 
1720 		length = sgl->keyed.length;
1721 		if (length > rtransport->transport.opts.max_io_size) {
1722 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1723 				    length, rtransport->transport.opts.max_io_size);
1724 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1725 			return -1;
1726 		}
1727 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1728 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1729 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1730 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1731 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1732 			}
1733 		}
1734 #endif
1735 
1736 		/* fill request length and populate iovs */
1737 		req->length = length;
1738 
1739 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1740 			req->dif.orig_length = length;
1741 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1742 			req->dif.elba_length = length;
1743 		}
1744 
1745 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1746 		if (spdk_unlikely(rc < 0)) {
1747 			if (rc == -EINVAL) {
1748 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1749 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1750 				return -1;
1751 			}
1752 			/* No available buffers. Queue this request up. */
1753 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1754 			return 0;
1755 		}
1756 
1757 		/* backward compatible */
1758 		req->data = req->iov[0].iov_base;
1759 
1760 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1761 			      req->iovcnt);
1762 
1763 		return 0;
1764 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1765 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1766 		uint64_t offset = sgl->address;
1767 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1768 
1769 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1770 			      offset, sgl->unkeyed.length);
1771 
1772 		if (offset > max_len) {
1773 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1774 				    offset, max_len);
1775 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1776 			return -1;
1777 		}
1778 		max_len -= (uint32_t)offset;
1779 
1780 		if (sgl->unkeyed.length > max_len) {
1781 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1782 				    sgl->unkeyed.length, max_len);
1783 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1784 			return -1;
1785 		}
1786 
1787 		rdma_req->num_outstanding_data_wr = 0;
1788 		req->data = rdma_req->recv->buf + offset;
1789 		req->data_from_pool = false;
1790 		req->length = sgl->unkeyed.length;
1791 
1792 		req->iov[0].iov_base = req->data;
1793 		req->iov[0].iov_len = req->length;
1794 		req->iovcnt = 1;
1795 
1796 		return 0;
1797 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1798 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1799 
1800 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1801 		if (rc == -ENOMEM) {
1802 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1803 			return 0;
1804 		} else if (rc == -EINVAL) {
1805 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1806 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1807 			return -1;
1808 		}
1809 
1810 		/* backward compatible */
1811 		req->data = req->iov[0].iov_base;
1812 
1813 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1814 			      req->iovcnt);
1815 
1816 		return 0;
1817 	}
1818 
1819 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1820 		    sgl->generic.type, sgl->generic.subtype);
1821 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1822 	return -1;
1823 }
1824 
1825 static void
1826 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1827 			struct spdk_nvmf_rdma_transport	*rtransport)
1828 {
1829 	struct spdk_nvmf_rdma_qpair		*rqpair;
1830 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1831 
1832 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1833 	if (rdma_req->req.data_from_pool) {
1834 		rgroup = rqpair->poller->group;
1835 
1836 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1837 	}
1838 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1839 	rdma_req->req.length = 0;
1840 	rdma_req->req.iovcnt = 0;
1841 	rdma_req->req.data = NULL;
1842 	rdma_req->rsp.wr.next = NULL;
1843 	rdma_req->data.wr.next = NULL;
1844 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1845 	rqpair->qd--;
1846 
1847 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1848 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1849 }
1850 
1851 bool
1852 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1853 			  struct spdk_nvmf_rdma_request *rdma_req)
1854 {
1855 	struct spdk_nvmf_rdma_qpair	*rqpair;
1856 	struct spdk_nvmf_rdma_device	*device;
1857 	struct spdk_nvmf_rdma_poll_group *rgroup;
1858 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1859 	int				rc;
1860 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1861 	enum spdk_nvmf_rdma_request_state prev_state;
1862 	bool				progress = false;
1863 	int				data_posted;
1864 	uint32_t			num_blocks;
1865 
1866 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1867 	device = rqpair->device;
1868 	rgroup = rqpair->poller->group;
1869 
1870 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1871 
1872 	/* If the queue pair is in an error state, force the request to the completed state
1873 	 * to release resources. */
1874 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1875 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1876 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1877 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1878 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1879 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1880 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1881 		}
1882 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1883 	}
1884 
1885 	/* The loop here is to allow for several back-to-back state changes. */
1886 	do {
1887 		prev_state = rdma_req->state;
1888 
1889 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
1890 
1891 		switch (rdma_req->state) {
1892 		case RDMA_REQUEST_STATE_FREE:
1893 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1894 			 * to escape this state. */
1895 			break;
1896 		case RDMA_REQUEST_STATE_NEW:
1897 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1898 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1899 			rdma_recv = rdma_req->recv;
1900 
1901 			/* The first element of the SGL is the NVMe command */
1902 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1903 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1904 
1905 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1906 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1907 				break;
1908 			}
1909 
1910 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
1911 				rdma_req->req.dif.dif_insert_or_strip = true;
1912 			}
1913 
1914 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1915 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1916 			rdma_req->rsp.wr.imm_data = 0;
1917 #endif
1918 
1919 			/* The next state transition depends on the data transfer needs of this request. */
1920 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
1921 
1922 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
1923 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
1924 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
1925 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1926 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
1927 				break;
1928 			}
1929 
1930 			/* If no data to transfer, ready to execute. */
1931 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1932 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1933 				break;
1934 			}
1935 
1936 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1937 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
1938 			break;
1939 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1940 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1941 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1942 
1943 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1944 
1945 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
1946 				/* This request needs to wait in line to obtain a buffer */
1947 				break;
1948 			}
1949 
1950 			/* Try to get a data buffer */
1951 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1952 			if (rc < 0) {
1953 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1954 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1955 				break;
1956 			}
1957 
1958 			if (!rdma_req->req.data) {
1959 				/* No buffers available. */
1960 				rgroup->stat.pending_data_buffer++;
1961 				break;
1962 			}
1963 
1964 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
1965 
1966 			/* If data is transferring from host to controller and the data didn't
1967 			 * arrive using in capsule data, we need to do a transfer from the host.
1968 			 */
1969 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
1970 			    rdma_req->req.data_from_pool) {
1971 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1972 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1973 				break;
1974 			}
1975 
1976 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1977 			break;
1978 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1979 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1980 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1981 
1982 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
1983 				/* This request needs to wait in line to perform RDMA */
1984 				break;
1985 			}
1986 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1987 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1988 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1989 				rqpair->poller->stat.pending_rdma_read++;
1990 				break;
1991 			}
1992 
1993 			/* We have already verified that this request is the head of the queue. */
1994 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
1995 
1996 			rc = request_transfer_in(&rdma_req->req);
1997 			if (!rc) {
1998 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
1999 			} else {
2000 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2001 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2002 			}
2003 			break;
2004 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2005 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2006 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2007 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2008 			 * to escape this state. */
2009 			break;
2010 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2011 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2012 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2013 
2014 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2015 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2016 					/* generate DIF for write operation */
2017 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2018 					assert(num_blocks > 0);
2019 
2020 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2021 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2022 					if (rc != 0) {
2023 						SPDK_ERRLOG("DIF generation failed\n");
2024 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2025 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2026 						break;
2027 					}
2028 				}
2029 
2030 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2031 				/* set extended length before IO operation */
2032 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2033 			}
2034 
2035 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2036 			spdk_nvmf_request_exec(&rdma_req->req);
2037 			break;
2038 		case RDMA_REQUEST_STATE_EXECUTING:
2039 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2040 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2041 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2042 			 * to escape this state. */
2043 			break;
2044 		case RDMA_REQUEST_STATE_EXECUTED:
2045 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2046 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2047 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2048 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2049 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2050 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2051 			} else {
2052 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2053 			}
2054 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2055 				/* restore the original length */
2056 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2057 
2058 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2059 					struct spdk_dif_error error_blk;
2060 
2061 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2062 
2063 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2064 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2065 					if (rc) {
2066 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2067 
2068 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2069 							    error_blk.err_offset);
2070 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2071 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2072 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2073 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2074 					}
2075 				}
2076 			}
2077 			break;
2078 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2079 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2080 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2081 
2082 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2083 				/* This request needs to wait in line to perform RDMA */
2084 				break;
2085 			}
2086 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2087 			    rqpair->max_send_depth) {
2088 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2089 				 * +1 since each request has an additional wr in the resp. */
2090 				rqpair->poller->stat.pending_rdma_write++;
2091 				break;
2092 			}
2093 
2094 			/* We have already verified that this request is the head of the queue. */
2095 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2096 
2097 			/* The data transfer will be kicked off from
2098 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2099 			 */
2100 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2101 			break;
2102 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2103 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2104 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2105 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2106 			assert(rc == 0); /* No good way to handle this currently */
2107 			if (rc) {
2108 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2109 			} else {
2110 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2111 						  RDMA_REQUEST_STATE_COMPLETING;
2112 			}
2113 			break;
2114 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2115 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2116 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2117 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2118 			 * to escape this state. */
2119 			break;
2120 		case RDMA_REQUEST_STATE_COMPLETING:
2121 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2122 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2123 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2124 			 * to escape this state. */
2125 			break;
2126 		case RDMA_REQUEST_STATE_COMPLETED:
2127 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2128 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2129 
2130 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2131 			_nvmf_rdma_request_free(rdma_req, rtransport);
2132 			break;
2133 		case RDMA_REQUEST_NUM_STATES:
2134 		default:
2135 			assert(0);
2136 			break;
2137 		}
2138 
2139 		if (rdma_req->state != prev_state) {
2140 			progress = true;
2141 		}
2142 	} while (rdma_req->state != prev_state);
2143 
2144 	return progress;
2145 }
2146 
2147 /* Public API callbacks begin here */
2148 
2149 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2150 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2151 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2152 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2153 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2154 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2155 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2156 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2157 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2158 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2159 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2160 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2161 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2162 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2163 
2164 static void
2165 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2166 {
2167 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2168 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2169 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2170 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2171 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2172 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2173 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2174 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2175 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2176 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2177 	opts->transport_specific =      NULL;
2178 }
2179 
2180 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2181 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2182 
2183 static inline bool
2184 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2185 {
2186 	return device->attr.vendor_id == NVMF_RXE_VENDOR_ID_OLD ||
2187 	       device->attr.vendor_id == NVMF_RXE_VENDOR_ID_NEW;
2188 }
2189 
2190 static struct spdk_nvmf_transport *
2191 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2192 {
2193 	int rc;
2194 	struct spdk_nvmf_rdma_transport *rtransport;
2195 	struct spdk_nvmf_rdma_device	*device, *tmp;
2196 	struct ibv_context		**contexts;
2197 	uint32_t			i;
2198 	int				flag;
2199 	uint32_t			sge_count;
2200 	uint32_t			min_shared_buffers;
2201 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2202 	pthread_mutexattr_t		attr;
2203 
2204 	rtransport = calloc(1, sizeof(*rtransport));
2205 	if (!rtransport) {
2206 		return NULL;
2207 	}
2208 
2209 	if (pthread_mutexattr_init(&attr)) {
2210 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2211 		free(rtransport);
2212 		return NULL;
2213 	}
2214 
2215 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2216 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2217 		pthread_mutexattr_destroy(&attr);
2218 		free(rtransport);
2219 		return NULL;
2220 	}
2221 
2222 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2223 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2224 		pthread_mutexattr_destroy(&attr);
2225 		free(rtransport);
2226 		return NULL;
2227 	}
2228 
2229 	pthread_mutexattr_destroy(&attr);
2230 
2231 	TAILQ_INIT(&rtransport->devices);
2232 	TAILQ_INIT(&rtransport->ports);
2233 	TAILQ_INIT(&rtransport->poll_groups);
2234 
2235 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2236 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2237 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2238 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2239 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2240 	if (opts->transport_specific != NULL &&
2241 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2242 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2243 					    &rtransport->rdma_opts)) {
2244 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2245 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2246 		return NULL;
2247 	}
2248 
2249 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2250 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2251 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2252 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2253 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d,"
2254 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2255 		     opts->max_queue_depth,
2256 		     opts->max_io_size,
2257 		     opts->max_qpairs_per_ctrlr - 1,
2258 		     opts->io_unit_size,
2259 		     opts->in_capsule_data_size,
2260 		     opts->max_aq_depth,
2261 		     opts->num_shared_buffers,
2262 		     rtransport->rdma_opts.max_srq_depth,
2263 		     rtransport->rdma_opts.no_srq,
2264 		     rtransport->rdma_opts.acceptor_backlog,
2265 		     rtransport->rdma_opts.no_wr_batching,
2266 		     opts->abort_timeout_sec);
2267 
2268 	/* I/O unit size cannot be larger than max I/O size */
2269 	if (opts->io_unit_size > opts->max_io_size) {
2270 		opts->io_unit_size = opts->max_io_size;
2271 	}
2272 
2273 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2274 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2275 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2276 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2277 	}
2278 
2279 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2280 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2281 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2282 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2283 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2284 		return NULL;
2285 	}
2286 
2287 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2288 	if (min_shared_buffers > opts->num_shared_buffers) {
2289 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2290 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2291 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2292 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2293 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2294 		return NULL;
2295 	}
2296 
2297 	sge_count = opts->max_io_size / opts->io_unit_size;
2298 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2299 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2300 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2301 		return NULL;
2302 	}
2303 
2304 	rtransport->event_channel = rdma_create_event_channel();
2305 	if (rtransport->event_channel == NULL) {
2306 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2307 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2308 		return NULL;
2309 	}
2310 
2311 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2312 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2313 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2314 			    rtransport->event_channel->fd, spdk_strerror(errno));
2315 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2316 		return NULL;
2317 	}
2318 
2319 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2320 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2321 				   sizeof(struct spdk_nvmf_rdma_request_data),
2322 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2323 				   SPDK_ENV_SOCKET_ID_ANY);
2324 	if (!rtransport->data_wr_pool) {
2325 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2326 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2327 		return NULL;
2328 	}
2329 
2330 	contexts = rdma_get_devices(NULL);
2331 	if (contexts == NULL) {
2332 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2333 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2334 		return NULL;
2335 	}
2336 
2337 	i = 0;
2338 	rc = 0;
2339 	while (contexts[i] != NULL) {
2340 		device = calloc(1, sizeof(*device));
2341 		if (!device) {
2342 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2343 			rc = -ENOMEM;
2344 			break;
2345 		}
2346 		device->context = contexts[i];
2347 		rc = ibv_query_device(device->context, &device->attr);
2348 		if (rc < 0) {
2349 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2350 			free(device);
2351 			break;
2352 
2353 		}
2354 
2355 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2356 
2357 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2358 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2359 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2360 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2361 		}
2362 
2363 		/**
2364 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2365 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2366 		 * but incorrectly reports that it does. There are changes making their way
2367 		 * through the kernel now that will enable this feature. When they are merged,
2368 		 * we can conditionally enable this feature.
2369 		 *
2370 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2371 		 */
2372 		if (nvmf_rdma_is_rxe_device(device)) {
2373 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2374 		}
2375 #endif
2376 
2377 		/* set up device context async ev fd as NON_BLOCKING */
2378 		flag = fcntl(device->context->async_fd, F_GETFL);
2379 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2380 		if (rc < 0) {
2381 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2382 			free(device);
2383 			break;
2384 		}
2385 
2386 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2387 		i++;
2388 
2389 		if (g_nvmf_hooks.get_ibv_pd) {
2390 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2391 		} else {
2392 			device->pd = ibv_alloc_pd(device->context);
2393 		}
2394 
2395 		if (!device->pd) {
2396 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2397 			rc = -ENOMEM;
2398 			break;
2399 		}
2400 
2401 		assert(device->map == NULL);
2402 
2403 		device->map = spdk_rdma_create_mem_map(device->pd, &g_nvmf_hooks);
2404 		if (!device->map) {
2405 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2406 			rc = -ENOMEM;
2407 			break;
2408 		}
2409 
2410 		assert(device->map != NULL);
2411 		assert(device->pd != NULL);
2412 	}
2413 	rdma_free_devices(contexts);
2414 
2415 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2416 		/* divide and round up. */
2417 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2418 
2419 		/* round up to the nearest 4k. */
2420 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2421 
2422 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2423 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2424 			       opts->io_unit_size);
2425 	}
2426 
2427 	if (rc < 0) {
2428 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2429 		return NULL;
2430 	}
2431 
2432 	/* Set up poll descriptor array to monitor events from RDMA and IB
2433 	 * in a single poll syscall
2434 	 */
2435 	rtransport->npoll_fds = i + 1;
2436 	i = 0;
2437 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2438 	if (rtransport->poll_fds == NULL) {
2439 		SPDK_ERRLOG("poll_fds allocation failed\n");
2440 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2441 		return NULL;
2442 	}
2443 
2444 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2445 	rtransport->poll_fds[i++].events = POLLIN;
2446 
2447 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2448 		rtransport->poll_fds[i].fd = device->context->async_fd;
2449 		rtransport->poll_fds[i++].events = POLLIN;
2450 	}
2451 
2452 	return &rtransport->transport;
2453 }
2454 
2455 static void
2456 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2457 {
2458 	struct spdk_nvmf_rdma_transport	*rtransport;
2459 	assert(w != NULL);
2460 
2461 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2462 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2463 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2464 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2465 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2466 }
2467 
2468 static int
2469 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2470 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2471 {
2472 	struct spdk_nvmf_rdma_transport	*rtransport;
2473 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2474 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2475 
2476 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2477 
2478 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2479 		TAILQ_REMOVE(&rtransport->ports, port, link);
2480 		rdma_destroy_id(port->id);
2481 		free(port);
2482 	}
2483 
2484 	if (rtransport->poll_fds != NULL) {
2485 		free(rtransport->poll_fds);
2486 	}
2487 
2488 	if (rtransport->event_channel != NULL) {
2489 		rdma_destroy_event_channel(rtransport->event_channel);
2490 	}
2491 
2492 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2493 		TAILQ_REMOVE(&rtransport->devices, device, link);
2494 		spdk_rdma_free_mem_map(&device->map);
2495 		if (device->pd) {
2496 			if (!g_nvmf_hooks.get_ibv_pd) {
2497 				ibv_dealloc_pd(device->pd);
2498 			}
2499 		}
2500 		free(device);
2501 	}
2502 
2503 	if (rtransport->data_wr_pool != NULL) {
2504 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2505 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2506 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2507 				    spdk_mempool_count(rtransport->data_wr_pool),
2508 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2509 		}
2510 	}
2511 
2512 	spdk_mempool_free(rtransport->data_wr_pool);
2513 
2514 	pthread_mutex_destroy(&rtransport->lock);
2515 	free(rtransport);
2516 
2517 	if (cb_fn) {
2518 		cb_fn(cb_arg);
2519 	}
2520 	return 0;
2521 }
2522 
2523 static int
2524 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2525 			  struct spdk_nvme_transport_id *trid,
2526 			  bool peer);
2527 
2528 static int
2529 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2530 		 struct spdk_nvmf_listen_opts *listen_opts)
2531 {
2532 	struct spdk_nvmf_rdma_transport	*rtransport;
2533 	struct spdk_nvmf_rdma_device	*device;
2534 	struct spdk_nvmf_rdma_port	*port;
2535 	struct addrinfo			*res;
2536 	struct addrinfo			hints;
2537 	int				family;
2538 	int				rc;
2539 
2540 	if (!strlen(trid->trsvcid)) {
2541 		SPDK_ERRLOG("Service id is required\n");
2542 		return -EINVAL;
2543 	}
2544 
2545 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2546 	assert(rtransport->event_channel != NULL);
2547 
2548 	pthread_mutex_lock(&rtransport->lock);
2549 	port = calloc(1, sizeof(*port));
2550 	if (!port) {
2551 		SPDK_ERRLOG("Port allocation failed\n");
2552 		pthread_mutex_unlock(&rtransport->lock);
2553 		return -ENOMEM;
2554 	}
2555 
2556 	port->trid = trid;
2557 
2558 	switch (trid->adrfam) {
2559 	case SPDK_NVMF_ADRFAM_IPV4:
2560 		family = AF_INET;
2561 		break;
2562 	case SPDK_NVMF_ADRFAM_IPV6:
2563 		family = AF_INET6;
2564 		break;
2565 	default:
2566 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2567 		free(port);
2568 		pthread_mutex_unlock(&rtransport->lock);
2569 		return -EINVAL;
2570 	}
2571 
2572 	memset(&hints, 0, sizeof(hints));
2573 	hints.ai_family = family;
2574 	hints.ai_flags = AI_NUMERICSERV;
2575 	hints.ai_socktype = SOCK_STREAM;
2576 	hints.ai_protocol = 0;
2577 
2578 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2579 	if (rc) {
2580 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2581 		free(port);
2582 		pthread_mutex_unlock(&rtransport->lock);
2583 		return -EINVAL;
2584 	}
2585 
2586 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2587 	if (rc < 0) {
2588 		SPDK_ERRLOG("rdma_create_id() failed\n");
2589 		freeaddrinfo(res);
2590 		free(port);
2591 		pthread_mutex_unlock(&rtransport->lock);
2592 		return rc;
2593 	}
2594 
2595 	rc = rdma_bind_addr(port->id, res->ai_addr);
2596 	freeaddrinfo(res);
2597 
2598 	if (rc < 0) {
2599 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2600 		rdma_destroy_id(port->id);
2601 		free(port);
2602 		pthread_mutex_unlock(&rtransport->lock);
2603 		return rc;
2604 	}
2605 
2606 	if (!port->id->verbs) {
2607 		SPDK_ERRLOG("ibv_context is null\n");
2608 		rdma_destroy_id(port->id);
2609 		free(port);
2610 		pthread_mutex_unlock(&rtransport->lock);
2611 		return -1;
2612 	}
2613 
2614 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2615 	if (rc < 0) {
2616 		SPDK_ERRLOG("rdma_listen() failed\n");
2617 		rdma_destroy_id(port->id);
2618 		free(port);
2619 		pthread_mutex_unlock(&rtransport->lock);
2620 		return rc;
2621 	}
2622 
2623 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2624 		if (device->context == port->id->verbs) {
2625 			port->device = device;
2626 			break;
2627 		}
2628 	}
2629 	if (!port->device) {
2630 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2631 			    port->id->verbs);
2632 		rdma_destroy_id(port->id);
2633 		free(port);
2634 		pthread_mutex_unlock(&rtransport->lock);
2635 		return -EINVAL;
2636 	}
2637 
2638 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2639 		       trid->traddr, trid->trsvcid);
2640 
2641 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2642 	pthread_mutex_unlock(&rtransport->lock);
2643 	return 0;
2644 }
2645 
2646 static void
2647 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2648 		      const struct spdk_nvme_transport_id *trid)
2649 {
2650 	struct spdk_nvmf_rdma_transport *rtransport;
2651 	struct spdk_nvmf_rdma_port *port, *tmp;
2652 
2653 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2654 
2655 	pthread_mutex_lock(&rtransport->lock);
2656 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2657 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2658 			TAILQ_REMOVE(&rtransport->ports, port, link);
2659 			rdma_destroy_id(port->id);
2660 			free(port);
2661 			break;
2662 		}
2663 	}
2664 
2665 	pthread_mutex_unlock(&rtransport->lock);
2666 }
2667 
2668 static void
2669 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2670 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2671 {
2672 	struct spdk_nvmf_request *req, *tmp;
2673 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2674 	struct spdk_nvmf_rdma_resources *resources;
2675 
2676 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2677 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2678 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2679 			break;
2680 		}
2681 	}
2682 
2683 	/* Then RDMA writes since reads have stronger restrictions than writes */
2684 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2685 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2686 			break;
2687 		}
2688 	}
2689 
2690 	/* Then we handle request waiting on memory buffers. */
2691 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2692 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2693 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2694 			break;
2695 		}
2696 	}
2697 
2698 	resources = rqpair->resources;
2699 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2700 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2701 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2702 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2703 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2704 
2705 		if (rqpair->srq != NULL) {
2706 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2707 			rdma_req->recv->qpair->qd++;
2708 		} else {
2709 			rqpair->qd++;
2710 		}
2711 
2712 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2713 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2714 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2715 			break;
2716 		}
2717 	}
2718 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2719 		rqpair->poller->stat.pending_free_request++;
2720 	}
2721 }
2722 
2723 static inline bool
2724 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
2725 {
2726 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
2727 	return nvmf_rdma_is_rxe_device(device) ||
2728 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
2729 }
2730 
2731 static void
2732 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2733 {
2734 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2735 			struct spdk_nvmf_rdma_transport, transport);
2736 
2737 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2738 
2739 	/* nvmr_rdma_close_qpair is not called */
2740 	if (!rqpair->to_close) {
2741 		return;
2742 	}
2743 
2744 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2745 	if (rqpair->current_send_depth != 0) {
2746 		return;
2747 	}
2748 
2749 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2750 		return;
2751 	}
2752 
2753 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
2754 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
2755 		return;
2756 	}
2757 
2758 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2759 
2760 	nvmf_rdma_qpair_destroy(rqpair);
2761 }
2762 
2763 static int
2764 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2765 {
2766 	struct spdk_nvmf_qpair		*qpair;
2767 	struct spdk_nvmf_rdma_qpair	*rqpair;
2768 
2769 	if (evt->id == NULL) {
2770 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2771 		return -1;
2772 	}
2773 
2774 	qpair = evt->id->context;
2775 	if (qpair == NULL) {
2776 		SPDK_ERRLOG("disconnect request: no active connection\n");
2777 		return -1;
2778 	}
2779 
2780 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2781 
2782 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2783 
2784 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2785 
2786 	return 0;
2787 }
2788 
2789 #ifdef DEBUG
2790 static const char *CM_EVENT_STR[] = {
2791 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2792 	"RDMA_CM_EVENT_ADDR_ERROR",
2793 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2794 	"RDMA_CM_EVENT_ROUTE_ERROR",
2795 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2796 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2797 	"RDMA_CM_EVENT_CONNECT_ERROR",
2798 	"RDMA_CM_EVENT_UNREACHABLE",
2799 	"RDMA_CM_EVENT_REJECTED",
2800 	"RDMA_CM_EVENT_ESTABLISHED",
2801 	"RDMA_CM_EVENT_DISCONNECTED",
2802 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2803 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2804 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2805 	"RDMA_CM_EVENT_ADDR_CHANGE",
2806 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2807 };
2808 #endif /* DEBUG */
2809 
2810 static void
2811 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2812 				    struct spdk_nvmf_rdma_port *port)
2813 {
2814 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2815 	struct spdk_nvmf_rdma_poller		*rpoller;
2816 	struct spdk_nvmf_rdma_qpair		*rqpair;
2817 
2818 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2819 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2820 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2821 				if (rqpair->listen_id == port->id) {
2822 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2823 				}
2824 			}
2825 		}
2826 	}
2827 }
2828 
2829 static bool
2830 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2831 				      struct rdma_cm_event *event)
2832 {
2833 	const struct spdk_nvme_transport_id	*trid;
2834 	struct spdk_nvmf_rdma_port		*port;
2835 	struct spdk_nvmf_rdma_transport		*rtransport;
2836 	bool					event_acked = false;
2837 
2838 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2839 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2840 		if (port->id == event->id) {
2841 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2842 			rdma_ack_cm_event(event);
2843 			event_acked = true;
2844 			trid = port->trid;
2845 			break;
2846 		}
2847 	}
2848 
2849 	if (event_acked) {
2850 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2851 
2852 		nvmf_rdma_stop_listen(transport, trid);
2853 		nvmf_rdma_listen(transport, trid, NULL);
2854 	}
2855 
2856 	return event_acked;
2857 }
2858 
2859 static void
2860 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2861 				       struct rdma_cm_event *event)
2862 {
2863 	struct spdk_nvmf_rdma_port		*port;
2864 	struct spdk_nvmf_rdma_transport		*rtransport;
2865 
2866 	port = event->id->context;
2867 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2868 
2869 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2870 
2871 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2872 
2873 	rdma_ack_cm_event(event);
2874 
2875 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2876 		;
2877 	}
2878 }
2879 
2880 static void
2881 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2882 {
2883 	struct spdk_nvmf_rdma_transport *rtransport;
2884 	struct rdma_cm_event		*event;
2885 	int				rc;
2886 	bool				event_acked;
2887 
2888 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2889 
2890 	if (rtransport->event_channel == NULL) {
2891 		return;
2892 	}
2893 
2894 	while (1) {
2895 		event_acked = false;
2896 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2897 		if (rc) {
2898 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2899 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2900 			}
2901 			break;
2902 		}
2903 
2904 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2905 
2906 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2907 
2908 		switch (event->event) {
2909 		case RDMA_CM_EVENT_ADDR_RESOLVED:
2910 		case RDMA_CM_EVENT_ADDR_ERROR:
2911 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
2912 		case RDMA_CM_EVENT_ROUTE_ERROR:
2913 			/* No action required. The target never attempts to resolve routes. */
2914 			break;
2915 		case RDMA_CM_EVENT_CONNECT_REQUEST:
2916 			rc = nvmf_rdma_connect(transport, event);
2917 			if (rc < 0) {
2918 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2919 				break;
2920 			}
2921 			break;
2922 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
2923 			/* The target never initiates a new connection. So this will not occur. */
2924 			break;
2925 		case RDMA_CM_EVENT_CONNECT_ERROR:
2926 			/* Can this happen? The docs say it can, but not sure what causes it. */
2927 			break;
2928 		case RDMA_CM_EVENT_UNREACHABLE:
2929 		case RDMA_CM_EVENT_REJECTED:
2930 			/* These only occur on the client side. */
2931 			break;
2932 		case RDMA_CM_EVENT_ESTABLISHED:
2933 			/* TODO: Should we be waiting for this event anywhere? */
2934 			break;
2935 		case RDMA_CM_EVENT_DISCONNECTED:
2936 			rc = nvmf_rdma_disconnect(event);
2937 			if (rc < 0) {
2938 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2939 				break;
2940 			}
2941 			break;
2942 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
2943 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
2944 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
2945 			 * Once these events are sent to SPDK, we should release all IB resources and
2946 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
2947 			 * ibv_destory* functions to release user space memory allocated by IB. All kernel
2948 			 * resources are already cleaned. */
2949 			if (event->id->qp) {
2950 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
2951 				 * corresponding qpair. Otherwise the event refers to a listening device */
2952 				rc = nvmf_rdma_disconnect(event);
2953 				if (rc < 0) {
2954 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2955 					break;
2956 				}
2957 			} else {
2958 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
2959 				event_acked = true;
2960 			}
2961 			break;
2962 		case RDMA_CM_EVENT_MULTICAST_JOIN:
2963 		case RDMA_CM_EVENT_MULTICAST_ERROR:
2964 			/* Multicast is not used */
2965 			break;
2966 		case RDMA_CM_EVENT_ADDR_CHANGE:
2967 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
2968 			break;
2969 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2970 			/* For now, do nothing. The target never re-uses queue pairs. */
2971 			break;
2972 		default:
2973 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2974 			break;
2975 		}
2976 		if (!event_acked) {
2977 			rdma_ack_cm_event(event);
2978 		}
2979 	}
2980 }
2981 
2982 static void
2983 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
2984 {
2985 	rqpair->last_wqe_reached = true;
2986 	nvmf_rdma_destroy_drained_qpair(rqpair);
2987 }
2988 
2989 static void
2990 nvmf_rdma_qpair_process_ibv_event(void *ctx)
2991 {
2992 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
2993 
2994 	if (event_ctx->rqpair) {
2995 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
2996 		if (event_ctx->cb_fn) {
2997 			event_ctx->cb_fn(event_ctx->rqpair);
2998 		}
2999 	}
3000 	free(event_ctx);
3001 }
3002 
3003 static int
3004 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3005 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3006 {
3007 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3008 	struct spdk_thread *thr = NULL;
3009 	int rc;
3010 
3011 	if (rqpair->qpair.group) {
3012 		thr = rqpair->qpair.group->thread;
3013 	} else if (rqpair->destruct_channel) {
3014 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3015 	}
3016 
3017 	if (!thr) {
3018 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3019 		return -EINVAL;
3020 	}
3021 
3022 	ctx = calloc(1, sizeof(*ctx));
3023 	if (!ctx) {
3024 		return -ENOMEM;
3025 	}
3026 
3027 	ctx->rqpair = rqpair;
3028 	ctx->cb_fn = fn;
3029 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3030 
3031 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3032 	if (rc) {
3033 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3034 		free(ctx);
3035 	}
3036 
3037 	return rc;
3038 }
3039 
3040 static int
3041 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3042 {
3043 	int				rc;
3044 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3045 	struct ibv_async_event		event;
3046 
3047 	rc = ibv_get_async_event(device->context, &event);
3048 
3049 	if (rc) {
3050 		/* In non-blocking mode -1 means there are no events available */
3051 		return rc;
3052 	}
3053 
3054 	switch (event.event_type) {
3055 	case IBV_EVENT_QP_FATAL:
3056 		rqpair = event.element.qp->qp_context;
3057 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3058 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3059 				  (uintptr_t)rqpair->cm_id, event.event_type);
3060 		nvmf_rdma_update_ibv_state(rqpair);
3061 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3062 		break;
3063 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3064 		/* This event only occurs for shared receive queues. */
3065 		rqpair = event.element.qp->qp_context;
3066 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3067 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3068 		if (rc) {
3069 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3070 			rqpair->last_wqe_reached = true;
3071 		}
3072 		break;
3073 	case IBV_EVENT_SQ_DRAINED:
3074 		/* This event occurs frequently in both error and non-error states.
3075 		 * Check if the qpair is in an error state before sending a message. */
3076 		rqpair = event.element.qp->qp_context;
3077 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3078 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3079 				  (uintptr_t)rqpair->cm_id, event.event_type);
3080 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3081 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3082 		}
3083 		break;
3084 	case IBV_EVENT_QP_REQ_ERR:
3085 	case IBV_EVENT_QP_ACCESS_ERR:
3086 	case IBV_EVENT_COMM_EST:
3087 	case IBV_EVENT_PATH_MIG:
3088 	case IBV_EVENT_PATH_MIG_ERR:
3089 		SPDK_NOTICELOG("Async event: %s\n",
3090 			       ibv_event_type_str(event.event_type));
3091 		rqpair = event.element.qp->qp_context;
3092 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3093 				  (uintptr_t)rqpair->cm_id, event.event_type);
3094 		nvmf_rdma_update_ibv_state(rqpair);
3095 		break;
3096 	case IBV_EVENT_CQ_ERR:
3097 	case IBV_EVENT_DEVICE_FATAL:
3098 	case IBV_EVENT_PORT_ACTIVE:
3099 	case IBV_EVENT_PORT_ERR:
3100 	case IBV_EVENT_LID_CHANGE:
3101 	case IBV_EVENT_PKEY_CHANGE:
3102 	case IBV_EVENT_SM_CHANGE:
3103 	case IBV_EVENT_SRQ_ERR:
3104 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3105 	case IBV_EVENT_CLIENT_REREGISTER:
3106 	case IBV_EVENT_GID_CHANGE:
3107 	default:
3108 		SPDK_NOTICELOG("Async event: %s\n",
3109 			       ibv_event_type_str(event.event_type));
3110 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3111 		break;
3112 	}
3113 	ibv_ack_async_event(&event);
3114 
3115 	return 0;
3116 }
3117 
3118 static void
3119 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3120 {
3121 	int rc = 0;
3122 	uint32_t i = 0;
3123 
3124 	for (i = 0; i < max_events; i++) {
3125 		rc = nvmf_process_ib_event(device);
3126 		if (rc) {
3127 			break;
3128 		}
3129 	}
3130 
3131 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3132 }
3133 
3134 static uint32_t
3135 nvmf_rdma_accept(struct spdk_nvmf_transport *transport)
3136 {
3137 	int	nfds, i = 0;
3138 	struct spdk_nvmf_rdma_transport *rtransport;
3139 	struct spdk_nvmf_rdma_device *device, *tmp;
3140 	uint32_t count;
3141 
3142 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3143 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3144 
3145 	if (nfds <= 0) {
3146 		return 0;
3147 	}
3148 
3149 	/* The first poll descriptor is RDMA CM event */
3150 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3151 		nvmf_process_cm_event(transport);
3152 		nfds--;
3153 	}
3154 
3155 	if (nfds == 0) {
3156 		return count;
3157 	}
3158 
3159 	/* Second and subsequent poll descriptors are IB async events */
3160 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3161 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3162 			nvmf_process_ib_events(device, 32);
3163 			nfds--;
3164 		}
3165 	}
3166 	/* check all flagged fd's have been served */
3167 	assert(nfds == 0);
3168 
3169 	return count;
3170 }
3171 
3172 static void
3173 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3174 		     struct spdk_nvmf_ctrlr_data *cdata)
3175 {
3176 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3177 
3178 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3179 	since in-capsule data only works with NVME drives that support SGL memory layout */
3180 	if (transport->opts.dif_insert_or_strip) {
3181 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3182 	}
3183 }
3184 
3185 static void
3186 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3187 		   struct spdk_nvme_transport_id *trid,
3188 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3189 {
3190 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3191 	entry->adrfam = trid->adrfam;
3192 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3193 
3194 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3195 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3196 
3197 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3198 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3199 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3200 }
3201 
3202 static void
3203 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3204 
3205 static struct spdk_nvmf_transport_poll_group *
3206 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3207 {
3208 	struct spdk_nvmf_rdma_transport		*rtransport;
3209 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3210 	struct spdk_nvmf_rdma_poller		*poller;
3211 	struct spdk_nvmf_rdma_device		*device;
3212 	struct ibv_srq_init_attr		srq_init_attr;
3213 	struct spdk_nvmf_rdma_resource_opts	opts;
3214 	int					num_cqe;
3215 
3216 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3217 
3218 	rgroup = calloc(1, sizeof(*rgroup));
3219 	if (!rgroup) {
3220 		return NULL;
3221 	}
3222 
3223 	TAILQ_INIT(&rgroup->pollers);
3224 
3225 	pthread_mutex_lock(&rtransport->lock);
3226 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3227 		poller = calloc(1, sizeof(*poller));
3228 		if (!poller) {
3229 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3230 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3231 			pthread_mutex_unlock(&rtransport->lock);
3232 			return NULL;
3233 		}
3234 
3235 		poller->device = device;
3236 		poller->group = rgroup;
3237 
3238 		TAILQ_INIT(&poller->qpairs);
3239 		STAILQ_INIT(&poller->qpairs_pending_send);
3240 		STAILQ_INIT(&poller->qpairs_pending_recv);
3241 
3242 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3243 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3244 			poller->max_srq_depth = rtransport->rdma_opts.max_srq_depth;
3245 
3246 			device->num_srq++;
3247 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3248 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3249 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3250 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3251 			if (!poller->srq) {
3252 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3253 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3254 				pthread_mutex_unlock(&rtransport->lock);
3255 				return NULL;
3256 			}
3257 
3258 			opts.qp = poller->srq;
3259 			opts.pd = device->pd;
3260 			opts.qpair = NULL;
3261 			opts.shared = true;
3262 			opts.max_queue_depth = poller->max_srq_depth;
3263 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3264 
3265 			poller->resources = nvmf_rdma_resources_create(&opts);
3266 			if (!poller->resources) {
3267 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3268 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3269 				pthread_mutex_unlock(&rtransport->lock);
3270 				return NULL;
3271 			}
3272 		}
3273 
3274 		/*
3275 		 * When using an srq, we can limit the completion queue at startup.
3276 		 * The following formula represents the calculation:
3277 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3278 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3279 		 */
3280 		if (poller->srq) {
3281 			num_cqe = poller->max_srq_depth * 3;
3282 		} else {
3283 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3284 		}
3285 
3286 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3287 		if (!poller->cq) {
3288 			SPDK_ERRLOG("Unable to create completion queue\n");
3289 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3290 			pthread_mutex_unlock(&rtransport->lock);
3291 			return NULL;
3292 		}
3293 		poller->num_cqe = num_cqe;
3294 	}
3295 
3296 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3297 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3298 		rtransport->conn_sched.next_admin_pg = rgroup;
3299 		rtransport->conn_sched.next_io_pg = rgroup;
3300 	}
3301 
3302 	pthread_mutex_unlock(&rtransport->lock);
3303 	return &rgroup->group;
3304 }
3305 
3306 static struct spdk_nvmf_transport_poll_group *
3307 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3308 {
3309 	struct spdk_nvmf_rdma_transport *rtransport;
3310 	struct spdk_nvmf_rdma_poll_group **pg;
3311 	struct spdk_nvmf_transport_poll_group *result;
3312 
3313 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3314 
3315 	pthread_mutex_lock(&rtransport->lock);
3316 
3317 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3318 		pthread_mutex_unlock(&rtransport->lock);
3319 		return NULL;
3320 	}
3321 
3322 	if (qpair->qid == 0) {
3323 		pg = &rtransport->conn_sched.next_admin_pg;
3324 	} else {
3325 		pg = &rtransport->conn_sched.next_io_pg;
3326 	}
3327 
3328 	assert(*pg != NULL);
3329 
3330 	result = &(*pg)->group;
3331 
3332 	*pg = TAILQ_NEXT(*pg, link);
3333 	if (*pg == NULL) {
3334 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3335 	}
3336 
3337 	pthread_mutex_unlock(&rtransport->lock);
3338 
3339 	return result;
3340 }
3341 
3342 static void
3343 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3344 {
3345 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3346 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3347 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3348 	struct spdk_nvmf_rdma_transport		*rtransport;
3349 
3350 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3351 	if (!rgroup) {
3352 		return;
3353 	}
3354 
3355 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3356 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3357 
3358 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3359 			nvmf_rdma_qpair_destroy(qpair);
3360 		}
3361 
3362 		if (poller->srq) {
3363 			if (poller->resources) {
3364 				nvmf_rdma_resources_destroy(poller->resources);
3365 			}
3366 			ibv_destroy_srq(poller->srq);
3367 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3368 		}
3369 
3370 		if (poller->cq) {
3371 			ibv_destroy_cq(poller->cq);
3372 		}
3373 
3374 		free(poller);
3375 	}
3376 
3377 	if (rgroup->group.transport == NULL) {
3378 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3379 		 * calls this function directly in a failure path. */
3380 		free(rgroup);
3381 		return;
3382 	}
3383 
3384 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3385 
3386 	pthread_mutex_lock(&rtransport->lock);
3387 	next_rgroup = TAILQ_NEXT(rgroup, link);
3388 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3389 	if (next_rgroup == NULL) {
3390 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3391 	}
3392 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3393 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3394 	}
3395 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3396 		rtransport->conn_sched.next_io_pg = next_rgroup;
3397 	}
3398 	pthread_mutex_unlock(&rtransport->lock);
3399 
3400 	free(rgroup);
3401 }
3402 
3403 static void
3404 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3405 {
3406 	if (rqpair->cm_id != NULL) {
3407 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3408 	}
3409 }
3410 
3411 static int
3412 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3413 			 struct spdk_nvmf_qpair *qpair)
3414 {
3415 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3416 	struct spdk_nvmf_rdma_qpair		*rqpair;
3417 	struct spdk_nvmf_rdma_device		*device;
3418 	struct spdk_nvmf_rdma_poller		*poller;
3419 	int					rc;
3420 
3421 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3422 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3423 
3424 	device = rqpair->device;
3425 
3426 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3427 		if (poller->device == device) {
3428 			break;
3429 		}
3430 	}
3431 
3432 	if (!poller) {
3433 		SPDK_ERRLOG("No poller found for device.\n");
3434 		return -1;
3435 	}
3436 
3437 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3438 	rqpair->poller = poller;
3439 	rqpair->srq = rqpair->poller->srq;
3440 
3441 	rc = nvmf_rdma_qpair_initialize(qpair);
3442 	if (rc < 0) {
3443 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3444 		return -1;
3445 	}
3446 
3447 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3448 	if (rc) {
3449 		/* Try to reject, but we probably can't */
3450 		nvmf_rdma_qpair_reject_connection(rqpair);
3451 		return -1;
3452 	}
3453 
3454 	nvmf_rdma_update_ibv_state(rqpair);
3455 
3456 	return 0;
3457 }
3458 
3459 static int
3460 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3461 			    struct spdk_nvmf_qpair *qpair)
3462 {
3463 	struct spdk_nvmf_rdma_qpair		*rqpair;
3464 
3465 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3466 	assert(group->transport->tgt != NULL);
3467 
3468 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3469 
3470 	if (!rqpair->destruct_channel) {
3471 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3472 		return 0;
3473 	}
3474 
3475 	/* Sanity check that we get io_channel on the correct thread */
3476 	if (qpair->group) {
3477 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3478 	}
3479 
3480 	return 0;
3481 }
3482 
3483 static int
3484 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3485 {
3486 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3487 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3488 			struct spdk_nvmf_rdma_transport, transport);
3489 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3490 					      struct spdk_nvmf_rdma_qpair, qpair);
3491 
3492 	/*
3493 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3494 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3495 	 * starved of RECV structures.
3496 	 */
3497 	if (rqpair->srq && rdma_req->recv) {
3498 		int rc;
3499 		struct ibv_recv_wr *bad_recv_wr;
3500 
3501 		rc = ibv_post_srq_recv(rqpair->srq, &rdma_req->recv->wr, &bad_recv_wr);
3502 		if (rc) {
3503 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3504 		}
3505 	}
3506 
3507 	_nvmf_rdma_request_free(rdma_req, rtransport);
3508 	return 0;
3509 }
3510 
3511 static int
3512 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3513 {
3514 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3515 			struct spdk_nvmf_rdma_transport, transport);
3516 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3517 			struct spdk_nvmf_rdma_request, req);
3518 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3519 			struct spdk_nvmf_rdma_qpair, qpair);
3520 
3521 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3522 		/* The connection is alive, so process the request as normal */
3523 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3524 	} else {
3525 		/* The connection is dead. Move the request directly to the completed state. */
3526 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3527 	}
3528 
3529 	nvmf_rdma_request_process(rtransport, rdma_req);
3530 
3531 	return 0;
3532 }
3533 
3534 static void
3535 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
3536 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
3537 {
3538 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3539 
3540 	rqpair->to_close = true;
3541 
3542 	/* This happens only when the qpair is disconnected before
3543 	 * it is added to the poll group. Since there is no poll group,
3544 	 * the RDMA qp has not been initialized yet and the RDMA CM
3545 	 * event has not yet been acknowledged, so we need to reject it.
3546 	 */
3547 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3548 		nvmf_rdma_qpair_reject_connection(rqpair);
3549 		nvmf_rdma_qpair_destroy(rqpair);
3550 		return;
3551 	}
3552 
3553 	if (rqpair->rdma_qp) {
3554 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3555 	}
3556 
3557 	nvmf_rdma_destroy_drained_qpair(rqpair);
3558 
3559 	if (cb_fn) {
3560 		cb_fn(cb_arg);
3561 	}
3562 }
3563 
3564 static struct spdk_nvmf_rdma_qpair *
3565 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3566 {
3567 	struct spdk_nvmf_rdma_qpair *rqpair;
3568 	/* @todo: improve QP search */
3569 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3570 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3571 			return rqpair;
3572 		}
3573 	}
3574 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3575 	return NULL;
3576 }
3577 
3578 #ifdef DEBUG
3579 static int
3580 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3581 {
3582 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3583 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3584 }
3585 #endif
3586 
3587 static void
3588 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3589 			   int rc)
3590 {
3591 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3592 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3593 
3594 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3595 	while (bad_recv_wr != NULL) {
3596 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3597 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3598 
3599 		rdma_recv->qpair->current_recv_depth++;
3600 		bad_recv_wr = bad_recv_wr->next;
3601 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3602 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3603 	}
3604 }
3605 
3606 static void
3607 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3608 {
3609 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3610 	while (bad_recv_wr != NULL) {
3611 		bad_recv_wr = bad_recv_wr->next;
3612 		rqpair->current_recv_depth++;
3613 	}
3614 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3615 }
3616 
3617 static void
3618 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3619 		     struct spdk_nvmf_rdma_poller *rpoller)
3620 {
3621 	struct spdk_nvmf_rdma_qpair	*rqpair;
3622 	struct ibv_recv_wr		*bad_recv_wr;
3623 	int				rc;
3624 
3625 	if (rpoller->srq) {
3626 		if (rpoller->resources->recvs_to_post.first != NULL) {
3627 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3628 			if (rc) {
3629 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3630 			}
3631 			rpoller->resources->recvs_to_post.first = NULL;
3632 			rpoller->resources->recvs_to_post.last = NULL;
3633 		}
3634 	} else {
3635 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3636 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3637 			assert(rqpair->resources->recvs_to_post.first != NULL);
3638 			rc = ibv_post_recv(rqpair->rdma_qp->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3639 			if (rc) {
3640 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3641 			}
3642 			rqpair->resources->recvs_to_post.first = NULL;
3643 			rqpair->resources->recvs_to_post.last = NULL;
3644 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3645 		}
3646 	}
3647 }
3648 
3649 static void
3650 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3651 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3652 {
3653 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3654 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3655 
3656 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3657 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3658 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3659 		assert(rqpair->current_send_depth > 0);
3660 		rqpair->current_send_depth--;
3661 		switch (bad_rdma_wr->type) {
3662 		case RDMA_WR_TYPE_DATA:
3663 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3664 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3665 				assert(rqpair->current_read_depth > 0);
3666 				rqpair->current_read_depth--;
3667 			}
3668 			break;
3669 		case RDMA_WR_TYPE_SEND:
3670 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3671 			break;
3672 		default:
3673 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3674 			prev_rdma_req = cur_rdma_req;
3675 			continue;
3676 		}
3677 
3678 		if (prev_rdma_req == cur_rdma_req) {
3679 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3680 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3681 			continue;
3682 		}
3683 
3684 		switch (cur_rdma_req->state) {
3685 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3686 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3687 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3688 			break;
3689 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3690 		case RDMA_REQUEST_STATE_COMPLETING:
3691 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3692 			break;
3693 		default:
3694 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3695 				    cur_rdma_req->state, rqpair);
3696 			continue;
3697 		}
3698 
3699 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3700 		prev_rdma_req = cur_rdma_req;
3701 	}
3702 
3703 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3704 		/* Disconnect the connection. */
3705 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3706 	}
3707 
3708 }
3709 
3710 static void
3711 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3712 		     struct spdk_nvmf_rdma_poller *rpoller)
3713 {
3714 	struct spdk_nvmf_rdma_qpair	*rqpair;
3715 	struct ibv_send_wr		*bad_wr = NULL;
3716 	int				rc;
3717 
3718 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3719 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3720 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3721 
3722 		/* bad wr always points to the first wr that failed. */
3723 		if (rc) {
3724 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3725 		}
3726 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3727 	}
3728 }
3729 
3730 static const char *
3731 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3732 {
3733 	switch (wr_type) {
3734 	case RDMA_WR_TYPE_RECV:
3735 		return "RECV";
3736 	case RDMA_WR_TYPE_SEND:
3737 		return "SEND";
3738 	case RDMA_WR_TYPE_DATA:
3739 		return "DATA";
3740 	default:
3741 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3742 		SPDK_UNREACHABLE();
3743 	}
3744 }
3745 
3746 static inline void
3747 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3748 {
3749 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3750 
3751 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3752 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3753 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3754 		SPDK_DEBUGLOG(rdma,
3755 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3756 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3757 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3758 	} else {
3759 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3760 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3761 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3762 	}
3763 }
3764 
3765 static int
3766 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3767 		      struct spdk_nvmf_rdma_poller *rpoller)
3768 {
3769 	struct ibv_wc wc[32];
3770 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3771 	struct spdk_nvmf_rdma_request	*rdma_req;
3772 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3773 	struct spdk_nvmf_rdma_qpair	*rqpair;
3774 	int reaped, i;
3775 	int count = 0;
3776 	bool error = false;
3777 	uint64_t poll_tsc = spdk_get_ticks();
3778 
3779 	/* Poll for completing operations. */
3780 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3781 	if (reaped < 0) {
3782 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3783 			    errno, spdk_strerror(errno));
3784 		return -1;
3785 	}
3786 
3787 	rpoller->stat.polls++;
3788 	rpoller->stat.completions += reaped;
3789 
3790 	for (i = 0; i < reaped; i++) {
3791 
3792 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3793 
3794 		switch (rdma_wr->type) {
3795 		case RDMA_WR_TYPE_SEND:
3796 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3797 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3798 
3799 			if (!wc[i].status) {
3800 				count++;
3801 				assert(wc[i].opcode == IBV_WC_SEND);
3802 				assert(nvmf_rdma_req_is_completing(rdma_req));
3803 			}
3804 
3805 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3806 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3807 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3808 			rdma_req->num_outstanding_data_wr = 0;
3809 
3810 			nvmf_rdma_request_process(rtransport, rdma_req);
3811 			break;
3812 		case RDMA_WR_TYPE_RECV:
3813 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3814 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3815 			if (rpoller->srq != NULL) {
3816 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3817 				/* It is possible that there are still some completions for destroyed QP
3818 				 * associated with SRQ. We just ignore these late completions and re-post
3819 				 * receive WRs back to SRQ.
3820 				 */
3821 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3822 					struct ibv_recv_wr *bad_wr;
3823 					int rc;
3824 
3825 					rdma_recv->wr.next = NULL;
3826 					rc = ibv_post_srq_recv(rpoller->srq,
3827 							       &rdma_recv->wr,
3828 							       &bad_wr);
3829 					if (rc) {
3830 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3831 					}
3832 					continue;
3833 				}
3834 			}
3835 			rqpair = rdma_recv->qpair;
3836 
3837 			assert(rqpair != NULL);
3838 			if (!wc[i].status) {
3839 				assert(wc[i].opcode == IBV_WC_RECV);
3840 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3841 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3842 					break;
3843 				}
3844 			}
3845 
3846 			rdma_recv->wr.next = NULL;
3847 			rqpair->current_recv_depth++;
3848 			rdma_recv->receive_tsc = poll_tsc;
3849 			rpoller->stat.requests++;
3850 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3851 			break;
3852 		case RDMA_WR_TYPE_DATA:
3853 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3854 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3855 
3856 			assert(rdma_req->num_outstanding_data_wr > 0);
3857 
3858 			rqpair->current_send_depth--;
3859 			rdma_req->num_outstanding_data_wr--;
3860 			if (!wc[i].status) {
3861 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3862 				rqpair->current_read_depth--;
3863 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3864 				if (rdma_req->num_outstanding_data_wr == 0) {
3865 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3866 					nvmf_rdma_request_process(rtransport, rdma_req);
3867 				}
3868 			} else {
3869 				/* If the data transfer fails still force the queue into the error state,
3870 				 * if we were performing an RDMA_READ, we need to force the request into a
3871 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3872 				 * case, we should wait for the SEND to complete. */
3873 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3874 					rqpair->current_read_depth--;
3875 					if (rdma_req->num_outstanding_data_wr == 0) {
3876 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3877 					}
3878 				}
3879 			}
3880 			break;
3881 		default:
3882 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3883 			continue;
3884 		}
3885 
3886 		/* Handle error conditions */
3887 		if (wc[i].status) {
3888 			nvmf_rdma_update_ibv_state(rqpair);
3889 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
3890 
3891 			error = true;
3892 
3893 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3894 				/* Disconnect the connection. */
3895 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3896 			} else {
3897 				nvmf_rdma_destroy_drained_qpair(rqpair);
3898 			}
3899 			continue;
3900 		}
3901 
3902 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3903 
3904 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3905 			nvmf_rdma_destroy_drained_qpair(rqpair);
3906 		}
3907 	}
3908 
3909 	if (error == true) {
3910 		return -1;
3911 	}
3912 
3913 	/* submit outstanding work requests. */
3914 	_poller_submit_recvs(rtransport, rpoller);
3915 	_poller_submit_sends(rtransport, rpoller);
3916 
3917 	return count;
3918 }
3919 
3920 static int
3921 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3922 {
3923 	struct spdk_nvmf_rdma_transport *rtransport;
3924 	struct spdk_nvmf_rdma_poll_group *rgroup;
3925 	struct spdk_nvmf_rdma_poller	*rpoller;
3926 	int				count, rc;
3927 
3928 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3929 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3930 
3931 	count = 0;
3932 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3933 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
3934 		if (rc < 0) {
3935 			return rc;
3936 		}
3937 		count += rc;
3938 	}
3939 
3940 	return count;
3941 }
3942 
3943 static int
3944 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3945 			  struct spdk_nvme_transport_id *trid,
3946 			  bool peer)
3947 {
3948 	struct sockaddr *saddr;
3949 	uint16_t port;
3950 
3951 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
3952 
3953 	if (peer) {
3954 		saddr = rdma_get_peer_addr(id);
3955 	} else {
3956 		saddr = rdma_get_local_addr(id);
3957 	}
3958 	switch (saddr->sa_family) {
3959 	case AF_INET: {
3960 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3961 
3962 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3963 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3964 			  trid->traddr, sizeof(trid->traddr));
3965 		if (peer) {
3966 			port = ntohs(rdma_get_dst_port(id));
3967 		} else {
3968 			port = ntohs(rdma_get_src_port(id));
3969 		}
3970 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3971 		break;
3972 	}
3973 	case AF_INET6: {
3974 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
3975 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
3976 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
3977 			  trid->traddr, sizeof(trid->traddr));
3978 		if (peer) {
3979 			port = ntohs(rdma_get_dst_port(id));
3980 		} else {
3981 			port = ntohs(rdma_get_src_port(id));
3982 		}
3983 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3984 		break;
3985 	}
3986 	default:
3987 		return -1;
3988 
3989 	}
3990 
3991 	return 0;
3992 }
3993 
3994 static int
3995 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3996 			      struct spdk_nvme_transport_id *trid)
3997 {
3998 	struct spdk_nvmf_rdma_qpair	*rqpair;
3999 
4000 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4001 
4002 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4003 }
4004 
4005 static int
4006 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4007 			       struct spdk_nvme_transport_id *trid)
4008 {
4009 	struct spdk_nvmf_rdma_qpair	*rqpair;
4010 
4011 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4012 
4013 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4014 }
4015 
4016 static int
4017 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4018 				struct spdk_nvme_transport_id *trid)
4019 {
4020 	struct spdk_nvmf_rdma_qpair	*rqpair;
4021 
4022 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4023 
4024 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4025 }
4026 
4027 void
4028 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4029 {
4030 	g_nvmf_hooks = *hooks;
4031 }
4032 
4033 static void
4034 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4035 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4036 {
4037 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4038 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4039 
4040 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4041 
4042 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4043 }
4044 
4045 static int
4046 _nvmf_rdma_qpair_abort_request(void *ctx)
4047 {
4048 	struct spdk_nvmf_request *req = ctx;
4049 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4050 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4051 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4052 					      struct spdk_nvmf_rdma_qpair, qpair);
4053 	int rc;
4054 
4055 	spdk_poller_unregister(&req->poller);
4056 
4057 	switch (rdma_req_to_abort->state) {
4058 	case RDMA_REQUEST_STATE_EXECUTING:
4059 		rc = nvmf_ctrlr_abort_request(req);
4060 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4061 			return SPDK_POLLER_BUSY;
4062 		}
4063 		break;
4064 
4065 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4066 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4067 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4068 
4069 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4070 		break;
4071 
4072 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4073 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4074 			      spdk_nvmf_rdma_request, state_link);
4075 
4076 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4077 		break;
4078 
4079 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4080 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4081 			      spdk_nvmf_rdma_request, state_link);
4082 
4083 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4084 		break;
4085 
4086 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4087 		if (spdk_get_ticks() < req->timeout_tsc) {
4088 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4089 			return SPDK_POLLER_BUSY;
4090 		}
4091 		break;
4092 
4093 	default:
4094 		break;
4095 	}
4096 
4097 	spdk_nvmf_request_complete(req);
4098 	return SPDK_POLLER_BUSY;
4099 }
4100 
4101 static void
4102 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4103 			      struct spdk_nvmf_request *req)
4104 {
4105 	struct spdk_nvmf_rdma_qpair *rqpair;
4106 	struct spdk_nvmf_rdma_transport *rtransport;
4107 	struct spdk_nvmf_transport *transport;
4108 	uint16_t cid;
4109 	uint32_t i;
4110 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL;
4111 
4112 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4113 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4114 	transport = &rtransport->transport;
4115 
4116 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4117 
4118 	for (i = 0; i < rqpair->max_queue_depth; i++) {
4119 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE &&
4120 		    rqpair->resources->reqs[i].req.cmd->nvme_cmd.cid == cid) {
4121 			rdma_req_to_abort = &rqpair->resources->reqs[i];
4122 			break;
4123 		}
4124 	}
4125 
4126 	if (rdma_req_to_abort == NULL) {
4127 		spdk_nvmf_request_complete(req);
4128 		return;
4129 	}
4130 
4131 	req->req_to_abort = &rdma_req_to_abort->req;
4132 	req->timeout_tsc = spdk_get_ticks() +
4133 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4134 	req->poller = NULL;
4135 
4136 	_nvmf_rdma_qpair_abort_request(req);
4137 }
4138 
4139 static int
4140 nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
4141 			      struct spdk_nvmf_transport_poll_group_stat **stat)
4142 {
4143 	struct spdk_io_channel *ch;
4144 	struct spdk_nvmf_poll_group *group;
4145 	struct spdk_nvmf_transport_poll_group *tgroup;
4146 	struct spdk_nvmf_rdma_poll_group *rgroup;
4147 	struct spdk_nvmf_rdma_poller *rpoller;
4148 	struct spdk_nvmf_rdma_device_stat *device_stat;
4149 	uint64_t num_devices = 0;
4150 
4151 	if (tgt == NULL || stat == NULL) {
4152 		return -EINVAL;
4153 	}
4154 
4155 	ch = spdk_get_io_channel(tgt);
4156 	group = spdk_io_channel_get_ctx(ch);;
4157 	spdk_put_io_channel(ch);
4158 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4159 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4160 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4161 			if (!*stat) {
4162 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4163 				return -ENOMEM;
4164 			}
4165 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4166 
4167 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4168 			/* Count devices to allocate enough memory */
4169 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4170 				++num_devices;
4171 			}
4172 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4173 			if (!(*stat)->rdma.devices) {
4174 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4175 				free(*stat);
4176 				return -ENOMEM;
4177 			}
4178 
4179 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4180 			(*stat)->rdma.num_devices = num_devices;
4181 			num_devices = 0;
4182 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4183 				device_stat = &(*stat)->rdma.devices[num_devices++];
4184 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4185 				device_stat->polls = rpoller->stat.polls;
4186 				device_stat->completions = rpoller->stat.completions;
4187 				device_stat->requests = rpoller->stat.requests;
4188 				device_stat->request_latency = rpoller->stat.request_latency;
4189 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4190 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4191 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4192 			}
4193 			return 0;
4194 		}
4195 	}
4196 	return -ENOENT;
4197 }
4198 
4199 static void
4200 nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4201 {
4202 	if (stat) {
4203 		free(stat->rdma.devices);
4204 	}
4205 	free(stat);
4206 }
4207 
4208 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4209 	.name = "RDMA",
4210 	.type = SPDK_NVME_TRANSPORT_RDMA,
4211 	.opts_init = nvmf_rdma_opts_init,
4212 	.create = nvmf_rdma_create,
4213 	.dump_opts = nvmf_rdma_dump_opts,
4214 	.destroy = nvmf_rdma_destroy,
4215 
4216 	.listen = nvmf_rdma_listen,
4217 	.stop_listen = nvmf_rdma_stop_listen,
4218 	.accept = nvmf_rdma_accept,
4219 	.cdata_init = nvmf_rdma_cdata_init,
4220 
4221 	.listener_discover = nvmf_rdma_discover,
4222 
4223 	.poll_group_create = nvmf_rdma_poll_group_create,
4224 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4225 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4226 	.poll_group_add = nvmf_rdma_poll_group_add,
4227 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4228 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4229 
4230 	.req_free = nvmf_rdma_request_free,
4231 	.req_complete = nvmf_rdma_request_complete,
4232 
4233 	.qpair_fini = nvmf_rdma_close_qpair,
4234 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4235 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4236 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4237 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4238 
4239 	.poll_group_get_stat = nvmf_rdma_poll_group_get_stat,
4240 	.poll_group_free_stat = nvmf_rdma_poll_group_free_stat,
4241 };
4242 
4243 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4244 SPDK_LOG_REGISTER_COMPONENT(rdma)
4245