xref: /spdk/lib/nvmf/rdma.c (revision d4d015a572e1af7b2818e44218c1e661a61545ec)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2016 Intel Corporation. All rights reserved.
3  *   Copyright (c) 2019-2021 Mellanox Technologies LTD. All rights reserved.
4  *   Copyright (c) 2021-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
5  */
6 
7 #include "spdk/stdinc.h"
8 
9 #include "spdk/config.h"
10 #include "spdk/thread.h"
11 #include "spdk/likely.h"
12 #include "spdk/nvmf_transport.h"
13 #include "spdk/string.h"
14 #include "spdk/trace.h"
15 #include "spdk/tree.h"
16 #include "spdk/util.h"
17 
18 #include "spdk_internal/assert.h"
19 #include "spdk/log.h"
20 #include "spdk_internal/rdma_provider.h"
21 #include "spdk_internal/rdma_utils.h"
22 
23 #include "nvmf_internal.h"
24 #include "transport.h"
25 
26 #include "spdk_internal/trace_defs.h"
27 
28 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
29 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
30 
31 /*
32  RDMA Connection Resource Defaults
33  */
34 #define NVMF_DEFAULT_MSDBD		16
35 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
36 #define NVMF_DEFAULT_RSP_SGE		1
37 #define NVMF_DEFAULT_RX_SGE		2
38 
39 #define NVMF_RDMA_MAX_EVENTS_PER_POLL	32
40 
41 SPDK_STATIC_ASSERT(NVMF_DEFAULT_MSDBD <= SPDK_NVMF_MAX_SGL_ENTRIES,
42 		   "MSDBD must not exceed SPDK_NVMF_MAX_SGL_ENTRIES");
43 
44 /* The RDMA completion queue size */
45 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
46 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
47 
48 enum spdk_nvmf_rdma_request_state {
49 	/* The request is not currently in use */
50 	RDMA_REQUEST_STATE_FREE = 0,
51 
52 	/* Initial state when request first received */
53 	RDMA_REQUEST_STATE_NEW,
54 
55 	/* The request is queued until a data buffer is available. */
56 	RDMA_REQUEST_STATE_NEED_BUFFER,
57 
58 	/* The request is waiting on RDMA queue depth availability
59 	 * to transfer data from the host to the controller.
60 	 */
61 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
62 
63 	/* The request is currently transferring data from the host to the controller. */
64 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
65 
66 	/* The request is ready to execute at the block device */
67 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
68 
69 	/* The request is currently executing at the block device */
70 	RDMA_REQUEST_STATE_EXECUTING,
71 
72 	/* The request finished executing at the block device */
73 	RDMA_REQUEST_STATE_EXECUTED,
74 
75 	/* The request is waiting on RDMA queue depth availability
76 	 * to transfer data from the controller to the host.
77 	 */
78 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
79 
80 	/* The request is waiting on RDMA queue depth availability
81 	 * to send response to the host.
82 	 */
83 	RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING,
84 
85 	/* The request is ready to send a completion */
86 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
87 
88 	/* The request is currently transferring data from the controller to the host. */
89 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
90 
91 	/* The request currently has an outstanding completion without an
92 	 * associated data transfer.
93 	 */
94 	RDMA_REQUEST_STATE_COMPLETING,
95 
96 	/* The request completed and can be marked free. */
97 	RDMA_REQUEST_STATE_COMPLETED,
98 
99 	/* Terminator */
100 	RDMA_REQUEST_NUM_STATES,
101 };
102 
103 static void
104 nvmf_trace(void)
105 {
106 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
107 
108 	struct spdk_trace_tpoint_opts opts[] = {
109 		{
110 			"RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
111 			OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 1,
112 			{
113 				{ "qpair", SPDK_TRACE_ARG_TYPE_PTR, 8 },
114 				{ "qd", SPDK_TRACE_ARG_TYPE_INT, 4 }
115 			}
116 		},
117 		{
118 			"RDMA_REQ_COMPLETED", TRACE_RDMA_REQUEST_STATE_COMPLETED,
119 			OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
120 			{
121 				{ "qpair", SPDK_TRACE_ARG_TYPE_PTR, 8 },
122 				{ "qd", SPDK_TRACE_ARG_TYPE_INT, 4 }
123 			}
124 		},
125 	};
126 
127 	spdk_trace_register_description_ext(opts, SPDK_COUNTOF(opts));
128 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
129 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
130 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
131 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
132 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
133 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
134 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
135 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
136 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
137 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
138 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
139 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
140 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
141 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
142 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
143 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
144 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
145 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
146 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
147 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
148 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
149 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
150 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
151 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
152 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
153 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
154 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
155 	spdk_trace_register_description("RDMA_REQ_RDY2COMPL_PEND",
156 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING,
157 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
158 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
159 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
160 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
161 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
162 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
163 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
164 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
165 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
166 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
167 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
168 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
169 					OWNER_TYPE_NONE, OBJECT_NVMF_RDMA_IO, 0,
170 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
171 
172 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
173 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
174 					SPDK_TRACE_ARG_TYPE_INT, "");
175 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
176 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
177 					SPDK_TRACE_ARG_TYPE_INT, "type");
178 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
179 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
180 					SPDK_TRACE_ARG_TYPE_INT, "type");
181 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
182 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
183 					SPDK_TRACE_ARG_TYPE_INT, "");
184 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
185 					OWNER_TYPE_NONE, OBJECT_NONE, 0,
186 					SPDK_TRACE_ARG_TYPE_INT, "");
187 
188 	spdk_trace_tpoint_register_relation(TRACE_BDEV_IO_START, OBJECT_NVMF_RDMA_IO, 1);
189 	spdk_trace_tpoint_register_relation(TRACE_BDEV_IO_DONE, OBJECT_NVMF_RDMA_IO, 0);
190 }
191 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
192 
193 enum spdk_nvmf_rdma_wr_type {
194 	RDMA_WR_TYPE_RECV,
195 	RDMA_WR_TYPE_SEND,
196 	RDMA_WR_TYPE_DATA,
197 };
198 
199 struct spdk_nvmf_rdma_wr {
200 	/* Uses enum spdk_nvmf_rdma_wr_type */
201 	uint8_t type;
202 };
203 
204 /* This structure holds commands as they are received off the wire.
205  * It must be dynamically paired with a full request object
206  * (spdk_nvmf_rdma_request) to service a request. It is separate
207  * from the request because RDMA does not appear to order
208  * completions, so occasionally we'll get a new incoming
209  * command when there aren't any free request objects.
210  */
211 struct spdk_nvmf_rdma_recv {
212 	struct ibv_recv_wr			wr;
213 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
214 
215 	struct spdk_nvmf_rdma_qpair		*qpair;
216 
217 	/* In-capsule data buffer */
218 	uint8_t					*buf;
219 
220 	struct spdk_nvmf_rdma_wr		rdma_wr;
221 	uint64_t				receive_tsc;
222 
223 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
224 };
225 
226 struct spdk_nvmf_rdma_request_data {
227 	struct ibv_send_wr		wr;
228 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
229 };
230 
231 struct spdk_nvmf_rdma_request {
232 	struct spdk_nvmf_request		req;
233 
234 	bool					fused_failed;
235 
236 	struct spdk_nvmf_rdma_wr		data_wr;
237 	struct spdk_nvmf_rdma_wr		rsp_wr;
238 
239 	/* Uses enum spdk_nvmf_rdma_request_state */
240 	uint8_t					state;
241 
242 	/* Data offset in req.iov */
243 	uint32_t				offset;
244 
245 	struct spdk_nvmf_rdma_recv		*recv;
246 
247 	struct {
248 		struct	ibv_send_wr		wr;
249 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
250 	} rsp;
251 
252 	uint16_t				iovpos;
253 	uint16_t				num_outstanding_data_wr;
254 	/* Used to split Write IO with multi SGL payload */
255 	uint16_t				num_remaining_data_wr;
256 	uint64_t				receive_tsc;
257 	struct spdk_nvmf_rdma_request		*fused_pair;
258 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
259 	struct ibv_send_wr			*remaining_tranfer_in_wrs;
260 	struct ibv_send_wr			*transfer_wr;
261 	struct spdk_nvmf_rdma_request_data	data;
262 };
263 
264 struct spdk_nvmf_rdma_resource_opts {
265 	struct spdk_nvmf_rdma_qpair	*qpair;
266 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
267 	void				*qp;
268 	struct spdk_rdma_utils_mem_map	*map;
269 	uint32_t			max_queue_depth;
270 	uint32_t			in_capsule_data_size;
271 	bool				shared;
272 };
273 
274 struct spdk_nvmf_rdma_resources {
275 	/* Array of size "max_queue_depth" containing RDMA requests. */
276 	struct spdk_nvmf_rdma_request		*reqs;
277 
278 	/* Array of size "max_queue_depth" containing RDMA recvs. */
279 	struct spdk_nvmf_rdma_recv		*recvs;
280 
281 	/* Array of size "max_queue_depth" containing 64 byte capsules
282 	 * used for receive.
283 	 */
284 	union nvmf_h2c_msg			*cmds;
285 
286 	/* Array of size "max_queue_depth" containing 16 byte completions
287 	 * to be sent back to the user.
288 	 */
289 	union nvmf_c2h_msg			*cpls;
290 
291 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
292 	 * buffers to be used for in capsule data.
293 	 */
294 	void					*bufs;
295 
296 	/* Receives that are waiting for a request object */
297 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
298 
299 	/* Queue to track free requests */
300 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
301 };
302 
303 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
304 
305 typedef void (*spdk_poller_destroy_cb)(void *ctx);
306 
307 struct spdk_nvmf_rdma_ibv_event_ctx {
308 	struct spdk_nvmf_rdma_qpair			*rqpair;
309 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
310 	/* Link to other ibv events associated with this qpair */
311 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
312 };
313 
314 struct spdk_nvmf_rdma_qpair {
315 	struct spdk_nvmf_qpair			qpair;
316 
317 	struct spdk_nvmf_rdma_device		*device;
318 	struct spdk_nvmf_rdma_poller		*poller;
319 
320 	struct spdk_rdma_provider_qp		*rdma_qp;
321 	struct rdma_cm_id			*cm_id;
322 	struct spdk_rdma_provider_srq		*srq;
323 	struct rdma_cm_id			*listen_id;
324 
325 	/* Cache the QP number to improve QP search by RB tree. */
326 	uint32_t				qp_num;
327 
328 	/* The maximum number of I/O outstanding on this connection at one time */
329 	uint16_t				max_queue_depth;
330 
331 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
332 	uint16_t				max_read_depth;
333 
334 	/* The maximum number of RDMA SEND operations at one time */
335 	uint32_t				max_send_depth;
336 
337 	/* The current number of outstanding WRs from this qpair's
338 	 * recv queue. Should not exceed device->attr.max_queue_depth.
339 	 */
340 	uint16_t				current_recv_depth;
341 
342 	/* The current number of active RDMA READ operations */
343 	uint16_t				current_read_depth;
344 
345 	/* The current number of posted WRs from this qpair's
346 	 * send queue. Should not exceed max_send_depth.
347 	 */
348 	uint32_t				current_send_depth;
349 
350 	/* The maximum number of SGEs per WR on the send queue */
351 	uint32_t				max_send_sge;
352 
353 	/* The maximum number of SGEs per WR on the recv queue */
354 	uint32_t				max_recv_sge;
355 
356 	struct spdk_nvmf_rdma_resources		*resources;
357 
358 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
359 
360 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
361 
362 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_send_queue;
363 
364 	/* Number of requests not in the free state */
365 	uint32_t				qd;
366 
367 	bool					ibv_in_error_state;
368 
369 	RB_ENTRY(spdk_nvmf_rdma_qpair)		node;
370 
371 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
372 
373 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
374 
375 	/* Points to the a request that has fuse bits set to
376 	 * SPDK_NVME_CMD_FUSE_FIRST, when the qpair is waiting
377 	 * for the request that has SPDK_NVME_CMD_FUSE_SECOND.
378 	 */
379 	struct spdk_nvmf_rdma_request		*fused_first;
380 
381 	/*
382 	 * io_channel which is used to destroy qpair when it is removed from poll group
383 	 */
384 	struct spdk_io_channel		*destruct_channel;
385 
386 	/* List of ibv async events */
387 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
388 
389 	/* Lets us know that we have received the last_wqe event. */
390 	bool					last_wqe_reached;
391 
392 	/* Indicate that nvmf_rdma_close_qpair is called */
393 	bool					to_close;
394 };
395 
396 struct spdk_nvmf_rdma_poller_stat {
397 	uint64_t				completions;
398 	uint64_t				polls;
399 	uint64_t				idle_polls;
400 	uint64_t				requests;
401 	uint64_t				request_latency;
402 	uint64_t				pending_free_request;
403 	uint64_t				pending_rdma_read;
404 	uint64_t				pending_rdma_write;
405 	uint64_t				pending_rdma_send;
406 	struct spdk_rdma_provider_qp_stats	qp_stats;
407 };
408 
409 struct spdk_nvmf_rdma_poller {
410 	struct spdk_nvmf_rdma_device		*device;
411 	struct spdk_nvmf_rdma_poll_group	*group;
412 
413 	int					num_cqe;
414 	int					required_num_wr;
415 	struct ibv_cq				*cq;
416 
417 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
418 	uint16_t				max_srq_depth;
419 	bool					need_destroy;
420 
421 	/* Shared receive queue */
422 	struct spdk_rdma_provider_srq		*srq;
423 
424 	struct spdk_nvmf_rdma_resources		*resources;
425 	struct spdk_nvmf_rdma_poller_stat	stat;
426 
427 	spdk_poller_destroy_cb			destroy_cb;
428 	void					*destroy_cb_ctx;
429 
430 	RB_HEAD(qpairs_tree, 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_utils_mem_map		*map;
461 	struct ibv_pd				*pd;
462 
463 	int					num_srq;
464 	bool					need_destroy;
465 	bool					ready_to_destroy;
466 	bool					is_ready;
467 
468 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
469 };
470 
471 struct spdk_nvmf_rdma_port {
472 	const struct spdk_nvme_transport_id	*trid;
473 	struct rdma_cm_id			*id;
474 	struct spdk_nvmf_rdma_device		*device;
475 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
476 };
477 
478 struct rdma_transport_opts {
479 	int		num_cqe;
480 	uint32_t	max_srq_depth;
481 	bool		no_srq;
482 	bool		no_wr_batching;
483 	int		acceptor_backlog;
484 };
485 
486 struct spdk_nvmf_rdma_transport {
487 	struct spdk_nvmf_transport	transport;
488 	struct rdma_transport_opts	rdma_opts;
489 
490 	struct spdk_nvmf_rdma_conn_sched conn_sched;
491 
492 	struct rdma_event_channel	*event_channel;
493 
494 	struct spdk_mempool		*data_wr_pool;
495 
496 	struct spdk_poller		*accept_poller;
497 
498 	/* fields used to poll RDMA/IB events */
499 	nfds_t			npoll_fds;
500 	struct pollfd		*poll_fds;
501 
502 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
503 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
504 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
505 
506 	/* ports that are removed unexpectedly and need retry listen */
507 	TAILQ_HEAD(, spdk_nvmf_rdma_port)		retry_ports;
508 };
509 
510 struct poller_manage_ctx {
511 	struct spdk_nvmf_rdma_transport		*rtransport;
512 	struct spdk_nvmf_rdma_poll_group	*rgroup;
513 	struct spdk_nvmf_rdma_poller		*rpoller;
514 	struct spdk_nvmf_rdma_device		*device;
515 
516 	struct spdk_thread			*thread;
517 	volatile int				*inflight_op_counter;
518 };
519 
520 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
521 	{
522 		"num_cqe", offsetof(struct rdma_transport_opts, num_cqe),
523 		spdk_json_decode_int32, true
524 	},
525 	{
526 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
527 		spdk_json_decode_uint32, true
528 	},
529 	{
530 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
531 		spdk_json_decode_bool, true
532 	},
533 	{
534 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
535 		spdk_json_decode_bool, true
536 	},
537 	{
538 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
539 		spdk_json_decode_int32, true
540 	},
541 };
542 
543 static int
544 nvmf_rdma_qpair_compare(struct spdk_nvmf_rdma_qpair *rqpair1, struct spdk_nvmf_rdma_qpair *rqpair2)
545 {
546 	return rqpair1->qp_num < rqpair2->qp_num ? -1 : rqpair1->qp_num > rqpair2->qp_num;
547 }
548 
549 RB_GENERATE_STATIC(qpairs_tree, spdk_nvmf_rdma_qpair, node, nvmf_rdma_qpair_compare);
550 
551 static bool nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
552 				      struct spdk_nvmf_rdma_request *rdma_req);
553 
554 static void _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
555 				 struct spdk_nvmf_rdma_poller *rpoller);
556 
557 static void _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
558 				 struct spdk_nvmf_rdma_poller *rpoller);
559 
560 static void _nvmf_rdma_remove_destroyed_device(void *c);
561 
562 static inline enum spdk_nvme_media_error_status_code
563 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
564 	enum spdk_nvme_media_error_status_code result;
565 	switch (err_type)
566 	{
567 	case SPDK_DIF_REFTAG_ERROR:
568 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
569 		break;
570 	case SPDK_DIF_APPTAG_ERROR:
571 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
572 		break;
573 	case SPDK_DIF_GUARD_ERROR:
574 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
575 		break;
576 	default:
577 		SPDK_UNREACHABLE();
578 	}
579 
580 	return result;
581 }
582 
583 /*
584  * Return data_wrs to pool starting from \b data_wr
585  * Request's own response and data WR are excluded
586  */
587 static void
588 _nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
589 			     struct ibv_send_wr *data_wr,
590 			     struct spdk_mempool *pool)
591 {
592 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
593 	struct spdk_nvmf_rdma_request_data	*nvmf_data;
594 	struct ibv_send_wr			*next_send_wr;
595 	uint64_t				req_wrid = (uint64_t)&rdma_req->data_wr;
596 	uint32_t				num_wrs = 0;
597 
598 	while (data_wr && data_wr->wr_id == req_wrid) {
599 		nvmf_data = SPDK_CONTAINEROF(data_wr, struct spdk_nvmf_rdma_request_data, wr);
600 		memset(nvmf_data->sgl, 0, sizeof(data_wr->sg_list[0]) * data_wr->num_sge);
601 		data_wr->num_sge = 0;
602 		next_send_wr = data_wr->next;
603 		if (data_wr != &rdma_req->data.wr) {
604 			data_wr->next = NULL;
605 			assert(num_wrs < SPDK_NVMF_MAX_SGL_ENTRIES);
606 			work_requests[num_wrs] = nvmf_data;
607 			num_wrs++;
608 		}
609 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL : next_send_wr;
610 	}
611 
612 	if (num_wrs) {
613 		spdk_mempool_put_bulk(pool, (void **) work_requests, num_wrs);
614 	}
615 }
616 
617 static void
618 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
619 			    struct spdk_nvmf_rdma_transport *rtransport)
620 {
621 	rdma_req->num_outstanding_data_wr = 0;
622 
623 	_nvmf_rdma_request_free_data(rdma_req, rdma_req->transfer_wr, rtransport->data_wr_pool);
624 
625 	if (rdma_req->remaining_tranfer_in_wrs) {
626 		_nvmf_rdma_request_free_data(rdma_req, rdma_req->remaining_tranfer_in_wrs,
627 					     rtransport->data_wr_pool);
628 		rdma_req->remaining_tranfer_in_wrs = NULL;
629 	}
630 
631 	rdma_req->data.wr.next = NULL;
632 	rdma_req->rsp.wr.next = NULL;
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 	spdk_free(resources->cmds);
664 	spdk_free(resources->cpls);
665 	spdk_free(resources->bufs);
666 	spdk_free(resources->reqs);
667 	spdk_free(resources->recvs);
668 	free(resources);
669 }
670 
671 
672 static struct spdk_nvmf_rdma_resources *
673 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
674 {
675 	struct spdk_nvmf_rdma_resources		*resources;
676 	struct spdk_nvmf_rdma_request		*rdma_req;
677 	struct spdk_nvmf_rdma_recv		*rdma_recv;
678 	struct spdk_rdma_provider_qp		*qp = NULL;
679 	struct spdk_rdma_provider_srq		*srq = NULL;
680 	struct ibv_recv_wr			*bad_wr = NULL;
681 	struct spdk_rdma_utils_memory_translation translation;
682 	uint32_t				i;
683 	int					rc = 0;
684 
685 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
686 	if (!resources) {
687 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
688 		return NULL;
689 	}
690 
691 	resources->reqs = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->reqs),
692 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
693 	resources->recvs = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->recvs),
694 					0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
695 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
696 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
697 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
698 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
699 
700 	if (opts->in_capsule_data_size > 0) {
701 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
702 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
703 					       SPDK_MALLOC_DMA);
704 	}
705 
706 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
707 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
708 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
709 		goto cleanup;
710 	}
711 
712 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx\n",
713 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds));
714 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx\n",
715 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls));
716 	if (resources->bufs) {
717 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x\n",
718 			      resources->bufs, opts->max_queue_depth *
719 			      opts->in_capsule_data_size);
720 	}
721 
722 	/* Initialize queues */
723 	STAILQ_INIT(&resources->incoming_queue);
724 	STAILQ_INIT(&resources->free_queue);
725 
726 	if (opts->shared) {
727 		srq = (struct spdk_rdma_provider_srq *)opts->qp;
728 	} else {
729 		qp = (struct spdk_rdma_provider_qp *)opts->qp;
730 	}
731 
732 	for (i = 0; i < opts->max_queue_depth; i++) {
733 		rdma_recv = &resources->recvs[i];
734 		rdma_recv->qpair = opts->qpair;
735 
736 		/* Set up memory to receive commands */
737 		if (resources->bufs) {
738 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
739 						  opts->in_capsule_data_size));
740 		}
741 
742 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
743 
744 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
745 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
746 		rc = spdk_rdma_utils_get_translation(opts->map, &resources->cmds[i], sizeof(resources->cmds[i]),
747 						     &translation);
748 		if (rc) {
749 			goto cleanup;
750 		}
751 		rdma_recv->sgl[0].lkey = spdk_rdma_utils_memory_translation_get_lkey(&translation);
752 		rdma_recv->wr.num_sge = 1;
753 
754 		if (rdma_recv->buf) {
755 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
756 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
757 			rc = spdk_rdma_utils_get_translation(opts->map, rdma_recv->buf, opts->in_capsule_data_size,
758 							     &translation);
759 			if (rc) {
760 				goto cleanup;
761 			}
762 			rdma_recv->sgl[1].lkey = spdk_rdma_utils_memory_translation_get_lkey(&translation);
763 			rdma_recv->wr.num_sge++;
764 		}
765 
766 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
767 		rdma_recv->wr.sg_list = rdma_recv->sgl;
768 		if (srq) {
769 			spdk_rdma_provider_srq_queue_recv_wrs(srq, &rdma_recv->wr);
770 		} else {
771 			spdk_rdma_provider_qp_queue_recv_wrs(qp, &rdma_recv->wr);
772 		}
773 	}
774 
775 	for (i = 0; i < opts->max_queue_depth; i++) {
776 		rdma_req = &resources->reqs[i];
777 
778 		if (opts->qpair != NULL) {
779 			rdma_req->req.qpair = &opts->qpair->qpair;
780 		} else {
781 			rdma_req->req.qpair = NULL;
782 		}
783 		rdma_req->req.cmd = NULL;
784 		rdma_req->req.iovcnt = 0;
785 		rdma_req->req.stripped_data = NULL;
786 
787 		/* Set up memory to send responses */
788 		rdma_req->req.rsp = &resources->cpls[i];
789 
790 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
791 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
792 		rc = spdk_rdma_utils_get_translation(opts->map, &resources->cpls[i], sizeof(resources->cpls[i]),
793 						     &translation);
794 		if (rc) {
795 			goto cleanup;
796 		}
797 		rdma_req->rsp.sgl[0].lkey = spdk_rdma_utils_memory_translation_get_lkey(&translation);
798 
799 		rdma_req->rsp_wr.type = RDMA_WR_TYPE_SEND;
800 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp_wr;
801 		rdma_req->rsp.wr.next = NULL;
802 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
803 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
804 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
805 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
806 
807 		/* Set up memory for data buffers */
808 		rdma_req->data_wr.type = RDMA_WR_TYPE_DATA;
809 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data_wr;
810 		rdma_req->data.wr.next = NULL;
811 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
812 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
813 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
814 
815 		/* Initialize request state to FREE */
816 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
817 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
818 	}
819 
820 	if (srq) {
821 		rc = spdk_rdma_provider_srq_flush_recv_wrs(srq, &bad_wr);
822 	} else {
823 		rc = spdk_rdma_provider_qp_flush_recv_wrs(qp, &bad_wr);
824 	}
825 
826 	if (rc) {
827 		goto cleanup;
828 	}
829 
830 	return resources;
831 
832 cleanup:
833 	nvmf_rdma_resources_destroy(resources);
834 	return NULL;
835 }
836 
837 static void
838 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
839 {
840 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
841 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
842 		ctx->rqpair = NULL;
843 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
844 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
845 	}
846 }
847 
848 static void nvmf_rdma_poller_destroy(struct spdk_nvmf_rdma_poller *poller);
849 
850 static void
851 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
852 {
853 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
854 	struct ibv_recv_wr		*bad_recv_wr = NULL;
855 	int				rc;
856 
857 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair);
858 
859 	if (rqpair->qd != 0) {
860 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
861 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
862 				struct spdk_nvmf_rdma_transport, transport);
863 		struct spdk_nvmf_rdma_request *req;
864 		uint32_t i, max_req_count = 0;
865 
866 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
867 
868 		if (rqpair->srq == NULL) {
869 			nvmf_rdma_dump_qpair_contents(rqpair);
870 			max_req_count = rqpair->max_queue_depth;
871 		} else if (rqpair->poller && rqpair->resources) {
872 			max_req_count = rqpair->poller->max_srq_depth;
873 		}
874 
875 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
876 		for (i = 0; i < max_req_count; i++) {
877 			req = &rqpair->resources->reqs[i];
878 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
879 				/* nvmf_rdma_request_process checks qpair ibv and internal state
880 				 * and completes a request */
881 				nvmf_rdma_request_process(rtransport, req);
882 			}
883 		}
884 		assert(rqpair->qd == 0);
885 	}
886 
887 	if (rqpair->poller) {
888 		RB_REMOVE(qpairs_tree, &rqpair->poller->qpairs, rqpair);
889 
890 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
891 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
892 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
893 				if (rqpair == rdma_recv->qpair) {
894 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
895 					spdk_rdma_provider_srq_queue_recv_wrs(rqpair->srq, &rdma_recv->wr);
896 					rc = spdk_rdma_provider_srq_flush_recv_wrs(rqpair->srq, &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_provider_qp_destroy(rqpair->rdma_qp);
908 			rqpair->rdma_qp = NULL;
909 		}
910 
911 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
912 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
913 		}
914 	}
915 
916 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
917 		nvmf_rdma_resources_destroy(rqpair->resources);
918 	}
919 
920 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
921 
922 	if (rqpair->destruct_channel) {
923 		spdk_put_io_channel(rqpair->destruct_channel);
924 		rqpair->destruct_channel = NULL;
925 	}
926 
927 	if (rqpair->poller && rqpair->poller->need_destroy && RB_EMPTY(&rqpair->poller->qpairs)) {
928 		nvmf_rdma_poller_destroy(rqpair->poller);
929 	}
930 
931 	/* destroy cm_id last so cma device will not be freed before we destroy the cq. */
932 	if (rqpair->cm_id) {
933 		rdma_destroy_id(rqpair->cm_id);
934 	}
935 
936 	free(rqpair);
937 }
938 
939 static int
940 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
941 {
942 	struct spdk_nvmf_rdma_poller	*rpoller;
943 	int				rc, num_cqe, required_num_wr;
944 
945 	/* Enlarge CQ size dynamically */
946 	rpoller = rqpair->poller;
947 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
948 	num_cqe = rpoller->num_cqe;
949 	if (num_cqe < required_num_wr) {
950 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
951 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
952 	}
953 
954 	if (rpoller->num_cqe != num_cqe) {
955 		if (device->context->device->transport_type == IBV_TRANSPORT_IWARP) {
956 			SPDK_ERRLOG("iWARP doesn't support CQ resize. Current capacity %u, required %u\n"
957 				    "Using CQ of insufficient size may lead to CQ overrun\n", rpoller->num_cqe, num_cqe);
958 			return -1;
959 		}
960 		if (required_num_wr > device->attr.max_cqe) {
961 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
962 				    required_num_wr, device->attr.max_cqe);
963 			return -1;
964 		}
965 
966 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
967 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
968 		if (rc) {
969 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
970 			return -1;
971 		}
972 
973 		rpoller->num_cqe = num_cqe;
974 	}
975 
976 	rpoller->required_num_wr = required_num_wr;
977 	return 0;
978 }
979 
980 static int
981 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
982 {
983 	struct spdk_nvmf_rdma_qpair		*rqpair;
984 	struct spdk_nvmf_rdma_transport		*rtransport;
985 	struct spdk_nvmf_transport		*transport;
986 	struct spdk_nvmf_rdma_resource_opts	opts;
987 	struct spdk_nvmf_rdma_device		*device;
988 	struct spdk_rdma_provider_qp_init_attr	qp_init_attr = {};
989 
990 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
991 	device = rqpair->device;
992 
993 	qp_init_attr.qp_context	= rqpair;
994 	qp_init_attr.pd		= device->pd;
995 	qp_init_attr.send_cq	= rqpair->poller->cq;
996 	qp_init_attr.recv_cq	= rqpair->poller->cq;
997 
998 	if (rqpair->srq) {
999 		qp_init_attr.srq		= rqpair->srq->srq;
1000 	} else {
1001 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
1002 	}
1003 
1004 	/* SEND, READ, and WRITE operations */
1005 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
1006 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1007 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1008 	qp_init_attr.stats		= &rqpair->poller->stat.qp_stats;
1009 
1010 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1011 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1012 		goto error;
1013 	}
1014 
1015 	rqpair->rdma_qp = spdk_rdma_provider_qp_create(rqpair->cm_id, &qp_init_attr);
1016 	if (!rqpair->rdma_qp) {
1017 		goto error;
1018 	}
1019 
1020 	rqpair->qp_num = rqpair->rdma_qp->qp->qp_num;
1021 
1022 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1023 					  qp_init_attr.cap.max_send_wr);
1024 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1025 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1026 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair);
1027 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1028 
1029 	if (rqpair->poller->srq == NULL) {
1030 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1031 		transport = &rtransport->transport;
1032 
1033 		opts.qp = rqpair->rdma_qp;
1034 		opts.map = device->map;
1035 		opts.qpair = rqpair;
1036 		opts.shared = false;
1037 		opts.max_queue_depth = rqpair->max_queue_depth;
1038 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1039 
1040 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1041 
1042 		if (!rqpair->resources) {
1043 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1044 			rdma_destroy_qp(rqpair->cm_id);
1045 			goto error;
1046 		}
1047 	} else {
1048 		rqpair->resources = rqpair->poller->resources;
1049 	}
1050 
1051 	rqpair->current_recv_depth = 0;
1052 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1053 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1054 	STAILQ_INIT(&rqpair->pending_rdma_send_queue);
1055 	rqpair->qpair.queue_depth = 0;
1056 
1057 	return 0;
1058 
1059 error:
1060 	rdma_destroy_id(rqpair->cm_id);
1061 	rqpair->cm_id = NULL;
1062 	return -1;
1063 }
1064 
1065 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1066 /* This function accepts either a single wr or the first wr in a linked list. */
1067 static void
1068 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1069 {
1070 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1071 			struct spdk_nvmf_rdma_transport, transport);
1072 
1073 	if (rqpair->srq != NULL) {
1074 		spdk_rdma_provider_srq_queue_recv_wrs(rqpair->srq, first);
1075 	} else {
1076 		if (spdk_rdma_provider_qp_queue_recv_wrs(rqpair->rdma_qp, first)) {
1077 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1078 		}
1079 	}
1080 
1081 	if (rtransport->rdma_opts.no_wr_batching) {
1082 		_poller_submit_recvs(rtransport, rqpair->poller);
1083 	}
1084 }
1085 
1086 static inline void
1087 request_transfer_in(struct spdk_nvmf_request *req)
1088 {
1089 	struct spdk_nvmf_rdma_request	*rdma_req;
1090 	struct spdk_nvmf_qpair		*qpair;
1091 	struct spdk_nvmf_rdma_qpair	*rqpair;
1092 	struct spdk_nvmf_rdma_transport *rtransport;
1093 
1094 	qpair = req->qpair;
1095 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1096 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1097 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1098 				      struct spdk_nvmf_rdma_transport, transport);
1099 
1100 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1101 	assert(rdma_req != NULL);
1102 
1103 	if (spdk_rdma_provider_qp_queue_send_wrs(rqpair->rdma_qp, rdma_req->transfer_wr)) {
1104 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1105 	}
1106 	if (rtransport->rdma_opts.no_wr_batching) {
1107 		_poller_submit_sends(rtransport, rqpair->poller);
1108 	}
1109 
1110 	assert(rqpair->current_read_depth + rdma_req->num_outstanding_data_wr <= rqpair->max_read_depth);
1111 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1112 	assert(rqpair->current_send_depth + rdma_req->num_outstanding_data_wr <= rqpair->max_send_depth);
1113 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1114 }
1115 
1116 static inline void
1117 nvmf_rdma_request_reset_transfer_in(struct spdk_nvmf_rdma_request *rdma_req,
1118 				    struct spdk_nvmf_rdma_transport *rtransport)
1119 {
1120 	/* Put completed WRs back to pool and move transfer_wr pointer */
1121 	_nvmf_rdma_request_free_data(rdma_req, rdma_req->transfer_wr, rtransport->data_wr_pool);
1122 	rdma_req->transfer_wr = rdma_req->remaining_tranfer_in_wrs;
1123 	rdma_req->remaining_tranfer_in_wrs = NULL;
1124 	rdma_req->num_outstanding_data_wr = rdma_req->num_remaining_data_wr;
1125 	rdma_req->num_remaining_data_wr = 0;
1126 }
1127 
1128 static inline int
1129 request_prepare_transfer_in_part(struct spdk_nvmf_request *req, uint32_t num_reads_available)
1130 {
1131 	struct spdk_nvmf_rdma_request	*rdma_req;
1132 	struct ibv_send_wr		*wr;
1133 	uint32_t i;
1134 
1135 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1136 
1137 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1138 	assert(rdma_req != NULL);
1139 	assert(num_reads_available > 0);
1140 	assert(rdma_req->num_outstanding_data_wr > num_reads_available);
1141 	wr = rdma_req->transfer_wr;
1142 
1143 	for (i = 0; i < num_reads_available - 1; i++) {
1144 		wr = wr->next;
1145 	}
1146 
1147 	rdma_req->remaining_tranfer_in_wrs = wr->next;
1148 	rdma_req->num_remaining_data_wr = rdma_req->num_outstanding_data_wr - num_reads_available;
1149 	rdma_req->num_outstanding_data_wr = num_reads_available;
1150 	/* Break chain of WRs to send only part. Once this portion completes, we continue sending RDMA_READs */
1151 	wr->next = NULL;
1152 
1153 	return 0;
1154 }
1155 
1156 static int
1157 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1158 {
1159 	int				num_outstanding_data_wr = 0;
1160 	struct spdk_nvmf_rdma_request	*rdma_req;
1161 	struct spdk_nvmf_qpair		*qpair;
1162 	struct spdk_nvmf_rdma_qpair	*rqpair;
1163 	struct spdk_nvme_cpl		*rsp;
1164 	struct ibv_send_wr		*first = NULL;
1165 	struct spdk_nvmf_rdma_transport *rtransport;
1166 
1167 	*data_posted = 0;
1168 	qpair = req->qpair;
1169 	rsp = &req->rsp->nvme_cpl;
1170 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1171 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1172 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1173 				      struct spdk_nvmf_rdma_transport, transport);
1174 
1175 	/* Advance our sq_head pointer */
1176 	if (qpair->sq_head == qpair->sq_head_max) {
1177 		qpair->sq_head = 0;
1178 	} else {
1179 		qpair->sq_head++;
1180 	}
1181 	rsp->sqhd = qpair->sq_head;
1182 
1183 	/* queue the capsule for the recv buffer */
1184 	assert(rdma_req->recv != NULL);
1185 
1186 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1187 
1188 	rdma_req->recv = NULL;
1189 	assert(rqpair->current_recv_depth > 0);
1190 	rqpair->current_recv_depth--;
1191 
1192 	/* Build the response which consists of optional
1193 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1194 	 * containing the response.
1195 	 */
1196 	first = &rdma_req->rsp.wr;
1197 
1198 	if (spdk_unlikely(rsp->status.sc != SPDK_NVME_SC_SUCCESS)) {
1199 		/* On failure, data was not read from the controller. So clear the
1200 		 * number of outstanding data WRs to zero.
1201 		 */
1202 		rdma_req->num_outstanding_data_wr = 0;
1203 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1204 		first = rdma_req->transfer_wr;
1205 		*data_posted = 1;
1206 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1207 	}
1208 	if (spdk_rdma_provider_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1209 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1210 	}
1211 	if (rtransport->rdma_opts.no_wr_batching) {
1212 		_poller_submit_sends(rtransport, rqpair->poller);
1213 	}
1214 
1215 	/* +1 for the rsp wr */
1216 	assert(rqpair->current_send_depth + num_outstanding_data_wr + 1 <= rqpair->max_send_depth);
1217 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1218 
1219 	return 0;
1220 }
1221 
1222 static int
1223 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1224 {
1225 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1226 	struct rdma_conn_param				ctrlr_event_data = {};
1227 	int						rc;
1228 
1229 	accept_data.recfmt = 0;
1230 	accept_data.crqsize = rqpair->max_queue_depth;
1231 
1232 	ctrlr_event_data.private_data = &accept_data;
1233 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1234 	if (id->ps == RDMA_PS_TCP) {
1235 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1236 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1237 	}
1238 
1239 	/* Configure infinite retries for the initiator side qpair.
1240 	 * We need to pass this value to the initiator to prevent the
1241 	 * initiator side NIC from completing SEND requests back to the
1242 	 * initiator with status rnr_retry_count_exceeded. */
1243 	ctrlr_event_data.rnr_retry_count = 0x7;
1244 
1245 	/* When qpair is created without use of rdma cm API, an additional
1246 	 * information must be provided to initiator in the connection response:
1247 	 * whether qpair is using SRQ and its qp_num
1248 	 * Fields below are ignored by rdma cm if qpair has been
1249 	 * created using rdma cm API. */
1250 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1251 	ctrlr_event_data.qp_num = rqpair->qp_num;
1252 
1253 	rc = spdk_rdma_provider_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1254 	if (rc) {
1255 		SPDK_ERRLOG("Error %d on spdk_rdma_provider_qp_accept\n", errno);
1256 	} else {
1257 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1258 	}
1259 
1260 	return rc;
1261 }
1262 
1263 static void
1264 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1265 {
1266 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1267 
1268 	rej_data.recfmt = 0;
1269 	rej_data.sts = error;
1270 
1271 	rdma_reject(id, &rej_data, sizeof(rej_data));
1272 }
1273 
1274 static int
1275 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1276 {
1277 	struct spdk_nvmf_rdma_transport *rtransport;
1278 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1279 	struct spdk_nvmf_rdma_port	*port;
1280 	struct rdma_conn_param		*rdma_param = NULL;
1281 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1282 	uint16_t			max_queue_depth;
1283 	uint16_t			max_read_depth;
1284 
1285 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1286 
1287 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1288 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1289 
1290 	rdma_param = &event->param.conn;
1291 	if (rdma_param->private_data == NULL ||
1292 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1293 		SPDK_ERRLOG("connect request: no private data provided\n");
1294 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1295 		return -1;
1296 	}
1297 
1298 	private_data = rdma_param->private_data;
1299 	if (private_data->recfmt != 0) {
1300 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1301 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1302 		return -1;
1303 	}
1304 
1305 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1306 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1307 
1308 	port = event->listen_id->context;
1309 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1310 		      event->listen_id, event->listen_id->verbs, port);
1311 
1312 	/* Figure out the supported queue depth. This is a multi-step process
1313 	 * that takes into account hardware maximums, host provided values,
1314 	 * and our target's internal memory limits */
1315 
1316 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1317 
1318 	/* Start with the maximum queue depth allowed by the target */
1319 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1320 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1321 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1322 		      rtransport->transport.opts.max_queue_depth);
1323 
1324 	/* Next check the local NIC's hardware limitations */
1325 	SPDK_DEBUGLOG(rdma,
1326 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1327 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1328 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1329 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1330 
1331 	/* Next check the remote NIC's hardware limitations */
1332 	SPDK_DEBUGLOG(rdma,
1333 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1334 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1335 	/* from man3 rdma_get_cm_event
1336 	 * responder_resources - Specifies the number of responder resources that is requested by the recipient.
1337 	 * The responder_resources field must match the initiator depth specified by the remote node when running
1338 	 * the rdma_connect and rdma_accept functions. */
1339 	if (rdma_param->responder_resources != 0) {
1340 		if (private_data->qid) {
1341 			SPDK_DEBUGLOG(rdma, "Host (Initiator) is not allowed to use RDMA operations,"
1342 				      " responder_resources must be 0 but set to %u\n",
1343 				      rdma_param->responder_resources);
1344 		} else {
1345 			SPDK_WARNLOG("Host (Initiator) is not allowed to use RDMA operations,"
1346 				     " responder_resources must be 0 but set to %u\n",
1347 				     rdma_param->responder_resources);
1348 		}
1349 	}
1350 	/* from man3 rdma_get_cm_event
1351 	 * initiator_depth - Specifies the maximum number of outstanding RDMA read operations that the recipient holds.
1352 	 * The initiator_depth field must match the responder resources specified by the remote node when running
1353 	 * the rdma_connect and rdma_accept functions. */
1354 	if (rdma_param->initiator_depth == 0) {
1355 		SPDK_ERRLOG("Host (Initiator) doesn't support RDMA_READ or atomic operations\n");
1356 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_IRD);
1357 		return -1;
1358 	}
1359 	max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1360 
1361 	SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1362 	SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1363 	max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1364 	max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1365 
1366 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1367 		      max_queue_depth, max_read_depth);
1368 
1369 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1370 	if (rqpair == NULL) {
1371 		SPDK_ERRLOG("Could not allocate new connection.\n");
1372 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1373 		return -1;
1374 	}
1375 
1376 	rqpair->device = port->device;
1377 	rqpair->max_queue_depth = max_queue_depth;
1378 	rqpair->max_read_depth = max_read_depth;
1379 	rqpair->cm_id = event->id;
1380 	rqpair->listen_id = event->listen_id;
1381 	rqpair->qpair.transport = transport;
1382 	STAILQ_INIT(&rqpair->ibv_events);
1383 	/* use qid from the private data to determine the qpair type
1384 	   qid will be set to the appropriate value when the controller is created */
1385 	rqpair->qpair.qid = private_data->qid;
1386 	rqpair->qpair.numa.id_valid = 1;
1387 	rqpair->qpair.numa.id = spdk_rdma_cm_id_get_numa_id(rqpair->cm_id);
1388 
1389 	event->id->context = &rqpair->qpair;
1390 
1391 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1392 
1393 	return 0;
1394 }
1395 
1396 static inline void
1397 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1398 		   enum spdk_nvme_data_transfer xfer)
1399 {
1400 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1401 		wr->opcode = IBV_WR_RDMA_WRITE;
1402 		wr->send_flags = 0;
1403 		wr->next = next;
1404 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1405 		wr->opcode = IBV_WR_RDMA_READ;
1406 		wr->send_flags = IBV_SEND_SIGNALED;
1407 		wr->next = NULL;
1408 	} else {
1409 		assert(0);
1410 	}
1411 }
1412 
1413 static int
1414 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1415 		       struct spdk_nvmf_rdma_request *rdma_req,
1416 		       uint32_t num_sgl_descriptors)
1417 {
1418 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1419 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1420 	uint32_t				i;
1421 
1422 	if (spdk_unlikely(num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES)) {
1423 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1424 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1425 		return -EINVAL;
1426 	}
1427 
1428 	if (spdk_unlikely(spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests,
1429 						num_sgl_descriptors))) {
1430 		return -ENOMEM;
1431 	}
1432 
1433 	current_data_wr = &rdma_req->data;
1434 
1435 	for (i = 0; i < num_sgl_descriptors; i++) {
1436 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1437 		current_data_wr->wr.next = &work_requests[i]->wr;
1438 		current_data_wr = work_requests[i];
1439 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1440 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1441 	}
1442 
1443 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1444 
1445 	return 0;
1446 }
1447 
1448 static inline void
1449 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1450 {
1451 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1452 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1453 
1454 	wr->wr.rdma.rkey = sgl->keyed.key;
1455 	wr->wr.rdma.remote_addr = sgl->address;
1456 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1457 }
1458 
1459 static inline void
1460 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1461 {
1462 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1463 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1464 	uint32_t			i;
1465 	int				j;
1466 	uint64_t			remote_addr_offset = 0;
1467 
1468 	for (i = 0; i < num_wrs; ++i) {
1469 		wr->wr.rdma.rkey = sgl->keyed.key;
1470 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1471 		for (j = 0; j < wr->num_sge; ++j) {
1472 			remote_addr_offset += wr->sg_list[j].length;
1473 		}
1474 		wr = wr->next;
1475 	}
1476 }
1477 
1478 static int
1479 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_device *device,
1480 		      struct spdk_nvmf_rdma_request *rdma_req,
1481 		      struct ibv_send_wr *wr,
1482 		      uint32_t total_length)
1483 {
1484 	struct spdk_rdma_utils_memory_translation mem_translation;
1485 	struct ibv_sge	*sg_ele;
1486 	struct iovec *iov;
1487 	uint32_t lkey, remaining;
1488 	int rc;
1489 
1490 	wr->num_sge = 0;
1491 
1492 	while (total_length && wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES) {
1493 		iov = &rdma_req->req.iov[rdma_req->iovpos];
1494 		rc = spdk_rdma_utils_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1495 		if (spdk_unlikely(rc)) {
1496 			return rc;
1497 		}
1498 
1499 		lkey = spdk_rdma_utils_memory_translation_get_lkey(&mem_translation);
1500 		sg_ele = &wr->sg_list[wr->num_sge];
1501 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1502 
1503 		sg_ele->lkey = lkey;
1504 		sg_ele->addr = (uintptr_t)iov->iov_base + rdma_req->offset;
1505 		sg_ele->length = remaining;
1506 		SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele, sg_ele->addr,
1507 			      sg_ele->length);
1508 		rdma_req->offset += sg_ele->length;
1509 		total_length -= sg_ele->length;
1510 		wr->num_sge++;
1511 
1512 		if (rdma_req->offset == iov->iov_len) {
1513 			rdma_req->offset = 0;
1514 			rdma_req->iovpos++;
1515 		}
1516 	}
1517 
1518 	if (spdk_unlikely(total_length)) {
1519 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1520 		return -EINVAL;
1521 	}
1522 
1523 	return 0;
1524 }
1525 
1526 static int
1527 nvmf_rdma_fill_wr_sgl_with_dif(struct spdk_nvmf_rdma_device *device,
1528 			       struct spdk_nvmf_rdma_request *rdma_req,
1529 			       struct ibv_send_wr *wr,
1530 			       uint32_t total_length,
1531 			       uint32_t num_extra_wrs)
1532 {
1533 	struct spdk_rdma_utils_memory_translation mem_translation;
1534 	struct spdk_dif_ctx *dif_ctx = &rdma_req->req.dif.dif_ctx;
1535 	struct ibv_sge *sg_ele;
1536 	struct iovec *iov;
1537 	struct iovec *rdma_iov;
1538 	uint32_t lkey, remaining;
1539 	uint32_t remaining_data_block, data_block_size, md_size;
1540 	uint32_t sge_len;
1541 	int rc;
1542 
1543 	data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1544 
1545 	if (spdk_likely(!rdma_req->req.stripped_data)) {
1546 		rdma_iov = rdma_req->req.iov;
1547 		remaining_data_block = data_block_size;
1548 		md_size = dif_ctx->md_size;
1549 	} else {
1550 		rdma_iov = rdma_req->req.stripped_data->iov;
1551 		total_length = total_length / dif_ctx->block_size * data_block_size;
1552 		remaining_data_block = total_length;
1553 		md_size = 0;
1554 	}
1555 
1556 	wr->num_sge = 0;
1557 
1558 	while (total_length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1559 		iov = rdma_iov + rdma_req->iovpos;
1560 		rc = spdk_rdma_utils_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1561 		if (spdk_unlikely(rc)) {
1562 			return rc;
1563 		}
1564 
1565 		lkey = spdk_rdma_utils_memory_translation_get_lkey(&mem_translation);
1566 		sg_ele = &wr->sg_list[wr->num_sge];
1567 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1568 
1569 		while (remaining) {
1570 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1571 				if (num_extra_wrs > 0 && wr->next) {
1572 					wr = wr->next;
1573 					wr->num_sge = 0;
1574 					sg_ele = &wr->sg_list[wr->num_sge];
1575 					num_extra_wrs--;
1576 				} else {
1577 					break;
1578 				}
1579 			}
1580 			sg_ele->lkey = lkey;
1581 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + rdma_req->offset);
1582 			sge_len = spdk_min(remaining, remaining_data_block);
1583 			sg_ele->length = sge_len;
1584 			SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele,
1585 				      sg_ele->addr, sg_ele->length);
1586 			remaining -= sge_len;
1587 			remaining_data_block -= sge_len;
1588 			rdma_req->offset += sge_len;
1589 			total_length -= sge_len;
1590 
1591 			sg_ele++;
1592 			wr->num_sge++;
1593 
1594 			if (remaining_data_block == 0) {
1595 				/* skip metadata */
1596 				rdma_req->offset += md_size;
1597 				total_length -= md_size;
1598 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1599 				remaining -= spdk_min(remaining, md_size);
1600 				remaining_data_block = data_block_size;
1601 			}
1602 
1603 			if (remaining == 0) {
1604 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1605 				   the remaining metadata bits at the beginning of the next buffer */
1606 				rdma_req->offset -= spdk_min(iov->iov_len, rdma_req->offset);
1607 				rdma_req->iovpos++;
1608 			}
1609 		}
1610 	}
1611 
1612 	if (spdk_unlikely(total_length)) {
1613 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1614 		return -EINVAL;
1615 	}
1616 
1617 	return 0;
1618 }
1619 
1620 static inline uint32_t
1621 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1622 {
1623 	/* estimate the number of SG entries and WRs needed to process the request */
1624 	uint32_t num_sge = 0;
1625 	uint32_t i;
1626 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1627 
1628 	for (i = 0; i < num_buffers && length > 0; i++) {
1629 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1630 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1631 
1632 		if (num_sge_in_block * block_size > buffer_len) {
1633 			++num_sge_in_block;
1634 		}
1635 		num_sge += num_sge_in_block;
1636 		length -= buffer_len;
1637 	}
1638 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1639 }
1640 
1641 static int
1642 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1643 			    struct spdk_nvmf_rdma_device *device,
1644 			    struct spdk_nvmf_rdma_request *rdma_req)
1645 {
1646 	struct spdk_nvmf_rdma_qpair		*rqpair;
1647 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1648 	struct spdk_nvmf_request		*req = &rdma_req->req;
1649 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1650 	int					rc;
1651 	uint32_t				num_wrs = 1;
1652 	uint32_t				length;
1653 
1654 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1655 	rgroup = rqpair->poller->group;
1656 
1657 	/* rdma wr specifics */
1658 	nvmf_rdma_setup_request(rdma_req);
1659 
1660 	length = req->length;
1661 	if (spdk_unlikely(req->dif_enabled)) {
1662 		req->dif.orig_length = length;
1663 		length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1664 		req->dif.elba_length = length;
1665 	}
1666 
1667 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1668 					   length);
1669 	if (spdk_unlikely(rc != 0)) {
1670 		return rc;
1671 	}
1672 
1673 	assert(req->iovcnt <= rqpair->max_send_sge);
1674 
1675 	/* When dif_insert_or_strip is true and the I/O data length is greater than one block,
1676 	 * the stripped_buffers are got for DIF stripping. */
1677 	if (spdk_unlikely(req->dif_enabled && (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST)
1678 			  && (req->dif.elba_length > req->dif.dif_ctx.block_size))) {
1679 		rc = nvmf_request_get_stripped_buffers(req, &rgroup->group,
1680 						       &rtransport->transport, req->dif.orig_length);
1681 		if (rc != 0) {
1682 			SPDK_INFOLOG(rdma, "Get stripped buffers fail %d, fallback to req.iov.\n", rc);
1683 		}
1684 	}
1685 
1686 	rdma_req->iovpos = 0;
1687 
1688 	if (spdk_unlikely(req->dif_enabled)) {
1689 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1690 						 req->dif.dif_ctx.block_size);
1691 		if (num_wrs > 1) {
1692 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1693 			if (spdk_unlikely(rc != 0)) {
1694 				goto err_exit;
1695 			}
1696 		}
1697 
1698 		rc = nvmf_rdma_fill_wr_sgl_with_dif(device, rdma_req, wr, length, num_wrs - 1);
1699 		if (spdk_unlikely(rc != 0)) {
1700 			goto err_exit;
1701 		}
1702 
1703 		if (num_wrs > 1) {
1704 			nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1705 		}
1706 	} else {
1707 		rc = nvmf_rdma_fill_wr_sgl(device, rdma_req, wr, length);
1708 		if (spdk_unlikely(rc != 0)) {
1709 			goto err_exit;
1710 		}
1711 	}
1712 
1713 	/* set the number of outstanding data WRs for this request. */
1714 	rdma_req->num_outstanding_data_wr = num_wrs;
1715 
1716 	return rc;
1717 
1718 err_exit:
1719 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1720 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1721 	req->iovcnt = 0;
1722 	return rc;
1723 }
1724 
1725 static int
1726 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1727 				      struct spdk_nvmf_rdma_device *device,
1728 				      struct spdk_nvmf_rdma_request *rdma_req)
1729 {
1730 	struct spdk_nvmf_rdma_qpair		*rqpair;
1731 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1732 	struct ibv_send_wr			*current_wr;
1733 	struct spdk_nvmf_request		*req = &rdma_req->req;
1734 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1735 	uint32_t				num_sgl_descriptors;
1736 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES], total_length = 0;
1737 	uint32_t				i;
1738 	int					rc;
1739 
1740 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1741 	rgroup = rqpair->poller->group;
1742 
1743 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1744 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1745 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1746 
1747 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1748 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1749 
1750 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1751 	for (i = 0; i < num_sgl_descriptors; i++) {
1752 		if (spdk_likely(!req->dif_enabled)) {
1753 			lengths[i] = desc->keyed.length;
1754 		} else {
1755 			req->dif.orig_length += desc->keyed.length;
1756 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1757 			req->dif.elba_length += lengths[i];
1758 		}
1759 		total_length += lengths[i];
1760 		desc++;
1761 	}
1762 
1763 	if (spdk_unlikely(total_length > rtransport->transport.opts.max_io_size)) {
1764 		SPDK_ERRLOG("Multi SGL length 0x%x exceeds max io size 0x%x\n",
1765 			    total_length, rtransport->transport.opts.max_io_size);
1766 		req->rsp->nvme_cpl.status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1767 		return -EINVAL;
1768 	}
1769 
1770 	rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1);
1771 	if (spdk_unlikely(rc != 0)) {
1772 		return -ENOMEM;
1773 	}
1774 
1775 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport, total_length);
1776 	if (spdk_unlikely(rc != 0)) {
1777 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1778 		return rc;
1779 	}
1780 
1781 	/* When dif_insert_or_strip is true and the I/O data length is greater than one block,
1782 	 * the stripped_buffers are got for DIF stripping. */
1783 	if (spdk_unlikely(req->dif_enabled && (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST)
1784 			  && (req->dif.elba_length > req->dif.dif_ctx.block_size))) {
1785 		rc = nvmf_request_get_stripped_buffers(req, &rgroup->group,
1786 						       &rtransport->transport, req->dif.orig_length);
1787 		if (spdk_unlikely(rc != 0)) {
1788 			SPDK_INFOLOG(rdma, "Get stripped buffers fail %d, fallback to req.iov.\n", rc);
1789 		}
1790 	}
1791 
1792 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1793 	current_wr = &rdma_req->data.wr;
1794 	assert(current_wr != NULL);
1795 
1796 	req->length = 0;
1797 	rdma_req->iovpos = 0;
1798 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1799 	for (i = 0; i < num_sgl_descriptors; i++) {
1800 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1801 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1802 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1803 			rc = -EINVAL;
1804 			goto err_exit;
1805 		}
1806 
1807 		if (spdk_likely(!req->dif_enabled)) {
1808 			rc = nvmf_rdma_fill_wr_sgl(device, rdma_req, current_wr, lengths[i]);
1809 		} else {
1810 			rc = nvmf_rdma_fill_wr_sgl_with_dif(device, rdma_req, current_wr,
1811 							    lengths[i], 0);
1812 		}
1813 		if (spdk_unlikely(rc != 0)) {
1814 			rc = -ENOMEM;
1815 			goto err_exit;
1816 		}
1817 
1818 		req->length += desc->keyed.length;
1819 		current_wr->wr.rdma.rkey = desc->keyed.key;
1820 		current_wr->wr.rdma.remote_addr = desc->address;
1821 		current_wr = current_wr->next;
1822 		desc++;
1823 	}
1824 
1825 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1826 	/* Go back to the last descriptor in the list. */
1827 	desc--;
1828 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1829 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1830 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1831 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1832 		}
1833 	}
1834 #endif
1835 
1836 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1837 
1838 	return 0;
1839 
1840 err_exit:
1841 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1842 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1843 	return rc;
1844 }
1845 
1846 static int
1847 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1848 			    struct spdk_nvmf_rdma_device *device,
1849 			    struct spdk_nvmf_rdma_request *rdma_req)
1850 {
1851 	struct spdk_nvmf_request		*req = &rdma_req->req;
1852 	struct spdk_nvme_cpl			*rsp;
1853 	struct spdk_nvme_sgl_descriptor		*sgl;
1854 	int					rc;
1855 	uint32_t				length;
1856 
1857 	rsp = &req->rsp->nvme_cpl;
1858 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1859 
1860 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1861 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1862 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1863 
1864 		length = sgl->keyed.length;
1865 		if (spdk_unlikely(length > rtransport->transport.opts.max_io_size)) {
1866 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1867 				    length, rtransport->transport.opts.max_io_size);
1868 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1869 			return -1;
1870 		}
1871 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1872 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1873 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1874 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1875 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1876 			}
1877 		}
1878 #endif
1879 
1880 		/* fill request length and populate iovs */
1881 		req->length = length;
1882 
1883 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req);
1884 		if (spdk_unlikely(rc < 0)) {
1885 			if (rc == -EINVAL) {
1886 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1887 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1888 				return -1;
1889 			}
1890 			/* No available buffers. Queue this request up. */
1891 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1892 			return 0;
1893 		}
1894 
1895 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1896 			      req->iovcnt);
1897 
1898 		return 0;
1899 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1900 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1901 		uint64_t offset = sgl->address;
1902 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1903 
1904 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1905 			      offset, sgl->unkeyed.length);
1906 
1907 		if (spdk_unlikely(offset > max_len)) {
1908 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1909 				    offset, max_len);
1910 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1911 			return -1;
1912 		}
1913 		max_len -= (uint32_t)offset;
1914 
1915 		if (spdk_unlikely(sgl->unkeyed.length > max_len)) {
1916 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1917 				    sgl->unkeyed.length, max_len);
1918 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1919 			return -1;
1920 		}
1921 
1922 		rdma_req->num_outstanding_data_wr = 0;
1923 		req->data_from_pool = false;
1924 		req->length = sgl->unkeyed.length;
1925 
1926 		req->iov[0].iov_base = rdma_req->recv->buf + offset;
1927 		req->iov[0].iov_len = req->length;
1928 		req->iovcnt = 1;
1929 
1930 		return 0;
1931 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1932 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1933 
1934 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1935 		if (spdk_unlikely(rc == -ENOMEM)) {
1936 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1937 			return 0;
1938 		} else if (spdk_unlikely(rc == -EINVAL)) {
1939 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1940 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1941 			return -1;
1942 		}
1943 
1944 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1945 			      req->iovcnt);
1946 
1947 		return 0;
1948 	}
1949 
1950 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1951 		    sgl->generic.type, sgl->generic.subtype);
1952 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1953 	return -1;
1954 }
1955 
1956 static void
1957 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1958 			struct spdk_nvmf_rdma_transport	*rtransport)
1959 {
1960 	struct spdk_nvmf_rdma_qpair		*rqpair;
1961 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1962 
1963 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1964 	if (rdma_req->req.data_from_pool) {
1965 		rgroup = rqpair->poller->group;
1966 
1967 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1968 	}
1969 	if (rdma_req->req.stripped_data) {
1970 		nvmf_request_free_stripped_buffers(&rdma_req->req,
1971 						   &rqpair->poller->group->group,
1972 						   &rtransport->transport);
1973 	}
1974 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1975 	rdma_req->req.length = 0;
1976 	rdma_req->req.iovcnt = 0;
1977 	rdma_req->offset = 0;
1978 	rdma_req->req.dif_enabled = false;
1979 	rdma_req->fused_failed = false;
1980 	rdma_req->transfer_wr = NULL;
1981 	if (rdma_req->fused_pair) {
1982 		/* This req was part of a valid fused pair, but failed before it got to
1983 		 * READ_TO_EXECUTE state.  This means we need to fail the other request
1984 		 * in the pair, because it is no longer part of a valid pair.  If the pair
1985 		 * already reached READY_TO_EXECUTE state, we need to kick it.
1986 		 */
1987 		rdma_req->fused_pair->fused_failed = true;
1988 		if (rdma_req->fused_pair->state == RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
1989 			nvmf_rdma_request_process(rtransport, rdma_req->fused_pair);
1990 		}
1991 		rdma_req->fused_pair = NULL;
1992 	}
1993 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1994 	rqpair->qd--;
1995 
1996 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1997 	rqpair->qpair.queue_depth--;
1998 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1999 }
2000 
2001 static void
2002 nvmf_rdma_check_fused_ordering(struct spdk_nvmf_rdma_transport *rtransport,
2003 			       struct spdk_nvmf_rdma_qpair *rqpair,
2004 			       struct spdk_nvmf_rdma_request *rdma_req)
2005 {
2006 	enum spdk_nvme_cmd_fuse last, next;
2007 
2008 	last = rqpair->fused_first ? rqpair->fused_first->req.cmd->nvme_cmd.fuse : SPDK_NVME_CMD_FUSE_NONE;
2009 	next = rdma_req->req.cmd->nvme_cmd.fuse;
2010 
2011 	assert(last != SPDK_NVME_CMD_FUSE_SECOND);
2012 
2013 	if (spdk_likely(last == SPDK_NVME_CMD_FUSE_NONE && next == SPDK_NVME_CMD_FUSE_NONE)) {
2014 		return;
2015 	}
2016 
2017 	if (last == SPDK_NVME_CMD_FUSE_FIRST) {
2018 		if (next == SPDK_NVME_CMD_FUSE_SECOND) {
2019 			/* This is a valid pair of fused commands.  Point them at each other
2020 			 * so they can be submitted consecutively once ready to be executed.
2021 			 */
2022 			rqpair->fused_first->fused_pair = rdma_req;
2023 			rdma_req->fused_pair = rqpair->fused_first;
2024 			rqpair->fused_first = NULL;
2025 			return;
2026 		} else {
2027 			/* Mark the last req as failed since it wasn't followed by a SECOND. */
2028 			rqpair->fused_first->fused_failed = true;
2029 
2030 			/* If the last req is in READY_TO_EXECUTE state, then call
2031 			 * nvmf_rdma_request_process(), otherwise nothing else will kick it.
2032 			 */
2033 			if (rqpair->fused_first->state == RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
2034 				nvmf_rdma_request_process(rtransport, rqpair->fused_first);
2035 			}
2036 
2037 			rqpair->fused_first = NULL;
2038 		}
2039 	}
2040 
2041 	if (next == SPDK_NVME_CMD_FUSE_FIRST) {
2042 		/* Set rqpair->fused_first here so that we know to check that the next request
2043 		 * is a SECOND (and to fail this one if it isn't).
2044 		 */
2045 		rqpair->fused_first = rdma_req;
2046 	} else if (next == SPDK_NVME_CMD_FUSE_SECOND) {
2047 		/* Mark this req failed since it ia SECOND and the last one was not a FIRST. */
2048 		rdma_req->fused_failed = true;
2049 	}
2050 }
2051 
2052 bool
2053 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
2054 			  struct spdk_nvmf_rdma_request *rdma_req)
2055 {
2056 	struct spdk_nvmf_rdma_qpair	*rqpair;
2057 	struct spdk_nvmf_rdma_device	*device;
2058 	struct spdk_nvmf_rdma_poll_group *rgroup;
2059 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
2060 	int				rc;
2061 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2062 	enum spdk_nvmf_rdma_request_state prev_state;
2063 	bool				progress = false;
2064 	int				data_posted;
2065 	uint32_t			num_blocks, num_rdma_reads_available, qdepth;
2066 
2067 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2068 	device = rqpair->device;
2069 	rgroup = rqpair->poller->group;
2070 
2071 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
2072 
2073 	/* If the queue pair is in an error state, force the request to the completed state
2074 	 * to release resources. */
2075 	if (spdk_unlikely(rqpair->ibv_in_error_state || !spdk_nvmf_qpair_is_active(&rqpair->qpair))) {
2076 		switch (rdma_req->state) {
2077 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2078 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
2079 			break;
2080 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2081 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2082 			break;
2083 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2084 			if (rdma_req->num_remaining_data_wr) {
2085 				/* Partially sent request is still in the pending_rdma_read_queue,
2086 				 * remove it before completing */
2087 				rdma_req->num_remaining_data_wr = 0;
2088 				STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2089 			}
2090 			break;
2091 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2092 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2093 			break;
2094 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING:
2095 			STAILQ_REMOVE(&rqpair->pending_rdma_send_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2096 			break;
2097 		default:
2098 			break;
2099 		}
2100 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2101 	}
2102 
2103 	/* The loop here is to allow for several back-to-back state changes. */
2104 	do {
2105 		prev_state = rdma_req->state;
2106 
2107 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
2108 
2109 		switch (rdma_req->state) {
2110 		case RDMA_REQUEST_STATE_FREE:
2111 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
2112 			 * to escape this state. */
2113 			break;
2114 		case RDMA_REQUEST_STATE_NEW:
2115 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
2116 					  (uintptr_t)rdma_req, (uintptr_t)rqpair, rqpair->qpair.queue_depth);
2117 			rdma_recv = rdma_req->recv;
2118 
2119 			/* The first element of the SGL is the NVMe command */
2120 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
2121 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
2122 			rdma_req->transfer_wr = &rdma_req->data.wr;
2123 
2124 			if (spdk_unlikely(rqpair->ibv_in_error_state || !spdk_nvmf_qpair_is_active(&rqpair->qpair))) {
2125 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2126 				break;
2127 			}
2128 
2129 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
2130 				rdma_req->req.dif_enabled = true;
2131 			}
2132 
2133 			nvmf_rdma_check_fused_ordering(rtransport, rqpair, rdma_req);
2134 
2135 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2136 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
2137 			rdma_req->rsp.wr.imm_data = 0;
2138 #endif
2139 
2140 			/* The next state transition depends on the data transfer needs of this request. */
2141 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
2142 
2143 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
2144 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2145 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
2146 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2147 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2148 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
2149 				break;
2150 			}
2151 
2152 			/* If no data to transfer, ready to execute. */
2153 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2154 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2155 				break;
2156 			}
2157 
2158 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2159 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2160 			break;
2161 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2162 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2163 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2164 
2165 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2166 
2167 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2168 				/* This request needs to wait in line to obtain a buffer */
2169 				break;
2170 			}
2171 
2172 			/* Try to get a data buffer */
2173 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2174 			if (spdk_unlikely(rc < 0)) {
2175 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2176 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2177 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2178 				break;
2179 			}
2180 
2181 			if (rdma_req->req.iovcnt == 0) {
2182 				/* No buffers available. */
2183 				rgroup->stat.pending_data_buffer++;
2184 				break;
2185 			}
2186 
2187 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2188 
2189 			/* If data is transferring from host to controller and the data didn't
2190 			 * arrive using in capsule data, we need to do a transfer from the host.
2191 			 */
2192 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2193 			    rdma_req->req.data_from_pool) {
2194 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2195 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2196 				break;
2197 			}
2198 
2199 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2200 			break;
2201 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2202 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2203 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2204 
2205 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2206 				/* This request needs to wait in line to perform RDMA */
2207 				break;
2208 			}
2209 			assert(rqpair->max_send_depth >= rqpair->current_send_depth);
2210 			qdepth = rqpair->max_send_depth - rqpair->current_send_depth;
2211 			assert(rqpair->max_read_depth >= rqpair->current_read_depth);
2212 			num_rdma_reads_available = rqpair->max_read_depth - rqpair->current_read_depth;
2213 			if (rdma_req->num_outstanding_data_wr > qdepth ||
2214 			    rdma_req->num_outstanding_data_wr > num_rdma_reads_available) {
2215 				if (num_rdma_reads_available && qdepth) {
2216 					/* Send as much as we can */
2217 					request_prepare_transfer_in_part(&rdma_req->req, spdk_min(num_rdma_reads_available, qdepth));
2218 				} else {
2219 					/* We can only have so many WRs outstanding. we have to wait until some finish. */
2220 					rqpair->poller->stat.pending_rdma_read++;
2221 					break;
2222 				}
2223 			}
2224 
2225 			/* We have already verified that this request is the head of the queue. */
2226 			if (rdma_req->num_remaining_data_wr == 0) {
2227 				STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2228 			}
2229 
2230 			request_transfer_in(&rdma_req->req);
2231 			rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2232 
2233 			break;
2234 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2235 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2236 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2237 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2238 			 * to escape this state. */
2239 			break;
2240 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2241 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2242 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2243 
2244 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2245 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2246 					/* generate DIF for write operation */
2247 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2248 					assert(num_blocks > 0);
2249 
2250 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2251 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2252 					if (rc != 0) {
2253 						SPDK_ERRLOG("DIF generation failed\n");
2254 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2255 						spdk_nvmf_qpair_disconnect(&rqpair->qpair);
2256 						break;
2257 					}
2258 				}
2259 
2260 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2261 				/* set extended length before IO operation */
2262 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2263 			}
2264 
2265 			if (rdma_req->req.cmd->nvme_cmd.fuse != SPDK_NVME_CMD_FUSE_NONE) {
2266 				if (rdma_req->fused_failed) {
2267 					/* This request failed FUSED semantics.  Fail it immediately, without
2268 					 * even sending it to the target layer.
2269 					 */
2270 					rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2271 					rsp->status.sc = SPDK_NVME_SC_ABORTED_MISSING_FUSED;
2272 					STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2273 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2274 					break;
2275 				}
2276 
2277 				if (rdma_req->fused_pair == NULL ||
2278 				    rdma_req->fused_pair->state != RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
2279 					/* This request is ready to execute, but either we don't know yet if it's
2280 					 * valid - i.e. this is a FIRST but we haven't received the next
2281 					 * request yet or the other request of this fused pair isn't ready to
2282 					 * execute.  So break here and this request will get processed later either
2283 					 * when the other request is ready or we find that this request isn't valid.
2284 					 */
2285 					break;
2286 				}
2287 			}
2288 
2289 			/* If we get to this point, and this request is a fused command, we know that
2290 			 * it is part of valid sequence (FIRST followed by a SECOND) and that both
2291 			 * requests are READY_TO_EXECUTE. So call spdk_nvmf_request_exec() both on this
2292 			 * request, and the other request of the fused pair, in the correct order.
2293 			 * Also clear the ->fused_pair pointers on both requests, since after this point
2294 			 * we no longer need to maintain the relationship between these two requests.
2295 			 */
2296 			if (rdma_req->req.cmd->nvme_cmd.fuse == SPDK_NVME_CMD_FUSE_SECOND) {
2297 				assert(rdma_req->fused_pair != NULL);
2298 				assert(rdma_req->fused_pair->fused_pair != NULL);
2299 				rdma_req->fused_pair->state = RDMA_REQUEST_STATE_EXECUTING;
2300 				spdk_nvmf_request_exec(&rdma_req->fused_pair->req);
2301 				rdma_req->fused_pair->fused_pair = NULL;
2302 				rdma_req->fused_pair = NULL;
2303 			}
2304 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2305 			spdk_nvmf_request_exec(&rdma_req->req);
2306 			if (rdma_req->req.cmd->nvme_cmd.fuse == SPDK_NVME_CMD_FUSE_FIRST) {
2307 				assert(rdma_req->fused_pair != NULL);
2308 				assert(rdma_req->fused_pair->fused_pair != NULL);
2309 				rdma_req->fused_pair->state = RDMA_REQUEST_STATE_EXECUTING;
2310 				spdk_nvmf_request_exec(&rdma_req->fused_pair->req);
2311 				rdma_req->fused_pair->fused_pair = NULL;
2312 				rdma_req->fused_pair = NULL;
2313 			}
2314 			break;
2315 		case RDMA_REQUEST_STATE_EXECUTING:
2316 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2317 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2318 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2319 			 * to escape this state. */
2320 			break;
2321 		case RDMA_REQUEST_STATE_EXECUTED:
2322 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2323 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2324 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2325 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2326 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2327 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2328 			} else {
2329 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2330 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2331 			}
2332 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2333 				/* restore the original length */
2334 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2335 
2336 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2337 					struct spdk_dif_error error_blk;
2338 
2339 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2340 					if (!rdma_req->req.stripped_data) {
2341 						rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2342 								     &rdma_req->req.dif.dif_ctx, &error_blk);
2343 					} else {
2344 						rc = spdk_dif_verify_copy(rdma_req->req.stripped_data->iov,
2345 									  rdma_req->req.stripped_data->iovcnt,
2346 									  rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2347 									  &rdma_req->req.dif.dif_ctx, &error_blk);
2348 					}
2349 					if (rc) {
2350 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2351 
2352 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2353 							    error_blk.err_offset);
2354 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2355 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2356 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2357 						STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req, state_link);
2358 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
2359 					}
2360 				}
2361 			}
2362 			break;
2363 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2364 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2365 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2366 
2367 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2368 				/* This request needs to wait in line to perform RDMA */
2369 				break;
2370 			}
2371 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2372 			    rqpair->max_send_depth) {
2373 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2374 				 * +1 since each request has an additional wr in the resp. */
2375 				rqpair->poller->stat.pending_rdma_write++;
2376 				break;
2377 			}
2378 
2379 			/* We have already verified that this request is the head of the queue. */
2380 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2381 
2382 			/* The data transfer will be kicked off from
2383 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2384 			 * We verified that data + response fit into send queue, so we can go to the next state directly
2385 			 */
2386 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2387 			break;
2388 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING:
2389 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING, 0, 0,
2390 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2391 
2392 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_send_queue)) {
2393 				/* This request needs to wait in line to send the completion */
2394 				break;
2395 			}
2396 
2397 			assert(rqpair->current_send_depth <= rqpair->max_send_depth);
2398 			if (rqpair->current_send_depth == rqpair->max_send_depth) {
2399 				/* We can only have so many WRs outstanding. we have to wait until some finish */
2400 				rqpair->poller->stat.pending_rdma_send++;
2401 				break;
2402 			}
2403 
2404 			/* We have already verified that this request is the head of the queue. */
2405 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_send_queue, state_link);
2406 
2407 			/* The response sending will be kicked off from
2408 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2409 			 */
2410 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2411 			break;
2412 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2413 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2414 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2415 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2416 			assert(rc == 0); /* No good way to handle this currently */
2417 			if (spdk_unlikely(rc)) {
2418 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2419 			} else {
2420 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2421 						  RDMA_REQUEST_STATE_COMPLETING;
2422 			}
2423 			break;
2424 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2425 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2426 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2427 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2428 			 * to escape this state. */
2429 			break;
2430 		case RDMA_REQUEST_STATE_COMPLETING:
2431 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2432 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2433 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2434 			 * to escape this state. */
2435 			break;
2436 		case RDMA_REQUEST_STATE_COMPLETED:
2437 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2438 					  (uintptr_t)rdma_req, (uintptr_t)rqpair, rqpair->qpair.queue_depth);
2439 
2440 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2441 			_nvmf_rdma_request_free(rdma_req, rtransport);
2442 			break;
2443 		case RDMA_REQUEST_NUM_STATES:
2444 		default:
2445 			assert(0);
2446 			break;
2447 		}
2448 
2449 		if (rdma_req->state != prev_state) {
2450 			progress = true;
2451 		}
2452 	} while (rdma_req->state != prev_state);
2453 
2454 	return progress;
2455 }
2456 
2457 /* Public API callbacks begin here */
2458 
2459 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2460 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2461 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2462 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2463 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2464 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2465 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2466 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2467 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE UINT32_MAX
2468 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2469 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2470 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2471 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2472 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2473 #define SPDK_NVMF_RDMA_DEFAULT_DATA_WR_POOL_SIZE 4095
2474 
2475 static void
2476 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2477 {
2478 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2479 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2480 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2481 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2482 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2483 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2484 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2485 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2486 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2487 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2488 	opts->transport_specific =      NULL;
2489 	opts->data_wr_pool_size	=	SPDK_NVMF_RDMA_DEFAULT_DATA_WR_POOL_SIZE;
2490 }
2491 
2492 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2493 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2494 
2495 static inline bool
2496 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2497 {
2498 	return device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_OLD ||
2499 	       device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_NEW;
2500 }
2501 
2502 static int nvmf_rdma_accept(void *ctx);
2503 static bool nvmf_rdma_retry_listen_port(struct spdk_nvmf_rdma_transport *rtransport);
2504 static void destroy_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
2505 			      struct spdk_nvmf_rdma_device *device);
2506 
2507 static int
2508 create_ib_device(struct spdk_nvmf_rdma_transport *rtransport, struct ibv_context *context,
2509 		 struct spdk_nvmf_rdma_device **new_device)
2510 {
2511 	struct spdk_nvmf_rdma_device	*device;
2512 	int				flag = 0;
2513 	int				rc = 0;
2514 
2515 	device = calloc(1, sizeof(*device));
2516 	if (!device) {
2517 		SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2518 		return -ENOMEM;
2519 	}
2520 	device->context = context;
2521 	rc = ibv_query_device(device->context, &device->attr);
2522 	if (rc < 0) {
2523 		SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2524 		free(device);
2525 		return rc;
2526 	}
2527 
2528 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2529 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2530 		SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2531 		SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2532 	}
2533 
2534 	/**
2535 	 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2536 	 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2537 	 * but incorrectly reports that it does. There are changes making their way
2538 	 * through the kernel now that will enable this feature. When they are merged,
2539 	 * we can conditionally enable this feature.
2540 	 *
2541 	 * TODO: enable this for versions of the kernel rxe driver that support it.
2542 	 */
2543 	if (nvmf_rdma_is_rxe_device(device)) {
2544 		device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2545 	}
2546 #endif
2547 
2548 	/* set up device context async ev fd as NON_BLOCKING */
2549 	flag = fcntl(device->context->async_fd, F_GETFL);
2550 	rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2551 	if (rc < 0) {
2552 		SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2553 		free(device);
2554 		return rc;
2555 	}
2556 
2557 	TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2558 	SPDK_DEBUGLOG(rdma, "New device %p is added to RDMA transport\n", device);
2559 
2560 	if (g_nvmf_hooks.get_ibv_pd) {
2561 		device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2562 	} else {
2563 		device->pd = ibv_alloc_pd(device->context);
2564 	}
2565 
2566 	if (!device->pd) {
2567 		SPDK_ERRLOG("Unable to allocate protection domain.\n");
2568 		destroy_ib_device(rtransport, device);
2569 		return -ENOMEM;
2570 	}
2571 
2572 	assert(device->map == NULL);
2573 
2574 	device->map = spdk_rdma_utils_create_mem_map(device->pd, &g_nvmf_hooks, IBV_ACCESS_LOCAL_WRITE);
2575 	if (!device->map) {
2576 		SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2577 		destroy_ib_device(rtransport, device);
2578 		return -ENOMEM;
2579 	}
2580 
2581 	assert(device->map != NULL);
2582 	assert(device->pd != NULL);
2583 
2584 	if (new_device) {
2585 		*new_device = device;
2586 	}
2587 	SPDK_NOTICELOG("Create IB device %s(%p/%p) succeed.\n", ibv_get_device_name(context->device),
2588 		       device, context);
2589 
2590 	return 0;
2591 }
2592 
2593 static void
2594 free_poll_fds(struct spdk_nvmf_rdma_transport *rtransport)
2595 {
2596 	if (rtransport->poll_fds) {
2597 		free(rtransport->poll_fds);
2598 		rtransport->poll_fds = NULL;
2599 	}
2600 	rtransport->npoll_fds = 0;
2601 }
2602 
2603 static int
2604 generate_poll_fds(struct spdk_nvmf_rdma_transport *rtransport)
2605 {
2606 	/* Set up poll descriptor array to monitor events from RDMA and IB
2607 	 * in a single poll syscall
2608 	 */
2609 	int device_count = 0;
2610 	int i = 0;
2611 	struct spdk_nvmf_rdma_device *device, *tmp;
2612 
2613 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2614 		device_count++;
2615 	}
2616 
2617 	rtransport->npoll_fds = device_count + 1;
2618 
2619 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2620 	if (rtransport->poll_fds == NULL) {
2621 		SPDK_ERRLOG("poll_fds allocation failed\n");
2622 		return -ENOMEM;
2623 	}
2624 
2625 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2626 	rtransport->poll_fds[i++].events = POLLIN;
2627 
2628 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2629 		rtransport->poll_fds[i].fd = device->context->async_fd;
2630 		rtransport->poll_fds[i++].events = POLLIN;
2631 	}
2632 
2633 	return 0;
2634 }
2635 
2636 static struct spdk_nvmf_transport *
2637 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2638 {
2639 	int rc;
2640 	struct spdk_nvmf_rdma_transport *rtransport;
2641 	struct spdk_nvmf_rdma_device	*device;
2642 	struct ibv_context		**contexts;
2643 	size_t				data_wr_pool_size;
2644 	uint32_t			i;
2645 	int				flag;
2646 	uint32_t			sge_count;
2647 	uint32_t			min_shared_buffers;
2648 	uint32_t			min_in_capsule_data_size;
2649 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2650 
2651 	rtransport = calloc(1, sizeof(*rtransport));
2652 	if (!rtransport) {
2653 		return NULL;
2654 	}
2655 
2656 	TAILQ_INIT(&rtransport->devices);
2657 	TAILQ_INIT(&rtransport->ports);
2658 	TAILQ_INIT(&rtransport->poll_groups);
2659 	TAILQ_INIT(&rtransport->retry_ports);
2660 
2661 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2662 	rtransport->rdma_opts.num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2663 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2664 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2665 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2666 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2667 	if (opts->transport_specific != NULL &&
2668 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2669 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2670 					    &rtransport->rdma_opts)) {
2671 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2672 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2673 		return NULL;
2674 	}
2675 
2676 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2677 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2678 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2679 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2680 		     "  num_shared_buffers=%d, num_cqe=%d, max_srq_depth=%d, no_srq=%d,"
2681 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2682 		     opts->max_queue_depth,
2683 		     opts->max_io_size,
2684 		     opts->max_qpairs_per_ctrlr - 1,
2685 		     opts->io_unit_size,
2686 		     opts->in_capsule_data_size,
2687 		     opts->max_aq_depth,
2688 		     opts->num_shared_buffers,
2689 		     rtransport->rdma_opts.num_cqe,
2690 		     rtransport->rdma_opts.max_srq_depth,
2691 		     rtransport->rdma_opts.no_srq,
2692 		     rtransport->rdma_opts.acceptor_backlog,
2693 		     rtransport->rdma_opts.no_wr_batching,
2694 		     opts->abort_timeout_sec);
2695 
2696 	/* I/O unit size cannot be larger than max I/O size */
2697 	if (opts->io_unit_size > opts->max_io_size) {
2698 		opts->io_unit_size = opts->max_io_size;
2699 	}
2700 
2701 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2702 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2703 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2704 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2705 	}
2706 
2707 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2708 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2709 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2710 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2711 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2712 		return NULL;
2713 	}
2714 
2715 	/* If buf_cache_size == UINT32_MAX, we will dynamically pick a cache size later that we know will fit. */
2716 	if (opts->buf_cache_size < UINT32_MAX) {
2717 		min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2718 		if (min_shared_buffers > opts->num_shared_buffers) {
2719 			SPDK_ERRLOG("There are not enough buffers to satisfy"
2720 				    "per-poll group caches for each thread. (%" PRIu32 ")"
2721 				    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2722 			SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2723 			nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2724 			return NULL;
2725 		}
2726 	}
2727 
2728 	sge_count = opts->max_io_size / opts->io_unit_size;
2729 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2730 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2731 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2732 		return NULL;
2733 	}
2734 
2735 	min_in_capsule_data_size = sizeof(struct spdk_nvme_sgl_descriptor) * SPDK_NVMF_MAX_SGL_ENTRIES;
2736 	if (opts->in_capsule_data_size < min_in_capsule_data_size) {
2737 		SPDK_WARNLOG("In capsule data size is set to %u, this is minimum size required to support msdbd=16\n",
2738 			     min_in_capsule_data_size);
2739 		opts->in_capsule_data_size = min_in_capsule_data_size;
2740 	}
2741 
2742 	rtransport->event_channel = rdma_create_event_channel();
2743 	if (rtransport->event_channel == NULL) {
2744 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2745 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2746 		return NULL;
2747 	}
2748 
2749 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2750 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2751 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2752 			    rtransport->event_channel->fd, spdk_strerror(errno));
2753 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2754 		return NULL;
2755 	}
2756 
2757 	data_wr_pool_size = opts->data_wr_pool_size;
2758 	if (data_wr_pool_size < SPDK_NVMF_MAX_SGL_ENTRIES * 2 * spdk_env_get_core_count()) {
2759 		data_wr_pool_size = SPDK_NVMF_MAX_SGL_ENTRIES * 2 * spdk_env_get_core_count();
2760 		SPDK_NOTICELOG("data_wr_pool_size is changed to %zu to guarantee enough cache for handling "
2761 			       "at least one IO in each core\n", data_wr_pool_size);
2762 	}
2763 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data", data_wr_pool_size,
2764 				   sizeof(struct spdk_nvmf_rdma_request_data), SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2765 				   SPDK_ENV_NUMA_ID_ANY);
2766 	if (!rtransport->data_wr_pool) {
2767 		if (spdk_mempool_lookup("spdk_nvmf_rdma_wr_data") != NULL) {
2768 			SPDK_ERRLOG("Unable to allocate work request pool for poll group: already exists\n");
2769 			SPDK_ERRLOG("Probably running in multiprocess environment, which is "
2770 				    "unsupported by the nvmf library\n");
2771 		} else {
2772 			SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2773 		}
2774 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2775 		return NULL;
2776 	}
2777 
2778 	contexts = rdma_get_devices(NULL);
2779 	if (contexts == NULL) {
2780 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2781 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2782 		return NULL;
2783 	}
2784 
2785 	i = 0;
2786 	rc = 0;
2787 	while (contexts[i] != NULL) {
2788 		rc = create_ib_device(rtransport, contexts[i], &device);
2789 		if (rc < 0) {
2790 			break;
2791 		}
2792 		i++;
2793 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2794 		device->is_ready = true;
2795 	}
2796 	rdma_free_devices(contexts);
2797 
2798 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2799 		/* divide and round up. */
2800 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2801 
2802 		/* round up to the nearest 4k. */
2803 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2804 
2805 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2806 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2807 			       opts->io_unit_size);
2808 	}
2809 
2810 	if (rc < 0) {
2811 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2812 		return NULL;
2813 	}
2814 
2815 	rc = generate_poll_fds(rtransport);
2816 	if (rc < 0) {
2817 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2818 		return NULL;
2819 	}
2820 
2821 	rtransport->accept_poller = SPDK_POLLER_REGISTER(nvmf_rdma_accept, &rtransport->transport,
2822 				    opts->acceptor_poll_rate);
2823 	if (!rtransport->accept_poller) {
2824 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2825 		return NULL;
2826 	}
2827 
2828 	return &rtransport->transport;
2829 }
2830 
2831 static void
2832 destroy_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
2833 		  struct spdk_nvmf_rdma_device *device)
2834 {
2835 	TAILQ_REMOVE(&rtransport->devices, device, link);
2836 	spdk_rdma_utils_free_mem_map(&device->map);
2837 	if (device->pd) {
2838 		if (!g_nvmf_hooks.get_ibv_pd) {
2839 			ibv_dealloc_pd(device->pd);
2840 		}
2841 	}
2842 	SPDK_DEBUGLOG(rdma, "IB device [%p] is destroyed.\n", device);
2843 	free(device);
2844 }
2845 
2846 static void
2847 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2848 {
2849 	struct spdk_nvmf_rdma_transport	*rtransport;
2850 	assert(w != NULL);
2851 
2852 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2853 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2854 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2855 	if (rtransport->rdma_opts.no_srq == true) {
2856 		spdk_json_write_named_int32(w, "num_cqe", rtransport->rdma_opts.num_cqe);
2857 	}
2858 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2859 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2860 }
2861 
2862 static int
2863 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2864 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2865 {
2866 	struct spdk_nvmf_rdma_transport	*rtransport;
2867 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2868 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2869 
2870 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2871 
2872 	TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, port_tmp) {
2873 		TAILQ_REMOVE(&rtransport->retry_ports, port, link);
2874 		free(port);
2875 	}
2876 
2877 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2878 		TAILQ_REMOVE(&rtransport->ports, port, link);
2879 		rdma_destroy_id(port->id);
2880 		free(port);
2881 	}
2882 
2883 	free_poll_fds(rtransport);
2884 
2885 	if (rtransport->event_channel != NULL) {
2886 		rdma_destroy_event_channel(rtransport->event_channel);
2887 	}
2888 
2889 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2890 		destroy_ib_device(rtransport, device);
2891 	}
2892 
2893 	if (rtransport->data_wr_pool != NULL) {
2894 		if (spdk_mempool_count(rtransport->data_wr_pool) != transport->opts.data_wr_pool_size) {
2895 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2896 				    spdk_mempool_count(rtransport->data_wr_pool),
2897 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2898 		}
2899 	}
2900 
2901 	spdk_mempool_free(rtransport->data_wr_pool);
2902 
2903 	spdk_poller_unregister(&rtransport->accept_poller);
2904 	free(rtransport);
2905 
2906 	if (cb_fn) {
2907 		cb_fn(cb_arg);
2908 	}
2909 	return 0;
2910 }
2911 
2912 static int nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2913 				     struct spdk_nvme_transport_id *trid,
2914 				     bool peer);
2915 
2916 static bool nvmf_rdma_rescan_devices(struct spdk_nvmf_rdma_transport *rtransport);
2917 
2918 static int
2919 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2920 		 struct spdk_nvmf_listen_opts *listen_opts)
2921 {
2922 	struct spdk_nvmf_rdma_transport	*rtransport;
2923 	struct spdk_nvmf_rdma_device	*device;
2924 	struct spdk_nvmf_rdma_port	*port, *tmp_port;
2925 	struct addrinfo			*res;
2926 	struct addrinfo			hints;
2927 	int				family;
2928 	int				rc;
2929 	long int			port_val;
2930 	bool				is_retry = false;
2931 
2932 	if (!strlen(trid->trsvcid)) {
2933 		SPDK_ERRLOG("Service id is required\n");
2934 		return -EINVAL;
2935 	}
2936 
2937 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2938 	assert(rtransport->event_channel != NULL);
2939 
2940 	port = calloc(1, sizeof(*port));
2941 	if (!port) {
2942 		SPDK_ERRLOG("Port allocation failed\n");
2943 		return -ENOMEM;
2944 	}
2945 
2946 	port->trid = trid;
2947 
2948 	switch (trid->adrfam) {
2949 	case SPDK_NVMF_ADRFAM_IPV4:
2950 		family = AF_INET;
2951 		break;
2952 	case SPDK_NVMF_ADRFAM_IPV6:
2953 		family = AF_INET6;
2954 		break;
2955 	default:
2956 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2957 		free(port);
2958 		return -EINVAL;
2959 	}
2960 
2961 	memset(&hints, 0, sizeof(hints));
2962 	hints.ai_family = family;
2963 	hints.ai_flags = AI_NUMERICSERV;
2964 	hints.ai_socktype = SOCK_STREAM;
2965 	hints.ai_protocol = 0;
2966 
2967 	/* Range check the trsvcid. Fail in 3 cases:
2968 	 * < 0: means that spdk_strtol hit an error
2969 	 * 0: this results in ephemeral port which we don't want
2970 	 * > 65535: port too high
2971 	 */
2972 	port_val = spdk_strtol(trid->trsvcid, 10);
2973 	if (port_val <= 0 || port_val > 65535) {
2974 		SPDK_ERRLOG("invalid trsvcid %s\n", trid->trsvcid);
2975 		free(port);
2976 		return -EINVAL;
2977 	}
2978 
2979 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2980 	if (rc) {
2981 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2982 		free(port);
2983 		return -(abs(rc));
2984 	}
2985 
2986 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2987 	if (rc < 0) {
2988 		SPDK_ERRLOG("rdma_create_id() failed\n");
2989 		freeaddrinfo(res);
2990 		free(port);
2991 		return rc;
2992 	}
2993 
2994 	rc = rdma_bind_addr(port->id, res->ai_addr);
2995 	freeaddrinfo(res);
2996 
2997 	if (rc < 0) {
2998 		TAILQ_FOREACH(tmp_port, &rtransport->retry_ports, link) {
2999 			if (spdk_nvme_transport_id_compare(tmp_port->trid, trid) == 0) {
3000 				is_retry = true;
3001 				break;
3002 			}
3003 		}
3004 		if (!is_retry) {
3005 			SPDK_ERRLOG("rdma_bind_addr() failed\n");
3006 		}
3007 		rdma_destroy_id(port->id);
3008 		free(port);
3009 		return rc;
3010 	}
3011 
3012 	if (!port->id->verbs) {
3013 		SPDK_ERRLOG("ibv_context is null\n");
3014 		rdma_destroy_id(port->id);
3015 		free(port);
3016 		return -1;
3017 	}
3018 
3019 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
3020 	if (rc < 0) {
3021 		SPDK_ERRLOG("rdma_listen() failed\n");
3022 		rdma_destroy_id(port->id);
3023 		free(port);
3024 		return rc;
3025 	}
3026 
3027 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3028 		if (device->context == port->id->verbs && device->is_ready) {
3029 			port->device = device;
3030 			break;
3031 		}
3032 	}
3033 	if (!port->device) {
3034 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
3035 			    port->id->verbs);
3036 		rdma_destroy_id(port->id);
3037 		free(port);
3038 		nvmf_rdma_rescan_devices(rtransport);
3039 		return -EINVAL;
3040 	}
3041 
3042 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
3043 		       trid->traddr, trid->trsvcid);
3044 
3045 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
3046 	return 0;
3047 }
3048 
3049 static void
3050 nvmf_rdma_stop_listen_ex(struct spdk_nvmf_transport *transport,
3051 			 const struct spdk_nvme_transport_id *trid, bool need_retry)
3052 {
3053 	struct spdk_nvmf_rdma_transport	*rtransport;
3054 	struct spdk_nvmf_rdma_port	*port, *tmp;
3055 
3056 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3057 
3058 	if (!need_retry) {
3059 		TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, tmp) {
3060 			if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
3061 				TAILQ_REMOVE(&rtransport->retry_ports, port, link);
3062 				free(port);
3063 			}
3064 		}
3065 	}
3066 
3067 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
3068 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
3069 			SPDK_DEBUGLOG(rdma, "Port %s:%s removed. need retry: %d\n",
3070 				      port->trid->traddr, port->trid->trsvcid, need_retry);
3071 			TAILQ_REMOVE(&rtransport->ports, port, link);
3072 			rdma_destroy_id(port->id);
3073 			port->id = NULL;
3074 			port->device = NULL;
3075 			if (need_retry) {
3076 				TAILQ_INSERT_TAIL(&rtransport->retry_ports, port, link);
3077 			} else {
3078 				free(port);
3079 			}
3080 			break;
3081 		}
3082 	}
3083 }
3084 
3085 static void
3086 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
3087 		      const struct spdk_nvme_transport_id *trid)
3088 {
3089 	nvmf_rdma_stop_listen_ex(transport, trid, false);
3090 }
3091 
3092 static void _nvmf_rdma_register_poller_in_group(void *c);
3093 static void _nvmf_rdma_remove_poller_in_group(void *c);
3094 
3095 static bool
3096 nvmf_rdma_all_pollers_management_done(void *c)
3097 {
3098 	struct poller_manage_ctx	*ctx = c;
3099 	int				counter;
3100 
3101 	counter = __atomic_sub_fetch(ctx->inflight_op_counter, 1, __ATOMIC_SEQ_CST);
3102 	SPDK_DEBUGLOG(rdma, "nvmf_rdma_all_pollers_management_done called. counter: %d, poller: %p\n",
3103 		      counter, ctx->rpoller);
3104 
3105 	if (counter == 0) {
3106 		free((void *)ctx->inflight_op_counter);
3107 	}
3108 	free(ctx);
3109 
3110 	return counter == 0;
3111 }
3112 
3113 static int
3114 nvmf_rdma_manage_poller(struct spdk_nvmf_rdma_transport *rtransport,
3115 			struct spdk_nvmf_rdma_device *device, bool *has_inflight, bool is_add)
3116 {
3117 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3118 	struct spdk_nvmf_rdma_poller		*rpoller;
3119 	struct spdk_nvmf_poll_group		*poll_group;
3120 	struct poller_manage_ctx		*ctx;
3121 	bool					found;
3122 	int					*inflight_counter;
3123 	spdk_msg_fn				do_fn;
3124 
3125 	*has_inflight = false;
3126 	do_fn = is_add ? _nvmf_rdma_register_poller_in_group : _nvmf_rdma_remove_poller_in_group;
3127 	inflight_counter = calloc(1, sizeof(int));
3128 	if (!inflight_counter) {
3129 		SPDK_ERRLOG("Failed to allocate inflight counter when removing pollers\n");
3130 		return -ENOMEM;
3131 	}
3132 
3133 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3134 		(*inflight_counter)++;
3135 	}
3136 
3137 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3138 		found = false;
3139 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3140 			if (rpoller->device == device) {
3141 				found = true;
3142 				break;
3143 			}
3144 		}
3145 		if (found == is_add) {
3146 			__atomic_fetch_sub(inflight_counter, 1, __ATOMIC_SEQ_CST);
3147 			continue;
3148 		}
3149 
3150 		ctx = calloc(1, sizeof(struct poller_manage_ctx));
3151 		if (!ctx) {
3152 			SPDK_ERRLOG("Failed to allocate poller_manage_ctx when removing pollers\n");
3153 			if (!*has_inflight) {
3154 				free(inflight_counter);
3155 			}
3156 			return -ENOMEM;
3157 		}
3158 
3159 		ctx->rtransport = rtransport;
3160 		ctx->rgroup = rgroup;
3161 		ctx->rpoller = rpoller;
3162 		ctx->device = device;
3163 		ctx->thread = spdk_get_thread();
3164 		ctx->inflight_op_counter = inflight_counter;
3165 		*has_inflight = true;
3166 
3167 		poll_group = rgroup->group.group;
3168 		if (poll_group->thread != spdk_get_thread()) {
3169 			spdk_thread_send_msg(poll_group->thread, do_fn, ctx);
3170 		} else {
3171 			do_fn(ctx);
3172 		}
3173 	}
3174 
3175 	if (!*has_inflight) {
3176 		free(inflight_counter);
3177 	}
3178 
3179 	return 0;
3180 }
3181 
3182 static void nvmf_rdma_handle_device_removal(struct spdk_nvmf_rdma_transport *rtransport,
3183 		struct spdk_nvmf_rdma_device *device);
3184 
3185 static struct spdk_nvmf_rdma_device *
3186 nvmf_rdma_find_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
3187 			 struct ibv_context *context)
3188 {
3189 	struct spdk_nvmf_rdma_device	*device, *tmp_device;
3190 
3191 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp_device) {
3192 		if (device->need_destroy) {
3193 			continue;
3194 		}
3195 
3196 		if (strcmp(device->context->device->dev_name, context->device->dev_name) == 0) {
3197 			return device;
3198 		}
3199 	}
3200 
3201 	return NULL;
3202 }
3203 
3204 static bool
3205 nvmf_rdma_check_devices_context(struct spdk_nvmf_rdma_transport *rtransport,
3206 				struct ibv_context *context)
3207 {
3208 	struct spdk_nvmf_rdma_device	*old_device, *new_device;
3209 	int				rc = 0;
3210 	bool				has_inflight;
3211 
3212 	old_device = nvmf_rdma_find_ib_device(rtransport, context);
3213 
3214 	if (old_device) {
3215 		if (old_device->context != context && !old_device->need_destroy && old_device->is_ready) {
3216 			/* context may not have time to be cleaned when rescan. exactly one context
3217 			 * is valid for a device so this context must be invalid and just remove it. */
3218 			SPDK_WARNLOG("Device %p has a invalid context %p\n", old_device, old_device->context);
3219 			old_device->need_destroy = true;
3220 			nvmf_rdma_handle_device_removal(rtransport, old_device);
3221 		}
3222 		return false;
3223 	}
3224 
3225 	rc = create_ib_device(rtransport, context, &new_device);
3226 	/* TODO: update transport opts. */
3227 	if (rc < 0) {
3228 		SPDK_ERRLOG("Failed to create ib device for context: %s(%p)\n",
3229 			    ibv_get_device_name(context->device), context);
3230 		return false;
3231 	}
3232 
3233 	rc = nvmf_rdma_manage_poller(rtransport, new_device, &has_inflight, true);
3234 	if (rc < 0) {
3235 		SPDK_ERRLOG("Failed to add poller for device context: %s(%p)\n",
3236 			    ibv_get_device_name(context->device), context);
3237 		return false;
3238 	}
3239 
3240 	if (has_inflight) {
3241 		new_device->is_ready = true;
3242 	}
3243 
3244 	return true;
3245 }
3246 
3247 static bool
3248 nvmf_rdma_rescan_devices(struct spdk_nvmf_rdma_transport *rtransport)
3249 {
3250 	struct spdk_nvmf_rdma_device	*device;
3251 	struct ibv_device		**ibv_device_list = NULL;
3252 	struct ibv_context		**contexts = NULL;
3253 	int				i = 0;
3254 	int				num_dev = 0;
3255 	bool				new_create = false, has_new_device = false;
3256 	struct ibv_context		*tmp_verbs = NULL;
3257 
3258 	/* do not rescan when any device is destroying, or context may be freed when
3259 	 * regenerating the poll fds.
3260 	 */
3261 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3262 		if (device->need_destroy) {
3263 			return false;
3264 		}
3265 	}
3266 
3267 	ibv_device_list = ibv_get_device_list(&num_dev);
3268 
3269 	/* There is a bug in librdmacm. If verbs init failed in rdma_get_devices, it'll be
3270 	 * marked as dead verbs and never be init again. So we need to make sure the
3271 	 * verbs is available before we call rdma_get_devices. */
3272 	if (num_dev >= 0) {
3273 		for (i = 0; i < num_dev; i++) {
3274 			tmp_verbs = ibv_open_device(ibv_device_list[i]);
3275 			if (!tmp_verbs) {
3276 				SPDK_WARNLOG("Failed to init ibv device %p, err %d. Skip rescan.\n", ibv_device_list[i], errno);
3277 				break;
3278 			}
3279 			if (nvmf_rdma_find_ib_device(rtransport, tmp_verbs) == NULL) {
3280 				SPDK_DEBUGLOG(rdma, "Find new verbs init ibv device %p(%s).\n", ibv_device_list[i],
3281 					      tmp_verbs->device->dev_name);
3282 				has_new_device = true;
3283 			}
3284 			ibv_close_device(tmp_verbs);
3285 		}
3286 		ibv_free_device_list(ibv_device_list);
3287 		if (!tmp_verbs || !has_new_device) {
3288 			return false;
3289 		}
3290 	}
3291 
3292 	contexts = rdma_get_devices(NULL);
3293 
3294 	for (i = 0; contexts && contexts[i] != NULL; i++) {
3295 		new_create |= nvmf_rdma_check_devices_context(rtransport, contexts[i]);
3296 	}
3297 
3298 	if (new_create) {
3299 		free_poll_fds(rtransport);
3300 		generate_poll_fds(rtransport);
3301 	}
3302 
3303 	if (contexts) {
3304 		rdma_free_devices(contexts);
3305 	}
3306 
3307 	return new_create;
3308 }
3309 
3310 static bool
3311 nvmf_rdma_retry_listen_port(struct spdk_nvmf_rdma_transport *rtransport)
3312 {
3313 	struct spdk_nvmf_rdma_port	*port, *tmp_port;
3314 	int				rc = 0;
3315 	bool				new_create = false;
3316 
3317 	if (TAILQ_EMPTY(&rtransport->retry_ports)) {
3318 		return false;
3319 	}
3320 
3321 	new_create = nvmf_rdma_rescan_devices(rtransport);
3322 
3323 	TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, tmp_port) {
3324 		rc = nvmf_rdma_listen(&rtransport->transport, port->trid, NULL);
3325 
3326 		TAILQ_REMOVE(&rtransport->retry_ports, port, link);
3327 		if (rc) {
3328 			if (new_create) {
3329 				SPDK_ERRLOG("Found new IB device but port %s:%s is still failed(%d) to listen.\n",
3330 					    port->trid->traddr, port->trid->trsvcid, rc);
3331 			}
3332 			TAILQ_INSERT_TAIL(&rtransport->retry_ports, port, link);
3333 			break;
3334 		} else {
3335 			SPDK_NOTICELOG("Port %s:%s come back\n", port->trid->traddr, port->trid->trsvcid);
3336 			free(port);
3337 		}
3338 	}
3339 
3340 	return true;
3341 }
3342 
3343 static void
3344 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
3345 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
3346 {
3347 	struct spdk_nvmf_request *req, *tmp;
3348 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
3349 	struct spdk_nvmf_rdma_resources *resources;
3350 
3351 	/* First process requests which are waiting for response to be sent */
3352 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_send_queue, state_link, req_tmp) {
3353 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3354 			break;
3355 		}
3356 	}
3357 
3358 	/* We process I/O in the data transfer pending queue at the highest priority. */
3359 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
3360 		if (rdma_req->state != RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
3361 			/* Requests in this queue might be in state RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
3362 			 * they are transmitting data over network but we keep them in the list to guarantee
3363 			 * fair processing. */
3364 			continue;
3365 		}
3366 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3367 			break;
3368 		}
3369 	}
3370 
3371 	/* Then RDMA writes since reads have stronger restrictions than writes */
3372 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
3373 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3374 			break;
3375 		}
3376 	}
3377 
3378 	/* Then we handle request waiting on memory buffers. */
3379 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
3380 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3381 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3382 			break;
3383 		}
3384 	}
3385 
3386 	resources = rqpair->resources;
3387 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
3388 		rdma_req = STAILQ_FIRST(&resources->free_queue);
3389 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
3390 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
3391 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
3392 
3393 		if (rqpair->srq != NULL) {
3394 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
3395 			rdma_req->recv->qpair->qd++;
3396 		} else {
3397 			rqpair->qd++;
3398 		}
3399 
3400 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
3401 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
3402 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
3403 			break;
3404 		}
3405 	}
3406 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
3407 		rqpair->poller->stat.pending_free_request++;
3408 	}
3409 }
3410 
3411 static void
3412 nvmf_rdma_poller_process_pending_buf_queue(struct spdk_nvmf_rdma_transport *rtransport,
3413 		struct spdk_nvmf_rdma_poller *rpoller)
3414 {
3415 	struct spdk_nvmf_request *req, *tmp;
3416 	struct spdk_nvmf_rdma_request *rdma_req;
3417 
3418 	STAILQ_FOREACH_SAFE(req, &rpoller->group->group.pending_buf_queue, buf_link, tmp) {
3419 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3420 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
3421 			break;
3422 		}
3423 	}
3424 }
3425 
3426 static inline bool
3427 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
3428 {
3429 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
3430 	return nvmf_rdma_is_rxe_device(device) ||
3431 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
3432 }
3433 
3434 static void
3435 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
3436 {
3437 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3438 			struct spdk_nvmf_rdma_transport, transport);
3439 
3440 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3441 
3442 	/* nvmf_rdma_close_qpair is not called */
3443 	if (!rqpair->to_close) {
3444 		return;
3445 	}
3446 
3447 	/* device is already destroyed and we should force destroy this qpair. */
3448 	if (rqpair->poller && rqpair->poller->need_destroy) {
3449 		nvmf_rdma_qpair_destroy(rqpair);
3450 		return;
3451 	}
3452 
3453 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
3454 	if (rqpair->current_send_depth != 0) {
3455 		return;
3456 	}
3457 
3458 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
3459 		return;
3460 	}
3461 
3462 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
3463 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
3464 		return;
3465 	}
3466 
3467 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
3468 
3469 	nvmf_rdma_qpair_destroy(rqpair);
3470 }
3471 
3472 static int
3473 nvmf_rdma_disconnect(struct rdma_cm_event *evt, bool *event_acked)
3474 {
3475 	struct spdk_nvmf_qpair		*qpair;
3476 	struct spdk_nvmf_rdma_qpair	*rqpair;
3477 
3478 	if (evt->id == NULL) {
3479 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
3480 		return -1;
3481 	}
3482 
3483 	qpair = evt->id->context;
3484 	if (qpair == NULL) {
3485 		SPDK_ERRLOG("disconnect request: no active connection\n");
3486 		return -1;
3487 	}
3488 
3489 	rdma_ack_cm_event(evt);
3490 	*event_acked = true;
3491 
3492 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3493 
3494 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair);
3495 
3496 	spdk_nvmf_qpair_disconnect(&rqpair->qpair);
3497 
3498 	return 0;
3499 }
3500 
3501 #ifdef DEBUG
3502 static const char *CM_EVENT_STR[] = {
3503 	"RDMA_CM_EVENT_ADDR_RESOLVED",
3504 	"RDMA_CM_EVENT_ADDR_ERROR",
3505 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
3506 	"RDMA_CM_EVENT_ROUTE_ERROR",
3507 	"RDMA_CM_EVENT_CONNECT_REQUEST",
3508 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
3509 	"RDMA_CM_EVENT_CONNECT_ERROR",
3510 	"RDMA_CM_EVENT_UNREACHABLE",
3511 	"RDMA_CM_EVENT_REJECTED",
3512 	"RDMA_CM_EVENT_ESTABLISHED",
3513 	"RDMA_CM_EVENT_DISCONNECTED",
3514 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
3515 	"RDMA_CM_EVENT_MULTICAST_JOIN",
3516 	"RDMA_CM_EVENT_MULTICAST_ERROR",
3517 	"RDMA_CM_EVENT_ADDR_CHANGE",
3518 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
3519 };
3520 #endif /* DEBUG */
3521 
3522 static void
3523 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
3524 				    struct spdk_nvmf_rdma_port *port)
3525 {
3526 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3527 	struct spdk_nvmf_rdma_poller		*rpoller;
3528 	struct spdk_nvmf_rdma_qpair		*rqpair;
3529 
3530 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3531 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3532 			RB_FOREACH(rqpair, qpairs_tree, &rpoller->qpairs) {
3533 				if (rqpair->listen_id == port->id) {
3534 					spdk_nvmf_qpair_disconnect(&rqpair->qpair);
3535 				}
3536 			}
3537 		}
3538 	}
3539 }
3540 
3541 static bool
3542 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
3543 				      struct rdma_cm_event *event)
3544 {
3545 	const struct spdk_nvme_transport_id	*trid;
3546 	struct spdk_nvmf_rdma_port		*port;
3547 	struct spdk_nvmf_rdma_transport		*rtransport;
3548 	bool					event_acked = false;
3549 
3550 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3551 	TAILQ_FOREACH(port, &rtransport->ports, link) {
3552 		if (port->id == event->id) {
3553 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
3554 			rdma_ack_cm_event(event);
3555 			event_acked = true;
3556 			trid = port->trid;
3557 			break;
3558 		}
3559 	}
3560 
3561 	if (event_acked) {
3562 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
3563 
3564 		nvmf_rdma_stop_listen(transport, trid);
3565 		nvmf_rdma_listen(transport, trid, NULL);
3566 	}
3567 
3568 	return event_acked;
3569 }
3570 
3571 static void
3572 nvmf_rdma_handle_device_removal(struct spdk_nvmf_rdma_transport *rtransport,
3573 				struct spdk_nvmf_rdma_device *device)
3574 {
3575 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
3576 	int				rc;
3577 	bool				has_inflight;
3578 
3579 	rc = nvmf_rdma_manage_poller(rtransport, device, &has_inflight, false);
3580 	if (rc) {
3581 		SPDK_ERRLOG("Failed to handle device removal, rc %d\n", rc);
3582 		return;
3583 	}
3584 
3585 	if (!has_inflight) {
3586 		/* no pollers, destroy the device */
3587 		device->ready_to_destroy = true;
3588 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_remove_destroyed_device, rtransport);
3589 	}
3590 
3591 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
3592 		if (port->device == device) {
3593 			SPDK_NOTICELOG("Port %s:%s on device %s is being removed.\n",
3594 				       port->trid->traddr,
3595 				       port->trid->trsvcid,
3596 				       ibv_get_device_name(port->device->context->device));
3597 
3598 			/* keep NVMF listener and only destroy structures of the
3599 			 * RDMA transport. when the device comes back we can retry listening
3600 			 * and the application's workflow will not be interrupted.
3601 			 */
3602 			nvmf_rdma_stop_listen_ex(&rtransport->transport, port->trid, true);
3603 		}
3604 	}
3605 }
3606 
3607 static void
3608 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
3609 				       struct rdma_cm_event *event)
3610 {
3611 	struct spdk_nvmf_rdma_port		*port, *tmp_port;
3612 	struct spdk_nvmf_rdma_transport		*rtransport;
3613 
3614 	port = event->id->context;
3615 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3616 
3617 	rdma_ack_cm_event(event);
3618 
3619 	/* if device removal happens during ctrl qpair disconnecting, it's possible that we receive
3620 	 * an DEVICE_REMOVAL event on qpair but the id->qp is just NULL. So we should make sure that
3621 	 * we are handling a port event here.
3622 	 */
3623 	TAILQ_FOREACH(tmp_port, &rtransport->ports, link) {
3624 		if (port == tmp_port && port->device && !port->device->need_destroy) {
3625 			port->device->need_destroy = true;
3626 			nvmf_rdma_handle_device_removal(rtransport, port->device);
3627 		}
3628 	}
3629 }
3630 
3631 static void
3632 nvmf_process_cm_events(struct spdk_nvmf_transport *transport, uint32_t max_events)
3633 {
3634 	struct spdk_nvmf_rdma_transport *rtransport;
3635 	struct rdma_cm_event		*event;
3636 	uint32_t			i;
3637 	int				rc;
3638 	bool				event_acked;
3639 
3640 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3641 
3642 	if (rtransport->event_channel == NULL) {
3643 		return;
3644 	}
3645 
3646 	for (i = 0; i < max_events; i++) {
3647 		event_acked = false;
3648 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
3649 		if (rc) {
3650 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
3651 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
3652 			}
3653 			break;
3654 		}
3655 
3656 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
3657 
3658 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
3659 
3660 		switch (event->event) {
3661 		case RDMA_CM_EVENT_ADDR_RESOLVED:
3662 		case RDMA_CM_EVENT_ADDR_ERROR:
3663 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
3664 		case RDMA_CM_EVENT_ROUTE_ERROR:
3665 			/* No action required. The target never attempts to resolve routes. */
3666 			break;
3667 		case RDMA_CM_EVENT_CONNECT_REQUEST:
3668 			rc = nvmf_rdma_connect(transport, event);
3669 			if (rc < 0) {
3670 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
3671 				break;
3672 			}
3673 			break;
3674 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
3675 			/* The target never initiates a new connection. So this will not occur. */
3676 			break;
3677 		case RDMA_CM_EVENT_CONNECT_ERROR:
3678 			/* Can this happen? The docs say it can, but not sure what causes it. */
3679 			break;
3680 		case RDMA_CM_EVENT_UNREACHABLE:
3681 		case RDMA_CM_EVENT_REJECTED:
3682 			/* These only occur on the client side. */
3683 			break;
3684 		case RDMA_CM_EVENT_ESTABLISHED:
3685 			/* TODO: Should we be waiting for this event anywhere? */
3686 			break;
3687 		case RDMA_CM_EVENT_DISCONNECTED:
3688 			rc = nvmf_rdma_disconnect(event, &event_acked);
3689 			if (rc < 0) {
3690 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3691 				break;
3692 			}
3693 			break;
3694 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
3695 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
3696 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
3697 			 * Once these events are sent to SPDK, we should release all IB resources and
3698 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
3699 			 * ibv_destroy* functions to release user space memory allocated by IB. All kernel
3700 			 * resources are already cleaned. */
3701 			if (event->id->qp) {
3702 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
3703 				 * corresponding qpair. Otherwise the event refers to a listening device. */
3704 				rc = nvmf_rdma_disconnect(event, &event_acked);
3705 				if (rc < 0) {
3706 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3707 					break;
3708 				}
3709 			} else {
3710 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3711 				event_acked = true;
3712 			}
3713 			break;
3714 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3715 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3716 			/* Multicast is not used */
3717 			break;
3718 		case RDMA_CM_EVENT_ADDR_CHANGE:
3719 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3720 			break;
3721 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3722 			/* For now, do nothing. The target never re-uses queue pairs. */
3723 			break;
3724 		default:
3725 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3726 			break;
3727 		}
3728 		if (!event_acked) {
3729 			rdma_ack_cm_event(event);
3730 		}
3731 	}
3732 }
3733 
3734 static void
3735 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3736 {
3737 	rqpair->last_wqe_reached = true;
3738 	nvmf_rdma_destroy_drained_qpair(rqpair);
3739 }
3740 
3741 static void
3742 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3743 {
3744 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3745 
3746 	if (event_ctx->rqpair) {
3747 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3748 		if (event_ctx->cb_fn) {
3749 			event_ctx->cb_fn(event_ctx->rqpair);
3750 		}
3751 	}
3752 	free(event_ctx);
3753 }
3754 
3755 static int
3756 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3757 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3758 {
3759 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3760 	struct spdk_thread *thr = NULL;
3761 	int rc;
3762 
3763 	if (rqpair->qpair.group) {
3764 		thr = rqpair->qpair.group->thread;
3765 	} else if (rqpair->destruct_channel) {
3766 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3767 	}
3768 
3769 	if (!thr) {
3770 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3771 		return -EINVAL;
3772 	}
3773 
3774 	ctx = calloc(1, sizeof(*ctx));
3775 	if (!ctx) {
3776 		return -ENOMEM;
3777 	}
3778 
3779 	ctx->rqpair = rqpair;
3780 	ctx->cb_fn = fn;
3781 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3782 
3783 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3784 	if (rc) {
3785 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3786 		free(ctx);
3787 	}
3788 
3789 	return rc;
3790 }
3791 
3792 static int
3793 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3794 {
3795 	int				rc;
3796 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3797 	struct ibv_async_event		event;
3798 
3799 	rc = ibv_get_async_event(device->context, &event);
3800 
3801 	if (rc) {
3802 		/* In non-blocking mode -1 means there are no events available */
3803 		return rc;
3804 	}
3805 
3806 	switch (event.event_type) {
3807 	case IBV_EVENT_QP_FATAL:
3808 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3809 	case IBV_EVENT_QP_REQ_ERR:
3810 	case IBV_EVENT_QP_ACCESS_ERR:
3811 	case IBV_EVENT_COMM_EST:
3812 	case IBV_EVENT_PATH_MIG:
3813 	case IBV_EVENT_PATH_MIG_ERR:
3814 		rqpair = event.element.qp->qp_context;
3815 		if (!rqpair) {
3816 			/* Any QP event for NVMe-RDMA initiator may be returned. */
3817 			SPDK_NOTICELOG("Async QP event for unknown QP: %s\n",
3818 				       ibv_event_type_str(event.event_type));
3819 			break;
3820 		}
3821 
3822 		switch (event.event_type) {
3823 		case IBV_EVENT_QP_FATAL:
3824 			SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3825 			spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3826 					  (uintptr_t)rqpair, event.event_type);
3827 			rqpair->ibv_in_error_state = true;
3828 			spdk_nvmf_qpair_disconnect(&rqpair->qpair);
3829 			break;
3830 		case IBV_EVENT_QP_LAST_WQE_REACHED:
3831 			/* This event only occurs for shared receive queues. */
3832 			SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3833 			rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3834 			if (rc) {
3835 				SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3836 				rqpair->last_wqe_reached = true;
3837 			}
3838 			break;
3839 		case IBV_EVENT_QP_REQ_ERR:
3840 		case IBV_EVENT_QP_ACCESS_ERR:
3841 		case IBV_EVENT_COMM_EST:
3842 		case IBV_EVENT_PATH_MIG:
3843 		case IBV_EVENT_PATH_MIG_ERR:
3844 			SPDK_NOTICELOG("Async QP event: %s\n",
3845 				       ibv_event_type_str(event.event_type));
3846 			spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3847 					  (uintptr_t)rqpair, event.event_type);
3848 			rqpair->ibv_in_error_state = true;
3849 			break;
3850 		default:
3851 			break;
3852 		}
3853 		break;
3854 	case IBV_EVENT_DEVICE_FATAL:
3855 		SPDK_ERRLOG("Device Fatal event[%s] received on %s. device: %p\n",
3856 			    ibv_event_type_str(event.event_type), ibv_get_device_name(device->context->device), device);
3857 		device->need_destroy = true;
3858 		break;
3859 	case IBV_EVENT_CQ_ERR:
3860 	case IBV_EVENT_PORT_ACTIVE:
3861 	case IBV_EVENT_PORT_ERR:
3862 	case IBV_EVENT_LID_CHANGE:
3863 	case IBV_EVENT_PKEY_CHANGE:
3864 	case IBV_EVENT_SM_CHANGE:
3865 	case IBV_EVENT_SRQ_ERR:
3866 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3867 	case IBV_EVENT_CLIENT_REREGISTER:
3868 	case IBV_EVENT_GID_CHANGE:
3869 	case IBV_EVENT_SQ_DRAINED:
3870 	default:
3871 		SPDK_NOTICELOG("Async event: %s\n",
3872 			       ibv_event_type_str(event.event_type));
3873 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3874 		break;
3875 	}
3876 	ibv_ack_async_event(&event);
3877 
3878 	return 0;
3879 }
3880 
3881 static void
3882 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3883 {
3884 	int rc = 0;
3885 	uint32_t i = 0;
3886 
3887 	for (i = 0; i < max_events; i++) {
3888 		rc = nvmf_process_ib_event(device);
3889 		if (rc) {
3890 			break;
3891 		}
3892 	}
3893 
3894 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3895 }
3896 
3897 static int
3898 nvmf_rdma_accept(void *ctx)
3899 {
3900 	int	nfds, i = 0;
3901 	struct spdk_nvmf_transport *transport = ctx;
3902 	struct spdk_nvmf_rdma_transport *rtransport;
3903 	struct spdk_nvmf_rdma_device *device, *tmp;
3904 	uint32_t count;
3905 	short revents;
3906 	bool do_retry;
3907 
3908 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3909 	do_retry = nvmf_rdma_retry_listen_port(rtransport);
3910 
3911 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3912 
3913 	if (nfds <= 0) {
3914 		return do_retry ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3915 	}
3916 
3917 	/* The first poll descriptor is RDMA CM event */
3918 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3919 		nvmf_process_cm_events(transport, NVMF_RDMA_MAX_EVENTS_PER_POLL);
3920 		nfds--;
3921 	}
3922 
3923 	if (nfds == 0) {
3924 		return SPDK_POLLER_BUSY;
3925 	}
3926 
3927 	/* Second and subsequent poll descriptors are IB async events */
3928 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3929 		revents = rtransport->poll_fds[i++].revents;
3930 		if (revents & POLLIN) {
3931 			if (spdk_likely(!device->need_destroy)) {
3932 				nvmf_process_ib_events(device, NVMF_RDMA_MAX_EVENTS_PER_POLL);
3933 				if (spdk_unlikely(device->need_destroy)) {
3934 					nvmf_rdma_handle_device_removal(rtransport, device);
3935 				}
3936 			}
3937 			nfds--;
3938 		} else if (revents & POLLNVAL || revents & POLLHUP) {
3939 			SPDK_ERRLOG("Receive unknown revent %x on device %p\n", (int)revents, device);
3940 			nfds--;
3941 		}
3942 	}
3943 	/* check all flagged fd's have been served */
3944 	assert(nfds == 0);
3945 
3946 	return count > 0 ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3947 }
3948 
3949 static void
3950 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3951 		     struct spdk_nvmf_ctrlr_data *cdata)
3952 {
3953 	cdata->nvmf_specific.msdbd = NVMF_DEFAULT_MSDBD;
3954 
3955 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3956 	since in-capsule data only works with NVME drives that support SGL memory layout */
3957 	if (transport->opts.dif_insert_or_strip) {
3958 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3959 	}
3960 
3961 	if (cdata->nvmf_specific.ioccsz > ((sizeof(struct spdk_nvme_cmd) + 0x1000) / 16)) {
3962 		SPDK_WARNLOG("RDMA is configured to support up to 16 SGL entries while in capsule"
3963 			     " data is greater than 4KiB.\n");
3964 		SPDK_WARNLOG("When used in conjunction with the NVMe-oF initiator from the Linux "
3965 			     "kernel between versions 5.4 and 5.12 data corruption may occur for "
3966 			     "writes that are not a multiple of 4KiB in size.\n");
3967 	}
3968 }
3969 
3970 static void
3971 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3972 		   struct spdk_nvme_transport_id *trid,
3973 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3974 {
3975 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3976 	entry->adrfam = trid->adrfam;
3977 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3978 
3979 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3980 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3981 
3982 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3983 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3984 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3985 }
3986 
3987 static int
3988 nvmf_rdma_poller_create(struct spdk_nvmf_rdma_transport *rtransport,
3989 			struct spdk_nvmf_rdma_poll_group *rgroup, struct spdk_nvmf_rdma_device *device,
3990 			struct spdk_nvmf_rdma_poller **out_poller)
3991 {
3992 	struct spdk_nvmf_rdma_poller		*poller;
3993 	struct spdk_rdma_provider_srq_init_attr	srq_init_attr;
3994 	struct spdk_nvmf_rdma_resource_opts	opts;
3995 	int					num_cqe;
3996 
3997 	poller = calloc(1, sizeof(*poller));
3998 	if (!poller) {
3999 		SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
4000 		return -1;
4001 	}
4002 
4003 	poller->device = device;
4004 	poller->group = rgroup;
4005 	*out_poller = poller;
4006 
4007 	RB_INIT(&poller->qpairs);
4008 	STAILQ_INIT(&poller->qpairs_pending_send);
4009 	STAILQ_INIT(&poller->qpairs_pending_recv);
4010 
4011 	TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
4012 	SPDK_DEBUGLOG(rdma, "Create poller %p on device %p in poll group %p.\n", poller, device, rgroup);
4013 	if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
4014 		if ((int)rtransport->rdma_opts.max_srq_depth > device->attr.max_srq_wr) {
4015 			SPDK_WARNLOG("Requested SRQ depth %u, max supported by dev %s is %d\n",
4016 				     rtransport->rdma_opts.max_srq_depth, device->context->device->name, device->attr.max_srq_wr);
4017 		}
4018 		poller->max_srq_depth = spdk_min((int)rtransport->rdma_opts.max_srq_depth, device->attr.max_srq_wr);
4019 
4020 		device->num_srq++;
4021 		memset(&srq_init_attr, 0, sizeof(srq_init_attr));
4022 		srq_init_attr.pd = device->pd;
4023 		srq_init_attr.stats = &poller->stat.qp_stats.recv;
4024 		srq_init_attr.srq_init_attr.attr.max_wr = poller->max_srq_depth;
4025 		srq_init_attr.srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
4026 		poller->srq = spdk_rdma_provider_srq_create(&srq_init_attr);
4027 		if (!poller->srq) {
4028 			SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
4029 			return -1;
4030 		}
4031 
4032 		opts.qp = poller->srq;
4033 		opts.map = device->map;
4034 		opts.qpair = NULL;
4035 		opts.shared = true;
4036 		opts.max_queue_depth = poller->max_srq_depth;
4037 		opts.in_capsule_data_size = rtransport->transport.opts.in_capsule_data_size;
4038 
4039 		poller->resources = nvmf_rdma_resources_create(&opts);
4040 		if (!poller->resources) {
4041 			SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
4042 			return -1;
4043 		}
4044 	}
4045 
4046 	/*
4047 	 * When using an srq, we can limit the completion queue at startup.
4048 	 * The following formula represents the calculation:
4049 	 * num_cqe = num_recv + num_data_wr + num_send_wr.
4050 	 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
4051 	 */
4052 	if (poller->srq) {
4053 		num_cqe = poller->max_srq_depth * 3;
4054 	} else {
4055 		num_cqe = rtransport->rdma_opts.num_cqe;
4056 	}
4057 
4058 	poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
4059 	if (!poller->cq) {
4060 		SPDK_ERRLOG("Unable to create completion queue\n");
4061 		return -1;
4062 	}
4063 	poller->num_cqe = num_cqe;
4064 	return 0;
4065 }
4066 
4067 static void
4068 _nvmf_rdma_register_poller_in_group(void *c)
4069 {
4070 	struct spdk_nvmf_rdma_poller	*poller;
4071 	struct poller_manage_ctx	*ctx = c;
4072 	struct spdk_nvmf_rdma_device	*device;
4073 	int				rc;
4074 
4075 	rc = nvmf_rdma_poller_create(ctx->rtransport, ctx->rgroup, ctx->device, &poller);
4076 	if (rc < 0 && poller) {
4077 		nvmf_rdma_poller_destroy(poller);
4078 	}
4079 
4080 	device = ctx->device;
4081 	if (nvmf_rdma_all_pollers_management_done(ctx)) {
4082 		device->is_ready = true;
4083 	}
4084 }
4085 
4086 static void nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
4087 
4088 static struct spdk_nvmf_transport_poll_group *
4089 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport,
4090 			    struct spdk_nvmf_poll_group *group)
4091 {
4092 	struct spdk_nvmf_rdma_transport		*rtransport;
4093 	struct spdk_nvmf_rdma_poll_group	*rgroup;
4094 	struct spdk_nvmf_rdma_poller		*poller;
4095 	struct spdk_nvmf_rdma_device		*device;
4096 	int					rc;
4097 
4098 	if (spdk_interrupt_mode_is_enabled()) {
4099 		SPDK_ERRLOG("RDMA transport does not support interrupt mode\n");
4100 		return NULL;
4101 	}
4102 
4103 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
4104 
4105 	rgroup = calloc(1, sizeof(*rgroup));
4106 	if (!rgroup) {
4107 		return NULL;
4108 	}
4109 
4110 	TAILQ_INIT(&rgroup->pollers);
4111 
4112 	TAILQ_FOREACH(device, &rtransport->devices, link) {
4113 		rc = nvmf_rdma_poller_create(rtransport, rgroup, device, &poller);
4114 		if (rc < 0) {
4115 			nvmf_rdma_poll_group_destroy(&rgroup->group);
4116 			return NULL;
4117 		}
4118 	}
4119 
4120 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
4121 	if (rtransport->conn_sched.next_admin_pg == NULL) {
4122 		rtransport->conn_sched.next_admin_pg = rgroup;
4123 		rtransport->conn_sched.next_io_pg = rgroup;
4124 	}
4125 
4126 	return &rgroup->group;
4127 }
4128 
4129 static uint32_t
4130 nvmf_poll_group_get_io_qpair_count(struct spdk_nvmf_poll_group *pg)
4131 {
4132 	uint32_t count;
4133 
4134 	/* Just assume that unassociated qpairs will eventually be io
4135 	 * qpairs.  This is close enough for the use cases for this
4136 	 * function.
4137 	 */
4138 	pthread_mutex_lock(&pg->mutex);
4139 	count = pg->stat.current_io_qpairs + pg->current_unassociated_qpairs;
4140 	pthread_mutex_unlock(&pg->mutex);
4141 
4142 	return count;
4143 }
4144 
4145 static struct spdk_nvmf_transport_poll_group *
4146 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
4147 {
4148 	struct spdk_nvmf_rdma_transport *rtransport;
4149 	struct spdk_nvmf_rdma_poll_group **pg;
4150 	struct spdk_nvmf_transport_poll_group *result;
4151 	uint32_t count;
4152 
4153 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4154 
4155 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
4156 		return NULL;
4157 	}
4158 
4159 	if (qpair->qid == 0) {
4160 		pg = &rtransport->conn_sched.next_admin_pg;
4161 	} else {
4162 		struct spdk_nvmf_rdma_poll_group *pg_min, *pg_start, *pg_current;
4163 		uint32_t min_value;
4164 
4165 		pg = &rtransport->conn_sched.next_io_pg;
4166 		pg_min = *pg;
4167 		pg_start = *pg;
4168 		pg_current = *pg;
4169 		min_value = nvmf_poll_group_get_io_qpair_count(pg_current->group.group);
4170 
4171 		while (1) {
4172 			count = nvmf_poll_group_get_io_qpair_count(pg_current->group.group);
4173 
4174 			if (count < min_value) {
4175 				min_value = count;
4176 				pg_min = pg_current;
4177 			}
4178 
4179 			pg_current = TAILQ_NEXT(pg_current, link);
4180 			if (pg_current == NULL) {
4181 				pg_current = TAILQ_FIRST(&rtransport->poll_groups);
4182 			}
4183 
4184 			if (pg_current == pg_start || min_value == 0) {
4185 				break;
4186 			}
4187 		}
4188 		*pg = pg_min;
4189 	}
4190 
4191 	assert(*pg != NULL);
4192 
4193 	result = &(*pg)->group;
4194 
4195 	*pg = TAILQ_NEXT(*pg, link);
4196 	if (*pg == NULL) {
4197 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
4198 	}
4199 
4200 	return result;
4201 }
4202 
4203 static void
4204 nvmf_rdma_poller_destroy(struct spdk_nvmf_rdma_poller *poller)
4205 {
4206 	struct spdk_nvmf_rdma_qpair	*qpair, *tmp_qpair;
4207 	int				rc;
4208 
4209 	TAILQ_REMOVE(&poller->group->pollers, poller, link);
4210 	RB_FOREACH_SAFE(qpair, qpairs_tree, &poller->qpairs, tmp_qpair) {
4211 		nvmf_rdma_qpair_destroy(qpair);
4212 	}
4213 
4214 	if (poller->srq) {
4215 		if (poller->resources) {
4216 			nvmf_rdma_resources_destroy(poller->resources);
4217 		}
4218 		spdk_rdma_provider_srq_destroy(poller->srq);
4219 		SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
4220 	}
4221 
4222 	if (poller->cq) {
4223 		rc = ibv_destroy_cq(poller->cq);
4224 		if (rc != 0) {
4225 			SPDK_ERRLOG("Destroy cq return %d, error: %s\n", rc, strerror(errno));
4226 		}
4227 	}
4228 
4229 	if (poller->destroy_cb) {
4230 		poller->destroy_cb(poller->destroy_cb_ctx);
4231 		poller->destroy_cb = NULL;
4232 	}
4233 
4234 	free(poller);
4235 }
4236 
4237 static void
4238 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
4239 {
4240 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
4241 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
4242 	struct spdk_nvmf_rdma_transport		*rtransport;
4243 
4244 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4245 	if (!rgroup) {
4246 		return;
4247 	}
4248 
4249 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
4250 		nvmf_rdma_poller_destroy(poller);
4251 	}
4252 
4253 	if (rgroup->group.transport == NULL) {
4254 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
4255 		 * calls this function directly in a failure path. */
4256 		free(rgroup);
4257 		return;
4258 	}
4259 
4260 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
4261 
4262 	next_rgroup = TAILQ_NEXT(rgroup, link);
4263 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
4264 	if (next_rgroup == NULL) {
4265 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
4266 	}
4267 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
4268 		rtransport->conn_sched.next_admin_pg = next_rgroup;
4269 	}
4270 	if (rtransport->conn_sched.next_io_pg == rgroup) {
4271 		rtransport->conn_sched.next_io_pg = next_rgroup;
4272 	}
4273 
4274 	free(rgroup);
4275 }
4276 
4277 static void
4278 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
4279 {
4280 	if (rqpair->cm_id != NULL) {
4281 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
4282 	}
4283 }
4284 
4285 static int
4286 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
4287 			 struct spdk_nvmf_qpair *qpair)
4288 {
4289 	struct spdk_nvmf_rdma_poll_group	*rgroup;
4290 	struct spdk_nvmf_rdma_qpair		*rqpair;
4291 	struct spdk_nvmf_rdma_device		*device;
4292 	struct spdk_nvmf_rdma_poller		*poller;
4293 	int					rc;
4294 
4295 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4296 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4297 
4298 	device = rqpair->device;
4299 
4300 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
4301 		if (poller->device == device) {
4302 			break;
4303 		}
4304 	}
4305 
4306 	if (!poller) {
4307 		SPDK_ERRLOG("No poller found for device.\n");
4308 		return -1;
4309 	}
4310 
4311 	if (poller->need_destroy) {
4312 		SPDK_ERRLOG("Poller is destroying.\n");
4313 		return -1;
4314 	}
4315 
4316 	rqpair->poller = poller;
4317 	rqpair->srq = rqpair->poller->srq;
4318 
4319 	rc = nvmf_rdma_qpair_initialize(qpair);
4320 	if (rc < 0) {
4321 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
4322 		rqpair->poller = NULL;
4323 		rqpair->srq = NULL;
4324 		return -1;
4325 	}
4326 
4327 	RB_INSERT(qpairs_tree, &poller->qpairs, rqpair);
4328 
4329 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
4330 	if (rc) {
4331 		/* Try to reject, but we probably can't */
4332 		nvmf_rdma_qpair_reject_connection(rqpair);
4333 		return -1;
4334 	}
4335 
4336 	return 0;
4337 }
4338 
4339 static int
4340 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
4341 			    struct spdk_nvmf_qpair *qpair)
4342 {
4343 	struct spdk_nvmf_rdma_qpair		*rqpair;
4344 
4345 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4346 	assert(group->transport->tgt != NULL);
4347 
4348 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
4349 
4350 	if (!rqpair->destruct_channel) {
4351 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
4352 		return 0;
4353 	}
4354 
4355 	/* Sanity check that we get io_channel on the correct thread */
4356 	if (qpair->group) {
4357 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
4358 	}
4359 
4360 	return 0;
4361 }
4362 
4363 static int
4364 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
4365 {
4366 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
4367 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
4368 			struct spdk_nvmf_rdma_transport, transport);
4369 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
4370 					      struct spdk_nvmf_rdma_qpair, qpair);
4371 
4372 	/*
4373 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
4374 	 * needs to be returned to the shared receive queue or the poll group will eventually be
4375 	 * starved of RECV structures.
4376 	 */
4377 	if (rqpair->srq && rdma_req->recv) {
4378 		int rc;
4379 		struct ibv_recv_wr *bad_recv_wr;
4380 
4381 		spdk_rdma_provider_srq_queue_recv_wrs(rqpair->srq, &rdma_req->recv->wr);
4382 		rc = spdk_rdma_provider_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
4383 		if (rc) {
4384 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
4385 		}
4386 	}
4387 
4388 	_nvmf_rdma_request_free(rdma_req, rtransport);
4389 	return 0;
4390 }
4391 
4392 static int
4393 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
4394 {
4395 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
4396 			struct spdk_nvmf_rdma_transport, transport);
4397 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
4398 			struct spdk_nvmf_rdma_request, req);
4399 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
4400 			struct spdk_nvmf_rdma_qpair, qpair);
4401 
4402 	if (spdk_unlikely(rqpair->ibv_in_error_state)) {
4403 		/* The connection is dead. Move the request directly to the completed state. */
4404 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4405 	} else {
4406 		/* The connection is alive, so process the request as normal */
4407 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
4408 	}
4409 
4410 	nvmf_rdma_request_process(rtransport, rdma_req);
4411 
4412 	return 0;
4413 }
4414 
4415 static void
4416 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
4417 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
4418 {
4419 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4420 
4421 	rqpair->to_close = true;
4422 
4423 	/* This happens only when the qpair is disconnected before
4424 	 * it is added to the poll group. Since there is no poll group,
4425 	 * the RDMA qp has not been initialized yet and the RDMA CM
4426 	 * event has not yet been acknowledged, so we need to reject it.
4427 	 */
4428 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
4429 		nvmf_rdma_qpair_reject_connection(rqpair);
4430 		nvmf_rdma_qpair_destroy(rqpair);
4431 		return;
4432 	}
4433 
4434 	if (rqpair->rdma_qp) {
4435 		spdk_rdma_provider_qp_disconnect(rqpair->rdma_qp);
4436 	}
4437 
4438 	nvmf_rdma_destroy_drained_qpair(rqpair);
4439 
4440 	if (cb_fn) {
4441 		cb_fn(cb_arg);
4442 	}
4443 }
4444 
4445 static struct spdk_nvmf_rdma_qpair *
4446 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
4447 {
4448 	struct spdk_nvmf_rdma_qpair find;
4449 
4450 	find.qp_num = wc->qp_num;
4451 
4452 	return RB_FIND(qpairs_tree, &rpoller->qpairs, &find);
4453 }
4454 
4455 #ifdef DEBUG
4456 static int
4457 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
4458 {
4459 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
4460 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
4461 }
4462 #endif
4463 
4464 static void
4465 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
4466 			   int rc)
4467 {
4468 	struct spdk_nvmf_rdma_recv	*rdma_recv;
4469 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
4470 
4471 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
4472 	while (bad_recv_wr != NULL) {
4473 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
4474 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
4475 
4476 		rdma_recv->qpair->current_recv_depth++;
4477 		bad_recv_wr = bad_recv_wr->next;
4478 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
4479 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair);
4480 	}
4481 }
4482 
4483 static void
4484 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
4485 {
4486 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
4487 	while (bad_recv_wr != NULL) {
4488 		bad_recv_wr = bad_recv_wr->next;
4489 		rqpair->current_recv_depth++;
4490 	}
4491 	spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4492 }
4493 
4494 static void
4495 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
4496 		     struct spdk_nvmf_rdma_poller *rpoller)
4497 {
4498 	struct spdk_nvmf_rdma_qpair	*rqpair;
4499 	struct ibv_recv_wr		*bad_recv_wr;
4500 	int				rc;
4501 
4502 	if (rpoller->srq) {
4503 		rc = spdk_rdma_provider_srq_flush_recv_wrs(rpoller->srq, &bad_recv_wr);
4504 		if (spdk_unlikely(rc)) {
4505 			_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
4506 		}
4507 	} else {
4508 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
4509 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
4510 			rc = spdk_rdma_provider_qp_flush_recv_wrs(rqpair->rdma_qp, &bad_recv_wr);
4511 			if (spdk_unlikely(rc)) {
4512 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
4513 			}
4514 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
4515 		}
4516 	}
4517 }
4518 
4519 static void
4520 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
4521 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
4522 {
4523 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
4524 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
4525 
4526 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
4527 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
4528 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
4529 		assert(rqpair->current_send_depth > 0);
4530 		rqpair->current_send_depth--;
4531 		switch (bad_rdma_wr->type) {
4532 		case RDMA_WR_TYPE_DATA:
4533 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data_wr);
4534 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
4535 				assert(rqpair->current_read_depth > 0);
4536 				rqpair->current_read_depth--;
4537 			}
4538 			break;
4539 		case RDMA_WR_TYPE_SEND:
4540 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp_wr);
4541 			break;
4542 		default:
4543 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
4544 			prev_rdma_req = cur_rdma_req;
4545 			continue;
4546 		}
4547 
4548 		if (prev_rdma_req == cur_rdma_req) {
4549 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
4550 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
4551 			continue;
4552 		}
4553 
4554 		switch (cur_rdma_req->state) {
4555 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4556 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
4557 			STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, cur_rdma_req, state_link);
4558 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
4559 			break;
4560 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
4561 		case RDMA_REQUEST_STATE_COMPLETING:
4562 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4563 			break;
4564 		default:
4565 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
4566 				    cur_rdma_req->state, rqpair);
4567 			continue;
4568 		}
4569 
4570 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
4571 		prev_rdma_req = cur_rdma_req;
4572 	}
4573 
4574 	if (spdk_nvmf_qpair_is_active(&rqpair->qpair)) {
4575 		/* Disconnect the connection. */
4576 		spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4577 	}
4578 
4579 }
4580 
4581 static void
4582 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
4583 		     struct spdk_nvmf_rdma_poller *rpoller)
4584 {
4585 	struct spdk_nvmf_rdma_qpair	*rqpair;
4586 	struct ibv_send_wr		*bad_wr = NULL;
4587 	int				rc;
4588 
4589 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
4590 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
4591 		rc = spdk_rdma_provider_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
4592 
4593 		/* bad wr always points to the first wr that failed. */
4594 		if (spdk_unlikely(rc)) {
4595 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
4596 		}
4597 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
4598 	}
4599 }
4600 
4601 static const char *
4602 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
4603 {
4604 	switch (wr_type) {
4605 	case RDMA_WR_TYPE_RECV:
4606 		return "RECV";
4607 	case RDMA_WR_TYPE_SEND:
4608 		return "SEND";
4609 	case RDMA_WR_TYPE_DATA:
4610 		return "DATA";
4611 	default:
4612 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
4613 		SPDK_UNREACHABLE();
4614 	}
4615 }
4616 
4617 static inline void
4618 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
4619 {
4620 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
4621 
4622 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
4623 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
4624 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
4625 		SPDK_DEBUGLOG(rdma,
4626 			      "Error on CQ %p, (qp state %d, in_error %d) request 0x%lu, type %s, status: (%d): %s\n",
4627 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_in_error_state, wc->wr_id,
4628 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
4629 	} else {
4630 		SPDK_ERRLOG("Error on CQ %p, (qp state %d, in_error %d) request 0x%lu, type %s, status: (%d): %s\n",
4631 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_in_error_state, wc->wr_id,
4632 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
4633 	}
4634 }
4635 
4636 static int
4637 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
4638 		      struct spdk_nvmf_rdma_poller *rpoller)
4639 {
4640 	struct ibv_wc wc[32];
4641 	struct spdk_nvmf_rdma_wr	*rdma_wr;
4642 	struct spdk_nvmf_rdma_request	*rdma_req;
4643 	struct spdk_nvmf_rdma_recv	*rdma_recv;
4644 	struct spdk_nvmf_rdma_qpair	*rqpair, *tmp_rqpair;
4645 	int reaped, i;
4646 	int count = 0;
4647 	int rc;
4648 	bool error = false;
4649 	uint64_t poll_tsc = spdk_get_ticks();
4650 
4651 	if (spdk_unlikely(rpoller->need_destroy)) {
4652 		/* If qpair is closed before poller destroy, nvmf_rdma_destroy_drained_qpair may not
4653 		 * be called because we cannot poll anything from cq. So we call that here to force
4654 		 * destroy the qpair after to_close turning true.
4655 		 */
4656 		RB_FOREACH_SAFE(rqpair, qpairs_tree, &rpoller->qpairs, tmp_rqpair) {
4657 			nvmf_rdma_destroy_drained_qpair(rqpair);
4658 		}
4659 		return 0;
4660 	}
4661 
4662 	/* Poll for completing operations. */
4663 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
4664 	if (spdk_unlikely(reaped < 0)) {
4665 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
4666 			    errno, spdk_strerror(errno));
4667 		return -1;
4668 	} else if (reaped == 0) {
4669 		rpoller->stat.idle_polls++;
4670 	}
4671 
4672 	rpoller->stat.polls++;
4673 	rpoller->stat.completions += reaped;
4674 
4675 	for (i = 0; i < reaped; i++) {
4676 
4677 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
4678 
4679 		switch (rdma_wr->type) {
4680 		case RDMA_WR_TYPE_SEND:
4681 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp_wr);
4682 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
4683 
4684 			if (spdk_likely(!wc[i].status)) {
4685 				count++;
4686 				assert(wc[i].opcode == IBV_WC_SEND);
4687 				assert(nvmf_rdma_req_is_completing(rdma_req));
4688 			}
4689 
4690 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4691 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
4692 			assert(rqpair->current_send_depth >= (uint32_t)rdma_req->num_outstanding_data_wr + 1);
4693 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
4694 			rdma_req->num_outstanding_data_wr = 0;
4695 
4696 			nvmf_rdma_request_process(rtransport, rdma_req);
4697 			break;
4698 		case RDMA_WR_TYPE_RECV:
4699 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
4700 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
4701 			if (rpoller->srq != NULL) {
4702 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
4703 				/* It is possible that there are still some completions for destroyed QP
4704 				 * associated with SRQ. We just ignore these late completions and re-post
4705 				 * receive WRs back to SRQ.
4706 				 */
4707 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
4708 					struct ibv_recv_wr *bad_wr;
4709 
4710 					rdma_recv->wr.next = NULL;
4711 					spdk_rdma_provider_srq_queue_recv_wrs(rpoller->srq, &rdma_recv->wr);
4712 					rc = spdk_rdma_provider_srq_flush_recv_wrs(rpoller->srq, &bad_wr);
4713 					if (rc) {
4714 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
4715 					}
4716 					continue;
4717 				}
4718 			}
4719 			rqpair = rdma_recv->qpair;
4720 
4721 			assert(rqpair != NULL);
4722 			if (spdk_likely(!wc[i].status)) {
4723 				assert(wc[i].opcode == IBV_WC_RECV);
4724 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
4725 					spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4726 					break;
4727 				}
4728 			}
4729 
4730 			rdma_recv->wr.next = NULL;
4731 			rqpair->current_recv_depth++;
4732 			rdma_recv->receive_tsc = poll_tsc;
4733 			rpoller->stat.requests++;
4734 			STAILQ_INSERT_HEAD(&rqpair->resources->incoming_queue, rdma_recv, link);
4735 			rqpair->qpair.queue_depth++;
4736 			break;
4737 		case RDMA_WR_TYPE_DATA:
4738 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data_wr);
4739 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
4740 
4741 			assert(rdma_req->num_outstanding_data_wr > 0);
4742 
4743 			rqpair->current_send_depth--;
4744 			rdma_req->num_outstanding_data_wr--;
4745 			if (spdk_likely(!wc[i].status)) {
4746 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
4747 				rqpair->current_read_depth--;
4748 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
4749 				if (rdma_req->num_outstanding_data_wr == 0) {
4750 					if (rdma_req->num_remaining_data_wr) {
4751 						/* Only part of RDMA_READ operations was submitted, process the rest */
4752 						nvmf_rdma_request_reset_transfer_in(rdma_req, rtransport);
4753 						rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
4754 						nvmf_rdma_request_process(rtransport, rdma_req);
4755 						break;
4756 					}
4757 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
4758 					nvmf_rdma_request_process(rtransport, rdma_req);
4759 				}
4760 			} else {
4761 				/* If the data transfer fails still force the queue into the error state,
4762 				 * if we were performing an RDMA_READ, we need to force the request into a
4763 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
4764 				 * case, we should wait for the SEND to complete. */
4765 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
4766 					rqpair->current_read_depth--;
4767 					if (rdma_req->num_outstanding_data_wr == 0) {
4768 						if (rdma_req->num_remaining_data_wr) {
4769 							/* Partially sent request is still in the pending_rdma_read_queue,
4770 							 * remove it now before completing */
4771 							rdma_req->num_remaining_data_wr = 0;
4772 							STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
4773 						}
4774 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4775 						nvmf_rdma_request_process(rtransport, rdma_req);
4776 					}
4777 				}
4778 			}
4779 			break;
4780 		default:
4781 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
4782 			continue;
4783 		}
4784 
4785 		/* Handle error conditions */
4786 		if (spdk_unlikely(wc[i].status)) {
4787 			rqpair->ibv_in_error_state = true;
4788 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
4789 
4790 			error = true;
4791 
4792 			if (spdk_nvmf_qpair_is_active(&rqpair->qpair)) {
4793 				/* Disconnect the connection. */
4794 				spdk_nvmf_qpair_disconnect(&rqpair->qpair);
4795 			} else {
4796 				nvmf_rdma_destroy_drained_qpair(rqpair);
4797 			}
4798 			continue;
4799 		}
4800 
4801 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
4802 
4803 		if (spdk_unlikely(!spdk_nvmf_qpair_is_active(&rqpair->qpair))) {
4804 			nvmf_rdma_destroy_drained_qpair(rqpair);
4805 		}
4806 	}
4807 
4808 	if (spdk_unlikely(error == true)) {
4809 		return -1;
4810 	}
4811 
4812 	if (reaped == 0) {
4813 		/* In some cases we may not receive any CQE but we still may have pending IO requests waiting for
4814 		 * a resource (e.g. a WR from the data_wr_pool).
4815 		 * We need to start processing of such requests if no CQE reaped */
4816 		nvmf_rdma_poller_process_pending_buf_queue(rtransport, rpoller);
4817 	}
4818 
4819 	/* submit outstanding work requests. */
4820 	_poller_submit_recvs(rtransport, rpoller);
4821 	_poller_submit_sends(rtransport, rpoller);
4822 
4823 	return count;
4824 }
4825 
4826 static void
4827 _nvmf_rdma_remove_destroyed_device(void *c)
4828 {
4829 	struct spdk_nvmf_rdma_transport	*rtransport = c;
4830 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
4831 	int				rc;
4832 
4833 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
4834 		if (device->ready_to_destroy) {
4835 			destroy_ib_device(rtransport, device);
4836 		}
4837 	}
4838 
4839 	free_poll_fds(rtransport);
4840 	rc = generate_poll_fds(rtransport);
4841 	/* cannot handle fd allocation error here */
4842 	if (rc != 0) {
4843 		SPDK_ERRLOG("Failed to generate poll fds after remove ib device.\n");
4844 	}
4845 }
4846 
4847 static void
4848 _nvmf_rdma_remove_poller_in_group_cb(void *c)
4849 {
4850 	struct poller_manage_ctx	*ctx = c;
4851 	struct spdk_nvmf_rdma_transport	*rtransport = ctx->rtransport;
4852 	struct spdk_nvmf_rdma_device	*device = ctx->device;
4853 	struct spdk_thread		*thread = ctx->thread;
4854 
4855 	if (nvmf_rdma_all_pollers_management_done(c)) {
4856 		/* destroy device when last poller is destroyed */
4857 		device->ready_to_destroy = true;
4858 		spdk_thread_send_msg(thread, _nvmf_rdma_remove_destroyed_device, rtransport);
4859 	}
4860 }
4861 
4862 static void
4863 _nvmf_rdma_remove_poller_in_group(void *c)
4864 {
4865 	struct poller_manage_ctx		*ctx = c;
4866 
4867 	ctx->rpoller->need_destroy = true;
4868 	ctx->rpoller->destroy_cb_ctx = ctx;
4869 	ctx->rpoller->destroy_cb = _nvmf_rdma_remove_poller_in_group_cb;
4870 
4871 	/* qp will be disconnected after receiving a RDMA_CM_EVENT_DEVICE_REMOVAL event. */
4872 	if (RB_EMPTY(&ctx->rpoller->qpairs)) {
4873 		nvmf_rdma_poller_destroy(ctx->rpoller);
4874 	}
4875 }
4876 
4877 static int
4878 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
4879 {
4880 	struct spdk_nvmf_rdma_transport *rtransport;
4881 	struct spdk_nvmf_rdma_poll_group *rgroup;
4882 	struct spdk_nvmf_rdma_poller	*rpoller, *tmp;
4883 	int				count = 0, rc, rc2 = 0;
4884 
4885 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
4886 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4887 
4888 	TAILQ_FOREACH_SAFE(rpoller, &rgroup->pollers, link, tmp) {
4889 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
4890 		if (spdk_unlikely(rc < 0)) {
4891 			if (rc2 == 0) {
4892 				rc2 = rc;
4893 			}
4894 			continue;
4895 		}
4896 		count += rc;
4897 	}
4898 
4899 	return rc2 ? rc2 : count;
4900 }
4901 
4902 static int
4903 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
4904 			  struct spdk_nvme_transport_id *trid,
4905 			  bool peer)
4906 {
4907 	struct sockaddr *saddr;
4908 	uint16_t port;
4909 
4910 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
4911 
4912 	if (peer) {
4913 		saddr = rdma_get_peer_addr(id);
4914 	} else {
4915 		saddr = rdma_get_local_addr(id);
4916 	}
4917 	switch (saddr->sa_family) {
4918 	case AF_INET: {
4919 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
4920 
4921 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
4922 		inet_ntop(AF_INET, &saddr_in->sin_addr,
4923 			  trid->traddr, sizeof(trid->traddr));
4924 		if (peer) {
4925 			port = ntohs(rdma_get_dst_port(id));
4926 		} else {
4927 			port = ntohs(rdma_get_src_port(id));
4928 		}
4929 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4930 		break;
4931 	}
4932 	case AF_INET6: {
4933 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4934 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4935 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4936 			  trid->traddr, sizeof(trid->traddr));
4937 		if (peer) {
4938 			port = ntohs(rdma_get_dst_port(id));
4939 		} else {
4940 			port = ntohs(rdma_get_src_port(id));
4941 		}
4942 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4943 		break;
4944 	}
4945 	default:
4946 		return -1;
4947 
4948 	}
4949 
4950 	return 0;
4951 }
4952 
4953 static int
4954 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4955 			      struct spdk_nvme_transport_id *trid)
4956 {
4957 	struct spdk_nvmf_rdma_qpair	*rqpair;
4958 
4959 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4960 
4961 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4962 }
4963 
4964 static int
4965 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4966 			       struct spdk_nvme_transport_id *trid)
4967 {
4968 	struct spdk_nvmf_rdma_qpair	*rqpair;
4969 
4970 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4971 
4972 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4973 }
4974 
4975 static int
4976 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4977 				struct spdk_nvme_transport_id *trid)
4978 {
4979 	struct spdk_nvmf_rdma_qpair	*rqpair;
4980 
4981 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4982 
4983 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4984 }
4985 
4986 void
4987 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4988 {
4989 	g_nvmf_hooks = *hooks;
4990 }
4991 
4992 static void
4993 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4994 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort,
4995 				   struct spdk_nvmf_rdma_qpair *rqpair)
4996 {
4997 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4998 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4999 
5000 	STAILQ_INSERT_TAIL(&rqpair->pending_rdma_send_queue, rdma_req_to_abort, state_link);
5001 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING;
5002 
5003 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
5004 }
5005 
5006 static int
5007 _nvmf_rdma_qpair_abort_request(void *ctx)
5008 {
5009 	struct spdk_nvmf_request *req = ctx;
5010 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
5011 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
5012 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
5013 					      struct spdk_nvmf_rdma_qpair, qpair);
5014 	int rc;
5015 
5016 	spdk_poller_unregister(&req->poller);
5017 
5018 	switch (rdma_req_to_abort->state) {
5019 	case RDMA_REQUEST_STATE_EXECUTING:
5020 		rc = nvmf_ctrlr_abort_request(req);
5021 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
5022 			return SPDK_POLLER_BUSY;
5023 		}
5024 		break;
5025 
5026 	case RDMA_REQUEST_STATE_NEED_BUFFER:
5027 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
5028 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
5029 
5030 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5031 		break;
5032 
5033 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
5034 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
5035 			      spdk_nvmf_rdma_request, state_link);
5036 
5037 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5038 		break;
5039 
5040 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
5041 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
5042 			      spdk_nvmf_rdma_request, state_link);
5043 
5044 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5045 		break;
5046 
5047 	case RDMA_REQUEST_STATE_READY_TO_COMPLETE_PENDING:
5048 		/* Remove req from the list here to re-use common function */
5049 		STAILQ_REMOVE(&rqpair->pending_rdma_send_queue, rdma_req_to_abort,
5050 			      spdk_nvmf_rdma_request, state_link);
5051 
5052 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort, rqpair);
5053 		break;
5054 
5055 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
5056 		if (spdk_get_ticks() < req->timeout_tsc) {
5057 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
5058 			return SPDK_POLLER_BUSY;
5059 		}
5060 		break;
5061 
5062 	default:
5063 		break;
5064 	}
5065 
5066 	spdk_nvmf_request_complete(req);
5067 	return SPDK_POLLER_BUSY;
5068 }
5069 
5070 static void
5071 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
5072 			      struct spdk_nvmf_request *req)
5073 {
5074 	struct spdk_nvmf_rdma_qpair *rqpair;
5075 	struct spdk_nvmf_rdma_transport *rtransport;
5076 	struct spdk_nvmf_transport *transport;
5077 	uint16_t cid;
5078 	uint32_t i, max_req_count;
5079 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL, *rdma_req;
5080 
5081 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
5082 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
5083 	transport = &rtransport->transport;
5084 
5085 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
5086 	max_req_count = rqpair->srq == NULL ? rqpair->max_queue_depth : rqpair->poller->max_srq_depth;
5087 
5088 	for (i = 0; i < max_req_count; i++) {
5089 		rdma_req = &rqpair->resources->reqs[i];
5090 		/* When SRQ == NULL, rqpair has its own requests and req.qpair pointer always points to the qpair
5091 		 * When SRQ != NULL all rqpairs share common requests and qpair pointer is assigned when we start to
5092 		 * process a request. So in both cases all requests which are not in FREE state have valid qpair ptr */
5093 		if (rdma_req->state != RDMA_REQUEST_STATE_FREE && rdma_req->req.cmd->nvme_cmd.cid == cid &&
5094 		    rdma_req->req.qpair == qpair) {
5095 			rdma_req_to_abort = rdma_req;
5096 			break;
5097 		}
5098 	}
5099 
5100 	if (rdma_req_to_abort == NULL) {
5101 		spdk_nvmf_request_complete(req);
5102 		return;
5103 	}
5104 
5105 	req->req_to_abort = &rdma_req_to_abort->req;
5106 	req->timeout_tsc = spdk_get_ticks() +
5107 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
5108 	req->poller = NULL;
5109 
5110 	_nvmf_rdma_qpair_abort_request(req);
5111 }
5112 
5113 static void
5114 nvmf_rdma_poll_group_dump_stat(struct spdk_nvmf_transport_poll_group *group,
5115 			       struct spdk_json_write_ctx *w)
5116 {
5117 	struct spdk_nvmf_rdma_poll_group *rgroup;
5118 	struct spdk_nvmf_rdma_poller *rpoller;
5119 
5120 	assert(w != NULL);
5121 
5122 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
5123 
5124 	spdk_json_write_named_uint64(w, "pending_data_buffer", rgroup->stat.pending_data_buffer);
5125 
5126 	spdk_json_write_named_array_begin(w, "devices");
5127 
5128 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
5129 		spdk_json_write_object_begin(w);
5130 		spdk_json_write_named_string(w, "name",
5131 					     ibv_get_device_name(rpoller->device->context->device));
5132 		spdk_json_write_named_uint64(w, "polls",
5133 					     rpoller->stat.polls);
5134 		spdk_json_write_named_uint64(w, "idle_polls",
5135 					     rpoller->stat.idle_polls);
5136 		spdk_json_write_named_uint64(w, "completions",
5137 					     rpoller->stat.completions);
5138 		spdk_json_write_named_uint64(w, "requests",
5139 					     rpoller->stat.requests);
5140 		spdk_json_write_named_uint64(w, "request_latency",
5141 					     rpoller->stat.request_latency);
5142 		spdk_json_write_named_uint64(w, "pending_free_request",
5143 					     rpoller->stat.pending_free_request);
5144 		spdk_json_write_named_uint64(w, "pending_rdma_read",
5145 					     rpoller->stat.pending_rdma_read);
5146 		spdk_json_write_named_uint64(w, "pending_rdma_write",
5147 					     rpoller->stat.pending_rdma_write);
5148 		spdk_json_write_named_uint64(w, "pending_rdma_send",
5149 					     rpoller->stat.pending_rdma_send);
5150 		spdk_json_write_named_uint64(w, "total_send_wrs",
5151 					     rpoller->stat.qp_stats.send.num_submitted_wrs);
5152 		spdk_json_write_named_uint64(w, "send_doorbell_updates",
5153 					     rpoller->stat.qp_stats.send.doorbell_updates);
5154 		spdk_json_write_named_uint64(w, "total_recv_wrs",
5155 					     rpoller->stat.qp_stats.recv.num_submitted_wrs);
5156 		spdk_json_write_named_uint64(w, "recv_doorbell_updates",
5157 					     rpoller->stat.qp_stats.recv.doorbell_updates);
5158 		spdk_json_write_object_end(w);
5159 	}
5160 
5161 	spdk_json_write_array_end(w);
5162 }
5163 
5164 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
5165 	.name = "RDMA",
5166 	.type = SPDK_NVME_TRANSPORT_RDMA,
5167 	.opts_init = nvmf_rdma_opts_init,
5168 	.create = nvmf_rdma_create,
5169 	.dump_opts = nvmf_rdma_dump_opts,
5170 	.destroy = nvmf_rdma_destroy,
5171 
5172 	.listen = nvmf_rdma_listen,
5173 	.stop_listen = nvmf_rdma_stop_listen,
5174 	.cdata_init = nvmf_rdma_cdata_init,
5175 
5176 	.listener_discover = nvmf_rdma_discover,
5177 
5178 	.poll_group_create = nvmf_rdma_poll_group_create,
5179 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
5180 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
5181 	.poll_group_add = nvmf_rdma_poll_group_add,
5182 	.poll_group_remove = nvmf_rdma_poll_group_remove,
5183 	.poll_group_poll = nvmf_rdma_poll_group_poll,
5184 
5185 	.req_free = nvmf_rdma_request_free,
5186 	.req_complete = nvmf_rdma_request_complete,
5187 
5188 	.qpair_fini = nvmf_rdma_close_qpair,
5189 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
5190 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
5191 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
5192 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
5193 
5194 	.poll_group_dump_stat = nvmf_rdma_poll_group_dump_stat,
5195 };
5196 
5197 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
5198 SPDK_LOG_REGISTER_COMPONENT(rdma)
5199