xref: /spdk/lib/nvmf/rdma.c (revision f6866117acb32c78d5ea7bd76ba330284655af35)
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, 2022 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.h"
21 
22 #include "nvmf_internal.h"
23 #include "transport.h"
24 
25 #include "spdk_internal/trace_defs.h"
26 
27 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
28 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
29 
30 /*
31  RDMA Connection Resource Defaults
32  */
33 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
34 #define NVMF_DEFAULT_RSP_SGE		1
35 #define NVMF_DEFAULT_RX_SGE		2
36 
37 /* The RDMA completion queue size */
38 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
39 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
40 
41 static int g_spdk_nvmf_ibv_query_mask =
42 	IBV_QP_STATE |
43 	IBV_QP_PKEY_INDEX |
44 	IBV_QP_PORT |
45 	IBV_QP_ACCESS_FLAGS |
46 	IBV_QP_AV |
47 	IBV_QP_PATH_MTU |
48 	IBV_QP_DEST_QPN |
49 	IBV_QP_RQ_PSN |
50 	IBV_QP_MAX_DEST_RD_ATOMIC |
51 	IBV_QP_MIN_RNR_TIMER |
52 	IBV_QP_SQ_PSN |
53 	IBV_QP_TIMEOUT |
54 	IBV_QP_RETRY_CNT |
55 	IBV_QP_RNR_RETRY |
56 	IBV_QP_MAX_QP_RD_ATOMIC;
57 
58 enum spdk_nvmf_rdma_request_state {
59 	/* The request is not currently in use */
60 	RDMA_REQUEST_STATE_FREE = 0,
61 
62 	/* Initial state when request first received */
63 	RDMA_REQUEST_STATE_NEW,
64 
65 	/* The request is queued until a data buffer is available. */
66 	RDMA_REQUEST_STATE_NEED_BUFFER,
67 
68 	/* The request is waiting on RDMA queue depth availability
69 	 * to transfer data from the host to the controller.
70 	 */
71 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
72 
73 	/* The request is currently transferring data from the host to the controller. */
74 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
75 
76 	/* The request is ready to execute at the block device */
77 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
78 
79 	/* The request is currently executing at the block device */
80 	RDMA_REQUEST_STATE_EXECUTING,
81 
82 	/* The request finished executing at the block device */
83 	RDMA_REQUEST_STATE_EXECUTED,
84 
85 	/* The request is waiting on RDMA queue depth availability
86 	 * to transfer data from the controller to the host.
87 	 */
88 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
89 
90 	/* The request is ready to send a completion */
91 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
92 
93 	/* The request is currently transferring data from the controller to the host. */
94 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
95 
96 	/* The request currently has an outstanding completion without an
97 	 * associated data transfer.
98 	 */
99 	RDMA_REQUEST_STATE_COMPLETING,
100 
101 	/* The request completed and can be marked free. */
102 	RDMA_REQUEST_STATE_COMPLETED,
103 
104 	/* Terminator */
105 	RDMA_REQUEST_NUM_STATES,
106 };
107 
108 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
109 {
110 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
111 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
112 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1,
113 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
114 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
115 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
116 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
117 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
118 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
119 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
120 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
121 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
122 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
123 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
124 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
125 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
126 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
127 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
128 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
129 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
130 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
131 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
132 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
133 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
134 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
135 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
136 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
137 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
138 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
139 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
140 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
141 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
142 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
143 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
144 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
145 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
146 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
147 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
148 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
149 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
150 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
151 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
152 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
153 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
154 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
155 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0,
156 					SPDK_TRACE_ARG_TYPE_PTR, "qpair");
157 
158 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
159 					OWNER_NONE, OBJECT_NONE, 0,
160 					SPDK_TRACE_ARG_TYPE_INT, "");
161 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
162 					OWNER_NONE, OBJECT_NONE, 0,
163 					SPDK_TRACE_ARG_TYPE_INT, "type");
164 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
165 					OWNER_NONE, OBJECT_NONE, 0,
166 					SPDK_TRACE_ARG_TYPE_INT, "type");
167 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
168 					OWNER_NONE, OBJECT_NONE, 0,
169 					SPDK_TRACE_ARG_TYPE_PTR, "state");
170 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
171 					OWNER_NONE, OBJECT_NONE, 0,
172 					SPDK_TRACE_ARG_TYPE_INT, "");
173 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
174 					OWNER_NONE, OBJECT_NONE, 0,
175 					SPDK_TRACE_ARG_TYPE_INT, "");
176 }
177 
178 enum spdk_nvmf_rdma_wr_type {
179 	RDMA_WR_TYPE_RECV,
180 	RDMA_WR_TYPE_SEND,
181 	RDMA_WR_TYPE_DATA,
182 };
183 
184 struct spdk_nvmf_rdma_wr {
185 	enum spdk_nvmf_rdma_wr_type	type;
186 };
187 
188 /* This structure holds commands as they are received off the wire.
189  * It must be dynamically paired with a full request object
190  * (spdk_nvmf_rdma_request) to service a request. It is separate
191  * from the request because RDMA does not appear to order
192  * completions, so occasionally we'll get a new incoming
193  * command when there aren't any free request objects.
194  */
195 struct spdk_nvmf_rdma_recv {
196 	struct ibv_recv_wr			wr;
197 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
198 
199 	struct spdk_nvmf_rdma_qpair		*qpair;
200 
201 	/* In-capsule data buffer */
202 	uint8_t					*buf;
203 
204 	struct spdk_nvmf_rdma_wr		rdma_wr;
205 	uint64_t				receive_tsc;
206 
207 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
208 };
209 
210 struct spdk_nvmf_rdma_request_data {
211 	struct spdk_nvmf_rdma_wr	rdma_wr;
212 	struct ibv_send_wr		wr;
213 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
214 };
215 
216 struct spdk_nvmf_rdma_request {
217 	struct spdk_nvmf_request		req;
218 
219 	enum spdk_nvmf_rdma_request_state	state;
220 
221 	/* Data offset in req.iov */
222 	uint32_t				offset;
223 
224 	struct spdk_nvmf_rdma_recv		*recv;
225 
226 	struct {
227 		struct spdk_nvmf_rdma_wr	rdma_wr;
228 		struct	ibv_send_wr		wr;
229 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
230 	} rsp;
231 
232 	struct spdk_nvmf_rdma_request_data	data;
233 
234 	uint32_t				iovpos;
235 
236 	uint32_t				num_outstanding_data_wr;
237 	uint64_t				receive_tsc;
238 
239 	bool					fused_failed;
240 	struct spdk_nvmf_rdma_request		*fused_pair;
241 
242 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
243 };
244 
245 struct spdk_nvmf_rdma_resource_opts {
246 	struct spdk_nvmf_rdma_qpair	*qpair;
247 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
248 	void				*qp;
249 	struct spdk_rdma_mem_map	*map;
250 	uint32_t			max_queue_depth;
251 	uint32_t			in_capsule_data_size;
252 	bool				shared;
253 };
254 
255 struct spdk_nvmf_rdma_resources {
256 	/* Array of size "max_queue_depth" containing RDMA requests. */
257 	struct spdk_nvmf_rdma_request		*reqs;
258 
259 	/* Array of size "max_queue_depth" containing RDMA recvs. */
260 	struct spdk_nvmf_rdma_recv		*recvs;
261 
262 	/* Array of size "max_queue_depth" containing 64 byte capsules
263 	 * used for receive.
264 	 */
265 	union nvmf_h2c_msg			*cmds;
266 
267 	/* Array of size "max_queue_depth" containing 16 byte completions
268 	 * to be sent back to the user.
269 	 */
270 	union nvmf_c2h_msg			*cpls;
271 
272 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
273 	 * buffers to be used for in capsule data.
274 	 */
275 	void					*bufs;
276 
277 	/* Receives that are waiting for a request object */
278 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
279 
280 	/* Queue to track free requests */
281 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
282 };
283 
284 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
285 
286 typedef void (*spdk_poller_destroy_cb)(void *ctx);
287 
288 struct spdk_nvmf_rdma_ibv_event_ctx {
289 	struct spdk_nvmf_rdma_qpair			*rqpair;
290 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
291 	/* Link to other ibv events associated with this qpair */
292 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
293 };
294 
295 struct spdk_nvmf_rdma_qpair {
296 	struct spdk_nvmf_qpair			qpair;
297 
298 	struct spdk_nvmf_rdma_device		*device;
299 	struct spdk_nvmf_rdma_poller		*poller;
300 
301 	struct spdk_rdma_qp			*rdma_qp;
302 	struct rdma_cm_id			*cm_id;
303 	struct spdk_rdma_srq			*srq;
304 	struct rdma_cm_id			*listen_id;
305 
306 	/* Cache the QP number to improve QP search by RB tree. */
307 	uint32_t				qp_num;
308 
309 	/* The maximum number of I/O outstanding on this connection at one time */
310 	uint16_t				max_queue_depth;
311 
312 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
313 	uint16_t				max_read_depth;
314 
315 	/* The maximum number of RDMA SEND operations at one time */
316 	uint32_t				max_send_depth;
317 
318 	/* The current number of outstanding WRs from this qpair's
319 	 * recv queue. Should not exceed device->attr.max_queue_depth.
320 	 */
321 	uint16_t				current_recv_depth;
322 
323 	/* The current number of active RDMA READ operations */
324 	uint16_t				current_read_depth;
325 
326 	/* The current number of posted WRs from this qpair's
327 	 * send queue. Should not exceed max_send_depth.
328 	 */
329 	uint32_t				current_send_depth;
330 
331 	/* The maximum number of SGEs per WR on the send queue */
332 	uint32_t				max_send_sge;
333 
334 	/* The maximum number of SGEs per WR on the recv queue */
335 	uint32_t				max_recv_sge;
336 
337 	struct spdk_nvmf_rdma_resources		*resources;
338 
339 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
340 
341 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
342 
343 	/* Number of requests not in the free state */
344 	uint32_t				qd;
345 
346 	RB_ENTRY(spdk_nvmf_rdma_qpair)		node;
347 
348 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
349 
350 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
351 
352 	/* IBV queue pair attributes: they are used to manage
353 	 * qp state and recover from errors.
354 	 */
355 	enum ibv_qp_state			ibv_state;
356 
357 	/* Points to the a request that has fuse bits set to
358 	 * SPDK_NVME_CMD_FUSE_FIRST, when the qpair is waiting
359 	 * for the request that has SPDK_NVME_CMD_FUSE_SECOND.
360 	 */
361 	struct spdk_nvmf_rdma_request		*fused_first;
362 
363 	/*
364 	 * io_channel which is used to destroy qpair when it is removed from poll group
365 	 */
366 	struct spdk_io_channel		*destruct_channel;
367 
368 	/* List of ibv async events */
369 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
370 
371 	/* Lets us know that we have received the last_wqe event. */
372 	bool					last_wqe_reached;
373 
374 	/* Indicate that nvmf_rdma_close_qpair is called */
375 	bool					to_close;
376 };
377 
378 struct spdk_nvmf_rdma_poller_stat {
379 	uint64_t				completions;
380 	uint64_t				polls;
381 	uint64_t				idle_polls;
382 	uint64_t				requests;
383 	uint64_t				request_latency;
384 	uint64_t				pending_free_request;
385 	uint64_t				pending_rdma_read;
386 	uint64_t				pending_rdma_write;
387 	struct spdk_rdma_qp_stats		qp_stats;
388 };
389 
390 struct spdk_nvmf_rdma_poller {
391 	struct spdk_nvmf_rdma_device		*device;
392 	struct spdk_nvmf_rdma_poll_group	*group;
393 
394 	int					num_cqe;
395 	int					required_num_wr;
396 	struct ibv_cq				*cq;
397 
398 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
399 	uint16_t				max_srq_depth;
400 	bool					need_destroy;
401 
402 	/* Shared receive queue */
403 	struct spdk_rdma_srq			*srq;
404 
405 	struct spdk_nvmf_rdma_resources		*resources;
406 	struct spdk_nvmf_rdma_poller_stat	stat;
407 
408 	spdk_poller_destroy_cb			destroy_cb;
409 	void					*destroy_cb_ctx;
410 
411 	RB_HEAD(qpairs_tree, spdk_nvmf_rdma_qpair) qpairs;
412 
413 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
414 
415 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
416 
417 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
418 };
419 
420 struct spdk_nvmf_rdma_poll_group_stat {
421 	uint64_t				pending_data_buffer;
422 };
423 
424 struct spdk_nvmf_rdma_poll_group {
425 	struct spdk_nvmf_transport_poll_group		group;
426 	struct spdk_nvmf_rdma_poll_group_stat		stat;
427 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
428 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
429 };
430 
431 struct spdk_nvmf_rdma_conn_sched {
432 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
433 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
434 };
435 
436 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
437 struct spdk_nvmf_rdma_device {
438 	struct ibv_device_attr			attr;
439 	struct ibv_context			*context;
440 
441 	struct spdk_rdma_mem_map		*map;
442 	struct ibv_pd				*pd;
443 
444 	int					num_srq;
445 	bool					need_destroy;
446 	bool					ready_to_destroy;
447 	bool					is_ready;
448 
449 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
450 };
451 
452 struct spdk_nvmf_rdma_port {
453 	const struct spdk_nvme_transport_id	*trid;
454 	struct rdma_cm_id			*id;
455 	struct spdk_nvmf_rdma_device		*device;
456 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
457 };
458 
459 struct rdma_transport_opts {
460 	int		num_cqe;
461 	uint32_t	max_srq_depth;
462 	bool		no_srq;
463 	bool		no_wr_batching;
464 	int		acceptor_backlog;
465 };
466 
467 struct spdk_nvmf_rdma_transport {
468 	struct spdk_nvmf_transport	transport;
469 	struct rdma_transport_opts	rdma_opts;
470 
471 	struct spdk_nvmf_rdma_conn_sched conn_sched;
472 
473 	struct rdma_event_channel	*event_channel;
474 
475 	struct spdk_mempool		*data_wr_pool;
476 
477 	struct spdk_poller		*accept_poller;
478 
479 	/* fields used to poll RDMA/IB events */
480 	nfds_t			npoll_fds;
481 	struct pollfd		*poll_fds;
482 
483 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
484 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
485 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
486 
487 	/* ports that are removed unexpectedly and need retry listen */
488 	TAILQ_HEAD(, spdk_nvmf_rdma_port)		retry_ports;
489 };
490 
491 struct poller_manage_ctx {
492 	struct spdk_nvmf_rdma_transport		*rtransport;
493 	struct spdk_nvmf_rdma_poll_group	*rgroup;
494 	struct spdk_nvmf_rdma_poller		*rpoller;
495 	struct spdk_nvmf_rdma_device		*device;
496 
497 	struct spdk_thread			*thread;
498 	volatile int				*inflight_op_counter;
499 };
500 
501 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
502 	{
503 		"num_cqe", offsetof(struct rdma_transport_opts, num_cqe),
504 		spdk_json_decode_int32, true
505 	},
506 	{
507 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
508 		spdk_json_decode_uint32, true
509 	},
510 	{
511 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
512 		spdk_json_decode_bool, true
513 	},
514 	{
515 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
516 		spdk_json_decode_bool, true
517 	},
518 	{
519 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
520 		spdk_json_decode_int32, true
521 	},
522 };
523 
524 static int
525 nvmf_rdma_qpair_compare(struct spdk_nvmf_rdma_qpair *rqpair1, struct spdk_nvmf_rdma_qpair *rqpair2)
526 {
527 	return rqpair1->qp_num < rqpair2->qp_num ? -1 : rqpair1->qp_num > rqpair2->qp_num;
528 }
529 
530 RB_GENERATE_STATIC(qpairs_tree, spdk_nvmf_rdma_qpair, node, nvmf_rdma_qpair_compare);
531 
532 static bool nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
533 				      struct spdk_nvmf_rdma_request *rdma_req);
534 
535 static void _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
536 				 struct spdk_nvmf_rdma_poller *rpoller);
537 
538 static void _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
539 				 struct spdk_nvmf_rdma_poller *rpoller);
540 
541 static void _nvmf_rdma_remove_destroyed_device(void *c);
542 
543 static inline int
544 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
545 {
546 	switch (state) {
547 	case IBV_QPS_RESET:
548 	case IBV_QPS_INIT:
549 	case IBV_QPS_RTR:
550 	case IBV_QPS_RTS:
551 	case IBV_QPS_SQD:
552 	case IBV_QPS_SQE:
553 	case IBV_QPS_ERR:
554 		return 0;
555 	default:
556 		return -1;
557 	}
558 }
559 
560 static inline enum spdk_nvme_media_error_status_code
561 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
562 	enum spdk_nvme_media_error_status_code result;
563 	switch (err_type)
564 	{
565 	case SPDK_DIF_REFTAG_ERROR:
566 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
567 		break;
568 	case SPDK_DIF_APPTAG_ERROR:
569 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
570 		break;
571 	case SPDK_DIF_GUARD_ERROR:
572 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
573 		break;
574 	default:
575 		SPDK_UNREACHABLE();
576 	}
577 
578 	return result;
579 }
580 
581 static enum ibv_qp_state
582 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
583 	enum ibv_qp_state old_state, new_state;
584 	struct ibv_qp_attr qp_attr;
585 	struct ibv_qp_init_attr init_attr;
586 	int rc;
587 
588 	old_state = rqpair->ibv_state;
589 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
590 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
591 
592 	if (rc)
593 	{
594 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
595 		return IBV_QPS_ERR + 1;
596 	}
597 
598 	new_state = qp_attr.qp_state;
599 	rqpair->ibv_state = new_state;
600 	qp_attr.ah_attr.port_num = qp_attr.port_num;
601 
602 	rc = nvmf_rdma_check_ibv_state(new_state);
603 	if (rc)
604 	{
605 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
606 		/*
607 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
608 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
609 		 */
610 		return IBV_QPS_ERR + 1;
611 	}
612 
613 	if (old_state != new_state)
614 	{
615 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0, (uintptr_t)rqpair, new_state);
616 	}
617 	return new_state;
618 }
619 
620 static void
621 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
622 			    struct spdk_nvmf_rdma_transport *rtransport)
623 {
624 	struct spdk_nvmf_rdma_request_data	*data_wr;
625 	struct ibv_send_wr			*next_send_wr;
626 	uint64_t				req_wrid;
627 
628 	rdma_req->num_outstanding_data_wr = 0;
629 	data_wr = &rdma_req->data;
630 	req_wrid = data_wr->wr.wr_id;
631 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
632 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
633 		data_wr->wr.num_sge = 0;
634 		next_send_wr = data_wr->wr.next;
635 		if (data_wr != &rdma_req->data) {
636 			data_wr->wr.next = NULL;
637 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
638 		}
639 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
640 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
641 	}
642 	rdma_req->data.wr.next = NULL;
643 	rdma_req->rsp.wr.next = NULL;
644 }
645 
646 static void
647 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
648 {
649 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
650 	if (req->req.cmd) {
651 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
652 	}
653 	if (req->recv) {
654 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
655 	}
656 }
657 
658 static void
659 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
660 {
661 	int i;
662 
663 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
664 	for (i = 0; i < rqpair->max_queue_depth; i++) {
665 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
666 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
667 		}
668 	}
669 }
670 
671 static void
672 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
673 {
674 	spdk_free(resources->cmds);
675 	spdk_free(resources->cpls);
676 	spdk_free(resources->bufs);
677 	spdk_free(resources->reqs);
678 	spdk_free(resources->recvs);
679 	free(resources);
680 }
681 
682 
683 static struct spdk_nvmf_rdma_resources *
684 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
685 {
686 	struct spdk_nvmf_rdma_resources		*resources;
687 	struct spdk_nvmf_rdma_request		*rdma_req;
688 	struct spdk_nvmf_rdma_recv		*rdma_recv;
689 	struct spdk_rdma_qp			*qp = NULL;
690 	struct spdk_rdma_srq			*srq = NULL;
691 	struct ibv_recv_wr			*bad_wr = NULL;
692 	struct spdk_rdma_memory_translation	translation;
693 	uint32_t				i;
694 	int					rc = 0;
695 
696 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
697 	if (!resources) {
698 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
699 		return NULL;
700 	}
701 
702 	resources->reqs = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->reqs),
703 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
704 	resources->recvs = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->recvs),
705 					0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
706 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
707 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
708 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
709 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
710 
711 	if (opts->in_capsule_data_size > 0) {
712 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
713 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
714 					       SPDK_MALLOC_DMA);
715 	}
716 
717 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
718 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
719 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
720 		goto cleanup;
721 	}
722 
723 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx\n",
724 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds));
725 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx\n",
726 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls));
727 	if (resources->bufs) {
728 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x\n",
729 			      resources->bufs, opts->max_queue_depth *
730 			      opts->in_capsule_data_size);
731 	}
732 
733 	/* Initialize queues */
734 	STAILQ_INIT(&resources->incoming_queue);
735 	STAILQ_INIT(&resources->free_queue);
736 
737 	if (opts->shared) {
738 		srq = (struct spdk_rdma_srq *)opts->qp;
739 	} else {
740 		qp = (struct spdk_rdma_qp *)opts->qp;
741 	}
742 
743 	for (i = 0; i < opts->max_queue_depth; i++) {
744 		rdma_recv = &resources->recvs[i];
745 		rdma_recv->qpair = opts->qpair;
746 
747 		/* Set up memory to receive commands */
748 		if (resources->bufs) {
749 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
750 						  opts->in_capsule_data_size));
751 		}
752 
753 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
754 
755 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
756 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
757 		rc = spdk_rdma_get_translation(opts->map, &resources->cmds[i], sizeof(resources->cmds[i]),
758 					       &translation);
759 		if (rc) {
760 			goto cleanup;
761 		}
762 		rdma_recv->sgl[0].lkey = spdk_rdma_memory_translation_get_lkey(&translation);
763 		rdma_recv->wr.num_sge = 1;
764 
765 		if (rdma_recv->buf) {
766 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
767 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
768 			rc = spdk_rdma_get_translation(opts->map, rdma_recv->buf, opts->in_capsule_data_size, &translation);
769 			if (rc) {
770 				goto cleanup;
771 			}
772 			rdma_recv->sgl[1].lkey = spdk_rdma_memory_translation_get_lkey(&translation);
773 			rdma_recv->wr.num_sge++;
774 		}
775 
776 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
777 		rdma_recv->wr.sg_list = rdma_recv->sgl;
778 		if (srq) {
779 			spdk_rdma_srq_queue_recv_wrs(srq, &rdma_recv->wr);
780 		} else {
781 			spdk_rdma_qp_queue_recv_wrs(qp, &rdma_recv->wr);
782 		}
783 	}
784 
785 	for (i = 0; i < opts->max_queue_depth; i++) {
786 		rdma_req = &resources->reqs[i];
787 
788 		if (opts->qpair != NULL) {
789 			rdma_req->req.qpair = &opts->qpair->qpair;
790 		} else {
791 			rdma_req->req.qpair = NULL;
792 		}
793 		rdma_req->req.cmd = NULL;
794 		rdma_req->req.iovcnt = 0;
795 		rdma_req->req.stripped_data = NULL;
796 
797 		/* Set up memory to send responses */
798 		rdma_req->req.rsp = &resources->cpls[i];
799 
800 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
801 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
802 		rc = spdk_rdma_get_translation(opts->map, &resources->cpls[i], sizeof(resources->cpls[i]),
803 					       &translation);
804 		if (rc) {
805 			goto cleanup;
806 		}
807 		rdma_req->rsp.sgl[0].lkey = spdk_rdma_memory_translation_get_lkey(&translation);
808 
809 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
810 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
811 		rdma_req->rsp.wr.next = NULL;
812 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
813 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
814 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
815 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
816 
817 		/* Set up memory for data buffers */
818 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
819 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
820 		rdma_req->data.wr.next = NULL;
821 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
822 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
823 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
824 
825 		/* Initialize request state to FREE */
826 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
827 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
828 	}
829 
830 	if (srq) {
831 		rc = spdk_rdma_srq_flush_recv_wrs(srq, &bad_wr);
832 	} else {
833 		rc = spdk_rdma_qp_flush_recv_wrs(qp, &bad_wr);
834 	}
835 
836 	if (rc) {
837 		goto cleanup;
838 	}
839 
840 	return resources;
841 
842 cleanup:
843 	nvmf_rdma_resources_destroy(resources);
844 	return NULL;
845 }
846 
847 static void
848 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
849 {
850 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
851 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
852 		ctx->rqpair = NULL;
853 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
854 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
855 	}
856 }
857 
858 static void nvmf_rdma_poller_destroy(struct spdk_nvmf_rdma_poller *poller);
859 
860 static void
861 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
862 {
863 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
864 	struct ibv_recv_wr		*bad_recv_wr = NULL;
865 	int				rc;
866 
867 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair);
868 
869 	if (rqpair->qd != 0) {
870 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
871 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
872 				struct spdk_nvmf_rdma_transport, transport);
873 		struct spdk_nvmf_rdma_request *req;
874 		uint32_t i, max_req_count = 0;
875 
876 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
877 
878 		if (rqpair->srq == NULL) {
879 			nvmf_rdma_dump_qpair_contents(rqpair);
880 			max_req_count = rqpair->max_queue_depth;
881 		} else if (rqpair->poller && rqpair->resources) {
882 			max_req_count = rqpair->poller->max_srq_depth;
883 		}
884 
885 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
886 		for (i = 0; i < max_req_count; i++) {
887 			req = &rqpair->resources->reqs[i];
888 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
889 				/* nvmf_rdma_request_process checks qpair ibv and internal state
890 				 * and completes a request */
891 				nvmf_rdma_request_process(rtransport, req);
892 			}
893 		}
894 		assert(rqpair->qd == 0);
895 	}
896 
897 	if (rqpair->poller) {
898 		RB_REMOVE(qpairs_tree, &rqpair->poller->qpairs, rqpair);
899 
900 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
901 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
902 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
903 				if (rqpair == rdma_recv->qpair) {
904 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
905 					spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_recv->wr);
906 					rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
907 					if (rc) {
908 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
909 					}
910 				}
911 			}
912 		}
913 	}
914 
915 	if (rqpair->cm_id) {
916 		if (rqpair->rdma_qp != NULL) {
917 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
918 			rqpair->rdma_qp = NULL;
919 		}
920 
921 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
922 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
923 		}
924 	}
925 
926 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
927 		nvmf_rdma_resources_destroy(rqpair->resources);
928 	}
929 
930 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
931 
932 	if (rqpair->destruct_channel) {
933 		spdk_put_io_channel(rqpair->destruct_channel);
934 		rqpair->destruct_channel = NULL;
935 	}
936 
937 	if (rqpair->poller && rqpair->poller->need_destroy && RB_EMPTY(&rqpair->poller->qpairs)) {
938 		nvmf_rdma_poller_destroy(rqpair->poller);
939 	}
940 
941 	/* destroy cm_id last so cma device will not be freed before we destroy the cq. */
942 	if (rqpair->cm_id) {
943 		rdma_destroy_id(rqpair->cm_id);
944 	}
945 
946 	free(rqpair);
947 }
948 
949 static int
950 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
951 {
952 	struct spdk_nvmf_rdma_poller	*rpoller;
953 	int				rc, num_cqe, required_num_wr;
954 
955 	/* Enlarge CQ size dynamically */
956 	rpoller = rqpair->poller;
957 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
958 	num_cqe = rpoller->num_cqe;
959 	if (num_cqe < required_num_wr) {
960 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
961 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
962 	}
963 
964 	if (rpoller->num_cqe != num_cqe) {
965 		if (device->context->device->transport_type == IBV_TRANSPORT_IWARP) {
966 			SPDK_ERRLOG("iWARP doesn't support CQ resize. Current capacity %u, required %u\n"
967 				    "Using CQ of insufficient size may lead to CQ overrun\n", rpoller->num_cqe, num_cqe);
968 			return -1;
969 		}
970 		if (required_num_wr > device->attr.max_cqe) {
971 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
972 				    required_num_wr, device->attr.max_cqe);
973 			return -1;
974 		}
975 
976 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
977 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
978 		if (rc) {
979 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
980 			return -1;
981 		}
982 
983 		rpoller->num_cqe = num_cqe;
984 	}
985 
986 	rpoller->required_num_wr = required_num_wr;
987 	return 0;
988 }
989 
990 static int
991 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
992 {
993 	struct spdk_nvmf_rdma_qpair		*rqpair;
994 	struct spdk_nvmf_rdma_transport		*rtransport;
995 	struct spdk_nvmf_transport		*transport;
996 	struct spdk_nvmf_rdma_resource_opts	opts;
997 	struct spdk_nvmf_rdma_device		*device;
998 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
999 
1000 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1001 	device = rqpair->device;
1002 
1003 	qp_init_attr.qp_context	= rqpair;
1004 	qp_init_attr.pd		= device->pd;
1005 	qp_init_attr.send_cq	= rqpair->poller->cq;
1006 	qp_init_attr.recv_cq	= rqpair->poller->cq;
1007 
1008 	if (rqpair->srq) {
1009 		qp_init_attr.srq		= rqpair->srq->srq;
1010 	} else {
1011 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
1012 	}
1013 
1014 	/* SEND, READ, and WRITE operations */
1015 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
1016 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1017 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1018 	qp_init_attr.stats		= &rqpair->poller->stat.qp_stats;
1019 
1020 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1021 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1022 		goto error;
1023 	}
1024 
1025 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1026 	if (!rqpair->rdma_qp) {
1027 		goto error;
1028 	}
1029 
1030 	rqpair->qp_num = rqpair->rdma_qp->qp->qp_num;
1031 
1032 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1033 					  qp_init_attr.cap.max_send_wr);
1034 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1035 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1036 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair);
1037 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1038 
1039 	if (rqpair->poller->srq == NULL) {
1040 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1041 		transport = &rtransport->transport;
1042 
1043 		opts.qp = rqpair->rdma_qp;
1044 		opts.map = device->map;
1045 		opts.qpair = rqpair;
1046 		opts.shared = false;
1047 		opts.max_queue_depth = rqpair->max_queue_depth;
1048 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1049 
1050 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1051 
1052 		if (!rqpair->resources) {
1053 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1054 			rdma_destroy_qp(rqpair->cm_id);
1055 			goto error;
1056 		}
1057 	} else {
1058 		rqpair->resources = rqpair->poller->resources;
1059 	}
1060 
1061 	rqpair->current_recv_depth = 0;
1062 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1063 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1064 
1065 	return 0;
1066 
1067 error:
1068 	rdma_destroy_id(rqpair->cm_id);
1069 	rqpair->cm_id = NULL;
1070 	return -1;
1071 }
1072 
1073 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1074 /* This function accepts either a single wr or the first wr in a linked list. */
1075 static void
1076 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1077 {
1078 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1079 			struct spdk_nvmf_rdma_transport, transport);
1080 
1081 	if (rqpair->srq != NULL) {
1082 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, first);
1083 	} else {
1084 		if (spdk_rdma_qp_queue_recv_wrs(rqpair->rdma_qp, first)) {
1085 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1086 		}
1087 	}
1088 
1089 	if (rtransport->rdma_opts.no_wr_batching) {
1090 		_poller_submit_recvs(rtransport, rqpair->poller);
1091 	}
1092 }
1093 
1094 static int
1095 request_transfer_in(struct spdk_nvmf_request *req)
1096 {
1097 	struct spdk_nvmf_rdma_request	*rdma_req;
1098 	struct spdk_nvmf_qpair		*qpair;
1099 	struct spdk_nvmf_rdma_qpair	*rqpair;
1100 	struct spdk_nvmf_rdma_transport *rtransport;
1101 
1102 	qpair = req->qpair;
1103 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1104 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1105 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1106 				      struct spdk_nvmf_rdma_transport, transport);
1107 
1108 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1109 	assert(rdma_req != NULL);
1110 
1111 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1112 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1113 	}
1114 	if (rtransport->rdma_opts.no_wr_batching) {
1115 		_poller_submit_sends(rtransport, rqpair->poller);
1116 	}
1117 
1118 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1119 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1120 	return 0;
1121 }
1122 
1123 static int
1124 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1125 {
1126 	int				num_outstanding_data_wr = 0;
1127 	struct spdk_nvmf_rdma_request	*rdma_req;
1128 	struct spdk_nvmf_qpair		*qpair;
1129 	struct spdk_nvmf_rdma_qpair	*rqpair;
1130 	struct spdk_nvme_cpl		*rsp;
1131 	struct ibv_send_wr		*first = NULL;
1132 	struct spdk_nvmf_rdma_transport *rtransport;
1133 
1134 	*data_posted = 0;
1135 	qpair = req->qpair;
1136 	rsp = &req->rsp->nvme_cpl;
1137 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1138 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1139 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1140 				      struct spdk_nvmf_rdma_transport, transport);
1141 
1142 	/* Advance our sq_head pointer */
1143 	if (qpair->sq_head == qpair->sq_head_max) {
1144 		qpair->sq_head = 0;
1145 	} else {
1146 		qpair->sq_head++;
1147 	}
1148 	rsp->sqhd = qpair->sq_head;
1149 
1150 	/* queue the capsule for the recv buffer */
1151 	assert(rdma_req->recv != NULL);
1152 
1153 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1154 
1155 	rdma_req->recv = NULL;
1156 	assert(rqpair->current_recv_depth > 0);
1157 	rqpair->current_recv_depth--;
1158 
1159 	/* Build the response which consists of optional
1160 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1161 	 * containing the response.
1162 	 */
1163 	first = &rdma_req->rsp.wr;
1164 
1165 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1166 		/* On failure, data was not read from the controller. So clear the
1167 		 * number of outstanding data WRs to zero.
1168 		 */
1169 		rdma_req->num_outstanding_data_wr = 0;
1170 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1171 		first = &rdma_req->data.wr;
1172 		*data_posted = 1;
1173 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1174 	}
1175 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1176 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1177 	}
1178 	if (rtransport->rdma_opts.no_wr_batching) {
1179 		_poller_submit_sends(rtransport, rqpair->poller);
1180 	}
1181 
1182 	/* +1 for the rsp wr */
1183 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1184 
1185 	return 0;
1186 }
1187 
1188 static int
1189 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1190 {
1191 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1192 	struct rdma_conn_param				ctrlr_event_data = {};
1193 	int						rc;
1194 
1195 	accept_data.recfmt = 0;
1196 	accept_data.crqsize = rqpair->max_queue_depth;
1197 
1198 	ctrlr_event_data.private_data = &accept_data;
1199 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1200 	if (id->ps == RDMA_PS_TCP) {
1201 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1202 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1203 	}
1204 
1205 	/* Configure infinite retries for the initiator side qpair.
1206 	 * We need to pass this value to the initiator to prevent the
1207 	 * initiator side NIC from completing SEND requests back to the
1208 	 * initiator with status rnr_retry_count_exceeded. */
1209 	ctrlr_event_data.rnr_retry_count = 0x7;
1210 
1211 	/* When qpair is created without use of rdma cm API, an additional
1212 	 * information must be provided to initiator in the connection response:
1213 	 * whether qpair is using SRQ and its qp_num
1214 	 * Fields below are ignored by rdma cm if qpair has been
1215 	 * created using rdma cm API. */
1216 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1217 	ctrlr_event_data.qp_num = rqpair->qp_num;
1218 
1219 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1220 	if (rc) {
1221 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1222 	} else {
1223 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1224 	}
1225 
1226 	return rc;
1227 }
1228 
1229 static void
1230 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1231 {
1232 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1233 
1234 	rej_data.recfmt = 0;
1235 	rej_data.sts = error;
1236 
1237 	rdma_reject(id, &rej_data, sizeof(rej_data));
1238 }
1239 
1240 static int
1241 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1242 {
1243 	struct spdk_nvmf_rdma_transport *rtransport;
1244 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1245 	struct spdk_nvmf_rdma_port	*port;
1246 	struct rdma_conn_param		*rdma_param = NULL;
1247 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1248 	uint16_t			max_queue_depth;
1249 	uint16_t			max_read_depth;
1250 
1251 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1252 
1253 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1254 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1255 
1256 	rdma_param = &event->param.conn;
1257 	if (rdma_param->private_data == NULL ||
1258 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1259 		SPDK_ERRLOG("connect request: no private data provided\n");
1260 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1261 		return -1;
1262 	}
1263 
1264 	private_data = rdma_param->private_data;
1265 	if (private_data->recfmt != 0) {
1266 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1267 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1268 		return -1;
1269 	}
1270 
1271 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1272 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1273 
1274 	port = event->listen_id->context;
1275 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1276 		      event->listen_id, event->listen_id->verbs, port);
1277 
1278 	/* Figure out the supported queue depth. This is a multi-step process
1279 	 * that takes into account hardware maximums, host provided values,
1280 	 * and our target's internal memory limits */
1281 
1282 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1283 
1284 	/* Start with the maximum queue depth allowed by the target */
1285 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1286 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1287 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1288 		      rtransport->transport.opts.max_queue_depth);
1289 
1290 	/* Next check the local NIC's hardware limitations */
1291 	SPDK_DEBUGLOG(rdma,
1292 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1293 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1294 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1295 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1296 
1297 	/* Next check the remote NIC's hardware limitations */
1298 	SPDK_DEBUGLOG(rdma,
1299 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1300 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1301 	if (rdma_param->initiator_depth > 0) {
1302 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1303 	}
1304 
1305 	/* Finally check for the host software requested values, which are
1306 	 * optional. */
1307 	if (rdma_param->private_data != NULL &&
1308 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1309 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1310 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1311 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1312 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1313 	}
1314 
1315 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1316 		      max_queue_depth, max_read_depth);
1317 
1318 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1319 	if (rqpair == NULL) {
1320 		SPDK_ERRLOG("Could not allocate new connection.\n");
1321 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1322 		return -1;
1323 	}
1324 
1325 	rqpair->device = port->device;
1326 	rqpair->max_queue_depth = max_queue_depth;
1327 	rqpair->max_read_depth = max_read_depth;
1328 	rqpair->cm_id = event->id;
1329 	rqpair->listen_id = event->listen_id;
1330 	rqpair->qpair.transport = transport;
1331 	STAILQ_INIT(&rqpair->ibv_events);
1332 	/* use qid from the private data to determine the qpair type
1333 	   qid will be set to the appropriate value when the controller is created */
1334 	rqpair->qpair.qid = private_data->qid;
1335 
1336 	event->id->context = &rqpair->qpair;
1337 
1338 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1339 
1340 	return 0;
1341 }
1342 
1343 static inline void
1344 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1345 		   enum spdk_nvme_data_transfer xfer)
1346 {
1347 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1348 		wr->opcode = IBV_WR_RDMA_WRITE;
1349 		wr->send_flags = 0;
1350 		wr->next = next;
1351 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1352 		wr->opcode = IBV_WR_RDMA_READ;
1353 		wr->send_flags = IBV_SEND_SIGNALED;
1354 		wr->next = NULL;
1355 	} else {
1356 		assert(0);
1357 	}
1358 }
1359 
1360 static int
1361 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1362 		       struct spdk_nvmf_rdma_request *rdma_req,
1363 		       uint32_t num_sgl_descriptors)
1364 {
1365 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1366 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1367 	uint32_t				i;
1368 
1369 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1370 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1371 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1372 		return -EINVAL;
1373 	}
1374 
1375 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1376 		return -ENOMEM;
1377 	}
1378 
1379 	current_data_wr = &rdma_req->data;
1380 
1381 	for (i = 0; i < num_sgl_descriptors; i++) {
1382 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1383 		current_data_wr->wr.next = &work_requests[i]->wr;
1384 		current_data_wr = work_requests[i];
1385 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1386 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1387 	}
1388 
1389 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1390 
1391 	return 0;
1392 }
1393 
1394 static inline void
1395 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1396 {
1397 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1398 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1399 
1400 	wr->wr.rdma.rkey = sgl->keyed.key;
1401 	wr->wr.rdma.remote_addr = sgl->address;
1402 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1403 }
1404 
1405 static inline void
1406 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1407 {
1408 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1409 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1410 	uint32_t			i;
1411 	int				j;
1412 	uint64_t			remote_addr_offset = 0;
1413 
1414 	for (i = 0; i < num_wrs; ++i) {
1415 		wr->wr.rdma.rkey = sgl->keyed.key;
1416 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1417 		for (j = 0; j < wr->num_sge; ++j) {
1418 			remote_addr_offset += wr->sg_list[j].length;
1419 		}
1420 		wr = wr->next;
1421 	}
1422 }
1423 
1424 static int
1425 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1426 		      struct spdk_nvmf_rdma_device *device,
1427 		      struct spdk_nvmf_rdma_request *rdma_req,
1428 		      struct ibv_send_wr *wr,
1429 		      uint32_t total_length)
1430 {
1431 	struct spdk_rdma_memory_translation mem_translation;
1432 	struct ibv_sge	*sg_ele;
1433 	struct iovec *iov;
1434 	uint32_t lkey, remaining;
1435 	int rc;
1436 
1437 	wr->num_sge = 0;
1438 
1439 	while (total_length && wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES) {
1440 		iov = &rdma_req->req.iov[rdma_req->iovpos];
1441 		rc = spdk_rdma_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1442 		if (spdk_unlikely(rc)) {
1443 			return rc;
1444 		}
1445 
1446 		lkey = spdk_rdma_memory_translation_get_lkey(&mem_translation);
1447 		sg_ele = &wr->sg_list[wr->num_sge];
1448 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1449 
1450 		sg_ele->lkey = lkey;
1451 		sg_ele->addr = (uintptr_t)iov->iov_base + rdma_req->offset;
1452 		sg_ele->length = remaining;
1453 		SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele, sg_ele->addr,
1454 			      sg_ele->length);
1455 		rdma_req->offset += sg_ele->length;
1456 		total_length -= sg_ele->length;
1457 		wr->num_sge++;
1458 
1459 		if (rdma_req->offset == iov->iov_len) {
1460 			rdma_req->offset = 0;
1461 			rdma_req->iovpos++;
1462 		}
1463 	}
1464 
1465 	if (total_length) {
1466 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1467 		return -EINVAL;
1468 	}
1469 
1470 	return 0;
1471 }
1472 
1473 static int
1474 nvmf_rdma_fill_wr_sgl_with_dif(struct spdk_nvmf_rdma_poll_group *rgroup,
1475 			       struct spdk_nvmf_rdma_device *device,
1476 			       struct spdk_nvmf_rdma_request *rdma_req,
1477 			       struct ibv_send_wr *wr,
1478 			       uint32_t total_length,
1479 			       uint32_t num_extra_wrs)
1480 {
1481 	struct spdk_rdma_memory_translation mem_translation;
1482 	struct spdk_dif_ctx *dif_ctx = &rdma_req->req.dif.dif_ctx;
1483 	struct ibv_sge *sg_ele;
1484 	struct iovec *iov;
1485 	struct iovec *rdma_iov;
1486 	uint32_t lkey, remaining;
1487 	uint32_t remaining_data_block, data_block_size, md_size;
1488 	uint32_t sge_len;
1489 	int rc;
1490 
1491 	data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1492 
1493 	if (spdk_likely(!rdma_req->req.stripped_data)) {
1494 		rdma_iov = rdma_req->req.iov;
1495 		remaining_data_block = data_block_size;
1496 		md_size = dif_ctx->md_size;
1497 	} else {
1498 		rdma_iov = rdma_req->req.stripped_data->iov;
1499 		total_length = total_length / dif_ctx->block_size * data_block_size;
1500 		remaining_data_block = total_length;
1501 		md_size = 0;
1502 	}
1503 
1504 	wr->num_sge = 0;
1505 
1506 	while (total_length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1507 		iov = rdma_iov + rdma_req->iovpos;
1508 		rc = spdk_rdma_get_translation(device->map, iov->iov_base, iov->iov_len, &mem_translation);
1509 		if (spdk_unlikely(rc)) {
1510 			return rc;
1511 		}
1512 
1513 		lkey = spdk_rdma_memory_translation_get_lkey(&mem_translation);
1514 		sg_ele = &wr->sg_list[wr->num_sge];
1515 		remaining = spdk_min((uint32_t)iov->iov_len - rdma_req->offset, total_length);
1516 
1517 		while (remaining) {
1518 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1519 				if (num_extra_wrs > 0 && wr->next) {
1520 					wr = wr->next;
1521 					wr->num_sge = 0;
1522 					sg_ele = &wr->sg_list[wr->num_sge];
1523 					num_extra_wrs--;
1524 				} else {
1525 					break;
1526 				}
1527 			}
1528 			sg_ele->lkey = lkey;
1529 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + rdma_req->offset);
1530 			sge_len = spdk_min(remaining, remaining_data_block);
1531 			sg_ele->length = sge_len;
1532 			SPDK_DEBUGLOG(rdma, "sge[%d] %p addr 0x%"PRIx64", len %u\n", wr->num_sge, sg_ele,
1533 				      sg_ele->addr, sg_ele->length);
1534 			remaining -= sge_len;
1535 			remaining_data_block -= sge_len;
1536 			rdma_req->offset += sge_len;
1537 			total_length -= sge_len;
1538 
1539 			sg_ele++;
1540 			wr->num_sge++;
1541 
1542 			if (remaining_data_block == 0) {
1543 				/* skip metadata */
1544 				rdma_req->offset += md_size;
1545 				total_length -= md_size;
1546 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1547 				remaining -= spdk_min(remaining, md_size);
1548 				remaining_data_block = data_block_size;
1549 			}
1550 
1551 			if (remaining == 0) {
1552 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1553 				   the remaining metadata bits at the beginning of the next buffer */
1554 				rdma_req->offset -= spdk_min(iov->iov_len, rdma_req->offset);
1555 				rdma_req->iovpos++;
1556 			}
1557 		}
1558 	}
1559 
1560 	if (total_length) {
1561 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1562 		return -EINVAL;
1563 	}
1564 
1565 	return 0;
1566 }
1567 
1568 static inline uint32_t
1569 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1570 {
1571 	/* estimate the number of SG entries and WRs needed to process the request */
1572 	uint32_t num_sge = 0;
1573 	uint32_t i;
1574 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1575 
1576 	for (i = 0; i < num_buffers && length > 0; i++) {
1577 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1578 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1579 
1580 		if (num_sge_in_block * block_size > buffer_len) {
1581 			++num_sge_in_block;
1582 		}
1583 		num_sge += num_sge_in_block;
1584 		length -= buffer_len;
1585 	}
1586 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1587 }
1588 
1589 static int
1590 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1591 			    struct spdk_nvmf_rdma_device *device,
1592 			    struct spdk_nvmf_rdma_request *rdma_req)
1593 {
1594 	struct spdk_nvmf_rdma_qpair		*rqpair;
1595 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1596 	struct spdk_nvmf_request		*req = &rdma_req->req;
1597 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1598 	int					rc;
1599 	uint32_t				num_wrs = 1;
1600 	uint32_t				length;
1601 
1602 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1603 	rgroup = rqpair->poller->group;
1604 
1605 	/* rdma wr specifics */
1606 	nvmf_rdma_setup_request(rdma_req);
1607 
1608 	length = req->length;
1609 	if (spdk_unlikely(req->dif_enabled)) {
1610 		req->dif.orig_length = length;
1611 		length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1612 		req->dif.elba_length = length;
1613 	}
1614 
1615 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1616 					   length);
1617 	if (rc != 0) {
1618 		return rc;
1619 	}
1620 
1621 	assert(req->iovcnt <= rqpair->max_send_sge);
1622 
1623 	/* When dif_insert_or_strip is true and the I/O data length is greater than one block,
1624 	 * the stripped_buffers are got for DIF stripping. */
1625 	if (spdk_unlikely(req->dif_enabled && (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST)
1626 			  && (req->dif.elba_length > req->dif.dif_ctx.block_size))) {
1627 		rc = nvmf_request_get_stripped_buffers(req, &rgroup->group,
1628 						       &rtransport->transport, req->dif.orig_length);
1629 		if (rc != 0) {
1630 			SPDK_INFOLOG(rdma, "Get stripped buffers fail %d, fallback to req.iov.\n", rc);
1631 		}
1632 	}
1633 
1634 	rdma_req->iovpos = 0;
1635 
1636 	if (spdk_unlikely(req->dif_enabled)) {
1637 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1638 						 req->dif.dif_ctx.block_size);
1639 		if (num_wrs > 1) {
1640 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1641 			if (rc != 0) {
1642 				goto err_exit;
1643 			}
1644 		}
1645 
1646 		rc = nvmf_rdma_fill_wr_sgl_with_dif(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1647 		if (spdk_unlikely(rc != 0)) {
1648 			goto err_exit;
1649 		}
1650 
1651 		if (num_wrs > 1) {
1652 			nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1653 		}
1654 	} else {
1655 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length);
1656 		if (spdk_unlikely(rc != 0)) {
1657 			goto err_exit;
1658 		}
1659 	}
1660 
1661 	/* set the number of outstanding data WRs for this request. */
1662 	rdma_req->num_outstanding_data_wr = num_wrs;
1663 
1664 	return rc;
1665 
1666 err_exit:
1667 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1668 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1669 	req->iovcnt = 0;
1670 	return rc;
1671 }
1672 
1673 static int
1674 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1675 				      struct spdk_nvmf_rdma_device *device,
1676 				      struct spdk_nvmf_rdma_request *rdma_req)
1677 {
1678 	struct spdk_nvmf_rdma_qpair		*rqpair;
1679 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1680 	struct ibv_send_wr			*current_wr;
1681 	struct spdk_nvmf_request		*req = &rdma_req->req;
1682 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1683 	uint32_t				num_sgl_descriptors;
1684 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES], total_length = 0;
1685 	uint32_t				i;
1686 	int					rc;
1687 
1688 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1689 	rgroup = rqpair->poller->group;
1690 
1691 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1692 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1693 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1694 
1695 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1696 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1697 
1698 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1699 	for (i = 0; i < num_sgl_descriptors; i++) {
1700 		if (spdk_likely(!req->dif_enabled)) {
1701 			lengths[i] = desc->keyed.length;
1702 		} else {
1703 			req->dif.orig_length += desc->keyed.length;
1704 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1705 			req->dif.elba_length += lengths[i];
1706 		}
1707 		total_length += lengths[i];
1708 		desc++;
1709 	}
1710 
1711 	if (total_length > rtransport->transport.opts.max_io_size) {
1712 		SPDK_ERRLOG("Multi SGL length 0x%x exceeds max io size 0x%x\n",
1713 			    total_length, rtransport->transport.opts.max_io_size);
1714 		req->rsp->nvme_cpl.status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1715 		return -EINVAL;
1716 	}
1717 
1718 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1719 		return -ENOMEM;
1720 	}
1721 
1722 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport, total_length);
1723 	if (rc != 0) {
1724 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1725 		return rc;
1726 	}
1727 
1728 	/* When dif_insert_or_strip is true and the I/O data length is greater than one block,
1729 	 * the stripped_buffers are got for DIF stripping. */
1730 	if (spdk_unlikely(req->dif_enabled && (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST)
1731 			  && (req->dif.elba_length > req->dif.dif_ctx.block_size))) {
1732 		rc = nvmf_request_get_stripped_buffers(req, &rgroup->group,
1733 						       &rtransport->transport, req->dif.orig_length);
1734 		if (rc != 0) {
1735 			SPDK_INFOLOG(rdma, "Get stripped buffers fail %d, fallback to req.iov.\n", rc);
1736 		}
1737 	}
1738 
1739 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1740 	current_wr = &rdma_req->data.wr;
1741 	assert(current_wr != NULL);
1742 
1743 	req->length = 0;
1744 	rdma_req->iovpos = 0;
1745 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1746 	for (i = 0; i < num_sgl_descriptors; i++) {
1747 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1748 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1749 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1750 			rc = -EINVAL;
1751 			goto err_exit;
1752 		}
1753 
1754 		if (spdk_likely(!req->dif_enabled)) {
1755 			rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i]);
1756 		} else {
1757 			rc = nvmf_rdma_fill_wr_sgl_with_dif(rgroup, device, rdma_req, current_wr,
1758 							    lengths[i], 0);
1759 		}
1760 		if (rc != 0) {
1761 			rc = -ENOMEM;
1762 			goto err_exit;
1763 		}
1764 
1765 		req->length += desc->keyed.length;
1766 		current_wr->wr.rdma.rkey = desc->keyed.key;
1767 		current_wr->wr.rdma.remote_addr = desc->address;
1768 		current_wr = current_wr->next;
1769 		desc++;
1770 	}
1771 
1772 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1773 	/* Go back to the last descriptor in the list. */
1774 	desc--;
1775 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1776 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1777 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1778 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1779 		}
1780 	}
1781 #endif
1782 
1783 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1784 
1785 	return 0;
1786 
1787 err_exit:
1788 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1789 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1790 	return rc;
1791 }
1792 
1793 static int
1794 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1795 			    struct spdk_nvmf_rdma_device *device,
1796 			    struct spdk_nvmf_rdma_request *rdma_req)
1797 {
1798 	struct spdk_nvmf_request		*req = &rdma_req->req;
1799 	struct spdk_nvme_cpl			*rsp;
1800 	struct spdk_nvme_sgl_descriptor		*sgl;
1801 	int					rc;
1802 	uint32_t				length;
1803 
1804 	rsp = &req->rsp->nvme_cpl;
1805 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1806 
1807 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1808 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1809 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1810 
1811 		length = sgl->keyed.length;
1812 		if (length > rtransport->transport.opts.max_io_size) {
1813 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1814 				    length, rtransport->transport.opts.max_io_size);
1815 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1816 			return -1;
1817 		}
1818 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1819 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1820 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1821 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1822 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1823 			}
1824 		}
1825 #endif
1826 
1827 		/* fill request length and populate iovs */
1828 		req->length = length;
1829 
1830 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req);
1831 		if (spdk_unlikely(rc < 0)) {
1832 			if (rc == -EINVAL) {
1833 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1834 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1835 				return -1;
1836 			}
1837 			/* No available buffers. Queue this request up. */
1838 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1839 			return 0;
1840 		}
1841 
1842 		/* backward compatible */
1843 		req->data = req->iov[0].iov_base;
1844 
1845 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1846 			      req->iovcnt);
1847 
1848 		return 0;
1849 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1850 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1851 		uint64_t offset = sgl->address;
1852 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1853 
1854 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1855 			      offset, sgl->unkeyed.length);
1856 
1857 		if (offset > max_len) {
1858 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1859 				    offset, max_len);
1860 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1861 			return -1;
1862 		}
1863 		max_len -= (uint32_t)offset;
1864 
1865 		if (sgl->unkeyed.length > max_len) {
1866 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1867 				    sgl->unkeyed.length, max_len);
1868 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1869 			return -1;
1870 		}
1871 
1872 		rdma_req->num_outstanding_data_wr = 0;
1873 		req->data_from_pool = false;
1874 		req->length = sgl->unkeyed.length;
1875 
1876 		req->iov[0].iov_base = rdma_req->recv->buf + offset;
1877 		req->iov[0].iov_len = req->length;
1878 		req->iovcnt = 1;
1879 		req->data = req->iov[0].iov_base;
1880 
1881 		return 0;
1882 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1883 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1884 
1885 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1886 		if (rc == -ENOMEM) {
1887 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1888 			return 0;
1889 		} else if (rc == -EINVAL) {
1890 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1891 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1892 			return -1;
1893 		}
1894 
1895 		/* backward compatible */
1896 		req->data = req->iov[0].iov_base;
1897 
1898 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1899 			      req->iovcnt);
1900 
1901 		return 0;
1902 	}
1903 
1904 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1905 		    sgl->generic.type, sgl->generic.subtype);
1906 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1907 	return -1;
1908 }
1909 
1910 static void
1911 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1912 			struct spdk_nvmf_rdma_transport	*rtransport)
1913 {
1914 	struct spdk_nvmf_rdma_qpair		*rqpair;
1915 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1916 
1917 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1918 	if (rdma_req->req.data_from_pool) {
1919 		rgroup = rqpair->poller->group;
1920 
1921 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1922 	}
1923 	if (rdma_req->req.stripped_data) {
1924 		nvmf_request_free_stripped_buffers(&rdma_req->req,
1925 						   &rqpair->poller->group->group,
1926 						   &rtransport->transport);
1927 	}
1928 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1929 	rdma_req->req.length = 0;
1930 	rdma_req->req.iovcnt = 0;
1931 	rdma_req->req.data = NULL;
1932 	rdma_req->offset = 0;
1933 	rdma_req->req.dif_enabled = false;
1934 	rdma_req->fused_failed = false;
1935 	if (rdma_req->fused_pair) {
1936 		/* This req was part of a valid fused pair, but failed before it got to
1937 		 * READ_TO_EXECUTE state.  This means we need to fail the other request
1938 		 * in the pair, because it is no longer part of a valid pair.  If the pair
1939 		 * already reached READY_TO_EXECUTE state, we need to kick it.
1940 		 */
1941 		rdma_req->fused_pair->fused_failed = true;
1942 		if (rdma_req->fused_pair->state == RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
1943 			nvmf_rdma_request_process(rtransport, rdma_req->fused_pair);
1944 		}
1945 		rdma_req->fused_pair = NULL;
1946 	}
1947 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1948 	rqpair->qd--;
1949 
1950 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1951 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1952 }
1953 
1954 static void
1955 nvmf_rdma_check_fused_ordering(struct spdk_nvmf_rdma_transport *rtransport,
1956 			       struct spdk_nvmf_rdma_qpair *rqpair,
1957 			       struct spdk_nvmf_rdma_request *rdma_req)
1958 {
1959 	enum spdk_nvme_cmd_fuse last, next;
1960 
1961 	last = rqpair->fused_first ? rqpair->fused_first->req.cmd->nvme_cmd.fuse : SPDK_NVME_CMD_FUSE_NONE;
1962 	next = rdma_req->req.cmd->nvme_cmd.fuse;
1963 
1964 	assert(last != SPDK_NVME_CMD_FUSE_SECOND);
1965 
1966 	if (spdk_likely(last == SPDK_NVME_CMD_FUSE_NONE && next == SPDK_NVME_CMD_FUSE_NONE)) {
1967 		return;
1968 	}
1969 
1970 	if (last == SPDK_NVME_CMD_FUSE_FIRST) {
1971 		if (next == SPDK_NVME_CMD_FUSE_SECOND) {
1972 			/* This is a valid pair of fused commands.  Point them at each other
1973 			 * so they can be submitted consecutively once ready to be executed.
1974 			 */
1975 			rqpair->fused_first->fused_pair = rdma_req;
1976 			rdma_req->fused_pair = rqpair->fused_first;
1977 			rqpair->fused_first = NULL;
1978 			return;
1979 		} else {
1980 			/* Mark the last req as failed since it wasn't followed by a SECOND. */
1981 			rqpair->fused_first->fused_failed = true;
1982 
1983 			/* If the last req is in READY_TO_EXECUTE state, then call
1984 			 * nvmf_rdma_request_process(), otherwise nothing else will kick it.
1985 			 */
1986 			if (rqpair->fused_first->state == RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
1987 				nvmf_rdma_request_process(rtransport, rqpair->fused_first);
1988 			}
1989 
1990 			rqpair->fused_first = NULL;
1991 		}
1992 	}
1993 
1994 	if (next == SPDK_NVME_CMD_FUSE_FIRST) {
1995 		/* Set rqpair->fused_first here so that we know to check that the next request
1996 		 * is a SECOND (and to fail this one if it isn't).
1997 		 */
1998 		rqpair->fused_first = rdma_req;
1999 	} else if (next == SPDK_NVME_CMD_FUSE_SECOND) {
2000 		/* Mark this req failed since it ia SECOND and the last one was not a FIRST. */
2001 		rdma_req->fused_failed = true;
2002 	}
2003 }
2004 
2005 bool
2006 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
2007 			  struct spdk_nvmf_rdma_request *rdma_req)
2008 {
2009 	struct spdk_nvmf_rdma_qpair	*rqpair;
2010 	struct spdk_nvmf_rdma_device	*device;
2011 	struct spdk_nvmf_rdma_poll_group *rgroup;
2012 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
2013 	int				rc;
2014 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2015 	enum spdk_nvmf_rdma_request_state prev_state;
2016 	bool				progress = false;
2017 	int				data_posted;
2018 	uint32_t			num_blocks;
2019 
2020 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2021 	device = rqpair->device;
2022 	rgroup = rqpair->poller->group;
2023 
2024 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
2025 
2026 	/* If the queue pair is in an error state, force the request to the completed state
2027 	 * to release resources. */
2028 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2029 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
2030 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
2031 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
2032 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2033 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
2034 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2035 		}
2036 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2037 	}
2038 
2039 	/* The loop here is to allow for several back-to-back state changes. */
2040 	do {
2041 		prev_state = rdma_req->state;
2042 
2043 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
2044 
2045 		switch (rdma_req->state) {
2046 		case RDMA_REQUEST_STATE_FREE:
2047 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
2048 			 * to escape this state. */
2049 			break;
2050 		case RDMA_REQUEST_STATE_NEW:
2051 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
2052 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2053 			rdma_recv = rdma_req->recv;
2054 
2055 			/* The first element of the SGL is the NVMe command */
2056 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
2057 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
2058 
2059 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2060 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2061 				break;
2062 			}
2063 
2064 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
2065 				rdma_req->req.dif_enabled = true;
2066 			}
2067 
2068 			nvmf_rdma_check_fused_ordering(rtransport, rqpair, rdma_req);
2069 
2070 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2071 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
2072 			rdma_req->rsp.wr.imm_data = 0;
2073 #endif
2074 
2075 			/* The next state transition depends on the data transfer needs of this request. */
2076 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
2077 
2078 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
2079 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2080 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
2081 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2082 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
2083 				break;
2084 			}
2085 
2086 			/* If no data to transfer, ready to execute. */
2087 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2088 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2089 				break;
2090 			}
2091 
2092 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2093 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2094 			break;
2095 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2096 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2097 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2098 
2099 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2100 
2101 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2102 				/* This request needs to wait in line to obtain a buffer */
2103 				break;
2104 			}
2105 
2106 			/* Try to get a data buffer */
2107 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2108 			if (rc < 0) {
2109 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2110 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2111 				break;
2112 			}
2113 
2114 			if (rdma_req->req.iovcnt == 0) {
2115 				/* No buffers available. */
2116 				rgroup->stat.pending_data_buffer++;
2117 				break;
2118 			}
2119 
2120 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2121 
2122 			/* If data is transferring from host to controller and the data didn't
2123 			 * arrive using in capsule data, we need to do a transfer from the host.
2124 			 */
2125 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2126 			    rdma_req->req.data_from_pool) {
2127 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2128 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2129 				break;
2130 			}
2131 
2132 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2133 			break;
2134 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2135 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2136 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2137 
2138 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2139 				/* This request needs to wait in line to perform RDMA */
2140 				break;
2141 			}
2142 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2143 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2144 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2145 				rqpair->poller->stat.pending_rdma_read++;
2146 				break;
2147 			}
2148 
2149 			/* We have already verified that this request is the head of the queue. */
2150 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2151 
2152 			rc = request_transfer_in(&rdma_req->req);
2153 			if (!rc) {
2154 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2155 			} else {
2156 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2157 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2158 			}
2159 			break;
2160 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2161 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2162 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2163 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2164 			 * to escape this state. */
2165 			break;
2166 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2167 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2168 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2169 
2170 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2171 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2172 					/* generate DIF for write operation */
2173 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2174 					assert(num_blocks > 0);
2175 
2176 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2177 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2178 					if (rc != 0) {
2179 						SPDK_ERRLOG("DIF generation failed\n");
2180 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2181 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2182 						break;
2183 					}
2184 				}
2185 
2186 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2187 				/* set extended length before IO operation */
2188 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2189 			}
2190 
2191 			if (rdma_req->req.cmd->nvme_cmd.fuse != SPDK_NVME_CMD_FUSE_NONE) {
2192 				if (rdma_req->fused_failed) {
2193 					/* This request failed FUSED semantics.  Fail it immediately, without
2194 					 * even sending it to the target layer.
2195 					 */
2196 					rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2197 					rsp->status.sc = SPDK_NVME_SC_ABORTED_MISSING_FUSED;
2198 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2199 					break;
2200 				}
2201 
2202 				if (rdma_req->fused_pair == NULL ||
2203 				    rdma_req->fused_pair->state != RDMA_REQUEST_STATE_READY_TO_EXECUTE) {
2204 					/* This request is ready to execute, but either we don't know yet if it's
2205 					 * valid - i.e. this is a FIRST but we haven't received the next
2206 					 * request yet or the other request of this fused pair isn't ready to
2207 					 * execute.  So break here and this request will get processed later either
2208 					 * when the other request is ready or we find that this request isn't valid.
2209 					 */
2210 					break;
2211 				}
2212 			}
2213 
2214 			/* If we get to this point, and this request is a fused command, we know that
2215 			 * it is part of valid sequence (FIRST followed by a SECOND) and that both
2216 			 * requests are READY_TO_EXECUTE. So call spdk_nvmf_request_exec() both on this
2217 			 * request, and the other request of the fused pair, in the correct order.
2218 			 * Also clear the ->fused_pair pointers on both requests, since after this point
2219 			 * we no longer need to maintain the relationship between these two requests.
2220 			 */
2221 			if (rdma_req->req.cmd->nvme_cmd.fuse == SPDK_NVME_CMD_FUSE_SECOND) {
2222 				assert(rdma_req->fused_pair != NULL);
2223 				assert(rdma_req->fused_pair->fused_pair != NULL);
2224 				rdma_req->fused_pair->state = RDMA_REQUEST_STATE_EXECUTING;
2225 				spdk_nvmf_request_exec(&rdma_req->fused_pair->req);
2226 				rdma_req->fused_pair->fused_pair = NULL;
2227 				rdma_req->fused_pair = NULL;
2228 			}
2229 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2230 			spdk_nvmf_request_exec(&rdma_req->req);
2231 			if (rdma_req->req.cmd->nvme_cmd.fuse == SPDK_NVME_CMD_FUSE_FIRST) {
2232 				assert(rdma_req->fused_pair != NULL);
2233 				assert(rdma_req->fused_pair->fused_pair != NULL);
2234 				rdma_req->fused_pair->state = RDMA_REQUEST_STATE_EXECUTING;
2235 				spdk_nvmf_request_exec(&rdma_req->fused_pair->req);
2236 				rdma_req->fused_pair->fused_pair = NULL;
2237 				rdma_req->fused_pair = NULL;
2238 			}
2239 			break;
2240 		case RDMA_REQUEST_STATE_EXECUTING:
2241 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2242 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2243 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2244 			 * to escape this state. */
2245 			break;
2246 		case RDMA_REQUEST_STATE_EXECUTED:
2247 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2248 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2249 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2250 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2251 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2252 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2253 			} else {
2254 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2255 			}
2256 			if (spdk_unlikely(rdma_req->req.dif_enabled)) {
2257 				/* restore the original length */
2258 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2259 
2260 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2261 					struct spdk_dif_error error_blk;
2262 
2263 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2264 					if (!rdma_req->req.stripped_data) {
2265 						rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2266 								     &rdma_req->req.dif.dif_ctx, &error_blk);
2267 					} else {
2268 						rc = spdk_dif_verify_copy(rdma_req->req.stripped_data->iov,
2269 									  rdma_req->req.stripped_data->iovcnt,
2270 									  rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2271 									  &rdma_req->req.dif.dif_ctx, &error_blk);
2272 					}
2273 					if (rc) {
2274 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2275 
2276 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2277 							    error_blk.err_offset);
2278 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2279 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2280 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2281 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2282 					}
2283 				}
2284 			}
2285 			break;
2286 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2287 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2288 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2289 
2290 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2291 				/* This request needs to wait in line to perform RDMA */
2292 				break;
2293 			}
2294 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2295 			    rqpair->max_send_depth) {
2296 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2297 				 * +1 since each request has an additional wr in the resp. */
2298 				rqpair->poller->stat.pending_rdma_write++;
2299 				break;
2300 			}
2301 
2302 			/* We have already verified that this request is the head of the queue. */
2303 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2304 
2305 			/* The data transfer will be kicked off from
2306 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2307 			 */
2308 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2309 			break;
2310 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2311 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2312 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2313 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2314 			assert(rc == 0); /* No good way to handle this currently */
2315 			if (rc) {
2316 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2317 			} else {
2318 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2319 						  RDMA_REQUEST_STATE_COMPLETING;
2320 			}
2321 			break;
2322 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2323 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2324 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2325 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2326 			 * to escape this state. */
2327 			break;
2328 		case RDMA_REQUEST_STATE_COMPLETING:
2329 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2330 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2331 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2332 			 * to escape this state. */
2333 			break;
2334 		case RDMA_REQUEST_STATE_COMPLETED:
2335 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2336 					  (uintptr_t)rdma_req, (uintptr_t)rqpair);
2337 
2338 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2339 			_nvmf_rdma_request_free(rdma_req, rtransport);
2340 			break;
2341 		case RDMA_REQUEST_NUM_STATES:
2342 		default:
2343 			assert(0);
2344 			break;
2345 		}
2346 
2347 		if (rdma_req->state != prev_state) {
2348 			progress = true;
2349 		}
2350 	} while (rdma_req->state != prev_state);
2351 
2352 	return progress;
2353 }
2354 
2355 /* Public API callbacks begin here */
2356 
2357 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2358 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2359 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2360 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2361 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2362 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2363 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2364 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2365 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2366 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2367 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2368 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2369 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2370 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2371 
2372 static void
2373 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2374 {
2375 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2376 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2377 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2378 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2379 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2380 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2381 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2382 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2383 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2384 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2385 	opts->transport_specific =      NULL;
2386 }
2387 
2388 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2389 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2390 
2391 static inline bool
2392 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2393 {
2394 	return device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_OLD ||
2395 	       device->attr.vendor_id == SPDK_RDMA_RXE_VENDOR_ID_NEW;
2396 }
2397 
2398 static int nvmf_rdma_accept(void *ctx);
2399 static bool nvmf_rdma_retry_listen_port(struct spdk_nvmf_rdma_transport *rtransport);
2400 static void destroy_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
2401 			      struct spdk_nvmf_rdma_device *device);
2402 
2403 static int
2404 create_ib_device(struct spdk_nvmf_rdma_transport *rtransport, struct ibv_context *context,
2405 		 struct spdk_nvmf_rdma_device **new_device)
2406 {
2407 	struct spdk_nvmf_rdma_device	*device;
2408 	int				flag = 0;
2409 	int				rc = 0;
2410 
2411 	device = calloc(1, sizeof(*device));
2412 	if (!device) {
2413 		SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2414 		return -ENOMEM;
2415 	}
2416 	device->context = context;
2417 	rc = ibv_query_device(device->context, &device->attr);
2418 	if (rc < 0) {
2419 		SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2420 		free(device);
2421 		return rc;
2422 	}
2423 
2424 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2425 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2426 		SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2427 		SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2428 	}
2429 
2430 	/**
2431 	 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2432 	 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2433 	 * but incorrectly reports that it does. There are changes making their way
2434 	 * through the kernel now that will enable this feature. When they are merged,
2435 	 * we can conditionally enable this feature.
2436 	 *
2437 	 * TODO: enable this for versions of the kernel rxe driver that support it.
2438 	 */
2439 	if (nvmf_rdma_is_rxe_device(device)) {
2440 		device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2441 	}
2442 #endif
2443 
2444 	/* set up device context async ev fd as NON_BLOCKING */
2445 	flag = fcntl(device->context->async_fd, F_GETFL);
2446 	rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2447 	if (rc < 0) {
2448 		SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2449 		free(device);
2450 		return rc;
2451 	}
2452 
2453 	TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2454 	SPDK_DEBUGLOG(rdma, "New device %p is added to RDMA trasport\n", device);
2455 
2456 	if (g_nvmf_hooks.get_ibv_pd) {
2457 		device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2458 	} else {
2459 		device->pd = ibv_alloc_pd(device->context);
2460 	}
2461 
2462 	if (!device->pd) {
2463 		SPDK_ERRLOG("Unable to allocate protection domain.\n");
2464 		destroy_ib_device(rtransport, device);
2465 		return -ENOMEM;
2466 	}
2467 
2468 	assert(device->map == NULL);
2469 
2470 	device->map = spdk_rdma_create_mem_map(device->pd, &g_nvmf_hooks, SPDK_RDMA_MEMORY_MAP_ROLE_TARGET);
2471 	if (!device->map) {
2472 		SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2473 		destroy_ib_device(rtransport, device);
2474 		return -ENOMEM;
2475 	}
2476 
2477 	assert(device->map != NULL);
2478 	assert(device->pd != NULL);
2479 
2480 	if (new_device) {
2481 		*new_device = device;
2482 	}
2483 	SPDK_NOTICELOG("Create IB device %s(%p/%p) succeed.\n", ibv_get_device_name(context->device),
2484 		       device, context);
2485 
2486 	return 0;
2487 }
2488 
2489 static void
2490 free_poll_fds(struct spdk_nvmf_rdma_transport *rtransport)
2491 {
2492 	if (rtransport->poll_fds) {
2493 		free(rtransport->poll_fds);
2494 		rtransport->poll_fds = NULL;
2495 	}
2496 	rtransport->npoll_fds = 0;
2497 }
2498 
2499 static int
2500 generate_poll_fds(struct spdk_nvmf_rdma_transport *rtransport)
2501 {
2502 	/* Set up poll descriptor array to monitor events from RDMA and IB
2503 	 * in a single poll syscall
2504 	 */
2505 	int device_count = 0;
2506 	int i = 0;
2507 	struct spdk_nvmf_rdma_device *device, *tmp;
2508 
2509 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2510 		device_count++;
2511 	}
2512 
2513 	rtransport->npoll_fds = device_count + 1;
2514 
2515 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2516 	if (rtransport->poll_fds == NULL) {
2517 		SPDK_ERRLOG("poll_fds allocation failed\n");
2518 		return -ENOMEM;
2519 	}
2520 
2521 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2522 	rtransport->poll_fds[i++].events = POLLIN;
2523 
2524 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2525 		rtransport->poll_fds[i].fd = device->context->async_fd;
2526 		rtransport->poll_fds[i++].events = POLLIN;
2527 	}
2528 
2529 	return 0;
2530 }
2531 
2532 static struct spdk_nvmf_transport *
2533 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2534 {
2535 	int rc;
2536 	struct spdk_nvmf_rdma_transport *rtransport;
2537 	struct spdk_nvmf_rdma_device	*device;
2538 	struct ibv_context		**contexts;
2539 	uint32_t			i;
2540 	int				flag;
2541 	uint32_t			sge_count;
2542 	uint32_t			min_shared_buffers;
2543 	uint32_t			min_in_capsule_data_size;
2544 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2545 
2546 	rtransport = calloc(1, sizeof(*rtransport));
2547 	if (!rtransport) {
2548 		return NULL;
2549 	}
2550 
2551 	TAILQ_INIT(&rtransport->devices);
2552 	TAILQ_INIT(&rtransport->ports);
2553 	TAILQ_INIT(&rtransport->poll_groups);
2554 	TAILQ_INIT(&rtransport->retry_ports);
2555 
2556 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2557 	rtransport->rdma_opts.num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
2558 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2559 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2560 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2561 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2562 	if (opts->transport_specific != NULL &&
2563 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2564 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2565 					    &rtransport->rdma_opts)) {
2566 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2567 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2568 		return NULL;
2569 	}
2570 
2571 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2572 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2573 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2574 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2575 		     "  num_shared_buffers=%d, num_cqe=%d, max_srq_depth=%d, no_srq=%d,"
2576 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2577 		     opts->max_queue_depth,
2578 		     opts->max_io_size,
2579 		     opts->max_qpairs_per_ctrlr - 1,
2580 		     opts->io_unit_size,
2581 		     opts->in_capsule_data_size,
2582 		     opts->max_aq_depth,
2583 		     opts->num_shared_buffers,
2584 		     rtransport->rdma_opts.num_cqe,
2585 		     rtransport->rdma_opts.max_srq_depth,
2586 		     rtransport->rdma_opts.no_srq,
2587 		     rtransport->rdma_opts.acceptor_backlog,
2588 		     rtransport->rdma_opts.no_wr_batching,
2589 		     opts->abort_timeout_sec);
2590 
2591 	/* I/O unit size cannot be larger than max I/O size */
2592 	if (opts->io_unit_size > opts->max_io_size) {
2593 		opts->io_unit_size = opts->max_io_size;
2594 	}
2595 
2596 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2597 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2598 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2599 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2600 	}
2601 
2602 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2603 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2604 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2605 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2606 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2607 		return NULL;
2608 	}
2609 
2610 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2611 	if (min_shared_buffers > opts->num_shared_buffers) {
2612 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2613 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2614 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2615 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2616 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2617 		return NULL;
2618 	}
2619 
2620 	sge_count = opts->max_io_size / opts->io_unit_size;
2621 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2622 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2623 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2624 		return NULL;
2625 	}
2626 
2627 	min_in_capsule_data_size = sizeof(struct spdk_nvme_sgl_descriptor) * SPDK_NVMF_MAX_SGL_ENTRIES;
2628 	if (opts->in_capsule_data_size < min_in_capsule_data_size) {
2629 		SPDK_WARNLOG("In capsule data size is set to %u, this is minimum size required to support msdbd=16\n",
2630 			     min_in_capsule_data_size);
2631 		opts->in_capsule_data_size = min_in_capsule_data_size;
2632 	}
2633 
2634 	rtransport->event_channel = rdma_create_event_channel();
2635 	if (rtransport->event_channel == NULL) {
2636 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2637 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2638 		return NULL;
2639 	}
2640 
2641 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2642 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2643 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2644 			    rtransport->event_channel->fd, spdk_strerror(errno));
2645 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2646 		return NULL;
2647 	}
2648 
2649 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2650 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2651 				   sizeof(struct spdk_nvmf_rdma_request_data),
2652 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2653 				   SPDK_ENV_SOCKET_ID_ANY);
2654 	if (!rtransport->data_wr_pool) {
2655 		if (spdk_mempool_lookup("spdk_nvmf_rdma_wr_data") != NULL) {
2656 			SPDK_ERRLOG("Unable to allocate work request pool for poll group: already exists\n");
2657 			SPDK_ERRLOG("Probably running in multiprocess environment, which is "
2658 				    "unsupported by the nvmf library\n");
2659 		} else {
2660 			SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2661 		}
2662 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2663 		return NULL;
2664 	}
2665 
2666 	contexts = rdma_get_devices(NULL);
2667 	if (contexts == NULL) {
2668 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2669 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2670 		return NULL;
2671 	}
2672 
2673 	i = 0;
2674 	rc = 0;
2675 	while (contexts[i] != NULL) {
2676 		rc = create_ib_device(rtransport, contexts[i], &device);
2677 		if (rc < 0) {
2678 			break;
2679 		}
2680 		i++;
2681 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2682 		device->is_ready = true;
2683 	}
2684 	rdma_free_devices(contexts);
2685 
2686 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2687 		/* divide and round up. */
2688 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2689 
2690 		/* round up to the nearest 4k. */
2691 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2692 
2693 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2694 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2695 			       opts->io_unit_size);
2696 	}
2697 
2698 	if (rc < 0) {
2699 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2700 		return NULL;
2701 	}
2702 
2703 	rc = generate_poll_fds(rtransport);
2704 	if (rc < 0) {
2705 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2706 		return NULL;
2707 	}
2708 
2709 	rtransport->accept_poller = SPDK_POLLER_REGISTER(nvmf_rdma_accept, &rtransport->transport,
2710 				    opts->acceptor_poll_rate);
2711 	if (!rtransport->accept_poller) {
2712 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2713 		return NULL;
2714 	}
2715 
2716 	return &rtransport->transport;
2717 }
2718 
2719 static void
2720 destroy_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
2721 		  struct spdk_nvmf_rdma_device *device)
2722 {
2723 	TAILQ_REMOVE(&rtransport->devices, device, link);
2724 	spdk_rdma_free_mem_map(&device->map);
2725 	if (device->pd) {
2726 		if (!g_nvmf_hooks.get_ibv_pd) {
2727 			ibv_dealloc_pd(device->pd);
2728 		}
2729 	}
2730 	SPDK_DEBUGLOG(rdma, "IB device [%p] is destroyed.\n", device);
2731 	free(device);
2732 }
2733 
2734 static void
2735 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2736 {
2737 	struct spdk_nvmf_rdma_transport	*rtransport;
2738 	assert(w != NULL);
2739 
2740 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2741 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2742 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2743 	if (rtransport->rdma_opts.no_srq == true) {
2744 		spdk_json_write_named_int32(w, "num_cqe", rtransport->rdma_opts.num_cqe);
2745 	}
2746 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2747 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2748 }
2749 
2750 static int
2751 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2752 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2753 {
2754 	struct spdk_nvmf_rdma_transport	*rtransport;
2755 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2756 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2757 
2758 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2759 
2760 	TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, port_tmp) {
2761 		TAILQ_REMOVE(&rtransport->retry_ports, port, link);
2762 		free(port);
2763 	}
2764 
2765 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2766 		TAILQ_REMOVE(&rtransport->ports, port, link);
2767 		rdma_destroy_id(port->id);
2768 		free(port);
2769 	}
2770 
2771 	free_poll_fds(rtransport);
2772 
2773 	if (rtransport->event_channel != NULL) {
2774 		rdma_destroy_event_channel(rtransport->event_channel);
2775 	}
2776 
2777 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2778 		destroy_ib_device(rtransport, device);
2779 	}
2780 
2781 	if (rtransport->data_wr_pool != NULL) {
2782 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2783 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2784 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2785 				    spdk_mempool_count(rtransport->data_wr_pool),
2786 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2787 		}
2788 	}
2789 
2790 	spdk_mempool_free(rtransport->data_wr_pool);
2791 
2792 	spdk_poller_unregister(&rtransport->accept_poller);
2793 	free(rtransport);
2794 
2795 	if (cb_fn) {
2796 		cb_fn(cb_arg);
2797 	}
2798 	return 0;
2799 }
2800 
2801 static int nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2802 				     struct spdk_nvme_transport_id *trid,
2803 				     bool peer);
2804 
2805 static bool nvmf_rdma_rescan_devices(struct spdk_nvmf_rdma_transport *rtransport);
2806 
2807 static int
2808 nvmf_rdma_listen(struct spdk_nvmf_transport *transport, const struct spdk_nvme_transport_id *trid,
2809 		 struct spdk_nvmf_listen_opts *listen_opts)
2810 {
2811 	struct spdk_nvmf_rdma_transport	*rtransport;
2812 	struct spdk_nvmf_rdma_device	*device;
2813 	struct spdk_nvmf_rdma_port	*port, *tmp_port;
2814 	struct addrinfo			*res;
2815 	struct addrinfo			hints;
2816 	int				family;
2817 	int				rc;
2818 	bool				is_retry = false;
2819 
2820 	if (!strlen(trid->trsvcid)) {
2821 		SPDK_ERRLOG("Service id is required\n");
2822 		return -EINVAL;
2823 	}
2824 
2825 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2826 	assert(rtransport->event_channel != NULL);
2827 
2828 	port = calloc(1, sizeof(*port));
2829 	if (!port) {
2830 		SPDK_ERRLOG("Port allocation failed\n");
2831 		return -ENOMEM;
2832 	}
2833 
2834 	port->trid = trid;
2835 
2836 	switch (trid->adrfam) {
2837 	case SPDK_NVMF_ADRFAM_IPV4:
2838 		family = AF_INET;
2839 		break;
2840 	case SPDK_NVMF_ADRFAM_IPV6:
2841 		family = AF_INET6;
2842 		break;
2843 	default:
2844 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2845 		free(port);
2846 		return -EINVAL;
2847 	}
2848 
2849 	memset(&hints, 0, sizeof(hints));
2850 	hints.ai_family = family;
2851 	hints.ai_flags = AI_NUMERICSERV;
2852 	hints.ai_socktype = SOCK_STREAM;
2853 	hints.ai_protocol = 0;
2854 
2855 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2856 	if (rc) {
2857 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2858 		free(port);
2859 		return -(abs(rc));
2860 	}
2861 
2862 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2863 	if (rc < 0) {
2864 		SPDK_ERRLOG("rdma_create_id() failed\n");
2865 		freeaddrinfo(res);
2866 		free(port);
2867 		return rc;
2868 	}
2869 
2870 	rc = rdma_bind_addr(port->id, res->ai_addr);
2871 	freeaddrinfo(res);
2872 
2873 	if (rc < 0) {
2874 		TAILQ_FOREACH(tmp_port, &rtransport->retry_ports, link) {
2875 			if (spdk_nvme_transport_id_compare(tmp_port->trid, trid) == 0) {
2876 				is_retry = true;
2877 				break;
2878 			}
2879 		}
2880 		if (!is_retry) {
2881 			SPDK_ERRLOG("rdma_bind_addr() failed\n");
2882 		}
2883 		rdma_destroy_id(port->id);
2884 		free(port);
2885 		return rc;
2886 	}
2887 
2888 	if (!port->id->verbs) {
2889 		SPDK_ERRLOG("ibv_context is null\n");
2890 		rdma_destroy_id(port->id);
2891 		free(port);
2892 		return -1;
2893 	}
2894 
2895 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2896 	if (rc < 0) {
2897 		SPDK_ERRLOG("rdma_listen() failed\n");
2898 		rdma_destroy_id(port->id);
2899 		free(port);
2900 		return rc;
2901 	}
2902 
2903 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2904 		if (device->context == port->id->verbs && device->is_ready) {
2905 			port->device = device;
2906 			break;
2907 		}
2908 	}
2909 	if (!port->device) {
2910 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2911 			    port->id->verbs);
2912 		rdma_destroy_id(port->id);
2913 		free(port);
2914 		return -EINVAL;
2915 	}
2916 
2917 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2918 		       trid->traddr, trid->trsvcid);
2919 
2920 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2921 	return 0;
2922 }
2923 
2924 static void
2925 nvmf_rdma_stop_listen_ex(struct spdk_nvmf_transport *transport,
2926 			 const struct spdk_nvme_transport_id *trid, bool need_retry)
2927 {
2928 	struct spdk_nvmf_rdma_transport	*rtransport;
2929 	struct spdk_nvmf_rdma_port	*port, *tmp;
2930 
2931 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2932 
2933 	if (!need_retry) {
2934 		TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, tmp) {
2935 			if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2936 				TAILQ_REMOVE(&rtransport->retry_ports, port, link);
2937 				free(port);
2938 			}
2939 		}
2940 	}
2941 
2942 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2943 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2944 			SPDK_DEBUGLOG(rdma, "Port %s:%s removed. need retry: %d\n",
2945 				      port->trid->traddr, port->trid->trsvcid, need_retry);
2946 			TAILQ_REMOVE(&rtransport->ports, port, link);
2947 			rdma_destroy_id(port->id);
2948 			port->id = NULL;
2949 			port->device = NULL;
2950 			if (need_retry) {
2951 				TAILQ_INSERT_TAIL(&rtransport->retry_ports, port, link);
2952 			} else {
2953 				free(port);
2954 			}
2955 			break;
2956 		}
2957 	}
2958 }
2959 
2960 static void
2961 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2962 		      const struct spdk_nvme_transport_id *trid)
2963 {
2964 	nvmf_rdma_stop_listen_ex(transport, trid, false);
2965 }
2966 
2967 static void _nvmf_rdma_register_poller_in_group(void *c);
2968 static void _nvmf_rdma_remove_poller_in_group(void *c);
2969 
2970 static bool
2971 nvmf_rdma_all_pollers_management_done(void *c)
2972 {
2973 	struct poller_manage_ctx	*ctx = c;
2974 	int				counter;
2975 
2976 	counter = __atomic_sub_fetch(ctx->inflight_op_counter, 1, __ATOMIC_SEQ_CST);
2977 	SPDK_DEBUGLOG(rdma, "nvmf_rdma_all_pollers_management_done called. counter: %d, poller: %p\n",
2978 		      counter, ctx->rpoller);
2979 
2980 	if (counter == 0) {
2981 		free((void *)ctx->inflight_op_counter);
2982 	}
2983 	free(ctx);
2984 
2985 	return counter == 0;
2986 }
2987 
2988 static int
2989 nvmf_rdma_manage_poller(struct spdk_nvmf_rdma_transport *rtransport,
2990 			struct spdk_nvmf_rdma_device *device, bool *has_inflight, bool is_add)
2991 {
2992 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2993 	struct spdk_nvmf_rdma_poller		*rpoller;
2994 	struct spdk_nvmf_poll_group		*poll_group;
2995 	struct poller_manage_ctx		*ctx;
2996 	bool					found;
2997 	int					*inflight_counter;
2998 	spdk_msg_fn				do_fn;
2999 
3000 	*has_inflight = false;
3001 	do_fn = is_add ? _nvmf_rdma_register_poller_in_group : _nvmf_rdma_remove_poller_in_group;
3002 	inflight_counter = calloc(1, sizeof(int));
3003 	if (!inflight_counter) {
3004 		SPDK_ERRLOG("Failed to allocate inflight counter when removing pollers\n");
3005 		return -ENOMEM;
3006 	}
3007 
3008 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3009 		(*inflight_counter)++;
3010 	}
3011 
3012 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3013 		found = false;
3014 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3015 			if (rpoller->device == device) {
3016 				found = true;
3017 				break;
3018 			}
3019 		}
3020 		if (found == is_add) {
3021 			__atomic_fetch_sub(inflight_counter, 1, __ATOMIC_SEQ_CST);
3022 			continue;
3023 		}
3024 
3025 		ctx = calloc(1, sizeof(struct poller_manage_ctx));
3026 		if (!ctx) {
3027 			SPDK_ERRLOG("Failed to allocate poller_manage_ctx when removing pollers\n");
3028 			if (!*has_inflight) {
3029 				free(inflight_counter);
3030 			}
3031 			return -ENOMEM;
3032 		}
3033 
3034 		ctx->rtransport = rtransport;
3035 		ctx->rgroup = rgroup;
3036 		ctx->rpoller = rpoller;
3037 		ctx->device = device;
3038 		ctx->thread = spdk_get_thread();
3039 		ctx->inflight_op_counter = inflight_counter;
3040 		*has_inflight = true;
3041 
3042 		poll_group = rgroup->group.group;
3043 		if (poll_group->thread != spdk_get_thread()) {
3044 			spdk_thread_send_msg(poll_group->thread, do_fn, ctx);
3045 		} else {
3046 			do_fn(ctx);
3047 		}
3048 	}
3049 
3050 	if (!*has_inflight) {
3051 		free(inflight_counter);
3052 	}
3053 
3054 	return 0;
3055 }
3056 
3057 static void nvmf_rdma_handle_device_removal(struct spdk_nvmf_rdma_transport *rtransport,
3058 		struct spdk_nvmf_rdma_device *device);
3059 
3060 static struct spdk_nvmf_rdma_device *
3061 nvmf_rdma_find_ib_device(struct spdk_nvmf_rdma_transport *rtransport,
3062 			 struct ibv_context *context)
3063 {
3064 	struct spdk_nvmf_rdma_device	*device, *tmp_device;
3065 
3066 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp_device) {
3067 		if (device->need_destroy) {
3068 			continue;
3069 		}
3070 
3071 		if (strcmp(device->context->device->dev_name, context->device->dev_name) == 0) {
3072 			return device;
3073 		}
3074 	}
3075 
3076 	return NULL;
3077 }
3078 
3079 static bool
3080 nvmf_rdma_check_devices_context(struct spdk_nvmf_rdma_transport *rtransport,
3081 				struct ibv_context *context)
3082 {
3083 	struct spdk_nvmf_rdma_device	*old_device, *new_device;
3084 	int				rc = 0;
3085 	bool				has_inflight;
3086 
3087 	old_device = nvmf_rdma_find_ib_device(rtransport, context);
3088 
3089 	if (old_device) {
3090 		if (old_device->context != context && !old_device->need_destroy && old_device->is_ready) {
3091 			/* context may not have time to be cleaned when rescan. exactly one context
3092 			 * is valid for a device so this context must be invalid and just remove it. */
3093 			SPDK_WARNLOG("Device %p has a invalid context %p\n", old_device, old_device->context);
3094 			old_device->need_destroy = true;
3095 			nvmf_rdma_handle_device_removal(rtransport, old_device);
3096 		}
3097 		return false;
3098 	}
3099 
3100 	rc = create_ib_device(rtransport, context, &new_device);
3101 	/* TODO: update transport opts. */
3102 	if (rc < 0) {
3103 		SPDK_ERRLOG("Failed to create ib device for context: %s(%p)\n",
3104 			    ibv_get_device_name(context->device), context);
3105 		return false;
3106 	}
3107 
3108 	rc = nvmf_rdma_manage_poller(rtransport, new_device, &has_inflight, true);
3109 	if (rc < 0) {
3110 		SPDK_ERRLOG("Failed to add poller for device context: %s(%p)\n",
3111 			    ibv_get_device_name(context->device), context);
3112 		return false;
3113 	}
3114 
3115 	if (has_inflight) {
3116 		new_device->is_ready = true;
3117 	}
3118 
3119 	return true;
3120 }
3121 
3122 static bool
3123 nvmf_rdma_rescan_devices(struct spdk_nvmf_rdma_transport *rtransport)
3124 {
3125 	struct spdk_nvmf_rdma_device	*device;
3126 	struct ibv_device		**ibv_device_list = NULL;
3127 	struct ibv_context		**contexts = NULL;
3128 	int				i = 0;
3129 	int				num_dev = 0;
3130 	bool				new_create = false, has_new_device = false;
3131 	struct ibv_context		*tmp_verbs = NULL;
3132 
3133 	/* do not rescan when any device is destroying, or context may be freed when
3134 	 * regenerating the poll fds.
3135 	 */
3136 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3137 		if (device->need_destroy) {
3138 			return false;
3139 		}
3140 	}
3141 
3142 	ibv_device_list = ibv_get_device_list(&num_dev);
3143 
3144 	/* There is a bug in librdmacm. If verbs init failed in rdma_get_devices, it'll be
3145 	 * marked as dead verbs and never be init again. So we need to make sure the
3146 	 * verbs is available before we call rdma_get_devices. */
3147 	if (num_dev >= 0) {
3148 		for (i = 0; i < num_dev; i++) {
3149 			tmp_verbs = ibv_open_device(ibv_device_list[i]);
3150 			if (!tmp_verbs) {
3151 				SPDK_WARNLOG("Failed to init ibv device %p, err %d. Skip rescan.\n", ibv_device_list[i], errno);
3152 				break;
3153 			}
3154 			if (nvmf_rdma_find_ib_device(rtransport, tmp_verbs) == NULL) {
3155 				SPDK_DEBUGLOG(rdma, "Find new verbs init ibv device %p(%s).\n", ibv_device_list[i],
3156 					      tmp_verbs->device->dev_name);
3157 				has_new_device = true;
3158 			}
3159 			ibv_close_device(tmp_verbs);
3160 		}
3161 		ibv_free_device_list(ibv_device_list);
3162 		if (!tmp_verbs || !has_new_device) {
3163 			return false;
3164 		}
3165 	}
3166 
3167 	contexts = rdma_get_devices(NULL);
3168 
3169 	for (i = 0; contexts && contexts[i] != NULL; i++) {
3170 		new_create |= nvmf_rdma_check_devices_context(rtransport, contexts[i]);
3171 	}
3172 
3173 	if (new_create) {
3174 		free_poll_fds(rtransport);
3175 		generate_poll_fds(rtransport);
3176 	}
3177 
3178 	if (contexts) {
3179 		rdma_free_devices(contexts);
3180 	}
3181 
3182 	return new_create;
3183 }
3184 
3185 static bool
3186 nvmf_rdma_retry_listen_port(struct spdk_nvmf_rdma_transport *rtransport)
3187 {
3188 	struct spdk_nvmf_rdma_port	*port, *tmp_port;
3189 	int				rc = 0;
3190 	bool				new_create = false;
3191 
3192 	if (TAILQ_EMPTY(&rtransport->retry_ports)) {
3193 		return false;
3194 	}
3195 
3196 	new_create = nvmf_rdma_rescan_devices(rtransport);
3197 
3198 	TAILQ_FOREACH_SAFE(port, &rtransport->retry_ports, link, tmp_port) {
3199 		rc = nvmf_rdma_listen(&rtransport->transport, port->trid, NULL);
3200 
3201 		TAILQ_REMOVE(&rtransport->retry_ports, port, link);
3202 		if (rc) {
3203 			if (new_create) {
3204 				SPDK_ERRLOG("Found new IB device but port %s:%s is still failed(%d) to listen.\n",
3205 					    port->trid->traddr, port->trid->trsvcid, rc);
3206 			}
3207 			TAILQ_INSERT_TAIL(&rtransport->retry_ports, port, link);
3208 			break;
3209 		} else {
3210 			SPDK_NOTICELOG("Port %s:%s come back\n", port->trid->traddr, port->trid->trsvcid);
3211 			free(port);
3212 		}
3213 	}
3214 
3215 	return true;
3216 }
3217 
3218 static void
3219 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
3220 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
3221 {
3222 	struct spdk_nvmf_request *req, *tmp;
3223 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
3224 	struct spdk_nvmf_rdma_resources *resources;
3225 
3226 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
3227 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
3228 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3229 			break;
3230 		}
3231 	}
3232 
3233 	/* Then RDMA writes since reads have stronger restrictions than writes */
3234 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
3235 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3236 			break;
3237 		}
3238 	}
3239 
3240 	/* Then we handle request waiting on memory buffers. */
3241 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
3242 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3243 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
3244 			break;
3245 		}
3246 	}
3247 
3248 	resources = rqpair->resources;
3249 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
3250 		rdma_req = STAILQ_FIRST(&resources->free_queue);
3251 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
3252 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
3253 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
3254 
3255 		if (rqpair->srq != NULL) {
3256 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
3257 			rdma_req->recv->qpair->qd++;
3258 		} else {
3259 			rqpair->qd++;
3260 		}
3261 
3262 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
3263 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
3264 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
3265 			break;
3266 		}
3267 	}
3268 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
3269 		rqpair->poller->stat.pending_free_request++;
3270 	}
3271 }
3272 
3273 static inline bool
3274 nvmf_rdma_can_ignore_last_wqe_reached(struct spdk_nvmf_rdma_device *device)
3275 {
3276 	/* iWARP transport and SoftRoCE driver don't support LAST_WQE_REACHED ibv async event */
3277 	return nvmf_rdma_is_rxe_device(device) ||
3278 	       device->context->device->transport_type == IBV_TRANSPORT_IWARP;
3279 }
3280 
3281 static void
3282 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
3283 {
3284 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3285 			struct spdk_nvmf_rdma_transport, transport);
3286 
3287 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3288 
3289 	/* nvmf_rdma_close_qpair is not called */
3290 	if (!rqpair->to_close) {
3291 		return;
3292 	}
3293 
3294 	/* device is already destroyed and we should force destroy this qpair. */
3295 	if (rqpair->poller && rqpair->poller->need_destroy) {
3296 		nvmf_rdma_qpair_destroy(rqpair);
3297 		return;
3298 	}
3299 
3300 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
3301 	if (rqpair->current_send_depth != 0) {
3302 		return;
3303 	}
3304 
3305 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
3306 		return;
3307 	}
3308 
3309 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
3310 	    !nvmf_rdma_can_ignore_last_wqe_reached(rqpair->device)) {
3311 		return;
3312 	}
3313 
3314 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
3315 
3316 	nvmf_rdma_qpair_destroy(rqpair);
3317 }
3318 
3319 static int
3320 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
3321 {
3322 	struct spdk_nvmf_qpair		*qpair;
3323 	struct spdk_nvmf_rdma_qpair	*rqpair;
3324 
3325 	if (evt->id == NULL) {
3326 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
3327 		return -1;
3328 	}
3329 
3330 	qpair = evt->id->context;
3331 	if (qpair == NULL) {
3332 		SPDK_ERRLOG("disconnect request: no active connection\n");
3333 		return -1;
3334 	}
3335 
3336 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3337 
3338 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair);
3339 
3340 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3341 
3342 	return 0;
3343 }
3344 
3345 #ifdef DEBUG
3346 static const char *CM_EVENT_STR[] = {
3347 	"RDMA_CM_EVENT_ADDR_RESOLVED",
3348 	"RDMA_CM_EVENT_ADDR_ERROR",
3349 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
3350 	"RDMA_CM_EVENT_ROUTE_ERROR",
3351 	"RDMA_CM_EVENT_CONNECT_REQUEST",
3352 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
3353 	"RDMA_CM_EVENT_CONNECT_ERROR",
3354 	"RDMA_CM_EVENT_UNREACHABLE",
3355 	"RDMA_CM_EVENT_REJECTED",
3356 	"RDMA_CM_EVENT_ESTABLISHED",
3357 	"RDMA_CM_EVENT_DISCONNECTED",
3358 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
3359 	"RDMA_CM_EVENT_MULTICAST_JOIN",
3360 	"RDMA_CM_EVENT_MULTICAST_ERROR",
3361 	"RDMA_CM_EVENT_ADDR_CHANGE",
3362 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
3363 };
3364 #endif /* DEBUG */
3365 
3366 static void
3367 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
3368 				    struct spdk_nvmf_rdma_port *port)
3369 {
3370 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3371 	struct spdk_nvmf_rdma_poller		*rpoller;
3372 	struct spdk_nvmf_rdma_qpair		*rqpair;
3373 
3374 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
3375 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3376 			RB_FOREACH(rqpair, qpairs_tree, &rpoller->qpairs) {
3377 				if (rqpair->listen_id == port->id) {
3378 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3379 				}
3380 			}
3381 		}
3382 	}
3383 }
3384 
3385 static bool
3386 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
3387 				      struct rdma_cm_event *event)
3388 {
3389 	const struct spdk_nvme_transport_id	*trid;
3390 	struct spdk_nvmf_rdma_port		*port;
3391 	struct spdk_nvmf_rdma_transport		*rtransport;
3392 	bool					event_acked = false;
3393 
3394 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3395 	TAILQ_FOREACH(port, &rtransport->ports, link) {
3396 		if (port->id == event->id) {
3397 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
3398 			rdma_ack_cm_event(event);
3399 			event_acked = true;
3400 			trid = port->trid;
3401 			break;
3402 		}
3403 	}
3404 
3405 	if (event_acked) {
3406 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
3407 
3408 		nvmf_rdma_stop_listen(transport, trid);
3409 		nvmf_rdma_listen(transport, trid, NULL);
3410 	}
3411 
3412 	return event_acked;
3413 }
3414 
3415 static void
3416 nvmf_rdma_handle_device_removal(struct spdk_nvmf_rdma_transport *rtransport,
3417 				struct spdk_nvmf_rdma_device *device)
3418 {
3419 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
3420 	int				rc;
3421 	bool				has_inflight;
3422 
3423 	rc = nvmf_rdma_manage_poller(rtransport, device, &has_inflight, false);
3424 	if (rc) {
3425 		SPDK_ERRLOG("Failed to handle device removal, rc %d\n", rc);
3426 		return;
3427 	}
3428 
3429 	if (!has_inflight) {
3430 		/* no pollers, destroy the device */
3431 		device->ready_to_destroy = true;
3432 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_remove_destroyed_device, rtransport);
3433 	}
3434 
3435 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
3436 		if (port->device == device) {
3437 			SPDK_NOTICELOG("Port %s:%s on device %s is being removed.\n",
3438 				       port->trid->traddr,
3439 				       port->trid->trsvcid,
3440 				       ibv_get_device_name(port->device->context->device));
3441 
3442 			/* keep NVMF listener and only destroy structures of the
3443 			 * RDMA transport. when the device comes back we can retry listening
3444 			 * and the application's workflow will not be interrupted.
3445 			 */
3446 			nvmf_rdma_stop_listen_ex(&rtransport->transport, port->trid, true);
3447 		}
3448 	}
3449 }
3450 
3451 static void
3452 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
3453 				       struct rdma_cm_event *event)
3454 {
3455 	struct spdk_nvmf_rdma_port		*port, *tmp_port;
3456 	struct spdk_nvmf_rdma_transport		*rtransport;
3457 
3458 	port = event->id->context;
3459 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3460 
3461 	rdma_ack_cm_event(event);
3462 
3463 	/* if device removal happens during ctrl qpair disconnecting, it's possible that we receive
3464 	 * an DEVICE_REMOVAL event on qpair but the id->qp is just NULL. So we should make sure that
3465 	 * we are handling a port event here.
3466 	 */
3467 	TAILQ_FOREACH(tmp_port, &rtransport->ports, link) {
3468 		if (port == tmp_port && port->device && !port->device->need_destroy) {
3469 			port->device->need_destroy = true;
3470 			nvmf_rdma_handle_device_removal(rtransport, port->device);
3471 		}
3472 	}
3473 }
3474 
3475 static void
3476 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
3477 {
3478 	struct spdk_nvmf_rdma_transport *rtransport;
3479 	struct rdma_cm_event		*event;
3480 	int				rc;
3481 	bool				event_acked;
3482 
3483 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3484 
3485 	if (rtransport->event_channel == NULL) {
3486 		return;
3487 	}
3488 
3489 	while (1) {
3490 		event_acked = false;
3491 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
3492 		if (rc) {
3493 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
3494 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
3495 			}
3496 			break;
3497 		}
3498 
3499 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
3500 
3501 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
3502 
3503 		switch (event->event) {
3504 		case RDMA_CM_EVENT_ADDR_RESOLVED:
3505 		case RDMA_CM_EVENT_ADDR_ERROR:
3506 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
3507 		case RDMA_CM_EVENT_ROUTE_ERROR:
3508 			/* No action required. The target never attempts to resolve routes. */
3509 			break;
3510 		case RDMA_CM_EVENT_CONNECT_REQUEST:
3511 			rc = nvmf_rdma_connect(transport, event);
3512 			if (rc < 0) {
3513 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
3514 				break;
3515 			}
3516 			break;
3517 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
3518 			/* The target never initiates a new connection. So this will not occur. */
3519 			break;
3520 		case RDMA_CM_EVENT_CONNECT_ERROR:
3521 			/* Can this happen? The docs say it can, but not sure what causes it. */
3522 			break;
3523 		case RDMA_CM_EVENT_UNREACHABLE:
3524 		case RDMA_CM_EVENT_REJECTED:
3525 			/* These only occur on the client side. */
3526 			break;
3527 		case RDMA_CM_EVENT_ESTABLISHED:
3528 			/* TODO: Should we be waiting for this event anywhere? */
3529 			break;
3530 		case RDMA_CM_EVENT_DISCONNECTED:
3531 			rc = nvmf_rdma_disconnect(event);
3532 			if (rc < 0) {
3533 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3534 				break;
3535 			}
3536 			break;
3537 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
3538 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
3539 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
3540 			 * Once these events are sent to SPDK, we should release all IB resources and
3541 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
3542 			 * ibv_destroy* functions to release user space memory allocated by IB. All kernel
3543 			 * resources are already cleaned. */
3544 			if (event->id->qp) {
3545 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
3546 				 * corresponding qpair. Otherwise the event refers to a listening device. */
3547 				rc = nvmf_rdma_disconnect(event);
3548 				if (rc < 0) {
3549 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3550 					break;
3551 				}
3552 			} else {
3553 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3554 				event_acked = true;
3555 			}
3556 			break;
3557 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3558 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3559 			/* Multicast is not used */
3560 			break;
3561 		case RDMA_CM_EVENT_ADDR_CHANGE:
3562 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3563 			break;
3564 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3565 			/* For now, do nothing. The target never re-uses queue pairs. */
3566 			break;
3567 		default:
3568 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3569 			break;
3570 		}
3571 		if (!event_acked) {
3572 			rdma_ack_cm_event(event);
3573 		}
3574 	}
3575 }
3576 
3577 static void
3578 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3579 {
3580 	rqpair->last_wqe_reached = true;
3581 	nvmf_rdma_destroy_drained_qpair(rqpair);
3582 }
3583 
3584 static void
3585 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3586 {
3587 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3588 
3589 	if (event_ctx->rqpair) {
3590 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3591 		if (event_ctx->cb_fn) {
3592 			event_ctx->cb_fn(event_ctx->rqpair);
3593 		}
3594 	}
3595 	free(event_ctx);
3596 }
3597 
3598 static int
3599 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3600 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3601 {
3602 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3603 	struct spdk_thread *thr = NULL;
3604 	int rc;
3605 
3606 	if (rqpair->qpair.group) {
3607 		thr = rqpair->qpair.group->thread;
3608 	} else if (rqpair->destruct_channel) {
3609 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3610 	}
3611 
3612 	if (!thr) {
3613 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3614 		return -EINVAL;
3615 	}
3616 
3617 	ctx = calloc(1, sizeof(*ctx));
3618 	if (!ctx) {
3619 		return -ENOMEM;
3620 	}
3621 
3622 	ctx->rqpair = rqpair;
3623 	ctx->cb_fn = fn;
3624 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3625 
3626 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3627 	if (rc) {
3628 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3629 		free(ctx);
3630 	}
3631 
3632 	return rc;
3633 }
3634 
3635 static int
3636 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3637 {
3638 	int				rc;
3639 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3640 	struct ibv_async_event		event;
3641 
3642 	rc = ibv_get_async_event(device->context, &event);
3643 
3644 	if (rc) {
3645 		/* In non-blocking mode -1 means there are no events available */
3646 		return rc;
3647 	}
3648 
3649 	switch (event.event_type) {
3650 	case IBV_EVENT_QP_FATAL:
3651 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3652 	case IBV_EVENT_SQ_DRAINED:
3653 	case IBV_EVENT_QP_REQ_ERR:
3654 	case IBV_EVENT_QP_ACCESS_ERR:
3655 	case IBV_EVENT_COMM_EST:
3656 	case IBV_EVENT_PATH_MIG:
3657 	case IBV_EVENT_PATH_MIG_ERR:
3658 		rqpair = event.element.qp->qp_context;
3659 		if (!rqpair) {
3660 			/* Any QP event for NVMe-RDMA initiator may be returned. */
3661 			SPDK_NOTICELOG("Async QP event for unknown QP: %s\n",
3662 				       ibv_event_type_str(event.event_type));
3663 			break;
3664 		}
3665 
3666 		switch (event.event_type) {
3667 		case IBV_EVENT_QP_FATAL:
3668 			SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3669 			spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3670 					  (uintptr_t)rqpair, event.event_type);
3671 			nvmf_rdma_update_ibv_state(rqpair);
3672 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3673 			break;
3674 		case IBV_EVENT_QP_LAST_WQE_REACHED:
3675 			/* This event only occurs for shared receive queues. */
3676 			SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3677 			rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3678 			if (rc) {
3679 				SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3680 				rqpair->last_wqe_reached = true;
3681 			}
3682 			break;
3683 		case IBV_EVENT_SQ_DRAINED:
3684 			/* This event occurs frequently in both error and non-error states.
3685 			 * Check if the qpair is in an error state before sending a message. */
3686 			SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3687 			spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3688 					  (uintptr_t)rqpair, event.event_type);
3689 			if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3690 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3691 			}
3692 			break;
3693 		case IBV_EVENT_QP_REQ_ERR:
3694 		case IBV_EVENT_QP_ACCESS_ERR:
3695 		case IBV_EVENT_COMM_EST:
3696 		case IBV_EVENT_PATH_MIG:
3697 		case IBV_EVENT_PATH_MIG_ERR:
3698 			SPDK_NOTICELOG("Async QP event: %s\n",
3699 				       ibv_event_type_str(event.event_type));
3700 			spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3701 					  (uintptr_t)rqpair, event.event_type);
3702 			nvmf_rdma_update_ibv_state(rqpair);
3703 			break;
3704 		default:
3705 			break;
3706 		}
3707 		break;
3708 	case IBV_EVENT_DEVICE_FATAL:
3709 		SPDK_ERRLOG("Device Fatal event[%s] received on %s. device: %p\n",
3710 			    ibv_event_type_str(event.event_type), ibv_get_device_name(device->context->device), device);
3711 		device->need_destroy = true;
3712 		break;
3713 	case IBV_EVENT_CQ_ERR:
3714 	case IBV_EVENT_PORT_ACTIVE:
3715 	case IBV_EVENT_PORT_ERR:
3716 	case IBV_EVENT_LID_CHANGE:
3717 	case IBV_EVENT_PKEY_CHANGE:
3718 	case IBV_EVENT_SM_CHANGE:
3719 	case IBV_EVENT_SRQ_ERR:
3720 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3721 	case IBV_EVENT_CLIENT_REREGISTER:
3722 	case IBV_EVENT_GID_CHANGE:
3723 	default:
3724 		SPDK_NOTICELOG("Async event: %s\n",
3725 			       ibv_event_type_str(event.event_type));
3726 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3727 		break;
3728 	}
3729 	ibv_ack_async_event(&event);
3730 
3731 	return 0;
3732 }
3733 
3734 static void
3735 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3736 {
3737 	int rc = 0;
3738 	uint32_t i = 0;
3739 
3740 	for (i = 0; i < max_events; i++) {
3741 		rc = nvmf_process_ib_event(device);
3742 		if (rc) {
3743 			break;
3744 		}
3745 	}
3746 
3747 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3748 }
3749 
3750 static int
3751 nvmf_rdma_accept(void *ctx)
3752 {
3753 	int	nfds, i = 0;
3754 	struct spdk_nvmf_transport *transport = ctx;
3755 	struct spdk_nvmf_rdma_transport *rtransport;
3756 	struct spdk_nvmf_rdma_device *device, *tmp;
3757 	uint32_t count;
3758 	short revents;
3759 	bool do_retry;
3760 
3761 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3762 	do_retry = nvmf_rdma_retry_listen_port(rtransport);
3763 
3764 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3765 
3766 	if (nfds <= 0) {
3767 		return do_retry ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3768 	}
3769 
3770 	/* The first poll descriptor is RDMA CM event */
3771 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3772 		nvmf_process_cm_event(transport);
3773 		nfds--;
3774 	}
3775 
3776 	if (nfds == 0) {
3777 		return SPDK_POLLER_BUSY;
3778 	}
3779 
3780 	/* Second and subsequent poll descriptors are IB async events */
3781 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3782 		revents = rtransport->poll_fds[i++].revents;
3783 		if (revents & POLLIN) {
3784 			if (spdk_likely(!device->need_destroy)) {
3785 				nvmf_process_ib_events(device, 32);
3786 				if (spdk_unlikely(device->need_destroy)) {
3787 					nvmf_rdma_handle_device_removal(rtransport, device);
3788 				}
3789 			}
3790 			nfds--;
3791 		} else if (revents & POLLNVAL || revents & POLLHUP) {
3792 			SPDK_ERRLOG("Receive unknown revent %x on device %p\n", (int)revents, device);
3793 			nfds--;
3794 		}
3795 	}
3796 	/* check all flagged fd's have been served */
3797 	assert(nfds == 0);
3798 
3799 	return count > 0 ? SPDK_POLLER_BUSY : SPDK_POLLER_IDLE;
3800 }
3801 
3802 static void
3803 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3804 		     struct spdk_nvmf_ctrlr_data *cdata)
3805 {
3806 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3807 
3808 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3809 	since in-capsule data only works with NVME drives that support SGL memory layout */
3810 	if (transport->opts.dif_insert_or_strip) {
3811 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3812 	}
3813 
3814 	if (cdata->nvmf_specific.ioccsz > ((sizeof(struct spdk_nvme_cmd) + 0x1000) / 16)) {
3815 		SPDK_WARNLOG("RDMA is configured to support up to 16 SGL entries while in capsule"
3816 			     " data is greater than 4KiB.\n");
3817 		SPDK_WARNLOG("When used in conjunction with the NVMe-oF initiator from the Linux "
3818 			     "kernel between versions 5.4 and 5.12 data corruption may occur for "
3819 			     "writes that are not a multiple of 4KiB in size.\n");
3820 	}
3821 }
3822 
3823 static void
3824 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3825 		   struct spdk_nvme_transport_id *trid,
3826 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3827 {
3828 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3829 	entry->adrfam = trid->adrfam;
3830 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3831 
3832 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3833 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3834 
3835 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3836 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3837 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3838 }
3839 
3840 static int
3841 nvmf_rdma_poller_create(struct spdk_nvmf_rdma_transport *rtransport,
3842 			struct spdk_nvmf_rdma_poll_group *rgroup, struct spdk_nvmf_rdma_device *device,
3843 			struct spdk_nvmf_rdma_poller **out_poller)
3844 {
3845 	struct spdk_nvmf_rdma_poller		*poller;
3846 	struct spdk_rdma_srq_init_attr		srq_init_attr;
3847 	struct spdk_nvmf_rdma_resource_opts	opts;
3848 	int					num_cqe;
3849 
3850 	poller = calloc(1, sizeof(*poller));
3851 	if (!poller) {
3852 		SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3853 		return -1;
3854 	}
3855 
3856 	poller->device = device;
3857 	poller->group = rgroup;
3858 	*out_poller = poller;
3859 
3860 	RB_INIT(&poller->qpairs);
3861 	STAILQ_INIT(&poller->qpairs_pending_send);
3862 	STAILQ_INIT(&poller->qpairs_pending_recv);
3863 
3864 	TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3865 	SPDK_DEBUGLOG(rdma, "Create poller %p on device %p in poll group %p.\n", poller, device, rgroup);
3866 	if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3867 		if ((int)rtransport->rdma_opts.max_srq_depth > device->attr.max_srq_wr) {
3868 			SPDK_WARNLOG("Requested SRQ depth %u, max supported by dev %s is %d\n",
3869 				     rtransport->rdma_opts.max_srq_depth, device->context->device->name, device->attr.max_srq_wr);
3870 		}
3871 		poller->max_srq_depth = spdk_min((int)rtransport->rdma_opts.max_srq_depth, device->attr.max_srq_wr);
3872 
3873 		device->num_srq++;
3874 		memset(&srq_init_attr, 0, sizeof(srq_init_attr));
3875 		srq_init_attr.pd = device->pd;
3876 		srq_init_attr.stats = &poller->stat.qp_stats.recv;
3877 		srq_init_attr.srq_init_attr.attr.max_wr = poller->max_srq_depth;
3878 		srq_init_attr.srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3879 		poller->srq = spdk_rdma_srq_create(&srq_init_attr);
3880 		if (!poller->srq) {
3881 			SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3882 			return -1;
3883 		}
3884 
3885 		opts.qp = poller->srq;
3886 		opts.map = device->map;
3887 		opts.qpair = NULL;
3888 		opts.shared = true;
3889 		opts.max_queue_depth = poller->max_srq_depth;
3890 		opts.in_capsule_data_size = rtransport->transport.opts.in_capsule_data_size;
3891 
3892 		poller->resources = nvmf_rdma_resources_create(&opts);
3893 		if (!poller->resources) {
3894 			SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3895 			return -1;
3896 		}
3897 	}
3898 
3899 	/*
3900 	 * When using an srq, we can limit the completion queue at startup.
3901 	 * The following formula represents the calculation:
3902 	 * num_cqe = num_recv + num_data_wr + num_send_wr.
3903 	 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3904 	 */
3905 	if (poller->srq) {
3906 		num_cqe = poller->max_srq_depth * 3;
3907 	} else {
3908 		num_cqe = rtransport->rdma_opts.num_cqe;
3909 	}
3910 
3911 	poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3912 	if (!poller->cq) {
3913 		SPDK_ERRLOG("Unable to create completion queue\n");
3914 		return -1;
3915 	}
3916 	poller->num_cqe = num_cqe;
3917 	return 0;
3918 }
3919 
3920 static void
3921 _nvmf_rdma_register_poller_in_group(void *c)
3922 {
3923 	struct spdk_nvmf_rdma_poller	*poller;
3924 	struct poller_manage_ctx	*ctx = c;
3925 	struct spdk_nvmf_rdma_device	*device;
3926 	int				rc;
3927 
3928 	rc = nvmf_rdma_poller_create(ctx->rtransport, ctx->rgroup, ctx->device, &poller);
3929 	if (rc < 0 && poller) {
3930 		nvmf_rdma_poller_destroy(poller);
3931 	}
3932 
3933 	device = ctx->device;
3934 	if (nvmf_rdma_all_pollers_management_done(ctx)) {
3935 		device->is_ready = true;
3936 	}
3937 }
3938 
3939 static void nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3940 
3941 static struct spdk_nvmf_transport_poll_group *
3942 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport,
3943 			    struct spdk_nvmf_poll_group *group)
3944 {
3945 	struct spdk_nvmf_rdma_transport		*rtransport;
3946 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3947 	struct spdk_nvmf_rdma_poller		*poller;
3948 	struct spdk_nvmf_rdma_device		*device;
3949 	int					rc;
3950 
3951 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3952 
3953 	rgroup = calloc(1, sizeof(*rgroup));
3954 	if (!rgroup) {
3955 		return NULL;
3956 	}
3957 
3958 	TAILQ_INIT(&rgroup->pollers);
3959 
3960 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3961 		rc = nvmf_rdma_poller_create(rtransport, rgroup, device, &poller);
3962 		if (rc < 0) {
3963 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3964 			return NULL;
3965 		}
3966 	}
3967 
3968 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3969 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3970 		rtransport->conn_sched.next_admin_pg = rgroup;
3971 		rtransport->conn_sched.next_io_pg = rgroup;
3972 	}
3973 
3974 	return &rgroup->group;
3975 }
3976 
3977 static uint32_t
3978 nvmf_poll_group_get_io_qpair_count(struct spdk_nvmf_poll_group *pg)
3979 {
3980 	uint32_t count;
3981 
3982 	/* Just assume that unassociated qpairs will eventually be io
3983 	 * qpairs.  This is close enough for the use cases for this
3984 	 * function.
3985 	 */
3986 	pthread_mutex_lock(&pg->mutex);
3987 	count = pg->stat.current_io_qpairs + pg->current_unassociated_qpairs;
3988 	pthread_mutex_unlock(&pg->mutex);
3989 
3990 	return count;
3991 }
3992 
3993 static struct spdk_nvmf_transport_poll_group *
3994 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3995 {
3996 	struct spdk_nvmf_rdma_transport *rtransport;
3997 	struct spdk_nvmf_rdma_poll_group **pg;
3998 	struct spdk_nvmf_transport_poll_group *result;
3999 	uint32_t count;
4000 
4001 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4002 
4003 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
4004 		return NULL;
4005 	}
4006 
4007 	if (qpair->qid == 0) {
4008 		pg = &rtransport->conn_sched.next_admin_pg;
4009 	} else {
4010 		struct spdk_nvmf_rdma_poll_group *pg_min, *pg_start, *pg_current;
4011 		uint32_t min_value;
4012 
4013 		pg = &rtransport->conn_sched.next_io_pg;
4014 		pg_min = *pg;
4015 		pg_start = *pg;
4016 		pg_current = *pg;
4017 		min_value = nvmf_poll_group_get_io_qpair_count(pg_current->group.group);
4018 
4019 		while ((count = nvmf_poll_group_get_io_qpair_count(pg_current->group.group)) > 0) {
4020 			pg_current = TAILQ_NEXT(pg_current, link);
4021 			if (pg_current == NULL) {
4022 				pg_current = TAILQ_FIRST(&rtransport->poll_groups);
4023 			}
4024 
4025 			if (count < min_value) {
4026 				min_value = count;
4027 				pg_min = pg_current;
4028 			}
4029 
4030 			if (pg_current == pg_start) {
4031 				break;
4032 			}
4033 		}
4034 		*pg = pg_min;
4035 	}
4036 
4037 	assert(*pg != NULL);
4038 
4039 	result = &(*pg)->group;
4040 
4041 	*pg = TAILQ_NEXT(*pg, link);
4042 	if (*pg == NULL) {
4043 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
4044 	}
4045 
4046 	return result;
4047 }
4048 
4049 static void
4050 nvmf_rdma_poller_destroy(struct spdk_nvmf_rdma_poller *poller)
4051 {
4052 	struct spdk_nvmf_rdma_qpair	*qpair, *tmp_qpair;
4053 	int				rc;
4054 
4055 	TAILQ_REMOVE(&poller->group->pollers, poller, link);
4056 	RB_FOREACH_SAFE(qpair, qpairs_tree, &poller->qpairs, tmp_qpair) {
4057 		nvmf_rdma_qpair_destroy(qpair);
4058 	}
4059 
4060 	if (poller->srq) {
4061 		if (poller->resources) {
4062 			nvmf_rdma_resources_destroy(poller->resources);
4063 		}
4064 		spdk_rdma_srq_destroy(poller->srq);
4065 		SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
4066 	}
4067 
4068 	if (poller->cq) {
4069 		rc = ibv_destroy_cq(poller->cq);
4070 		if (rc != 0) {
4071 			SPDK_ERRLOG("Destroy cq return %d, error: %s\n", rc, strerror(errno));
4072 		}
4073 	}
4074 
4075 	if (poller->destroy_cb) {
4076 		poller->destroy_cb(poller->destroy_cb_ctx);
4077 		poller->destroy_cb = NULL;
4078 	}
4079 
4080 	free(poller);
4081 }
4082 
4083 static void
4084 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
4085 {
4086 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
4087 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
4088 	struct spdk_nvmf_rdma_transport		*rtransport;
4089 
4090 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4091 	if (!rgroup) {
4092 		return;
4093 	}
4094 
4095 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
4096 		nvmf_rdma_poller_destroy(poller);
4097 	}
4098 
4099 	if (rgroup->group.transport == NULL) {
4100 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
4101 		 * calls this function directly in a failure path. */
4102 		free(rgroup);
4103 		return;
4104 	}
4105 
4106 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
4107 
4108 	next_rgroup = TAILQ_NEXT(rgroup, link);
4109 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
4110 	if (next_rgroup == NULL) {
4111 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
4112 	}
4113 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
4114 		rtransport->conn_sched.next_admin_pg = next_rgroup;
4115 	}
4116 	if (rtransport->conn_sched.next_io_pg == rgroup) {
4117 		rtransport->conn_sched.next_io_pg = next_rgroup;
4118 	}
4119 
4120 	free(rgroup);
4121 }
4122 
4123 static void
4124 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
4125 {
4126 	if (rqpair->cm_id != NULL) {
4127 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
4128 	}
4129 }
4130 
4131 static int
4132 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
4133 			 struct spdk_nvmf_qpair *qpair)
4134 {
4135 	struct spdk_nvmf_rdma_poll_group	*rgroup;
4136 	struct spdk_nvmf_rdma_qpair		*rqpair;
4137 	struct spdk_nvmf_rdma_device		*device;
4138 	struct spdk_nvmf_rdma_poller		*poller;
4139 	int					rc;
4140 
4141 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4142 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4143 
4144 	device = rqpair->device;
4145 
4146 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
4147 		if (poller->device == device) {
4148 			break;
4149 		}
4150 	}
4151 
4152 	if (!poller) {
4153 		SPDK_ERRLOG("No poller found for device.\n");
4154 		return -1;
4155 	}
4156 
4157 	if (poller->need_destroy) {
4158 		SPDK_ERRLOG("Poller is destroying.\n");
4159 		return -1;
4160 	}
4161 
4162 	rqpair->poller = poller;
4163 	rqpair->srq = rqpair->poller->srq;
4164 
4165 	rc = nvmf_rdma_qpair_initialize(qpair);
4166 	if (rc < 0) {
4167 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
4168 		rqpair->poller = NULL;
4169 		rqpair->srq = NULL;
4170 		return -1;
4171 	}
4172 
4173 	RB_INSERT(qpairs_tree, &poller->qpairs, rqpair);
4174 
4175 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
4176 	if (rc) {
4177 		/* Try to reject, but we probably can't */
4178 		nvmf_rdma_qpair_reject_connection(rqpair);
4179 		return -1;
4180 	}
4181 
4182 	nvmf_rdma_update_ibv_state(rqpair);
4183 
4184 	return 0;
4185 }
4186 
4187 static int
4188 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
4189 			    struct spdk_nvmf_qpair *qpair)
4190 {
4191 	struct spdk_nvmf_rdma_qpair		*rqpair;
4192 
4193 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4194 	assert(group->transport->tgt != NULL);
4195 
4196 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
4197 
4198 	if (!rqpair->destruct_channel) {
4199 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
4200 		return 0;
4201 	}
4202 
4203 	/* Sanity check that we get io_channel on the correct thread */
4204 	if (qpair->group) {
4205 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
4206 	}
4207 
4208 	return 0;
4209 }
4210 
4211 static int
4212 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
4213 {
4214 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
4215 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
4216 			struct spdk_nvmf_rdma_transport, transport);
4217 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
4218 					      struct spdk_nvmf_rdma_qpair, qpair);
4219 
4220 	/*
4221 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
4222 	 * needs to be returned to the shared receive queue or the poll group will eventually be
4223 	 * starved of RECV structures.
4224 	 */
4225 	if (rqpair->srq && rdma_req->recv) {
4226 		int rc;
4227 		struct ibv_recv_wr *bad_recv_wr;
4228 
4229 		spdk_rdma_srq_queue_recv_wrs(rqpair->srq, &rdma_req->recv->wr);
4230 		rc = spdk_rdma_srq_flush_recv_wrs(rqpair->srq, &bad_recv_wr);
4231 		if (rc) {
4232 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
4233 		}
4234 	}
4235 
4236 	_nvmf_rdma_request_free(rdma_req, rtransport);
4237 	return 0;
4238 }
4239 
4240 static int
4241 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
4242 {
4243 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
4244 			struct spdk_nvmf_rdma_transport, transport);
4245 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
4246 			struct spdk_nvmf_rdma_request, req);
4247 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
4248 			struct spdk_nvmf_rdma_qpair, qpair);
4249 
4250 	if (rqpair->ibv_state != IBV_QPS_ERR) {
4251 		/* The connection is alive, so process the request as normal */
4252 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
4253 	} else {
4254 		/* The connection is dead. Move the request directly to the completed state. */
4255 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4256 	}
4257 
4258 	nvmf_rdma_request_process(rtransport, rdma_req);
4259 
4260 	return 0;
4261 }
4262 
4263 static void
4264 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
4265 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
4266 {
4267 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4268 
4269 	rqpair->to_close = true;
4270 
4271 	/* This happens only when the qpair is disconnected before
4272 	 * it is added to the poll group. Since there is no poll group,
4273 	 * the RDMA qp has not been initialized yet and the RDMA CM
4274 	 * event has not yet been acknowledged, so we need to reject it.
4275 	 */
4276 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
4277 		nvmf_rdma_qpair_reject_connection(rqpair);
4278 		nvmf_rdma_qpair_destroy(rqpair);
4279 		return;
4280 	}
4281 
4282 	if (rqpair->rdma_qp) {
4283 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
4284 	}
4285 
4286 	nvmf_rdma_destroy_drained_qpair(rqpair);
4287 
4288 	if (cb_fn) {
4289 		cb_fn(cb_arg);
4290 	}
4291 }
4292 
4293 static struct spdk_nvmf_rdma_qpair *
4294 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
4295 {
4296 	struct spdk_nvmf_rdma_qpair find;
4297 
4298 	find.qp_num = wc->qp_num;
4299 
4300 	return RB_FIND(qpairs_tree, &rpoller->qpairs, &find);
4301 }
4302 
4303 #ifdef DEBUG
4304 static int
4305 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
4306 {
4307 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
4308 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
4309 }
4310 #endif
4311 
4312 static void
4313 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
4314 			   int rc)
4315 {
4316 	struct spdk_nvmf_rdma_recv	*rdma_recv;
4317 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
4318 
4319 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
4320 	while (bad_recv_wr != NULL) {
4321 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
4322 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
4323 
4324 		rdma_recv->qpair->current_recv_depth++;
4325 		bad_recv_wr = bad_recv_wr->next;
4326 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
4327 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
4328 	}
4329 }
4330 
4331 static void
4332 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
4333 {
4334 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
4335 	while (bad_recv_wr != NULL) {
4336 		bad_recv_wr = bad_recv_wr->next;
4337 		rqpair->current_recv_depth++;
4338 	}
4339 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
4340 }
4341 
4342 static void
4343 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
4344 		     struct spdk_nvmf_rdma_poller *rpoller)
4345 {
4346 	struct spdk_nvmf_rdma_qpair	*rqpair;
4347 	struct ibv_recv_wr		*bad_recv_wr;
4348 	int				rc;
4349 
4350 	if (rpoller->srq) {
4351 		rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_recv_wr);
4352 		if (rc) {
4353 			_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
4354 		}
4355 	} else {
4356 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
4357 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
4358 			rc = spdk_rdma_qp_flush_recv_wrs(rqpair->rdma_qp, &bad_recv_wr);
4359 			if (rc) {
4360 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
4361 			}
4362 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
4363 		}
4364 	}
4365 }
4366 
4367 static void
4368 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
4369 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
4370 {
4371 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
4372 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
4373 
4374 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
4375 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
4376 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
4377 		assert(rqpair->current_send_depth > 0);
4378 		rqpair->current_send_depth--;
4379 		switch (bad_rdma_wr->type) {
4380 		case RDMA_WR_TYPE_DATA:
4381 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
4382 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
4383 				assert(rqpair->current_read_depth > 0);
4384 				rqpair->current_read_depth--;
4385 			}
4386 			break;
4387 		case RDMA_WR_TYPE_SEND:
4388 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
4389 			break;
4390 		default:
4391 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
4392 			prev_rdma_req = cur_rdma_req;
4393 			continue;
4394 		}
4395 
4396 		if (prev_rdma_req == cur_rdma_req) {
4397 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
4398 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
4399 			continue;
4400 		}
4401 
4402 		switch (cur_rdma_req->state) {
4403 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4404 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
4405 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4406 			break;
4407 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
4408 		case RDMA_REQUEST_STATE_COMPLETING:
4409 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4410 			break;
4411 		default:
4412 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
4413 				    cur_rdma_req->state, rqpair);
4414 			continue;
4415 		}
4416 
4417 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
4418 		prev_rdma_req = cur_rdma_req;
4419 	}
4420 
4421 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
4422 		/* Disconnect the connection. */
4423 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
4424 	}
4425 
4426 }
4427 
4428 static void
4429 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
4430 		     struct spdk_nvmf_rdma_poller *rpoller)
4431 {
4432 	struct spdk_nvmf_rdma_qpair	*rqpair;
4433 	struct ibv_send_wr		*bad_wr = NULL;
4434 	int				rc;
4435 
4436 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
4437 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
4438 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
4439 
4440 		/* bad wr always points to the first wr that failed. */
4441 		if (rc) {
4442 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
4443 		}
4444 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
4445 	}
4446 }
4447 
4448 static const char *
4449 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
4450 {
4451 	switch (wr_type) {
4452 	case RDMA_WR_TYPE_RECV:
4453 		return "RECV";
4454 	case RDMA_WR_TYPE_SEND:
4455 		return "SEND";
4456 	case RDMA_WR_TYPE_DATA:
4457 		return "DATA";
4458 	default:
4459 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
4460 		SPDK_UNREACHABLE();
4461 	}
4462 }
4463 
4464 static inline void
4465 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
4466 {
4467 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
4468 
4469 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
4470 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
4471 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
4472 		SPDK_DEBUGLOG(rdma,
4473 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
4474 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
4475 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
4476 	} else {
4477 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
4478 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
4479 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
4480 	}
4481 }
4482 
4483 static int
4484 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
4485 		      struct spdk_nvmf_rdma_poller *rpoller)
4486 {
4487 	struct ibv_wc wc[32];
4488 	struct spdk_nvmf_rdma_wr	*rdma_wr;
4489 	struct spdk_nvmf_rdma_request	*rdma_req;
4490 	struct spdk_nvmf_rdma_recv	*rdma_recv;
4491 	struct spdk_nvmf_rdma_qpair	*rqpair, *tmp_rqpair;
4492 	int reaped, i;
4493 	int count = 0;
4494 	bool error = false;
4495 	uint64_t poll_tsc = spdk_get_ticks();
4496 
4497 	if (spdk_unlikely(rpoller->need_destroy)) {
4498 		/* If qpair is closed before poller destroy, nvmf_rdma_destroy_drained_qpair may not
4499 		 * be called because we cannot poll anything from cq. So we call that here to force
4500 		 * destroy the qpair after to_close turning true.
4501 		 */
4502 		RB_FOREACH_SAFE(rqpair, qpairs_tree, &rpoller->qpairs, tmp_rqpair) {
4503 			nvmf_rdma_destroy_drained_qpair(rqpair);
4504 		}
4505 		return 0;
4506 	}
4507 
4508 	/* Poll for completing operations. */
4509 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
4510 	if (reaped < 0) {
4511 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
4512 			    errno, spdk_strerror(errno));
4513 		return -1;
4514 	} else if (reaped == 0) {
4515 		rpoller->stat.idle_polls++;
4516 	}
4517 
4518 	rpoller->stat.polls++;
4519 	rpoller->stat.completions += reaped;
4520 
4521 	for (i = 0; i < reaped; i++) {
4522 
4523 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
4524 
4525 		switch (rdma_wr->type) {
4526 		case RDMA_WR_TYPE_SEND:
4527 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
4528 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
4529 
4530 			if (!wc[i].status) {
4531 				count++;
4532 				assert(wc[i].opcode == IBV_WC_SEND);
4533 				assert(nvmf_rdma_req_is_completing(rdma_req));
4534 			}
4535 
4536 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4537 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
4538 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
4539 			rdma_req->num_outstanding_data_wr = 0;
4540 
4541 			nvmf_rdma_request_process(rtransport, rdma_req);
4542 			break;
4543 		case RDMA_WR_TYPE_RECV:
4544 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
4545 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
4546 			if (rpoller->srq != NULL) {
4547 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
4548 				/* It is possible that there are still some completions for destroyed QP
4549 				 * associated with SRQ. We just ignore these late completions and re-post
4550 				 * receive WRs back to SRQ.
4551 				 */
4552 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
4553 					struct ibv_recv_wr *bad_wr;
4554 					int rc;
4555 
4556 					rdma_recv->wr.next = NULL;
4557 					spdk_rdma_srq_queue_recv_wrs(rpoller->srq, &rdma_recv->wr);
4558 					rc = spdk_rdma_srq_flush_recv_wrs(rpoller->srq, &bad_wr);
4559 					if (rc) {
4560 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
4561 					}
4562 					continue;
4563 				}
4564 			}
4565 			rqpair = rdma_recv->qpair;
4566 
4567 			assert(rqpair != NULL);
4568 			if (!wc[i].status) {
4569 				assert(wc[i].opcode == IBV_WC_RECV);
4570 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
4571 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
4572 					break;
4573 				}
4574 			}
4575 
4576 			rdma_recv->wr.next = NULL;
4577 			rqpair->current_recv_depth++;
4578 			rdma_recv->receive_tsc = poll_tsc;
4579 			rpoller->stat.requests++;
4580 			STAILQ_INSERT_HEAD(&rqpair->resources->incoming_queue, rdma_recv, link);
4581 			break;
4582 		case RDMA_WR_TYPE_DATA:
4583 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
4584 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
4585 
4586 			assert(rdma_req->num_outstanding_data_wr > 0);
4587 
4588 			rqpair->current_send_depth--;
4589 			rdma_req->num_outstanding_data_wr--;
4590 			if (!wc[i].status) {
4591 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
4592 				rqpair->current_read_depth--;
4593 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
4594 				if (rdma_req->num_outstanding_data_wr == 0) {
4595 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
4596 					nvmf_rdma_request_process(rtransport, rdma_req);
4597 				}
4598 			} else {
4599 				/* If the data transfer fails still force the queue into the error state,
4600 				 * if we were performing an RDMA_READ, we need to force the request into a
4601 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
4602 				 * case, we should wait for the SEND to complete. */
4603 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
4604 					rqpair->current_read_depth--;
4605 					if (rdma_req->num_outstanding_data_wr == 0) {
4606 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
4607 					}
4608 				}
4609 			}
4610 			break;
4611 		default:
4612 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
4613 			continue;
4614 		}
4615 
4616 		/* Handle error conditions */
4617 		if (wc[i].status) {
4618 			nvmf_rdma_update_ibv_state(rqpair);
4619 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
4620 
4621 			error = true;
4622 
4623 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
4624 				/* Disconnect the connection. */
4625 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
4626 			} else {
4627 				nvmf_rdma_destroy_drained_qpair(rqpair);
4628 			}
4629 			continue;
4630 		}
4631 
4632 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
4633 
4634 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
4635 			nvmf_rdma_destroy_drained_qpair(rqpair);
4636 		}
4637 	}
4638 
4639 	if (error == true) {
4640 		return -1;
4641 	}
4642 
4643 	/* submit outstanding work requests. */
4644 	_poller_submit_recvs(rtransport, rpoller);
4645 	_poller_submit_sends(rtransport, rpoller);
4646 
4647 	return count;
4648 }
4649 
4650 static void
4651 _nvmf_rdma_remove_destroyed_device(void *c)
4652 {
4653 	struct spdk_nvmf_rdma_transport	*rtransport = c;
4654 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
4655 	int				rc;
4656 
4657 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
4658 		if (device->ready_to_destroy) {
4659 			destroy_ib_device(rtransport, device);
4660 		}
4661 	}
4662 
4663 	free_poll_fds(rtransport);
4664 	rc = generate_poll_fds(rtransport);
4665 	/* cannot handle fd allocation error here */
4666 	if (rc != 0) {
4667 		SPDK_ERRLOG("Failed to generate poll fds after remove ib device.\n");
4668 	}
4669 }
4670 
4671 static void
4672 _nvmf_rdma_remove_poller_in_group_cb(void *c)
4673 {
4674 	struct poller_manage_ctx	*ctx = c;
4675 	struct spdk_nvmf_rdma_transport	*rtransport = ctx->rtransport;
4676 	struct spdk_nvmf_rdma_device	*device = ctx->device;
4677 	struct spdk_thread		*thread = ctx->thread;
4678 
4679 	if (nvmf_rdma_all_pollers_management_done(c)) {
4680 		/* destroy device when last poller is destroyed */
4681 		device->ready_to_destroy = true;
4682 		spdk_thread_send_msg(thread, _nvmf_rdma_remove_destroyed_device, rtransport);
4683 	}
4684 }
4685 
4686 static void
4687 _nvmf_rdma_remove_poller_in_group(void *c)
4688 {
4689 	struct poller_manage_ctx		*ctx = c;
4690 
4691 	ctx->rpoller->need_destroy = true;
4692 	ctx->rpoller->destroy_cb_ctx = ctx;
4693 	ctx->rpoller->destroy_cb = _nvmf_rdma_remove_poller_in_group_cb;
4694 
4695 	/* qp will be disconnected after receiving a RDMA_CM_EVENT_DEVICE_REMOVAL event. */
4696 	if (RB_EMPTY(&ctx->rpoller->qpairs)) {
4697 		nvmf_rdma_poller_destroy(ctx->rpoller);
4698 	}
4699 }
4700 
4701 static int
4702 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
4703 {
4704 	struct spdk_nvmf_rdma_transport *rtransport;
4705 	struct spdk_nvmf_rdma_poll_group *rgroup;
4706 	struct spdk_nvmf_rdma_poller	*rpoller, *tmp;
4707 	int				count, rc;
4708 
4709 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
4710 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4711 
4712 	count = 0;
4713 	TAILQ_FOREACH_SAFE(rpoller, &rgroup->pollers, link, tmp) {
4714 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
4715 		if (rc < 0) {
4716 			return rc;
4717 		}
4718 		count += rc;
4719 	}
4720 
4721 	return count;
4722 }
4723 
4724 static int
4725 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
4726 			  struct spdk_nvme_transport_id *trid,
4727 			  bool peer)
4728 {
4729 	struct sockaddr *saddr;
4730 	uint16_t port;
4731 
4732 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
4733 
4734 	if (peer) {
4735 		saddr = rdma_get_peer_addr(id);
4736 	} else {
4737 		saddr = rdma_get_local_addr(id);
4738 	}
4739 	switch (saddr->sa_family) {
4740 	case AF_INET: {
4741 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
4742 
4743 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
4744 		inet_ntop(AF_INET, &saddr_in->sin_addr,
4745 			  trid->traddr, sizeof(trid->traddr));
4746 		if (peer) {
4747 			port = ntohs(rdma_get_dst_port(id));
4748 		} else {
4749 			port = ntohs(rdma_get_src_port(id));
4750 		}
4751 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4752 		break;
4753 	}
4754 	case AF_INET6: {
4755 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4756 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4757 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4758 			  trid->traddr, sizeof(trid->traddr));
4759 		if (peer) {
4760 			port = ntohs(rdma_get_dst_port(id));
4761 		} else {
4762 			port = ntohs(rdma_get_src_port(id));
4763 		}
4764 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4765 		break;
4766 	}
4767 	default:
4768 		return -1;
4769 
4770 	}
4771 
4772 	return 0;
4773 }
4774 
4775 static int
4776 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4777 			      struct spdk_nvme_transport_id *trid)
4778 {
4779 	struct spdk_nvmf_rdma_qpair	*rqpair;
4780 
4781 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4782 
4783 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4784 }
4785 
4786 static int
4787 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4788 			       struct spdk_nvme_transport_id *trid)
4789 {
4790 	struct spdk_nvmf_rdma_qpair	*rqpair;
4791 
4792 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4793 
4794 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4795 }
4796 
4797 static int
4798 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4799 				struct spdk_nvme_transport_id *trid)
4800 {
4801 	struct spdk_nvmf_rdma_qpair	*rqpair;
4802 
4803 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4804 
4805 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4806 }
4807 
4808 void
4809 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4810 {
4811 	g_nvmf_hooks = *hooks;
4812 }
4813 
4814 static void
4815 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4816 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4817 {
4818 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4819 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4820 
4821 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4822 
4823 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4824 }
4825 
4826 static int
4827 _nvmf_rdma_qpair_abort_request(void *ctx)
4828 {
4829 	struct spdk_nvmf_request *req = ctx;
4830 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4831 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4832 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4833 					      struct spdk_nvmf_rdma_qpair, qpair);
4834 	int rc;
4835 
4836 	spdk_poller_unregister(&req->poller);
4837 
4838 	switch (rdma_req_to_abort->state) {
4839 	case RDMA_REQUEST_STATE_EXECUTING:
4840 		rc = nvmf_ctrlr_abort_request(req);
4841 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4842 			return SPDK_POLLER_BUSY;
4843 		}
4844 		break;
4845 
4846 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4847 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4848 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4849 
4850 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4851 		break;
4852 
4853 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4854 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4855 			      spdk_nvmf_rdma_request, state_link);
4856 
4857 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4858 		break;
4859 
4860 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4861 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4862 			      spdk_nvmf_rdma_request, state_link);
4863 
4864 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4865 		break;
4866 
4867 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4868 		if (spdk_get_ticks() < req->timeout_tsc) {
4869 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4870 			return SPDK_POLLER_BUSY;
4871 		}
4872 		break;
4873 
4874 	default:
4875 		break;
4876 	}
4877 
4878 	spdk_nvmf_request_complete(req);
4879 	return SPDK_POLLER_BUSY;
4880 }
4881 
4882 static void
4883 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4884 			      struct spdk_nvmf_request *req)
4885 {
4886 	struct spdk_nvmf_rdma_qpair *rqpair;
4887 	struct spdk_nvmf_rdma_transport *rtransport;
4888 	struct spdk_nvmf_transport *transport;
4889 	uint16_t cid;
4890 	uint32_t i, max_req_count;
4891 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL, *rdma_req;
4892 
4893 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4894 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4895 	transport = &rtransport->transport;
4896 
4897 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4898 	max_req_count = rqpair->srq == NULL ? rqpair->max_queue_depth : rqpair->poller->max_srq_depth;
4899 
4900 	for (i = 0; i < max_req_count; i++) {
4901 		rdma_req = &rqpair->resources->reqs[i];
4902 		/* When SRQ == NULL, rqpair has its own requests and req.qpair pointer always points to the qpair
4903 		 * When SRQ != NULL all rqpairs share common requests and qpair pointer is assigned when we start to
4904 		 * process a request. So in both cases all requests which are not in FREE state have valid qpair ptr */
4905 		if (rdma_req->state != RDMA_REQUEST_STATE_FREE && rdma_req->req.cmd->nvme_cmd.cid == cid &&
4906 		    rdma_req->req.qpair == qpair) {
4907 			rdma_req_to_abort = rdma_req;
4908 			break;
4909 		}
4910 	}
4911 
4912 	if (rdma_req_to_abort == NULL) {
4913 		spdk_nvmf_request_complete(req);
4914 		return;
4915 	}
4916 
4917 	req->req_to_abort = &rdma_req_to_abort->req;
4918 	req->timeout_tsc = spdk_get_ticks() +
4919 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4920 	req->poller = NULL;
4921 
4922 	_nvmf_rdma_qpair_abort_request(req);
4923 }
4924 
4925 static void
4926 nvmf_rdma_poll_group_dump_stat(struct spdk_nvmf_transport_poll_group *group,
4927 			       struct spdk_json_write_ctx *w)
4928 {
4929 	struct spdk_nvmf_rdma_poll_group *rgroup;
4930 	struct spdk_nvmf_rdma_poller *rpoller;
4931 
4932 	assert(w != NULL);
4933 
4934 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4935 
4936 	spdk_json_write_named_uint64(w, "pending_data_buffer", rgroup->stat.pending_data_buffer);
4937 
4938 	spdk_json_write_named_array_begin(w, "devices");
4939 
4940 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4941 		spdk_json_write_object_begin(w);
4942 		spdk_json_write_named_string(w, "name",
4943 					     ibv_get_device_name(rpoller->device->context->device));
4944 		spdk_json_write_named_uint64(w, "polls",
4945 					     rpoller->stat.polls);
4946 		spdk_json_write_named_uint64(w, "idle_polls",
4947 					     rpoller->stat.idle_polls);
4948 		spdk_json_write_named_uint64(w, "completions",
4949 					     rpoller->stat.completions);
4950 		spdk_json_write_named_uint64(w, "requests",
4951 					     rpoller->stat.requests);
4952 		spdk_json_write_named_uint64(w, "request_latency",
4953 					     rpoller->stat.request_latency);
4954 		spdk_json_write_named_uint64(w, "pending_free_request",
4955 					     rpoller->stat.pending_free_request);
4956 		spdk_json_write_named_uint64(w, "pending_rdma_read",
4957 					     rpoller->stat.pending_rdma_read);
4958 		spdk_json_write_named_uint64(w, "pending_rdma_write",
4959 					     rpoller->stat.pending_rdma_write);
4960 		spdk_json_write_named_uint64(w, "total_send_wrs",
4961 					     rpoller->stat.qp_stats.send.num_submitted_wrs);
4962 		spdk_json_write_named_uint64(w, "send_doorbell_updates",
4963 					     rpoller->stat.qp_stats.send.doorbell_updates);
4964 		spdk_json_write_named_uint64(w, "total_recv_wrs",
4965 					     rpoller->stat.qp_stats.recv.num_submitted_wrs);
4966 		spdk_json_write_named_uint64(w, "recv_doorbell_updates",
4967 					     rpoller->stat.qp_stats.recv.doorbell_updates);
4968 		spdk_json_write_object_end(w);
4969 	}
4970 
4971 	spdk_json_write_array_end(w);
4972 }
4973 
4974 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4975 	.name = "RDMA",
4976 	.type = SPDK_NVME_TRANSPORT_RDMA,
4977 	.opts_init = nvmf_rdma_opts_init,
4978 	.create = nvmf_rdma_create,
4979 	.dump_opts = nvmf_rdma_dump_opts,
4980 	.destroy = nvmf_rdma_destroy,
4981 
4982 	.listen = nvmf_rdma_listen,
4983 	.stop_listen = nvmf_rdma_stop_listen,
4984 	.cdata_init = nvmf_rdma_cdata_init,
4985 
4986 	.listener_discover = nvmf_rdma_discover,
4987 
4988 	.poll_group_create = nvmf_rdma_poll_group_create,
4989 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4990 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4991 	.poll_group_add = nvmf_rdma_poll_group_add,
4992 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4993 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4994 
4995 	.req_free = nvmf_rdma_request_free,
4996 	.req_complete = nvmf_rdma_request_complete,
4997 
4998 	.qpair_fini = nvmf_rdma_close_qpair,
4999 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
5000 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
5001 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
5002 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
5003 
5004 	.poll_group_dump_stat = nvmf_rdma_poll_group_dump_stat,
5005 };
5006 
5007 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
5008 SPDK_LOG_REGISTER_COMPONENT(rdma)
5009