xref: /spdk/lib/nvmf/rdma.c (revision b94d358a498a9c4f2b3416aeb6a73200d9fdb514)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019, 2020 Mellanox Technologies LTD. All rights reserved.
6  *
7  *   Redistribution and use in source and binary forms, with or without
8  *   modification, are permitted provided that the following conditions
9  *   are met:
10  *
11  *     * Redistributions of source code must retain the above copyright
12  *       notice, this list of conditions and the following disclaimer.
13  *     * Redistributions in binary form must reproduce the above copyright
14  *       notice, this list of conditions and the following disclaimer in
15  *       the documentation and/or other materials provided with the
16  *       distribution.
17  *     * Neither the name of Intel Corporation nor the names of its
18  *       contributors may be used to endorse or promote products derived
19  *       from this software without specific prior written permission.
20  *
21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include "spdk/stdinc.h"
35 
36 #include "spdk/config.h"
37 #include "spdk/thread.h"
38 #include "spdk/likely.h"
39 #include "spdk/nvmf_transport.h"
40 #include "spdk/string.h"
41 #include "spdk/trace.h"
42 #include "spdk/util.h"
43 
44 #include "spdk_internal/assert.h"
45 #include "spdk/log.h"
46 #include "spdk_internal/rdma.h"
47 
48 #include "nvmf_internal.h"
49 
50 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
51 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma;
52 
53 /*
54  RDMA Connection Resource Defaults
55  */
56 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
57 #define NVMF_DEFAULT_RSP_SGE		1
58 #define NVMF_DEFAULT_RX_SGE		2
59 
60 /* The RDMA completion queue size */
61 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
62 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
63 
64 /* rxe driver vendor_id has been changed from 0 to 0XFFFFFF in 0184afd15a141d7ce24c32c0d86a1e3ba6bc0eb3 */
65 #define NVMF_RXE_VENDOR_ID_OLD 0
66 #define NVMF_RXE_VENDOR_ID_NEW 0XFFFFFF
67 
68 static int g_spdk_nvmf_ibv_query_mask =
69 	IBV_QP_STATE |
70 	IBV_QP_PKEY_INDEX |
71 	IBV_QP_PORT |
72 	IBV_QP_ACCESS_FLAGS |
73 	IBV_QP_AV |
74 	IBV_QP_PATH_MTU |
75 	IBV_QP_DEST_QPN |
76 	IBV_QP_RQ_PSN |
77 	IBV_QP_MAX_DEST_RD_ATOMIC |
78 	IBV_QP_MIN_RNR_TIMER |
79 	IBV_QP_SQ_PSN |
80 	IBV_QP_TIMEOUT |
81 	IBV_QP_RETRY_CNT |
82 	IBV_QP_RNR_RETRY |
83 	IBV_QP_MAX_QP_RD_ATOMIC;
84 
85 enum spdk_nvmf_rdma_request_state {
86 	/* The request is not currently in use */
87 	RDMA_REQUEST_STATE_FREE = 0,
88 
89 	/* Initial state when request first received */
90 	RDMA_REQUEST_STATE_NEW,
91 
92 	/* The request is queued until a data buffer is available. */
93 	RDMA_REQUEST_STATE_NEED_BUFFER,
94 
95 	/* The request is waiting on RDMA queue depth availability
96 	 * to transfer data from the host to the controller.
97 	 */
98 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
99 
100 	/* The request is currently transferring data from the host to the controller. */
101 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
102 
103 	/* The request is ready to execute at the block device */
104 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
105 
106 	/* The request is currently executing at the block device */
107 	RDMA_REQUEST_STATE_EXECUTING,
108 
109 	/* The request finished executing at the block device */
110 	RDMA_REQUEST_STATE_EXECUTED,
111 
112 	/* The request is waiting on RDMA queue depth availability
113 	 * to transfer data from the controller to the host.
114 	 */
115 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
116 
117 	/* The request is ready to send a completion */
118 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
119 
120 	/* The request is currently transferring data from the controller to the host. */
121 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
122 
123 	/* The request currently has an outstanding completion without an
124 	 * associated data transfer.
125 	 */
126 	RDMA_REQUEST_STATE_COMPLETING,
127 
128 	/* The request completed and can be marked free. */
129 	RDMA_REQUEST_STATE_COMPLETED,
130 
131 	/* Terminator */
132 	RDMA_REQUEST_NUM_STATES,
133 };
134 
135 #define OBJECT_NVMF_RDMA_IO				0x40
136 
137 #define TRACE_GROUP_NVMF_RDMA				0x4
138 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
139 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
140 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
141 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
142 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
143 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
144 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
145 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
146 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
147 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
148 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
149 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
150 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
151 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
152 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
153 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
154 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
155 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
156 
157 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
158 {
159 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
160 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
161 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
162 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
163 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
164 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
165 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
168 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
169 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
170 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
171 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
172 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
173 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
174 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
175 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
176 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
177 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
178 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
179 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
180 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
181 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
182 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
183 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
184 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
185 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
186 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
187 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
188 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
189 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
190 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
191 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
192 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
193 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
194 
195 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
196 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
197 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
198 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
199 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
200 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
201 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
202 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
203 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
204 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
205 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
206 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
207 }
208 
209 enum spdk_nvmf_rdma_wr_type {
210 	RDMA_WR_TYPE_RECV,
211 	RDMA_WR_TYPE_SEND,
212 	RDMA_WR_TYPE_DATA,
213 };
214 
215 struct spdk_nvmf_rdma_wr {
216 	enum spdk_nvmf_rdma_wr_type	type;
217 };
218 
219 /* This structure holds commands as they are received off the wire.
220  * It must be dynamically paired with a full request object
221  * (spdk_nvmf_rdma_request) to service a request. It is separate
222  * from the request because RDMA does not appear to order
223  * completions, so occasionally we'll get a new incoming
224  * command when there aren't any free request objects.
225  */
226 struct spdk_nvmf_rdma_recv {
227 	struct ibv_recv_wr			wr;
228 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
229 
230 	struct spdk_nvmf_rdma_qpair		*qpair;
231 
232 	/* In-capsule data buffer */
233 	uint8_t					*buf;
234 
235 	struct spdk_nvmf_rdma_wr		rdma_wr;
236 	uint64_t				receive_tsc;
237 
238 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
239 };
240 
241 struct spdk_nvmf_rdma_request_data {
242 	struct spdk_nvmf_rdma_wr	rdma_wr;
243 	struct ibv_send_wr		wr;
244 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
245 };
246 
247 struct spdk_nvmf_rdma_request {
248 	struct spdk_nvmf_request		req;
249 
250 	enum spdk_nvmf_rdma_request_state	state;
251 
252 	struct spdk_nvmf_rdma_recv		*recv;
253 
254 	struct {
255 		struct spdk_nvmf_rdma_wr	rdma_wr;
256 		struct	ibv_send_wr		wr;
257 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
258 	} rsp;
259 
260 	struct spdk_nvmf_rdma_request_data	data;
261 
262 	uint32_t				iovpos;
263 
264 	uint32_t				num_outstanding_data_wr;
265 	uint64_t				receive_tsc;
266 
267 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
268 };
269 
270 struct spdk_nvmf_rdma_resource_opts {
271 	struct spdk_nvmf_rdma_qpair	*qpair;
272 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
273 	void				*qp;
274 	struct ibv_pd			*pd;
275 	uint32_t			max_queue_depth;
276 	uint32_t			in_capsule_data_size;
277 	bool				shared;
278 };
279 
280 struct spdk_nvmf_recv_wr_list {
281 	struct ibv_recv_wr	*first;
282 	struct ibv_recv_wr	*last;
283 };
284 
285 struct spdk_nvmf_rdma_resources {
286 	/* Array of size "max_queue_depth" containing RDMA requests. */
287 	struct spdk_nvmf_rdma_request		*reqs;
288 
289 	/* Array of size "max_queue_depth" containing RDMA recvs. */
290 	struct spdk_nvmf_rdma_recv		*recvs;
291 
292 	/* Array of size "max_queue_depth" containing 64 byte capsules
293 	 * used for receive.
294 	 */
295 	union nvmf_h2c_msg			*cmds;
296 	struct ibv_mr				*cmds_mr;
297 
298 	/* Array of size "max_queue_depth" containing 16 byte completions
299 	 * to be sent back to the user.
300 	 */
301 	union nvmf_c2h_msg			*cpls;
302 	struct ibv_mr				*cpls_mr;
303 
304 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
305 	 * buffers to be used for in capsule data.
306 	 */
307 	void					*bufs;
308 	struct ibv_mr				*bufs_mr;
309 
310 	/* The list of pending recvs to transfer */
311 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
312 
313 	/* Receives that are waiting for a request object */
314 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
315 
316 	/* Queue to track free requests */
317 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
318 };
319 
320 typedef void (*spdk_nvmf_rdma_qpair_ibv_event)(struct spdk_nvmf_rdma_qpair *rqpair);
321 
322 struct spdk_nvmf_rdma_ibv_event_ctx {
323 	struct spdk_nvmf_rdma_qpair			*rqpair;
324 	spdk_nvmf_rdma_qpair_ibv_event			cb_fn;
325 	/* Link to other ibv events associated with this qpair */
326 	STAILQ_ENTRY(spdk_nvmf_rdma_ibv_event_ctx)	link;
327 };
328 
329 struct spdk_nvmf_rdma_qpair {
330 	struct spdk_nvmf_qpair			qpair;
331 
332 	struct spdk_nvmf_rdma_device		*device;
333 	struct spdk_nvmf_rdma_poller		*poller;
334 
335 	struct spdk_rdma_qp			*rdma_qp;
336 	struct rdma_cm_id			*cm_id;
337 	struct ibv_srq				*srq;
338 	struct rdma_cm_id			*listen_id;
339 
340 	/* The maximum number of I/O outstanding on this connection at one time */
341 	uint16_t				max_queue_depth;
342 
343 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
344 	uint16_t				max_read_depth;
345 
346 	/* The maximum number of RDMA SEND operations at one time */
347 	uint32_t				max_send_depth;
348 
349 	/* The current number of outstanding WRs from this qpair's
350 	 * recv queue. Should not exceed device->attr.max_queue_depth.
351 	 */
352 	uint16_t				current_recv_depth;
353 
354 	/* The current number of active RDMA READ operations */
355 	uint16_t				current_read_depth;
356 
357 	/* The current number of posted WRs from this qpair's
358 	 * send queue. Should not exceed max_send_depth.
359 	 */
360 	uint32_t				current_send_depth;
361 
362 	/* The maximum number of SGEs per WR on the send queue */
363 	uint32_t				max_send_sge;
364 
365 	/* The maximum number of SGEs per WR on the recv queue */
366 	uint32_t				max_recv_sge;
367 
368 	struct spdk_nvmf_rdma_resources		*resources;
369 
370 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
371 
372 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
373 
374 	/* Number of requests not in the free state */
375 	uint32_t				qd;
376 
377 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
378 
379 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
380 
381 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
382 
383 	/* IBV queue pair attributes: they are used to manage
384 	 * qp state and recover from errors.
385 	 */
386 	enum ibv_qp_state			ibv_state;
387 
388 	/*
389 	 * io_channel which is used to destroy qpair when it is removed from poll group
390 	 */
391 	struct spdk_io_channel		*destruct_channel;
392 
393 	/* List of ibv async events */
394 	STAILQ_HEAD(, spdk_nvmf_rdma_ibv_event_ctx)	ibv_events;
395 
396 	/* Lets us know that we have received the last_wqe event. */
397 	bool					last_wqe_reached;
398 
399 	/* Indicate that nvmf_rdma_close_qpair is called */
400 	bool					to_close;
401 };
402 
403 struct spdk_nvmf_rdma_poller_stat {
404 	uint64_t				completions;
405 	uint64_t				polls;
406 	uint64_t				requests;
407 	uint64_t				request_latency;
408 	uint64_t				pending_free_request;
409 	uint64_t				pending_rdma_read;
410 	uint64_t				pending_rdma_write;
411 };
412 
413 struct spdk_nvmf_rdma_poller {
414 	struct spdk_nvmf_rdma_device		*device;
415 	struct spdk_nvmf_rdma_poll_group	*group;
416 
417 	int					num_cqe;
418 	int					required_num_wr;
419 	struct ibv_cq				*cq;
420 
421 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
422 	uint16_t				max_srq_depth;
423 
424 	/* Shared receive queue */
425 	struct ibv_srq				*srq;
426 
427 	struct spdk_nvmf_rdma_resources		*resources;
428 	struct spdk_nvmf_rdma_poller_stat	stat;
429 
430 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
431 
432 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
433 
434 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
435 
436 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
437 };
438 
439 struct spdk_nvmf_rdma_poll_group_stat {
440 	uint64_t				pending_data_buffer;
441 };
442 
443 struct spdk_nvmf_rdma_poll_group {
444 	struct spdk_nvmf_transport_poll_group		group;
445 	struct spdk_nvmf_rdma_poll_group_stat		stat;
446 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
447 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
448 	/*
449 	 * buffers which are split across multiple RDMA
450 	 * memory regions cannot be used by this transport.
451 	 */
452 	STAILQ_HEAD(, spdk_nvmf_transport_pg_cache_buf)	retired_bufs;
453 };
454 
455 struct spdk_nvmf_rdma_conn_sched {
456 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
457 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
458 };
459 
460 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
461 struct spdk_nvmf_rdma_device {
462 	struct ibv_device_attr			attr;
463 	struct ibv_context			*context;
464 
465 	struct spdk_mem_map			*map;
466 	struct ibv_pd				*pd;
467 
468 	int					num_srq;
469 
470 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
471 };
472 
473 struct spdk_nvmf_rdma_port {
474 	const struct spdk_nvme_transport_id	*trid;
475 	struct rdma_cm_id			*id;
476 	struct spdk_nvmf_rdma_device		*device;
477 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
478 };
479 
480 struct rdma_transport_opts {
481 	uint32_t	max_srq_depth;
482 	bool		no_srq;
483 	bool		no_wr_batching;
484 	int		acceptor_backlog;
485 };
486 
487 struct spdk_nvmf_rdma_transport {
488 	struct spdk_nvmf_transport	transport;
489 	struct rdma_transport_opts	rdma_opts;
490 
491 	struct spdk_nvmf_rdma_conn_sched conn_sched;
492 
493 	struct rdma_event_channel	*event_channel;
494 
495 	struct spdk_mempool		*data_wr_pool;
496 
497 	pthread_mutex_t			lock;
498 
499 	/* fields used to poll RDMA/IB events */
500 	nfds_t			npoll_fds;
501 	struct pollfd		*poll_fds;
502 
503 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
504 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
505 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
506 };
507 
508 static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = {
509 	{
510 		"max_srq_depth", offsetof(struct rdma_transport_opts, max_srq_depth),
511 		spdk_json_decode_uint32, true
512 	},
513 	{
514 		"no_srq", offsetof(struct rdma_transport_opts, no_srq),
515 		spdk_json_decode_bool, true
516 	},
517 	{
518 		"no_wr_batching", offsetof(struct rdma_transport_opts, no_wr_batching),
519 		spdk_json_decode_bool, true
520 	},
521 	{
522 		"acceptor_backlog", offsetof(struct rdma_transport_opts, acceptor_backlog),
523 		spdk_json_decode_int32, true
524 	},
525 };
526 
527 static bool
528 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
529 			  struct spdk_nvmf_rdma_request *rdma_req);
530 
531 static void
532 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
533 		     struct spdk_nvmf_rdma_poller *rpoller);
534 
535 static void
536 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
537 		     struct spdk_nvmf_rdma_poller *rpoller);
538 
539 static inline int
540 nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
541 {
542 	switch (state) {
543 	case IBV_QPS_RESET:
544 	case IBV_QPS_INIT:
545 	case IBV_QPS_RTR:
546 	case IBV_QPS_RTS:
547 	case IBV_QPS_SQD:
548 	case IBV_QPS_SQE:
549 	case IBV_QPS_ERR:
550 		return 0;
551 	default:
552 		return -1;
553 	}
554 }
555 
556 static inline enum spdk_nvme_media_error_status_code
557 nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
558 	enum spdk_nvme_media_error_status_code result;
559 	switch (err_type)
560 	{
561 	case SPDK_DIF_REFTAG_ERROR:
562 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
563 		break;
564 	case SPDK_DIF_APPTAG_ERROR:
565 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
566 		break;
567 	case SPDK_DIF_GUARD_ERROR:
568 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
569 		break;
570 	default:
571 		SPDK_UNREACHABLE();
572 	}
573 
574 	return result;
575 }
576 
577 static enum ibv_qp_state
578 nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
579 	enum ibv_qp_state old_state, new_state;
580 	struct ibv_qp_attr qp_attr;
581 	struct ibv_qp_init_attr init_attr;
582 	int rc;
583 
584 	old_state = rqpair->ibv_state;
585 	rc = ibv_query_qp(rqpair->rdma_qp->qp, &qp_attr,
586 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
587 
588 	if (rc)
589 	{
590 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
591 		return IBV_QPS_ERR + 1;
592 	}
593 
594 	new_state = qp_attr.qp_state;
595 	rqpair->ibv_state = new_state;
596 	qp_attr.ah_attr.port_num = qp_attr.port_num;
597 
598 	rc = nvmf_rdma_check_ibv_state(new_state);
599 	if (rc)
600 	{
601 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
602 		/*
603 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
604 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
605 		 */
606 		return IBV_QPS_ERR + 1;
607 	}
608 
609 	if (old_state != new_state)
610 	{
611 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
612 				  (uintptr_t)rqpair->cm_id, new_state);
613 	}
614 	return new_state;
615 }
616 
617 static void
618 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
619 			    struct spdk_nvmf_rdma_transport *rtransport)
620 {
621 	struct spdk_nvmf_rdma_request_data	*data_wr;
622 	struct ibv_send_wr			*next_send_wr;
623 	uint64_t				req_wrid;
624 
625 	rdma_req->num_outstanding_data_wr = 0;
626 	data_wr = &rdma_req->data;
627 	req_wrid = data_wr->wr.wr_id;
628 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
629 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
630 		data_wr->wr.num_sge = 0;
631 		next_send_wr = data_wr->wr.next;
632 		if (data_wr != &rdma_req->data) {
633 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
634 		}
635 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
636 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
637 	}
638 }
639 
640 static void
641 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
642 {
643 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
644 	if (req->req.cmd) {
645 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
646 	}
647 	if (req->recv) {
648 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
649 	}
650 }
651 
652 static void
653 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
654 {
655 	int i;
656 
657 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
658 	for (i = 0; i < rqpair->max_queue_depth; i++) {
659 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
660 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
661 		}
662 	}
663 }
664 
665 static void
666 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
667 {
668 	if (resources->cmds_mr) {
669 		ibv_dereg_mr(resources->cmds_mr);
670 	}
671 
672 	if (resources->cpls_mr) {
673 		ibv_dereg_mr(resources->cpls_mr);
674 	}
675 
676 	if (resources->bufs_mr) {
677 		ibv_dereg_mr(resources->bufs_mr);
678 	}
679 
680 	spdk_free(resources->cmds);
681 	spdk_free(resources->cpls);
682 	spdk_free(resources->bufs);
683 	free(resources->reqs);
684 	free(resources->recvs);
685 	free(resources);
686 }
687 
688 
689 static struct spdk_nvmf_rdma_resources *
690 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
691 {
692 	struct spdk_nvmf_rdma_resources	*resources;
693 	struct spdk_nvmf_rdma_request	*rdma_req;
694 	struct spdk_nvmf_rdma_recv	*rdma_recv;
695 	struct ibv_qp			*qp;
696 	struct ibv_srq			*srq;
697 	uint32_t			i;
698 	int				rc;
699 
700 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
701 	if (!resources) {
702 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
703 		return NULL;
704 	}
705 
706 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
707 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
708 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
709 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
710 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
711 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
712 
713 	if (opts->in_capsule_data_size > 0) {
714 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
715 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
716 					       SPDK_MALLOC_DMA);
717 	}
718 
719 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
720 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
721 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
722 		goto cleanup;
723 	}
724 
725 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
726 					opts->max_queue_depth * sizeof(*resources->cmds),
727 					IBV_ACCESS_LOCAL_WRITE);
728 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
729 					opts->max_queue_depth * sizeof(*resources->cpls),
730 					0);
731 
732 	if (opts->in_capsule_data_size) {
733 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
734 						opts->max_queue_depth *
735 						opts->in_capsule_data_size,
736 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
737 	}
738 
739 	if (!resources->cmds_mr || !resources->cpls_mr ||
740 	    (opts->in_capsule_data_size &&
741 	     !resources->bufs_mr)) {
742 		goto cleanup;
743 	}
744 	SPDK_DEBUGLOG(rdma, "Command Array: %p Length: %lx LKey: %x\n",
745 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
746 		      resources->cmds_mr->lkey);
747 	SPDK_DEBUGLOG(rdma, "Completion Array: %p Length: %lx LKey: %x\n",
748 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
749 		      resources->cpls_mr->lkey);
750 	if (resources->bufs && resources->bufs_mr) {
751 		SPDK_DEBUGLOG(rdma, "In Capsule Data Array: %p Length: %x LKey: %x\n",
752 			      resources->bufs, opts->max_queue_depth *
753 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
754 	}
755 
756 	/* Initialize queues */
757 	STAILQ_INIT(&resources->incoming_queue);
758 	STAILQ_INIT(&resources->free_queue);
759 
760 	for (i = 0; i < opts->max_queue_depth; i++) {
761 		struct ibv_recv_wr *bad_wr = NULL;
762 
763 		rdma_recv = &resources->recvs[i];
764 		rdma_recv->qpair = opts->qpair;
765 
766 		/* Set up memory to receive commands */
767 		if (resources->bufs) {
768 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
769 						  opts->in_capsule_data_size));
770 		}
771 
772 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
773 
774 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
775 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
776 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
777 		rdma_recv->wr.num_sge = 1;
778 
779 		if (rdma_recv->buf && resources->bufs_mr) {
780 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
781 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
782 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
783 			rdma_recv->wr.num_sge++;
784 		}
785 
786 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
787 		rdma_recv->wr.sg_list = rdma_recv->sgl;
788 		if (opts->shared) {
789 			srq = (struct ibv_srq *)opts->qp;
790 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
791 		} else {
792 			qp = (struct ibv_qp *)opts->qp;
793 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
794 		}
795 		if (rc) {
796 			goto cleanup;
797 		}
798 	}
799 
800 	for (i = 0; i < opts->max_queue_depth; i++) {
801 		rdma_req = &resources->reqs[i];
802 
803 		if (opts->qpair != NULL) {
804 			rdma_req->req.qpair = &opts->qpair->qpair;
805 		} else {
806 			rdma_req->req.qpair = NULL;
807 		}
808 		rdma_req->req.cmd = NULL;
809 
810 		/* Set up memory to send responses */
811 		rdma_req->req.rsp = &resources->cpls[i];
812 
813 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
814 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
815 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
816 
817 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
818 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
819 		rdma_req->rsp.wr.next = NULL;
820 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
821 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
822 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
823 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
824 
825 		/* Set up memory for data buffers */
826 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
827 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
828 		rdma_req->data.wr.next = NULL;
829 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
830 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
831 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
832 
833 		/* Initialize request state to FREE */
834 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
835 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
836 	}
837 
838 	return resources;
839 
840 cleanup:
841 	nvmf_rdma_resources_destroy(resources);
842 	return NULL;
843 }
844 
845 static void
846 nvmf_rdma_qpair_clean_ibv_events(struct spdk_nvmf_rdma_qpair *rqpair)
847 {
848 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx, *tctx;
849 	STAILQ_FOREACH_SAFE(ctx, &rqpair->ibv_events, link, tctx) {
850 		ctx->rqpair = NULL;
851 		/* Memory allocated for ctx is freed in nvmf_rdma_qpair_process_ibv_event */
852 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
853 	}
854 }
855 
856 static void
857 nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
858 {
859 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
860 	struct ibv_recv_wr		*bad_recv_wr = NULL;
861 	int				rc;
862 
863 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
864 
865 	if (rqpair->qd != 0) {
866 		struct spdk_nvmf_qpair *qpair = &rqpair->qpair;
867 		struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(qpair->transport,
868 				struct spdk_nvmf_rdma_transport, transport);
869 		struct spdk_nvmf_rdma_request *req;
870 		uint32_t i, max_req_count = 0;
871 
872 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
873 
874 		if (rqpair->srq == NULL) {
875 			nvmf_rdma_dump_qpair_contents(rqpair);
876 			max_req_count = rqpair->max_queue_depth;
877 		} else if (rqpair->poller && rqpair->resources) {
878 			max_req_count = rqpair->poller->max_srq_depth;
879 		}
880 
881 		SPDK_DEBUGLOG(rdma, "Release incomplete requests\n");
882 		for (i = 0; i < max_req_count; i++) {
883 			req = &rqpair->resources->reqs[i];
884 			if (req->req.qpair == qpair && req->state != RDMA_REQUEST_STATE_FREE) {
885 				/* nvmf_rdma_request_process checks qpair ibv and internal state
886 				 * and completes a request */
887 				nvmf_rdma_request_process(rtransport, req);
888 			}
889 		}
890 		assert(rqpair->qd == 0);
891 	}
892 
893 	if (rqpair->poller) {
894 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
895 
896 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
897 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
898 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
899 				if (rqpair == rdma_recv->qpair) {
900 					STAILQ_REMOVE(&rqpair->resources->incoming_queue, rdma_recv, spdk_nvmf_rdma_recv, link);
901 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
902 					if (rc) {
903 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
904 					}
905 				}
906 			}
907 		}
908 	}
909 
910 	if (rqpair->cm_id) {
911 		if (rqpair->rdma_qp != NULL) {
912 			spdk_rdma_qp_destroy(rqpair->rdma_qp);
913 			rqpair->rdma_qp = NULL;
914 		}
915 		rdma_destroy_id(rqpair->cm_id);
916 
917 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
918 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
919 		}
920 	}
921 
922 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
923 		nvmf_rdma_resources_destroy(rqpair->resources);
924 	}
925 
926 	nvmf_rdma_qpair_clean_ibv_events(rqpair);
927 
928 	if (rqpair->destruct_channel) {
929 		spdk_put_io_channel(rqpair->destruct_channel);
930 		rqpair->destruct_channel = NULL;
931 	}
932 
933 	free(rqpair);
934 }
935 
936 static int
937 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
938 {
939 	struct spdk_nvmf_rdma_poller	*rpoller;
940 	int				rc, num_cqe, required_num_wr;
941 
942 	/* Enlarge CQ size dynamically */
943 	rpoller = rqpair->poller;
944 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
945 	num_cqe = rpoller->num_cqe;
946 	if (num_cqe < required_num_wr) {
947 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
948 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
949 	}
950 
951 	if (rpoller->num_cqe != num_cqe) {
952 		if (required_num_wr > device->attr.max_cqe) {
953 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
954 				    required_num_wr, device->attr.max_cqe);
955 			return -1;
956 		}
957 
958 		SPDK_DEBUGLOG(rdma, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
959 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
960 		if (rc) {
961 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
962 			return -1;
963 		}
964 
965 		rpoller->num_cqe = num_cqe;
966 	}
967 
968 	rpoller->required_num_wr = required_num_wr;
969 	return 0;
970 }
971 
972 static int
973 nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
974 {
975 	struct spdk_nvmf_rdma_qpair		*rqpair;
976 	struct spdk_nvmf_rdma_transport		*rtransport;
977 	struct spdk_nvmf_transport		*transport;
978 	struct spdk_nvmf_rdma_resource_opts	opts;
979 	struct spdk_nvmf_rdma_device		*device;
980 	struct spdk_rdma_qp_init_attr		qp_init_attr = {};
981 
982 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
983 	device = rqpair->device;
984 
985 	qp_init_attr.qp_context	= rqpair;
986 	qp_init_attr.pd		= device->pd;
987 	qp_init_attr.send_cq	= rqpair->poller->cq;
988 	qp_init_attr.recv_cq	= rqpair->poller->cq;
989 
990 	if (rqpair->srq) {
991 		qp_init_attr.srq		= rqpair->srq;
992 	} else {
993 		qp_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth;
994 	}
995 
996 	/* SEND, READ, and WRITE operations */
997 	qp_init_attr.cap.max_send_wr	= (uint32_t)rqpair->max_queue_depth * 2;
998 	qp_init_attr.cap.max_send_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
999 	qp_init_attr.cap.max_recv_sge	= spdk_min((uint32_t)device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1000 
1001 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1002 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1003 		goto error;
1004 	}
1005 
1006 	rqpair->rdma_qp = spdk_rdma_qp_create(rqpair->cm_id, &qp_init_attr);
1007 	if (!rqpair->rdma_qp) {
1008 		goto error;
1009 	}
1010 
1011 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),
1012 					  qp_init_attr.cap.max_send_wr);
1013 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
1014 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, qp_init_attr.cap.max_recv_sge);
1015 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1016 	SPDK_DEBUGLOG(rdma, "New RDMA Connection: %p\n", qpair);
1017 
1018 	if (rqpair->poller->srq == NULL) {
1019 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1020 		transport = &rtransport->transport;
1021 
1022 		opts.qp = rqpair->rdma_qp->qp;
1023 		opts.pd = rqpair->cm_id->pd;
1024 		opts.qpair = rqpair;
1025 		opts.shared = false;
1026 		opts.max_queue_depth = rqpair->max_queue_depth;
1027 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1028 
1029 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1030 
1031 		if (!rqpair->resources) {
1032 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1033 			rdma_destroy_qp(rqpair->cm_id);
1034 			goto error;
1035 		}
1036 	} else {
1037 		rqpair->resources = rqpair->poller->resources;
1038 	}
1039 
1040 	rqpair->current_recv_depth = 0;
1041 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1042 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1043 
1044 	return 0;
1045 
1046 error:
1047 	rdma_destroy_id(rqpair->cm_id);
1048 	rqpair->cm_id = NULL;
1049 	return -1;
1050 }
1051 
1052 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1053 /* This function accepts either a single wr or the first wr in a linked list. */
1054 static void
1055 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1056 {
1057 	struct ibv_recv_wr *last;
1058 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1059 			struct spdk_nvmf_rdma_transport, transport);
1060 
1061 	last = first;
1062 	while (last->next != NULL) {
1063 		last = last->next;
1064 	}
1065 
1066 	if (rqpair->resources->recvs_to_post.first == NULL) {
1067 		rqpair->resources->recvs_to_post.first = first;
1068 		rqpair->resources->recvs_to_post.last = last;
1069 		if (rqpair->srq == NULL) {
1070 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1071 		}
1072 	} else {
1073 		rqpair->resources->recvs_to_post.last->next = first;
1074 		rqpair->resources->recvs_to_post.last = last;
1075 	}
1076 
1077 	if (rtransport->rdma_opts.no_wr_batching) {
1078 		_poller_submit_recvs(rtransport, rqpair->poller);
1079 	}
1080 }
1081 
1082 static int
1083 request_transfer_in(struct spdk_nvmf_request *req)
1084 {
1085 	struct spdk_nvmf_rdma_request	*rdma_req;
1086 	struct spdk_nvmf_qpair		*qpair;
1087 	struct spdk_nvmf_rdma_qpair	*rqpair;
1088 	struct spdk_nvmf_rdma_transport *rtransport;
1089 
1090 	qpair = req->qpair;
1091 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1092 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1093 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1094 				      struct spdk_nvmf_rdma_transport, transport);
1095 
1096 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1097 	assert(rdma_req != NULL);
1098 
1099 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, &rdma_req->data.wr)) {
1100 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1101 	}
1102 	if (rtransport->rdma_opts.no_wr_batching) {
1103 		_poller_submit_sends(rtransport, rqpair->poller);
1104 	}
1105 
1106 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1107 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1108 	return 0;
1109 }
1110 
1111 static int
1112 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1113 {
1114 	int				num_outstanding_data_wr = 0;
1115 	struct spdk_nvmf_rdma_request	*rdma_req;
1116 	struct spdk_nvmf_qpair		*qpair;
1117 	struct spdk_nvmf_rdma_qpair	*rqpair;
1118 	struct spdk_nvme_cpl		*rsp;
1119 	struct ibv_send_wr		*first = NULL;
1120 	struct spdk_nvmf_rdma_transport *rtransport;
1121 
1122 	*data_posted = 0;
1123 	qpair = req->qpair;
1124 	rsp = &req->rsp->nvme_cpl;
1125 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1126 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1127 	rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
1128 				      struct spdk_nvmf_rdma_transport, transport);
1129 
1130 	/* Advance our sq_head pointer */
1131 	if (qpair->sq_head == qpair->sq_head_max) {
1132 		qpair->sq_head = 0;
1133 	} else {
1134 		qpair->sq_head++;
1135 	}
1136 	rsp->sqhd = qpair->sq_head;
1137 
1138 	/* queue the capsule for the recv buffer */
1139 	assert(rdma_req->recv != NULL);
1140 
1141 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1142 
1143 	rdma_req->recv = NULL;
1144 	assert(rqpair->current_recv_depth > 0);
1145 	rqpair->current_recv_depth--;
1146 
1147 	/* Build the response which consists of optional
1148 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1149 	 * containing the response.
1150 	 */
1151 	first = &rdma_req->rsp.wr;
1152 
1153 	if (rsp->status.sc != SPDK_NVME_SC_SUCCESS) {
1154 		/* On failure, data was not read from the controller. So clear the
1155 		 * number of outstanding data WRs to zero.
1156 		 */
1157 		rdma_req->num_outstanding_data_wr = 0;
1158 	} else if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1159 		first = &rdma_req->data.wr;
1160 		*data_posted = 1;
1161 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1162 	}
1163 	if (spdk_rdma_qp_queue_send_wrs(rqpair->rdma_qp, first)) {
1164 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1165 	}
1166 	if (rtransport->rdma_opts.no_wr_batching) {
1167 		_poller_submit_sends(rtransport, rqpair->poller);
1168 	}
1169 
1170 	/* +1 for the rsp wr */
1171 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1172 
1173 	return 0;
1174 }
1175 
1176 static int
1177 nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1178 {
1179 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1180 	struct rdma_conn_param				ctrlr_event_data = {};
1181 	int						rc;
1182 
1183 	accept_data.recfmt = 0;
1184 	accept_data.crqsize = rqpair->max_queue_depth;
1185 
1186 	ctrlr_event_data.private_data = &accept_data;
1187 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1188 	if (id->ps == RDMA_PS_TCP) {
1189 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1190 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1191 	}
1192 
1193 	/* Configure infinite retries for the initiator side qpair.
1194 	 * When using a shared receive queue on the target side,
1195 	 * we need to pass this value to the initiator to prevent the
1196 	 * initiator side NIC from completing SEND requests back to the
1197 	 * initiator with status rnr_retry_count_exceeded. */
1198 	if (rqpair->srq != NULL) {
1199 		ctrlr_event_data.rnr_retry_count = 0x7;
1200 	}
1201 
1202 	/* When qpair is created without use of rdma cm API, an additional
1203 	 * information must be provided to initiator in the connection response:
1204 	 * whether qpair is using SRQ and its qp_num
1205 	 * Fields below are ignored by rdma cm if qpair has been
1206 	 * created using rdma cm API. */
1207 	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;
1208 	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;
1209 
1210 	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);
1211 	if (rc) {
1212 		SPDK_ERRLOG("Error %d on spdk_rdma_qp_accept\n", errno);
1213 	} else {
1214 		SPDK_DEBUGLOG(rdma, "Sent back the accept\n");
1215 	}
1216 
1217 	return rc;
1218 }
1219 
1220 static void
1221 nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1222 {
1223 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1224 
1225 	rej_data.recfmt = 0;
1226 	rej_data.sts = error;
1227 
1228 	rdma_reject(id, &rej_data, sizeof(rej_data));
1229 }
1230 
1231 static int
1232 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event)
1233 {
1234 	struct spdk_nvmf_rdma_transport *rtransport;
1235 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1236 	struct spdk_nvmf_rdma_port	*port;
1237 	struct rdma_conn_param		*rdma_param = NULL;
1238 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1239 	uint16_t			max_queue_depth;
1240 	uint16_t			max_read_depth;
1241 
1242 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1243 
1244 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1245 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1246 
1247 	rdma_param = &event->param.conn;
1248 	if (rdma_param->private_data == NULL ||
1249 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1250 		SPDK_ERRLOG("connect request: no private data provided\n");
1251 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1252 		return -1;
1253 	}
1254 
1255 	private_data = rdma_param->private_data;
1256 	if (private_data->recfmt != 0) {
1257 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1258 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1259 		return -1;
1260 	}
1261 
1262 	SPDK_DEBUGLOG(rdma, "Connect Recv on fabric intf name %s, dev_name %s\n",
1263 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1264 
1265 	port = event->listen_id->context;
1266 	SPDK_DEBUGLOG(rdma, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1267 		      event->listen_id, event->listen_id->verbs, port);
1268 
1269 	/* Figure out the supported queue depth. This is a multi-step process
1270 	 * that takes into account hardware maximums, host provided values,
1271 	 * and our target's internal memory limits */
1272 
1273 	SPDK_DEBUGLOG(rdma, "Calculating Queue Depth\n");
1274 
1275 	/* Start with the maximum queue depth allowed by the target */
1276 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1277 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1278 	SPDK_DEBUGLOG(rdma, "Target Max Queue Depth: %d\n",
1279 		      rtransport->transport.opts.max_queue_depth);
1280 
1281 	/* Next check the local NIC's hardware limitations */
1282 	SPDK_DEBUGLOG(rdma,
1283 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1284 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1285 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1286 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1287 
1288 	/* Next check the remote NIC's hardware limitations */
1289 	SPDK_DEBUGLOG(rdma,
1290 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1291 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1292 	if (rdma_param->initiator_depth > 0) {
1293 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1294 	}
1295 
1296 	/* Finally check for the host software requested values, which are
1297 	 * optional. */
1298 	if (rdma_param->private_data != NULL &&
1299 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1300 		SPDK_DEBUGLOG(rdma, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1301 		SPDK_DEBUGLOG(rdma, "Host Send Queue Size: %d\n", private_data->hsqsize);
1302 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1303 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1304 	}
1305 
1306 	SPDK_DEBUGLOG(rdma, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1307 		      max_queue_depth, max_read_depth);
1308 
1309 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1310 	if (rqpair == NULL) {
1311 		SPDK_ERRLOG("Could not allocate new connection.\n");
1312 		nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1313 		return -1;
1314 	}
1315 
1316 	rqpair->device = port->device;
1317 	rqpair->max_queue_depth = max_queue_depth;
1318 	rqpair->max_read_depth = max_read_depth;
1319 	rqpair->cm_id = event->id;
1320 	rqpair->listen_id = event->listen_id;
1321 	rqpair->qpair.transport = transport;
1322 	rqpair->qpair.trid = port->trid;
1323 	STAILQ_INIT(&rqpair->ibv_events);
1324 	/* use qid from the private data to determine the qpair type
1325 	   qid will be set to the appropriate value when the controller is created */
1326 	rqpair->qpair.qid = private_data->qid;
1327 
1328 	event->id->context = &rqpair->qpair;
1329 
1330 	spdk_nvmf_tgt_new_qpair(transport->tgt, &rqpair->qpair);
1331 
1332 	return 0;
1333 }
1334 
1335 static int
1336 nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1337 		     enum spdk_mem_map_notify_action action,
1338 		     void *vaddr, size_t size)
1339 {
1340 	struct ibv_pd *pd = cb_ctx;
1341 	struct ibv_mr *mr;
1342 	int rc;
1343 
1344 	switch (action) {
1345 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1346 		if (!g_nvmf_hooks.get_rkey) {
1347 			mr = ibv_reg_mr(pd, vaddr, size,
1348 					IBV_ACCESS_LOCAL_WRITE |
1349 					IBV_ACCESS_REMOTE_READ |
1350 					IBV_ACCESS_REMOTE_WRITE);
1351 			if (mr == NULL) {
1352 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1353 				return -1;
1354 			} else {
1355 				rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1356 			}
1357 		} else {
1358 			rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1359 							  g_nvmf_hooks.get_rkey(pd, vaddr, size));
1360 		}
1361 		break;
1362 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1363 		if (!g_nvmf_hooks.get_rkey) {
1364 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1365 			if (mr) {
1366 				ibv_dereg_mr(mr);
1367 			}
1368 		}
1369 		rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1370 		break;
1371 	default:
1372 		SPDK_UNREACHABLE();
1373 	}
1374 
1375 	return rc;
1376 }
1377 
1378 static int
1379 nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1380 {
1381 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1382 	return addr_1 == addr_2;
1383 }
1384 
1385 static inline void
1386 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1387 		   enum spdk_nvme_data_transfer xfer)
1388 {
1389 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1390 		wr->opcode = IBV_WR_RDMA_WRITE;
1391 		wr->send_flags = 0;
1392 		wr->next = next;
1393 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1394 		wr->opcode = IBV_WR_RDMA_READ;
1395 		wr->send_flags = IBV_SEND_SIGNALED;
1396 		wr->next = NULL;
1397 	} else {
1398 		assert(0);
1399 	}
1400 }
1401 
1402 static int
1403 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1404 		       struct spdk_nvmf_rdma_request *rdma_req,
1405 		       uint32_t num_sgl_descriptors)
1406 {
1407 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1408 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1409 	uint32_t				i;
1410 
1411 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1412 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1413 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1414 		return -EINVAL;
1415 	}
1416 
1417 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1418 		return -ENOMEM;
1419 	}
1420 
1421 	current_data_wr = &rdma_req->data;
1422 
1423 	for (i = 0; i < num_sgl_descriptors; i++) {
1424 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1425 		current_data_wr->wr.next = &work_requests[i]->wr;
1426 		current_data_wr = work_requests[i];
1427 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1428 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1429 	}
1430 
1431 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1432 
1433 	return 0;
1434 }
1435 
1436 static inline void
1437 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1438 {
1439 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1440 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1441 
1442 	wr->wr.rdma.rkey = sgl->keyed.key;
1443 	wr->wr.rdma.remote_addr = sgl->address;
1444 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1445 }
1446 
1447 static inline void
1448 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1449 {
1450 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1451 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1452 	uint32_t			i;
1453 	int				j;
1454 	uint64_t			remote_addr_offset = 0;
1455 
1456 	for (i = 0; i < num_wrs; ++i) {
1457 		wr->wr.rdma.rkey = sgl->keyed.key;
1458 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1459 		for (j = 0; j < wr->num_sge; ++j) {
1460 			remote_addr_offset += wr->sg_list[j].length;
1461 		}
1462 		wr = wr->next;
1463 	}
1464 }
1465 
1466 /* This function is used in the rare case that we have a buffer split over multiple memory regions. */
1467 static int
1468 nvmf_rdma_replace_buffer(struct spdk_nvmf_rdma_poll_group *rgroup, void **buf)
1469 {
1470 	struct spdk_nvmf_transport_poll_group	*group = &rgroup->group;
1471 	struct spdk_nvmf_transport		*transport = group->transport;
1472 	struct spdk_nvmf_transport_pg_cache_buf	*old_buf;
1473 	void					*new_buf;
1474 
1475 	if (!(STAILQ_EMPTY(&group->buf_cache))) {
1476 		group->buf_cache_count--;
1477 		new_buf = STAILQ_FIRST(&group->buf_cache);
1478 		STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1479 		assert(*buf != NULL);
1480 	} else {
1481 		new_buf = spdk_mempool_get(transport->data_buf_pool);
1482 	}
1483 
1484 	if (*buf == NULL) {
1485 		return -ENOMEM;
1486 	}
1487 
1488 	old_buf = *buf;
1489 	STAILQ_INSERT_HEAD(&rgroup->retired_bufs, old_buf, link);
1490 	*buf = new_buf;
1491 	return 0;
1492 }
1493 
1494 static bool
1495 nvmf_rdma_get_lkey(struct spdk_nvmf_rdma_device *device, struct iovec *iov,
1496 		   uint32_t *_lkey)
1497 {
1498 	uint64_t	translation_len;
1499 	uint32_t	lkey;
1500 
1501 	translation_len = iov->iov_len;
1502 
1503 	if (!g_nvmf_hooks.get_rkey) {
1504 		lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1505 				(uint64_t)iov->iov_base, &translation_len))->lkey;
1506 	} else {
1507 		lkey = spdk_mem_map_translate(device->map,
1508 					      (uint64_t)iov->iov_base, &translation_len);
1509 	}
1510 
1511 	if (spdk_unlikely(translation_len < iov->iov_len)) {
1512 		return false;
1513 	}
1514 
1515 	*_lkey = lkey;
1516 	return true;
1517 }
1518 
1519 static bool
1520 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1521 		      struct iovec *iov, struct ibv_send_wr **_wr,
1522 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1523 		      uint32_t *_num_extra_wrs,
1524 		      const struct spdk_dif_ctx *dif_ctx)
1525 {
1526 	struct ibv_send_wr *wr = *_wr;
1527 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1528 	uint32_t	lkey = 0;
1529 	uint32_t	remaining, data_block_size, md_size, sge_len;
1530 
1531 	if (spdk_unlikely(!nvmf_rdma_get_lkey(device, iov, &lkey))) {
1532 		/* This is a very rare case that can occur when using DPDK version < 19.05 */
1533 		SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions. Removing it from circulation.\n");
1534 		return false;
1535 	}
1536 
1537 	if (spdk_likely(!dif_ctx)) {
1538 		sg_ele->lkey = lkey;
1539 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1540 		sg_ele->length = iov->iov_len;
1541 		wr->num_sge++;
1542 	} else {
1543 		remaining = iov->iov_len - *_offset;
1544 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1545 		md_size = dif_ctx->md_size;
1546 
1547 		while (remaining) {
1548 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1549 				if (*_num_extra_wrs > 0 && wr->next) {
1550 					*_wr = wr->next;
1551 					wr = *_wr;
1552 					wr->num_sge = 0;
1553 					sg_ele = &wr->sg_list[wr->num_sge];
1554 					(*_num_extra_wrs)--;
1555 				} else {
1556 					break;
1557 				}
1558 			}
1559 			sg_ele->lkey = lkey;
1560 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1561 			sge_len = spdk_min(remaining, *_remaining_data_block);
1562 			sg_ele->length = sge_len;
1563 			remaining -= sge_len;
1564 			*_remaining_data_block -= sge_len;
1565 			*_offset += sge_len;
1566 
1567 			sg_ele++;
1568 			wr->num_sge++;
1569 
1570 			if (*_remaining_data_block == 0) {
1571 				/* skip metadata */
1572 				*_offset += md_size;
1573 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1574 				remaining -= spdk_min(remaining, md_size);
1575 				*_remaining_data_block = data_block_size;
1576 			}
1577 
1578 			if (remaining == 0) {
1579 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1580 				   the remaining metadata bits at the beginning of the next buffer */
1581 				*_offset -= iov->iov_len;
1582 			}
1583 		}
1584 	}
1585 
1586 	return true;
1587 }
1588 
1589 static int
1590 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1591 		      struct spdk_nvmf_rdma_device *device,
1592 		      struct spdk_nvmf_rdma_request *rdma_req,
1593 		      struct ibv_send_wr *wr,
1594 		      uint32_t length,
1595 		      uint32_t num_extra_wrs)
1596 {
1597 	struct spdk_nvmf_request *req = &rdma_req->req;
1598 	struct spdk_dif_ctx *dif_ctx = NULL;
1599 	uint32_t remaining_data_block = 0;
1600 	uint32_t offset = 0;
1601 
1602 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1603 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1604 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1605 	}
1606 
1607 	wr->num_sge = 0;
1608 
1609 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1610 		while (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1611 				     &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1612 			if (nvmf_rdma_replace_buffer(rgroup, &req->buffers[rdma_req->iovpos]) == -ENOMEM) {
1613 				return -ENOMEM;
1614 			}
1615 			req->iov[rdma_req->iovpos].iov_base = (void *)((uintptr_t)(req->buffers[rdma_req->iovpos] +
1616 							      NVMF_DATA_BUFFER_MASK) &
1617 							      ~NVMF_DATA_BUFFER_MASK);
1618 		}
1619 
1620 		length -= req->iov[rdma_req->iovpos].iov_len;
1621 		rdma_req->iovpos++;
1622 	}
1623 
1624 	if (length) {
1625 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1626 		return -EINVAL;
1627 	}
1628 
1629 	return 0;
1630 }
1631 
1632 static inline uint32_t
1633 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1634 {
1635 	/* estimate the number of SG entries and WRs needed to process the request */
1636 	uint32_t num_sge = 0;
1637 	uint32_t i;
1638 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1639 
1640 	for (i = 0; i < num_buffers && length > 0; i++) {
1641 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1642 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1643 
1644 		if (num_sge_in_block * block_size > buffer_len) {
1645 			++num_sge_in_block;
1646 		}
1647 		num_sge += num_sge_in_block;
1648 		length -= buffer_len;
1649 	}
1650 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1651 }
1652 
1653 static int
1654 nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1655 			    struct spdk_nvmf_rdma_device *device,
1656 			    struct spdk_nvmf_rdma_request *rdma_req,
1657 			    uint32_t length)
1658 {
1659 	struct spdk_nvmf_rdma_qpair		*rqpair;
1660 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1661 	struct spdk_nvmf_request		*req = &rdma_req->req;
1662 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1663 	int					rc;
1664 	uint32_t				num_wrs = 1;
1665 
1666 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1667 	rgroup = rqpair->poller->group;
1668 
1669 	/* rdma wr specifics */
1670 	nvmf_rdma_setup_request(rdma_req);
1671 
1672 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1673 					   length);
1674 	if (rc != 0) {
1675 		return rc;
1676 	}
1677 
1678 	assert(req->iovcnt <= rqpair->max_send_sge);
1679 
1680 	rdma_req->iovpos = 0;
1681 
1682 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1683 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1684 						 req->dif.dif_ctx.block_size);
1685 		if (num_wrs > 1) {
1686 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1687 			if (rc != 0) {
1688 				goto err_exit;
1689 			}
1690 		}
1691 	}
1692 
1693 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1694 	if (spdk_unlikely(rc != 0)) {
1695 		goto err_exit;
1696 	}
1697 
1698 	if (spdk_unlikely(num_wrs > 1)) {
1699 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1700 	}
1701 
1702 	/* set the number of outstanding data WRs for this request. */
1703 	rdma_req->num_outstanding_data_wr = num_wrs;
1704 
1705 	return rc;
1706 
1707 err_exit:
1708 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1709 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1710 	req->iovcnt = 0;
1711 	return rc;
1712 }
1713 
1714 static int
1715 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1716 				      struct spdk_nvmf_rdma_device *device,
1717 				      struct spdk_nvmf_rdma_request *rdma_req)
1718 {
1719 	struct spdk_nvmf_rdma_qpair		*rqpair;
1720 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1721 	struct ibv_send_wr			*current_wr;
1722 	struct spdk_nvmf_request		*req = &rdma_req->req;
1723 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1724 	uint32_t				num_sgl_descriptors;
1725 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1726 	uint32_t				i;
1727 	int					rc;
1728 
1729 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1730 	rgroup = rqpair->poller->group;
1731 
1732 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1733 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1734 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1735 
1736 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1737 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1738 
1739 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1740 		return -ENOMEM;
1741 	}
1742 
1743 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1744 	for (i = 0; i < num_sgl_descriptors; i++) {
1745 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1746 			lengths[i] = desc->keyed.length;
1747 		} else {
1748 			req->dif.orig_length += desc->keyed.length;
1749 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1750 			req->dif.elba_length += lengths[i];
1751 		}
1752 		desc++;
1753 	}
1754 
1755 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1756 			lengths, num_sgl_descriptors);
1757 	if (rc != 0) {
1758 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1759 		return rc;
1760 	}
1761 
1762 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1763 	current_wr = &rdma_req->data.wr;
1764 	assert(current_wr != NULL);
1765 
1766 	req->length = 0;
1767 	rdma_req->iovpos = 0;
1768 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1769 	for (i = 0; i < num_sgl_descriptors; i++) {
1770 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1771 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1772 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1773 			rc = -EINVAL;
1774 			goto err_exit;
1775 		}
1776 
1777 		current_wr->num_sge = 0;
1778 
1779 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1780 		if (rc != 0) {
1781 			rc = -ENOMEM;
1782 			goto err_exit;
1783 		}
1784 
1785 		req->length += desc->keyed.length;
1786 		current_wr->wr.rdma.rkey = desc->keyed.key;
1787 		current_wr->wr.rdma.remote_addr = desc->address;
1788 		current_wr = current_wr->next;
1789 		desc++;
1790 	}
1791 
1792 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1793 	/* Go back to the last descriptor in the list. */
1794 	desc--;
1795 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1796 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1797 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1798 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1799 		}
1800 	}
1801 #endif
1802 
1803 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1804 
1805 	return 0;
1806 
1807 err_exit:
1808 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1809 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1810 	return rc;
1811 }
1812 
1813 static int
1814 nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1815 			    struct spdk_nvmf_rdma_device *device,
1816 			    struct spdk_nvmf_rdma_request *rdma_req)
1817 {
1818 	struct spdk_nvmf_request		*req = &rdma_req->req;
1819 	struct spdk_nvme_cpl			*rsp;
1820 	struct spdk_nvme_sgl_descriptor		*sgl;
1821 	int					rc;
1822 	uint32_t				length;
1823 
1824 	rsp = &req->rsp->nvme_cpl;
1825 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1826 
1827 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1828 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1829 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1830 
1831 		length = sgl->keyed.length;
1832 		if (length > rtransport->transport.opts.max_io_size) {
1833 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1834 				    length, rtransport->transport.opts.max_io_size);
1835 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1836 			return -1;
1837 		}
1838 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1839 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1840 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1841 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1842 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1843 			}
1844 		}
1845 #endif
1846 
1847 		/* fill request length and populate iovs */
1848 		req->length = length;
1849 
1850 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1851 			req->dif.orig_length = length;
1852 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1853 			req->dif.elba_length = length;
1854 		}
1855 
1856 		rc = nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1857 		if (spdk_unlikely(rc < 0)) {
1858 			if (rc == -EINVAL) {
1859 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1860 				rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1861 				return -1;
1862 			}
1863 			/* No available buffers. Queue this request up. */
1864 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1865 			return 0;
1866 		}
1867 
1868 		/* backward compatible */
1869 		req->data = req->iov[0].iov_base;
1870 
1871 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1872 			      req->iovcnt);
1873 
1874 		return 0;
1875 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1876 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1877 		uint64_t offset = sgl->address;
1878 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1879 
1880 		SPDK_DEBUGLOG(nvmf, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1881 			      offset, sgl->unkeyed.length);
1882 
1883 		if (offset > max_len) {
1884 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1885 				    offset, max_len);
1886 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1887 			return -1;
1888 		}
1889 		max_len -= (uint32_t)offset;
1890 
1891 		if (sgl->unkeyed.length > max_len) {
1892 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1893 				    sgl->unkeyed.length, max_len);
1894 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1895 			return -1;
1896 		}
1897 
1898 		rdma_req->num_outstanding_data_wr = 0;
1899 		req->data = rdma_req->recv->buf + offset;
1900 		req->data_from_pool = false;
1901 		req->length = sgl->unkeyed.length;
1902 
1903 		req->iov[0].iov_base = req->data;
1904 		req->iov[0].iov_len = req->length;
1905 		req->iovcnt = 1;
1906 
1907 		return 0;
1908 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1909 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1910 
1911 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1912 		if (rc == -ENOMEM) {
1913 			SPDK_DEBUGLOG(rdma, "No available large data buffers. Queueing request %p\n", rdma_req);
1914 			return 0;
1915 		} else if (rc == -EINVAL) {
1916 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1917 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1918 			return -1;
1919 		}
1920 
1921 		/* backward compatible */
1922 		req->data = req->iov[0].iov_base;
1923 
1924 		SPDK_DEBUGLOG(rdma, "Request %p took %d buffer/s from central pool\n", rdma_req,
1925 			      req->iovcnt);
1926 
1927 		return 0;
1928 	}
1929 
1930 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1931 		    sgl->generic.type, sgl->generic.subtype);
1932 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1933 	return -1;
1934 }
1935 
1936 static void
1937 _nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1938 			struct spdk_nvmf_rdma_transport	*rtransport)
1939 {
1940 	struct spdk_nvmf_rdma_qpair		*rqpair;
1941 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1942 
1943 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1944 	if (rdma_req->req.data_from_pool) {
1945 		rgroup = rqpair->poller->group;
1946 
1947 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1948 	}
1949 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1950 	rdma_req->req.length = 0;
1951 	rdma_req->req.iovcnt = 0;
1952 	rdma_req->req.data = NULL;
1953 	rdma_req->rsp.wr.next = NULL;
1954 	rdma_req->data.wr.next = NULL;
1955 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
1956 	rqpair->qd--;
1957 
1958 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1959 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1960 }
1961 
1962 bool
1963 nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1964 			  struct spdk_nvmf_rdma_request *rdma_req)
1965 {
1966 	struct spdk_nvmf_rdma_qpair	*rqpair;
1967 	struct spdk_nvmf_rdma_device	*device;
1968 	struct spdk_nvmf_rdma_poll_group *rgroup;
1969 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1970 	int				rc;
1971 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1972 	enum spdk_nvmf_rdma_request_state prev_state;
1973 	bool				progress = false;
1974 	int				data_posted;
1975 	uint32_t			num_blocks;
1976 
1977 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1978 	device = rqpair->device;
1979 	rgroup = rqpair->poller->group;
1980 
1981 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1982 
1983 	/* If the queue pair is in an error state, force the request to the completed state
1984 	 * to release resources. */
1985 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1986 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1987 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1988 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1989 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1990 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1991 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1992 		}
1993 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1994 	}
1995 
1996 	/* The loop here is to allow for several back-to-back state changes. */
1997 	do {
1998 		prev_state = rdma_req->state;
1999 
2000 		SPDK_DEBUGLOG(rdma, "Request %p entering state %d\n", rdma_req, prev_state);
2001 
2002 		switch (rdma_req->state) {
2003 		case RDMA_REQUEST_STATE_FREE:
2004 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
2005 			 * to escape this state. */
2006 			break;
2007 		case RDMA_REQUEST_STATE_NEW:
2008 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
2009 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2010 			rdma_recv = rdma_req->recv;
2011 
2012 			/* The first element of the SGL is the NVMe command */
2013 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
2014 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
2015 
2016 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2017 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2018 				break;
2019 			}
2020 
2021 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
2022 				rdma_req->req.dif.dif_insert_or_strip = true;
2023 			}
2024 
2025 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2026 			rdma_req->rsp.wr.opcode = IBV_WR_SEND;
2027 			rdma_req->rsp.wr.imm_data = 0;
2028 #endif
2029 
2030 			/* The next state transition depends on the data transfer needs of this request. */
2031 			rdma_req->req.xfer = spdk_nvmf_req_get_xfer(&rdma_req->req);
2032 
2033 			if (spdk_unlikely(rdma_req->req.xfer == SPDK_NVME_DATA_BIDIRECTIONAL)) {
2034 				rsp->status.sct = SPDK_NVME_SCT_GENERIC;
2035 				rsp->status.sc = SPDK_NVME_SC_INVALID_OPCODE;
2036 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2037 				SPDK_DEBUGLOG(rdma, "Request %p: invalid xfer type (BIDIRECTIONAL)\n", rdma_req);
2038 				break;
2039 			}
2040 
2041 			/* If no data to transfer, ready to execute. */
2042 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2043 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2044 				break;
2045 			}
2046 
2047 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2048 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2049 			break;
2050 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2051 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2052 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2053 
2054 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2055 
2056 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2057 				/* This request needs to wait in line to obtain a buffer */
2058 				break;
2059 			}
2060 
2061 			/* Try to get a data buffer */
2062 			rc = nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2063 			if (rc < 0) {
2064 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2065 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2066 				break;
2067 			}
2068 
2069 			if (!rdma_req->req.data) {
2070 				/* No buffers available. */
2071 				rgroup->stat.pending_data_buffer++;
2072 				break;
2073 			}
2074 
2075 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2076 
2077 			/* If data is transferring from host to controller and the data didn't
2078 			 * arrive using in capsule data, we need to do a transfer from the host.
2079 			 */
2080 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2081 			    rdma_req->req.data_from_pool) {
2082 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2083 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2084 				break;
2085 			}
2086 
2087 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2088 			break;
2089 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2090 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2091 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2092 
2093 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2094 				/* This request needs to wait in line to perform RDMA */
2095 				break;
2096 			}
2097 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2098 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2099 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2100 				rqpair->poller->stat.pending_rdma_read++;
2101 				break;
2102 			}
2103 
2104 			/* We have already verified that this request is the head of the queue. */
2105 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2106 
2107 			rc = request_transfer_in(&rdma_req->req);
2108 			if (!rc) {
2109 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2110 			} else {
2111 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2112 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2113 			}
2114 			break;
2115 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2116 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2117 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2118 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2119 			 * to escape this state. */
2120 			break;
2121 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2122 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2123 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2124 
2125 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2126 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2127 					/* generate DIF for write operation */
2128 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2129 					assert(num_blocks > 0);
2130 
2131 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2132 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2133 					if (rc != 0) {
2134 						SPDK_ERRLOG("DIF generation failed\n");
2135 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2136 						spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2137 						break;
2138 					}
2139 				}
2140 
2141 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2142 				/* set extended length before IO operation */
2143 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2144 			}
2145 
2146 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2147 			spdk_nvmf_request_exec(&rdma_req->req);
2148 			break;
2149 		case RDMA_REQUEST_STATE_EXECUTING:
2150 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2151 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2152 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2153 			 * to escape this state. */
2154 			break;
2155 		case RDMA_REQUEST_STATE_EXECUTED:
2156 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2157 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2158 			if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
2159 			    rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2160 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2161 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2162 			} else {
2163 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2164 			}
2165 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2166 				/* restore the original length */
2167 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2168 
2169 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2170 					struct spdk_dif_error error_blk;
2171 
2172 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2173 
2174 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2175 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2176 					if (rc) {
2177 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2178 
2179 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2180 							    error_blk.err_offset);
2181 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2182 						rsp->status.sc = nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2183 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2184 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2185 					}
2186 				}
2187 			}
2188 			break;
2189 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2190 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2191 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2192 
2193 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2194 				/* This request needs to wait in line to perform RDMA */
2195 				break;
2196 			}
2197 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2198 			    rqpair->max_send_depth) {
2199 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2200 				 * +1 since each request has an additional wr in the resp. */
2201 				rqpair->poller->stat.pending_rdma_write++;
2202 				break;
2203 			}
2204 
2205 			/* We have already verified that this request is the head of the queue. */
2206 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2207 
2208 			/* The data transfer will be kicked off from
2209 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2210 			 */
2211 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2212 			break;
2213 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2214 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2215 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2216 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2217 			assert(rc == 0); /* No good way to handle this currently */
2218 			if (rc) {
2219 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2220 			} else {
2221 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2222 						  RDMA_REQUEST_STATE_COMPLETING;
2223 			}
2224 			break;
2225 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2226 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2227 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2228 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2229 			 * to escape this state. */
2230 			break;
2231 		case RDMA_REQUEST_STATE_COMPLETING:
2232 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2233 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2234 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2235 			 * to escape this state. */
2236 			break;
2237 		case RDMA_REQUEST_STATE_COMPLETED:
2238 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2239 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2240 
2241 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2242 			_nvmf_rdma_request_free(rdma_req, rtransport);
2243 			break;
2244 		case RDMA_REQUEST_NUM_STATES:
2245 		default:
2246 			assert(0);
2247 			break;
2248 		}
2249 
2250 		if (rdma_req->state != prev_state) {
2251 			progress = true;
2252 		}
2253 	} while (rdma_req->state != prev_state);
2254 
2255 	return progress;
2256 }
2257 
2258 /* Public API callbacks begin here */
2259 
2260 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2261 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2262 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2263 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2264 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2265 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2266 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2267 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2268 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2269 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2270 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2271 #define SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG 100
2272 #define SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC 1
2273 #define SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING false
2274 
2275 static void
2276 nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2277 {
2278 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2279 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2280 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2281 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2282 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2283 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2284 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2285 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2286 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2287 	opts->abort_timeout_sec =	SPDK_NVMF_RDMA_DEFAULT_ABORT_TIMEOUT_SEC;
2288 	opts->transport_specific =      NULL;
2289 }
2290 
2291 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2292 	.notify_cb = nvmf_rdma_mem_notify,
2293 	.are_contiguous = nvmf_rdma_check_contiguous_entries
2294 };
2295 
2296 static int nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2297 			     spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg);
2298 
2299 static inline bool
2300 nvmf_rdma_is_rxe_device(struct spdk_nvmf_rdma_device *device)
2301 {
2302 	return device->attr.vendor_id == NVMF_RXE_VENDOR_ID_OLD ||
2303 	       device->attr.vendor_id == NVMF_RXE_VENDOR_ID_NEW;
2304 }
2305 
2306 static struct spdk_nvmf_transport *
2307 nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2308 {
2309 	int rc;
2310 	struct spdk_nvmf_rdma_transport *rtransport;
2311 	struct spdk_nvmf_rdma_device	*device, *tmp;
2312 	struct ibv_context		**contexts;
2313 	uint32_t			i;
2314 	int				flag;
2315 	uint32_t			sge_count;
2316 	uint32_t			min_shared_buffers;
2317 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2318 	pthread_mutexattr_t		attr;
2319 
2320 	rtransport = calloc(1, sizeof(*rtransport));
2321 	if (!rtransport) {
2322 		return NULL;
2323 	}
2324 
2325 	if (pthread_mutexattr_init(&attr)) {
2326 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2327 		free(rtransport);
2328 		return NULL;
2329 	}
2330 
2331 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2332 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2333 		pthread_mutexattr_destroy(&attr);
2334 		free(rtransport);
2335 		return NULL;
2336 	}
2337 
2338 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2339 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2340 		pthread_mutexattr_destroy(&attr);
2341 		free(rtransport);
2342 		return NULL;
2343 	}
2344 
2345 	pthread_mutexattr_destroy(&attr);
2346 
2347 	TAILQ_INIT(&rtransport->devices);
2348 	TAILQ_INIT(&rtransport->ports);
2349 	TAILQ_INIT(&rtransport->poll_groups);
2350 
2351 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2352 	rtransport->rdma_opts.max_srq_depth = SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2353 	rtransport->rdma_opts.no_srq = SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2354 	rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2355 	rtransport->rdma_opts.no_wr_batching = SPDK_NVMF_RDMA_DEFAULT_NO_WR_BATCHING;
2356 	if (opts->transport_specific != NULL &&
2357 	    spdk_json_decode_object_relaxed(opts->transport_specific, rdma_transport_opts_decoder,
2358 					    SPDK_COUNTOF(rdma_transport_opts_decoder),
2359 					    &rtransport->rdma_opts)) {
2360 		SPDK_ERRLOG("spdk_json_decode_object_relaxed failed\n");
2361 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2362 		return NULL;
2363 	}
2364 
2365 	SPDK_INFOLOG(rdma, "*** RDMA Transport Init ***\n"
2366 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2367 		     "  max_io_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2368 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2369 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d,"
2370 		     "  acceptor_backlog=%d, no_wr_batching=%d abort_timeout_sec=%d\n",
2371 		     opts->max_queue_depth,
2372 		     opts->max_io_size,
2373 		     opts->max_qpairs_per_ctrlr - 1,
2374 		     opts->io_unit_size,
2375 		     opts->in_capsule_data_size,
2376 		     opts->max_aq_depth,
2377 		     opts->num_shared_buffers,
2378 		     rtransport->rdma_opts.max_srq_depth,
2379 		     rtransport->rdma_opts.no_srq,
2380 		     rtransport->rdma_opts.acceptor_backlog,
2381 		     rtransport->rdma_opts.no_wr_batching,
2382 		     opts->abort_timeout_sec);
2383 
2384 	/* I/O unit size cannot be larger than max I/O size */
2385 	if (opts->io_unit_size > opts->max_io_size) {
2386 		opts->io_unit_size = opts->max_io_size;
2387 	}
2388 
2389 	if (rtransport->rdma_opts.acceptor_backlog <= 0) {
2390 		SPDK_ERRLOG("The acceptor backlog cannot be less than 1, setting to the default value of (%d).\n",
2391 			    SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG);
2392 		rtransport->rdma_opts.acceptor_backlog = SPDK_NVMF_RDMA_ACCEPTOR_BACKLOG;
2393 	}
2394 
2395 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2396 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2397 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2398 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2399 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2400 		return NULL;
2401 	}
2402 
2403 	min_shared_buffers = spdk_env_get_core_count() * opts->buf_cache_size;
2404 	if (min_shared_buffers > opts->num_shared_buffers) {
2405 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2406 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2407 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2408 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2409 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2410 		return NULL;
2411 	}
2412 
2413 	sge_count = opts->max_io_size / opts->io_unit_size;
2414 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2415 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2416 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2417 		return NULL;
2418 	}
2419 
2420 	rtransport->event_channel = rdma_create_event_channel();
2421 	if (rtransport->event_channel == NULL) {
2422 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2423 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2424 		return NULL;
2425 	}
2426 
2427 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2428 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2429 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2430 			    rtransport->event_channel->fd, spdk_strerror(errno));
2431 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2432 		return NULL;
2433 	}
2434 
2435 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2436 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2437 				   sizeof(struct spdk_nvmf_rdma_request_data),
2438 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2439 				   SPDK_ENV_SOCKET_ID_ANY);
2440 	if (!rtransport->data_wr_pool) {
2441 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2442 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2443 		return NULL;
2444 	}
2445 
2446 	contexts = rdma_get_devices(NULL);
2447 	if (contexts == NULL) {
2448 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2449 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2450 		return NULL;
2451 	}
2452 
2453 	i = 0;
2454 	rc = 0;
2455 	while (contexts[i] != NULL) {
2456 		device = calloc(1, sizeof(*device));
2457 		if (!device) {
2458 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2459 			rc = -ENOMEM;
2460 			break;
2461 		}
2462 		device->context = contexts[i];
2463 		rc = ibv_query_device(device->context, &device->attr);
2464 		if (rc < 0) {
2465 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2466 			free(device);
2467 			break;
2468 
2469 		}
2470 
2471 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2472 
2473 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2474 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2475 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2476 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2477 		}
2478 
2479 		/**
2480 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2481 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2482 		 * but incorrectly reports that it does. There are changes making their way
2483 		 * through the kernel now that will enable this feature. When they are merged,
2484 		 * we can conditionally enable this feature.
2485 		 *
2486 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2487 		 */
2488 		if (nvmf_rdma_is_rxe_device(device)) {
2489 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2490 		}
2491 #endif
2492 
2493 		/* set up device context async ev fd as NON_BLOCKING */
2494 		flag = fcntl(device->context->async_fd, F_GETFL);
2495 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2496 		if (rc < 0) {
2497 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2498 			free(device);
2499 			break;
2500 		}
2501 
2502 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2503 		i++;
2504 
2505 		if (g_nvmf_hooks.get_ibv_pd) {
2506 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2507 		} else {
2508 			device->pd = ibv_alloc_pd(device->context);
2509 		}
2510 
2511 		if (!device->pd) {
2512 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2513 			rc = -ENOMEM;
2514 			break;
2515 		}
2516 
2517 		assert(device->map == NULL);
2518 
2519 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2520 		if (!device->map) {
2521 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2522 			rc = -ENOMEM;
2523 			break;
2524 		}
2525 
2526 		assert(device->map != NULL);
2527 		assert(device->pd != NULL);
2528 	}
2529 	rdma_free_devices(contexts);
2530 
2531 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2532 		/* divide and round up. */
2533 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2534 
2535 		/* round up to the nearest 4k. */
2536 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2537 
2538 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2539 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2540 			       opts->io_unit_size);
2541 	}
2542 
2543 	if (rc < 0) {
2544 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2545 		return NULL;
2546 	}
2547 
2548 	/* Set up poll descriptor array to monitor events from RDMA and IB
2549 	 * in a single poll syscall
2550 	 */
2551 	rtransport->npoll_fds = i + 1;
2552 	i = 0;
2553 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2554 	if (rtransport->poll_fds == NULL) {
2555 		SPDK_ERRLOG("poll_fds allocation failed\n");
2556 		nvmf_rdma_destroy(&rtransport->transport, NULL, NULL);
2557 		return NULL;
2558 	}
2559 
2560 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2561 	rtransport->poll_fds[i++].events = POLLIN;
2562 
2563 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2564 		rtransport->poll_fds[i].fd = device->context->async_fd;
2565 		rtransport->poll_fds[i++].events = POLLIN;
2566 	}
2567 
2568 	return &rtransport->transport;
2569 }
2570 
2571 static void
2572 nvmf_rdma_dump_opts(struct spdk_nvmf_transport *transport, struct spdk_json_write_ctx *w)
2573 {
2574 	struct spdk_nvmf_rdma_transport	*rtransport;
2575 	assert(w != NULL);
2576 
2577 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2578 	spdk_json_write_named_uint32(w, "max_srq_depth", rtransport->rdma_opts.max_srq_depth);
2579 	spdk_json_write_named_bool(w, "no_srq", rtransport->rdma_opts.no_srq);
2580 	spdk_json_write_named_int32(w, "acceptor_backlog", rtransport->rdma_opts.acceptor_backlog);
2581 	spdk_json_write_named_bool(w, "no_wr_batching", rtransport->rdma_opts.no_wr_batching);
2582 }
2583 
2584 static int
2585 nvmf_rdma_destroy(struct spdk_nvmf_transport *transport,
2586 		  spdk_nvmf_transport_destroy_done_cb cb_fn, void *cb_arg)
2587 {
2588 	struct spdk_nvmf_rdma_transport	*rtransport;
2589 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2590 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2591 
2592 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2593 
2594 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2595 		TAILQ_REMOVE(&rtransport->ports, port, link);
2596 		rdma_destroy_id(port->id);
2597 		free(port);
2598 	}
2599 
2600 	if (rtransport->poll_fds != NULL) {
2601 		free(rtransport->poll_fds);
2602 	}
2603 
2604 	if (rtransport->event_channel != NULL) {
2605 		rdma_destroy_event_channel(rtransport->event_channel);
2606 	}
2607 
2608 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2609 		TAILQ_REMOVE(&rtransport->devices, device, link);
2610 		if (device->map) {
2611 			spdk_mem_map_free(&device->map);
2612 		}
2613 		if (device->pd) {
2614 			if (!g_nvmf_hooks.get_ibv_pd) {
2615 				ibv_dealloc_pd(device->pd);
2616 			}
2617 		}
2618 		free(device);
2619 	}
2620 
2621 	if (rtransport->data_wr_pool != NULL) {
2622 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2623 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2624 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2625 				    spdk_mempool_count(rtransport->data_wr_pool),
2626 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2627 		}
2628 	}
2629 
2630 	spdk_mempool_free(rtransport->data_wr_pool);
2631 
2632 	pthread_mutex_destroy(&rtransport->lock);
2633 	free(rtransport);
2634 
2635 	if (cb_fn) {
2636 		cb_fn(cb_arg);
2637 	}
2638 	return 0;
2639 }
2640 
2641 static int
2642 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2643 			  struct spdk_nvme_transport_id *trid,
2644 			  bool peer);
2645 
2646 static int
2647 nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2648 		 const struct spdk_nvme_transport_id *trid)
2649 {
2650 	struct spdk_nvmf_rdma_transport	*rtransport;
2651 	struct spdk_nvmf_rdma_device	*device;
2652 	struct spdk_nvmf_rdma_port	*port;
2653 	struct addrinfo			*res;
2654 	struct addrinfo			hints;
2655 	int				family;
2656 	int				rc;
2657 
2658 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2659 	assert(rtransport->event_channel != NULL);
2660 
2661 	pthread_mutex_lock(&rtransport->lock);
2662 	port = calloc(1, sizeof(*port));
2663 	if (!port) {
2664 		SPDK_ERRLOG("Port allocation failed\n");
2665 		pthread_mutex_unlock(&rtransport->lock);
2666 		return -ENOMEM;
2667 	}
2668 
2669 	port->trid = trid;
2670 
2671 	switch (trid->adrfam) {
2672 	case SPDK_NVMF_ADRFAM_IPV4:
2673 		family = AF_INET;
2674 		break;
2675 	case SPDK_NVMF_ADRFAM_IPV6:
2676 		family = AF_INET6;
2677 		break;
2678 	default:
2679 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", trid->adrfam);
2680 		free(port);
2681 		pthread_mutex_unlock(&rtransport->lock);
2682 		return -EINVAL;
2683 	}
2684 
2685 	memset(&hints, 0, sizeof(hints));
2686 	hints.ai_family = family;
2687 	hints.ai_flags = AI_NUMERICSERV;
2688 	hints.ai_socktype = SOCK_STREAM;
2689 	hints.ai_protocol = 0;
2690 
2691 	rc = getaddrinfo(trid->traddr, trid->trsvcid, &hints, &res);
2692 	if (rc) {
2693 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2694 		free(port);
2695 		pthread_mutex_unlock(&rtransport->lock);
2696 		return -EINVAL;
2697 	}
2698 
2699 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2700 	if (rc < 0) {
2701 		SPDK_ERRLOG("rdma_create_id() failed\n");
2702 		freeaddrinfo(res);
2703 		free(port);
2704 		pthread_mutex_unlock(&rtransport->lock);
2705 		return rc;
2706 	}
2707 
2708 	rc = rdma_bind_addr(port->id, res->ai_addr);
2709 	freeaddrinfo(res);
2710 
2711 	if (rc < 0) {
2712 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2713 		rdma_destroy_id(port->id);
2714 		free(port);
2715 		pthread_mutex_unlock(&rtransport->lock);
2716 		return rc;
2717 	}
2718 
2719 	if (!port->id->verbs) {
2720 		SPDK_ERRLOG("ibv_context is null\n");
2721 		rdma_destroy_id(port->id);
2722 		free(port);
2723 		pthread_mutex_unlock(&rtransport->lock);
2724 		return -1;
2725 	}
2726 
2727 	rc = rdma_listen(port->id, rtransport->rdma_opts.acceptor_backlog);
2728 	if (rc < 0) {
2729 		SPDK_ERRLOG("rdma_listen() failed\n");
2730 		rdma_destroy_id(port->id);
2731 		free(port);
2732 		pthread_mutex_unlock(&rtransport->lock);
2733 		return rc;
2734 	}
2735 
2736 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2737 		if (device->context == port->id->verbs) {
2738 			port->device = device;
2739 			break;
2740 		}
2741 	}
2742 	if (!port->device) {
2743 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2744 			    port->id->verbs);
2745 		rdma_destroy_id(port->id);
2746 		free(port);
2747 		pthread_mutex_unlock(&rtransport->lock);
2748 		return -EINVAL;
2749 	}
2750 
2751 	SPDK_NOTICELOG("*** NVMe/RDMA Target Listening on %s port %s ***\n",
2752 		       trid->traddr, trid->trsvcid);
2753 
2754 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2755 	pthread_mutex_unlock(&rtransport->lock);
2756 	return 0;
2757 }
2758 
2759 static void
2760 nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2761 		      const struct spdk_nvme_transport_id *trid)
2762 {
2763 	struct spdk_nvmf_rdma_transport *rtransport;
2764 	struct spdk_nvmf_rdma_port *port, *tmp;
2765 
2766 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2767 
2768 	pthread_mutex_lock(&rtransport->lock);
2769 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2770 		if (spdk_nvme_transport_id_compare(port->trid, trid) == 0) {
2771 			TAILQ_REMOVE(&rtransport->ports, port, link);
2772 			rdma_destroy_id(port->id);
2773 			free(port);
2774 			break;
2775 		}
2776 	}
2777 
2778 	pthread_mutex_unlock(&rtransport->lock);
2779 }
2780 
2781 static void
2782 nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2783 				struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2784 {
2785 	struct spdk_nvmf_request *req, *tmp;
2786 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2787 	struct spdk_nvmf_rdma_resources *resources;
2788 
2789 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2790 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2791 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2792 			break;
2793 		}
2794 	}
2795 
2796 	/* Then RDMA writes since reads have stronger restrictions than writes */
2797 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2798 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2799 			break;
2800 		}
2801 	}
2802 
2803 	/* The second highest priority is I/O waiting on memory buffers. */
2804 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2805 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2806 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2807 			break;
2808 		}
2809 	}
2810 
2811 	resources = rqpair->resources;
2812 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2813 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2814 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2815 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2816 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2817 
2818 		if (rqpair->srq != NULL) {
2819 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2820 			rdma_req->recv->qpair->qd++;
2821 		} else {
2822 			rqpair->qd++;
2823 		}
2824 
2825 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2826 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2827 		if (nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2828 			break;
2829 		}
2830 	}
2831 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2832 		rqpair->poller->stat.pending_free_request++;
2833 	}
2834 }
2835 
2836 static void
2837 nvmf_rdma_destroy_drained_qpair(struct spdk_nvmf_rdma_qpair *rqpair)
2838 {
2839 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2840 			struct spdk_nvmf_rdma_transport, transport);
2841 
2842 	nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2843 
2844 	/* nvmr_rdma_close_qpair is not called */
2845 	if (!rqpair->to_close) {
2846 		return;
2847 	}
2848 
2849 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2850 	if (rqpair->current_send_depth != 0) {
2851 		return;
2852 	}
2853 
2854 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2855 		return;
2856 	}
2857 
2858 	/* Judge whether the device is emulated by Software RoCE.
2859 	 * And it will not send last_wqe event
2860 	 */
2861 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false &&
2862 	    !nvmf_rdma_is_rxe_device(rqpair->device)) {
2863 		return;
2864 	}
2865 
2866 	assert(rqpair->qpair.state == SPDK_NVMF_QPAIR_ERROR);
2867 
2868 	nvmf_rdma_qpair_destroy(rqpair);
2869 }
2870 
2871 static int
2872 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2873 {
2874 	struct spdk_nvmf_qpair		*qpair;
2875 	struct spdk_nvmf_rdma_qpair	*rqpair;
2876 
2877 	if (evt->id == NULL) {
2878 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2879 		return -1;
2880 	}
2881 
2882 	qpair = evt->id->context;
2883 	if (qpair == NULL) {
2884 		SPDK_ERRLOG("disconnect request: no active connection\n");
2885 		return -1;
2886 	}
2887 
2888 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2889 
2890 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2891 
2892 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2893 
2894 	return 0;
2895 }
2896 
2897 #ifdef DEBUG
2898 static const char *CM_EVENT_STR[] = {
2899 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2900 	"RDMA_CM_EVENT_ADDR_ERROR",
2901 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2902 	"RDMA_CM_EVENT_ROUTE_ERROR",
2903 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2904 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2905 	"RDMA_CM_EVENT_CONNECT_ERROR",
2906 	"RDMA_CM_EVENT_UNREACHABLE",
2907 	"RDMA_CM_EVENT_REJECTED",
2908 	"RDMA_CM_EVENT_ESTABLISHED",
2909 	"RDMA_CM_EVENT_DISCONNECTED",
2910 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2911 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2912 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2913 	"RDMA_CM_EVENT_ADDR_CHANGE",
2914 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2915 };
2916 #endif /* DEBUG */
2917 
2918 static void
2919 nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport,
2920 				    struct spdk_nvmf_rdma_port *port)
2921 {
2922 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2923 	struct spdk_nvmf_rdma_poller		*rpoller;
2924 	struct spdk_nvmf_rdma_qpair		*rqpair;
2925 
2926 	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {
2927 		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2928 			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
2929 				if (rqpair->listen_id == port->id) {
2930 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2931 				}
2932 			}
2933 		}
2934 	}
2935 }
2936 
2937 static bool
2938 nvmf_rdma_handle_cm_event_addr_change(struct spdk_nvmf_transport *transport,
2939 				      struct rdma_cm_event *event)
2940 {
2941 	const struct spdk_nvme_transport_id	*trid;
2942 	struct spdk_nvmf_rdma_port		*port;
2943 	struct spdk_nvmf_rdma_transport		*rtransport;
2944 	bool					event_acked = false;
2945 
2946 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2947 	TAILQ_FOREACH(port, &rtransport->ports, link) {
2948 		if (port->id == event->id) {
2949 			SPDK_ERRLOG("ADDR_CHANGE: IP %s:%s migrated\n", port->trid->traddr, port->trid->trsvcid);
2950 			rdma_ack_cm_event(event);
2951 			event_acked = true;
2952 			trid = port->trid;
2953 			break;
2954 		}
2955 	}
2956 
2957 	if (event_acked) {
2958 		nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2959 
2960 		nvmf_rdma_stop_listen(transport, trid);
2961 		nvmf_rdma_listen(transport, trid);
2962 	}
2963 
2964 	return event_acked;
2965 }
2966 
2967 static void
2968 nvmf_rdma_handle_cm_event_port_removal(struct spdk_nvmf_transport *transport,
2969 				       struct rdma_cm_event *event)
2970 {
2971 	struct spdk_nvmf_rdma_port		*port;
2972 	struct spdk_nvmf_rdma_transport		*rtransport;
2973 
2974 	port = event->id->context;
2975 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2976 
2977 	SPDK_NOTICELOG("Port %s:%s is being removed\n", port->trid->traddr, port->trid->trsvcid);
2978 
2979 	nvmf_rdma_disconnect_qpairs_on_port(rtransport, port);
2980 
2981 	rdma_ack_cm_event(event);
2982 
2983 	while (spdk_nvmf_transport_stop_listen(transport, port->trid) == 0) {
2984 		;
2985 	}
2986 }
2987 
2988 static void
2989 nvmf_process_cm_event(struct spdk_nvmf_transport *transport)
2990 {
2991 	struct spdk_nvmf_rdma_transport *rtransport;
2992 	struct rdma_cm_event		*event;
2993 	int				rc;
2994 	bool				event_acked;
2995 
2996 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2997 
2998 	if (rtransport->event_channel == NULL) {
2999 		return;
3000 	}
3001 
3002 	while (1) {
3003 		event_acked = false;
3004 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
3005 		if (rc) {
3006 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
3007 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
3008 			}
3009 			break;
3010 		}
3011 
3012 		SPDK_DEBUGLOG(rdma, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
3013 
3014 		spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
3015 
3016 		switch (event->event) {
3017 		case RDMA_CM_EVENT_ADDR_RESOLVED:
3018 		case RDMA_CM_EVENT_ADDR_ERROR:
3019 		case RDMA_CM_EVENT_ROUTE_RESOLVED:
3020 		case RDMA_CM_EVENT_ROUTE_ERROR:
3021 			/* No action required. The target never attempts to resolve routes. */
3022 			break;
3023 		case RDMA_CM_EVENT_CONNECT_REQUEST:
3024 			rc = nvmf_rdma_connect(transport, event);
3025 			if (rc < 0) {
3026 				SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
3027 				break;
3028 			}
3029 			break;
3030 		case RDMA_CM_EVENT_CONNECT_RESPONSE:
3031 			/* The target never initiates a new connection. So this will not occur. */
3032 			break;
3033 		case RDMA_CM_EVENT_CONNECT_ERROR:
3034 			/* Can this happen? The docs say it can, but not sure what causes it. */
3035 			break;
3036 		case RDMA_CM_EVENT_UNREACHABLE:
3037 		case RDMA_CM_EVENT_REJECTED:
3038 			/* These only occur on the client side. */
3039 			break;
3040 		case RDMA_CM_EVENT_ESTABLISHED:
3041 			/* TODO: Should we be waiting for this event anywhere? */
3042 			break;
3043 		case RDMA_CM_EVENT_DISCONNECTED:
3044 			rc = nvmf_rdma_disconnect(event);
3045 			if (rc < 0) {
3046 				SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3047 				break;
3048 			}
3049 			break;
3050 		case RDMA_CM_EVENT_DEVICE_REMOVAL:
3051 			/* In case of device removal, kernel IB part triggers IBV_EVENT_DEVICE_FATAL
3052 			 * which triggers RDMA_CM_EVENT_DEVICE_REMOVAL on all cma_id’s.
3053 			 * Once these events are sent to SPDK, we should release all IB resources and
3054 			 * don't make attempts to call any ibv_query/modify/create functions. We can only call
3055 			 * ibv_destory* functions to release user space memory allocated by IB. All kernel
3056 			 * resources are already cleaned. */
3057 			if (event->id->qp) {
3058 				/* If rdma_cm event has a valid `qp` pointer then the event refers to the
3059 				 * corresponding qpair. Otherwise the event refers to a listening device */
3060 				rc = nvmf_rdma_disconnect(event);
3061 				if (rc < 0) {
3062 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3063 					break;
3064 				}
3065 			} else {
3066 				nvmf_rdma_handle_cm_event_port_removal(transport, event);
3067 				event_acked = true;
3068 			}
3069 			break;
3070 		case RDMA_CM_EVENT_MULTICAST_JOIN:
3071 		case RDMA_CM_EVENT_MULTICAST_ERROR:
3072 			/* Multicast is not used */
3073 			break;
3074 		case RDMA_CM_EVENT_ADDR_CHANGE:
3075 			event_acked = nvmf_rdma_handle_cm_event_addr_change(transport, event);
3076 			break;
3077 		case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3078 			/* For now, do nothing. The target never re-uses queue pairs. */
3079 			break;
3080 		default:
3081 			SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3082 			break;
3083 		}
3084 		if (!event_acked) {
3085 			rdma_ack_cm_event(event);
3086 		}
3087 	}
3088 }
3089 
3090 static void
3091 nvmf_rdma_handle_last_wqe_reached(struct spdk_nvmf_rdma_qpair *rqpair)
3092 {
3093 	rqpair->last_wqe_reached = true;
3094 	nvmf_rdma_destroy_drained_qpair(rqpair);
3095 }
3096 
3097 static void
3098 nvmf_rdma_qpair_process_ibv_event(void *ctx)
3099 {
3100 	struct spdk_nvmf_rdma_ibv_event_ctx *event_ctx = ctx;
3101 
3102 	if (event_ctx->rqpair) {
3103 		STAILQ_REMOVE(&event_ctx->rqpair->ibv_events, event_ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3104 		if (event_ctx->cb_fn) {
3105 			event_ctx->cb_fn(event_ctx->rqpair);
3106 		}
3107 	}
3108 	free(event_ctx);
3109 }
3110 
3111 static int
3112 nvmf_rdma_send_qpair_async_event(struct spdk_nvmf_rdma_qpair *rqpair,
3113 				 spdk_nvmf_rdma_qpair_ibv_event fn)
3114 {
3115 	struct spdk_nvmf_rdma_ibv_event_ctx *ctx;
3116 	struct spdk_thread *thr = NULL;
3117 	int rc;
3118 
3119 	if (rqpair->qpair.group) {
3120 		thr = rqpair->qpair.group->thread;
3121 	} else if (rqpair->destruct_channel) {
3122 		thr = spdk_io_channel_get_thread(rqpair->destruct_channel);
3123 	}
3124 
3125 	if (!thr) {
3126 		SPDK_DEBUGLOG(rdma, "rqpair %p has no thread\n", rqpair);
3127 		return -EINVAL;
3128 	}
3129 
3130 	ctx = calloc(1, sizeof(*ctx));
3131 	if (!ctx) {
3132 		return -ENOMEM;
3133 	}
3134 
3135 	ctx->rqpair = rqpair;
3136 	ctx->cb_fn = fn;
3137 	STAILQ_INSERT_TAIL(&rqpair->ibv_events, ctx, link);
3138 
3139 	rc = spdk_thread_send_msg(thr, nvmf_rdma_qpair_process_ibv_event, ctx);
3140 	if (rc) {
3141 		STAILQ_REMOVE(&rqpair->ibv_events, ctx, spdk_nvmf_rdma_ibv_event_ctx, link);
3142 		free(ctx);
3143 	}
3144 
3145 	return rc;
3146 }
3147 
3148 static int
3149 nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3150 {
3151 	int				rc;
3152 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3153 	struct ibv_async_event		event;
3154 
3155 	rc = ibv_get_async_event(device->context, &event);
3156 
3157 	if (rc) {
3158 		/* In non-blocking mode -1 means there are no events available */
3159 		return rc;
3160 	}
3161 
3162 	switch (event.event_type) {
3163 	case IBV_EVENT_QP_FATAL:
3164 		rqpair = event.element.qp->qp_context;
3165 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3166 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3167 				  (uintptr_t)rqpair->cm_id, event.event_type);
3168 		nvmf_rdma_update_ibv_state(rqpair);
3169 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3170 		break;
3171 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3172 		/* This event only occurs for shared receive queues. */
3173 		rqpair = event.element.qp->qp_context;
3174 		SPDK_DEBUGLOG(rdma, "Last WQE reached event received for rqpair %p\n", rqpair);
3175 		rc = nvmf_rdma_send_qpair_async_event(rqpair, nvmf_rdma_handle_last_wqe_reached);
3176 		if (rc) {
3177 			SPDK_WARNLOG("Failed to send LAST_WQE_REACHED event. rqpair %p, err %d\n", rqpair, rc);
3178 			rqpair->last_wqe_reached = true;
3179 		}
3180 		break;
3181 	case IBV_EVENT_SQ_DRAINED:
3182 		/* This event occurs frequently in both error and non-error states.
3183 		 * Check if the qpair is in an error state before sending a message. */
3184 		rqpair = event.element.qp->qp_context;
3185 		SPDK_DEBUGLOG(rdma, "Last sq drained event received for rqpair %p\n", rqpair);
3186 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3187 				  (uintptr_t)rqpair->cm_id, event.event_type);
3188 		if (nvmf_rdma_update_ibv_state(rqpair) == IBV_QPS_ERR) {
3189 			spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3190 		}
3191 		break;
3192 	case IBV_EVENT_QP_REQ_ERR:
3193 	case IBV_EVENT_QP_ACCESS_ERR:
3194 	case IBV_EVENT_COMM_EST:
3195 	case IBV_EVENT_PATH_MIG:
3196 	case IBV_EVENT_PATH_MIG_ERR:
3197 		SPDK_NOTICELOG("Async event: %s\n",
3198 			       ibv_event_type_str(event.event_type));
3199 		rqpair = event.element.qp->qp_context;
3200 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3201 				  (uintptr_t)rqpair->cm_id, event.event_type);
3202 		nvmf_rdma_update_ibv_state(rqpair);
3203 		break;
3204 	case IBV_EVENT_CQ_ERR:
3205 	case IBV_EVENT_DEVICE_FATAL:
3206 	case IBV_EVENT_PORT_ACTIVE:
3207 	case IBV_EVENT_PORT_ERR:
3208 	case IBV_EVENT_LID_CHANGE:
3209 	case IBV_EVENT_PKEY_CHANGE:
3210 	case IBV_EVENT_SM_CHANGE:
3211 	case IBV_EVENT_SRQ_ERR:
3212 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3213 	case IBV_EVENT_CLIENT_REREGISTER:
3214 	case IBV_EVENT_GID_CHANGE:
3215 	default:
3216 		SPDK_NOTICELOG("Async event: %s\n",
3217 			       ibv_event_type_str(event.event_type));
3218 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3219 		break;
3220 	}
3221 	ibv_ack_async_event(&event);
3222 
3223 	return 0;
3224 }
3225 
3226 static void
3227 nvmf_process_ib_events(struct spdk_nvmf_rdma_device *device, uint32_t max_events)
3228 {
3229 	int rc = 0;
3230 	uint32_t i = 0;
3231 
3232 	for (i = 0; i < max_events; i++) {
3233 		rc = nvmf_process_ib_event(device);
3234 		if (rc) {
3235 			break;
3236 		}
3237 	}
3238 
3239 	SPDK_DEBUGLOG(rdma, "Device %s: %u events processed\n", device->context->device->name, i);
3240 }
3241 
3242 static uint32_t
3243 nvmf_rdma_accept(struct spdk_nvmf_transport *transport)
3244 {
3245 	int	nfds, i = 0;
3246 	struct spdk_nvmf_rdma_transport *rtransport;
3247 	struct spdk_nvmf_rdma_device *device, *tmp;
3248 	uint32_t count;
3249 
3250 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3251 	count = nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3252 
3253 	if (nfds <= 0) {
3254 		return 0;
3255 	}
3256 
3257 	/* The first poll descriptor is RDMA CM event */
3258 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3259 		nvmf_process_cm_event(transport);
3260 		nfds--;
3261 	}
3262 
3263 	if (nfds == 0) {
3264 		return count;
3265 	}
3266 
3267 	/* Second and subsequent poll descriptors are IB async events */
3268 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3269 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3270 			nvmf_process_ib_events(device, 32);
3271 			nfds--;
3272 		}
3273 	}
3274 	/* check all flagged fd's have been served */
3275 	assert(nfds == 0);
3276 
3277 	return count;
3278 }
3279 
3280 static void
3281 nvmf_rdma_cdata_init(struct spdk_nvmf_transport *transport, struct spdk_nvmf_subsystem *subsystem,
3282 		     struct spdk_nvmf_ctrlr_data *cdata)
3283 {
3284 	cdata->nvmf_specific.msdbd = SPDK_NVMF_MAX_SGL_ENTRIES;
3285 
3286 	/* Disable in-capsule data transfer for RDMA controller when dif_insert_or_strip is enabled
3287 	since in-capsule data only works with NVME drives that support SGL memory layout */
3288 	if (transport->opts.dif_insert_or_strip) {
3289 		cdata->nvmf_specific.ioccsz = sizeof(struct spdk_nvme_cmd) / 16;
3290 	}
3291 }
3292 
3293 static void
3294 nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3295 		   struct spdk_nvme_transport_id *trid,
3296 		   struct spdk_nvmf_discovery_log_page_entry *entry)
3297 {
3298 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3299 	entry->adrfam = trid->adrfam;
3300 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3301 
3302 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3303 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3304 
3305 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3306 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3307 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3308 }
3309 
3310 static void
3311 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3312 
3313 static struct spdk_nvmf_transport_poll_group *
3314 nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3315 {
3316 	struct spdk_nvmf_rdma_transport		*rtransport;
3317 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3318 	struct spdk_nvmf_rdma_poller		*poller;
3319 	struct spdk_nvmf_rdma_device		*device;
3320 	struct ibv_srq_init_attr		srq_init_attr;
3321 	struct spdk_nvmf_rdma_resource_opts	opts;
3322 	int					num_cqe;
3323 
3324 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3325 
3326 	rgroup = calloc(1, sizeof(*rgroup));
3327 	if (!rgroup) {
3328 		return NULL;
3329 	}
3330 
3331 	TAILQ_INIT(&rgroup->pollers);
3332 	STAILQ_INIT(&rgroup->retired_bufs);
3333 
3334 	pthread_mutex_lock(&rtransport->lock);
3335 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3336 		poller = calloc(1, sizeof(*poller));
3337 		if (!poller) {
3338 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3339 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3340 			pthread_mutex_unlock(&rtransport->lock);
3341 			return NULL;
3342 		}
3343 
3344 		poller->device = device;
3345 		poller->group = rgroup;
3346 
3347 		TAILQ_INIT(&poller->qpairs);
3348 		STAILQ_INIT(&poller->qpairs_pending_send);
3349 		STAILQ_INIT(&poller->qpairs_pending_recv);
3350 
3351 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3352 		if (rtransport->rdma_opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3353 			poller->max_srq_depth = rtransport->rdma_opts.max_srq_depth;
3354 
3355 			device->num_srq++;
3356 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3357 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3358 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3359 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3360 			if (!poller->srq) {
3361 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3362 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3363 				pthread_mutex_unlock(&rtransport->lock);
3364 				return NULL;
3365 			}
3366 
3367 			opts.qp = poller->srq;
3368 			opts.pd = device->pd;
3369 			opts.qpair = NULL;
3370 			opts.shared = true;
3371 			opts.max_queue_depth = poller->max_srq_depth;
3372 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3373 
3374 			poller->resources = nvmf_rdma_resources_create(&opts);
3375 			if (!poller->resources) {
3376 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3377 				nvmf_rdma_poll_group_destroy(&rgroup->group);
3378 				pthread_mutex_unlock(&rtransport->lock);
3379 				return NULL;
3380 			}
3381 		}
3382 
3383 		/*
3384 		 * When using an srq, we can limit the completion queue at startup.
3385 		 * The following formula represents the calculation:
3386 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3387 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3388 		 */
3389 		if (poller->srq) {
3390 			num_cqe = poller->max_srq_depth * 3;
3391 		} else {
3392 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3393 		}
3394 
3395 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3396 		if (!poller->cq) {
3397 			SPDK_ERRLOG("Unable to create completion queue\n");
3398 			nvmf_rdma_poll_group_destroy(&rgroup->group);
3399 			pthread_mutex_unlock(&rtransport->lock);
3400 			return NULL;
3401 		}
3402 		poller->num_cqe = num_cqe;
3403 	}
3404 
3405 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3406 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3407 		rtransport->conn_sched.next_admin_pg = rgroup;
3408 		rtransport->conn_sched.next_io_pg = rgroup;
3409 	}
3410 
3411 	pthread_mutex_unlock(&rtransport->lock);
3412 	return &rgroup->group;
3413 }
3414 
3415 static struct spdk_nvmf_transport_poll_group *
3416 nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3417 {
3418 	struct spdk_nvmf_rdma_transport *rtransport;
3419 	struct spdk_nvmf_rdma_poll_group **pg;
3420 	struct spdk_nvmf_transport_poll_group *result;
3421 
3422 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3423 
3424 	pthread_mutex_lock(&rtransport->lock);
3425 
3426 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3427 		pthread_mutex_unlock(&rtransport->lock);
3428 		return NULL;
3429 	}
3430 
3431 	if (qpair->qid == 0) {
3432 		pg = &rtransport->conn_sched.next_admin_pg;
3433 	} else {
3434 		pg = &rtransport->conn_sched.next_io_pg;
3435 	}
3436 
3437 	assert(*pg != NULL);
3438 
3439 	result = &(*pg)->group;
3440 
3441 	*pg = TAILQ_NEXT(*pg, link);
3442 	if (*pg == NULL) {
3443 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3444 	}
3445 
3446 	pthread_mutex_unlock(&rtransport->lock);
3447 
3448 	return result;
3449 }
3450 
3451 static void
3452 nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3453 {
3454 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3455 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3456 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3457 	struct spdk_nvmf_transport_pg_cache_buf	*buf, *tmp_buf;
3458 	struct spdk_nvmf_rdma_transport		*rtransport;
3459 
3460 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3461 	if (!rgroup) {
3462 		return;
3463 	}
3464 
3465 	/* free all retired buffers back to the transport so we don't short the mempool. */
3466 	STAILQ_FOREACH_SAFE(buf, &rgroup->retired_bufs, link, tmp_buf) {
3467 		STAILQ_REMOVE(&rgroup->retired_bufs, buf, spdk_nvmf_transport_pg_cache_buf, link);
3468 		assert(group->transport != NULL);
3469 		spdk_mempool_put(group->transport->data_buf_pool, buf);
3470 	}
3471 
3472 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3473 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3474 
3475 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3476 			nvmf_rdma_qpair_destroy(qpair);
3477 		}
3478 
3479 		if (poller->srq) {
3480 			if (poller->resources) {
3481 				nvmf_rdma_resources_destroy(poller->resources);
3482 			}
3483 			ibv_destroy_srq(poller->srq);
3484 			SPDK_DEBUGLOG(rdma, "Destroyed RDMA shared queue %p\n", poller->srq);
3485 		}
3486 
3487 		if (poller->cq) {
3488 			ibv_destroy_cq(poller->cq);
3489 		}
3490 
3491 		free(poller);
3492 	}
3493 
3494 	if (rgroup->group.transport == NULL) {
3495 		/* Transport can be NULL when nvmf_rdma_poll_group_create()
3496 		 * calls this function directly in a failure path. */
3497 		free(rgroup);
3498 		return;
3499 	}
3500 
3501 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3502 
3503 	pthread_mutex_lock(&rtransport->lock);
3504 	next_rgroup = TAILQ_NEXT(rgroup, link);
3505 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3506 	if (next_rgroup == NULL) {
3507 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3508 	}
3509 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3510 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3511 	}
3512 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3513 		rtransport->conn_sched.next_io_pg = next_rgroup;
3514 	}
3515 	pthread_mutex_unlock(&rtransport->lock);
3516 
3517 	free(rgroup);
3518 }
3519 
3520 static void
3521 nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3522 {
3523 	if (rqpair->cm_id != NULL) {
3524 		nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3525 	}
3526 }
3527 
3528 static int
3529 nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3530 			 struct spdk_nvmf_qpair *qpair)
3531 {
3532 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3533 	struct spdk_nvmf_rdma_qpair		*rqpair;
3534 	struct spdk_nvmf_rdma_device		*device;
3535 	struct spdk_nvmf_rdma_poller		*poller;
3536 	int					rc;
3537 
3538 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3539 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3540 
3541 	device = rqpair->device;
3542 
3543 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3544 		if (poller->device == device) {
3545 			break;
3546 		}
3547 	}
3548 
3549 	if (!poller) {
3550 		SPDK_ERRLOG("No poller found for device.\n");
3551 		return -1;
3552 	}
3553 
3554 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3555 	rqpair->poller = poller;
3556 	rqpair->srq = rqpair->poller->srq;
3557 
3558 	rc = nvmf_rdma_qpair_initialize(qpair);
3559 	if (rc < 0) {
3560 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3561 		return -1;
3562 	}
3563 
3564 	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3565 	if (rc) {
3566 		/* Try to reject, but we probably can't */
3567 		nvmf_rdma_qpair_reject_connection(rqpair);
3568 		return -1;
3569 	}
3570 
3571 	nvmf_rdma_update_ibv_state(rqpair);
3572 
3573 	return 0;
3574 }
3575 
3576 static int
3577 nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
3578 			    struct spdk_nvmf_qpair *qpair)
3579 {
3580 	struct spdk_nvmf_rdma_qpair		*rqpair;
3581 
3582 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3583 	assert(group->transport->tgt != NULL);
3584 
3585 	rqpair->destruct_channel = spdk_get_io_channel(group->transport->tgt);
3586 
3587 	if (!rqpair->destruct_channel) {
3588 		SPDK_WARNLOG("failed to get io_channel, qpair %p\n", qpair);
3589 		return 0;
3590 	}
3591 
3592 	/* Sanity check that we get io_channel on the correct thread */
3593 	if (qpair->group) {
3594 		assert(qpair->group->thread == spdk_io_channel_get_thread(rqpair->destruct_channel));
3595 	}
3596 
3597 	return 0;
3598 }
3599 
3600 static int
3601 nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3602 {
3603 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3604 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3605 			struct spdk_nvmf_rdma_transport, transport);
3606 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3607 					      struct spdk_nvmf_rdma_qpair, qpair);
3608 
3609 	/*
3610 	 * AER requests are freed when a qpair is destroyed. The recv corresponding to that request
3611 	 * needs to be returned to the shared receive queue or the poll group will eventually be
3612 	 * starved of RECV structures.
3613 	 */
3614 	if (rqpair->srq && rdma_req->recv) {
3615 		int rc;
3616 		struct ibv_recv_wr *bad_recv_wr;
3617 
3618 		rc = ibv_post_srq_recv(rqpair->srq, &rdma_req->recv->wr, &bad_recv_wr);
3619 		if (rc) {
3620 			SPDK_ERRLOG("Unable to re-post rx descriptor\n");
3621 		}
3622 	}
3623 
3624 	_nvmf_rdma_request_free(rdma_req, rtransport);
3625 	return 0;
3626 }
3627 
3628 static int
3629 nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3630 {
3631 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3632 			struct spdk_nvmf_rdma_transport, transport);
3633 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3634 			struct spdk_nvmf_rdma_request, req);
3635 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3636 			struct spdk_nvmf_rdma_qpair, qpair);
3637 
3638 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3639 		/* The connection is alive, so process the request as normal */
3640 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3641 	} else {
3642 		/* The connection is dead. Move the request directly to the completed state. */
3643 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3644 	}
3645 
3646 	nvmf_rdma_request_process(rtransport, rdma_req);
3647 
3648 	return 0;
3649 }
3650 
3651 static void
3652 nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair,
3653 		      spdk_nvmf_transport_qpair_fini_cb cb_fn, void *cb_arg)
3654 {
3655 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3656 
3657 	rqpair->to_close = true;
3658 
3659 	/* This happens only when the qpair is disconnected before
3660 	 * it is added to the poll group. Since there is no poll group,
3661 	 * the RDMA qp has not been initialized yet and the RDMA CM
3662 	 * event has not yet been acknowledged, so we need to reject it.
3663 	 */
3664 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3665 		nvmf_rdma_qpair_reject_connection(rqpair);
3666 		nvmf_rdma_qpair_destroy(rqpair);
3667 		return;
3668 	}
3669 
3670 	if (rqpair->rdma_qp) {
3671 		spdk_rdma_qp_disconnect(rqpair->rdma_qp);
3672 	}
3673 
3674 	nvmf_rdma_destroy_drained_qpair(rqpair);
3675 
3676 	if (cb_fn) {
3677 		cb_fn(cb_arg);
3678 	}
3679 }
3680 
3681 static struct spdk_nvmf_rdma_qpair *
3682 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3683 {
3684 	struct spdk_nvmf_rdma_qpair *rqpair;
3685 	/* @todo: improve QP search */
3686 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3687 		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {
3688 			return rqpair;
3689 		}
3690 	}
3691 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3692 	return NULL;
3693 }
3694 
3695 #ifdef DEBUG
3696 static int
3697 nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3698 {
3699 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3700 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3701 }
3702 #endif
3703 
3704 static void
3705 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3706 			   int rc)
3707 {
3708 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3709 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3710 
3711 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3712 	while (bad_recv_wr != NULL) {
3713 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3714 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3715 
3716 		rdma_recv->qpair->current_recv_depth++;
3717 		bad_recv_wr = bad_recv_wr->next;
3718 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3719 		spdk_nvmf_qpair_disconnect(&rdma_recv->qpair->qpair, NULL, NULL);
3720 	}
3721 }
3722 
3723 static void
3724 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3725 {
3726 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3727 	while (bad_recv_wr != NULL) {
3728 		bad_recv_wr = bad_recv_wr->next;
3729 		rqpair->current_recv_depth++;
3730 	}
3731 	spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3732 }
3733 
3734 static void
3735 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3736 		     struct spdk_nvmf_rdma_poller *rpoller)
3737 {
3738 	struct spdk_nvmf_rdma_qpair	*rqpair;
3739 	struct ibv_recv_wr		*bad_recv_wr;
3740 	int				rc;
3741 
3742 	if (rpoller->srq) {
3743 		if (rpoller->resources->recvs_to_post.first != NULL) {
3744 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3745 			if (rc) {
3746 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3747 			}
3748 			rpoller->resources->recvs_to_post.first = NULL;
3749 			rpoller->resources->recvs_to_post.last = NULL;
3750 		}
3751 	} else {
3752 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3753 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3754 			assert(rqpair->resources->recvs_to_post.first != NULL);
3755 			rc = ibv_post_recv(rqpair->rdma_qp->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3756 			if (rc) {
3757 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3758 			}
3759 			rqpair->resources->recvs_to_post.first = NULL;
3760 			rqpair->resources->recvs_to_post.last = NULL;
3761 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3762 		}
3763 	}
3764 }
3765 
3766 static void
3767 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3768 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3769 {
3770 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3771 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3772 
3773 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3774 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3775 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3776 		assert(rqpair->current_send_depth > 0);
3777 		rqpair->current_send_depth--;
3778 		switch (bad_rdma_wr->type) {
3779 		case RDMA_WR_TYPE_DATA:
3780 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3781 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3782 				assert(rqpair->current_read_depth > 0);
3783 				rqpair->current_read_depth--;
3784 			}
3785 			break;
3786 		case RDMA_WR_TYPE_SEND:
3787 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3788 			break;
3789 		default:
3790 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3791 			prev_rdma_req = cur_rdma_req;
3792 			continue;
3793 		}
3794 
3795 		if (prev_rdma_req == cur_rdma_req) {
3796 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3797 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3798 			continue;
3799 		}
3800 
3801 		switch (cur_rdma_req->state) {
3802 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3803 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3804 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3805 			break;
3806 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3807 		case RDMA_REQUEST_STATE_COMPLETING:
3808 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3809 			break;
3810 		default:
3811 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3812 				    cur_rdma_req->state, rqpair);
3813 			continue;
3814 		}
3815 
3816 		nvmf_rdma_request_process(rtransport, cur_rdma_req);
3817 		prev_rdma_req = cur_rdma_req;
3818 	}
3819 
3820 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3821 		/* Disconnect the connection. */
3822 		spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3823 	}
3824 
3825 }
3826 
3827 static void
3828 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3829 		     struct spdk_nvmf_rdma_poller *rpoller)
3830 {
3831 	struct spdk_nvmf_rdma_qpair	*rqpair;
3832 	struct ibv_send_wr		*bad_wr = NULL;
3833 	int				rc;
3834 
3835 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3836 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3837 		rc = spdk_rdma_qp_flush_send_wrs(rqpair->rdma_qp, &bad_wr);
3838 
3839 		/* bad wr always points to the first wr that failed. */
3840 		if (rc) {
3841 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3842 		}
3843 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3844 	}
3845 }
3846 
3847 static const char *
3848 nvmf_rdma_wr_type_str(enum spdk_nvmf_rdma_wr_type wr_type)
3849 {
3850 	switch (wr_type) {
3851 	case RDMA_WR_TYPE_RECV:
3852 		return "RECV";
3853 	case RDMA_WR_TYPE_SEND:
3854 		return "SEND";
3855 	case RDMA_WR_TYPE_DATA:
3856 		return "DATA";
3857 	default:
3858 		SPDK_ERRLOG("Unknown WR type %d\n", wr_type);
3859 		SPDK_UNREACHABLE();
3860 	}
3861 }
3862 
3863 static inline void
3864 nvmf_rdma_log_wc_status(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_wc *wc)
3865 {
3866 	enum spdk_nvmf_rdma_wr_type wr_type = ((struct spdk_nvmf_rdma_wr *)wc->wr_id)->type;
3867 
3868 	if (wc->status == IBV_WC_WR_FLUSH_ERR) {
3869 		/* If qpair is in ERR state, we will receive completions for all posted and not completed
3870 		 * Work Requests with IBV_WC_WR_FLUSH_ERR status. Don't log an error in that case */
3871 		SPDK_DEBUGLOG(rdma,
3872 			      "Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3873 			      rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3874 			      nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3875 	} else {
3876 		SPDK_ERRLOG("Error on CQ %p, (qp state %d ibv_state %d) request 0x%lu, type %s, status: (%d): %s\n",
3877 			    rqpair->poller->cq, rqpair->qpair.state, rqpair->ibv_state, wc->wr_id,
3878 			    nvmf_rdma_wr_type_str(wr_type), wc->status, ibv_wc_status_str(wc->status));
3879 	}
3880 }
3881 
3882 static int
3883 nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3884 		      struct spdk_nvmf_rdma_poller *rpoller)
3885 {
3886 	struct ibv_wc wc[32];
3887 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3888 	struct spdk_nvmf_rdma_request	*rdma_req;
3889 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3890 	struct spdk_nvmf_rdma_qpair	*rqpair;
3891 	int reaped, i;
3892 	int count = 0;
3893 	bool error = false;
3894 	uint64_t poll_tsc = spdk_get_ticks();
3895 
3896 	/* Poll for completing operations. */
3897 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3898 	if (reaped < 0) {
3899 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3900 			    errno, spdk_strerror(errno));
3901 		return -1;
3902 	}
3903 
3904 	rpoller->stat.polls++;
3905 	rpoller->stat.completions += reaped;
3906 
3907 	for (i = 0; i < reaped; i++) {
3908 
3909 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3910 
3911 		switch (rdma_wr->type) {
3912 		case RDMA_WR_TYPE_SEND:
3913 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3914 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3915 
3916 			if (!wc[i].status) {
3917 				count++;
3918 				assert(wc[i].opcode == IBV_WC_SEND);
3919 				assert(nvmf_rdma_req_is_completing(rdma_req));
3920 			}
3921 
3922 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3923 			/* RDMA_WRITE operation completed. +1 since it was chained with rsp WR */
3924 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3925 			rdma_req->num_outstanding_data_wr = 0;
3926 
3927 			nvmf_rdma_request_process(rtransport, rdma_req);
3928 			break;
3929 		case RDMA_WR_TYPE_RECV:
3930 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3931 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3932 			if (rpoller->srq != NULL) {
3933 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3934 				/* It is possible that there are still some completions for destroyed QP
3935 				 * associated with SRQ. We just ignore these late completions and re-post
3936 				 * receive WRs back to SRQ.
3937 				 */
3938 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3939 					struct ibv_recv_wr *bad_wr;
3940 					int rc;
3941 
3942 					rdma_recv->wr.next = NULL;
3943 					rc = ibv_post_srq_recv(rpoller->srq,
3944 							       &rdma_recv->wr,
3945 							       &bad_wr);
3946 					if (rc) {
3947 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3948 					}
3949 					continue;
3950 				}
3951 			}
3952 			rqpair = rdma_recv->qpair;
3953 
3954 			assert(rqpair != NULL);
3955 			if (!wc[i].status) {
3956 				assert(wc[i].opcode == IBV_WC_RECV);
3957 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3958 					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
3959 					break;
3960 				}
3961 			}
3962 
3963 			rdma_recv->wr.next = NULL;
3964 			rqpair->current_recv_depth++;
3965 			rdma_recv->receive_tsc = poll_tsc;
3966 			rpoller->stat.requests++;
3967 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3968 			break;
3969 		case RDMA_WR_TYPE_DATA:
3970 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3971 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3972 
3973 			assert(rdma_req->num_outstanding_data_wr > 0);
3974 
3975 			rqpair->current_send_depth--;
3976 			rdma_req->num_outstanding_data_wr--;
3977 			if (!wc[i].status) {
3978 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3979 				rqpair->current_read_depth--;
3980 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3981 				if (rdma_req->num_outstanding_data_wr == 0) {
3982 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3983 					nvmf_rdma_request_process(rtransport, rdma_req);
3984 				}
3985 			} else {
3986 				/* If the data transfer fails still force the queue into the error state,
3987 				 * if we were performing an RDMA_READ, we need to force the request into a
3988 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3989 				 * case, we should wait for the SEND to complete. */
3990 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3991 					rqpair->current_read_depth--;
3992 					if (rdma_req->num_outstanding_data_wr == 0) {
3993 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3994 					}
3995 				}
3996 			}
3997 			break;
3998 		default:
3999 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
4000 			continue;
4001 		}
4002 
4003 		/* Handle error conditions */
4004 		if (wc[i].status) {
4005 			nvmf_rdma_update_ibv_state(rqpair);
4006 			nvmf_rdma_log_wc_status(rqpair, &wc[i]);
4007 
4008 			error = true;
4009 
4010 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
4011 				/* Disconnect the connection. */
4012 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
4013 			} else {
4014 				nvmf_rdma_destroy_drained_qpair(rqpair);
4015 			}
4016 			continue;
4017 		}
4018 
4019 		nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
4020 
4021 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
4022 			nvmf_rdma_destroy_drained_qpair(rqpair);
4023 		}
4024 	}
4025 
4026 	if (error == true) {
4027 		return -1;
4028 	}
4029 
4030 	/* submit outstanding work requests. */
4031 	_poller_submit_recvs(rtransport, rpoller);
4032 	_poller_submit_sends(rtransport, rpoller);
4033 
4034 	return count;
4035 }
4036 
4037 static int
4038 nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
4039 {
4040 	struct spdk_nvmf_rdma_transport *rtransport;
4041 	struct spdk_nvmf_rdma_poll_group *rgroup;
4042 	struct spdk_nvmf_rdma_poller	*rpoller;
4043 	int				count, rc;
4044 
4045 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
4046 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
4047 
4048 	count = 0;
4049 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4050 		rc = nvmf_rdma_poller_poll(rtransport, rpoller);
4051 		if (rc < 0) {
4052 			return rc;
4053 		}
4054 		count += rc;
4055 	}
4056 
4057 	return count;
4058 }
4059 
4060 static int
4061 nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
4062 			  struct spdk_nvme_transport_id *trid,
4063 			  bool peer)
4064 {
4065 	struct sockaddr *saddr;
4066 	uint16_t port;
4067 
4068 	spdk_nvme_trid_populate_transport(trid, SPDK_NVME_TRANSPORT_RDMA);
4069 
4070 	if (peer) {
4071 		saddr = rdma_get_peer_addr(id);
4072 	} else {
4073 		saddr = rdma_get_local_addr(id);
4074 	}
4075 	switch (saddr->sa_family) {
4076 	case AF_INET: {
4077 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
4078 
4079 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
4080 		inet_ntop(AF_INET, &saddr_in->sin_addr,
4081 			  trid->traddr, sizeof(trid->traddr));
4082 		if (peer) {
4083 			port = ntohs(rdma_get_dst_port(id));
4084 		} else {
4085 			port = ntohs(rdma_get_src_port(id));
4086 		}
4087 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4088 		break;
4089 	}
4090 	case AF_INET6: {
4091 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
4092 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
4093 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
4094 			  trid->traddr, sizeof(trid->traddr));
4095 		if (peer) {
4096 			port = ntohs(rdma_get_dst_port(id));
4097 		} else {
4098 			port = ntohs(rdma_get_src_port(id));
4099 		}
4100 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
4101 		break;
4102 	}
4103 	default:
4104 		return -1;
4105 
4106 	}
4107 
4108 	return 0;
4109 }
4110 
4111 static int
4112 nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
4113 			      struct spdk_nvme_transport_id *trid)
4114 {
4115 	struct spdk_nvmf_rdma_qpair	*rqpair;
4116 
4117 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4118 
4119 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
4120 }
4121 
4122 static int
4123 nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
4124 			       struct spdk_nvme_transport_id *trid)
4125 {
4126 	struct spdk_nvmf_rdma_qpair	*rqpair;
4127 
4128 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4129 
4130 	return nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
4131 }
4132 
4133 static int
4134 nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
4135 				struct spdk_nvme_transport_id *trid)
4136 {
4137 	struct spdk_nvmf_rdma_qpair	*rqpair;
4138 
4139 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4140 
4141 	return nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
4142 }
4143 
4144 void
4145 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
4146 {
4147 	g_nvmf_hooks = *hooks;
4148 }
4149 
4150 static void
4151 nvmf_rdma_request_set_abort_status(struct spdk_nvmf_request *req,
4152 				   struct spdk_nvmf_rdma_request *rdma_req_to_abort)
4153 {
4154 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sct = SPDK_NVME_SCT_GENERIC;
4155 	rdma_req_to_abort->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_ABORTED_BY_REQUEST;
4156 
4157 	rdma_req_to_abort->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
4158 
4159 	req->rsp->nvme_cpl.cdw0 &= ~1U;	/* Command was successfully aborted. */
4160 }
4161 
4162 static int
4163 _nvmf_rdma_qpair_abort_request(void *ctx)
4164 {
4165 	struct spdk_nvmf_request *req = ctx;
4166 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = SPDK_CONTAINEROF(
4167 				req->req_to_abort, struct spdk_nvmf_rdma_request, req);
4168 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(req->req_to_abort->qpair,
4169 					      struct spdk_nvmf_rdma_qpair, qpair);
4170 	int rc;
4171 
4172 	spdk_poller_unregister(&req->poller);
4173 
4174 	switch (rdma_req_to_abort->state) {
4175 	case RDMA_REQUEST_STATE_EXECUTING:
4176 		rc = nvmf_ctrlr_abort_request(req);
4177 		if (rc == SPDK_NVMF_REQUEST_EXEC_STATUS_ASYNCHRONOUS) {
4178 			return SPDK_POLLER_BUSY;
4179 		}
4180 		break;
4181 
4182 	case RDMA_REQUEST_STATE_NEED_BUFFER:
4183 		STAILQ_REMOVE(&rqpair->poller->group->group.pending_buf_queue,
4184 			      &rdma_req_to_abort->req, spdk_nvmf_request, buf_link);
4185 
4186 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4187 		break;
4188 
4189 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
4190 		STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req_to_abort,
4191 			      spdk_nvmf_rdma_request, state_link);
4192 
4193 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4194 		break;
4195 
4196 	case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
4197 		STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req_to_abort,
4198 			      spdk_nvmf_rdma_request, state_link);
4199 
4200 		nvmf_rdma_request_set_abort_status(req, rdma_req_to_abort);
4201 		break;
4202 
4203 	case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
4204 		if (spdk_get_ticks() < req->timeout_tsc) {
4205 			req->poller = SPDK_POLLER_REGISTER(_nvmf_rdma_qpair_abort_request, req, 0);
4206 			return SPDK_POLLER_BUSY;
4207 		}
4208 		break;
4209 
4210 	default:
4211 		break;
4212 	}
4213 
4214 	spdk_nvmf_request_complete(req);
4215 	return SPDK_POLLER_BUSY;
4216 }
4217 
4218 static void
4219 nvmf_rdma_qpair_abort_request(struct spdk_nvmf_qpair *qpair,
4220 			      struct spdk_nvmf_request *req)
4221 {
4222 	struct spdk_nvmf_rdma_qpair *rqpair;
4223 	struct spdk_nvmf_rdma_transport *rtransport;
4224 	struct spdk_nvmf_transport *transport;
4225 	uint16_t cid;
4226 	uint32_t i;
4227 	struct spdk_nvmf_rdma_request *rdma_req_to_abort = NULL;
4228 
4229 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
4230 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
4231 	transport = &rtransport->transport;
4232 
4233 	cid = req->cmd->nvme_cmd.cdw10_bits.abort.cid;
4234 
4235 	for (i = 0; i < rqpair->max_queue_depth; i++) {
4236 		rdma_req_to_abort = &rqpair->resources->reqs[i];
4237 
4238 		if (rdma_req_to_abort->state != RDMA_REQUEST_STATE_FREE &&
4239 		    rdma_req_to_abort->req.cmd->nvme_cmd.cid == cid) {
4240 			break;
4241 		}
4242 	}
4243 
4244 	if (rdma_req_to_abort == NULL) {
4245 		spdk_nvmf_request_complete(req);
4246 		return;
4247 	}
4248 
4249 	req->req_to_abort = &rdma_req_to_abort->req;
4250 	req->timeout_tsc = spdk_get_ticks() +
4251 			   transport->opts.abort_timeout_sec * spdk_get_ticks_hz();
4252 	req->poller = NULL;
4253 
4254 	_nvmf_rdma_qpair_abort_request(req);
4255 }
4256 
4257 static int
4258 nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
4259 			      struct spdk_nvmf_transport_poll_group_stat **stat)
4260 {
4261 	struct spdk_io_channel *ch;
4262 	struct spdk_nvmf_poll_group *group;
4263 	struct spdk_nvmf_transport_poll_group *tgroup;
4264 	struct spdk_nvmf_rdma_poll_group *rgroup;
4265 	struct spdk_nvmf_rdma_poller *rpoller;
4266 	struct spdk_nvmf_rdma_device_stat *device_stat;
4267 	uint64_t num_devices = 0;
4268 
4269 	if (tgt == NULL || stat == NULL) {
4270 		return -EINVAL;
4271 	}
4272 
4273 	ch = spdk_get_io_channel(tgt);
4274 	group = spdk_io_channel_get_ctx(ch);;
4275 	spdk_put_io_channel(ch);
4276 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4277 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4278 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4279 			if (!*stat) {
4280 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4281 				return -ENOMEM;
4282 			}
4283 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4284 
4285 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4286 			/* Count devices to allocate enough memory */
4287 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4288 				++num_devices;
4289 			}
4290 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4291 			if (!(*stat)->rdma.devices) {
4292 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4293 				free(*stat);
4294 				return -ENOMEM;
4295 			}
4296 
4297 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4298 			(*stat)->rdma.num_devices = num_devices;
4299 			num_devices = 0;
4300 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4301 				device_stat = &(*stat)->rdma.devices[num_devices++];
4302 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4303 				device_stat->polls = rpoller->stat.polls;
4304 				device_stat->completions = rpoller->stat.completions;
4305 				device_stat->requests = rpoller->stat.requests;
4306 				device_stat->request_latency = rpoller->stat.request_latency;
4307 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4308 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4309 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4310 			}
4311 			return 0;
4312 		}
4313 	}
4314 	return -ENOENT;
4315 }
4316 
4317 static void
4318 nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4319 {
4320 	if (stat) {
4321 		free(stat->rdma.devices);
4322 	}
4323 	free(stat);
4324 }
4325 
4326 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4327 	.name = "RDMA",
4328 	.type = SPDK_NVME_TRANSPORT_RDMA,
4329 	.opts_init = nvmf_rdma_opts_init,
4330 	.create = nvmf_rdma_create,
4331 	.dump_opts = nvmf_rdma_dump_opts,
4332 	.destroy = nvmf_rdma_destroy,
4333 
4334 	.listen = nvmf_rdma_listen,
4335 	.stop_listen = nvmf_rdma_stop_listen,
4336 	.accept = nvmf_rdma_accept,
4337 	.cdata_init = nvmf_rdma_cdata_init,
4338 
4339 	.listener_discover = nvmf_rdma_discover,
4340 
4341 	.poll_group_create = nvmf_rdma_poll_group_create,
4342 	.get_optimal_poll_group = nvmf_rdma_get_optimal_poll_group,
4343 	.poll_group_destroy = nvmf_rdma_poll_group_destroy,
4344 	.poll_group_add = nvmf_rdma_poll_group_add,
4345 	.poll_group_remove = nvmf_rdma_poll_group_remove,
4346 	.poll_group_poll = nvmf_rdma_poll_group_poll,
4347 
4348 	.req_free = nvmf_rdma_request_free,
4349 	.req_complete = nvmf_rdma_request_complete,
4350 
4351 	.qpair_fini = nvmf_rdma_close_qpair,
4352 	.qpair_get_peer_trid = nvmf_rdma_qpair_get_peer_trid,
4353 	.qpair_get_local_trid = nvmf_rdma_qpair_get_local_trid,
4354 	.qpair_get_listen_trid = nvmf_rdma_qpair_get_listen_trid,
4355 	.qpair_abort_request = nvmf_rdma_qpair_abort_request,
4356 
4357 	.poll_group_get_stat = nvmf_rdma_poll_group_get_stat,
4358 	.poll_group_free_stat = nvmf_rdma_poll_group_free_stat,
4359 };
4360 
4361 SPDK_NVMF_TRANSPORT_REGISTER(rdma, &spdk_nvmf_transport_rdma);
4362 SPDK_LOG_REGISTER_COMPONENT(rdma)
4363