xref: /spdk/lib/nvmf/rdma.c (revision 9889ab2dc80e40dae92dcef361d53dcba722043d)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2019 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 <infiniband/verbs.h>
37 #include <rdma/rdma_cma.h>
38 #include <rdma/rdma_verbs.h>
39 
40 #include "nvmf_internal.h"
41 #include "transport.h"
42 
43 #include "spdk/config.h"
44 #include "spdk/thread.h"
45 #include "spdk/nvmf.h"
46 #include "spdk/nvmf_spec.h"
47 #include "spdk/string.h"
48 #include "spdk/trace.h"
49 #include "spdk/util.h"
50 
51 #include "spdk_internal/assert.h"
52 #include "spdk_internal/log.h"
53 
54 struct spdk_nvme_rdma_hooks g_nvmf_hooks = {};
55 
56 /*
57  RDMA Connection Resource Defaults
58  */
59 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
60 #define NVMF_DEFAULT_RSP_SGE		1
61 #define NVMF_DEFAULT_RX_SGE		2
62 
63 /* The RDMA completion queue size */
64 #define DEFAULT_NVMF_RDMA_CQ_SIZE	4096
65 #define MAX_WR_PER_QP(queue_depth)	(queue_depth * 3 + 2)
66 
67 /* Timeout for destroying defunct rqpairs */
68 #define NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US	4000000
69 
70 /* The maximum number of buffers per request */
71 #define NVMF_REQ_MAX_BUFFERS	(SPDK_NVMF_MAX_SGL_ENTRIES * 2)
72 
73 static int g_spdk_nvmf_ibv_query_mask =
74 	IBV_QP_STATE |
75 	IBV_QP_PKEY_INDEX |
76 	IBV_QP_PORT |
77 	IBV_QP_ACCESS_FLAGS |
78 	IBV_QP_AV |
79 	IBV_QP_PATH_MTU |
80 	IBV_QP_DEST_QPN |
81 	IBV_QP_RQ_PSN |
82 	IBV_QP_MAX_DEST_RD_ATOMIC |
83 	IBV_QP_MIN_RNR_TIMER |
84 	IBV_QP_SQ_PSN |
85 	IBV_QP_TIMEOUT |
86 	IBV_QP_RETRY_CNT |
87 	IBV_QP_RNR_RETRY |
88 	IBV_QP_MAX_QP_RD_ATOMIC;
89 
90 enum spdk_nvmf_rdma_request_state {
91 	/* The request is not currently in use */
92 	RDMA_REQUEST_STATE_FREE = 0,
93 
94 	/* Initial state when request first received */
95 	RDMA_REQUEST_STATE_NEW,
96 
97 	/* The request is queued until a data buffer is available. */
98 	RDMA_REQUEST_STATE_NEED_BUFFER,
99 
100 	/* The request is waiting on RDMA queue depth availability
101 	 * to transfer data from the host to the controller.
102 	 */
103 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
104 
105 	/* The request is currently transferring data from the host to the controller. */
106 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
107 
108 	/* The request is ready to execute at the block device */
109 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
110 
111 	/* The request is currently executing at the block device */
112 	RDMA_REQUEST_STATE_EXECUTING,
113 
114 	/* The request finished executing at the block device */
115 	RDMA_REQUEST_STATE_EXECUTED,
116 
117 	/* The request is waiting on RDMA queue depth availability
118 	 * to transfer data from the controller to the host.
119 	 */
120 	RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
121 
122 	/* The request is ready to send a completion */
123 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
124 
125 	/* The request is currently transferring data from the controller to the host. */
126 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
127 
128 	/* The request currently has an outstanding completion without an
129 	 * associated data transfer.
130 	 */
131 	RDMA_REQUEST_STATE_COMPLETING,
132 
133 	/* The request completed and can be marked free. */
134 	RDMA_REQUEST_STATE_COMPLETED,
135 
136 	/* Terminator */
137 	RDMA_REQUEST_NUM_STATES,
138 };
139 
140 #define OBJECT_NVMF_RDMA_IO				0x40
141 
142 #define TRACE_GROUP_NVMF_RDMA				0x4
143 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
144 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
145 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
146 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
147 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
148 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
149 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
150 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING		SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
151 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
152 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
153 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
154 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
155 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
156 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
157 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
158 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
159 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
160 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x11)
161 
162 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
163 {
164 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
165 	spdk_trace_register_description("RDMA_REQ_NEW", TRACE_RDMA_REQUEST_STATE_NEW,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
168 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
169 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C2H",
170 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING,
171 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
172 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H2C",
173 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING,
174 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
175 	spdk_trace_register_description("RDMA_REQ_TX_H2C",
176 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
177 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
178 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE",
179 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
180 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
181 	spdk_trace_register_description("RDMA_REQ_EXECUTING",
182 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
183 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
184 	spdk_trace_register_description("RDMA_REQ_EXECUTED",
185 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
186 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
187 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPL",
188 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
189 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
190 	spdk_trace_register_description("RDMA_REQ_COMPLETING_C2H",
191 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
192 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
193 	spdk_trace_register_description("RDMA_REQ_COMPLETING",
194 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
195 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
196 	spdk_trace_register_description("RDMA_REQ_COMPLETED",
197 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
198 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
199 
200 	spdk_trace_register_description("RDMA_QP_CREATE", TRACE_RDMA_QP_CREATE,
201 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
202 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", TRACE_RDMA_IBV_ASYNC_EVENT,
203 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
204 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", TRACE_RDMA_CM_ASYNC_EVENT,
205 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
206 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", TRACE_RDMA_QP_STATE_CHANGE,
207 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
208 	spdk_trace_register_description("RDMA_QP_DISCONNECT", TRACE_RDMA_QP_DISCONNECT,
209 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
210 	spdk_trace_register_description("RDMA_QP_DESTROY", TRACE_RDMA_QP_DESTROY,
211 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
212 }
213 
214 enum spdk_nvmf_rdma_wr_type {
215 	RDMA_WR_TYPE_RECV,
216 	RDMA_WR_TYPE_SEND,
217 	RDMA_WR_TYPE_DATA,
218 };
219 
220 struct spdk_nvmf_rdma_wr {
221 	enum spdk_nvmf_rdma_wr_type	type;
222 };
223 
224 /* This structure holds commands as they are received off the wire.
225  * It must be dynamically paired with a full request object
226  * (spdk_nvmf_rdma_request) to service a request. It is separate
227  * from the request because RDMA does not appear to order
228  * completions, so occasionally we'll get a new incoming
229  * command when there aren't any free request objects.
230  */
231 struct spdk_nvmf_rdma_recv {
232 	struct ibv_recv_wr			wr;
233 	struct ibv_sge				sgl[NVMF_DEFAULT_RX_SGE];
234 
235 	struct spdk_nvmf_rdma_qpair		*qpair;
236 
237 	/* In-capsule data buffer */
238 	uint8_t					*buf;
239 
240 	struct spdk_nvmf_rdma_wr		rdma_wr;
241 	uint64_t				receive_tsc;
242 
243 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
244 };
245 
246 struct spdk_nvmf_rdma_request_data {
247 	struct spdk_nvmf_rdma_wr	rdma_wr;
248 	struct ibv_send_wr		wr;
249 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
250 };
251 
252 struct spdk_nvmf_rdma_request {
253 	struct spdk_nvmf_request		req;
254 
255 	enum spdk_nvmf_rdma_request_state	state;
256 
257 	struct spdk_nvmf_rdma_recv		*recv;
258 
259 	struct {
260 		struct spdk_nvmf_rdma_wr	rdma_wr;
261 		struct	ibv_send_wr		wr;
262 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
263 	} rsp;
264 
265 	struct spdk_nvmf_rdma_request_data	data;
266 
267 	uint32_t				iovpos;
268 
269 	uint32_t				num_outstanding_data_wr;
270 	uint64_t				receive_tsc;
271 
272 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
273 };
274 
275 enum spdk_nvmf_rdma_qpair_disconnect_flags {
276 	RDMA_QP_DISCONNECTING		= 1,
277 	RDMA_QP_RECV_DRAINED		= 1 << 1,
278 	RDMA_QP_SEND_DRAINED		= 1 << 2
279 };
280 
281 struct spdk_nvmf_rdma_resource_opts {
282 	struct spdk_nvmf_rdma_qpair	*qpair;
283 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
284 	void				*qp;
285 	struct ibv_pd			*pd;
286 	uint32_t			max_queue_depth;
287 	uint32_t			in_capsule_data_size;
288 	bool				shared;
289 };
290 
291 struct spdk_nvmf_send_wr_list {
292 	struct ibv_send_wr	*first;
293 	struct ibv_send_wr	*last;
294 };
295 
296 struct spdk_nvmf_recv_wr_list {
297 	struct ibv_recv_wr	*first;
298 	struct ibv_recv_wr	*last;
299 };
300 
301 struct spdk_nvmf_rdma_resources {
302 	/* Array of size "max_queue_depth" containing RDMA requests. */
303 	struct spdk_nvmf_rdma_request		*reqs;
304 
305 	/* Array of size "max_queue_depth" containing RDMA recvs. */
306 	struct spdk_nvmf_rdma_recv		*recvs;
307 
308 	/* Array of size "max_queue_depth" containing 64 byte capsules
309 	 * used for receive.
310 	 */
311 	union nvmf_h2c_msg			*cmds;
312 	struct ibv_mr				*cmds_mr;
313 
314 	/* Array of size "max_queue_depth" containing 16 byte completions
315 	 * to be sent back to the user.
316 	 */
317 	union nvmf_c2h_msg			*cpls;
318 	struct ibv_mr				*cpls_mr;
319 
320 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
321 	 * buffers to be used for in capsule data.
322 	 */
323 	void					*bufs;
324 	struct ibv_mr				*bufs_mr;
325 
326 	/* The list of pending recvs to transfer */
327 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
328 
329 	/* Receives that are waiting for a request object */
330 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
331 
332 	/* Queue to track free requests */
333 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
334 };
335 
336 struct spdk_nvmf_rdma_qpair {
337 	struct spdk_nvmf_qpair			qpair;
338 
339 	struct spdk_nvmf_rdma_port		*port;
340 	struct spdk_nvmf_rdma_poller		*poller;
341 
342 	struct rdma_cm_id			*cm_id;
343 	struct ibv_srq				*srq;
344 	struct rdma_cm_id			*listen_id;
345 
346 	/* The maximum number of I/O outstanding on this connection at one time */
347 	uint16_t				max_queue_depth;
348 
349 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
350 	uint16_t				max_read_depth;
351 
352 	/* The maximum number of RDMA SEND operations at one time */
353 	uint32_t				max_send_depth;
354 
355 	/* The current number of outstanding WRs from this qpair's
356 	 * recv queue. Should not exceed device->attr.max_queue_depth.
357 	 */
358 	uint16_t				current_recv_depth;
359 
360 	/* The current number of active RDMA READ operations */
361 	uint16_t				current_read_depth;
362 
363 	/* The current number of posted WRs from this qpair's
364 	 * send queue. Should not exceed max_send_depth.
365 	 */
366 	uint32_t				current_send_depth;
367 
368 	/* The maximum number of SGEs per WR on the send queue */
369 	uint32_t				max_send_sge;
370 
371 	/* The maximum number of SGEs per WR on the recv queue */
372 	uint32_t				max_recv_sge;
373 
374 	/* The list of pending send requests for a transfer */
375 	struct spdk_nvmf_send_wr_list		sends_to_post;
376 
377 	struct spdk_nvmf_rdma_resources		*resources;
378 
379 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
380 
381 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
382 
383 	/* Number of requests not in the free state */
384 	uint32_t				qd;
385 
386 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
387 
388 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
389 
390 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
391 
392 	/* IBV queue pair attributes: they are used to manage
393 	 * qp state and recover from errors.
394 	 */
395 	enum ibv_qp_state			ibv_state;
396 
397 	uint32_t				disconnect_flags;
398 
399 	/* Poller registered in case the qpair doesn't properly
400 	 * complete the qpair destruct process and becomes defunct.
401 	 */
402 
403 	struct spdk_poller			*destruct_poller;
404 
405 	/* There are several ways a disconnect can start on a qpair
406 	 * and they are not all mutually exclusive. It is important
407 	 * that we only initialize one of these paths.
408 	 */
409 	bool					disconnect_started;
410 	/* Lets us know that we have received the last_wqe event. */
411 	bool					last_wqe_reached;
412 };
413 
414 struct spdk_nvmf_rdma_poller_stat {
415 	uint64_t				completions;
416 	uint64_t				polls;
417 	uint64_t				requests;
418 	uint64_t				request_latency;
419 	uint64_t				pending_free_request;
420 	uint64_t				pending_rdma_read;
421 	uint64_t				pending_rdma_write;
422 };
423 
424 struct spdk_nvmf_rdma_poller {
425 	struct spdk_nvmf_rdma_device		*device;
426 	struct spdk_nvmf_rdma_poll_group	*group;
427 
428 	int					num_cqe;
429 	int					required_num_wr;
430 	struct ibv_cq				*cq;
431 
432 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
433 	uint16_t				max_srq_depth;
434 
435 	/* Shared receive queue */
436 	struct ibv_srq				*srq;
437 
438 	struct spdk_nvmf_rdma_resources		*resources;
439 	struct spdk_nvmf_rdma_poller_stat	stat;
440 
441 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
442 
443 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
444 
445 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
446 
447 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
448 };
449 
450 struct spdk_nvmf_rdma_poll_group_stat {
451 	uint64_t				pending_data_buffer;
452 };
453 
454 struct spdk_nvmf_rdma_poll_group {
455 	struct spdk_nvmf_transport_poll_group		group;
456 	struct spdk_nvmf_rdma_poll_group_stat		stat;
457 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
458 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
459 	/*
460 	 * buffers which are split across multiple RDMA
461 	 * memory regions cannot be used by this transport.
462 	 */
463 	STAILQ_HEAD(, spdk_nvmf_transport_pg_cache_buf)	retired_bufs;
464 };
465 
466 struct spdk_nvmf_rdma_conn_sched {
467 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
468 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
469 };
470 
471 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
472 struct spdk_nvmf_rdma_device {
473 	struct ibv_device_attr			attr;
474 	struct ibv_context			*context;
475 
476 	struct spdk_mem_map			*map;
477 	struct ibv_pd				*pd;
478 
479 	int					num_srq;
480 
481 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
482 };
483 
484 struct spdk_nvmf_rdma_port {
485 	struct spdk_nvme_transport_id		trid;
486 	struct rdma_cm_id			*id;
487 	struct spdk_nvmf_rdma_device		*device;
488 	uint32_t				ref;
489 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
490 };
491 
492 struct spdk_nvmf_rdma_transport {
493 	struct spdk_nvmf_transport	transport;
494 
495 	struct spdk_nvmf_rdma_conn_sched conn_sched;
496 
497 	struct rdma_event_channel	*event_channel;
498 
499 	struct spdk_mempool		*data_wr_pool;
500 
501 	pthread_mutex_t			lock;
502 
503 	/* fields used to poll RDMA/IB events */
504 	nfds_t			npoll_fds;
505 	struct pollfd		*poll_fds;
506 
507 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
508 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
509 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
510 };
511 
512 static inline void
513 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair);
514 
515 static inline int
516 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
517 {
518 	switch (state) {
519 	case IBV_QPS_RESET:
520 	case IBV_QPS_INIT:
521 	case IBV_QPS_RTR:
522 	case IBV_QPS_RTS:
523 	case IBV_QPS_SQD:
524 	case IBV_QPS_SQE:
525 	case IBV_QPS_ERR:
526 		return 0;
527 	default:
528 		return -1;
529 	}
530 }
531 
532 static inline enum spdk_nvme_media_error_status_code
533 spdk_nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
534 	enum spdk_nvme_media_error_status_code result;
535 	switch (err_type)
536 	{
537 	case SPDK_DIF_REFTAG_ERROR:
538 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
539 		break;
540 	case SPDK_DIF_APPTAG_ERROR:
541 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
542 		break;
543 	case SPDK_DIF_GUARD_ERROR:
544 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
545 		break;
546 	default:
547 		SPDK_UNREACHABLE();
548 	}
549 
550 	return result;
551 }
552 
553 static enum ibv_qp_state
554 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
555 	enum ibv_qp_state old_state, new_state;
556 	struct ibv_qp_attr qp_attr;
557 	struct ibv_qp_init_attr init_attr;
558 	int rc;
559 
560 	old_state = rqpair->ibv_state;
561 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
562 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
563 
564 	if (rc)
565 	{
566 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
567 		return IBV_QPS_ERR + 1;
568 	}
569 
570 	new_state = qp_attr.qp_state;
571 	rqpair->ibv_state = new_state;
572 	qp_attr.ah_attr.port_num = qp_attr.port_num;
573 
574 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
575 	if (rc)
576 	{
577 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
578 		/*
579 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
580 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
581 		 */
582 		return IBV_QPS_ERR + 1;
583 	}
584 
585 	if (old_state != new_state)
586 	{
587 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
588 				  (uintptr_t)rqpair->cm_id, new_state);
589 	}
590 	return new_state;
591 }
592 
593 static const char *str_ibv_qp_state[] = {
594 	"IBV_QPS_RESET",
595 	"IBV_QPS_INIT",
596 	"IBV_QPS_RTR",
597 	"IBV_QPS_RTS",
598 	"IBV_QPS_SQD",
599 	"IBV_QPS_SQE",
600 	"IBV_QPS_ERR",
601 	"IBV_QPS_UNKNOWN"
602 };
603 
604 static int
605 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
606 			     enum ibv_qp_state new_state)
607 {
608 	struct ibv_qp_attr qp_attr;
609 	struct ibv_qp_init_attr init_attr;
610 	int rc;
611 	enum ibv_qp_state state;
612 	static int attr_mask_rc[] = {
613 		[IBV_QPS_RESET] = IBV_QP_STATE,
614 		[IBV_QPS_INIT] = (IBV_QP_STATE |
615 				  IBV_QP_PKEY_INDEX |
616 				  IBV_QP_PORT |
617 				  IBV_QP_ACCESS_FLAGS),
618 		[IBV_QPS_RTR] = (IBV_QP_STATE |
619 				 IBV_QP_AV |
620 				 IBV_QP_PATH_MTU |
621 				 IBV_QP_DEST_QPN |
622 				 IBV_QP_RQ_PSN |
623 				 IBV_QP_MAX_DEST_RD_ATOMIC |
624 				 IBV_QP_MIN_RNR_TIMER),
625 		[IBV_QPS_RTS] = (IBV_QP_STATE |
626 				 IBV_QP_SQ_PSN |
627 				 IBV_QP_TIMEOUT |
628 				 IBV_QP_RETRY_CNT |
629 				 IBV_QP_RNR_RETRY |
630 				 IBV_QP_MAX_QP_RD_ATOMIC),
631 		[IBV_QPS_SQD] = IBV_QP_STATE,
632 		[IBV_QPS_SQE] = IBV_QP_STATE,
633 		[IBV_QPS_ERR] = IBV_QP_STATE,
634 	};
635 
636 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
637 	if (rc) {
638 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
639 			    rqpair->qpair.qid, new_state);
640 		return rc;
641 	}
642 
643 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
644 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
645 
646 	if (rc) {
647 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
648 		assert(false);
649 	}
650 
651 	qp_attr.cur_qp_state = rqpair->ibv_state;
652 	qp_attr.qp_state = new_state;
653 
654 	rc = ibv_modify_qp(rqpair->cm_id->qp, &qp_attr,
655 			   attr_mask_rc[new_state]);
656 
657 	if (rc) {
658 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
659 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
660 		return rc;
661 	}
662 
663 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
664 
665 	if (state != new_state) {
666 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
667 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
668 			    str_ibv_qp_state[state]);
669 		return -1;
670 	}
671 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
672 		      str_ibv_qp_state[state]);
673 	return 0;
674 }
675 
676 static void
677 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
678 			    struct spdk_nvmf_rdma_transport *rtransport)
679 {
680 	struct spdk_nvmf_rdma_request_data	*data_wr;
681 	struct ibv_send_wr			*next_send_wr;
682 	uint64_t				req_wrid;
683 
684 	rdma_req->num_outstanding_data_wr = 0;
685 	data_wr = &rdma_req->data;
686 	req_wrid = data_wr->wr.wr_id;
687 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
688 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
689 		data_wr->wr.num_sge = 0;
690 		next_send_wr = data_wr->wr.next;
691 		if (data_wr != &rdma_req->data) {
692 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
693 		}
694 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
695 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
696 	}
697 }
698 
699 static void
700 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
701 {
702 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
703 	if (req->req.cmd) {
704 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
705 	}
706 	if (req->recv) {
707 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
708 	}
709 }
710 
711 static void
712 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
713 {
714 	int i;
715 
716 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
717 	for (i = 0; i < rqpair->max_queue_depth; i++) {
718 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
719 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
720 		}
721 	}
722 }
723 
724 static void
725 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
726 {
727 	if (resources->cmds_mr) {
728 		ibv_dereg_mr(resources->cmds_mr);
729 	}
730 
731 	if (resources->cpls_mr) {
732 		ibv_dereg_mr(resources->cpls_mr);
733 	}
734 
735 	if (resources->bufs_mr) {
736 		ibv_dereg_mr(resources->bufs_mr);
737 	}
738 
739 	spdk_free(resources->cmds);
740 	spdk_free(resources->cpls);
741 	spdk_free(resources->bufs);
742 	free(resources->reqs);
743 	free(resources->recvs);
744 	free(resources);
745 }
746 
747 
748 static struct spdk_nvmf_rdma_resources *
749 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
750 {
751 	struct spdk_nvmf_rdma_resources	*resources;
752 	struct spdk_nvmf_rdma_request	*rdma_req;
753 	struct spdk_nvmf_rdma_recv	*rdma_recv;
754 	struct ibv_qp			*qp;
755 	struct ibv_srq			*srq;
756 	uint32_t			i;
757 	int				rc;
758 
759 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
760 	if (!resources) {
761 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
762 		return NULL;
763 	}
764 
765 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
766 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
767 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
768 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
769 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
770 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
771 
772 	if (opts->in_capsule_data_size > 0) {
773 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
774 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
775 					       SPDK_MALLOC_DMA);
776 	}
777 
778 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
779 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
780 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
781 		goto cleanup;
782 	}
783 
784 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
785 					opts->max_queue_depth * sizeof(*resources->cmds),
786 					IBV_ACCESS_LOCAL_WRITE);
787 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
788 					opts->max_queue_depth * sizeof(*resources->cpls),
789 					0);
790 
791 	if (opts->in_capsule_data_size) {
792 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
793 						opts->max_queue_depth *
794 						opts->in_capsule_data_size,
795 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
796 	}
797 
798 	if (!resources->cmds_mr || !resources->cpls_mr ||
799 	    (opts->in_capsule_data_size &&
800 	     !resources->bufs_mr)) {
801 		goto cleanup;
802 	}
803 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
804 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
805 		      resources->cmds_mr->lkey);
806 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
807 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
808 		      resources->cpls_mr->lkey);
809 	if (resources->bufs && resources->bufs_mr) {
810 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
811 			      resources->bufs, opts->max_queue_depth *
812 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
813 	}
814 
815 	/* Initialize queues */
816 	STAILQ_INIT(&resources->incoming_queue);
817 	STAILQ_INIT(&resources->free_queue);
818 
819 	for (i = 0; i < opts->max_queue_depth; i++) {
820 		struct ibv_recv_wr *bad_wr = NULL;
821 
822 		rdma_recv = &resources->recvs[i];
823 		rdma_recv->qpair = opts->qpair;
824 
825 		/* Set up memory to receive commands */
826 		if (resources->bufs) {
827 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
828 						  opts->in_capsule_data_size));
829 		}
830 
831 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
832 
833 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
834 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
835 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
836 		rdma_recv->wr.num_sge = 1;
837 
838 		if (rdma_recv->buf && resources->bufs_mr) {
839 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
840 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
841 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
842 			rdma_recv->wr.num_sge++;
843 		}
844 
845 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
846 		rdma_recv->wr.sg_list = rdma_recv->sgl;
847 		if (opts->shared) {
848 			srq = (struct ibv_srq *)opts->qp;
849 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
850 		} else {
851 			qp = (struct ibv_qp *)opts->qp;
852 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
853 		}
854 		if (rc) {
855 			goto cleanup;
856 		}
857 	}
858 
859 	for (i = 0; i < opts->max_queue_depth; i++) {
860 		rdma_req = &resources->reqs[i];
861 
862 		if (opts->qpair != NULL) {
863 			rdma_req->req.qpair = &opts->qpair->qpair;
864 		} else {
865 			rdma_req->req.qpair = NULL;
866 		}
867 		rdma_req->req.cmd = NULL;
868 
869 		/* Set up memory to send responses */
870 		rdma_req->req.rsp = &resources->cpls[i];
871 
872 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
873 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
874 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
875 
876 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
877 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
878 		rdma_req->rsp.wr.next = NULL;
879 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
880 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
881 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
882 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
883 
884 		/* Set up memory for data buffers */
885 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
886 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
887 		rdma_req->data.wr.next = NULL;
888 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
889 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
890 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
891 
892 		/* Initialize request state to FREE */
893 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
894 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
895 	}
896 
897 	return resources;
898 
899 cleanup:
900 	nvmf_rdma_resources_destroy(resources);
901 	return NULL;
902 }
903 
904 static void
905 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
906 {
907 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
908 	struct ibv_recv_wr		*bad_recv_wr = NULL;
909 	int				rc;
910 
911 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
912 
913 	spdk_poller_unregister(&rqpair->destruct_poller);
914 
915 	if (rqpair->qd != 0) {
916 		if (rqpair->srq == NULL) {
917 			nvmf_rdma_dump_qpair_contents(rqpair);
918 		}
919 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
920 	}
921 
922 	if (rqpair->poller) {
923 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
924 
925 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
926 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
927 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
928 				if (rqpair == rdma_recv->qpair) {
929 					STAILQ_REMOVE_HEAD(&rqpair->resources->incoming_queue, link);
930 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
931 					if (rc) {
932 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
933 					}
934 				}
935 			}
936 		}
937 	}
938 
939 	if (rqpair->cm_id) {
940 		if (rqpair->cm_id->qp != NULL) {
941 			rdma_destroy_qp(rqpair->cm_id);
942 		}
943 		rdma_destroy_id(rqpair->cm_id);
944 
945 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
946 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
947 		}
948 	}
949 
950 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
951 		nvmf_rdma_resources_destroy(rqpair->resources);
952 	}
953 
954 	free(rqpair);
955 }
956 
957 static int
958 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
959 {
960 	struct spdk_nvmf_rdma_poller	*rpoller;
961 	int				rc, num_cqe, required_num_wr;
962 
963 	/* Enlarge CQ size dynamically */
964 	rpoller = rqpair->poller;
965 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
966 	num_cqe = rpoller->num_cqe;
967 	if (num_cqe < required_num_wr) {
968 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
969 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
970 	}
971 
972 	if (rpoller->num_cqe != num_cqe) {
973 		if (required_num_wr > device->attr.max_cqe) {
974 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
975 				    required_num_wr, device->attr.max_cqe);
976 			return -1;
977 		}
978 
979 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
980 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
981 		if (rc) {
982 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
983 			return -1;
984 		}
985 
986 		rpoller->num_cqe = num_cqe;
987 	}
988 
989 	rpoller->required_num_wr = required_num_wr;
990 	return 0;
991 }
992 
993 static int
994 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
995 {
996 	struct spdk_nvmf_rdma_qpair		*rqpair;
997 	int					rc;
998 	struct spdk_nvmf_rdma_transport		*rtransport;
999 	struct spdk_nvmf_transport		*transport;
1000 	struct spdk_nvmf_rdma_resource_opts	opts;
1001 	struct spdk_nvmf_rdma_device		*device;
1002 	struct ibv_qp_init_attr			ibv_init_attr;
1003 
1004 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1005 	device = rqpair->port->device;
1006 
1007 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
1008 	ibv_init_attr.qp_context	= rqpair;
1009 	ibv_init_attr.qp_type		= IBV_QPT_RC;
1010 	ibv_init_attr.send_cq		= rqpair->poller->cq;
1011 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
1012 
1013 	if (rqpair->srq) {
1014 		ibv_init_attr.srq		= rqpair->srq;
1015 	} else {
1016 		ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
1017 						  1; /* RECV operations + dummy drain WR */
1018 	}
1019 
1020 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
1021 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
1022 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1023 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1024 
1025 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1026 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1027 		goto error;
1028 	}
1029 
1030 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
1031 	if (rc) {
1032 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
1033 		goto error;
1034 	}
1035 
1036 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2 + 1),
1037 					  ibv_init_attr.cap.max_send_wr);
1038 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
1039 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
1040 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1041 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
1042 
1043 	rqpair->sends_to_post.first = NULL;
1044 	rqpair->sends_to_post.last = NULL;
1045 
1046 	if (rqpair->poller->srq == NULL) {
1047 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1048 		transport = &rtransport->transport;
1049 
1050 		opts.qp = rqpair->cm_id->qp;
1051 		opts.pd = rqpair->cm_id->pd;
1052 		opts.qpair = rqpair;
1053 		opts.shared = false;
1054 		opts.max_queue_depth = rqpair->max_queue_depth;
1055 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1056 
1057 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1058 
1059 		if (!rqpair->resources) {
1060 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1061 			rdma_destroy_qp(rqpair->cm_id);
1062 			goto error;
1063 		}
1064 	} else {
1065 		rqpair->resources = rqpair->poller->resources;
1066 	}
1067 
1068 	rqpair->current_recv_depth = 0;
1069 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1070 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1071 
1072 	return 0;
1073 
1074 error:
1075 	rdma_destroy_id(rqpair->cm_id);
1076 	rqpair->cm_id = NULL;
1077 	return -1;
1078 }
1079 
1080 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1081 /* This function accepts either a single wr or the first wr in a linked list. */
1082 static void
1083 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1084 {
1085 	struct ibv_recv_wr *last;
1086 
1087 	last = first;
1088 	while (last->next != NULL) {
1089 		last = last->next;
1090 	}
1091 
1092 	if (rqpair->resources->recvs_to_post.first == NULL) {
1093 		rqpair->resources->recvs_to_post.first = first;
1094 		rqpair->resources->recvs_to_post.last = last;
1095 		if (rqpair->srq == NULL) {
1096 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1097 		}
1098 	} else {
1099 		rqpair->resources->recvs_to_post.last->next = first;
1100 		rqpair->resources->recvs_to_post.last = last;
1101 	}
1102 }
1103 
1104 /* Append the given send wr structure to the qpair's outstanding sends list. */
1105 /* This function accepts either a single wr or the first wr in a linked list. */
1106 static void
1107 nvmf_rdma_qpair_queue_send_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *first)
1108 {
1109 	struct ibv_send_wr *last;
1110 
1111 	last = first;
1112 	while (last->next != NULL) {
1113 		last = last->next;
1114 	}
1115 
1116 	if (rqpair->sends_to_post.first == NULL) {
1117 		rqpair->sends_to_post.first = first;
1118 		rqpair->sends_to_post.last = last;
1119 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1120 	} else {
1121 		rqpair->sends_to_post.last->next = first;
1122 		rqpair->sends_to_post.last = last;
1123 	}
1124 }
1125 
1126 static int
1127 request_transfer_in(struct spdk_nvmf_request *req)
1128 {
1129 	struct spdk_nvmf_rdma_request	*rdma_req;
1130 	struct spdk_nvmf_qpair		*qpair;
1131 	struct spdk_nvmf_rdma_qpair	*rqpair;
1132 
1133 	qpair = req->qpair;
1134 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1135 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1136 
1137 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1138 	assert(rdma_req != NULL);
1139 
1140 	nvmf_rdma_qpair_queue_send_wrs(rqpair, &rdma_req->data.wr);
1141 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1142 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1143 	return 0;
1144 }
1145 
1146 static int
1147 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1148 {
1149 	int				num_outstanding_data_wr = 0;
1150 	struct spdk_nvmf_rdma_request	*rdma_req;
1151 	struct spdk_nvmf_qpair		*qpair;
1152 	struct spdk_nvmf_rdma_qpair	*rqpair;
1153 	struct spdk_nvme_cpl		*rsp;
1154 	struct ibv_send_wr		*first = NULL;
1155 
1156 	*data_posted = 0;
1157 	qpair = req->qpair;
1158 	rsp = &req->rsp->nvme_cpl;
1159 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1160 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1161 
1162 	/* Advance our sq_head pointer */
1163 	if (qpair->sq_head == qpair->sq_head_max) {
1164 		qpair->sq_head = 0;
1165 	} else {
1166 		qpair->sq_head++;
1167 	}
1168 	rsp->sqhd = qpair->sq_head;
1169 
1170 	/* queue the capsule for the recv buffer */
1171 	assert(rdma_req->recv != NULL);
1172 
1173 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1174 
1175 	rdma_req->recv = NULL;
1176 	assert(rqpair->current_recv_depth > 0);
1177 	rqpair->current_recv_depth--;
1178 
1179 	/* Build the response which consists of optional
1180 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1181 	 * containing the response.
1182 	 */
1183 	first = &rdma_req->rsp.wr;
1184 
1185 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
1186 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1187 		first = &rdma_req->data.wr;
1188 		*data_posted = 1;
1189 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1190 	}
1191 	nvmf_rdma_qpair_queue_send_wrs(rqpair, first);
1192 	/* +1 for the rsp wr */
1193 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1194 
1195 	return 0;
1196 }
1197 
1198 static int
1199 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1200 {
1201 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1202 	struct rdma_conn_param				ctrlr_event_data = {};
1203 	int						rc;
1204 
1205 	accept_data.recfmt = 0;
1206 	accept_data.crqsize = rqpair->max_queue_depth;
1207 
1208 	ctrlr_event_data.private_data = &accept_data;
1209 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1210 	if (id->ps == RDMA_PS_TCP) {
1211 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1212 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1213 	}
1214 
1215 	/* Configure infinite retries for the initiator side qpair.
1216 	 * When using a shared receive queue on the target side,
1217 	 * we need to pass this value to the initiator to prevent the
1218 	 * initiator side NIC from completing SEND requests back to the
1219 	 * initiator with status rnr_retry_count_exceeded. */
1220 	if (rqpair->srq != NULL) {
1221 		ctrlr_event_data.rnr_retry_count = 0x7;
1222 	}
1223 
1224 	rc = rdma_accept(id, &ctrlr_event_data);
1225 	if (rc) {
1226 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
1227 	} else {
1228 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
1229 	}
1230 
1231 	return rc;
1232 }
1233 
1234 static void
1235 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1236 {
1237 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1238 
1239 	rej_data.recfmt = 0;
1240 	rej_data.sts = error;
1241 
1242 	rdma_reject(id, &rej_data, sizeof(rej_data));
1243 }
1244 
1245 static int
1246 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
1247 		  new_qpair_fn cb_fn, void *cb_arg)
1248 {
1249 	struct spdk_nvmf_rdma_transport *rtransport;
1250 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1251 	struct spdk_nvmf_rdma_port	*port;
1252 	struct rdma_conn_param		*rdma_param = NULL;
1253 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1254 	uint16_t			max_queue_depth;
1255 	uint16_t			max_read_depth;
1256 
1257 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1258 
1259 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1260 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1261 
1262 	rdma_param = &event->param.conn;
1263 	if (rdma_param->private_data == NULL ||
1264 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1265 		SPDK_ERRLOG("connect request: no private data provided\n");
1266 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1267 		return -1;
1268 	}
1269 
1270 	private_data = rdma_param->private_data;
1271 	if (private_data->recfmt != 0) {
1272 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1273 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1274 		return -1;
1275 	}
1276 
1277 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1278 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1279 
1280 	port = event->listen_id->context;
1281 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1282 		      event->listen_id, event->listen_id->verbs, port);
1283 
1284 	/* Figure out the supported queue depth. This is a multi-step process
1285 	 * that takes into account hardware maximums, host provided values,
1286 	 * and our target's internal memory limits */
1287 
1288 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1289 
1290 	/* Start with the maximum queue depth allowed by the target */
1291 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1292 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1293 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1294 		      rtransport->transport.opts.max_queue_depth);
1295 
1296 	/* Next check the local NIC's hardware limitations */
1297 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1298 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1299 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1300 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1301 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1302 
1303 	/* Next check the remote NIC's hardware limitations */
1304 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1305 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1306 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1307 	if (rdma_param->initiator_depth > 0) {
1308 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1309 	}
1310 
1311 	/* Finally check for the host software requested values, which are
1312 	 * optional. */
1313 	if (rdma_param->private_data != NULL &&
1314 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1315 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1316 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1317 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1318 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1319 	}
1320 
1321 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1322 		      max_queue_depth, max_read_depth);
1323 
1324 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1325 	if (rqpair == NULL) {
1326 		SPDK_ERRLOG("Could not allocate new connection.\n");
1327 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1328 		return -1;
1329 	}
1330 
1331 	rqpair->port = port;
1332 	rqpair->max_queue_depth = max_queue_depth;
1333 	rqpair->max_read_depth = max_read_depth;
1334 	rqpair->cm_id = event->id;
1335 	rqpair->listen_id = event->listen_id;
1336 	rqpair->qpair.transport = transport;
1337 	/* use qid from the private data to determine the qpair type
1338 	   qid will be set to the appropriate value when the controller is created */
1339 	rqpair->qpair.qid = private_data->qid;
1340 
1341 	event->id->context = &rqpair->qpair;
1342 
1343 	cb_fn(&rqpair->qpair, cb_arg);
1344 
1345 	return 0;
1346 }
1347 
1348 static int
1349 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1350 			  enum spdk_mem_map_notify_action action,
1351 			  void *vaddr, size_t size)
1352 {
1353 	struct ibv_pd *pd = cb_ctx;
1354 	struct ibv_mr *mr;
1355 	int rc;
1356 
1357 	switch (action) {
1358 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1359 		if (!g_nvmf_hooks.get_rkey) {
1360 			mr = ibv_reg_mr(pd, vaddr, size,
1361 					IBV_ACCESS_LOCAL_WRITE |
1362 					IBV_ACCESS_REMOTE_READ |
1363 					IBV_ACCESS_REMOTE_WRITE);
1364 			if (mr == NULL) {
1365 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1366 				return -1;
1367 			} else {
1368 				rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1369 			}
1370 		} else {
1371 			rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1372 							  g_nvmf_hooks.get_rkey(pd, vaddr, size));
1373 		}
1374 		break;
1375 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1376 		if (!g_nvmf_hooks.get_rkey) {
1377 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1378 			if (mr) {
1379 				ibv_dereg_mr(mr);
1380 			}
1381 		}
1382 		rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1383 		break;
1384 	default:
1385 		SPDK_UNREACHABLE();
1386 	}
1387 
1388 	return rc;
1389 }
1390 
1391 static int
1392 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1393 {
1394 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1395 	return addr_1 == addr_2;
1396 }
1397 
1398 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1399 
1400 static spdk_nvme_data_transfer_t
1401 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1402 {
1403 	enum spdk_nvme_data_transfer xfer;
1404 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1405 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1406 
1407 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1408 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1409 	rdma_req->rsp.wr.imm_data = 0;
1410 #endif
1411 
1412 	/* Figure out data transfer direction */
1413 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1414 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1415 	} else {
1416 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1417 
1418 		/* Some admin commands are special cases */
1419 		if ((rdma_req->req.qpair->qid == 0) &&
1420 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1421 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1422 			switch (cmd->cdw10 & 0xff) {
1423 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1424 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1425 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1426 				break;
1427 			default:
1428 				xfer = SPDK_NVME_DATA_NONE;
1429 			}
1430 		}
1431 	}
1432 
1433 	if (xfer == SPDK_NVME_DATA_NONE) {
1434 		return xfer;
1435 	}
1436 
1437 	/* Even for commands that may transfer data, they could have specified 0 length.
1438 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1439 	 */
1440 	switch (sgl->generic.type) {
1441 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1442 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1443 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1444 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1445 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1446 		if (sgl->unkeyed.length == 0) {
1447 			xfer = SPDK_NVME_DATA_NONE;
1448 		}
1449 		break;
1450 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1451 		if (sgl->keyed.length == 0) {
1452 			xfer = SPDK_NVME_DATA_NONE;
1453 		}
1454 		break;
1455 	}
1456 
1457 	return xfer;
1458 }
1459 
1460 static inline void
1461 nvmf_rdma_setup_wr(struct ibv_send_wr *wr, struct ibv_send_wr *next,
1462 		   enum spdk_nvme_data_transfer xfer)
1463 {
1464 	if (xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1465 		wr->opcode = IBV_WR_RDMA_WRITE;
1466 		wr->send_flags = 0;
1467 		wr->next = next;
1468 	} else if (xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1469 		wr->opcode = IBV_WR_RDMA_READ;
1470 		wr->send_flags = IBV_SEND_SIGNALED;
1471 		wr->next = NULL;
1472 	} else {
1473 		assert(0);
1474 	}
1475 }
1476 
1477 static int
1478 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1479 		       struct spdk_nvmf_rdma_request *rdma_req,
1480 		       uint32_t num_sgl_descriptors)
1481 {
1482 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1483 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1484 	uint32_t				i;
1485 
1486 	if (num_sgl_descriptors > SPDK_NVMF_MAX_SGL_ENTRIES) {
1487 		SPDK_ERRLOG("Requested too much entries (%u), the limit is %u\n",
1488 			    num_sgl_descriptors, SPDK_NVMF_MAX_SGL_ENTRIES);
1489 		return -EINVAL;
1490 	}
1491 
1492 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1493 		return -ENOMEM;
1494 	}
1495 
1496 	current_data_wr = &rdma_req->data;
1497 
1498 	for (i = 0; i < num_sgl_descriptors; i++) {
1499 		nvmf_rdma_setup_wr(&current_data_wr->wr, &work_requests[i]->wr, rdma_req->req.xfer);
1500 		current_data_wr->wr.next = &work_requests[i]->wr;
1501 		current_data_wr = work_requests[i];
1502 		current_data_wr->wr.sg_list = current_data_wr->sgl;
1503 		current_data_wr->wr.wr_id = rdma_req->data.wr.wr_id;
1504 	}
1505 
1506 	nvmf_rdma_setup_wr(&current_data_wr->wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1507 
1508 	return 0;
1509 }
1510 
1511 static inline void
1512 nvmf_rdma_setup_request(struct spdk_nvmf_rdma_request *rdma_req)
1513 {
1514 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1515 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1516 
1517 	wr->wr.rdma.rkey = sgl->keyed.key;
1518 	wr->wr.rdma.remote_addr = sgl->address;
1519 	nvmf_rdma_setup_wr(wr, &rdma_req->rsp.wr, rdma_req->req.xfer);
1520 }
1521 
1522 static inline void
1523 nvmf_rdma_update_remote_addr(struct spdk_nvmf_rdma_request *rdma_req, uint32_t num_wrs)
1524 {
1525 	struct ibv_send_wr		*wr = &rdma_req->data.wr;
1526 	struct spdk_nvme_sgl_descriptor	*sgl = &rdma_req->req.cmd->nvme_cmd.dptr.sgl1;
1527 	uint32_t			i;
1528 	int				j;
1529 	uint64_t			remote_addr_offset = 0;
1530 
1531 	for (i = 0; i < num_wrs; ++i) {
1532 		wr->wr.rdma.rkey = sgl->keyed.key;
1533 		wr->wr.rdma.remote_addr = sgl->address + remote_addr_offset;
1534 		for (j = 0; j < wr->num_sge; ++j) {
1535 			remote_addr_offset += wr->sg_list[j].length;
1536 		}
1537 		wr = wr->next;
1538 	}
1539 }
1540 
1541 /* This function is used in the rare case that we have a buffer split over multiple memory regions. */
1542 static int
1543 nvmf_rdma_replace_buffer(struct spdk_nvmf_rdma_poll_group *rgroup, void **buf)
1544 {
1545 	struct spdk_nvmf_transport_poll_group	*group = &rgroup->group;
1546 	struct spdk_nvmf_transport		*transport = group->transport;
1547 	struct spdk_nvmf_transport_pg_cache_buf	*old_buf;
1548 	void					*new_buf;
1549 
1550 	if (!(STAILQ_EMPTY(&group->buf_cache))) {
1551 		group->buf_cache_count--;
1552 		new_buf = STAILQ_FIRST(&group->buf_cache);
1553 		STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1554 		assert(*buf != NULL);
1555 	} else {
1556 		new_buf = spdk_mempool_get(transport->data_buf_pool);
1557 	}
1558 
1559 	if (*buf == NULL) {
1560 		return -ENOMEM;
1561 	}
1562 
1563 	old_buf = *buf;
1564 	STAILQ_INSERT_HEAD(&rgroup->retired_bufs, old_buf, link);
1565 	*buf = new_buf;
1566 	return 0;
1567 }
1568 
1569 static bool
1570 nvmf_rdma_get_lkey(struct spdk_nvmf_rdma_device *device, struct iovec *iov,
1571 		   uint32_t *_lkey)
1572 {
1573 	uint64_t	translation_len;
1574 	uint32_t	lkey;
1575 
1576 	translation_len = iov->iov_len;
1577 
1578 	if (!g_nvmf_hooks.get_rkey) {
1579 		lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1580 				(uint64_t)iov->iov_base, &translation_len))->lkey;
1581 	} else {
1582 		lkey = spdk_mem_map_translate(device->map,
1583 					      (uint64_t)iov->iov_base, &translation_len);
1584 	}
1585 
1586 	if (spdk_unlikely(translation_len < iov->iov_len)) {
1587 		return false;
1588 	}
1589 
1590 	*_lkey = lkey;
1591 	return true;
1592 }
1593 
1594 static bool
1595 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1596 		      struct iovec *iov, struct ibv_send_wr **_wr,
1597 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1598 		      uint32_t *_num_extra_wrs,
1599 		      const struct spdk_dif_ctx *dif_ctx)
1600 {
1601 	struct ibv_send_wr *wr = *_wr;
1602 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1603 	uint32_t	lkey = 0;
1604 	uint32_t	remaining, data_block_size, md_size, sge_len;
1605 
1606 	if (spdk_unlikely(!nvmf_rdma_get_lkey(device, iov, &lkey))) {
1607 		/* This is a very rare case that can occur when using DPDK version < 19.05 */
1608 		SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions. Removing it from circulation.\n");
1609 		return false;
1610 	}
1611 
1612 	if (spdk_likely(!dif_ctx)) {
1613 		sg_ele->lkey = lkey;
1614 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1615 		sg_ele->length = iov->iov_len;
1616 		wr->num_sge++;
1617 	} else {
1618 		remaining = iov->iov_len - *_offset;
1619 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1620 		md_size = dif_ctx->md_size;
1621 
1622 		while (remaining) {
1623 			if (wr->num_sge >= SPDK_NVMF_MAX_SGL_ENTRIES) {
1624 				if (*_num_extra_wrs > 0 && wr->next) {
1625 					*_wr = wr->next;
1626 					wr = *_wr;
1627 					wr->num_sge = 0;
1628 					sg_ele = &wr->sg_list[wr->num_sge];
1629 					(*_num_extra_wrs)--;
1630 				} else {
1631 					break;
1632 				}
1633 			}
1634 			sg_ele->lkey = lkey;
1635 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1636 			sge_len = spdk_min(remaining, *_remaining_data_block);
1637 			sg_ele->length = sge_len;
1638 			remaining -= sge_len;
1639 			*_remaining_data_block -= sge_len;
1640 			*_offset += sge_len;
1641 
1642 			sg_ele++;
1643 			wr->num_sge++;
1644 
1645 			if (*_remaining_data_block == 0) {
1646 				/* skip metadata */
1647 				*_offset += md_size;
1648 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1649 				remaining -= spdk_min(remaining, md_size);
1650 				*_remaining_data_block = data_block_size;
1651 			}
1652 
1653 			if (remaining == 0) {
1654 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1655 				   the remaining metadata bits at the beginning of the next buffer */
1656 				*_offset -= iov->iov_len;
1657 			}
1658 		}
1659 	}
1660 
1661 	return true;
1662 }
1663 
1664 static int
1665 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1666 		      struct spdk_nvmf_rdma_device *device,
1667 		      struct spdk_nvmf_rdma_request *rdma_req,
1668 		      struct ibv_send_wr *wr,
1669 		      uint32_t length,
1670 		      uint32_t num_extra_wrs)
1671 {
1672 	struct spdk_nvmf_request *req = &rdma_req->req;
1673 	struct spdk_dif_ctx *dif_ctx = NULL;
1674 	uint32_t remaining_data_block = 0;
1675 	uint32_t offset = 0;
1676 
1677 	if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
1678 		dif_ctx = &rdma_req->req.dif.dif_ctx;
1679 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1680 	}
1681 
1682 	wr->num_sge = 0;
1683 
1684 	while (length && (num_extra_wrs || wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES)) {
1685 		while (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], &wr,
1686 				     &remaining_data_block, &offset, &num_extra_wrs, dif_ctx))) {
1687 			if (nvmf_rdma_replace_buffer(rgroup, &req->buffers[rdma_req->iovpos]) == -ENOMEM) {
1688 				return -ENOMEM;
1689 			}
1690 			req->iov[rdma_req->iovpos].iov_base = (void *)((uintptr_t)(req->buffers[rdma_req->iovpos] +
1691 							      NVMF_DATA_BUFFER_MASK) &
1692 							      ~NVMF_DATA_BUFFER_MASK);
1693 		}
1694 
1695 		length -= req->iov[rdma_req->iovpos].iov_len;
1696 		rdma_req->iovpos++;
1697 	}
1698 
1699 	if (length) {
1700 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1701 		return -EINVAL;
1702 	}
1703 
1704 	return 0;
1705 }
1706 
1707 static inline uint32_t
1708 nvmf_rdma_calc_num_wrs(uint32_t length, uint32_t io_unit_size, uint32_t block_size)
1709 {
1710 	/* estimate the number of SG entries and WRs needed to process the request */
1711 	uint32_t num_sge = 0;
1712 	uint32_t i;
1713 	uint32_t num_buffers = SPDK_CEIL_DIV(length, io_unit_size);
1714 
1715 	for (i = 0; i < num_buffers && length > 0; i++) {
1716 		uint32_t buffer_len = spdk_min(length, io_unit_size);
1717 		uint32_t num_sge_in_block = SPDK_CEIL_DIV(buffer_len, block_size);
1718 
1719 		if (num_sge_in_block * block_size > buffer_len) {
1720 			++num_sge_in_block;
1721 		}
1722 		num_sge += num_sge_in_block;
1723 		length -= buffer_len;
1724 	}
1725 	return SPDK_CEIL_DIV(num_sge, SPDK_NVMF_MAX_SGL_ENTRIES);
1726 }
1727 
1728 static int
1729 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1730 				 struct spdk_nvmf_rdma_device *device,
1731 				 struct spdk_nvmf_rdma_request *rdma_req,
1732 				 uint32_t length)
1733 {
1734 	struct spdk_nvmf_rdma_qpair		*rqpair;
1735 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1736 	struct spdk_nvmf_request		*req = &rdma_req->req;
1737 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1738 	int					rc;
1739 	uint32_t				num_wrs = 1;
1740 
1741 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1742 	rgroup = rqpair->poller->group;
1743 
1744 	/* rdma wr specifics */
1745 	nvmf_rdma_setup_request(rdma_req);
1746 
1747 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1748 					   length);
1749 	if (rc != 0) {
1750 		return rc;
1751 	}
1752 
1753 	assert(req->iovcnt <= rqpair->max_send_sge);
1754 
1755 	rdma_req->iovpos = 0;
1756 
1757 	if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1758 		num_wrs = nvmf_rdma_calc_num_wrs(length, rtransport->transport.opts.io_unit_size,
1759 						 req->dif.dif_ctx.block_size);
1760 		if (num_wrs > 1) {
1761 			rc = nvmf_request_alloc_wrs(rtransport, rdma_req, num_wrs - 1);
1762 			if (rc != 0) {
1763 				goto err_exit;
1764 			}
1765 		}
1766 	}
1767 
1768 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length, num_wrs - 1);
1769 	if (spdk_unlikely(rc != 0)) {
1770 		goto err_exit;
1771 	}
1772 
1773 	if (spdk_unlikely(num_wrs > 1)) {
1774 		nvmf_rdma_update_remote_addr(rdma_req, num_wrs);
1775 	}
1776 
1777 	/* set the number of outstanding data WRs for this request. */
1778 	rdma_req->num_outstanding_data_wr = num_wrs;
1779 
1780 	return rc;
1781 
1782 err_exit:
1783 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1784 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1785 	req->iovcnt = 0;
1786 	return rc;
1787 }
1788 
1789 static int
1790 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1791 				      struct spdk_nvmf_rdma_device *device,
1792 				      struct spdk_nvmf_rdma_request *rdma_req)
1793 {
1794 	struct spdk_nvmf_rdma_qpair		*rqpair;
1795 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1796 	struct ibv_send_wr			*current_wr;
1797 	struct spdk_nvmf_request		*req = &rdma_req->req;
1798 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1799 	uint32_t				num_sgl_descriptors;
1800 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1801 	uint32_t				i;
1802 	int					rc;
1803 
1804 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1805 	rgroup = rqpair->poller->group;
1806 
1807 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1808 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1809 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1810 
1811 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1812 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1813 
1814 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1815 		return -ENOMEM;
1816 	}
1817 
1818 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1819 	for (i = 0; i < num_sgl_descriptors; i++) {
1820 		if (spdk_likely(!req->dif.dif_insert_or_strip)) {
1821 			lengths[i] = desc->keyed.length;
1822 		} else {
1823 			req->dif.orig_length += desc->keyed.length;
1824 			lengths[i] = spdk_dif_get_length_with_md(desc->keyed.length, &req->dif.dif_ctx);
1825 			req->dif.elba_length += lengths[i];
1826 		}
1827 		desc++;
1828 	}
1829 
1830 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1831 			lengths, num_sgl_descriptors);
1832 	if (rc != 0) {
1833 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1834 		return rc;
1835 	}
1836 
1837 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1838 	current_wr = &rdma_req->data.wr;
1839 	assert(current_wr != NULL);
1840 
1841 	req->length = 0;
1842 	rdma_req->iovpos = 0;
1843 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1844 	for (i = 0; i < num_sgl_descriptors; i++) {
1845 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1846 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1847 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1848 			rc = -EINVAL;
1849 			goto err_exit;
1850 		}
1851 
1852 		current_wr->num_sge = 0;
1853 
1854 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, lengths[i], 0);
1855 		if (rc != 0) {
1856 			rc = -ENOMEM;
1857 			goto err_exit;
1858 		}
1859 
1860 		req->length += desc->keyed.length;
1861 		current_wr->wr.rdma.rkey = desc->keyed.key;
1862 		current_wr->wr.rdma.remote_addr = desc->address;
1863 		current_wr = current_wr->next;
1864 		desc++;
1865 	}
1866 
1867 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1868 	/* Go back to the last descriptor in the list. */
1869 	desc--;
1870 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1871 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1872 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1873 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1874 		}
1875 	}
1876 #endif
1877 
1878 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1879 
1880 	return 0;
1881 
1882 err_exit:
1883 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1884 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1885 	return rc;
1886 }
1887 
1888 static int
1889 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1890 				 struct spdk_nvmf_rdma_device *device,
1891 				 struct spdk_nvmf_rdma_request *rdma_req)
1892 {
1893 	struct spdk_nvmf_request		*req = &rdma_req->req;
1894 	struct spdk_nvme_cpl			*rsp;
1895 	struct spdk_nvme_sgl_descriptor		*sgl;
1896 	int					rc;
1897 	uint32_t				length;
1898 
1899 	rsp = &req->rsp->nvme_cpl;
1900 	sgl = &req->cmd->nvme_cmd.dptr.sgl1;
1901 
1902 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1903 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1904 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1905 
1906 		length = sgl->keyed.length;
1907 		if (length > rtransport->transport.opts.max_io_size) {
1908 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1909 				    length, rtransport->transport.opts.max_io_size);
1910 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1911 			return -1;
1912 		}
1913 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1914 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1915 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1916 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1917 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1918 			}
1919 		}
1920 #endif
1921 
1922 		/* fill request length and populate iovs */
1923 		req->length = length;
1924 
1925 		if (spdk_unlikely(req->dif.dif_insert_or_strip)) {
1926 			req->dif.orig_length = length;
1927 			length = spdk_dif_get_length_with_md(length, &req->dif.dif_ctx);
1928 			req->dif.elba_length = length;
1929 		}
1930 
1931 		rc = spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length);
1932 		if (spdk_unlikely(rc < 0)) {
1933 			if (rc == -EINVAL) {
1934 				SPDK_ERRLOG("SGL length exceeds the max I/O size\n");
1935 				return -1;
1936 			}
1937 			/* No available buffers. Queue this request up. */
1938 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1939 			return 0;
1940 		}
1941 
1942 		/* backward compatible */
1943 		req->data = req->iov[0].iov_base;
1944 
1945 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1946 			      req->iovcnt);
1947 
1948 		return 0;
1949 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1950 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1951 		uint64_t offset = sgl->address;
1952 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1953 
1954 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1955 			      offset, sgl->unkeyed.length);
1956 
1957 		if (offset > max_len) {
1958 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1959 				    offset, max_len);
1960 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1961 			return -1;
1962 		}
1963 		max_len -= (uint32_t)offset;
1964 
1965 		if (sgl->unkeyed.length > max_len) {
1966 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1967 				    sgl->unkeyed.length, max_len);
1968 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1969 			return -1;
1970 		}
1971 
1972 		rdma_req->num_outstanding_data_wr = 0;
1973 		req->data = rdma_req->recv->buf + offset;
1974 		req->data_from_pool = false;
1975 		req->length = sgl->unkeyed.length;
1976 
1977 		req->iov[0].iov_base = req->data;
1978 		req->iov[0].iov_len = req->length;
1979 		req->iovcnt = 1;
1980 
1981 		return 0;
1982 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1983 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1984 
1985 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1986 		if (rc == -ENOMEM) {
1987 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1988 			return 0;
1989 		} else if (rc == -EINVAL) {
1990 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1991 			return -1;
1992 		}
1993 
1994 		/* backward compatible */
1995 		req->data = req->iov[0].iov_base;
1996 
1997 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1998 			      req->iovcnt);
1999 
2000 		return 0;
2001 	}
2002 
2003 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
2004 		    sgl->generic.type, sgl->generic.subtype);
2005 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
2006 	return -1;
2007 }
2008 
2009 static void
2010 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
2011 		       struct spdk_nvmf_rdma_transport	*rtransport)
2012 {
2013 	struct spdk_nvmf_rdma_qpair		*rqpair;
2014 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2015 
2016 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2017 	if (rdma_req->req.data_from_pool) {
2018 		rgroup = rqpair->poller->group;
2019 
2020 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
2021 	}
2022 	nvmf_rdma_request_free_data(rdma_req, rtransport);
2023 	rdma_req->req.length = 0;
2024 	rdma_req->req.iovcnt = 0;
2025 	rdma_req->req.data = NULL;
2026 	rdma_req->rsp.wr.next = NULL;
2027 	rdma_req->data.wr.next = NULL;
2028 	memset(&rdma_req->req.dif, 0, sizeof(rdma_req->req.dif));
2029 	rqpair->qd--;
2030 
2031 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
2032 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
2033 }
2034 
2035 static bool
2036 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
2037 			       struct spdk_nvmf_rdma_request *rdma_req)
2038 {
2039 	struct spdk_nvmf_rdma_qpair	*rqpair;
2040 	struct spdk_nvmf_rdma_device	*device;
2041 	struct spdk_nvmf_rdma_poll_group *rgroup;
2042 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
2043 	int				rc;
2044 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2045 	enum spdk_nvmf_rdma_request_state prev_state;
2046 	bool				progress = false;
2047 	int				data_posted;
2048 	uint32_t			num_blocks;
2049 
2050 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2051 	device = rqpair->port->device;
2052 	rgroup = rqpair->poller->group;
2053 
2054 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
2055 
2056 	/* If the queue pair is in an error state, force the request to the completed state
2057 	 * to release resources. */
2058 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2059 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
2060 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
2061 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
2062 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2063 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
2064 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2065 		}
2066 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2067 	}
2068 
2069 	/* The loop here is to allow for several back-to-back state changes. */
2070 	do {
2071 		prev_state = rdma_req->state;
2072 
2073 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
2074 
2075 		switch (rdma_req->state) {
2076 		case RDMA_REQUEST_STATE_FREE:
2077 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
2078 			 * to escape this state. */
2079 			break;
2080 		case RDMA_REQUEST_STATE_NEW:
2081 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
2082 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2083 			rdma_recv = rdma_req->recv;
2084 
2085 			/* The first element of the SGL is the NVMe command */
2086 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
2087 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
2088 
2089 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2090 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2091 				break;
2092 			}
2093 
2094 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->req.dif.dif_ctx))) {
2095 				rdma_req->req.dif.dif_insert_or_strip = true;
2096 			}
2097 
2098 			/* The next state transition depends on the data transfer needs of this request. */
2099 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
2100 
2101 			/* If no data to transfer, ready to execute. */
2102 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2103 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2104 				break;
2105 			}
2106 
2107 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2108 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2109 			break;
2110 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2111 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2112 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2113 
2114 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2115 
2116 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2117 				/* This request needs to wait in line to obtain a buffer */
2118 				break;
2119 			}
2120 
2121 			/* Try to get a data buffer */
2122 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2123 			if (rc < 0) {
2124 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2125 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2126 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2127 				break;
2128 			}
2129 
2130 			if (!rdma_req->req.data) {
2131 				/* No buffers available. */
2132 				rgroup->stat.pending_data_buffer++;
2133 				break;
2134 			}
2135 
2136 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2137 
2138 			/* If data is transferring from host to controller and the data didn't
2139 			 * arrive using in capsule data, we need to do a transfer from the host.
2140 			 */
2141 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2142 			    rdma_req->req.data_from_pool) {
2143 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2144 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2145 				break;
2146 			}
2147 
2148 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2149 			break;
2150 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2151 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2152 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2153 
2154 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2155 				/* This request needs to wait in line to perform RDMA */
2156 				break;
2157 			}
2158 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2159 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2160 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2161 				rqpair->poller->stat.pending_rdma_read++;
2162 				break;
2163 			}
2164 
2165 			/* We have already verified that this request is the head of the queue. */
2166 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2167 
2168 			rc = request_transfer_in(&rdma_req->req);
2169 			if (!rc) {
2170 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2171 			} else {
2172 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2173 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2174 			}
2175 			break;
2176 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2177 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2178 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2179 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2180 			 * to escape this state. */
2181 			break;
2182 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2183 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2184 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2185 
2186 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2187 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2188 					/* generate DIF for write operation */
2189 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2190 					assert(num_blocks > 0);
2191 
2192 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2193 							       num_blocks, &rdma_req->req.dif.dif_ctx);
2194 					if (rc != 0) {
2195 						SPDK_ERRLOG("DIF generation failed\n");
2196 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2197 						spdk_nvmf_rdma_start_disconnect(rqpair);
2198 						break;
2199 					}
2200 				}
2201 
2202 				assert(rdma_req->req.dif.elba_length >= rdma_req->req.length);
2203 				/* set extended length before IO operation */
2204 				rdma_req->req.length = rdma_req->req.dif.elba_length;
2205 			}
2206 
2207 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2208 			spdk_nvmf_request_exec(&rdma_req->req);
2209 			break;
2210 		case RDMA_REQUEST_STATE_EXECUTING:
2211 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2212 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2213 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2214 			 * to escape this state. */
2215 			break;
2216 		case RDMA_REQUEST_STATE_EXECUTED:
2217 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2218 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2219 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2220 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2221 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2222 			} else {
2223 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2224 			}
2225 			if (spdk_unlikely(rdma_req->req.dif.dif_insert_or_strip)) {
2226 				/* restore the original length */
2227 				rdma_req->req.length = rdma_req->req.dif.orig_length;
2228 
2229 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2230 					struct spdk_dif_error error_blk;
2231 
2232 					num_blocks = SPDK_CEIL_DIV(rdma_req->req.dif.elba_length, rdma_req->req.dif.dif_ctx.block_size);
2233 
2234 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks,
2235 							     &rdma_req->req.dif.dif_ctx, &error_blk);
2236 					if (rc) {
2237 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2238 
2239 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2240 							    error_blk.err_offset);
2241 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2242 						rsp->status.sc = spdk_nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2243 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2244 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2245 					}
2246 				}
2247 			}
2248 			break;
2249 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2250 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2251 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2252 
2253 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2254 				/* This request needs to wait in line to perform RDMA */
2255 				break;
2256 			}
2257 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2258 			    rqpair->max_send_depth) {
2259 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2260 				 * +1 since each request has an additional wr in the resp. */
2261 				rqpair->poller->stat.pending_rdma_write++;
2262 				break;
2263 			}
2264 
2265 			/* We have already verified that this request is the head of the queue. */
2266 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2267 
2268 			/* The data transfer will be kicked off from
2269 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2270 			 */
2271 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2272 			break;
2273 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2274 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2275 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2276 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2277 			assert(rc == 0); /* No good way to handle this currently */
2278 			if (rc) {
2279 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2280 			} else {
2281 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2282 						  RDMA_REQUEST_STATE_COMPLETING;
2283 			}
2284 			break;
2285 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2286 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2287 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2288 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2289 			 * to escape this state. */
2290 			break;
2291 		case RDMA_REQUEST_STATE_COMPLETING:
2292 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2293 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2294 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2295 			 * to escape this state. */
2296 			break;
2297 		case RDMA_REQUEST_STATE_COMPLETED:
2298 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2299 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2300 
2301 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2302 			nvmf_rdma_request_free(rdma_req, rtransport);
2303 			break;
2304 		case RDMA_REQUEST_NUM_STATES:
2305 		default:
2306 			assert(0);
2307 			break;
2308 		}
2309 
2310 		if (rdma_req->state != prev_state) {
2311 			progress = true;
2312 		}
2313 	} while (rdma_req->state != prev_state);
2314 
2315 	return progress;
2316 }
2317 
2318 /* Public API callbacks begin here */
2319 
2320 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2321 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2322 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2323 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2324 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2325 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2326 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2327 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2328 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2329 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2330 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2331 
2332 static void
2333 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2334 {
2335 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2336 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2337 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2338 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2339 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2340 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2341 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2342 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2343 	opts->max_srq_depth =		SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2344 	opts->no_srq =			SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2345 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2346 }
2347 
2348 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2349 	.notify_cb = spdk_nvmf_rdma_mem_notify,
2350 	.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
2351 };
2352 
2353 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
2354 
2355 static struct spdk_nvmf_transport *
2356 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2357 {
2358 	int rc;
2359 	struct spdk_nvmf_rdma_transport *rtransport;
2360 	struct spdk_nvmf_rdma_device	*device, *tmp;
2361 	struct ibv_context		**contexts;
2362 	uint32_t			i;
2363 	int				flag;
2364 	uint32_t			sge_count;
2365 	uint32_t			min_shared_buffers;
2366 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2367 	pthread_mutexattr_t		attr;
2368 
2369 	rtransport = calloc(1, sizeof(*rtransport));
2370 	if (!rtransport) {
2371 		return NULL;
2372 	}
2373 
2374 	if (pthread_mutexattr_init(&attr)) {
2375 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2376 		free(rtransport);
2377 		return NULL;
2378 	}
2379 
2380 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2381 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2382 		pthread_mutexattr_destroy(&attr);
2383 		free(rtransport);
2384 		return NULL;
2385 	}
2386 
2387 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2388 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2389 		pthread_mutexattr_destroy(&attr);
2390 		free(rtransport);
2391 		return NULL;
2392 	}
2393 
2394 	pthread_mutexattr_destroy(&attr);
2395 
2396 	TAILQ_INIT(&rtransport->devices);
2397 	TAILQ_INIT(&rtransport->ports);
2398 	TAILQ_INIT(&rtransport->poll_groups);
2399 
2400 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2401 
2402 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
2403 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2404 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2405 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2406 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d\n",
2407 		     opts->max_queue_depth,
2408 		     opts->max_io_size,
2409 		     opts->max_qpairs_per_ctrlr,
2410 		     opts->io_unit_size,
2411 		     opts->in_capsule_data_size,
2412 		     opts->max_aq_depth,
2413 		     opts->num_shared_buffers,
2414 		     opts->max_srq_depth,
2415 		     opts->no_srq);
2416 
2417 	/* I/O unit size cannot be larger than max I/O size */
2418 	if (opts->io_unit_size > opts->max_io_size) {
2419 		opts->io_unit_size = opts->max_io_size;
2420 	}
2421 
2422 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2423 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2424 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2425 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2426 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2427 		return NULL;
2428 	}
2429 
2430 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
2431 	if (min_shared_buffers > opts->num_shared_buffers) {
2432 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2433 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2434 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2435 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2436 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2437 		return NULL;
2438 	}
2439 
2440 	sge_count = opts->max_io_size / opts->io_unit_size;
2441 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2442 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2443 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2444 		return NULL;
2445 	}
2446 
2447 	rtransport->event_channel = rdma_create_event_channel();
2448 	if (rtransport->event_channel == NULL) {
2449 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2450 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2451 		return NULL;
2452 	}
2453 
2454 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2455 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2456 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2457 			    rtransport->event_channel->fd, spdk_strerror(errno));
2458 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2459 		return NULL;
2460 	}
2461 
2462 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2463 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2464 				   sizeof(struct spdk_nvmf_rdma_request_data),
2465 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2466 				   SPDK_ENV_SOCKET_ID_ANY);
2467 	if (!rtransport->data_wr_pool) {
2468 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2469 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2470 		return NULL;
2471 	}
2472 
2473 	contexts = rdma_get_devices(NULL);
2474 	if (contexts == NULL) {
2475 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2476 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2477 		return NULL;
2478 	}
2479 
2480 	i = 0;
2481 	rc = 0;
2482 	while (contexts[i] != NULL) {
2483 		device = calloc(1, sizeof(*device));
2484 		if (!device) {
2485 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2486 			rc = -ENOMEM;
2487 			break;
2488 		}
2489 		device->context = contexts[i];
2490 		rc = ibv_query_device(device->context, &device->attr);
2491 		if (rc < 0) {
2492 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2493 			free(device);
2494 			break;
2495 
2496 		}
2497 
2498 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2499 
2500 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2501 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2502 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2503 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2504 		}
2505 
2506 		/**
2507 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2508 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2509 		 * but incorrectly reports that it does. There are changes making their way
2510 		 * through the kernel now that will enable this feature. When they are merged,
2511 		 * we can conditionally enable this feature.
2512 		 *
2513 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2514 		 */
2515 		if (device->attr.vendor_id == 0) {
2516 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2517 		}
2518 #endif
2519 
2520 		/* set up device context async ev fd as NON_BLOCKING */
2521 		flag = fcntl(device->context->async_fd, F_GETFL);
2522 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2523 		if (rc < 0) {
2524 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2525 			free(device);
2526 			break;
2527 		}
2528 
2529 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2530 		i++;
2531 
2532 		if (g_nvmf_hooks.get_ibv_pd) {
2533 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2534 		} else {
2535 			device->pd = ibv_alloc_pd(device->context);
2536 		}
2537 
2538 		if (!device->pd) {
2539 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2540 			rc = -ENOMEM;
2541 			break;
2542 		}
2543 
2544 		assert(device->map == NULL);
2545 
2546 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2547 		if (!device->map) {
2548 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2549 			rc = -ENOMEM;
2550 			break;
2551 		}
2552 
2553 		assert(device->map != NULL);
2554 		assert(device->pd != NULL);
2555 	}
2556 	rdma_free_devices(contexts);
2557 
2558 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2559 		/* divide and round up. */
2560 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2561 
2562 		/* round up to the nearest 4k. */
2563 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2564 
2565 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2566 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2567 			       opts->io_unit_size);
2568 	}
2569 
2570 	if (rc < 0) {
2571 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2572 		return NULL;
2573 	}
2574 
2575 	/* Set up poll descriptor array to monitor events from RDMA and IB
2576 	 * in a single poll syscall
2577 	 */
2578 	rtransport->npoll_fds = i + 1;
2579 	i = 0;
2580 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2581 	if (rtransport->poll_fds == NULL) {
2582 		SPDK_ERRLOG("poll_fds allocation failed\n");
2583 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2584 		return NULL;
2585 	}
2586 
2587 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2588 	rtransport->poll_fds[i++].events = POLLIN;
2589 
2590 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2591 		rtransport->poll_fds[i].fd = device->context->async_fd;
2592 		rtransport->poll_fds[i++].events = POLLIN;
2593 	}
2594 
2595 	return &rtransport->transport;
2596 }
2597 
2598 static int
2599 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
2600 {
2601 	struct spdk_nvmf_rdma_transport	*rtransport;
2602 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2603 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2604 
2605 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2606 
2607 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2608 		TAILQ_REMOVE(&rtransport->ports, port, link);
2609 		rdma_destroy_id(port->id);
2610 		free(port);
2611 	}
2612 
2613 	if (rtransport->poll_fds != NULL) {
2614 		free(rtransport->poll_fds);
2615 	}
2616 
2617 	if (rtransport->event_channel != NULL) {
2618 		rdma_destroy_event_channel(rtransport->event_channel);
2619 	}
2620 
2621 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2622 		TAILQ_REMOVE(&rtransport->devices, device, link);
2623 		if (device->map) {
2624 			spdk_mem_map_free(&device->map);
2625 		}
2626 		if (device->pd) {
2627 			if (!g_nvmf_hooks.get_ibv_pd) {
2628 				ibv_dealloc_pd(device->pd);
2629 			}
2630 		}
2631 		free(device);
2632 	}
2633 
2634 	if (rtransport->data_wr_pool != NULL) {
2635 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2636 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2637 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2638 				    spdk_mempool_count(rtransport->data_wr_pool),
2639 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2640 		}
2641 	}
2642 
2643 	spdk_mempool_free(rtransport->data_wr_pool);
2644 
2645 	pthread_mutex_destroy(&rtransport->lock);
2646 	free(rtransport);
2647 
2648 	return 0;
2649 }
2650 
2651 static int
2652 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2653 			       struct spdk_nvme_transport_id *trid,
2654 			       bool peer);
2655 
2656 static int
2657 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2658 		      const struct spdk_nvme_transport_id *trid)
2659 {
2660 	struct spdk_nvmf_rdma_transport	*rtransport;
2661 	struct spdk_nvmf_rdma_device	*device;
2662 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
2663 	struct addrinfo			*res;
2664 	struct addrinfo			hints;
2665 	int				family;
2666 	int				rc;
2667 
2668 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2669 
2670 	port = calloc(1, sizeof(*port));
2671 	if (!port) {
2672 		return -ENOMEM;
2673 	}
2674 
2675 	/* Selectively copy the trid. Things like NQN don't matter here - that
2676 	 * mapping is enforced elsewhere.
2677 	 */
2678 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2679 	port->trid.adrfam = trid->adrfam;
2680 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
2681 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
2682 
2683 	switch (port->trid.adrfam) {
2684 	case SPDK_NVMF_ADRFAM_IPV4:
2685 		family = AF_INET;
2686 		break;
2687 	case SPDK_NVMF_ADRFAM_IPV6:
2688 		family = AF_INET6;
2689 		break;
2690 	default:
2691 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
2692 		free(port);
2693 		return -EINVAL;
2694 	}
2695 
2696 	memset(&hints, 0, sizeof(hints));
2697 	hints.ai_family = family;
2698 	hints.ai_flags = AI_NUMERICSERV;
2699 	hints.ai_socktype = SOCK_STREAM;
2700 	hints.ai_protocol = 0;
2701 
2702 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
2703 	if (rc) {
2704 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2705 		free(port);
2706 		return -EINVAL;
2707 	}
2708 
2709 	pthread_mutex_lock(&rtransport->lock);
2710 	assert(rtransport->event_channel != NULL);
2711 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
2712 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
2713 			port_tmp->ref++;
2714 			freeaddrinfo(res);
2715 			free(port);
2716 			/* Already listening at this address */
2717 			pthread_mutex_unlock(&rtransport->lock);
2718 			return 0;
2719 		}
2720 	}
2721 
2722 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2723 	if (rc < 0) {
2724 		SPDK_ERRLOG("rdma_create_id() failed\n");
2725 		freeaddrinfo(res);
2726 		free(port);
2727 		pthread_mutex_unlock(&rtransport->lock);
2728 		return rc;
2729 	}
2730 
2731 	rc = rdma_bind_addr(port->id, res->ai_addr);
2732 	freeaddrinfo(res);
2733 
2734 	if (rc < 0) {
2735 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2736 		rdma_destroy_id(port->id);
2737 		free(port);
2738 		pthread_mutex_unlock(&rtransport->lock);
2739 		return rc;
2740 	}
2741 
2742 	if (!port->id->verbs) {
2743 		SPDK_ERRLOG("ibv_context is null\n");
2744 		rdma_destroy_id(port->id);
2745 		free(port);
2746 		pthread_mutex_unlock(&rtransport->lock);
2747 		return -1;
2748 	}
2749 
2750 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
2751 	if (rc < 0) {
2752 		SPDK_ERRLOG("rdma_listen() failed\n");
2753 		rdma_destroy_id(port->id);
2754 		free(port);
2755 		pthread_mutex_unlock(&rtransport->lock);
2756 		return rc;
2757 	}
2758 
2759 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2760 		if (device->context == port->id->verbs) {
2761 			port->device = device;
2762 			break;
2763 		}
2764 	}
2765 	if (!port->device) {
2766 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2767 			    port->id->verbs);
2768 		rdma_destroy_id(port->id);
2769 		free(port);
2770 		pthread_mutex_unlock(&rtransport->lock);
2771 		return -EINVAL;
2772 	}
2773 
2774 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
2775 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
2776 
2777 	port->ref = 1;
2778 
2779 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2780 	pthread_mutex_unlock(&rtransport->lock);
2781 
2782 	return 0;
2783 }
2784 
2785 static int
2786 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2787 			   const struct spdk_nvme_transport_id *_trid)
2788 {
2789 	struct spdk_nvmf_rdma_transport *rtransport;
2790 	struct spdk_nvmf_rdma_port *port, *tmp;
2791 	struct spdk_nvme_transport_id trid = {};
2792 
2793 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2794 
2795 	/* Selectively copy the trid. Things like NQN don't matter here - that
2796 	 * mapping is enforced elsewhere.
2797 	 */
2798 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2799 	trid.adrfam = _trid->adrfam;
2800 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2801 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2802 
2803 	pthread_mutex_lock(&rtransport->lock);
2804 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2805 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2806 			assert(port->ref > 0);
2807 			port->ref--;
2808 			if (port->ref == 0) {
2809 				TAILQ_REMOVE(&rtransport->ports, port, link);
2810 				rdma_destroy_id(port->id);
2811 				free(port);
2812 			}
2813 			break;
2814 		}
2815 	}
2816 
2817 	pthread_mutex_unlock(&rtransport->lock);
2818 	return 0;
2819 }
2820 
2821 static void
2822 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2823 				     struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2824 {
2825 	struct spdk_nvmf_request *req, *tmp;
2826 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2827 	struct spdk_nvmf_rdma_resources *resources;
2828 
2829 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2830 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2831 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2832 			break;
2833 		}
2834 	}
2835 
2836 	/* Then RDMA writes since reads have stronger restrictions than writes */
2837 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2838 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2839 			break;
2840 		}
2841 	}
2842 
2843 	/* The second highest priority is I/O waiting on memory buffers. */
2844 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2845 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2846 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2847 			break;
2848 		}
2849 	}
2850 
2851 	resources = rqpair->resources;
2852 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2853 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2854 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2855 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2856 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2857 
2858 		if (rqpair->srq != NULL) {
2859 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2860 			rdma_req->recv->qpair->qd++;
2861 		} else {
2862 			rqpair->qd++;
2863 		}
2864 
2865 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2866 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2867 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2868 			break;
2869 		}
2870 	}
2871 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2872 		rqpair->poller->stat.pending_free_request++;
2873 	}
2874 }
2875 
2876 static void
2877 _nvmf_rdma_qpair_disconnect(void *ctx)
2878 {
2879 	struct spdk_nvmf_qpair *qpair = ctx;
2880 
2881 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2882 }
2883 
2884 static void
2885 _nvmf_rdma_try_disconnect(void *ctx)
2886 {
2887 	struct spdk_nvmf_qpair *qpair = ctx;
2888 	struct spdk_nvmf_poll_group *group;
2889 
2890 	/* Read the group out of the qpair. This is normally set and accessed only from
2891 	 * the thread that created the group. Here, we're not on that thread necessarily.
2892 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2893 	 * a pointer and never changes. So fortunately reading this and checking for
2894 	 * non-NULL is thread safe in the x86_64 memory model. */
2895 	group = qpair->group;
2896 
2897 	if (group == NULL) {
2898 		/* The qpair hasn't been assigned to a group yet, so we can't
2899 		 * process a disconnect. Send a message to ourself and try again. */
2900 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2901 		return;
2902 	}
2903 
2904 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2905 }
2906 
2907 static inline void
2908 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2909 {
2910 	if (!__atomic_test_and_set(&rqpair->disconnect_started, __ATOMIC_RELAXED)) {
2911 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2912 	}
2913 }
2914 
2915 static void nvmf_rdma_destroy_drained_qpair(void *ctx)
2916 {
2917 	struct spdk_nvmf_rdma_qpair *rqpair = ctx;
2918 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2919 			struct spdk_nvmf_rdma_transport, transport);
2920 
2921 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2922 	if (rqpair->current_send_depth != 0) {
2923 		return;
2924 	}
2925 
2926 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2927 		return;
2928 	}
2929 
2930 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false) {
2931 		return;
2932 	}
2933 
2934 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2935 
2936 	/* Qpair will be destroyed after nvmf layer closes this qpair */
2937 	if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ERROR) {
2938 		return;
2939 	}
2940 
2941 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2942 }
2943 
2944 
2945 static int
2946 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2947 {
2948 	struct spdk_nvmf_qpair		*qpair;
2949 	struct spdk_nvmf_rdma_qpair	*rqpair;
2950 
2951 	if (evt->id == NULL) {
2952 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2953 		return -1;
2954 	}
2955 
2956 	qpair = evt->id->context;
2957 	if (qpair == NULL) {
2958 		SPDK_ERRLOG("disconnect request: no active connection\n");
2959 		return -1;
2960 	}
2961 
2962 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2963 
2964 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2965 
2966 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2967 
2968 	spdk_nvmf_rdma_start_disconnect(rqpair);
2969 
2970 	return 0;
2971 }
2972 
2973 #ifdef DEBUG
2974 static const char *CM_EVENT_STR[] = {
2975 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2976 	"RDMA_CM_EVENT_ADDR_ERROR",
2977 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2978 	"RDMA_CM_EVENT_ROUTE_ERROR",
2979 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2980 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2981 	"RDMA_CM_EVENT_CONNECT_ERROR",
2982 	"RDMA_CM_EVENT_UNREACHABLE",
2983 	"RDMA_CM_EVENT_REJECTED",
2984 	"RDMA_CM_EVENT_ESTABLISHED",
2985 	"RDMA_CM_EVENT_DISCONNECTED",
2986 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2987 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2988 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2989 	"RDMA_CM_EVENT_ADDR_CHANGE",
2990 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2991 };
2992 #endif /* DEBUG */
2993 
2994 static void
2995 nvmf_rdma_handle_last_wqe_reached(void *ctx)
2996 {
2997 	struct spdk_nvmf_rdma_qpair *rqpair = ctx;
2998 	rqpair->last_wqe_reached = true;
2999 
3000 	nvmf_rdma_destroy_drained_qpair(rqpair);
3001 }
3002 
3003 static void
3004 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn, void *cb_arg)
3005 {
3006 	struct spdk_nvmf_rdma_transport *rtransport;
3007 	struct rdma_cm_event		*event;
3008 	int				rc;
3009 
3010 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3011 
3012 	if (rtransport->event_channel == NULL) {
3013 		return;
3014 	}
3015 
3016 	while (1) {
3017 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
3018 		if (rc == 0) {
3019 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
3020 
3021 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
3022 
3023 			switch (event->event) {
3024 			case RDMA_CM_EVENT_ADDR_RESOLVED:
3025 			case RDMA_CM_EVENT_ADDR_ERROR:
3026 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
3027 			case RDMA_CM_EVENT_ROUTE_ERROR:
3028 				/* No action required. The target never attempts to resolve routes. */
3029 				break;
3030 			case RDMA_CM_EVENT_CONNECT_REQUEST:
3031 				rc = nvmf_rdma_connect(transport, event, cb_fn, cb_arg);
3032 				if (rc < 0) {
3033 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
3034 					break;
3035 				}
3036 				break;
3037 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
3038 				/* The target never initiates a new connection. So this will not occur. */
3039 				break;
3040 			case RDMA_CM_EVENT_CONNECT_ERROR:
3041 				/* Can this happen? The docs say it can, but not sure what causes it. */
3042 				break;
3043 			case RDMA_CM_EVENT_UNREACHABLE:
3044 			case RDMA_CM_EVENT_REJECTED:
3045 				/* These only occur on the client side. */
3046 				break;
3047 			case RDMA_CM_EVENT_ESTABLISHED:
3048 				/* TODO: Should we be waiting for this event anywhere? */
3049 				break;
3050 			case RDMA_CM_EVENT_DISCONNECTED:
3051 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
3052 				rc = nvmf_rdma_disconnect(event);
3053 				if (rc < 0) {
3054 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
3055 					break;
3056 				}
3057 				break;
3058 			case RDMA_CM_EVENT_MULTICAST_JOIN:
3059 			case RDMA_CM_EVENT_MULTICAST_ERROR:
3060 				/* Multicast is not used */
3061 				break;
3062 			case RDMA_CM_EVENT_ADDR_CHANGE:
3063 				/* Not utilizing this event */
3064 				break;
3065 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
3066 				/* For now, do nothing. The target never re-uses queue pairs. */
3067 				break;
3068 			default:
3069 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
3070 				break;
3071 			}
3072 
3073 			rdma_ack_cm_event(event);
3074 		} else {
3075 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
3076 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
3077 			}
3078 			break;
3079 		}
3080 	}
3081 }
3082 
3083 static void
3084 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3085 {
3086 	int				rc;
3087 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3088 	struct ibv_async_event		event;
3089 	enum ibv_qp_state		state;
3090 
3091 	rc = ibv_get_async_event(device->context, &event);
3092 
3093 	if (rc) {
3094 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
3095 			    errno, spdk_strerror(errno));
3096 		return;
3097 	}
3098 
3099 	switch (event.event_type) {
3100 	case IBV_EVENT_QP_FATAL:
3101 		rqpair = event.element.qp->qp_context;
3102 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3103 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3104 				  (uintptr_t)rqpair->cm_id, event.event_type);
3105 		spdk_nvmf_rdma_update_ibv_state(rqpair);
3106 		spdk_nvmf_rdma_start_disconnect(rqpair);
3107 		break;
3108 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3109 		/* This event only occurs for shared receive queues. */
3110 		rqpair = event.element.qp->qp_context;
3111 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last WQE reached event received for rqpair %p\n", rqpair);
3112 		/* This must be handled on the polling thread if it exists. Otherwise the timeout will catch it. */
3113 		if (rqpair->qpair.group) {
3114 			spdk_thread_send_msg(rqpair->qpair.group->thread, nvmf_rdma_handle_last_wqe_reached, rqpair);
3115 		} else {
3116 			SPDK_ERRLOG("Unable to destroy the qpair %p since it does not have a poll group.\n", rqpair);
3117 			rqpair->last_wqe_reached = true;
3118 		}
3119 
3120 		break;
3121 	case IBV_EVENT_SQ_DRAINED:
3122 		/* This event occurs frequently in both error and non-error states.
3123 		 * Check if the qpair is in an error state before sending a message.
3124 		 * Note that we're not on the correct thread to access the qpair, but
3125 		 * the operations that the below calls make all happen to be thread
3126 		 * safe. */
3127 		rqpair = event.element.qp->qp_context;
3128 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last sq drained event received for rqpair %p\n", rqpair);
3129 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3130 				  (uintptr_t)rqpair->cm_id, event.event_type);
3131 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
3132 		if (state == IBV_QPS_ERR) {
3133 			spdk_nvmf_rdma_start_disconnect(rqpair);
3134 		}
3135 		break;
3136 	case IBV_EVENT_QP_REQ_ERR:
3137 	case IBV_EVENT_QP_ACCESS_ERR:
3138 	case IBV_EVENT_COMM_EST:
3139 	case IBV_EVENT_PATH_MIG:
3140 	case IBV_EVENT_PATH_MIG_ERR:
3141 		SPDK_NOTICELOG("Async event: %s\n",
3142 			       ibv_event_type_str(event.event_type));
3143 		rqpair = event.element.qp->qp_context;
3144 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3145 				  (uintptr_t)rqpair->cm_id, event.event_type);
3146 		spdk_nvmf_rdma_update_ibv_state(rqpair);
3147 		break;
3148 	case IBV_EVENT_CQ_ERR:
3149 	case IBV_EVENT_DEVICE_FATAL:
3150 	case IBV_EVENT_PORT_ACTIVE:
3151 	case IBV_EVENT_PORT_ERR:
3152 	case IBV_EVENT_LID_CHANGE:
3153 	case IBV_EVENT_PKEY_CHANGE:
3154 	case IBV_EVENT_SM_CHANGE:
3155 	case IBV_EVENT_SRQ_ERR:
3156 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3157 	case IBV_EVENT_CLIENT_REREGISTER:
3158 	case IBV_EVENT_GID_CHANGE:
3159 	default:
3160 		SPDK_NOTICELOG("Async event: %s\n",
3161 			       ibv_event_type_str(event.event_type));
3162 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3163 		break;
3164 	}
3165 	ibv_ack_async_event(&event);
3166 }
3167 
3168 static void
3169 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn, void *cb_arg)
3170 {
3171 	int	nfds, i = 0;
3172 	struct spdk_nvmf_rdma_transport *rtransport;
3173 	struct spdk_nvmf_rdma_device *device, *tmp;
3174 
3175 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3176 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3177 
3178 	if (nfds <= 0) {
3179 		return;
3180 	}
3181 
3182 	/* The first poll descriptor is RDMA CM event */
3183 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3184 		spdk_nvmf_process_cm_event(transport, cb_fn, cb_arg);
3185 		nfds--;
3186 	}
3187 
3188 	if (nfds == 0) {
3189 		return;
3190 	}
3191 
3192 	/* Second and subsequent poll descriptors are IB async events */
3193 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3194 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3195 			spdk_nvmf_process_ib_event(device);
3196 			nfds--;
3197 		}
3198 	}
3199 	/* check all flagged fd's have been served */
3200 	assert(nfds == 0);
3201 }
3202 
3203 static void
3204 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3205 			struct spdk_nvme_transport_id *trid,
3206 			struct spdk_nvmf_discovery_log_page_entry *entry)
3207 {
3208 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3209 	entry->adrfam = trid->adrfam;
3210 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3211 
3212 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3213 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3214 
3215 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3216 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3217 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3218 }
3219 
3220 static void
3221 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3222 
3223 static struct spdk_nvmf_transport_poll_group *
3224 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3225 {
3226 	struct spdk_nvmf_rdma_transport		*rtransport;
3227 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3228 	struct spdk_nvmf_rdma_poller		*poller;
3229 	struct spdk_nvmf_rdma_device		*device;
3230 	struct ibv_srq_init_attr		srq_init_attr;
3231 	struct spdk_nvmf_rdma_resource_opts	opts;
3232 	int					num_cqe;
3233 
3234 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3235 
3236 	rgroup = calloc(1, sizeof(*rgroup));
3237 	if (!rgroup) {
3238 		return NULL;
3239 	}
3240 
3241 	TAILQ_INIT(&rgroup->pollers);
3242 	STAILQ_INIT(&rgroup->retired_bufs);
3243 
3244 	pthread_mutex_lock(&rtransport->lock);
3245 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3246 		poller = calloc(1, sizeof(*poller));
3247 		if (!poller) {
3248 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3249 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3250 			pthread_mutex_unlock(&rtransport->lock);
3251 			return NULL;
3252 		}
3253 
3254 		poller->device = device;
3255 		poller->group = rgroup;
3256 
3257 		TAILQ_INIT(&poller->qpairs);
3258 		STAILQ_INIT(&poller->qpairs_pending_send);
3259 		STAILQ_INIT(&poller->qpairs_pending_recv);
3260 
3261 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3262 		if (transport->opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3263 			poller->max_srq_depth = transport->opts.max_srq_depth;
3264 
3265 			device->num_srq++;
3266 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3267 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3268 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3269 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3270 			if (!poller->srq) {
3271 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3272 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3273 				pthread_mutex_unlock(&rtransport->lock);
3274 				return NULL;
3275 			}
3276 
3277 			opts.qp = poller->srq;
3278 			opts.pd = device->pd;
3279 			opts.qpair = NULL;
3280 			opts.shared = true;
3281 			opts.max_queue_depth = poller->max_srq_depth;
3282 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3283 
3284 			poller->resources = nvmf_rdma_resources_create(&opts);
3285 			if (!poller->resources) {
3286 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3287 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3288 				pthread_mutex_unlock(&rtransport->lock);
3289 				return NULL;
3290 			}
3291 		}
3292 
3293 		/*
3294 		 * When using an srq, we can limit the completion queue at startup.
3295 		 * The following formula represents the calculation:
3296 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3297 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3298 		 */
3299 		if (poller->srq) {
3300 			num_cqe = poller->max_srq_depth * 3;
3301 		} else {
3302 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3303 		}
3304 
3305 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3306 		if (!poller->cq) {
3307 			SPDK_ERRLOG("Unable to create completion queue\n");
3308 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3309 			pthread_mutex_unlock(&rtransport->lock);
3310 			return NULL;
3311 		}
3312 		poller->num_cqe = num_cqe;
3313 	}
3314 
3315 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3316 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3317 		rtransport->conn_sched.next_admin_pg = rgroup;
3318 		rtransport->conn_sched.next_io_pg = rgroup;
3319 	}
3320 
3321 	pthread_mutex_unlock(&rtransport->lock);
3322 	return &rgroup->group;
3323 }
3324 
3325 static struct spdk_nvmf_transport_poll_group *
3326 spdk_nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3327 {
3328 	struct spdk_nvmf_rdma_transport *rtransport;
3329 	struct spdk_nvmf_rdma_poll_group **pg;
3330 	struct spdk_nvmf_transport_poll_group *result;
3331 
3332 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3333 
3334 	pthread_mutex_lock(&rtransport->lock);
3335 
3336 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3337 		pthread_mutex_unlock(&rtransport->lock);
3338 		return NULL;
3339 	}
3340 
3341 	if (qpair->qid == 0) {
3342 		pg = &rtransport->conn_sched.next_admin_pg;
3343 	} else {
3344 		pg = &rtransport->conn_sched.next_io_pg;
3345 	}
3346 
3347 	assert(*pg != NULL);
3348 
3349 	result = &(*pg)->group;
3350 
3351 	*pg = TAILQ_NEXT(*pg, link);
3352 	if (*pg == NULL) {
3353 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3354 	}
3355 
3356 	pthread_mutex_unlock(&rtransport->lock);
3357 
3358 	return result;
3359 }
3360 
3361 static void
3362 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3363 {
3364 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3365 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3366 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3367 	struct spdk_nvmf_transport_pg_cache_buf	*buf, *tmp_buf;
3368 	struct spdk_nvmf_rdma_transport		*rtransport;
3369 
3370 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3371 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3372 
3373 	if (!rgroup) {
3374 		return;
3375 	}
3376 
3377 	/* free all retired buffers back to the transport so we don't short the mempool. */
3378 	STAILQ_FOREACH_SAFE(buf, &rgroup->retired_bufs, link, tmp_buf) {
3379 		STAILQ_REMOVE(&rgroup->retired_bufs, buf, spdk_nvmf_transport_pg_cache_buf, link);
3380 		assert(group->transport != NULL);
3381 		spdk_mempool_put(group->transport->data_buf_pool, buf);
3382 	}
3383 
3384 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3385 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3386 
3387 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3388 			spdk_nvmf_rdma_qpair_destroy(qpair);
3389 		}
3390 
3391 		if (poller->srq) {
3392 			nvmf_rdma_resources_destroy(poller->resources);
3393 			ibv_destroy_srq(poller->srq);
3394 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Destroyed RDMA shared queue %p\n", poller->srq);
3395 		}
3396 
3397 		if (poller->cq) {
3398 			ibv_destroy_cq(poller->cq);
3399 		}
3400 
3401 		free(poller);
3402 	}
3403 
3404 	pthread_mutex_lock(&rtransport->lock);
3405 	next_rgroup = TAILQ_NEXT(rgroup, link);
3406 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3407 	if (next_rgroup == NULL) {
3408 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3409 	}
3410 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3411 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3412 	}
3413 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3414 		rtransport->conn_sched.next_io_pg = next_rgroup;
3415 	}
3416 	pthread_mutex_unlock(&rtransport->lock);
3417 
3418 	free(rgroup);
3419 }
3420 
3421 static void
3422 spdk_nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3423 {
3424 	if (rqpair->cm_id != NULL) {
3425 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3426 	}
3427 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3428 }
3429 
3430 static int
3431 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3432 			      struct spdk_nvmf_qpair *qpair)
3433 {
3434 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3435 	struct spdk_nvmf_rdma_qpair		*rqpair;
3436 	struct spdk_nvmf_rdma_device		*device;
3437 	struct spdk_nvmf_rdma_poller		*poller;
3438 	int					rc;
3439 
3440 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3441 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3442 
3443 	device = rqpair->port->device;
3444 
3445 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3446 		if (poller->device == device) {
3447 			break;
3448 		}
3449 	}
3450 
3451 	if (!poller) {
3452 		SPDK_ERRLOG("No poller found for device.\n");
3453 		return -1;
3454 	}
3455 
3456 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3457 	rqpair->poller = poller;
3458 	rqpair->srq = rqpair->poller->srq;
3459 
3460 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
3461 	if (rc < 0) {
3462 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3463 		return -1;
3464 	}
3465 
3466 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3467 	if (rc) {
3468 		/* Try to reject, but we probably can't */
3469 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3470 		return -1;
3471 	}
3472 
3473 	spdk_nvmf_rdma_update_ibv_state(rqpair);
3474 
3475 	return 0;
3476 }
3477 
3478 static int
3479 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3480 {
3481 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3482 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3483 			struct spdk_nvmf_rdma_transport, transport);
3484 
3485 	nvmf_rdma_request_free(rdma_req, rtransport);
3486 	return 0;
3487 }
3488 
3489 static int
3490 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3491 {
3492 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3493 			struct spdk_nvmf_rdma_transport, transport);
3494 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3495 			struct spdk_nvmf_rdma_request, req);
3496 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3497 			struct spdk_nvmf_rdma_qpair, qpair);
3498 
3499 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3500 		/* The connection is alive, so process the request as normal */
3501 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3502 	} else {
3503 		/* The connection is dead. Move the request directly to the completed state. */
3504 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3505 	}
3506 
3507 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3508 
3509 	return 0;
3510 }
3511 
3512 static int
3513 spdk_nvmf_rdma_destroy_defunct_qpair(void *ctx)
3514 {
3515 	struct spdk_nvmf_rdma_qpair	*rqpair = ctx;
3516 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3517 			struct spdk_nvmf_rdma_transport, transport);
3518 
3519 	SPDK_INFOLOG(SPDK_LOG_RDMA, "QP#%d hasn't been drained as expected, manually destroy it\n",
3520 		     rqpair->qpair.qid);
3521 
3522 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3523 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3524 
3525 	return 0;
3526 }
3527 
3528 static void
3529 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
3530 {
3531 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3532 
3533 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
3534 		return;
3535 	}
3536 
3537 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
3538 
3539 	/* This happens only when the qpair is disconnected before
3540 	 * it is added to the poll group. Since there is no poll group,
3541 	 * the RDMA qp has not been initialized yet and the RDMA CM
3542 	 * event has not yet been acknowledged, so we need to reject it.
3543 	 */
3544 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3545 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3546 		return;
3547 	}
3548 
3549 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3550 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
3551 	}
3552 
3553 	rqpair->destruct_poller = spdk_poller_register(spdk_nvmf_rdma_destroy_defunct_qpair, (void *)rqpair,
3554 				  NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US);
3555 }
3556 
3557 static struct spdk_nvmf_rdma_qpair *
3558 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3559 {
3560 	struct spdk_nvmf_rdma_qpair *rqpair;
3561 	/* @todo: improve QP search */
3562 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3563 		if (wc->qp_num == rqpair->cm_id->qp->qp_num) {
3564 			return rqpair;
3565 		}
3566 	}
3567 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3568 	return NULL;
3569 }
3570 
3571 #ifdef DEBUG
3572 static int
3573 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3574 {
3575 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3576 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3577 }
3578 #endif
3579 
3580 static void
3581 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3582 			   int rc)
3583 {
3584 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3585 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3586 
3587 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3588 	while (bad_recv_wr != NULL) {
3589 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3590 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3591 
3592 		rdma_recv->qpair->current_recv_depth++;
3593 		bad_recv_wr = bad_recv_wr->next;
3594 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3595 		spdk_nvmf_rdma_start_disconnect(rdma_recv->qpair);
3596 	}
3597 }
3598 
3599 static void
3600 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3601 {
3602 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3603 	while (bad_recv_wr != NULL) {
3604 		bad_recv_wr = bad_recv_wr->next;
3605 		rqpair->current_recv_depth++;
3606 	}
3607 	spdk_nvmf_rdma_start_disconnect(rqpair);
3608 }
3609 
3610 static void
3611 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3612 		     struct spdk_nvmf_rdma_poller *rpoller)
3613 {
3614 	struct spdk_nvmf_rdma_qpair	*rqpair;
3615 	struct ibv_recv_wr		*bad_recv_wr;
3616 	int				rc;
3617 
3618 	if (rpoller->srq) {
3619 		if (rpoller->resources->recvs_to_post.first != NULL) {
3620 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3621 			if (rc) {
3622 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3623 			}
3624 			rpoller->resources->recvs_to_post.first = NULL;
3625 			rpoller->resources->recvs_to_post.last = NULL;
3626 		}
3627 	} else {
3628 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3629 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3630 			assert(rqpair->resources->recvs_to_post.first != NULL);
3631 			rc = ibv_post_recv(rqpair->cm_id->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3632 			if (rc) {
3633 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3634 			}
3635 			rqpair->resources->recvs_to_post.first = NULL;
3636 			rqpair->resources->recvs_to_post.last = NULL;
3637 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3638 		}
3639 	}
3640 }
3641 
3642 static void
3643 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3644 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3645 {
3646 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3647 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3648 
3649 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3650 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3651 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3652 		assert(rqpair->current_send_depth > 0);
3653 		rqpair->current_send_depth--;
3654 		switch (bad_rdma_wr->type) {
3655 		case RDMA_WR_TYPE_DATA:
3656 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3657 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3658 				assert(rqpair->current_read_depth > 0);
3659 				rqpair->current_read_depth--;
3660 			}
3661 			break;
3662 		case RDMA_WR_TYPE_SEND:
3663 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3664 			break;
3665 		default:
3666 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3667 			prev_rdma_req = cur_rdma_req;
3668 			continue;
3669 		}
3670 
3671 		if (prev_rdma_req == cur_rdma_req) {
3672 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3673 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3674 			continue;
3675 		}
3676 
3677 		switch (cur_rdma_req->state) {
3678 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3679 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3680 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3681 			break;
3682 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3683 		case RDMA_REQUEST_STATE_COMPLETING:
3684 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3685 			break;
3686 		default:
3687 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3688 				    cur_rdma_req->state, rqpair);
3689 			continue;
3690 		}
3691 
3692 		spdk_nvmf_rdma_request_process(rtransport, cur_rdma_req);
3693 		prev_rdma_req = cur_rdma_req;
3694 	}
3695 
3696 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3697 		/* Disconnect the connection. */
3698 		spdk_nvmf_rdma_start_disconnect(rqpair);
3699 	}
3700 
3701 }
3702 
3703 static void
3704 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3705 		     struct spdk_nvmf_rdma_poller *rpoller)
3706 {
3707 	struct spdk_nvmf_rdma_qpair	*rqpair;
3708 	struct ibv_send_wr		*bad_wr = NULL;
3709 	int				rc;
3710 
3711 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3712 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3713 		assert(rqpair->sends_to_post.first != NULL);
3714 		rc = ibv_post_send(rqpair->cm_id->qp, rqpair->sends_to_post.first, &bad_wr);
3715 
3716 		/* bad wr always points to the first wr that failed. */
3717 		if (rc) {
3718 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3719 		}
3720 		rqpair->sends_to_post.first = NULL;
3721 		rqpair->sends_to_post.last = NULL;
3722 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3723 	}
3724 }
3725 
3726 static int
3727 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3728 			   struct spdk_nvmf_rdma_poller *rpoller)
3729 {
3730 	struct ibv_wc wc[32];
3731 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3732 	struct spdk_nvmf_rdma_request	*rdma_req;
3733 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3734 	struct spdk_nvmf_rdma_qpair	*rqpair;
3735 	int reaped, i;
3736 	int count = 0;
3737 	bool error = false;
3738 	uint64_t poll_tsc = spdk_get_ticks();
3739 
3740 	/* Poll for completing operations. */
3741 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3742 	if (reaped < 0) {
3743 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3744 			    errno, spdk_strerror(errno));
3745 		return -1;
3746 	}
3747 
3748 	rpoller->stat.polls++;
3749 	rpoller->stat.completions += reaped;
3750 
3751 	for (i = 0; i < reaped; i++) {
3752 
3753 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3754 
3755 		switch (rdma_wr->type) {
3756 		case RDMA_WR_TYPE_SEND:
3757 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3758 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3759 
3760 			if (!wc[i].status) {
3761 				count++;
3762 				assert(wc[i].opcode == IBV_WC_SEND);
3763 				assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
3764 			} else {
3765 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3766 			}
3767 
3768 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3769 			/* +1 for the response wr */
3770 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3771 			rdma_req->num_outstanding_data_wr = 0;
3772 
3773 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3774 			break;
3775 		case RDMA_WR_TYPE_RECV:
3776 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3777 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3778 			if (rpoller->srq != NULL) {
3779 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3780 				/* It is possible that there are still some completions for destroyed QP
3781 				 * associated with SRQ. We just ignore these late completions and re-post
3782 				 * receive WRs back to SRQ.
3783 				 */
3784 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3785 					struct ibv_recv_wr *bad_wr;
3786 					int rc;
3787 
3788 					rdma_recv->wr.next = NULL;
3789 					rc = ibv_post_srq_recv(rpoller->srq,
3790 							       &rdma_recv->wr,
3791 							       &bad_wr);
3792 					if (rc) {
3793 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3794 					}
3795 					continue;
3796 				}
3797 			}
3798 			rqpair = rdma_recv->qpair;
3799 
3800 			assert(rqpair != NULL);
3801 			if (!wc[i].status) {
3802 				assert(wc[i].opcode == IBV_WC_RECV);
3803 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3804 					spdk_nvmf_rdma_start_disconnect(rqpair);
3805 					break;
3806 				}
3807 			}
3808 
3809 			rdma_recv->wr.next = NULL;
3810 			rqpair->current_recv_depth++;
3811 			rdma_recv->receive_tsc = poll_tsc;
3812 			rpoller->stat.requests++;
3813 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3814 			break;
3815 		case RDMA_WR_TYPE_DATA:
3816 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3817 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3818 
3819 			assert(rdma_req->num_outstanding_data_wr > 0);
3820 
3821 			rqpair->current_send_depth--;
3822 			rdma_req->num_outstanding_data_wr--;
3823 			if (!wc[i].status) {
3824 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3825 				rqpair->current_read_depth--;
3826 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3827 				if (rdma_req->num_outstanding_data_wr == 0) {
3828 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3829 					spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3830 				}
3831 			} else {
3832 				/* If the data transfer fails still force the queue into the error state,
3833 				 * if we were performing an RDMA_READ, we need to force the request into a
3834 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3835 				 * case, we should wait for the SEND to complete. */
3836 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3837 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3838 					rqpair->current_read_depth--;
3839 					if (rdma_req->num_outstanding_data_wr == 0) {
3840 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3841 					}
3842 				}
3843 			}
3844 			break;
3845 		default:
3846 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3847 			continue;
3848 		}
3849 
3850 		/* Handle error conditions */
3851 		if (wc[i].status) {
3852 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
3853 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
3854 
3855 			error = true;
3856 
3857 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3858 				/* Disconnect the connection. */
3859 				spdk_nvmf_rdma_start_disconnect(rqpair);
3860 			} else {
3861 				nvmf_rdma_destroy_drained_qpair(rqpair);
3862 			}
3863 			continue;
3864 		}
3865 
3866 		spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3867 
3868 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3869 			nvmf_rdma_destroy_drained_qpair(rqpair);
3870 		}
3871 	}
3872 
3873 	if (error == true) {
3874 		return -1;
3875 	}
3876 
3877 	/* submit outstanding work requests. */
3878 	_poller_submit_recvs(rtransport, rpoller);
3879 	_poller_submit_sends(rtransport, rpoller);
3880 
3881 	return count;
3882 }
3883 
3884 static int
3885 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3886 {
3887 	struct spdk_nvmf_rdma_transport *rtransport;
3888 	struct spdk_nvmf_rdma_poll_group *rgroup;
3889 	struct spdk_nvmf_rdma_poller	*rpoller;
3890 	int				count, rc;
3891 
3892 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3893 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3894 
3895 	count = 0;
3896 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3897 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
3898 		if (rc < 0) {
3899 			return rc;
3900 		}
3901 		count += rc;
3902 	}
3903 
3904 	return count;
3905 }
3906 
3907 static int
3908 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3909 			       struct spdk_nvme_transport_id *trid,
3910 			       bool peer)
3911 {
3912 	struct sockaddr *saddr;
3913 	uint16_t port;
3914 
3915 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
3916 
3917 	if (peer) {
3918 		saddr = rdma_get_peer_addr(id);
3919 	} else {
3920 		saddr = rdma_get_local_addr(id);
3921 	}
3922 	switch (saddr->sa_family) {
3923 	case AF_INET: {
3924 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3925 
3926 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3927 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3928 			  trid->traddr, sizeof(trid->traddr));
3929 		if (peer) {
3930 			port = ntohs(rdma_get_dst_port(id));
3931 		} else {
3932 			port = ntohs(rdma_get_src_port(id));
3933 		}
3934 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3935 		break;
3936 	}
3937 	case AF_INET6: {
3938 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
3939 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
3940 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
3941 			  trid->traddr, sizeof(trid->traddr));
3942 		if (peer) {
3943 			port = ntohs(rdma_get_dst_port(id));
3944 		} else {
3945 			port = ntohs(rdma_get_src_port(id));
3946 		}
3947 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3948 		break;
3949 	}
3950 	default:
3951 		return -1;
3952 
3953 	}
3954 
3955 	return 0;
3956 }
3957 
3958 static int
3959 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3960 				   struct spdk_nvme_transport_id *trid)
3961 {
3962 	struct spdk_nvmf_rdma_qpair	*rqpair;
3963 
3964 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3965 
3966 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
3967 }
3968 
3969 static int
3970 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
3971 				    struct spdk_nvme_transport_id *trid)
3972 {
3973 	struct spdk_nvmf_rdma_qpair	*rqpair;
3974 
3975 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3976 
3977 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
3978 }
3979 
3980 static int
3981 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
3982 				     struct spdk_nvme_transport_id *trid)
3983 {
3984 	struct spdk_nvmf_rdma_qpair	*rqpair;
3985 
3986 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3987 
3988 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
3989 }
3990 
3991 void
3992 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
3993 {
3994 	g_nvmf_hooks = *hooks;
3995 }
3996 
3997 static int
3998 spdk_nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
3999 				   struct spdk_nvmf_transport_poll_group_stat **stat)
4000 {
4001 	struct spdk_io_channel *ch;
4002 	struct spdk_nvmf_poll_group *group;
4003 	struct spdk_nvmf_transport_poll_group *tgroup;
4004 	struct spdk_nvmf_rdma_poll_group *rgroup;
4005 	struct spdk_nvmf_rdma_poller *rpoller;
4006 	struct spdk_nvmf_rdma_device_stat *device_stat;
4007 	uint64_t num_devices = 0;
4008 
4009 	if (tgt == NULL || stat == NULL) {
4010 		return -EINVAL;
4011 	}
4012 
4013 	ch = spdk_get_io_channel(tgt);
4014 	group = spdk_io_channel_get_ctx(ch);;
4015 	spdk_put_io_channel(ch);
4016 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
4017 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
4018 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
4019 			if (!*stat) {
4020 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
4021 				return -ENOMEM;
4022 			}
4023 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
4024 
4025 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
4026 			/* Count devices to allocate enough memory */
4027 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4028 				++num_devices;
4029 			}
4030 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
4031 			if (!(*stat)->rdma.devices) {
4032 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
4033 				free(*stat);
4034 				return -ENOMEM;
4035 			}
4036 
4037 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
4038 			(*stat)->rdma.num_devices = num_devices;
4039 			num_devices = 0;
4040 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
4041 				device_stat = &(*stat)->rdma.devices[num_devices++];
4042 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
4043 				device_stat->polls = rpoller->stat.polls;
4044 				device_stat->completions = rpoller->stat.completions;
4045 				device_stat->requests = rpoller->stat.requests;
4046 				device_stat->request_latency = rpoller->stat.request_latency;
4047 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
4048 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
4049 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
4050 			}
4051 			return 0;
4052 		}
4053 	}
4054 	return -ENOENT;
4055 }
4056 
4057 static void
4058 spdk_nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
4059 {
4060 	if (stat) {
4061 		free(stat->rdma.devices);
4062 	}
4063 	free(stat);
4064 }
4065 
4066 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
4067 	.type = SPDK_NVME_TRANSPORT_RDMA,
4068 	.opts_init = spdk_nvmf_rdma_opts_init,
4069 	.create = spdk_nvmf_rdma_create,
4070 	.destroy = spdk_nvmf_rdma_destroy,
4071 
4072 	.listen = spdk_nvmf_rdma_listen,
4073 	.stop_listen = spdk_nvmf_rdma_stop_listen,
4074 	.accept = spdk_nvmf_rdma_accept,
4075 
4076 	.listener_discover = spdk_nvmf_rdma_discover,
4077 
4078 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
4079 	.get_optimal_poll_group = spdk_nvmf_rdma_get_optimal_poll_group,
4080 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
4081 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
4082 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
4083 
4084 	.req_free = spdk_nvmf_rdma_request_free,
4085 	.req_complete = spdk_nvmf_rdma_request_complete,
4086 
4087 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
4088 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
4089 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
4090 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
4091 
4092 	.poll_group_get_stat = spdk_nvmf_rdma_poll_group_get_stat,
4093 	.poll_group_free_stat = spdk_nvmf_rdma_poll_group_free_stat,
4094 };
4095 
4096 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
4097