xref: /spdk/lib/nvmf/rdma.c (revision 7ed0ec6832d9a5cf49bdc35f8e9c00fa80a5f67b)
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 	struct spdk_dif_ctx			dif_ctx;
273 	bool					dif_insert_or_strip;
274 	uint32_t				elba_length;
275 	uint32_t				orig_length;
276 
277 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
278 };
279 
280 enum spdk_nvmf_rdma_qpair_disconnect_flags {
281 	RDMA_QP_DISCONNECTING		= 1,
282 	RDMA_QP_RECV_DRAINED		= 1 << 1,
283 	RDMA_QP_SEND_DRAINED		= 1 << 2
284 };
285 
286 struct spdk_nvmf_rdma_resource_opts {
287 	struct spdk_nvmf_rdma_qpair	*qpair;
288 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
289 	void				*qp;
290 	struct ibv_pd			*pd;
291 	uint32_t			max_queue_depth;
292 	uint32_t			in_capsule_data_size;
293 	bool				shared;
294 };
295 
296 struct spdk_nvmf_send_wr_list {
297 	struct ibv_send_wr	*first;
298 	struct ibv_send_wr	*last;
299 };
300 
301 struct spdk_nvmf_recv_wr_list {
302 	struct ibv_recv_wr	*first;
303 	struct ibv_recv_wr	*last;
304 };
305 
306 struct spdk_nvmf_rdma_resources {
307 	/* Array of size "max_queue_depth" containing RDMA requests. */
308 	struct spdk_nvmf_rdma_request		*reqs;
309 
310 	/* Array of size "max_queue_depth" containing RDMA recvs. */
311 	struct spdk_nvmf_rdma_recv		*recvs;
312 
313 	/* Array of size "max_queue_depth" containing 64 byte capsules
314 	 * used for receive.
315 	 */
316 	union nvmf_h2c_msg			*cmds;
317 	struct ibv_mr				*cmds_mr;
318 
319 	/* Array of size "max_queue_depth" containing 16 byte completions
320 	 * to be sent back to the user.
321 	 */
322 	union nvmf_c2h_msg			*cpls;
323 	struct ibv_mr				*cpls_mr;
324 
325 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
326 	 * buffers to be used for in capsule data.
327 	 */
328 	void					*bufs;
329 	struct ibv_mr				*bufs_mr;
330 
331 	/* The list of pending recvs to transfer */
332 	struct spdk_nvmf_recv_wr_list		recvs_to_post;
333 
334 	/* Receives that are waiting for a request object */
335 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
336 
337 	/* Queue to track free requests */
338 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
339 };
340 
341 struct spdk_nvmf_rdma_qpair {
342 	struct spdk_nvmf_qpair			qpair;
343 
344 	struct spdk_nvmf_rdma_port		*port;
345 	struct spdk_nvmf_rdma_poller		*poller;
346 
347 	struct rdma_cm_id			*cm_id;
348 	struct ibv_srq				*srq;
349 	struct rdma_cm_id			*listen_id;
350 
351 	/* The maximum number of I/O outstanding on this connection at one time */
352 	uint16_t				max_queue_depth;
353 
354 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
355 	uint16_t				max_read_depth;
356 
357 	/* The maximum number of RDMA SEND operations at one time */
358 	uint32_t				max_send_depth;
359 
360 	/* The current number of outstanding WRs from this qpair's
361 	 * recv queue. Should not exceed device->attr.max_queue_depth.
362 	 */
363 	uint16_t				current_recv_depth;
364 
365 	/* The current number of active RDMA READ operations */
366 	uint16_t				current_read_depth;
367 
368 	/* The current number of posted WRs from this qpair's
369 	 * send queue. Should not exceed max_send_depth.
370 	 */
371 	uint32_t				current_send_depth;
372 
373 	/* The maximum number of SGEs per WR on the send queue */
374 	uint32_t				max_send_sge;
375 
376 	/* The maximum number of SGEs per WR on the recv queue */
377 	uint32_t				max_recv_sge;
378 
379 	/* The list of pending send requests for a transfer */
380 	struct spdk_nvmf_send_wr_list		sends_to_post;
381 
382 	struct spdk_nvmf_rdma_resources		*resources;
383 
384 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
385 
386 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
387 
388 	/* Number of requests not in the free state */
389 	uint32_t				qd;
390 
391 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
392 
393 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
394 
395 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
396 
397 	/* IBV queue pair attributes: they are used to manage
398 	 * qp state and recover from errors.
399 	 */
400 	enum ibv_qp_state			ibv_state;
401 
402 	uint32_t				disconnect_flags;
403 
404 	/* Poller registered in case the qpair doesn't properly
405 	 * complete the qpair destruct process and becomes defunct.
406 	 */
407 
408 	struct spdk_poller			*destruct_poller;
409 
410 	/* There are several ways a disconnect can start on a qpair
411 	 * and they are not all mutually exclusive. It is important
412 	 * that we only initialize one of these paths.
413 	 */
414 	bool					disconnect_started;
415 	/* Lets us know that we have received the last_wqe event. */
416 	bool					last_wqe_reached;
417 };
418 
419 struct spdk_nvmf_rdma_poller_stat {
420 	uint64_t				completions;
421 	uint64_t				polls;
422 	uint64_t				requests;
423 	uint64_t				request_latency;
424 	uint64_t				pending_free_request;
425 	uint64_t				pending_rdma_read;
426 	uint64_t				pending_rdma_write;
427 };
428 
429 struct spdk_nvmf_rdma_poller {
430 	struct spdk_nvmf_rdma_device		*device;
431 	struct spdk_nvmf_rdma_poll_group	*group;
432 
433 	int					num_cqe;
434 	int					required_num_wr;
435 	struct ibv_cq				*cq;
436 
437 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
438 	uint16_t				max_srq_depth;
439 
440 	/* Shared receive queue */
441 	struct ibv_srq				*srq;
442 
443 	struct spdk_nvmf_rdma_resources		*resources;
444 	struct spdk_nvmf_rdma_poller_stat	stat;
445 
446 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
447 
448 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
449 
450 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
451 
452 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
453 };
454 
455 struct spdk_nvmf_rdma_poll_group_stat {
456 	uint64_t				pending_data_buffer;
457 };
458 
459 struct spdk_nvmf_rdma_poll_group {
460 	struct spdk_nvmf_transport_poll_group		group;
461 	struct spdk_nvmf_rdma_poll_group_stat		stat;
462 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)		pollers;
463 	TAILQ_ENTRY(spdk_nvmf_rdma_poll_group)		link;
464 	/*
465 	 * buffers which are split across multiple RDMA
466 	 * memory regions cannot be used by this transport.
467 	 */
468 	STAILQ_HEAD(, spdk_nvmf_transport_pg_cache_buf)	retired_bufs;
469 };
470 
471 struct spdk_nvmf_rdma_conn_sched {
472 	struct spdk_nvmf_rdma_poll_group *next_admin_pg;
473 	struct spdk_nvmf_rdma_poll_group *next_io_pg;
474 };
475 
476 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
477 struct spdk_nvmf_rdma_device {
478 	struct ibv_device_attr			attr;
479 	struct ibv_context			*context;
480 
481 	struct spdk_mem_map			*map;
482 	struct ibv_pd				*pd;
483 
484 	int					num_srq;
485 
486 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
487 };
488 
489 struct spdk_nvmf_rdma_port {
490 	struct spdk_nvme_transport_id		trid;
491 	struct rdma_cm_id			*id;
492 	struct spdk_nvmf_rdma_device		*device;
493 	uint32_t				ref;
494 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
495 };
496 
497 struct spdk_nvmf_rdma_transport {
498 	struct spdk_nvmf_transport	transport;
499 
500 	struct spdk_nvmf_rdma_conn_sched conn_sched;
501 
502 	struct rdma_event_channel	*event_channel;
503 
504 	struct spdk_mempool		*data_wr_pool;
505 
506 	pthread_mutex_t			lock;
507 
508 	/* fields used to poll RDMA/IB events */
509 	nfds_t			npoll_fds;
510 	struct pollfd		*poll_fds;
511 
512 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
513 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
514 	TAILQ_HEAD(, spdk_nvmf_rdma_poll_group)	poll_groups;
515 };
516 
517 static inline void
518 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair);
519 
520 static inline int
521 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
522 {
523 	switch (state) {
524 	case IBV_QPS_RESET:
525 	case IBV_QPS_INIT:
526 	case IBV_QPS_RTR:
527 	case IBV_QPS_RTS:
528 	case IBV_QPS_SQD:
529 	case IBV_QPS_SQE:
530 	case IBV_QPS_ERR:
531 		return 0;
532 	default:
533 		return -1;
534 	}
535 }
536 
537 static inline enum spdk_nvme_media_error_status_code
538 spdk_nvmf_rdma_dif_error_to_compl_status(uint8_t err_type) {
539 	enum spdk_nvme_media_error_status_code result;
540 	switch (err_type)
541 	{
542 	case SPDK_DIF_REFTAG_ERROR:
543 		result = SPDK_NVME_SC_REFERENCE_TAG_CHECK_ERROR;
544 		break;
545 	case SPDK_DIF_APPTAG_ERROR:
546 		result = SPDK_NVME_SC_APPLICATION_TAG_CHECK_ERROR;
547 		break;
548 	case SPDK_DIF_GUARD_ERROR:
549 		result = SPDK_NVME_SC_GUARD_CHECK_ERROR;
550 		break;
551 	default:
552 		SPDK_UNREACHABLE();
553 	}
554 
555 	return result;
556 }
557 
558 static enum ibv_qp_state
559 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
560 	enum ibv_qp_state old_state, new_state;
561 	struct ibv_qp_attr qp_attr;
562 	struct ibv_qp_init_attr init_attr;
563 	int rc;
564 
565 	old_state = rqpair->ibv_state;
566 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
567 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
568 
569 	if (rc)
570 	{
571 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
572 		return IBV_QPS_ERR + 1;
573 	}
574 
575 	new_state = qp_attr.qp_state;
576 	rqpair->ibv_state = new_state;
577 	qp_attr.ah_attr.port_num = qp_attr.port_num;
578 
579 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
580 	if (rc)
581 	{
582 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
583 		/*
584 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
585 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
586 		 */
587 		return IBV_QPS_ERR + 1;
588 	}
589 
590 	if (old_state != new_state)
591 	{
592 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
593 				  (uintptr_t)rqpair->cm_id, new_state);
594 	}
595 	return new_state;
596 }
597 
598 static const char *str_ibv_qp_state[] = {
599 	"IBV_QPS_RESET",
600 	"IBV_QPS_INIT",
601 	"IBV_QPS_RTR",
602 	"IBV_QPS_RTS",
603 	"IBV_QPS_SQD",
604 	"IBV_QPS_SQE",
605 	"IBV_QPS_ERR",
606 	"IBV_QPS_UNKNOWN"
607 };
608 
609 static int
610 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
611 			     enum ibv_qp_state new_state)
612 {
613 	struct ibv_qp_attr qp_attr;
614 	struct ibv_qp_init_attr init_attr;
615 	int rc;
616 	enum ibv_qp_state state;
617 	static int attr_mask_rc[] = {
618 		[IBV_QPS_RESET] = IBV_QP_STATE,
619 		[IBV_QPS_INIT] = (IBV_QP_STATE |
620 				  IBV_QP_PKEY_INDEX |
621 				  IBV_QP_PORT |
622 				  IBV_QP_ACCESS_FLAGS),
623 		[IBV_QPS_RTR] = (IBV_QP_STATE |
624 				 IBV_QP_AV |
625 				 IBV_QP_PATH_MTU |
626 				 IBV_QP_DEST_QPN |
627 				 IBV_QP_RQ_PSN |
628 				 IBV_QP_MAX_DEST_RD_ATOMIC |
629 				 IBV_QP_MIN_RNR_TIMER),
630 		[IBV_QPS_RTS] = (IBV_QP_STATE |
631 				 IBV_QP_SQ_PSN |
632 				 IBV_QP_TIMEOUT |
633 				 IBV_QP_RETRY_CNT |
634 				 IBV_QP_RNR_RETRY |
635 				 IBV_QP_MAX_QP_RD_ATOMIC),
636 		[IBV_QPS_SQD] = IBV_QP_STATE,
637 		[IBV_QPS_SQE] = IBV_QP_STATE,
638 		[IBV_QPS_ERR] = IBV_QP_STATE,
639 	};
640 
641 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
642 	if (rc) {
643 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
644 			    rqpair->qpair.qid, new_state);
645 		return rc;
646 	}
647 
648 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
649 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
650 
651 	if (rc) {
652 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
653 		assert(false);
654 	}
655 
656 	qp_attr.cur_qp_state = rqpair->ibv_state;
657 	qp_attr.qp_state = new_state;
658 
659 	rc = ibv_modify_qp(rqpair->cm_id->qp, &qp_attr,
660 			   attr_mask_rc[new_state]);
661 
662 	if (rc) {
663 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
664 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
665 		return rc;
666 	}
667 
668 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
669 
670 	if (state != new_state) {
671 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
672 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
673 			    str_ibv_qp_state[state]);
674 		return -1;
675 	}
676 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
677 		      str_ibv_qp_state[state]);
678 	return 0;
679 }
680 
681 static void
682 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
683 			    struct spdk_nvmf_rdma_transport *rtransport)
684 {
685 	struct spdk_nvmf_rdma_request_data	*data_wr;
686 	struct ibv_send_wr			*next_send_wr;
687 	uint64_t				req_wrid;
688 
689 	rdma_req->num_outstanding_data_wr = 0;
690 	data_wr = &rdma_req->data;
691 	req_wrid = data_wr->wr.wr_id;
692 	while (data_wr && data_wr->wr.wr_id == req_wrid) {
693 		memset(data_wr->sgl, 0, sizeof(data_wr->wr.sg_list[0]) * data_wr->wr.num_sge);
694 		data_wr->wr.num_sge = 0;
695 		next_send_wr = data_wr->wr.next;
696 		if (data_wr != &rdma_req->data) {
697 			spdk_mempool_put(rtransport->data_wr_pool, data_wr);
698 		}
699 		data_wr = (!next_send_wr || next_send_wr == &rdma_req->rsp.wr) ? NULL :
700 			  SPDK_CONTAINEROF(next_send_wr, struct spdk_nvmf_rdma_request_data, wr);
701 	}
702 }
703 
704 static void
705 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
706 {
707 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->req.data_from_pool);
708 	if (req->req.cmd) {
709 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
710 	}
711 	if (req->recv) {
712 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
713 	}
714 }
715 
716 static void
717 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
718 {
719 	int i;
720 
721 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
722 	for (i = 0; i < rqpair->max_queue_depth; i++) {
723 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
724 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
725 		}
726 	}
727 }
728 
729 static void
730 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
731 {
732 	if (resources->cmds_mr) {
733 		ibv_dereg_mr(resources->cmds_mr);
734 	}
735 
736 	if (resources->cpls_mr) {
737 		ibv_dereg_mr(resources->cpls_mr);
738 	}
739 
740 	if (resources->bufs_mr) {
741 		ibv_dereg_mr(resources->bufs_mr);
742 	}
743 
744 	spdk_free(resources->cmds);
745 	spdk_free(resources->cpls);
746 	spdk_free(resources->bufs);
747 	free(resources->reqs);
748 	free(resources->recvs);
749 	free(resources);
750 }
751 
752 
753 static struct spdk_nvmf_rdma_resources *
754 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
755 {
756 	struct spdk_nvmf_rdma_resources	*resources;
757 	struct spdk_nvmf_rdma_request	*rdma_req;
758 	struct spdk_nvmf_rdma_recv	*rdma_recv;
759 	struct ibv_qp			*qp;
760 	struct ibv_srq			*srq;
761 	uint32_t			i;
762 	int				rc;
763 
764 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
765 	if (!resources) {
766 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
767 		return NULL;
768 	}
769 
770 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
771 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
772 	resources->cmds = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
773 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
774 	resources->cpls = spdk_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
775 				       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY, SPDK_MALLOC_DMA);
776 
777 	if (opts->in_capsule_data_size > 0) {
778 		resources->bufs = spdk_zmalloc(opts->max_queue_depth * opts->in_capsule_data_size,
779 					       0x1000, NULL, SPDK_ENV_LCORE_ID_ANY,
780 					       SPDK_MALLOC_DMA);
781 	}
782 
783 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
784 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
785 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
786 		goto cleanup;
787 	}
788 
789 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
790 					opts->max_queue_depth * sizeof(*resources->cmds),
791 					IBV_ACCESS_LOCAL_WRITE);
792 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
793 					opts->max_queue_depth * sizeof(*resources->cpls),
794 					0);
795 
796 	if (opts->in_capsule_data_size) {
797 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
798 						opts->max_queue_depth *
799 						opts->in_capsule_data_size,
800 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
801 	}
802 
803 	if (!resources->cmds_mr || !resources->cpls_mr ||
804 	    (opts->in_capsule_data_size &&
805 	     !resources->bufs_mr)) {
806 		goto cleanup;
807 	}
808 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
809 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
810 		      resources->cmds_mr->lkey);
811 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
812 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
813 		      resources->cpls_mr->lkey);
814 	if (resources->bufs && resources->bufs_mr) {
815 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
816 			      resources->bufs, opts->max_queue_depth *
817 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
818 	}
819 
820 	/* Initialize queues */
821 	STAILQ_INIT(&resources->incoming_queue);
822 	STAILQ_INIT(&resources->free_queue);
823 
824 	for (i = 0; i < opts->max_queue_depth; i++) {
825 		struct ibv_recv_wr *bad_wr = NULL;
826 
827 		rdma_recv = &resources->recvs[i];
828 		rdma_recv->qpair = opts->qpair;
829 
830 		/* Set up memory to receive commands */
831 		if (resources->bufs) {
832 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
833 						  opts->in_capsule_data_size));
834 		}
835 
836 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
837 
838 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
839 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
840 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
841 		rdma_recv->wr.num_sge = 1;
842 
843 		if (rdma_recv->buf && resources->bufs_mr) {
844 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
845 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
846 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
847 			rdma_recv->wr.num_sge++;
848 		}
849 
850 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
851 		rdma_recv->wr.sg_list = rdma_recv->sgl;
852 		if (opts->shared) {
853 			srq = (struct ibv_srq *)opts->qp;
854 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
855 		} else {
856 			qp = (struct ibv_qp *)opts->qp;
857 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
858 		}
859 		if (rc) {
860 			goto cleanup;
861 		}
862 	}
863 
864 	for (i = 0; i < opts->max_queue_depth; i++) {
865 		rdma_req = &resources->reqs[i];
866 
867 		if (opts->qpair != NULL) {
868 			rdma_req->req.qpair = &opts->qpair->qpair;
869 		} else {
870 			rdma_req->req.qpair = NULL;
871 		}
872 		rdma_req->req.cmd = NULL;
873 
874 		/* Set up memory to send responses */
875 		rdma_req->req.rsp = &resources->cpls[i];
876 
877 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
878 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
879 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
880 
881 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
882 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
883 		rdma_req->rsp.wr.next = NULL;
884 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
885 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
886 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
887 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
888 
889 		/* Set up memory for data buffers */
890 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
891 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
892 		rdma_req->data.wr.next = NULL;
893 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
894 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
895 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
896 
897 		/* Initialize request state to FREE */
898 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
899 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
900 	}
901 
902 	return resources;
903 
904 cleanup:
905 	nvmf_rdma_resources_destroy(resources);
906 	return NULL;
907 }
908 
909 static void
910 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
911 {
912 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
913 	struct ibv_recv_wr		*bad_recv_wr = NULL;
914 	int				rc;
915 
916 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
917 
918 	spdk_poller_unregister(&rqpair->destruct_poller);
919 
920 	if (rqpair->qd != 0) {
921 		if (rqpair->srq == NULL) {
922 			nvmf_rdma_dump_qpair_contents(rqpair);
923 		}
924 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
925 	}
926 
927 	if (rqpair->poller) {
928 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
929 
930 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
931 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
932 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
933 				if (rqpair == rdma_recv->qpair) {
934 					STAILQ_REMOVE_HEAD(&rqpair->resources->incoming_queue, link);
935 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
936 					if (rc) {
937 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
938 					}
939 				}
940 			}
941 		}
942 	}
943 
944 	if (rqpair->cm_id) {
945 		if (rqpair->cm_id->qp != NULL) {
946 			rdma_destroy_qp(rqpair->cm_id);
947 		}
948 		rdma_destroy_id(rqpair->cm_id);
949 
950 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
951 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
952 		}
953 	}
954 
955 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
956 		nvmf_rdma_resources_destroy(rqpair->resources);
957 	}
958 
959 	free(rqpair);
960 }
961 
962 static int
963 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
964 {
965 	struct spdk_nvmf_rdma_poller	*rpoller;
966 	int				rc, num_cqe, required_num_wr;
967 
968 	/* Enlarge CQ size dynamically */
969 	rpoller = rqpair->poller;
970 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
971 	num_cqe = rpoller->num_cqe;
972 	if (num_cqe < required_num_wr) {
973 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
974 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
975 	}
976 
977 	if (rpoller->num_cqe != num_cqe) {
978 		if (required_num_wr > device->attr.max_cqe) {
979 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
980 				    required_num_wr, device->attr.max_cqe);
981 			return -1;
982 		}
983 
984 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
985 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
986 		if (rc) {
987 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
988 			return -1;
989 		}
990 
991 		rpoller->num_cqe = num_cqe;
992 	}
993 
994 	rpoller->required_num_wr = required_num_wr;
995 	return 0;
996 }
997 
998 static int
999 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
1000 {
1001 	struct spdk_nvmf_rdma_qpair		*rqpair;
1002 	int					rc;
1003 	struct spdk_nvmf_rdma_transport		*rtransport;
1004 	struct spdk_nvmf_transport		*transport;
1005 	struct spdk_nvmf_rdma_resource_opts	opts;
1006 	struct spdk_nvmf_rdma_device		*device;
1007 	struct ibv_qp_init_attr			ibv_init_attr;
1008 
1009 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1010 	device = rqpair->port->device;
1011 
1012 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
1013 	ibv_init_attr.qp_context	= rqpair;
1014 	ibv_init_attr.qp_type		= IBV_QPT_RC;
1015 	ibv_init_attr.send_cq		= rqpair->poller->cq;
1016 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
1017 
1018 	if (rqpair->srq) {
1019 		ibv_init_attr.srq		= rqpair->srq;
1020 	} else {
1021 		ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
1022 						  1; /* RECV operations + dummy drain WR */
1023 	}
1024 
1025 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
1026 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
1027 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
1028 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
1029 
1030 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
1031 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
1032 		goto error;
1033 	}
1034 
1035 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
1036 	if (rc) {
1037 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
1038 		goto error;
1039 	}
1040 
1041 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2 + 1),
1042 					  ibv_init_attr.cap.max_send_wr);
1043 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
1044 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
1045 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
1046 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
1047 
1048 	rqpair->sends_to_post.first = NULL;
1049 	rqpair->sends_to_post.last = NULL;
1050 
1051 	if (rqpair->poller->srq == NULL) {
1052 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1053 		transport = &rtransport->transport;
1054 
1055 		opts.qp = rqpair->cm_id->qp;
1056 		opts.pd = rqpair->cm_id->pd;
1057 		opts.qpair = rqpair;
1058 		opts.shared = false;
1059 		opts.max_queue_depth = rqpair->max_queue_depth;
1060 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1061 
1062 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1063 
1064 		if (!rqpair->resources) {
1065 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1066 			rdma_destroy_qp(rqpair->cm_id);
1067 			goto error;
1068 		}
1069 	} else {
1070 		rqpair->resources = rqpair->poller->resources;
1071 	}
1072 
1073 	rqpair->current_recv_depth = 0;
1074 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1075 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1076 
1077 	return 0;
1078 
1079 error:
1080 	rdma_destroy_id(rqpair->cm_id);
1081 	rqpair->cm_id = NULL;
1082 	return -1;
1083 }
1084 
1085 /* Append the given recv wr structure to the resource structs outstanding recvs list. */
1086 /* This function accepts either a single wr or the first wr in a linked list. */
1087 static void
1088 nvmf_rdma_qpair_queue_recv_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *first)
1089 {
1090 	struct ibv_recv_wr *last;
1091 
1092 	last = first;
1093 	while (last->next != NULL) {
1094 		last = last->next;
1095 	}
1096 
1097 	if (rqpair->resources->recvs_to_post.first == NULL) {
1098 		rqpair->resources->recvs_to_post.first = first;
1099 		rqpair->resources->recvs_to_post.last = last;
1100 		if (rqpair->srq == NULL) {
1101 			STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_recv, rqpair, recv_link);
1102 		}
1103 	} else {
1104 		rqpair->resources->recvs_to_post.last->next = first;
1105 		rqpair->resources->recvs_to_post.last = last;
1106 	}
1107 }
1108 
1109 /* Append the given send wr structure to the qpair's outstanding sends list. */
1110 /* This function accepts either a single wr or the first wr in a linked list. */
1111 static void
1112 nvmf_rdma_qpair_queue_send_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *first)
1113 {
1114 	struct ibv_send_wr *last;
1115 
1116 	last = first;
1117 	while (last->next != NULL) {
1118 		last = last->next;
1119 	}
1120 
1121 	if (rqpair->sends_to_post.first == NULL) {
1122 		rqpair->sends_to_post.first = first;
1123 		rqpair->sends_to_post.last = last;
1124 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1125 	} else {
1126 		rqpair->sends_to_post.last->next = first;
1127 		rqpair->sends_to_post.last = last;
1128 	}
1129 }
1130 
1131 static int
1132 request_transfer_in(struct spdk_nvmf_request *req)
1133 {
1134 	struct spdk_nvmf_rdma_request	*rdma_req;
1135 	struct spdk_nvmf_qpair		*qpair;
1136 	struct spdk_nvmf_rdma_qpair	*rqpair;
1137 
1138 	qpair = req->qpair;
1139 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1140 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1141 
1142 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1143 	assert(rdma_req != NULL);
1144 
1145 	nvmf_rdma_qpair_queue_send_wrs(rqpair, &rdma_req->data.wr);
1146 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1147 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1148 	return 0;
1149 }
1150 
1151 static int
1152 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1153 {
1154 	int				num_outstanding_data_wr = 0;
1155 	struct spdk_nvmf_rdma_request	*rdma_req;
1156 	struct spdk_nvmf_qpair		*qpair;
1157 	struct spdk_nvmf_rdma_qpair	*rqpair;
1158 	struct spdk_nvme_cpl		*rsp;
1159 	struct ibv_send_wr		*first = NULL;
1160 
1161 	*data_posted = 0;
1162 	qpair = req->qpair;
1163 	rsp = &req->rsp->nvme_cpl;
1164 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1165 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1166 
1167 	/* Advance our sq_head pointer */
1168 	if (qpair->sq_head == qpair->sq_head_max) {
1169 		qpair->sq_head = 0;
1170 	} else {
1171 		qpair->sq_head++;
1172 	}
1173 	rsp->sqhd = qpair->sq_head;
1174 
1175 	/* queue the capsule for the recv buffer */
1176 	assert(rdma_req->recv != NULL);
1177 
1178 	nvmf_rdma_qpair_queue_recv_wrs(rqpair, &rdma_req->recv->wr);
1179 
1180 	rdma_req->recv = NULL;
1181 	assert(rqpair->current_recv_depth > 0);
1182 	rqpair->current_recv_depth--;
1183 
1184 	/* Build the response which consists of optional
1185 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1186 	 * containing the response.
1187 	 */
1188 	first = &rdma_req->rsp.wr;
1189 
1190 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
1191 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1192 		first = &rdma_req->data.wr;
1193 		*data_posted = 1;
1194 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1195 	}
1196 	nvmf_rdma_qpair_queue_send_wrs(rqpair, first);
1197 	/* +1 for the rsp wr */
1198 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1199 
1200 	return 0;
1201 }
1202 
1203 static int
1204 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1205 {
1206 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1207 	struct rdma_conn_param				ctrlr_event_data = {};
1208 	int						rc;
1209 
1210 	accept_data.recfmt = 0;
1211 	accept_data.crqsize = rqpair->max_queue_depth;
1212 
1213 	ctrlr_event_data.private_data = &accept_data;
1214 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1215 	if (id->ps == RDMA_PS_TCP) {
1216 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1217 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1218 	}
1219 
1220 	/* Configure infinite retries for the initiator side qpair.
1221 	 * When using a shared receive queue on the target side,
1222 	 * we need to pass this value to the initiator to prevent the
1223 	 * initiator side NIC from completing SEND requests back to the
1224 	 * initiator with status rnr_retry_count_exceeded. */
1225 	if (rqpair->srq != NULL) {
1226 		ctrlr_event_data.rnr_retry_count = 0x7;
1227 	}
1228 
1229 	rc = rdma_accept(id, &ctrlr_event_data);
1230 	if (rc) {
1231 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
1232 	} else {
1233 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
1234 	}
1235 
1236 	return rc;
1237 }
1238 
1239 static void
1240 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1241 {
1242 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1243 
1244 	rej_data.recfmt = 0;
1245 	rej_data.sts = error;
1246 
1247 	rdma_reject(id, &rej_data, sizeof(rej_data));
1248 }
1249 
1250 static int
1251 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
1252 		  new_qpair_fn cb_fn)
1253 {
1254 	struct spdk_nvmf_rdma_transport *rtransport;
1255 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1256 	struct spdk_nvmf_rdma_port	*port;
1257 	struct rdma_conn_param		*rdma_param = NULL;
1258 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1259 	uint16_t			max_queue_depth;
1260 	uint16_t			max_read_depth;
1261 
1262 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1263 
1264 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1265 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1266 
1267 	rdma_param = &event->param.conn;
1268 	if (rdma_param->private_data == NULL ||
1269 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1270 		SPDK_ERRLOG("connect request: no private data provided\n");
1271 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1272 		return -1;
1273 	}
1274 
1275 	private_data = rdma_param->private_data;
1276 	if (private_data->recfmt != 0) {
1277 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1278 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1279 		return -1;
1280 	}
1281 
1282 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1283 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1284 
1285 	port = event->listen_id->context;
1286 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1287 		      event->listen_id, event->listen_id->verbs, port);
1288 
1289 	/* Figure out the supported queue depth. This is a multi-step process
1290 	 * that takes into account hardware maximums, host provided values,
1291 	 * and our target's internal memory limits */
1292 
1293 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1294 
1295 	/* Start with the maximum queue depth allowed by the target */
1296 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1297 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1298 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1299 		      rtransport->transport.opts.max_queue_depth);
1300 
1301 	/* Next check the local NIC's hardware limitations */
1302 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1303 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1304 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1305 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1306 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1307 
1308 	/* Next check the remote NIC's hardware limitations */
1309 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1310 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1311 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1312 	if (rdma_param->initiator_depth > 0) {
1313 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1314 	}
1315 
1316 	/* Finally check for the host software requested values, which are
1317 	 * optional. */
1318 	if (rdma_param->private_data != NULL &&
1319 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1320 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1321 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1322 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1323 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1324 	}
1325 
1326 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1327 		      max_queue_depth, max_read_depth);
1328 
1329 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1330 	if (rqpair == NULL) {
1331 		SPDK_ERRLOG("Could not allocate new connection.\n");
1332 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1333 		return -1;
1334 	}
1335 
1336 	rqpair->port = port;
1337 	rqpair->max_queue_depth = max_queue_depth;
1338 	rqpair->max_read_depth = max_read_depth;
1339 	rqpair->cm_id = event->id;
1340 	rqpair->listen_id = event->listen_id;
1341 	rqpair->qpair.transport = transport;
1342 	/* use qid from the private data to determine the qpair type
1343 	   qid will be set to the appropriate value when the controller is created */
1344 	rqpair->qpair.qid = private_data->qid;
1345 
1346 	event->id->context = &rqpair->qpair;
1347 
1348 	cb_fn(&rqpair->qpair);
1349 
1350 	return 0;
1351 }
1352 
1353 static int
1354 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1355 			  enum spdk_mem_map_notify_action action,
1356 			  void *vaddr, size_t size)
1357 {
1358 	struct ibv_pd *pd = cb_ctx;
1359 	struct ibv_mr *mr;
1360 	int rc;
1361 
1362 	switch (action) {
1363 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1364 		if (!g_nvmf_hooks.get_rkey) {
1365 			mr = ibv_reg_mr(pd, vaddr, size,
1366 					IBV_ACCESS_LOCAL_WRITE |
1367 					IBV_ACCESS_REMOTE_READ |
1368 					IBV_ACCESS_REMOTE_WRITE);
1369 			if (mr == NULL) {
1370 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1371 				return -1;
1372 			} else {
1373 				rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1374 			}
1375 		} else {
1376 			rc = spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1377 							  g_nvmf_hooks.get_rkey(pd, vaddr, size));
1378 		}
1379 		break;
1380 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1381 		if (!g_nvmf_hooks.get_rkey) {
1382 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1383 			if (mr) {
1384 				ibv_dereg_mr(mr);
1385 			}
1386 		}
1387 		rc = spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1388 		break;
1389 	default:
1390 		SPDK_UNREACHABLE();
1391 	}
1392 
1393 	return rc;
1394 }
1395 
1396 static int
1397 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1398 {
1399 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1400 	return addr_1 == addr_2;
1401 }
1402 
1403 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1404 
1405 static spdk_nvme_data_transfer_t
1406 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1407 {
1408 	enum spdk_nvme_data_transfer xfer;
1409 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1410 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1411 
1412 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1413 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1414 	rdma_req->rsp.wr.imm_data = 0;
1415 #endif
1416 
1417 	/* Figure out data transfer direction */
1418 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1419 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1420 	} else {
1421 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1422 
1423 		/* Some admin commands are special cases */
1424 		if ((rdma_req->req.qpair->qid == 0) &&
1425 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1426 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1427 			switch (cmd->cdw10 & 0xff) {
1428 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1429 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1430 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1431 				break;
1432 			default:
1433 				xfer = SPDK_NVME_DATA_NONE;
1434 			}
1435 		}
1436 	}
1437 
1438 	if (xfer == SPDK_NVME_DATA_NONE) {
1439 		return xfer;
1440 	}
1441 
1442 	/* Even for commands that may transfer data, they could have specified 0 length.
1443 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1444 	 */
1445 	switch (sgl->generic.type) {
1446 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1447 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1448 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1449 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1450 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1451 		if (sgl->unkeyed.length == 0) {
1452 			xfer = SPDK_NVME_DATA_NONE;
1453 		}
1454 		break;
1455 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1456 		if (sgl->keyed.length == 0) {
1457 			xfer = SPDK_NVME_DATA_NONE;
1458 		}
1459 		break;
1460 	}
1461 
1462 	return xfer;
1463 }
1464 
1465 static int
1466 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1467 		       struct spdk_nvmf_rdma_request *rdma_req,
1468 		       uint32_t num_sgl_descriptors)
1469 {
1470 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1471 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1472 	uint32_t				i;
1473 
1474 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1475 		return -ENOMEM;
1476 	}
1477 
1478 	current_data_wr = &rdma_req->data;
1479 
1480 	for (i = 0; i < num_sgl_descriptors; i++) {
1481 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1482 			current_data_wr->wr.opcode = IBV_WR_RDMA_WRITE;
1483 			current_data_wr->wr.send_flags = 0;
1484 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1485 			current_data_wr->wr.opcode = IBV_WR_RDMA_READ;
1486 			current_data_wr->wr.send_flags = IBV_SEND_SIGNALED;
1487 		} else {
1488 			assert(false);
1489 		}
1490 		work_requests[i]->wr.sg_list = work_requests[i]->sgl;
1491 		work_requests[i]->wr.wr_id = rdma_req->data.wr.wr_id;
1492 		current_data_wr->wr.next = &work_requests[i]->wr;
1493 		current_data_wr = work_requests[i];
1494 	}
1495 
1496 	if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1497 		current_data_wr->wr.opcode = IBV_WR_RDMA_WRITE;
1498 		current_data_wr->wr.next = &rdma_req->rsp.wr;
1499 		current_data_wr->wr.send_flags = 0;
1500 	} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1501 		current_data_wr->wr.opcode = IBV_WR_RDMA_READ;
1502 		current_data_wr->wr.next = NULL;
1503 		current_data_wr->wr.send_flags = IBV_SEND_SIGNALED;
1504 	}
1505 	return 0;
1506 }
1507 
1508 /* This function is used in the rare case that we have a buffer split over multiple memory regions. */
1509 static int
1510 nvmf_rdma_replace_buffer(struct spdk_nvmf_rdma_poll_group *rgroup, void **buf)
1511 {
1512 	struct spdk_nvmf_transport_poll_group	*group = &rgroup->group;
1513 	struct spdk_nvmf_transport		*transport = group->transport;
1514 	struct spdk_nvmf_transport_pg_cache_buf	*old_buf;
1515 	void					*new_buf;
1516 
1517 	if (!(STAILQ_EMPTY(&group->buf_cache))) {
1518 		group->buf_cache_count--;
1519 		new_buf = STAILQ_FIRST(&group->buf_cache);
1520 		STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1521 		assert(*buf != NULL);
1522 	} else {
1523 		new_buf = spdk_mempool_get(transport->data_buf_pool);
1524 	}
1525 
1526 	if (*buf == NULL) {
1527 		return -ENOMEM;
1528 	}
1529 
1530 	old_buf = *buf;
1531 	STAILQ_INSERT_HEAD(&rgroup->retired_bufs, old_buf, link);
1532 	*buf = new_buf;
1533 	return 0;
1534 }
1535 
1536 static bool
1537 nvmf_rdma_get_lkey(struct spdk_nvmf_rdma_device *device, struct iovec *iov,
1538 		   uint32_t *_lkey)
1539 {
1540 	uint64_t	translation_len;
1541 	uint32_t	lkey;
1542 
1543 	translation_len = iov->iov_len;
1544 
1545 	if (!g_nvmf_hooks.get_rkey) {
1546 		lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1547 				(uint64_t)iov->iov_base, &translation_len))->lkey;
1548 	} else {
1549 		lkey = spdk_mem_map_translate(device->map,
1550 					      (uint64_t)iov->iov_base, &translation_len);
1551 	}
1552 
1553 	if (spdk_unlikely(translation_len < iov->iov_len)) {
1554 		return false;
1555 	}
1556 
1557 	*_lkey = lkey;
1558 	return true;
1559 }
1560 
1561 static bool
1562 nvmf_rdma_fill_wr_sge(struct spdk_nvmf_rdma_device *device,
1563 		      struct iovec *iov, struct ibv_send_wr *wr,
1564 		      uint32_t *_remaining_data_block, uint32_t *_offset,
1565 		      const struct spdk_dif_ctx *dif_ctx)
1566 {
1567 	struct ibv_sge	*sg_ele = &wr->sg_list[wr->num_sge];
1568 	uint32_t	lkey = 0;
1569 	uint32_t	remaining, data_block_size, md_size, sge_len;
1570 
1571 	if (spdk_unlikely(!nvmf_rdma_get_lkey(device, iov, &lkey))) {
1572 		/* This is a very rare case that can occur when using DPDK version < 19.05 */
1573 		SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions. Removing it from circulation.\n");
1574 		return false;
1575 	}
1576 
1577 	if (spdk_likely(!dif_ctx)) {
1578 		sg_ele->lkey = lkey;
1579 		sg_ele->addr = (uintptr_t)(iov->iov_base);
1580 		sg_ele->length = iov->iov_len;
1581 		wr->num_sge++;
1582 	} else {
1583 		remaining = iov->iov_len - *_offset;
1584 		data_block_size = dif_ctx->block_size - dif_ctx->md_size;
1585 		md_size = dif_ctx->md_size;
1586 
1587 		while (remaining && wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES) {
1588 			sg_ele->lkey = lkey;
1589 			sg_ele->addr = (uintptr_t)((char *)iov->iov_base + *_offset);
1590 			sge_len = spdk_min(remaining, *_remaining_data_block);
1591 			sg_ele->length = sge_len;
1592 			remaining -= sge_len;
1593 			*_remaining_data_block -= sge_len;
1594 			*_offset += sge_len;
1595 
1596 			sg_ele++;
1597 			wr->num_sge++;
1598 
1599 			if (*_remaining_data_block == 0) {
1600 				/* skip metadata */
1601 				*_offset += md_size;
1602 				/* Metadata that do not fit this IO buffer will be included in the next IO buffer */
1603 				remaining -= spdk_min(remaining, md_size);
1604 				*_remaining_data_block = data_block_size;
1605 			}
1606 
1607 			if (remaining == 0) {
1608 				/* By subtracting the size of the last IOV from the offset, we ensure that we skip
1609 				   the remaining metadata bits at the beginning of the next buffer */
1610 				*_offset -= iov->iov_len;
1611 			}
1612 		}
1613 	}
1614 
1615 	return true;
1616 }
1617 
1618 static int
1619 nvmf_rdma_fill_wr_sgl(struct spdk_nvmf_rdma_poll_group *rgroup,
1620 		      struct spdk_nvmf_rdma_device *device,
1621 		      struct spdk_nvmf_rdma_request *rdma_req,
1622 		      struct ibv_send_wr *wr,
1623 		      uint32_t length)
1624 {
1625 	struct spdk_nvmf_request *req = &rdma_req->req;
1626 	struct spdk_dif_ctx *dif_ctx = NULL;
1627 	uint32_t remaining_data_block = 0;
1628 	uint32_t offset = 0;
1629 
1630 	if (spdk_unlikely(rdma_req->dif_insert_or_strip)) {
1631 		dif_ctx = &rdma_req->dif_ctx;
1632 		remaining_data_block = dif_ctx->block_size - dif_ctx->md_size;
1633 	}
1634 
1635 	wr->num_sge = 0;
1636 
1637 	while (length && wr->num_sge < SPDK_NVMF_MAX_SGL_ENTRIES) {
1638 		while (spdk_unlikely(!nvmf_rdma_fill_wr_sge(device, &req->iov[rdma_req->iovpos], wr,
1639 				     &remaining_data_block, &offset, dif_ctx))) {
1640 			if (nvmf_rdma_replace_buffer(rgroup, &req->buffers[rdma_req->iovpos]) == -ENOMEM) {
1641 				return -ENOMEM;
1642 			}
1643 			req->iov[rdma_req->iovpos].iov_base = (void *)((uintptr_t)(req->buffers[rdma_req->iovpos] +
1644 							      NVMF_DATA_BUFFER_MASK) &
1645 							      ~NVMF_DATA_BUFFER_MASK);
1646 		}
1647 
1648 		length -= req->iov[rdma_req->iovpos].iov_len;
1649 		rdma_req->iovpos++;
1650 	}
1651 
1652 	if (length) {
1653 		SPDK_ERRLOG("Not enough SG entries to hold data buffer\n");
1654 		return -EINVAL;
1655 	}
1656 
1657 	return 0;
1658 }
1659 
1660 static int
1661 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1662 				 struct spdk_nvmf_rdma_device *device,
1663 				 struct spdk_nvmf_rdma_request *rdma_req,
1664 				 uint32_t length)
1665 {
1666 	struct spdk_nvmf_rdma_qpair		*rqpair;
1667 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1668 	struct spdk_nvmf_request		*req = &rdma_req->req;
1669 	struct ibv_send_wr			*wr = &rdma_req->data.wr;
1670 	int					rc;
1671 
1672 	rqpair = SPDK_CONTAINEROF(req->qpair, struct spdk_nvmf_rdma_qpair, qpair);
1673 	rgroup = rqpair->poller->group;
1674 
1675 	rc = spdk_nvmf_request_get_buffers(req, &rgroup->group, &rtransport->transport,
1676 					   length);
1677 	if (rc != 0) {
1678 		return rc;
1679 	}
1680 
1681 	assert(req->iovcnt <= rqpair->max_send_sge);
1682 
1683 	rdma_req->iovpos = 0;
1684 
1685 	rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, wr, length);
1686 	if (rc != 0) {
1687 		goto err_exit;
1688 	}
1689 
1690 	return rc;
1691 
1692 err_exit:
1693 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1694 	memset(wr->sg_list, 0, sizeof(wr->sg_list[0]) * wr->num_sge);
1695 	wr->num_sge = 0;
1696 	req->iovcnt = 0;
1697 	return rc;
1698 }
1699 
1700 static int
1701 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1702 				      struct spdk_nvmf_rdma_device *device,
1703 				      struct spdk_nvmf_rdma_request *rdma_req)
1704 {
1705 	struct spdk_nvmf_rdma_qpair		*rqpair;
1706 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1707 	struct ibv_send_wr			*current_wr;
1708 	struct spdk_nvmf_request		*req = &rdma_req->req;
1709 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1710 	uint32_t				num_sgl_descriptors;
1711 	uint32_t				lengths[SPDK_NVMF_MAX_SGL_ENTRIES];
1712 	uint32_t				i;
1713 	int					rc;
1714 
1715 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1716 	rgroup = rqpair->poller->group;
1717 
1718 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1719 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1720 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1721 
1722 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1723 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1724 
1725 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1726 		return -ENOMEM;
1727 	}
1728 
1729 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1730 	for (i = 0; i < num_sgl_descriptors; i++) {
1731 		lengths[i] = desc->keyed.length;
1732 		desc++;
1733 	}
1734 
1735 	rc = spdk_nvmf_request_get_buffers_multi(req, &rgroup->group, &rtransport->transport,
1736 			lengths, num_sgl_descriptors);
1737 	if (rc != 0) {
1738 		nvmf_rdma_request_free_data(rdma_req, rtransport);
1739 		return rc;
1740 	}
1741 
1742 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1743 	current_wr = &rdma_req->data.wr;
1744 	assert(current_wr != NULL);
1745 
1746 	req->length = 0;
1747 	rdma_req->iovpos = 0;
1748 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1749 	for (i = 0; i < num_sgl_descriptors; i++) {
1750 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1751 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1752 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1753 			rc = -EINVAL;
1754 			goto err_exit;
1755 		}
1756 
1757 		current_wr->num_sge = 0;
1758 
1759 		rc = nvmf_rdma_fill_wr_sgl(rgroup, device, rdma_req, current_wr, desc->keyed.length);
1760 		if (rc != 0) {
1761 			rc = -ENOMEM;
1762 			goto err_exit;
1763 		}
1764 
1765 		req->length += desc->keyed.length;
1766 		current_wr->wr.rdma.rkey = desc->keyed.key;
1767 		current_wr->wr.rdma.remote_addr = desc->address;
1768 		current_wr = current_wr->next;
1769 		desc++;
1770 	}
1771 
1772 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1773 	/* Go back to the last descriptor in the list. */
1774 	desc--;
1775 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1776 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1777 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1778 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1779 		}
1780 	}
1781 #endif
1782 
1783 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1784 
1785 	return 0;
1786 
1787 err_exit:
1788 	spdk_nvmf_request_free_buffers(req, &rgroup->group, &rtransport->transport);
1789 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1790 	return rc;
1791 }
1792 
1793 static int
1794 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1795 				 struct spdk_nvmf_rdma_device *device,
1796 				 struct spdk_nvmf_rdma_request *rdma_req)
1797 {
1798 	struct spdk_nvmf_request		*req = &rdma_req->req;
1799 	struct spdk_nvme_cmd			*cmd;
1800 	struct spdk_nvme_cpl			*rsp;
1801 	struct spdk_nvme_sgl_descriptor		*sgl;
1802 	struct ibv_send_wr			*wr;
1803 	int					rc;
1804 	uint32_t				length;
1805 
1806 	cmd = &req->cmd->nvme_cmd;
1807 	rsp = &req->rsp->nvme_cpl;
1808 	sgl = &cmd->dptr.sgl1;
1809 
1810 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1811 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1812 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1813 
1814 		length = sgl->keyed.length;
1815 		if (length > rtransport->transport.opts.max_io_size) {
1816 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1817 				    length, rtransport->transport.opts.max_io_size);
1818 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1819 			return -1;
1820 		}
1821 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1822 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1823 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1824 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1825 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1826 			}
1827 		}
1828 #endif
1829 
1830 		/* fill request length and populate iovs */
1831 		req->length = length;
1832 
1833 		if (spdk_unlikely(rdma_req->dif_insert_or_strip)) {
1834 			rdma_req->orig_length = length;
1835 			length = spdk_dif_get_length_with_md(length, &rdma_req->dif_ctx);
1836 			rdma_req->elba_length = length;
1837 		}
1838 
1839 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req, length) < 0) {
1840 			/* No available buffers. Queue this request up. */
1841 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1842 			return 0;
1843 		}
1844 
1845 		/* backward compatible */
1846 		req->data = req->iov[0].iov_base;
1847 
1848 		/* rdma wr specifics */
1849 		wr = &rdma_req->data.wr;
1850 		wr->wr.rdma.rkey = sgl->keyed.key;
1851 		wr->wr.rdma.remote_addr = sgl->address;
1852 		if (req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1853 			wr->opcode = IBV_WR_RDMA_WRITE;
1854 			wr->next = &rdma_req->rsp.wr;
1855 			wr->send_flags &= ~IBV_SEND_SIGNALED;
1856 		} else if (req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1857 			wr->opcode = IBV_WR_RDMA_READ;
1858 			wr->next = NULL;
1859 			wr->send_flags |= IBV_SEND_SIGNALED;
1860 		}
1861 
1862 		/* set the number of outstanding data WRs for this request. */
1863 		rdma_req->num_outstanding_data_wr = 1;
1864 
1865 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1866 			      req->iovcnt);
1867 
1868 		return 0;
1869 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1870 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1871 		uint64_t offset = sgl->address;
1872 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1873 
1874 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1875 			      offset, sgl->unkeyed.length);
1876 
1877 		if (offset > max_len) {
1878 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1879 				    offset, max_len);
1880 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1881 			return -1;
1882 		}
1883 		max_len -= (uint32_t)offset;
1884 
1885 		if (sgl->unkeyed.length > max_len) {
1886 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1887 				    sgl->unkeyed.length, max_len);
1888 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1889 			return -1;
1890 		}
1891 
1892 		rdma_req->num_outstanding_data_wr = 0;
1893 		req->data = rdma_req->recv->buf + offset;
1894 		req->data_from_pool = false;
1895 		req->length = sgl->unkeyed.length;
1896 
1897 		req->iov[0].iov_base = req->data;
1898 		req->iov[0].iov_len = req->length;
1899 		req->iovcnt = 1;
1900 
1901 		return 0;
1902 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1903 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1904 
1905 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1906 		if (rc == -ENOMEM) {
1907 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1908 			return 0;
1909 		} else if (rc == -EINVAL) {
1910 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1911 			return -1;
1912 		}
1913 
1914 		/* backward compatible */
1915 		req->data = req->iov[0].iov_base;
1916 
1917 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1918 			      req->iovcnt);
1919 
1920 		return 0;
1921 	}
1922 
1923 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1924 		    sgl->generic.type, sgl->generic.subtype);
1925 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1926 	return -1;
1927 }
1928 
1929 static void
1930 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1931 		       struct spdk_nvmf_rdma_transport	*rtransport)
1932 {
1933 	struct spdk_nvmf_rdma_qpair		*rqpair;
1934 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1935 
1936 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1937 	if (rdma_req->req.data_from_pool) {
1938 		rgroup = rqpair->poller->group;
1939 
1940 		spdk_nvmf_request_free_buffers(&rdma_req->req, &rgroup->group, &rtransport->transport);
1941 	}
1942 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1943 	rdma_req->req.length = 0;
1944 	rdma_req->req.iovcnt = 0;
1945 	rdma_req->req.data = NULL;
1946 	rdma_req->rsp.wr.next = NULL;
1947 	rdma_req->data.wr.next = NULL;
1948 	rdma_req->dif_insert_or_strip = false;
1949 	rdma_req->elba_length = 0;
1950 	rdma_req->orig_length = 0;
1951 	memset(&rdma_req->dif_ctx, 0, sizeof(rdma_req->dif_ctx));
1952 	rqpair->qd--;
1953 
1954 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1955 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1956 }
1957 
1958 static bool
1959 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1960 			       struct spdk_nvmf_rdma_request *rdma_req)
1961 {
1962 	struct spdk_nvmf_rdma_qpair	*rqpair;
1963 	struct spdk_nvmf_rdma_device	*device;
1964 	struct spdk_nvmf_rdma_poll_group *rgroup;
1965 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1966 	int				rc;
1967 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1968 	enum spdk_nvmf_rdma_request_state prev_state;
1969 	bool				progress = false;
1970 	int				data_posted;
1971 	uint32_t			num_blocks;
1972 
1973 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1974 	device = rqpair->port->device;
1975 	rgroup = rqpair->poller->group;
1976 
1977 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1978 
1979 	/* If the queue pair is in an error state, force the request to the completed state
1980 	 * to release resources. */
1981 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1982 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1983 			STAILQ_REMOVE(&rgroup->group.pending_buf_queue, &rdma_req->req, spdk_nvmf_request, buf_link);
1984 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1985 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1986 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1987 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1988 		}
1989 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1990 	}
1991 
1992 	/* The loop here is to allow for several back-to-back state changes. */
1993 	do {
1994 		prev_state = rdma_req->state;
1995 
1996 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1997 
1998 		switch (rdma_req->state) {
1999 		case RDMA_REQUEST_STATE_FREE:
2000 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
2001 			 * to escape this state. */
2002 			break;
2003 		case RDMA_REQUEST_STATE_NEW:
2004 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
2005 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2006 			rdma_recv = rdma_req->recv;
2007 
2008 			/* The first element of the SGL is the NVMe command */
2009 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
2010 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
2011 
2012 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
2013 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2014 				break;
2015 			}
2016 
2017 			if (spdk_unlikely(spdk_nvmf_request_get_dif_ctx(&rdma_req->req, &rdma_req->dif_ctx))) {
2018 				rdma_req->dif_insert_or_strip = true;
2019 			}
2020 
2021 			/* The next state transition depends on the data transfer needs of this request. */
2022 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
2023 
2024 			/* If no data to transfer, ready to execute. */
2025 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
2026 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2027 				break;
2028 			}
2029 
2030 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
2031 			STAILQ_INSERT_TAIL(&rgroup->group.pending_buf_queue, &rdma_req->req, buf_link);
2032 			break;
2033 		case RDMA_REQUEST_STATE_NEED_BUFFER:
2034 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
2035 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2036 
2037 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
2038 
2039 			if (&rdma_req->req != STAILQ_FIRST(&rgroup->group.pending_buf_queue)) {
2040 				/* This request needs to wait in line to obtain a buffer */
2041 				break;
2042 			}
2043 
2044 			/* Try to get a data buffer */
2045 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
2046 			if (rc < 0) {
2047 				STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2048 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2049 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2050 				break;
2051 			}
2052 
2053 			if (!rdma_req->req.data) {
2054 				/* No buffers available. */
2055 				rgroup->stat.pending_data_buffer++;
2056 				break;
2057 			}
2058 
2059 			STAILQ_REMOVE_HEAD(&rgroup->group.pending_buf_queue, buf_link);
2060 
2061 			/* If data is transferring from host to controller and the data didn't
2062 			 * arrive using in capsule data, we need to do a transfer from the host.
2063 			 */
2064 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER &&
2065 			    rdma_req->req.data_from_pool) {
2066 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
2067 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
2068 				break;
2069 			}
2070 
2071 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2072 			break;
2073 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
2074 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
2075 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2076 
2077 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
2078 				/* This request needs to wait in line to perform RDMA */
2079 				break;
2080 			}
2081 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
2082 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
2083 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
2084 				rqpair->poller->stat.pending_rdma_read++;
2085 				break;
2086 			}
2087 
2088 			/* We have already verified that this request is the head of the queue. */
2089 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
2090 
2091 			rc = request_transfer_in(&rdma_req->req);
2092 			if (!rc) {
2093 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
2094 			} else {
2095 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
2096 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2097 			}
2098 			break;
2099 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
2100 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
2101 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2102 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
2103 			 * to escape this state. */
2104 			break;
2105 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
2106 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
2107 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2108 
2109 			if (spdk_unlikely(rdma_req->dif_insert_or_strip)) {
2110 				if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
2111 					/* generate DIF for write operation */
2112 					num_blocks = SPDK_CEIL_DIV(rdma_req->elba_length, rdma_req->dif_ctx.block_size);
2113 					assert(num_blocks > 0);
2114 
2115 					rc = spdk_dif_generate(rdma_req->req.iov, rdma_req->req.iovcnt,
2116 							       num_blocks, &rdma_req->dif_ctx);
2117 					if (rc != 0) {
2118 						SPDK_ERRLOG("DIF generation failed\n");
2119 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2120 						spdk_nvmf_rdma_start_disconnect(rqpair);
2121 						break;
2122 					}
2123 				}
2124 
2125 				assert(rdma_req->elba_length >= rdma_req->req.length);
2126 				/* set extended length before IO operation */
2127 				rdma_req->req.length = rdma_req->elba_length;
2128 			}
2129 
2130 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
2131 			spdk_nvmf_request_exec(&rdma_req->req);
2132 			break;
2133 		case RDMA_REQUEST_STATE_EXECUTING:
2134 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
2135 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2136 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
2137 			 * to escape this state. */
2138 			break;
2139 		case RDMA_REQUEST_STATE_EXECUTED:
2140 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
2141 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2142 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2143 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
2144 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
2145 			} else {
2146 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2147 			}
2148 			if (spdk_unlikely(rdma_req->dif_insert_or_strip)) {
2149 				/* restore the original length */
2150 				rdma_req->req.length = rdma_req->orig_length;
2151 
2152 				if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
2153 					struct spdk_dif_error error_blk;
2154 
2155 					num_blocks = SPDK_CEIL_DIV(rdma_req->elba_length, rdma_req->dif_ctx.block_size);
2156 
2157 					rc = spdk_dif_verify(rdma_req->req.iov, rdma_req->req.iovcnt, num_blocks, &rdma_req->dif_ctx,
2158 							     &error_blk);
2159 					if (rc) {
2160 						struct spdk_nvme_cpl *rsp = &rdma_req->req.rsp->nvme_cpl;
2161 
2162 						SPDK_ERRLOG("DIF error detected. type=%d, offset=%" PRIu32 "\n", error_blk.err_type,
2163 							    error_blk.err_offset);
2164 						rsp->status.sct = SPDK_NVME_SCT_MEDIA_ERROR;
2165 						rsp->status.sc = spdk_nvmf_rdma_dif_error_to_compl_status(error_blk.err_type);
2166 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2167 						STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
2168 					}
2169 				}
2170 			}
2171 			break;
2172 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
2173 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
2174 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2175 
2176 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
2177 				/* This request needs to wait in line to perform RDMA */
2178 				break;
2179 			}
2180 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2181 			    rqpair->max_send_depth) {
2182 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2183 				 * +1 since each request has an additional wr in the resp. */
2184 				rqpair->poller->stat.pending_rdma_write++;
2185 				break;
2186 			}
2187 
2188 			/* We have already verified that this request is the head of the queue. */
2189 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2190 
2191 			/* The data transfer will be kicked off from
2192 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2193 			 */
2194 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2195 			break;
2196 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2197 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2198 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2199 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2200 			assert(rc == 0); /* No good way to handle this currently */
2201 			if (rc) {
2202 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2203 			} else {
2204 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2205 						  RDMA_REQUEST_STATE_COMPLETING;
2206 			}
2207 			break;
2208 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2209 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2210 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2211 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2212 			 * to escape this state. */
2213 			break;
2214 		case RDMA_REQUEST_STATE_COMPLETING:
2215 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2216 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2217 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2218 			 * to escape this state. */
2219 			break;
2220 		case RDMA_REQUEST_STATE_COMPLETED:
2221 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2222 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2223 
2224 			rqpair->poller->stat.request_latency += spdk_get_ticks() - rdma_req->receive_tsc;
2225 			nvmf_rdma_request_free(rdma_req, rtransport);
2226 			break;
2227 		case RDMA_REQUEST_NUM_STATES:
2228 		default:
2229 			assert(0);
2230 			break;
2231 		}
2232 
2233 		if (rdma_req->state != prev_state) {
2234 			progress = true;
2235 		}
2236 	} while (rdma_req->state != prev_state);
2237 
2238 	return progress;
2239 }
2240 
2241 /* Public API callbacks begin here */
2242 
2243 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2244 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2245 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2246 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 128
2247 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2248 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2249 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2250 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2251 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2252 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false
2253 #define SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP false
2254 
2255 static void
2256 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2257 {
2258 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2259 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2260 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2261 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2262 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2263 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2264 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2265 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2266 	opts->max_srq_depth =		SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2267 	opts->no_srq =			SPDK_NVMF_RDMA_DEFAULT_NO_SRQ;
2268 	opts->dif_insert_or_strip =	SPDK_NVMF_RDMA_DIF_INSERT_OR_STRIP;
2269 }
2270 
2271 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2272 	.notify_cb = spdk_nvmf_rdma_mem_notify,
2273 	.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
2274 };
2275 
2276 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
2277 
2278 static struct spdk_nvmf_transport *
2279 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2280 {
2281 	int rc;
2282 	struct spdk_nvmf_rdma_transport *rtransport;
2283 	struct spdk_nvmf_rdma_device	*device, *tmp;
2284 	struct ibv_context		**contexts;
2285 	uint32_t			i;
2286 	int				flag;
2287 	uint32_t			sge_count;
2288 	uint32_t			min_shared_buffers;
2289 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2290 	pthread_mutexattr_t		attr;
2291 
2292 	rtransport = calloc(1, sizeof(*rtransport));
2293 	if (!rtransport) {
2294 		return NULL;
2295 	}
2296 
2297 	if (pthread_mutexattr_init(&attr)) {
2298 		SPDK_ERRLOG("pthread_mutexattr_init() failed\n");
2299 		free(rtransport);
2300 		return NULL;
2301 	}
2302 
2303 	if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
2304 		SPDK_ERRLOG("pthread_mutexattr_settype() failed\n");
2305 		pthread_mutexattr_destroy(&attr);
2306 		free(rtransport);
2307 		return NULL;
2308 	}
2309 
2310 	if (pthread_mutex_init(&rtransport->lock, &attr)) {
2311 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2312 		pthread_mutexattr_destroy(&attr);
2313 		free(rtransport);
2314 		return NULL;
2315 	}
2316 
2317 	pthread_mutexattr_destroy(&attr);
2318 
2319 	TAILQ_INIT(&rtransport->devices);
2320 	TAILQ_INIT(&rtransport->ports);
2321 	TAILQ_INIT(&rtransport->poll_groups);
2322 
2323 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2324 
2325 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
2326 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2327 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2328 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2329 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d\n",
2330 		     opts->max_queue_depth,
2331 		     opts->max_io_size,
2332 		     opts->max_qpairs_per_ctrlr,
2333 		     opts->io_unit_size,
2334 		     opts->in_capsule_data_size,
2335 		     opts->max_aq_depth,
2336 		     opts->num_shared_buffers,
2337 		     opts->max_srq_depth,
2338 		     opts->no_srq);
2339 
2340 	/* I/O unit size cannot be larger than max I/O size */
2341 	if (opts->io_unit_size > opts->max_io_size) {
2342 		opts->io_unit_size = opts->max_io_size;
2343 	}
2344 
2345 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2346 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2347 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2348 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2349 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2350 		return NULL;
2351 	}
2352 
2353 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
2354 	if (min_shared_buffers > opts->num_shared_buffers) {
2355 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2356 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2357 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2358 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2359 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2360 		return NULL;
2361 	}
2362 
2363 	sge_count = opts->max_io_size / opts->io_unit_size;
2364 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2365 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2366 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2367 		return NULL;
2368 	}
2369 
2370 	rtransport->event_channel = rdma_create_event_channel();
2371 	if (rtransport->event_channel == NULL) {
2372 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2373 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2374 		return NULL;
2375 	}
2376 
2377 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2378 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2379 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2380 			    rtransport->event_channel->fd, spdk_strerror(errno));
2381 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2382 		return NULL;
2383 	}
2384 
2385 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2386 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2387 				   sizeof(struct spdk_nvmf_rdma_request_data),
2388 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2389 				   SPDK_ENV_SOCKET_ID_ANY);
2390 	if (!rtransport->data_wr_pool) {
2391 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2392 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2393 		return NULL;
2394 	}
2395 
2396 	contexts = rdma_get_devices(NULL);
2397 	if (contexts == NULL) {
2398 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2399 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2400 		return NULL;
2401 	}
2402 
2403 	i = 0;
2404 	rc = 0;
2405 	while (contexts[i] != NULL) {
2406 		device = calloc(1, sizeof(*device));
2407 		if (!device) {
2408 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2409 			rc = -ENOMEM;
2410 			break;
2411 		}
2412 		device->context = contexts[i];
2413 		rc = ibv_query_device(device->context, &device->attr);
2414 		if (rc < 0) {
2415 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2416 			free(device);
2417 			break;
2418 
2419 		}
2420 
2421 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2422 
2423 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2424 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2425 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2426 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2427 		}
2428 
2429 		/**
2430 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2431 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2432 		 * but incorrectly reports that it does. There are changes making their way
2433 		 * through the kernel now that will enable this feature. When they are merged,
2434 		 * we can conditionally enable this feature.
2435 		 *
2436 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2437 		 */
2438 		if (device->attr.vendor_id == 0) {
2439 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2440 		}
2441 #endif
2442 
2443 		/* set up device context async ev fd as NON_BLOCKING */
2444 		flag = fcntl(device->context->async_fd, F_GETFL);
2445 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2446 		if (rc < 0) {
2447 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2448 			free(device);
2449 			break;
2450 		}
2451 
2452 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2453 		i++;
2454 
2455 		if (g_nvmf_hooks.get_ibv_pd) {
2456 			device->pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2457 		} else {
2458 			device->pd = ibv_alloc_pd(device->context);
2459 		}
2460 
2461 		if (!device->pd) {
2462 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
2463 			rc = -ENOMEM;
2464 			break;
2465 		}
2466 
2467 		assert(device->map == NULL);
2468 
2469 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2470 		if (!device->map) {
2471 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2472 			rc = -ENOMEM;
2473 			break;
2474 		}
2475 
2476 		assert(device->map != NULL);
2477 		assert(device->pd != NULL);
2478 	}
2479 	rdma_free_devices(contexts);
2480 
2481 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2482 		/* divide and round up. */
2483 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2484 
2485 		/* round up to the nearest 4k. */
2486 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2487 
2488 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2489 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2490 			       opts->io_unit_size);
2491 	}
2492 
2493 	if (rc < 0) {
2494 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2495 		return NULL;
2496 	}
2497 
2498 	/* Set up poll descriptor array to monitor events from RDMA and IB
2499 	 * in a single poll syscall
2500 	 */
2501 	rtransport->npoll_fds = i + 1;
2502 	i = 0;
2503 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2504 	if (rtransport->poll_fds == NULL) {
2505 		SPDK_ERRLOG("poll_fds allocation failed\n");
2506 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2507 		return NULL;
2508 	}
2509 
2510 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2511 	rtransport->poll_fds[i++].events = POLLIN;
2512 
2513 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2514 		rtransport->poll_fds[i].fd = device->context->async_fd;
2515 		rtransport->poll_fds[i++].events = POLLIN;
2516 	}
2517 
2518 	return &rtransport->transport;
2519 }
2520 
2521 static int
2522 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
2523 {
2524 	struct spdk_nvmf_rdma_transport	*rtransport;
2525 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2526 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2527 
2528 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2529 
2530 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2531 		TAILQ_REMOVE(&rtransport->ports, port, link);
2532 		rdma_destroy_id(port->id);
2533 		free(port);
2534 	}
2535 
2536 	if (rtransport->poll_fds != NULL) {
2537 		free(rtransport->poll_fds);
2538 	}
2539 
2540 	if (rtransport->event_channel != NULL) {
2541 		rdma_destroy_event_channel(rtransport->event_channel);
2542 	}
2543 
2544 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2545 		TAILQ_REMOVE(&rtransport->devices, device, link);
2546 		if (device->map) {
2547 			spdk_mem_map_free(&device->map);
2548 		}
2549 		if (device->pd) {
2550 			if (!g_nvmf_hooks.get_ibv_pd) {
2551 				ibv_dealloc_pd(device->pd);
2552 			}
2553 		}
2554 		free(device);
2555 	}
2556 
2557 	if (rtransport->data_wr_pool != NULL) {
2558 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2559 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2560 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2561 				    spdk_mempool_count(rtransport->data_wr_pool),
2562 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2563 		}
2564 	}
2565 
2566 	spdk_mempool_free(rtransport->data_wr_pool);
2567 
2568 	pthread_mutex_destroy(&rtransport->lock);
2569 	free(rtransport);
2570 
2571 	return 0;
2572 }
2573 
2574 static int
2575 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2576 			       struct spdk_nvme_transport_id *trid,
2577 			       bool peer);
2578 
2579 static int
2580 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2581 		      const struct spdk_nvme_transport_id *trid)
2582 {
2583 	struct spdk_nvmf_rdma_transport	*rtransport;
2584 	struct spdk_nvmf_rdma_device	*device;
2585 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
2586 	struct addrinfo			*res;
2587 	struct addrinfo			hints;
2588 	int				family;
2589 	int				rc;
2590 
2591 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2592 
2593 	port = calloc(1, sizeof(*port));
2594 	if (!port) {
2595 		return -ENOMEM;
2596 	}
2597 
2598 	/* Selectively copy the trid. Things like NQN don't matter here - that
2599 	 * mapping is enforced elsewhere.
2600 	 */
2601 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2602 	port->trid.adrfam = trid->adrfam;
2603 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
2604 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
2605 
2606 	switch (port->trid.adrfam) {
2607 	case SPDK_NVMF_ADRFAM_IPV4:
2608 		family = AF_INET;
2609 		break;
2610 	case SPDK_NVMF_ADRFAM_IPV6:
2611 		family = AF_INET6;
2612 		break;
2613 	default:
2614 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
2615 		free(port);
2616 		return -EINVAL;
2617 	}
2618 
2619 	memset(&hints, 0, sizeof(hints));
2620 	hints.ai_family = family;
2621 	hints.ai_flags = AI_NUMERICSERV;
2622 	hints.ai_socktype = SOCK_STREAM;
2623 	hints.ai_protocol = 0;
2624 
2625 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
2626 	if (rc) {
2627 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2628 		free(port);
2629 		return -EINVAL;
2630 	}
2631 
2632 	pthread_mutex_lock(&rtransport->lock);
2633 	assert(rtransport->event_channel != NULL);
2634 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
2635 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
2636 			port_tmp->ref++;
2637 			freeaddrinfo(res);
2638 			free(port);
2639 			/* Already listening at this address */
2640 			pthread_mutex_unlock(&rtransport->lock);
2641 			return 0;
2642 		}
2643 	}
2644 
2645 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2646 	if (rc < 0) {
2647 		SPDK_ERRLOG("rdma_create_id() failed\n");
2648 		freeaddrinfo(res);
2649 		free(port);
2650 		pthread_mutex_unlock(&rtransport->lock);
2651 		return rc;
2652 	}
2653 
2654 	rc = rdma_bind_addr(port->id, res->ai_addr);
2655 	freeaddrinfo(res);
2656 
2657 	if (rc < 0) {
2658 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2659 		rdma_destroy_id(port->id);
2660 		free(port);
2661 		pthread_mutex_unlock(&rtransport->lock);
2662 		return rc;
2663 	}
2664 
2665 	if (!port->id->verbs) {
2666 		SPDK_ERRLOG("ibv_context is null\n");
2667 		rdma_destroy_id(port->id);
2668 		free(port);
2669 		pthread_mutex_unlock(&rtransport->lock);
2670 		return -1;
2671 	}
2672 
2673 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
2674 	if (rc < 0) {
2675 		SPDK_ERRLOG("rdma_listen() failed\n");
2676 		rdma_destroy_id(port->id);
2677 		free(port);
2678 		pthread_mutex_unlock(&rtransport->lock);
2679 		return rc;
2680 	}
2681 
2682 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2683 		if (device->context == port->id->verbs) {
2684 			port->device = device;
2685 			break;
2686 		}
2687 	}
2688 	if (!port->device) {
2689 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2690 			    port->id->verbs);
2691 		rdma_destroy_id(port->id);
2692 		free(port);
2693 		pthread_mutex_unlock(&rtransport->lock);
2694 		return -EINVAL;
2695 	}
2696 
2697 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
2698 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
2699 
2700 	port->ref = 1;
2701 
2702 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2703 	pthread_mutex_unlock(&rtransport->lock);
2704 
2705 	return 0;
2706 }
2707 
2708 static int
2709 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2710 			   const struct spdk_nvme_transport_id *_trid)
2711 {
2712 	struct spdk_nvmf_rdma_transport *rtransport;
2713 	struct spdk_nvmf_rdma_port *port, *tmp;
2714 	struct spdk_nvme_transport_id trid = {};
2715 
2716 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2717 
2718 	/* Selectively copy the trid. Things like NQN don't matter here - that
2719 	 * mapping is enforced elsewhere.
2720 	 */
2721 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2722 	trid.adrfam = _trid->adrfam;
2723 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2724 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2725 
2726 	pthread_mutex_lock(&rtransport->lock);
2727 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2728 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2729 			assert(port->ref > 0);
2730 			port->ref--;
2731 			if (port->ref == 0) {
2732 				TAILQ_REMOVE(&rtransport->ports, port, link);
2733 				rdma_destroy_id(port->id);
2734 				free(port);
2735 			}
2736 			break;
2737 		}
2738 	}
2739 
2740 	pthread_mutex_unlock(&rtransport->lock);
2741 	return 0;
2742 }
2743 
2744 static void
2745 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2746 				     struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2747 {
2748 	struct spdk_nvmf_request *req, *tmp;
2749 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2750 	struct spdk_nvmf_rdma_resources *resources;
2751 
2752 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2753 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2754 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2755 			break;
2756 		}
2757 	}
2758 
2759 	/* Then RDMA writes since reads have stronger restrictions than writes */
2760 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2761 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2762 			break;
2763 		}
2764 	}
2765 
2766 	/* The second highest priority is I/O waiting on memory buffers. */
2767 	STAILQ_FOREACH_SAFE(req, &rqpair->poller->group->group.pending_buf_queue, buf_link, tmp) {
2768 		rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2769 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2770 			break;
2771 		}
2772 	}
2773 
2774 	resources = rqpair->resources;
2775 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2776 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2777 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2778 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2779 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2780 
2781 		if (rqpair->srq != NULL) {
2782 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2783 			rdma_req->recv->qpair->qd++;
2784 		} else {
2785 			rqpair->qd++;
2786 		}
2787 
2788 		rdma_req->receive_tsc = rdma_req->recv->receive_tsc;
2789 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2790 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2791 			break;
2792 		}
2793 	}
2794 	if (!STAILQ_EMPTY(&resources->incoming_queue) && STAILQ_EMPTY(&resources->free_queue)) {
2795 		rqpair->poller->stat.pending_free_request++;
2796 	}
2797 }
2798 
2799 static void
2800 _nvmf_rdma_qpair_disconnect(void *ctx)
2801 {
2802 	struct spdk_nvmf_qpair *qpair = ctx;
2803 
2804 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2805 }
2806 
2807 static void
2808 _nvmf_rdma_try_disconnect(void *ctx)
2809 {
2810 	struct spdk_nvmf_qpair *qpair = ctx;
2811 	struct spdk_nvmf_poll_group *group;
2812 
2813 	/* Read the group out of the qpair. This is normally set and accessed only from
2814 	 * the thread that created the group. Here, we're not on that thread necessarily.
2815 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2816 	 * a pointer and never changes. So fortunately reading this and checking for
2817 	 * non-NULL is thread safe in the x86_64 memory model. */
2818 	group = qpair->group;
2819 
2820 	if (group == NULL) {
2821 		/* The qpair hasn't been assigned to a group yet, so we can't
2822 		 * process a disconnect. Send a message to ourself and try again. */
2823 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2824 		return;
2825 	}
2826 
2827 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2828 }
2829 
2830 static inline void
2831 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2832 {
2833 	if (__sync_bool_compare_and_swap(&rqpair->disconnect_started, false, true)) {
2834 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2835 	}
2836 }
2837 
2838 static void nvmf_rdma_destroy_drained_qpair(void *ctx)
2839 {
2840 	struct spdk_nvmf_rdma_qpair *rqpair = ctx;
2841 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2842 			struct spdk_nvmf_rdma_transport, transport);
2843 
2844 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2845 	if (rqpair->current_send_depth != 0) {
2846 		return;
2847 	}
2848 
2849 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2850 		return;
2851 	}
2852 
2853 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false) {
2854 		return;
2855 	}
2856 
2857 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2858 
2859 	/* Qpair will be destroyed after nvmf layer closes this qpair */
2860 	if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ERROR) {
2861 		return;
2862 	}
2863 
2864 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2865 }
2866 
2867 
2868 static int
2869 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2870 {
2871 	struct spdk_nvmf_qpair		*qpair;
2872 	struct spdk_nvmf_rdma_qpair	*rqpair;
2873 
2874 	if (evt->id == NULL) {
2875 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2876 		return -1;
2877 	}
2878 
2879 	qpair = evt->id->context;
2880 	if (qpair == NULL) {
2881 		SPDK_ERRLOG("disconnect request: no active connection\n");
2882 		return -1;
2883 	}
2884 
2885 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2886 
2887 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2888 
2889 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2890 
2891 	spdk_nvmf_rdma_start_disconnect(rqpair);
2892 
2893 	return 0;
2894 }
2895 
2896 #ifdef DEBUG
2897 static const char *CM_EVENT_STR[] = {
2898 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2899 	"RDMA_CM_EVENT_ADDR_ERROR",
2900 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2901 	"RDMA_CM_EVENT_ROUTE_ERROR",
2902 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2903 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2904 	"RDMA_CM_EVENT_CONNECT_ERROR",
2905 	"RDMA_CM_EVENT_UNREACHABLE",
2906 	"RDMA_CM_EVENT_REJECTED",
2907 	"RDMA_CM_EVENT_ESTABLISHED",
2908 	"RDMA_CM_EVENT_DISCONNECTED",
2909 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2910 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2911 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2912 	"RDMA_CM_EVENT_ADDR_CHANGE",
2913 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2914 };
2915 #endif /* DEBUG */
2916 
2917 static void
2918 nvmf_rdma_handle_last_wqe_reached(void *ctx)
2919 {
2920 	struct spdk_nvmf_rdma_qpair *rqpair = ctx;
2921 	rqpair->last_wqe_reached = true;
2922 
2923 	nvmf_rdma_destroy_drained_qpair(rqpair);
2924 }
2925 
2926 static void
2927 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2928 {
2929 	struct spdk_nvmf_rdma_transport *rtransport;
2930 	struct rdma_cm_event		*event;
2931 	int				rc;
2932 
2933 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2934 
2935 	if (rtransport->event_channel == NULL) {
2936 		return;
2937 	}
2938 
2939 	while (1) {
2940 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2941 		if (rc == 0) {
2942 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2943 
2944 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2945 
2946 			switch (event->event) {
2947 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2948 			case RDMA_CM_EVENT_ADDR_ERROR:
2949 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2950 			case RDMA_CM_EVENT_ROUTE_ERROR:
2951 				/* No action required. The target never attempts to resolve routes. */
2952 				break;
2953 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2954 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2955 				if (rc < 0) {
2956 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2957 					break;
2958 				}
2959 				break;
2960 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2961 				/* The target never initiates a new connection. So this will not occur. */
2962 				break;
2963 			case RDMA_CM_EVENT_CONNECT_ERROR:
2964 				/* Can this happen? The docs say it can, but not sure what causes it. */
2965 				break;
2966 			case RDMA_CM_EVENT_UNREACHABLE:
2967 			case RDMA_CM_EVENT_REJECTED:
2968 				/* These only occur on the client side. */
2969 				break;
2970 			case RDMA_CM_EVENT_ESTABLISHED:
2971 				/* TODO: Should we be waiting for this event anywhere? */
2972 				break;
2973 			case RDMA_CM_EVENT_DISCONNECTED:
2974 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2975 				rc = nvmf_rdma_disconnect(event);
2976 				if (rc < 0) {
2977 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2978 					break;
2979 				}
2980 				break;
2981 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2982 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2983 				/* Multicast is not used */
2984 				break;
2985 			case RDMA_CM_EVENT_ADDR_CHANGE:
2986 				/* Not utilizing this event */
2987 				break;
2988 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2989 				/* For now, do nothing. The target never re-uses queue pairs. */
2990 				break;
2991 			default:
2992 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2993 				break;
2994 			}
2995 
2996 			rdma_ack_cm_event(event);
2997 		} else {
2998 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2999 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
3000 			}
3001 			break;
3002 		}
3003 	}
3004 }
3005 
3006 static void
3007 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
3008 {
3009 	int				rc;
3010 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
3011 	struct ibv_async_event		event;
3012 	enum ibv_qp_state		state;
3013 
3014 	rc = ibv_get_async_event(device->context, &event);
3015 
3016 	if (rc) {
3017 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
3018 			    errno, spdk_strerror(errno));
3019 		return;
3020 	}
3021 
3022 	switch (event.event_type) {
3023 	case IBV_EVENT_QP_FATAL:
3024 		rqpair = event.element.qp->qp_context;
3025 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
3026 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3027 				  (uintptr_t)rqpair->cm_id, event.event_type);
3028 		spdk_nvmf_rdma_update_ibv_state(rqpair);
3029 		spdk_nvmf_rdma_start_disconnect(rqpair);
3030 		break;
3031 	case IBV_EVENT_QP_LAST_WQE_REACHED:
3032 		/* This event only occurs for shared receive queues. */
3033 		rqpair = event.element.qp->qp_context;
3034 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last WQE reached event received for rqpair %p\n", rqpair);
3035 		/* This must be handled on the polling thread if it exists. Otherwise the timeout will catch it. */
3036 		if (rqpair->qpair.group) {
3037 			spdk_thread_send_msg(rqpair->qpair.group->thread, nvmf_rdma_handle_last_wqe_reached, rqpair);
3038 		} else {
3039 			SPDK_ERRLOG("Unable to destroy the qpair %p since it does not have a poll group.\n", rqpair);
3040 			rqpair->last_wqe_reached = true;
3041 		}
3042 
3043 		break;
3044 	case IBV_EVENT_SQ_DRAINED:
3045 		/* This event occurs frequently in both error and non-error states.
3046 		 * Check if the qpair is in an error state before sending a message.
3047 		 * Note that we're not on the correct thread to access the qpair, but
3048 		 * the operations that the below calls make all happen to be thread
3049 		 * safe. */
3050 		rqpair = event.element.qp->qp_context;
3051 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last sq drained event received for rqpair %p\n", rqpair);
3052 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3053 				  (uintptr_t)rqpair->cm_id, event.event_type);
3054 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
3055 		if (state == IBV_QPS_ERR) {
3056 			spdk_nvmf_rdma_start_disconnect(rqpair);
3057 		}
3058 		break;
3059 	case IBV_EVENT_QP_REQ_ERR:
3060 	case IBV_EVENT_QP_ACCESS_ERR:
3061 	case IBV_EVENT_COMM_EST:
3062 	case IBV_EVENT_PATH_MIG:
3063 	case IBV_EVENT_PATH_MIG_ERR:
3064 		SPDK_NOTICELOG("Async event: %s\n",
3065 			       ibv_event_type_str(event.event_type));
3066 		rqpair = event.element.qp->qp_context;
3067 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
3068 				  (uintptr_t)rqpair->cm_id, event.event_type);
3069 		spdk_nvmf_rdma_update_ibv_state(rqpair);
3070 		break;
3071 	case IBV_EVENT_CQ_ERR:
3072 	case IBV_EVENT_DEVICE_FATAL:
3073 	case IBV_EVENT_PORT_ACTIVE:
3074 	case IBV_EVENT_PORT_ERR:
3075 	case IBV_EVENT_LID_CHANGE:
3076 	case IBV_EVENT_PKEY_CHANGE:
3077 	case IBV_EVENT_SM_CHANGE:
3078 	case IBV_EVENT_SRQ_ERR:
3079 	case IBV_EVENT_SRQ_LIMIT_REACHED:
3080 	case IBV_EVENT_CLIENT_REREGISTER:
3081 	case IBV_EVENT_GID_CHANGE:
3082 	default:
3083 		SPDK_NOTICELOG("Async event: %s\n",
3084 			       ibv_event_type_str(event.event_type));
3085 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
3086 		break;
3087 	}
3088 	ibv_ack_async_event(&event);
3089 }
3090 
3091 static void
3092 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
3093 {
3094 	int	nfds, i = 0;
3095 	struct spdk_nvmf_rdma_transport *rtransport;
3096 	struct spdk_nvmf_rdma_device *device, *tmp;
3097 
3098 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3099 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
3100 
3101 	if (nfds <= 0) {
3102 		return;
3103 	}
3104 
3105 	/* The first poll descriptor is RDMA CM event */
3106 	if (rtransport->poll_fds[i++].revents & POLLIN) {
3107 		spdk_nvmf_process_cm_event(transport, cb_fn);
3108 		nfds--;
3109 	}
3110 
3111 	if (nfds == 0) {
3112 		return;
3113 	}
3114 
3115 	/* Second and subsequent poll descriptors are IB async events */
3116 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
3117 		if (rtransport->poll_fds[i++].revents & POLLIN) {
3118 			spdk_nvmf_process_ib_event(device);
3119 			nfds--;
3120 		}
3121 	}
3122 	/* check all flagged fd's have been served */
3123 	assert(nfds == 0);
3124 }
3125 
3126 static void
3127 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
3128 			struct spdk_nvme_transport_id *trid,
3129 			struct spdk_nvmf_discovery_log_page_entry *entry)
3130 {
3131 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
3132 	entry->adrfam = trid->adrfam;
3133 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_REQUIRED;
3134 
3135 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
3136 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
3137 
3138 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
3139 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
3140 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
3141 }
3142 
3143 static void
3144 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
3145 
3146 static struct spdk_nvmf_transport_poll_group *
3147 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
3148 {
3149 	struct spdk_nvmf_rdma_transport		*rtransport;
3150 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3151 	struct spdk_nvmf_rdma_poller		*poller;
3152 	struct spdk_nvmf_rdma_device		*device;
3153 	struct ibv_srq_init_attr		srq_init_attr;
3154 	struct spdk_nvmf_rdma_resource_opts	opts;
3155 	int					num_cqe;
3156 
3157 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
3158 
3159 	rgroup = calloc(1, sizeof(*rgroup));
3160 	if (!rgroup) {
3161 		return NULL;
3162 	}
3163 
3164 	TAILQ_INIT(&rgroup->pollers);
3165 	STAILQ_INIT(&rgroup->retired_bufs);
3166 
3167 	pthread_mutex_lock(&rtransport->lock);
3168 	TAILQ_FOREACH(device, &rtransport->devices, link) {
3169 		poller = calloc(1, sizeof(*poller));
3170 		if (!poller) {
3171 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
3172 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3173 			pthread_mutex_unlock(&rtransport->lock);
3174 			return NULL;
3175 		}
3176 
3177 		poller->device = device;
3178 		poller->group = rgroup;
3179 
3180 		TAILQ_INIT(&poller->qpairs);
3181 		STAILQ_INIT(&poller->qpairs_pending_send);
3182 		STAILQ_INIT(&poller->qpairs_pending_recv);
3183 
3184 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
3185 		if (transport->opts.no_srq == false && device->num_srq < device->attr.max_srq) {
3186 			poller->max_srq_depth = transport->opts.max_srq_depth;
3187 
3188 			device->num_srq++;
3189 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
3190 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
3191 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
3192 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
3193 			if (!poller->srq) {
3194 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
3195 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3196 				pthread_mutex_unlock(&rtransport->lock);
3197 				return NULL;
3198 			}
3199 
3200 			opts.qp = poller->srq;
3201 			opts.pd = device->pd;
3202 			opts.qpair = NULL;
3203 			opts.shared = true;
3204 			opts.max_queue_depth = poller->max_srq_depth;
3205 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
3206 
3207 			poller->resources = nvmf_rdma_resources_create(&opts);
3208 			if (!poller->resources) {
3209 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
3210 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3211 				pthread_mutex_unlock(&rtransport->lock);
3212 				return NULL;
3213 			}
3214 		}
3215 
3216 		/*
3217 		 * When using an srq, we can limit the completion queue at startup.
3218 		 * The following formula represents the calculation:
3219 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
3220 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3221 		 */
3222 		if (poller->srq) {
3223 			num_cqe = poller->max_srq_depth * 3;
3224 		} else {
3225 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3226 		}
3227 
3228 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3229 		if (!poller->cq) {
3230 			SPDK_ERRLOG("Unable to create completion queue\n");
3231 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3232 			pthread_mutex_unlock(&rtransport->lock);
3233 			return NULL;
3234 		}
3235 		poller->num_cqe = num_cqe;
3236 	}
3237 
3238 	TAILQ_INSERT_TAIL(&rtransport->poll_groups, rgroup, link);
3239 	if (rtransport->conn_sched.next_admin_pg == NULL) {
3240 		rtransport->conn_sched.next_admin_pg = rgroup;
3241 		rtransport->conn_sched.next_io_pg = rgroup;
3242 	}
3243 
3244 	pthread_mutex_unlock(&rtransport->lock);
3245 	return &rgroup->group;
3246 }
3247 
3248 static struct spdk_nvmf_transport_poll_group *
3249 spdk_nvmf_rdma_get_optimal_poll_group(struct spdk_nvmf_qpair *qpair)
3250 {
3251 	struct spdk_nvmf_rdma_transport *rtransport;
3252 	struct spdk_nvmf_rdma_poll_group **pg;
3253 	struct spdk_nvmf_transport_poll_group *result;
3254 
3255 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
3256 
3257 	pthread_mutex_lock(&rtransport->lock);
3258 
3259 	if (TAILQ_EMPTY(&rtransport->poll_groups)) {
3260 		pthread_mutex_unlock(&rtransport->lock);
3261 		return NULL;
3262 	}
3263 
3264 	if (qpair->qid == 0) {
3265 		pg = &rtransport->conn_sched.next_admin_pg;
3266 	} else {
3267 		pg = &rtransport->conn_sched.next_io_pg;
3268 	}
3269 
3270 	assert(*pg != NULL);
3271 
3272 	result = &(*pg)->group;
3273 
3274 	*pg = TAILQ_NEXT(*pg, link);
3275 	if (*pg == NULL) {
3276 		*pg = TAILQ_FIRST(&rtransport->poll_groups);
3277 	}
3278 
3279 	pthread_mutex_unlock(&rtransport->lock);
3280 
3281 	return result;
3282 }
3283 
3284 static void
3285 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3286 {
3287 	struct spdk_nvmf_rdma_poll_group	*rgroup, *next_rgroup;
3288 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3289 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3290 	struct spdk_nvmf_transport_pg_cache_buf	*buf, *tmp_buf;
3291 	struct spdk_nvmf_rdma_transport		*rtransport;
3292 
3293 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3294 	rtransport = SPDK_CONTAINEROF(rgroup->group.transport, struct spdk_nvmf_rdma_transport, transport);
3295 
3296 	if (!rgroup) {
3297 		return;
3298 	}
3299 
3300 	/* free all retired buffers back to the transport so we don't short the mempool. */
3301 	STAILQ_FOREACH_SAFE(buf, &rgroup->retired_bufs, link, tmp_buf) {
3302 		STAILQ_REMOVE(&rgroup->retired_bufs, buf, spdk_nvmf_transport_pg_cache_buf, link);
3303 		assert(group->transport != NULL);
3304 		spdk_mempool_put(group->transport->data_buf_pool, buf);
3305 	}
3306 
3307 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3308 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3309 
3310 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3311 			spdk_nvmf_rdma_qpair_destroy(qpair);
3312 		}
3313 
3314 		if (poller->srq) {
3315 			nvmf_rdma_resources_destroy(poller->resources);
3316 			ibv_destroy_srq(poller->srq);
3317 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Destroyed RDMA shared queue %p\n", poller->srq);
3318 		}
3319 
3320 		if (poller->cq) {
3321 			ibv_destroy_cq(poller->cq);
3322 		}
3323 
3324 		free(poller);
3325 	}
3326 
3327 	pthread_mutex_lock(&rtransport->lock);
3328 	next_rgroup = TAILQ_NEXT(rgroup, link);
3329 	TAILQ_REMOVE(&rtransport->poll_groups, rgroup, link);
3330 	if (next_rgroup == NULL) {
3331 		next_rgroup = TAILQ_FIRST(&rtransport->poll_groups);
3332 	}
3333 	if (rtransport->conn_sched.next_admin_pg == rgroup) {
3334 		rtransport->conn_sched.next_admin_pg = next_rgroup;
3335 	}
3336 	if (rtransport->conn_sched.next_io_pg == rgroup) {
3337 		rtransport->conn_sched.next_io_pg = next_rgroup;
3338 	}
3339 	pthread_mutex_unlock(&rtransport->lock);
3340 
3341 	free(rgroup);
3342 }
3343 
3344 static void
3345 spdk_nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3346 {
3347 	if (rqpair->cm_id != NULL) {
3348 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3349 	}
3350 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3351 }
3352 
3353 static int
3354 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3355 			      struct spdk_nvmf_qpair *qpair)
3356 {
3357 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3358 	struct spdk_nvmf_rdma_qpair		*rqpair;
3359 	struct spdk_nvmf_rdma_device		*device;
3360 	struct spdk_nvmf_rdma_poller		*poller;
3361 	int					rc;
3362 
3363 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3364 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3365 
3366 	device = rqpair->port->device;
3367 
3368 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3369 		if (poller->device == device) {
3370 			break;
3371 		}
3372 	}
3373 
3374 	if (!poller) {
3375 		SPDK_ERRLOG("No poller found for device.\n");
3376 		return -1;
3377 	}
3378 
3379 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3380 	rqpair->poller = poller;
3381 	rqpair->srq = rqpair->poller->srq;
3382 
3383 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
3384 	if (rc < 0) {
3385 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3386 		return -1;
3387 	}
3388 
3389 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3390 	if (rc) {
3391 		/* Try to reject, but we probably can't */
3392 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3393 		return -1;
3394 	}
3395 
3396 	spdk_nvmf_rdma_update_ibv_state(rqpair);
3397 
3398 	return 0;
3399 }
3400 
3401 static int
3402 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3403 {
3404 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3405 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3406 			struct spdk_nvmf_rdma_transport, transport);
3407 
3408 	nvmf_rdma_request_free(rdma_req, rtransport);
3409 	return 0;
3410 }
3411 
3412 static int
3413 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3414 {
3415 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3416 			struct spdk_nvmf_rdma_transport, transport);
3417 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3418 			struct spdk_nvmf_rdma_request, req);
3419 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3420 			struct spdk_nvmf_rdma_qpair, qpair);
3421 
3422 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3423 		/* The connection is alive, so process the request as normal */
3424 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3425 	} else {
3426 		/* The connection is dead. Move the request directly to the completed state. */
3427 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3428 	}
3429 
3430 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3431 
3432 	return 0;
3433 }
3434 
3435 static int
3436 spdk_nvmf_rdma_destroy_defunct_qpair(void *ctx)
3437 {
3438 	struct spdk_nvmf_rdma_qpair	*rqpair = ctx;
3439 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3440 			struct spdk_nvmf_rdma_transport, transport);
3441 
3442 	SPDK_INFOLOG(SPDK_LOG_RDMA, "QP#%d hasn't been drained as expected, manually destroy it\n",
3443 		     rqpair->qpair.qid);
3444 
3445 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3446 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3447 
3448 	return 0;
3449 }
3450 
3451 static void
3452 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
3453 {
3454 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3455 
3456 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
3457 		return;
3458 	}
3459 
3460 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
3461 
3462 	/* This happens only when the qpair is disconnected before
3463 	 * it is added to the poll group. Since there is no poll group,
3464 	 * the RDMA qp has not been initialized yet and the RDMA CM
3465 	 * event has not yet been acknowledged, so we need to reject it.
3466 	 */
3467 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3468 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3469 		return;
3470 	}
3471 
3472 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3473 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
3474 	}
3475 
3476 	rqpair->destruct_poller = spdk_poller_register(spdk_nvmf_rdma_destroy_defunct_qpair, (void *)rqpair,
3477 				  NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US);
3478 }
3479 
3480 static struct spdk_nvmf_rdma_qpair *
3481 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3482 {
3483 	struct spdk_nvmf_rdma_qpair *rqpair;
3484 	/* @todo: improve QP search */
3485 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3486 		if (wc->qp_num == rqpair->cm_id->qp->qp_num) {
3487 			return rqpair;
3488 		}
3489 	}
3490 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3491 	return NULL;
3492 }
3493 
3494 #ifdef DEBUG
3495 static int
3496 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3497 {
3498 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3499 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3500 }
3501 #endif
3502 
3503 static void
3504 _poller_reset_failed_recvs(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_recv_wr *bad_recv_wr,
3505 			   int rc)
3506 {
3507 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3508 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3509 
3510 	SPDK_ERRLOG("Failed to post a recv for the poller %p with errno %d\n", rpoller, -rc);
3511 	while (bad_recv_wr != NULL) {
3512 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_recv_wr->wr_id;
3513 		rdma_recv = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3514 
3515 		rdma_recv->qpair->current_recv_depth++;
3516 		bad_recv_wr = bad_recv_wr->next;
3517 		SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rdma_recv->qpair, -rc);
3518 		spdk_nvmf_rdma_start_disconnect(rdma_recv->qpair);
3519 	}
3520 }
3521 
3522 static void
3523 _qp_reset_failed_recvs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_recv_wr *bad_recv_wr, int rc)
3524 {
3525 	SPDK_ERRLOG("Failed to post a recv for the qpair %p with errno %d\n", rqpair, -rc);
3526 	while (bad_recv_wr != NULL) {
3527 		bad_recv_wr = bad_recv_wr->next;
3528 		rqpair->current_recv_depth++;
3529 	}
3530 	spdk_nvmf_rdma_start_disconnect(rqpair);
3531 }
3532 
3533 static void
3534 _poller_submit_recvs(struct spdk_nvmf_rdma_transport *rtransport,
3535 		     struct spdk_nvmf_rdma_poller *rpoller)
3536 {
3537 	struct spdk_nvmf_rdma_qpair	*rqpair;
3538 	struct ibv_recv_wr		*bad_recv_wr;
3539 	int				rc;
3540 
3541 	if (rpoller->srq) {
3542 		if (rpoller->resources->recvs_to_post.first != NULL) {
3543 			rc = ibv_post_srq_recv(rpoller->srq, rpoller->resources->recvs_to_post.first, &bad_recv_wr);
3544 			if (rc) {
3545 				_poller_reset_failed_recvs(rpoller, bad_recv_wr, rc);
3546 			}
3547 			rpoller->resources->recvs_to_post.first = NULL;
3548 			rpoller->resources->recvs_to_post.last = NULL;
3549 		}
3550 	} else {
3551 		while (!STAILQ_EMPTY(&rpoller->qpairs_pending_recv)) {
3552 			rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_recv);
3553 			assert(rqpair->resources->recvs_to_post.first != NULL);
3554 			rc = ibv_post_recv(rqpair->cm_id->qp, rqpair->resources->recvs_to_post.first, &bad_recv_wr);
3555 			if (rc) {
3556 				_qp_reset_failed_recvs(rqpair, bad_recv_wr, rc);
3557 			}
3558 			rqpair->resources->recvs_to_post.first = NULL;
3559 			rqpair->resources->recvs_to_post.last = NULL;
3560 			STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_recv, recv_link);
3561 		}
3562 	}
3563 }
3564 
3565 static void
3566 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3567 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3568 {
3569 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3570 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3571 
3572 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3573 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3574 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3575 		assert(rqpair->current_send_depth > 0);
3576 		rqpair->current_send_depth--;
3577 		switch (bad_rdma_wr->type) {
3578 		case RDMA_WR_TYPE_DATA:
3579 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3580 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3581 				assert(rqpair->current_read_depth > 0);
3582 				rqpair->current_read_depth--;
3583 			}
3584 			break;
3585 		case RDMA_WR_TYPE_SEND:
3586 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3587 			break;
3588 		default:
3589 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3590 			prev_rdma_req = cur_rdma_req;
3591 			continue;
3592 		}
3593 
3594 		if (prev_rdma_req == cur_rdma_req) {
3595 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3596 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3597 			continue;
3598 		}
3599 
3600 		switch (cur_rdma_req->state) {
3601 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3602 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3603 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3604 			break;
3605 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3606 		case RDMA_REQUEST_STATE_COMPLETING:
3607 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3608 			break;
3609 		default:
3610 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3611 				    cur_rdma_req->state, rqpair);
3612 			continue;
3613 		}
3614 
3615 		spdk_nvmf_rdma_request_process(rtransport, cur_rdma_req);
3616 		prev_rdma_req = cur_rdma_req;
3617 	}
3618 
3619 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3620 		/* Disconnect the connection. */
3621 		spdk_nvmf_rdma_start_disconnect(rqpair);
3622 	}
3623 
3624 }
3625 
3626 static void
3627 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3628 		     struct spdk_nvmf_rdma_poller *rpoller)
3629 {
3630 	struct spdk_nvmf_rdma_qpair	*rqpair;
3631 	struct ibv_send_wr		*bad_wr = NULL;
3632 	int				rc;
3633 
3634 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3635 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3636 		assert(rqpair->sends_to_post.first != NULL);
3637 		rc = ibv_post_send(rqpair->cm_id->qp, rqpair->sends_to_post.first, &bad_wr);
3638 
3639 		/* bad wr always points to the first wr that failed. */
3640 		if (rc) {
3641 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3642 		}
3643 		rqpair->sends_to_post.first = NULL;
3644 		rqpair->sends_to_post.last = NULL;
3645 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3646 	}
3647 }
3648 
3649 static int
3650 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3651 			   struct spdk_nvmf_rdma_poller *rpoller)
3652 {
3653 	struct ibv_wc wc[32];
3654 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3655 	struct spdk_nvmf_rdma_request	*rdma_req;
3656 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3657 	struct spdk_nvmf_rdma_qpair	*rqpair;
3658 	int reaped, i;
3659 	int count = 0;
3660 	bool error = false;
3661 	uint64_t poll_tsc = spdk_get_ticks();
3662 
3663 	/* Poll for completing operations. */
3664 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3665 	if (reaped < 0) {
3666 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3667 			    errno, spdk_strerror(errno));
3668 		return -1;
3669 	}
3670 
3671 	rpoller->stat.polls++;
3672 	rpoller->stat.completions += reaped;
3673 
3674 	for (i = 0; i < reaped; i++) {
3675 
3676 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3677 
3678 		switch (rdma_wr->type) {
3679 		case RDMA_WR_TYPE_SEND:
3680 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3681 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3682 
3683 			if (!wc[i].status) {
3684 				count++;
3685 				assert(wc[i].opcode == IBV_WC_SEND);
3686 				assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
3687 			} else {
3688 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3689 			}
3690 
3691 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3692 			/* +1 for the response wr */
3693 			rqpair->current_send_depth -= rdma_req->num_outstanding_data_wr + 1;
3694 			rdma_req->num_outstanding_data_wr = 0;
3695 
3696 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3697 			break;
3698 		case RDMA_WR_TYPE_RECV:
3699 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3700 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3701 			if (rpoller->srq != NULL) {
3702 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3703 				/* It is possible that there are still some completions for destroyed QP
3704 				 * associated with SRQ. We just ignore these late completions and re-post
3705 				 * receive WRs back to SRQ.
3706 				 */
3707 				if (spdk_unlikely(NULL == rdma_recv->qpair)) {
3708 					struct ibv_recv_wr *bad_wr;
3709 					int rc;
3710 
3711 					rdma_recv->wr.next = NULL;
3712 					rc = ibv_post_srq_recv(rpoller->srq,
3713 							       &rdma_recv->wr,
3714 							       &bad_wr);
3715 					if (rc) {
3716 						SPDK_ERRLOG("Failed to re-post recv WR to SRQ, err %d\n", rc);
3717 					}
3718 					continue;
3719 				}
3720 			}
3721 			rqpair = rdma_recv->qpair;
3722 
3723 			assert(rqpair != NULL);
3724 			if (!wc[i].status) {
3725 				assert(wc[i].opcode == IBV_WC_RECV);
3726 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3727 					spdk_nvmf_rdma_start_disconnect(rqpair);
3728 					break;
3729 				}
3730 			}
3731 
3732 			rdma_recv->wr.next = NULL;
3733 			rqpair->current_recv_depth++;
3734 			rdma_recv->receive_tsc = poll_tsc;
3735 			rpoller->stat.requests++;
3736 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3737 			break;
3738 		case RDMA_WR_TYPE_DATA:
3739 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3740 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3741 
3742 			assert(rdma_req->num_outstanding_data_wr > 0);
3743 
3744 			rqpair->current_send_depth--;
3745 			rdma_req->num_outstanding_data_wr--;
3746 			if (!wc[i].status) {
3747 				assert(wc[i].opcode == IBV_WC_RDMA_READ);
3748 				rqpair->current_read_depth--;
3749 				/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3750 				if (rdma_req->num_outstanding_data_wr == 0) {
3751 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3752 					spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3753 				}
3754 			} else {
3755 				/* If the data transfer fails still force the queue into the error state,
3756 				 * if we were performing an RDMA_READ, we need to force the request into a
3757 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3758 				 * case, we should wait for the SEND to complete. */
3759 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3760 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3761 					rqpair->current_read_depth--;
3762 					if (rdma_req->num_outstanding_data_wr == 0) {
3763 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3764 					}
3765 				}
3766 			}
3767 			break;
3768 		default:
3769 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3770 			continue;
3771 		}
3772 
3773 		/* Handle error conditions */
3774 		if (wc[i].status) {
3775 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
3776 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
3777 
3778 			error = true;
3779 
3780 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3781 				/* Disconnect the connection. */
3782 				spdk_nvmf_rdma_start_disconnect(rqpair);
3783 			} else {
3784 				nvmf_rdma_destroy_drained_qpair(rqpair);
3785 			}
3786 			continue;
3787 		}
3788 
3789 		spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3790 
3791 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3792 			nvmf_rdma_destroy_drained_qpair(rqpair);
3793 		}
3794 	}
3795 
3796 	if (error == true) {
3797 		return -1;
3798 	}
3799 
3800 	/* submit outstanding work requests. */
3801 	_poller_submit_recvs(rtransport, rpoller);
3802 	_poller_submit_sends(rtransport, rpoller);
3803 
3804 	return count;
3805 }
3806 
3807 static int
3808 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3809 {
3810 	struct spdk_nvmf_rdma_transport *rtransport;
3811 	struct spdk_nvmf_rdma_poll_group *rgroup;
3812 	struct spdk_nvmf_rdma_poller	*rpoller;
3813 	int				count, rc;
3814 
3815 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3816 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3817 
3818 	count = 0;
3819 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3820 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
3821 		if (rc < 0) {
3822 			return rc;
3823 		}
3824 		count += rc;
3825 	}
3826 
3827 	return count;
3828 }
3829 
3830 static int
3831 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3832 			       struct spdk_nvme_transport_id *trid,
3833 			       bool peer)
3834 {
3835 	struct sockaddr *saddr;
3836 	uint16_t port;
3837 
3838 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
3839 
3840 	if (peer) {
3841 		saddr = rdma_get_peer_addr(id);
3842 	} else {
3843 		saddr = rdma_get_local_addr(id);
3844 	}
3845 	switch (saddr->sa_family) {
3846 	case AF_INET: {
3847 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3848 
3849 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3850 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3851 			  trid->traddr, sizeof(trid->traddr));
3852 		if (peer) {
3853 			port = ntohs(rdma_get_dst_port(id));
3854 		} else {
3855 			port = ntohs(rdma_get_src_port(id));
3856 		}
3857 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3858 		break;
3859 	}
3860 	case AF_INET6: {
3861 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
3862 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
3863 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
3864 			  trid->traddr, sizeof(trid->traddr));
3865 		if (peer) {
3866 			port = ntohs(rdma_get_dst_port(id));
3867 		} else {
3868 			port = ntohs(rdma_get_src_port(id));
3869 		}
3870 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3871 		break;
3872 	}
3873 	default:
3874 		return -1;
3875 
3876 	}
3877 
3878 	return 0;
3879 }
3880 
3881 static int
3882 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3883 				   struct spdk_nvme_transport_id *trid)
3884 {
3885 	struct spdk_nvmf_rdma_qpair	*rqpair;
3886 
3887 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3888 
3889 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
3890 }
3891 
3892 static int
3893 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
3894 				    struct spdk_nvme_transport_id *trid)
3895 {
3896 	struct spdk_nvmf_rdma_qpair	*rqpair;
3897 
3898 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3899 
3900 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
3901 }
3902 
3903 static int
3904 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
3905 				     struct spdk_nvme_transport_id *trid)
3906 {
3907 	struct spdk_nvmf_rdma_qpair	*rqpair;
3908 
3909 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3910 
3911 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
3912 }
3913 
3914 void
3915 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
3916 {
3917 	g_nvmf_hooks = *hooks;
3918 }
3919 
3920 static int
3921 spdk_nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
3922 				   struct spdk_nvmf_transport_poll_group_stat **stat)
3923 {
3924 	struct spdk_io_channel *ch;
3925 	struct spdk_nvmf_poll_group *group;
3926 	struct spdk_nvmf_transport_poll_group *tgroup;
3927 	struct spdk_nvmf_rdma_poll_group *rgroup;
3928 	struct spdk_nvmf_rdma_poller *rpoller;
3929 	struct spdk_nvmf_rdma_device_stat *device_stat;
3930 	uint64_t num_devices = 0;
3931 
3932 	if (tgt == NULL || stat == NULL) {
3933 		return -EINVAL;
3934 	}
3935 
3936 	ch = spdk_get_io_channel(tgt);
3937 	group = spdk_io_channel_get_ctx(ch);;
3938 	spdk_put_io_channel(ch);
3939 	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
3940 		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
3941 			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
3942 			if (!*stat) {
3943 				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
3944 				return -ENOMEM;
3945 			}
3946 			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
3947 
3948 			rgroup = SPDK_CONTAINEROF(tgroup, struct spdk_nvmf_rdma_poll_group, group);
3949 			/* Count devices to allocate enough memory */
3950 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3951 				++num_devices;
3952 			}
3953 			(*stat)->rdma.devices = calloc(num_devices, sizeof(struct spdk_nvmf_rdma_device_stat));
3954 			if (!(*stat)->rdma.devices) {
3955 				SPDK_ERRLOG("Failed to allocate NVMf RDMA devices statistics\n");
3956 				free(*stat);
3957 				return -ENOMEM;
3958 			}
3959 
3960 			(*stat)->rdma.pending_data_buffer = rgroup->stat.pending_data_buffer;
3961 			(*stat)->rdma.num_devices = num_devices;
3962 			num_devices = 0;
3963 			TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3964 				device_stat = &(*stat)->rdma.devices[num_devices++];
3965 				device_stat->name = ibv_get_device_name(rpoller->device->context->device);
3966 				device_stat->polls = rpoller->stat.polls;
3967 				device_stat->completions = rpoller->stat.completions;
3968 				device_stat->requests = rpoller->stat.requests;
3969 				device_stat->request_latency = rpoller->stat.request_latency;
3970 				device_stat->pending_free_request = rpoller->stat.pending_free_request;
3971 				device_stat->pending_rdma_read = rpoller->stat.pending_rdma_read;
3972 				device_stat->pending_rdma_write = rpoller->stat.pending_rdma_write;
3973 			}
3974 			return 0;
3975 		}
3976 	}
3977 	return -ENOENT;
3978 }
3979 
3980 static void
3981 spdk_nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
3982 {
3983 	if (stat) {
3984 		free(stat->rdma.devices);
3985 	}
3986 	free(stat);
3987 }
3988 
3989 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
3990 	.type = SPDK_NVME_TRANSPORT_RDMA,
3991 	.opts_init = spdk_nvmf_rdma_opts_init,
3992 	.create = spdk_nvmf_rdma_create,
3993 	.destroy = spdk_nvmf_rdma_destroy,
3994 
3995 	.listen = spdk_nvmf_rdma_listen,
3996 	.stop_listen = spdk_nvmf_rdma_stop_listen,
3997 	.accept = spdk_nvmf_rdma_accept,
3998 
3999 	.listener_discover = spdk_nvmf_rdma_discover,
4000 
4001 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
4002 	.get_optimal_poll_group = spdk_nvmf_rdma_get_optimal_poll_group,
4003 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
4004 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
4005 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
4006 
4007 	.req_free = spdk_nvmf_rdma_request_free,
4008 	.req_complete = spdk_nvmf_rdma_request_complete,
4009 
4010 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
4011 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
4012 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
4013 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
4014 
4015 	.poll_group_get_stat = spdk_nvmf_rdma_poll_group_get_stat,
4016 	.poll_group_free_stat = spdk_nvmf_rdma_poll_group_free_stat,
4017 };
4018 
4019 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
4020