xref: /spdk/lib/nvmf/rdma.c (revision dfbbcc74dd024a0189f95d7959bebb44e15eae4a)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation. All rights reserved.
5  *   Copyright (c) 2018 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/assert.h"
45 #include "spdk/thread.h"
46 #include "spdk/nvmf.h"
47 #include "spdk/nvmf_spec.h"
48 #include "spdk/string.h"
49 #include "spdk/trace.h"
50 #include "spdk/util.h"
51 
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 
242 	STAILQ_ENTRY(spdk_nvmf_rdma_recv)	link;
243 };
244 
245 struct spdk_nvmf_rdma_request_data {
246 	struct spdk_nvmf_rdma_wr	rdma_wr;
247 	struct ibv_send_wr		wr;
248 	struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
249 };
250 
251 struct spdk_nvmf_rdma_request {
252 	struct spdk_nvmf_request		req;
253 	bool					data_from_pool;
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 	void					*buffers[NVMF_REQ_MAX_BUFFERS];
267 
268 	uint32_t				num_outstanding_data_wr;
269 
270 	STAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
271 };
272 
273 enum spdk_nvmf_rdma_qpair_disconnect_flags {
274 	RDMA_QP_DISCONNECTING		= 1,
275 	RDMA_QP_RECV_DRAINED		= 1 << 1,
276 	RDMA_QP_SEND_DRAINED		= 1 << 2
277 };
278 
279 struct spdk_nvmf_rdma_resource_opts {
280 	struct spdk_nvmf_rdma_qpair	*qpair;
281 	/* qp points either to an ibv_qp object or an ibv_srq object depending on the value of shared. */
282 	void				*qp;
283 	struct ibv_pd			*pd;
284 	uint32_t			max_queue_depth;
285 	uint32_t			in_capsule_data_size;
286 	bool				shared;
287 };
288 
289 struct spdk_nvmf_send_wr_list {
290 	struct ibv_send_wr	*first;
291 	struct ibv_send_wr	*last;
292 };
293 
294 struct spdk_nvmf_rdma_resources {
295 	/* Array of size "max_queue_depth" containing RDMA requests. */
296 	struct spdk_nvmf_rdma_request		*reqs;
297 
298 	/* Array of size "max_queue_depth" containing RDMA recvs. */
299 	struct spdk_nvmf_rdma_recv		*recvs;
300 
301 	/* Array of size "max_queue_depth" containing 64 byte capsules
302 	 * used for receive.
303 	 */
304 	union nvmf_h2c_msg			*cmds;
305 	struct ibv_mr				*cmds_mr;
306 
307 	/* Array of size "max_queue_depth" containing 16 byte completions
308 	 * to be sent back to the user.
309 	 */
310 	union nvmf_c2h_msg			*cpls;
311 	struct ibv_mr				*cpls_mr;
312 
313 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
314 	 * buffers to be used for in capsule data.
315 	 */
316 	void					*bufs;
317 	struct ibv_mr				*bufs_mr;
318 
319 	/* Receives that are waiting for a request object */
320 	STAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
321 
322 	/* Queue to track free requests */
323 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
324 };
325 
326 struct spdk_nvmf_rdma_qpair {
327 	struct spdk_nvmf_qpair			qpair;
328 
329 	struct spdk_nvmf_rdma_port		*port;
330 	struct spdk_nvmf_rdma_poller		*poller;
331 
332 	struct rdma_cm_id			*cm_id;
333 	struct ibv_srq				*srq;
334 	struct rdma_cm_id			*listen_id;
335 
336 	/* The maximum number of I/O outstanding on this connection at one time */
337 	uint16_t				max_queue_depth;
338 
339 	/* The maximum number of active RDMA READ and ATOMIC operations at one time */
340 	uint16_t				max_read_depth;
341 
342 	/* The maximum number of RDMA SEND operations at one time */
343 	uint32_t				max_send_depth;
344 
345 	/* The current number of outstanding WRs from this qpair's
346 	 * recv queue. Should not exceed device->attr.max_queue_depth.
347 	 */
348 	uint16_t				current_recv_depth;
349 
350 	/* The current number of active RDMA READ operations */
351 	uint16_t				current_read_depth;
352 
353 	/* The current number of posted WRs from this qpair's
354 	 * send queue. Should not exceed max_send_depth.
355 	 */
356 	uint32_t				current_send_depth;
357 
358 	/* The maximum number of SGEs per WR on the send queue */
359 	uint32_t				max_send_sge;
360 
361 	/* The maximum number of SGEs per WR on the recv queue */
362 	uint32_t				max_recv_sge;
363 
364 	/* The list of pending send requests for a transfer */
365 	struct spdk_nvmf_send_wr_list		sends_to_post;
366 
367 	struct spdk_nvmf_rdma_resources		*resources;
368 
369 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_read_queue;
370 
371 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_write_queue;
372 
373 	/* Number of requests not in the free state */
374 	uint32_t				qd;
375 
376 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
377 
378 	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	send_link;
379 
380 	/* IBV queue pair attributes: they are used to manage
381 	 * qp state and recover from errors.
382 	 */
383 	enum ibv_qp_state			ibv_state;
384 
385 	uint32_t				disconnect_flags;
386 
387 	/* Poller registered in case the qpair doesn't properly
388 	 * complete the qpair destruct process and becomes defunct.
389 	 */
390 
391 	struct spdk_poller			*destruct_poller;
392 
393 	/* There are several ways a disconnect can start on a qpair
394 	 * and they are not all mutually exclusive. It is important
395 	 * that we only initialize one of these paths.
396 	 */
397 	bool					disconnect_started;
398 	/* Lets us know that we have received the last_wqe event. */
399 	bool					last_wqe_reached;
400 };
401 
402 struct spdk_nvmf_rdma_poller {
403 	struct spdk_nvmf_rdma_device		*device;
404 	struct spdk_nvmf_rdma_poll_group	*group;
405 
406 	int					num_cqe;
407 	int					required_num_wr;
408 	struct ibv_cq				*cq;
409 
410 	/* The maximum number of I/O outstanding on the shared receive queue at one time */
411 	uint16_t				max_srq_depth;
412 
413 	/* Shared receive queue */
414 	struct ibv_srq				*srq;
415 
416 	struct spdk_nvmf_rdma_resources		*resources;
417 
418 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
419 
420 	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_send;
421 
422 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
423 };
424 
425 struct spdk_nvmf_rdma_poll_group {
426 	struct spdk_nvmf_transport_poll_group	group;
427 
428 	/* Requests that are waiting to obtain a data buffer */
429 	STAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
430 
431 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
432 };
433 
434 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
435 struct spdk_nvmf_rdma_device {
436 	struct ibv_device_attr			attr;
437 	struct ibv_context			*context;
438 
439 	struct spdk_mem_map			*map;
440 	struct ibv_pd				*pd;
441 
442 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
443 };
444 
445 struct spdk_nvmf_rdma_port {
446 	struct spdk_nvme_transport_id		trid;
447 	struct rdma_cm_id			*id;
448 	struct spdk_nvmf_rdma_device		*device;
449 	uint32_t				ref;
450 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
451 };
452 
453 struct spdk_nvmf_rdma_transport {
454 	struct spdk_nvmf_transport	transport;
455 
456 	struct rdma_event_channel	*event_channel;
457 
458 	struct spdk_mempool		*data_wr_pool;
459 
460 	pthread_mutex_t			lock;
461 
462 	/* fields used to poll RDMA/IB events */
463 	nfds_t			npoll_fds;
464 	struct pollfd		*poll_fds;
465 
466 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
467 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
468 };
469 
470 static inline int
471 spdk_nvmf_rdma_check_ibv_state(enum ibv_qp_state state)
472 {
473 	switch (state) {
474 	case IBV_QPS_RESET:
475 	case IBV_QPS_INIT:
476 	case IBV_QPS_RTR:
477 	case IBV_QPS_RTS:
478 	case IBV_QPS_SQD:
479 	case IBV_QPS_SQE:
480 	case IBV_QPS_ERR:
481 		return 0;
482 	default:
483 		return -1;
484 	}
485 }
486 
487 static enum ibv_qp_state
488 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
489 	enum ibv_qp_state old_state, new_state;
490 	struct ibv_qp_attr qp_attr;
491 	struct ibv_qp_init_attr init_attr;
492 	int rc;
493 
494 	old_state = rqpair->ibv_state;
495 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
496 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
497 
498 	if (rc)
499 	{
500 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
501 		return IBV_QPS_ERR + 1;
502 	}
503 
504 	new_state = qp_attr.qp_state;
505 	rqpair->ibv_state = new_state;
506 	qp_attr.ah_attr.port_num = qp_attr.port_num;
507 
508 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
509 	if (rc)
510 	{
511 		SPDK_ERRLOG("QP#%d: bad state updated: %u, maybe hardware issue\n", rqpair->qpair.qid, new_state);
512 		/*
513 		 * IBV_QPS_UNKNOWN undefined if lib version smaller than libibverbs-1.1.8
514 		 * IBV_QPS_UNKNOWN is the enum element after IBV_QPS_ERR
515 		 */
516 		return IBV_QPS_ERR + 1;
517 	}
518 
519 	if (old_state != new_state)
520 	{
521 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
522 				  (uintptr_t)rqpair->cm_id, new_state);
523 	}
524 	return new_state;
525 }
526 
527 static const char *str_ibv_qp_state[] = {
528 	"IBV_QPS_RESET",
529 	"IBV_QPS_INIT",
530 	"IBV_QPS_RTR",
531 	"IBV_QPS_RTS",
532 	"IBV_QPS_SQD",
533 	"IBV_QPS_SQE",
534 	"IBV_QPS_ERR",
535 	"IBV_QPS_UNKNOWN"
536 };
537 
538 static int
539 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
540 			     enum ibv_qp_state new_state)
541 {
542 	struct ibv_qp_attr qp_attr;
543 	struct ibv_qp_init_attr init_attr;
544 	int rc;
545 	enum ibv_qp_state state;
546 	static int attr_mask_rc[] = {
547 		[IBV_QPS_RESET] = IBV_QP_STATE,
548 		[IBV_QPS_INIT] = (IBV_QP_STATE |
549 				  IBV_QP_PKEY_INDEX |
550 				  IBV_QP_PORT |
551 				  IBV_QP_ACCESS_FLAGS),
552 		[IBV_QPS_RTR] = (IBV_QP_STATE |
553 				 IBV_QP_AV |
554 				 IBV_QP_PATH_MTU |
555 				 IBV_QP_DEST_QPN |
556 				 IBV_QP_RQ_PSN |
557 				 IBV_QP_MAX_DEST_RD_ATOMIC |
558 				 IBV_QP_MIN_RNR_TIMER),
559 		[IBV_QPS_RTS] = (IBV_QP_STATE |
560 				 IBV_QP_SQ_PSN |
561 				 IBV_QP_TIMEOUT |
562 				 IBV_QP_RETRY_CNT |
563 				 IBV_QP_RNR_RETRY |
564 				 IBV_QP_MAX_QP_RD_ATOMIC),
565 		[IBV_QPS_SQD] = IBV_QP_STATE,
566 		[IBV_QPS_SQE] = IBV_QP_STATE,
567 		[IBV_QPS_ERR] = IBV_QP_STATE,
568 	};
569 
570 	rc = spdk_nvmf_rdma_check_ibv_state(new_state);
571 	if (rc) {
572 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
573 			    rqpair->qpair.qid, new_state);
574 		return rc;
575 	}
576 
577 	rc = ibv_query_qp(rqpair->cm_id->qp, &qp_attr,
578 			  g_spdk_nvmf_ibv_query_mask, &init_attr);
579 
580 	if (rc) {
581 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
582 		assert(false);
583 	}
584 
585 	qp_attr.cur_qp_state = rqpair->ibv_state;
586 	qp_attr.qp_state = new_state;
587 
588 	rc = ibv_modify_qp(rqpair->cm_id->qp, &qp_attr,
589 			   attr_mask_rc[new_state]);
590 
591 	if (rc) {
592 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
593 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
594 		return rc;
595 	}
596 
597 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
598 
599 	if (state != new_state) {
600 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
601 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
602 			    str_ibv_qp_state[state]);
603 		return -1;
604 	}
605 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
606 		      str_ibv_qp_state[state]);
607 	return 0;
608 }
609 
610 static void
611 nvmf_rdma_request_free_data(struct spdk_nvmf_rdma_request *rdma_req,
612 			    struct spdk_nvmf_rdma_transport *rtransport)
613 {
614 	struct spdk_nvmf_rdma_request_data	*current_data_wr = NULL, *next_data_wr = NULL;
615 	struct ibv_send_wr			*send_wr;
616 	int					i;
617 
618 	rdma_req->num_outstanding_data_wr = 0;
619 	current_data_wr = &rdma_req->data;
620 	for (i = 0; i < current_data_wr->wr.num_sge; i++) {
621 		current_data_wr->wr.sg_list[i].addr = 0;
622 		current_data_wr->wr.sg_list[i].length = 0;
623 		current_data_wr->wr.sg_list[i].lkey = 0;
624 	}
625 	current_data_wr->wr.num_sge = 0;
626 
627 	send_wr = current_data_wr->wr.next;
628 	if (send_wr != NULL && send_wr != &rdma_req->rsp.wr) {
629 		next_data_wr = SPDK_CONTAINEROF(send_wr, struct spdk_nvmf_rdma_request_data, wr);
630 	}
631 	while (next_data_wr) {
632 		current_data_wr = next_data_wr;
633 		send_wr = current_data_wr->wr.next;
634 		if (send_wr != NULL && send_wr != &rdma_req->rsp.wr &&
635 		    send_wr->wr_id == current_data_wr->wr.wr_id) {
636 			next_data_wr = SPDK_CONTAINEROF(send_wr, struct spdk_nvmf_rdma_request_data, wr);
637 		} else {
638 			next_data_wr = NULL;
639 		}
640 
641 		for (i = 0; i < current_data_wr->wr.num_sge; i++) {
642 			current_data_wr->wr.sg_list[i].addr = 0;
643 			current_data_wr->wr.sg_list[i].length = 0;
644 			current_data_wr->wr.sg_list[i].lkey = 0;
645 		}
646 		current_data_wr->wr.num_sge = 0;
647 		spdk_mempool_put(rtransport->data_wr_pool, current_data_wr);
648 	}
649 }
650 
651 static void
652 nvmf_rdma_dump_request(struct spdk_nvmf_rdma_request *req)
653 {
654 	SPDK_ERRLOG("\t\tRequest Data From Pool: %d\n", req->data_from_pool);
655 	if (req->req.cmd) {
656 		SPDK_ERRLOG("\t\tRequest opcode: %d\n", req->req.cmd->nvmf_cmd.opcode);
657 	}
658 	if (req->recv) {
659 		SPDK_ERRLOG("\t\tRequest recv wr_id%lu\n", req->recv->wr.wr_id);
660 	}
661 }
662 
663 static void
664 nvmf_rdma_dump_qpair_contents(struct spdk_nvmf_rdma_qpair *rqpair)
665 {
666 	int i;
667 
668 	SPDK_ERRLOG("Dumping contents of queue pair (QID %d)\n", rqpair->qpair.qid);
669 	for (i = 0; i < rqpair->max_queue_depth; i++) {
670 		if (rqpair->resources->reqs[i].state != RDMA_REQUEST_STATE_FREE) {
671 			nvmf_rdma_dump_request(&rqpair->resources->reqs[i]);
672 		}
673 	}
674 }
675 
676 static void
677 nvmf_rdma_resources_destroy(struct spdk_nvmf_rdma_resources *resources)
678 {
679 	if (resources->cmds_mr) {
680 		ibv_dereg_mr(resources->cmds_mr);
681 	}
682 
683 	if (resources->cpls_mr) {
684 		ibv_dereg_mr(resources->cpls_mr);
685 	}
686 
687 	if (resources->bufs_mr) {
688 		ibv_dereg_mr(resources->bufs_mr);
689 	}
690 
691 	spdk_dma_free(resources->cmds);
692 	spdk_dma_free(resources->cpls);
693 	spdk_dma_free(resources->bufs);
694 	free(resources->reqs);
695 	free(resources->recvs);
696 	free(resources);
697 }
698 
699 
700 static struct spdk_nvmf_rdma_resources *
701 nvmf_rdma_resources_create(struct spdk_nvmf_rdma_resource_opts *opts)
702 {
703 	struct spdk_nvmf_rdma_resources	*resources;
704 	struct spdk_nvmf_rdma_request	*rdma_req;
705 	struct spdk_nvmf_rdma_recv	*rdma_recv;
706 	struct ibv_qp			*qp;
707 	struct ibv_srq			*srq;
708 	uint32_t			i;
709 	int				rc;
710 
711 	resources = calloc(1, sizeof(struct spdk_nvmf_rdma_resources));
712 	if (!resources) {
713 		SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
714 		return NULL;
715 	}
716 
717 	resources->reqs = calloc(opts->max_queue_depth, sizeof(*resources->reqs));
718 	resources->recvs = calloc(opts->max_queue_depth, sizeof(*resources->recvs));
719 	resources->cmds = spdk_dma_zmalloc(opts->max_queue_depth * sizeof(*resources->cmds),
720 					   0x1000, NULL);
721 	resources->cpls = spdk_dma_zmalloc(opts->max_queue_depth * sizeof(*resources->cpls),
722 					   0x1000, NULL);
723 
724 	if (opts->in_capsule_data_size > 0) {
725 		resources->bufs = spdk_dma_zmalloc(opts->max_queue_depth *
726 						   opts->in_capsule_data_size,
727 						   0x1000, NULL);
728 	}
729 
730 	if (!resources->reqs || !resources->recvs || !resources->cmds ||
731 	    !resources->cpls || (opts->in_capsule_data_size && !resources->bufs)) {
732 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
733 		goto cleanup;
734 	}
735 
736 	resources->cmds_mr = ibv_reg_mr(opts->pd, resources->cmds,
737 					opts->max_queue_depth * sizeof(*resources->cmds),
738 					IBV_ACCESS_LOCAL_WRITE);
739 	resources->cpls_mr = ibv_reg_mr(opts->pd, resources->cpls,
740 					opts->max_queue_depth * sizeof(*resources->cpls),
741 					0);
742 
743 	if (opts->in_capsule_data_size) {
744 		resources->bufs_mr = ibv_reg_mr(opts->pd, resources->bufs,
745 						opts->max_queue_depth *
746 						opts->in_capsule_data_size,
747 						IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
748 	}
749 
750 	if (!resources->cmds_mr || !resources->cpls_mr ||
751 	    (opts->in_capsule_data_size &&
752 	     !resources->bufs_mr)) {
753 		goto cleanup;
754 	}
755 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
756 		      resources->cmds, opts->max_queue_depth * sizeof(*resources->cmds),
757 		      resources->cmds_mr->lkey);
758 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
759 		      resources->cpls, opts->max_queue_depth * sizeof(*resources->cpls),
760 		      resources->cpls_mr->lkey);
761 	if (resources->bufs && resources->bufs_mr) {
762 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
763 			      resources->bufs, opts->max_queue_depth *
764 			      opts->in_capsule_data_size, resources->bufs_mr->lkey);
765 	}
766 
767 	/* Initialize queues */
768 	STAILQ_INIT(&resources->incoming_queue);
769 	STAILQ_INIT(&resources->free_queue);
770 
771 	for (i = 0; i < opts->max_queue_depth; i++) {
772 		struct ibv_recv_wr *bad_wr = NULL;
773 
774 		rdma_recv = &resources->recvs[i];
775 		rdma_recv->qpair = opts->qpair;
776 
777 		/* Set up memory to receive commands */
778 		if (resources->bufs) {
779 			rdma_recv->buf = (void *)((uintptr_t)resources->bufs + (i *
780 						  opts->in_capsule_data_size));
781 		}
782 
783 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
784 
785 		rdma_recv->sgl[0].addr = (uintptr_t)&resources->cmds[i];
786 		rdma_recv->sgl[0].length = sizeof(resources->cmds[i]);
787 		rdma_recv->sgl[0].lkey = resources->cmds_mr->lkey;
788 		rdma_recv->wr.num_sge = 1;
789 
790 		if (rdma_recv->buf && resources->bufs_mr) {
791 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
792 			rdma_recv->sgl[1].length = opts->in_capsule_data_size;
793 			rdma_recv->sgl[1].lkey = resources->bufs_mr->lkey;
794 			rdma_recv->wr.num_sge++;
795 		}
796 
797 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
798 		rdma_recv->wr.sg_list = rdma_recv->sgl;
799 		if (opts->shared) {
800 			srq = (struct ibv_srq *)opts->qp;
801 			rc = ibv_post_srq_recv(srq, &rdma_recv->wr, &bad_wr);
802 		} else {
803 			qp = (struct ibv_qp *)opts->qp;
804 			rc = ibv_post_recv(qp, &rdma_recv->wr, &bad_wr);
805 		}
806 		if (rc) {
807 			goto cleanup;
808 		}
809 	}
810 
811 	for (i = 0; i < opts->max_queue_depth; i++) {
812 		rdma_req = &resources->reqs[i];
813 
814 		if (opts->qpair != NULL) {
815 			rdma_req->req.qpair = &opts->qpair->qpair;
816 		} else {
817 			rdma_req->req.qpair = NULL;
818 		}
819 		rdma_req->req.cmd = NULL;
820 
821 		/* Set up memory to send responses */
822 		rdma_req->req.rsp = &resources->cpls[i];
823 
824 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&resources->cpls[i];
825 		rdma_req->rsp.sgl[0].length = sizeof(resources->cpls[i]);
826 		rdma_req->rsp.sgl[0].lkey = resources->cpls_mr->lkey;
827 
828 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
829 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
830 		rdma_req->rsp.wr.next = NULL;
831 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
832 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
833 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
834 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
835 
836 		/* Set up memory for data buffers */
837 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
838 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
839 		rdma_req->data.wr.next = NULL;
840 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
841 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
842 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
843 
844 		/* Initialize request state to FREE */
845 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
846 		STAILQ_INSERT_TAIL(&resources->free_queue, rdma_req, state_link);
847 	}
848 
849 	return resources;
850 
851 cleanup:
852 	nvmf_rdma_resources_destroy(resources);
853 	return NULL;
854 }
855 
856 static void
857 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
858 {
859 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
860 	struct ibv_recv_wr		*bad_recv_wr = NULL;
861 	int				rc;
862 
863 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
864 
865 	spdk_poller_unregister(&rqpair->destruct_poller);
866 
867 	if (rqpair->qd != 0) {
868 		if (rqpair->srq == NULL) {
869 			nvmf_rdma_dump_qpair_contents(rqpair);
870 		}
871 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", rqpair->qd);
872 	}
873 
874 	if (rqpair->poller) {
875 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
876 
877 		if (rqpair->srq != NULL && rqpair->resources != NULL) {
878 			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
879 			STAILQ_FOREACH_SAFE(rdma_recv, &rqpair->resources->incoming_queue, link, recv_tmp) {
880 				if (rqpair == rdma_recv->qpair) {
881 					STAILQ_REMOVE_HEAD(&rqpair->resources->incoming_queue, link);
882 					rc = ibv_post_srq_recv(rqpair->srq, &rdma_recv->wr, &bad_recv_wr);
883 					if (rc) {
884 						SPDK_ERRLOG("Unable to re-post rx descriptor\n");
885 					}
886 				}
887 			}
888 		}
889 	}
890 
891 	if (rqpair->cm_id) {
892 		if (rqpair->cm_id->qp != NULL) {
893 			rdma_destroy_qp(rqpair->cm_id);
894 		}
895 		rdma_destroy_id(rqpair->cm_id);
896 
897 		if (rqpair->poller != NULL && rqpair->srq == NULL) {
898 			rqpair->poller->required_num_wr -= MAX_WR_PER_QP(rqpair->max_queue_depth);
899 		}
900 	}
901 
902 	if (rqpair->srq == NULL && rqpair->resources != NULL) {
903 		nvmf_rdma_resources_destroy(rqpair->resources);
904 	}
905 
906 	free(rqpair);
907 }
908 
909 static int
910 nvmf_rdma_resize_cq(struct spdk_nvmf_rdma_qpair *rqpair, struct spdk_nvmf_rdma_device *device)
911 {
912 	struct spdk_nvmf_rdma_poller	*rpoller;
913 	int				rc, num_cqe, required_num_wr;
914 
915 	/* Enlarge CQ size dynamically */
916 	rpoller = rqpair->poller;
917 	required_num_wr = rpoller->required_num_wr + MAX_WR_PER_QP(rqpair->max_queue_depth);
918 	num_cqe = rpoller->num_cqe;
919 	if (num_cqe < required_num_wr) {
920 		num_cqe = spdk_max(num_cqe * 2, required_num_wr);
921 		num_cqe = spdk_min(num_cqe, device->attr.max_cqe);
922 	}
923 
924 	if (rpoller->num_cqe != num_cqe) {
925 		if (required_num_wr > device->attr.max_cqe) {
926 			SPDK_ERRLOG("RDMA CQE requirement (%d) exceeds device max_cqe limitation (%d)\n",
927 				    required_num_wr, device->attr.max_cqe);
928 			return -1;
929 		}
930 
931 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Resize RDMA CQ from %d to %d\n", rpoller->num_cqe, num_cqe);
932 		rc = ibv_resize_cq(rpoller->cq, num_cqe);
933 		if (rc) {
934 			SPDK_ERRLOG("RDMA CQ resize failed: errno %d: %s\n", errno, spdk_strerror(errno));
935 			return -1;
936 		}
937 
938 		rpoller->num_cqe = num_cqe;
939 	}
940 
941 	rpoller->required_num_wr = required_num_wr;
942 	return 0;
943 }
944 
945 static int
946 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
947 {
948 	struct spdk_nvmf_rdma_qpair		*rqpair;
949 	int					rc;
950 	struct spdk_nvmf_rdma_transport		*rtransport;
951 	struct spdk_nvmf_transport		*transport;
952 	struct spdk_nvmf_rdma_resource_opts	opts;
953 	struct spdk_nvmf_rdma_device		*device;
954 	struct ibv_qp_init_attr			ibv_init_attr;
955 
956 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
957 	device = rqpair->port->device;
958 
959 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
960 	ibv_init_attr.qp_context	= rqpair;
961 	ibv_init_attr.qp_type		= IBV_QPT_RC;
962 	ibv_init_attr.send_cq		= rqpair->poller->cq;
963 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
964 
965 	if (rqpair->srq) {
966 		ibv_init_attr.srq		= rqpair->srq;
967 	} else {
968 		ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
969 						  1; /* RECV operations + dummy drain WR */
970 	}
971 
972 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
973 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
974 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
975 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
976 
977 	if (rqpair->srq == NULL && nvmf_rdma_resize_cq(rqpair, device) < 0) {
978 		SPDK_ERRLOG("Failed to resize the completion queue. Cannot initialize qpair.\n");
979 		goto error;
980 	}
981 
982 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
983 	if (rc) {
984 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
985 		goto error;
986 	}
987 
988 	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2 + 1),
989 					  ibv_init_attr.cap.max_send_wr);
990 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
991 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
992 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
993 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
994 
995 	rqpair->sends_to_post.first = NULL;
996 	rqpair->sends_to_post.last = NULL;
997 
998 	if (rqpair->poller->srq == NULL) {
999 		rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1000 		transport = &rtransport->transport;
1001 
1002 		opts.qp = rqpair->cm_id->qp;
1003 		opts.pd = rqpair->cm_id->pd;
1004 		opts.qpair = rqpair;
1005 		opts.shared = false;
1006 		opts.max_queue_depth = rqpair->max_queue_depth;
1007 		opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
1008 
1009 		rqpair->resources = nvmf_rdma_resources_create(&opts);
1010 
1011 		if (!rqpair->resources) {
1012 			SPDK_ERRLOG("Unable to allocate resources for receive queue.\n");
1013 			goto error;
1014 		}
1015 	} else {
1016 		rqpair->resources = rqpair->poller->resources;
1017 	}
1018 
1019 	rqpair->current_recv_depth = 0;
1020 	STAILQ_INIT(&rqpair->pending_rdma_read_queue);
1021 	STAILQ_INIT(&rqpair->pending_rdma_write_queue);
1022 
1023 	return 0;
1024 
1025 error:
1026 	rdma_destroy_id(rqpair->cm_id);
1027 	rqpair->cm_id = NULL;
1028 	spdk_nvmf_rdma_qpair_destroy(rqpair);
1029 	return -1;
1030 }
1031 
1032 
1033 /* Append the given send wr structure to the qpair's outstanding sends list. */
1034 /* This function accepts either a single wr or the first wr in a linked list. */
1035 static void
1036 nvmf_rdma_qpair_queue_send_wrs(struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *first)
1037 {
1038 	struct ibv_send_wr *last;
1039 
1040 	last = first;
1041 	while (last->next != NULL) {
1042 		last = last->next;
1043 	}
1044 
1045 	if (rqpair->sends_to_post.first == NULL) {
1046 		rqpair->sends_to_post.first = first;
1047 		rqpair->sends_to_post.last = last;
1048 		STAILQ_INSERT_TAIL(&rqpair->poller->qpairs_pending_send, rqpair, send_link);
1049 	} else {
1050 		rqpair->sends_to_post.last->next = first;
1051 		rqpair->sends_to_post.last = last;
1052 	}
1053 }
1054 
1055 static int
1056 request_transfer_in(struct spdk_nvmf_request *req)
1057 {
1058 	struct spdk_nvmf_rdma_request	*rdma_req;
1059 	struct spdk_nvmf_qpair		*qpair;
1060 	struct spdk_nvmf_rdma_qpair	*rqpair;
1061 
1062 	qpair = req->qpair;
1063 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1064 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1065 
1066 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
1067 	assert(rdma_req != NULL);
1068 
1069 	nvmf_rdma_qpair_queue_send_wrs(rqpair, &rdma_req->data.wr);
1070 	rqpair->current_read_depth += rdma_req->num_outstanding_data_wr;
1071 	rqpair->current_send_depth += rdma_req->num_outstanding_data_wr;
1072 	return 0;
1073 }
1074 
1075 static int
1076 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
1077 {
1078 	int				rc;
1079 	int				num_outstanding_data_wr = 0;
1080 	struct spdk_nvmf_rdma_request	*rdma_req;
1081 	struct spdk_nvmf_qpair		*qpair;
1082 	struct spdk_nvmf_rdma_qpair	*rqpair;
1083 	struct spdk_nvme_cpl		*rsp;
1084 	struct ibv_recv_wr		*bad_recv_wr = NULL;
1085 	struct ibv_send_wr		*first = NULL;
1086 
1087 	*data_posted = 0;
1088 	qpair = req->qpair;
1089 	rsp = &req->rsp->nvme_cpl;
1090 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1091 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1092 
1093 	/* Advance our sq_head pointer */
1094 	if (qpair->sq_head == qpair->sq_head_max) {
1095 		qpair->sq_head = 0;
1096 	} else {
1097 		qpair->sq_head++;
1098 	}
1099 	rsp->sqhd = qpair->sq_head;
1100 
1101 	/* Post the capsule to the recv buffer */
1102 	assert(rdma_req->recv != NULL);
1103 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
1104 		      rqpair);
1105 	if (rqpair->srq == NULL) {
1106 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
1107 	} else {
1108 		rc = ibv_post_srq_recv(rqpair->srq, &rdma_req->recv->wr, &bad_recv_wr);
1109 	}
1110 
1111 	if (rc) {
1112 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
1113 		return rc;
1114 	}
1115 	rdma_req->recv = NULL;
1116 	assert(rqpair->current_recv_depth > 0);
1117 	rqpair->current_recv_depth--;
1118 
1119 	/* Build the response which consists of optional
1120 	 * RDMA WRITEs to transfer data, plus an RDMA SEND
1121 	 * containing the response.
1122 	 */
1123 	first = &rdma_req->rsp.wr;
1124 
1125 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
1126 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1127 		first = &rdma_req->data.wr;
1128 		*data_posted = 1;
1129 		num_outstanding_data_wr = rdma_req->num_outstanding_data_wr;
1130 	}
1131 	nvmf_rdma_qpair_queue_send_wrs(rqpair, first);
1132 	/* +1 for the rsp wr */
1133 	rqpair->current_send_depth += num_outstanding_data_wr + 1;
1134 
1135 	return 0;
1136 }
1137 
1138 static int
1139 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
1140 {
1141 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
1142 	struct rdma_conn_param				ctrlr_event_data = {};
1143 	int						rc;
1144 
1145 	accept_data.recfmt = 0;
1146 	accept_data.crqsize = rqpair->max_queue_depth;
1147 
1148 	ctrlr_event_data.private_data = &accept_data;
1149 	ctrlr_event_data.private_data_len = sizeof(accept_data);
1150 	if (id->ps == RDMA_PS_TCP) {
1151 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
1152 		ctrlr_event_data.initiator_depth = rqpair->max_read_depth;
1153 	}
1154 
1155 	/* Configure infinite retries for the initiator side qpair.
1156 	 * When using a shared receive queue on the target side,
1157 	 * we need to pass this value to the initiator to prevent the
1158 	 * initiator side NIC from completing SEND requests back to the
1159 	 * initiator with status rnr_retry_count_exceeded. */
1160 	if (rqpair->srq != NULL) {
1161 		ctrlr_event_data.rnr_retry_count = 0x7;
1162 	}
1163 
1164 	rc = rdma_accept(id, &ctrlr_event_data);
1165 	if (rc) {
1166 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
1167 	} else {
1168 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
1169 	}
1170 
1171 	return rc;
1172 }
1173 
1174 static void
1175 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
1176 {
1177 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
1178 
1179 	rej_data.recfmt = 0;
1180 	rej_data.sts = error;
1181 
1182 	rdma_reject(id, &rej_data, sizeof(rej_data));
1183 }
1184 
1185 static int
1186 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
1187 		  new_qpair_fn cb_fn)
1188 {
1189 	struct spdk_nvmf_rdma_transport *rtransport;
1190 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
1191 	struct spdk_nvmf_rdma_port	*port;
1192 	struct rdma_conn_param		*rdma_param = NULL;
1193 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
1194 	uint16_t			max_queue_depth;
1195 	uint16_t			max_read_depth;
1196 
1197 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1198 
1199 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
1200 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
1201 
1202 	rdma_param = &event->param.conn;
1203 	if (rdma_param->private_data == NULL ||
1204 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1205 		SPDK_ERRLOG("connect request: no private data provided\n");
1206 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
1207 		return -1;
1208 	}
1209 
1210 	private_data = rdma_param->private_data;
1211 	if (private_data->recfmt != 0) {
1212 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
1213 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
1214 		return -1;
1215 	}
1216 
1217 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
1218 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
1219 
1220 	port = event->listen_id->context;
1221 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
1222 		      event->listen_id, event->listen_id->verbs, port);
1223 
1224 	/* Figure out the supported queue depth. This is a multi-step process
1225 	 * that takes into account hardware maximums, host provided values,
1226 	 * and our target's internal memory limits */
1227 
1228 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
1229 
1230 	/* Start with the maximum queue depth allowed by the target */
1231 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
1232 	max_read_depth = rtransport->transport.opts.max_queue_depth;
1233 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
1234 		      rtransport->transport.opts.max_queue_depth);
1235 
1236 	/* Next check the local NIC's hardware limitations */
1237 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1238 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
1239 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
1240 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
1241 	max_read_depth = spdk_min(max_read_depth, port->device->attr.max_qp_init_rd_atom);
1242 
1243 	/* Next check the remote NIC's hardware limitations */
1244 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1245 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1246 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1247 	if (rdma_param->initiator_depth > 0) {
1248 		max_read_depth = spdk_min(max_read_depth, rdma_param->initiator_depth);
1249 	}
1250 
1251 	/* Finally check for the host software requested values, which are
1252 	 * optional. */
1253 	if (rdma_param->private_data != NULL &&
1254 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1255 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1256 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1257 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1258 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1259 	}
1260 
1261 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1262 		      max_queue_depth, max_read_depth);
1263 
1264 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1265 	if (rqpair == NULL) {
1266 		SPDK_ERRLOG("Could not allocate new connection.\n");
1267 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1268 		return -1;
1269 	}
1270 
1271 	rqpair->port = port;
1272 	rqpair->max_queue_depth = max_queue_depth;
1273 	rqpair->max_read_depth = max_read_depth;
1274 	rqpair->cm_id = event->id;
1275 	rqpair->listen_id = event->listen_id;
1276 	rqpair->qpair.transport = transport;
1277 
1278 	event->id->context = &rqpair->qpair;
1279 
1280 	cb_fn(&rqpair->qpair);
1281 
1282 	return 0;
1283 }
1284 
1285 static int
1286 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1287 			  enum spdk_mem_map_notify_action action,
1288 			  void *vaddr, size_t size)
1289 {
1290 	struct ibv_pd *pd = cb_ctx;
1291 	struct ibv_mr *mr;
1292 
1293 	switch (action) {
1294 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1295 		if (!g_nvmf_hooks.get_rkey) {
1296 			mr = ibv_reg_mr(pd, vaddr, size,
1297 					IBV_ACCESS_LOCAL_WRITE |
1298 					IBV_ACCESS_REMOTE_READ |
1299 					IBV_ACCESS_REMOTE_WRITE);
1300 			if (mr == NULL) {
1301 				SPDK_ERRLOG("ibv_reg_mr() failed\n");
1302 				return -1;
1303 			} else {
1304 				spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1305 			}
1306 		} else {
1307 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size,
1308 						     g_nvmf_hooks.get_rkey(pd, vaddr, size));
1309 		}
1310 		break;
1311 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1312 		if (!g_nvmf_hooks.get_rkey) {
1313 			mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1314 			spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1315 			if (mr) {
1316 				ibv_dereg_mr(mr);
1317 			}
1318 		}
1319 		break;
1320 	}
1321 
1322 	return 0;
1323 }
1324 
1325 static int
1326 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1327 {
1328 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1329 	return addr_1 == addr_2;
1330 }
1331 
1332 static void
1333 spdk_nvmf_rdma_request_free_buffers(struct spdk_nvmf_rdma_request *rdma_req,
1334 				    struct spdk_nvmf_transport_poll_group *group, struct spdk_nvmf_transport *transport,
1335 				    uint32_t num_buffers)
1336 {
1337 	uint32_t i;
1338 
1339 	for (i = 0; i < num_buffers; i++) {
1340 		if (group->buf_cache_count < group->buf_cache_size) {
1341 			STAILQ_INSERT_HEAD(&group->buf_cache,
1342 					   (struct spdk_nvmf_transport_pg_cache_buf *)rdma_req->buffers[i], link);
1343 			group->buf_cache_count++;
1344 		} else {
1345 			spdk_mempool_put(transport->data_buf_pool, rdma_req->buffers[i]);
1346 		}
1347 		rdma_req->req.iov[i].iov_base = NULL;
1348 		rdma_req->buffers[i] = NULL;
1349 		rdma_req->req.iov[i].iov_len = 0;
1350 
1351 	}
1352 	rdma_req->data_from_pool = false;
1353 }
1354 
1355 static int
1356 nvmf_rdma_request_get_buffers(struct spdk_nvmf_rdma_request *rdma_req,
1357 			      struct spdk_nvmf_transport_poll_group *group, struct spdk_nvmf_transport *transport,
1358 			      uint32_t num_buffers)
1359 {
1360 	uint32_t i = 0;
1361 
1362 	while (i < num_buffers) {
1363 		if (!(STAILQ_EMPTY(&group->buf_cache))) {
1364 			group->buf_cache_count--;
1365 			rdma_req->buffers[i] = STAILQ_FIRST(&group->buf_cache);
1366 			STAILQ_REMOVE_HEAD(&group->buf_cache, link);
1367 			assert(rdma_req->buffers[i] != NULL);
1368 			i++;
1369 		} else {
1370 			if (spdk_mempool_get_bulk(transport->data_buf_pool, &rdma_req->buffers[i], num_buffers - i)) {
1371 				goto err_exit;
1372 			}
1373 			i += num_buffers - i;
1374 		}
1375 	}
1376 
1377 	return 0;
1378 
1379 err_exit:
1380 	spdk_nvmf_rdma_request_free_buffers(rdma_req, group, transport, i);
1381 	return -ENOMEM;
1382 }
1383 
1384 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1385 
1386 static spdk_nvme_data_transfer_t
1387 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1388 {
1389 	enum spdk_nvme_data_transfer xfer;
1390 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1391 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1392 
1393 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1394 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1395 	rdma_req->rsp.wr.imm_data = 0;
1396 #endif
1397 
1398 	/* Figure out data transfer direction */
1399 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1400 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1401 	} else {
1402 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1403 
1404 		/* Some admin commands are special cases */
1405 		if ((rdma_req->req.qpair->qid == 0) &&
1406 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1407 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1408 			switch (cmd->cdw10 & 0xff) {
1409 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1410 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1411 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1412 				break;
1413 			default:
1414 				xfer = SPDK_NVME_DATA_NONE;
1415 			}
1416 		}
1417 	}
1418 
1419 	if (xfer == SPDK_NVME_DATA_NONE) {
1420 		return xfer;
1421 	}
1422 
1423 	/* Even for commands that may transfer data, they could have specified 0 length.
1424 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1425 	 */
1426 	switch (sgl->generic.type) {
1427 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1428 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1429 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1430 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1431 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1432 		if (sgl->unkeyed.length == 0) {
1433 			xfer = SPDK_NVME_DATA_NONE;
1434 		}
1435 		break;
1436 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1437 		if (sgl->keyed.length == 0) {
1438 			xfer = SPDK_NVME_DATA_NONE;
1439 		}
1440 		break;
1441 	}
1442 
1443 	return xfer;
1444 }
1445 
1446 static int
1447 nvmf_request_alloc_wrs(struct spdk_nvmf_rdma_transport *rtransport,
1448 		       struct spdk_nvmf_rdma_request *rdma_req,
1449 		       uint32_t num_sgl_descriptors)
1450 {
1451 	struct spdk_nvmf_rdma_request_data	*work_requests[SPDK_NVMF_MAX_SGL_ENTRIES];
1452 	struct spdk_nvmf_rdma_request_data	*current_data_wr;
1453 	uint32_t				i;
1454 
1455 	if (spdk_mempool_get_bulk(rtransport->data_wr_pool, (void **)work_requests, num_sgl_descriptors)) {
1456 		return -ENOMEM;
1457 	}
1458 
1459 	current_data_wr = &rdma_req->data;
1460 
1461 	for (i = 0; i < num_sgl_descriptors; i++) {
1462 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1463 			current_data_wr->wr.opcode = IBV_WR_RDMA_WRITE;
1464 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1465 			current_data_wr->wr.opcode = IBV_WR_RDMA_READ;
1466 		} else {
1467 			assert(false);
1468 		}
1469 		work_requests[i]->wr.send_flags = IBV_SEND_SIGNALED;
1470 		work_requests[i]->wr.sg_list = work_requests[i]->sgl;
1471 		work_requests[i]->wr.wr_id = rdma_req->data.wr.wr_id;
1472 		current_data_wr->wr.next = &work_requests[i]->wr;
1473 		current_data_wr = work_requests[i];
1474 	}
1475 
1476 	if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1477 		current_data_wr->wr.opcode = IBV_WR_RDMA_WRITE;
1478 		current_data_wr->wr.next = &rdma_req->rsp.wr;
1479 	} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1480 		current_data_wr->wr.opcode = IBV_WR_RDMA_READ;
1481 		current_data_wr->wr.next = NULL;
1482 	}
1483 	return 0;
1484 }
1485 
1486 static int
1487 nvmf_rdma_fill_buffers(struct spdk_nvmf_rdma_transport *rtransport,
1488 		       struct spdk_nvmf_rdma_poll_group *rgroup,
1489 		       struct spdk_nvmf_rdma_device *device,
1490 		       struct spdk_nvmf_rdma_request *rdma_req,
1491 		       struct ibv_send_wr *wr,
1492 		       uint32_t length)
1493 {
1494 	uint64_t	translation_len;
1495 	uint32_t	remaining_length = length;
1496 	uint32_t	iovcnt;
1497 	uint32_t	i = 0;
1498 
1499 
1500 	while (remaining_length) {
1501 		iovcnt = rdma_req->req.iovcnt;
1502 		rdma_req->req.iov[iovcnt].iov_base = (void *)((uintptr_t)(rdma_req->buffers[iovcnt] +
1503 						     NVMF_DATA_BUFFER_MASK) &
1504 						     ~NVMF_DATA_BUFFER_MASK);
1505 		rdma_req->req.iov[iovcnt].iov_len  = spdk_min(remaining_length,
1506 						     rtransport->transport.opts.io_unit_size);
1507 		rdma_req->req.iovcnt++;
1508 		wr->sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[iovcnt].iov_base);
1509 		wr->sg_list[i].length = rdma_req->req.iov[iovcnt].iov_len;
1510 		translation_len = rdma_req->req.iov[iovcnt].iov_len;
1511 
1512 		if (!g_nvmf_hooks.get_rkey) {
1513 			wr->sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1514 					       (uint64_t)rdma_req->buffers[iovcnt], &translation_len))->lkey;
1515 		} else {
1516 			wr->sg_list[i].lkey = spdk_mem_map_translate(device->map,
1517 					      (uint64_t)rdma_req->buffers[iovcnt], &translation_len);
1518 		}
1519 
1520 		remaining_length -= rdma_req->req.iov[iovcnt].iov_len;
1521 
1522 		if (translation_len < rdma_req->req.iov[iovcnt].iov_len) {
1523 			SPDK_ERRLOG("Data buffer split over multiple RDMA Memory Regions\n");
1524 			return -EINVAL;
1525 		}
1526 		i++;
1527 	}
1528 	wr->num_sge = i;
1529 
1530 	return 0;
1531 }
1532 
1533 static int
1534 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1535 				 struct spdk_nvmf_rdma_device *device,
1536 				 struct spdk_nvmf_rdma_request *rdma_req)
1537 {
1538 	struct spdk_nvmf_rdma_qpair		*rqpair;
1539 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1540 	uint32_t				num_buffers;
1541 	uint32_t				i = 0;
1542 	int					rc = 0;
1543 
1544 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1545 	rgroup = rqpair->poller->group;
1546 	rdma_req->req.iovcnt = 0;
1547 
1548 	num_buffers = rdma_req->req.length / rtransport->transport.opts.io_unit_size;
1549 	if (rdma_req->req.length % rtransport->transport.opts.io_unit_size) {
1550 		num_buffers++;
1551 	}
1552 
1553 	if (nvmf_rdma_request_get_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers)) {
1554 		return -ENOMEM;
1555 	}
1556 
1557 	rdma_req->req.iovcnt = 0;
1558 
1559 	rc = nvmf_rdma_fill_buffers(rtransport, rgroup, device, rdma_req, &rdma_req->data.wr,
1560 				    rdma_req->req.length);
1561 	if (rc != 0) {
1562 		goto err_exit;
1563 	}
1564 
1565 	assert(rdma_req->req.iovcnt <= rqpair->max_send_sge);
1566 
1567 	rdma_req->data_from_pool = true;
1568 
1569 	return rc;
1570 
1571 err_exit:
1572 	spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers);
1573 	while (i) {
1574 		i--;
1575 		rdma_req->data.wr.sg_list[i].addr = 0;
1576 		rdma_req->data.wr.sg_list[i].length = 0;
1577 		rdma_req->data.wr.sg_list[i].lkey = 0;
1578 	}
1579 	rdma_req->req.iovcnt = 0;
1580 	return rc;
1581 }
1582 
1583 static int
1584 nvmf_rdma_request_fill_iovs_multi_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1585 				      struct spdk_nvmf_rdma_device *device,
1586 				      struct spdk_nvmf_rdma_request *rdma_req)
1587 {
1588 	struct spdk_nvmf_rdma_qpair		*rqpair;
1589 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1590 	struct ibv_send_wr			*current_wr;
1591 	struct spdk_nvmf_request		*req = &rdma_req->req;
1592 	struct spdk_nvme_sgl_descriptor		*inline_segment, *desc;
1593 	uint32_t				num_sgl_descriptors;
1594 	uint32_t				num_buffers = 0;
1595 	uint32_t				i;
1596 	int					rc;
1597 
1598 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1599 	rgroup = rqpair->poller->group;
1600 
1601 	inline_segment = &req->cmd->nvme_cmd.dptr.sgl1;
1602 	assert(inline_segment->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT);
1603 	assert(inline_segment->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET);
1604 
1605 	num_sgl_descriptors = inline_segment->unkeyed.length / sizeof(struct spdk_nvme_sgl_descriptor);
1606 	assert(num_sgl_descriptors <= SPDK_NVMF_MAX_SGL_ENTRIES);
1607 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1608 
1609 	for (i = 0; i < num_sgl_descriptors; i++) {
1610 		num_buffers += desc->keyed.length / rtransport->transport.opts.io_unit_size;
1611 		if (desc->keyed.length % rtransport->transport.opts.io_unit_size) {
1612 			num_buffers++;
1613 		}
1614 		desc++;
1615 	}
1616 	/* If the number of buffers is too large, then we know the I/O is larger than allowed. Fail it. */
1617 	if (num_buffers > NVMF_REQ_MAX_BUFFERS) {
1618 		return -EINVAL;
1619 	}
1620 	if (nvmf_rdma_request_get_buffers(rdma_req, &rgroup->group, &rtransport->transport,
1621 					  num_buffers) != 0) {
1622 		return -ENOMEM;
1623 	}
1624 
1625 	if (nvmf_request_alloc_wrs(rtransport, rdma_req, num_sgl_descriptors - 1) != 0) {
1626 		spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers);
1627 		return -ENOMEM;
1628 	}
1629 
1630 	/* The first WR must always be the embedded data WR. This is how we unwind them later. */
1631 	current_wr = &rdma_req->data.wr;
1632 
1633 	req->iovcnt = 0;
1634 	desc = (struct spdk_nvme_sgl_descriptor *)rdma_req->recv->buf + inline_segment->address;
1635 	for (i = 0; i < num_sgl_descriptors; i++) {
1636 		/* The descriptors must be keyed data block descriptors with an address, not an offset. */
1637 		if (spdk_unlikely(desc->generic.type != SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK ||
1638 				  desc->keyed.subtype != SPDK_NVME_SGL_SUBTYPE_ADDRESS)) {
1639 			rc = -EINVAL;
1640 			goto err_exit;
1641 		}
1642 
1643 		current_wr->num_sge = 0;
1644 		req->length += desc->keyed.length;
1645 
1646 		rc = nvmf_rdma_fill_buffers(rtransport, rgroup, device, rdma_req, current_wr,
1647 					    desc->keyed.length);
1648 		if (rc != 0) {
1649 			rc = -ENOMEM;
1650 			goto err_exit;
1651 		}
1652 
1653 		current_wr->wr.rdma.rkey = desc->keyed.key;
1654 		current_wr->wr.rdma.remote_addr = desc->address;
1655 		current_wr = current_wr->next;
1656 		desc++;
1657 	}
1658 
1659 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1660 	/* Go back to the last descriptor in the list. */
1661 	desc--;
1662 	if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1663 		if (desc->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1664 			rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1665 			rdma_req->rsp.wr.imm_data = desc->keyed.key;
1666 		}
1667 	}
1668 #endif
1669 
1670 	rdma_req->num_outstanding_data_wr = num_sgl_descriptors;
1671 	rdma_req->data_from_pool = true;
1672 
1673 	return 0;
1674 
1675 err_exit:
1676 	spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport, num_buffers);
1677 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1678 	return rc;
1679 }
1680 
1681 static int
1682 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1683 				 struct spdk_nvmf_rdma_device *device,
1684 				 struct spdk_nvmf_rdma_request *rdma_req)
1685 {
1686 	struct spdk_nvme_cmd			*cmd;
1687 	struct spdk_nvme_cpl			*rsp;
1688 	struct spdk_nvme_sgl_descriptor		*sgl;
1689 	int					rc;
1690 
1691 	cmd = &rdma_req->req.cmd->nvme_cmd;
1692 	rsp = &rdma_req->req.rsp->nvme_cpl;
1693 	sgl = &cmd->dptr.sgl1;
1694 
1695 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1696 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1697 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1698 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1699 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1700 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1701 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1702 			return -1;
1703 		}
1704 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1705 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1706 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1707 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1708 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1709 			}
1710 		}
1711 #endif
1712 
1713 		/* fill request length and populate iovs */
1714 		rdma_req->req.length = sgl->keyed.length;
1715 
1716 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1717 			/* No available buffers. Queue this request up. */
1718 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1719 			return 0;
1720 		}
1721 
1722 		/* backward compatible */
1723 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1724 
1725 		/* rdma wr specifics */
1726 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1727 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1728 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1729 		if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1730 			rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
1731 			rdma_req->data.wr.next = &rdma_req->rsp.wr;
1732 		} else if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1733 			rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
1734 			rdma_req->data.wr.next = NULL;
1735 		}
1736 
1737 		/* set the number of outstanding data WRs for this request. */
1738 		rdma_req->num_outstanding_data_wr = 1;
1739 
1740 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1741 			      rdma_req->req.iovcnt);
1742 
1743 		return 0;
1744 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1745 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1746 		uint64_t offset = sgl->address;
1747 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1748 
1749 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1750 			      offset, sgl->unkeyed.length);
1751 
1752 		if (offset > max_len) {
1753 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1754 				    offset, max_len);
1755 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1756 			return -1;
1757 		}
1758 		max_len -= (uint32_t)offset;
1759 
1760 		if (sgl->unkeyed.length > max_len) {
1761 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1762 				    sgl->unkeyed.length, max_len);
1763 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1764 			return -1;
1765 		}
1766 
1767 		rdma_req->num_outstanding_data_wr = 0;
1768 		rdma_req->req.data = rdma_req->recv->buf + offset;
1769 		rdma_req->data_from_pool = false;
1770 		rdma_req->req.length = sgl->unkeyed.length;
1771 
1772 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1773 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1774 		rdma_req->req.iovcnt = 1;
1775 
1776 		return 0;
1777 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_LAST_SEGMENT &&
1778 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1779 
1780 		rc = nvmf_rdma_request_fill_iovs_multi_sgl(rtransport, device, rdma_req);
1781 		if (rc == -ENOMEM) {
1782 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1783 			return 0;
1784 		} else if (rc == -EINVAL) {
1785 			SPDK_ERRLOG("Multi SGL element request length exceeds the max I/O size\n");
1786 			return -1;
1787 		}
1788 
1789 		/* backward compatible */
1790 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1791 
1792 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1793 			      rdma_req->req.iovcnt);
1794 
1795 		return 0;
1796 	}
1797 
1798 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1799 		    sgl->generic.type, sgl->generic.subtype);
1800 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1801 	return -1;
1802 }
1803 
1804 static void
1805 nvmf_rdma_request_free(struct spdk_nvmf_rdma_request *rdma_req,
1806 		       struct spdk_nvmf_rdma_transport	*rtransport)
1807 {
1808 	struct spdk_nvmf_rdma_qpair		*rqpair;
1809 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1810 
1811 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1812 	if (rdma_req->data_from_pool) {
1813 		rgroup = rqpair->poller->group;
1814 
1815 		spdk_nvmf_rdma_request_free_buffers(rdma_req, &rgroup->group, &rtransport->transport,
1816 						    rdma_req->req.iovcnt);
1817 	}
1818 	nvmf_rdma_request_free_data(rdma_req, rtransport);
1819 	rdma_req->req.length = 0;
1820 	rdma_req->req.iovcnt = 0;
1821 	rdma_req->req.data = NULL;
1822 	rdma_req->rsp.wr.next = NULL;
1823 	rdma_req->data.wr.next = NULL;
1824 	rqpair->qd--;
1825 
1826 	STAILQ_INSERT_HEAD(&rqpair->resources->free_queue, rdma_req, state_link);
1827 	rdma_req->state = RDMA_REQUEST_STATE_FREE;
1828 }
1829 
1830 static bool
1831 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1832 			       struct spdk_nvmf_rdma_request *rdma_req)
1833 {
1834 	struct spdk_nvmf_rdma_qpair	*rqpair;
1835 	struct spdk_nvmf_rdma_device	*device;
1836 	struct spdk_nvmf_rdma_poll_group *rgroup;
1837 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1838 	int				rc;
1839 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1840 	enum spdk_nvmf_rdma_request_state prev_state;
1841 	bool				progress = false;
1842 	int				data_posted;
1843 
1844 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1845 	device = rqpair->port->device;
1846 	rgroup = rqpair->poller->group;
1847 
1848 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1849 
1850 	/* If the queue pair is in an error state, force the request to the completed state
1851 	 * to release resources. */
1852 	if (rqpair->ibv_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1853 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1854 			STAILQ_REMOVE(&rgroup->pending_data_buf_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1855 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING) {
1856 			STAILQ_REMOVE(&rqpair->pending_rdma_read_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1857 		} else if (rdma_req->state == RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING) {
1858 			STAILQ_REMOVE(&rqpair->pending_rdma_write_queue, rdma_req, spdk_nvmf_rdma_request, state_link);
1859 		}
1860 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1861 	}
1862 
1863 	/* The loop here is to allow for several back-to-back state changes. */
1864 	do {
1865 		prev_state = rdma_req->state;
1866 
1867 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1868 
1869 		switch (rdma_req->state) {
1870 		case RDMA_REQUEST_STATE_FREE:
1871 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1872 			 * to escape this state. */
1873 			break;
1874 		case RDMA_REQUEST_STATE_NEW:
1875 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1876 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1877 			rdma_recv = rdma_req->recv;
1878 
1879 			/* The first element of the SGL is the NVMe command */
1880 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1881 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1882 
1883 			if (rqpair->ibv_state == IBV_QPS_ERR  || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1884 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
1885 				break;
1886 			}
1887 
1888 			/* The next state transition depends on the data transfer needs of this request. */
1889 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1890 
1891 			/* If no data to transfer, ready to execute. */
1892 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1893 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1894 				break;
1895 			}
1896 
1897 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1898 			STAILQ_INSERT_TAIL(&rgroup->pending_data_buf_queue, rdma_req, state_link);
1899 			break;
1900 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1901 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1902 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1903 
1904 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1905 
1906 			if (rdma_req != STAILQ_FIRST(&rgroup->pending_data_buf_queue)) {
1907 				/* This request needs to wait in line to obtain a buffer */
1908 				break;
1909 			}
1910 
1911 			/* Try to get a data buffer */
1912 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1913 			if (rc < 0) {
1914 				STAILQ_REMOVE_HEAD(&rgroup->pending_data_buf_queue, state_link);
1915 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1916 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1917 				break;
1918 			}
1919 
1920 			if (!rdma_req->req.data) {
1921 				/* No buffers available. */
1922 				break;
1923 			}
1924 
1925 			STAILQ_REMOVE_HEAD(&rgroup->pending_data_buf_queue, state_link);
1926 
1927 			/* If data is transferring from host to controller and the data didn't
1928 			 * arrive using in capsule data, we need to do a transfer from the host.
1929 			 */
1930 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1931 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_read_queue, rdma_req, state_link);
1932 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING;
1933 				break;
1934 			}
1935 
1936 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1937 			break;
1938 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING:
1939 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_CONTROLLER_PENDING, 0, 0,
1940 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1941 
1942 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_read_queue)) {
1943 				/* This request needs to wait in line to perform RDMA */
1944 				break;
1945 			}
1946 			if (rqpair->current_send_depth + rdma_req->num_outstanding_data_wr > rqpair->max_send_depth
1947 			    || rqpair->current_read_depth + rdma_req->num_outstanding_data_wr > rqpair->max_read_depth) {
1948 				/* We can only have so many WRs outstanding. we have to wait until some finish. */
1949 				break;
1950 			}
1951 
1952 			/* We have already verified that this request is the head of the queue. */
1953 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_read_queue, state_link);
1954 
1955 			rc = request_transfer_in(&rdma_req->req);
1956 			if (!rc) {
1957 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
1958 			} else {
1959 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1960 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1961 			}
1962 			break;
1963 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1964 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1965 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1966 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1967 			 * to escape this state. */
1968 			break;
1969 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1970 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1971 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1972 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
1973 			spdk_nvmf_request_exec(&rdma_req->req);
1974 			break;
1975 		case RDMA_REQUEST_STATE_EXECUTING:
1976 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1977 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1978 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1979 			 * to escape this state. */
1980 			break;
1981 		case RDMA_REQUEST_STATE_EXECUTED:
1982 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1983 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1984 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1985 				STAILQ_INSERT_TAIL(&rqpair->pending_rdma_write_queue, rdma_req, state_link);
1986 				rdma_req->state = RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING;
1987 			} else {
1988 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1989 			}
1990 			break;
1991 		case RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING:
1992 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_TO_HOST_PENDING, 0, 0,
1993 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1994 
1995 			if (rdma_req != STAILQ_FIRST(&rqpair->pending_rdma_write_queue)) {
1996 				/* This request needs to wait in line to perform RDMA */
1997 				break;
1998 			}
1999 			if ((rqpair->current_send_depth + rdma_req->num_outstanding_data_wr + 1) >
2000 			    rqpair->max_send_depth) {
2001 				/* We can only have so many WRs outstanding. we have to wait until some finish.
2002 				 * +1 since each request has an additional wr in the resp. */
2003 				break;
2004 			}
2005 
2006 			/* We have already verified that this request is the head of the queue. */
2007 			STAILQ_REMOVE_HEAD(&rqpair->pending_rdma_write_queue, state_link);
2008 
2009 			/* The data transfer will be kicked off from
2010 			 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
2011 			 */
2012 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
2013 			break;
2014 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
2015 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
2016 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2017 			rc = request_transfer_out(&rdma_req->req, &data_posted);
2018 			assert(rc == 0); /* No good way to handle this currently */
2019 			if (rc) {
2020 				rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2021 			} else {
2022 				rdma_req->state = data_posted ? RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
2023 						  RDMA_REQUEST_STATE_COMPLETING;
2024 			}
2025 			break;
2026 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
2027 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
2028 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2029 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2030 			 * to escape this state. */
2031 			break;
2032 		case RDMA_REQUEST_STATE_COMPLETING:
2033 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
2034 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2035 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
2036 			 * to escape this state. */
2037 			break;
2038 		case RDMA_REQUEST_STATE_COMPLETED:
2039 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
2040 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
2041 
2042 			nvmf_rdma_request_free(rdma_req, rtransport);
2043 			break;
2044 		case RDMA_REQUEST_NUM_STATES:
2045 		default:
2046 			assert(0);
2047 			break;
2048 		}
2049 
2050 		if (rdma_req->state != prev_state) {
2051 			progress = true;
2052 		}
2053 	} while (rdma_req->state != prev_state);
2054 
2055 	return progress;
2056 }
2057 
2058 /* Public API callbacks begin here */
2059 
2060 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
2061 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
2062 #define SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH 4096
2063 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
2064 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
2065 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
2066 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
2067 #define SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS 4095
2068 #define SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE 32
2069 #define SPDK_NVMF_RDMA_DEFAULT_NO_SRQ false;
2070 
2071 static void
2072 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
2073 {
2074 	opts->max_queue_depth =		SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
2075 	opts->max_qpairs_per_ctrlr =	SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
2076 	opts->in_capsule_data_size =	SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
2077 	opts->max_io_size =		SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
2078 	opts->io_unit_size =		SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE;
2079 	opts->max_aq_depth =		SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
2080 	opts->num_shared_buffers =	SPDK_NVMF_RDMA_DEFAULT_NUM_SHARED_BUFFERS;
2081 	opts->buf_cache_size =		SPDK_NVMF_RDMA_DEFAULT_BUFFER_CACHE_SIZE;
2082 	opts->max_srq_depth =		SPDK_NVMF_RDMA_DEFAULT_SRQ_DEPTH;
2083 	opts->no_srq =			SPDK_NVMF_RDMA_DEFAULT_NO_SRQ
2084 }
2085 
2086 const struct spdk_mem_map_ops g_nvmf_rdma_map_ops = {
2087 	.notify_cb = spdk_nvmf_rdma_mem_notify,
2088 	.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
2089 };
2090 
2091 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
2092 
2093 static struct spdk_nvmf_transport *
2094 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
2095 {
2096 	int rc;
2097 	struct spdk_nvmf_rdma_transport *rtransport;
2098 	struct spdk_nvmf_rdma_device	*device, *tmp;
2099 	struct ibv_pd			*pd;
2100 	struct ibv_context		**contexts;
2101 	uint32_t			i;
2102 	int				flag;
2103 	uint32_t			sge_count;
2104 	uint32_t			min_shared_buffers;
2105 	int				max_device_sge = SPDK_NVMF_MAX_SGL_ENTRIES;
2106 
2107 	rtransport = calloc(1, sizeof(*rtransport));
2108 	if (!rtransport) {
2109 		return NULL;
2110 	}
2111 
2112 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
2113 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
2114 		free(rtransport);
2115 		return NULL;
2116 	}
2117 
2118 	TAILQ_INIT(&rtransport->devices);
2119 	TAILQ_INIT(&rtransport->ports);
2120 
2121 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
2122 
2123 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
2124 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
2125 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
2126 		     "  in_capsule_data_size=%d, max_aq_depth=%d,\n"
2127 		     "  num_shared_buffers=%d, max_srq_depth=%d, no_srq=%d\n",
2128 		     opts->max_queue_depth,
2129 		     opts->max_io_size,
2130 		     opts->max_qpairs_per_ctrlr,
2131 		     opts->io_unit_size,
2132 		     opts->in_capsule_data_size,
2133 		     opts->max_aq_depth,
2134 		     opts->num_shared_buffers,
2135 		     opts->max_srq_depth,
2136 		     opts->no_srq);
2137 
2138 	/* I/O unit size cannot be larger than max I/O size */
2139 	if (opts->io_unit_size > opts->max_io_size) {
2140 		opts->io_unit_size = opts->max_io_size;
2141 	}
2142 
2143 	if (opts->num_shared_buffers < (SPDK_NVMF_MAX_SGL_ENTRIES * 2)) {
2144 		SPDK_ERRLOG("The number of shared data buffers (%d) is less than"
2145 			    "the minimum number required to guarantee that forward progress can be made (%d)\n",
2146 			    opts->num_shared_buffers, (SPDK_NVMF_MAX_SGL_ENTRIES * 2));
2147 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2148 		return NULL;
2149 	}
2150 
2151 	min_shared_buffers = spdk_thread_get_count() * opts->buf_cache_size;
2152 	if (min_shared_buffers > opts->num_shared_buffers) {
2153 		SPDK_ERRLOG("There are not enough buffers to satisfy"
2154 			    "per-poll group caches for each thread. (%" PRIu32 ")"
2155 			    "supplied. (%" PRIu32 ") required\n", opts->num_shared_buffers, min_shared_buffers);
2156 		SPDK_ERRLOG("Please specify a larger number of shared buffers\n");
2157 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2158 		return NULL;
2159 	}
2160 
2161 	sge_count = opts->max_io_size / opts->io_unit_size;
2162 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
2163 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
2164 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2165 		return NULL;
2166 	}
2167 
2168 	rtransport->event_channel = rdma_create_event_channel();
2169 	if (rtransport->event_channel == NULL) {
2170 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
2171 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2172 		return NULL;
2173 	}
2174 
2175 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
2176 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
2177 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
2178 			    rtransport->event_channel->fd, spdk_strerror(errno));
2179 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2180 		return NULL;
2181 	}
2182 
2183 	rtransport->data_wr_pool = spdk_mempool_create("spdk_nvmf_rdma_wr_data",
2184 				   opts->max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES,
2185 				   sizeof(struct spdk_nvmf_rdma_request_data),
2186 				   SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
2187 				   SPDK_ENV_SOCKET_ID_ANY);
2188 	if (!rtransport->data_wr_pool) {
2189 		SPDK_ERRLOG("Unable to allocate work request pool for poll group\n");
2190 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2191 		return NULL;
2192 	}
2193 
2194 	contexts = rdma_get_devices(NULL);
2195 	if (contexts == NULL) {
2196 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
2197 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2198 		return NULL;
2199 	}
2200 
2201 	i = 0;
2202 	rc = 0;
2203 	while (contexts[i] != NULL) {
2204 		device = calloc(1, sizeof(*device));
2205 		if (!device) {
2206 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
2207 			rc = -ENOMEM;
2208 			break;
2209 		}
2210 		device->context = contexts[i];
2211 		rc = ibv_query_device(device->context, &device->attr);
2212 		if (rc < 0) {
2213 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
2214 			free(device);
2215 			break;
2216 
2217 		}
2218 
2219 		max_device_sge = spdk_min(max_device_sge, device->attr.max_sge);
2220 
2221 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
2222 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
2223 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
2224 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
2225 		}
2226 
2227 		/**
2228 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
2229 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
2230 		 * but incorrectly reports that it does. There are changes making their way
2231 		 * through the kernel now that will enable this feature. When they are merged,
2232 		 * we can conditionally enable this feature.
2233 		 *
2234 		 * TODO: enable this for versions of the kernel rxe driver that support it.
2235 		 */
2236 		if (device->attr.vendor_id == 0) {
2237 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
2238 		}
2239 #endif
2240 
2241 		/* set up device context async ev fd as NON_BLOCKING */
2242 		flag = fcntl(device->context->async_fd, F_GETFL);
2243 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
2244 		if (rc < 0) {
2245 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
2246 			free(device);
2247 			break;
2248 		}
2249 
2250 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
2251 		i++;
2252 
2253 		pd = NULL;
2254 		if (g_nvmf_hooks.get_ibv_pd) {
2255 			pd = g_nvmf_hooks.get_ibv_pd(NULL, device->context);
2256 		}
2257 
2258 		if (!g_nvmf_hooks.get_ibv_pd) {
2259 			device->pd = ibv_alloc_pd(device->context);
2260 			if (!device->pd) {
2261 				SPDK_ERRLOG("Unable to allocate protection domain.\n");
2262 				spdk_nvmf_rdma_destroy(&rtransport->transport);
2263 				return NULL;
2264 			}
2265 		} else {
2266 			device->pd = pd;
2267 		}
2268 
2269 		assert(device->map == NULL);
2270 
2271 		device->map = spdk_mem_map_alloc(0, &g_nvmf_rdma_map_ops, device->pd);
2272 		if (!device->map) {
2273 			SPDK_ERRLOG("Unable to allocate memory map for listen address\n");
2274 			spdk_nvmf_rdma_destroy(&rtransport->transport);
2275 			return NULL;
2276 		}
2277 
2278 		assert(device->map != NULL);
2279 		assert(device->pd != NULL);
2280 	}
2281 	rdma_free_devices(contexts);
2282 
2283 	if (opts->io_unit_size * max_device_sge < opts->max_io_size) {
2284 		/* divide and round up. */
2285 		opts->io_unit_size = (opts->max_io_size + max_device_sge - 1) / max_device_sge;
2286 
2287 		/* round up to the nearest 4k. */
2288 		opts->io_unit_size = (opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT - 1) & ~NVMF_DATA_BUFFER_MASK;
2289 
2290 		opts->io_unit_size = spdk_max(opts->io_unit_size, SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
2291 		SPDK_NOTICELOG("Adjusting the io unit size to fit the device's maximum I/O size. New I/O unit size %u\n",
2292 			       opts->io_unit_size);
2293 	}
2294 
2295 	if (rc < 0) {
2296 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2297 		return NULL;
2298 	}
2299 
2300 	/* Set up poll descriptor array to monitor events from RDMA and IB
2301 	 * in a single poll syscall
2302 	 */
2303 	rtransport->npoll_fds = i + 1;
2304 	i = 0;
2305 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
2306 	if (rtransport->poll_fds == NULL) {
2307 		SPDK_ERRLOG("poll_fds allocation failed\n");
2308 		spdk_nvmf_rdma_destroy(&rtransport->transport);
2309 		return NULL;
2310 	}
2311 
2312 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
2313 	rtransport->poll_fds[i++].events = POLLIN;
2314 
2315 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2316 		rtransport->poll_fds[i].fd = device->context->async_fd;
2317 		rtransport->poll_fds[i++].events = POLLIN;
2318 	}
2319 
2320 	return &rtransport->transport;
2321 }
2322 
2323 static int
2324 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
2325 {
2326 	struct spdk_nvmf_rdma_transport	*rtransport;
2327 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
2328 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
2329 
2330 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2331 
2332 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
2333 		TAILQ_REMOVE(&rtransport->ports, port, link);
2334 		rdma_destroy_id(port->id);
2335 		free(port);
2336 	}
2337 
2338 	if (rtransport->poll_fds != NULL) {
2339 		free(rtransport->poll_fds);
2340 	}
2341 
2342 	if (rtransport->event_channel != NULL) {
2343 		rdma_destroy_event_channel(rtransport->event_channel);
2344 	}
2345 
2346 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
2347 		TAILQ_REMOVE(&rtransport->devices, device, link);
2348 		if (device->map) {
2349 			spdk_mem_map_free(&device->map);
2350 		}
2351 		if (device->pd) {
2352 			if (!g_nvmf_hooks.get_ibv_pd) {
2353 				ibv_dealloc_pd(device->pd);
2354 			}
2355 		}
2356 		free(device);
2357 	}
2358 
2359 	if (rtransport->data_wr_pool != NULL) {
2360 		if (spdk_mempool_count(rtransport->data_wr_pool) !=
2361 		    (transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES)) {
2362 			SPDK_ERRLOG("transport wr pool count is %zu but should be %u\n",
2363 				    spdk_mempool_count(rtransport->data_wr_pool),
2364 				    transport->opts.max_queue_depth * SPDK_NVMF_MAX_SGL_ENTRIES);
2365 		}
2366 	}
2367 
2368 	spdk_mempool_free(rtransport->data_wr_pool);
2369 	pthread_mutex_destroy(&rtransport->lock);
2370 	free(rtransport);
2371 
2372 	return 0;
2373 }
2374 
2375 static int
2376 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2377 			       struct spdk_nvme_transport_id *trid,
2378 			       bool peer);
2379 
2380 static int
2381 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
2382 		      const struct spdk_nvme_transport_id *trid)
2383 {
2384 	struct spdk_nvmf_rdma_transport	*rtransport;
2385 	struct spdk_nvmf_rdma_device	*device;
2386 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
2387 	struct addrinfo			*res;
2388 	struct addrinfo			hints;
2389 	int				family;
2390 	int				rc;
2391 
2392 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2393 
2394 	port = calloc(1, sizeof(*port));
2395 	if (!port) {
2396 		return -ENOMEM;
2397 	}
2398 
2399 	/* Selectively copy the trid. Things like NQN don't matter here - that
2400 	 * mapping is enforced elsewhere.
2401 	 */
2402 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2403 	port->trid.adrfam = trid->adrfam;
2404 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
2405 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
2406 
2407 	pthread_mutex_lock(&rtransport->lock);
2408 	assert(rtransport->event_channel != NULL);
2409 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
2410 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
2411 			port_tmp->ref++;
2412 			free(port);
2413 			/* Already listening at this address */
2414 			pthread_mutex_unlock(&rtransport->lock);
2415 			return 0;
2416 		}
2417 	}
2418 
2419 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
2420 	if (rc < 0) {
2421 		SPDK_ERRLOG("rdma_create_id() failed\n");
2422 		free(port);
2423 		pthread_mutex_unlock(&rtransport->lock);
2424 		return rc;
2425 	}
2426 
2427 	switch (port->trid.adrfam) {
2428 	case SPDK_NVMF_ADRFAM_IPV4:
2429 		family = AF_INET;
2430 		break;
2431 	case SPDK_NVMF_ADRFAM_IPV6:
2432 		family = AF_INET6;
2433 		break;
2434 	default:
2435 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
2436 		free(port);
2437 		pthread_mutex_unlock(&rtransport->lock);
2438 		return -EINVAL;
2439 	}
2440 
2441 	memset(&hints, 0, sizeof(hints));
2442 	hints.ai_family = family;
2443 	hints.ai_flags = AI_NUMERICSERV;
2444 	hints.ai_socktype = SOCK_STREAM;
2445 	hints.ai_protocol = 0;
2446 
2447 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
2448 	if (rc) {
2449 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
2450 		free(port);
2451 		pthread_mutex_unlock(&rtransport->lock);
2452 		return -EINVAL;
2453 	}
2454 
2455 	rc = rdma_bind_addr(port->id, res->ai_addr);
2456 	freeaddrinfo(res);
2457 
2458 	if (rc < 0) {
2459 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
2460 		rdma_destroy_id(port->id);
2461 		free(port);
2462 		pthread_mutex_unlock(&rtransport->lock);
2463 		return rc;
2464 	}
2465 
2466 	if (!port->id->verbs) {
2467 		SPDK_ERRLOG("ibv_context is null\n");
2468 		rdma_destroy_id(port->id);
2469 		free(port);
2470 		pthread_mutex_unlock(&rtransport->lock);
2471 		return -1;
2472 	}
2473 
2474 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
2475 	if (rc < 0) {
2476 		SPDK_ERRLOG("rdma_listen() failed\n");
2477 		rdma_destroy_id(port->id);
2478 		free(port);
2479 		pthread_mutex_unlock(&rtransport->lock);
2480 		return rc;
2481 	}
2482 
2483 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2484 		if (device->context == port->id->verbs) {
2485 			port->device = device;
2486 			break;
2487 		}
2488 	}
2489 	if (!port->device) {
2490 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
2491 			    port->id->verbs);
2492 		rdma_destroy_id(port->id);
2493 		free(port);
2494 		pthread_mutex_unlock(&rtransport->lock);
2495 		return -EINVAL;
2496 	}
2497 
2498 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
2499 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
2500 
2501 	port->ref = 1;
2502 
2503 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
2504 	pthread_mutex_unlock(&rtransport->lock);
2505 
2506 	return 0;
2507 }
2508 
2509 static int
2510 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
2511 			   const struct spdk_nvme_transport_id *_trid)
2512 {
2513 	struct spdk_nvmf_rdma_transport *rtransport;
2514 	struct spdk_nvmf_rdma_port *port, *tmp;
2515 	struct spdk_nvme_transport_id trid = {};
2516 
2517 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2518 
2519 	/* Selectively copy the trid. Things like NQN don't matter here - that
2520 	 * mapping is enforced elsewhere.
2521 	 */
2522 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
2523 	trid.adrfam = _trid->adrfam;
2524 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
2525 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
2526 
2527 	pthread_mutex_lock(&rtransport->lock);
2528 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
2529 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
2530 			assert(port->ref > 0);
2531 			port->ref--;
2532 			if (port->ref == 0) {
2533 				TAILQ_REMOVE(&rtransport->ports, port, link);
2534 				rdma_destroy_id(port->id);
2535 				free(port);
2536 			}
2537 			break;
2538 		}
2539 	}
2540 
2541 	pthread_mutex_unlock(&rtransport->lock);
2542 	return 0;
2543 }
2544 
2545 static void
2546 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
2547 				     struct spdk_nvmf_rdma_qpair *rqpair, bool drain)
2548 {
2549 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
2550 	struct spdk_nvmf_rdma_resources *resources;
2551 
2552 	/* We process I/O in the data transfer pending queue at the highest priority. RDMA reads first */
2553 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_read_queue, state_link, req_tmp) {
2554 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2555 			break;
2556 		}
2557 	}
2558 
2559 	/* Then RDMA writes since reads have stronger restrictions than writes */
2560 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_write_queue, state_link, req_tmp) {
2561 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2562 			break;
2563 		}
2564 	}
2565 
2566 	/* The second highest priority is I/O waiting on memory buffers. */
2567 	STAILQ_FOREACH_SAFE(rdma_req, &rqpair->poller->group->pending_data_buf_queue, state_link,
2568 			    req_tmp) {
2569 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false && drain == false) {
2570 			break;
2571 		}
2572 	}
2573 
2574 	resources = rqpair->resources;
2575 	while (!STAILQ_EMPTY(&resources->free_queue) && !STAILQ_EMPTY(&resources->incoming_queue)) {
2576 		rdma_req = STAILQ_FIRST(&resources->free_queue);
2577 		STAILQ_REMOVE_HEAD(&resources->free_queue, state_link);
2578 		rdma_req->recv = STAILQ_FIRST(&resources->incoming_queue);
2579 		STAILQ_REMOVE_HEAD(&resources->incoming_queue, link);
2580 
2581 		if (rqpair->srq != NULL) {
2582 			rdma_req->req.qpair = &rdma_req->recv->qpair->qpair;
2583 			rdma_req->recv->qpair->qd++;
2584 		} else {
2585 			rqpair->qd++;
2586 		}
2587 
2588 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
2589 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
2590 			break;
2591 		}
2592 	}
2593 }
2594 
2595 static void
2596 _nvmf_rdma_qpair_disconnect(void *ctx)
2597 {
2598 	struct spdk_nvmf_qpair *qpair = ctx;
2599 
2600 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2601 }
2602 
2603 static void
2604 _nvmf_rdma_try_disconnect(void *ctx)
2605 {
2606 	struct spdk_nvmf_qpair *qpair = ctx;
2607 	struct spdk_nvmf_poll_group *group;
2608 
2609 	/* Read the group out of the qpair. This is normally set and accessed only from
2610 	 * the thread that created the group. Here, we're not on that thread necessarily.
2611 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2612 	 * a pointer and never changes. So fortunately reading this and checking for
2613 	 * non-NULL is thread safe in the x86_64 memory model. */
2614 	group = qpair->group;
2615 
2616 	if (group == NULL) {
2617 		/* The qpair hasn't been assigned to a group yet, so we can't
2618 		 * process a disconnect. Send a message to ourself and try again. */
2619 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_try_disconnect, qpair);
2620 		return;
2621 	}
2622 
2623 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2624 }
2625 
2626 static inline void
2627 spdk_nvmf_rdma_start_disconnect(struct spdk_nvmf_rdma_qpair *rqpair)
2628 {
2629 	if (__sync_bool_compare_and_swap(&rqpair->disconnect_started, false, true)) {
2630 		_nvmf_rdma_try_disconnect(&rqpair->qpair);
2631 	}
2632 }
2633 
2634 static void nvmf_rdma_destroy_drained_qpair(void *ctx)
2635 {
2636 	struct spdk_nvmf_rdma_qpair *rqpair = ctx;
2637 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
2638 			struct spdk_nvmf_rdma_transport, transport);
2639 
2640 	/* In non SRQ path, we will reach rqpair->max_queue_depth. In SRQ path, we will get the last_wqe event. */
2641 	if (rqpair->current_send_depth != 0) {
2642 		return;
2643 	}
2644 
2645 	if (rqpair->srq == NULL && rqpair->current_recv_depth != rqpair->max_queue_depth) {
2646 		return;
2647 	}
2648 
2649 	if (rqpair->srq != NULL && rqpair->last_wqe_reached == false) {
2650 		return;
2651 	}
2652 
2653 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
2654 	spdk_nvmf_rdma_qpair_destroy(rqpair);
2655 }
2656 
2657 
2658 static int
2659 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2660 {
2661 	struct spdk_nvmf_qpair		*qpair;
2662 	struct spdk_nvmf_rdma_qpair	*rqpair;
2663 
2664 	if (evt->id == NULL) {
2665 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2666 		return -1;
2667 	}
2668 
2669 	qpair = evt->id->context;
2670 	if (qpair == NULL) {
2671 		SPDK_ERRLOG("disconnect request: no active connection\n");
2672 		return -1;
2673 	}
2674 
2675 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2676 
2677 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2678 
2679 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2680 
2681 	spdk_nvmf_rdma_start_disconnect(rqpair);
2682 
2683 	return 0;
2684 }
2685 
2686 #ifdef DEBUG
2687 static const char *CM_EVENT_STR[] = {
2688 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2689 	"RDMA_CM_EVENT_ADDR_ERROR",
2690 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2691 	"RDMA_CM_EVENT_ROUTE_ERROR",
2692 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2693 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2694 	"RDMA_CM_EVENT_CONNECT_ERROR",
2695 	"RDMA_CM_EVENT_UNREACHABLE",
2696 	"RDMA_CM_EVENT_REJECTED",
2697 	"RDMA_CM_EVENT_ESTABLISHED",
2698 	"RDMA_CM_EVENT_DISCONNECTED",
2699 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2700 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2701 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2702 	"RDMA_CM_EVENT_ADDR_CHANGE",
2703 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2704 };
2705 #endif /* DEBUG */
2706 
2707 static void
2708 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2709 {
2710 	struct spdk_nvmf_rdma_transport *rtransport;
2711 	struct rdma_cm_event		*event;
2712 	int				rc;
2713 
2714 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2715 
2716 	if (rtransport->event_channel == NULL) {
2717 		return;
2718 	}
2719 
2720 	while (1) {
2721 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2722 		if (rc == 0) {
2723 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2724 
2725 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2726 
2727 			switch (event->event) {
2728 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2729 			case RDMA_CM_EVENT_ADDR_ERROR:
2730 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2731 			case RDMA_CM_EVENT_ROUTE_ERROR:
2732 				/* No action required. The target never attempts to resolve routes. */
2733 				break;
2734 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2735 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2736 				if (rc < 0) {
2737 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2738 					break;
2739 				}
2740 				break;
2741 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2742 				/* The target never initiates a new connection. So this will not occur. */
2743 				break;
2744 			case RDMA_CM_EVENT_CONNECT_ERROR:
2745 				/* Can this happen? The docs say it can, but not sure what causes it. */
2746 				break;
2747 			case RDMA_CM_EVENT_UNREACHABLE:
2748 			case RDMA_CM_EVENT_REJECTED:
2749 				/* These only occur on the client side. */
2750 				break;
2751 			case RDMA_CM_EVENT_ESTABLISHED:
2752 				/* TODO: Should we be waiting for this event anywhere? */
2753 				break;
2754 			case RDMA_CM_EVENT_DISCONNECTED:
2755 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2756 				rc = nvmf_rdma_disconnect(event);
2757 				if (rc < 0) {
2758 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2759 					break;
2760 				}
2761 				break;
2762 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2763 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2764 				/* Multicast is not used */
2765 				break;
2766 			case RDMA_CM_EVENT_ADDR_CHANGE:
2767 				/* Not utilizing this event */
2768 				break;
2769 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2770 				/* For now, do nothing. The target never re-uses queue pairs. */
2771 				break;
2772 			default:
2773 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2774 				break;
2775 			}
2776 
2777 			rdma_ack_cm_event(event);
2778 		} else {
2779 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2780 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2781 			}
2782 			break;
2783 		}
2784 	}
2785 }
2786 
2787 static void
2788 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2789 {
2790 	int				rc;
2791 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
2792 	struct ibv_async_event		event;
2793 	enum ibv_qp_state		state;
2794 
2795 	rc = ibv_get_async_event(device->context, &event);
2796 
2797 	if (rc) {
2798 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2799 			    errno, spdk_strerror(errno));
2800 		return;
2801 	}
2802 
2803 	switch (event.event_type) {
2804 	case IBV_EVENT_QP_FATAL:
2805 		rqpair = event.element.qp->qp_context;
2806 		SPDK_ERRLOG("Fatal event received for rqpair %p\n", rqpair);
2807 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2808 				  (uintptr_t)rqpair->cm_id, event.event_type);
2809 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2810 		spdk_nvmf_rdma_start_disconnect(rqpair);
2811 		break;
2812 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2813 		/* This event only occurs for shared receive queues. */
2814 		rqpair = event.element.qp->qp_context;
2815 		rqpair->last_wqe_reached = true;
2816 
2817 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last WQE reached event received for rqpair %p\n", rqpair);
2818 		/* This must be handled on the polling thread if it exists. Otherwise the timeout will catch it. */
2819 		if (rqpair->qpair.group) {
2820 			spdk_thread_send_msg(rqpair->qpair.group->thread, nvmf_rdma_destroy_drained_qpair, rqpair);
2821 		} else {
2822 			SPDK_ERRLOG("Unable to destroy the qpair %p since it does not have a poll group.\n", rqpair);
2823 		}
2824 
2825 		break;
2826 	case IBV_EVENT_SQ_DRAINED:
2827 		/* This event occurs frequently in both error and non-error states.
2828 		 * Check if the qpair is in an error state before sending a message.
2829 		 * Note that we're not on the correct thread to access the qpair, but
2830 		 * the operations that the below calls make all happen to be thread
2831 		 * safe. */
2832 		rqpair = event.element.qp->qp_context;
2833 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Last sq drained event received for rqpair %p\n", rqpair);
2834 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2835 				  (uintptr_t)rqpair->cm_id, event.event_type);
2836 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2837 		if (state == IBV_QPS_ERR) {
2838 			spdk_nvmf_rdma_start_disconnect(rqpair);
2839 		}
2840 		break;
2841 	case IBV_EVENT_QP_REQ_ERR:
2842 	case IBV_EVENT_QP_ACCESS_ERR:
2843 	case IBV_EVENT_COMM_EST:
2844 	case IBV_EVENT_PATH_MIG:
2845 	case IBV_EVENT_PATH_MIG_ERR:
2846 		SPDK_NOTICELOG("Async event: %s\n",
2847 			       ibv_event_type_str(event.event_type));
2848 		rqpair = event.element.qp->qp_context;
2849 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2850 				  (uintptr_t)rqpair->cm_id, event.event_type);
2851 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2852 		break;
2853 	case IBV_EVENT_CQ_ERR:
2854 	case IBV_EVENT_DEVICE_FATAL:
2855 	case IBV_EVENT_PORT_ACTIVE:
2856 	case IBV_EVENT_PORT_ERR:
2857 	case IBV_EVENT_LID_CHANGE:
2858 	case IBV_EVENT_PKEY_CHANGE:
2859 	case IBV_EVENT_SM_CHANGE:
2860 	case IBV_EVENT_SRQ_ERR:
2861 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2862 	case IBV_EVENT_CLIENT_REREGISTER:
2863 	case IBV_EVENT_GID_CHANGE:
2864 	default:
2865 		SPDK_NOTICELOG("Async event: %s\n",
2866 			       ibv_event_type_str(event.event_type));
2867 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2868 		break;
2869 	}
2870 	ibv_ack_async_event(&event);
2871 }
2872 
2873 static void
2874 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2875 {
2876 	int	nfds, i = 0;
2877 	struct spdk_nvmf_rdma_transport *rtransport;
2878 	struct spdk_nvmf_rdma_device *device, *tmp;
2879 
2880 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2881 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2882 
2883 	if (nfds <= 0) {
2884 		return;
2885 	}
2886 
2887 	/* The first poll descriptor is RDMA CM event */
2888 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2889 		spdk_nvmf_process_cm_event(transport, cb_fn);
2890 		nfds--;
2891 	}
2892 
2893 	if (nfds == 0) {
2894 		return;
2895 	}
2896 
2897 	/* Second and subsequent poll descriptors are IB async events */
2898 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2899 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2900 			spdk_nvmf_process_ib_event(device);
2901 			nfds--;
2902 		}
2903 	}
2904 	/* check all flagged fd's have been served */
2905 	assert(nfds == 0);
2906 }
2907 
2908 static void
2909 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2910 			struct spdk_nvme_transport_id *trid,
2911 			struct spdk_nvmf_discovery_log_page_entry *entry)
2912 {
2913 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2914 	entry->adrfam = trid->adrfam;
2915 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2916 
2917 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2918 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2919 
2920 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2921 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2922 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2923 }
2924 
2925 static void
2926 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group);
2927 
2928 static struct spdk_nvmf_transport_poll_group *
2929 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2930 {
2931 	struct spdk_nvmf_rdma_transport		*rtransport;
2932 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2933 	struct spdk_nvmf_rdma_poller		*poller;
2934 	struct spdk_nvmf_rdma_device		*device;
2935 	struct ibv_srq_init_attr		srq_init_attr;
2936 	struct spdk_nvmf_rdma_resource_opts	opts;
2937 	int					num_cqe;
2938 
2939 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2940 
2941 	rgroup = calloc(1, sizeof(*rgroup));
2942 	if (!rgroup) {
2943 		return NULL;
2944 	}
2945 
2946 	TAILQ_INIT(&rgroup->pollers);
2947 	STAILQ_INIT(&rgroup->pending_data_buf_queue);
2948 
2949 	pthread_mutex_lock(&rtransport->lock);
2950 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2951 		poller = calloc(1, sizeof(*poller));
2952 		if (!poller) {
2953 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2954 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
2955 			pthread_mutex_unlock(&rtransport->lock);
2956 			return NULL;
2957 		}
2958 
2959 		poller->device = device;
2960 		poller->group = rgroup;
2961 
2962 		TAILQ_INIT(&poller->qpairs);
2963 		STAILQ_INIT(&poller->qpairs_pending_send);
2964 
2965 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2966 		if (transport->opts.no_srq == false && device->attr.max_srq != 0) {
2967 			poller->max_srq_depth = transport->opts.max_srq_depth;
2968 
2969 			memset(&srq_init_attr, 0, sizeof(struct ibv_srq_init_attr));
2970 			srq_init_attr.attr.max_wr = poller->max_srq_depth;
2971 			srq_init_attr.attr.max_sge = spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
2972 			poller->srq = ibv_create_srq(device->pd, &srq_init_attr);
2973 			if (!poller->srq) {
2974 				SPDK_ERRLOG("Unable to create shared receive queue, errno %d\n", errno);
2975 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
2976 				pthread_mutex_unlock(&rtransport->lock);
2977 				return NULL;
2978 			}
2979 
2980 			opts.qp = poller->srq;
2981 			opts.pd = device->pd;
2982 			opts.qpair = NULL;
2983 			opts.shared = true;
2984 			opts.max_queue_depth = poller->max_srq_depth;
2985 			opts.in_capsule_data_size = transport->opts.in_capsule_data_size;
2986 
2987 			poller->resources = nvmf_rdma_resources_create(&opts);
2988 			if (!poller->resources) {
2989 				SPDK_ERRLOG("Unable to allocate resources for shared receive queue.\n");
2990 				spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
2991 				pthread_mutex_unlock(&rtransport->lock);
2992 			}
2993 		}
2994 
2995 		/*
2996 		 * When using an srq, we can limit the completion queue at startup.
2997 		 * The following formula represents the calculation:
2998 		 * num_cqe = num_recv + num_data_wr + num_send_wr.
2999 		 * where num_recv=num_data_wr=and num_send_wr=poller->max_srq_depth
3000 		 */
3001 		if (poller->srq) {
3002 			num_cqe = poller->max_srq_depth * 3;
3003 		} else {
3004 			num_cqe = DEFAULT_NVMF_RDMA_CQ_SIZE;
3005 		}
3006 
3007 		poller->cq = ibv_create_cq(device->context, num_cqe, poller, NULL, 0);
3008 		if (!poller->cq) {
3009 			SPDK_ERRLOG("Unable to create completion queue\n");
3010 			spdk_nvmf_rdma_poll_group_destroy(&rgroup->group);
3011 			pthread_mutex_unlock(&rtransport->lock);
3012 			return NULL;
3013 		}
3014 		poller->num_cqe = num_cqe;
3015 	}
3016 
3017 	pthread_mutex_unlock(&rtransport->lock);
3018 	return &rgroup->group;
3019 }
3020 
3021 static void
3022 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
3023 {
3024 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3025 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
3026 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
3027 
3028 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3029 
3030 	if (!rgroup) {
3031 		return;
3032 	}
3033 
3034 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
3035 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
3036 
3037 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
3038 			spdk_nvmf_rdma_qpair_destroy(qpair);
3039 		}
3040 
3041 		if (poller->srq) {
3042 			nvmf_rdma_resources_destroy(poller->resources);
3043 			ibv_destroy_srq(poller->srq);
3044 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Destroyed RDMA shared queue %p\n", poller->srq);
3045 		}
3046 
3047 		if (poller->cq) {
3048 			ibv_destroy_cq(poller->cq);
3049 		}
3050 
3051 		free(poller);
3052 	}
3053 
3054 	if (!STAILQ_EMPTY(&rgroup->pending_data_buf_queue)) {
3055 		SPDK_ERRLOG("Pending I/O list wasn't empty on poll group destruction\n");
3056 	}
3057 
3058 	free(rgroup);
3059 }
3060 
3061 static void
3062 spdk_nvmf_rdma_qpair_reject_connection(struct spdk_nvmf_rdma_qpair *rqpair)
3063 {
3064 	if (rqpair->cm_id != NULL) {
3065 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
3066 	}
3067 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3068 }
3069 
3070 static int
3071 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
3072 			      struct spdk_nvmf_qpair *qpair)
3073 {
3074 	struct spdk_nvmf_rdma_poll_group	*rgroup;
3075 	struct spdk_nvmf_rdma_qpair		*rqpair;
3076 	struct spdk_nvmf_rdma_device		*device;
3077 	struct spdk_nvmf_rdma_poller		*poller;
3078 	int					rc;
3079 
3080 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3081 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3082 
3083 	device = rqpair->port->device;
3084 
3085 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
3086 		if (poller->device == device) {
3087 			break;
3088 		}
3089 	}
3090 
3091 	if (!poller) {
3092 		SPDK_ERRLOG("No poller found for device.\n");
3093 		return -1;
3094 	}
3095 
3096 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
3097 	rqpair->poller = poller;
3098 	rqpair->srq = rqpair->poller->srq;
3099 
3100 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
3101 	if (rc < 0) {
3102 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
3103 		return -1;
3104 	}
3105 
3106 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
3107 	if (rc) {
3108 		/* Try to reject, but we probably can't */
3109 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3110 		return -1;
3111 	}
3112 
3113 	spdk_nvmf_rdma_update_ibv_state(rqpair);
3114 
3115 	return 0;
3116 }
3117 
3118 static int
3119 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
3120 {
3121 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
3122 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3123 			struct spdk_nvmf_rdma_transport, transport);
3124 
3125 	nvmf_rdma_request_free(rdma_req, rtransport);
3126 	return 0;
3127 }
3128 
3129 static int
3130 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
3131 {
3132 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
3133 			struct spdk_nvmf_rdma_transport, transport);
3134 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
3135 			struct spdk_nvmf_rdma_request, req);
3136 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
3137 			struct spdk_nvmf_rdma_qpair, qpair);
3138 
3139 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3140 		/* The connection is alive, so process the request as normal */
3141 		rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
3142 	} else {
3143 		/* The connection is dead. Move the request directly to the completed state. */
3144 		rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3145 	}
3146 
3147 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3148 
3149 	return 0;
3150 }
3151 
3152 static int
3153 spdk_nvmf_rdma_destroy_defunct_qpair(void *ctx)
3154 {
3155 	struct spdk_nvmf_rdma_qpair	*rqpair = ctx;
3156 	struct spdk_nvmf_rdma_transport *rtransport = SPDK_CONTAINEROF(rqpair->qpair.transport,
3157 			struct spdk_nvmf_rdma_transport, transport);
3158 
3159 	spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, true);
3160 	spdk_nvmf_rdma_qpair_destroy(rqpair);
3161 
3162 	return 0;
3163 }
3164 
3165 static void
3166 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
3167 {
3168 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3169 
3170 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
3171 		return;
3172 	}
3173 
3174 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
3175 
3176 	/* This happens only when the qpair is disconnected before
3177 	 * it is added to the poll group. Since there is no poll group,
3178 	 * the RDMA qp has not been initialized yet and the RDMA CM
3179 	 * event has not yet been acknowledged, so we need to reject it.
3180 	 */
3181 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_UNINITIALIZED) {
3182 		spdk_nvmf_rdma_qpair_reject_connection(rqpair);
3183 		return;
3184 	}
3185 
3186 	if (rqpair->ibv_state != IBV_QPS_ERR) {
3187 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
3188 	}
3189 
3190 	rqpair->destruct_poller = spdk_poller_register(spdk_nvmf_rdma_destroy_defunct_qpair, (void *)rqpair,
3191 				  NVMF_RDMA_QPAIR_DESTROY_TIMEOUT_US);
3192 }
3193 
3194 static struct spdk_nvmf_rdma_qpair *
3195 get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)
3196 {
3197 	struct spdk_nvmf_rdma_qpair *rqpair;
3198 	/* @todo: improve QP search */
3199 	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {
3200 		if (wc->qp_num == rqpair->cm_id->qp->qp_num) {
3201 			return rqpair;
3202 		}
3203 	}
3204 	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);
3205 	return NULL;
3206 }
3207 
3208 #ifdef DEBUG
3209 static int
3210 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
3211 {
3212 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
3213 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
3214 }
3215 #endif
3216 
3217 static void
3218 _qp_reset_failed_sends(struct spdk_nvmf_rdma_transport *rtransport,
3219 		       struct spdk_nvmf_rdma_qpair *rqpair, struct ibv_send_wr *bad_wr, int rc)
3220 {
3221 	struct spdk_nvmf_rdma_wr	*bad_rdma_wr;
3222 	struct spdk_nvmf_rdma_request	*prev_rdma_req = NULL, *cur_rdma_req = NULL;
3223 
3224 	SPDK_ERRLOG("Failed to post a send for the qpair %p with errno %d\n", rqpair, -rc);
3225 	for (; bad_wr != NULL; bad_wr = bad_wr->next) {
3226 		bad_rdma_wr = (struct spdk_nvmf_rdma_wr *)bad_wr->wr_id;
3227 		assert(rqpair->current_send_depth > 0);
3228 		rqpair->current_send_depth--;
3229 		switch (bad_rdma_wr->type) {
3230 		case RDMA_WR_TYPE_DATA:
3231 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3232 			if (bad_wr->opcode == IBV_WR_RDMA_READ) {
3233 				assert(rqpair->current_read_depth > 0);
3234 				rqpair->current_read_depth--;
3235 			}
3236 			break;
3237 		case RDMA_WR_TYPE_SEND:
3238 			cur_rdma_req = SPDK_CONTAINEROF(bad_rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3239 			break;
3240 		default:
3241 			SPDK_ERRLOG("Found a RECV in the list of pending SEND requests for qpair %p\n", rqpair);
3242 			prev_rdma_req = cur_rdma_req;
3243 			continue;
3244 		}
3245 
3246 		if (prev_rdma_req == cur_rdma_req) {
3247 			/* this request was handled by an earlier wr. i.e. we were performing an nvme read. */
3248 			/* We only have to check against prev_wr since each requests wrs are contiguous in this list. */
3249 			continue;
3250 		}
3251 
3252 		switch (cur_rdma_req->state) {
3253 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
3254 			cur_rdma_req->req.rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
3255 			cur_rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
3256 			break;
3257 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
3258 		case RDMA_REQUEST_STATE_COMPLETING:
3259 			cur_rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3260 			break;
3261 		default:
3262 			SPDK_ERRLOG("Found a request in a bad state %d when draining pending SEND requests for qpair %p\n",
3263 				    cur_rdma_req->state, rqpair);
3264 			continue;
3265 		}
3266 
3267 		spdk_nvmf_rdma_request_process(rtransport, cur_rdma_req);
3268 		prev_rdma_req = cur_rdma_req;
3269 	}
3270 
3271 	if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3272 		/* Disconnect the connection. */
3273 		spdk_nvmf_rdma_start_disconnect(rqpair);
3274 	}
3275 
3276 }
3277 
3278 static void
3279 _poller_submit_sends(struct spdk_nvmf_rdma_transport *rtransport,
3280 		     struct spdk_nvmf_rdma_poller *rpoller)
3281 {
3282 	struct spdk_nvmf_rdma_qpair	*rqpair;
3283 	struct ibv_send_wr		*bad_wr = NULL;
3284 	int				rc;
3285 
3286 	while (!STAILQ_EMPTY(&rpoller->qpairs_pending_send)) {
3287 		rqpair = STAILQ_FIRST(&rpoller->qpairs_pending_send);
3288 		assert(rqpair->sends_to_post.first != NULL);
3289 		rc = ibv_post_send(rqpair->cm_id->qp, rqpair->sends_to_post.first, &bad_wr);
3290 
3291 		/* bad wr always points to the first wr that failed. */
3292 		if (rc) {
3293 			_qp_reset_failed_sends(rtransport, rqpair, bad_wr, rc);
3294 		}
3295 		rqpair->sends_to_post.first = NULL;
3296 		rqpair->sends_to_post.last = NULL;
3297 		STAILQ_REMOVE_HEAD(&rpoller->qpairs_pending_send, send_link);
3298 	}
3299 }
3300 
3301 static int
3302 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
3303 			   struct spdk_nvmf_rdma_poller *rpoller)
3304 {
3305 	struct ibv_wc wc[32];
3306 	struct spdk_nvmf_rdma_wr	*rdma_wr;
3307 	struct spdk_nvmf_rdma_request	*rdma_req;
3308 	struct spdk_nvmf_rdma_recv	*rdma_recv;
3309 	struct spdk_nvmf_rdma_qpair	*rqpair;
3310 	int reaped, i;
3311 	int count = 0;
3312 	bool error = false;
3313 
3314 	/* Poll for completing operations. */
3315 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
3316 	if (reaped < 0) {
3317 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
3318 			    errno, spdk_strerror(errno));
3319 		return -1;
3320 	}
3321 
3322 	for (i = 0; i < reaped; i++) {
3323 
3324 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
3325 
3326 		switch (rdma_wr->type) {
3327 		case RDMA_WR_TYPE_SEND:
3328 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
3329 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3330 
3331 			if (!wc[i].status) {
3332 				count++;
3333 				assert(wc[i].opcode == IBV_WC_SEND);
3334 				assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
3335 			} else {
3336 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3337 			}
3338 
3339 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3340 			rqpair->current_send_depth--;
3341 
3342 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3343 			assert(rdma_req->num_outstanding_data_wr == 0);
3344 			break;
3345 		case RDMA_WR_TYPE_RECV:
3346 			/* rdma_recv->qpair will be invalid if using an SRQ.  In that case we have to get the qpair from the wc. */
3347 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
3348 			if (rpoller->srq != NULL) {
3349 				rdma_recv->qpair = get_rdma_qpair_from_wc(rpoller, &wc[i]);
3350 			}
3351 			rqpair = rdma_recv->qpair;
3352 
3353 			assert(rqpair != NULL);
3354 			if (!wc[i].status) {
3355 				assert(wc[i].opcode == IBV_WC_RECV);
3356 				if (rqpair->current_recv_depth >= rqpair->max_queue_depth) {
3357 					spdk_nvmf_rdma_start_disconnect(rqpair);
3358 					break;
3359 				}
3360 			}
3361 
3362 			rqpair->current_recv_depth++;
3363 			STAILQ_INSERT_TAIL(&rqpair->resources->incoming_queue, rdma_recv, link);
3364 			break;
3365 		case RDMA_WR_TYPE_DATA:
3366 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
3367 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
3368 
3369 			assert(rdma_req->num_outstanding_data_wr > 0);
3370 
3371 			rqpair->current_send_depth--;
3372 			rdma_req->num_outstanding_data_wr--;
3373 			if (!wc[i].status) {
3374 				if (wc[i].opcode == IBV_WC_RDMA_READ) {
3375 					rqpair->current_read_depth--;
3376 					/* wait for all outstanding reads associated with the same rdma_req to complete before proceeding. */
3377 					if (rdma_req->num_outstanding_data_wr == 0) {
3378 						rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
3379 						spdk_nvmf_rdma_request_process(rtransport, rdma_req);
3380 					}
3381 				} else {
3382 					assert(wc[i].opcode == IBV_WC_RDMA_WRITE);
3383 				}
3384 			} else {
3385 				/* If the data transfer fails still force the queue into the error state,
3386 				 * if we were performing an RDMA_READ, we need to force the request into a
3387 				 * completed state since it wasn't linked to a send. However, in the RDMA_WRITE
3388 				 * case, we should wait for the SEND to complete. */
3389 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
3390 				if (rdma_req->data.wr.opcode == IBV_WR_RDMA_READ) {
3391 					rqpair->current_read_depth--;
3392 					if (rdma_req->num_outstanding_data_wr == 0) {
3393 						rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
3394 					}
3395 				}
3396 			}
3397 			break;
3398 		default:
3399 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
3400 			continue;
3401 		}
3402 
3403 		/* Handle error conditions */
3404 		if (wc[i].status) {
3405 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
3406 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
3407 
3408 			error = true;
3409 
3410 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
3411 				/* Disconnect the connection. */
3412 				spdk_nvmf_rdma_start_disconnect(rqpair);
3413 			} else {
3414 				nvmf_rdma_destroy_drained_qpair(rqpair);
3415 			}
3416 			continue;
3417 		}
3418 
3419 		spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair, false);
3420 
3421 		if (rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
3422 			nvmf_rdma_destroy_drained_qpair(rqpair);
3423 		}
3424 	}
3425 
3426 	if (error == true) {
3427 		return -1;
3428 	}
3429 
3430 	/* submit outstanding work requests. */
3431 	_poller_submit_sends(rtransport, rpoller);
3432 
3433 	return count;
3434 }
3435 
3436 static int
3437 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
3438 {
3439 	struct spdk_nvmf_rdma_transport *rtransport;
3440 	struct spdk_nvmf_rdma_poll_group *rgroup;
3441 	struct spdk_nvmf_rdma_poller	*rpoller;
3442 	int				count, rc;
3443 
3444 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
3445 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
3446 
3447 	count = 0;
3448 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
3449 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
3450 		if (rc < 0) {
3451 			return rc;
3452 		}
3453 		count += rc;
3454 	}
3455 
3456 	return count;
3457 }
3458 
3459 static int
3460 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
3461 			       struct spdk_nvme_transport_id *trid,
3462 			       bool peer)
3463 {
3464 	struct sockaddr *saddr;
3465 	uint16_t port;
3466 
3467 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
3468 
3469 	if (peer) {
3470 		saddr = rdma_get_peer_addr(id);
3471 	} else {
3472 		saddr = rdma_get_local_addr(id);
3473 	}
3474 	switch (saddr->sa_family) {
3475 	case AF_INET: {
3476 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
3477 
3478 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
3479 		inet_ntop(AF_INET, &saddr_in->sin_addr,
3480 			  trid->traddr, sizeof(trid->traddr));
3481 		if (peer) {
3482 			port = ntohs(rdma_get_dst_port(id));
3483 		} else {
3484 			port = ntohs(rdma_get_src_port(id));
3485 		}
3486 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3487 		break;
3488 	}
3489 	case AF_INET6: {
3490 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
3491 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
3492 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
3493 			  trid->traddr, sizeof(trid->traddr));
3494 		if (peer) {
3495 			port = ntohs(rdma_get_dst_port(id));
3496 		} else {
3497 			port = ntohs(rdma_get_src_port(id));
3498 		}
3499 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
3500 		break;
3501 	}
3502 	default:
3503 		return -1;
3504 
3505 	}
3506 
3507 	return 0;
3508 }
3509 
3510 static int
3511 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
3512 				   struct spdk_nvme_transport_id *trid)
3513 {
3514 	struct spdk_nvmf_rdma_qpair	*rqpair;
3515 
3516 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3517 
3518 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
3519 }
3520 
3521 static int
3522 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
3523 				    struct spdk_nvme_transport_id *trid)
3524 {
3525 	struct spdk_nvmf_rdma_qpair	*rqpair;
3526 
3527 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3528 
3529 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
3530 }
3531 
3532 static int
3533 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
3534 				     struct spdk_nvme_transport_id *trid)
3535 {
3536 	struct spdk_nvmf_rdma_qpair	*rqpair;
3537 
3538 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
3539 
3540 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
3541 }
3542 
3543 void
3544 spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
3545 {
3546 	g_nvmf_hooks = *hooks;
3547 }
3548 
3549 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
3550 	.type = SPDK_NVME_TRANSPORT_RDMA,
3551 	.opts_init = spdk_nvmf_rdma_opts_init,
3552 	.create = spdk_nvmf_rdma_create,
3553 	.destroy = spdk_nvmf_rdma_destroy,
3554 
3555 	.listen = spdk_nvmf_rdma_listen,
3556 	.stop_listen = spdk_nvmf_rdma_stop_listen,
3557 	.accept = spdk_nvmf_rdma_accept,
3558 
3559 	.listener_discover = spdk_nvmf_rdma_discover,
3560 
3561 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
3562 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
3563 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
3564 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
3565 
3566 	.req_free = spdk_nvmf_rdma_request_free,
3567 	.req_complete = spdk_nvmf_rdma_request_complete,
3568 
3569 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
3570 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
3571 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
3572 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
3573 
3574 };
3575 
3576 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
3577