xref: /spdk/lib/nvmf/rdma.c (revision 7d38f16674f1bc7071d08f4d4dad68fc3ffad965)
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 /*
55  RDMA Connection Resource Defaults
56  */
57 #define NVMF_DEFAULT_TX_SGE		SPDK_NVMF_MAX_SGL_ENTRIES
58 #define NVMF_DEFAULT_RSP_SGE		1
59 #define NVMF_DEFAULT_RX_SGE		2
60 
61 /* The RDMA completion queue size */
62 #define NVMF_RDMA_CQ_SIZE	4096
63 
64 /* AIO backend requires block size aligned data buffers,
65  * extra 4KiB aligned data buffer should work for most devices.
66  */
67 #define SHIFT_4KB			12
68 #define NVMF_DATA_BUFFER_ALIGNMENT	(1 << SHIFT_4KB)
69 #define NVMF_DATA_BUFFER_MASK		(NVMF_DATA_BUFFER_ALIGNMENT - 1)
70 
71 enum spdk_nvmf_rdma_request_state {
72 	/* The request is not currently in use */
73 	RDMA_REQUEST_STATE_FREE = 0,
74 
75 	/* Initial state when request first received */
76 	RDMA_REQUEST_STATE_NEW,
77 
78 	/* The request is queued until a data buffer is available. */
79 	RDMA_REQUEST_STATE_NEED_BUFFER,
80 
81 	/* The request is waiting on RDMA queue depth availability
82 	 * to transfer data between the host and the controller.
83 	 */
84 	RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
85 
86 	/* The request is currently transferring data from the host to the controller. */
87 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
88 
89 	/* The request is ready to execute at the block device */
90 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
91 
92 	/* The request is currently executing at the block device */
93 	RDMA_REQUEST_STATE_EXECUTING,
94 
95 	/* The request finished executing at the block device */
96 	RDMA_REQUEST_STATE_EXECUTED,
97 
98 	/* The request is ready to send a completion */
99 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
100 
101 	/* The request is currently transferring data from the controller to the host. */
102 	RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
103 
104 	/* The request currently has an outstanding completion without an
105 	 * associated data transfer.
106 	 */
107 	RDMA_REQUEST_STATE_COMPLETING,
108 
109 	/* The request completed and can be marked free. */
110 	RDMA_REQUEST_STATE_COMPLETED,
111 
112 	/* Terminator */
113 	RDMA_REQUEST_NUM_STATES,
114 };
115 
116 #define OBJECT_NVMF_RDMA_IO				0x40
117 
118 #define TRACE_GROUP_NVMF_RDMA				0x4
119 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
120 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
121 #define TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
122 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
123 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
124 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
125 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
126 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
127 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
128 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
129 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
130 #define TRACE_RDMA_QP_CREATE						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xB)
131 #define TRACE_RDMA_IBV_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xC)
132 #define TRACE_RDMA_CM_ASYNC_EVENT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xD)
133 #define TRACE_RDMA_QP_STATE_CHANGE					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xE)
134 #define TRACE_RDMA_QP_DISCONNECT					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xF)
135 #define TRACE_RDMA_QP_DESTROY						SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x10)
136 
137 SPDK_TRACE_REGISTER_FN(nvmf_trace, "nvmf_rdma", TRACE_GROUP_NVMF_RDMA)
138 {
139 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
140 	spdk_trace_register_description("RDMA_REQ_NEW", "",
141 					TRACE_RDMA_REQUEST_STATE_NEW,
142 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 1, "cmid:   ");
143 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
144 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
145 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
146 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
147 					TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING,
148 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
149 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
150 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
151 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
152 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
153 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
154 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
155 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
156 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
157 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
158 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
159 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
160 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
161 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
162 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
163 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
164 	spdk_trace_register_description("RDMA_REQ_COMPLETING_CONTROLLER_TO_HOST", "",
165 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST,
166 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
167 	spdk_trace_register_description("RDMA_REQ_COMPLETING_INCAPSULE", "",
168 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
169 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
170 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
171 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
172 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 1, "cmid:   ");
173 
174 	spdk_trace_register_description("RDMA_QP_CREATE", "", TRACE_RDMA_QP_CREATE,
175 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
176 	spdk_trace_register_description("RDMA_IBV_ASYNC_EVENT", "", TRACE_RDMA_IBV_ASYNC_EVENT,
177 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
178 	spdk_trace_register_description("RDMA_CM_ASYNC_EVENT", "", TRACE_RDMA_CM_ASYNC_EVENT,
179 					OWNER_NONE, OBJECT_NONE, 0, 0, "type:   ");
180 	spdk_trace_register_description("RDMA_QP_STATE_CHANGE", "", TRACE_RDMA_QP_STATE_CHANGE,
181 					OWNER_NONE, OBJECT_NONE, 0, 1, "state:  ");
182 	spdk_trace_register_description("RDMA_QP_DISCONNECT", "", TRACE_RDMA_QP_DISCONNECT,
183 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
184 	spdk_trace_register_description("RDMA_QP_DESTROY", "", TRACE_RDMA_QP_DESTROY,
185 					OWNER_NONE, OBJECT_NONE, 0, 0, "");
186 }
187 
188 enum spdk_nvmf_rdma_wr_type {
189 	RDMA_WR_TYPE_RECV,
190 	RDMA_WR_TYPE_SEND,
191 	RDMA_WR_TYPE_DATA,
192 	RDMA_WR_TYPE_DRAIN_SEND,
193 	RDMA_WR_TYPE_DRAIN_RECV
194 };
195 
196 struct spdk_nvmf_rdma_wr {
197 	enum spdk_nvmf_rdma_wr_type	type;
198 };
199 
200 /* This structure holds commands as they are received off the wire.
201  * It must be dynamically paired with a full request object
202  * (spdk_nvmf_rdma_request) to service a request. It is separate
203  * from the request because RDMA does not appear to order
204  * completions, so occasionally we'll get a new incoming
205  * command when there aren't any free request objects.
206  */
207 struct spdk_nvmf_rdma_recv {
208 	struct ibv_recv_wr		wr;
209 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
210 
211 	struct spdk_nvmf_rdma_qpair	*qpair;
212 
213 	/* In-capsule data buffer */
214 	uint8_t				*buf;
215 
216 	struct spdk_nvmf_rdma_wr	rdma_wr;
217 
218 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
219 };
220 
221 struct spdk_nvmf_rdma_request {
222 	struct spdk_nvmf_request		req;
223 	bool					data_from_pool;
224 
225 	enum spdk_nvmf_rdma_request_state	state;
226 
227 	struct spdk_nvmf_rdma_recv		*recv;
228 
229 	struct {
230 		struct spdk_nvmf_rdma_wr	rdma_wr;
231 		struct	ibv_send_wr		wr;
232 		struct	ibv_sge			sgl[NVMF_DEFAULT_RSP_SGE];
233 	} rsp;
234 
235 	struct {
236 		struct spdk_nvmf_rdma_wr	rdma_wr;
237 		struct ibv_send_wr		wr;
238 		struct ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
239 		void				*buffers[NVMF_DEFAULT_TX_SGE];
240 	} data;
241 
242 	struct spdk_nvmf_rdma_wr		rdma_wr;
243 
244 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
245 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	state_link;
246 };
247 
248 enum spdk_nvmf_rdma_qpair_disconnect_flags {
249 	RDMA_QP_DISCONNECTING		= 1,
250 	RDMA_QP_RECV_DRAINED		= 1 << 1,
251 	RDMA_QP_SEND_DRAINED		= 1 << 2
252 };
253 
254 struct spdk_nvmf_rdma_qpair {
255 	struct spdk_nvmf_qpair			qpair;
256 
257 	struct spdk_nvmf_rdma_port		*port;
258 	struct spdk_nvmf_rdma_poller		*poller;
259 
260 	struct rdma_cm_id			*cm_id;
261 	struct rdma_cm_id			*listen_id;
262 
263 	/* The maximum number of I/O outstanding on this connection at one time */
264 	uint16_t				max_queue_depth;
265 
266 	/* The maximum number of active RDMA READ and WRITE operations at one time */
267 	uint16_t				max_rw_depth;
268 
269 	/* The maximum number of SGEs per WR on the send queue */
270 	uint32_t				max_send_sge;
271 
272 	/* The maximum number of SGEs per WR on the recv queue */
273 	uint32_t				max_recv_sge;
274 
275 	/* Receives that are waiting for a request object */
276 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
277 
278 	/* Queues to track the requests in all states */
279 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	state_queue[RDMA_REQUEST_NUM_STATES];
280 
281 	/* Number of requests in each state */
282 	uint32_t				state_cntr[RDMA_REQUEST_NUM_STATES];
283 
284 	/* Array of size "max_queue_depth" containing RDMA requests. */
285 	struct spdk_nvmf_rdma_request		*reqs;
286 
287 	/* Array of size "max_queue_depth" containing RDMA recvs. */
288 	struct spdk_nvmf_rdma_recv		*recvs;
289 
290 	/* Array of size "max_queue_depth" containing 64 byte capsules
291 	 * used for receive.
292 	 */
293 	union nvmf_h2c_msg			*cmds;
294 	struct ibv_mr				*cmds_mr;
295 
296 	/* Array of size "max_queue_depth" containing 16 byte completions
297 	 * to be sent back to the user.
298 	 */
299 	union nvmf_c2h_msg			*cpls;
300 	struct ibv_mr				*cpls_mr;
301 
302 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
303 	 * buffers to be used for in capsule data.
304 	 */
305 	void					*bufs;
306 	struct ibv_mr				*bufs_mr;
307 
308 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
309 
310 	/* Mgmt channel */
311 	struct spdk_io_channel			*mgmt_channel;
312 	struct spdk_nvmf_rdma_mgmt_channel	*ch;
313 
314 	/* IBV queue pair attributes: they are used to manage
315 	 * qp state and recover from errors.
316 	 */
317 	struct ibv_qp_attr			ibv_attr;
318 
319 	uint32_t				disconnect_flags;
320 	struct spdk_nvmf_rdma_wr		drain_send_wr;
321 	struct spdk_nvmf_rdma_wr		drain_recv_wr;
322 
323 	/* Reference counter for how many unprocessed messages
324 	 * from other threads are currently outstanding. The
325 	 * qpair cannot be destroyed until this is 0. This is
326 	 * atomically incremented from any thread, but only
327 	 * decremented and read from the thread that owns this
328 	 * qpair.
329 	 */
330 	uint32_t				refcnt;
331 };
332 
333 struct spdk_nvmf_rdma_poller {
334 	struct spdk_nvmf_rdma_device		*device;
335 	struct spdk_nvmf_rdma_poll_group	*group;
336 
337 	struct ibv_cq				*cq;
338 
339 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
340 
341 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
342 };
343 
344 struct spdk_nvmf_rdma_poll_group {
345 	struct spdk_nvmf_transport_poll_group	group;
346 
347 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
348 };
349 
350 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
351 struct spdk_nvmf_rdma_device {
352 	struct ibv_device_attr			attr;
353 	struct ibv_context			*context;
354 
355 	struct spdk_mem_map			*map;
356 	struct ibv_pd				*pd;
357 
358 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
359 };
360 
361 struct spdk_nvmf_rdma_port {
362 	struct spdk_nvme_transport_id		trid;
363 	struct rdma_cm_id			*id;
364 	struct spdk_nvmf_rdma_device		*device;
365 	uint32_t				ref;
366 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
367 };
368 
369 struct spdk_nvmf_rdma_transport {
370 	struct spdk_nvmf_transport	transport;
371 
372 	struct rdma_event_channel	*event_channel;
373 
374 	struct spdk_mempool		*data_buf_pool;
375 
376 	pthread_mutex_t			lock;
377 
378 	/* fields used to poll RDMA/IB events */
379 	nfds_t			npoll_fds;
380 	struct pollfd		*poll_fds;
381 
382 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
383 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
384 };
385 
386 struct spdk_nvmf_rdma_mgmt_channel {
387 	/* Requests that are waiting to obtain a data buffer */
388 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
389 };
390 
391 static inline void
392 spdk_nvmf_rdma_qpair_inc_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
393 {
394 	__sync_fetch_and_add(&rqpair->refcnt, 1);
395 }
396 
397 static inline uint32_t
398 spdk_nvmf_rdma_qpair_dec_refcnt(struct spdk_nvmf_rdma_qpair *rqpair)
399 {
400 	uint32_t old_refcnt, new_refcnt;
401 
402 	do {
403 		old_refcnt = rqpair->refcnt;
404 		assert(old_refcnt > 0);
405 		new_refcnt = old_refcnt - 1;
406 	} while (__sync_bool_compare_and_swap(&rqpair->refcnt, old_refcnt, new_refcnt) == false);
407 
408 	return new_refcnt;
409 }
410 
411 static enum ibv_qp_state
412 spdk_nvmf_rdma_update_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair) {
413 	enum ibv_qp_state old_state, new_state;
414 	struct ibv_qp_init_attr init_attr;
415 	int rc;
416 
417 	/* All the attributes needed for recovery */
418 	static int spdk_nvmf_ibv_attr_mask =
419 	IBV_QP_STATE |
420 	IBV_QP_PKEY_INDEX |
421 	IBV_QP_PORT |
422 	IBV_QP_ACCESS_FLAGS |
423 	IBV_QP_AV |
424 	IBV_QP_PATH_MTU |
425 	IBV_QP_DEST_QPN |
426 	IBV_QP_RQ_PSN |
427 	IBV_QP_MAX_DEST_RD_ATOMIC |
428 	IBV_QP_MIN_RNR_TIMER |
429 	IBV_QP_SQ_PSN |
430 	IBV_QP_TIMEOUT |
431 	IBV_QP_RETRY_CNT |
432 	IBV_QP_RNR_RETRY |
433 	IBV_QP_MAX_QP_RD_ATOMIC;
434 
435 	old_state = rqpair->ibv_attr.qp_state;
436 	rc = ibv_query_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
437 			  spdk_nvmf_ibv_attr_mask, &init_attr);
438 
439 	if (rc)
440 	{
441 		SPDK_ERRLOG("Failed to get updated RDMA queue pair state!\n");
442 		assert(false);
443 	}
444 
445 	new_state = rqpair->ibv_attr.qp_state;
446 	if (old_state != new_state)
447 	{
448 		spdk_trace_record(TRACE_RDMA_QP_STATE_CHANGE, 0, 0,
449 				  (uintptr_t)rqpair->cm_id, new_state);
450 	}
451 	return new_state;
452 }
453 
454 static const char *str_ibv_qp_state[] = {
455 	"IBV_QPS_RESET",
456 	"IBV_QPS_INIT",
457 	"IBV_QPS_RTR",
458 	"IBV_QPS_RTS",
459 	"IBV_QPS_SQD",
460 	"IBV_QPS_SQE",
461 	"IBV_QPS_ERR"
462 };
463 
464 static int
465 spdk_nvmf_rdma_set_ibv_state(struct spdk_nvmf_rdma_qpair *rqpair,
466 			     enum ibv_qp_state new_state)
467 {
468 	int rc;
469 	enum ibv_qp_state state;
470 	static int attr_mask_rc[] = {
471 		[IBV_QPS_RESET] = IBV_QP_STATE,
472 		[IBV_QPS_INIT] = (IBV_QP_STATE |
473 				  IBV_QP_PKEY_INDEX |
474 				  IBV_QP_PORT |
475 				  IBV_QP_ACCESS_FLAGS),
476 		[IBV_QPS_RTR] = (IBV_QP_STATE |
477 				 IBV_QP_AV |
478 				 IBV_QP_PATH_MTU |
479 				 IBV_QP_DEST_QPN |
480 				 IBV_QP_RQ_PSN |
481 				 IBV_QP_MAX_DEST_RD_ATOMIC |
482 				 IBV_QP_MIN_RNR_TIMER),
483 		[IBV_QPS_RTS] = (IBV_QP_STATE |
484 				 IBV_QP_SQ_PSN |
485 				 IBV_QP_TIMEOUT |
486 				 IBV_QP_RETRY_CNT |
487 				 IBV_QP_RNR_RETRY |
488 				 IBV_QP_MAX_QP_RD_ATOMIC),
489 		[IBV_QPS_SQD] = IBV_QP_STATE,
490 		[IBV_QPS_SQE] = IBV_QP_STATE,
491 		[IBV_QPS_ERR] = IBV_QP_STATE,
492 	};
493 
494 	switch (new_state) {
495 	case IBV_QPS_RESET:
496 	case IBV_QPS_INIT:
497 	case IBV_QPS_RTR:
498 	case IBV_QPS_RTS:
499 	case IBV_QPS_SQD:
500 	case IBV_QPS_SQE:
501 	case IBV_QPS_ERR:
502 		break;
503 	default:
504 		SPDK_ERRLOG("QP#%d: bad state requested: %u\n",
505 			    rqpair->qpair.qid, new_state);
506 		return -1;
507 	}
508 	rqpair->ibv_attr.cur_qp_state = rqpair->ibv_attr.qp_state;
509 	rqpair->ibv_attr.qp_state = new_state;
510 	rqpair->ibv_attr.ah_attr.port_num = rqpair->ibv_attr.port_num;
511 
512 	rc = ibv_modify_qp(rqpair->cm_id->qp, &rqpair->ibv_attr,
513 			   attr_mask_rc[new_state]);
514 
515 	if (rc) {
516 		SPDK_ERRLOG("QP#%d: failed to set state to: %s, %d (%s)\n",
517 			    rqpair->qpair.qid, str_ibv_qp_state[new_state], errno, strerror(errno));
518 		return rc;
519 	}
520 
521 	state = spdk_nvmf_rdma_update_ibv_state(rqpair);
522 
523 	if (state != new_state) {
524 		SPDK_ERRLOG("QP#%d: expected state: %s, actual state: %s\n",
525 			    rqpair->qpair.qid, str_ibv_qp_state[new_state],
526 			    str_ibv_qp_state[state]);
527 		return -1;
528 	}
529 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "IBV QP#%u changed to: %s\n", rqpair->qpair.qid,
530 		      str_ibv_qp_state[state]);
531 	return 0;
532 }
533 
534 static void
535 spdk_nvmf_rdma_request_set_state(struct spdk_nvmf_rdma_request *rdma_req,
536 				 enum spdk_nvmf_rdma_request_state state)
537 {
538 	struct spdk_nvmf_qpair		*qpair;
539 	struct spdk_nvmf_rdma_qpair	*rqpair;
540 
541 	qpair = rdma_req->req.qpair;
542 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
543 
544 	TAILQ_REMOVE(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
545 	rqpair->state_cntr[rdma_req->state]--;
546 
547 	rdma_req->state = state;
548 
549 	TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
550 	rqpair->state_cntr[rdma_req->state]++;
551 }
552 
553 static int
554 spdk_nvmf_rdma_mgmt_channel_create(void *io_device, void *ctx_buf)
555 {
556 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
557 
558 	TAILQ_INIT(&ch->pending_data_buf_queue);
559 	return 0;
560 }
561 
562 static void
563 spdk_nvmf_rdma_mgmt_channel_destroy(void *io_device, void *ctx_buf)
564 {
565 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
566 
567 	if (!TAILQ_EMPTY(&ch->pending_data_buf_queue)) {
568 		SPDK_ERRLOG("Pending I/O list wasn't empty on channel destruction\n");
569 	}
570 }
571 
572 static int
573 spdk_nvmf_rdma_cur_rw_depth(struct spdk_nvmf_rdma_qpair *rqpair)
574 {
575 	return rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER] +
576 	       rqpair->state_cntr[RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST];
577 }
578 
579 static int
580 spdk_nvmf_rdma_cur_queue_depth(struct spdk_nvmf_rdma_qpair *rqpair)
581 {
582 	return rqpair->max_queue_depth -
583 	       rqpair->state_cntr[RDMA_REQUEST_STATE_FREE];
584 }
585 
586 static void
587 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
588 {
589 	int qd;
590 
591 	if (rqpair->refcnt == 0) {
592 		return;
593 	}
594 
595 	spdk_trace_record(TRACE_RDMA_QP_DESTROY, 0, 0, (uintptr_t)rqpair->cm_id, 0);
596 
597 	qd = spdk_nvmf_rdma_cur_queue_depth(rqpair);
598 	if (qd != 0) {
599 		SPDK_WARNLOG("Destroying qpair when queue depth is %d\n", qd);
600 	}
601 
602 	if (rqpair->poller) {
603 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
604 	}
605 
606 	if (rqpair->cmds_mr) {
607 		ibv_dereg_mr(rqpair->cmds_mr);
608 	}
609 
610 	if (rqpair->cpls_mr) {
611 		ibv_dereg_mr(rqpair->cpls_mr);
612 	}
613 
614 	if (rqpair->bufs_mr) {
615 		ibv_dereg_mr(rqpair->bufs_mr);
616 	}
617 
618 	if (rqpair->cm_id) {
619 		rdma_destroy_qp(rqpair->cm_id);
620 		rdma_destroy_id(rqpair->cm_id);
621 	}
622 
623 	if (rqpair->mgmt_channel) {
624 		spdk_put_io_channel(rqpair->mgmt_channel);
625 	}
626 
627 	/* Free all memory */
628 	spdk_dma_free(rqpair->cmds);
629 	spdk_dma_free(rqpair->cpls);
630 	spdk_dma_free(rqpair->bufs);
631 	free(rqpair->reqs);
632 	free(rqpair->recvs);
633 	free(rqpair);
634 }
635 
636 static int
637 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
638 {
639 	struct spdk_nvmf_rdma_transport *rtransport;
640 	struct spdk_nvmf_rdma_qpair	*rqpair;
641 	int				rc, i;
642 	struct spdk_nvmf_rdma_recv	*rdma_recv;
643 	struct spdk_nvmf_rdma_request	*rdma_req;
644 	struct spdk_nvmf_transport	*transport;
645 	struct spdk_nvmf_rdma_device	*device;
646 	struct ibv_qp_init_attr		ibv_init_attr;
647 
648 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
649 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
650 	transport = &rtransport->transport;
651 	device = rqpair->port->device;
652 
653 	memset(&ibv_init_attr, 0, sizeof(struct ibv_qp_init_attr));
654 	ibv_init_attr.qp_context	= rqpair;
655 	ibv_init_attr.qp_type		= IBV_QPT_RC;
656 	ibv_init_attr.send_cq		= rqpair->poller->cq;
657 	ibv_init_attr.recv_cq		= rqpair->poller->cq;
658 	ibv_init_attr.cap.max_send_wr	= rqpair->max_queue_depth *
659 					  2 + 1; /* SEND, READ, and WRITE operations + dummy drain WR */
660 	ibv_init_attr.cap.max_recv_wr	= rqpair->max_queue_depth +
661 					  1; /* RECV operations + dummy drain WR */
662 	ibv_init_attr.cap.max_send_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_TX_SGE);
663 	ibv_init_attr.cap.max_recv_sge	= spdk_min(device->attr.max_sge, NVMF_DEFAULT_RX_SGE);
664 
665 	rc = rdma_create_qp(rqpair->cm_id, rqpair->port->device->pd, &ibv_init_attr);
666 	if (rc) {
667 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
668 		rdma_destroy_id(rqpair->cm_id);
669 		rqpair->cm_id = NULL;
670 		spdk_nvmf_rdma_qpair_destroy(rqpair);
671 		return -1;
672 	}
673 
674 	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, ibv_init_attr.cap.max_send_sge);
675 	rqpair->max_recv_sge = spdk_min(NVMF_DEFAULT_RX_SGE, ibv_init_attr.cap.max_recv_sge);
676 	spdk_trace_record(TRACE_RDMA_QP_CREATE, 0, 0, (uintptr_t)rqpair->cm_id, 0);
677 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
678 
679 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
680 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
681 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
682 					0x1000, NULL);
683 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
684 					0x1000, NULL);
685 
686 
687 	if (transport->opts.in_capsule_data_size > 0) {
688 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth *
689 						transport->opts.in_capsule_data_size,
690 						0x1000, NULL);
691 	}
692 
693 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
694 	    !rqpair->cpls || (transport->opts.in_capsule_data_size && !rqpair->bufs)) {
695 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
696 		spdk_nvmf_rdma_qpair_destroy(rqpair);
697 		return -1;
698 	}
699 
700 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
701 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
702 				     IBV_ACCESS_LOCAL_WRITE);
703 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
704 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
705 				     0);
706 
707 	if (transport->opts.in_capsule_data_size) {
708 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
709 					     rqpair->max_queue_depth *
710 					     transport->opts.in_capsule_data_size,
711 					     IBV_ACCESS_LOCAL_WRITE | IBV_ACCESS_REMOTE_WRITE);
712 	}
713 
714 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (transport->opts.in_capsule_data_size &&
715 			!rqpair->bufs_mr)) {
716 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
717 		spdk_nvmf_rdma_qpair_destroy(rqpair);
718 		return -1;
719 	}
720 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
721 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
722 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
723 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
724 	if (rqpair->bufs && rqpair->bufs_mr) {
725 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
726 			      rqpair->bufs, rqpair->max_queue_depth *
727 			      transport->opts.in_capsule_data_size, rqpair->bufs_mr->lkey);
728 	}
729 
730 	/* Initialise request state queues and counters of the queue pair */
731 	for (i = RDMA_REQUEST_STATE_FREE; i < RDMA_REQUEST_NUM_STATES; i++) {
732 		TAILQ_INIT(&rqpair->state_queue[i]);
733 		rqpair->state_cntr[i] = 0;
734 	}
735 
736 	for (i = 0; i < rqpair->max_queue_depth; i++) {
737 		struct ibv_recv_wr *bad_wr = NULL;
738 
739 		rdma_recv = &rqpair->recvs[i];
740 		rdma_recv->qpair = rqpair;
741 
742 		/* Set up memory to receive commands */
743 		if (rqpair->bufs) {
744 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i *
745 						  transport->opts.in_capsule_data_size));
746 		}
747 
748 		rdma_recv->rdma_wr.type = RDMA_WR_TYPE_RECV;
749 
750 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
751 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
752 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
753 		rdma_recv->wr.num_sge = 1;
754 
755 		if (rdma_recv->buf && rqpair->bufs_mr) {
756 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
757 			rdma_recv->sgl[1].length = transport->opts.in_capsule_data_size;
758 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
759 			rdma_recv->wr.num_sge++;
760 		}
761 
762 		rdma_recv->wr.wr_id = (uintptr_t)&rdma_recv->rdma_wr;
763 		rdma_recv->wr.sg_list = rdma_recv->sgl;
764 
765 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
766 		if (rc) {
767 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
768 			spdk_nvmf_rdma_qpair_destroy(rqpair);
769 			return -1;
770 		}
771 	}
772 
773 	for (i = 0; i < rqpair->max_queue_depth; i++) {
774 		rdma_req = &rqpair->reqs[i];
775 
776 		rdma_req->req.qpair = &rqpair->qpair;
777 		rdma_req->req.cmd = NULL;
778 
779 		/* Set up memory to send responses */
780 		rdma_req->req.rsp = &rqpair->cpls[i];
781 
782 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
783 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
784 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
785 
786 		rdma_req->rsp.rdma_wr.type = RDMA_WR_TYPE_SEND;
787 		rdma_req->rsp.wr.wr_id = (uintptr_t)&rdma_req->rsp.rdma_wr;
788 		rdma_req->rsp.wr.next = NULL;
789 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
790 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
791 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
792 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
793 
794 		/* Set up memory for data buffers */
795 		rdma_req->data.rdma_wr.type = RDMA_WR_TYPE_DATA;
796 		rdma_req->data.wr.wr_id = (uintptr_t)&rdma_req->data.rdma_wr;
797 		rdma_req->data.wr.next = NULL;
798 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
799 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
800 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
801 
802 		/* Initialize request state to FREE */
803 		rdma_req->state = RDMA_REQUEST_STATE_FREE;
804 		TAILQ_INSERT_TAIL(&rqpair->state_queue[rdma_req->state], rdma_req, state_link);
805 		rqpair->state_cntr[rdma_req->state]++;
806 	}
807 
808 	return 0;
809 }
810 
811 static int
812 request_transfer_in(struct spdk_nvmf_request *req)
813 {
814 	int				rc;
815 	struct spdk_nvmf_rdma_request	*rdma_req;
816 	struct spdk_nvmf_qpair		*qpair;
817 	struct spdk_nvmf_rdma_qpair	*rqpair;
818 	struct ibv_send_wr		*bad_wr = NULL;
819 
820 	qpair = req->qpair;
821 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
822 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
823 
824 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
825 
826 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
827 
828 	rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
829 	rdma_req->data.wr.next = NULL;
830 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
831 	if (rc) {
832 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
833 		return -1;
834 	}
835 	return 0;
836 }
837 
838 static int
839 request_transfer_out(struct spdk_nvmf_request *req, int *data_posted)
840 {
841 	int				rc;
842 	struct spdk_nvmf_rdma_request	*rdma_req;
843 	struct spdk_nvmf_qpair		*qpair;
844 	struct spdk_nvmf_rdma_qpair	*rqpair;
845 	struct spdk_nvme_cpl		*rsp;
846 	struct ibv_recv_wr		*bad_recv_wr = NULL;
847 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
848 
849 	*data_posted = 0;
850 	qpair = req->qpair;
851 	rsp = &req->rsp->nvme_cpl;
852 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
853 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
854 
855 	/* Advance our sq_head pointer */
856 	if (qpair->sq_head == qpair->sq_head_max) {
857 		qpair->sq_head = 0;
858 	} else {
859 		qpair->sq_head++;
860 	}
861 	rsp->sqhd = qpair->sq_head;
862 
863 	/* Post the capsule to the recv buffer */
864 	assert(rdma_req->recv != NULL);
865 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
866 		      rqpair);
867 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
868 	if (rc) {
869 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
870 		return rc;
871 	}
872 	rdma_req->recv = NULL;
873 
874 	/* Build the response which consists of an optional
875 	 * RDMA WRITE to transfer data, plus an RDMA SEND
876 	 * containing the response.
877 	 */
878 	send_wr = &rdma_req->rsp.wr;
879 
880 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
881 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
882 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
883 
884 		rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
885 
886 		rdma_req->data.wr.next = send_wr;
887 		*data_posted = 1;
888 		send_wr = &rdma_req->data.wr;
889 	}
890 
891 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
892 
893 	/* Send the completion */
894 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
895 	if (rc) {
896 		SPDK_ERRLOG("Unable to send response capsule\n");
897 	}
898 
899 	return rc;
900 }
901 
902 static int
903 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
904 {
905 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
906 	struct rdma_conn_param				ctrlr_event_data = {};
907 	int						rc;
908 
909 	accept_data.recfmt = 0;
910 	accept_data.crqsize = rqpair->max_queue_depth;
911 
912 	ctrlr_event_data.private_data = &accept_data;
913 	ctrlr_event_data.private_data_len = sizeof(accept_data);
914 	if (id->ps == RDMA_PS_TCP) {
915 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
916 		ctrlr_event_data.initiator_depth = rqpair->max_rw_depth;
917 	}
918 
919 	rc = rdma_accept(id, &ctrlr_event_data);
920 	if (rc) {
921 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
922 	} else {
923 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
924 	}
925 
926 	return rc;
927 }
928 
929 static void
930 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
931 {
932 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
933 
934 	rej_data.recfmt = 0;
935 	rej_data.sts = error;
936 
937 	rdma_reject(id, &rej_data, sizeof(rej_data));
938 }
939 
940 static int
941 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
942 		  new_qpair_fn cb_fn)
943 {
944 	struct spdk_nvmf_rdma_transport *rtransport;
945 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
946 	struct spdk_nvmf_rdma_port	*port;
947 	struct rdma_conn_param		*rdma_param = NULL;
948 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
949 	uint16_t			max_queue_depth;
950 	uint16_t			max_rw_depth;
951 
952 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
953 
954 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
955 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
956 
957 	rdma_param = &event->param.conn;
958 	if (rdma_param->private_data == NULL ||
959 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
960 		SPDK_ERRLOG("connect request: no private data provided\n");
961 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
962 		return -1;
963 	}
964 
965 	private_data = rdma_param->private_data;
966 	if (private_data->recfmt != 0) {
967 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
968 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
969 		return -1;
970 	}
971 
972 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
973 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
974 
975 	port = event->listen_id->context;
976 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
977 		      event->listen_id, event->listen_id->verbs, port);
978 
979 	/* Figure out the supported queue depth. This is a multi-step process
980 	 * that takes into account hardware maximums, host provided values,
981 	 * and our target's internal memory limits */
982 
983 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
984 
985 	/* Start with the maximum queue depth allowed by the target */
986 	max_queue_depth = rtransport->transport.opts.max_queue_depth;
987 	max_rw_depth = rtransport->transport.opts.max_queue_depth;
988 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n",
989 		      rtransport->transport.opts.max_queue_depth);
990 
991 	/* Next check the local NIC's hardware limitations */
992 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
993 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
994 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
995 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
996 	max_rw_depth = spdk_min(max_rw_depth, port->device->attr.max_qp_rd_atom);
997 
998 	/* Next check the remote NIC's hardware limitations */
999 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
1000 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
1001 		      rdma_param->initiator_depth, rdma_param->responder_resources);
1002 	if (rdma_param->initiator_depth > 0) {
1003 		max_rw_depth = spdk_min(max_rw_depth, rdma_param->initiator_depth);
1004 	}
1005 
1006 	/* Finally check for the host software requested values, which are
1007 	 * optional. */
1008 	if (rdma_param->private_data != NULL &&
1009 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
1010 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
1011 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
1012 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
1013 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
1014 	}
1015 
1016 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
1017 		      max_queue_depth, max_rw_depth);
1018 
1019 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
1020 	if (rqpair == NULL) {
1021 		SPDK_ERRLOG("Could not allocate new connection.\n");
1022 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1023 		return -1;
1024 	}
1025 
1026 	rqpair->port = port;
1027 	rqpair->max_queue_depth = max_queue_depth;
1028 	rqpair->max_rw_depth = max_rw_depth;
1029 	rqpair->cm_id = event->id;
1030 	rqpair->listen_id = event->listen_id;
1031 	rqpair->qpair.transport = transport;
1032 	TAILQ_INIT(&rqpair->incoming_queue);
1033 	event->id->context = &rqpair->qpair;
1034 
1035 	cb_fn(&rqpair->qpair);
1036 
1037 	return 0;
1038 }
1039 
1040 static int
1041 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
1042 			  enum spdk_mem_map_notify_action action,
1043 			  void *vaddr, size_t size)
1044 {
1045 	struct spdk_nvmf_rdma_device *device = cb_ctx;
1046 	struct ibv_pd *pd = device->pd;
1047 	struct ibv_mr *mr;
1048 
1049 	switch (action) {
1050 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
1051 		mr = ibv_reg_mr(pd, vaddr, size,
1052 				IBV_ACCESS_LOCAL_WRITE |
1053 				IBV_ACCESS_REMOTE_READ |
1054 				IBV_ACCESS_REMOTE_WRITE);
1055 		if (mr == NULL) {
1056 			SPDK_ERRLOG("ibv_reg_mr() failed\n");
1057 			return -1;
1058 		} else {
1059 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
1060 		}
1061 		break;
1062 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
1063 		mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, NULL);
1064 		spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
1065 		if (mr) {
1066 			ibv_dereg_mr(mr);
1067 		}
1068 		break;
1069 	}
1070 
1071 	return 0;
1072 }
1073 
1074 static int
1075 spdk_nvmf_rdma_check_contiguous_entries(uint64_t addr_1, uint64_t addr_2)
1076 {
1077 	/* Two contiguous mappings will point to the same address which is the start of the RDMA MR. */
1078 	return addr_1 == addr_2;
1079 }
1080 
1081 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
1082 
1083 static spdk_nvme_data_transfer_t
1084 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
1085 {
1086 	enum spdk_nvme_data_transfer xfer;
1087 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
1088 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
1089 
1090 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1091 	rdma_req->rsp.wr.opcode = IBV_WR_SEND;
1092 	rdma_req->rsp.wr.imm_data = 0;
1093 #endif
1094 
1095 	/* Figure out data transfer direction */
1096 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
1097 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
1098 	} else {
1099 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
1100 
1101 		/* Some admin commands are special cases */
1102 		if ((rdma_req->req.qpair->qid == 0) &&
1103 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
1104 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
1105 			switch (cmd->cdw10 & 0xff) {
1106 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
1107 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
1108 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
1109 				break;
1110 			default:
1111 				xfer = SPDK_NVME_DATA_NONE;
1112 			}
1113 		}
1114 	}
1115 
1116 	if (xfer == SPDK_NVME_DATA_NONE) {
1117 		return xfer;
1118 	}
1119 
1120 	/* Even for commands that may transfer data, they could have specified 0 length.
1121 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
1122 	 */
1123 	switch (sgl->generic.type) {
1124 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
1125 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
1126 	case SPDK_NVME_SGL_TYPE_SEGMENT:
1127 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
1128 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
1129 		if (sgl->unkeyed.length == 0) {
1130 			xfer = SPDK_NVME_DATA_NONE;
1131 		}
1132 		break;
1133 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
1134 		if (sgl->keyed.length == 0) {
1135 			xfer = SPDK_NVME_DATA_NONE;
1136 		}
1137 		break;
1138 	}
1139 
1140 	return xfer;
1141 }
1142 
1143 static int
1144 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
1145 				 struct spdk_nvmf_rdma_device *device,
1146 				 struct spdk_nvmf_rdma_request *rdma_req)
1147 {
1148 	void		*buf = NULL;
1149 	uint32_t	length = rdma_req->req.length;
1150 	uint32_t	i = 0;
1151 
1152 	rdma_req->req.iovcnt = 0;
1153 	while (length) {
1154 		buf = spdk_mempool_get(rtransport->data_buf_pool);
1155 		if (!buf) {
1156 			goto nomem;
1157 		}
1158 
1159 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
1160 						~NVMF_DATA_BUFFER_MASK);
1161 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->transport.opts.io_unit_size);
1162 		rdma_req->req.iovcnt++;
1163 		rdma_req->data.buffers[i] = buf;
1164 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
1165 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
1166 		rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
1167 						     (uint64_t)buf, NULL))->lkey;
1168 
1169 		length -= rdma_req->req.iov[i].iov_len;
1170 		i++;
1171 	}
1172 
1173 	rdma_req->data_from_pool = true;
1174 
1175 	return 0;
1176 
1177 nomem:
1178 	while (i) {
1179 		i--;
1180 		spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1181 		rdma_req->req.iov[i].iov_base = NULL;
1182 		rdma_req->req.iov[i].iov_len = 0;
1183 
1184 		rdma_req->data.wr.sg_list[i].addr = 0;
1185 		rdma_req->data.wr.sg_list[i].length = 0;
1186 		rdma_req->data.wr.sg_list[i].lkey = 0;
1187 	}
1188 	rdma_req->req.iovcnt = 0;
1189 	return -ENOMEM;
1190 }
1191 
1192 static int
1193 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
1194 				 struct spdk_nvmf_rdma_device *device,
1195 				 struct spdk_nvmf_rdma_request *rdma_req)
1196 {
1197 	struct spdk_nvme_cmd			*cmd;
1198 	struct spdk_nvme_cpl			*rsp;
1199 	struct spdk_nvme_sgl_descriptor		*sgl;
1200 
1201 	cmd = &rdma_req->req.cmd->nvme_cmd;
1202 	rsp = &rdma_req->req.rsp->nvme_cpl;
1203 	sgl = &cmd->dptr.sgl1;
1204 
1205 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
1206 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
1207 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
1208 		if (sgl->keyed.length > rtransport->transport.opts.max_io_size) {
1209 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
1210 				    sgl->keyed.length, rtransport->transport.opts.max_io_size);
1211 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1212 			return -1;
1213 		}
1214 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1215 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) != 0) {
1216 			if (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY) {
1217 				rdma_req->rsp.wr.opcode = IBV_WR_SEND_WITH_INV;
1218 				rdma_req->rsp.wr.imm_data = sgl->keyed.key;
1219 			}
1220 		}
1221 #endif
1222 
1223 		/* fill request length and populate iovs */
1224 		rdma_req->req.length = sgl->keyed.length;
1225 
1226 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
1227 			/* No available buffers. Queue this request up. */
1228 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
1229 			return 0;
1230 		}
1231 
1232 		/* backward compatible */
1233 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
1234 
1235 		/* rdma wr specifics */
1236 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1237 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1238 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1239 
1240 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1241 			      rdma_req->req.iovcnt);
1242 
1243 		return 0;
1244 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1245 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1246 		uint64_t offset = sgl->address;
1247 		uint32_t max_len = rtransport->transport.opts.in_capsule_data_size;
1248 
1249 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1250 			      offset, sgl->unkeyed.length);
1251 
1252 		if (offset > max_len) {
1253 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1254 				    offset, max_len);
1255 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1256 			return -1;
1257 		}
1258 		max_len -= (uint32_t)offset;
1259 
1260 		if (sgl->unkeyed.length > max_len) {
1261 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1262 				    sgl->unkeyed.length, max_len);
1263 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1264 			return -1;
1265 		}
1266 
1267 		rdma_req->req.data = rdma_req->recv->buf + offset;
1268 		rdma_req->data_from_pool = false;
1269 		rdma_req->req.length = sgl->unkeyed.length;
1270 
1271 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1272 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1273 		rdma_req->req.iovcnt = 1;
1274 
1275 		return 0;
1276 	}
1277 
1278 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1279 		    sgl->generic.type, sgl->generic.subtype);
1280 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1281 	return -1;
1282 }
1283 
1284 static bool
1285 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1286 			       struct spdk_nvmf_rdma_request *rdma_req)
1287 {
1288 	struct spdk_nvmf_rdma_qpair	*rqpair;
1289 	struct spdk_nvmf_rdma_device	*device;
1290 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1291 	int				rc;
1292 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1293 	enum spdk_nvmf_rdma_request_state prev_state;
1294 	bool				progress = false;
1295 	int				data_posted;
1296 	int				cur_rdma_rw_depth;
1297 
1298 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1299 	device = rqpair->port->device;
1300 
1301 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1302 
1303 	/* If the queue pair is in an error state, force the request to the completed state
1304 	 * to release resources. */
1305 	if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR || rqpair->qpair.state != SPDK_NVMF_QPAIR_ACTIVE) {
1306 		if (rdma_req->state == RDMA_REQUEST_STATE_NEED_BUFFER) {
1307 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1308 		}
1309 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1310 	}
1311 
1312 	/* The loop here is to allow for several back-to-back state changes. */
1313 	do {
1314 		prev_state = rdma_req->state;
1315 
1316 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1317 
1318 		switch (rdma_req->state) {
1319 		case RDMA_REQUEST_STATE_FREE:
1320 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1321 			 * to escape this state. */
1322 			break;
1323 		case RDMA_REQUEST_STATE_NEW:
1324 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0,
1325 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1326 			rdma_recv = rdma_req->recv;
1327 
1328 			/* The first element of the SGL is the NVMe command */
1329 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1330 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1331 
1332 			TAILQ_REMOVE(&rqpair->incoming_queue, rdma_recv, link);
1333 
1334 			if (rqpair->ibv_attr.qp_state == IBV_QPS_ERR) {
1335 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1336 				break;
1337 			}
1338 
1339 			/* The next state transition depends on the data transfer needs of this request. */
1340 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1341 
1342 			/* If no data to transfer, ready to execute. */
1343 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1344 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1345 				break;
1346 			}
1347 
1348 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEED_BUFFER);
1349 			TAILQ_INSERT_TAIL(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1350 			break;
1351 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1352 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0,
1353 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1354 
1355 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1356 
1357 			if (rdma_req != TAILQ_FIRST(&rqpair->ch->pending_data_buf_queue)) {
1358 				/* This request needs to wait in line to obtain a buffer */
1359 				break;
1360 			}
1361 
1362 			/* Try to get a data buffer */
1363 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1364 			if (rc < 0) {
1365 				TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1366 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1367 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1368 				break;
1369 			}
1370 
1371 			if (!rdma_req->req.data) {
1372 				/* No buffers available. */
1373 				break;
1374 			}
1375 
1376 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1377 
1378 			/* If data is transferring from host to controller and the data didn't
1379 			 * arrive using in capsule data, we need to do a transfer from the host.
1380 			 */
1381 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1382 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1383 				break;
1384 			}
1385 
1386 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
1387 			break;
1388 		case RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING:
1389 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING, 0, 0,
1390 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1391 
1392 			if (rdma_req != TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING])) {
1393 				/* This request needs to wait in line to perform RDMA */
1394 				break;
1395 			}
1396 			cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
1397 
1398 			if (cur_rdma_rw_depth >= rqpair->max_rw_depth) {
1399 				/* R/W queue is full, need to wait */
1400 				break;
1401 			}
1402 
1403 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER) {
1404 				rc = request_transfer_in(&rdma_req->req);
1405 				if (!rc) {
1406 					spdk_nvmf_rdma_request_set_state(rdma_req,
1407 									 RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
1408 				} else {
1409 					rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1410 					spdk_nvmf_rdma_request_set_state(rdma_req,
1411 									 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1412 				}
1413 			} else if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1414 				/* The data transfer will be kicked off from
1415 				 * RDMA_REQUEST_STATE_READY_TO_COMPLETE state.
1416 				 */
1417 				spdk_nvmf_rdma_request_set_state(rdma_req,
1418 								 RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1419 			} else {
1420 				SPDK_ERRLOG("Cannot perform data transfer, unknown state: %u\n",
1421 					    rdma_req->req.xfer);
1422 				assert(0);
1423 			}
1424 			break;
1425 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1426 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1427 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1428 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1429 			 * to escape this state. */
1430 			break;
1431 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1432 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0,
1433 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1434 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTING);
1435 			spdk_nvmf_request_exec(&rdma_req->req);
1436 			break;
1437 		case RDMA_REQUEST_STATE_EXECUTING:
1438 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0,
1439 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1440 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1441 			 * to escape this state. */
1442 			break;
1443 		case RDMA_REQUEST_STATE_EXECUTED:
1444 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0,
1445 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1446 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1447 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING);
1448 			} else {
1449 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_COMPLETE);
1450 			}
1451 			break;
1452 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1453 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0,
1454 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1455 			rc = request_transfer_out(&rdma_req->req, &data_posted);
1456 			assert(rc == 0); /* No good way to handle this currently */
1457 			if (rc) {
1458 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
1459 			} else {
1460 				spdk_nvmf_rdma_request_set_state(rdma_req,
1461 								 data_posted ?
1462 								 RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST :
1463 								 RDMA_REQUEST_STATE_COMPLETING);
1464 			}
1465 			break;
1466 		case RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST:
1467 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST, 0, 0,
1468 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1469 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1470 			 * to escape this state. */
1471 			break;
1472 		case RDMA_REQUEST_STATE_COMPLETING:
1473 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0,
1474 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1475 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1476 			 * to escape this state. */
1477 			break;
1478 		case RDMA_REQUEST_STATE_COMPLETED:
1479 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0,
1480 					  (uintptr_t)rdma_req, (uintptr_t)rqpair->cm_id);
1481 
1482 			if (rdma_req->data_from_pool) {
1483 				/* Put the buffer/s back in the pool */
1484 				for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1485 					spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1486 					rdma_req->req.iov[i].iov_base = NULL;
1487 					rdma_req->data.buffers[i] = NULL;
1488 				}
1489 				rdma_req->data_from_pool = false;
1490 			}
1491 			rdma_req->req.length = 0;
1492 			rdma_req->req.iovcnt = 0;
1493 			rdma_req->req.data = NULL;
1494 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
1495 			break;
1496 		case RDMA_REQUEST_NUM_STATES:
1497 		default:
1498 			assert(0);
1499 			break;
1500 		}
1501 
1502 		if (rdma_req->state != prev_state) {
1503 			progress = true;
1504 		}
1505 	} while (rdma_req->state != prev_state);
1506 
1507 	return progress;
1508 }
1509 
1510 /* Public API callbacks begin here */
1511 
1512 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH 128
1513 #define SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH 128
1514 #define SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR 64
1515 #define SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE 4096
1516 #define SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE 131072
1517 #define SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE 4096
1518 #define SPDK_NVMF_RDMA_DEFAULT_IO_BUFFER_SIZE (SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE / SPDK_NVMF_MAX_SGL_ENTRIES)
1519 
1520 static void
1521 spdk_nvmf_rdma_opts_init(struct spdk_nvmf_transport_opts *opts)
1522 {
1523 	opts->max_queue_depth =      SPDK_NVMF_RDMA_DEFAULT_MAX_QUEUE_DEPTH;
1524 	opts->max_qpairs_per_ctrlr = SPDK_NVMF_RDMA_DEFAULT_MAX_QPAIRS_PER_CTRLR;
1525 	opts->in_capsule_data_size = SPDK_NVMF_RDMA_DEFAULT_IN_CAPSULE_DATA_SIZE;
1526 	opts->max_io_size =          SPDK_NVMF_RDMA_DEFAULT_MAX_IO_SIZE;
1527 	opts->io_unit_size =         spdk_max(SPDK_NVMF_RDMA_DEFAULT_IO_BUFFER_SIZE,
1528 					      SPDK_NVMF_RDMA_MIN_IO_BUFFER_SIZE);
1529 	opts->max_aq_depth =         SPDK_NVMF_RDMA_DEFAULT_AQ_DEPTH;
1530 }
1531 
1532 static int spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport);
1533 
1534 static struct spdk_nvmf_transport *
1535 spdk_nvmf_rdma_create(struct spdk_nvmf_transport_opts *opts)
1536 {
1537 	int rc;
1538 	struct spdk_nvmf_rdma_transport *rtransport;
1539 	struct spdk_nvmf_rdma_device	*device, *tmp;
1540 	struct ibv_context		**contexts;
1541 	uint32_t			i;
1542 	int				flag;
1543 	uint32_t			sge_count;
1544 
1545 	const struct spdk_mem_map_ops nvmf_rdma_map_ops = {
1546 		.notify_cb = spdk_nvmf_rdma_mem_notify,
1547 		.are_contiguous = spdk_nvmf_rdma_check_contiguous_entries
1548 	};
1549 
1550 	rtransport = calloc(1, sizeof(*rtransport));
1551 	if (!rtransport) {
1552 		return NULL;
1553 	}
1554 
1555 	if (pthread_mutex_init(&rtransport->lock, NULL)) {
1556 		SPDK_ERRLOG("pthread_mutex_init() failed\n");
1557 		free(rtransport);
1558 		return NULL;
1559 	}
1560 
1561 	spdk_io_device_register(rtransport, spdk_nvmf_rdma_mgmt_channel_create,
1562 				spdk_nvmf_rdma_mgmt_channel_destroy,
1563 				sizeof(struct spdk_nvmf_rdma_mgmt_channel),
1564 				"rdma_transport");
1565 
1566 	TAILQ_INIT(&rtransport->devices);
1567 	TAILQ_INIT(&rtransport->ports);
1568 
1569 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1570 
1571 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n"
1572 		     "  Transport opts:  max_ioq_depth=%d, max_io_size=%d,\n"
1573 		     "  max_qpairs_per_ctrlr=%d, io_unit_size=%d,\n"
1574 		     "  in_capsule_data_size=%d, max_aq_depth=%d\n",
1575 		     opts->max_queue_depth,
1576 		     opts->max_io_size,
1577 		     opts->max_qpairs_per_ctrlr,
1578 		     opts->io_unit_size,
1579 		     opts->in_capsule_data_size,
1580 		     opts->max_aq_depth);
1581 
1582 	/* I/O unit size cannot be larger than max I/O size */
1583 	if (opts->io_unit_size > opts->max_io_size) {
1584 		opts->io_unit_size = opts->max_io_size;
1585 	}
1586 
1587 	sge_count = opts->max_io_size / opts->io_unit_size;
1588 	if (sge_count > NVMF_DEFAULT_TX_SGE) {
1589 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", opts->io_unit_size);
1590 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1591 		return NULL;
1592 	}
1593 
1594 	rtransport->event_channel = rdma_create_event_channel();
1595 	if (rtransport->event_channel == NULL) {
1596 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1597 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1598 		return NULL;
1599 	}
1600 
1601 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1602 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1603 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1604 			    rtransport->event_channel->fd, spdk_strerror(errno));
1605 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1606 		return NULL;
1607 	}
1608 
1609 	/* The maximum number of buffers we will need for a given request is equal to just less than double the number of SGL elements */
1610 	rtransport->data_buf_pool = spdk_mempool_create("spdk_nvmf_rdma",
1611 				    opts->max_queue_depth * (SPDK_NVMF_MAX_SGL_ENTRIES * 2) * 4,
1612 				    opts->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT,
1613 				    SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1614 				    SPDK_ENV_SOCKET_ID_ANY);
1615 	if (!rtransport->data_buf_pool) {
1616 		SPDK_ERRLOG("Unable to allocate buffer pool for poll group\n");
1617 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1618 		return NULL;
1619 	}
1620 
1621 	contexts = rdma_get_devices(NULL);
1622 	if (contexts == NULL) {
1623 		SPDK_ERRLOG("rdma_get_devices() failed: %s (%d)\n", spdk_strerror(errno), errno);
1624 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1625 		return NULL;
1626 	}
1627 
1628 	i = 0;
1629 	rc = 0;
1630 	while (contexts[i] != NULL) {
1631 		device = calloc(1, sizeof(*device));
1632 		if (!device) {
1633 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1634 			rc = -ENOMEM;
1635 			break;
1636 		}
1637 		device->context = contexts[i];
1638 		rc = ibv_query_device(device->context, &device->attr);
1639 		if (rc < 0) {
1640 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1641 			free(device);
1642 			break;
1643 
1644 		}
1645 
1646 #ifdef SPDK_CONFIG_RDMA_SEND_WITH_INVAL
1647 		if ((device->attr.device_cap_flags & IBV_DEVICE_MEM_MGT_EXTENSIONS) == 0) {
1648 			SPDK_WARNLOG("The libibverbs on this system supports SEND_WITH_INVALIDATE,");
1649 			SPDK_WARNLOG("but the device with vendor ID %u does not.\n", device->attr.vendor_id);
1650 		}
1651 
1652 		/**
1653 		 * The vendor ID is assigned by the IEEE and an ID of 0 implies Soft-RoCE.
1654 		 * The Soft-RoCE RXE driver does not currently support send with invalidate,
1655 		 * but incorrectly reports that it does. There are changes making their way
1656 		 * through the kernel now that will enable this feature. When they are merged,
1657 		 * we can conditionally enable this feature.
1658 		 *
1659 		 * TODO: enable this for versions of the kernel rxe driver that support it.
1660 		 */
1661 		if (device->attr.vendor_id == 0) {
1662 			device->attr.device_cap_flags &= ~(IBV_DEVICE_MEM_MGT_EXTENSIONS);
1663 		}
1664 #endif
1665 
1666 		/* set up device context async ev fd as NON_BLOCKING */
1667 		flag = fcntl(device->context->async_fd, F_GETFL);
1668 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1669 		if (rc < 0) {
1670 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1671 			free(device);
1672 			break;
1673 		}
1674 
1675 		device->pd = ibv_alloc_pd(device->context);
1676 		if (!device->pd) {
1677 			SPDK_ERRLOG("Unable to allocate protection domain.\n");
1678 			free(device);
1679 			rc = -1;
1680 			break;
1681 		}
1682 
1683 		device->map = spdk_mem_map_alloc(0, &nvmf_rdma_map_ops, device);
1684 		if (!device->map) {
1685 			SPDK_ERRLOG("Unable to allocate memory map for new poll group\n");
1686 			ibv_dealloc_pd(device->pd);
1687 			free(device);
1688 			rc = -1;
1689 			break;
1690 		}
1691 
1692 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1693 		i++;
1694 	}
1695 	rdma_free_devices(contexts);
1696 
1697 	if (rc < 0) {
1698 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1699 		return NULL;
1700 	}
1701 
1702 	/* Set up poll descriptor array to monitor events from RDMA and IB
1703 	 * in a single poll syscall
1704 	 */
1705 	rtransport->npoll_fds = i + 1;
1706 	i = 0;
1707 	rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1708 	if (rtransport->poll_fds == NULL) {
1709 		SPDK_ERRLOG("poll_fds allocation failed\n");
1710 		spdk_nvmf_rdma_destroy(&rtransport->transport);
1711 		return NULL;
1712 	}
1713 
1714 	rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1715 	rtransport->poll_fds[i++].events = POLLIN;
1716 
1717 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1718 		rtransport->poll_fds[i].fd = device->context->async_fd;
1719 		rtransport->poll_fds[i++].events = POLLIN;
1720 	}
1721 
1722 	return &rtransport->transport;
1723 }
1724 
1725 static int
1726 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1727 {
1728 	struct spdk_nvmf_rdma_transport	*rtransport;
1729 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1730 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1731 
1732 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1733 
1734 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1735 		TAILQ_REMOVE(&rtransport->ports, port, link);
1736 		rdma_destroy_id(port->id);
1737 		free(port);
1738 	}
1739 
1740 	if (rtransport->poll_fds != NULL) {
1741 		free(rtransport->poll_fds);
1742 	}
1743 
1744 	if (rtransport->event_channel != NULL) {
1745 		rdma_destroy_event_channel(rtransport->event_channel);
1746 	}
1747 
1748 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1749 		TAILQ_REMOVE(&rtransport->devices, device, link);
1750 		if (device->map) {
1751 			spdk_mem_map_free(&device->map);
1752 		}
1753 		if (device->pd) {
1754 			ibv_dealloc_pd(device->pd);
1755 		}
1756 		free(device);
1757 	}
1758 
1759 	if (rtransport->data_buf_pool != NULL) {
1760 		if (spdk_mempool_count(rtransport->data_buf_pool) !=
1761 		    (transport->opts.max_queue_depth * (SPDK_NVMF_MAX_SGL_ENTRIES * 2) * 4)) {
1762 			SPDK_ERRLOG("transport buffer pool count is %zu but should be %u\n",
1763 				    spdk_mempool_count(rtransport->data_buf_pool),
1764 				    transport->opts.max_queue_depth * (SPDK_NVMF_MAX_SGL_ENTRIES * 2) * 4);
1765 		}
1766 	}
1767 
1768 	spdk_mempool_free(rtransport->data_buf_pool);
1769 	spdk_io_device_unregister(rtransport, NULL);
1770 	pthread_mutex_destroy(&rtransport->lock);
1771 	free(rtransport);
1772 
1773 	return 0;
1774 }
1775 
1776 static int
1777 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1778 		      const struct spdk_nvme_transport_id *trid)
1779 {
1780 	struct spdk_nvmf_rdma_transport	*rtransport;
1781 	struct spdk_nvmf_rdma_device	*device;
1782 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1783 	struct addrinfo			*res;
1784 	struct addrinfo			hints;
1785 	int				family;
1786 	int				rc;
1787 
1788 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1789 
1790 	port = calloc(1, sizeof(*port));
1791 	if (!port) {
1792 		return -ENOMEM;
1793 	}
1794 
1795 	/* Selectively copy the trid. Things like NQN don't matter here - that
1796 	 * mapping is enforced elsewhere.
1797 	 */
1798 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1799 	port->trid.adrfam = trid->adrfam;
1800 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1801 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1802 
1803 	pthread_mutex_lock(&rtransport->lock);
1804 	assert(rtransport->event_channel != NULL);
1805 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1806 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1807 			port_tmp->ref++;
1808 			free(port);
1809 			/* Already listening at this address */
1810 			pthread_mutex_unlock(&rtransport->lock);
1811 			return 0;
1812 		}
1813 	}
1814 
1815 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1816 	if (rc < 0) {
1817 		SPDK_ERRLOG("rdma_create_id() failed\n");
1818 		free(port);
1819 		pthread_mutex_unlock(&rtransport->lock);
1820 		return rc;
1821 	}
1822 
1823 	switch (port->trid.adrfam) {
1824 	case SPDK_NVMF_ADRFAM_IPV4:
1825 		family = AF_INET;
1826 		break;
1827 	case SPDK_NVMF_ADRFAM_IPV6:
1828 		family = AF_INET6;
1829 		break;
1830 	default:
1831 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1832 		free(port);
1833 		pthread_mutex_unlock(&rtransport->lock);
1834 		return -EINVAL;
1835 	}
1836 
1837 	memset(&hints, 0, sizeof(hints));
1838 	hints.ai_family = family;
1839 	hints.ai_flags = AI_NUMERICSERV;
1840 	hints.ai_socktype = SOCK_STREAM;
1841 	hints.ai_protocol = 0;
1842 
1843 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1844 	if (rc) {
1845 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1846 		free(port);
1847 		pthread_mutex_unlock(&rtransport->lock);
1848 		return -EINVAL;
1849 	}
1850 
1851 	rc = rdma_bind_addr(port->id, res->ai_addr);
1852 	freeaddrinfo(res);
1853 
1854 	if (rc < 0) {
1855 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1856 		rdma_destroy_id(port->id);
1857 		free(port);
1858 		pthread_mutex_unlock(&rtransport->lock);
1859 		return rc;
1860 	}
1861 
1862 	if (!port->id->verbs) {
1863 		SPDK_ERRLOG("ibv_context is null\n");
1864 		rdma_destroy_id(port->id);
1865 		free(port);
1866 		pthread_mutex_unlock(&rtransport->lock);
1867 		return -1;
1868 	}
1869 
1870 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
1871 	if (rc < 0) {
1872 		SPDK_ERRLOG("rdma_listen() failed\n");
1873 		rdma_destroy_id(port->id);
1874 		free(port);
1875 		pthread_mutex_unlock(&rtransport->lock);
1876 		return rc;
1877 	}
1878 
1879 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1880 		if (device->context == port->id->verbs) {
1881 			port->device = device;
1882 			break;
1883 		}
1884 	}
1885 	if (!port->device) {
1886 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
1887 			    port->id->verbs);
1888 		rdma_destroy_id(port->id);
1889 		free(port);
1890 		pthread_mutex_unlock(&rtransport->lock);
1891 		return -EINVAL;
1892 	}
1893 
1894 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
1895 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
1896 
1897 	port->ref = 1;
1898 
1899 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
1900 	pthread_mutex_unlock(&rtransport->lock);
1901 
1902 	return 0;
1903 }
1904 
1905 static int
1906 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
1907 			   const struct spdk_nvme_transport_id *_trid)
1908 {
1909 	struct spdk_nvmf_rdma_transport *rtransport;
1910 	struct spdk_nvmf_rdma_port *port, *tmp;
1911 	struct spdk_nvme_transport_id trid = {};
1912 
1913 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1914 
1915 	/* Selectively copy the trid. Things like NQN don't matter here - that
1916 	 * mapping is enforced elsewhere.
1917 	 */
1918 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1919 	trid.adrfam = _trid->adrfam;
1920 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
1921 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
1922 
1923 	pthread_mutex_lock(&rtransport->lock);
1924 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
1925 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
1926 			assert(port->ref > 0);
1927 			port->ref--;
1928 			if (port->ref == 0) {
1929 				TAILQ_REMOVE(&rtransport->ports, port, link);
1930 				rdma_destroy_id(port->id);
1931 				free(port);
1932 			}
1933 			break;
1934 		}
1935 	}
1936 
1937 	pthread_mutex_unlock(&rtransport->lock);
1938 	return 0;
1939 }
1940 
1941 static bool
1942 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
1943 {
1944 	int cur_queue_depth, cur_rdma_rw_depth;
1945 	struct spdk_nvmf_rdma_qpair *rqpair;
1946 
1947 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1948 	cur_queue_depth = spdk_nvmf_rdma_cur_queue_depth(rqpair);
1949 	cur_rdma_rw_depth = spdk_nvmf_rdma_cur_rw_depth(rqpair);
1950 
1951 	if (cur_queue_depth == 0 && cur_rdma_rw_depth == 0) {
1952 		return true;
1953 	}
1954 	return false;
1955 }
1956 
1957 static void
1958 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
1959 				     struct spdk_nvmf_rdma_qpair *rqpair)
1960 {
1961 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
1962 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
1963 
1964 	/* We process I/O in the data transfer pending queue at the highest priority. */
1965 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->state_queue[RDMA_REQUEST_STATE_DATA_TRANSFER_PENDING],
1966 			   state_link, req_tmp) {
1967 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1968 			break;
1969 		}
1970 	}
1971 
1972 	/* The second highest priority is I/O waiting on memory buffers. */
1973 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->ch->pending_data_buf_queue, link,
1974 			   req_tmp) {
1975 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1976 			break;
1977 		}
1978 	}
1979 
1980 	/* The lowest priority is processing newly received commands */
1981 	TAILQ_FOREACH_SAFE(rdma_recv, &rqpair->incoming_queue, link, recv_tmp) {
1982 		if (TAILQ_EMPTY(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE])) {
1983 			break;
1984 		}
1985 
1986 		rdma_req = TAILQ_FIRST(&rqpair->state_queue[RDMA_REQUEST_STATE_FREE]);
1987 		rdma_req->recv = rdma_recv;
1988 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_NEW);
1989 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1990 			break;
1991 		}
1992 	}
1993 }
1994 
1995 static void
1996 _nvmf_rdma_qpair_disconnect(void *ctx)
1997 {
1998 	struct spdk_nvmf_qpair *qpair = ctx;
1999 	struct spdk_nvmf_rdma_qpair *rqpair;
2000 
2001 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2002 
2003 	spdk_nvmf_rdma_qpair_dec_refcnt(rqpair);
2004 
2005 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
2006 }
2007 
2008 static void
2009 _nvmf_rdma_disconnect_retry(void *ctx)
2010 {
2011 	struct spdk_nvmf_qpair *qpair = ctx;
2012 	struct spdk_nvmf_poll_group *group;
2013 
2014 	/* Read the group out of the qpair. This is normally set and accessed only from
2015 	 * the thread that created the group. Here, we're not on that thread necessarily.
2016 	 * The data member qpair->group begins it's life as NULL and then is assigned to
2017 	 * a pointer and never changes. So fortunately reading this and checking for
2018 	 * non-NULL is thread safe in the x86_64 memory model. */
2019 	group = qpair->group;
2020 
2021 	if (group == NULL) {
2022 		/* The qpair hasn't been assigned to a group yet, so we can't
2023 		 * process a disconnect. Send a message to ourself and try again. */
2024 		spdk_thread_send_msg(spdk_get_thread(), _nvmf_rdma_disconnect_retry, qpair);
2025 		return;
2026 	}
2027 
2028 	spdk_thread_send_msg(group->thread, _nvmf_rdma_qpair_disconnect, qpair);
2029 }
2030 
2031 static int
2032 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
2033 {
2034 	struct spdk_nvmf_qpair		*qpair;
2035 	struct spdk_nvmf_rdma_qpair	*rqpair;
2036 
2037 	if (evt->id == NULL) {
2038 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
2039 		return -1;
2040 	}
2041 
2042 	qpair = evt->id->context;
2043 	if (qpair == NULL) {
2044 		SPDK_ERRLOG("disconnect request: no active connection\n");
2045 		return -1;
2046 	}
2047 
2048 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2049 
2050 	spdk_trace_record(TRACE_RDMA_QP_DISCONNECT, 0, 0, (uintptr_t)rqpair->cm_id, 0);
2051 
2052 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2053 	spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2054 
2055 	_nvmf_rdma_disconnect_retry(qpair);
2056 
2057 	return 0;
2058 }
2059 
2060 #ifdef DEBUG
2061 static const char *CM_EVENT_STR[] = {
2062 	"RDMA_CM_EVENT_ADDR_RESOLVED",
2063 	"RDMA_CM_EVENT_ADDR_ERROR",
2064 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
2065 	"RDMA_CM_EVENT_ROUTE_ERROR",
2066 	"RDMA_CM_EVENT_CONNECT_REQUEST",
2067 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
2068 	"RDMA_CM_EVENT_CONNECT_ERROR",
2069 	"RDMA_CM_EVENT_UNREACHABLE",
2070 	"RDMA_CM_EVENT_REJECTED",
2071 	"RDMA_CM_EVENT_ESTABLISHED",
2072 	"RDMA_CM_EVENT_DISCONNECTED",
2073 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
2074 	"RDMA_CM_EVENT_MULTICAST_JOIN",
2075 	"RDMA_CM_EVENT_MULTICAST_ERROR",
2076 	"RDMA_CM_EVENT_ADDR_CHANGE",
2077 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
2078 };
2079 #endif /* DEBUG */
2080 
2081 static void
2082 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2083 {
2084 	struct spdk_nvmf_rdma_transport *rtransport;
2085 	struct rdma_cm_event		*event;
2086 	int				rc;
2087 
2088 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2089 
2090 	if (rtransport->event_channel == NULL) {
2091 		return;
2092 	}
2093 
2094 	while (1) {
2095 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
2096 		if (rc == 0) {
2097 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
2098 
2099 			spdk_trace_record(TRACE_RDMA_CM_ASYNC_EVENT, 0, 0, 0, event->event);
2100 
2101 			switch (event->event) {
2102 			case RDMA_CM_EVENT_ADDR_RESOLVED:
2103 			case RDMA_CM_EVENT_ADDR_ERROR:
2104 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
2105 			case RDMA_CM_EVENT_ROUTE_ERROR:
2106 				/* No action required. The target never attempts to resolve routes. */
2107 				break;
2108 			case RDMA_CM_EVENT_CONNECT_REQUEST:
2109 				rc = nvmf_rdma_connect(transport, event, cb_fn);
2110 				if (rc < 0) {
2111 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
2112 					break;
2113 				}
2114 				break;
2115 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
2116 				/* The target never initiates a new connection. So this will not occur. */
2117 				break;
2118 			case RDMA_CM_EVENT_CONNECT_ERROR:
2119 				/* Can this happen? The docs say it can, but not sure what causes it. */
2120 				break;
2121 			case RDMA_CM_EVENT_UNREACHABLE:
2122 			case RDMA_CM_EVENT_REJECTED:
2123 				/* These only occur on the client side. */
2124 				break;
2125 			case RDMA_CM_EVENT_ESTABLISHED:
2126 				/* TODO: Should we be waiting for this event anywhere? */
2127 				break;
2128 			case RDMA_CM_EVENT_DISCONNECTED:
2129 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
2130 				rc = nvmf_rdma_disconnect(event);
2131 				if (rc < 0) {
2132 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
2133 					break;
2134 				}
2135 				break;
2136 			case RDMA_CM_EVENT_MULTICAST_JOIN:
2137 			case RDMA_CM_EVENT_MULTICAST_ERROR:
2138 				/* Multicast is not used */
2139 				break;
2140 			case RDMA_CM_EVENT_ADDR_CHANGE:
2141 				/* Not utilizing this event */
2142 				break;
2143 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
2144 				/* For now, do nothing. The target never re-uses queue pairs. */
2145 				break;
2146 			default:
2147 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
2148 				break;
2149 			}
2150 
2151 			rdma_ack_cm_event(event);
2152 		} else {
2153 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
2154 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
2155 			}
2156 			break;
2157 		}
2158 	}
2159 }
2160 
2161 static void
2162 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
2163 {
2164 	int				rc;
2165 	struct spdk_nvmf_rdma_qpair	*rqpair;
2166 	struct ibv_async_event		event;
2167 	enum ibv_qp_state		state;
2168 
2169 	rc = ibv_get_async_event(device->context, &event);
2170 
2171 	if (rc) {
2172 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
2173 			    errno, spdk_strerror(errno));
2174 		return;
2175 	}
2176 
2177 	SPDK_NOTICELOG("Async event: %s\n",
2178 		       ibv_event_type_str(event.event_type));
2179 
2180 	switch (event.event_type) {
2181 	case IBV_EVENT_QP_FATAL:
2182 		rqpair = event.element.qp->qp_context;
2183 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2184 				  (uintptr_t)rqpair->cm_id, event.event_type);
2185 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2186 		spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2187 		spdk_thread_send_msg(rqpair->qpair.group->thread, _nvmf_rdma_qpair_disconnect, &rqpair->qpair);
2188 		break;
2189 	case IBV_EVENT_QP_LAST_WQE_REACHED:
2190 		/* This event only occurs for shared receive queues, which are not currently supported. */
2191 		break;
2192 	case IBV_EVENT_SQ_DRAINED:
2193 		/* This event occurs frequently in both error and non-error states.
2194 		 * Check if the qpair is in an error state before sending a message.
2195 		 * Note that we're not on the correct thread to access the qpair, but
2196 		 * the operations that the below calls make all happen to be thread
2197 		 * safe. */
2198 		rqpair = event.element.qp->qp_context;
2199 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2200 				  (uintptr_t)rqpair->cm_id, event.event_type);
2201 		state = spdk_nvmf_rdma_update_ibv_state(rqpair);
2202 		if (state == IBV_QPS_ERR) {
2203 			spdk_nvmf_rdma_qpair_inc_refcnt(rqpair);
2204 			spdk_thread_send_msg(rqpair->qpair.group->thread, _nvmf_rdma_qpair_disconnect, &rqpair->qpair);
2205 		}
2206 		break;
2207 	case IBV_EVENT_QP_REQ_ERR:
2208 	case IBV_EVENT_QP_ACCESS_ERR:
2209 	case IBV_EVENT_COMM_EST:
2210 	case IBV_EVENT_PATH_MIG:
2211 	case IBV_EVENT_PATH_MIG_ERR:
2212 		rqpair = event.element.qp->qp_context;
2213 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0,
2214 				  (uintptr_t)rqpair->cm_id, event.event_type);
2215 		spdk_nvmf_rdma_update_ibv_state(rqpair);
2216 		break;
2217 	case IBV_EVENT_CQ_ERR:
2218 	case IBV_EVENT_DEVICE_FATAL:
2219 	case IBV_EVENT_PORT_ACTIVE:
2220 	case IBV_EVENT_PORT_ERR:
2221 	case IBV_EVENT_LID_CHANGE:
2222 	case IBV_EVENT_PKEY_CHANGE:
2223 	case IBV_EVENT_SM_CHANGE:
2224 	case IBV_EVENT_SRQ_ERR:
2225 	case IBV_EVENT_SRQ_LIMIT_REACHED:
2226 	case IBV_EVENT_CLIENT_REREGISTER:
2227 	case IBV_EVENT_GID_CHANGE:
2228 	default:
2229 		spdk_trace_record(TRACE_RDMA_IBV_ASYNC_EVENT, 0, 0, 0, event.event_type);
2230 		break;
2231 	}
2232 	ibv_ack_async_event(&event);
2233 }
2234 
2235 static void
2236 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
2237 {
2238 	int	nfds, i = 0;
2239 	struct spdk_nvmf_rdma_transport *rtransport;
2240 	struct spdk_nvmf_rdma_device *device, *tmp;
2241 
2242 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2243 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
2244 
2245 	if (nfds <= 0) {
2246 		return;
2247 	}
2248 
2249 	/* The first poll descriptor is RDMA CM event */
2250 	if (rtransport->poll_fds[i++].revents & POLLIN) {
2251 		spdk_nvmf_process_cm_event(transport, cb_fn);
2252 		nfds--;
2253 	}
2254 
2255 	if (nfds == 0) {
2256 		return;
2257 	}
2258 
2259 	/* Second and subsequent poll descriptors are IB async events */
2260 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
2261 		if (rtransport->poll_fds[i++].revents & POLLIN) {
2262 			spdk_nvmf_process_ib_event(device);
2263 			nfds--;
2264 		}
2265 	}
2266 	/* check all flagged fd's have been served */
2267 	assert(nfds == 0);
2268 }
2269 
2270 static void
2271 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
2272 			struct spdk_nvme_transport_id *trid,
2273 			struct spdk_nvmf_discovery_log_page_entry *entry)
2274 {
2275 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
2276 	entry->adrfam = trid->adrfam;
2277 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
2278 
2279 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
2280 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
2281 
2282 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
2283 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
2284 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
2285 }
2286 
2287 static struct spdk_nvmf_transport_poll_group *
2288 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
2289 {
2290 	struct spdk_nvmf_rdma_transport		*rtransport;
2291 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2292 	struct spdk_nvmf_rdma_poller		*poller;
2293 	struct spdk_nvmf_rdma_device		*device;
2294 
2295 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
2296 
2297 	rgroup = calloc(1, sizeof(*rgroup));
2298 	if (!rgroup) {
2299 		return NULL;
2300 	}
2301 
2302 	TAILQ_INIT(&rgroup->pollers);
2303 
2304 	pthread_mutex_lock(&rtransport->lock);
2305 	TAILQ_FOREACH(device, &rtransport->devices, link) {
2306 		poller = calloc(1, sizeof(*poller));
2307 		if (!poller) {
2308 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
2309 			free(rgroup);
2310 			pthread_mutex_unlock(&rtransport->lock);
2311 			return NULL;
2312 		}
2313 
2314 		poller->device = device;
2315 		poller->group = rgroup;
2316 
2317 		TAILQ_INIT(&poller->qpairs);
2318 
2319 		poller->cq = ibv_create_cq(device->context, NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
2320 		if (!poller->cq) {
2321 			SPDK_ERRLOG("Unable to create completion queue\n");
2322 			free(poller);
2323 			free(rgroup);
2324 			pthread_mutex_unlock(&rtransport->lock);
2325 			return NULL;
2326 		}
2327 
2328 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
2329 	}
2330 
2331 	pthread_mutex_unlock(&rtransport->lock);
2332 	return &rgroup->group;
2333 }
2334 
2335 static void
2336 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
2337 {
2338 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2339 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
2340 	struct spdk_nvmf_rdma_qpair		*qpair, *tmp_qpair;
2341 
2342 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2343 
2344 	if (!rgroup) {
2345 		return;
2346 	}
2347 
2348 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
2349 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
2350 
2351 		if (poller->cq) {
2352 			ibv_destroy_cq(poller->cq);
2353 		}
2354 		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {
2355 			spdk_nvmf_rdma_qpair_destroy(qpair);
2356 		}
2357 
2358 		free(poller);
2359 	}
2360 
2361 	free(rgroup);
2362 }
2363 
2364 static int
2365 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
2366 			      struct spdk_nvmf_qpair *qpair)
2367 {
2368 	struct spdk_nvmf_rdma_transport		*rtransport;
2369 	struct spdk_nvmf_rdma_poll_group	*rgroup;
2370 	struct spdk_nvmf_rdma_qpair		*rqpair;
2371 	struct spdk_nvmf_rdma_device		*device;
2372 	struct spdk_nvmf_rdma_poller		*poller;
2373 	int					rc;
2374 
2375 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
2376 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2377 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2378 
2379 	device = rqpair->port->device;
2380 
2381 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
2382 		if (poller->device == device) {
2383 			break;
2384 		}
2385 	}
2386 
2387 	if (!poller) {
2388 		SPDK_ERRLOG("No poller found for device.\n");
2389 		return -1;
2390 	}
2391 
2392 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
2393 	rqpair->poller = poller;
2394 
2395 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
2396 	if (rc < 0) {
2397 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
2398 		return -1;
2399 	}
2400 
2401 	rqpair->mgmt_channel = spdk_get_io_channel(rtransport);
2402 	if (!rqpair->mgmt_channel) {
2403 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2404 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2405 		return -1;
2406 	}
2407 
2408 	rqpair->ch = spdk_io_channel_get_ctx(rqpair->mgmt_channel);
2409 	assert(rqpair->ch != NULL);
2410 
2411 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
2412 	if (rc) {
2413 		/* Try to reject, but we probably can't */
2414 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
2415 		spdk_nvmf_rdma_qpair_destroy(rqpair);
2416 		return -1;
2417 	}
2418 
2419 	spdk_nvmf_rdma_update_ibv_state(rqpair);
2420 
2421 	return 0;
2422 }
2423 
2424 static int
2425 spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
2426 {
2427 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
2428 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2429 			struct spdk_nvmf_rdma_transport, transport);
2430 
2431 	if (rdma_req->data_from_pool) {
2432 		/* Put the buffer/s back in the pool */
2433 		for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
2434 			spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
2435 			rdma_req->req.iov[i].iov_base = NULL;
2436 			rdma_req->data.buffers[i] = NULL;
2437 		}
2438 		rdma_req->data_from_pool = false;
2439 	}
2440 	rdma_req->req.length = 0;
2441 	rdma_req->req.iovcnt = 0;
2442 	rdma_req->req.data = NULL;
2443 	spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
2444 	return 0;
2445 }
2446 
2447 static int
2448 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
2449 {
2450 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
2451 			struct spdk_nvmf_rdma_transport, transport);
2452 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req,
2453 			struct spdk_nvmf_rdma_request, req);
2454 	struct spdk_nvmf_rdma_qpair     *rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair,
2455 			struct spdk_nvmf_rdma_qpair, qpair);
2456 
2457 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2458 		/* The connection is alive, so process the request as normal */
2459 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_EXECUTED);
2460 	} else {
2461 		/* The connection is dead. Move the request directly to the completed state. */
2462 		spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2463 	}
2464 
2465 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2466 
2467 	return 0;
2468 }
2469 
2470 static void
2471 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
2472 {
2473 	struct spdk_nvmf_rdma_qpair *rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2474 	struct ibv_recv_wr recv_wr = {};
2475 	struct ibv_recv_wr *bad_recv_wr;
2476 	struct ibv_send_wr send_wr = {};
2477 	struct ibv_send_wr *bad_send_wr;
2478 	int rc;
2479 
2480 	if (rqpair->disconnect_flags & RDMA_QP_DISCONNECTING) {
2481 		return;
2482 	}
2483 
2484 	rqpair->disconnect_flags |= RDMA_QP_DISCONNECTING;
2485 
2486 	if (rqpair->ibv_attr.qp_state != IBV_QPS_ERR) {
2487 		spdk_nvmf_rdma_set_ibv_state(rqpair, IBV_QPS_ERR);
2488 	}
2489 
2490 	rqpair->drain_recv_wr.type = RDMA_WR_TYPE_DRAIN_RECV;
2491 	recv_wr.wr_id = (uintptr_t)&rqpair->drain_recv_wr;
2492 	rc = ibv_post_recv(rqpair->cm_id->qp, &recv_wr, &bad_recv_wr);
2493 	if (rc) {
2494 		SPDK_ERRLOG("Failed to post dummy receive WR, errno %d\n", errno);
2495 		assert(false);
2496 		return;
2497 	}
2498 
2499 	rqpair->drain_send_wr.type = RDMA_WR_TYPE_DRAIN_SEND;
2500 	send_wr.wr_id = (uintptr_t)&rqpair->drain_send_wr;
2501 	send_wr.opcode = IBV_WR_SEND;
2502 	rc = ibv_post_send(rqpair->cm_id->qp, &send_wr, &bad_send_wr);
2503 	if (rc) {
2504 		SPDK_ERRLOG("Failed to post dummy send WR, errno %d\n", errno);
2505 		assert(false);
2506 		return;
2507 	}
2508 }
2509 
2510 #ifdef DEBUG
2511 static int
2512 spdk_nvmf_rdma_req_is_completing(struct spdk_nvmf_rdma_request *rdma_req)
2513 {
2514 	return rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_CONTROLLER_TO_HOST ||
2515 	       rdma_req->state == RDMA_REQUEST_STATE_COMPLETING;
2516 }
2517 #endif
2518 
2519 static int
2520 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2521 			   struct spdk_nvmf_rdma_poller *rpoller)
2522 {
2523 	struct ibv_wc wc[32];
2524 	struct spdk_nvmf_rdma_wr	*rdma_wr;
2525 	struct spdk_nvmf_rdma_request	*rdma_req;
2526 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2527 	struct spdk_nvmf_rdma_qpair	*rqpair;
2528 	int reaped, i;
2529 	int count = 0;
2530 	bool error = false;
2531 
2532 	/* Poll for completing operations. */
2533 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2534 	if (reaped < 0) {
2535 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2536 			    errno, spdk_strerror(errno));
2537 		return -1;
2538 	}
2539 
2540 	for (i = 0; i < reaped; i++) {
2541 
2542 		rdma_wr = (struct spdk_nvmf_rdma_wr *)wc[i].wr_id;
2543 
2544 		/* Handle error conditions */
2545 		if (wc[i].status) {
2546 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2547 				      rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2548 
2549 			error = true;
2550 
2551 			switch (rdma_wr->type) {
2552 			case RDMA_WR_TYPE_SEND:
2553 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2554 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2555 
2556 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2557 				/* We're going to attempt an error recovery, so force the request into
2558 				 * the completed state. */
2559 				spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2560 				spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2561 				break;
2562 			case RDMA_WR_TYPE_RECV:
2563 				rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2564 				rqpair = rdma_recv->qpair;
2565 
2566 				/* Dump this into the incoming queue. This gets cleaned up when
2567 				 * the queue pair disconnects or recovers. */
2568 				TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2569 				break;
2570 			case RDMA_WR_TYPE_DATA:
2571 				/* If the data transfer fails still force the queue into the error state,
2572 				 * but the rdma_req objects should only be manipulated in response to
2573 				 * SEND and RECV operations. */
2574 				rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2575 				SPDK_ERRLOG("data=%p length=%u\n", rdma_req->req.data, rdma_req->req.length);
2576 				rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2577 				break;
2578 			case RDMA_WR_TYPE_DRAIN_RECV:
2579 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_recv_wr);
2580 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2581 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP RECV %u (%p)\n", rqpair->qpair.qid, rqpair);
2582 				rqpair->disconnect_flags |= RDMA_QP_RECV_DRAINED;
2583 				if (rqpair->disconnect_flags & RDMA_QP_SEND_DRAINED) {
2584 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2585 				}
2586 				/* Continue so that this does not trigger the disconnect path below. */
2587 				continue;
2588 			case RDMA_WR_TYPE_DRAIN_SEND:
2589 				rqpair = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_qpair, drain_send_wr);
2590 				assert(rqpair->disconnect_flags & RDMA_QP_DISCONNECTING);
2591 				SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Drained QP SEND %u (%p)\n", rqpair->qpair.qid, rqpair);
2592 				rqpair->disconnect_flags |= RDMA_QP_SEND_DRAINED;
2593 				if (rqpair->disconnect_flags & RDMA_QP_RECV_DRAINED) {
2594 					spdk_nvmf_rdma_qpair_destroy(rqpair);
2595 				}
2596 				/* Continue so that this does not trigger the disconnect path below. */
2597 				continue;
2598 			default:
2599 				SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2600 				continue;
2601 			}
2602 
2603 			if (rqpair->qpair.state == SPDK_NVMF_QPAIR_ACTIVE) {
2604 				/* Disconnect the connection. */
2605 				spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);
2606 			}
2607 			continue;
2608 		}
2609 
2610 		switch (wc[i].opcode) {
2611 		case IBV_WC_SEND:
2612 			assert(rdma_wr->type == RDMA_WR_TYPE_SEND);
2613 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, rsp.rdma_wr);
2614 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2615 
2616 			assert(spdk_nvmf_rdma_req_is_completing(rdma_req));
2617 
2618 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_COMPLETED);
2619 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2620 
2621 			count++;
2622 
2623 			/* Try to process other queued requests */
2624 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2625 			break;
2626 
2627 		case IBV_WC_RDMA_WRITE:
2628 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2629 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2630 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2631 
2632 			/* Try to process other queued requests */
2633 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2634 			break;
2635 
2636 		case IBV_WC_RDMA_READ:
2637 			assert(rdma_wr->type == RDMA_WR_TYPE_DATA);
2638 			rdma_req = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_request, data.rdma_wr);
2639 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2640 
2641 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2642 			spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_READY_TO_EXECUTE);
2643 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2644 
2645 			/* Try to process other queued requests */
2646 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2647 			break;
2648 
2649 		case IBV_WC_RECV:
2650 			assert(rdma_wr->type == RDMA_WR_TYPE_RECV);
2651 			rdma_recv = SPDK_CONTAINEROF(rdma_wr, struct spdk_nvmf_rdma_recv, rdma_wr);
2652 			rqpair = rdma_recv->qpair;
2653 
2654 			TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2655 			/* Try to process other queued requests */
2656 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2657 			break;
2658 
2659 		default:
2660 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2661 			continue;
2662 		}
2663 	}
2664 
2665 	if (error == true) {
2666 		return -1;
2667 	}
2668 
2669 	return count;
2670 }
2671 
2672 static int
2673 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2674 {
2675 	struct spdk_nvmf_rdma_transport *rtransport;
2676 	struct spdk_nvmf_rdma_poll_group *rgroup;
2677 	struct spdk_nvmf_rdma_poller	*rpoller;
2678 	int				count, rc;
2679 
2680 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2681 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2682 
2683 	count = 0;
2684 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2685 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2686 		if (rc < 0) {
2687 			return rc;
2688 		}
2689 		count += rc;
2690 	}
2691 
2692 	return count;
2693 }
2694 
2695 static int
2696 spdk_nvmf_rdma_trid_from_cm_id(struct rdma_cm_id *id,
2697 			       struct spdk_nvme_transport_id *trid,
2698 			       bool peer)
2699 {
2700 	struct sockaddr *saddr;
2701 	uint16_t port;
2702 
2703 	trid->trtype = SPDK_NVME_TRANSPORT_RDMA;
2704 
2705 	if (peer) {
2706 		saddr = rdma_get_peer_addr(id);
2707 	} else {
2708 		saddr = rdma_get_local_addr(id);
2709 	}
2710 	switch (saddr->sa_family) {
2711 	case AF_INET: {
2712 		struct sockaddr_in *saddr_in = (struct sockaddr_in *)saddr;
2713 
2714 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV4;
2715 		inet_ntop(AF_INET, &saddr_in->sin_addr,
2716 			  trid->traddr, sizeof(trid->traddr));
2717 		if (peer) {
2718 			port = ntohs(rdma_get_dst_port(id));
2719 		} else {
2720 			port = ntohs(rdma_get_src_port(id));
2721 		}
2722 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2723 		break;
2724 	}
2725 	case AF_INET6: {
2726 		struct sockaddr_in6 *saddr_in = (struct sockaddr_in6 *)saddr;
2727 		trid->adrfam = SPDK_NVMF_ADRFAM_IPV6;
2728 		inet_ntop(AF_INET6, &saddr_in->sin6_addr,
2729 			  trid->traddr, sizeof(trid->traddr));
2730 		if (peer) {
2731 			port = ntohs(rdma_get_dst_port(id));
2732 		} else {
2733 			port = ntohs(rdma_get_src_port(id));
2734 		}
2735 		snprintf(trid->trsvcid, sizeof(trid->trsvcid), "%u", port);
2736 		break;
2737 	}
2738 	default:
2739 		return -1;
2740 
2741 	}
2742 
2743 	return 0;
2744 }
2745 
2746 static int
2747 spdk_nvmf_rdma_qpair_get_peer_trid(struct spdk_nvmf_qpair *qpair,
2748 				   struct spdk_nvme_transport_id *trid)
2749 {
2750 	struct spdk_nvmf_rdma_qpair	*rqpair;
2751 
2752 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2753 
2754 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, true);
2755 }
2756 
2757 static int
2758 spdk_nvmf_rdma_qpair_get_local_trid(struct spdk_nvmf_qpair *qpair,
2759 				    struct spdk_nvme_transport_id *trid)
2760 {
2761 	struct spdk_nvmf_rdma_qpair	*rqpair;
2762 
2763 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2764 
2765 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->cm_id, trid, false);
2766 }
2767 
2768 static int
2769 spdk_nvmf_rdma_qpair_get_listen_trid(struct spdk_nvmf_qpair *qpair,
2770 				     struct spdk_nvme_transport_id *trid)
2771 {
2772 	struct spdk_nvmf_rdma_qpair	*rqpair;
2773 
2774 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2775 
2776 	return spdk_nvmf_rdma_trid_from_cm_id(rqpair->listen_id, trid, false);
2777 }
2778 
2779 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
2780 	.type = SPDK_NVME_TRANSPORT_RDMA,
2781 	.opts_init = spdk_nvmf_rdma_opts_init,
2782 	.create = spdk_nvmf_rdma_create,
2783 	.destroy = spdk_nvmf_rdma_destroy,
2784 
2785 	.listen = spdk_nvmf_rdma_listen,
2786 	.stop_listen = spdk_nvmf_rdma_stop_listen,
2787 	.accept = spdk_nvmf_rdma_accept,
2788 
2789 	.listener_discover = spdk_nvmf_rdma_discover,
2790 
2791 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
2792 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
2793 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
2794 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
2795 
2796 	.req_free = spdk_nvmf_rdma_request_free,
2797 	.req_complete = spdk_nvmf_rdma_request_complete,
2798 
2799 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
2800 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
2801 	.qpair_get_peer_trid = spdk_nvmf_rdma_qpair_get_peer_trid,
2802 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
2803 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
2804 
2805 };
2806 
2807 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
2808