xref: /spdk/lib/nvmf/rdma.c (revision 6f9e81eea00d89dcf41c6789fdc06cf0ebfb169a)
1 /*-
2  *   BSD LICENSE
3  *
4  *   Copyright (c) Intel Corporation.
5  *   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/assert.h"
44 #include "spdk/thread.h"
45 #include "spdk/nvmf.h"
46 #include "spdk/nvmf_spec.h"
47 #include "spdk/string.h"
48 #include "spdk/trace.h"
49 #include "spdk/util.h"
50 
51 #include "spdk_internal/log.h"
52 
53 /*
54  RDMA Connection Resouce Defaults
55  */
56 #define NVMF_DEFAULT_TX_SGE		1
57 #define NVMF_DEFAULT_RX_SGE		2
58 #define NVMF_DEFAULT_DATA_SGE		16
59 
60 /* The RDMA completion queue size */
61 #define NVMF_RDMA_CQ_SIZE	4096
62 
63 /* AIO backend requires block size aligned data buffers,
64  * extra 4KiB aligned data buffer should work for most devices.
65  */
66 #define SHIFT_4KB			12
67 #define NVMF_DATA_BUFFER_ALIGNMENT	(1 << SHIFT_4KB)
68 #define NVMF_DATA_BUFFER_MASK		(NVMF_DATA_BUFFER_ALIGNMENT - 1)
69 
70 enum spdk_nvmf_rdma_request_state {
71 	/* The request is not currently in use */
72 	RDMA_REQUEST_STATE_FREE = 0,
73 
74 	/* Initial state when request first received */
75 	RDMA_REQUEST_STATE_NEW,
76 
77 	/* The request is queued until a data buffer is available. */
78 	RDMA_REQUEST_STATE_NEED_BUFFER,
79 
80 	/* The request is waiting on RDMA queue depth availability
81 	 * to transfer data from the host to the controller.
82 	 */
83 	RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER,
84 
85 	/* The request is currently transferring data from the host to the controller. */
86 	RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
87 
88 	/* The request is ready to execute at the block device */
89 	RDMA_REQUEST_STATE_READY_TO_EXECUTE,
90 
91 	/* The request is currently executing at the block device */
92 	RDMA_REQUEST_STATE_EXECUTING,
93 
94 	/* The request finished executing at the block device */
95 	RDMA_REQUEST_STATE_EXECUTED,
96 
97 	/* The request is waiting on RDMA queue depth availability
98 	 * to transfer data from the controller to the host.
99 	 */
100 	RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST,
101 
102 	/* The request is ready to send a completion */
103 	RDMA_REQUEST_STATE_READY_TO_COMPLETE,
104 
105 	/* The request currently has a completion outstanding */
106 	RDMA_REQUEST_STATE_COMPLETING,
107 
108 	/* The request completed and can be marked free. */
109 	RDMA_REQUEST_STATE_COMPLETED,
110 };
111 
112 #define OBJECT_NVMF_RDMA_IO				0x40
113 
114 #define									TRACE_GROUP_NVMF_RDMA 0x4
115 #define TRACE_RDMA_REQUEST_STATE_NEW					SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x0)
116 #define TRACE_RDMA_REQUEST_STATE_NEED_BUFFER				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x1)
117 #define TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x2)
118 #define TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x3)
119 #define TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x4)
120 #define TRACE_RDMA_REQUEST_STATE_EXECUTING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x5)
121 #define TRACE_RDMA_REQUEST_STATE_EXECUTED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x6)
122 #define TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST	SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x7)
123 #define TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE			SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x8)
124 #define TRACE_RDMA_REQUEST_STATE_COMPLETING				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0x9)
125 #define TRACE_RDMA_REQUEST_STATE_COMPLETED				SPDK_TPOINT_ID(TRACE_GROUP_NVMF_RDMA, 0xA)
126 
127 SPDK_TRACE_REGISTER_FN(nvmf_trace)
128 {
129 	spdk_trace_register_object(OBJECT_NVMF_RDMA_IO, 'r');
130 	spdk_trace_register_description("RDMA_REQ_NEW", "",
131 					TRACE_RDMA_REQUEST_STATE_NEW,
132 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 1, 0, 0, "");
133 	spdk_trace_register_description("RDMA_REQ_NEED_BUFFER", "",
134 					TRACE_RDMA_REQUEST_STATE_NEED_BUFFER,
135 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
136 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_H_TO_C", "",
137 					TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER,
138 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
139 	spdk_trace_register_description("RDMA_REQ_TX_H_TO_C", "",
140 					TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER,
141 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
142 	spdk_trace_register_description("RDMA_REQ_RDY_TO_EXECUTE", "",
143 					TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE,
144 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
145 	spdk_trace_register_description("RDMA_REQ_EXECUTING", "",
146 					TRACE_RDMA_REQUEST_STATE_EXECUTING,
147 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
148 	spdk_trace_register_description("RDMA_REQ_EXECUTED", "",
149 					TRACE_RDMA_REQUEST_STATE_EXECUTED,
150 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
151 	spdk_trace_register_description("RDMA_REQ_TX_PENDING_C_TO_H", "",
152 					TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST,
153 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
154 	spdk_trace_register_description("RDMA_REQ_RDY_TO_COMPLETE", "",
155 					TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE,
156 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
157 	spdk_trace_register_description("RDMA_REQ_COMPLETING", "",
158 					TRACE_RDMA_REQUEST_STATE_COMPLETING,
159 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
160 	spdk_trace_register_description("RDMA_REQ_COMPLETED", "",
161 					TRACE_RDMA_REQUEST_STATE_COMPLETED,
162 					OWNER_NONE, OBJECT_NVMF_RDMA_IO, 0, 0, 0, "");
163 }
164 
165 /* This structure holds commands as they are received off the wire.
166  * It must be dynamically paired with a full request object
167  * (spdk_nvmf_rdma_request) to service a request. It is separate
168  * from the request because RDMA does not appear to order
169  * completions, so occasionally we'll get a new incoming
170  * command when there aren't any free request objects.
171  */
172 struct spdk_nvmf_rdma_recv {
173 	struct ibv_recv_wr		wr;
174 	struct ibv_sge			sgl[NVMF_DEFAULT_RX_SGE];
175 
176 	struct spdk_nvmf_rdma_qpair	*qpair;
177 
178 	/* In-capsule data buffer */
179 	uint8_t				*buf;
180 
181 	TAILQ_ENTRY(spdk_nvmf_rdma_recv) link;
182 };
183 
184 struct spdk_nvmf_rdma_request {
185 	struct spdk_nvmf_request		req;
186 	bool					data_from_pool;
187 
188 	enum spdk_nvmf_rdma_request_state	state;
189 
190 	struct spdk_nvmf_rdma_recv		*recv;
191 
192 	struct {
193 		struct	ibv_send_wr		wr;
194 		struct	ibv_sge			sgl[NVMF_DEFAULT_TX_SGE];
195 	} rsp;
196 
197 	struct {
198 		struct ibv_send_wr		wr;
199 		struct ibv_sge			sgl[SPDK_NVMF_MAX_SGL_ENTRIES];
200 		void				*buffers[SPDK_NVMF_MAX_SGL_ENTRIES];
201 	} data;
202 
203 	TAILQ_ENTRY(spdk_nvmf_rdma_request)	link;
204 };
205 
206 struct spdk_nvmf_rdma_qpair {
207 	struct spdk_nvmf_qpair			qpair;
208 
209 	struct spdk_nvmf_rdma_port		*port;
210 	struct spdk_nvmf_rdma_poller		*poller;
211 
212 	struct rdma_cm_id			*cm_id;
213 
214 	/* The maximum number of I/O outstanding on this connection at one time */
215 	uint16_t				max_queue_depth;
216 
217 	/* The maximum number of active RDMA READ and WRITE operations at one time */
218 	uint16_t				max_rw_depth;
219 
220 	/* The current number of I/O outstanding on this connection. This number
221 	 * includes all I/O from the time the capsule is first received until it is
222 	 * completed.
223 	 */
224 	uint16_t				cur_queue_depth;
225 
226 	/* The number of RDMA READ and WRITE requests that are outstanding */
227 	uint16_t				cur_rdma_rw_depth;
228 
229 	/* Receives that are waiting for a request object */
230 	TAILQ_HEAD(, spdk_nvmf_rdma_recv)	incoming_queue;
231 
232 	/* Requests that are not in use */
233 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	free_queue;
234 
235 	/* Requests that are waiting to perform an RDMA READ or WRITE */
236 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_rdma_rw_queue;
237 
238 	/* Array of size "max_queue_depth" containing RDMA requests. */
239 	struct spdk_nvmf_rdma_request		*reqs;
240 
241 	/* Array of size "max_queue_depth" containing RDMA recvs. */
242 	struct spdk_nvmf_rdma_recv		*recvs;
243 
244 	/* Array of size "max_queue_depth" containing 64 byte capsules
245 	 * used for receive.
246 	 */
247 	union nvmf_h2c_msg			*cmds;
248 	struct ibv_mr				*cmds_mr;
249 
250 	/* Array of size "max_queue_depth" containing 16 byte completions
251 	 * to be sent back to the user.
252 	 */
253 	union nvmf_c2h_msg			*cpls;
254 	struct ibv_mr				*cpls_mr;
255 
256 	/* Array of size "max_queue_depth * InCapsuleDataSize" containing
257 	 * buffers to be used for in capsule data.
258 	 */
259 	void					*bufs;
260 	struct ibv_mr				*bufs_mr;
261 
262 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;
263 	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	pending_link;
264 
265 	/* Mgmt channel */
266 	struct spdk_io_channel			*mgmt_channel;
267 	struct spdk_nvmf_rdma_mgmt_channel	*ch;
268 };
269 
270 struct spdk_nvmf_rdma_poller {
271 	struct spdk_nvmf_rdma_device		*device;
272 	struct spdk_nvmf_rdma_poll_group	*group;
273 
274 	struct ibv_cq				*cq;
275 
276 	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;
277 
278 	TAILQ_ENTRY(spdk_nvmf_rdma_poller)	link;
279 };
280 
281 struct spdk_nvmf_rdma_poll_group {
282 	struct spdk_nvmf_transport_poll_group	group;
283 
284 	TAILQ_HEAD(, spdk_nvmf_rdma_poller)	pollers;
285 };
286 
287 /* Assuming rdma_cm uses just one protection domain per ibv_context. */
288 struct spdk_nvmf_rdma_device {
289 	struct ibv_device_attr			attr;
290 	struct ibv_context			*context;
291 
292 	struct spdk_mem_map			*map;
293 	struct ibv_pd				*pd;
294 
295 	TAILQ_ENTRY(spdk_nvmf_rdma_device)	link;
296 };
297 
298 struct spdk_nvmf_rdma_port {
299 	struct spdk_nvme_transport_id		trid;
300 	struct rdma_cm_id			*id;
301 	struct spdk_nvmf_rdma_device		*device;
302 	uint32_t				ref;
303 	TAILQ_ENTRY(spdk_nvmf_rdma_port)	link;
304 };
305 
306 struct spdk_nvmf_rdma_transport {
307 	struct spdk_nvmf_transport	transport;
308 
309 	struct rdma_event_channel	*event_channel;
310 
311 	struct spdk_mempool		*data_buf_pool;
312 
313 	pthread_mutex_t			lock;
314 
315 	uint16_t			max_queue_depth;
316 	uint32_t			max_io_size;
317 	uint32_t			io_unit_size;
318 	uint32_t			in_capsule_data_size;
319 
320 	/* fields used to poll RDMA/IB events */
321 	nfds_t			npoll_fds;
322 	struct pollfd		*poll_fds;
323 
324 	TAILQ_HEAD(, spdk_nvmf_rdma_device)	devices;
325 	TAILQ_HEAD(, spdk_nvmf_rdma_port)	ports;
326 };
327 
328 struct spdk_nvmf_rdma_mgmt_channel {
329 	/* Requests that are waiting to obtain a data buffer */
330 	TAILQ_HEAD(, spdk_nvmf_rdma_request)	pending_data_buf_queue;
331 };
332 
333 static int
334 spdk_nvmf_rdma_mgmt_channel_create(void *io_device, void *ctx_buf)
335 {
336 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
337 
338 	TAILQ_INIT(&ch->pending_data_buf_queue);
339 	return 0;
340 }
341 
342 static void
343 spdk_nvmf_rdma_mgmt_channel_destroy(void *io_device, void *ctx_buf)
344 {
345 	struct spdk_nvmf_rdma_mgmt_channel *ch = ctx_buf;
346 
347 	if (!TAILQ_EMPTY(&ch->pending_data_buf_queue)) {
348 		SPDK_ERRLOG("Pending I/O list wasn't empty on channel destruction\n");
349 	}
350 }
351 
352 static void
353 spdk_nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair)
354 {
355 	if (rqpair->poller) {
356 		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);
357 	}
358 
359 	if (rqpair->cmds_mr) {
360 		ibv_dereg_mr(rqpair->cmds_mr);
361 	}
362 
363 	if (rqpair->cpls_mr) {
364 		ibv_dereg_mr(rqpair->cpls_mr);
365 	}
366 
367 	if (rqpair->bufs_mr) {
368 		ibv_dereg_mr(rqpair->bufs_mr);
369 	}
370 
371 	if (rqpair->cm_id) {
372 		rdma_destroy_qp(rqpair->cm_id);
373 		rdma_destroy_id(rqpair->cm_id);
374 	}
375 
376 	if (rqpair->mgmt_channel) {
377 		spdk_put_io_channel(rqpair->mgmt_channel);
378 	}
379 
380 	/* Free all memory */
381 	spdk_dma_free(rqpair->cmds);
382 	spdk_dma_free(rqpair->cpls);
383 	spdk_dma_free(rqpair->bufs);
384 	free(rqpair->reqs);
385 	free(rqpair->recvs);
386 	free(rqpair);
387 }
388 
389 static int
390 spdk_nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair)
391 {
392 	struct spdk_nvmf_rdma_transport *rtransport;
393 	struct spdk_nvmf_rdma_qpair	*rqpair;
394 	int				rc, i;
395 	struct ibv_qp_init_attr		attr;
396 	struct spdk_nvmf_rdma_recv	*rdma_recv;
397 	struct spdk_nvmf_rdma_request	*rdma_req;
398 
399 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
400 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
401 
402 	memset(&attr, 0, sizeof(struct ibv_qp_init_attr));
403 	attr.qp_type		= IBV_QPT_RC;
404 	attr.send_cq		= rqpair->poller->cq;
405 	attr.recv_cq		= rqpair->poller->cq;
406 	attr.cap.max_send_wr	= rqpair->max_queue_depth * 2; /* SEND, READ, and WRITE operations */
407 	attr.cap.max_recv_wr	= rqpair->max_queue_depth; /* RECV operations */
408 	attr.cap.max_send_sge	= SPDK_NVMF_MAX_SGL_ENTRIES;
409 	attr.cap.max_recv_sge	= NVMF_DEFAULT_RX_SGE;
410 
411 	rc = rdma_create_qp(rqpair->cm_id, NULL, &attr);
412 	if (rc) {
413 		SPDK_ERRLOG("rdma_create_qp failed: errno %d: %s\n", errno, spdk_strerror(errno));
414 		rdma_destroy_id(rqpair->cm_id);
415 		rqpair->cm_id = NULL;
416 		spdk_nvmf_rdma_qpair_destroy(rqpair);
417 		return -1;
418 	}
419 
420 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "New RDMA Connection: %p\n", qpair);
421 
422 	rqpair->reqs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->reqs));
423 	rqpair->recvs = calloc(rqpair->max_queue_depth, sizeof(*rqpair->recvs));
424 	rqpair->cmds = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cmds),
425 					0x1000, NULL);
426 	rqpair->cpls = spdk_dma_zmalloc(rqpair->max_queue_depth * sizeof(*rqpair->cpls),
427 					0x1000, NULL);
428 
429 	if (rtransport->in_capsule_data_size) {
430 		rqpair->bufs = spdk_dma_zmalloc(rqpair->max_queue_depth * rtransport->in_capsule_data_size,
431 						0x1000, NULL);
432 	}
433 
434 	if (!rqpair->reqs || !rqpair->recvs || !rqpair->cmds ||
435 	    !rqpair->cpls || (rtransport->in_capsule_data_size && !rqpair->bufs)) {
436 		SPDK_ERRLOG("Unable to allocate sufficient memory for RDMA queue.\n");
437 		spdk_nvmf_rdma_qpair_destroy(rqpair);
438 		return -1;
439 	}
440 
441 	rqpair->cmds_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cmds,
442 				     rqpair->max_queue_depth * sizeof(*rqpair->cmds),
443 				     IBV_ACCESS_LOCAL_WRITE);
444 	rqpair->cpls_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->cpls,
445 				     rqpair->max_queue_depth * sizeof(*rqpair->cpls),
446 				     0);
447 
448 	if (rtransport->in_capsule_data_size) {
449 		rqpair->bufs_mr = ibv_reg_mr(rqpair->cm_id->pd, rqpair->bufs,
450 					     rqpair->max_queue_depth * rtransport->in_capsule_data_size,
451 					     IBV_ACCESS_LOCAL_WRITE |
452 					     IBV_ACCESS_REMOTE_WRITE);
453 	}
454 
455 	if (!rqpair->cmds_mr || !rqpair->cpls_mr || (rtransport->in_capsule_data_size &&
456 			!rqpair->bufs_mr)) {
457 		SPDK_ERRLOG("Unable to register required memory for RDMA queue.\n");
458 		spdk_nvmf_rdma_qpair_destroy(rqpair);
459 		return -1;
460 	}
461 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Command Array: %p Length: %lx LKey: %x\n",
462 		      rqpair->cmds, rqpair->max_queue_depth * sizeof(*rqpair->cmds), rqpair->cmds_mr->lkey);
463 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Completion Array: %p Length: %lx LKey: %x\n",
464 		      rqpair->cpls, rqpair->max_queue_depth * sizeof(*rqpair->cpls), rqpair->cpls_mr->lkey);
465 	if (rqpair->bufs && rqpair->bufs_mr) {
466 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "In Capsule Data Array: %p Length: %x LKey: %x\n",
467 			      rqpair->bufs, rqpair->max_queue_depth * rtransport->in_capsule_data_size, rqpair->bufs_mr->lkey);
468 	}
469 
470 	for (i = 0; i < rqpair->max_queue_depth; i++) {
471 		struct ibv_recv_wr *bad_wr = NULL;
472 
473 		rdma_recv = &rqpair->recvs[i];
474 		rdma_recv->qpair = rqpair;
475 
476 		/* Set up memory to receive commands */
477 		if (rqpair->bufs) {
478 			rdma_recv->buf = (void *)((uintptr_t)rqpair->bufs + (i * rtransport->in_capsule_data_size));
479 		}
480 
481 		rdma_recv->sgl[0].addr = (uintptr_t)&rqpair->cmds[i];
482 		rdma_recv->sgl[0].length = sizeof(rqpair->cmds[i]);
483 		rdma_recv->sgl[0].lkey = rqpair->cmds_mr->lkey;
484 		rdma_recv->wr.num_sge = 1;
485 
486 		if (rdma_recv->buf && rqpair->bufs_mr) {
487 			rdma_recv->sgl[1].addr = (uintptr_t)rdma_recv->buf;
488 			rdma_recv->sgl[1].length = rtransport->in_capsule_data_size;
489 			rdma_recv->sgl[1].lkey = rqpair->bufs_mr->lkey;
490 			rdma_recv->wr.num_sge++;
491 		}
492 
493 		rdma_recv->wr.wr_id = (uintptr_t)rdma_recv;
494 		rdma_recv->wr.sg_list = rdma_recv->sgl;
495 
496 		rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_recv->wr, &bad_wr);
497 		if (rc) {
498 			SPDK_ERRLOG("Unable to post capsule for RDMA RECV\n");
499 			spdk_nvmf_rdma_qpair_destroy(rqpair);
500 			return -1;
501 		}
502 	}
503 
504 	for (i = 0; i < rqpair->max_queue_depth; i++) {
505 		rdma_req = &rqpair->reqs[i];
506 
507 		rdma_req->req.qpair = &rqpair->qpair;
508 		rdma_req->req.cmd = NULL;
509 
510 		/* Set up memory to send responses */
511 		rdma_req->req.rsp = &rqpair->cpls[i];
512 
513 		rdma_req->rsp.sgl[0].addr = (uintptr_t)&rqpair->cpls[i];
514 		rdma_req->rsp.sgl[0].length = sizeof(rqpair->cpls[i]);
515 		rdma_req->rsp.sgl[0].lkey = rqpair->cpls_mr->lkey;
516 
517 		rdma_req->rsp.wr.wr_id = (uintptr_t)rdma_req;
518 		rdma_req->rsp.wr.next = NULL;
519 		rdma_req->rsp.wr.opcode = IBV_WR_SEND;
520 		rdma_req->rsp.wr.send_flags = IBV_SEND_SIGNALED;
521 		rdma_req->rsp.wr.sg_list = rdma_req->rsp.sgl;
522 		rdma_req->rsp.wr.num_sge = SPDK_COUNTOF(rdma_req->rsp.sgl);
523 
524 		/* Set up memory for data buffers */
525 		rdma_req->data.wr.wr_id = (uint64_t)rdma_req;
526 		rdma_req->data.wr.next = NULL;
527 		rdma_req->data.wr.send_flags = IBV_SEND_SIGNALED;
528 		rdma_req->data.wr.sg_list = rdma_req->data.sgl;
529 		rdma_req->data.wr.num_sge = SPDK_COUNTOF(rdma_req->data.sgl);
530 
531 		TAILQ_INSERT_TAIL(&rqpair->free_queue, rdma_req, link);
532 	}
533 
534 	return 0;
535 }
536 
537 static int
538 request_transfer_in(struct spdk_nvmf_request *req)
539 {
540 	int				rc;
541 	struct spdk_nvmf_rdma_request	*rdma_req;
542 	struct spdk_nvmf_qpair		*qpair;
543 	struct spdk_nvmf_rdma_qpair	*rqpair;
544 	struct ibv_send_wr		*bad_wr = NULL;
545 
546 	qpair = req->qpair;
547 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
548 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
549 
550 	assert(req->xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER);
551 
552 	rqpair->cur_rdma_rw_depth++;
553 
554 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA READ POSTED. Request: %p Connection: %p\n", req, qpair);
555 
556 	rdma_req->data.wr.opcode = IBV_WR_RDMA_READ;
557 	rdma_req->data.wr.next = NULL;
558 	rc = ibv_post_send(rqpair->cm_id->qp, &rdma_req->data.wr, &bad_wr);
559 	if (rc) {
560 		SPDK_ERRLOG("Unable to transfer data from host to target\n");
561 
562 		/* Decrement r/w counter back since data transfer
563 		 * has not started.
564 		 */
565 		rqpair->cur_rdma_rw_depth--;
566 		return -1;
567 	}
568 
569 	return 0;
570 }
571 
572 static int
573 request_transfer_out(struct spdk_nvmf_request *req)
574 {
575 	int				rc;
576 	struct spdk_nvmf_rdma_request	*rdma_req;
577 	struct spdk_nvmf_qpair		*qpair;
578 	struct spdk_nvmf_rdma_qpair	*rqpair;
579 	struct spdk_nvme_cpl		*rsp;
580 	struct ibv_recv_wr		*bad_recv_wr = NULL;
581 	struct ibv_send_wr		*send_wr, *bad_send_wr = NULL;
582 
583 	qpair = req->qpair;
584 	rsp = &req->rsp->nvme_cpl;
585 	rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
586 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
587 
588 	/* Advance our sq_head pointer */
589 	if (qpair->sq_head == qpair->sq_head_max) {
590 		qpair->sq_head = 0;
591 	} else {
592 		qpair->sq_head++;
593 	}
594 	rsp->sqhd = qpair->sq_head;
595 
596 	/* Post the capsule to the recv buffer */
597 	assert(rdma_req->recv != NULL);
598 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA RECV POSTED. Recv: %p Connection: %p\n", rdma_req->recv,
599 		      rqpair);
600 	rc = ibv_post_recv(rqpair->cm_id->qp, &rdma_req->recv->wr, &bad_recv_wr);
601 	if (rc) {
602 		SPDK_ERRLOG("Unable to re-post rx descriptor\n");
603 		return rc;
604 	}
605 	rdma_req->recv = NULL;
606 
607 	/* Build the response which consists of an optional
608 	 * RDMA WRITE to transfer data, plus an RDMA SEND
609 	 * containing the response.
610 	 */
611 	send_wr = &rdma_req->rsp.wr;
612 
613 	if (rsp->status.sc == SPDK_NVME_SC_SUCCESS &&
614 	    req->xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
615 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA WRITE POSTED. Request: %p Connection: %p\n", req, qpair);
616 
617 		rqpair->cur_rdma_rw_depth++;
618 		rdma_req->data.wr.opcode = IBV_WR_RDMA_WRITE;
619 
620 		rdma_req->data.wr.next = send_wr;
621 		send_wr = &rdma_req->data.wr;
622 	}
623 
624 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "RDMA SEND POSTED. Request: %p Connection: %p\n", req, qpair);
625 
626 	/* Send the completion */
627 	rc = ibv_post_send(rqpair->cm_id->qp, send_wr, &bad_send_wr);
628 	if (rc) {
629 		SPDK_ERRLOG("Unable to send response capsule\n");
630 
631 		if (rdma_req->data.wr.opcode == IBV_WR_RDMA_WRITE) {
632 			/* Decrement r/w counter back since data transfer
633 			 * has not started.
634 			 */
635 			rqpair->cur_rdma_rw_depth--;
636 		}
637 	}
638 
639 	return rc;
640 }
641 
642 static int
643 spdk_nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpair)
644 {
645 	struct spdk_nvmf_rdma_accept_private_data	accept_data;
646 	struct rdma_conn_param				ctrlr_event_data = {};
647 	int						rc;
648 
649 	accept_data.recfmt = 0;
650 	accept_data.crqsize = rqpair->max_queue_depth;
651 
652 	ctrlr_event_data.private_data = &accept_data;
653 	ctrlr_event_data.private_data_len = sizeof(accept_data);
654 	if (id->ps == RDMA_PS_TCP) {
655 		ctrlr_event_data.responder_resources = 0; /* We accept 0 reads from the host */
656 		ctrlr_event_data.initiator_depth = rqpair->max_rw_depth;
657 	}
658 
659 	rc = rdma_accept(id, &ctrlr_event_data);
660 	if (rc) {
661 		SPDK_ERRLOG("Error %d on rdma_accept\n", errno);
662 	} else {
663 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Sent back the accept\n");
664 	}
665 
666 	return rc;
667 }
668 
669 static void
670 spdk_nvmf_rdma_event_reject(struct rdma_cm_id *id, enum spdk_nvmf_rdma_transport_error error)
671 {
672 	struct spdk_nvmf_rdma_reject_private_data	rej_data;
673 
674 	rej_data.recfmt = 0;
675 	rej_data.sts = error;
676 
677 	rdma_reject(id, &rej_data, sizeof(rej_data));
678 }
679 
680 static int
681 nvmf_rdma_connect(struct spdk_nvmf_transport *transport, struct rdma_cm_event *event,
682 		  new_qpair_fn cb_fn)
683 {
684 	struct spdk_nvmf_rdma_transport *rtransport;
685 	struct spdk_nvmf_rdma_qpair	*rqpair = NULL;
686 	struct spdk_nvmf_rdma_port	*port;
687 	struct rdma_conn_param		*rdma_param = NULL;
688 	const struct spdk_nvmf_rdma_request_private_data *private_data = NULL;
689 	uint16_t			max_queue_depth;
690 	uint16_t			max_rw_depth;
691 
692 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
693 
694 	assert(event->id != NULL); /* Impossible. Can't even reject the connection. */
695 	assert(event->id->verbs != NULL); /* Impossible. No way to handle this. */
696 
697 	rdma_param = &event->param.conn;
698 	if (rdma_param->private_data == NULL ||
699 	    rdma_param->private_data_len < sizeof(struct spdk_nvmf_rdma_request_private_data)) {
700 		SPDK_ERRLOG("connect request: no private data provided\n");
701 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_PRIVATE_DATA_LENGTH);
702 		return -1;
703 	}
704 
705 	private_data = rdma_param->private_data;
706 	if (private_data->recfmt != 0) {
707 		SPDK_ERRLOG("Received RDMA private data with RECFMT != 0\n");
708 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_INVALID_RECFMT);
709 		return -1;
710 	}
711 
712 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Connect Recv on fabric intf name %s, dev_name %s\n",
713 		      event->id->verbs->device->name, event->id->verbs->device->dev_name);
714 
715 	port = event->listen_id->context;
716 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Listen Id was %p with verbs %p. ListenAddr: %p\n",
717 		      event->listen_id, event->listen_id->verbs, port);
718 
719 	/* Figure out the supported queue depth. This is a multi-step process
720 	 * that takes into account hardware maximums, host provided values,
721 	 * and our target's internal memory limits */
722 
723 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Calculating Queue Depth\n");
724 
725 	/* Start with the maximum queue depth allowed by the target */
726 	max_queue_depth = rtransport->max_queue_depth;
727 	max_rw_depth = rtransport->max_queue_depth;
728 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Target Max Queue Depth: %d\n", rtransport->max_queue_depth);
729 
730 	/* Next check the local NIC's hardware limitations */
731 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
732 		      "Local NIC Max Send/Recv Queue Depth: %d Max Read/Write Queue Depth: %d\n",
733 		      port->device->attr.max_qp_wr, port->device->attr.max_qp_rd_atom);
734 	max_queue_depth = spdk_min(max_queue_depth, port->device->attr.max_qp_wr);
735 	max_rw_depth = spdk_min(max_rw_depth, port->device->attr.max_qp_rd_atom);
736 
737 	/* Next check the remote NIC's hardware limitations */
738 	SPDK_DEBUGLOG(SPDK_LOG_RDMA,
739 		      "Host (Initiator) NIC Max Incoming RDMA R/W operations: %d Max Outgoing RDMA R/W operations: %d\n",
740 		      rdma_param->initiator_depth, rdma_param->responder_resources);
741 	if (rdma_param->initiator_depth > 0) {
742 		max_rw_depth = spdk_min(max_rw_depth, rdma_param->initiator_depth);
743 	}
744 
745 	/* Finally check for the host software requested values, which are
746 	 * optional. */
747 	if (rdma_param->private_data != NULL &&
748 	    rdma_param->private_data_len >= sizeof(struct spdk_nvmf_rdma_request_private_data)) {
749 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Receive Queue Size: %d\n", private_data->hrqsize);
750 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Host Send Queue Size: %d\n", private_data->hsqsize);
751 		max_queue_depth = spdk_min(max_queue_depth, private_data->hrqsize);
752 		max_queue_depth = spdk_min(max_queue_depth, private_data->hsqsize + 1);
753 	}
754 
755 	SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Final Negotiated Queue Depth: %d R/W Depth: %d\n",
756 		      max_queue_depth, max_rw_depth);
757 
758 	rqpair = calloc(1, sizeof(struct spdk_nvmf_rdma_qpair));
759 	if (rqpair == NULL) {
760 		SPDK_ERRLOG("Could not allocate new connection.\n");
761 		spdk_nvmf_rdma_event_reject(event->id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
762 		return -1;
763 	}
764 
765 	rqpair->port = port;
766 	rqpair->max_queue_depth = max_queue_depth;
767 	rqpair->max_rw_depth = max_rw_depth;
768 	rqpair->cm_id = event->id;
769 	rqpair->qpair.transport = transport;
770 	TAILQ_INIT(&rqpair->incoming_queue);
771 	TAILQ_INIT(&rqpair->free_queue);
772 	TAILQ_INIT(&rqpair->pending_rdma_rw_queue);
773 
774 	event->id->context = &rqpair->qpair;
775 
776 	cb_fn(&rqpair->qpair);
777 
778 	return 0;
779 }
780 
781 static int
782 nvmf_rdma_disconnect(struct rdma_cm_event *evt)
783 {
784 	struct spdk_nvmf_qpair		*qpair;
785 
786 	if (evt->id == NULL) {
787 		SPDK_ERRLOG("disconnect request: missing cm_id\n");
788 		return -1;
789 	}
790 
791 	qpair = evt->id->context;
792 	if (qpair == NULL) {
793 		SPDK_ERRLOG("disconnect request: no active connection\n");
794 		return -1;
795 	}
796 	/* ack the disconnect event before rdma_destroy_id */
797 	rdma_ack_cm_event(evt);
798 
799 	spdk_nvmf_qpair_disconnect(qpair, NULL, NULL);
800 
801 	return 0;
802 }
803 
804 #ifdef DEBUG
805 static const char *CM_EVENT_STR[] = {
806 	"RDMA_CM_EVENT_ADDR_RESOLVED",
807 	"RDMA_CM_EVENT_ADDR_ERROR",
808 	"RDMA_CM_EVENT_ROUTE_RESOLVED",
809 	"RDMA_CM_EVENT_ROUTE_ERROR",
810 	"RDMA_CM_EVENT_CONNECT_REQUEST",
811 	"RDMA_CM_EVENT_CONNECT_RESPONSE",
812 	"RDMA_CM_EVENT_CONNECT_ERROR",
813 	"RDMA_CM_EVENT_UNREACHABLE",
814 	"RDMA_CM_EVENT_REJECTED",
815 	"RDMA_CM_EVENT_ESTABLISHED",
816 	"RDMA_CM_EVENT_DISCONNECTED",
817 	"RDMA_CM_EVENT_DEVICE_REMOVAL",
818 	"RDMA_CM_EVENT_MULTICAST_JOIN",
819 	"RDMA_CM_EVENT_MULTICAST_ERROR",
820 	"RDMA_CM_EVENT_ADDR_CHANGE",
821 	"RDMA_CM_EVENT_TIMEWAIT_EXIT"
822 };
823 #endif /* DEBUG */
824 
825 static int
826 spdk_nvmf_rdma_mem_notify(void *cb_ctx, struct spdk_mem_map *map,
827 			  enum spdk_mem_map_notify_action action,
828 			  void *vaddr, size_t size)
829 {
830 	struct spdk_nvmf_rdma_device *device = cb_ctx;
831 	struct ibv_pd *pd = device->pd;
832 	struct ibv_mr *mr;
833 
834 	switch (action) {
835 	case SPDK_MEM_MAP_NOTIFY_REGISTER:
836 		mr = ibv_reg_mr(pd, vaddr, size,
837 				IBV_ACCESS_LOCAL_WRITE |
838 				IBV_ACCESS_REMOTE_READ |
839 				IBV_ACCESS_REMOTE_WRITE);
840 		if (mr == NULL) {
841 			SPDK_ERRLOG("ibv_reg_mr() failed\n");
842 			return -1;
843 		} else {
844 			spdk_mem_map_set_translation(map, (uint64_t)vaddr, size, (uint64_t)mr);
845 		}
846 		break;
847 	case SPDK_MEM_MAP_NOTIFY_UNREGISTER:
848 		mr = (struct ibv_mr *)spdk_mem_map_translate(map, (uint64_t)vaddr, size);
849 		spdk_mem_map_clear_translation(map, (uint64_t)vaddr, size);
850 		if (mr) {
851 			ibv_dereg_mr(mr);
852 		}
853 		break;
854 	}
855 
856 	return 0;
857 }
858 
859 typedef enum spdk_nvme_data_transfer spdk_nvme_data_transfer_t;
860 
861 static spdk_nvme_data_transfer_t
862 spdk_nvmf_rdma_request_get_xfer(struct spdk_nvmf_rdma_request *rdma_req)
863 {
864 	enum spdk_nvme_data_transfer xfer;
865 	struct spdk_nvme_cmd *cmd = &rdma_req->req.cmd->nvme_cmd;
866 	struct spdk_nvme_sgl_descriptor *sgl = &cmd->dptr.sgl1;
867 
868 	/* Figure out data transfer direction */
869 	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
870 		xfer = spdk_nvme_opc_get_data_transfer(rdma_req->req.cmd->nvmf_cmd.fctype);
871 	} else {
872 		xfer = spdk_nvme_opc_get_data_transfer(cmd->opc);
873 
874 		/* Some admin commands are special cases */
875 		if ((rdma_req->req.qpair->qid == 0) &&
876 		    ((cmd->opc == SPDK_NVME_OPC_GET_FEATURES) ||
877 		     (cmd->opc == SPDK_NVME_OPC_SET_FEATURES))) {
878 			switch (cmd->cdw10 & 0xff) {
879 			case SPDK_NVME_FEAT_LBA_RANGE_TYPE:
880 			case SPDK_NVME_FEAT_AUTONOMOUS_POWER_STATE_TRANSITION:
881 			case SPDK_NVME_FEAT_HOST_IDENTIFIER:
882 				break;
883 			default:
884 				xfer = SPDK_NVME_DATA_NONE;
885 			}
886 		}
887 	}
888 
889 	if (xfer == SPDK_NVME_DATA_NONE) {
890 		return xfer;
891 	}
892 
893 	/* Even for commands that may transfer data, they could have specified 0 length.
894 	 * We want those to show up with xfer SPDK_NVME_DATA_NONE.
895 	 */
896 	switch (sgl->generic.type) {
897 	case SPDK_NVME_SGL_TYPE_DATA_BLOCK:
898 	case SPDK_NVME_SGL_TYPE_BIT_BUCKET:
899 	case SPDK_NVME_SGL_TYPE_SEGMENT:
900 	case SPDK_NVME_SGL_TYPE_LAST_SEGMENT:
901 	case SPDK_NVME_SGL_TYPE_TRANSPORT_DATA_BLOCK:
902 		if (sgl->unkeyed.length == 0) {
903 			xfer = SPDK_NVME_DATA_NONE;
904 		}
905 		break;
906 	case SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK:
907 		if (sgl->keyed.length == 0) {
908 			xfer = SPDK_NVME_DATA_NONE;
909 		}
910 		break;
911 	}
912 
913 	return xfer;
914 }
915 
916 static int
917 spdk_nvmf_rdma_request_fill_iovs(struct spdk_nvmf_rdma_transport *rtransport,
918 				 struct spdk_nvmf_rdma_device *device,
919 				 struct spdk_nvmf_rdma_request *rdma_req)
920 {
921 	void		*buf = NULL;
922 	uint32_t	length = rdma_req->req.length;
923 	uint32_t	i = 0;
924 
925 	rdma_req->req.iovcnt = 0;
926 	while (length) {
927 		buf = spdk_mempool_get(rtransport->data_buf_pool);
928 		if (!buf) {
929 			goto nomem;
930 		}
931 
932 		rdma_req->req.iov[i].iov_base = (void *)((uintptr_t)(buf + NVMF_DATA_BUFFER_MASK) &
933 						~NVMF_DATA_BUFFER_MASK);
934 		rdma_req->req.iov[i].iov_len  = spdk_min(length, rtransport->io_unit_size);
935 		rdma_req->req.iovcnt++;
936 		rdma_req->data.buffers[i] = buf;
937 		rdma_req->data.wr.sg_list[i].addr = (uintptr_t)(rdma_req->req.iov[i].iov_base);
938 		rdma_req->data.wr.sg_list[i].length = rdma_req->req.iov[i].iov_len;
939 		rdma_req->data.wr.sg_list[i].lkey = ((struct ibv_mr *)spdk_mem_map_translate(device->map,
940 						     (uint64_t)buf, rdma_req->req.iov[i].iov_len))->lkey;
941 
942 		length -= rdma_req->req.iov[i].iov_len;
943 		i++;
944 	}
945 
946 	rdma_req->data_from_pool = true;
947 
948 	return 0;
949 
950 nomem:
951 	while (i) {
952 		i--;
953 		spdk_mempool_put(rtransport->data_buf_pool, rdma_req->req.iov[i].iov_base);
954 		rdma_req->req.iov[i].iov_base = NULL;
955 		rdma_req->req.iov[i].iov_len = 0;
956 
957 		rdma_req->data.wr.sg_list[i].addr = 0;
958 		rdma_req->data.wr.sg_list[i].length = 0;
959 		rdma_req->data.wr.sg_list[i].lkey = 0;
960 	}
961 	rdma_req->req.iovcnt = 0;
962 	return -ENOMEM;
963 }
964 
965 static int
966 spdk_nvmf_rdma_request_parse_sgl(struct spdk_nvmf_rdma_transport *rtransport,
967 				 struct spdk_nvmf_rdma_device *device,
968 				 struct spdk_nvmf_rdma_request *rdma_req)
969 {
970 	struct spdk_nvme_cmd			*cmd;
971 	struct spdk_nvme_cpl			*rsp;
972 	struct spdk_nvme_sgl_descriptor		*sgl;
973 
974 	cmd = &rdma_req->req.cmd->nvme_cmd;
975 	rsp = &rdma_req->req.rsp->nvme_cpl;
976 	sgl = &cmd->dptr.sgl1;
977 
978 	if (sgl->generic.type == SPDK_NVME_SGL_TYPE_KEYED_DATA_BLOCK &&
979 	    (sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_ADDRESS ||
980 	     sgl->keyed.subtype == SPDK_NVME_SGL_SUBTYPE_INVALIDATE_KEY)) {
981 		if (sgl->keyed.length > rtransport->max_io_size) {
982 			SPDK_ERRLOG("SGL length 0x%x exceeds max io size 0x%x\n",
983 				    sgl->keyed.length, rtransport->max_io_size);
984 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
985 			return -1;
986 		}
987 
988 		/* fill request length and populate iovs */
989 		rdma_req->req.length = sgl->keyed.length;
990 
991 		if (spdk_nvmf_rdma_request_fill_iovs(rtransport, device, rdma_req) < 0) {
992 			/* No available buffers. Queue this request up. */
993 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "No available large data buffers. Queueing request %p\n", rdma_req);
994 			return 0;
995 		}
996 
997 		/* backward compatible */
998 		rdma_req->req.data = rdma_req->req.iov[0].iov_base;
999 
1000 		/* rdma wr specifics */
1001 		rdma_req->data.wr.num_sge = rdma_req->req.iovcnt;
1002 		rdma_req->data.wr.wr.rdma.rkey = sgl->keyed.key;
1003 		rdma_req->data.wr.wr.rdma.remote_addr = sgl->address;
1004 
1005 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p took %d buffer/s from central pool\n", rdma_req,
1006 			      rdma_req->req.iovcnt);
1007 
1008 		return 0;
1009 	} else if (sgl->generic.type == SPDK_NVME_SGL_TYPE_DATA_BLOCK &&
1010 		   sgl->unkeyed.subtype == SPDK_NVME_SGL_SUBTYPE_OFFSET) {
1011 		uint64_t offset = sgl->address;
1012 		uint32_t max_len = rtransport->in_capsule_data_size;
1013 
1014 		SPDK_DEBUGLOG(SPDK_LOG_NVMF, "In-capsule data: offset 0x%" PRIx64 ", length 0x%x\n",
1015 			      offset, sgl->unkeyed.length);
1016 
1017 		if (offset > max_len) {
1018 			SPDK_ERRLOG("In-capsule offset 0x%" PRIx64 " exceeds capsule length 0x%x\n",
1019 				    offset, max_len);
1020 			rsp->status.sc = SPDK_NVME_SC_INVALID_SGL_OFFSET;
1021 			return -1;
1022 		}
1023 		max_len -= (uint32_t)offset;
1024 
1025 		if (sgl->unkeyed.length > max_len) {
1026 			SPDK_ERRLOG("In-capsule data length 0x%x exceeds capsule length 0x%x\n",
1027 				    sgl->unkeyed.length, max_len);
1028 			rsp->status.sc = SPDK_NVME_SC_DATA_SGL_LENGTH_INVALID;
1029 			return -1;
1030 		}
1031 
1032 		rdma_req->req.data = rdma_req->recv->buf + offset;
1033 		rdma_req->data_from_pool = false;
1034 		rdma_req->req.length = sgl->unkeyed.length;
1035 
1036 		rdma_req->req.iov[0].iov_base = rdma_req->req.data;
1037 		rdma_req->req.iov[0].iov_len = rdma_req->req.length;
1038 		rdma_req->req.iovcnt = 1;
1039 
1040 		return 0;
1041 	}
1042 
1043 	SPDK_ERRLOG("Invalid NVMf I/O Command SGL:  Type 0x%x, Subtype 0x%x\n",
1044 		    sgl->generic.type, sgl->generic.subtype);
1045 	rsp->status.sc = SPDK_NVME_SC_SGL_DESCRIPTOR_TYPE_INVALID;
1046 	return -1;
1047 }
1048 
1049 static bool
1050 spdk_nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,
1051 			       struct spdk_nvmf_rdma_request *rdma_req)
1052 {
1053 	struct spdk_nvmf_rdma_qpair	*rqpair;
1054 	struct spdk_nvmf_rdma_device	*device;
1055 	struct spdk_nvme_cpl		*rsp = &rdma_req->req.rsp->nvme_cpl;
1056 	int				rc;
1057 	struct spdk_nvmf_rdma_recv	*rdma_recv;
1058 	enum spdk_nvmf_rdma_request_state prev_state;
1059 	bool				progress = false;
1060 
1061 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
1062 	device = rqpair->port->device;
1063 
1064 	assert(rdma_req->state != RDMA_REQUEST_STATE_FREE);
1065 
1066 	/* The loop here is to allow for several back-to-back state changes. */
1067 	do {
1068 		prev_state = rdma_req->state;
1069 
1070 		SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Request %p entering state %d\n", rdma_req, prev_state);
1071 
1072 		switch (rdma_req->state) {
1073 		case RDMA_REQUEST_STATE_FREE:
1074 			/* Some external code must kick a request into RDMA_REQUEST_STATE_NEW
1075 			 * to escape this state. */
1076 			break;
1077 		case RDMA_REQUEST_STATE_NEW:
1078 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEW, 0, 0, (uintptr_t)rdma_req, 0);
1079 
1080 			rqpair->cur_queue_depth++;
1081 			rdma_recv = rdma_req->recv;
1082 
1083 			/* The first element of the SGL is the NVMe command */
1084 			rdma_req->req.cmd = (union nvmf_h2c_msg *)rdma_recv->sgl[0].addr;
1085 			memset(rdma_req->req.rsp, 0, sizeof(*rdma_req->req.rsp));
1086 
1087 			TAILQ_REMOVE(&rqpair->incoming_queue, rdma_recv, link);
1088 			TAILQ_REMOVE(&rqpair->free_queue, rdma_req, link);
1089 
1090 			/* The next state transition depends on the data transfer needs of this request. */
1091 			rdma_req->req.xfer = spdk_nvmf_rdma_request_get_xfer(rdma_req);
1092 
1093 			/* If no data to transfer, ready to execute. */
1094 			if (rdma_req->req.xfer == SPDK_NVME_DATA_NONE) {
1095 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1096 				break;
1097 			}
1098 
1099 			rdma_req->state = RDMA_REQUEST_STATE_NEED_BUFFER;
1100 			TAILQ_INSERT_TAIL(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1101 			break;
1102 		case RDMA_REQUEST_STATE_NEED_BUFFER:
1103 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_NEED_BUFFER, 0, 0, (uintptr_t)rdma_req, 0);
1104 
1105 			assert(rdma_req->req.xfer != SPDK_NVME_DATA_NONE);
1106 
1107 			if (rdma_req != TAILQ_FIRST(&rqpair->ch->pending_data_buf_queue)) {
1108 				/* This request needs to wait in line to obtain a buffer */
1109 				break;
1110 			}
1111 
1112 			/* Try to get a data buffer */
1113 			rc = spdk_nvmf_rdma_request_parse_sgl(rtransport, device, rdma_req);
1114 			if (rc < 0) {
1115 				TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1116 				rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1117 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1118 				break;
1119 			}
1120 
1121 			if (!rdma_req->req.data) {
1122 				/* No buffers available. */
1123 				break;
1124 			}
1125 
1126 			TAILQ_REMOVE(&rqpair->ch->pending_data_buf_queue, rdma_req, link);
1127 
1128 			/* If data is transferring from host to controller and the data didn't
1129 			 * arrive using in capsule data, we need to do a transfer from the host.
1130 			 */
1131 			if (rdma_req->req.xfer == SPDK_NVME_DATA_HOST_TO_CONTROLLER && rdma_req->data_from_pool) {
1132 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER;
1133 				TAILQ_INSERT_TAIL(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1134 				break;
1135 			}
1136 
1137 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
1138 			break;
1139 		case RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER:
1140 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_HOST_TO_CONTROLLER, 0, 0,
1141 					  (uintptr_t)rdma_req, 0);
1142 
1143 			if (rdma_req != TAILQ_FIRST(&rqpair->pending_rdma_rw_queue)) {
1144 				/* This request needs to wait in line to perform RDMA */
1145 				break;
1146 			}
1147 
1148 			if (rqpair->cur_rdma_rw_depth < rqpair->max_rw_depth) {
1149 				TAILQ_REMOVE(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1150 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER;
1151 				rc = request_transfer_in(&rdma_req->req);
1152 				if (rc) {
1153 					rsp->status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
1154 					rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1155 				}
1156 			}
1157 			break;
1158 		case RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER:
1159 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER, 0, 0,
1160 					  (uintptr_t)rdma_req, 0);
1161 			/* Some external code must kick a request into RDMA_REQUEST_STATE_READY_TO_EXECUTE
1162 			 * to escape this state. */
1163 			break;
1164 		case RDMA_REQUEST_STATE_READY_TO_EXECUTE:
1165 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_EXECUTE, 0, 0, (uintptr_t)rdma_req, 0);
1166 			rdma_req->state = RDMA_REQUEST_STATE_EXECUTING;
1167 			spdk_nvmf_request_exec(&rdma_req->req);
1168 			break;
1169 		case RDMA_REQUEST_STATE_EXECUTING:
1170 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTING, 0, 0, (uintptr_t)rdma_req, 0);
1171 			/* Some external code must kick a request into RDMA_REQUEST_STATE_EXECUTED
1172 			 * to escape this state. */
1173 			break;
1174 		case RDMA_REQUEST_STATE_EXECUTED:
1175 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_EXECUTED, 0, 0, (uintptr_t)rdma_req, 0);
1176 			if (rdma_req->req.xfer == SPDK_NVME_DATA_CONTROLLER_TO_HOST) {
1177 				rdma_req->state = RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST;
1178 				TAILQ_INSERT_TAIL(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1179 			} else {
1180 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1181 			}
1182 			break;
1183 		case RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST:
1184 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_TRANSFER_PENDING_CONTROLLER_TO_HOST, 0, 0,
1185 					  (uintptr_t)rdma_req, 0);
1186 			if (rdma_req != TAILQ_FIRST(&rqpair->pending_rdma_rw_queue)) {
1187 				/* This request needs to wait in line to perform RDMA */
1188 				break;
1189 			}
1190 
1191 			if (rqpair->cur_rdma_rw_depth < rqpair->max_rw_depth) {
1192 				rdma_req->state = RDMA_REQUEST_STATE_READY_TO_COMPLETE;
1193 				TAILQ_REMOVE(&rqpair->pending_rdma_rw_queue, rdma_req, link);
1194 			}
1195 			break;
1196 		case RDMA_REQUEST_STATE_READY_TO_COMPLETE:
1197 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_READY_TO_COMPLETE, 0, 0, (uintptr_t)rdma_req, 0);
1198 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETING;
1199 
1200 			rc = request_transfer_out(&rdma_req->req);
1201 			assert(rc == 0); /* No good way to handle this currently */
1202 			break;
1203 		case RDMA_REQUEST_STATE_COMPLETING:
1204 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETING, 0, 0, (uintptr_t)rdma_req, 0);
1205 			/* Some external code must kick a request into RDMA_REQUEST_STATE_COMPLETED
1206 			 * to escape this state. */
1207 			break;
1208 		case RDMA_REQUEST_STATE_COMPLETED:
1209 			spdk_trace_record(TRACE_RDMA_REQUEST_STATE_COMPLETED, 0, 0, (uintptr_t)rdma_req, 0);
1210 			assert(rqpair->cur_queue_depth > 0);
1211 			rqpair->cur_queue_depth--;
1212 
1213 			if (rdma_req->data_from_pool) {
1214 				/* Put the buffer/s back in the pool */
1215 				for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
1216 					spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
1217 					rdma_req->req.iov[i].iov_base = NULL;
1218 					rdma_req->data.buffers[i] = NULL;
1219 				}
1220 				rdma_req->data_from_pool = false;
1221 			}
1222 			rdma_req->req.length = 0;
1223 			rdma_req->req.iovcnt = 0;
1224 			rdma_req->req.data = NULL;
1225 			rdma_req->state = RDMA_REQUEST_STATE_FREE;
1226 			TAILQ_INSERT_TAIL(&rqpair->free_queue, rdma_req, link);
1227 			break;
1228 		}
1229 
1230 		if (rdma_req->state != prev_state) {
1231 			progress = true;
1232 		}
1233 	} while (rdma_req->state != prev_state);
1234 
1235 	return progress;
1236 }
1237 
1238 /* Public API callbacks begin here */
1239 
1240 static struct spdk_nvmf_transport *
1241 spdk_nvmf_rdma_create(struct spdk_nvmf_tgt *tgt)
1242 {
1243 	int rc;
1244 	struct spdk_nvmf_rdma_transport *rtransport;
1245 	struct spdk_nvmf_rdma_device	*device, *tmp;
1246 	struct ibv_context		**contexts;
1247 	uint32_t			i;
1248 	int				flag;
1249 	uint32_t			sge_count;
1250 
1251 	rtransport = calloc(1, sizeof(*rtransport));
1252 	if (!rtransport) {
1253 		return NULL;
1254 	}
1255 
1256 	pthread_mutex_init(&rtransport->lock, NULL);
1257 	TAILQ_INIT(&rtransport->devices);
1258 	TAILQ_INIT(&rtransport->ports);
1259 
1260 	rtransport->transport.tgt = tgt;
1261 	rtransport->transport.ops = &spdk_nvmf_transport_rdma;
1262 
1263 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** RDMA Transport Init ***\n");
1264 
1265 	rtransport->max_queue_depth = tgt->opts.max_queue_depth;
1266 	rtransport->max_io_size = tgt->opts.max_io_size;
1267 	rtransport->io_unit_size = tgt->opts.io_unit_size;
1268 	rtransport->in_capsule_data_size = tgt->opts.in_capsule_data_size;
1269 
1270 	/* I/O unit size cannot be larger than max I/O size */
1271 	if (rtransport->io_unit_size > rtransport->max_io_size) {
1272 		rtransport->io_unit_size = rtransport->max_io_size;
1273 	}
1274 
1275 	sge_count = rtransport->max_io_size / rtransport->io_unit_size;
1276 	if (sge_count > SPDK_NVMF_MAX_SGL_ENTRIES) {
1277 		SPDK_ERRLOG("Unsupported IO Unit size specified, %d bytes\n", rtransport->io_unit_size);
1278 		free(rtransport);
1279 		return NULL;
1280 	}
1281 
1282 	rtransport->event_channel = rdma_create_event_channel();
1283 	if (rtransport->event_channel == NULL) {
1284 		SPDK_ERRLOG("rdma_create_event_channel() failed, %s\n", spdk_strerror(errno));
1285 		free(rtransport);
1286 		return NULL;
1287 	}
1288 
1289 	flag = fcntl(rtransport->event_channel->fd, F_GETFL);
1290 	if (fcntl(rtransport->event_channel->fd, F_SETFL, flag | O_NONBLOCK) < 0) {
1291 		SPDK_ERRLOG("fcntl can't set nonblocking mode for socket, fd: %d (%s)\n",
1292 			    rtransport->event_channel->fd, spdk_strerror(errno));
1293 		free(rtransport);
1294 		return NULL;
1295 	}
1296 
1297 	rtransport->data_buf_pool = spdk_mempool_create("spdk_nvmf_rdma",
1298 				    rtransport->max_queue_depth * 4, /* The 4 is arbitrarily chosen. Needs to be configurable. */
1299 				    rtransport->io_unit_size + NVMF_DATA_BUFFER_ALIGNMENT,
1300 				    SPDK_MEMPOOL_DEFAULT_CACHE_SIZE,
1301 				    SPDK_ENV_SOCKET_ID_ANY);
1302 	if (!rtransport->data_buf_pool) {
1303 		SPDK_ERRLOG("Unable to allocate buffer pool for poll group\n");
1304 		free(rtransport);
1305 		return NULL;
1306 	}
1307 
1308 	spdk_io_device_register(rtransport, spdk_nvmf_rdma_mgmt_channel_create,
1309 				spdk_nvmf_rdma_mgmt_channel_destroy,
1310 				sizeof(struct spdk_nvmf_rdma_mgmt_channel));
1311 
1312 	contexts = rdma_get_devices(NULL);
1313 	i = 0;
1314 	rc = 0;
1315 	while (contexts[i] != NULL) {
1316 		device = calloc(1, sizeof(*device));
1317 		if (!device) {
1318 			SPDK_ERRLOG("Unable to allocate memory for RDMA devices.\n");
1319 			rc = -ENOMEM;
1320 			break;
1321 		}
1322 		device->context = contexts[i];
1323 		rc = ibv_query_device(device->context, &device->attr);
1324 		if (rc < 0) {
1325 			SPDK_ERRLOG("Failed to query RDMA device attributes.\n");
1326 			free(device);
1327 			break;
1328 
1329 		}
1330 		/* set up device context async ev fd as NON_BLOCKING */
1331 		flag = fcntl(device->context->async_fd, F_GETFL);
1332 		rc = fcntl(device->context->async_fd, F_SETFL, flag | O_NONBLOCK);
1333 		if (rc < 0) {
1334 			SPDK_ERRLOG("Failed to set context async fd to NONBLOCK.\n");
1335 			free(device);
1336 			break;
1337 		}
1338 
1339 		device->pd = NULL;
1340 		device->map = NULL;
1341 
1342 		TAILQ_INSERT_TAIL(&rtransport->devices, device, link);
1343 		i++;
1344 	}
1345 
1346 	if (rc < 0) {
1347 		TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1348 			TAILQ_REMOVE(&rtransport->devices, device, link);
1349 			free(device);
1350 		}
1351 		spdk_mempool_free(rtransport->data_buf_pool);
1352 		rdma_destroy_event_channel(rtransport->event_channel);
1353 		free(rtransport);
1354 		rdma_free_devices(contexts);
1355 		return NULL;
1356 	} else {
1357 		/* Set up poll descriptor array to monitor events from RDMA and IB
1358 		 * in a single poll syscall
1359 		 */
1360 		rtransport->npoll_fds = i + 1;
1361 		i = 0;
1362 		rtransport->poll_fds = calloc(rtransport->npoll_fds, sizeof(struct pollfd));
1363 		rtransport->poll_fds[i].fd = rtransport->event_channel->fd;
1364 		rtransport->poll_fds[i++].events = POLLIN;
1365 
1366 		TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1367 			rtransport->poll_fds[i].fd = device->context->async_fd;
1368 			rtransport->poll_fds[i++].events = POLLIN;
1369 		}
1370 	}
1371 
1372 	rdma_free_devices(contexts);
1373 
1374 	return &rtransport->transport;
1375 }
1376 
1377 static int
1378 spdk_nvmf_rdma_destroy(struct spdk_nvmf_transport *transport)
1379 {
1380 	struct spdk_nvmf_rdma_transport	*rtransport;
1381 	struct spdk_nvmf_rdma_port	*port, *port_tmp;
1382 	struct spdk_nvmf_rdma_device	*device, *device_tmp;
1383 
1384 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1385 
1386 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, port_tmp) {
1387 		TAILQ_REMOVE(&rtransport->ports, port, link);
1388 		rdma_destroy_id(port->id);
1389 		free(port);
1390 	}
1391 
1392 	if (rtransport->poll_fds != NULL) {
1393 		free(rtransport->poll_fds);
1394 	}
1395 
1396 	if (rtransport->event_channel != NULL) {
1397 		rdma_destroy_event_channel(rtransport->event_channel);
1398 	}
1399 
1400 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, device_tmp) {
1401 		TAILQ_REMOVE(&rtransport->devices, device, link);
1402 		if (device->map) {
1403 			spdk_mem_map_free(&device->map);
1404 		}
1405 		free(device);
1406 	}
1407 
1408 	if (spdk_mempool_count(rtransport->data_buf_pool) != (rtransport->max_queue_depth * 4)) {
1409 		SPDK_ERRLOG("transport buffer pool count is %zu but should be %u\n",
1410 			    spdk_mempool_count(rtransport->data_buf_pool),
1411 			    rtransport->max_queue_depth * 4);
1412 	}
1413 
1414 	spdk_mempool_free(rtransport->data_buf_pool);
1415 	spdk_io_device_unregister(rtransport, NULL);
1416 	free(rtransport);
1417 
1418 	return 0;
1419 }
1420 
1421 static int
1422 spdk_nvmf_rdma_listen(struct spdk_nvmf_transport *transport,
1423 		      const struct spdk_nvme_transport_id *trid)
1424 {
1425 	struct spdk_nvmf_rdma_transport	*rtransport;
1426 	struct spdk_nvmf_rdma_device	*device;
1427 	struct spdk_nvmf_rdma_port	*port_tmp, *port;
1428 	struct addrinfo			*res;
1429 	struct addrinfo			hints;
1430 	int				family;
1431 	int				rc;
1432 
1433 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1434 
1435 	port = calloc(1, sizeof(*port));
1436 	if (!port) {
1437 		return -ENOMEM;
1438 	}
1439 
1440 	/* Selectively copy the trid. Things like NQN don't matter here - that
1441 	 * mapping is enforced elsewhere.
1442 	 */
1443 	port->trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1444 	port->trid.adrfam = trid->adrfam;
1445 	snprintf(port->trid.traddr, sizeof(port->trid.traddr), "%s", trid->traddr);
1446 	snprintf(port->trid.trsvcid, sizeof(port->trid.trsvcid), "%s", trid->trsvcid);
1447 
1448 	pthread_mutex_lock(&rtransport->lock);
1449 	assert(rtransport->event_channel != NULL);
1450 	TAILQ_FOREACH(port_tmp, &rtransport->ports, link) {
1451 		if (spdk_nvme_transport_id_compare(&port_tmp->trid, &port->trid) == 0) {
1452 			port_tmp->ref++;
1453 			free(port);
1454 			/* Already listening at this address */
1455 			pthread_mutex_unlock(&rtransport->lock);
1456 			return 0;
1457 		}
1458 	}
1459 
1460 	rc = rdma_create_id(rtransport->event_channel, &port->id, port, RDMA_PS_TCP);
1461 	if (rc < 0) {
1462 		SPDK_ERRLOG("rdma_create_id() failed\n");
1463 		free(port);
1464 		pthread_mutex_unlock(&rtransport->lock);
1465 		return rc;
1466 	}
1467 
1468 	switch (port->trid.adrfam) {
1469 	case SPDK_NVMF_ADRFAM_IPV4:
1470 		family = AF_INET;
1471 		break;
1472 	case SPDK_NVMF_ADRFAM_IPV6:
1473 		family = AF_INET6;
1474 		break;
1475 	default:
1476 		SPDK_ERRLOG("Unhandled ADRFAM %d\n", port->trid.adrfam);
1477 		free(port);
1478 		pthread_mutex_unlock(&rtransport->lock);
1479 		return -EINVAL;
1480 	}
1481 
1482 	memset(&hints, 0, sizeof(hints));
1483 	hints.ai_family = family;
1484 	hints.ai_socktype = SOCK_STREAM;
1485 	hints.ai_protocol = 0;
1486 
1487 	rc = getaddrinfo(port->trid.traddr, port->trid.trsvcid, &hints, &res);
1488 	if (rc) {
1489 		SPDK_ERRLOG("getaddrinfo failed: %s (%d)\n", gai_strerror(rc), rc);
1490 		free(port);
1491 		pthread_mutex_unlock(&rtransport->lock);
1492 		return -EINVAL;
1493 	}
1494 
1495 	rc = rdma_bind_addr(port->id, res->ai_addr);
1496 	freeaddrinfo(res);
1497 
1498 	if (rc < 0) {
1499 		SPDK_ERRLOG("rdma_bind_addr() failed\n");
1500 		rdma_destroy_id(port->id);
1501 		free(port);
1502 		pthread_mutex_unlock(&rtransport->lock);
1503 		return rc;
1504 	}
1505 
1506 	if (!port->id->verbs) {
1507 		SPDK_ERRLOG("ibv_context is null\n");
1508 		rdma_destroy_id(port->id);
1509 		free(port);
1510 		pthread_mutex_unlock(&rtransport->lock);
1511 		return -1;
1512 	}
1513 
1514 	rc = rdma_listen(port->id, 10); /* 10 = backlog */
1515 	if (rc < 0) {
1516 		SPDK_ERRLOG("rdma_listen() failed\n");
1517 		rdma_destroy_id(port->id);
1518 		free(port);
1519 		pthread_mutex_unlock(&rtransport->lock);
1520 		return rc;
1521 	}
1522 
1523 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1524 		if (device->context == port->id->verbs) {
1525 			port->device = device;
1526 			break;
1527 		}
1528 	}
1529 	if (!port->device) {
1530 		SPDK_ERRLOG("Accepted a connection with verbs %p, but unable to find a corresponding device.\n",
1531 			    port->id->verbs);
1532 		rdma_destroy_id(port->id);
1533 		free(port);
1534 		pthread_mutex_unlock(&rtransport->lock);
1535 		return -EINVAL;
1536 	}
1537 
1538 	if (!device->map) {
1539 		device->pd = port->id->pd;
1540 		device->map = spdk_mem_map_alloc(0, spdk_nvmf_rdma_mem_notify, device);
1541 		if (!device->map) {
1542 			SPDK_ERRLOG("Unable to allocate memory map for new poll group\n");
1543 			return -1;
1544 		}
1545 	} else {
1546 		assert(device->pd == port->id->pd);
1547 	}
1548 
1549 	SPDK_INFOLOG(SPDK_LOG_RDMA, "*** NVMf Target Listening on %s port %d ***\n",
1550 		     port->trid.traddr, ntohs(rdma_get_src_port(port->id)));
1551 
1552 	port->ref = 1;
1553 
1554 	TAILQ_INSERT_TAIL(&rtransport->ports, port, link);
1555 	pthread_mutex_unlock(&rtransport->lock);
1556 
1557 	return 0;
1558 }
1559 
1560 static int
1561 spdk_nvmf_rdma_stop_listen(struct spdk_nvmf_transport *transport,
1562 			   const struct spdk_nvme_transport_id *_trid)
1563 {
1564 	struct spdk_nvmf_rdma_transport *rtransport;
1565 	struct spdk_nvmf_rdma_port *port, *tmp;
1566 	struct spdk_nvme_transport_id trid = {};
1567 
1568 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1569 
1570 	/* Selectively copy the trid. Things like NQN don't matter here - that
1571 	 * mapping is enforced elsewhere.
1572 	 */
1573 	trid.trtype = SPDK_NVME_TRANSPORT_RDMA;
1574 	trid.adrfam = _trid->adrfam;
1575 	snprintf(trid.traddr, sizeof(port->trid.traddr), "%s", _trid->traddr);
1576 	snprintf(trid.trsvcid, sizeof(port->trid.trsvcid), "%s", _trid->trsvcid);
1577 
1578 	pthread_mutex_lock(&rtransport->lock);
1579 	TAILQ_FOREACH_SAFE(port, &rtransport->ports, link, tmp) {
1580 		if (spdk_nvme_transport_id_compare(&port->trid, &trid) == 0) {
1581 			assert(port->ref > 0);
1582 			port->ref--;
1583 			if (port->ref == 0) {
1584 				TAILQ_REMOVE(&rtransport->ports, port, link);
1585 				rdma_destroy_id(port->id);
1586 				free(port);
1587 			}
1588 			break;
1589 		}
1590 	}
1591 
1592 	pthread_mutex_unlock(&rtransport->lock);
1593 	return 0;
1594 }
1595 
1596 static void
1597 spdk_nvmf_process_cm_event(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
1598 {
1599 	struct spdk_nvmf_rdma_transport *rtransport;
1600 	struct rdma_cm_event		*event;
1601 	int				rc;
1602 
1603 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1604 
1605 	if (rtransport->event_channel == NULL) {
1606 		return;
1607 	}
1608 
1609 	while (1) {
1610 		rc = rdma_get_cm_event(rtransport->event_channel, &event);
1611 		if (rc == 0) {
1612 			SPDK_DEBUGLOG(SPDK_LOG_RDMA, "Acceptor Event: %s\n", CM_EVENT_STR[event->event]);
1613 
1614 			switch (event->event) {
1615 			case RDMA_CM_EVENT_ADDR_RESOLVED:
1616 			case RDMA_CM_EVENT_ADDR_ERROR:
1617 			case RDMA_CM_EVENT_ROUTE_RESOLVED:
1618 			case RDMA_CM_EVENT_ROUTE_ERROR:
1619 				/* No action required. The target never attempts to resolve routes. */
1620 				break;
1621 			case RDMA_CM_EVENT_CONNECT_REQUEST:
1622 				rc = nvmf_rdma_connect(transport, event, cb_fn);
1623 				if (rc < 0) {
1624 					SPDK_ERRLOG("Unable to process connect event. rc: %d\n", rc);
1625 					break;
1626 				}
1627 				break;
1628 			case RDMA_CM_EVENT_CONNECT_RESPONSE:
1629 				/* The target never initiates a new connection. So this will not occur. */
1630 				break;
1631 			case RDMA_CM_EVENT_CONNECT_ERROR:
1632 				/* Can this happen? The docs say it can, but not sure what causes it. */
1633 				break;
1634 			case RDMA_CM_EVENT_UNREACHABLE:
1635 			case RDMA_CM_EVENT_REJECTED:
1636 				/* These only occur on the client side. */
1637 				break;
1638 			case RDMA_CM_EVENT_ESTABLISHED:
1639 				/* TODO: Should we be waiting for this event anywhere? */
1640 				break;
1641 			case RDMA_CM_EVENT_DISCONNECTED:
1642 			case RDMA_CM_EVENT_DEVICE_REMOVAL:
1643 				rc = nvmf_rdma_disconnect(event);
1644 				if (rc < 0) {
1645 					SPDK_ERRLOG("Unable to process disconnect event. rc: %d\n", rc);
1646 					break;
1647 				}
1648 				continue;
1649 			case RDMA_CM_EVENT_MULTICAST_JOIN:
1650 			case RDMA_CM_EVENT_MULTICAST_ERROR:
1651 				/* Multicast is not used */
1652 				break;
1653 			case RDMA_CM_EVENT_ADDR_CHANGE:
1654 				/* Not utilizing this event */
1655 				break;
1656 			case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1657 				/* For now, do nothing. The target never re-uses queue pairs. */
1658 				break;
1659 			default:
1660 				SPDK_ERRLOG("Unexpected Acceptor Event [%d]\n", event->event);
1661 				break;
1662 			}
1663 
1664 			rdma_ack_cm_event(event);
1665 		} else {
1666 			if (errno != EAGAIN && errno != EWOULDBLOCK) {
1667 				SPDK_ERRLOG("Acceptor Event Error: %s\n", spdk_strerror(errno));
1668 			}
1669 			break;
1670 		}
1671 	}
1672 }
1673 
1674 static void
1675 spdk_nvmf_process_ib_event(struct spdk_nvmf_rdma_device *device)
1676 {
1677 	int rc;
1678 	struct ibv_async_event event;
1679 
1680 	rc = ibv_get_async_event(device->context, &event);
1681 
1682 	if (rc) {
1683 		SPDK_ERRLOG("Failed to get async_event (%d): %s\n",
1684 			    errno, spdk_strerror(errno));
1685 		return;
1686 	}
1687 
1688 	SPDK_NOTICELOG("Async event: %s\n",
1689 		       ibv_event_type_str(event.event_type));
1690 	ibv_ack_async_event(&event);
1691 }
1692 
1693 static void
1694 spdk_nvmf_rdma_accept(struct spdk_nvmf_transport *transport, new_qpair_fn cb_fn)
1695 {
1696 	int	nfds, i = 0;
1697 	struct spdk_nvmf_rdma_transport *rtransport;
1698 	struct spdk_nvmf_rdma_device *device, *tmp;
1699 
1700 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1701 	nfds = poll(rtransport->poll_fds, rtransport->npoll_fds, 0);
1702 
1703 	if (nfds <= 0) {
1704 		return;
1705 	}
1706 
1707 	/* The first poll descriptor is RDMA CM event */
1708 	if (rtransport->poll_fds[i++].revents & POLLIN) {
1709 		spdk_nvmf_process_cm_event(transport, cb_fn);
1710 		nfds--;
1711 	}
1712 
1713 	if (nfds == 0) {
1714 		return;
1715 	}
1716 
1717 	/* Second and subsequent poll descriptors are IB async events */
1718 	TAILQ_FOREACH_SAFE(device, &rtransport->devices, link, tmp) {
1719 		if (rtransport->poll_fds[i++].revents & POLLIN) {
1720 			spdk_nvmf_process_ib_event(device);
1721 			nfds--;
1722 		}
1723 	}
1724 	/* check all flagged fd's have been served */
1725 	assert(nfds == 0);
1726 }
1727 
1728 static void
1729 spdk_nvmf_rdma_discover(struct spdk_nvmf_transport *transport,
1730 			struct spdk_nvme_transport_id *trid,
1731 			struct spdk_nvmf_discovery_log_page_entry *entry)
1732 {
1733 	entry->trtype = SPDK_NVMF_TRTYPE_RDMA;
1734 	entry->adrfam = trid->adrfam;
1735 	entry->treq.secure_channel = SPDK_NVMF_TREQ_SECURE_CHANNEL_NOT_SPECIFIED;
1736 
1737 	spdk_strcpy_pad(entry->trsvcid, trid->trsvcid, sizeof(entry->trsvcid), ' ');
1738 	spdk_strcpy_pad(entry->traddr, trid->traddr, sizeof(entry->traddr), ' ');
1739 
1740 	entry->tsas.rdma.rdma_qptype = SPDK_NVMF_RDMA_QPTYPE_RELIABLE_CONNECTED;
1741 	entry->tsas.rdma.rdma_prtype = SPDK_NVMF_RDMA_PRTYPE_NONE;
1742 	entry->tsas.rdma.rdma_cms = SPDK_NVMF_RDMA_CMS_RDMA_CM;
1743 }
1744 
1745 static struct spdk_nvmf_transport_poll_group *
1746 spdk_nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport)
1747 {
1748 	struct spdk_nvmf_rdma_transport		*rtransport;
1749 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1750 	struct spdk_nvmf_rdma_poller		*poller;
1751 	struct spdk_nvmf_rdma_device		*device;
1752 
1753 	rtransport = SPDK_CONTAINEROF(transport, struct spdk_nvmf_rdma_transport, transport);
1754 
1755 	rgroup = calloc(1, sizeof(*rgroup));
1756 	if (!rgroup) {
1757 		return NULL;
1758 	}
1759 
1760 	TAILQ_INIT(&rgroup->pollers);
1761 
1762 	pthread_mutex_lock(&rtransport->lock);
1763 	TAILQ_FOREACH(device, &rtransport->devices, link) {
1764 		if (device->map == NULL) {
1765 			/*
1766 			 * The device is not in use (no listeners),
1767 			 * so no protection domain has been constructed.
1768 			 * Skip it.
1769 			 */
1770 			SPDK_NOTICELOG("Skipping unused RDMA device when creating poll group.\n");
1771 			continue;
1772 		}
1773 
1774 		poller = calloc(1, sizeof(*poller));
1775 		if (!poller) {
1776 			SPDK_ERRLOG("Unable to allocate memory for new RDMA poller\n");
1777 			free(rgroup);
1778 			pthread_mutex_unlock(&rtransport->lock);
1779 			return NULL;
1780 		}
1781 
1782 		poller->device = device;
1783 		poller->group = rgroup;
1784 
1785 		TAILQ_INIT(&poller->qpairs);
1786 
1787 		poller->cq = ibv_create_cq(device->context, NVMF_RDMA_CQ_SIZE, poller, NULL, 0);
1788 		if (!poller->cq) {
1789 			SPDK_ERRLOG("Unable to create completion queue\n");
1790 			free(poller);
1791 			free(rgroup);
1792 			pthread_mutex_unlock(&rtransport->lock);
1793 			return NULL;
1794 		}
1795 
1796 		TAILQ_INSERT_TAIL(&rgroup->pollers, poller, link);
1797 	}
1798 
1799 	pthread_mutex_unlock(&rtransport->lock);
1800 	return &rgroup->group;
1801 }
1802 
1803 static void
1804 spdk_nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group)
1805 {
1806 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1807 	struct spdk_nvmf_rdma_poller		*poller, *tmp;
1808 
1809 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
1810 
1811 	if (!rgroup) {
1812 		return;
1813 	}
1814 
1815 	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {
1816 		TAILQ_REMOVE(&rgroup->pollers, poller, link);
1817 
1818 		if (poller->cq) {
1819 			ibv_destroy_cq(poller->cq);
1820 		}
1821 
1822 		free(poller);
1823 	}
1824 
1825 	free(rgroup);
1826 }
1827 
1828 static int
1829 spdk_nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group,
1830 			      struct spdk_nvmf_qpair *qpair)
1831 {
1832 	struct spdk_nvmf_rdma_transport		*rtransport;
1833 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1834 	struct spdk_nvmf_rdma_qpair		*rqpair;
1835 	struct spdk_nvmf_rdma_device		*device;
1836 	struct spdk_nvmf_rdma_poller		*poller;
1837 	int					rc;
1838 
1839 	rtransport = SPDK_CONTAINEROF(qpair->transport, struct spdk_nvmf_rdma_transport, transport);
1840 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
1841 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1842 
1843 	device = rqpair->port->device;
1844 
1845 	if (device->pd != rqpair->cm_id->pd) {
1846 		SPDK_ERRLOG("Mismatched protection domains\n");
1847 		return -1;
1848 	}
1849 
1850 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
1851 		if (poller->device == device) {
1852 			break;
1853 		}
1854 	}
1855 
1856 	if (!poller) {
1857 		SPDK_ERRLOG("No poller found for device.\n");
1858 		return -1;
1859 	}
1860 
1861 	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);
1862 	rqpair->poller = poller;
1863 
1864 	rc = spdk_nvmf_rdma_qpair_initialize(qpair);
1865 	if (rc < 0) {
1866 		SPDK_ERRLOG("Failed to initialize nvmf_rdma_qpair with qpair=%p\n", qpair);
1867 		return -1;
1868 	}
1869 
1870 	rqpair->mgmt_channel = spdk_get_io_channel(rtransport);
1871 	if (!rqpair->mgmt_channel) {
1872 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1873 		spdk_nvmf_rdma_qpair_destroy(rqpair);
1874 		return -1;
1875 	}
1876 
1877 	rqpair->ch = spdk_io_channel_get_ctx(rqpair->mgmt_channel);
1878 	assert(rqpair->ch != NULL);
1879 
1880 	rc = spdk_nvmf_rdma_event_accept(rqpair->cm_id, rqpair);
1881 	if (rc) {
1882 		/* Try to reject, but we probably can't */
1883 		spdk_nvmf_rdma_event_reject(rqpair->cm_id, SPDK_NVMF_RDMA_ERROR_NO_RESOURCES);
1884 		spdk_nvmf_rdma_qpair_destroy(rqpair);
1885 		return -1;
1886 	}
1887 
1888 	return 0;
1889 }
1890 
1891 static int
1892 spdk_nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
1893 				 struct spdk_nvmf_qpair *qpair)
1894 {
1895 	struct spdk_nvmf_rdma_poll_group	*rgroup;
1896 	struct spdk_nvmf_rdma_qpair		*rqpair;
1897 	struct spdk_nvmf_rdma_device		*device;
1898 	struct spdk_nvmf_rdma_poller		*poller;
1899 	struct spdk_nvmf_rdma_qpair		*rq, *trq;
1900 
1901 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
1902 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
1903 
1904 	device = rqpair->port->device;
1905 
1906 	TAILQ_FOREACH(poller, &rgroup->pollers, link) {
1907 		if (poller->device == device) {
1908 			break;
1909 		}
1910 	}
1911 
1912 	if (!poller) {
1913 		SPDK_ERRLOG("No poller found for device.\n");
1914 		return -1;
1915 	}
1916 
1917 	TAILQ_FOREACH_SAFE(rq, &poller->qpairs, link, trq) {
1918 		if (rq == rqpair) {
1919 			TAILQ_REMOVE(&poller->qpairs, rqpair, link);
1920 			rqpair->poller = NULL;
1921 			break;
1922 		}
1923 	}
1924 
1925 	if (rq == NULL) {
1926 		SPDK_ERRLOG("RDMA qpair cannot be removed from group (not in group).\n");
1927 		return -1;
1928 	}
1929 
1930 	return 0;
1931 }
1932 
1933 static int
1934 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
1935 {
1936 	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
1937 			struct spdk_nvmf_rdma_transport, transport);
1938 	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
1939 
1940 	rdma_req->state = RDMA_REQUEST_STATE_EXECUTED;
1941 	spdk_nvmf_rdma_request_process(rtransport, rdma_req);
1942 
1943 	return 0;
1944 }
1945 
1946 static void
1947 spdk_nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair)
1948 {
1949 	spdk_nvmf_rdma_qpair_destroy(SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair));
1950 }
1951 
1952 static void
1953 spdk_nvmf_rdma_qpair_process_pending(struct spdk_nvmf_rdma_transport *rtransport,
1954 				     struct spdk_nvmf_rdma_qpair *rqpair)
1955 {
1956 	struct spdk_nvmf_rdma_recv	*rdma_recv, *recv_tmp;
1957 	struct spdk_nvmf_rdma_request	*rdma_req, *req_tmp;
1958 
1959 	/* We process I/O in the pending_rdma_rw queue at the highest priority. */
1960 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->pending_rdma_rw_queue, link, req_tmp) {
1961 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1962 			break;
1963 		}
1964 	}
1965 
1966 	/* The second highest priority is I/O waiting on memory buffers. */
1967 	TAILQ_FOREACH_SAFE(rdma_req, &rqpair->ch->pending_data_buf_queue, link, req_tmp) {
1968 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1969 			break;
1970 		}
1971 	}
1972 
1973 	/* The lowest priority is processing newly received commands */
1974 	TAILQ_FOREACH_SAFE(rdma_recv, &rqpair->incoming_queue, link, recv_tmp) {
1975 		rdma_req = TAILQ_FIRST(&rqpair->free_queue);
1976 		if (rdma_req == NULL) {
1977 			/* Need to wait for more SEND completions */
1978 			break;
1979 		}
1980 
1981 		rdma_req->recv = rdma_recv;
1982 		rdma_req->state = RDMA_REQUEST_STATE_NEW;
1983 		if (spdk_nvmf_rdma_request_process(rtransport, rdma_req) == false) {
1984 			break;
1985 		}
1986 	}
1987 }
1988 
1989 static struct spdk_nvmf_rdma_request *
1990 get_rdma_req_from_wc(struct ibv_wc *wc)
1991 {
1992 	struct spdk_nvmf_rdma_request *rdma_req;
1993 
1994 	rdma_req = (struct spdk_nvmf_rdma_request *)wc->wr_id;
1995 	assert(rdma_req != NULL);
1996 
1997 #ifdef DEBUG
1998 	struct spdk_nvmf_rdma_qpair *rqpair;
1999 	rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2000 
2001 	assert(rdma_req - rqpair->reqs >= 0);
2002 	assert(rdma_req - rqpair->reqs < (ptrdiff_t)rqpair->max_queue_depth);
2003 #endif
2004 
2005 	return rdma_req;
2006 }
2007 
2008 static struct spdk_nvmf_rdma_recv *
2009 get_rdma_recv_from_wc(struct ibv_wc *wc)
2010 {
2011 	struct spdk_nvmf_rdma_recv *rdma_recv;
2012 
2013 	assert(wc->byte_len >= sizeof(struct spdk_nvmf_capsule_cmd));
2014 
2015 	rdma_recv = (struct spdk_nvmf_rdma_recv *)wc->wr_id;
2016 	assert(rdma_recv != NULL);
2017 
2018 #ifdef DEBUG
2019 	struct spdk_nvmf_rdma_qpair *rqpair = rdma_recv->qpair;
2020 
2021 	assert(rdma_recv - rqpair->recvs >= 0);
2022 	assert(rdma_recv - rqpair->recvs < (ptrdiff_t)rqpair->max_queue_depth);
2023 #endif
2024 
2025 	return rdma_recv;
2026 }
2027 
2028 static int
2029 spdk_nvmf_rdma_poller_poll(struct spdk_nvmf_rdma_transport *rtransport,
2030 			   struct spdk_nvmf_rdma_poller *rpoller)
2031 {
2032 	struct ibv_wc wc[32];
2033 	struct spdk_nvmf_rdma_request	*rdma_req;
2034 	struct spdk_nvmf_rdma_recv	*rdma_recv;
2035 	struct spdk_nvmf_rdma_qpair	*rqpair;
2036 	int reaped, i;
2037 	int count = 0;
2038 	bool error = false;
2039 
2040 	/* Poll for completing operations. */
2041 	reaped = ibv_poll_cq(rpoller->cq, 32, wc);
2042 	if (reaped < 0) {
2043 		SPDK_ERRLOG("Error polling CQ! (%d): %s\n",
2044 			    errno, spdk_strerror(errno));
2045 		return -1;
2046 	}
2047 
2048 	for (i = 0; i < reaped; i++) {
2049 		if (wc[i].status) {
2050 			SPDK_ERRLOG("CQ error on CQ %p, Request 0x%lu (%d): %s\n",
2051 				    rpoller->cq, wc[i].wr_id, wc[i].status, ibv_wc_status_str(wc[i].status));
2052 			error = true;
2053 			continue;
2054 		}
2055 
2056 		switch (wc[i].opcode) {
2057 		case IBV_WC_SEND:
2058 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2059 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2060 
2061 			assert(rdma_req->state == RDMA_REQUEST_STATE_COMPLETING);
2062 			rdma_req->state = RDMA_REQUEST_STATE_COMPLETED;
2063 
2064 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2065 
2066 			count++;
2067 
2068 			/* Try to process other queued requests */
2069 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2070 			break;
2071 
2072 		case IBV_WC_RDMA_WRITE:
2073 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2074 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2075 
2076 			rqpair->cur_rdma_rw_depth--;
2077 
2078 			/* Try to process other queued requests */
2079 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2080 			break;
2081 
2082 		case IBV_WC_RDMA_READ:
2083 			rdma_req = get_rdma_req_from_wc(&wc[i]);
2084 			rqpair = SPDK_CONTAINEROF(rdma_req->req.qpair, struct spdk_nvmf_rdma_qpair, qpair);
2085 
2086 			assert(rdma_req->state == RDMA_REQUEST_STATE_TRANSFERRING_HOST_TO_CONTROLLER);
2087 			rqpair->cur_rdma_rw_depth--;
2088 			rdma_req->state = RDMA_REQUEST_STATE_READY_TO_EXECUTE;
2089 
2090 			spdk_nvmf_rdma_request_process(rtransport, rdma_req);
2091 
2092 			/* Try to process other queued requests */
2093 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2094 			break;
2095 
2096 		case IBV_WC_RECV:
2097 			rdma_recv = get_rdma_recv_from_wc(&wc[i]);
2098 			rqpair = rdma_recv->qpair;
2099 
2100 			TAILQ_INSERT_TAIL(&rqpair->incoming_queue, rdma_recv, link);
2101 
2102 			/* Try to process other queued requests */
2103 			spdk_nvmf_rdma_qpair_process_pending(rtransport, rqpair);
2104 			break;
2105 
2106 		default:
2107 			SPDK_ERRLOG("Received an unknown opcode on the CQ: %d\n", wc[i].opcode);
2108 			continue;
2109 		}
2110 	}
2111 
2112 	if (error == true) {
2113 		return -1;
2114 	}
2115 
2116 	return count;
2117 }
2118 
2119 static int
2120 spdk_nvmf_rdma_poll_group_poll(struct spdk_nvmf_transport_poll_group *group)
2121 {
2122 	struct spdk_nvmf_rdma_transport *rtransport;
2123 	struct spdk_nvmf_rdma_poll_group *rgroup;
2124 	struct spdk_nvmf_rdma_poller	*rpoller;
2125 	int				count, rc;
2126 
2127 	rtransport = SPDK_CONTAINEROF(group->transport, struct spdk_nvmf_rdma_transport, transport);
2128 	rgroup = SPDK_CONTAINEROF(group, struct spdk_nvmf_rdma_poll_group, group);
2129 
2130 	count = 0;
2131 	TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {
2132 		rc = spdk_nvmf_rdma_poller_poll(rtransport, rpoller);
2133 		if (rc < 0) {
2134 			return rc;
2135 		}
2136 		count += rc;
2137 	}
2138 
2139 	return count;
2140 }
2141 
2142 static bool
2143 spdk_nvmf_rdma_qpair_is_idle(struct spdk_nvmf_qpair *qpair)
2144 {
2145 	struct spdk_nvmf_rdma_qpair *rqpair;
2146 
2147 	rqpair = SPDK_CONTAINEROF(qpair, struct spdk_nvmf_rdma_qpair, qpair);
2148 
2149 	if (rqpair->cur_queue_depth == 0 && rqpair->cur_rdma_rw_depth == 0) {
2150 		return true;
2151 	}
2152 	return false;
2153 }
2154 
2155 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
2156 	.type = SPDK_NVME_TRANSPORT_RDMA,
2157 	.create = spdk_nvmf_rdma_create,
2158 	.destroy = spdk_nvmf_rdma_destroy,
2159 
2160 	.listen = spdk_nvmf_rdma_listen,
2161 	.stop_listen = spdk_nvmf_rdma_stop_listen,
2162 	.accept = spdk_nvmf_rdma_accept,
2163 
2164 	.listener_discover = spdk_nvmf_rdma_discover,
2165 
2166 	.poll_group_create = spdk_nvmf_rdma_poll_group_create,
2167 	.poll_group_destroy = spdk_nvmf_rdma_poll_group_destroy,
2168 	.poll_group_add = spdk_nvmf_rdma_poll_group_add,
2169 	.poll_group_remove = spdk_nvmf_rdma_poll_group_remove,
2170 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
2171 
2172 	.req_complete = spdk_nvmf_rdma_request_complete,
2173 
2174 	.qpair_fini = spdk_nvmf_rdma_close_qpair,
2175 	.qpair_is_idle = spdk_nvmf_rdma_qpair_is_idle,
2176 
2177 };
2178 
2179 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)
2180