xref: /spdk/lib/vhost/vhost_internal.h (revision fecffda6ecf8853b82edccde429b68252f0a62c5)
1 /*   SPDX-License-Identifier: BSD-3-Clause
2  *   Copyright (C) 2017 Intel Corporation.
3  *   All rights reserved.
4  */
5 
6 #ifndef SPDK_VHOST_INTERNAL_H
7 #define SPDK_VHOST_INTERNAL_H
8 #include <linux/virtio_config.h>
9 
10 #include "spdk/stdinc.h"
11 
12 #include <rte_vhost.h>
13 
14 #include "spdk_internal/vhost_user.h"
15 #include "spdk/bdev.h"
16 #include "spdk/log.h"
17 #include "spdk/util.h"
18 #include "spdk/rpc.h"
19 #include "spdk/config.h"
20 
21 #define SPDK_VHOST_MAX_VQUEUES	256
22 #define SPDK_VHOST_MAX_VQ_SIZE	1024
23 
24 #define SPDK_VHOST_SCSI_CTRLR_MAX_DEVS 8
25 
26 #define SPDK_VHOST_IOVS_MAX 129
27 
28 #define SPDK_VHOST_VQ_MAX_SUBMISSIONS	32
29 
30 /*
31  * Rate at which stats are checked for interrupt coalescing.
32  */
33 #define SPDK_VHOST_STATS_CHECK_INTERVAL_MS 10
34 /*
35  * Default threshold at which interrupts start to be coalesced.
36  */
37 #define SPDK_VHOST_VQ_IOPS_COALESCING_THRESHOLD 60000
38 
39 /*
40  * Currently coalescing is not used by default.
41  * Setting this to value > 0 here or by RPC will enable coalescing.
42  */
43 #define SPDK_VHOST_COALESCING_DELAY_BASE_US 0
44 
45 #define SPDK_VHOST_FEATURES ((1ULL << VHOST_F_LOG_ALL) | \
46 	(1ULL << VHOST_USER_F_PROTOCOL_FEATURES) | \
47 	(1ULL << VIRTIO_F_VERSION_1) | \
48 	(1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \
49 	(1ULL << VIRTIO_RING_F_EVENT_IDX) | \
50 	(1ULL << VIRTIO_RING_F_INDIRECT_DESC) | \
51 	(1ULL << VIRTIO_F_RING_PACKED) | \
52 	(1ULL << VIRTIO_F_ANY_LAYOUT))
53 
54 #define SPDK_VHOST_DISABLED_FEATURES ((1ULL << VIRTIO_RING_F_EVENT_IDX) | \
55 	(1ULL << VIRTIO_F_NOTIFY_ON_EMPTY))
56 
57 #define VRING_DESC_F_AVAIL	(1ULL << VRING_PACKED_DESC_F_AVAIL)
58 #define VRING_DESC_F_USED	(1ULL << VRING_PACKED_DESC_F_USED)
59 #define VRING_DESC_F_AVAIL_USED	(VRING_DESC_F_AVAIL | VRING_DESC_F_USED)
60 
61 typedef struct rte_vhost_resubmit_desc spdk_vhost_resubmit_desc;
62 typedef struct rte_vhost_resubmit_info spdk_vhost_resubmit_info;
63 typedef struct rte_vhost_inflight_desc_packed	spdk_vhost_inflight_desc;
64 
65 struct spdk_vhost_virtqueue {
66 	struct rte_vhost_vring vring;
67 	struct rte_vhost_ring_inflight vring_inflight;
68 	uint16_t last_avail_idx;
69 	uint16_t last_used_idx;
70 
71 	struct {
72 		/* To mark a descriptor as available in packed ring
73 		 * Equal to avail_wrap_counter in spec.
74 		 */
75 		uint8_t avail_phase	: 1;
76 		/* To mark a descriptor as used in packed ring
77 		 * Equal to used_wrap_counter in spec.
78 		 */
79 		uint8_t used_phase	: 1;
80 		uint8_t padding		: 5;
81 		bool packed_ring	: 1;
82 	} packed;
83 
84 	void *tasks;
85 
86 	/* Request count from last stats check */
87 	uint32_t req_cnt;
88 
89 	/* Request count from last event */
90 	uint16_t used_req_cnt;
91 
92 	/* How long interrupt is delayed */
93 	uint32_t irq_delay_time;
94 
95 	/* Next time when we need to send event */
96 	uint64_t next_event_time;
97 
98 	/* Associated vhost_virtqueue in the virtio device's virtqueue list */
99 	uint32_t vring_idx;
100 
101 	struct spdk_vhost_session *vsession;
102 
103 	struct spdk_interrupt *intr;
104 } __attribute((aligned(SPDK_CACHE_LINE_SIZE)));
105 
106 struct spdk_vhost_session {
107 	struct spdk_vhost_dev *vdev;
108 
109 	/* rte_vhost connection ID. */
110 	int vid;
111 
112 	/* Unique session ID. */
113 	uint64_t id;
114 	/* Unique session name. */
115 	char *name;
116 
117 	bool started;
118 	bool interrupt_mode;
119 
120 	struct rte_vhost_memory *mem;
121 
122 	int task_cnt;
123 
124 	uint16_t max_queues;
125 
126 	uint64_t negotiated_features;
127 
128 	/* Local copy of device coalescing settings. */
129 	uint32_t coalescing_delay_time_base;
130 	uint32_t coalescing_io_rate_threshold;
131 
132 	/* Next time when stats for event coalescing will be checked. */
133 	uint64_t next_stats_check_time;
134 
135 	/* Interval used for event coalescing checking. */
136 	uint64_t stats_check_interval;
137 
138 	/* Session's stop poller will only try limited times to destroy the session. */
139 	uint32_t stop_retry_count;
140 
141 	struct spdk_vhost_virtqueue virtqueue[SPDK_VHOST_MAX_VQUEUES];
142 
143 	TAILQ_ENTRY(spdk_vhost_session) tailq;
144 };
145 
146 struct spdk_vhost_user_dev {
147 	struct spdk_vhost_dev *vdev;
148 
149 	const struct spdk_vhost_user_dev_backend *user_backend;
150 
151 	/* Saved original values used to setup coalescing to avoid integer
152 	 * rounding issues during save/load config.
153 	 */
154 	uint32_t coalescing_delay_us;
155 	uint32_t coalescing_iops_threshold;
156 
157 	bool registered;
158 
159 	/* Current connections to the device */
160 	TAILQ_HEAD(, spdk_vhost_session) vsessions;
161 
162 	/* Increment-only session counter */
163 	uint64_t vsessions_num;
164 
165 	/* Number of started and actively polled sessions */
166 	uint32_t active_session_num;
167 
168 	/* Number of pending asynchronous operations */
169 	uint32_t pending_async_op_num;
170 };
171 
172 struct spdk_vhost_dev {
173 	char *name;
174 	char *path;
175 
176 	struct spdk_thread *thread;
177 
178 	uint64_t virtio_features;
179 	uint64_t disabled_features;
180 	uint64_t protocol_features;
181 	bool packed_ring_recovery;
182 
183 	const struct spdk_vhost_dev_backend *backend;
184 
185 	/* Context passed from transport */
186 	void *ctxt;
187 
188 	TAILQ_ENTRY(spdk_vhost_dev) tailq;
189 };
190 
191 /**
192  * \param vdev vhost device.
193  * \param vsession vhost session.
194  * \param arg user-provided parameter.
195  *
196  * \return negative values will break the foreach call, meaning
197  * the function won't be called again. Return codes zero and
198  * positive don't have any effect.
199  */
200 typedef int (*spdk_vhost_session_fn)(struct spdk_vhost_dev *vdev,
201 				     struct spdk_vhost_session *vsession,
202 				     void *arg);
203 
204 /**
205  * \param vdev vhost device.
206  * \param arg user-provided parameter.
207  */
208 typedef void (*spdk_vhost_dev_fn)(struct spdk_vhost_dev *vdev, void *arg);
209 
210 struct spdk_vhost_user_dev_backend {
211 	/**
212 	 * Size of additional per-session context data
213 	 * allocated whenever a new client connects.
214 	 */
215 	size_t session_ctx_size;
216 
217 	spdk_vhost_session_fn start_session;
218 	int (*stop_session)(struct spdk_vhost_session *vsession);
219 	int (*alloc_vq_tasks)(struct spdk_vhost_session *vsession, uint16_t qid);
220 };
221 
222 enum vhost_backend_type {
223 	VHOST_BACKEND_BLK = 0,
224 	VHOST_BACKEND_SCSI,
225 };
226 
227 struct spdk_vhost_dev_backend {
228 	enum vhost_backend_type type;
229 
230 	int (*vhost_get_config)(struct spdk_vhost_dev *vdev, uint8_t *config, uint32_t len);
231 	int (*vhost_set_config)(struct spdk_vhost_dev *vdev, uint8_t *config,
232 				uint32_t offset, uint32_t size, uint32_t flags);
233 
234 	void (*dump_info_json)(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w);
235 	void (*write_config_json)(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w);
236 	int (*remove_device)(struct spdk_vhost_dev *vdev);
237 	int (*set_coalescing)(struct spdk_vhost_dev *vdev, uint32_t delay_base_us,
238 			      uint32_t iops_threshold);
239 	void (*get_coalescing)(struct spdk_vhost_dev *vdev, uint32_t *delay_base_us,
240 			       uint32_t *iops_threshold);
241 };
242 
243 void *vhost_gpa_to_vva(struct spdk_vhost_session *vsession, uint64_t addr, uint64_t len);
244 
245 uint16_t vhost_vq_avail_ring_get(struct spdk_vhost_virtqueue *vq, uint16_t *reqs,
246 				 uint16_t reqs_len);
247 
248 /**
249  * Get a virtio split descriptor at given index in given virtqueue.
250  * The descriptor will provide access to the entire descriptor
251  * chain. The subsequent descriptors are accessible via
252  * \c spdk_vhost_vring_desc_get_next.
253  * \param vsession vhost session
254  * \param vq virtqueue
255  * \param req_idx descriptor index
256  * \param desc pointer to be set to the descriptor
257  * \param desc_table descriptor table to be used with
258  * \c spdk_vhost_vring_desc_get_next. This might be either
259  * default virtqueue descriptor table or per-chain indirect
260  * table.
261  * \param desc_table_size size of the *desc_table*
262  * \return 0 on success, -1 if given index is invalid.
263  * If -1 is returned, the content of params is undefined.
264  */
265 int vhost_vq_get_desc(struct spdk_vhost_session *vsession, struct spdk_vhost_virtqueue *vq,
266 		      uint16_t req_idx, struct vring_desc **desc, struct vring_desc **desc_table,
267 		      uint32_t *desc_table_size);
268 
269 /**
270  * Get a virtio packed descriptor at given index in given virtqueue.
271  * The descriptor will provide access to the entire descriptor
272  * chain. The subsequent descriptors are accessible via
273  * \c vhost_vring_packed_desc_get_next.
274  * \param vsession vhost session
275  * \param vq virtqueue
276  * \param req_idx descriptor index
277  * \param desc pointer to be set to the descriptor
278  * \param desc_table descriptor table to be used with
279  * \c spdk_vhost_vring_desc_get_next. This might be either
280  * \c NULL or per-chain indirect table.
281  * \param desc_table_size size of the *desc_table*
282  * \return 0 on success, -1 if given index is invalid.
283  * If -1 is returned, the content of params is undefined.
284  */
285 int vhost_vq_get_desc_packed(struct spdk_vhost_session *vsession,
286 			     struct spdk_vhost_virtqueue *virtqueue,
287 			     uint16_t req_idx, struct vring_packed_desc **desc,
288 			     struct vring_packed_desc **desc_table, uint32_t *desc_table_size);
289 
290 int vhost_inflight_queue_get_desc(struct spdk_vhost_session *vsession,
291 				  spdk_vhost_inflight_desc *desc_array,
292 				  uint16_t req_idx, spdk_vhost_inflight_desc **desc,
293 				  struct vring_packed_desc  **desc_table, uint32_t *desc_table_size);
294 
295 /**
296  * Send IRQ/call client (if pending) for \c vq.
297  * \param vsession vhost session
298  * \param vq virtqueue
299  * \return
300  *   0 - if no interrupt was signalled
301  *   1 - if interrupt was signalled
302  */
303 int vhost_vq_used_signal(struct spdk_vhost_session *vsession, struct spdk_vhost_virtqueue *vq);
304 
305 /**
306  * Send IRQs for the queue that need to be signaled.
307  * \param vq virtqueue
308  */
309 void vhost_session_vq_used_signal(struct spdk_vhost_virtqueue *virtqueue);
310 
311 void vhost_vq_used_ring_enqueue(struct spdk_vhost_session *vsession,
312 				struct spdk_vhost_virtqueue *vq,
313 				uint16_t id, uint32_t len);
314 
315 /**
316  * Enqueue the entry to the used ring when device complete the request.
317  * \param vsession vhost session
318  * \param vq virtqueue
319  * \req_idx descriptor index. It's the first index of this descriptor chain.
320  * \num_descs descriptor count. It's the count of the number of buffers in the chain.
321  * \buffer_id descriptor buffer ID.
322  * \length device write length. Specify the length of the buffer that has been initialized
323  * (written to) by the device
324  * \inflight_head the head idx of this IO inflight desc chain.
325  */
326 void vhost_vq_packed_ring_enqueue(struct spdk_vhost_session *vsession,
327 				  struct spdk_vhost_virtqueue *virtqueue,
328 				  uint16_t num_descs, uint16_t buffer_id,
329 				  uint32_t length, uint16_t inflight_head);
330 
331 /**
332  * Get subsequent descriptor from given table.
333  * \param desc current descriptor, will be set to the
334  * next descriptor (NULL in case this is the last
335  * descriptor in the chain or the next desc is invalid)
336  * \param desc_table descriptor table
337  * \param desc_table_size size of the *desc_table*
338  * \return 0 on success, -1 if given index is invalid
339  * The *desc* param will be set regardless of the
340  * return value.
341  */
342 int vhost_vring_desc_get_next(struct vring_desc **desc,
343 			      struct vring_desc *desc_table, uint32_t desc_table_size);
344 static inline bool
345 vhost_vring_desc_is_wr(struct vring_desc *cur_desc)
346 {
347 	return !!(cur_desc->flags & VRING_DESC_F_WRITE);
348 }
349 
350 int vhost_vring_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec *iov,
351 			    uint16_t *iov_index, const struct vring_desc *desc);
352 
353 bool vhost_vq_packed_ring_is_avail(struct spdk_vhost_virtqueue *virtqueue);
354 
355 /**
356  * Get subsequent descriptor from vq or desc table.
357  * \param desc current descriptor, will be set to the
358  * next descriptor (NULL in case this is the last
359  * descriptor in the chain or the next desc is invalid)
360  * \req_idx index of current desc, will be set to the next
361  * index. If desc_table != NULL the req_idx is the the vring index
362  * or the req_idx is the desc_table index.
363  * \param desc_table descriptor table
364  * \param desc_table_size size of the *desc_table*
365  * \return 0 on success, -1 if given index is invalid
366  * The *desc* param will be set regardless of the
367  * return value.
368  */
369 int vhost_vring_packed_desc_get_next(struct vring_packed_desc **desc, uint16_t *req_idx,
370 				     struct spdk_vhost_virtqueue *vq,
371 				     struct vring_packed_desc *desc_table,
372 				     uint32_t desc_table_size);
373 
374 bool vhost_vring_packed_desc_is_wr(struct vring_packed_desc *cur_desc);
375 
376 int vhost_vring_packed_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec *iov,
377 				   uint16_t *iov_index, const struct vring_packed_desc *desc);
378 
379 bool vhost_vring_inflight_desc_is_wr(spdk_vhost_inflight_desc *cur_desc);
380 
381 int vhost_vring_inflight_desc_to_iov(struct spdk_vhost_session *vsession, struct iovec *iov,
382 				     uint16_t *iov_index, const spdk_vhost_inflight_desc *desc);
383 
384 uint16_t vhost_vring_packed_desc_get_buffer_id(struct spdk_vhost_virtqueue *vq, uint16_t req_idx,
385 		uint16_t *num_descs);
386 
387 static inline bool
388 __attribute__((always_inline))
389 vhost_dev_has_feature(struct spdk_vhost_session *vsession, unsigned feature_id)
390 {
391 	return vsession->negotiated_features & (1ULL << feature_id);
392 }
393 
394 int vhost_dev_register(struct spdk_vhost_dev *vdev, const char *name, const char *mask_str,
395 		       const struct spdk_json_val *params,
396 		       const struct spdk_vhost_dev_backend *backend,
397 		       const struct spdk_vhost_user_dev_backend *user_backend);
398 int vhost_dev_unregister(struct spdk_vhost_dev *vdev);
399 
400 void vhost_dump_info_json(struct spdk_vhost_dev *vdev, struct spdk_json_write_ctx *w);
401 
402 /*
403  * Set vhost session to run in interrupt or poll mode
404  */
405 void vhost_user_session_set_interrupt_mode(struct spdk_vhost_session *vsession,
406 		bool interrupt_mode);
407 
408 /*
409  * Memory registration functions used in start/stop device callbacks
410  */
411 void vhost_session_mem_register(struct rte_vhost_memory *mem);
412 void vhost_session_mem_unregister(struct rte_vhost_memory *mem);
413 
414 /*
415  * Call a function for each session of the provided vhost device.
416  * The function will be called one-by-one on each session's thread.
417  *
418  * \param vdev vhost device
419  * \param fn function to call on each session's thread
420  * \param cpl_fn function to be called at the end of the iteration on
421  * the vhost management thread.
422  * Optional, can be NULL.
423  * \param arg additional argument to the both callbacks
424  */
425 void vhost_user_dev_foreach_session(struct spdk_vhost_dev *dev,
426 				    spdk_vhost_session_fn fn,
427 				    spdk_vhost_dev_fn cpl_fn,
428 				    void *arg);
429 
430 /**
431  * Call a function on the provided lcore and block until either
432  * vhost_user_session_start_done() or vhost_user_session_stop_done()
433  * is called.
434  *
435  * This must be called under the global vhost mutex, which this function
436  * will unlock for the time it's waiting. It's meant to be called only
437  * from start/stop session callbacks.
438  *
439  * \param vsession vhost session
440  * \param cb_fn the function to call. The void *arg parameter in cb_fn
441  * is always NULL.
442  * \param timeout_sec timeout in seconds. This function will still
443  * block after the timeout expires, but will print the provided errmsg.
444  * \param errmsg error message to print once the timeout expires
445  * \return return the code passed to spdk_vhost_session_event_done().
446  */
447 int vhost_user_session_send_event(struct spdk_vhost_session *vsession,
448 				  spdk_vhost_session_fn cb_fn, unsigned timeout_sec,
449 				  const char *errmsg);
450 
451 /**
452  * Finish a blocking spdk_vhost_user_session_send_event() call and finally
453  * start the session. This must be called on the target lcore, which
454  * will now receive all session-related messages (e.g. from
455  * vhost_user_dev_foreach_session()).
456  *
457  * Must be called under the global vhost lock.
458  *
459  * \param vsession vhost session
460  * \param response return code
461  */
462 void vhost_user_session_start_done(struct spdk_vhost_session *vsession, int response);
463 
464 /**
465  * Finish a blocking spdk_vhost_user_session_send_event() call and finally
466  * stop the session. This must be called on the session's lcore which
467  * used to receive all session-related messages (e.g. from
468  * vhost_user_dev_foreach_session()). After this call, the session-
469  * related messages will be once again processed by any arbitrary thread.
470  *
471  * Must be called under the global vhost lock.
472  *
473  * Must be called under the global vhost mutex.
474  *
475  * \param vsession vhost session
476  * \param response return code
477  */
478 void vhost_user_session_stop_done(struct spdk_vhost_session *vsession, int response);
479 
480 struct spdk_vhost_session *vhost_session_find_by_vid(int vid);
481 void vhost_session_install_rte_compat_hooks(struct spdk_vhost_session *vsession);
482 int vhost_register_unix_socket(const char *path, const char *ctrl_name,
483 			       uint64_t virtio_features, uint64_t disabled_features, uint64_t protocol_features);
484 int vhost_driver_unregister(const char *path);
485 int vhost_get_mem_table(int vid, struct rte_vhost_memory **mem);
486 int vhost_get_negotiated_features(int vid, uint64_t *negotiated_features);
487 
488 int remove_vhost_controller(struct spdk_vhost_dev *vdev);
489 
490 struct spdk_io_channel *vhost_blk_get_io_channel(struct spdk_vhost_dev *vdev);
491 void vhost_blk_put_io_channel(struct spdk_io_channel *ch);
492 
493 /* The spdk_bdev pointer should only be used to retrieve
494  * the device properties, ex. number of blocks or I/O type supported. */
495 struct spdk_bdev *vhost_blk_get_bdev(struct spdk_vhost_dev *vdev);
496 
497 /* Function calls from vhost.c to rte_vhost_user.c,
498  * shall removed once virtio transport abstraction is complete. */
499 int vhost_user_session_set_coalescing(struct spdk_vhost_dev *dev,
500 				      struct spdk_vhost_session *vsession, void *ctx);
501 int vhost_user_dev_set_coalescing(struct spdk_vhost_user_dev *user_dev, uint32_t delay_base_us,
502 				  uint32_t iops_threshold);
503 int vhost_user_dev_register(struct spdk_vhost_dev *vdev, const char *name,
504 			    struct spdk_cpuset *cpumask, const struct spdk_vhost_user_dev_backend *user_backend);
505 int vhost_user_dev_unregister(struct spdk_vhost_dev *vdev);
506 int vhost_user_init(void);
507 void vhost_user_fini(spdk_vhost_fini_cb vhost_cb);
508 int vhost_user_set_coalescing(struct spdk_vhost_dev *vdev, uint32_t delay_base_us,
509 			      uint32_t iops_threshold);
510 void vhost_user_get_coalescing(struct spdk_vhost_dev *vdev, uint32_t *delay_base_us,
511 			       uint32_t *iops_threshold);
512 
513 int virtio_blk_construct_ctrlr(struct spdk_vhost_dev *vdev, const char *address,
514 			       struct spdk_cpuset *cpumask, const struct spdk_json_val *params,
515 			       const struct spdk_vhost_user_dev_backend *user_backend);
516 int virtio_blk_destroy_ctrlr(struct spdk_vhost_dev *vdev);
517 
518 struct spdk_vhost_blk_task;
519 
520 typedef void (*virtio_blk_request_cb)(uint8_t status, struct spdk_vhost_blk_task *task,
521 				      void *cb_arg);
522 
523 struct spdk_vhost_blk_task {
524 	struct spdk_bdev_io *bdev_io;
525 	virtio_blk_request_cb cb;
526 	void *cb_arg;
527 
528 	volatile uint8_t *status;
529 
530 	/* for io wait */
531 	struct spdk_bdev_io_wait_entry bdev_io_wait;
532 	struct spdk_io_channel *bdev_io_wait_ch;
533 	struct spdk_vhost_dev *bdev_io_wait_vdev;
534 
535 	/** Number of bytes that were written. */
536 	uint32_t used_len;
537 	uint16_t iovcnt;
538 	struct iovec iovs[SPDK_VHOST_IOVS_MAX];
539 
540 	/** Size of whole payload in bytes */
541 	uint32_t payload_size;
542 };
543 
544 int virtio_blk_process_request(struct spdk_vhost_dev *vdev, struct spdk_io_channel *ch,
545 			       struct spdk_vhost_blk_task *task, virtio_blk_request_cb cb, void *cb_arg);
546 
547 typedef void (*bdev_event_cb_complete)(struct spdk_vhost_dev *vdev, void *ctx);
548 
549 #define SPDK_VIRTIO_BLK_TRSTRING_MAX_LEN 32
550 
551 struct spdk_virtio_blk_transport_ops {
552 	/**
553 	 * Transport name
554 	 */
555 	char name[SPDK_VIRTIO_BLK_TRSTRING_MAX_LEN];
556 
557 	/**
558 	 * Create a transport for the given transport opts
559 	 */
560 	struct spdk_virtio_blk_transport *(*create)(const struct spdk_json_val *params);
561 
562 	/**
563 	 * Dump transport-specific opts into JSON
564 	 */
565 	void (*dump_opts)(struct spdk_virtio_blk_transport *transport, struct spdk_json_write_ctx *w);
566 
567 	/**
568 	 * Destroy the transport
569 	 */
570 	int (*destroy)(struct spdk_virtio_blk_transport *transport,
571 		       spdk_vhost_fini_cb cb_fn);
572 
573 	/**
574 	 * Create vhost block controller
575 	 */
576 	int (*create_ctrlr)(struct spdk_vhost_dev *vdev, struct spdk_cpuset *cpumask,
577 			    const char *address, const struct spdk_json_val *params,
578 			    void *custom_opts);
579 
580 	/**
581 	 * Destroy vhost block controller
582 	 */
583 	int (*destroy_ctrlr)(struct spdk_vhost_dev *vdev);
584 
585 	/*
586 	 * Signal removal of the bdev.
587 	 */
588 	void (*bdev_event)(enum spdk_bdev_event_type type, struct spdk_vhost_dev *vdev,
589 			   bdev_event_cb_complete cb, void *cb_arg);
590 
591 	/**
592 	 * Set coalescing parameters.
593 	 */
594 	int (*set_coalescing)(struct spdk_vhost_dev *vdev, uint32_t delay_base_us,
595 			      uint32_t iops_threshold);
596 
597 	/**
598 	 * Get coalescing parameters.
599 	 */
600 	void (*get_coalescing)(struct spdk_vhost_dev *vdev, uint32_t *delay_base_us,
601 			       uint32_t *iops_threshold);
602 };
603 
604 struct spdk_virtio_blk_transport {
605 	const struct spdk_virtio_blk_transport_ops	*ops;
606 	TAILQ_ENTRY(spdk_virtio_blk_transport)		tailq;
607 };
608 
609 struct virtio_blk_transport_ops_list_element {
610 	struct spdk_virtio_blk_transport_ops			ops;
611 	TAILQ_ENTRY(virtio_blk_transport_ops_list_element)	link;
612 };
613 
614 void virtio_blk_transport_register(const struct spdk_virtio_blk_transport_ops *ops);
615 int virtio_blk_transport_create(const char *transport_name, const struct spdk_json_val *params);
616 int virtio_blk_transport_destroy(struct spdk_virtio_blk_transport *transport,
617 				 spdk_vhost_fini_cb cb_fn);
618 
619 const struct spdk_virtio_blk_transport_ops *virtio_blk_get_transport_ops(
620 	const char *transport_name);
621 
622 
623 /*
624  * Macro used to register new transports.
625  */
626 #define SPDK_VIRTIO_BLK_TRANSPORT_REGISTER(name, transport_ops) \
627 static void __attribute__((constructor)) _virtio_blk_transport_register_##name(void) \
628 { \
629 	virtio_blk_transport_register(transport_ops); \
630 }
631 
632 #endif /* SPDK_VHOST_INTERNAL_H */
633