1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2016 Intel Corporation
3  */
4 
5 #include <sys/socket.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <unistd.h>
9 #include <fcntl.h>
10 #include <sys/un.h>
11 #include <string.h>
12 #include <errno.h>
13 
14 #include <rte_alarm.h>
15 #include <rte_string_fns.h>
16 #include <rte_fbarray.h>
17 
18 #include "vhost.h"
19 #include "virtio_user_dev.h"
20 
21 struct vhost_user_data {
22 	int vhostfd;
23 	int listenfd;
24 	uint64_t protocol_features;
25 };
26 
27 #ifndef VHOST_USER_F_PROTOCOL_FEATURES
28 #define VHOST_USER_F_PROTOCOL_FEATURES 30
29 #endif
30 
31 /** Protocol features. */
32 #ifndef VHOST_USER_PROTOCOL_F_MQ
33 #define VHOST_USER_PROTOCOL_F_MQ 0
34 #endif
35 
36 #ifndef VHOST_USER_PROTOCOL_F_REPLY_ACK
37 #define VHOST_USER_PROTOCOL_F_REPLY_ACK 3
38 #endif
39 
40 #ifndef VHOST_USER_PROTOCOL_F_STATUS
41 #define VHOST_USER_PROTOCOL_F_STATUS 16
42 #endif
43 
44 #define VHOST_USER_SUPPORTED_PROTOCOL_FEATURES		\
45 	(1ULL << VHOST_USER_PROTOCOL_F_MQ |		\
46 	 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |	\
47 	 1ULL << VHOST_USER_PROTOCOL_F_STATUS)
48 
49 /* The version of the protocol we support */
50 #define VHOST_USER_VERSION    0x1
51 
52 #define VHOST_MEMORY_MAX_NREGIONS 8
53 struct vhost_memory {
54 	uint32_t nregions;
55 	uint32_t padding;
56 	struct vhost_memory_region regions[VHOST_MEMORY_MAX_NREGIONS];
57 };
58 
59 enum vhost_user_request {
60 	VHOST_USER_NONE = 0,
61 	VHOST_USER_GET_FEATURES = 1,
62 	VHOST_USER_SET_FEATURES = 2,
63 	VHOST_USER_SET_OWNER = 3,
64 	VHOST_USER_RESET_OWNER = 4,
65 	VHOST_USER_SET_MEM_TABLE = 5,
66 	VHOST_USER_SET_LOG_BASE = 6,
67 	VHOST_USER_SET_LOG_FD = 7,
68 	VHOST_USER_SET_VRING_NUM = 8,
69 	VHOST_USER_SET_VRING_ADDR = 9,
70 	VHOST_USER_SET_VRING_BASE = 10,
71 	VHOST_USER_GET_VRING_BASE = 11,
72 	VHOST_USER_SET_VRING_KICK = 12,
73 	VHOST_USER_SET_VRING_CALL = 13,
74 	VHOST_USER_SET_VRING_ERR = 14,
75 	VHOST_USER_GET_PROTOCOL_FEATURES = 15,
76 	VHOST_USER_SET_PROTOCOL_FEATURES = 16,
77 	VHOST_USER_GET_QUEUE_NUM = 17,
78 	VHOST_USER_SET_VRING_ENABLE = 18,
79 	VHOST_USER_SET_STATUS = 39,
80 	VHOST_USER_GET_STATUS = 40,
81 	VHOST_USER_MAX
82 };
83 
84 struct vhost_user_msg {
85 	enum vhost_user_request request;
86 
87 #define VHOST_USER_VERSION_MASK     0x3
88 #define VHOST_USER_REPLY_MASK       (0x1 << 2)
89 #define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
90 	uint32_t flags;
91 	uint32_t size; /* the following payload size */
92 	union {
93 #define VHOST_USER_VRING_IDX_MASK   0xff
94 #define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
95 		uint64_t u64;
96 		struct vhost_vring_state state;
97 		struct vhost_vring_addr addr;
98 		struct vhost_memory memory;
99 	} payload;
100 } __rte_packed;
101 
102 #define VHOST_USER_HDR_SIZE offsetof(struct vhost_user_msg, payload.u64)
103 #define VHOST_USER_PAYLOAD_SIZE \
104 	(sizeof(struct vhost_user_msg) - VHOST_USER_HDR_SIZE)
105 
106 static int
107 vhost_user_write(int fd, struct vhost_user_msg *msg, int *fds, int fd_num)
108 {
109 	int r;
110 	struct msghdr msgh;
111 	struct iovec iov;
112 	size_t fd_size = fd_num * sizeof(int);
113 	char control[CMSG_SPACE(fd_size)];
114 	struct cmsghdr *cmsg;
115 
116 	memset(&msgh, 0, sizeof(msgh));
117 	memset(control, 0, sizeof(control));
118 
119 	iov.iov_base = (uint8_t *)msg;
120 	iov.iov_len = VHOST_USER_HDR_SIZE + msg->size;
121 
122 	msgh.msg_iov = &iov;
123 	msgh.msg_iovlen = 1;
124 	msgh.msg_control = control;
125 	msgh.msg_controllen = sizeof(control);
126 
127 	cmsg = CMSG_FIRSTHDR(&msgh);
128 	cmsg->cmsg_len = CMSG_LEN(fd_size);
129 	cmsg->cmsg_level = SOL_SOCKET;
130 	cmsg->cmsg_type = SCM_RIGHTS;
131 	memcpy(CMSG_DATA(cmsg), fds, fd_size);
132 
133 	do {
134 		r = sendmsg(fd, &msgh, 0);
135 	} while (r < 0 && errno == EINTR);
136 
137 	if (r < 0)
138 		PMD_DRV_LOG(ERR, "Failed to send msg: %s", strerror(errno));
139 
140 	return r;
141 }
142 
143 static int
144 vhost_user_read(int fd, struct vhost_user_msg *msg)
145 {
146 	uint32_t valid_flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
147 	int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
148 
149 	ret = recv(fd, (void *)msg, sz_hdr, 0);
150 	if (ret < 0) {
151 		PMD_DRV_LOG(ERR, "Failed to recv msg header: %s", strerror(errno));
152 		return -1;
153 	} else if (ret < sz_hdr) {
154 		PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
155 			    ret, sz_hdr);
156 		return -1;
157 	}
158 
159 	/* validate msg flags */
160 	if (msg->flags != (valid_flags)) {
161 		PMD_DRV_LOG(ERR, "Failed to recv msg: flags 0x%x instead of 0x%x.",
162 			    msg->flags, valid_flags);
163 		return -1;
164 	}
165 
166 	sz_payload = msg->size;
167 
168 	if ((size_t)sz_payload > sizeof(msg->payload)) {
169 		PMD_DRV_LOG(ERR, "Payload size overflow, header says %d but max %zu",
170 				sz_payload, sizeof(msg->payload));
171 		return -1;
172 	}
173 
174 	if (sz_payload) {
175 		ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
176 		if (ret < 0) {
177 			PMD_DRV_LOG(ERR, "Failed to recv msg payload: %s", strerror(errno));
178 			return -1;
179 		} else if (ret < sz_payload) {
180 			PMD_DRV_LOG(ERR, "Failed to recv msg payload: %d instead of %u.",
181 				ret, msg->size);
182 			return -1;
183 		}
184 	}
185 
186 	return 0;
187 }
188 
189 static int
190 vhost_user_check_reply_ack(struct virtio_user_dev *dev, struct vhost_user_msg *msg)
191 {
192 	struct vhost_user_data *data = dev->backend_data;
193 	enum vhost_user_request req = msg->request;
194 	int ret;
195 
196 	if (!(msg->flags & VHOST_USER_NEED_REPLY_MASK))
197 		return 0;
198 
199 	ret = vhost_user_read(data->vhostfd, msg);
200 	if (ret < 0) {
201 		PMD_DRV_LOG(ERR, "Failed to read reply-ack");
202 		return -1;
203 	}
204 
205 	if (req != msg->request) {
206 		PMD_DRV_LOG(ERR, "Unexpected reply-ack request type (%d)", msg->request);
207 		return -1;
208 	}
209 
210 	if (msg->size != sizeof(msg->payload.u64)) {
211 		PMD_DRV_LOG(ERR, "Unexpected reply-ack payload size (%u)", msg->size);
212 		return -1;
213 	}
214 
215 	if (msg->payload.u64) {
216 		PMD_DRV_LOG(ERR, "Slave replied NACK to request type (%d)", msg->request);
217 		return -1;
218 	}
219 
220 	return 0;
221 }
222 
223 static int
224 vhost_user_set_owner(struct virtio_user_dev *dev)
225 {
226 	int ret;
227 	struct vhost_user_data *data = dev->backend_data;
228 	struct vhost_user_msg msg = {
229 		.request = VHOST_USER_SET_OWNER,
230 		.flags = VHOST_USER_VERSION,
231 	};
232 
233 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
234 	if (ret < 0) {
235 		PMD_DRV_LOG(ERR, "Failed to set owner");
236 		return -1;
237 	}
238 
239 	return 0;
240 }
241 
242 static int
243 vhost_user_get_protocol_features(struct virtio_user_dev *dev, uint64_t *features)
244 {
245 	int ret;
246 	struct vhost_user_data *data = dev->backend_data;
247 	struct vhost_user_msg msg = {
248 		.request = VHOST_USER_GET_PROTOCOL_FEATURES,
249 		.flags = VHOST_USER_VERSION,
250 	};
251 
252 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
253 	if (ret < 0)
254 		goto err;
255 
256 	ret = vhost_user_read(data->vhostfd, &msg);
257 	if (ret < 0)
258 		goto err;
259 
260 	if (msg.request != VHOST_USER_GET_PROTOCOL_FEATURES) {
261 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
262 		goto err;
263 	}
264 
265 	if (msg.size != sizeof(*features)) {
266 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
267 		goto err;
268 	}
269 
270 	*features = msg.payload.u64;
271 
272 	return 0;
273 err:
274 	PMD_DRV_LOG(ERR, "Failed to get backend protocol features");
275 
276 	return -1;
277 }
278 
279 static int
280 vhost_user_set_protocol_features(struct virtio_user_dev *dev, uint64_t features)
281 {
282 	int ret;
283 	struct vhost_user_data *data = dev->backend_data;
284 	struct vhost_user_msg msg = {
285 		.request = VHOST_USER_SET_PROTOCOL_FEATURES,
286 		.flags = VHOST_USER_VERSION,
287 		.size = sizeof(features),
288 		.payload.u64 = features,
289 	};
290 
291 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
292 	if (ret < 0) {
293 		PMD_DRV_LOG(ERR, "Failed to set protocol features");
294 		return -1;
295 	}
296 
297 	return 0;
298 }
299 
300 static int
301 vhost_user_get_features(struct virtio_user_dev *dev, uint64_t *features)
302 {
303 	int ret;
304 	struct vhost_user_data *data = dev->backend_data;
305 	struct vhost_user_msg msg = {
306 		.request = VHOST_USER_GET_FEATURES,
307 		.flags = VHOST_USER_VERSION,
308 	};
309 
310 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
311 	if (ret < 0)
312 		goto err;
313 
314 	ret = vhost_user_read(data->vhostfd, &msg);
315 	if (ret < 0)
316 		goto err;
317 
318 	if (msg.request != VHOST_USER_GET_FEATURES) {
319 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
320 		goto err;
321 	}
322 
323 	if (msg.size != sizeof(*features)) {
324 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
325 		goto err;
326 	}
327 
328 	*features = msg.payload.u64;
329 
330 	if (!(*features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)))
331 		return 0;
332 
333 	/* Negotiate protocol features */
334 	ret = vhost_user_get_protocol_features(dev, &data->protocol_features);
335 	if (ret < 0)
336 		goto err;
337 
338 	data->protocol_features &= VHOST_USER_SUPPORTED_PROTOCOL_FEATURES;
339 
340 	ret = vhost_user_set_protocol_features(dev, data->protocol_features);
341 	if (ret < 0)
342 		goto err;
343 
344 	if (!(data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)))
345 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
346 
347 	return 0;
348 err:
349 	PMD_DRV_LOG(ERR, "Failed to get backend features");
350 
351 	return -1;
352 }
353 
354 static int
355 vhost_user_set_features(struct virtio_user_dev *dev, uint64_t features)
356 {
357 	int ret;
358 	struct vhost_user_data *data = dev->backend_data;
359 	struct vhost_user_msg msg = {
360 		.request = VHOST_USER_SET_FEATURES,
361 		.flags = VHOST_USER_VERSION,
362 		.size = sizeof(features),
363 		.payload.u64 = features,
364 	};
365 
366 	msg.payload.u64 |= dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
367 
368 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
369 	if (ret < 0) {
370 		PMD_DRV_LOG(ERR, "Failed to set features");
371 		return -1;
372 	}
373 
374 	return 0;
375 }
376 
377 struct walk_arg {
378 	struct vhost_memory *vm;
379 	int *fds;
380 	int region_nr;
381 };
382 
383 static int
384 update_memory_region(const struct rte_memseg_list *msl __rte_unused,
385 		const struct rte_memseg *ms, void *arg)
386 {
387 	struct walk_arg *wa = arg;
388 	struct vhost_memory_region *mr;
389 	uint64_t start_addr, end_addr;
390 	size_t offset;
391 	int i, fd;
392 
393 	fd = rte_memseg_get_fd_thread_unsafe(ms);
394 	if (fd < 0) {
395 		PMD_DRV_LOG(ERR, "Failed to get fd, ms=%p rte_errno=%d",
396 			ms, rte_errno);
397 		return -1;
398 	}
399 
400 	if (rte_memseg_get_fd_offset_thread_unsafe(ms, &offset) < 0) {
401 		PMD_DRV_LOG(ERR, "Failed to get offset, ms=%p rte_errno=%d",
402 			ms, rte_errno);
403 		return -1;
404 	}
405 
406 	start_addr = (uint64_t)(uintptr_t)ms->addr;
407 	end_addr = start_addr + ms->len;
408 
409 	for (i = 0; i < wa->region_nr; i++) {
410 		if (wa->fds[i] != fd)
411 			continue;
412 
413 		mr = &wa->vm->regions[i];
414 
415 		if (mr->userspace_addr + mr->memory_size < end_addr)
416 			mr->memory_size = end_addr - mr->userspace_addr;
417 
418 		if (mr->userspace_addr > start_addr) {
419 			mr->userspace_addr = start_addr;
420 			mr->guest_phys_addr = start_addr;
421 		}
422 
423 		if (mr->mmap_offset > offset)
424 			mr->mmap_offset = offset;
425 
426 		PMD_DRV_LOG(DEBUG, "index=%d fd=%d offset=0x%" PRIx64
427 			" addr=0x%" PRIx64 " len=%" PRIu64, i, fd,
428 			mr->mmap_offset, mr->userspace_addr,
429 			mr->memory_size);
430 
431 		return 0;
432 	}
433 
434 	if (i >= VHOST_MEMORY_MAX_NREGIONS) {
435 		PMD_DRV_LOG(ERR, "Too many memory regions");
436 		return -1;
437 	}
438 
439 	mr = &wa->vm->regions[i];
440 	wa->fds[i] = fd;
441 
442 	mr->guest_phys_addr = start_addr;
443 	mr->userspace_addr = start_addr;
444 	mr->memory_size = ms->len;
445 	mr->mmap_offset = offset;
446 
447 	PMD_DRV_LOG(DEBUG, "index=%d fd=%d offset=0x%" PRIx64
448 		" addr=0x%" PRIx64 " len=%" PRIu64, i, fd,
449 		mr->mmap_offset, mr->userspace_addr,
450 		mr->memory_size);
451 
452 	wa->region_nr++;
453 
454 	return 0;
455 }
456 
457 static int
458 vhost_user_set_memory_table(struct virtio_user_dev *dev)
459 {
460 	struct walk_arg wa;
461 	int fds[VHOST_MEMORY_MAX_NREGIONS];
462 	int ret, fd_num;
463 	struct vhost_user_data *data = dev->backend_data;
464 	struct vhost_user_msg msg = {
465 		.request = VHOST_USER_SET_MEM_TABLE,
466 		.flags = VHOST_USER_VERSION,
467 	};
468 
469 	if (data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
470 		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
471 
472 	wa.region_nr = 0;
473 	wa.vm = &msg.payload.memory;
474 	wa.fds = fds;
475 
476 	/*
477 	 * The memory lock has already been taken by memory subsystem
478 	 * or virtio_user_start_device().
479 	 */
480 	ret = rte_memseg_walk_thread_unsafe(update_memory_region, &wa);
481 	if (ret < 0)
482 		goto err;
483 
484 	fd_num = wa.region_nr;
485 	msg.payload.memory.nregions = wa.region_nr;
486 	msg.payload.memory.padding = 0;
487 
488 	msg.size = sizeof(msg.payload.memory.nregions);
489 	msg.size += sizeof(msg.payload.memory.padding);
490 	msg.size += fd_num * sizeof(struct vhost_memory_region);
491 
492 	ret = vhost_user_write(data->vhostfd, &msg, fds, fd_num);
493 	if (ret < 0)
494 		goto err;
495 
496 	return vhost_user_check_reply_ack(dev, &msg);
497 err:
498 	PMD_DRV_LOG(ERR, "Failed to set memory table");
499 	return -1;
500 }
501 
502 static int
503 vhost_user_set_vring(struct virtio_user_dev *dev, enum vhost_user_request req,
504 		struct vhost_vring_state *state)
505 {
506 	int ret;
507 	struct vhost_user_data *data = dev->backend_data;
508 	struct vhost_user_msg msg = {
509 		.request = req,
510 		.flags = VHOST_USER_VERSION,
511 		.size = sizeof(*state),
512 		.payload.state = *state,
513 	};
514 
515 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
516 	if (ret < 0) {
517 		PMD_DRV_LOG(ERR, "Failed to set vring state (request %d)", req);
518 		return -1;
519 	}
520 
521 	return 0;
522 }
523 
524 static int
525 vhost_user_set_vring_enable(struct virtio_user_dev *dev, struct vhost_vring_state *state)
526 {
527 	return vhost_user_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, state);
528 }
529 
530 static int
531 vhost_user_set_vring_num(struct virtio_user_dev *dev, struct vhost_vring_state *state)
532 {
533 	return vhost_user_set_vring(dev, VHOST_USER_SET_VRING_NUM, state);
534 }
535 
536 static int
537 vhost_user_set_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
538 {
539 	return vhost_user_set_vring(dev, VHOST_USER_SET_VRING_BASE, state);
540 }
541 
542 static int
543 vhost_user_get_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
544 {
545 	int ret;
546 	struct vhost_user_msg msg;
547 	struct vhost_user_data *data = dev->backend_data;
548 	unsigned int index = state->index;
549 
550 	ret = vhost_user_set_vring(dev, VHOST_USER_GET_VRING_BASE, state);
551 	if (ret < 0) {
552 		PMD_DRV_LOG(ERR, "Failed to send request");
553 		goto err;
554 	}
555 
556 	ret = vhost_user_read(data->vhostfd, &msg);
557 	if (ret < 0) {
558 		PMD_DRV_LOG(ERR, "Failed to read reply");
559 		goto err;
560 	}
561 
562 	if (msg.request != VHOST_USER_GET_VRING_BASE) {
563 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
564 		goto err;
565 	}
566 
567 	if (msg.size != sizeof(*state)) {
568 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
569 		goto err;
570 	}
571 
572 	if (msg.payload.state.index != index) {
573 		PMD_DRV_LOG(ERR, "Unexpected ring index (%u)", state->index);
574 		goto err;
575 	}
576 
577 	*state = msg.payload.state;
578 
579 	return 0;
580 err:
581 	PMD_DRV_LOG(ERR, "Failed to get vring base");
582 	return -1;
583 }
584 
585 static int
586 vhost_user_set_vring_file(struct virtio_user_dev *dev, enum vhost_user_request req,
587 		struct vhost_vring_file *file)
588 {
589 	int ret;
590 	int fd = file->fd;
591 	int num_fd = 0;
592 	struct vhost_user_data *data = dev->backend_data;
593 	struct vhost_user_msg msg = {
594 		.request = req,
595 		.flags = VHOST_USER_VERSION,
596 		.size = sizeof(msg.payload.u64),
597 		.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
598 	};
599 
600 	if (fd >= 0)
601 		num_fd++;
602 	else
603 		msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
604 
605 	ret = vhost_user_write(data->vhostfd, &msg, &fd, num_fd);
606 	if (ret < 0) {
607 		PMD_DRV_LOG(ERR, "Failed to set vring file (request %d)", req);
608 		return -1;
609 	}
610 
611 	return 0;
612 }
613 
614 static int
615 vhost_user_set_vring_call(struct virtio_user_dev *dev, struct vhost_vring_file *file)
616 {
617 	return vhost_user_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
618 }
619 
620 static int
621 vhost_user_set_vring_kick(struct virtio_user_dev *dev, struct vhost_vring_file *file)
622 {
623 	return vhost_user_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
624 }
625 
626 
627 static int
628 vhost_user_set_vring_addr(struct virtio_user_dev *dev, struct vhost_vring_addr *addr)
629 {
630 	int ret;
631 	struct vhost_user_data *data = dev->backend_data;
632 	struct vhost_user_msg msg = {
633 		.request = VHOST_USER_SET_VRING_ADDR,
634 		.flags = VHOST_USER_VERSION,
635 		.size = sizeof(*addr),
636 		.payload.addr = *addr,
637 	};
638 
639 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
640 	if (ret < 0) {
641 		PMD_DRV_LOG(ERR, "Failed to send vring addresses");
642 		return -1;
643 	}
644 
645 	return 0;
646 }
647 
648 static int
649 vhost_user_get_status(struct virtio_user_dev *dev, uint8_t *status)
650 {
651 	int ret;
652 	struct vhost_user_data *data = dev->backend_data;
653 	struct vhost_user_msg msg = {
654 		.request = VHOST_USER_GET_STATUS,
655 		.flags = VHOST_USER_VERSION,
656 	};
657 
658 	/*
659 	 * If features have not been negotiated, we don't know if the backend
660 	 * supports protocol features
661 	 */
662 	if (!(dev->status & VIRTIO_CONFIG_STATUS_FEATURES_OK))
663 		return -ENOTSUP;
664 
665 	/* Status protocol feature requires protocol features support */
666 	if (!(dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)))
667 		return -ENOTSUP;
668 
669 	if (!(data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
670 		return -ENOTSUP;
671 
672 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
673 	if (ret < 0) {
674 		PMD_DRV_LOG(ERR, "Failed to send request");
675 		goto err;
676 	}
677 
678 	ret = vhost_user_read(data->vhostfd, &msg);
679 	if (ret < 0) {
680 		PMD_DRV_LOG(ERR, "Failed to recv request");
681 		goto err;
682 	}
683 
684 	if (msg.request != VHOST_USER_GET_STATUS) {
685 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
686 		goto err;
687 	}
688 
689 	if (msg.size != sizeof(msg.payload.u64)) {
690 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
691 		goto err;
692 	}
693 
694 	*status = (uint8_t)msg.payload.u64;
695 
696 	return 0;
697 err:
698 	PMD_DRV_LOG(ERR, "Failed to get device status");
699 	return -1;
700 }
701 
702 static int
703 vhost_user_set_status(struct virtio_user_dev *dev, uint8_t status)
704 {
705 	int ret;
706 	struct vhost_user_data *data = dev->backend_data;
707 	struct vhost_user_msg msg = {
708 		.request = VHOST_USER_SET_STATUS,
709 		.flags = VHOST_USER_VERSION,
710 		.size = sizeof(msg.payload.u64),
711 		.payload.u64 = status,
712 	};
713 
714 	/*
715 	 * If features have not been negotiated, we don't know if the backend
716 	 * supports protocol features
717 	 */
718 	if (!(dev->status & VIRTIO_CONFIG_STATUS_FEATURES_OK))
719 		return -ENOTSUP;
720 
721 	/* Status protocol feature requires protocol features support */
722 	if (!(dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)))
723 		return -ENOTSUP;
724 
725 	if (!(data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
726 		return -ENOTSUP;
727 
728 	if (data->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
729 		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
730 
731 	ret = vhost_user_write(data->vhostfd, &msg, NULL, 0);
732 	if (ret < 0) {
733 		PMD_DRV_LOG(ERR, "Failed to send get status request");
734 		return -1;
735 	}
736 
737 	return vhost_user_check_reply_ack(dev, &msg);
738 }
739 
740 #define MAX_VIRTIO_USER_BACKLOG 1
741 static int
742 vhost_user_start_server(struct virtio_user_dev *dev, struct sockaddr_un *un)
743 {
744 	int ret;
745 	int flag;
746 	struct vhost_user_data *data = dev->backend_data;
747 	int fd = data->listenfd;
748 
749 	ret = bind(fd, (struct sockaddr *)un, sizeof(*un));
750 	if (ret < 0) {
751 		PMD_DRV_LOG(ERR, "failed to bind to %s: %s; remove it and try again",
752 			    dev->path, strerror(errno));
753 		return -1;
754 	}
755 	ret = listen(fd, MAX_VIRTIO_USER_BACKLOG);
756 	if (ret < 0)
757 		return -1;
758 
759 	PMD_DRV_LOG(NOTICE, "(%s) waiting for client connection...", dev->path);
760 	data->vhostfd = accept(fd, NULL, NULL);
761 	if (data->vhostfd < 0) {
762 		PMD_DRV_LOG(ERR, "Failed to accept initial client connection (%s)",
763 				strerror(errno));
764 		return -1;
765 	}
766 
767 	flag = fcntl(fd, F_GETFL);
768 	if (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0) {
769 		PMD_DRV_LOG(ERR, "fcntl failed, %s", strerror(errno));
770 		return -1;
771 	}
772 
773 	return 0;
774 }
775 
776 static int
777 vhost_user_server_disconnect(struct virtio_user_dev *dev)
778 {
779 	struct vhost_user_data *data = dev->backend_data;
780 
781 	if (data->vhostfd < 0) {
782 		PMD_DRV_LOG(ERR, "(%s) Expected valid Vhost FD", dev->path);
783 		return -1;
784 	}
785 
786 	close(data->vhostfd);
787 	data->vhostfd = -1;
788 
789 	return 0;
790 }
791 
792 static int
793 vhost_user_server_reconnect(struct virtio_user_dev *dev)
794 {
795 	struct vhost_user_data *data = dev->backend_data;
796 	int fd;
797 
798 	fd = accept(data->listenfd, NULL, NULL);
799 	if (fd < 0)
800 		return -1;
801 
802 	data->vhostfd = fd;
803 
804 	return 0;
805 }
806 
807 /**
808  * Set up environment to talk with a vhost user backend.
809  *
810  * @return
811  *   - (-1) if fail;
812  *   - (0) if succeed.
813  */
814 static int
815 vhost_user_setup(struct virtio_user_dev *dev)
816 {
817 	int fd;
818 	int flag;
819 	struct sockaddr_un un;
820 	struct vhost_user_data *data;
821 
822 	data = malloc(sizeof(*data));
823 	if (!data) {
824 		PMD_DRV_LOG(ERR, "(%s) Failed to allocate Vhost-user data", dev->path);
825 		return -1;
826 	}
827 
828 	memset(data, 0, sizeof(*data));
829 
830 	dev->backend_data = data;
831 
832 	data->vhostfd = -1;
833 	data->listenfd = -1;
834 
835 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
836 	if (fd < 0) {
837 		PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
838 		goto err_data;
839 	}
840 
841 	flag = fcntl(fd, F_GETFD);
842 	if (flag == -1)
843 		PMD_DRV_LOG(WARNING, "fcntl get fd failed, %s", strerror(errno));
844 	else if (fcntl(fd, F_SETFD, flag | FD_CLOEXEC) < 0)
845 		PMD_DRV_LOG(WARNING, "fcntl set fd failed, %s", strerror(errno));
846 
847 	memset(&un, 0, sizeof(un));
848 	un.sun_family = AF_UNIX;
849 	strlcpy(un.sun_path, dev->path, sizeof(un.sun_path));
850 
851 	if (dev->is_server) {
852 		data->listenfd = fd;
853 		if (vhost_user_start_server(dev, &un) < 0) {
854 			PMD_DRV_LOG(ERR, "virtio-user startup fails in server mode");
855 			goto err_socket;
856 		}
857 	} else {
858 		if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
859 			PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
860 			goto err_socket;
861 		}
862 		data->vhostfd = fd;
863 	}
864 
865 	return 0;
866 
867 err_socket:
868 	close(fd);
869 err_data:
870 	free(data);
871 	dev->backend_data = NULL;
872 
873 	return -1;
874 }
875 
876 static int
877 vhost_user_destroy(struct virtio_user_dev *dev)
878 {
879 	struct vhost_user_data *data = dev->backend_data;
880 
881 	if (!data)
882 		return 0;
883 
884 	if (data->vhostfd >= 0) {
885 		close(data->vhostfd);
886 		data->vhostfd = -1;
887 	}
888 
889 	if (data->listenfd >= 0) {
890 		close(data->listenfd);
891 		data->listenfd = -1;
892 	}
893 
894 	free(data);
895 	dev->backend_data = NULL;
896 
897 	return 0;
898 }
899 
900 static int
901 vhost_user_enable_queue_pair(struct virtio_user_dev *dev,
902 			     uint16_t pair_idx,
903 			     int enable)
904 {
905 	struct vhost_user_data *data = dev->backend_data;
906 	int i;
907 
908 	if (data->vhostfd < 0)
909 		return 0;
910 
911 	if (dev->qp_enabled[pair_idx] == enable)
912 		return 0;
913 
914 	for (i = 0; i < 2; ++i) {
915 		struct vhost_vring_state state = {
916 			.index = pair_idx * 2 + i,
917 			.num = enable,
918 		};
919 
920 		if (vhost_user_set_vring_enable(dev, &state))
921 			return -1;
922 	}
923 
924 	dev->qp_enabled[pair_idx] = enable;
925 	return 0;
926 }
927 
928 static int
929 vhost_user_get_backend_features(uint64_t *features)
930 {
931 	*features = 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
932 
933 	return 0;
934 }
935 
936 static int
937 vhost_user_update_link_state(struct virtio_user_dev *dev)
938 {
939 	struct vhost_user_data *data = dev->backend_data;
940 	char buf[128];
941 
942 	if (data->vhostfd >= 0) {
943 		int r;
944 		int flags;
945 
946 		flags = fcntl(data->vhostfd, F_GETFL);
947 		if (fcntl(data->vhostfd, F_SETFL, flags | O_NONBLOCK) == -1) {
948 			PMD_DRV_LOG(ERR, "error setting O_NONBLOCK flag");
949 			return -1;
950 		}
951 
952 		r = recv(data->vhostfd, buf, 128, MSG_PEEK);
953 		if (r == 0 || (r < 0 && errno != EAGAIN)) {
954 			dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
955 			PMD_DRV_LOG(ERR, "virtio-user port %u is down", dev->hw.port_id);
956 
957 			/* This function could be called in the process
958 			 * of interrupt handling, callback cannot be
959 			 * unregistered here, set an alarm to do it.
960 			 */
961 			rte_eal_alarm_set(1,
962 				virtio_user_dev_delayed_disconnect_handler,
963 				(void *)dev);
964 		} else {
965 			dev->net_status |= VIRTIO_NET_S_LINK_UP;
966 		}
967 
968 		if (fcntl(data->vhostfd, F_SETFL,
969 					flags & ~O_NONBLOCK) == -1) {
970 			PMD_DRV_LOG(ERR, "error clearing O_NONBLOCK flag");
971 			return -1;
972 		}
973 	} else if (dev->is_server) {
974 		dev->net_status &= (~VIRTIO_NET_S_LINK_UP);
975 		if (virtio_user_dev_server_reconnect(dev) >= 0)
976 			dev->net_status |= VIRTIO_NET_S_LINK_UP;
977 	}
978 
979 	return 0;
980 }
981 
982 static int
983 vhost_user_get_intr_fd(struct virtio_user_dev *dev)
984 {
985 	struct vhost_user_data *data = dev->backend_data;
986 
987 	if (dev->is_server && data->vhostfd == -1)
988 		return data->listenfd;
989 
990 	return data->vhostfd;
991 }
992 
993 struct virtio_user_backend_ops virtio_ops_user = {
994 	.setup = vhost_user_setup,
995 	.destroy = vhost_user_destroy,
996 	.get_backend_features = vhost_user_get_backend_features,
997 	.set_owner = vhost_user_set_owner,
998 	.get_features = vhost_user_get_features,
999 	.set_features = vhost_user_set_features,
1000 	.set_memory_table = vhost_user_set_memory_table,
1001 	.set_vring_num = vhost_user_set_vring_num,
1002 	.set_vring_base = vhost_user_set_vring_base,
1003 	.get_vring_base = vhost_user_get_vring_base,
1004 	.set_vring_call = vhost_user_set_vring_call,
1005 	.set_vring_kick = vhost_user_set_vring_kick,
1006 	.set_vring_addr = vhost_user_set_vring_addr,
1007 	.get_status = vhost_user_get_status,
1008 	.set_status = vhost_user_set_status,
1009 	.enable_qp = vhost_user_enable_queue_pair,
1010 	.update_link_state = vhost_user_update_link_state,
1011 	.server_disconnect = vhost_user_server_disconnect,
1012 	.server_reconnect = vhost_user_server_reconnect,
1013 	.get_intr_fd = vhost_user_get_intr_fd,
1014 };
1015