xref: /dpdk/drivers/net/virtio/virtio_user/vhost_user.c (revision 1b34ad28a9a452b4c1ffab2e31a2bb6b5dbf65e2)
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_string_fns.h>
15 #include <rte_fbarray.h>
16 
17 #include "vhost.h"
18 #include "virtio_user_dev.h"
19 
20 /* The version of the protocol we support */
21 #define VHOST_USER_VERSION    0x1
22 
23 #define VHOST_MEMORY_MAX_NREGIONS 8
24 struct vhost_memory {
25 	uint32_t nregions;
26 	uint32_t padding;
27 	struct vhost_memory_region regions[VHOST_MEMORY_MAX_NREGIONS];
28 };
29 
30 struct vhost_user_msg {
31 	enum vhost_user_request request;
32 
33 #define VHOST_USER_VERSION_MASK     0x3
34 #define VHOST_USER_REPLY_MASK       (0x1 << 2)
35 #define VHOST_USER_NEED_REPLY_MASK  (0x1 << 3)
36 	uint32_t flags;
37 	uint32_t size; /* the following payload size */
38 	union {
39 #define VHOST_USER_VRING_IDX_MASK   0xff
40 #define VHOST_USER_VRING_NOFD_MASK  (0x1 << 8)
41 		uint64_t u64;
42 		struct vhost_vring_state state;
43 		struct vhost_vring_addr addr;
44 		struct vhost_memory memory;
45 	} payload;
46 	int fds[VHOST_MEMORY_MAX_NREGIONS];
47 } __rte_packed;
48 
49 #define VHOST_USER_HDR_SIZE offsetof(struct vhost_user_msg, payload.u64)
50 #define VHOST_USER_PAYLOAD_SIZE \
51 	(sizeof(struct vhost_user_msg) - VHOST_USER_HDR_SIZE)
52 
53 static int
54 vhost_user_write(int fd, struct vhost_user_msg *msg, int *fds, int fd_num)
55 {
56 	int r;
57 	struct msghdr msgh;
58 	struct iovec iov;
59 	size_t fd_size = fd_num * sizeof(int);
60 	char control[CMSG_SPACE(fd_size)];
61 	struct cmsghdr *cmsg;
62 
63 	memset(&msgh, 0, sizeof(msgh));
64 	memset(control, 0, sizeof(control));
65 
66 	iov.iov_base = (uint8_t *)msg;
67 	iov.iov_len = VHOST_USER_HDR_SIZE + msg->size;
68 
69 	msgh.msg_iov = &iov;
70 	msgh.msg_iovlen = 1;
71 	msgh.msg_control = control;
72 	msgh.msg_controllen = sizeof(control);
73 
74 	cmsg = CMSG_FIRSTHDR(&msgh);
75 	cmsg->cmsg_len = CMSG_LEN(fd_size);
76 	cmsg->cmsg_level = SOL_SOCKET;
77 	cmsg->cmsg_type = SCM_RIGHTS;
78 	memcpy(CMSG_DATA(cmsg), fds, fd_size);
79 
80 	do {
81 		r = sendmsg(fd, &msgh, 0);
82 	} while (r < 0 && errno == EINTR);
83 
84 	if (r < 0)
85 		PMD_DRV_LOG(ERR, "Failed to send msg: %s", strerror(errno));
86 
87 	return r;
88 }
89 
90 static int
91 vhost_user_read(int fd, struct vhost_user_msg *msg)
92 {
93 	uint32_t valid_flags = VHOST_USER_REPLY_MASK | VHOST_USER_VERSION;
94 	int ret, sz_hdr = VHOST_USER_HDR_SIZE, sz_payload;
95 
96 	ret = recv(fd, (void *)msg, sz_hdr, 0);
97 	if (ret < sz_hdr) {
98 		PMD_DRV_LOG(ERR, "Failed to recv msg hdr: %d instead of %d.",
99 			    ret, sz_hdr);
100 		goto fail;
101 	}
102 
103 	/* validate msg flags */
104 	if (msg->flags != (valid_flags)) {
105 		PMD_DRV_LOG(ERR, "Failed to recv msg: flags %x instead of %x.",
106 			    msg->flags, valid_flags);
107 		goto fail;
108 	}
109 
110 	sz_payload = msg->size;
111 
112 	if ((size_t)sz_payload > sizeof(msg->payload))
113 		goto fail;
114 
115 	if (sz_payload) {
116 		ret = recv(fd, (void *)((char *)msg + sz_hdr), sz_payload, 0);
117 		if (ret < sz_payload) {
118 			PMD_DRV_LOG(ERR,
119 				"Failed to recv msg payload: %d instead of %d.",
120 				ret, msg->size);
121 			goto fail;
122 		}
123 	}
124 
125 	return 0;
126 
127 fail:
128 	return -1;
129 }
130 
131 static int
132 vhost_user_check_reply_ack(struct virtio_user_dev *dev, struct vhost_user_msg *msg)
133 {
134 	enum vhost_user_request req = msg->request;
135 	int ret;
136 
137 	if (!(msg->flags & VHOST_USER_NEED_REPLY_MASK))
138 		return 0;
139 
140 	ret = vhost_user_read(dev->vhostfd, msg);
141 	if (ret < 0) {
142 		PMD_DRV_LOG(ERR, "Failed to read reply-ack");
143 		return -1;
144 	}
145 
146 	if (req != msg->request) {
147 		PMD_DRV_LOG(ERR, "Unexpected reply-ack request type (%d)", msg->request);
148 		return -1;
149 	}
150 
151 	if (msg->size != sizeof(msg->payload.u64)) {
152 		PMD_DRV_LOG(ERR, "Unexpected reply-ack payload size (%u)", msg->size);
153 		return -1;
154 	}
155 
156 	if (msg->payload.u64) {
157 		PMD_DRV_LOG(ERR, "Slave replied NACK to request type (%d)", msg->request);
158 		return -1;
159 	}
160 
161 	return 0;
162 }
163 
164 static int
165 vhost_user_set_owner(struct virtio_user_dev *dev)
166 {
167 	int ret;
168 	struct vhost_user_msg msg = {
169 		.request = VHOST_USER_SET_OWNER,
170 		.flags = VHOST_USER_VERSION,
171 	};
172 
173 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
174 	if (ret < 0) {
175 		PMD_DRV_LOG(ERR, "Failed to set owner");
176 		return -1;
177 	}
178 
179 	return 0;
180 }
181 
182 static int
183 vhost_user_get_features(struct virtio_user_dev *dev, uint64_t *features)
184 {
185 	int ret;
186 	struct vhost_user_msg msg = {
187 		.request = VHOST_USER_GET_FEATURES,
188 		.flags = VHOST_USER_VERSION,
189 	};
190 
191 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
192 	if (ret < 0)
193 		goto err;
194 
195 	ret = vhost_user_read(dev->vhostfd, &msg);
196 	if (ret < 0)
197 		goto err;
198 
199 	if (msg.request != VHOST_USER_GET_FEATURES) {
200 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
201 		goto err;
202 	}
203 
204 	if (msg.size != sizeof(*features)) {
205 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
206 		goto err;
207 	}
208 
209 	*features = msg.payload.u64;
210 
211 	return 0;
212 err:
213 	PMD_DRV_LOG(ERR, "Failed to get backend features");
214 
215 	return -1;
216 }
217 
218 static int
219 vhost_user_set_features(struct virtio_user_dev *dev, uint64_t features)
220 {
221 	int ret;
222 	struct vhost_user_msg msg = {
223 		.request = VHOST_USER_SET_FEATURES,
224 		.flags = VHOST_USER_VERSION,
225 		.size = sizeof(features),
226 		.payload.u64 = features,
227 	};
228 
229 	msg.payload.u64 |= dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
230 
231 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
232 	if (ret < 0) {
233 		PMD_DRV_LOG(ERR, "Failed to set features");
234 		return -1;
235 	}
236 
237 	return 0;
238 }
239 
240 static int
241 vhost_user_get_protocol_features(struct virtio_user_dev *dev, uint64_t *features)
242 {
243 	int ret;
244 	struct vhost_user_msg msg = {
245 		.request = VHOST_USER_GET_PROTOCOL_FEATURES,
246 		.flags = VHOST_USER_VERSION,
247 	};
248 
249 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
250 	if (ret < 0)
251 		goto err;
252 
253 	ret = vhost_user_read(dev->vhostfd, &msg);
254 	if (ret < 0)
255 		goto err;
256 
257 	if (msg.request != VHOST_USER_GET_PROTOCOL_FEATURES) {
258 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
259 		goto err;
260 	}
261 
262 	if (msg.size != sizeof(*features)) {
263 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
264 		goto err;
265 	}
266 
267 	*features = msg.payload.u64;
268 
269 	return 0;
270 err:
271 	PMD_DRV_LOG(ERR, "Failed to get backend protocol features");
272 
273 	return -1;
274 }
275 
276 static int
277 vhost_user_set_protocol_features(struct virtio_user_dev *dev, uint64_t features)
278 {
279 	int ret;
280 	struct vhost_user_msg msg = {
281 		.request = VHOST_USER_SET_PROTOCOL_FEATURES,
282 		.flags = VHOST_USER_VERSION,
283 		.size = sizeof(features),
284 		.payload.u64 = features,
285 	};
286 
287 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
288 	if (ret < 0) {
289 		PMD_DRV_LOG(ERR, "Failed to set protocol features");
290 		return -1;
291 	}
292 
293 	return 0;
294 }
295 
296 struct walk_arg {
297 	struct vhost_memory *vm;
298 	int *fds;
299 	int region_nr;
300 };
301 
302 static int
303 update_memory_region(const struct rte_memseg_list *msl __rte_unused,
304 		const struct rte_memseg *ms, void *arg)
305 {
306 	struct walk_arg *wa = arg;
307 	struct vhost_memory_region *mr;
308 	uint64_t start_addr, end_addr;
309 	size_t offset;
310 	int i, fd;
311 
312 	fd = rte_memseg_get_fd_thread_unsafe(ms);
313 	if (fd < 0) {
314 		PMD_DRV_LOG(ERR, "Failed to get fd, ms=%p rte_errno=%d",
315 			ms, rte_errno);
316 		return -1;
317 	}
318 
319 	if (rte_memseg_get_fd_offset_thread_unsafe(ms, &offset) < 0) {
320 		PMD_DRV_LOG(ERR, "Failed to get offset, ms=%p rte_errno=%d",
321 			ms, rte_errno);
322 		return -1;
323 	}
324 
325 	start_addr = (uint64_t)(uintptr_t)ms->addr;
326 	end_addr = start_addr + ms->len;
327 
328 	for (i = 0; i < wa->region_nr; i++) {
329 		if (wa->fds[i] != fd)
330 			continue;
331 
332 		mr = &wa->vm->regions[i];
333 
334 		if (mr->userspace_addr + mr->memory_size < end_addr)
335 			mr->memory_size = end_addr - mr->userspace_addr;
336 
337 		if (mr->userspace_addr > start_addr) {
338 			mr->userspace_addr = start_addr;
339 			mr->guest_phys_addr = start_addr;
340 		}
341 
342 		if (mr->mmap_offset > offset)
343 			mr->mmap_offset = offset;
344 
345 		PMD_DRV_LOG(DEBUG, "index=%d fd=%d offset=0x%" PRIx64
346 			" addr=0x%" PRIx64 " len=%" PRIu64, i, fd,
347 			mr->mmap_offset, mr->userspace_addr,
348 			mr->memory_size);
349 
350 		return 0;
351 	}
352 
353 	if (i >= VHOST_MEMORY_MAX_NREGIONS) {
354 		PMD_DRV_LOG(ERR, "Too many memory regions");
355 		return -1;
356 	}
357 
358 	mr = &wa->vm->regions[i];
359 	wa->fds[i] = fd;
360 
361 	mr->guest_phys_addr = start_addr;
362 	mr->userspace_addr = start_addr;
363 	mr->memory_size = ms->len;
364 	mr->mmap_offset = offset;
365 
366 	PMD_DRV_LOG(DEBUG, "index=%d fd=%d offset=0x%" PRIx64
367 		" addr=0x%" PRIx64 " len=%" PRIu64, i, fd,
368 		mr->mmap_offset, mr->userspace_addr,
369 		mr->memory_size);
370 
371 	wa->region_nr++;
372 
373 	return 0;
374 }
375 
376 static int
377 vhost_user_set_memory_table(struct virtio_user_dev *dev)
378 {
379 	struct walk_arg wa;
380 	int fds[VHOST_MEMORY_MAX_NREGIONS];
381 	int ret, fd_num;
382 	struct vhost_user_msg msg = {
383 		.request = VHOST_USER_SET_MEM_TABLE,
384 		.flags = VHOST_USER_VERSION,
385 	};
386 
387 	if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
388 		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
389 
390 	wa.region_nr = 0;
391 	wa.vm = &msg.payload.memory;
392 	wa.fds = fds;
393 
394 	/*
395 	 * The memory lock has already been taken by memory subsystem
396 	 * or virtio_user_start_device().
397 	 */
398 	ret = rte_memseg_walk_thread_unsafe(update_memory_region, &wa);
399 	if (ret < 0)
400 		goto err;
401 
402 	fd_num = wa.region_nr;
403 	msg.payload.memory.nregions = wa.region_nr;
404 	msg.payload.memory.padding = 0;
405 
406 	msg.size = sizeof(msg.payload.memory.nregions);
407 	msg.size += sizeof(msg.payload.memory.padding);
408 	msg.size += fd_num * sizeof(struct vhost_memory_region);
409 
410 	ret = vhost_user_write(dev->vhostfd, &msg, fds, fd_num);
411 	if (ret < 0)
412 		goto err;
413 
414 	return vhost_user_check_reply_ack(dev, &msg);
415 err:
416 	PMD_DRV_LOG(ERR, "Failed to set memory table");
417 	return -1;
418 }
419 
420 static int
421 vhost_user_set_vring(struct virtio_user_dev *dev, enum vhost_user_request req,
422 		struct vhost_vring_state *state)
423 {
424 	int ret;
425 	struct vhost_user_msg msg = {
426 		.request = req,
427 		.flags = VHOST_USER_VERSION,
428 		.size = sizeof(*state),
429 		.payload.state = *state,
430 	};
431 
432 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
433 	if (ret < 0) {
434 		PMD_DRV_LOG(ERR, "Failed to set vring state (request %d)", req);
435 		return -1;
436 	}
437 
438 	return 0;
439 }
440 
441 static int
442 vhost_user_set_vring_enable(struct virtio_user_dev *dev, struct vhost_vring_state *state)
443 {
444 	return vhost_user_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, state);
445 }
446 
447 static int
448 vhost_user_set_vring_num(struct virtio_user_dev *dev, struct vhost_vring_state *state)
449 {
450 	return vhost_user_set_vring(dev, VHOST_USER_SET_VRING_NUM, state);
451 }
452 
453 static int
454 vhost_user_set_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
455 {
456 	return vhost_user_set_vring(dev, VHOST_USER_SET_VRING_BASE, state);
457 }
458 
459 static int
460 vhost_user_get_vring_base(struct virtio_user_dev *dev, struct vhost_vring_state *state)
461 {
462 	int ret;
463 	struct vhost_user_msg msg;
464 	unsigned int index = state->index;
465 
466 	ret = vhost_user_set_vring(dev, VHOST_USER_GET_VRING_BASE, state);
467 	if (ret < 0) {
468 		PMD_DRV_LOG(ERR, "Failed to send request");
469 		goto err;
470 	}
471 
472 	ret = vhost_user_read(dev->vhostfd, &msg);
473 	if (ret < 0) {
474 		PMD_DRV_LOG(ERR, "Failed to read reply");
475 		goto err;
476 	}
477 
478 	if (msg.request != VHOST_USER_GET_VRING_BASE) {
479 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
480 		goto err;
481 	}
482 
483 	if (msg.size != sizeof(*state)) {
484 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
485 		goto err;
486 	}
487 
488 	if (msg.payload.state.index != index) {
489 		PMD_DRV_LOG(ERR, "Unexpected ring index (%u)", state->index);
490 		goto err;
491 	}
492 
493 	*state = msg.payload.state;
494 
495 	return 0;
496 err:
497 	PMD_DRV_LOG(ERR, "Failed to get vring base");
498 	return -1;
499 }
500 
501 static int
502 vhost_user_set_vring_file(struct virtio_user_dev *dev, enum vhost_user_request req,
503 		struct vhost_vring_file *file)
504 {
505 	int ret;
506 	int fd = file->fd;
507 	int num_fd = 0;
508 	struct vhost_user_msg msg = {
509 		.request = req,
510 		.flags = VHOST_USER_VERSION,
511 		.size = sizeof(msg.payload.u64),
512 		.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
513 	};
514 
515 	if (fd >= 0)
516 		num_fd++;
517 	else
518 		msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
519 
520 	ret = vhost_user_write(dev->vhostfd, &msg, &fd, num_fd);
521 	if (ret < 0) {
522 		PMD_DRV_LOG(ERR, "Failed to set vring file (request %d)", req);
523 		return -1;
524 	}
525 
526 	return 0;
527 }
528 
529 static int
530 vhost_user_set_vring_call(struct virtio_user_dev *dev, struct vhost_vring_file *file)
531 {
532 	return vhost_user_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
533 }
534 
535 static int
536 vhost_user_set_vring_kick(struct virtio_user_dev *dev, struct vhost_vring_file *file)
537 {
538 	return vhost_user_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
539 }
540 
541 
542 static int
543 vhost_user_set_vring_addr(struct virtio_user_dev *dev, struct vhost_vring_addr *addr)
544 {
545 	int ret;
546 	struct vhost_user_msg msg = {
547 		.request = VHOST_USER_SET_VRING_ADDR,
548 		.flags = VHOST_USER_VERSION,
549 		.size = sizeof(*addr),
550 		.payload.addr = *addr,
551 	};
552 
553 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
554 	if (ret < 0) {
555 		PMD_DRV_LOG(ERR, "Failed to send vring addresses");
556 		return -1;
557 	}
558 
559 	return 0;
560 }
561 
562 static int
563 vhost_user_get_status(struct virtio_user_dev *dev, uint8_t *status)
564 {
565 	int ret;
566 	struct vhost_user_msg msg = {
567 		.request = VHOST_USER_GET_STATUS,
568 		.flags = VHOST_USER_VERSION,
569 	};
570 
571 	/*
572 	 * If features have not been negotiated, we don't know if the backend
573 	 * supports protocol features
574 	 */
575 	if (!(dev->status & VIRTIO_CONFIG_STATUS_FEATURES_OK))
576 		return -ENOTSUP;
577 
578 	/* Status protocol feature requires protocol features support */
579 	if (!(dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)))
580 		return -ENOTSUP;
581 
582 	if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
583 		return -ENOTSUP;
584 
585 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
586 	if (ret < 0) {
587 		PMD_DRV_LOG(ERR, "Failed to send request");
588 		goto err;
589 	}
590 
591 	ret = vhost_user_read(dev->vhostfd, &msg);
592 	if (ret < 0) {
593 		PMD_DRV_LOG(ERR, "Failed to recv request");
594 		goto err;
595 	}
596 
597 	if (msg.request != VHOST_USER_GET_STATUS) {
598 		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
599 		goto err;
600 	}
601 
602 	if (msg.size != sizeof(msg.payload.u64)) {
603 		PMD_DRV_LOG(ERR, "Unexpected payload size (%u)", msg.size);
604 		goto err;
605 	}
606 
607 	*status = (uint8_t)msg.payload.u64;
608 
609 	return 0;
610 err:
611 	PMD_DRV_LOG(ERR, "Failed to get device status");
612 	return -1;
613 }
614 
615 static int
616 vhost_user_set_status(struct virtio_user_dev *dev, uint8_t status)
617 {
618 	int ret;
619 	struct vhost_user_msg msg = {
620 		.request = VHOST_USER_SET_STATUS,
621 		.flags = VHOST_USER_VERSION,
622 		.size = sizeof(msg.payload.u64),
623 		.payload.u64 = status,
624 	};
625 
626 	/*
627 	 * If features have not been negotiated, we don't know if the backend
628 	 * supports protocol features
629 	 */
630 	if (!(dev->status & VIRTIO_CONFIG_STATUS_FEATURES_OK))
631 		return -ENOTSUP;
632 
633 	/* Status protocol feature requires protocol features support */
634 	if (!(dev->device_features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES)))
635 		return -ENOTSUP;
636 
637 	if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
638 		return -ENOTSUP;
639 
640 	if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK))
641 		msg.flags |= VHOST_USER_NEED_REPLY_MASK;
642 
643 	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
644 	if (ret < 0) {
645 		PMD_DRV_LOG(ERR, "Failed to send get status request");
646 		return -1;
647 	}
648 
649 	return vhost_user_check_reply_ack(dev, &msg);
650 }
651 
652 #define MAX_VIRTIO_USER_BACKLOG 1
653 static int
654 virtio_user_start_server(struct virtio_user_dev *dev, struct sockaddr_un *un)
655 {
656 	int ret;
657 	int flag;
658 	int fd = dev->listenfd;
659 
660 	ret = bind(fd, (struct sockaddr *)un, sizeof(*un));
661 	if (ret < 0) {
662 		PMD_DRV_LOG(ERR, "failed to bind to %s: %s; remove it and try again\n",
663 			    dev->path, strerror(errno));
664 		return -1;
665 	}
666 	ret = listen(fd, MAX_VIRTIO_USER_BACKLOG);
667 	if (ret < 0)
668 		return -1;
669 
670 	flag = fcntl(fd, F_GETFL);
671 	if (fcntl(fd, F_SETFL, flag | O_NONBLOCK) < 0) {
672 		PMD_DRV_LOG(ERR, "fcntl failed, %s", strerror(errno));
673 		return -1;
674 	}
675 
676 	return 0;
677 }
678 
679 /**
680  * Set up environment to talk with a vhost user backend.
681  *
682  * @return
683  *   - (-1) if fail;
684  *   - (0) if succeed.
685  */
686 static int
687 vhost_user_setup(struct virtio_user_dev *dev)
688 {
689 	int fd;
690 	int flag;
691 	struct sockaddr_un un;
692 
693 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
694 	if (fd < 0) {
695 		PMD_DRV_LOG(ERR, "socket() error, %s", strerror(errno));
696 		return -1;
697 	}
698 
699 	flag = fcntl(fd, F_GETFD);
700 	if (fcntl(fd, F_SETFD, flag | FD_CLOEXEC) < 0)
701 		PMD_DRV_LOG(WARNING, "fcntl failed, %s", strerror(errno));
702 
703 	memset(&un, 0, sizeof(un));
704 	un.sun_family = AF_UNIX;
705 	strlcpy(un.sun_path, dev->path, sizeof(un.sun_path));
706 
707 	if (dev->is_server) {
708 		dev->listenfd = fd;
709 		if (virtio_user_start_server(dev, &un) < 0) {
710 			PMD_DRV_LOG(ERR, "virtio-user startup fails in server mode");
711 			close(fd);
712 			return -1;
713 		}
714 		dev->vhostfd = -1;
715 	} else {
716 		if (connect(fd, (struct sockaddr *)&un, sizeof(un)) < 0) {
717 			PMD_DRV_LOG(ERR, "connect error, %s", strerror(errno));
718 			close(fd);
719 			return -1;
720 		}
721 		dev->vhostfd = fd;
722 	}
723 
724 	return 0;
725 }
726 
727 static int
728 vhost_user_enable_queue_pair(struct virtio_user_dev *dev,
729 			     uint16_t pair_idx,
730 			     int enable)
731 {
732 	int i;
733 
734 	if (dev->qp_enabled[pair_idx] == enable)
735 		return 0;
736 
737 	for (i = 0; i < 2; ++i) {
738 		struct vhost_vring_state state = {
739 			.index = pair_idx * 2 + i,
740 			.num = enable,
741 		};
742 
743 		if (vhost_user_set_vring_enable(dev, &state))
744 			return -1;
745 	}
746 
747 	dev->qp_enabled[pair_idx] = enable;
748 	return 0;
749 }
750 
751 struct virtio_user_backend_ops virtio_ops_user = {
752 	.setup = vhost_user_setup,
753 	.set_owner = vhost_user_set_owner,
754 	.get_features = vhost_user_get_features,
755 	.set_features = vhost_user_set_features,
756 	.get_protocol_features = vhost_user_get_protocol_features,
757 	.set_protocol_features = vhost_user_set_protocol_features,
758 	.set_memory_table = vhost_user_set_memory_table,
759 	.set_vring_num = vhost_user_set_vring_num,
760 	.set_vring_base = vhost_user_set_vring_base,
761 	.get_vring_base = vhost_user_get_vring_base,
762 	.set_vring_call = vhost_user_set_vring_call,
763 	.set_vring_kick = vhost_user_set_vring_kick,
764 	.set_vring_addr = vhost_user_set_vring_addr,
765 	.get_status = vhost_user_get_status,
766 	.set_status = vhost_user_set_status,
767 	.enable_qp = vhost_user_enable_queue_pair
768 };
769