xref: /dpdk/drivers/net/virtio/virtio_user/virtio_user_dev.c (revision db4e81351fb85ff623bd0438d1b5a8fb55fe9fee)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2016 Intel Corporation
3  */
4 
5 #include <stdint.h>
6 #include <stdio.h>
7 #include <fcntl.h>
8 #include <string.h>
9 #include <errno.h>
10 #include <sys/mman.h>
11 #include <unistd.h>
12 #include <sys/eventfd.h>
13 #include <sys/types.h>
14 #include <sys/stat.h>
15 
16 #include <rte_string_fns.h>
17 #include <rte_eal_memconfig.h>
18 
19 #include "vhost.h"
20 #include "virtio_user_dev.h"
21 #include "../virtio_ethdev.h"
22 
23 #define VIRTIO_USER_MEM_EVENT_CLB_NAME "virtio_user_mem_event_clb"
24 
25 static int
26 virtio_user_create_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
27 {
28 	/* Of all per virtqueue MSGs, make sure VHOST_SET_VRING_CALL come
29 	 * firstly because vhost depends on this msg to allocate virtqueue
30 	 * pair.
31 	 */
32 	struct vhost_vring_file file;
33 
34 	file.index = queue_sel;
35 	file.fd = dev->callfds[queue_sel];
36 	dev->ops->send_request(dev, VHOST_USER_SET_VRING_CALL, &file);
37 
38 	return 0;
39 }
40 
41 static int
42 virtio_user_kick_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
43 {
44 	struct vhost_vring_file file;
45 	struct vhost_vring_state state;
46 	struct vring *vring = &dev->vrings[queue_sel];
47 	struct vring_packed *pq_vring = &dev->packed_vrings[queue_sel];
48 	struct vhost_vring_addr addr = {
49 		.index = queue_sel,
50 		.log_guest_addr = 0,
51 		.flags = 0, /* disable log */
52 	};
53 
54 	if (dev->features & (1ULL << VIRTIO_F_RING_PACKED)) {
55 		addr.desc_user_addr =
56 			(uint64_t)(uintptr_t)pq_vring->desc;
57 		addr.avail_user_addr =
58 			(uint64_t)(uintptr_t)pq_vring->driver;
59 		addr.used_user_addr =
60 			(uint64_t)(uintptr_t)pq_vring->device;
61 	} else {
62 		addr.desc_user_addr = (uint64_t)(uintptr_t)vring->desc;
63 		addr.avail_user_addr = (uint64_t)(uintptr_t)vring->avail;
64 		addr.used_user_addr = (uint64_t)(uintptr_t)vring->used;
65 	}
66 
67 	state.index = queue_sel;
68 	state.num = vring->num;
69 	dev->ops->send_request(dev, VHOST_USER_SET_VRING_NUM, &state);
70 
71 	state.index = queue_sel;
72 	state.num = 0; /* no reservation */
73 	if (dev->features & (1ULL << VIRTIO_F_RING_PACKED))
74 		state.num |= (1 << 15);
75 	dev->ops->send_request(dev, VHOST_USER_SET_VRING_BASE, &state);
76 
77 	dev->ops->send_request(dev, VHOST_USER_SET_VRING_ADDR, &addr);
78 
79 	/* Of all per virtqueue MSGs, make sure VHOST_USER_SET_VRING_KICK comes
80 	 * lastly because vhost depends on this msg to judge if
81 	 * virtio is ready.
82 	 */
83 	file.index = queue_sel;
84 	file.fd = dev->kickfds[queue_sel];
85 	dev->ops->send_request(dev, VHOST_USER_SET_VRING_KICK, &file);
86 
87 	return 0;
88 }
89 
90 static int
91 virtio_user_queue_setup(struct virtio_user_dev *dev,
92 			int (*fn)(struct virtio_user_dev *, uint32_t))
93 {
94 	uint32_t i, queue_sel;
95 
96 	for (i = 0; i < dev->max_queue_pairs; ++i) {
97 		queue_sel = 2 * i + VTNET_SQ_RQ_QUEUE_IDX;
98 		if (fn(dev, queue_sel) < 0) {
99 			PMD_DRV_LOG(INFO, "setup rx vq fails: %u", i);
100 			return -1;
101 		}
102 	}
103 	for (i = 0; i < dev->max_queue_pairs; ++i) {
104 		queue_sel = 2 * i + VTNET_SQ_TQ_QUEUE_IDX;
105 		if (fn(dev, queue_sel) < 0) {
106 			PMD_DRV_LOG(INFO, "setup tx vq fails: %u", i);
107 			return -1;
108 		}
109 	}
110 
111 	return 0;
112 }
113 
114 int
115 is_vhost_user_by_type(const char *path)
116 {
117 	struct stat sb;
118 
119 	if (stat(path, &sb) == -1)
120 		return 0;
121 
122 	return S_ISSOCK(sb.st_mode);
123 }
124 
125 int
126 virtio_user_start_device(struct virtio_user_dev *dev)
127 {
128 	uint64_t features;
129 	int ret;
130 
131 	/*
132 	 * XXX workaround!
133 	 *
134 	 * We need to make sure that the locks will be
135 	 * taken in the correct order to avoid deadlocks.
136 	 *
137 	 * Before releasing this lock, this thread should
138 	 * not trigger any memory hotplug events.
139 	 *
140 	 * This is a temporary workaround, and should be
141 	 * replaced when we get proper supports from the
142 	 * memory subsystem in the future.
143 	 */
144 	rte_mcfg_mem_read_lock();
145 	pthread_mutex_lock(&dev->mutex);
146 
147 	if (is_vhost_user_by_type(dev->path) && dev->vhostfd < 0)
148 		goto error;
149 
150 	/* Step 0: tell vhost to create queues */
151 	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
152 		goto error;
153 
154 	/* Step 1: negotiate protocol features & set features */
155 	features = dev->features;
156 
157 
158 	/* Strip VIRTIO_NET_F_MAC, as MAC address is handled in vdev init */
159 	features &= ~(1ull << VIRTIO_NET_F_MAC);
160 	/* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */
161 	features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
162 	features &= ~(1ull << VIRTIO_NET_F_STATUS);
163 	ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES, &features);
164 	if (ret < 0)
165 		goto error;
166 	PMD_DRV_LOG(INFO, "set features: %" PRIx64, features);
167 
168 	/* Step 2: share memory regions */
169 	ret = dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
170 	if (ret < 0)
171 		goto error;
172 
173 	/* Step 3: kick queues */
174 	if (virtio_user_queue_setup(dev, virtio_user_kick_queue) < 0)
175 		goto error;
176 
177 	/* Step 4: enable queues
178 	 * we enable the 1st queue pair by default.
179 	 */
180 	dev->ops->enable_qp(dev, 0, 1);
181 
182 	dev->started = true;
183 	pthread_mutex_unlock(&dev->mutex);
184 	rte_mcfg_mem_read_unlock();
185 
186 	return 0;
187 error:
188 	pthread_mutex_unlock(&dev->mutex);
189 	rte_mcfg_mem_read_unlock();
190 	/* TODO: free resource here or caller to check */
191 	return -1;
192 }
193 
194 int virtio_user_stop_device(struct virtio_user_dev *dev)
195 {
196 	struct vhost_vring_state state;
197 	uint32_t i;
198 	int error = 0;
199 
200 	pthread_mutex_lock(&dev->mutex);
201 	if (!dev->started)
202 		goto out;
203 
204 	for (i = 0; i < dev->max_queue_pairs; ++i)
205 		dev->ops->enable_qp(dev, i, 0);
206 
207 	/* Stop the backend. */
208 	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
209 		state.index = i;
210 		if (dev->ops->send_request(dev, VHOST_USER_GET_VRING_BASE,
211 					   &state) < 0) {
212 			PMD_DRV_LOG(ERR, "get_vring_base failed, index=%u\n",
213 				    i);
214 			error = -1;
215 			goto out;
216 		}
217 	}
218 
219 	dev->started = false;
220 out:
221 	pthread_mutex_unlock(&dev->mutex);
222 
223 	return error;
224 }
225 
226 static inline void
227 parse_mac(struct virtio_user_dev *dev, const char *mac)
228 {
229 	struct rte_ether_addr tmp;
230 
231 	if (!mac)
232 		return;
233 
234 	if (rte_ether_unformat_addr(mac, &tmp) == 0) {
235 		memcpy(dev->mac_addr, &tmp, RTE_ETHER_ADDR_LEN);
236 		dev->mac_specified = 1;
237 	} else {
238 		/* ignore the wrong mac, use random mac */
239 		PMD_DRV_LOG(ERR, "wrong format of mac: %s", mac);
240 	}
241 }
242 
243 static int
244 virtio_user_dev_init_notify(struct virtio_user_dev *dev)
245 {
246 	uint32_t i, j;
247 	int callfd;
248 	int kickfd;
249 
250 	for (i = 0; i < VIRTIO_MAX_VIRTQUEUES; ++i) {
251 		if (i >= dev->max_queue_pairs * 2) {
252 			dev->kickfds[i] = -1;
253 			dev->callfds[i] = -1;
254 			continue;
255 		}
256 
257 		/* May use invalid flag, but some backend uses kickfd and
258 		 * callfd as criteria to judge if dev is alive. so finally we
259 		 * use real event_fd.
260 		 */
261 		callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
262 		if (callfd < 0) {
263 			PMD_DRV_LOG(ERR, "callfd error, %s", strerror(errno));
264 			break;
265 		}
266 		kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
267 		if (kickfd < 0) {
268 			PMD_DRV_LOG(ERR, "kickfd error, %s", strerror(errno));
269 			break;
270 		}
271 		dev->callfds[i] = callfd;
272 		dev->kickfds[i] = kickfd;
273 	}
274 
275 	if (i < VIRTIO_MAX_VIRTQUEUES) {
276 		for (j = 0; j <= i; ++j) {
277 			close(dev->callfds[j]);
278 			close(dev->kickfds[j]);
279 		}
280 
281 		return -1;
282 	}
283 
284 	return 0;
285 }
286 
287 static int
288 virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
289 {
290 	uint32_t i;
291 	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
292 
293 	if (!eth_dev->intr_handle) {
294 		eth_dev->intr_handle = malloc(sizeof(*eth_dev->intr_handle));
295 		if (!eth_dev->intr_handle) {
296 			PMD_DRV_LOG(ERR, "fail to allocate intr_handle");
297 			return -1;
298 		}
299 		memset(eth_dev->intr_handle, 0, sizeof(*eth_dev->intr_handle));
300 	}
301 
302 	for (i = 0; i < dev->max_queue_pairs; ++i)
303 		eth_dev->intr_handle->efds[i] = dev->callfds[i];
304 	eth_dev->intr_handle->nb_efd = dev->max_queue_pairs;
305 	eth_dev->intr_handle->max_intr = dev->max_queue_pairs + 1;
306 	eth_dev->intr_handle->type = RTE_INTR_HANDLE_VDEV;
307 	/* For virtio vdev, no need to read counter for clean */
308 	eth_dev->intr_handle->efd_counter_size = 0;
309 	eth_dev->intr_handle->fd = -1;
310 	if (dev->vhostfd >= 0)
311 		eth_dev->intr_handle->fd = dev->vhostfd;
312 	else if (dev->is_server)
313 		eth_dev->intr_handle->fd = dev->listenfd;
314 
315 	return 0;
316 }
317 
318 static void
319 virtio_user_mem_event_cb(enum rte_mem_event type __rte_unused,
320 			 const void *addr,
321 			 size_t len __rte_unused,
322 			 void *arg)
323 {
324 	struct virtio_user_dev *dev = arg;
325 	struct rte_memseg_list *msl;
326 	uint16_t i;
327 
328 	/* ignore externally allocated memory */
329 	msl = rte_mem_virt2memseg_list(addr);
330 	if (msl->external)
331 		return;
332 
333 	pthread_mutex_lock(&dev->mutex);
334 
335 	if (dev->started == false)
336 		goto exit;
337 
338 	/* Step 1: pause the active queues */
339 	for (i = 0; i < dev->queue_pairs; i++)
340 		dev->ops->enable_qp(dev, i, 0);
341 
342 	/* Step 2: update memory regions */
343 	dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
344 
345 	/* Step 3: resume the active queues */
346 	for (i = 0; i < dev->queue_pairs; i++)
347 		dev->ops->enable_qp(dev, i, 1);
348 
349 exit:
350 	pthread_mutex_unlock(&dev->mutex);
351 }
352 
353 static int
354 virtio_user_dev_setup(struct virtio_user_dev *dev)
355 {
356 	uint32_t q;
357 
358 	dev->vhostfd = -1;
359 	dev->vhostfds = NULL;
360 	dev->tapfds = NULL;
361 
362 	if (dev->is_server) {
363 		if (access(dev->path, F_OK) == 0 &&
364 		    !is_vhost_user_by_type(dev->path)) {
365 			PMD_DRV_LOG(ERR, "Server mode doesn't support vhost-kernel!");
366 			return -1;
367 		}
368 		dev->ops = &virtio_ops_user;
369 	} else {
370 		if (is_vhost_user_by_type(dev->path)) {
371 			dev->ops = &virtio_ops_user;
372 		} else {
373 			dev->ops = &virtio_ops_kernel;
374 
375 			dev->vhostfds = malloc(dev->max_queue_pairs *
376 					       sizeof(int));
377 			dev->tapfds = malloc(dev->max_queue_pairs *
378 					     sizeof(int));
379 			if (!dev->vhostfds || !dev->tapfds) {
380 				PMD_INIT_LOG(ERR, "Failed to malloc");
381 				return -1;
382 			}
383 
384 			for (q = 0; q < dev->max_queue_pairs; ++q) {
385 				dev->vhostfds[q] = -1;
386 				dev->tapfds[q] = -1;
387 			}
388 		}
389 	}
390 
391 	if (dev->ops->setup(dev) < 0)
392 		return -1;
393 
394 	if (virtio_user_dev_init_notify(dev) < 0)
395 		return -1;
396 
397 	if (virtio_user_fill_intr_handle(dev) < 0)
398 		return -1;
399 
400 	return 0;
401 }
402 
403 /* Use below macro to filter features from vhost backend */
404 #define VIRTIO_USER_SUPPORTED_FEATURES			\
405 	(1ULL << VIRTIO_NET_F_MAC		|	\
406 	 1ULL << VIRTIO_NET_F_STATUS		|	\
407 	 1ULL << VIRTIO_NET_F_MQ		|	\
408 	 1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR	|	\
409 	 1ULL << VIRTIO_NET_F_CTRL_VQ		|	\
410 	 1ULL << VIRTIO_NET_F_CTRL_RX		|	\
411 	 1ULL << VIRTIO_NET_F_CTRL_VLAN		|	\
412 	 1ULL << VIRTIO_NET_F_CSUM		|	\
413 	 1ULL << VIRTIO_NET_F_HOST_TSO4		|	\
414 	 1ULL << VIRTIO_NET_F_HOST_TSO6		|	\
415 	 1ULL << VIRTIO_NET_F_MRG_RXBUF		|	\
416 	 1ULL << VIRTIO_RING_F_INDIRECT_DESC	|	\
417 	 1ULL << VIRTIO_NET_F_GUEST_CSUM	|	\
418 	 1ULL << VIRTIO_NET_F_GUEST_TSO4	|	\
419 	 1ULL << VIRTIO_NET_F_GUEST_TSO6	|	\
420 	 1ULL << VIRTIO_F_IN_ORDER		|	\
421 	 1ULL << VIRTIO_F_VERSION_1		|	\
422 	 1ULL << VIRTIO_F_RING_PACKED		|	\
423 	 1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
424 
425 #define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES		\
426 	(1ULL << VHOST_USER_PROTOCOL_F_MQ |		\
427 	 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |	\
428 	 1ULL << VHOST_USER_PROTOCOL_F_STATUS)
429 
430 int
431 virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
432 		     int cq, int queue_size, const char *mac, char **ifname,
433 		     int server, int mrg_rxbuf, int in_order, int packed_vq)
434 {
435 	uint64_t protocol_features = 0;
436 
437 	pthread_mutex_init(&dev->mutex, NULL);
438 	strlcpy(dev->path, path, PATH_MAX);
439 	dev->started = 0;
440 	dev->max_queue_pairs = queues;
441 	dev->queue_pairs = 1; /* mq disabled by default */
442 	dev->queue_size = queue_size;
443 	dev->is_server = server;
444 	dev->mac_specified = 0;
445 	dev->frontend_features = 0;
446 	dev->unsupported_features = ~VIRTIO_USER_SUPPORTED_FEATURES;
447 	dev->protocol_features = VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES;
448 	parse_mac(dev, mac);
449 
450 	if (*ifname) {
451 		dev->ifname = *ifname;
452 		*ifname = NULL;
453 	}
454 
455 	if (virtio_user_dev_setup(dev) < 0) {
456 		PMD_INIT_LOG(ERR, "backend set up fails");
457 		return -1;
458 	}
459 
460 	if (!is_vhost_user_by_type(dev->path))
461 		dev->unsupported_features |=
462 			(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
463 
464 	if (!dev->is_server) {
465 		if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER,
466 					   NULL) < 0) {
467 			PMD_INIT_LOG(ERR, "set_owner fails: %s",
468 				     strerror(errno));
469 			return -1;
470 		}
471 
472 		if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
473 					   &dev->device_features) < 0) {
474 			PMD_INIT_LOG(ERR, "get_features failed: %s",
475 				     strerror(errno));
476 			return -1;
477 		}
478 
479 
480 		if (dev->device_features &
481 				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) {
482 			if (dev->ops->send_request(dev,
483 					VHOST_USER_GET_PROTOCOL_FEATURES,
484 					&protocol_features))
485 				return -1;
486 
487 			dev->protocol_features &= protocol_features;
488 
489 			if (dev->ops->send_request(dev,
490 					VHOST_USER_SET_PROTOCOL_FEATURES,
491 					&dev->protocol_features))
492 				return -1;
493 
494 			if (!(dev->protocol_features &
495 					(1ULL << VHOST_USER_PROTOCOL_F_MQ)))
496 				dev->unsupported_features |=
497 					(1ull << VIRTIO_NET_F_MQ);
498 		}
499 	} else {
500 		/* We just pretend vhost-user can support all these features.
501 		 * Note that this could be problematic that if some feature is
502 		 * negotiated but not supported by the vhost-user which comes
503 		 * later.
504 		 */
505 		dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
506 	}
507 
508 
509 
510 	if (!mrg_rxbuf)
511 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MRG_RXBUF);
512 
513 	if (!in_order)
514 		dev->unsupported_features |= (1ull << VIRTIO_F_IN_ORDER);
515 
516 	if (!packed_vq)
517 		dev->unsupported_features |= (1ull << VIRTIO_F_RING_PACKED);
518 
519 	if (dev->mac_specified)
520 		dev->frontend_features |= (1ull << VIRTIO_NET_F_MAC);
521 	else
522 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MAC);
523 
524 	if (cq) {
525 		/* device does not really need to know anything about CQ,
526 		 * so if necessary, we just claim to support CQ
527 		 */
528 		dev->frontend_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
529 	} else {
530 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
531 		/* Also disable features that depend on VIRTIO_NET_F_CTRL_VQ */
532 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_RX);
533 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VLAN);
534 		dev->unsupported_features |=
535 			(1ull << VIRTIO_NET_F_GUEST_ANNOUNCE);
536 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
537 		dev->unsupported_features |=
538 			(1ull << VIRTIO_NET_F_CTRL_MAC_ADDR);
539 	}
540 
541 	/* The backend will not report this feature, we add it explicitly */
542 	if (is_vhost_user_by_type(dev->path))
543 		dev->frontend_features |= (1ull << VIRTIO_NET_F_STATUS);
544 
545 	/*
546 	 * Device features =
547 	 *     (frontend_features | backend_features) & ~unsupported_features;
548 	 */
549 	dev->device_features |= dev->frontend_features;
550 	dev->device_features &= ~dev->unsupported_features;
551 
552 	if (rte_mem_event_callback_register(VIRTIO_USER_MEM_EVENT_CLB_NAME,
553 				virtio_user_mem_event_cb, dev)) {
554 		if (rte_errno != ENOTSUP) {
555 			PMD_INIT_LOG(ERR, "Failed to register mem event"
556 					" callback\n");
557 			return -1;
558 		}
559 	}
560 
561 	return 0;
562 }
563 
564 void
565 virtio_user_dev_uninit(struct virtio_user_dev *dev)
566 {
567 	uint32_t i;
568 
569 	virtio_user_stop_device(dev);
570 
571 	rte_mem_event_callback_unregister(VIRTIO_USER_MEM_EVENT_CLB_NAME, dev);
572 
573 	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
574 		close(dev->callfds[i]);
575 		close(dev->kickfds[i]);
576 	}
577 
578 	if (dev->vhostfd >= 0)
579 		close(dev->vhostfd);
580 
581 	if (dev->is_server && dev->listenfd >= 0) {
582 		close(dev->listenfd);
583 		dev->listenfd = -1;
584 	}
585 
586 	if (dev->vhostfds) {
587 		for (i = 0; i < dev->max_queue_pairs; ++i) {
588 			close(dev->vhostfds[i]);
589 			if (dev->tapfds[i] >= 0)
590 				close(dev->tapfds[i]);
591 		}
592 		free(dev->vhostfds);
593 		free(dev->tapfds);
594 	}
595 
596 	free(dev->ifname);
597 
598 	if (dev->is_server)
599 		unlink(dev->path);
600 }
601 
602 uint8_t
603 virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs)
604 {
605 	uint16_t i;
606 	uint8_t ret = 0;
607 
608 	if (q_pairs > dev->max_queue_pairs) {
609 		PMD_INIT_LOG(ERR, "multi-q config %u, but only %u supported",
610 			     q_pairs, dev->max_queue_pairs);
611 		return -1;
612 	}
613 
614 	/* Server mode can't enable queue pairs if vhostfd is invalid,
615 	 * always return 0 in this case.
616 	 */
617 	if (!dev->is_server || dev->vhostfd >= 0) {
618 		for (i = 0; i < q_pairs; ++i)
619 			ret |= dev->ops->enable_qp(dev, i, 1);
620 		for (i = q_pairs; i < dev->max_queue_pairs; ++i)
621 			ret |= dev->ops->enable_qp(dev, i, 0);
622 	}
623 	dev->queue_pairs = q_pairs;
624 
625 	return ret;
626 }
627 
628 static uint32_t
629 virtio_user_handle_ctrl_msg(struct virtio_user_dev *dev, struct vring *vring,
630 			    uint16_t idx_hdr)
631 {
632 	struct virtio_net_ctrl_hdr *hdr;
633 	virtio_net_ctrl_ack status = ~0;
634 	uint16_t i, idx_data, idx_status;
635 	uint32_t n_descs = 0;
636 
637 	/* locate desc for header, data, and status */
638 	idx_data = vring->desc[idx_hdr].next;
639 	n_descs++;
640 
641 	i = idx_data;
642 	while (vring->desc[i].flags == VRING_DESC_F_NEXT) {
643 		i = vring->desc[i].next;
644 		n_descs++;
645 	}
646 
647 	/* locate desc for status */
648 	idx_status = i;
649 	n_descs++;
650 
651 	hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
652 	if (hdr->class == VIRTIO_NET_CTRL_MQ &&
653 	    hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
654 		uint16_t queues;
655 
656 		queues = *(uint16_t *)(uintptr_t)vring->desc[idx_data].addr;
657 		status = virtio_user_handle_mq(dev, queues);
658 	} else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
659 		   hdr->class == VIRTIO_NET_CTRL_MAC ||
660 		   hdr->class == VIRTIO_NET_CTRL_VLAN) {
661 		status = 0;
662 	}
663 
664 	/* Update status */
665 	*(virtio_net_ctrl_ack *)(uintptr_t)vring->desc[idx_status].addr = status;
666 
667 	return n_descs;
668 }
669 
670 static inline int
671 desc_is_avail(struct vring_packed_desc *desc, bool wrap_counter)
672 {
673 	uint16_t flags = __atomic_load_n(&desc->flags, __ATOMIC_ACQUIRE);
674 
675 	return wrap_counter == !!(flags & VRING_PACKED_DESC_F_AVAIL) &&
676 		wrap_counter != !!(flags & VRING_PACKED_DESC_F_USED);
677 }
678 
679 static uint32_t
680 virtio_user_handle_ctrl_msg_packed(struct virtio_user_dev *dev,
681 				   struct vring_packed *vring,
682 				   uint16_t idx_hdr)
683 {
684 	struct virtio_net_ctrl_hdr *hdr;
685 	virtio_net_ctrl_ack status = ~0;
686 	uint16_t idx_data, idx_status;
687 	/* initialize to one, header is first */
688 	uint32_t n_descs = 1;
689 
690 	/* locate desc for header, data, and status */
691 	idx_data = idx_hdr + 1;
692 	if (idx_data >= dev->queue_size)
693 		idx_data -= dev->queue_size;
694 
695 	n_descs++;
696 
697 	idx_status = idx_data;
698 	while (vring->desc[idx_status].flags & VRING_DESC_F_NEXT) {
699 		idx_status++;
700 		if (idx_status >= dev->queue_size)
701 			idx_status -= dev->queue_size;
702 		n_descs++;
703 	}
704 
705 	hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
706 	if (hdr->class == VIRTIO_NET_CTRL_MQ &&
707 	    hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
708 		uint16_t queues;
709 
710 		queues = *(uint16_t *)(uintptr_t)
711 				vring->desc[idx_data].addr;
712 		status = virtio_user_handle_mq(dev, queues);
713 	} else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
714 		   hdr->class == VIRTIO_NET_CTRL_MAC ||
715 		   hdr->class == VIRTIO_NET_CTRL_VLAN) {
716 		status = 0;
717 	}
718 
719 	/* Update status */
720 	*(virtio_net_ctrl_ack *)(uintptr_t)
721 		vring->desc[idx_status].addr = status;
722 
723 	/* Update used descriptor */
724 	vring->desc[idx_hdr].id = vring->desc[idx_status].id;
725 	vring->desc[idx_hdr].len = sizeof(status);
726 
727 	return n_descs;
728 }
729 
730 void
731 virtio_user_handle_cq_packed(struct virtio_user_dev *dev, uint16_t queue_idx)
732 {
733 	struct virtio_user_queue *vq = &dev->packed_queues[queue_idx];
734 	struct vring_packed *vring = &dev->packed_vrings[queue_idx];
735 	uint16_t n_descs, flags;
736 
737 	/* Perform a load-acquire barrier in desc_is_avail to
738 	 * enforce the ordering between desc flags and desc
739 	 * content.
740 	 */
741 	while (desc_is_avail(&vring->desc[vq->used_idx],
742 			     vq->used_wrap_counter)) {
743 
744 		n_descs = virtio_user_handle_ctrl_msg_packed(dev, vring,
745 				vq->used_idx);
746 
747 		flags = VRING_DESC_F_WRITE;
748 		if (vq->used_wrap_counter)
749 			flags |= VRING_PACKED_DESC_F_AVAIL_USED;
750 
751 		__atomic_store_n(&vring->desc[vq->used_idx].flags, flags,
752 				 __ATOMIC_RELEASE);
753 
754 		vq->used_idx += n_descs;
755 		if (vq->used_idx >= dev->queue_size) {
756 			vq->used_idx -= dev->queue_size;
757 			vq->used_wrap_counter ^= 1;
758 		}
759 	}
760 }
761 
762 void
763 virtio_user_handle_cq(struct virtio_user_dev *dev, uint16_t queue_idx)
764 {
765 	uint16_t avail_idx, desc_idx;
766 	struct vring_used_elem *uep;
767 	uint32_t n_descs;
768 	struct vring *vring = &dev->vrings[queue_idx];
769 
770 	/* Consume avail ring, using used ring idx as first one */
771 	while (__atomic_load_n(&vring->used->idx, __ATOMIC_RELAXED)
772 	       != vring->avail->idx) {
773 		avail_idx = __atomic_load_n(&vring->used->idx, __ATOMIC_RELAXED)
774 			    & (vring->num - 1);
775 		desc_idx = vring->avail->ring[avail_idx];
776 
777 		n_descs = virtio_user_handle_ctrl_msg(dev, vring, desc_idx);
778 
779 		/* Update used ring */
780 		uep = &vring->used->ring[avail_idx];
781 		uep->id = desc_idx;
782 		uep->len = n_descs;
783 
784 		__atomic_add_fetch(&vring->used->idx, 1, __ATOMIC_RELAXED);
785 	}
786 }
787 
788 int
789 virtio_user_send_status_update(struct virtio_user_dev *dev, uint8_t status)
790 {
791 	int ret;
792 	uint64_t arg = status;
793 
794 	/* Vhost-user only for now */
795 	if (!is_vhost_user_by_type(dev->path))
796 		return 0;
797 
798 	if (!(dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_STATUS)))
799 		return 0;
800 
801 	ret = dev->ops->send_request(dev, VHOST_USER_SET_STATUS, &arg);
802 	if (ret) {
803 		PMD_INIT_LOG(ERR, "VHOST_USER_SET_STATUS failed (%d): %s", ret,
804 			     strerror(errno));
805 		return -1;
806 	}
807 
808 	return 0;
809 }
810 
811 int
812 virtio_user_update_status(struct virtio_user_dev *dev)
813 {
814 	uint64_t ret;
815 	int err;
816 
817 	/* Vhost-user only for now */
818 	if (!is_vhost_user_by_type(dev->path))
819 		return 0;
820 
821 	if (!(dev->protocol_features & (1UL << VHOST_USER_PROTOCOL_F_STATUS)))
822 		return 0;
823 
824 	err = dev->ops->send_request(dev, VHOST_USER_GET_STATUS, &ret);
825 	if (err) {
826 		PMD_INIT_LOG(ERR, "VHOST_USER_GET_STATUS failed (%d): %s", err,
827 			     strerror(errno));
828 		return -1;
829 	}
830 	if (ret > UINT8_MAX) {
831 		PMD_INIT_LOG(ERR, "Invalid VHOST_USER_GET_STATUS response 0x%" PRIx64 "\n", ret);
832 		return -1;
833 	}
834 
835 	dev->status = ret;
836 	PMD_INIT_LOG(DEBUG, "Updated Device Status(0x%08x):\n"
837 			"\t-RESET: %u\n"
838 			"\t-ACKNOWLEDGE: %u\n"
839 			"\t-DRIVER: %u\n"
840 			"\t-DRIVER_OK: %u\n"
841 			"\t-FEATURES_OK: %u\n"
842 			"\t-DEVICE_NEED_RESET: %u\n"
843 			"\t-FAILED: %u\n",
844 			dev->status,
845 			(dev->status == VIRTIO_CONFIG_STATUS_RESET),
846 			!!(dev->status & VIRTIO_CONFIG_STATUS_ACK),
847 			!!(dev->status & VIRTIO_CONFIG_STATUS_DRIVER),
848 			!!(dev->status & VIRTIO_CONFIG_STATUS_DRIVER_OK),
849 			!!(dev->status & VIRTIO_CONFIG_STATUS_FEATURES_OK),
850 			!!(dev->status & VIRTIO_CONFIG_STATUS_DEV_NEED_RESET),
851 			!!(dev->status & VIRTIO_CONFIG_STATUS_FAILED));
852 	return 0;
853 }
854