xref: /dpdk/drivers/net/virtio/virtio_user/virtio_user_dev.c (revision f5057be340e44f3edc0fe90fa875eb89a4c49b4f)
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 virtio_user_dev_set_features(struct virtio_user_dev *dev)
116 {
117 	uint64_t features;
118 	int ret = -1;
119 
120 	pthread_mutex_lock(&dev->mutex);
121 
122 	if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER &&
123 			dev->vhostfd < 0)
124 		goto error;
125 
126 	/* Step 0: tell vhost to create queues */
127 	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
128 		goto error;
129 
130 	features = dev->features;
131 
132 	/* Strip VIRTIO_NET_F_MAC, as MAC address is handled in vdev init */
133 	features &= ~(1ull << VIRTIO_NET_F_MAC);
134 	/* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */
135 	features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
136 	features &= ~(1ull << VIRTIO_NET_F_STATUS);
137 	ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES, &features);
138 	if (ret < 0)
139 		goto error;
140 	PMD_DRV_LOG(INFO, "set features: %" PRIx64, features);
141 error:
142 	pthread_mutex_unlock(&dev->mutex);
143 
144 	return ret;
145 }
146 
147 int
148 virtio_user_start_device(struct virtio_user_dev *dev)
149 {
150 	int ret;
151 
152 	/*
153 	 * XXX workaround!
154 	 *
155 	 * We need to make sure that the locks will be
156 	 * taken in the correct order to avoid deadlocks.
157 	 *
158 	 * Before releasing this lock, this thread should
159 	 * not trigger any memory hotplug events.
160 	 *
161 	 * This is a temporary workaround, and should be
162 	 * replaced when we get proper supports from the
163 	 * memory subsystem in the future.
164 	 */
165 	rte_mcfg_mem_read_lock();
166 	pthread_mutex_lock(&dev->mutex);
167 
168 	if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER &&
169 			dev->vhostfd < 0)
170 		goto error;
171 
172 	/* Step 2: share memory regions */
173 	ret = dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
174 	if (ret < 0)
175 		goto error;
176 
177 	/* Step 3: kick queues */
178 	if (virtio_user_queue_setup(dev, virtio_user_kick_queue) < 0)
179 		goto error;
180 
181 	/* Step 4: enable queues
182 	 * we enable the 1st queue pair by default.
183 	 */
184 	dev->ops->enable_qp(dev, 0, 1);
185 
186 	dev->started = true;
187 	pthread_mutex_unlock(&dev->mutex);
188 	rte_mcfg_mem_read_unlock();
189 
190 	return 0;
191 error:
192 	pthread_mutex_unlock(&dev->mutex);
193 	rte_mcfg_mem_read_unlock();
194 	/* TODO: free resource here or caller to check */
195 	return -1;
196 }
197 
198 int virtio_user_stop_device(struct virtio_user_dev *dev)
199 {
200 	struct vhost_vring_state state;
201 	uint32_t i;
202 	int error = 0;
203 
204 	pthread_mutex_lock(&dev->mutex);
205 	if (!dev->started)
206 		goto out;
207 
208 	for (i = 0; i < dev->max_queue_pairs; ++i)
209 		dev->ops->enable_qp(dev, i, 0);
210 
211 	/* Stop the backend. */
212 	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
213 		state.index = i;
214 		if (dev->ops->send_request(dev, VHOST_USER_GET_VRING_BASE,
215 					   &state) < 0) {
216 			PMD_DRV_LOG(ERR, "get_vring_base failed, index=%u\n",
217 				    i);
218 			error = -1;
219 			goto out;
220 		}
221 	}
222 
223 	dev->started = false;
224 out:
225 	pthread_mutex_unlock(&dev->mutex);
226 
227 	return error;
228 }
229 
230 static inline void
231 parse_mac(struct virtio_user_dev *dev, const char *mac)
232 {
233 	struct rte_ether_addr tmp;
234 
235 	if (!mac)
236 		return;
237 
238 	if (rte_ether_unformat_addr(mac, &tmp) == 0) {
239 		memcpy(dev->mac_addr, &tmp, RTE_ETHER_ADDR_LEN);
240 		dev->mac_specified = 1;
241 	} else {
242 		/* ignore the wrong mac, use random mac */
243 		PMD_DRV_LOG(ERR, "wrong format of mac: %s", mac);
244 	}
245 }
246 
247 static int
248 virtio_user_dev_init_notify(struct virtio_user_dev *dev)
249 {
250 	uint32_t i, j;
251 	int callfd;
252 	int kickfd;
253 
254 	for (i = 0; i < VIRTIO_MAX_VIRTQUEUES; ++i) {
255 		if (i >= dev->max_queue_pairs * 2) {
256 			dev->kickfds[i] = -1;
257 			dev->callfds[i] = -1;
258 			continue;
259 		}
260 
261 		/* May use invalid flag, but some backend uses kickfd and
262 		 * callfd as criteria to judge if dev is alive. so finally we
263 		 * use real event_fd.
264 		 */
265 		callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
266 		if (callfd < 0) {
267 			PMD_DRV_LOG(ERR, "callfd error, %s", strerror(errno));
268 			break;
269 		}
270 		kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
271 		if (kickfd < 0) {
272 			PMD_DRV_LOG(ERR, "kickfd error, %s", strerror(errno));
273 			break;
274 		}
275 		dev->callfds[i] = callfd;
276 		dev->kickfds[i] = kickfd;
277 	}
278 
279 	if (i < VIRTIO_MAX_VIRTQUEUES) {
280 		for (j = 0; j <= i; ++j) {
281 			close(dev->callfds[j]);
282 			close(dev->kickfds[j]);
283 		}
284 
285 		return -1;
286 	}
287 
288 	return 0;
289 }
290 
291 static int
292 virtio_user_fill_intr_handle(struct virtio_user_dev *dev)
293 {
294 	uint32_t i;
295 	struct rte_eth_dev *eth_dev = &rte_eth_devices[dev->port_id];
296 
297 	if (!eth_dev->intr_handle) {
298 		eth_dev->intr_handle = malloc(sizeof(*eth_dev->intr_handle));
299 		if (!eth_dev->intr_handle) {
300 			PMD_DRV_LOG(ERR, "fail to allocate intr_handle");
301 			return -1;
302 		}
303 		memset(eth_dev->intr_handle, 0, sizeof(*eth_dev->intr_handle));
304 	}
305 
306 	for (i = 0; i < dev->max_queue_pairs; ++i)
307 		eth_dev->intr_handle->efds[i] = dev->callfds[i];
308 	eth_dev->intr_handle->nb_efd = dev->max_queue_pairs;
309 	eth_dev->intr_handle->max_intr = dev->max_queue_pairs + 1;
310 	eth_dev->intr_handle->type = RTE_INTR_HANDLE_VDEV;
311 	/* For virtio vdev, no need to read counter for clean */
312 	eth_dev->intr_handle->efd_counter_size = 0;
313 	eth_dev->intr_handle->fd = -1;
314 	if (dev->vhostfd >= 0)
315 		eth_dev->intr_handle->fd = dev->vhostfd;
316 	else if (dev->is_server)
317 		eth_dev->intr_handle->fd = dev->listenfd;
318 
319 	return 0;
320 }
321 
322 static void
323 virtio_user_mem_event_cb(enum rte_mem_event type __rte_unused,
324 			 const void *addr,
325 			 size_t len __rte_unused,
326 			 void *arg)
327 {
328 	struct virtio_user_dev *dev = arg;
329 	struct rte_memseg_list *msl;
330 	uint16_t i;
331 
332 	/* ignore externally allocated memory */
333 	msl = rte_mem_virt2memseg_list(addr);
334 	if (msl->external)
335 		return;
336 
337 	pthread_mutex_lock(&dev->mutex);
338 
339 	if (dev->started == false)
340 		goto exit;
341 
342 	/* Step 1: pause the active queues */
343 	for (i = 0; i < dev->queue_pairs; i++)
344 		dev->ops->enable_qp(dev, i, 0);
345 
346 	/* Step 2: update memory regions */
347 	dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
348 
349 	/* Step 3: resume the active queues */
350 	for (i = 0; i < dev->queue_pairs; i++)
351 		dev->ops->enable_qp(dev, i, 1);
352 
353 exit:
354 	pthread_mutex_unlock(&dev->mutex);
355 }
356 
357 static int
358 virtio_user_dev_setup(struct virtio_user_dev *dev)
359 {
360 	uint32_t q;
361 
362 	dev->vhostfd = -1;
363 	dev->vhostfds = NULL;
364 	dev->tapfds = NULL;
365 
366 	if (dev->is_server) {
367 		if (dev->backend_type != VIRTIO_USER_BACKEND_VHOST_USER) {
368 			PMD_DRV_LOG(ERR, "Server mode only supports vhost-user!");
369 			return -1;
370 		}
371 		dev->ops = &virtio_ops_user;
372 	} else {
373 		if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER) {
374 			dev->ops = &virtio_ops_user;
375 		} else if (dev->backend_type ==
376 					VIRTIO_USER_BACKEND_VHOST_KERNEL) {
377 			dev->ops = &virtio_ops_kernel;
378 
379 			dev->vhostfds = malloc(dev->max_queue_pairs *
380 					       sizeof(int));
381 			dev->tapfds = malloc(dev->max_queue_pairs *
382 					     sizeof(int));
383 			if (!dev->vhostfds || !dev->tapfds) {
384 				PMD_INIT_LOG(ERR, "Failed to malloc");
385 				return -1;
386 			}
387 
388 			for (q = 0; q < dev->max_queue_pairs; ++q) {
389 				dev->vhostfds[q] = -1;
390 				dev->tapfds[q] = -1;
391 			}
392 		} else if (dev->backend_type ==
393 				VIRTIO_USER_BACKEND_VHOST_VDPA) {
394 			dev->ops = &virtio_ops_vdpa;
395 		} else {
396 			PMD_DRV_LOG(ERR, "Unknown backend type");
397 			return -1;
398 		}
399 	}
400 
401 	if (dev->ops->setup(dev) < 0)
402 		return -1;
403 
404 	if (virtio_user_dev_init_notify(dev) < 0)
405 		return -1;
406 
407 	if (virtio_user_fill_intr_handle(dev) < 0)
408 		return -1;
409 
410 	return 0;
411 }
412 
413 /* Use below macro to filter features from vhost backend */
414 #define VIRTIO_USER_SUPPORTED_FEATURES			\
415 	(1ULL << VIRTIO_NET_F_MAC		|	\
416 	 1ULL << VIRTIO_NET_F_STATUS		|	\
417 	 1ULL << VIRTIO_NET_F_MQ		|	\
418 	 1ULL << VIRTIO_NET_F_CTRL_MAC_ADDR	|	\
419 	 1ULL << VIRTIO_NET_F_CTRL_VQ		|	\
420 	 1ULL << VIRTIO_NET_F_CTRL_RX		|	\
421 	 1ULL << VIRTIO_NET_F_CTRL_VLAN		|	\
422 	 1ULL << VIRTIO_NET_F_CSUM		|	\
423 	 1ULL << VIRTIO_NET_F_HOST_TSO4		|	\
424 	 1ULL << VIRTIO_NET_F_HOST_TSO6		|	\
425 	 1ULL << VIRTIO_NET_F_MRG_RXBUF		|	\
426 	 1ULL << VIRTIO_RING_F_INDIRECT_DESC	|	\
427 	 1ULL << VIRTIO_NET_F_GUEST_CSUM	|	\
428 	 1ULL << VIRTIO_NET_F_GUEST_TSO4	|	\
429 	 1ULL << VIRTIO_NET_F_GUEST_TSO6	|	\
430 	 1ULL << VIRTIO_F_IN_ORDER		|	\
431 	 1ULL << VIRTIO_F_VERSION_1		|	\
432 	 1ULL << VIRTIO_F_RING_PACKED		|	\
433 	 1ULL << VHOST_USER_F_PROTOCOL_FEATURES)
434 
435 #define VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES		\
436 	(1ULL << VHOST_USER_PROTOCOL_F_MQ |		\
437 	 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK |	\
438 	 1ULL << VHOST_USER_PROTOCOL_F_STATUS)
439 
440 int
441 virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
442 		     int cq, int queue_size, const char *mac, char **ifname,
443 		     int server, int mrg_rxbuf, int in_order, int packed_vq,
444 		     enum virtio_user_backend_type backend_type)
445 {
446 	uint64_t protocol_features = 0;
447 
448 	pthread_mutex_init(&dev->mutex, NULL);
449 	strlcpy(dev->path, path, PATH_MAX);
450 	dev->started = 0;
451 	dev->max_queue_pairs = queues;
452 	dev->queue_pairs = 1; /* mq disabled by default */
453 	dev->queue_size = queue_size;
454 	dev->is_server = server;
455 	dev->mac_specified = 0;
456 	dev->frontend_features = 0;
457 	dev->unsupported_features = ~VIRTIO_USER_SUPPORTED_FEATURES;
458 	dev->protocol_features = VIRTIO_USER_SUPPORTED_PROTOCOL_FEATURES;
459 	dev->backend_type = backend_type;
460 
461 	parse_mac(dev, mac);
462 
463 	if (*ifname) {
464 		dev->ifname = *ifname;
465 		*ifname = NULL;
466 	}
467 
468 	if (virtio_user_dev_setup(dev) < 0) {
469 		PMD_INIT_LOG(ERR, "backend set up fails");
470 		return -1;
471 	}
472 
473 	if (dev->backend_type != VIRTIO_USER_BACKEND_VHOST_USER)
474 		dev->unsupported_features |=
475 			(1ULL << VHOST_USER_F_PROTOCOL_FEATURES);
476 
477 	if (!dev->is_server) {
478 		if (dev->ops->send_request(dev, VHOST_USER_SET_OWNER,
479 					   NULL) < 0) {
480 			PMD_INIT_LOG(ERR, "set_owner fails: %s",
481 				     strerror(errno));
482 			return -1;
483 		}
484 
485 		if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
486 					   &dev->device_features) < 0) {
487 			PMD_INIT_LOG(ERR, "get_features failed: %s",
488 				     strerror(errno));
489 			return -1;
490 		}
491 
492 
493 		if (dev->device_features &
494 				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES)) {
495 			if (dev->ops->send_request(dev,
496 					VHOST_USER_GET_PROTOCOL_FEATURES,
497 					&protocol_features))
498 				return -1;
499 
500 			dev->protocol_features &= protocol_features;
501 
502 			if (dev->ops->send_request(dev,
503 					VHOST_USER_SET_PROTOCOL_FEATURES,
504 					&dev->protocol_features))
505 				return -1;
506 
507 			if (!(dev->protocol_features &
508 					(1ULL << VHOST_USER_PROTOCOL_F_MQ)))
509 				dev->unsupported_features |=
510 					(1ull << VIRTIO_NET_F_MQ);
511 		}
512 	} else {
513 		/* We just pretend vhost-user can support all these features.
514 		 * Note that this could be problematic that if some feature is
515 		 * negotiated but not supported by the vhost-user which comes
516 		 * later.
517 		 */
518 		dev->device_features = VIRTIO_USER_SUPPORTED_FEATURES;
519 	}
520 
521 
522 
523 	if (!mrg_rxbuf)
524 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MRG_RXBUF);
525 
526 	if (!in_order)
527 		dev->unsupported_features |= (1ull << VIRTIO_F_IN_ORDER);
528 
529 	if (!packed_vq)
530 		dev->unsupported_features |= (1ull << VIRTIO_F_RING_PACKED);
531 
532 	if (dev->mac_specified)
533 		dev->frontend_features |= (1ull << VIRTIO_NET_F_MAC);
534 	else
535 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MAC);
536 
537 	if (cq) {
538 		/* device does not really need to know anything about CQ,
539 		 * so if necessary, we just claim to support CQ
540 		 */
541 		dev->frontend_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
542 	} else {
543 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VQ);
544 		/* Also disable features that depend on VIRTIO_NET_F_CTRL_VQ */
545 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_RX);
546 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_CTRL_VLAN);
547 		dev->unsupported_features |=
548 			(1ull << VIRTIO_NET_F_GUEST_ANNOUNCE);
549 		dev->unsupported_features |= (1ull << VIRTIO_NET_F_MQ);
550 		dev->unsupported_features |=
551 			(1ull << VIRTIO_NET_F_CTRL_MAC_ADDR);
552 	}
553 
554 	/* The backend will not report this feature, we add it explicitly */
555 	if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER)
556 		dev->frontend_features |= (1ull << VIRTIO_NET_F_STATUS);
557 
558 	/*
559 	 * Device features =
560 	 *     (frontend_features | backend_features) & ~unsupported_features;
561 	 */
562 	dev->device_features |= dev->frontend_features;
563 	dev->device_features &= ~dev->unsupported_features;
564 
565 	if (rte_mem_event_callback_register(VIRTIO_USER_MEM_EVENT_CLB_NAME,
566 				virtio_user_mem_event_cb, dev)) {
567 		if (rte_errno != ENOTSUP) {
568 			PMD_INIT_LOG(ERR, "Failed to register mem event"
569 					" callback\n");
570 			return -1;
571 		}
572 	}
573 
574 	return 0;
575 }
576 
577 void
578 virtio_user_dev_uninit(struct virtio_user_dev *dev)
579 {
580 	uint32_t i;
581 
582 	virtio_user_stop_device(dev);
583 
584 	rte_mem_event_callback_unregister(VIRTIO_USER_MEM_EVENT_CLB_NAME, dev);
585 
586 	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
587 		close(dev->callfds[i]);
588 		close(dev->kickfds[i]);
589 	}
590 
591 	if (dev->vhostfd >= 0)
592 		close(dev->vhostfd);
593 
594 	if (dev->is_server && dev->listenfd >= 0) {
595 		close(dev->listenfd);
596 		dev->listenfd = -1;
597 	}
598 
599 	if (dev->vhostfds) {
600 		for (i = 0; i < dev->max_queue_pairs; ++i) {
601 			close(dev->vhostfds[i]);
602 			if (dev->tapfds[i] >= 0)
603 				close(dev->tapfds[i]);
604 		}
605 		free(dev->vhostfds);
606 		free(dev->tapfds);
607 	}
608 
609 	free(dev->ifname);
610 
611 	if (dev->is_server)
612 		unlink(dev->path);
613 }
614 
615 uint8_t
616 virtio_user_handle_mq(struct virtio_user_dev *dev, uint16_t q_pairs)
617 {
618 	uint16_t i;
619 	uint8_t ret = 0;
620 
621 	if (q_pairs > dev->max_queue_pairs) {
622 		PMD_INIT_LOG(ERR, "multi-q config %u, but only %u supported",
623 			     q_pairs, dev->max_queue_pairs);
624 		return -1;
625 	}
626 
627 	/* Server mode can't enable queue pairs if vhostfd is invalid,
628 	 * always return 0 in this case.
629 	 */
630 	if (!dev->is_server || dev->vhostfd >= 0) {
631 		for (i = 0; i < q_pairs; ++i)
632 			ret |= dev->ops->enable_qp(dev, i, 1);
633 		for (i = q_pairs; i < dev->max_queue_pairs; ++i)
634 			ret |= dev->ops->enable_qp(dev, i, 0);
635 	}
636 	dev->queue_pairs = q_pairs;
637 
638 	return ret;
639 }
640 
641 static uint32_t
642 virtio_user_handle_ctrl_msg(struct virtio_user_dev *dev, struct vring *vring,
643 			    uint16_t idx_hdr)
644 {
645 	struct virtio_net_ctrl_hdr *hdr;
646 	virtio_net_ctrl_ack status = ~0;
647 	uint16_t i, idx_data, idx_status;
648 	uint32_t n_descs = 0;
649 
650 	/* locate desc for header, data, and status */
651 	idx_data = vring->desc[idx_hdr].next;
652 	n_descs++;
653 
654 	i = idx_data;
655 	while (vring->desc[i].flags == VRING_DESC_F_NEXT) {
656 		i = vring->desc[i].next;
657 		n_descs++;
658 	}
659 
660 	/* locate desc for status */
661 	idx_status = i;
662 	n_descs++;
663 
664 	hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
665 	if (hdr->class == VIRTIO_NET_CTRL_MQ &&
666 	    hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
667 		uint16_t queues;
668 
669 		queues = *(uint16_t *)(uintptr_t)vring->desc[idx_data].addr;
670 		status = virtio_user_handle_mq(dev, queues);
671 	} else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
672 		   hdr->class == VIRTIO_NET_CTRL_MAC ||
673 		   hdr->class == VIRTIO_NET_CTRL_VLAN) {
674 		status = 0;
675 	}
676 
677 	/* Update status */
678 	*(virtio_net_ctrl_ack *)(uintptr_t)vring->desc[idx_status].addr = status;
679 
680 	return n_descs;
681 }
682 
683 static inline int
684 desc_is_avail(struct vring_packed_desc *desc, bool wrap_counter)
685 {
686 	uint16_t flags = __atomic_load_n(&desc->flags, __ATOMIC_ACQUIRE);
687 
688 	return wrap_counter == !!(flags & VRING_PACKED_DESC_F_AVAIL) &&
689 		wrap_counter != !!(flags & VRING_PACKED_DESC_F_USED);
690 }
691 
692 static uint32_t
693 virtio_user_handle_ctrl_msg_packed(struct virtio_user_dev *dev,
694 				   struct vring_packed *vring,
695 				   uint16_t idx_hdr)
696 {
697 	struct virtio_net_ctrl_hdr *hdr;
698 	virtio_net_ctrl_ack status = ~0;
699 	uint16_t idx_data, idx_status;
700 	/* initialize to one, header is first */
701 	uint32_t n_descs = 1;
702 
703 	/* locate desc for header, data, and status */
704 	idx_data = idx_hdr + 1;
705 	if (idx_data >= dev->queue_size)
706 		idx_data -= dev->queue_size;
707 
708 	n_descs++;
709 
710 	idx_status = idx_data;
711 	while (vring->desc[idx_status].flags & VRING_DESC_F_NEXT) {
712 		idx_status++;
713 		if (idx_status >= dev->queue_size)
714 			idx_status -= dev->queue_size;
715 		n_descs++;
716 	}
717 
718 	hdr = (void *)(uintptr_t)vring->desc[idx_hdr].addr;
719 	if (hdr->class == VIRTIO_NET_CTRL_MQ &&
720 	    hdr->cmd == VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET) {
721 		uint16_t queues;
722 
723 		queues = *(uint16_t *)(uintptr_t)
724 				vring->desc[idx_data].addr;
725 		status = virtio_user_handle_mq(dev, queues);
726 	} else if (hdr->class == VIRTIO_NET_CTRL_RX  ||
727 		   hdr->class == VIRTIO_NET_CTRL_MAC ||
728 		   hdr->class == VIRTIO_NET_CTRL_VLAN) {
729 		status = 0;
730 	}
731 
732 	/* Update status */
733 	*(virtio_net_ctrl_ack *)(uintptr_t)
734 		vring->desc[idx_status].addr = status;
735 
736 	/* Update used descriptor */
737 	vring->desc[idx_hdr].id = vring->desc[idx_status].id;
738 	vring->desc[idx_hdr].len = sizeof(status);
739 
740 	return n_descs;
741 }
742 
743 void
744 virtio_user_handle_cq_packed(struct virtio_user_dev *dev, uint16_t queue_idx)
745 {
746 	struct virtio_user_queue *vq = &dev->packed_queues[queue_idx];
747 	struct vring_packed *vring = &dev->packed_vrings[queue_idx];
748 	uint16_t n_descs, flags;
749 
750 	/* Perform a load-acquire barrier in desc_is_avail to
751 	 * enforce the ordering between desc flags and desc
752 	 * content.
753 	 */
754 	while (desc_is_avail(&vring->desc[vq->used_idx],
755 			     vq->used_wrap_counter)) {
756 
757 		n_descs = virtio_user_handle_ctrl_msg_packed(dev, vring,
758 				vq->used_idx);
759 
760 		flags = VRING_DESC_F_WRITE;
761 		if (vq->used_wrap_counter)
762 			flags |= VRING_PACKED_DESC_F_AVAIL_USED;
763 
764 		__atomic_store_n(&vring->desc[vq->used_idx].flags, flags,
765 				 __ATOMIC_RELEASE);
766 
767 		vq->used_idx += n_descs;
768 		if (vq->used_idx >= dev->queue_size) {
769 			vq->used_idx -= dev->queue_size;
770 			vq->used_wrap_counter ^= 1;
771 		}
772 	}
773 }
774 
775 void
776 virtio_user_handle_cq(struct virtio_user_dev *dev, uint16_t queue_idx)
777 {
778 	uint16_t avail_idx, desc_idx;
779 	struct vring_used_elem *uep;
780 	uint32_t n_descs;
781 	struct vring *vring = &dev->vrings[queue_idx];
782 
783 	/* Consume avail ring, using used ring idx as first one */
784 	while (__atomic_load_n(&vring->used->idx, __ATOMIC_RELAXED)
785 	       != vring->avail->idx) {
786 		avail_idx = __atomic_load_n(&vring->used->idx, __ATOMIC_RELAXED)
787 			    & (vring->num - 1);
788 		desc_idx = vring->avail->ring[avail_idx];
789 
790 		n_descs = virtio_user_handle_ctrl_msg(dev, vring, desc_idx);
791 
792 		/* Update used ring */
793 		uep = &vring->used->ring[avail_idx];
794 		uep->id = desc_idx;
795 		uep->len = n_descs;
796 
797 		__atomic_add_fetch(&vring->used->idx, 1, __ATOMIC_RELAXED);
798 	}
799 }
800 
801 int
802 virtio_user_send_status_update(struct virtio_user_dev *dev, uint8_t status)
803 {
804 	int ret;
805 	uint64_t arg = status;
806 
807 	if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER)
808 		ret = dev->ops->send_request(dev,
809 				VHOST_USER_SET_STATUS, &arg);
810 	else if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_VDPA)
811 		ret = dev->ops->send_request(dev,
812 				VHOST_USER_SET_STATUS, &status);
813 	else
814 		return 0;
815 
816 	if (ret) {
817 		PMD_INIT_LOG(ERR, "VHOST_USER_SET_STATUS failed (%d): %s", ret,
818 			     strerror(errno));
819 		return -1;
820 	}
821 
822 	return 0;
823 }
824 
825 int
826 virtio_user_update_status(struct virtio_user_dev *dev)
827 {
828 	uint64_t ret;
829 	uint8_t status;
830 	int err;
831 
832 	if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_USER) {
833 		err = dev->ops->send_request(dev, VHOST_USER_GET_STATUS, &ret);
834 		if (!err && ret > UINT8_MAX) {
835 			PMD_INIT_LOG(ERR, "Invalid VHOST_USER_GET_STATUS "
836 					"response 0x%" PRIx64 "\n", ret);
837 			return -1;
838 		}
839 
840 		status = ret;
841 	} else if (dev->backend_type == VIRTIO_USER_BACKEND_VHOST_VDPA) {
842 		err = dev->ops->send_request(dev, VHOST_USER_GET_STATUS,
843 				&status);
844 	} else {
845 		return 0;
846 	}
847 
848 	if (err) {
849 		PMD_INIT_LOG(ERR, "VHOST_USER_GET_STATUS failed (%d): %s", err,
850 			     strerror(errno));
851 		return -1;
852 	}
853 
854 	dev->status = status;
855 	PMD_INIT_LOG(DEBUG, "Updated Device Status(0x%08x):\n"
856 			"\t-RESET: %u\n"
857 			"\t-ACKNOWLEDGE: %u\n"
858 			"\t-DRIVER: %u\n"
859 			"\t-DRIVER_OK: %u\n"
860 			"\t-FEATURES_OK: %u\n"
861 			"\t-DEVICE_NEED_RESET: %u\n"
862 			"\t-FAILED: %u\n",
863 			dev->status,
864 			(dev->status == VIRTIO_CONFIG_STATUS_RESET),
865 			!!(dev->status & VIRTIO_CONFIG_STATUS_ACK),
866 			!!(dev->status & VIRTIO_CONFIG_STATUS_DRIVER),
867 			!!(dev->status & VIRTIO_CONFIG_STATUS_DRIVER_OK),
868 			!!(dev->status & VIRTIO_CONFIG_STATUS_FEATURES_OK),
869 			!!(dev->status & VIRTIO_CONFIG_STATUS_DEV_NEED_RESET),
870 			!!(dev->status & VIRTIO_CONFIG_STATUS_FAILED));
871 	return 0;
872 }
873