xref: /kvmtool/virtio/net.c (revision 754c8ce3306161434cdfd1f0eb42b24cd0fa822b)
1 #include "kvm/virtio-pci-dev.h"
2 #include "kvm/virtio-net.h"
3 #include "kvm/virtio.h"
4 #include "kvm/types.h"
5 #include "kvm/mutex.h"
6 #include "kvm/util.h"
7 #include "kvm/kvm.h"
8 #include "kvm/irq.h"
9 #include "kvm/uip.h"
10 #include "kvm/guest_compat.h"
11 #include "kvm/virtio-trans.h"
12 
13 #include <linux/vhost.h>
14 #include <linux/virtio_net.h>
15 #include <linux/if_tun.h>
16 #include <linux/types.h>
17 
18 #include <arpa/inet.h>
19 #include <net/if.h>
20 
21 #include <unistd.h>
22 #include <assert.h>
23 #include <fcntl.h>
24 
25 #include <sys/socket.h>
26 #include <sys/ioctl.h>
27 #include <sys/types.h>
28 #include <sys/wait.h>
29 #include <sys/eventfd.h>
30 
31 #define VIRTIO_NET_QUEUE_SIZE		128
32 #define VIRTIO_NET_NUM_QUEUES		2
33 #define VIRTIO_NET_RX_QUEUE		0
34 #define VIRTIO_NET_TX_QUEUE		1
35 
36 struct net_dev;
37 
38 extern struct kvm *kvm;
39 
40 struct net_dev_operations {
41 	int (*rx)(struct iovec *iov, u16 in, struct net_dev *ndev);
42 	int (*tx)(struct iovec *iov, u16 in, struct net_dev *ndev);
43 };
44 
45 struct net_dev {
46 	pthread_mutex_t			mutex;
47 	struct virtio_trans		vtrans;
48 	struct list_head		list;
49 
50 	struct virt_queue		vqs[VIRTIO_NET_NUM_QUEUES];
51 	struct virtio_net_config	config;
52 	u32				features;
53 
54 	pthread_t			io_rx_thread;
55 	pthread_mutex_t			io_rx_lock;
56 	pthread_cond_t			io_rx_cond;
57 
58 	pthread_t			io_tx_thread;
59 	pthread_mutex_t			io_tx_lock;
60 	pthread_cond_t			io_tx_cond;
61 
62 	int				vhost_fd;
63 	int				tap_fd;
64 	char				tap_name[IFNAMSIZ];
65 
66 	int				mode;
67 
68 	struct uip_info			info;
69 	struct net_dev_operations	*ops;
70 	struct kvm			*kvm;
71 };
72 
73 static LIST_HEAD(ndevs);
74 static int compat_id = -1;
75 
76 static void *virtio_net_rx_thread(void *p)
77 {
78 	struct iovec iov[VIRTIO_NET_QUEUE_SIZE];
79 	struct virt_queue *vq;
80 	struct kvm *kvm;
81 	struct net_dev *ndev = p;
82 	u16 out, in;
83 	u16 head;
84 	int len;
85 
86 	kvm	= ndev->kvm;
87 	vq	= &ndev->vqs[VIRTIO_NET_RX_QUEUE];
88 
89 	while (1) {
90 
91 		mutex_lock(&ndev->io_rx_lock);
92 		if (!virt_queue__available(vq))
93 			pthread_cond_wait(&ndev->io_rx_cond, &ndev->io_rx_lock);
94 		mutex_unlock(&ndev->io_rx_lock);
95 
96 		while (virt_queue__available(vq)) {
97 
98 			head = virt_queue__get_iov(vq, iov, &out, &in, kvm);
99 
100 			len = ndev->ops->rx(iov, in, ndev);
101 
102 			virt_queue__set_used_elem(vq, head, len);
103 
104 			/* We should interrupt guest right now, otherwise latency is huge. */
105 			if (virtio_queue__should_signal(&ndev->vqs[VIRTIO_NET_RX_QUEUE]))
106 				ndev->vtrans.trans_ops->signal_vq(kvm, &ndev->vtrans,
107 								VIRTIO_NET_RX_QUEUE);
108 		}
109 
110 	}
111 
112 	pthread_exit(NULL);
113 	return NULL;
114 
115 }
116 
117 static void *virtio_net_tx_thread(void *p)
118 {
119 	struct iovec iov[VIRTIO_NET_QUEUE_SIZE];
120 	struct virt_queue *vq;
121 	struct kvm *kvm;
122 	struct net_dev *ndev = p;
123 	u16 out, in;
124 	u16 head;
125 	int len;
126 
127 	kvm	= ndev->kvm;
128 	vq	= &ndev->vqs[VIRTIO_NET_TX_QUEUE];
129 
130 	while (1) {
131 		mutex_lock(&ndev->io_tx_lock);
132 		if (!virt_queue__available(vq))
133 			pthread_cond_wait(&ndev->io_tx_cond, &ndev->io_tx_lock);
134 		mutex_unlock(&ndev->io_tx_lock);
135 
136 		while (virt_queue__available(vq)) {
137 
138 			head = virt_queue__get_iov(vq, iov, &out, &in, kvm);
139 
140 			len = ndev->ops->tx(iov, out, ndev);
141 
142 			virt_queue__set_used_elem(vq, head, len);
143 		}
144 
145 		if (virtio_queue__should_signal(&ndev->vqs[VIRTIO_NET_TX_QUEUE]))
146 			ndev->vtrans.trans_ops->signal_vq(kvm, &ndev->vtrans, VIRTIO_NET_TX_QUEUE);
147 	}
148 
149 	pthread_exit(NULL);
150 
151 	return NULL;
152 
153 }
154 
155 static void virtio_net_handle_callback(struct kvm *kvm, struct net_dev *ndev, int queue)
156 {
157 	switch (queue) {
158 	case VIRTIO_NET_TX_QUEUE:
159 		mutex_lock(&ndev->io_tx_lock);
160 		pthread_cond_signal(&ndev->io_tx_cond);
161 		mutex_unlock(&ndev->io_tx_lock);
162 		break;
163 	case VIRTIO_NET_RX_QUEUE:
164 		mutex_lock(&ndev->io_rx_lock);
165 		pthread_cond_signal(&ndev->io_rx_cond);
166 		mutex_unlock(&ndev->io_rx_lock);
167 		break;
168 	default:
169 		pr_warning("Unknown queue index %u", queue);
170 	}
171 }
172 
173 static bool virtio_net__tap_init(const struct virtio_net_params *params,
174 					struct net_dev *ndev)
175 {
176 	int sock = socket(AF_INET, SOCK_STREAM, 0);
177 	int pid, status, offload, hdr_len;
178 	struct sockaddr_in sin = {0};
179 	struct ifreq ifr;
180 
181 	ndev->tap_fd = open("/dev/net/tun", O_RDWR);
182 	if (ndev->tap_fd < 0) {
183 		pr_warning("Unable to open /dev/net/tun");
184 		goto fail;
185 	}
186 
187 	memset(&ifr, 0, sizeof(ifr));
188 	ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
189 	if (ioctl(ndev->tap_fd, TUNSETIFF, &ifr) < 0) {
190 		pr_warning("Config tap device error. Are you root?");
191 		goto fail;
192 	}
193 
194 	strncpy(ndev->tap_name, ifr.ifr_name, sizeof(ndev->tap_name));
195 
196 	if (ioctl(ndev->tap_fd, TUNSETNOCSUM, 1) < 0) {
197 		pr_warning("Config tap device TUNSETNOCSUM error");
198 		goto fail;
199 	}
200 
201 	hdr_len = sizeof(struct virtio_net_hdr);
202 	if (ioctl(ndev->tap_fd, TUNSETVNETHDRSZ, &hdr_len) < 0)
203 		pr_warning("Config tap device TUNSETVNETHDRSZ error");
204 
205 	offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | TUN_F_UFO;
206 	if (ioctl(ndev->tap_fd, TUNSETOFFLOAD, offload) < 0) {
207 		pr_warning("Config tap device TUNSETOFFLOAD error");
208 		goto fail;
209 	}
210 
211 	if (strcmp(params->script, "none")) {
212 		pid = fork();
213 		if (pid == 0) {
214 			execl(params->script, params->script, ndev->tap_name, NULL);
215 			_exit(1);
216 		} else {
217 			waitpid(pid, &status, 0);
218 			if (WIFEXITED(status) && WEXITSTATUS(status) != 0) {
219 				pr_warning("Fail to setup tap by %s", params->script);
220 				goto fail;
221 			}
222 		}
223 	} else {
224 		memset(&ifr, 0, sizeof(ifr));
225 		strncpy(ifr.ifr_name, ndev->tap_name, sizeof(ndev->tap_name));
226 		sin.sin_addr.s_addr = inet_addr(params->host_ip);
227 		memcpy(&(ifr.ifr_addr), &sin, sizeof(ifr.ifr_addr));
228 		ifr.ifr_addr.sa_family = AF_INET;
229 		if (ioctl(sock, SIOCSIFADDR, &ifr) < 0) {
230 			pr_warning("Could not set ip address on tap device");
231 			goto fail;
232 		}
233 	}
234 
235 	memset(&ifr, 0, sizeof(ifr));
236 	strncpy(ifr.ifr_name, ndev->tap_name, sizeof(ndev->tap_name));
237 	ioctl(sock, SIOCGIFFLAGS, &ifr);
238 	ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
239 	if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0)
240 		pr_warning("Could not bring tap device up");
241 
242 	close(sock);
243 
244 	return 1;
245 
246 fail:
247 	if (sock >= 0)
248 		close(sock);
249 	if (ndev->tap_fd >= 0)
250 		close(ndev->tap_fd);
251 
252 	return 0;
253 }
254 
255 static void virtio_net__io_thread_init(struct kvm *kvm, struct net_dev *ndev)
256 {
257 	pthread_mutex_init(&ndev->io_tx_lock, NULL);
258 	pthread_mutex_init(&ndev->io_rx_lock, NULL);
259 
260 	pthread_cond_init(&ndev->io_tx_cond, NULL);
261 	pthread_cond_init(&ndev->io_rx_cond, NULL);
262 
263 	pthread_create(&ndev->io_tx_thread, NULL, virtio_net_tx_thread, ndev);
264 	pthread_create(&ndev->io_rx_thread, NULL, virtio_net_rx_thread, ndev);
265 }
266 
267 static inline int tap_ops_tx(struct iovec *iov, u16 out, struct net_dev *ndev)
268 {
269 	return writev(ndev->tap_fd, iov, out);
270 }
271 
272 static inline int tap_ops_rx(struct iovec *iov, u16 in, struct net_dev *ndev)
273 {
274 	return readv(ndev->tap_fd, iov, in);
275 }
276 
277 static inline int uip_ops_tx(struct iovec *iov, u16 out, struct net_dev *ndev)
278 {
279 	return uip_tx(iov, out, &ndev->info);
280 }
281 
282 static inline int uip_ops_rx(struct iovec *iov, u16 in, struct net_dev *ndev)
283 {
284 	return uip_rx(iov, in, &ndev->info);
285 }
286 
287 static struct net_dev_operations tap_ops = {
288 	.rx	= tap_ops_rx,
289 	.tx	= tap_ops_tx,
290 };
291 
292 static struct net_dev_operations uip_ops = {
293 	.rx	= uip_ops_rx,
294 	.tx	= uip_ops_tx,
295 };
296 
297 static void set_config(struct kvm *kvm, void *dev, u8 data, u32 offset)
298 {
299 	struct net_dev *ndev = dev;
300 
301 	((u8 *)(&ndev->config))[offset] = data;
302 }
303 
304 static u8 get_config(struct kvm *kvm, void *dev, u32 offset)
305 {
306 	struct net_dev *ndev = dev;
307 
308 	return ((u8 *)(&ndev->config))[offset];
309 }
310 
311 static u32 get_host_features(struct kvm *kvm, void *dev)
312 {
313 	return 1UL << VIRTIO_NET_F_MAC
314 		| 1UL << VIRTIO_NET_F_CSUM
315 		| 1UL << VIRTIO_NET_F_HOST_UFO
316 		| 1UL << VIRTIO_NET_F_HOST_TSO4
317 		| 1UL << VIRTIO_NET_F_HOST_TSO6
318 		| 1UL << VIRTIO_NET_F_GUEST_UFO
319 		| 1UL << VIRTIO_NET_F_GUEST_TSO4
320 		| 1UL << VIRTIO_NET_F_GUEST_TSO6
321 		| 1UL << VIRTIO_RING_F_EVENT_IDX
322 		| 1UL << VIRTIO_RING_F_INDIRECT_DESC;
323 }
324 
325 static void set_guest_features(struct kvm *kvm, void *dev, u32 features)
326 {
327 	struct net_dev *ndev = dev;
328 
329 	ndev->features = features;
330 }
331 
332 static int init_vq(struct kvm *kvm, void *dev, u32 vq, u32 pfn)
333 {
334 	struct vhost_vring_state state = { .index = vq };
335 	struct vhost_vring_addr addr;
336 	struct net_dev *ndev = dev;
337 	struct virt_queue *queue;
338 	void *p;
339 	int r;
340 
341 	compat__remove_message(compat_id);
342 
343 	queue			= &ndev->vqs[vq];
344 	queue->pfn		= pfn;
345 	p			= guest_pfn_to_host(kvm, queue->pfn);
346 
347 	vring_init(&queue->vring, VIRTIO_NET_QUEUE_SIZE, p, VIRTIO_PCI_VRING_ALIGN);
348 
349 	if (ndev->vhost_fd == 0)
350 		return 0;
351 
352 	state.num = queue->vring.num;
353 	r = ioctl(ndev->vhost_fd, VHOST_SET_VRING_NUM, &state);
354 	if (r < 0)
355 		die_perror("VHOST_SET_VRING_NUM failed");
356 	state.num = 0;
357 	r = ioctl(ndev->vhost_fd, VHOST_SET_VRING_BASE, &state);
358 	if (r < 0)
359 		die_perror("VHOST_SET_VRING_BASE failed");
360 
361 	addr = (struct vhost_vring_addr) {
362 		.index = vq,
363 		.desc_user_addr = (u64)(unsigned long)queue->vring.desc,
364 		.avail_user_addr = (u64)(unsigned long)queue->vring.avail,
365 		.used_user_addr = (u64)(unsigned long)queue->vring.used,
366 	};
367 
368 	r = ioctl(ndev->vhost_fd, VHOST_SET_VRING_ADDR, &addr);
369 	if (r < 0)
370 		die_perror("VHOST_SET_VRING_ADDR failed");
371 
372 	return 0;
373 }
374 
375 static void notify_vq_gsi(struct kvm *kvm, void *dev, u32 vq, u32 gsi)
376 {
377 	struct net_dev *ndev = dev;
378 	struct kvm_irqfd irq;
379 	struct vhost_vring_file file;
380 	int r;
381 
382 	if (ndev->vhost_fd == 0)
383 		return;
384 
385 	irq = (struct kvm_irqfd) {
386 		.gsi	= gsi,
387 		.fd	= eventfd(0, 0),
388 	};
389 	file = (struct vhost_vring_file) {
390 		.index	= vq,
391 		.fd	= irq.fd,
392 	};
393 
394 	r = ioctl(kvm->vm_fd, KVM_IRQFD, &irq);
395 	if (r < 0)
396 		die_perror("KVM_IRQFD failed");
397 
398 	r = ioctl(ndev->vhost_fd, VHOST_SET_VRING_CALL, &file);
399 	if (r < 0)
400 		die_perror("VHOST_SET_VRING_CALL failed");
401 	file.fd = ndev->tap_fd;
402 	r = ioctl(ndev->vhost_fd, VHOST_NET_SET_BACKEND, &file);
403 	if (r != 0)
404 		die("VHOST_NET_SET_BACKEND failed %d", errno);
405 
406 }
407 
408 static void notify_vq_eventfd(struct kvm *kvm, void *dev, u32 vq, u32 efd)
409 {
410 	struct net_dev *ndev = dev;
411 	struct vhost_vring_file file = {
412 		.index	= vq,
413 		.fd	= efd,
414 	};
415 	int r;
416 
417 	if (ndev->vhost_fd == 0)
418 		return;
419 
420 	r = ioctl(ndev->vhost_fd, VHOST_SET_VRING_KICK, &file);
421 	if (r < 0)
422 		die_perror("VHOST_SET_VRING_KICK failed");
423 }
424 
425 static int notify_vq(struct kvm *kvm, void *dev, u32 vq)
426 {
427 	struct net_dev *ndev = dev;
428 
429 	virtio_net_handle_callback(kvm, ndev, vq);
430 
431 	return 0;
432 }
433 
434 static int get_pfn_vq(struct kvm *kvm, void *dev, u32 vq)
435 {
436 	struct net_dev *ndev = dev;
437 
438 	return ndev->vqs[vq].pfn;
439 }
440 
441 static int get_size_vq(struct kvm *kvm, void *dev, u32 vq)
442 {
443 	return VIRTIO_NET_QUEUE_SIZE;
444 }
445 
446 static struct virtio_ops net_dev_virtio_ops = (struct virtio_ops) {
447 	.set_config		= set_config,
448 	.get_config		= get_config,
449 	.get_host_features	= get_host_features,
450 	.set_guest_features	= set_guest_features,
451 	.init_vq		= init_vq,
452 	.notify_vq		= notify_vq,
453 	.get_pfn_vq		= get_pfn_vq,
454 	.get_size_vq		= get_size_vq,
455 	.notify_vq_gsi		= notify_vq_gsi,
456 	.notify_vq_eventfd	= notify_vq_eventfd,
457 };
458 
459 static void virtio_net__vhost_init(struct kvm *kvm, struct net_dev *ndev)
460 {
461 	u64 features = 1UL << VIRTIO_RING_F_EVENT_IDX;
462 	struct vhost_memory *mem;
463 	int r;
464 
465 	ndev->vhost_fd = open("/dev/vhost-net", O_RDWR);
466 	if (ndev->vhost_fd < 0)
467 		die_perror("Failed openning vhost-net device");
468 
469 	mem = malloc(sizeof(*mem) + sizeof(struct vhost_memory_region));
470 	if (mem == NULL)
471 		die("Failed allocating memory for vhost memory map");
472 
473 	mem->nregions = 1;
474 	mem->regions[0] = (struct vhost_memory_region) {
475 		.guest_phys_addr	= 0,
476 		.memory_size		= kvm->ram_size,
477 		.userspace_addr		= (unsigned long)kvm->ram_start,
478 	};
479 
480 	r = ioctl(ndev->vhost_fd, VHOST_SET_OWNER);
481 	if (r != 0)
482 		die_perror("VHOST_SET_OWNER failed");
483 
484 	r = ioctl(ndev->vhost_fd, VHOST_SET_FEATURES, &features);
485 	if (r != 0)
486 		die_perror("VHOST_SET_FEATURES failed");
487 	r = ioctl(ndev->vhost_fd, VHOST_SET_MEM_TABLE, mem);
488 	if (r != 0)
489 		die_perror("VHOST_SET_MEM_TABLE failed");
490 	free(mem);
491 }
492 
493 void virtio_net__init(const struct virtio_net_params *params)
494 {
495 	int i;
496 	struct net_dev *ndev;
497 
498 	if (!params)
499 		return;
500 
501 	ndev = calloc(1, sizeof(struct net_dev));
502 	if (ndev == NULL)
503 		die("Failed allocating ndev");
504 
505 	list_add_tail(&ndev->list, &ndevs);
506 
507 	ndev->kvm = params->kvm;
508 
509 	mutex_init(&ndev->mutex);
510 	ndev->config.status = VIRTIO_NET_S_LINK_UP;
511 
512 	for (i = 0 ; i < 6 ; i++) {
513 		ndev->config.mac[i]		= params->guest_mac[i];
514 		ndev->info.guest_mac.addr[i]	= params->guest_mac[i];
515 		ndev->info.host_mac.addr[i]	= params->host_mac[i];
516 	}
517 
518 	ndev->mode = params->mode;
519 	if (ndev->mode == NET_MODE_TAP) {
520 		if (!virtio_net__tap_init(params, ndev))
521 			die_perror("You have requested a TAP device, but creation of one has"
522 					"failed because:");
523 		ndev->ops = &tap_ops;
524 	} else {
525 		ndev->info.host_ip		= ntohl(inet_addr(params->host_ip));
526 		ndev->info.guest_ip		= ntohl(inet_addr(params->guest_ip));
527 		ndev->info.guest_netmask	= ntohl(inet_addr("255.255.255.0"));
528 		ndev->info.buf_nr		= 20,
529 		uip_init(&ndev->info);
530 		ndev->ops = &uip_ops;
531 	}
532 
533 	virtio_trans_init(&ndev->vtrans, VIRTIO_PCI);
534 	ndev->vtrans.trans_ops->init(kvm, &ndev->vtrans, ndev, PCI_DEVICE_ID_VIRTIO_NET,
535 					VIRTIO_ID_NET, PCI_CLASS_NET);
536 	ndev->vtrans.virtio_ops = &net_dev_virtio_ops;
537 
538 	if (params->vhost)
539 		virtio_net__vhost_init(params->kvm, ndev);
540 	else
541 		virtio_net__io_thread_init(params->kvm, ndev);
542 
543 	if (compat_id != -1)
544 		compat_id = compat__add_message("virtio-net device was not detected",
545 						"While you have requested a virtio-net device, "
546 						"the guest kernel did not initialize it.\n"
547 						"Please make sure that the guest kernel was "
548 						"compiled with CONFIG_VIRTIO_NET=y enabled "
549 						"in its .config");
550 }
551