xref: /qemu/hw/net/vhost_net.c (revision 814bb12a) 
1 /*
2  * vhost-net support
3  *
4  * Copyright Red Hat, Inc. 2010
5  *
6  * Authors:
7  *  Michael S. Tsirkin <mst@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2.  See
10  * the COPYING file in the top-level directory.
11  *
12  * Contributions after 2012-01-13 are licensed under the terms of the
13  * GNU GPL, version 2 or (at your option) any later version.
14  */
15 
16 #include "qemu/osdep.h"
17 #include "net/net.h"
18 #include "net/tap.h"
19 #include "net/vhost-user.h"
20 
21 #include "hw/virtio/virtio-net.h"
22 #include "net/vhost_net.h"
23 #include "qemu/error-report.h"
24 
25 
26 #ifdef CONFIG_VHOST_NET
27 #include <linux/vhost.h>
28 #include <sys/socket.h>
29 #include <linux/kvm.h>
30 #include <netpacket/packet.h>
31 #include <net/ethernet.h>
32 #include <net/if.h>
33 #include <netinet/in.h>
34 
35 
36 #include "standard-headers/linux/virtio_ring.h"
37 #include "hw/virtio/vhost.h"
38 #include "hw/virtio/virtio-bus.h"
39 
40 struct vhost_net {
41     struct vhost_dev dev;
42     struct vhost_virtqueue vqs[2];
43     int backend;
44     NetClientState *nc;
45 };
46 
47 /* Features supported by host kernel. */
48 static const int kernel_feature_bits[] = {
49     VIRTIO_F_NOTIFY_ON_EMPTY,
50     VIRTIO_RING_F_INDIRECT_DESC,
51     VIRTIO_RING_F_EVENT_IDX,
52     VIRTIO_NET_F_MRG_RXBUF,
53     VIRTIO_F_VERSION_1,
54     VHOST_INVALID_FEATURE_BIT
55 };
56 
57 /* Features supported by others. */
58 static const int user_feature_bits[] = {
59     VIRTIO_F_NOTIFY_ON_EMPTY,
60     VIRTIO_RING_F_INDIRECT_DESC,
61     VIRTIO_RING_F_EVENT_IDX,
62 
63     VIRTIO_F_ANY_LAYOUT,
64     VIRTIO_F_VERSION_1,
65     VIRTIO_NET_F_CSUM,
66     VIRTIO_NET_F_GUEST_CSUM,
67     VIRTIO_NET_F_GSO,
68     VIRTIO_NET_F_GUEST_TSO4,
69     VIRTIO_NET_F_GUEST_TSO6,
70     VIRTIO_NET_F_GUEST_ECN,
71     VIRTIO_NET_F_GUEST_UFO,
72     VIRTIO_NET_F_HOST_TSO4,
73     VIRTIO_NET_F_HOST_TSO6,
74     VIRTIO_NET_F_HOST_ECN,
75     VIRTIO_NET_F_HOST_UFO,
76     VIRTIO_NET_F_MRG_RXBUF,
77 
78     /* This bit implies RARP isn't sent by QEMU out of band */
79     VIRTIO_NET_F_GUEST_ANNOUNCE,
80 
81     VIRTIO_NET_F_MQ,
82 
83     VHOST_INVALID_FEATURE_BIT
84 };
85 
86 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
87 {
88     const int *feature_bits = 0;
89 
90     switch (net->nc->info->type) {
91     case NET_CLIENT_DRIVER_TAP:
92         feature_bits = kernel_feature_bits;
93         break;
94     case NET_CLIENT_DRIVER_VHOST_USER:
95         feature_bits = user_feature_bits;
96         break;
97     default:
98         error_report("Feature bits not defined for this type: %d",
99                 net->nc->info->type);
100         break;
101     }
102 
103     return feature_bits;
104 }
105 
106 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
107 {
108     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
109             features);
110 }
111 
112 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
113 {
114     net->dev.acked_features = net->dev.backend_features;
115     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
116 }
117 
118 uint64_t vhost_net_get_max_queues(VHostNetState *net)
119 {
120     return net->dev.max_queues;
121 }
122 
123 uint64_t vhost_net_get_acked_features(VHostNetState *net)
124 {
125     return net->dev.acked_features;
126 }
127 
128 static int vhost_net_get_fd(NetClientState *backend)
129 {
130     switch (backend->info->type) {
131     case NET_CLIENT_DRIVER_TAP:
132         return tap_get_fd(backend);
133     default:
134         fprintf(stderr, "vhost-net requires tap backend\n");
135         return -EBADFD;
136     }
137 }
138 
139 struct vhost_net *vhost_net_init(VhostNetOptions *options)
140 {
141     int r;
142     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
143     struct vhost_net *net = g_new0(struct vhost_net, 1);
144     uint64_t features = 0;
145 
146     if (!options->net_backend) {
147         fprintf(stderr, "vhost-net requires net backend to be setup\n");
148         goto fail;
149     }
150     net->nc = options->net_backend;
151 
152     net->dev.max_queues = 1;
153     net->dev.nvqs = 2;
154     net->dev.vqs = net->vqs;
155 
156     if (backend_kernel) {
157         r = vhost_net_get_fd(options->net_backend);
158         if (r < 0) {
159             goto fail;
160         }
161         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
162             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
163         net->backend = r;
164         net->dev.protocol_features = 0;
165     } else {
166         net->dev.backend_features = 0;
167         net->dev.protocol_features = 0;
168         net->backend = -1;
169 
170         /* vhost-user needs vq_index to initiate a specific queue pair */
171         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
172     }
173 
174     r = vhost_dev_init(&net->dev, options->opaque,
175                        options->backend_type, options->busyloop_timeout);
176     if (r < 0) {
177         goto fail;
178     }
179     if (backend_kernel) {
180         if (!qemu_has_vnet_hdr_len(options->net_backend,
181                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
182             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
183         }
184         if (~net->dev.features & net->dev.backend_features) {
185             fprintf(stderr, "vhost lacks feature mask %" PRIu64
186                    " for backend\n",
187                    (uint64_t)(~net->dev.features & net->dev.backend_features));
188             goto fail;
189         }
190     }
191 
192     /* Set sane init value. Override when guest acks. */
193     if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
194         features = vhost_user_get_acked_features(net->nc);
195         if (~net->dev.features & features) {
196             fprintf(stderr, "vhost lacks feature mask %" PRIu64
197                     " for backend\n",
198                     (uint64_t)(~net->dev.features & features));
199             goto fail;
200         }
201     }
202 
203     vhost_net_ack_features(net, features);
204 
205     return net;
206 
207 fail:
208     vhost_dev_cleanup(&net->dev);
209     g_free(net);
210     return NULL;
211 }
212 
213 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
214 {
215     net->dev.vq_index = vq_index;
216 }
217 
218 static int vhost_net_start_one(struct vhost_net *net,
219                                VirtIODevice *dev)
220 {
221     struct vhost_vring_file file = { };
222     int r;
223 
224     net->dev.nvqs = 2;
225     net->dev.vqs = net->vqs;
226 
227     r = vhost_dev_enable_notifiers(&net->dev, dev);
228     if (r < 0) {
229         goto fail_notifiers;
230     }
231 
232     r = vhost_dev_start(&net->dev, dev);
233     if (r < 0) {
234         goto fail_start;
235     }
236 
237     if (net->nc->info->poll) {
238         net->nc->info->poll(net->nc, false);
239     }
240 
241     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
242         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
243         file.fd = net->backend;
244         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
245             r = vhost_net_set_backend(&net->dev, &file);
246             if (r < 0) {
247                 r = -errno;
248                 goto fail;
249             }
250         }
251     }
252     return 0;
253 fail:
254     file.fd = -1;
255     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
256         while (file.index-- > 0) {
257             int r = vhost_net_set_backend(&net->dev, &file);
258             assert(r >= 0);
259         }
260     }
261     if (net->nc->info->poll) {
262         net->nc->info->poll(net->nc, true);
263     }
264     vhost_dev_stop(&net->dev, dev);
265 fail_start:
266     vhost_dev_disable_notifiers(&net->dev, dev);
267 fail_notifiers:
268     return r;
269 }
270 
271 static void vhost_net_stop_one(struct vhost_net *net,
272                                VirtIODevice *dev)
273 {
274     struct vhost_vring_file file = { .fd = -1 };
275 
276     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
277         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
278             int r = vhost_net_set_backend(&net->dev, &file);
279             assert(r >= 0);
280         }
281     }
282     if (net->nc->info->poll) {
283         net->nc->info->poll(net->nc, true);
284     }
285     vhost_dev_stop(&net->dev, dev);
286     vhost_dev_disable_notifiers(&net->dev, dev);
287 }
288 
289 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
290                     int total_queues)
291 {
292     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
293     VirtioBusState *vbus = VIRTIO_BUS(qbus);
294     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
295     int r, e, i;
296 
297     if (!k->set_guest_notifiers) {
298         error_report("binding does not support guest notifiers");
299         return -ENOSYS;
300     }
301 
302     for (i = 0; i < total_queues; i++) {
303         struct vhost_net *net;
304 
305         net = get_vhost_net(ncs[i].peer);
306         vhost_net_set_vq_index(net, i * 2);
307 
308         /* Suppress the masking guest notifiers on vhost user
309          * because vhost user doesn't interrupt masking/unmasking
310          * properly.
311          */
312         if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
313             dev->use_guest_notifier_mask = false;
314         }
315      }
316 
317     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
318     if (r < 0) {
319         error_report("Error binding guest notifier: %d", -r);
320         goto err;
321     }
322 
323     for (i = 0; i < total_queues; i++) {
324         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
325 
326         if (r < 0) {
327             goto err_start;
328         }
329 
330         if (ncs[i].peer->vring_enable) {
331             /* restore vring enable state */
332             r = vhost_set_vring_enable(ncs[i].peer, ncs[i].peer->vring_enable);
333 
334             if (r < 0) {
335                 goto err_start;
336             }
337         }
338     }
339 
340     return 0;
341 
342 err_start:
343     while (--i >= 0) {
344         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
345     }
346     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
347     if (e < 0) {
348         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
349         fflush(stderr);
350     }
351 err:
352     return r;
353 }
354 
355 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
356                     int total_queues)
357 {
358     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
359     VirtioBusState *vbus = VIRTIO_BUS(qbus);
360     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
361     int i, r;
362 
363     for (i = 0; i < total_queues; i++) {
364         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
365     }
366 
367     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
368     if (r < 0) {
369         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
370         fflush(stderr);
371     }
372     assert(r >= 0);
373 }
374 
375 void vhost_net_cleanup(struct vhost_net *net)
376 {
377     vhost_dev_cleanup(&net->dev);
378 }
379 
380 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
381 {
382     const VhostOps *vhost_ops = net->dev.vhost_ops;
383 
384     assert(vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
385     assert(vhost_ops->vhost_migration_done);
386 
387     return vhost_ops->vhost_migration_done(&net->dev, mac_addr);
388 }
389 
390 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
391 {
392     return vhost_virtqueue_pending(&net->dev, idx);
393 }
394 
395 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
396                               int idx, bool mask)
397 {
398     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
399 }
400 
401 VHostNetState *get_vhost_net(NetClientState *nc)
402 {
403     VHostNetState *vhost_net = 0;
404 
405     if (!nc) {
406         return 0;
407     }
408 
409     switch (nc->info->type) {
410     case NET_CLIENT_DRIVER_TAP:
411         vhost_net = tap_get_vhost_net(nc);
412         break;
413     case NET_CLIENT_DRIVER_VHOST_USER:
414         vhost_net = vhost_user_get_vhost_net(nc);
415         assert(vhost_net);
416         break;
417     default:
418         break;
419     }
420 
421     return vhost_net;
422 }
423 
424 int vhost_set_vring_enable(NetClientState *nc, int enable)
425 {
426     VHostNetState *net = get_vhost_net(nc);
427     const VhostOps *vhost_ops = net->dev.vhost_ops;
428 
429     nc->vring_enable = enable;
430 
431     if (vhost_ops && vhost_ops->vhost_set_vring_enable) {
432         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
433     }
434 
435     return 0;
436 }
437 
438 #else
439 uint64_t vhost_net_get_max_queues(VHostNetState *net)
440 {
441     return 1;
442 }
443 
444 struct vhost_net *vhost_net_init(VhostNetOptions *options)
445 {
446     error_report("vhost-net support is not compiled in");
447     return NULL;
448 }
449 
450 int vhost_net_start(VirtIODevice *dev,
451                     NetClientState *ncs,
452                     int total_queues)
453 {
454     return -ENOSYS;
455 }
456 void vhost_net_stop(VirtIODevice *dev,
457                     NetClientState *ncs,
458                     int total_queues)
459 {
460 }
461 
462 void vhost_net_cleanup(struct vhost_net *net)
463 {
464 }
465 
466 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
467 {
468     return features;
469 }
470 
471 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
472 {
473 }
474 
475 uint64_t vhost_net_get_acked_features(VHostNetState *net)
476 {
477     return 0;
478 }
479 
480 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
481 {
482     return false;
483 }
484 
485 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
486                               int idx, bool mask)
487 {
488 }
489 
490 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
491 {
492     return -1;
493 }
494 
495 VHostNetState *get_vhost_net(NetClientState *nc)
496 {
497     return 0;
498 }
499 
500 int vhost_set_vring_enable(NetClientState *nc, int enable)
501 {
502     return 0;
503 }
504 #endif
505