xref: /qemu/hw/net/vhost_net.c (revision bb12e761e8e7b5c3c3d77bd08de9f007727a941e) 
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             const VhostOps *vhost_ops = net->dev.vhost_ops;
246             r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
247             if (r < 0) {
248                 r = -errno;
249                 goto fail;
250             }
251         }
252     }
253     return 0;
254 fail:
255     file.fd = -1;
256     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
257         while (file.index-- > 0) {
258             const VhostOps *vhost_ops = net->dev.vhost_ops;
259             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
260             assert(r >= 0);
261         }
262     }
263     if (net->nc->info->poll) {
264         net->nc->info->poll(net->nc, true);
265     }
266     vhost_dev_stop(&net->dev, dev);
267 fail_start:
268     vhost_dev_disable_notifiers(&net->dev, dev);
269 fail_notifiers:
270     return r;
271 }
272 
273 static void vhost_net_stop_one(struct vhost_net *net,
274                                VirtIODevice *dev)
275 {
276     struct vhost_vring_file file = { .fd = -1 };
277 
278     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
279         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
280             const VhostOps *vhost_ops = net->dev.vhost_ops;
281             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
282             assert(r >= 0);
283         }
284     }
285     if (net->nc->info->poll) {
286         net->nc->info->poll(net->nc, true);
287     }
288     vhost_dev_stop(&net->dev, dev);
289     vhost_dev_disable_notifiers(&net->dev, dev);
290 }
291 
292 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
293                     int total_queues)
294 {
295     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
296     VirtioBusState *vbus = VIRTIO_BUS(qbus);
297     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
298     int r, e, i;
299 
300     if (!k->set_guest_notifiers) {
301         error_report("binding does not support guest notifiers");
302         return -ENOSYS;
303     }
304 
305     for (i = 0; i < total_queues; i++) {
306         struct vhost_net *net;
307 
308         net = get_vhost_net(ncs[i].peer);
309         vhost_net_set_vq_index(net, i * 2);
310 
311         /* Suppress the masking guest notifiers on vhost user
312          * because vhost user doesn't interrupt masking/unmasking
313          * properly.
314          */
315         if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
316             dev->use_guest_notifier_mask = false;
317         }
318      }
319 
320     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
321     if (r < 0) {
322         error_report("Error binding guest notifier: %d", -r);
323         goto err;
324     }
325 
326     for (i = 0; i < total_queues; i++) {
327         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
328 
329         if (r < 0) {
330             goto err_start;
331         }
332 
333         if (ncs[i].peer->vring_enable) {
334             /* restore vring enable state */
335             r = vhost_set_vring_enable(ncs[i].peer, ncs[i].peer->vring_enable);
336 
337             if (r < 0) {
338                 goto err_start;
339             }
340         }
341     }
342 
343     return 0;
344 
345 err_start:
346     while (--i >= 0) {
347         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
348     }
349     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
350     if (e < 0) {
351         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
352         fflush(stderr);
353     }
354 err:
355     return r;
356 }
357 
358 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
359                     int total_queues)
360 {
361     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
362     VirtioBusState *vbus = VIRTIO_BUS(qbus);
363     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
364     int i, r;
365 
366     for (i = 0; i < total_queues; i++) {
367         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
368     }
369 
370     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
371     if (r < 0) {
372         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
373         fflush(stderr);
374     }
375     assert(r >= 0);
376 }
377 
378 void vhost_net_cleanup(struct vhost_net *net)
379 {
380     vhost_dev_cleanup(&net->dev);
381 }
382 
383 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
384 {
385     const VhostOps *vhost_ops = net->dev.vhost_ops;
386     int r = -1;
387 
388     if (vhost_ops->vhost_migration_done) {
389         r = vhost_ops->vhost_migration_done(&net->dev, mac_addr);
390     }
391 
392     return r;
393 }
394 
395 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
396 {
397     return vhost_virtqueue_pending(&net->dev, idx);
398 }
399 
400 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
401                               int idx, bool mask)
402 {
403     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
404 }
405 
406 VHostNetState *get_vhost_net(NetClientState *nc)
407 {
408     VHostNetState *vhost_net = 0;
409 
410     if (!nc) {
411         return 0;
412     }
413 
414     switch (nc->info->type) {
415     case NET_CLIENT_DRIVER_TAP:
416         vhost_net = tap_get_vhost_net(nc);
417         break;
418     case NET_CLIENT_DRIVER_VHOST_USER:
419         vhost_net = vhost_user_get_vhost_net(nc);
420         assert(vhost_net);
421         break;
422     default:
423         break;
424     }
425 
426     return vhost_net;
427 }
428 
429 int vhost_set_vring_enable(NetClientState *nc, int enable)
430 {
431     VHostNetState *net = get_vhost_net(nc);
432     const VhostOps *vhost_ops = net->dev.vhost_ops;
433 
434     nc->vring_enable = enable;
435 
436     if (vhost_ops->vhost_set_vring_enable) {
437         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
438     }
439 
440     return 0;
441 }
442 
443 #else
444 uint64_t vhost_net_get_max_queues(VHostNetState *net)
445 {
446     return 1;
447 }
448 
449 struct vhost_net *vhost_net_init(VhostNetOptions *options)
450 {
451     error_report("vhost-net support is not compiled in");
452     return NULL;
453 }
454 
455 int vhost_net_start(VirtIODevice *dev,
456                     NetClientState *ncs,
457                     int total_queues)
458 {
459     return -ENOSYS;
460 }
461 void vhost_net_stop(VirtIODevice *dev,
462                     NetClientState *ncs,
463                     int total_queues)
464 {
465 }
466 
467 void vhost_net_cleanup(struct vhost_net *net)
468 {
469 }
470 
471 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
472 {
473     return features;
474 }
475 
476 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
477 {
478 }
479 
480 uint64_t vhost_net_get_acked_features(VHostNetState *net)
481 {
482     return 0;
483 }
484 
485 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
486 {
487     return false;
488 }
489 
490 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
491                               int idx, bool mask)
492 {
493 }
494 
495 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
496 {
497     return -1;
498 }
499 
500 VHostNetState *get_vhost_net(NetClientState *nc)
501 {
502     return 0;
503 }
504 
505 int vhost_set_vring_enable(NetClientState *nc, int enable)
506 {
507     return 0;
508 }
509 #endif
510