xref: /qemu/hw/net/vhost_net.c (revision 20daa90a) 
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     VIRTIO_NET_F_MTU,
55     VIRTIO_F_IOMMU_PLATFORM,
56     VHOST_INVALID_FEATURE_BIT
57 };
58 
59 /* Features supported by others. */
60 static const int user_feature_bits[] = {
61     VIRTIO_F_NOTIFY_ON_EMPTY,
62     VIRTIO_RING_F_INDIRECT_DESC,
63     VIRTIO_RING_F_EVENT_IDX,
64 
65     VIRTIO_F_ANY_LAYOUT,
66     VIRTIO_F_VERSION_1,
67     VIRTIO_NET_F_CSUM,
68     VIRTIO_NET_F_GUEST_CSUM,
69     VIRTIO_NET_F_GSO,
70     VIRTIO_NET_F_GUEST_TSO4,
71     VIRTIO_NET_F_GUEST_TSO6,
72     VIRTIO_NET_F_GUEST_ECN,
73     VIRTIO_NET_F_GUEST_UFO,
74     VIRTIO_NET_F_HOST_TSO4,
75     VIRTIO_NET_F_HOST_TSO6,
76     VIRTIO_NET_F_HOST_ECN,
77     VIRTIO_NET_F_HOST_UFO,
78     VIRTIO_NET_F_MRG_RXBUF,
79     VIRTIO_NET_F_MTU,
80 
81     /* This bit implies RARP isn't sent by QEMU out of band */
82     VIRTIO_NET_F_GUEST_ANNOUNCE,
83 
84     VIRTIO_NET_F_MQ,
85 
86     VHOST_INVALID_FEATURE_BIT
87 };
88 
89 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
90 {
91     const int *feature_bits = 0;
92 
93     switch (net->nc->info->type) {
94     case NET_CLIENT_DRIVER_TAP:
95         feature_bits = kernel_feature_bits;
96         break;
97     case NET_CLIENT_DRIVER_VHOST_USER:
98         feature_bits = user_feature_bits;
99         break;
100     default:
101         error_report("Feature bits not defined for this type: %d",
102                 net->nc->info->type);
103         break;
104     }
105 
106     return feature_bits;
107 }
108 
109 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
110 {
111     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
112             features);
113 }
114 
115 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
116 {
117     net->dev.acked_features = net->dev.backend_features;
118     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
119 }
120 
121 uint64_t vhost_net_get_max_queues(VHostNetState *net)
122 {
123     return net->dev.max_queues;
124 }
125 
126 uint64_t vhost_net_get_acked_features(VHostNetState *net)
127 {
128     return net->dev.acked_features;
129 }
130 
131 static int vhost_net_get_fd(NetClientState *backend)
132 {
133     switch (backend->info->type) {
134     case NET_CLIENT_DRIVER_TAP:
135         return tap_get_fd(backend);
136     default:
137         fprintf(stderr, "vhost-net requires tap backend\n");
138         return -EBADFD;
139     }
140 }
141 
142 struct vhost_net *vhost_net_init(VhostNetOptions *options)
143 {
144     int r;
145     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
146     struct vhost_net *net = g_new0(struct vhost_net, 1);
147     uint64_t features = 0;
148 
149     if (!options->net_backend) {
150         fprintf(stderr, "vhost-net requires net backend to be setup\n");
151         goto fail;
152     }
153     net->nc = options->net_backend;
154 
155     net->dev.max_queues = 1;
156     net->dev.nvqs = 2;
157     net->dev.vqs = net->vqs;
158 
159     if (backend_kernel) {
160         r = vhost_net_get_fd(options->net_backend);
161         if (r < 0) {
162             goto fail;
163         }
164         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
165             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
166         net->backend = r;
167         net->dev.protocol_features = 0;
168     } else {
169         net->dev.backend_features = 0;
170         net->dev.protocol_features = 0;
171         net->backend = -1;
172 
173         /* vhost-user needs vq_index to initiate a specific queue pair */
174         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
175     }
176 
177     r = vhost_dev_init(&net->dev, options->opaque,
178                        options->backend_type, options->busyloop_timeout);
179     if (r < 0) {
180         goto fail;
181     }
182     if (backend_kernel) {
183         if (!qemu_has_vnet_hdr_len(options->net_backend,
184                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
185             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
186         }
187         if (~net->dev.features & net->dev.backend_features) {
188             fprintf(stderr, "vhost lacks feature mask %" PRIu64
189                    " for backend\n",
190                    (uint64_t)(~net->dev.features & net->dev.backend_features));
191             goto fail;
192         }
193     }
194 
195     /* Set sane init value. Override when guest acks. */
196     if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
197         features = vhost_user_get_acked_features(net->nc);
198         if (~net->dev.features & features) {
199             fprintf(stderr, "vhost lacks feature mask %" PRIu64
200                     " for backend\n",
201                     (uint64_t)(~net->dev.features & features));
202             goto fail;
203         }
204     }
205 
206     vhost_net_ack_features(net, features);
207 
208     return net;
209 
210 fail:
211     vhost_dev_cleanup(&net->dev);
212     g_free(net);
213     return NULL;
214 }
215 
216 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
217 {
218     net->dev.vq_index = vq_index;
219 }
220 
221 static int vhost_net_start_one(struct vhost_net *net,
222                                VirtIODevice *dev)
223 {
224     struct vhost_vring_file file = { };
225     int r;
226 
227     net->dev.nvqs = 2;
228     net->dev.vqs = net->vqs;
229 
230     r = vhost_dev_enable_notifiers(&net->dev, dev);
231     if (r < 0) {
232         goto fail_notifiers;
233     }
234 
235     r = vhost_dev_start(&net->dev, dev);
236     if (r < 0) {
237         goto fail_start;
238     }
239 
240     if (net->nc->info->poll) {
241         net->nc->info->poll(net->nc, false);
242     }
243 
244     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
245         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
246         file.fd = net->backend;
247         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
248             r = vhost_net_set_backend(&net->dev, &file);
249             if (r < 0) {
250                 r = -errno;
251                 goto fail;
252             }
253         }
254     }
255     return 0;
256 fail:
257     file.fd = -1;
258     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
259         while (file.index-- > 0) {
260             int r = vhost_net_set_backend(&net->dev, &file);
261             assert(r >= 0);
262         }
263     }
264     if (net->nc->info->poll) {
265         net->nc->info->poll(net->nc, true);
266     }
267     vhost_dev_stop(&net->dev, dev);
268 fail_start:
269     vhost_dev_disable_notifiers(&net->dev, dev);
270 fail_notifiers:
271     return r;
272 }
273 
274 static void vhost_net_stop_one(struct vhost_net *net,
275                                VirtIODevice *dev)
276 {
277     struct vhost_vring_file file = { .fd = -1 };
278 
279     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
280         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
281             int r = 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 
387     assert(vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
388     assert(vhost_ops->vhost_migration_done);
389 
390     return vhost_ops->vhost_migration_done(&net->dev, mac_addr);
391 }
392 
393 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
394 {
395     return vhost_virtqueue_pending(&net->dev, idx);
396 }
397 
398 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
399                               int idx, bool mask)
400 {
401     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
402 }
403 
404 VHostNetState *get_vhost_net(NetClientState *nc)
405 {
406     VHostNetState *vhost_net = 0;
407 
408     if (!nc) {
409         return 0;
410     }
411 
412     switch (nc->info->type) {
413     case NET_CLIENT_DRIVER_TAP:
414         vhost_net = tap_get_vhost_net(nc);
415         break;
416     case NET_CLIENT_DRIVER_VHOST_USER:
417         vhost_net = vhost_user_get_vhost_net(nc);
418         assert(vhost_net);
419         break;
420     default:
421         break;
422     }
423 
424     return vhost_net;
425 }
426 
427 int vhost_set_vring_enable(NetClientState *nc, int enable)
428 {
429     VHostNetState *net = get_vhost_net(nc);
430     const VhostOps *vhost_ops = net->dev.vhost_ops;
431 
432     nc->vring_enable = enable;
433 
434     if (vhost_ops && vhost_ops->vhost_set_vring_enable) {
435         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
436     }
437 
438     return 0;
439 }
440 
441 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
442 {
443     const VhostOps *vhost_ops = net->dev.vhost_ops;
444 
445     if (!vhost_ops->vhost_net_set_mtu) {
446         return 0;
447     }
448 
449     return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
450 }
451 
452 #else
453 uint64_t vhost_net_get_max_queues(VHostNetState *net)
454 {
455     return 1;
456 }
457 
458 struct vhost_net *vhost_net_init(VhostNetOptions *options)
459 {
460     error_report("vhost-net support is not compiled in");
461     return NULL;
462 }
463 
464 int vhost_net_start(VirtIODevice *dev,
465                     NetClientState *ncs,
466                     int total_queues)
467 {
468     return -ENOSYS;
469 }
470 void vhost_net_stop(VirtIODevice *dev,
471                     NetClientState *ncs,
472                     int total_queues)
473 {
474 }
475 
476 void vhost_net_cleanup(struct vhost_net *net)
477 {
478 }
479 
480 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
481 {
482     return features;
483 }
484 
485 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
486 {
487 }
488 
489 uint64_t vhost_net_get_acked_features(VHostNetState *net)
490 {
491     return 0;
492 }
493 
494 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
495 {
496     return false;
497 }
498 
499 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
500                               int idx, bool mask)
501 {
502 }
503 
504 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
505 {
506     return -1;
507 }
508 
509 VHostNetState *get_vhost_net(NetClientState *nc)
510 {
511     return 0;
512 }
513 
514 int vhost_set_vring_enable(NetClientState *nc, int enable)
515 {
516     return 0;
517 }
518 
519 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
520 {
521     return 0;
522 }
523 #endif
524