xref: /qemu/hw/net/vhost_net.c (revision 6402cbbb) 
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     VIRTIO_F_IOMMU_PLATFORM,
81 
82     /* This bit implies RARP isn't sent by QEMU out of band */
83     VIRTIO_NET_F_GUEST_ANNOUNCE,
84 
85     VIRTIO_NET_F_MQ,
86 
87     VHOST_INVALID_FEATURE_BIT
88 };
89 
90 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
91 {
92     const int *feature_bits = 0;
93 
94     switch (net->nc->info->type) {
95     case NET_CLIENT_DRIVER_TAP:
96         feature_bits = kernel_feature_bits;
97         break;
98     case NET_CLIENT_DRIVER_VHOST_USER:
99         feature_bits = user_feature_bits;
100         break;
101     default:
102         error_report("Feature bits not defined for this type: %d",
103                 net->nc->info->type);
104         break;
105     }
106 
107     return feature_bits;
108 }
109 
110 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
111 {
112     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
113             features);
114 }
115 
116 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
117 {
118     net->dev.acked_features = net->dev.backend_features;
119     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
120 }
121 
122 uint64_t vhost_net_get_max_queues(VHostNetState *net)
123 {
124     return net->dev.max_queues;
125 }
126 
127 uint64_t vhost_net_get_acked_features(VHostNetState *net)
128 {
129     return net->dev.acked_features;
130 }
131 
132 static int vhost_net_get_fd(NetClientState *backend)
133 {
134     switch (backend->info->type) {
135     case NET_CLIENT_DRIVER_TAP:
136         return tap_get_fd(backend);
137     default:
138         fprintf(stderr, "vhost-net requires tap backend\n");
139         return -EBADFD;
140     }
141 }
142 
143 struct vhost_net *vhost_net_init(VhostNetOptions *options)
144 {
145     int r;
146     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
147     struct vhost_net *net = g_new0(struct vhost_net, 1);
148     uint64_t features = 0;
149 
150     if (!options->net_backend) {
151         fprintf(stderr, "vhost-net requires net backend to be setup\n");
152         goto fail;
153     }
154     net->nc = options->net_backend;
155 
156     net->dev.max_queues = 1;
157     net->dev.nvqs = 2;
158     net->dev.vqs = net->vqs;
159 
160     if (backend_kernel) {
161         r = vhost_net_get_fd(options->net_backend);
162         if (r < 0) {
163             goto fail;
164         }
165         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
166             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
167         net->backend = r;
168         net->dev.protocol_features = 0;
169     } else {
170         net->dev.backend_features = 0;
171         net->dev.protocol_features = 0;
172         net->backend = -1;
173 
174         /* vhost-user needs vq_index to initiate a specific queue pair */
175         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
176     }
177 
178     r = vhost_dev_init(&net->dev, options->opaque,
179                        options->backend_type, options->busyloop_timeout);
180     if (r < 0) {
181         goto fail;
182     }
183     if (backend_kernel) {
184         if (!qemu_has_vnet_hdr_len(options->net_backend,
185                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
186             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
187         }
188         if (~net->dev.features & net->dev.backend_features) {
189             fprintf(stderr, "vhost lacks feature mask %" PRIu64
190                    " for backend\n",
191                    (uint64_t)(~net->dev.features & net->dev.backend_features));
192             goto fail;
193         }
194     }
195 
196     /* Set sane init value. Override when guest acks. */
197     if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
198         features = vhost_user_get_acked_features(net->nc);
199         if (~net->dev.features & features) {
200             fprintf(stderr, "vhost lacks feature mask %" PRIu64
201                     " for backend\n",
202                     (uint64_t)(~net->dev.features & features));
203             goto fail;
204         }
205     }
206 
207     vhost_net_ack_features(net, features);
208 
209     return net;
210 
211 fail:
212     vhost_dev_cleanup(&net->dev);
213     g_free(net);
214     return NULL;
215 }
216 
217 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
218 {
219     net->dev.vq_index = vq_index;
220 }
221 
222 static int vhost_net_start_one(struct vhost_net *net,
223                                VirtIODevice *dev)
224 {
225     struct vhost_vring_file file = { };
226     int r;
227 
228     net->dev.nvqs = 2;
229     net->dev.vqs = net->vqs;
230 
231     r = vhost_dev_enable_notifiers(&net->dev, dev);
232     if (r < 0) {
233         goto fail_notifiers;
234     }
235 
236     r = vhost_dev_start(&net->dev, dev);
237     if (r < 0) {
238         goto fail_start;
239     }
240 
241     if (net->nc->info->poll) {
242         net->nc->info->poll(net->nc, false);
243     }
244 
245     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
246         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
247         file.fd = net->backend;
248         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
249             r = vhost_net_set_backend(&net->dev, &file);
250             if (r < 0) {
251                 r = -errno;
252                 goto fail;
253             }
254         }
255     }
256     return 0;
257 fail:
258     file.fd = -1;
259     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
260         while (file.index-- > 0) {
261             int r = vhost_net_set_backend(&net->dev, &file);
262             assert(r >= 0);
263         }
264     }
265     if (net->nc->info->poll) {
266         net->nc->info->poll(net->nc, true);
267     }
268     vhost_dev_stop(&net->dev, dev);
269 fail_start:
270     vhost_dev_disable_notifiers(&net->dev, dev);
271 fail_notifiers:
272     return r;
273 }
274 
275 static void vhost_net_stop_one(struct vhost_net *net,
276                                VirtIODevice *dev)
277 {
278     struct vhost_vring_file file = { .fd = -1 };
279 
280     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
281         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
282             int r = vhost_net_set_backend(&net->dev, &file);
283             assert(r >= 0);
284         }
285     }
286     if (net->nc->info->poll) {
287         net->nc->info->poll(net->nc, true);
288     }
289     vhost_dev_stop(&net->dev, dev);
290     vhost_dev_disable_notifiers(&net->dev, dev);
291 }
292 
293 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
294                     int total_queues)
295 {
296     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
297     VirtioBusState *vbus = VIRTIO_BUS(qbus);
298     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
299     int r, e, i;
300 
301     if (!k->set_guest_notifiers) {
302         error_report("binding does not support guest notifiers");
303         return -ENOSYS;
304     }
305 
306     for (i = 0; i < total_queues; i++) {
307         struct vhost_net *net;
308 
309         net = get_vhost_net(ncs[i].peer);
310         vhost_net_set_vq_index(net, i * 2);
311 
312         /* Suppress the masking guest notifiers on vhost user
313          * because vhost user doesn't interrupt masking/unmasking
314          * properly.
315          */
316         if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
317             dev->use_guest_notifier_mask = false;
318         }
319      }
320 
321     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
322     if (r < 0) {
323         error_report("Error binding guest notifier: %d", -r);
324         goto err;
325     }
326 
327     for (i = 0; i < total_queues; i++) {
328         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
329 
330         if (r < 0) {
331             goto err_start;
332         }
333 
334         if (ncs[i].peer->vring_enable) {
335             /* restore vring enable state */
336             r = vhost_set_vring_enable(ncs[i].peer, ncs[i].peer->vring_enable);
337 
338             if (r < 0) {
339                 goto err_start;
340             }
341         }
342     }
343 
344     return 0;
345 
346 err_start:
347     while (--i >= 0) {
348         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
349     }
350     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
351     if (e < 0) {
352         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
353         fflush(stderr);
354     }
355 err:
356     return r;
357 }
358 
359 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
360                     int total_queues)
361 {
362     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
363     VirtioBusState *vbus = VIRTIO_BUS(qbus);
364     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
365     int i, r;
366 
367     for (i = 0; i < total_queues; i++) {
368         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
369     }
370 
371     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
372     if (r < 0) {
373         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
374         fflush(stderr);
375     }
376     assert(r >= 0);
377 }
378 
379 void vhost_net_cleanup(struct vhost_net *net)
380 {
381     vhost_dev_cleanup(&net->dev);
382 }
383 
384 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
385 {
386     const VhostOps *vhost_ops = net->dev.vhost_ops;
387 
388     assert(vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
389     assert(vhost_ops->vhost_migration_done);
390 
391     return vhost_ops->vhost_migration_done(&net->dev, mac_addr);
392 }
393 
394 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
395 {
396     return vhost_virtqueue_pending(&net->dev, idx);
397 }
398 
399 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
400                               int idx, bool mask)
401 {
402     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
403 }
404 
405 VHostNetState *get_vhost_net(NetClientState *nc)
406 {
407     VHostNetState *vhost_net = 0;
408 
409     if (!nc) {
410         return 0;
411     }
412 
413     switch (nc->info->type) {
414     case NET_CLIENT_DRIVER_TAP:
415         vhost_net = tap_get_vhost_net(nc);
416         break;
417     case NET_CLIENT_DRIVER_VHOST_USER:
418         vhost_net = vhost_user_get_vhost_net(nc);
419         assert(vhost_net);
420         break;
421     default:
422         break;
423     }
424 
425     return vhost_net;
426 }
427 
428 int vhost_set_vring_enable(NetClientState *nc, int enable)
429 {
430     VHostNetState *net = get_vhost_net(nc);
431     const VhostOps *vhost_ops = net->dev.vhost_ops;
432 
433     nc->vring_enable = enable;
434 
435     if (vhost_ops && vhost_ops->vhost_set_vring_enable) {
436         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
437     }
438 
439     return 0;
440 }
441 
442 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
443 {
444     const VhostOps *vhost_ops = net->dev.vhost_ops;
445 
446     if (!vhost_ops->vhost_net_set_mtu) {
447         return 0;
448     }
449 
450     return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
451 }
452 
453 #else
454 uint64_t vhost_net_get_max_queues(VHostNetState *net)
455 {
456     return 1;
457 }
458 
459 struct vhost_net *vhost_net_init(VhostNetOptions *options)
460 {
461     error_report("vhost-net support is not compiled in");
462     return NULL;
463 }
464 
465 int vhost_net_start(VirtIODevice *dev,
466                     NetClientState *ncs,
467                     int total_queues)
468 {
469     return -ENOSYS;
470 }
471 void vhost_net_stop(VirtIODevice *dev,
472                     NetClientState *ncs,
473                     int total_queues)
474 {
475 }
476 
477 void vhost_net_cleanup(struct vhost_net *net)
478 {
479 }
480 
481 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
482 {
483     return features;
484 }
485 
486 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
487 {
488 }
489 
490 uint64_t vhost_net_get_acked_features(VHostNetState *net)
491 {
492     return 0;
493 }
494 
495 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
496 {
497     return false;
498 }
499 
500 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
501                               int idx, bool mask)
502 {
503 }
504 
505 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
506 {
507     return -1;
508 }
509 
510 VHostNetState *get_vhost_net(NetClientState *nc)
511 {
512     return 0;
513 }
514 
515 int vhost_set_vring_enable(NetClientState *nc, int enable)
516 {
517     return 0;
518 }
519 
520 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
521 {
522     return 0;
523 }
524 #endif
525