xref: /openbmc/qemu/hw/net/vhost_net.c (revision 91bfcdb0) 
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 "net/net.h"
17 #include "net/tap.h"
18 #include "net/vhost-user.h"
19 
20 #include "hw/virtio/virtio-net.h"
21 #include "net/vhost_net.h"
22 #include "qemu/error-report.h"
23 
24 #include "config.h"
25 
26 #ifdef CONFIG_VHOST_NET
27 #include <linux/vhost.h>
28 #include <sys/socket.h>
29 #include <linux/kvm.h>
30 #include <fcntl.h>
31 #include <netpacket/packet.h>
32 #include <net/ethernet.h>
33 #include <net/if.h>
34 #include <netinet/in.h>
35 
36 #include <stdio.h>
37 
38 #include "standard-headers/linux/virtio_ring.h"
39 #include "hw/virtio/vhost.h"
40 #include "hw/virtio/virtio-bus.h"
41 #include "hw/virtio/virtio-access.h"
42 
43 struct vhost_net {
44     struct vhost_dev dev;
45     struct vhost_virtqueue vqs[2];
46     int backend;
47     NetClientState *nc;
48 };
49 
50 /* Features supported by host kernel. */
51 static const int kernel_feature_bits[] = {
52     VIRTIO_F_NOTIFY_ON_EMPTY,
53     VIRTIO_RING_F_INDIRECT_DESC,
54     VIRTIO_RING_F_EVENT_IDX,
55     VIRTIO_NET_F_MRG_RXBUF,
56     VIRTIO_F_VERSION_1,
57     VHOST_INVALID_FEATURE_BIT
58 };
59 
60 /* Features supported by others. */
61 static const int user_feature_bits[] = {
62     VIRTIO_F_NOTIFY_ON_EMPTY,
63     VIRTIO_RING_F_INDIRECT_DESC,
64     VIRTIO_RING_F_EVENT_IDX,
65 
66     VIRTIO_F_ANY_LAYOUT,
67     VIRTIO_F_VERSION_1,
68     VIRTIO_NET_F_CSUM,
69     VIRTIO_NET_F_GUEST_CSUM,
70     VIRTIO_NET_F_GSO,
71     VIRTIO_NET_F_GUEST_TSO4,
72     VIRTIO_NET_F_GUEST_TSO6,
73     VIRTIO_NET_F_GUEST_ECN,
74     VIRTIO_NET_F_GUEST_UFO,
75     VIRTIO_NET_F_HOST_TSO4,
76     VIRTIO_NET_F_HOST_TSO6,
77     VIRTIO_NET_F_HOST_ECN,
78     VIRTIO_NET_F_HOST_UFO,
79     VIRTIO_NET_F_MRG_RXBUF,
80     VIRTIO_NET_F_STATUS,
81     VIRTIO_NET_F_CTRL_VQ,
82     VIRTIO_NET_F_CTRL_RX,
83     VIRTIO_NET_F_CTRL_VLAN,
84     VIRTIO_NET_F_CTRL_RX_EXTRA,
85     VIRTIO_NET_F_CTRL_MAC_ADDR,
86     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
87 
88     VIRTIO_NET_F_GUEST_ANNOUNCE,
89 
90     VIRTIO_NET_F_MQ,
91 
92     VHOST_INVALID_FEATURE_BIT
93 };
94 
95 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
96 {
97     const int *feature_bits = 0;
98 
99     switch (net->nc->info->type) {
100     case NET_CLIENT_OPTIONS_KIND_TAP:
101         feature_bits = kernel_feature_bits;
102         break;
103     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
104         feature_bits = user_feature_bits;
105         break;
106     default:
107         error_report("Feature bits not defined for this type: %d",
108                 net->nc->info->type);
109         break;
110     }
111 
112     return feature_bits;
113 }
114 
115 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
116 {
117     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
118             features);
119 }
120 
121 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
122 {
123     net->dev.acked_features = net->dev.backend_features;
124     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
125 }
126 
127 uint64_t vhost_net_get_max_queues(VHostNetState *net)
128 {
129     return net->dev.max_queues;
130 }
131 
132 static int vhost_net_get_fd(NetClientState *backend)
133 {
134     switch (backend->info->type) {
135     case NET_CLIENT_OPTIONS_KIND_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_malloc(sizeof *net);
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);
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             vhost_dev_cleanup(&net->dev);
192             goto fail;
193         }
194     }
195     /* Set sane init value. Override when guest acks. */
196     vhost_net_ack_features(net, 0);
197     return net;
198 fail:
199     g_free(net);
200     return NULL;
201 }
202 
203 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
204 {
205     net->dev.vq_index = vq_index;
206 }
207 
208 static int vhost_net_set_vnet_endian(VirtIODevice *dev, NetClientState *peer,
209                                      bool set)
210 {
211     int r = 0;
212 
213     if (virtio_vdev_has_feature(dev, VIRTIO_F_VERSION_1) ||
214         (virtio_legacy_is_cross_endian(dev) && !virtio_is_big_endian(dev))) {
215         r = qemu_set_vnet_le(peer, set);
216         if (r) {
217             error_report("backend does not support LE vnet headers");
218         }
219     } else if (virtio_legacy_is_cross_endian(dev)) {
220         r = qemu_set_vnet_be(peer, set);
221         if (r) {
222             error_report("backend does not support BE vnet headers");
223         }
224     }
225 
226     return r;
227 }
228 
229 static int vhost_net_start_one(struct vhost_net *net,
230                                VirtIODevice *dev)
231 {
232     struct vhost_vring_file file = { };
233     int r;
234 
235     net->dev.nvqs = 2;
236     net->dev.vqs = net->vqs;
237 
238     r = vhost_dev_enable_notifiers(&net->dev, dev);
239     if (r < 0) {
240         goto fail_notifiers;
241     }
242 
243     r = vhost_dev_start(&net->dev, dev);
244     if (r < 0) {
245         goto fail_start;
246     }
247 
248     if (net->nc->info->poll) {
249         net->nc->info->poll(net->nc, false);
250     }
251 
252     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
253         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
254         file.fd = net->backend;
255         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
256             const VhostOps *vhost_ops = net->dev.vhost_ops;
257             r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
258             if (r < 0) {
259                 r = -errno;
260                 goto fail;
261             }
262         }
263     }
264     return 0;
265 fail:
266     file.fd = -1;
267     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
268         while (file.index-- > 0) {
269             const VhostOps *vhost_ops = net->dev.vhost_ops;
270             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
271             assert(r >= 0);
272         }
273     }
274     if (net->nc->info->poll) {
275         net->nc->info->poll(net->nc, true);
276     }
277     vhost_dev_stop(&net->dev, dev);
278 fail_start:
279     vhost_dev_disable_notifiers(&net->dev, dev);
280 fail_notifiers:
281     return r;
282 }
283 
284 static void vhost_net_stop_one(struct vhost_net *net,
285                                VirtIODevice *dev)
286 {
287     struct vhost_vring_file file = { .fd = -1 };
288 
289     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
290         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
291             const VhostOps *vhost_ops = net->dev.vhost_ops;
292             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
293             assert(r >= 0);
294         }
295     } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
296         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
297             const VhostOps *vhost_ops = net->dev.vhost_ops;
298             int r = vhost_ops->vhost_reset_device(&net->dev);
299             assert(r >= 0);
300         }
301     }
302     if (net->nc->info->poll) {
303         net->nc->info->poll(net->nc, true);
304     }
305     vhost_dev_stop(&net->dev, dev);
306     vhost_dev_disable_notifiers(&net->dev, dev);
307 }
308 
309 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
310                     int total_queues)
311 {
312     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
313     VirtioBusState *vbus = VIRTIO_BUS(qbus);
314     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
315     int r, e, i;
316 
317     if (!k->set_guest_notifiers) {
318         error_report("binding does not support guest notifiers");
319         r = -ENOSYS;
320         goto err;
321     }
322 
323     r = vhost_net_set_vnet_endian(dev, ncs[0].peer, true);
324     if (r < 0) {
325         goto err;
326     }
327 
328     for (i = 0; i < total_queues; i++) {
329         vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
330     }
331 
332     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
333     if (r < 0) {
334         error_report("Error binding guest notifier: %d", -r);
335         goto err_endian;
336     }
337 
338     for (i = 0; i < total_queues; i++) {
339         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
340 
341         if (r < 0) {
342             goto err_start;
343         }
344     }
345 
346     return 0;
347 
348 err_start:
349     while (--i >= 0) {
350         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
351     }
352     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
353     if (e < 0) {
354         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
355         fflush(stderr);
356     }
357 err_endian:
358     vhost_net_set_vnet_endian(dev, ncs[0].peer, false);
359 err:
360     return r;
361 }
362 
363 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
364                     int total_queues)
365 {
366     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
367     VirtioBusState *vbus = VIRTIO_BUS(qbus);
368     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
369     int i, r;
370 
371     for (i = 0; i < total_queues; i++) {
372         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
373     }
374 
375     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
376     if (r < 0) {
377         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
378         fflush(stderr);
379     }
380     assert(r >= 0);
381 
382     assert(vhost_net_set_vnet_endian(dev, ncs[0].peer, false) >= 0);
383 }
384 
385 void vhost_net_cleanup(struct vhost_net *net)
386 {
387     vhost_dev_cleanup(&net->dev);
388     g_free(net);
389 }
390 
391 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
392 {
393     const VhostOps *vhost_ops = net->dev.vhost_ops;
394     int r = -1;
395 
396     if (vhost_ops->vhost_migration_done) {
397         r = vhost_ops->vhost_migration_done(&net->dev, mac_addr);
398     }
399 
400     return r;
401 }
402 
403 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
404 {
405     return vhost_virtqueue_pending(&net->dev, idx);
406 }
407 
408 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
409                               int idx, bool mask)
410 {
411     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
412 }
413 
414 VHostNetState *get_vhost_net(NetClientState *nc)
415 {
416     VHostNetState *vhost_net = 0;
417 
418     if (!nc) {
419         return 0;
420     }
421 
422     switch (nc->info->type) {
423     case NET_CLIENT_OPTIONS_KIND_TAP:
424         vhost_net = tap_get_vhost_net(nc);
425         break;
426     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
427         vhost_net = vhost_user_get_vhost_net(nc);
428         break;
429     default:
430         break;
431     }
432 
433     return vhost_net;
434 }
435 
436 int vhost_set_vring_enable(NetClientState *nc, int enable)
437 {
438     VHostNetState *net = get_vhost_net(nc);
439     const VhostOps *vhost_ops = net->dev.vhost_ops;
440 
441     if (vhost_ops->vhost_set_vring_enable) {
442         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
443     }
444 
445     return 0;
446 }
447 
448 #else
449 uint64_t vhost_net_get_max_queues(VHostNetState *net)
450 {
451     return 1;
452 }
453 
454 struct vhost_net *vhost_net_init(VhostNetOptions *options)
455 {
456     error_report("vhost-net support is not compiled in");
457     return NULL;
458 }
459 
460 int vhost_net_start(VirtIODevice *dev,
461                     NetClientState *ncs,
462                     int total_queues)
463 {
464     return -ENOSYS;
465 }
466 void vhost_net_stop(VirtIODevice *dev,
467                     NetClientState *ncs,
468                     int total_queues)
469 {
470 }
471 
472 void vhost_net_cleanup(struct vhost_net *net)
473 {
474 }
475 
476 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
477 {
478     return features;
479 }
480 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
481 {
482 }
483 
484 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
485 {
486     return false;
487 }
488 
489 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
490                               int idx, bool mask)
491 {
492 }
493 
494 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
495 {
496     return -1;
497 }
498 
499 VHostNetState *get_vhost_net(NetClientState *nc)
500 {
501     return 0;
502 }
503 
504 int vhost_set_vring_enable(NetClientState *nc, int enable)
505 {
506     return 0;
507 }
508 #endif
509