xref: /qemu/hw/net/vhost_net.c (revision 96d885b9) 
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_MQ,
89 
90     VHOST_INVALID_FEATURE_BIT
91 };
92 
93 static const int *vhost_net_get_feature_bits(struct vhost_net *net)
94 {
95     const int *feature_bits = 0;
96 
97     switch (net->nc->info->type) {
98     case NET_CLIENT_OPTIONS_KIND_TAP:
99         feature_bits = kernel_feature_bits;
100         break;
101     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
102         feature_bits = user_feature_bits;
103         break;
104     default:
105         error_report("Feature bits not defined for this type: %d",
106                 net->nc->info->type);
107         break;
108     }
109 
110     return feature_bits;
111 }
112 
113 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
114 {
115     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
116             features);
117 }
118 
119 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
120 {
121     net->dev.acked_features = net->dev.backend_features;
122     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
123 }
124 
125 uint64_t vhost_net_get_max_queues(VHostNetState *net)
126 {
127     return net->dev.max_queues;
128 }
129 
130 static int vhost_net_get_fd(NetClientState *backend)
131 {
132     switch (backend->info->type) {
133     case NET_CLIENT_OPTIONS_KIND_TAP:
134         return tap_get_fd(backend);
135     default:
136         fprintf(stderr, "vhost-net requires tap backend\n");
137         return -EBADFD;
138     }
139 }
140 
141 struct vhost_net *vhost_net_init(VhostNetOptions *options)
142 {
143     int r;
144     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
145     struct vhost_net *net = g_malloc(sizeof *net);
146 
147     if (!options->net_backend) {
148         fprintf(stderr, "vhost-net requires net backend to be setup\n");
149         goto fail;
150     }
151     net->nc = options->net_backend;
152 
153     net->dev.max_queues = 1;
154     net->dev.nvqs = 2;
155     net->dev.vqs = net->vqs;
156 
157     if (backend_kernel) {
158         r = vhost_net_get_fd(options->net_backend);
159         if (r < 0) {
160             goto fail;
161         }
162         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
163             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
164         net->backend = r;
165         net->dev.protocol_features = 0;
166     } else {
167         net->dev.backend_features = 0;
168         net->dev.protocol_features = 0;
169         net->backend = -1;
170 
171         /* vhost-user needs vq_index to initiate a specific queue pair */
172         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
173     }
174 
175     r = vhost_dev_init(&net->dev, options->opaque,
176                        options->backend_type);
177     if (r < 0) {
178         goto fail;
179     }
180     if (backend_kernel) {
181         if (!qemu_has_vnet_hdr_len(options->net_backend,
182                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
183             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
184         }
185         if (~net->dev.features & net->dev.backend_features) {
186             fprintf(stderr, "vhost lacks feature mask %" PRIu64
187                    " for backend\n",
188                    (uint64_t)(~net->dev.features & net->dev.backend_features));
189             vhost_dev_cleanup(&net->dev);
190             goto fail;
191         }
192     }
193     /* Set sane init value. Override when guest acks. */
194     vhost_net_ack_features(net, 0);
195     return net;
196 fail:
197     g_free(net);
198     return NULL;
199 }
200 
201 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
202 {
203     net->dev.vq_index = vq_index;
204 }
205 
206 static int vhost_net_set_vnet_endian(VirtIODevice *dev, NetClientState *peer,
207                                      bool set)
208 {
209     int r = 0;
210 
211     if (virtio_vdev_has_feature(dev, VIRTIO_F_VERSION_1) ||
212         (virtio_legacy_is_cross_endian(dev) && !virtio_is_big_endian(dev))) {
213         r = qemu_set_vnet_le(peer, set);
214         if (r) {
215             error_report("backend does not support LE vnet headers");
216         }
217     } else if (virtio_legacy_is_cross_endian(dev)) {
218         r = qemu_set_vnet_be(peer, set);
219         if (r) {
220             error_report("backend does not support BE vnet headers");
221         }
222     }
223 
224     return r;
225 }
226 
227 static int vhost_net_start_one(struct vhost_net *net,
228                                VirtIODevice *dev)
229 {
230     struct vhost_vring_file file = { };
231     int r;
232 
233     net->dev.nvqs = 2;
234     net->dev.vqs = net->vqs;
235 
236     r = vhost_dev_enable_notifiers(&net->dev, dev);
237     if (r < 0) {
238         goto fail_notifiers;
239     }
240 
241     r = vhost_dev_start(&net->dev, dev);
242     if (r < 0) {
243         goto fail_start;
244     }
245 
246     if (net->nc->info->poll) {
247         net->nc->info->poll(net->nc, false);
248     }
249 
250     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
251         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
252         file.fd = net->backend;
253         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
254             const VhostOps *vhost_ops = net->dev.vhost_ops;
255             r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
256                                       &file);
257             if (r < 0) {
258                 r = -errno;
259                 goto fail;
260             }
261         }
262     }
263     return 0;
264 fail:
265     file.fd = -1;
266     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
267         while (file.index-- > 0) {
268             const VhostOps *vhost_ops = net->dev.vhost_ops;
269             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
270                                           &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_call(&net->dev, VHOST_NET_SET_BACKEND,
293                                           &file);
294             assert(r >= 0);
295         }
296     } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
297         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
298             const VhostOps *vhost_ops = net->dev.vhost_ops;
299             int r = vhost_ops->vhost_call(&net->dev, VHOST_RESET_DEVICE,
300                                           NULL);
301             assert(r >= 0);
302         }
303     }
304     if (net->nc->info->poll) {
305         net->nc->info->poll(net->nc, true);
306     }
307     vhost_dev_stop(&net->dev, dev);
308     vhost_dev_disable_notifiers(&net->dev, dev);
309 }
310 
311 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
312                     int total_queues)
313 {
314     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
315     VirtioBusState *vbus = VIRTIO_BUS(qbus);
316     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
317     int r, e, i;
318 
319     if (!k->set_guest_notifiers) {
320         error_report("binding does not support guest notifiers");
321         r = -ENOSYS;
322         goto err;
323     }
324 
325     r = vhost_net_set_vnet_endian(dev, ncs[0].peer, true);
326     if (r < 0) {
327         goto err;
328     }
329 
330     for (i = 0; i < total_queues; i++) {
331         vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
332     }
333 
334     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
335     if (r < 0) {
336         error_report("Error binding guest notifier: %d", -r);
337         goto err_endian;
338     }
339 
340     for (i = 0; i < total_queues; i++) {
341         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
342 
343         if (r < 0) {
344             goto err_start;
345         }
346     }
347 
348     return 0;
349 
350 err_start:
351     while (--i >= 0) {
352         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
353     }
354     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
355     if (e < 0) {
356         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
357         fflush(stderr);
358     }
359 err_endian:
360     vhost_net_set_vnet_endian(dev, ncs[0].peer, false);
361 err:
362     return r;
363 }
364 
365 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
366                     int total_queues)
367 {
368     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
369     VirtioBusState *vbus = VIRTIO_BUS(qbus);
370     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
371     int i, r;
372 
373     for (i = 0; i < total_queues; i++) {
374         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
375     }
376 
377     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
378     if (r < 0) {
379         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
380         fflush(stderr);
381     }
382     assert(r >= 0);
383 
384     assert(vhost_net_set_vnet_endian(dev, ncs[0].peer, false) >= 0);
385 }
386 
387 void vhost_net_cleanup(struct vhost_net *net)
388 {
389     vhost_dev_cleanup(&net->dev);
390     g_free(net);
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_OPTIONS_KIND_TAP:
414         vhost_net = tap_get_vhost_net(nc);
415         break;
416     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
417         vhost_net = vhost_user_get_vhost_net(nc);
418         break;
419     default:
420         break;
421     }
422 
423     return vhost_net;
424 }
425 
426 int vhost_set_vring_enable(NetClientState *nc, int enable)
427 {
428     VHostNetState *net = get_vhost_net(nc);
429     const VhostOps *vhost_ops = net->dev.vhost_ops;
430 
431     if (vhost_ops->vhost_backend_set_vring_enable) {
432         return vhost_ops->vhost_backend_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 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
471 {
472 }
473 
474 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
475 {
476     return false;
477 }
478 
479 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
480                               int idx, bool mask)
481 {
482 }
483 
484 VHostNetState *get_vhost_net(NetClientState *nc)
485 {
486     return 0;
487 }
488 
489 int vhost_set_vring_enable(NetClientState *nc, int enable)
490 {
491     return 0;
492 }
493 #endif
494