xref: /openbmc/qemu/hw/net/vhost_net.c (revision 30456d5b) 
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_OPTIONS_KIND_TAP:
92         feature_bits = kernel_feature_bits;
93         break;
94     case NET_CLIENT_OPTIONS_KIND_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 static int vhost_net_get_fd(NetClientState *backend)
124 {
125     switch (backend->info->type) {
126     case NET_CLIENT_OPTIONS_KIND_TAP:
127         return tap_get_fd(backend);
128     default:
129         fprintf(stderr, "vhost-net requires tap backend\n");
130         return -EBADFD;
131     }
132 }
133 
134 struct vhost_net *vhost_net_init(VhostNetOptions *options)
135 {
136     int r;
137     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
138     struct vhost_net *net = g_malloc(sizeof *net);
139 
140     if (!options->net_backend) {
141         fprintf(stderr, "vhost-net requires net backend to be setup\n");
142         goto fail;
143     }
144     net->nc = options->net_backend;
145 
146     net->dev.max_queues = 1;
147     net->dev.nvqs = 2;
148     net->dev.vqs = net->vqs;
149 
150     if (backend_kernel) {
151         r = vhost_net_get_fd(options->net_backend);
152         if (r < 0) {
153             goto fail;
154         }
155         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
156             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
157         net->backend = r;
158         net->dev.protocol_features = 0;
159     } else {
160         net->dev.backend_features = 0;
161         net->dev.protocol_features = 0;
162         net->backend = -1;
163 
164         /* vhost-user needs vq_index to initiate a specific queue pair */
165         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
166     }
167 
168     r = vhost_dev_init(&net->dev, options->opaque,
169                        options->backend_type);
170     if (r < 0) {
171         goto fail;
172     }
173     if (backend_kernel) {
174         if (!qemu_has_vnet_hdr_len(options->net_backend,
175                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
176             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
177         }
178         if (~net->dev.features & net->dev.backend_features) {
179             fprintf(stderr, "vhost lacks feature mask %" PRIu64
180                    " for backend\n",
181                    (uint64_t)(~net->dev.features & net->dev.backend_features));
182             vhost_dev_cleanup(&net->dev);
183             goto fail;
184         }
185     }
186     /* Set sane init value. Override when guest acks. */
187     vhost_net_ack_features(net, 0);
188     return net;
189 fail:
190     g_free(net);
191     return NULL;
192 }
193 
194 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
195 {
196     net->dev.vq_index = vq_index;
197 }
198 
199 static int vhost_net_start_one(struct vhost_net *net,
200                                VirtIODevice *dev)
201 {
202     struct vhost_vring_file file = { };
203     int r;
204 
205     net->dev.nvqs = 2;
206     net->dev.vqs = net->vqs;
207 
208     r = vhost_dev_enable_notifiers(&net->dev, dev);
209     if (r < 0) {
210         goto fail_notifiers;
211     }
212 
213     r = vhost_dev_start(&net->dev, dev);
214     if (r < 0) {
215         goto fail_start;
216     }
217 
218     if (net->nc->info->poll) {
219         net->nc->info->poll(net->nc, false);
220     }
221 
222     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
223         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
224         file.fd = net->backend;
225         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
226             const VhostOps *vhost_ops = net->dev.vhost_ops;
227             r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
228             if (r < 0) {
229                 r = -errno;
230                 goto fail;
231             }
232         }
233     }
234     return 0;
235 fail:
236     file.fd = -1;
237     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
238         while (file.index-- > 0) {
239             const VhostOps *vhost_ops = net->dev.vhost_ops;
240             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
241             assert(r >= 0);
242         }
243     }
244     if (net->nc->info->poll) {
245         net->nc->info->poll(net->nc, true);
246     }
247     vhost_dev_stop(&net->dev, dev);
248 fail_start:
249     vhost_dev_disable_notifiers(&net->dev, dev);
250 fail_notifiers:
251     return r;
252 }
253 
254 static void vhost_net_stop_one(struct vhost_net *net,
255                                VirtIODevice *dev)
256 {
257     struct vhost_vring_file file = { .fd = -1 };
258 
259     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
260         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
261             const VhostOps *vhost_ops = net->dev.vhost_ops;
262             int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
263             assert(r >= 0);
264         }
265     }
266     if (net->nc->info->poll) {
267         net->nc->info->poll(net->nc, true);
268     }
269     vhost_dev_stop(&net->dev, dev);
270     vhost_dev_disable_notifiers(&net->dev, dev);
271 }
272 
273 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
274                     int total_queues)
275 {
276     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
277     VirtioBusState *vbus = VIRTIO_BUS(qbus);
278     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
279     int r, e, i;
280 
281     if (!k->set_guest_notifiers) {
282         error_report("binding does not support guest notifiers");
283         return -ENOSYS;
284     }
285 
286     for (i = 0; i < total_queues; i++) {
287         struct vhost_net *net;
288 
289         net = get_vhost_net(ncs[i].peer);
290         vhost_net_set_vq_index(net, i * 2);
291 
292         /* Suppress the masking guest notifiers on vhost user
293          * because vhost user doesn't interrupt masking/unmasking
294          * properly.
295          */
296         if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
297                 dev->use_guest_notifier_mask = false;
298         }
299      }
300 
301     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
302     if (r < 0) {
303         error_report("Error binding guest notifier: %d", -r);
304         goto err;
305     }
306 
307     for (i = 0; i < total_queues; i++) {
308         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
309 
310         if (r < 0) {
311             goto err_start;
312         }
313     }
314 
315     return 0;
316 
317 err_start:
318     while (--i >= 0) {
319         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
320     }
321     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
322     if (e < 0) {
323         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
324         fflush(stderr);
325     }
326 err:
327     return r;
328 }
329 
330 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
331                     int total_queues)
332 {
333     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
334     VirtioBusState *vbus = VIRTIO_BUS(qbus);
335     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
336     int i, r;
337 
338     for (i = 0; i < total_queues; i++) {
339         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
340     }
341 
342     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
343     if (r < 0) {
344         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
345         fflush(stderr);
346     }
347     assert(r >= 0);
348 }
349 
350 void vhost_net_cleanup(struct vhost_net *net)
351 {
352     vhost_dev_cleanup(&net->dev);
353     g_free(net);
354 }
355 
356 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
357 {
358     const VhostOps *vhost_ops = net->dev.vhost_ops;
359     int r = -1;
360 
361     if (vhost_ops->vhost_migration_done) {
362         r = vhost_ops->vhost_migration_done(&net->dev, mac_addr);
363     }
364 
365     return r;
366 }
367 
368 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
369 {
370     return vhost_virtqueue_pending(&net->dev, idx);
371 }
372 
373 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
374                               int idx, bool mask)
375 {
376     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
377 }
378 
379 VHostNetState *get_vhost_net(NetClientState *nc)
380 {
381     VHostNetState *vhost_net = 0;
382 
383     if (!nc) {
384         return 0;
385     }
386 
387     switch (nc->info->type) {
388     case NET_CLIENT_OPTIONS_KIND_TAP:
389         vhost_net = tap_get_vhost_net(nc);
390         break;
391     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
392         vhost_net = vhost_user_get_vhost_net(nc);
393         break;
394     default:
395         break;
396     }
397 
398     return vhost_net;
399 }
400 
401 int vhost_set_vring_enable(NetClientState *nc, int enable)
402 {
403     VHostNetState *net = get_vhost_net(nc);
404     const VhostOps *vhost_ops = net->dev.vhost_ops;
405 
406     if (vhost_ops->vhost_set_vring_enable) {
407         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
408     }
409 
410     return 0;
411 }
412 
413 #else
414 uint64_t vhost_net_get_max_queues(VHostNetState *net)
415 {
416     return 1;
417 }
418 
419 struct vhost_net *vhost_net_init(VhostNetOptions *options)
420 {
421     error_report("vhost-net support is not compiled in");
422     return NULL;
423 }
424 
425 int vhost_net_start(VirtIODevice *dev,
426                     NetClientState *ncs,
427                     int total_queues)
428 {
429     return -ENOSYS;
430 }
431 void vhost_net_stop(VirtIODevice *dev,
432                     NetClientState *ncs,
433                     int total_queues)
434 {
435 }
436 
437 void vhost_net_cleanup(struct vhost_net *net)
438 {
439 }
440 
441 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
442 {
443     return features;
444 }
445 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
446 {
447 }
448 
449 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
450 {
451     return false;
452 }
453 
454 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
455                               int idx, bool mask)
456 {
457 }
458 
459 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
460 {
461     return -1;
462 }
463 
464 VHostNetState *get_vhost_net(NetClientState *nc)
465 {
466     return 0;
467 }
468 
469 int vhost_set_vring_enable(NetClientState *nc, int enable)
470 {
471     return 0;
472 }
473 #endif
474