xref: /qemu/hw/net/vhost_net.c (revision e5b6353c) 
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 "standard-headers/linux/vhost_types.h"
22 #include "hw/virtio/virtio-net.h"
23 #include "net/vhost_net.h"
24 #include "qemu/error-report.h"
25 #include "qemu/main-loop.h"
26 
27 #include <sys/socket.h>
28 #include <net/if.h>
29 #include <netinet/in.h>
30 
31 
32 #include "standard-headers/linux/virtio_ring.h"
33 #include "hw/virtio/vhost.h"
34 #include "hw/virtio/virtio-bus.h"
35 
36 struct vhost_net {
37     struct vhost_dev dev;
38     struct vhost_virtqueue vqs[2];
39     int backend;
40     NetClientState *nc;
41 };
42 
43 /* Features supported by host kernel. */
44 static const int kernel_feature_bits[] = {
45     VIRTIO_F_NOTIFY_ON_EMPTY,
46     VIRTIO_RING_F_INDIRECT_DESC,
47     VIRTIO_RING_F_EVENT_IDX,
48     VIRTIO_NET_F_MRG_RXBUF,
49     VIRTIO_F_VERSION_1,
50     VIRTIO_NET_F_MTU,
51     VIRTIO_F_IOMMU_PLATFORM,
52     VHOST_INVALID_FEATURE_BIT
53 };
54 
55 /* Features supported by others. */
56 static const int user_feature_bits[] = {
57     VIRTIO_F_NOTIFY_ON_EMPTY,
58     VIRTIO_RING_F_INDIRECT_DESC,
59     VIRTIO_RING_F_EVENT_IDX,
60 
61     VIRTIO_F_ANY_LAYOUT,
62     VIRTIO_F_VERSION_1,
63     VIRTIO_NET_F_CSUM,
64     VIRTIO_NET_F_GUEST_CSUM,
65     VIRTIO_NET_F_GSO,
66     VIRTIO_NET_F_GUEST_TSO4,
67     VIRTIO_NET_F_GUEST_TSO6,
68     VIRTIO_NET_F_GUEST_ECN,
69     VIRTIO_NET_F_GUEST_UFO,
70     VIRTIO_NET_F_HOST_TSO4,
71     VIRTIO_NET_F_HOST_TSO6,
72     VIRTIO_NET_F_HOST_ECN,
73     VIRTIO_NET_F_HOST_UFO,
74     VIRTIO_NET_F_MRG_RXBUF,
75     VIRTIO_NET_F_MTU,
76     VIRTIO_F_IOMMU_PLATFORM,
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_DRIVER_TAP:
92         feature_bits = kernel_feature_bits;
93         break;
94     case NET_CLIENT_DRIVER_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 uint64_t vhost_net_get_acked_features(VHostNetState *net)
124 {
125     return net->dev.acked_features;
126 }
127 
128 static int vhost_net_get_fd(NetClientState *backend)
129 {
130     switch (backend->info->type) {
131     case NET_CLIENT_DRIVER_TAP:
132         return tap_get_fd(backend);
133     default:
134         fprintf(stderr, "vhost-net requires tap backend\n");
135         return -ENOSYS;
136     }
137 }
138 
139 struct vhost_net *vhost_net_init(VhostNetOptions *options)
140 {
141     int r;
142     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
143     struct vhost_net *net = g_new0(struct vhost_net, 1);
144     uint64_t features = 0;
145 
146     if (!options->net_backend) {
147         fprintf(stderr, "vhost-net requires net backend to be setup\n");
148         goto fail;
149     }
150     net->nc = options->net_backend;
151 
152     net->dev.max_queues = 1;
153     net->dev.nvqs = 2;
154     net->dev.vqs = net->vqs;
155 
156     if (backend_kernel) {
157         r = vhost_net_get_fd(options->net_backend);
158         if (r < 0) {
159             goto fail;
160         }
161         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
162             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
163         net->backend = r;
164         net->dev.protocol_features = 0;
165     } else {
166         net->dev.backend_features = 0;
167         net->dev.protocol_features = 0;
168         net->backend = -1;
169 
170         /* vhost-user needs vq_index to initiate a specific queue pair */
171         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
172     }
173 
174     r = vhost_dev_init(&net->dev, options->opaque,
175                        options->backend_type, options->busyloop_timeout);
176     if (r < 0) {
177         goto fail;
178     }
179     if (backend_kernel) {
180         if (!qemu_has_vnet_hdr_len(options->net_backend,
181                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
182             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
183         }
184         if (~net->dev.features & net->dev.backend_features) {
185             fprintf(stderr, "vhost lacks feature mask %" PRIu64
186                    " for backend\n",
187                    (uint64_t)(~net->dev.features & net->dev.backend_features));
188             goto fail;
189         }
190     }
191 
192     /* Set sane init value. Override when guest acks. */
193 #ifdef CONFIG_VHOST_NET_USER
194     if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
195         features = vhost_user_get_acked_features(net->nc);
196         if (~net->dev.features & features) {
197             fprintf(stderr, "vhost lacks feature mask %" PRIu64
198                     " for backend\n",
199                     (uint64_t)(~net->dev.features & features));
200             goto fail;
201         }
202     }
203 #endif
204 
205     vhost_net_ack_features(net, features);
206 
207     return net;
208 
209 fail:
210     vhost_dev_cleanup(&net->dev);
211     g_free(net);
212     return NULL;
213 }
214 
215 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
216 {
217     net->dev.vq_index = vq_index;
218 }
219 
220 static int vhost_net_start_one(struct vhost_net *net,
221                                VirtIODevice *dev)
222 {
223     struct vhost_vring_file file = { };
224     int r;
225 
226     net->dev.nvqs = 2;
227     net->dev.vqs = net->vqs;
228 
229     r = vhost_dev_enable_notifiers(&net->dev, dev);
230     if (r < 0) {
231         goto fail_notifiers;
232     }
233 
234     r = vhost_dev_start(&net->dev, dev);
235     if (r < 0) {
236         goto fail_start;
237     }
238 
239     if (net->nc->info->poll) {
240         net->nc->info->poll(net->nc, false);
241     }
242 
243     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
244         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
245         file.fd = net->backend;
246         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
247             if (!virtio_queue_enabled(dev, net->dev.vq_index +
248                                       file.index)) {
249                 /* Queue might not be ready for start */
250                 continue;
251             }
252             r = vhost_net_set_backend(&net->dev, &file);
253             if (r < 0) {
254                 r = -errno;
255                 goto fail;
256             }
257         }
258     }
259     return 0;
260 fail:
261     file.fd = -1;
262     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
263         while (file.index-- > 0) {
264             if (!virtio_queue_enabled(dev, net->dev.vq_index +
265                                       file.index)) {
266                 /* Queue might not be ready for start */
267                 continue;
268             }
269             int r = vhost_net_set_backend(&net->dev, &file);
270             assert(r >= 0);
271         }
272     }
273     if (net->nc->info->poll) {
274         net->nc->info->poll(net->nc, true);
275     }
276     vhost_dev_stop(&net->dev, dev);
277 fail_start:
278     vhost_dev_disable_notifiers(&net->dev, dev);
279 fail_notifiers:
280     return r;
281 }
282 
283 static void vhost_net_stop_one(struct vhost_net *net,
284                                VirtIODevice *dev)
285 {
286     struct vhost_vring_file file = { .fd = -1 };
287 
288     if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
289         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
290             int r = vhost_net_set_backend(&net->dev, &file);
291             assert(r >= 0);
292         }
293     }
294     if (net->nc->info->poll) {
295         net->nc->info->poll(net->nc, true);
296     }
297     vhost_dev_stop(&net->dev, dev);
298     vhost_dev_disable_notifiers(&net->dev, dev);
299 }
300 
301 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
302                     int total_queues)
303 {
304     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
305     VirtioBusState *vbus = VIRTIO_BUS(qbus);
306     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
307     int r, e, i;
308 
309     if (!k->set_guest_notifiers) {
310         error_report("binding does not support guest notifiers");
311         return -ENOSYS;
312     }
313 
314     for (i = 0; i < total_queues; i++) {
315         struct vhost_net *net;
316 
317         net = get_vhost_net(ncs[i].peer);
318         vhost_net_set_vq_index(net, i * 2);
319 
320         /* Suppress the masking guest notifiers on vhost user
321          * because vhost user doesn't interrupt masking/unmasking
322          * properly.
323          */
324         if (net->nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
325             dev->use_guest_notifier_mask = false;
326         }
327      }
328 
329     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
330     if (r < 0) {
331         error_report("Error binding guest notifier: %d", -r);
332         goto err;
333     }
334 
335     for (i = 0; i < total_queues; i++) {
336         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
337 
338         if (r < 0) {
339             goto err_start;
340         }
341 
342         if (ncs[i].peer->vring_enable) {
343             /* restore vring enable state */
344             r = vhost_set_vring_enable(ncs[i].peer, ncs[i].peer->vring_enable);
345 
346             if (r < 0) {
347                 goto err_start;
348             }
349         }
350     }
351 
352     return 0;
353 
354 err_start:
355     while (--i >= 0) {
356         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
357     }
358     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
359     if (e < 0) {
360         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
361         fflush(stderr);
362     }
363 err:
364     return r;
365 }
366 
367 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
368                     int total_queues)
369 {
370     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
371     VirtioBusState *vbus = VIRTIO_BUS(qbus);
372     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
373     int i, r;
374 
375     for (i = 0; i < total_queues; i++) {
376         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
377     }
378 
379     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
380     if (r < 0) {
381         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
382         fflush(stderr);
383     }
384     assert(r >= 0);
385 }
386 
387 void vhost_net_cleanup(struct vhost_net *net)
388 {
389     vhost_dev_cleanup(&net->dev);
390 }
391 
392 int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
393 {
394     const VhostOps *vhost_ops = net->dev.vhost_ops;
395 
396     assert(vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
397     assert(vhost_ops->vhost_migration_done);
398 
399     return vhost_ops->vhost_migration_done(&net->dev, mac_addr);
400 }
401 
402 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
403 {
404     return vhost_virtqueue_pending(&net->dev, idx);
405 }
406 
407 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
408                               int idx, bool mask)
409 {
410     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
411 }
412 
413 VHostNetState *get_vhost_net(NetClientState *nc)
414 {
415     VHostNetState *vhost_net = 0;
416 
417     if (!nc) {
418         return 0;
419     }
420 
421     switch (nc->info->type) {
422     case NET_CLIENT_DRIVER_TAP:
423         vhost_net = tap_get_vhost_net(nc);
424         break;
425 #ifdef CONFIG_VHOST_NET_USER
426     case NET_CLIENT_DRIVER_VHOST_USER:
427         vhost_net = vhost_user_get_vhost_net(nc);
428         assert(vhost_net);
429         break;
430 #endif
431     default:
432         break;
433     }
434 
435     return vhost_net;
436 }
437 
438 int vhost_set_vring_enable(NetClientState *nc, int enable)
439 {
440     VHostNetState *net = get_vhost_net(nc);
441     const VhostOps *vhost_ops = net->dev.vhost_ops;
442 
443     nc->vring_enable = enable;
444 
445     if (vhost_ops && vhost_ops->vhost_set_vring_enable) {
446         return vhost_ops->vhost_set_vring_enable(&net->dev, enable);
447     }
448 
449     return 0;
450 }
451 
452 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
453 {
454     const VhostOps *vhost_ops = net->dev.vhost_ops;
455 
456     if (!vhost_ops->vhost_net_set_mtu) {
457         return 0;
458     }
459 
460     return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
461 }
462