xref: /openbmc/qemu/hw/net/vhost_net.c (revision be9f8a08727e46c790adb8caa8a4525a1e8e9e73) 
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 
42 struct vhost_net {
43     struct vhost_dev dev;
44     struct vhost_virtqueue vqs[2];
45     int backend;
46     NetClientState *nc;
47 };
48 
49 /* Features supported by host kernel. */
50 static const int kernel_feature_bits[] = {
51     VIRTIO_F_NOTIFY_ON_EMPTY,
52     VIRTIO_RING_F_INDIRECT_DESC,
53     VIRTIO_RING_F_EVENT_IDX,
54     VIRTIO_NET_F_MRG_RXBUF,
55     VHOST_INVALID_FEATURE_BIT
56 };
57 
58 /* Features supported by others. */
59 static const int user_feature_bits[] = {
60     VIRTIO_F_NOTIFY_ON_EMPTY,
61     VIRTIO_RING_F_INDIRECT_DESC,
62     VIRTIO_RING_F_EVENT_IDX,
63 
64     VIRTIO_F_ANY_LAYOUT,
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     VIRTIO_NET_F_STATUS,
78     VIRTIO_NET_F_CTRL_VQ,
79     VIRTIO_NET_F_CTRL_RX,
80     VIRTIO_NET_F_CTRL_VLAN,
81     VIRTIO_NET_F_CTRL_RX_EXTRA,
82     VIRTIO_NET_F_CTRL_MAC_ADDR,
83     VIRTIO_NET_F_CTRL_GUEST_OFFLOADS,
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_OPTIONS_KIND_TAP:
96         feature_bits = kernel_feature_bits;
97         break;
98     case NET_CLIENT_OPTIONS_KIND_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 unsigned vhost_net_get_features(struct vhost_net *net, unsigned 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, unsigned 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 static int vhost_net_get_fd(NetClientState *backend)
123 {
124     switch (backend->info->type) {
125     case NET_CLIENT_OPTIONS_KIND_TAP:
126         return tap_get_fd(backend);
127     default:
128         fprintf(stderr, "vhost-net requires tap backend\n");
129         return -EBADFD;
130     }
131 }
132 
133 struct vhost_net *vhost_net_init(VhostNetOptions *options)
134 {
135     int r;
136     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
137     struct vhost_net *net = g_malloc(sizeof *net);
138 
139     if (!options->net_backend) {
140         fprintf(stderr, "vhost-net requires net backend to be setup\n");
141         goto fail;
142     }
143 
144     if (backend_kernel) {
145         r = vhost_net_get_fd(options->net_backend);
146         if (r < 0) {
147             goto fail;
148         }
149         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
150             ? 0 : (1 << VHOST_NET_F_VIRTIO_NET_HDR);
151         net->backend = r;
152     } else {
153         net->dev.backend_features = 0;
154         net->backend = -1;
155     }
156     net->nc = options->net_backend;
157 
158     net->dev.nvqs = 2;
159     net->dev.vqs = net->vqs;
160     net->dev.vq_index = net->nc->queue_index;
161 
162     r = vhost_dev_init(&net->dev, options->opaque,
163                        options->backend_type, options->force);
164     if (r < 0) {
165         goto fail;
166     }
167     if (backend_kernel) {
168         if (!qemu_has_vnet_hdr_len(options->net_backend,
169                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
170             net->dev.features &= ~(1 << VIRTIO_NET_F_MRG_RXBUF);
171         }
172         if (~net->dev.features & net->dev.backend_features) {
173             fprintf(stderr, "vhost lacks feature mask %" PRIu64
174                    " for backend\n",
175                    (uint64_t)(~net->dev.features & net->dev.backend_features));
176             vhost_dev_cleanup(&net->dev);
177             goto fail;
178         }
179     }
180     /* Set sane init value. Override when guest acks. */
181     vhost_net_ack_features(net, 0);
182     return net;
183 fail:
184     g_free(net);
185     return NULL;
186 }
187 
188 bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
189 {
190     return vhost_dev_query(&net->dev, dev);
191 }
192 
193 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
194 {
195     net->dev.vq_index = vq_index;
196 }
197 
198 static int vhost_net_start_one(struct vhost_net *net,
199                                VirtIODevice *dev)
200 {
201     struct vhost_vring_file file = { };
202     int r;
203 
204     net->dev.nvqs = 2;
205     net->dev.vqs = net->vqs;
206 
207     r = vhost_dev_enable_notifiers(&net->dev, dev);
208     if (r < 0) {
209         goto fail_notifiers;
210     }
211 
212     r = vhost_dev_start(&net->dev, dev);
213     if (r < 0) {
214         goto fail_start;
215     }
216 
217     if (net->nc->info->poll) {
218         net->nc->info->poll(net->nc, false);
219     }
220 
221     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
222         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
223         file.fd = net->backend;
224         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
225             const VhostOps *vhost_ops = net->dev.vhost_ops;
226             r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
227                                       &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_call(&net->dev, VHOST_NET_SET_BACKEND,
241                                           &file);
242             assert(r >= 0);
243         }
244     }
245     if (net->nc->info->poll) {
246         net->nc->info->poll(net->nc, true);
247     }
248     vhost_dev_stop(&net->dev, dev);
249 fail_start:
250     vhost_dev_disable_notifiers(&net->dev, dev);
251 fail_notifiers:
252     return r;
253 }
254 
255 static void vhost_net_stop_one(struct vhost_net *net,
256                                VirtIODevice *dev)
257 {
258     struct vhost_vring_file file = { .fd = -1 };
259 
260     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
261         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
262             const VhostOps *vhost_ops = net->dev.vhost_ops;
263             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
264                                           &file);
265             assert(r >= 0);
266         }
267     } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
268         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
269             const VhostOps *vhost_ops = net->dev.vhost_ops;
270             int r = vhost_ops->vhost_call(&net->dev, VHOST_RESET_OWNER,
271                                           &file);
272             assert(r >= 0);
273         }
274     }
275     if (net->nc->info->poll) {
276         net->nc->info->poll(net->nc, true);
277     }
278     vhost_dev_stop(&net->dev, dev);
279     vhost_dev_disable_notifiers(&net->dev, dev);
280 }
281 
282 static bool vhost_net_device_endian_ok(VirtIODevice *vdev)
283 {
284 #ifdef TARGET_IS_BIENDIAN
285 #ifdef HOST_WORDS_BIGENDIAN
286     return virtio_is_big_endian(vdev);
287 #else
288     return !virtio_is_big_endian(vdev);
289 #endif
290 #else
291     return true;
292 #endif
293 }
294 
295 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
296                     int total_queues)
297 {
298     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
299     VirtioBusState *vbus = VIRTIO_BUS(qbus);
300     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
301     int r, e, i;
302 
303     if (!vhost_net_device_endian_ok(dev)) {
304         error_report("vhost-net does not support cross-endian");
305         r = -ENOSYS;
306         goto err;
307     }
308 
309     if (!k->set_guest_notifiers) {
310         error_report("binding does not support guest notifiers");
311         r = -ENOSYS;
312         goto err;
313     }
314 
315     for (i = 0; i < total_queues; i++) {
316         vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
317     }
318 
319     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
320     if (r < 0) {
321         error_report("Error binding guest notifier: %d", -r);
322         goto err;
323     }
324 
325     for (i = 0; i < total_queues; i++) {
326         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
327 
328         if (r < 0) {
329             goto err_start;
330         }
331     }
332 
333     return 0;
334 
335 err_start:
336     while (--i >= 0) {
337         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
338     }
339     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
340     if (e < 0) {
341         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
342         fflush(stderr);
343     }
344 err:
345     return r;
346 }
347 
348 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
349                     int total_queues)
350 {
351     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
352     VirtioBusState *vbus = VIRTIO_BUS(qbus);
353     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
354     int i, r;
355 
356     for (i = 0; i < total_queues; i++) {
357         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
358     }
359 
360     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
361     if (r < 0) {
362         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
363         fflush(stderr);
364     }
365     assert(r >= 0);
366 }
367 
368 void vhost_net_cleanup(struct vhost_net *net)
369 {
370     vhost_dev_cleanup(&net->dev);
371     g_free(net);
372 }
373 
374 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
375 {
376     return vhost_virtqueue_pending(&net->dev, idx);
377 }
378 
379 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
380                               int idx, bool mask)
381 {
382     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
383 }
384 
385 VHostNetState *get_vhost_net(NetClientState *nc)
386 {
387     VHostNetState *vhost_net = 0;
388 
389     if (!nc) {
390         return 0;
391     }
392 
393     switch (nc->info->type) {
394     case NET_CLIENT_OPTIONS_KIND_TAP:
395         vhost_net = tap_get_vhost_net(nc);
396         break;
397     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
398         vhost_net = vhost_user_get_vhost_net(nc);
399         break;
400     default:
401         break;
402     }
403 
404     return vhost_net;
405 }
406 #else
407 struct vhost_net *vhost_net_init(VhostNetOptions *options)
408 {
409     error_report("vhost-net support is not compiled in");
410     return NULL;
411 }
412 
413 bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
414 {
415     return false;
416 }
417 
418 int vhost_net_start(VirtIODevice *dev,
419                     NetClientState *ncs,
420                     int total_queues)
421 {
422     return -ENOSYS;
423 }
424 void vhost_net_stop(VirtIODevice *dev,
425                     NetClientState *ncs,
426                     int total_queues)
427 {
428 }
429 
430 void vhost_net_cleanup(struct vhost_net *net)
431 {
432 }
433 
434 unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
435 {
436     return features;
437 }
438 void vhost_net_ack_features(struct vhost_net *net, unsigned features)
439 {
440 }
441 
442 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
443 {
444     return false;
445 }
446 
447 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
448                               int idx, bool mask)
449 {
450 }
451 
452 VHostNetState *get_vhost_net(NetClientState *nc)
453 {
454     return 0;
455 }
456 #endif
457