xref: /openbmc/qemu/hw/net/vhost_net.c (revision b45c03f5) 
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 static int vhost_net_get_fd(NetClientState *backend)
126 {
127     switch (backend->info->type) {
128     case NET_CLIENT_OPTIONS_KIND_TAP:
129         return tap_get_fd(backend);
130     default:
131         fprintf(stderr, "vhost-net requires tap backend\n");
132         return -EBADFD;
133     }
134 }
135 
136 struct vhost_net *vhost_net_init(VhostNetOptions *options)
137 {
138     int r;
139     bool backend_kernel = options->backend_type == VHOST_BACKEND_TYPE_KERNEL;
140     struct vhost_net *net = g_malloc(sizeof *net);
141 
142     if (!options->net_backend) {
143         fprintf(stderr, "vhost-net requires net backend to be setup\n");
144         goto fail;
145     }
146 
147     if (backend_kernel) {
148         r = vhost_net_get_fd(options->net_backend);
149         if (r < 0) {
150             goto fail;
151         }
152         net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend)
153             ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR);
154         net->backend = r;
155     } else {
156         net->dev.backend_features = 0;
157         net->backend = -1;
158     }
159     net->nc = options->net_backend;
160 
161     net->dev.nvqs = 2;
162     net->dev.vqs = net->vqs;
163 
164     r = vhost_dev_init(&net->dev, options->opaque,
165                        options->backend_type);
166     if (r < 0) {
167         goto fail;
168     }
169     if (backend_kernel) {
170         if (!qemu_has_vnet_hdr_len(options->net_backend,
171                                sizeof(struct virtio_net_hdr_mrg_rxbuf))) {
172             net->dev.features &= ~(1ULL << VIRTIO_NET_F_MRG_RXBUF);
173         }
174         if (~net->dev.features & net->dev.backend_features) {
175             fprintf(stderr, "vhost lacks feature mask %" PRIu64
176                    " for backend\n",
177                    (uint64_t)(~net->dev.features & net->dev.backend_features));
178             vhost_dev_cleanup(&net->dev);
179             goto fail;
180         }
181     }
182     /* Set sane init value. Override when guest acks. */
183     vhost_net_ack_features(net, 0);
184     return net;
185 fail:
186     g_free(net);
187     return NULL;
188 }
189 
190 static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
191 {
192     net->dev.vq_index = vq_index;
193 }
194 
195 static int vhost_net_set_vnet_endian(VirtIODevice *dev, NetClientState *peer,
196                                      bool set)
197 {
198     int r = 0;
199 
200     if (virtio_has_feature(dev, VIRTIO_F_VERSION_1) ||
201         (virtio_legacy_is_cross_endian(dev) && !virtio_is_big_endian(dev))) {
202         r = qemu_set_vnet_le(peer, set);
203         if (r) {
204             error_report("backend does not support LE vnet headers");
205         }
206     } else if (virtio_legacy_is_cross_endian(dev)) {
207         r = qemu_set_vnet_be(peer, set);
208         if (r) {
209             error_report("backend does not support BE vnet headers");
210         }
211     }
212 
213     return r;
214 }
215 
216 static int vhost_net_start_one(struct vhost_net *net,
217                                VirtIODevice *dev)
218 {
219     struct vhost_vring_file file = { };
220     int r;
221 
222     net->dev.nvqs = 2;
223     net->dev.vqs = net->vqs;
224 
225     r = vhost_dev_enable_notifiers(&net->dev, dev);
226     if (r < 0) {
227         goto fail_notifiers;
228     }
229 
230     r = vhost_dev_start(&net->dev, dev);
231     if (r < 0) {
232         goto fail_start;
233     }
234 
235     if (net->nc->info->poll) {
236         net->nc->info->poll(net->nc, false);
237     }
238 
239     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
240         qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
241         file.fd = net->backend;
242         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
243             const VhostOps *vhost_ops = net->dev.vhost_ops;
244             r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
245                                       &file);
246             if (r < 0) {
247                 r = -errno;
248                 goto fail;
249             }
250         }
251     }
252     return 0;
253 fail:
254     file.fd = -1;
255     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
256         while (file.index-- > 0) {
257             const VhostOps *vhost_ops = net->dev.vhost_ops;
258             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
259                                           &file);
260             assert(r >= 0);
261         }
262     }
263     if (net->nc->info->poll) {
264         net->nc->info->poll(net->nc, true);
265     }
266     vhost_dev_stop(&net->dev, dev);
267 fail_start:
268     vhost_dev_disable_notifiers(&net->dev, dev);
269 fail_notifiers:
270     return r;
271 }
272 
273 static void vhost_net_stop_one(struct vhost_net *net,
274                                VirtIODevice *dev)
275 {
276     struct vhost_vring_file file = { .fd = -1 };
277 
278     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
279         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
280             const VhostOps *vhost_ops = net->dev.vhost_ops;
281             int r = vhost_ops->vhost_call(&net->dev, VHOST_NET_SET_BACKEND,
282                                           &file);
283             assert(r >= 0);
284         }
285     } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
286         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
287             const VhostOps *vhost_ops = net->dev.vhost_ops;
288             int r = vhost_ops->vhost_call(&net->dev, VHOST_RESET_OWNER,
289                                           NULL);
290             assert(r >= 0);
291         }
292     }
293     if (net->nc->info->poll) {
294         net->nc->info->poll(net->nc, true);
295     }
296     vhost_dev_stop(&net->dev, dev);
297     vhost_dev_disable_notifiers(&net->dev, dev);
298 }
299 
300 int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
301                     int total_queues)
302 {
303     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
304     VirtioBusState *vbus = VIRTIO_BUS(qbus);
305     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
306     int r, e, i;
307 
308     if (!k->set_guest_notifiers) {
309         error_report("binding does not support guest notifiers");
310         r = -ENOSYS;
311         goto err;
312     }
313 
314     r = vhost_net_set_vnet_endian(dev, ncs[0].peer, true);
315     if (r < 0) {
316         goto err;
317     }
318 
319     for (i = 0; i < total_queues; i++) {
320         vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
321     }
322 
323     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
324     if (r < 0) {
325         error_report("Error binding guest notifier: %d", -r);
326         goto err_endian;
327     }
328 
329     for (i = 0; i < total_queues; i++) {
330         r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
331 
332         if (r < 0) {
333             goto err_start;
334         }
335     }
336 
337     return 0;
338 
339 err_start:
340     while (--i >= 0) {
341         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
342     }
343     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
344     if (e < 0) {
345         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
346         fflush(stderr);
347     }
348 err_endian:
349     vhost_net_set_vnet_endian(dev, ncs[0].peer, false);
350 err:
351     return r;
352 }
353 
354 void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
355                     int total_queues)
356 {
357     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
358     VirtioBusState *vbus = VIRTIO_BUS(qbus);
359     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
360     int i, r;
361 
362     for (i = 0; i < total_queues; i++) {
363         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
364     }
365 
366     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
367     if (r < 0) {
368         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
369         fflush(stderr);
370     }
371     assert(r >= 0);
372 
373     assert(vhost_net_set_vnet_endian(dev, ncs[0].peer, false) >= 0);
374 }
375 
376 void vhost_net_cleanup(struct vhost_net *net)
377 {
378     vhost_dev_cleanup(&net->dev);
379     g_free(net);
380 }
381 
382 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
383 {
384     return vhost_virtqueue_pending(&net->dev, idx);
385 }
386 
387 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
388                               int idx, bool mask)
389 {
390     vhost_virtqueue_mask(&net->dev, dev, idx, mask);
391 }
392 
393 VHostNetState *get_vhost_net(NetClientState *nc)
394 {
395     VHostNetState *vhost_net = 0;
396 
397     if (!nc) {
398         return 0;
399     }
400 
401     switch (nc->info->type) {
402     case NET_CLIENT_OPTIONS_KIND_TAP:
403         vhost_net = tap_get_vhost_net(nc);
404         break;
405     case NET_CLIENT_OPTIONS_KIND_VHOST_USER:
406         vhost_net = vhost_user_get_vhost_net(nc);
407         break;
408     default:
409         break;
410     }
411 
412     return vhost_net;
413 }
414 #else
415 struct vhost_net *vhost_net_init(VhostNetOptions *options)
416 {
417     error_report("vhost-net support is not compiled in");
418     return NULL;
419 }
420 
421 int vhost_net_start(VirtIODevice *dev,
422                     NetClientState *ncs,
423                     int total_queues)
424 {
425     return -ENOSYS;
426 }
427 void vhost_net_stop(VirtIODevice *dev,
428                     NetClientState *ncs,
429                     int total_queues)
430 {
431 }
432 
433 void vhost_net_cleanup(struct vhost_net *net)
434 {
435 }
436 
437 uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
438 {
439     return features;
440 }
441 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
442 {
443 }
444 
445 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
446 {
447     return false;
448 }
449 
450 void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
451                               int idx, bool mask)
452 {
453 }
454 
455 VHostNetState *get_vhost_net(NetClientState *nc)
456 {
457     return 0;
458 }
459 #endif
460