Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2017-03-16' into staging
[qemu.git] / net / vhost-user.c
1 /*
2 * vhost-user.c
3 *
4 * Copyright (c) 2013 Virtual Open Systems Sarl.
5 *
6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
7 * See the COPYING file in the top-level directory.
8 *
9 */
10
11 #include "qemu/osdep.h"
12 #include "clients.h"
13 #include "net/vhost_net.h"
14 #include "net/vhost-user.h"
15 #include "sysemu/char.h"
16 #include "qemu/config-file.h"
17 #include "qemu/error-report.h"
18 #include "qmp-commands.h"
19 #include "trace.h"
20
21 typedef struct VhostUserState {
22 NetClientState nc;
23 CharBackend chr; /* only queue index 0 */
24 VHostNetState *vhost_net;
25 guint watch;
26 uint64_t acked_features;
27 bool started;
28 } VhostUserState;
29
30 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
31 {
32 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
33 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
34 return s->vhost_net;
35 }
36
37 uint64_t vhost_user_get_acked_features(NetClientState *nc)
38 {
39 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
40 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
41 return s->acked_features;
42 }
43
44 static void vhost_user_stop(int queues, NetClientState *ncs[])
45 {
46 VhostUserState *s;
47 int i;
48
49 for (i = 0; i < queues; i++) {
50 assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
51
52 s = DO_UPCAST(VhostUserState, nc, ncs[i]);
53
54 if (s->vhost_net) {
55 /* save acked features */
56 uint64_t features = vhost_net_get_acked_features(s->vhost_net);
57 if (features) {
58 s->acked_features = features;
59 }
60 vhost_net_cleanup(s->vhost_net);
61 }
62 }
63 }
64
65 static int vhost_user_start(int queues, NetClientState *ncs[], CharBackend *be)
66 {
67 VhostNetOptions options;
68 struct vhost_net *net = NULL;
69 VhostUserState *s;
70 int max_queues;
71 int i;
72
73 options.backend_type = VHOST_BACKEND_TYPE_USER;
74
75 for (i = 0; i < queues; i++) {
76 assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
77
78 s = DO_UPCAST(VhostUserState, nc, ncs[i]);
79
80 options.net_backend = ncs[i];
81 options.opaque = be;
82 options.busyloop_timeout = 0;
83 net = vhost_net_init(&options);
84 if (!net) {
85 error_report("failed to init vhost_net for queue %d", i);
86 goto err;
87 }
88
89 if (i == 0) {
90 max_queues = vhost_net_get_max_queues(net);
91 if (queues > max_queues) {
92 error_report("you are asking more queues than supported: %d",
93 max_queues);
94 goto err;
95 }
96 }
97
98 if (s->vhost_net) {
99 vhost_net_cleanup(s->vhost_net);
100 g_free(s->vhost_net);
101 }
102 s->vhost_net = net;
103 }
104
105 return 0;
106
107 err:
108 if (net) {
109 vhost_net_cleanup(net);
110 }
111 vhost_user_stop(i, ncs);
112 return -1;
113 }
114
115 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
116 size_t size)
117 {
118 /* In case of RARP (message size is 60) notify backup to send a fake RARP.
119 This fake RARP will be sent by backend only for guest
120 without GUEST_ANNOUNCE capability.
121 */
122 if (size == 60) {
123 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
124 int r;
125 static int display_rarp_failure = 1;
126 char mac_addr[6];
127
128 /* extract guest mac address from the RARP message */
129 memcpy(mac_addr, &buf[6], 6);
130
131 r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
132
133 if ((r != 0) && (display_rarp_failure)) {
134 fprintf(stderr,
135 "Vhost user backend fails to broadcast fake RARP\n");
136 fflush(stderr);
137 display_rarp_failure = 0;
138 }
139 }
140
141 return size;
142 }
143
144 static void vhost_user_cleanup(NetClientState *nc)
145 {
146 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
147
148 if (s->vhost_net) {
149 vhost_net_cleanup(s->vhost_net);
150 g_free(s->vhost_net);
151 s->vhost_net = NULL;
152 }
153 if (nc->queue_index == 0) {
154 Chardev *chr = qemu_chr_fe_get_driver(&s->chr);
155
156 qemu_chr_fe_deinit(&s->chr);
157 qemu_chr_delete(chr);
158 }
159
160 qemu_purge_queued_packets(nc);
161 }
162
163 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
164 {
165 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
166
167 return true;
168 }
169
170 static bool vhost_user_has_ufo(NetClientState *nc)
171 {
172 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
173
174 return true;
175 }
176
177 static NetClientInfo net_vhost_user_info = {
178 .type = NET_CLIENT_DRIVER_VHOST_USER,
179 .size = sizeof(VhostUserState),
180 .receive = vhost_user_receive,
181 .cleanup = vhost_user_cleanup,
182 .has_vnet_hdr = vhost_user_has_vnet_hdr,
183 .has_ufo = vhost_user_has_ufo,
184 };
185
186 static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
187 void *opaque)
188 {
189 VhostUserState *s = opaque;
190
191 qemu_chr_fe_disconnect(&s->chr);
192
193 return TRUE;
194 }
195
196 static void net_vhost_user_event(void *opaque, int event);
197
198 static void chr_closed_bh(void *opaque)
199 {
200 const char *name = opaque;
201 NetClientState *ncs[MAX_QUEUE_NUM];
202 VhostUserState *s;
203 Error *err = NULL;
204 int queues;
205
206 queues = qemu_find_net_clients_except(name, ncs,
207 NET_CLIENT_DRIVER_NIC,
208 MAX_QUEUE_NUM);
209 assert(queues < MAX_QUEUE_NUM);
210
211 s = DO_UPCAST(VhostUserState, nc, ncs[0]);
212
213 qmp_set_link(name, false, &err);
214 vhost_user_stop(queues, ncs);
215
216 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
217 opaque, NULL, true);
218
219 if (err) {
220 error_report_err(err);
221 }
222 }
223
224 static void net_vhost_user_event(void *opaque, int event)
225 {
226 const char *name = opaque;
227 NetClientState *ncs[MAX_QUEUE_NUM];
228 VhostUserState *s;
229 Chardev *chr;
230 Error *err = NULL;
231 int queues;
232
233 queues = qemu_find_net_clients_except(name, ncs,
234 NET_CLIENT_DRIVER_NIC,
235 MAX_QUEUE_NUM);
236 assert(queues < MAX_QUEUE_NUM);
237
238 s = DO_UPCAST(VhostUserState, nc, ncs[0]);
239 chr = qemu_chr_fe_get_driver(&s->chr);
240 trace_vhost_user_event(chr->label, event);
241 switch (event) {
242 case CHR_EVENT_OPENED:
243 if (vhost_user_start(queues, ncs, &s->chr) < 0) {
244 qemu_chr_fe_disconnect(&s->chr);
245 return;
246 }
247 s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP,
248 net_vhost_user_watch, s);
249 qmp_set_link(name, true, &err);
250 s->started = true;
251 break;
252 case CHR_EVENT_CLOSED:
253 /* a close event may happen during a read/write, but vhost
254 * code assumes the vhost_dev remains setup, so delay the
255 * stop & clear to idle.
256 * FIXME: better handle failure in vhost code, remove bh
257 */
258 if (s->watch) {
259 AioContext *ctx = qemu_get_current_aio_context();
260
261 g_source_remove(s->watch);
262 s->watch = 0;
263 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL,
264 NULL, NULL, false);
265
266 aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque);
267 }
268 break;
269 }
270
271 if (err) {
272 error_report_err(err);
273 }
274 }
275
276 static int net_vhost_user_init(NetClientState *peer, const char *device,
277 const char *name, Chardev *chr,
278 int queues)
279 {
280 Error *err = NULL;
281 NetClientState *nc, *nc0 = NULL;
282 VhostUserState *s;
283 int i;
284
285 assert(name);
286 assert(queues > 0);
287
288 for (i = 0; i < queues; i++) {
289 nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
290 snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
291 i, chr->label);
292 nc->queue_index = i;
293 if (!nc0) {
294 nc0 = nc;
295 s = DO_UPCAST(VhostUserState, nc, nc);
296 if (!qemu_chr_fe_init(&s->chr, chr, &err)) {
297 error_report_err(err);
298 return -1;
299 }
300 }
301
302 }
303
304 s = DO_UPCAST(VhostUserState, nc, nc0);
305 do {
306 if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) {
307 error_report_err(err);
308 return -1;
309 }
310 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL,
311 net_vhost_user_event, nc0->name, NULL, true);
312 } while (!s->started);
313
314 assert(s->vhost_net);
315
316 return 0;
317 }
318
319 static Chardev *net_vhost_claim_chardev(
320 const NetdevVhostUserOptions *opts, Error **errp)
321 {
322 Chardev *chr = qemu_chr_find(opts->chardev);
323
324 if (chr == NULL) {
325 error_setg(errp, "chardev \"%s\" not found", opts->chardev);
326 return NULL;
327 }
328
329 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
330 error_setg(errp, "chardev \"%s\" is not reconnectable",
331 opts->chardev);
332 return NULL;
333 }
334 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) {
335 error_setg(errp, "chardev \"%s\" does not support FD passing",
336 opts->chardev);
337 return NULL;
338 }
339
340 return chr;
341 }
342
343 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
344 {
345 const char *name = opaque;
346 const char *driver, *netdev;
347
348 driver = qemu_opt_get(opts, "driver");
349 netdev = qemu_opt_get(opts, "netdev");
350
351 if (!driver || !netdev) {
352 return 0;
353 }
354
355 if (strcmp(netdev, name) == 0 &&
356 !g_str_has_prefix(driver, "virtio-net-")) {
357 error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
358 return -1;
359 }
360
361 return 0;
362 }
363
364 int net_init_vhost_user(const Netdev *netdev, const char *name,
365 NetClientState *peer, Error **errp)
366 {
367 int queues;
368 const NetdevVhostUserOptions *vhost_user_opts;
369 Chardev *chr;
370
371 assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
372 vhost_user_opts = &netdev->u.vhost_user;
373
374 chr = net_vhost_claim_chardev(vhost_user_opts, errp);
375 if (!chr) {
376 return -1;
377 }
378
379 /* verify net frontend */
380 if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
381 (char *)name, errp)) {
382 return -1;
383 }
384
385 queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
386 if (queues < 1 || queues > MAX_QUEUE_NUM) {
387 error_setg(errp,
388 "vhost-user number of queues must be in range [1, %d]",
389 MAX_QUEUE_NUM);
390 return -1;
391 }
392
393 return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
394 }