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 "hw/virtio/vhost-user.h"
16#include "chardev/char-fe.h"
17#include "qapi/error.h"
18#include "qapi/qapi-commands-net.h"
19#include "qemu/config-file.h"
20#include "qemu/error-report.h"
21#include "qemu/option.h"
22#include "trace.h"
23
24typedef struct NetVhostUserState {
25 NetClientState nc;
26 CharBackend chr; /* only queue index 0 */
27 VhostUserState *vhost_user;
28 VHostNetState *vhost_net;
29 guint watch;
30 uint64_t acked_features;
31 bool started;
32} NetVhostUserState;
33
34VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
35{
36 NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
37 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
38 return s->vhost_net;
39}
40
41uint64_t vhost_user_get_acked_features(NetClientState *nc)
42{
43 NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
44 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
45 return s->acked_features;
46}
47
48static void vhost_user_stop(int queues, NetClientState *ncs[])
49{
50 NetVhostUserState *s;
51 int i;
52
53 for (i = 0; i < queues; i++) {
54 assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
55
56 s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
57
58 if (s->vhost_net) {
59 /* save acked features */
60 uint64_t features = vhost_net_get_acked_features(s->vhost_net);
61 if (features) {
62 s->acked_features = features;
63 }
64 vhost_net_cleanup(s->vhost_net);
65 }
66 }
67}
68
69static int vhost_user_start(int queues, NetClientState *ncs[],
70 VhostUserState *be)
71{
72 VhostNetOptions options;
73 struct vhost_net *net = NULL;
74 NetVhostUserState *s;
75 int max_queues;
76 int i;
77
78 options.backend_type = VHOST_BACKEND_TYPE_USER;
79
80 for (i = 0; i < queues; i++) {
81 assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
82
83 s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
84
85 options.net_backend = ncs[i];
86 options.opaque = be;
87 options.busyloop_timeout = 0;
88 net = vhost_net_init(&options);
89 if (!net) {
90 error_report("failed to init vhost_net for queue %d", i);
91 goto err;
92 }
93
94 if (i == 0) {
95 max_queues = vhost_net_get_max_queues(net);
96 if (queues > max_queues) {
97 error_report("you are asking more queues than supported: %d",
98 max_queues);
99 goto err;
100 }
101 }
102
103 if (s->vhost_net) {
104 vhost_net_cleanup(s->vhost_net);
105 g_free(s->vhost_net);
106 }
107 s->vhost_net = net;
108 }
109
110 return 0;
111
112err:
113 if (net) {
114 vhost_net_cleanup(net);
115 g_free(net);
116 }
117 vhost_user_stop(i, ncs);
118 return -1;
119}
120
121static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
122 size_t size)
123{
124 /* In case of RARP (message size is 60) notify backup to send a fake RARP.
125 This fake RARP will be sent by backend only for guest
126 without GUEST_ANNOUNCE capability.
127 */
128 if (size == 60) {
129 NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
130 int r;
131 static int display_rarp_failure = 1;
132 char mac_addr[6];
133
134 /* extract guest mac address from the RARP message */
135 memcpy(mac_addr, &buf[6], 6);
136
137 r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
138
139 if ((r != 0) && (display_rarp_failure)) {
140 fprintf(stderr,
141 "Vhost user backend fails to broadcast fake RARP\n");
142 fflush(stderr);
143 display_rarp_failure = 0;
144 }
145 }
146
147 return size;
148}
149
150static void net_vhost_user_cleanup(NetClientState *nc)
151{
152 NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
153
154 if (s->vhost_net) {
155 vhost_net_cleanup(s->vhost_net);
156 g_free(s->vhost_net);
157 s->vhost_net = NULL;
158 }
159 if (nc->queue_index == 0) {
160 if (s->watch) {
161 g_source_remove(s->watch);
162 s->watch = 0;
163 }
164 qemu_chr_fe_deinit(&s->chr, true);
165 if (s->vhost_user) {
166 vhost_user_cleanup(s->vhost_user);
167 g_free(s->vhost_user);
168 s->vhost_user = NULL;
169 }
170 }
171
172 qemu_purge_queued_packets(nc);
173}
174
175static int vhost_user_set_vnet_endianness(NetClientState *nc,
176 bool enable)
177{
178 /* Nothing to do. If the server supports
179 * VHOST_USER_PROTOCOL_F_CROSS_ENDIAN, it will get the
180 * vnet header endianness from there. If it doesn't, negotiation
181 * fails.
182 */
183 return 0;
184}
185
186static bool vhost_user_has_vnet_hdr(NetClientState *nc)
187{
188 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
189
190 return true;
191}
192
193static bool vhost_user_has_ufo(NetClientState *nc)
194{
195 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
196
197 return true;
198}
199
200static NetClientInfo net_vhost_user_info = {
201 .type = NET_CLIENT_DRIVER_VHOST_USER,
202 .size = sizeof(NetVhostUserState),
203 .receive = vhost_user_receive,
204 .cleanup = net_vhost_user_cleanup,
205 .has_vnet_hdr = vhost_user_has_vnet_hdr,
206 .has_ufo = vhost_user_has_ufo,
207 .set_vnet_be = vhost_user_set_vnet_endianness,
208 .set_vnet_le = vhost_user_set_vnet_endianness,
209};
210
211static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
212 void *opaque)
213{
214 NetVhostUserState *s = opaque;
215
216 qemu_chr_fe_disconnect(&s->chr);
217
218 return TRUE;
219}
220
221static void net_vhost_user_event(void *opaque, int event);
222
223static void chr_closed_bh(void *opaque)
224{
225 const char *name = opaque;
226 NetClientState *ncs[MAX_QUEUE_NUM];
227 NetVhostUserState *s;
228 Error *err = NULL;
229 int queues;
230
231 queues = qemu_find_net_clients_except(name, ncs,
232 NET_CLIENT_DRIVER_NIC,
233 MAX_QUEUE_NUM);
234 assert(queues < MAX_QUEUE_NUM);
235
236 s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
237
238 qmp_set_link(name, false, &err);
239
240 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
241 NULL, opaque, NULL, true);
242
243 if (err) {
244 error_report_err(err);
245 }
246}
247
248static void net_vhost_user_event(void *opaque, int event)
249{
250 const char *name = opaque;
251 NetClientState *ncs[MAX_QUEUE_NUM];
252 NetVhostUserState *s;
253 Chardev *chr;
254 Error *err = NULL;
255 int queues;
256
257 queues = qemu_find_net_clients_except(name, ncs,
258 NET_CLIENT_DRIVER_NIC,
259 MAX_QUEUE_NUM);
260 assert(queues < MAX_QUEUE_NUM);
261
262 s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
263 chr = qemu_chr_fe_get_driver(&s->chr);
264 trace_vhost_user_event(chr->label, event);
265 switch (event) {
266 case CHR_EVENT_OPENED:
267 if (vhost_user_start(queues, ncs, s->vhost_user) < 0) {
268 qemu_chr_fe_disconnect(&s->chr);
269 return;
270 }
271 s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP,
272 net_vhost_user_watch, s);
273 qmp_set_link(name, true, &err);
274 s->started = true;
275 break;
276 case CHR_EVENT_CLOSED:
277 /* a close event may happen during a read/write, but vhost
278 * code assumes the vhost_dev remains setup, so delay the
279 * stop & clear to idle.
280 * FIXME: better handle failure in vhost code, remove bh
281 */
282 if (s->watch) {
283 AioContext *ctx = qemu_get_current_aio_context();
284
285 g_source_remove(s->watch);
286 s->watch = 0;
287 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL,
288 NULL, NULL, false);
289
290 aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque);
291 }
292 break;
293 }
294
295 if (err) {
296 error_report_err(err);
297 }
298}
299
300static int net_vhost_user_init(NetClientState *peer, const char *device,
301 const char *name, Chardev *chr,
302 int queues)
303{
304 Error *err = NULL;
305 NetClientState *nc, *nc0 = NULL;
306 NetVhostUserState *s = NULL;
307 VhostUserState *user;
308 int i;
309
310 assert(name);
311 assert(queues > 0);
312
313 user = g_new0(struct VhostUserState, 1);
314 for (i = 0; i < queues; i++) {
315 nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
316 snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
317 i, chr->label);
318 nc->queue_index = i;
319 if (!nc0) {
320 nc0 = nc;
321 s = DO_UPCAST(NetVhostUserState, nc, nc);
322 if (!qemu_chr_fe_init(&s->chr, chr, &err) ||
323 !vhost_user_init(user, &s->chr, &err)) {
324 error_report_err(err);
325 goto err;
326 }
327 }
328 s = DO_UPCAST(NetVhostUserState, nc, nc);
329 s->vhost_user = user;
330 }
331
332 s = DO_UPCAST(NetVhostUserState, nc, nc0);
333 do {
334 if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) {
335 error_report_err(err);
336 goto err;
337 }
338 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL,
339 net_vhost_user_event, NULL, nc0->name, NULL,
340 true);
341 } while (!s->started);
342
343 assert(s->vhost_net);
344
345 return 0;
346
347err:
348 if (user) {
349 vhost_user_cleanup(user);
350 g_free(user);
351 if (s) {
352 s->vhost_user = NULL;
353 }
354 }
355 if (nc0) {
356 qemu_del_net_client(nc0);
357 }
358
359 return -1;
360}
361
362static Chardev *net_vhost_claim_chardev(
363 const NetdevVhostUserOptions *opts, Error **errp)
364{
365 Chardev *chr = qemu_chr_find(opts->chardev);
366
367 if (chr == NULL) {
368 error_setg(errp, "chardev \"%s\" not found", opts->chardev);
369 return NULL;
370 }
371
372 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
373 error_setg(errp, "chardev \"%s\" is not reconnectable",
374 opts->chardev);
375 return NULL;
376 }
377 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) {
378 error_setg(errp, "chardev \"%s\" does not support FD passing",
379 opts->chardev);
380 return NULL;
381 }
382
383 return chr;
384}
385
386static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
387{
388 const char *name = opaque;
389 const char *driver, *netdev;
390
391 driver = qemu_opt_get(opts, "driver");
392 netdev = qemu_opt_get(opts, "netdev");
393
394 if (!driver || !netdev) {
395 return 0;
396 }
397
398 if (strcmp(netdev, name) == 0 &&
399 !g_str_has_prefix(driver, "virtio-net-")) {
400 error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
401 return -1;
402 }
403
404 return 0;
405}
406
407int net_init_vhost_user(const Netdev *netdev, const char *name,
408 NetClientState *peer, Error **errp)
409{
410 int queues;
411 const NetdevVhostUserOptions *vhost_user_opts;
412 Chardev *chr;
413
414 assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
415 vhost_user_opts = &netdev->u.vhost_user;
416
417 chr = net_vhost_claim_chardev(vhost_user_opts, errp);
418 if (!chr) {
419 return -1;
420 }
421
422 /* verify net frontend */
423 if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
424 (char *)name, errp)) {
425 return -1;
426 }
427
428 queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
429 if (queues < 1 || queues > MAX_QUEUE_NUM) {
430 error_setg(errp,
431 "vhost-user number of queues must be in range [1, %d]",
432 MAX_QUEUE_NUM);
433 return -1;
434 }
435
436 return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
437}
438