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 "chardev/char-fe.h" 16 #include "qapi/error.h" 17 #include "qapi/qapi-commands-net.h" 18 #include "qemu/config-file.h" 19 #include "qemu/error-report.h" 20 #include "qemu/option.h" 21 #include "trace.h" 22 23 typedef struct VhostUserState { 24 NetClientState nc; 25 CharBackend chr; /* only queue index 0 */ 26 VHostNetState *vhost_net; 27 guint watch; 28 uint64_t acked_features; 29 bool started; 30 } VhostUserState; 31 32 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc) 33 { 34 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc); 35 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER); 36 return s->vhost_net; 37 } 38 39 uint64_t vhost_user_get_acked_features(NetClientState *nc) 40 { 41 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc); 42 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER); 43 return s->acked_features; 44 } 45 46 static void vhost_user_stop(int queues, NetClientState *ncs[]) 47 { 48 VhostUserState *s; 49 int i; 50 51 for (i = 0; i < queues; i++) { 52 assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER); 53 54 s = DO_UPCAST(VhostUserState, nc, ncs[i]); 55 56 if (s->vhost_net) { 57 /* save acked features */ 58 uint64_t features = vhost_net_get_acked_features(s->vhost_net); 59 if (features) { 60 s->acked_features = features; 61 } 62 vhost_net_cleanup(s->vhost_net); 63 } 64 } 65 } 66 67 static int vhost_user_start(int queues, NetClientState *ncs[], CharBackend *be) 68 { 69 VhostNetOptions options; 70 struct vhost_net *net = NULL; 71 VhostUserState *s; 72 int max_queues; 73 int i; 74 75 options.backend_type = VHOST_BACKEND_TYPE_USER; 76 77 for (i = 0; i < queues; i++) { 78 assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER); 79 80 s = DO_UPCAST(VhostUserState, nc, ncs[i]); 81 82 options.net_backend = ncs[i]; 83 options.opaque = be; 84 options.busyloop_timeout = 0; 85 net = vhost_net_init(&options); 86 if (!net) { 87 error_report("failed to init vhost_net for queue %d", i); 88 goto err; 89 } 90 91 if (i == 0) { 92 max_queues = vhost_net_get_max_queues(net); 93 if (queues > max_queues) { 94 error_report("you are asking more queues than supported: %d", 95 max_queues); 96 goto err; 97 } 98 } 99 100 if (s->vhost_net) { 101 vhost_net_cleanup(s->vhost_net); 102 g_free(s->vhost_net); 103 } 104 s->vhost_net = net; 105 } 106 107 return 0; 108 109 err: 110 if (net) { 111 vhost_net_cleanup(net); 112 g_free(net); 113 } 114 vhost_user_stop(i, ncs); 115 return -1; 116 } 117 118 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf, 119 size_t size) 120 { 121 /* In case of RARP (message size is 60) notify backup to send a fake RARP. 122 This fake RARP will be sent by backend only for guest 123 without GUEST_ANNOUNCE capability. 124 */ 125 if (size == 60) { 126 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc); 127 int r; 128 static int display_rarp_failure = 1; 129 char mac_addr[6]; 130 131 /* extract guest mac address from the RARP message */ 132 memcpy(mac_addr, &buf[6], 6); 133 134 r = vhost_net_notify_migration_done(s->vhost_net, mac_addr); 135 136 if ((r != 0) && (display_rarp_failure)) { 137 fprintf(stderr, 138 "Vhost user backend fails to broadcast fake RARP\n"); 139 fflush(stderr); 140 display_rarp_failure = 0; 141 } 142 } 143 144 return size; 145 } 146 147 static void vhost_user_cleanup(NetClientState *nc) 148 { 149 VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc); 150 151 if (s->vhost_net) { 152 vhost_net_cleanup(s->vhost_net); 153 g_free(s->vhost_net); 154 s->vhost_net = NULL; 155 } 156 if (nc->queue_index == 0) { 157 if (s->watch) { 158 g_source_remove(s->watch); 159 s->watch = 0; 160 } 161 qemu_chr_fe_deinit(&s->chr, true); 162 } 163 164 qemu_purge_queued_packets(nc); 165 } 166 167 static bool vhost_user_has_vnet_hdr(NetClientState *nc) 168 { 169 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER); 170 171 return true; 172 } 173 174 static bool vhost_user_has_ufo(NetClientState *nc) 175 { 176 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER); 177 178 return true; 179 } 180 181 static NetClientInfo net_vhost_user_info = { 182 .type = NET_CLIENT_DRIVER_VHOST_USER, 183 .size = sizeof(VhostUserState), 184 .receive = vhost_user_receive, 185 .cleanup = vhost_user_cleanup, 186 .has_vnet_hdr = vhost_user_has_vnet_hdr, 187 .has_ufo = vhost_user_has_ufo, 188 }; 189 190 static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond, 191 void *opaque) 192 { 193 VhostUserState *s = opaque; 194 195 qemu_chr_fe_disconnect(&s->chr); 196 197 return TRUE; 198 } 199 200 static void net_vhost_user_event(void *opaque, int event); 201 202 static void chr_closed_bh(void *opaque) 203 { 204 const char *name = opaque; 205 NetClientState *ncs[MAX_QUEUE_NUM]; 206 VhostUserState *s; 207 Error *err = NULL; 208 int queues; 209 210 queues = qemu_find_net_clients_except(name, ncs, 211 NET_CLIENT_DRIVER_NIC, 212 MAX_QUEUE_NUM); 213 assert(queues < MAX_QUEUE_NUM); 214 215 s = DO_UPCAST(VhostUserState, nc, ncs[0]); 216 217 qmp_set_link(name, false, &err); 218 vhost_user_stop(queues, ncs); 219 220 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event, 221 NULL, opaque, NULL, true); 222 223 if (err) { 224 error_report_err(err); 225 } 226 } 227 228 static void net_vhost_user_event(void *opaque, int event) 229 { 230 const char *name = opaque; 231 NetClientState *ncs[MAX_QUEUE_NUM]; 232 VhostUserState *s; 233 Chardev *chr; 234 Error *err = NULL; 235 int queues; 236 237 queues = qemu_find_net_clients_except(name, ncs, 238 NET_CLIENT_DRIVER_NIC, 239 MAX_QUEUE_NUM); 240 assert(queues < MAX_QUEUE_NUM); 241 242 s = DO_UPCAST(VhostUserState, nc, ncs[0]); 243 chr = qemu_chr_fe_get_driver(&s->chr); 244 trace_vhost_user_event(chr->label, event); 245 switch (event) { 246 case CHR_EVENT_OPENED: 247 if (vhost_user_start(queues, ncs, &s->chr) < 0) { 248 qemu_chr_fe_disconnect(&s->chr); 249 return; 250 } 251 s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP, 252 net_vhost_user_watch, s); 253 qmp_set_link(name, true, &err); 254 s->started = true; 255 break; 256 case CHR_EVENT_CLOSED: 257 /* a close event may happen during a read/write, but vhost 258 * code assumes the vhost_dev remains setup, so delay the 259 * stop & clear to idle. 260 * FIXME: better handle failure in vhost code, remove bh 261 */ 262 if (s->watch) { 263 AioContext *ctx = qemu_get_current_aio_context(); 264 265 g_source_remove(s->watch); 266 s->watch = 0; 267 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL, 268 NULL, NULL, false); 269 270 aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque); 271 } 272 break; 273 } 274 275 if (err) { 276 error_report_err(err); 277 } 278 } 279 280 static int net_vhost_user_init(NetClientState *peer, const char *device, 281 const char *name, Chardev *chr, 282 int queues) 283 { 284 Error *err = NULL; 285 NetClientState *nc, *nc0 = NULL; 286 VhostUserState *s; 287 int i; 288 289 assert(name); 290 assert(queues > 0); 291 292 for (i = 0; i < queues; i++) { 293 nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name); 294 snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s", 295 i, chr->label); 296 nc->queue_index = i; 297 if (!nc0) { 298 nc0 = nc; 299 s = DO_UPCAST(VhostUserState, nc, nc); 300 if (!qemu_chr_fe_init(&s->chr, chr, &err)) { 301 error_report_err(err); 302 return -1; 303 } 304 } 305 306 } 307 308 s = DO_UPCAST(VhostUserState, nc, nc0); 309 do { 310 if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) { 311 error_report_err(err); 312 return -1; 313 } 314 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, 315 net_vhost_user_event, NULL, nc0->name, NULL, 316 true); 317 } while (!s->started); 318 319 assert(s->vhost_net); 320 321 return 0; 322 } 323 324 static Chardev *net_vhost_claim_chardev( 325 const NetdevVhostUserOptions *opts, Error **errp) 326 { 327 Chardev *chr = qemu_chr_find(opts->chardev); 328 329 if (chr == NULL) { 330 error_setg(errp, "chardev \"%s\" not found", opts->chardev); 331 return NULL; 332 } 333 334 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) { 335 error_setg(errp, "chardev \"%s\" is not reconnectable", 336 opts->chardev); 337 return NULL; 338 } 339 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) { 340 error_setg(errp, "chardev \"%s\" does not support FD passing", 341 opts->chardev); 342 return NULL; 343 } 344 345 return chr; 346 } 347 348 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp) 349 { 350 const char *name = opaque; 351 const char *driver, *netdev; 352 353 driver = qemu_opt_get(opts, "driver"); 354 netdev = qemu_opt_get(opts, "netdev"); 355 356 if (!driver || !netdev) { 357 return 0; 358 } 359 360 if (strcmp(netdev, name) == 0 && 361 !g_str_has_prefix(driver, "virtio-net-")) { 362 error_setg(errp, "vhost-user requires frontend driver virtio-net-*"); 363 return -1; 364 } 365 366 return 0; 367 } 368 369 int net_init_vhost_user(const Netdev *netdev, const char *name, 370 NetClientState *peer, Error **errp) 371 { 372 int queues; 373 const NetdevVhostUserOptions *vhost_user_opts; 374 Chardev *chr; 375 376 assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER); 377 vhost_user_opts = &netdev->u.vhost_user; 378 379 chr = net_vhost_claim_chardev(vhost_user_opts, errp); 380 if (!chr) { 381 return -1; 382 } 383 384 /* verify net frontend */ 385 if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net, 386 (char *)name, errp)) { 387 return -1; 388 } 389 390 queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1; 391 if (queues < 1 || queues > MAX_QUEUE_NUM) { 392 error_setg(errp, 393 "vhost-user number of queues must be in range [1, %d]", 394 MAX_QUEUE_NUM); 395 return -1; 396 } 397 398 return net_vhost_user_init(peer, "vhost_user", name, chr, queues); 399 } 400