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