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 "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 if (s->watch) { 155 g_source_remove(s->watch); 156 s->watch = 0; 157 } 158 qemu_chr_fe_deinit(&s->chr, true); 159 } 160 161 qemu_purge_queued_packets(nc); 162 } 163 164 static bool vhost_user_has_vnet_hdr(NetClientState *nc) 165 { 166 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER); 167 168 return true; 169 } 170 171 static bool vhost_user_has_ufo(NetClientState *nc) 172 { 173 assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER); 174 175 return true; 176 } 177 178 static NetClientInfo net_vhost_user_info = { 179 .type = NET_CLIENT_DRIVER_VHOST_USER, 180 .size = sizeof(VhostUserState), 181 .receive = vhost_user_receive, 182 .cleanup = vhost_user_cleanup, 183 .has_vnet_hdr = vhost_user_has_vnet_hdr, 184 .has_ufo = vhost_user_has_ufo, 185 }; 186 187 static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond, 188 void *opaque) 189 { 190 VhostUserState *s = opaque; 191 192 qemu_chr_fe_disconnect(&s->chr); 193 194 return TRUE; 195 } 196 197 static void net_vhost_user_event(void *opaque, int event); 198 199 static void chr_closed_bh(void *opaque) 200 { 201 const char *name = opaque; 202 NetClientState *ncs[MAX_QUEUE_NUM]; 203 VhostUserState *s; 204 Error *err = NULL; 205 int queues; 206 207 queues = qemu_find_net_clients_except(name, ncs, 208 NET_CLIENT_DRIVER_NIC, 209 MAX_QUEUE_NUM); 210 assert(queues < MAX_QUEUE_NUM); 211 212 s = DO_UPCAST(VhostUserState, nc, ncs[0]); 213 214 qmp_set_link(name, false, &err); 215 vhost_user_stop(queues, ncs); 216 217 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event, 218 NULL, opaque, NULL, true); 219 220 if (err) { 221 error_report_err(err); 222 } 223 } 224 225 static void net_vhost_user_event(void *opaque, int event) 226 { 227 const char *name = opaque; 228 NetClientState *ncs[MAX_QUEUE_NUM]; 229 VhostUserState *s; 230 Chardev *chr; 231 Error *err = NULL; 232 int queues; 233 234 queues = qemu_find_net_clients_except(name, ncs, 235 NET_CLIENT_DRIVER_NIC, 236 MAX_QUEUE_NUM); 237 assert(queues < MAX_QUEUE_NUM); 238 239 s = DO_UPCAST(VhostUserState, nc, ncs[0]); 240 chr = qemu_chr_fe_get_driver(&s->chr); 241 trace_vhost_user_event(chr->label, event); 242 switch (event) { 243 case CHR_EVENT_OPENED: 244 if (vhost_user_start(queues, ncs, &s->chr) < 0) { 245 qemu_chr_fe_disconnect(&s->chr); 246 return; 247 } 248 s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP, 249 net_vhost_user_watch, s); 250 qmp_set_link(name, true, &err); 251 s->started = true; 252 break; 253 case CHR_EVENT_CLOSED: 254 /* a close event may happen during a read/write, but vhost 255 * code assumes the vhost_dev remains setup, so delay the 256 * stop & clear to idle. 257 * FIXME: better handle failure in vhost code, remove bh 258 */ 259 if (s->watch) { 260 AioContext *ctx = qemu_get_current_aio_context(); 261 262 g_source_remove(s->watch); 263 s->watch = 0; 264 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL, 265 NULL, NULL, false); 266 267 aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque); 268 } 269 break; 270 } 271 272 if (err) { 273 error_report_err(err); 274 } 275 } 276 277 static int net_vhost_user_init(NetClientState *peer, const char *device, 278 const char *name, Chardev *chr, 279 int queues) 280 { 281 Error *err = NULL; 282 NetClientState *nc, *nc0 = NULL; 283 VhostUserState *s; 284 int i; 285 286 assert(name); 287 assert(queues > 0); 288 289 for (i = 0; i < queues; i++) { 290 nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name); 291 snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s", 292 i, chr->label); 293 nc->queue_index = i; 294 if (!nc0) { 295 nc0 = nc; 296 s = DO_UPCAST(VhostUserState, nc, nc); 297 if (!qemu_chr_fe_init(&s->chr, chr, &err)) { 298 error_report_err(err); 299 return -1; 300 } 301 } 302 303 } 304 305 s = DO_UPCAST(VhostUserState, nc, nc0); 306 do { 307 if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) { 308 error_report_err(err); 309 return -1; 310 } 311 qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, 312 net_vhost_user_event, NULL, nc0->name, NULL, 313 true); 314 } while (!s->started); 315 316 assert(s->vhost_net); 317 318 return 0; 319 } 320 321 static Chardev *net_vhost_claim_chardev( 322 const NetdevVhostUserOptions *opts, Error **errp) 323 { 324 Chardev *chr = qemu_chr_find(opts->chardev); 325 326 if (chr == NULL) { 327 error_setg(errp, "chardev \"%s\" not found", opts->chardev); 328 return NULL; 329 } 330 331 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) { 332 error_setg(errp, "chardev \"%s\" is not reconnectable", 333 opts->chardev); 334 return NULL; 335 } 336 if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) { 337 error_setg(errp, "chardev \"%s\" does not support FD passing", 338 opts->chardev); 339 return NULL; 340 } 341 342 return chr; 343 } 344 345 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp) 346 { 347 const char *name = opaque; 348 const char *driver, *netdev; 349 350 driver = qemu_opt_get(opts, "driver"); 351 netdev = qemu_opt_get(opts, "netdev"); 352 353 if (!driver || !netdev) { 354 return 0; 355 } 356 357 if (strcmp(netdev, name) == 0 && 358 !g_str_has_prefix(driver, "virtio-net-")) { 359 error_setg(errp, "vhost-user requires frontend driver virtio-net-*"); 360 return -1; 361 } 362 363 return 0; 364 } 365 366 int net_init_vhost_user(const Netdev *netdev, const char *name, 367 NetClientState *peer, Error **errp) 368 { 369 int queues; 370 const NetdevVhostUserOptions *vhost_user_opts; 371 Chardev *chr; 372 373 assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER); 374 vhost_user_opts = &netdev->u.vhost_user; 375 376 chr = net_vhost_claim_chardev(vhost_user_opts, errp); 377 if (!chr) { 378 return -1; 379 } 380 381 /* verify net frontend */ 382 if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net, 383 (char *)name, errp)) { 384 return -1; 385 } 386 387 queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1; 388 if (queues < 1 || queues > MAX_QUEUE_NUM) { 389 error_setg(errp, 390 "vhost-user number of queues must be in range [1, %d]", 391 MAX_QUEUE_NUM); 392 return -1; 393 } 394 395 return net_vhost_user_init(peer, "vhost_user", name, chr, queues); 396 } 397