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 "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
  24 typedef 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
  34 VHostNetState *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
  41 uint64_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
  48 static 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
  69 static 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
 112 err:
 113     if (net) {
 114         vhost_net_cleanup(net);
 115         g_free(net);
 116     }
 117     vhost_user_stop(i, ncs);
 118     return -1;
 119 }
 120
 121 static 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
 150 static 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
 175 static 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
 186 static 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
 193 static bool vhost_user_has_ufo(NetClientState *nc)
 194 {
 195     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
 196
 197     return true;
 198 }
 199
 200 static 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
 211 static 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
 221 static void net_vhost_user_event(void *opaque, int event);
 222
 223 static 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
 248 static 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
 300 static 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
 347 err:
 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
 362 static 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
 386 static 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
 407 int 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 }