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         options.nvqs = 2;
  89         net = vhost_net_init(&options);
  90         if (!net) {
  91             error_report("failed to init vhost_net for queue %d", i);
  92             goto err;
  93         }
  94
  95         if (i == 0) {
  96             max_queues = vhost_net_get_max_queues(net);
  97             if (queues > max_queues) {
  98                 error_report("you are asking more queues than supported: %d",
  99                              max_queues);
 100                 goto err;
 101             }
 102         }
 103
 104         if (s->vhost_net) {
 105             vhost_net_cleanup(s->vhost_net);
 106             g_free(s->vhost_net);
 107         }
 108         s->vhost_net = net;
 109     }
 110
 111     return 0;
 112
 113 err:
 114     if (net) {
 115         vhost_net_cleanup(net);
 116         g_free(net);
 117     }
 118     vhost_user_stop(i, ncs);
 119     return -1;
 120 }
 121
 122 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
 123                                   size_t size)
 124 {
 125     /* In case of RARP (message size is 60) notify backup to send a fake RARP.
 126        This fake RARP will be sent by backend only for guest
 127        without GUEST_ANNOUNCE capability.
 128      */
 129     if (size == 60) {
 130         NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
 131         int r;
 132         static int display_rarp_failure = 1;
 133         char mac_addr[6];
 134
 135         /* extract guest mac address from the RARP message */
 136         memcpy(mac_addr, &buf[6], 6);
 137
 138         r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
 139
 140         if ((r != 0) && (display_rarp_failure)) {
 141             fprintf(stderr,
 142                     "Vhost user backend fails to broadcast fake RARP\n");
 143             fflush(stderr);
 144             display_rarp_failure = 0;
 145         }
 146     }
 147
 148     return size;
 149 }
 150
 151 static void net_vhost_user_cleanup(NetClientState *nc)
 152 {
 153     NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
 154
 155     if (s->vhost_net) {
 156         vhost_net_cleanup(s->vhost_net);
 157         g_free(s->vhost_net);
 158         s->vhost_net = NULL;
 159     }
 160     if (nc->queue_index == 0) {
 161         if (s->watch) {
 162             g_source_remove(s->watch);
 163             s->watch = 0;
 164         }
 165         qemu_chr_fe_deinit(&s->chr, true);
 166         if (s->vhost_user) {
 167             vhost_user_cleanup(s->vhost_user);
 168             g_free(s->vhost_user);
 169             s->vhost_user = NULL;
 170         }
 171     }
 172
 173     qemu_purge_queued_packets(nc);
 174 }
 175
 176 static int vhost_user_set_vnet_endianness(NetClientState *nc,
 177                                           bool enable)
 178 {
 179     /* Nothing to do.  If the server supports
 180      * VHOST_USER_PROTOCOL_F_CROSS_ENDIAN, it will get the
 181      * vnet header endianness from there.  If it doesn't, negotiation
 182      * fails.
 183      */
 184     return 0;
 185 }
 186
 187 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
 188 {
 189     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
 190
 191     return true;
 192 }
 193
 194 static bool vhost_user_has_ufo(NetClientState *nc)
 195 {
 196     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
 197
 198     return true;
 199 }
 200
 201 static NetClientInfo net_vhost_user_info = {
 202         .type = NET_CLIENT_DRIVER_VHOST_USER,
 203         .size = sizeof(NetVhostUserState),
 204         .receive = vhost_user_receive,
 205         .cleanup = net_vhost_user_cleanup,
 206         .has_vnet_hdr = vhost_user_has_vnet_hdr,
 207         .has_ufo = vhost_user_has_ufo,
 208         .set_vnet_be = vhost_user_set_vnet_endianness,
 209         .set_vnet_le = vhost_user_set_vnet_endianness,
 210 };
 211
 212 static gboolean net_vhost_user_watch(void *do_not_use, GIOCondition cond,
 213                                      void *opaque)
 214 {
 215     NetVhostUserState *s = opaque;
 216
 217     qemu_chr_fe_disconnect(&s->chr);
 218
 219     return TRUE;
 220 }
 221
 222 static void net_vhost_user_event(void *opaque, QEMUChrEvent event);
 223
 224 static void chr_closed_bh(void *opaque)
 225 {
 226     const char *name = opaque;
 227     NetClientState *ncs[MAX_QUEUE_NUM];
 228     NetVhostUserState *s;
 229     Error *err = NULL;
 230     int queues, i;
 231
 232     queues = qemu_find_net_clients_except(name, ncs,
 233                                           NET_CLIENT_DRIVER_NIC,
 234                                           MAX_QUEUE_NUM);
 235     assert(queues < MAX_QUEUE_NUM);
 236
 237     s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
 238
 239     for (i = queues -1; i >= 0; i--) {
 240         s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
 241
 242         if (s->vhost_net) {
 243             s->acked_features = vhost_net_get_acked_features(s->vhost_net);
 244         }
 245     }
 246
 247     qmp_set_link(name, false, &err);
 248
 249     qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
 250                              NULL, opaque, NULL, true);
 251
 252     if (err) {
 253         error_report_err(err);
 254     }
 255 }
 256
 257 static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
 258 {
 259     const char *name = opaque;
 260     NetClientState *ncs[MAX_QUEUE_NUM];
 261     NetVhostUserState *s;
 262     Chardev *chr;
 263     Error *err = NULL;
 264     int queues;
 265
 266     queues = qemu_find_net_clients_except(name, ncs,
 267                                           NET_CLIENT_DRIVER_NIC,
 268                                           MAX_QUEUE_NUM);
 269     assert(queues < MAX_QUEUE_NUM);
 270
 271     s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
 272     chr = qemu_chr_fe_get_driver(&s->chr);
 273     trace_vhost_user_event(chr->label, event);
 274     switch (event) {
 275     case CHR_EVENT_OPENED:
 276         if (vhost_user_start(queues, ncs, s->vhost_user) < 0) {
 277             qemu_chr_fe_disconnect(&s->chr);
 278             return;
 279         }
 280         s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP,
 281                                          net_vhost_user_watch, s);
 282         qmp_set_link(name, true, &err);
 283         s->started = true;
 284         break;
 285     case CHR_EVENT_CLOSED:
 286         /* a close event may happen during a read/write, but vhost
 287          * code assumes the vhost_dev remains setup, so delay the
 288          * stop & clear to idle.
 289          * FIXME: better handle failure in vhost code, remove bh
 290          */
 291         if (s->watch) {
 292             AioContext *ctx = qemu_get_current_aio_context();
 293
 294             g_source_remove(s->watch);
 295             s->watch = 0;
 296             qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL,
 297                                      NULL, NULL, false);
 298
 299             aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque);
 300         }
 301         break;
 302     case CHR_EVENT_BREAK:
 303     case CHR_EVENT_MUX_IN:
 304     case CHR_EVENT_MUX_OUT:
 305         /* Ignore */
 306         break;
 307     }
 308
 309     if (err) {
 310         error_report_err(err);
 311     }
 312 }
 313
 314 static int net_vhost_user_init(NetClientState *peer, const char *device,
 315                                const char *name, Chardev *chr,
 316                                int queues)
 317 {
 318     Error *err = NULL;
 319     NetClientState *nc, *nc0 = NULL;
 320     NetVhostUserState *s = NULL;
 321     VhostUserState *user;
 322     int i;
 323
 324     assert(name);
 325     assert(queues > 0);
 326
 327     user = g_new0(struct VhostUserState, 1);
 328     for (i = 0; i < queues; i++) {
 329         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 330         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
 331                  i, chr->label);
 332         nc->queue_index = i;
 333         if (!nc0) {
 334             nc0 = nc;
 335             s = DO_UPCAST(NetVhostUserState, nc, nc);
 336             if (!qemu_chr_fe_init(&s->chr, chr, &err) ||
 337                 !vhost_user_init(user, &s->chr, &err)) {
 338                 error_report_err(err);
 339                 goto err;
 340             }
 341         }
 342         s = DO_UPCAST(NetVhostUserState, nc, nc);
 343         s->vhost_user = user;
 344     }
 345
 346     s = DO_UPCAST(NetVhostUserState, nc, nc0);
 347     do {
 348         if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) {
 349             error_report_err(err);
 350             goto err;
 351         }
 352         qemu_chr_fe_set_handlers(&s->chr, NULL, NULL,
 353                                  net_vhost_user_event, NULL, nc0->name, NULL,
 354                                  true);
 355     } while (!s->started);
 356
 357     assert(s->vhost_net);
 358
 359     return 0;
 360
 361 err:
 362     if (user) {
 363         vhost_user_cleanup(user);
 364         g_free(user);
 365         if (s) {
 366             s->vhost_user = NULL;
 367         }
 368     }
 369     if (nc0) {
 370         qemu_del_net_client(nc0);
 371     }
 372
 373     return -1;
 374 }
 375
 376 static Chardev *net_vhost_claim_chardev(
 377     const NetdevVhostUserOptions *opts, Error **errp)
 378 {
 379     Chardev *chr = qemu_chr_find(opts->chardev);
 380
 381     if (chr == NULL) {
 382         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 383         return NULL;
 384     }
 385
 386     if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
 387         error_setg(errp, "chardev \"%s\" is not reconnectable",
 388                    opts->chardev);
 389         return NULL;
 390     }
 391     if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) {
 392         error_setg(errp, "chardev \"%s\" does not support FD passing",
 393                    opts->chardev);
 394         return NULL;
 395     }
 396
 397     return chr;
 398 }
 399
 400 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 401 {
 402     const char *name = opaque;
 403     const char *driver, *netdev;
 404
 405     driver = qemu_opt_get(opts, "driver");
 406     netdev = qemu_opt_get(opts, "netdev");
 407
 408     if (!driver || !netdev) {
 409         return 0;
 410     }
 411
 412     if (strcmp(netdev, name) == 0 &&
 413         !g_str_has_prefix(driver, "virtio-net-")) {
 414         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 415         return -1;
 416     }
 417
 418     return 0;
 419 }
 420
 421 int net_init_vhost_user(const Netdev *netdev, const char *name,
 422                         NetClientState *peer, Error **errp)
 423 {
 424     int queues;
 425     const NetdevVhostUserOptions *vhost_user_opts;
 426     Chardev *chr;
 427
 428     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
 429     vhost_user_opts = &netdev->u.vhost_user;
 430
 431     chr = net_vhost_claim_chardev(vhost_user_opts, errp);
 432     if (!chr) {
 433         return -1;
 434     }
 435
 436     /* verify net frontend */
 437     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 438                           (char *)name, errp)) {
 439         return -1;
 440     }
 441
 442     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
 443     if (queues < 1 || queues > MAX_QUEUE_NUM) {
 444         error_setg(errp,
 445                    "vhost-user number of queues must be in range [1, %d]",
 446                    MAX_QUEUE_NUM);
 447         return -1;
 448     }
 449
 450     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 451 }