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     vhost_user_stop(queues, ncs);
 240
 241     qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
 242                              NULL, opaque, NULL, true);
 243
 244     if (err) {
 245         error_report_err(err);
 246     }
 247 }
 248
 249 static void net_vhost_user_event(void *opaque, int event)
 250 {
 251     const char *name = opaque;
 252     NetClientState *ncs[MAX_QUEUE_NUM];
 253     NetVhostUserState *s;
 254     Chardev *chr;
 255     Error *err = NULL;
 256     int queues;
 257
 258     queues = qemu_find_net_clients_except(name, ncs,
 259                                           NET_CLIENT_DRIVER_NIC,
 260                                           MAX_QUEUE_NUM);
 261     assert(queues < MAX_QUEUE_NUM);
 262
 263     s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
 264     chr = qemu_chr_fe_get_driver(&s->chr);
 265     trace_vhost_user_event(chr->label, event);
 266     switch (event) {
 267     case CHR_EVENT_OPENED:
 268         if (vhost_user_start(queues, ncs, s->vhost_user) < 0) {
 269             qemu_chr_fe_disconnect(&s->chr);
 270             return;
 271         }
 272         s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP,
 273                                          net_vhost_user_watch, s);
 274         qmp_set_link(name, true, &err);
 275         s->started = true;
 276         break;
 277     case CHR_EVENT_CLOSED:
 278         /* a close event may happen during a read/write, but vhost
 279          * code assumes the vhost_dev remains setup, so delay the
 280          * stop & clear to idle.
 281          * FIXME: better handle failure in vhost code, remove bh
 282          */
 283         if (s->watch) {
 284             AioContext *ctx = qemu_get_current_aio_context();
 285
 286             g_source_remove(s->watch);
 287             s->watch = 0;
 288             qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL,
 289                                      NULL, NULL, false);
 290
 291             aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque);
 292         }
 293         break;
 294     }
 295
 296     if (err) {
 297         error_report_err(err);
 298     }
 299 }
 300
 301 static int net_vhost_user_init(NetClientState *peer, const char *device,
 302                                const char *name, Chardev *chr,
 303                                int queues)
 304 {
 305     Error *err = NULL;
 306     NetClientState *nc, *nc0 = NULL;
 307     NetVhostUserState *s = NULL;
 308     VhostUserState *user;
 309     int i;
 310
 311     assert(name);
 312     assert(queues > 0);
 313
 314     user = g_new0(struct VhostUserState, 1);
 315     for (i = 0; i < queues; i++) {
 316         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 317         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
 318                  i, chr->label);
 319         nc->queue_index = i;
 320         if (!nc0) {
 321             nc0 = nc;
 322             s = DO_UPCAST(NetVhostUserState, nc, nc);
 323             if (!qemu_chr_fe_init(&s->chr, chr, &err) ||
 324                 !vhost_user_init(user, &s->chr, &err)) {
 325                 error_report_err(err);
 326                 goto err;
 327             }
 328         }
 329         s = DO_UPCAST(NetVhostUserState, nc, nc);
 330         s->vhost_user = user;
 331     }
 332
 333     s = DO_UPCAST(NetVhostUserState, nc, nc0);
 334     do {
 335         if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) {
 336             error_report_err(err);
 337             goto err;
 338         }
 339         qemu_chr_fe_set_handlers(&s->chr, NULL, NULL,
 340                                  net_vhost_user_event, NULL, nc0->name, NULL,
 341                                  true);
 342     } while (!s->started);
 343
 344     assert(s->vhost_net);
 345
 346     return 0;
 347
 348 err:
 349     if (user) {
 350         vhost_user_cleanup(user);
 351         g_free(user);
 352         if (s) {
 353             s->vhost_user = NULL;
 354         }
 355     }
 356     if (nc0) {
 357         qemu_del_net_client(nc0);
 358     }
 359
 360     return -1;
 361 }
 362
 363 static Chardev *net_vhost_claim_chardev(
 364     const NetdevVhostUserOptions *opts, Error **errp)
 365 {
 366     Chardev *chr = qemu_chr_find(opts->chardev);
 367
 368     if (chr == NULL) {
 369         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 370         return NULL;
 371     }
 372
 373     if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
 374         error_setg(errp, "chardev \"%s\" is not reconnectable",
 375                    opts->chardev);
 376         return NULL;
 377     }
 378     if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) {
 379         error_setg(errp, "chardev \"%s\" does not support FD passing",
 380                    opts->chardev);
 381         return NULL;
 382     }
 383
 384     return chr;
 385 }
 386
 387 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 388 {
 389     const char *name = opaque;
 390     const char *driver, *netdev;
 391
 392     driver = qemu_opt_get(opts, "driver");
 393     netdev = qemu_opt_get(opts, "netdev");
 394
 395     if (!driver || !netdev) {
 396         return 0;
 397     }
 398
 399     if (strcmp(netdev, name) == 0 &&
 400         !g_str_has_prefix(driver, "virtio-net-")) {
 401         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 402         return -1;
 403     }
 404
 405     return 0;
 406 }
 407
 408 int net_init_vhost_user(const Netdev *netdev, const char *name,
 409                         NetClientState *peer, Error **errp)
 410 {
 411     int queues;
 412     const NetdevVhostUserOptions *vhost_user_opts;
 413     Chardev *chr;
 414
 415     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
 416     vhost_user_opts = &netdev->u.vhost_user;
 417
 418     chr = net_vhost_claim_chardev(vhost_user_opts, errp);
 419     if (!chr) {
 420         return -1;
 421     }
 422
 423     /* verify net frontend */
 424     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 425                           (char *)name, errp)) {
 426         return -1;
 427     }
 428
 429     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
 430     if (queues < 1 || queues > MAX_QUEUE_NUM) {
 431         error_setg(errp,
 432                    "vhost-user number of queues must be in range [1, %d]",
 433                    MAX_QUEUE_NUM);
 434         return -1;
 435     }
 436
 437     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 438 }