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 "sysemu/char.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     CharDriverState *chr;
  24     VHostNetState *vhost_net;
  25     guint watch;
  26     uint64_t acked_features;
  27 } VhostUserState;
  28
  29 typedef struct VhostUserChardevProps {
  30     bool is_socket;
  31     bool is_unix;
  32 } VhostUserChardevProps;
  33
  34 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
  35 {
  36     VhostUserState *s = DO_UPCAST(VhostUserState, 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     VhostUserState *s = DO_UPCAST(VhostUserState, 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     VhostUserState *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(VhostUserState, 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 {
  71     VhostNetOptions options;
  72     struct vhost_net *net = NULL;
  73     VhostUserState *s;
  74     int max_queues;
  75     int i;
  76
  77     options.backend_type = VHOST_BACKEND_TYPE_USER;
  78
  79     for (i = 0; i < queues; i++) {
  80         assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
  81
  82         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
  83
  84         options.net_backend = ncs[i];
  85         options.opaque      = s->chr;
  86         options.busyloop_timeout = 0;
  87         net = vhost_net_init(&options);
  88         if (!net) {
  89             error_report("failed to init vhost_net for queue %d", i);
  90             goto err;
  91         }
  92
  93         if (i == 0) {
  94             max_queues = vhost_net_get_max_queues(net);
  95             if (queues > max_queues) {
  96                 error_report("you are asking more queues than supported: %d",
  97                              max_queues);
  98                 goto err;
  99             }
 100         }
 101
 102         if (s->vhost_net) {
 103             vhost_net_cleanup(s->vhost_net);
 104             g_free(s->vhost_net);
 105         }
 106         s->vhost_net = net;
 107     }
 108
 109     return 0;
 110
 111 err:
 112     if (net) {
 113         vhost_net_cleanup(net);
 114     }
 115     vhost_user_stop(i, ncs);
 116     return -1;
 117 }
 118
 119 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
 120                                   size_t size)
 121 {
 122     /* In case of RARP (message size is 60) notify backup to send a fake RARP.
 123        This fake RARP will be sent by backend only for guest
 124        without GUEST_ANNOUNCE capability.
 125      */
 126     if (size == 60) {
 127         VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 128         int r;
 129         static int display_rarp_failure = 1;
 130         char mac_addr[6];
 131
 132         /* extract guest mac address from the RARP message */
 133         memcpy(mac_addr, &buf[6], 6);
 134
 135         r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
 136
 137         if ((r != 0) && (display_rarp_failure)) {
 138             fprintf(stderr,
 139                     "Vhost user backend fails to broadcast fake RARP\n");
 140             fflush(stderr);
 141             display_rarp_failure = 0;
 142         }
 143     }
 144
 145     return size;
 146 }
 147
 148 static void vhost_user_cleanup(NetClientState *nc)
 149 {
 150     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 151
 152     if (s->vhost_net) {
 153         vhost_net_cleanup(s->vhost_net);
 154         g_free(s->vhost_net);
 155         s->vhost_net = NULL;
 156     }
 157     if (s->chr) {
 158         qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, NULL);
 159         qemu_chr_fe_release(s->chr);
 160         s->chr = NULL;
 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_disconnect(s->chr);
 195
 196     return FALSE;
 197 }
 198
 199 static void net_vhost_user_event(void *opaque, int event)
 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     trace_vhost_user_event(s->chr->label, event);
 214     switch (event) {
 215     case CHR_EVENT_OPENED:
 216         s->watch = qemu_chr_fe_add_watch(s->chr, G_IO_HUP,
 217                                          net_vhost_user_watch, s);
 218         if (vhost_user_start(queues, ncs) < 0) {
 219             qemu_chr_disconnect(s->chr);
 220             return;
 221         }
 222         qmp_set_link(name, true, &err);
 223         break;
 224     case CHR_EVENT_CLOSED:
 225         qmp_set_link(name, false, &err);
 226         vhost_user_stop(queues, ncs);
 227         g_source_remove(s->watch);
 228         s->watch = 0;
 229         break;
 230     }
 231
 232     if (err) {
 233         error_report_err(err);
 234     }
 235 }
 236
 237 static int net_vhost_user_init(NetClientState *peer, const char *device,
 238                                const char *name, CharDriverState *chr,
 239                                int queues)
 240 {
 241     NetClientState *nc;
 242     VhostUserState *s;
 243     int i;
 244
 245     assert(name);
 246     assert(queues > 0);
 247
 248     for (i = 0; i < queues; i++) {
 249         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 250
 251         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
 252                  i, chr->label);
 253
 254         nc->queue_index = i;
 255
 256         s = DO_UPCAST(VhostUserState, nc, nc);
 257         s->chr = chr;
 258     }
 259
 260     qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, nc[0].name);
 261
 262     return 0;
 263 }
 264
 265 static int net_vhost_chardev_opts(void *opaque,
 266                                   const char *name, const char *value,
 267                                   Error **errp)
 268 {
 269     VhostUserChardevProps *props = opaque;
 270
 271     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
 272         props->is_socket = true;
 273     } else if (strcmp(name, "path") == 0) {
 274         props->is_unix = true;
 275     } else if (strcmp(name, "server") == 0) {
 276     } else {
 277         error_setg(errp,
 278                    "vhost-user does not support a chardev with option %s=%s",
 279                    name, value);
 280         return -1;
 281     }
 282     return 0;
 283 }
 284
 285 static CharDriverState *net_vhost_parse_chardev(
 286     const NetdevVhostUserOptions *opts, Error **errp)
 287 {
 288     CharDriverState *chr = qemu_chr_find(opts->chardev);
 289     VhostUserChardevProps props;
 290
 291     if (chr == NULL) {
 292         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 293         return NULL;
 294     }
 295
 296     /* inspect chardev opts */
 297     memset(&props, 0, sizeof(props));
 298     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
 299         return NULL;
 300     }
 301
 302     if (!props.is_socket || !props.is_unix) {
 303         error_setg(errp, "chardev \"%s\" is not a unix socket",
 304                    opts->chardev);
 305         return NULL;
 306     }
 307
 308     qemu_chr_fe_claim_no_fail(chr);
 309
 310     return chr;
 311 }
 312
 313 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 314 {
 315     const char *name = opaque;
 316     const char *driver, *netdev;
 317
 318     driver = qemu_opt_get(opts, "driver");
 319     netdev = qemu_opt_get(opts, "netdev");
 320
 321     if (!driver || !netdev) {
 322         return 0;
 323     }
 324
 325     if (strcmp(netdev, name) == 0 &&
 326         !g_str_has_prefix(driver, "virtio-net-")) {
 327         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 328         return -1;
 329     }
 330
 331     return 0;
 332 }
 333
 334 int net_init_vhost_user(const Netdev *netdev, const char *name,
 335                         NetClientState *peer, Error **errp)
 336 {
 337     int queues;
 338     const NetdevVhostUserOptions *vhost_user_opts;
 339     CharDriverState *chr;
 340
 341     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
 342     vhost_user_opts = &netdev->u.vhost_user;
 343
 344     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
 345     if (!chr) {
 346         return -1;
 347     }
 348
 349     /* verify net frontend */
 350     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 351                           (char *)name, errp)) {
 352         return -1;
 353     }
 354
 355     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
 356     if (queues < 1 || queues > MAX_QUEUE_NUM) {
 357         error_setg(errp,
 358                    "vhost-user number of queues must be in range [1, %d]",
 359                    MAX_QUEUE_NUM);
 360         return -1;
 361     }
 362
 363     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 364 }