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     int watch;
  26 } VhostUserState;
  27
  28 typedef struct VhostUserChardevProps {
  29     bool is_socket;
  30     bool is_unix;
  31 } VhostUserChardevProps;
  32
  33 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
  34 {
  35     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  36     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  37     return s->vhost_net;
  38 }
  39
  40 static int vhost_user_running(VhostUserState *s)
  41 {
  42     return (s->vhost_net) ? 1 : 0;
  43 }
  44
  45 static void vhost_user_stop(int queues, NetClientState *ncs[])
  46 {
  47     VhostUserState *s;
  48     int i;
  49
  50     for (i = 0; i < queues; i++) {
  51         assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  52
  53         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
  54         if (!vhost_user_running(s)) {
  55             continue;
  56         }
  57
  58         if (s->vhost_net) {
  59             vhost_net_cleanup(s->vhost_net);
  60             s->vhost_net = NULL;
  61         }
  62     }
  63 }
  64
  65 static int vhost_user_start(int queues, NetClientState *ncs[])
  66 {
  67     VhostNetOptions options;
  68     VhostUserState *s;
  69     int max_queues;
  70     int i;
  71
  72     options.backend_type = VHOST_BACKEND_TYPE_USER;
  73
  74     for (i = 0; i < queues; i++) {
  75         assert (ncs[i]->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  76
  77         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
  78         if (vhost_user_running(s)) {
  79             continue;
  80         }
  81
  82         options.net_backend = ncs[i];
  83         options.opaque      = s->chr;
  84         s->vhost_net = vhost_net_init(&options);
  85         if (!s->vhost_net) {
  86             error_report("failed to init vhost_net for queue %d", i);
  87             goto err;
  88         }
  89
  90         if (i == 0) {
  91             max_queues = vhost_net_get_max_queues(s->vhost_net);
  92             if (queues > max_queues) {
  93                 error_report("you are asking more queues than supported: %d",
  94                              max_queues);
  95                 goto err;
  96             }
  97         }
  98     }
  99
 100     return 0;
 101
 102 err:
 103     vhost_user_stop(i + 1, ncs);
 104     return -1;
 105 }
 106
 107 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
 108                                   size_t size)
 109 {
 110     /* In case of RARP (message size is 60) notify backup to send a fake RARP.
 111        This fake RARP will be sent by backend only for guest
 112        without GUEST_ANNOUNCE capability.
 113      */
 114     if (size == 60) {
 115         VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 116         int r;
 117         static int display_rarp_failure = 1;
 118         char mac_addr[6];
 119
 120         /* extract guest mac address from the RARP message */
 121         memcpy(mac_addr, &buf[6], 6);
 122
 123         r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
 124
 125         if ((r != 0) && (display_rarp_failure)) {
 126             fprintf(stderr,
 127                     "Vhost user backend fails to broadcast fake RARP\n");
 128             fflush(stderr);
 129             display_rarp_failure = 0;
 130         }
 131     }
 132
 133     return size;
 134 }
 135
 136 static void vhost_user_cleanup(NetClientState *nc)
 137 {
 138     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 139
 140     if (s->vhost_net) {
 141         vhost_net_cleanup(s->vhost_net);
 142         s->vhost_net = NULL;
 143     }
 144
 145     qemu_purge_queued_packets(nc);
 146 }
 147
 148 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
 149 {
 150     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 151
 152     return true;
 153 }
 154
 155 static bool vhost_user_has_ufo(NetClientState *nc)
 156 {
 157     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 158
 159     return true;
 160 }
 161
 162 static NetClientInfo net_vhost_user_info = {
 163         .type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
 164         .size = sizeof(VhostUserState),
 165         .receive = vhost_user_receive,
 166         .cleanup = vhost_user_cleanup,
 167         .has_vnet_hdr = vhost_user_has_vnet_hdr,
 168         .has_ufo = vhost_user_has_ufo,
 169 };
 170
 171 static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
 172                                            void *opaque)
 173 {
 174     VhostUserState *s = opaque;
 175     uint8_t buf[1];
 176
 177     /* We don't actually want to read anything, but CHR_EVENT_CLOSED will be
 178      * raised as a side-effect of the read.
 179      */
 180     qemu_chr_fe_read_all(s->chr, buf, sizeof(buf));
 181
 182     return FALSE;
 183 }
 184
 185 static void net_vhost_user_event(void *opaque, int event)
 186 {
 187     const char *name = opaque;
 188     NetClientState *ncs[MAX_QUEUE_NUM];
 189     VhostUserState *s;
 190     Error *err = NULL;
 191     int queues;
 192
 193     queues = qemu_find_net_clients_except(name, ncs,
 194                                           NET_CLIENT_OPTIONS_KIND_NIC,
 195                                           MAX_QUEUE_NUM);
 196     assert(queues < MAX_QUEUE_NUM);
 197
 198     s = DO_UPCAST(VhostUserState, nc, ncs[0]);
 199     trace_vhost_user_event(s->chr->label, event);
 200     switch (event) {
 201     case CHR_EVENT_OPENED:
 202         s->watch = qemu_chr_fe_add_watch(s->chr, G_IO_HUP,
 203                                          net_vhost_user_watch, s);
 204         if (vhost_user_start(queues, ncs) < 0) {
 205             qemu_chr_disconnect(s->chr);
 206             return;
 207         }
 208         qmp_set_link(name, true, &err);
 209         break;
 210     case CHR_EVENT_CLOSED:
 211         qmp_set_link(name, false, &err);
 212         vhost_user_stop(queues, ncs);
 213         g_source_remove(s->watch);
 214         s->watch = 0;
 215         break;
 216     }
 217
 218     if (err) {
 219         error_report_err(err);
 220     }
 221 }
 222
 223 static int net_vhost_user_init(NetClientState *peer, const char *device,
 224                                const char *name, CharDriverState *chr,
 225                                int queues)
 226 {
 227     NetClientState *nc;
 228     VhostUserState *s;
 229     int i;
 230
 231     assert(name);
 232     assert(queues > 0);
 233
 234     for (i = 0; i < queues; i++) {
 235         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 236
 237         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
 238                  i, chr->label);
 239
 240         nc->queue_index = i;
 241
 242         s = DO_UPCAST(VhostUserState, nc, nc);
 243         s->chr = chr;
 244     }
 245
 246     qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, nc[0].name);
 247
 248     return 0;
 249 }
 250
 251 static int net_vhost_chardev_opts(void *opaque,
 252                                   const char *name, const char *value,
 253                                   Error **errp)
 254 {
 255     VhostUserChardevProps *props = opaque;
 256
 257     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
 258         props->is_socket = true;
 259     } else if (strcmp(name, "path") == 0) {
 260         props->is_unix = true;
 261     } else if (strcmp(name, "server") == 0) {
 262     } else {
 263         error_setg(errp,
 264                    "vhost-user does not support a chardev with option %s=%s",
 265                    name, value);
 266         return -1;
 267     }
 268     return 0;
 269 }
 270
 271 static CharDriverState *net_vhost_parse_chardev(
 272     const NetdevVhostUserOptions *opts, Error **errp)
 273 {
 274     CharDriverState *chr = qemu_chr_find(opts->chardev);
 275     VhostUserChardevProps props;
 276
 277     if (chr == NULL) {
 278         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 279         return NULL;
 280     }
 281
 282     /* inspect chardev opts */
 283     memset(&props, 0, sizeof(props));
 284     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
 285         return NULL;
 286     }
 287
 288     if (!props.is_socket || !props.is_unix) {
 289         error_setg(errp, "chardev \"%s\" is not a unix socket",
 290                    opts->chardev);
 291         return NULL;
 292     }
 293
 294     qemu_chr_fe_claim_no_fail(chr);
 295
 296     return chr;
 297 }
 298
 299 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 300 {
 301     const char *name = opaque;
 302     const char *driver, *netdev;
 303     const char virtio_name[] = "virtio-net-";
 304
 305     driver = qemu_opt_get(opts, "driver");
 306     netdev = qemu_opt_get(opts, "netdev");
 307
 308     if (!driver || !netdev) {
 309         return 0;
 310     }
 311
 312     if (strcmp(netdev, name) == 0 &&
 313         strncmp(driver, virtio_name, strlen(virtio_name)) != 0) {
 314         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 315         return -1;
 316     }
 317
 318     return 0;
 319 }
 320
 321 int net_init_vhost_user(const NetClientOptions *opts, const char *name,
 322                         NetClientState *peer, Error **errp)
 323 {
 324     int queues;
 325     const NetdevVhostUserOptions *vhost_user_opts;
 326     CharDriverState *chr;
 327
 328     assert(opts->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 329     vhost_user_opts = opts->u.vhost_user.data;
 330
 331     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
 332     if (!chr) {
 333         return -1;
 334     }
 335
 336     /* verify net frontend */
 337     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 338                           (char *)name, errp)) {
 339         return -1;
 340     }
 341
 342     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
 343     if (queues < 1 || queues > MAX_QUEUE_NUM) {
 344         error_setg(errp,
 345                    "vhost-user number of queues must be in range [1, %d]",
 346                    MAX_QUEUE_NUM);
 347         return -1;
 348     }
 349
 350     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 351 }