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 int vhost_user_running(VhostUserState *s)
  49 {
  50     return (s->vhost_net) ? 1 : 0;
  51 }
  52
  53 static void vhost_user_stop(int queues, NetClientState *ncs[])
  54 {
  55     VhostUserState *s;
  56     int i;
  57
  58     for (i = 0; i < queues; i++) {
  59         assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
  60
  61         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
  62         if (!vhost_user_running(s)) {
  63             continue;
  64         }
  65
  66         if (s->vhost_net) {
  67             /* save acked features */
  68             s->acked_features = vhost_net_get_acked_features(s->vhost_net);
  69             vhost_net_cleanup(s->vhost_net);
  70             s->vhost_net = NULL;
  71         }
  72     }
  73 }
  74
  75 static int vhost_user_start(int queues, NetClientState *ncs[])
  76 {
  77     VhostNetOptions options;
  78     VhostUserState *s;
  79     int max_queues;
  80     int i;
  81
  82     options.backend_type = VHOST_BACKEND_TYPE_USER;
  83
  84     for (i = 0; i < queues; i++) {
  85         assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
  86
  87         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
  88         if (vhost_user_running(s)) {
  89             continue;
  90         }
  91
  92         options.net_backend = ncs[i];
  93         options.opaque      = s->chr;
  94         options.busyloop_timeout = 0;
  95         s->vhost_net = vhost_net_init(&options);
  96         if (!s->vhost_net) {
  97             error_report("failed to init vhost_net for queue %d", i);
  98             goto err;
  99         }
 100
 101         if (i == 0) {
 102             max_queues = vhost_net_get_max_queues(s->vhost_net);
 103             if (queues > max_queues) {
 104                 error_report("you are asking more queues than supported: %d",
 105                              max_queues);
 106                 goto err;
 107             }
 108         }
 109     }
 110
 111     return 0;
 112
 113 err:
 114     vhost_user_stop(i + 1, ncs);
 115     return -1;
 116 }
 117
 118 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
 119                                   size_t size)
 120 {
 121     /* In case of RARP (message size is 60) notify backup to send a fake RARP.
 122        This fake RARP will be sent by backend only for guest
 123        without GUEST_ANNOUNCE capability.
 124      */
 125     if (size == 60) {
 126         VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 127         int r;
 128         static int display_rarp_failure = 1;
 129         char mac_addr[6];
 130
 131         /* extract guest mac address from the RARP message */
 132         memcpy(mac_addr, &buf[6], 6);
 133
 134         r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
 135
 136         if ((r != 0) && (display_rarp_failure)) {
 137             fprintf(stderr,
 138                     "Vhost user backend fails to broadcast fake RARP\n");
 139             fflush(stderr);
 140             display_rarp_failure = 0;
 141         }
 142     }
 143
 144     return size;
 145 }
 146
 147 static void vhost_user_cleanup(NetClientState *nc)
 148 {
 149     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 150
 151     if (s->vhost_net) {
 152         vhost_net_cleanup(s->vhost_net);
 153         s->vhost_net = NULL;
 154     }
 155     if (s->chr) {
 156         qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, NULL);
 157         qemu_chr_fe_release(s->chr);
 158         s->chr = NULL;
 159     }
 160
 161     qemu_purge_queued_packets(nc);
 162 }
 163
 164 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
 165 {
 166     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
 167
 168     return true;
 169 }
 170
 171 static bool vhost_user_has_ufo(NetClientState *nc)
 172 {
 173     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
 174
 175     return true;
 176 }
 177
 178 static NetClientInfo net_vhost_user_info = {
 179         .type = NET_CLIENT_DRIVER_VHOST_USER,
 180         .size = sizeof(VhostUserState),
 181         .receive = vhost_user_receive,
 182         .cleanup = vhost_user_cleanup,
 183         .has_vnet_hdr = vhost_user_has_vnet_hdr,
 184         .has_ufo = vhost_user_has_ufo,
 185 };
 186
 187 static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
 188                                            void *opaque)
 189 {
 190     VhostUserState *s = opaque;
 191
 192     qemu_chr_disconnect(s->chr);
 193
 194     return FALSE;
 195 }
 196
 197 static void net_vhost_user_event(void *opaque, int event)
 198 {
 199     const char *name = opaque;
 200     NetClientState *ncs[MAX_QUEUE_NUM];
 201     VhostUserState *s;
 202     Error *err = NULL;
 203     int queues;
 204
 205     queues = qemu_find_net_clients_except(name, ncs,
 206                                           NET_CLIENT_DRIVER_NIC,
 207                                           MAX_QUEUE_NUM);
 208     assert(queues < MAX_QUEUE_NUM);
 209
 210     s = DO_UPCAST(VhostUserState, nc, ncs[0]);
 211     trace_vhost_user_event(s->chr->label, event);
 212     switch (event) {
 213     case CHR_EVENT_OPENED:
 214         s->watch = qemu_chr_fe_add_watch(s->chr, G_IO_HUP,
 215                                          net_vhost_user_watch, s);
 216         if (vhost_user_start(queues, ncs) < 0) {
 217             qemu_chr_disconnect(s->chr);
 218             return;
 219         }
 220         qmp_set_link(name, true, &err);
 221         break;
 222     case CHR_EVENT_CLOSED:
 223         qmp_set_link(name, false, &err);
 224         vhost_user_stop(queues, ncs);
 225         g_source_remove(s->watch);
 226         s->watch = 0;
 227         break;
 228     }
 229
 230     if (err) {
 231         error_report_err(err);
 232     }
 233 }
 234
 235 static int net_vhost_user_init(NetClientState *peer, const char *device,
 236                                const char *name, CharDriverState *chr,
 237                                int queues)
 238 {
 239     NetClientState *nc;
 240     VhostUserState *s;
 241     int i;
 242
 243     assert(name);
 244     assert(queues > 0);
 245
 246     for (i = 0; i < queues; i++) {
 247         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 248
 249         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
 250                  i, chr->label);
 251
 252         nc->queue_index = i;
 253
 254         s = DO_UPCAST(VhostUserState, nc, nc);
 255         s->chr = chr;
 256     }
 257
 258     qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, nc[0].name);
 259
 260     return 0;
 261 }
 262
 263 static int net_vhost_chardev_opts(void *opaque,
 264                                   const char *name, const char *value,
 265                                   Error **errp)
 266 {
 267     VhostUserChardevProps *props = opaque;
 268
 269     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
 270         props->is_socket = true;
 271     } else if (strcmp(name, "path") == 0) {
 272         props->is_unix = true;
 273     } else if (strcmp(name, "server") == 0) {
 274     } else {
 275         error_setg(errp,
 276                    "vhost-user does not support a chardev with option %s=%s",
 277                    name, value);
 278         return -1;
 279     }
 280     return 0;
 281 }
 282
 283 static CharDriverState *net_vhost_parse_chardev(
 284     const NetdevVhostUserOptions *opts, Error **errp)
 285 {
 286     CharDriverState *chr = qemu_chr_find(opts->chardev);
 287     VhostUserChardevProps props;
 288
 289     if (chr == NULL) {
 290         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 291         return NULL;
 292     }
 293
 294     /* inspect chardev opts */
 295     memset(&props, 0, sizeof(props));
 296     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
 297         return NULL;
 298     }
 299
 300     if (!props.is_socket || !props.is_unix) {
 301         error_setg(errp, "chardev \"%s\" is not a unix socket",
 302                    opts->chardev);
 303         return NULL;
 304     }
 305
 306     qemu_chr_fe_claim_no_fail(chr);
 307
 308     return chr;
 309 }
 310
 311 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 312 {
 313     const char *name = opaque;
 314     const char *driver, *netdev;
 315
 316     driver = qemu_opt_get(opts, "driver");
 317     netdev = qemu_opt_get(opts, "netdev");
 318
 319     if (!driver || !netdev) {
 320         return 0;
 321     }
 322
 323     if (strcmp(netdev, name) == 0 &&
 324         !g_str_has_prefix(driver, "virtio-net-")) {
 325         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 326         return -1;
 327     }
 328
 329     return 0;
 330 }
 331
 332 int net_init_vhost_user(const Netdev *netdev, const char *name,
 333                         NetClientState *peer, Error **errp)
 334 {
 335     int queues;
 336     const NetdevVhostUserOptions *vhost_user_opts;
 337     CharDriverState *chr;
 338
 339     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
 340     vhost_user_opts = &netdev->u.vhost_user;
 341
 342     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
 343     if (!chr) {
 344         return -1;
 345     }
 346
 347     /* verify net frontend */
 348     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 349                           (char *)name, errp)) {
 350         return -1;
 351     }
 352
 353     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
 354     if (queues < 1 || queues > MAX_QUEUE_NUM) {
 355         error_setg(errp,
 356                    "vhost-user number of queues must be in range [1, %d]",
 357                    MAX_QUEUE_NUM);
 358         return -1;
 359     }
 360
 361     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 362 }