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     bool started;
  28 } VhostUserState;
  29
  30 typedef struct VhostUserChardevProps {
  31     bool is_socket;
  32     bool is_unix;
  33 } VhostUserChardevProps;
  34
  35 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
  36 {
  37     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  38     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
  39     return s->vhost_net;
  40 }
  41
  42 uint64_t vhost_user_get_acked_features(NetClientState *nc)
  43 {
  44     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  45     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
  46     return s->acked_features;
  47 }
  48
  49 static void vhost_user_stop(int queues, NetClientState *ncs[])
  50 {
  51     VhostUserState *s;
  52     int i;
  53
  54     for (i = 0; i < queues; i++) {
  55         assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
  56
  57         s = DO_UPCAST(VhostUserState, nc, ncs[i]);
  58
  59         if (s->vhost_net) {
  60             /* save acked features */
  61             uint64_t features = vhost_net_get_acked_features(s->vhost_net);
  62             if (features) {
  63                 s->acked_features = features;
  64             }
  65             vhost_net_cleanup(s->vhost_net);
  66         }
  67     }
  68 }
  69
  70 static int vhost_user_start(int queues, NetClientState *ncs[])
  71 {
  72     VhostNetOptions options;
  73     struct vhost_net *net = NULL;
  74     VhostUserState *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(VhostUserState, nc, ncs[i]);
  84
  85         options.net_backend = ncs[i];
  86         options.opaque      = s->chr;
  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     }
 116     vhost_user_stop(i, ncs);
 117     return -1;
 118 }
 119
 120 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
 121                                   size_t size)
 122 {
 123     /* In case of RARP (message size is 60) notify backup to send a fake RARP.
 124        This fake RARP will be sent by backend only for guest
 125        without GUEST_ANNOUNCE capability.
 126      */
 127     if (size == 60) {
 128         VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 129         int r;
 130         static int display_rarp_failure = 1;
 131         char mac_addr[6];
 132
 133         /* extract guest mac address from the RARP message */
 134         memcpy(mac_addr, &buf[6], 6);
 135
 136         r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
 137
 138         if ((r != 0) && (display_rarp_failure)) {
 139             fprintf(stderr,
 140                     "Vhost user backend fails to broadcast fake RARP\n");
 141             fflush(stderr);
 142             display_rarp_failure = 0;
 143         }
 144     }
 145
 146     return size;
 147 }
 148
 149 static void vhost_user_cleanup(NetClientState *nc)
 150 {
 151     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 152
 153     if (s->vhost_net) {
 154         vhost_net_cleanup(s->vhost_net);
 155         g_free(s->vhost_net);
 156         s->vhost_net = NULL;
 157     }
 158     if (s->chr) {
 159         qemu_chr_add_handlers(s->chr, NULL, NULL, NULL, NULL);
 160         qemu_chr_fe_release(s->chr);
 161         s->chr = NULL;
 162     }
 163
 164     qemu_purge_queued_packets(nc);
 165 }
 166
 167 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
 168 {
 169     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
 170
 171     return true;
 172 }
 173
 174 static bool vhost_user_has_ufo(NetClientState *nc)
 175 {
 176     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
 177
 178     return true;
 179 }
 180
 181 static NetClientInfo net_vhost_user_info = {
 182         .type = NET_CLIENT_DRIVER_VHOST_USER,
 183         .size = sizeof(VhostUserState),
 184         .receive = vhost_user_receive,
 185         .cleanup = vhost_user_cleanup,
 186         .has_vnet_hdr = vhost_user_has_vnet_hdr,
 187         .has_ufo = vhost_user_has_ufo,
 188 };
 189
 190 static gboolean net_vhost_user_watch(GIOChannel *chan, GIOCondition cond,
 191                                            void *opaque)
 192 {
 193     VhostUserState *s = opaque;
 194
 195     qemu_chr_disconnect(s->chr);
 196
 197     return FALSE;
 198 }
 199
 200 static void net_vhost_user_event(void *opaque, int event)
 201 {
 202     const char *name = opaque;
 203     NetClientState *ncs[MAX_QUEUE_NUM];
 204     VhostUserState *s;
 205     Error *err = NULL;
 206     int queues;
 207
 208     queues = qemu_find_net_clients_except(name, ncs,
 209                                           NET_CLIENT_DRIVER_NIC,
 210                                           MAX_QUEUE_NUM);
 211     assert(queues < MAX_QUEUE_NUM);
 212
 213     s = DO_UPCAST(VhostUserState, nc, ncs[0]);
 214     trace_vhost_user_event(s->chr->label, event);
 215     switch (event) {
 216     case CHR_EVENT_OPENED:
 217         s->watch = qemu_chr_fe_add_watch(s->chr, G_IO_HUP,
 218                                          net_vhost_user_watch, s);
 219         if (vhost_user_start(queues, ncs) < 0) {
 220             qemu_chr_disconnect(s->chr);
 221             return;
 222         }
 223         qmp_set_link(name, true, &err);
 224         s->started = true;
 225         break;
 226     case CHR_EVENT_CLOSED:
 227         qmp_set_link(name, false, &err);
 228         vhost_user_stop(queues, ncs);
 229         g_source_remove(s->watch);
 230         s->watch = 0;
 231         break;
 232     }
 233
 234     if (err) {
 235         error_report_err(err);
 236     }
 237 }
 238
 239 static int net_vhost_user_init(NetClientState *peer, const char *device,
 240                                const char *name, CharDriverState *chr,
 241                                int queues)
 242 {
 243     NetClientState *nc, *nc0 = NULL;
 244     VhostUserState *s;
 245     int i;
 246
 247     assert(name);
 248     assert(queues > 0);
 249
 250     for (i = 0; i < queues; i++) {
 251         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 252         if (!nc0) {
 253             nc0 = nc;
 254         }
 255
 256         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
 257                  i, chr->label);
 258
 259         nc->queue_index = i;
 260
 261         s = DO_UPCAST(VhostUserState, nc, nc);
 262         s->chr = chr;
 263     }
 264
 265     s = DO_UPCAST(VhostUserState, nc, nc0);
 266     do {
 267         Error *err = NULL;
 268         if (qemu_chr_wait_connected(chr, &err) < 0) {
 269             error_report_err(err);
 270             return -1;
 271         }
 272         qemu_chr_add_handlers(chr, NULL, NULL,
 273                               net_vhost_user_event, nc0->name);
 274     } while (!s->started);
 275
 276     assert(s->vhost_net);
 277
 278     return 0;
 279 }
 280
 281 static int net_vhost_chardev_opts(void *opaque,
 282                                   const char *name, const char *value,
 283                                   Error **errp)
 284 {
 285     VhostUserChardevProps *props = opaque;
 286
 287     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
 288         props->is_socket = true;
 289     } else if (strcmp(name, "path") == 0) {
 290         props->is_unix = true;
 291     } else if (strcmp(name, "server") == 0) {
 292     } else {
 293         error_setg(errp,
 294                    "vhost-user does not support a chardev with option %s=%s",
 295                    name, value);
 296         return -1;
 297     }
 298     return 0;
 299 }
 300
 301 static CharDriverState *net_vhost_parse_chardev(
 302     const NetdevVhostUserOptions *opts, Error **errp)
 303 {
 304     CharDriverState *chr = qemu_chr_find(opts->chardev);
 305     VhostUserChardevProps props;
 306
 307     if (chr == NULL) {
 308         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 309         return NULL;
 310     }
 311
 312     /* inspect chardev opts */
 313     memset(&props, 0, sizeof(props));
 314     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
 315         return NULL;
 316     }
 317
 318     if (!props.is_socket || !props.is_unix) {
 319         error_setg(errp, "chardev \"%s\" is not a unix socket",
 320                    opts->chardev);
 321         return NULL;
 322     }
 323
 324     qemu_chr_fe_claim_no_fail(chr);
 325
 326     return chr;
 327 }
 328
 329 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 330 {
 331     const char *name = opaque;
 332     const char *driver, *netdev;
 333
 334     driver = qemu_opt_get(opts, "driver");
 335     netdev = qemu_opt_get(opts, "netdev");
 336
 337     if (!driver || !netdev) {
 338         return 0;
 339     }
 340
 341     if (strcmp(netdev, name) == 0 &&
 342         !g_str_has_prefix(driver, "virtio-net-")) {
 343         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 344         return -1;
 345     }
 346
 347     return 0;
 348 }
 349
 350 int net_init_vhost_user(const Netdev *netdev, const char *name,
 351                         NetClientState *peer, Error **errp)
 352 {
 353     int queues;
 354     const NetdevVhostUserOptions *vhost_user_opts;
 355     CharDriverState *chr;
 356
 357     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
 358     vhost_user_opts = &netdev->u.vhost_user;
 359
 360     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
 361     if (!chr) {
 362         return -1;
 363     }
 364
 365     /* verify net frontend */
 366     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 367                           (char *)name, errp)) {
 368         return -1;
 369     }
 370
 371     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
 372     if (queues < 1 || queues > MAX_QUEUE_NUM) {
 373         error_setg(errp,
 374                    "vhost-user number of queues must be in range [1, %d]",
 375                    MAX_QUEUE_NUM);
 376         return -1;
 377     }
 378
 379     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 380 }