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