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