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vhost-user.c (12149B)

      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 "hw/virtio/vhost-user.h"
     16 #include "chardev/char-fe.h"
     17 #include "qapi/error.h"
     18 #include "qapi/qapi-commands-net.h"
     19 #include "qemu/config-file.h"
     20 #include "qemu/error-report.h"
     21 #include "qemu/option.h"
     22 #include "trace.h"
     23 
     24 typedef struct NetVhostUserState {
     25     NetClientState nc;
     26     CharBackend chr; /* only queue index 0 */
     27     VhostUserState *vhost_user;
     28     VHostNetState *vhost_net;
     29     guint watch;
     30     uint64_t acked_features;
     31     bool started;
     32 } NetVhostUserState;
     33 
     34 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
     35 {
     36     NetVhostUserState *s = DO_UPCAST(NetVhostUserState, 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     NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
     44     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
     45     return s->acked_features;
     46 }
     47 
     48 static void vhost_user_stop(int queues, NetClientState *ncs[])
     49 {
     50     NetVhostUserState *s;
     51     int i;
     52 
     53     for (i = 0; i < queues; i++) {
     54         assert(ncs[i]->info->type == NET_CLIENT_DRIVER_VHOST_USER);
     55 
     56         s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
     57 
     58         if (s->vhost_net) {
     59             /* save acked features */
     60             uint64_t features = vhost_net_get_acked_features(s->vhost_net);
     61             if (features) {
     62                 s->acked_features = features;
     63             }
     64             vhost_net_cleanup(s->vhost_net);
     65         }
     66     }
     67 }
     68 
     69 static int vhost_user_start(int queues, NetClientState *ncs[],
     70                             VhostUserState *be)
     71 {
     72     VhostNetOptions options;
     73     struct vhost_net *net = NULL;
     74     NetVhostUserState *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(NetVhostUserState, nc, ncs[i]);
     84 
     85         options.net_backend = ncs[i];
     86         options.opaque      = be;
     87         options.busyloop_timeout = 0;
     88         options.nvqs = 2;
     89         net = vhost_net_init(&options);
     90         if (!net) {
     91             error_report("failed to init vhost_net for queue %d", i);
     92             goto err;
     93         }
     94 
     95         if (i == 0) {
     96             max_queues = vhost_net_get_max_queues(net);
     97             if (queues > max_queues) {
     98                 error_report("you are asking more queues than supported: %d",
     99                              max_queues);
    100                 goto err;
    101             }
    102         }
    103 
    104         if (s->vhost_net) {
    105             vhost_net_cleanup(s->vhost_net);
    106             g_free(s->vhost_net);
    107         }
    108         s->vhost_net = net;
    109     }
    110 
    111     return 0;
    112 
    113 err:
    114     if (net) {
    115         vhost_net_cleanup(net);
    116         g_free(net);
    117     }
    118     vhost_user_stop(i, ncs);
    119     return -1;
    120 }
    121 
    122 static ssize_t vhost_user_receive(NetClientState *nc, const uint8_t *buf,
    123                                   size_t size)
    124 {
    125     /* In case of RARP (message size is 60) notify backup to send a fake RARP.
    126        This fake RARP will be sent by backend only for guest
    127        without GUEST_ANNOUNCE capability.
    128      */
    129     if (size == 60) {
    130         NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
    131         int r;
    132         static int display_rarp_failure = 1;
    133         char mac_addr[6];
    134 
    135         /* extract guest mac address from the RARP message */
    136         memcpy(mac_addr, &buf[6], 6);
    137 
    138         r = vhost_net_notify_migration_done(s->vhost_net, mac_addr);
    139 
    140         if ((r != 0) && (display_rarp_failure)) {
    141             fprintf(stderr,
    142                     "Vhost user backend fails to broadcast fake RARP\n");
    143             fflush(stderr);
    144             display_rarp_failure = 0;
    145         }
    146     }
    147 
    148     return size;
    149 }
    150 
    151 static void net_vhost_user_cleanup(NetClientState *nc)
    152 {
    153     NetVhostUserState *s = DO_UPCAST(NetVhostUserState, nc, nc);
    154 
    155     if (s->vhost_net) {
    156         vhost_net_cleanup(s->vhost_net);
    157         g_free(s->vhost_net);
    158         s->vhost_net = NULL;
    159     }
    160     if (nc->queue_index == 0) {
    161         if (s->watch) {
    162             g_source_remove(s->watch);
    163             s->watch = 0;
    164         }
    165         qemu_chr_fe_deinit(&s->chr, true);
    166         if (s->vhost_user) {
    167             vhost_user_cleanup(s->vhost_user);
    168             g_free(s->vhost_user);
    169             s->vhost_user = NULL;
    170         }
    171     }
    172 
    173     qemu_purge_queued_packets(nc);
    174 }
    175 
    176 static int vhost_user_set_vnet_endianness(NetClientState *nc,
    177                                           bool enable)
    178 {
    179     /* Nothing to do.  If the server supports
    180      * VHOST_USER_PROTOCOL_F_CROSS_ENDIAN, it will get the
    181      * vnet header endianness from there.  If it doesn't, negotiation
    182      * fails.
    183      */
    184     return 0;
    185 }
    186 
    187 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
    188 {
    189     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
    190 
    191     return true;
    192 }
    193 
    194 static bool vhost_user_has_ufo(NetClientState *nc)
    195 {
    196     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
    197 
    198     return true;
    199 }
    200 
    201 static bool vhost_user_check_peer_type(NetClientState *nc, ObjectClass *oc,
    202                                        Error **errp)
    203 {
    204     const char *driver = object_class_get_name(oc);
    205 
    206     if (!g_str_has_prefix(driver, "virtio-net-")) {
    207         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
    208         return false;
    209     }
    210 
    211     return true;
    212 }
    213 
    214 static NetClientInfo net_vhost_user_info = {
    215         .type = NET_CLIENT_DRIVER_VHOST_USER,
    216         .size = sizeof(NetVhostUserState),
    217         .receive = vhost_user_receive,
    218         .cleanup = net_vhost_user_cleanup,
    219         .has_vnet_hdr = vhost_user_has_vnet_hdr,
    220         .has_ufo = vhost_user_has_ufo,
    221         .set_vnet_be = vhost_user_set_vnet_endianness,
    222         .set_vnet_le = vhost_user_set_vnet_endianness,
    223         .check_peer_type = vhost_user_check_peer_type,
    224 };
    225 
    226 static gboolean net_vhost_user_watch(void *do_not_use, GIOCondition cond,
    227                                      void *opaque)
    228 {
    229     NetVhostUserState *s = opaque;
    230 
    231     qemu_chr_fe_disconnect(&s->chr);
    232 
    233     return TRUE;
    234 }
    235 
    236 static void net_vhost_user_event(void *opaque, QEMUChrEvent event);
    237 
    238 static void chr_closed_bh(void *opaque)
    239 {
    240     const char *name = opaque;
    241     NetClientState *ncs[MAX_QUEUE_NUM];
    242     NetVhostUserState *s;
    243     Error *err = NULL;
    244     int queues, i;
    245 
    246     queues = qemu_find_net_clients_except(name, ncs,
    247                                           NET_CLIENT_DRIVER_NIC,
    248                                           MAX_QUEUE_NUM);
    249     assert(queues < MAX_QUEUE_NUM);
    250 
    251     s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
    252 
    253     for (i = queues -1; i >= 0; i--) {
    254         s = DO_UPCAST(NetVhostUserState, nc, ncs[i]);
    255 
    256         if (s->vhost_net) {
    257             s->acked_features = vhost_net_get_acked_features(s->vhost_net);
    258         }
    259     }
    260 
    261     qmp_set_link(name, false, &err);
    262 
    263     qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, net_vhost_user_event,
    264                              NULL, opaque, NULL, true);
    265 
    266     if (err) {
    267         error_report_err(err);
    268     }
    269 }
    270 
    271 static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
    272 {
    273     const char *name = opaque;
    274     NetClientState *ncs[MAX_QUEUE_NUM];
    275     NetVhostUserState *s;
    276     Chardev *chr;
    277     Error *err = NULL;
    278     int queues;
    279 
    280     queues = qemu_find_net_clients_except(name, ncs,
    281                                           NET_CLIENT_DRIVER_NIC,
    282                                           MAX_QUEUE_NUM);
    283     assert(queues < MAX_QUEUE_NUM);
    284 
    285     s = DO_UPCAST(NetVhostUserState, nc, ncs[0]);
    286     chr = qemu_chr_fe_get_driver(&s->chr);
    287     trace_vhost_user_event(chr->label, event);
    288     switch (event) {
    289     case CHR_EVENT_OPENED:
    290         if (vhost_user_start(queues, ncs, s->vhost_user) < 0) {
    291             qemu_chr_fe_disconnect(&s->chr);
    292             return;
    293         }
    294         s->watch = qemu_chr_fe_add_watch(&s->chr, G_IO_HUP,
    295                                          net_vhost_user_watch, s);
    296         qmp_set_link(name, true, &err);
    297         s->started = true;
    298         break;
    299     case CHR_EVENT_CLOSED:
    300         /* a close event may happen during a read/write, but vhost
    301          * code assumes the vhost_dev remains setup, so delay the
    302          * stop & clear to idle.
    303          * FIXME: better handle failure in vhost code, remove bh
    304          */
    305         if (s->watch) {
    306             AioContext *ctx = qemu_get_current_aio_context();
    307 
    308             g_source_remove(s->watch);
    309             s->watch = 0;
    310             qemu_chr_fe_set_handlers(&s->chr, NULL, NULL, NULL, NULL,
    311                                      NULL, NULL, false);
    312 
    313             aio_bh_schedule_oneshot(ctx, chr_closed_bh, opaque);
    314         }
    315         break;
    316     case CHR_EVENT_BREAK:
    317     case CHR_EVENT_MUX_IN:
    318     case CHR_EVENT_MUX_OUT:
    319         /* Ignore */
    320         break;
    321     }
    322 
    323     if (err) {
    324         error_report_err(err);
    325     }
    326 }
    327 
    328 static int net_vhost_user_init(NetClientState *peer, const char *device,
    329                                const char *name, Chardev *chr,
    330                                int queues)
    331 {
    332     Error *err = NULL;
    333     NetClientState *nc, *nc0 = NULL;
    334     NetVhostUserState *s = NULL;
    335     VhostUserState *user;
    336     int i;
    337 
    338     assert(name);
    339     assert(queues > 0);
    340 
    341     user = g_new0(struct VhostUserState, 1);
    342     for (i = 0; i < queues; i++) {
    343         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
    344         qemu_set_info_str(nc, "vhost-user%d to %s", i, chr->label);
    345         nc->queue_index = i;
    346         if (!nc0) {
    347             nc0 = nc;
    348             s = DO_UPCAST(NetVhostUserState, nc, nc);
    349             if (!qemu_chr_fe_init(&s->chr, chr, &err) ||
    350                 !vhost_user_init(user, &s->chr, &err)) {
    351                 error_report_err(err);
    352                 goto err;
    353             }
    354         }
    355         s = DO_UPCAST(NetVhostUserState, nc, nc);
    356         s->vhost_user = user;
    357     }
    358 
    359     s = DO_UPCAST(NetVhostUserState, nc, nc0);
    360     do {
    361         if (qemu_chr_fe_wait_connected(&s->chr, &err) < 0) {
    362             error_report_err(err);
    363             goto err;
    364         }
    365         qemu_chr_fe_set_handlers(&s->chr, NULL, NULL,
    366                                  net_vhost_user_event, NULL, nc0->name, NULL,
    367                                  true);
    368     } while (!s->started);
    369 
    370     assert(s->vhost_net);
    371 
    372     return 0;
    373 
    374 err:
    375     if (user) {
    376         vhost_user_cleanup(user);
    377         g_free(user);
    378         if (s) {
    379             s->vhost_user = NULL;
    380         }
    381     }
    382     if (nc0) {
    383         qemu_del_net_client(nc0);
    384     }
    385 
    386     return -1;
    387 }
    388 
    389 static Chardev *net_vhost_claim_chardev(
    390     const NetdevVhostUserOptions *opts, Error **errp)
    391 {
    392     Chardev *chr = qemu_chr_find(opts->chardev);
    393 
    394     if (chr == NULL) {
    395         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
    396         return NULL;
    397     }
    398 
    399     if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_RECONNECTABLE)) {
    400         error_setg(errp, "chardev \"%s\" is not reconnectable",
    401                    opts->chardev);
    402         return NULL;
    403     }
    404     if (!qemu_chr_has_feature(chr, QEMU_CHAR_FEATURE_FD_PASS)) {
    405         error_setg(errp, "chardev \"%s\" does not support FD passing",
    406                    opts->chardev);
    407         return NULL;
    408     }
    409 
    410     return chr;
    411 }
    412 
    413 int net_init_vhost_user(const Netdev *netdev, const char *name,
    414                         NetClientState *peer, Error **errp)
    415 {
    416     int queues;
    417     const NetdevVhostUserOptions *vhost_user_opts;
    418     Chardev *chr;
    419 
    420     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
    421     vhost_user_opts = &netdev->u.vhost_user;
    422 
    423     chr = net_vhost_claim_chardev(vhost_user_opts, errp);
    424     if (!chr) {
    425         return -1;
    426     }
    427 
    428     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
    429     if (queues < 1 || queues > MAX_QUEUE_NUM) {
    430         error_setg(errp,
    431                    "vhost-user number of queues must be in range [1, %d]",
    432                    MAX_QUEUE_NUM);
    433         return -1;
    434     }
    435 
    436     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
    437 }