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 "clients.h"
  12 #include "net/vhost_net.h"
  13 #include "net/vhost-user.h"
  14 #include "sysemu/char.h"
  15 #include "qemu/config-file.h"
  16 #include "qemu/error-report.h"
  17 #include "qmp-commands.h"
  18 #include "trace.h"
  19
  20 typedef struct VhostUserState {
  21     NetClientState nc;
  22     CharDriverState *chr;
  23     VHostNetState *vhost_net;
  24 } VhostUserState;
  25
  26 typedef struct VhostUserChardevProps {
  27     bool is_socket;
  28     bool is_unix;
  29     bool is_server;
  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\n", 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 "
  93                              "supported: %d\n", 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     /* Discard the request that is received and managed by backend
 110      * by an other way.
 111      */
 112     return size;
 113 }
 114
 115 static void vhost_user_cleanup(NetClientState *nc)
 116 {
 117     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
 118
 119     if (s->vhost_net) {
 120         vhost_net_cleanup(s->vhost_net);
 121         s->vhost_net = NULL;
 122     }
 123
 124     qemu_purge_queued_packets(nc);
 125 }
 126
 127 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
 128 {
 129     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 130
 131     return true;
 132 }
 133
 134 static bool vhost_user_has_ufo(NetClientState *nc)
 135 {
 136     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 137
 138     return true;
 139 }
 140
 141 static NetClientInfo net_vhost_user_info = {
 142         .type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
 143         .size = sizeof(VhostUserState),
 144         .receive = vhost_user_receive,
 145         .cleanup = vhost_user_cleanup,
 146         .has_vnet_hdr = vhost_user_has_vnet_hdr,
 147         .has_ufo = vhost_user_has_ufo,
 148 };
 149
 150 static void net_vhost_user_event(void *opaque, int event)
 151 {
 152     const char *name = opaque;
 153     NetClientState *ncs[MAX_QUEUE_NUM];
 154     VhostUserState *s;
 155     Error *err = NULL;
 156     int queues;
 157
 158     queues = qemu_find_net_clients_except(name, ncs,
 159                                           NET_CLIENT_OPTIONS_KIND_NIC,
 160                                           MAX_QUEUE_NUM);
 161     s = DO_UPCAST(VhostUserState, nc, ncs[0]);
 162     trace_vhost_user_event(s->chr->label, event);
 163     switch (event) {
 164     case CHR_EVENT_OPENED:
 165         if (vhost_user_start(queues, ncs) < 0) {
 166             exit(1);
 167         }
 168         qmp_set_link(name, true, &err);
 169         break;
 170     case CHR_EVENT_CLOSED:
 171         qmp_set_link(name, true, &err);
 172         vhost_user_stop(queues, ncs);
 173         break;
 174     }
 175
 176     if (err) {
 177         error_report_err(err);
 178     }
 179 }
 180
 181 static int net_vhost_user_init(NetClientState *peer, const char *device,
 182                                const char *name, CharDriverState *chr,
 183                                int queues)
 184 {
 185     NetClientState *nc;
 186     VhostUserState *s;
 187     int i;
 188
 189     for (i = 0; i < queues; i++) {
 190         nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 191
 192         snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user%d to %s",
 193                  i, chr->label);
 194
 195         nc->queue_index = i;
 196
 197         s = DO_UPCAST(VhostUserState, nc, nc);
 198         s->chr = chr;
 199     }
 200
 201     qemu_chr_add_handlers(chr, NULL, NULL, net_vhost_user_event, (void*)name);
 202
 203     return 0;
 204 }
 205
 206 static int net_vhost_chardev_opts(void *opaque,
 207                                   const char *name, const char *value,
 208                                   Error **errp)
 209 {
 210     VhostUserChardevProps *props = opaque;
 211
 212     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
 213         props->is_socket = true;
 214     } else if (strcmp(name, "path") == 0) {
 215         props->is_unix = true;
 216     } else if (strcmp(name, "server") == 0) {
 217         props->is_server = true;
 218     } else {
 219         error_setg(errp,
 220                    "vhost-user does not support a chardev with option %s=%s",
 221                    name, value);
 222         return -1;
 223     }
 224     return 0;
 225 }
 226
 227 static CharDriverState *net_vhost_parse_chardev(
 228     const NetdevVhostUserOptions *opts, Error **errp)
 229 {
 230     CharDriverState *chr = qemu_chr_find(opts->chardev);
 231     VhostUserChardevProps props;
 232
 233     if (chr == NULL) {
 234         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 235         return NULL;
 236     }
 237
 238     /* inspect chardev opts */
 239     memset(&props, 0, sizeof(props));
 240     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
 241         return NULL;
 242     }
 243
 244     if (!props.is_socket || !props.is_unix) {
 245         error_setg(errp, "chardev \"%s\" is not a unix socket",
 246                    opts->chardev);
 247         return NULL;
 248     }
 249
 250     qemu_chr_fe_claim_no_fail(chr);
 251
 252     return chr;
 253 }
 254
 255 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 256 {
 257     const char *name = opaque;
 258     const char *driver, *netdev;
 259     const char virtio_name[] = "virtio-net-";
 260
 261     driver = qemu_opt_get(opts, "driver");
 262     netdev = qemu_opt_get(opts, "netdev");
 263
 264     if (!driver || !netdev) {
 265         return 0;
 266     }
 267
 268     if (strcmp(netdev, name) == 0 &&
 269         strncmp(driver, virtio_name, strlen(virtio_name)) != 0) {
 270         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 271         return -1;
 272     }
 273
 274     return 0;
 275 }
 276
 277 int net_init_vhost_user(const NetClientOptions *opts, const char *name,
 278                         NetClientState *peer, Error **errp)
 279 {
 280     int queues;
 281     const NetdevVhostUserOptions *vhost_user_opts;
 282     CharDriverState *chr;
 283
 284     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 285     vhost_user_opts = opts->vhost_user;
 286
 287     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
 288     if (!chr) {
 289         return -1;
 290     }
 291
 292     /* verify net frontend */
 293     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 294                           (char *)name, errp)) {
 295         return -1;
 296     }
 297
 298     queues = vhost_user_opts->has_queues ? vhost_user_opts->queues : 1;
 299
 300     return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
 301 }