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
  18 typedef struct VhostUserState {
  19     NetClientState nc;
  20     CharDriverState *chr;
  21     VHostNetState *vhost_net;
  22 } VhostUserState;
  23
  24 typedef struct VhostUserChardevProps {
  25     bool is_socket;
  26     bool is_unix;
  27     bool is_server;
  28 } VhostUserChardevProps;
  29
  30 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
  31 {
  32     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  33     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  34     return s->vhost_net;
  35 }
  36
  37 static int vhost_user_running(VhostUserState *s)
  38 {
  39     return (s->vhost_net) ? 1 : 0;
  40 }
  41
  42 static int vhost_user_start(VhostUserState *s)
  43 {
  44     VhostNetOptions options;
  45
  46     if (vhost_user_running(s)) {
  47         return 0;
  48     }
  49
  50     options.backend_type = VHOST_BACKEND_TYPE_USER;
  51     options.net_backend = &s->nc;
  52     options.opaque = s->chr;
  53
  54     s->vhost_net = vhost_net_init(&options);
  55
  56     return vhost_user_running(s) ? 0 : -1;
  57 }
  58
  59 static void vhost_user_stop(VhostUserState *s)
  60 {
  61     if (vhost_user_running(s)) {
  62         vhost_net_cleanup(s->vhost_net);
  63     }
  64
  65     s->vhost_net = 0;
  66 }
  67
  68 static void vhost_user_cleanup(NetClientState *nc)
  69 {
  70     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  71
  72     vhost_user_stop(s);
  73     qemu_purge_queued_packets(nc);
  74 }
  75
  76 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
  77 {
  78     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  79
  80     return true;
  81 }
  82
  83 static bool vhost_user_has_ufo(NetClientState *nc)
  84 {
  85     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  86
  87     return true;
  88 }
  89
  90 static NetClientInfo net_vhost_user_info = {
  91         .type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
  92         .size = sizeof(VhostUserState),
  93         .cleanup = vhost_user_cleanup,
  94         .has_vnet_hdr = vhost_user_has_vnet_hdr,
  95         .has_ufo = vhost_user_has_ufo,
  96 };
  97
  98 static void net_vhost_link_down(VhostUserState *s, bool link_down)
  99 {
 100     s->nc.link_down = link_down;
 101
 102     if (s->nc.peer) {
 103         s->nc.peer->link_down = link_down;
 104     }
 105
 106     if (s->nc.info->link_status_changed) {
 107         s->nc.info->link_status_changed(&s->nc);
 108     }
 109
 110     if (s->nc.peer && s->nc.peer->info->link_status_changed) {
 111         s->nc.peer->info->link_status_changed(s->nc.peer);
 112     }
 113 }
 114
 115 static void net_vhost_user_event(void *opaque, int event)
 116 {
 117     VhostUserState *s = opaque;
 118
 119     switch (event) {
 120     case CHR_EVENT_OPENED:
 121         vhost_user_start(s);
 122         net_vhost_link_down(s, false);
 123         error_report("chardev \"%s\" went up", s->chr->label);
 124         break;
 125     case CHR_EVENT_CLOSED:
 126         net_vhost_link_down(s, true);
 127         vhost_user_stop(s);
 128         error_report("chardev \"%s\" went down", s->chr->label);
 129         break;
 130     }
 131 }
 132
 133 static int net_vhost_user_init(NetClientState *peer, const char *device,
 134                                const char *name, CharDriverState *chr)
 135 {
 136     NetClientState *nc;
 137     VhostUserState *s;
 138
 139     nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 140
 141     snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user to %s",
 142              chr->label);
 143
 144     s = DO_UPCAST(VhostUserState, nc, nc);
 145
 146     /* We don't provide a receive callback */
 147     s->nc.receive_disabled = 1;
 148     s->chr = chr;
 149
 150     qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s);
 151
 152     return 0;
 153 }
 154
 155 static int net_vhost_chardev_opts(void *opaque,
 156                                   const char *name, const char *value,
 157                                   Error **errp)
 158 {
 159     VhostUserChardevProps *props = opaque;
 160
 161     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
 162         props->is_socket = true;
 163     } else if (strcmp(name, "path") == 0) {
 164         props->is_unix = true;
 165     } else if (strcmp(name, "server") == 0) {
 166         props->is_server = true;
 167     } else {
 168         error_setg(errp,
 169                    "vhost-user does not support a chardev with option %s=%s",
 170                    name, value);
 171         return -1;
 172     }
 173     return 0;
 174 }
 175
 176 static CharDriverState *net_vhost_parse_chardev(
 177     const NetdevVhostUserOptions *opts, Error **errp)
 178 {
 179     CharDriverState *chr = qemu_chr_find(opts->chardev);
 180     VhostUserChardevProps props;
 181
 182     if (chr == NULL) {
 183         error_setg(errp, "chardev \"%s\" not found", opts->chardev);
 184         return NULL;
 185     }
 186
 187     /* inspect chardev opts */
 188     memset(&props, 0, sizeof(props));
 189     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, errp)) {
 190         return NULL;
 191     }
 192
 193     if (!props.is_socket || !props.is_unix) {
 194         error_setg(errp, "chardev \"%s\" is not a unix socket",
 195                    opts->chardev);
 196         return NULL;
 197     }
 198
 199     qemu_chr_fe_claim_no_fail(chr);
 200
 201     return chr;
 202 }
 203
 204 static int net_vhost_check_net(void *opaque, QemuOpts *opts, Error **errp)
 205 {
 206     const char *name = opaque;
 207     const char *driver, *netdev;
 208     const char virtio_name[] = "virtio-net-";
 209
 210     driver = qemu_opt_get(opts, "driver");
 211     netdev = qemu_opt_get(opts, "netdev");
 212
 213     if (!driver || !netdev) {
 214         return 0;
 215     }
 216
 217     if (strcmp(netdev, name) == 0 &&
 218         strncmp(driver, virtio_name, strlen(virtio_name)) != 0) {
 219         error_setg(errp, "vhost-user requires frontend driver virtio-net-*");
 220         return -1;
 221     }
 222
 223     return 0;
 224 }
 225
 226 int net_init_vhost_user(const NetClientOptions *opts, const char *name,
 227                         NetClientState *peer, Error **errp)
 228 {
 229     const NetdevVhostUserOptions *vhost_user_opts;
 230     CharDriverState *chr;
 231
 232     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 233     vhost_user_opts = opts->vhost_user;
 234
 235     chr = net_vhost_parse_chardev(vhost_user_opts, errp);
 236     if (!chr) {
 237         return -1;
 238     }
 239
 240     /* verify net frontend */
 241     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 242                           (char *)name, errp)) {
 243         return -1;
 244     }
 245
 246
 247     return net_vhost_user_init(peer, "vhost_user", name, chr);
 248 }