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     options.force = true;
  54
  55     s->vhost_net = vhost_net_init(&options);
  56
  57     return vhost_user_running(s) ? 0 : -1;
  58 }
  59
  60 static void vhost_user_stop(VhostUserState *s)
  61 {
  62     if (vhost_user_running(s)) {
  63         vhost_net_cleanup(s->vhost_net);
  64     }
  65
  66     s->vhost_net = 0;
  67 }
  68
  69 static void vhost_user_cleanup(NetClientState *nc)
  70 {
  71     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  72
  73     vhost_user_stop(s);
  74     qemu_purge_queued_packets(nc);
  75 }
  76
  77 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
  78 {
  79     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  80
  81     return true;
  82 }
  83
  84 static bool vhost_user_has_ufo(NetClientState *nc)
  85 {
  86     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  87
  88     return true;
  89 }
  90
  91 static NetClientInfo net_vhost_user_info = {
  92         .type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
  93         .size = sizeof(VhostUserState),
  94         .cleanup = vhost_user_cleanup,
  95         .has_vnet_hdr = vhost_user_has_vnet_hdr,
  96         .has_ufo = vhost_user_has_ufo,
  97 };
  98
  99 static void net_vhost_link_down(VhostUserState *s, bool link_down)
 100 {
 101     s->nc.link_down = link_down;
 102
 103     if (s->nc.peer) {
 104         s->nc.peer->link_down = link_down;
 105     }
 106
 107     if (s->nc.info->link_status_changed) {
 108         s->nc.info->link_status_changed(&s->nc);
 109     }
 110
 111     if (s->nc.peer && s->nc.peer->info->link_status_changed) {
 112         s->nc.peer->info->link_status_changed(s->nc.peer);
 113     }
 114 }
 115
 116 static void net_vhost_user_event(void *opaque, int event)
 117 {
 118     VhostUserState *s = opaque;
 119
 120     switch (event) {
 121     case CHR_EVENT_OPENED:
 122         vhost_user_start(s);
 123         net_vhost_link_down(s, false);
 124         error_report("chardev \"%s\" went up", s->chr->label);
 125         break;
 126     case CHR_EVENT_CLOSED:
 127         net_vhost_link_down(s, true);
 128         vhost_user_stop(s);
 129         error_report("chardev \"%s\" went down", s->chr->label);
 130         break;
 131     }
 132 }
 133
 134 static int net_vhost_user_init(NetClientState *peer, const char *device,
 135                                const char *name, CharDriverState *chr)
 136 {
 137     NetClientState *nc;
 138     VhostUserState *s;
 139
 140     nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 141
 142     snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user to %s",
 143              chr->label);
 144
 145     s = DO_UPCAST(VhostUserState, nc, nc);
 146
 147     /* We don't provide a receive callback */
 148     s->nc.receive_disabled = 1;
 149     s->chr = chr;
 150
 151     qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s);
 152
 153     return 0;
 154 }
 155
 156 static int net_vhost_chardev_opts(const char *name, const char *value,
 157                                   void *opaque)
 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_report("vhost-user does not support a chardev"
 169                      " with the following option:\n %s = %s",
 170                      name, value);
 171         return -1;
 172     }
 173     return 0;
 174 }
 175
 176 static CharDriverState *net_vhost_parse_chardev(const NetdevVhostUserOptions *opts)
 177 {
 178     CharDriverState *chr = qemu_chr_find(opts->chardev);
 179     VhostUserChardevProps props;
 180
 181     if (chr == NULL) {
 182         error_report("chardev \"%s\" not found", opts->chardev);
 183         return NULL;
 184     }
 185
 186     /* inspect chardev opts */
 187     memset(&props, 0, sizeof(props));
 188     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, true) != 0) {
 189         return NULL;
 190     }
 191
 192     if (!props.is_socket || !props.is_unix) {
 193         error_report("chardev \"%s\" is not a unix socket",
 194                      opts->chardev);
 195         return NULL;
 196     }
 197
 198     qemu_chr_fe_claim_no_fail(chr);
 199
 200     return chr;
 201 }
 202
 203 static int net_vhost_check_net(QemuOpts *opts, void *opaque)
 204 {
 205     const char *name = opaque;
 206     const char *driver, *netdev;
 207     const char virtio_name[] = "virtio-net-";
 208
 209     driver = qemu_opt_get(opts, "driver");
 210     netdev = qemu_opt_get(opts, "netdev");
 211
 212     if (!driver || !netdev) {
 213         return 0;
 214     }
 215
 216     if (strcmp(netdev, name) == 0 &&
 217         strncmp(driver, virtio_name, strlen(virtio_name)) != 0) {
 218         error_report("vhost-user requires frontend driver virtio-net-*");
 219         return -1;
 220     }
 221
 222     return 0;
 223 }
 224
 225 int net_init_vhost_user(const NetClientOptions *opts, const char *name,
 226                         NetClientState *peer)
 227 {
 228     const NetdevVhostUserOptions *vhost_user_opts;
 229     CharDriverState *chr;
 230
 231     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 232     vhost_user_opts = opts->vhost_user;
 233
 234     chr = net_vhost_parse_chardev(vhost_user_opts);
 235     if (!chr) {
 236         error_report("No suitable chardev found");
 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, true) == -1) {
 243         return -1;
 244     }
 245
 246
 247     return net_vhost_user_init(peer, "vhost_user", name, chr);
 248 }