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     bool vhostforce;
  22     VHostNetState *vhost_net;
  23 } VhostUserState;
  24
  25 typedef struct VhostUserChardevProps {
  26     bool is_socket;
  27     bool is_unix;
  28     bool is_server;
  29 } VhostUserChardevProps;
  30
  31 VHostNetState *vhost_user_get_vhost_net(NetClientState *nc)
  32 {
  33     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  34     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  35     return s->vhost_net;
  36 }
  37
  38 static int vhost_user_running(VhostUserState *s)
  39 {
  40     return (s->vhost_net) ? 1 : 0;
  41 }
  42
  43 static int vhost_user_start(VhostUserState *s)
  44 {
  45     VhostNetOptions options;
  46
  47     if (vhost_user_running(s)) {
  48         return 0;
  49     }
  50
  51     options.backend_type = VHOST_BACKEND_TYPE_USER;
  52     options.net_backend = &s->nc;
  53     options.opaque = s->chr;
  54     options.force = s->vhostforce;
  55
  56     s->vhost_net = vhost_net_init(&options);
  57
  58     return vhost_user_running(s) ? 0 : -1;
  59 }
  60
  61 static void vhost_user_stop(VhostUserState *s)
  62 {
  63     if (vhost_user_running(s)) {
  64         vhost_net_cleanup(s->vhost_net);
  65     }
  66
  67     s->vhost_net = 0;
  68 }
  69
  70 static void vhost_user_cleanup(NetClientState *nc)
  71 {
  72     VhostUserState *s = DO_UPCAST(VhostUserState, nc, nc);
  73
  74     vhost_user_stop(s);
  75     qemu_purge_queued_packets(nc);
  76 }
  77
  78 static bool vhost_user_has_vnet_hdr(NetClientState *nc)
  79 {
  80     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  81
  82     return true;
  83 }
  84
  85 static bool vhost_user_has_ufo(NetClientState *nc)
  86 {
  87     assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
  88
  89     return true;
  90 }
  91
  92 static NetClientInfo net_vhost_user_info = {
  93         .type = NET_CLIENT_OPTIONS_KIND_VHOST_USER,
  94         .size = sizeof(VhostUserState),
  95         .cleanup = vhost_user_cleanup,
  96         .has_vnet_hdr = vhost_user_has_vnet_hdr,
  97         .has_ufo = vhost_user_has_ufo,
  98 };
  99
 100 static void net_vhost_link_down(VhostUserState *s, bool link_down)
 101 {
 102     s->nc.link_down = link_down;
 103
 104     if (s->nc.peer) {
 105         s->nc.peer->link_down = link_down;
 106     }
 107
 108     if (s->nc.info->link_status_changed) {
 109         s->nc.info->link_status_changed(&s->nc);
 110     }
 111
 112     if (s->nc.peer && s->nc.peer->info->link_status_changed) {
 113         s->nc.peer->info->link_status_changed(s->nc.peer);
 114     }
 115 }
 116
 117 static void net_vhost_user_event(void *opaque, int event)
 118 {
 119     VhostUserState *s = opaque;
 120
 121     switch (event) {
 122     case CHR_EVENT_OPENED:
 123         vhost_user_start(s);
 124         net_vhost_link_down(s, false);
 125         error_report("chardev \"%s\" went up\n", s->chr->label);
 126         break;
 127     case CHR_EVENT_CLOSED:
 128         net_vhost_link_down(s, true);
 129         vhost_user_stop(s);
 130         error_report("chardev \"%s\" went down\n", s->chr->label);
 131         break;
 132     }
 133 }
 134
 135 static int net_vhost_user_init(NetClientState *peer, const char *device,
 136                                const char *name, CharDriverState *chr,
 137                                bool vhostforce)
 138 {
 139     NetClientState *nc;
 140     VhostUserState *s;
 141
 142     nc = qemu_new_net_client(&net_vhost_user_info, peer, device, name);
 143
 144     snprintf(nc->info_str, sizeof(nc->info_str), "vhost-user to %s",
 145              chr->label);
 146
 147     s = DO_UPCAST(VhostUserState, nc, nc);
 148
 149     /* We don't provide a receive callback */
 150     s->nc.receive_disabled = 1;
 151     s->chr = chr;
 152     s->vhostforce = vhostforce;
 153
 154     qemu_chr_add_handlers(s->chr, NULL, NULL, net_vhost_user_event, s);
 155
 156     return 0;
 157 }
 158
 159 static int net_vhost_chardev_opts(const char *name, const char *value,
 160                                   void *opaque)
 161 {
 162     VhostUserChardevProps *props = opaque;
 163
 164     if (strcmp(name, "backend") == 0 && strcmp(value, "socket") == 0) {
 165         props->is_socket = true;
 166     } else if (strcmp(name, "path") == 0) {
 167         props->is_unix = true;
 168     } else if (strcmp(name, "server") == 0) {
 169         props->is_server = true;
 170     } else {
 171         error_report("vhost-user does not support a chardev"
 172                      " with the following option:\n %s = %s",
 173                      name, value);
 174         return -1;
 175     }
 176     return 0;
 177 }
 178
 179 static CharDriverState *net_vhost_parse_chardev(const NetdevVhostUserOptions *opts)
 180 {
 181     CharDriverState *chr = qemu_chr_find(opts->chardev);
 182     VhostUserChardevProps props;
 183
 184     if (chr == NULL) {
 185         error_report("chardev \"%s\" not found", opts->chardev);
 186         return NULL;
 187     }
 188
 189     /* inspect chardev opts */
 190     memset(&props, 0, sizeof(props));
 191     if (qemu_opt_foreach(chr->opts, net_vhost_chardev_opts, &props, true) != 0) {
 192         return NULL;
 193     }
 194
 195     if (!props.is_socket || !props.is_unix) {
 196         error_report("chardev \"%s\" is not a unix socket",
 197                      opts->chardev);
 198         return NULL;
 199     }
 200
 201     qemu_chr_fe_claim_no_fail(chr);
 202
 203     return chr;
 204 }
 205
 206 static int net_vhost_check_net(QemuOpts *opts, void *opaque)
 207 {
 208     const char *name = opaque;
 209     const char *driver, *netdev;
 210     const char virtio_name[] = "virtio-net-";
 211
 212     driver = qemu_opt_get(opts, "driver");
 213     netdev = qemu_opt_get(opts, "netdev");
 214
 215     if (!driver || !netdev) {
 216         return 0;
 217     }
 218
 219     if (strcmp(netdev, name) == 0 &&
 220         strncmp(driver, virtio_name, strlen(virtio_name)) != 0) {
 221         error_report("vhost-user requires frontend driver virtio-net-*");
 222         return -1;
 223     }
 224
 225     return 0;
 226 }
 227
 228 int net_init_vhost_user(const NetClientOptions *opts, const char *name,
 229                         NetClientState *peer)
 230 {
 231     const NetdevVhostUserOptions *vhost_user_opts;
 232     CharDriverState *chr;
 233     bool vhostforce;
 234
 235     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_VHOST_USER);
 236     vhost_user_opts = opts->vhost_user;
 237
 238     chr = net_vhost_parse_chardev(vhost_user_opts);
 239     if (!chr) {
 240         error_report("No suitable chardev found");
 241         return -1;
 242     }
 243
 244     /* verify net frontend */
 245     if (qemu_opts_foreach(qemu_find_opts("device"), net_vhost_check_net,
 246                           (char *)name, true) == -1) {
 247         return -1;
 248     }
 249
 250     /* vhostforce for non-MSIX */
 251     if (vhost_user_opts->has_vhostforce) {
 252         vhostforce = vhost_user_opts->vhostforce;
 253     } else {
 254         vhostforce = false;
 255     }
 256
 257     return net_vhost_user_init(peer, "vhost_user", name, chr, vhostforce);
 258 }