migration-tcp.c

   1 /*
   2  * QEMU live migration
   3  *
   4  * Copyright IBM, Corp. 2008
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qemu-common.h"
  15 #include "qemu_socket.h"
  16 #include "migration.h"
  17 #include "qemu-char.h"
  18 #include "sysemu.h"
  19 #include "buffered_file.h"
  20 #include "block.h"
  21
  22 //#define DEBUG_MIGRATION_TCP
  23
  24 #ifdef DEBUG_MIGRATION_TCP
  25 #define DPRINTF(fmt, ...) \
  26     do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
  27 #else
  28 #define DPRINTF(fmt, ...) \
  29     do { } while (0)
  30 #endif
  31
  32 static int socket_errno(FdMigrationState *s)
  33 {
  34     return socket_error();
  35 }
  36
  37 static int socket_write(FdMigrationState *s, const void * buf, size_t size)
  38 {
  39     return send(s->fd, buf, size, 0);
  40 }
  41
  42 static int tcp_close(FdMigrationState *s)
  43 {
  44     DPRINTF("tcp_close\n");
  45     if (s->fd != -1) {
  46         close(s->fd);
  47         s->fd = -1;
  48     }
  49     return 0;
  50 }
  51
  52
  53 static void tcp_wait_for_connect(void *opaque)
  54 {
  55     FdMigrationState *s = opaque;
  56     int val, ret;
  57     socklen_t valsize = sizeof(val);
  58
  59     DPRINTF("connect completed\n");
  60     do {
  61         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
  62     } while (ret == -1 && (s->get_error(s)) == EINTR);
  63
  64     if (ret < 0) {
  65         migrate_fd_error(s);
  66         return;
  67     }
  68
  69     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
  70
  71     if (val == 0)
  72         migrate_fd_connect(s);
  73     else {
  74         DPRINTF("error connecting %d\n", val);
  75         migrate_fd_error(s);
  76     }
  77 }
  78
  79 MigrationState *tcp_start_outgoing_migration(Monitor *mon,
  80                                              const char *host_port,
  81                                              int64_t bandwidth_limit,
  82                                              int detach,
  83                                              int blk,
  84                                              int inc)
  85 {
  86     struct sockaddr_in addr;
  87     FdMigrationState *s;
  88     int ret;
  89
  90     if (parse_host_port(&addr, host_port) < 0)
  91         return NULL;
  92
  93     s = qemu_mallocz(sizeof(*s));
  94
  95     s->get_error = socket_errno;
  96     s->write = socket_write;
  97     s->close = tcp_close;
  98     s->mig_state.cancel = migrate_fd_cancel;
  99     s->mig_state.get_status = migrate_fd_get_status;
 100     s->mig_state.release = migrate_fd_release;
 101
 102     s->mig_state.blk = blk;
 103     s->mig_state.shared = inc;
 104
 105     s->state = MIG_STATE_ACTIVE;
 106     s->mon = NULL;
 107     s->bandwidth_limit = bandwidth_limit;
 108     s->fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 109     if (s->fd == -1) {
 110         qemu_free(s);
 111         return NULL;
 112     }
 113
 114     socket_set_nonblock(s->fd);
 115
 116     if (!detach) {
 117         migrate_fd_monitor_suspend(s, mon);
 118     }
 119
 120     do {
 121         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 122         if (ret == -1)
 123             ret = -(s->get_error(s));
 124
 125         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
 126             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 127     } while (ret == -EINTR);
 128
 129     if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
 130         DPRINTF("connect failed\n");
 131         close(s->fd);
 132         qemu_free(s);
 133         return NULL;
 134     } else if (ret >= 0)
 135         migrate_fd_connect(s);
 136
 137     return &s->mig_state;
 138 }
 139
 140 static void tcp_accept_incoming_migration(void *opaque)
 141 {
 142     struct sockaddr_in addr;
 143     socklen_t addrlen = sizeof(addr);
 144     int s = (unsigned long)opaque;
 145     QEMUFile *f;
 146     int c, ret;
 147
 148     do {
 149         c = qemu_accept(s, (struct sockaddr *)&addr, &addrlen);
 150     } while (c == -1 && socket_error() == EINTR);
 151
 152     DPRINTF("accepted migration\n");
 153
 154     if (c == -1) {
 155         fprintf(stderr, "could not accept migration connection\n");
 156         return;
 157     }
 158
 159     f = qemu_fopen_socket(c);
 160     if (f == NULL) {
 161         fprintf(stderr, "could not qemu_fopen socket\n");
 162         goto out;
 163     }
 164
 165     ret = qemu_loadvm_state(f);
 166     if (ret < 0) {
 167         fprintf(stderr, "load of migration failed\n");
 168         goto out_fopen;
 169     }
 170     qemu_announce_self();
 171     DPRINTF("successfully loaded vm state\n");
 172
 173     if (autostart)
 174         vm_start();
 175
 176 out_fopen:
 177     qemu_fclose(f);
 178 out:
 179     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 180     close(s);
 181     close(c);
 182 }
 183
 184 int tcp_start_incoming_migration(const char *host_port)
 185 {
 186     struct sockaddr_in addr;
 187     int val;
 188     int s;
 189
 190     if (parse_host_port(&addr, host_port) < 0) {
 191         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 192         return -EINVAL;
 193     }
 194
 195     s = qemu_socket(PF_INET, SOCK_STREAM, 0);
 196     if (s == -1)
 197         return -socket_error();
 198
 199     val = 1;
 200     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 201
 202     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
 203         goto err;
 204
 205     if (listen(s, 1) == -1)
 206         goto err;
 207
 208     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 209                          (void *)(unsigned long)s);
 210
 211     return 0;
 212
 213 err:
 214     close(s);
 215     return -socket_error();
 216 }