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 "console.h"
  20 #include "buffered_file.h"
  21 #include "block.h"
  22
  23 //#define DEBUG_MIGRATION_TCP
  24
  25 #ifdef DEBUG_MIGRATION_TCP
  26 #define dprintf(fmt, ...) \
  27     do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
  28 #else
  29 #define dprintf(fmt, ...) \
  30     do { } while (0)
  31 #endif
  32
  33 static int socket_errno(FdMigrationState *s)
  34 {
  35     return socket_error();
  36 }
  37
  38 static int socket_write(FdMigrationState *s, const void * buf, size_t size)
  39 {
  40     return send(s->fd, buf, size, 0);
  41 }
  42
  43 static int tcp_close(FdMigrationState *s)
  44 {
  45     dprintf("tcp_close\n");
  46     if (s->fd != -1) {
  47         close(s->fd);
  48         s->fd = -1;
  49     }
  50     return 0;
  51 }
  52
  53
  54 static void tcp_wait_for_connect(void *opaque)
  55 {
  56     FdMigrationState *s = opaque;
  57     int val, ret;
  58     socklen_t valsize = sizeof(val);
  59
  60     dprintf("connect completed\n");
  61     do {
  62         ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &val, &valsize);
  63     } while (ret == -1 && (s->get_error(s)) == EINTR);
  64
  65     if (ret < 0) {
  66         migrate_fd_error(s);
  67         return;
  68     }
  69
  70     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
  71
  72     if (val == 0)
  73         migrate_fd_connect(s);
  74     else {
  75         dprintf("error connecting %d\n", val);
  76         migrate_fd_error(s);
  77     }
  78 }
  79
  80 MigrationState *tcp_start_outgoing_migration(const char *host_port,
  81                                              int64_t bandwidth_limit,
  82                                              int async)
  83 {
  84     struct sockaddr_in addr;
  85     FdMigrationState *s;
  86     int ret;
  87
  88     if (parse_host_port(&addr, host_port) < 0)
  89         return NULL;
  90
  91     s = qemu_mallocz(sizeof(*s));
  92     if (s == NULL)
  93         return NULL;
  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->state = MIG_STATE_ACTIVE;
 103     s->detach = !async;
 104     s->bandwidth_limit = bandwidth_limit;
 105     s->fd = socket(PF_INET, SOCK_STREAM, 0);
 106     if (s->fd == -1) {
 107         qemu_free(s);
 108         return NULL;
 109     }
 110
 111     socket_set_nonblock(s->fd);
 112
 113     if (s->detach == 1) {
 114         dprintf("detaching from monitor\n");
 115         monitor_suspend();
 116         s->detach = 2;
 117     }
 118
 119     do {
 120         ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
 121         if (ret == -1)
 122             ret = -(s->get_error(s));
 123
 124         if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
 125             qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
 126     } while (ret == -EINTR);
 127
 128     if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
 129         dprintf("connect failed\n");
 130         close(s->fd);
 131         qemu_free(s);
 132         return NULL;
 133     } else if (ret >= 0)
 134         migrate_fd_connect(s);
 135
 136     return &s->mig_state;
 137 }
 138
 139 static void tcp_accept_incoming_migration(void *opaque)
 140 {
 141     struct sockaddr_in addr;
 142     socklen_t addrlen = sizeof(addr);
 143     int s = (unsigned long)opaque;
 144     QEMUFile *f;
 145     int c, ret;
 146
 147     do {
 148         c = accept(s, (struct sockaddr *)&addr, &addrlen);
 149     } while (c == -1 && socket_error() == EINTR);
 150
 151     dprintf("accepted migration\n");
 152
 153     if (c == -1) {
 154         fprintf(stderr, "could not accept migration connection\n");
 155         return;
 156     }
 157
 158     f = qemu_fopen_socket(c);
 159     if (f == NULL) {
 160         fprintf(stderr, "could not qemu_fopen socket\n");
 161         goto out;
 162     }
 163
 164     vm_stop(0); /* just in case */
 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     /* we've successfully migrated, close the server socket */
 174     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
 175     close(s);
 176
 177     vm_start();
 178
 179 out_fopen:
 180     qemu_fclose(f);
 181 out:
 182     close(c);
 183 }
 184
 185 int tcp_start_incoming_migration(const char *host_port)
 186 {
 187     struct sockaddr_in addr;
 188     int val;
 189     int s;
 190
 191     if (parse_host_port(&addr, host_port) < 0) {
 192         fprintf(stderr, "invalid host/port combination: %s\n", host_port);
 193         return -EINVAL;
 194     }
 195
 196     s = socket(PF_INET, SOCK_STREAM, 0);
 197     if (s == -1)
 198         return -socket_error();
 199
 200     val = 1;
 201     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
 202
 203     if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
 204         goto err;
 205
 206     if (listen(s, 1) == -1)
 207         goto err;
 208
 209     qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
 210                          (void *)(unsigned long)s);
 211
 212     return 0;
 213
 214 err:
 215     close(s);
 216     return -socket_error();
 217 }