migration-exec.c

   1 /*
   2  * QEMU live migration
   3  *
   4  * Copyright IBM, Corp. 2008
   5  * Copyright Dell MessageOne 2008
   6  *
   7  * Authors:
   8  *  Anthony Liguori   <[email protected]>
   9  *  Charles Duffy     <[email protected]>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2.  See
  12  * the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include "qemu-common.h"
  17 #include "qemu_socket.h"
  18 #include "migration.h"
  19 #include "qemu-char.h"
  20 #include "sysemu.h"
  21 #include "buffered_file.h"
  22 #include "block.h"
  23
  24 //#define DEBUG_MIGRATION_EXEC
  25
  26 #ifdef DEBUG_MIGRATION_EXEC
  27 #define dprintf(fmt, ...) \
  28     do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0)
  29 #else
  30 #define dprintf(fmt, ...) \
  31     do { } while (0)
  32 #endif
  33
  34 static int file_errno(FdMigrationState *s)
  35 {
  36     return errno;
  37 }
  38
  39 static int file_write(FdMigrationState *s, const void * buf, size_t size)
  40 {
  41     return write(s->fd, buf, size);
  42 }
  43
  44 static int exec_close(FdMigrationState *s)
  45 {
  46     dprintf("exec_close\n");
  47     if (s->opaque) {
  48         qemu_fclose(s->opaque);
  49         s->opaque = NULL;
  50         s->fd = -1;
  51     }
  52     return 0;
  53 }
  54
  55 MigrationState *exec_start_outgoing_migration(const char *command,
  56                                              int64_t bandwidth_limit,
  57                                              int detach)
  58 {
  59     FdMigrationState *s;
  60     FILE *f;
  61
  62     s = qemu_mallocz(sizeof(*s));
  63
  64     f = popen(command, "w");
  65     if (f == NULL) {
  66         dprintf("Unable to popen exec target\n");
  67         goto err_after_alloc;
  68     }
  69
  70     s->fd = fileno(f);
  71     if (s->fd == -1) {
  72         dprintf("Unable to retrieve file descriptor for popen'd handle\n");
  73         goto err_after_open;
  74     }
  75
  76     socket_set_nonblock(s->fd);
  77
  78     s->opaque = qemu_popen(f, "w");
  79
  80     s->close = exec_close;
  81     s->get_error = file_errno;
  82     s->write = file_write;
  83     s->mig_state.cancel = migrate_fd_cancel;
  84     s->mig_state.get_status = migrate_fd_get_status;
  85     s->mig_state.release = migrate_fd_release;
  86
  87     s->state = MIG_STATE_ACTIVE;
  88     s->mon_resume = NULL;
  89     s->bandwidth_limit = bandwidth_limit;
  90
  91     if (!detach)
  92         migrate_fd_monitor_suspend(s);
  93
  94     migrate_fd_connect(s);
  95     return &s->mig_state;
  96
  97 err_after_open:
  98     pclose(f);
  99 err_after_alloc:
 100     qemu_free(s);
 101     return NULL;
 102 }
 103
 104 static void exec_accept_incoming_migration(void *opaque)
 105 {
 106     QEMUFile *f = opaque;
 107     int ret;
 108
 109     ret = qemu_loadvm_state(f);
 110     if (ret < 0) {
 111         fprintf(stderr, "load of migration failed\n");
 112         goto err;
 113     }
 114     qemu_announce_self();
 115     dprintf("successfully loaded vm state\n");
 116     /* we've successfully migrated, close the fd */
 117     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 118     if (autostart)
 119         vm_start();
 120
 121 err:
 122     qemu_fclose(f);
 123 }
 124
 125 int exec_start_incoming_migration(const char *command)
 126 {
 127     QEMUFile *f;
 128
 129     dprintf("Attempting to start an incoming migration\n");
 130     f = qemu_popen_cmd(command, "r");
 131     if(f == NULL) {
 132         dprintf("Unable to apply qemu wrapper to popen file\n");
 133         return -errno;
 134     }
 135
 136     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 137                          exec_accept_incoming_migration, NULL,
 138                          (void *)(unsigned long)f);
 139
 140     return 0;
 141 }