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   <aliguori@us.ibm.com>
   9  *  Charles Duffy     <charles_duffy@messageone.com>
  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     int ret = 0;
  47     DPRINTF("exec_close\n");
  48     if (s->opaque) {
  49         ret = qemu_fclose(s->opaque);
  50         s->opaque = NULL;
  51         s->fd = -1;
  52         if (ret != -1 &&
  53             WIFEXITED(ret)
  54             && WEXITSTATUS(ret) == 0) {
  55             ret = 0;
  56         } else {
  57             ret = -1;
  58         }
  59     }
  60     return ret;
  61 }
  62
  63 MigrationState *exec_start_outgoing_migration(Monitor *mon,
  64                                               const char *command,
  65                                               int64_t bandwidth_limit,
  66                                               int detach,
  67                                               int blk,
  68                                               int inc)
  69 {
  70     FdMigrationState *s;
  71     FILE *f;
  72
  73     s = qemu_mallocz(sizeof(*s));
  74
  75     f = popen(command, "w");
  76     if (f == NULL) {
  77         DPRINTF("Unable to popen exec target\n");
  78         goto err_after_alloc;
  79     }
  80
  81     s->fd = fileno(f);
  82     if (s->fd == -1) {
  83         DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  84         goto err_after_open;
  85     }
  86
  87     socket_set_nonblock(s->fd);
  88
  89     s->opaque = qemu_popen(f, "w");
  90
  91     s->close = exec_close;
  92     s->get_error = file_errno;
  93     s->write = file_write;
  94     s->mig_state.cancel = migrate_fd_cancel;
  95     s->mig_state.get_status = migrate_fd_get_status;
  96     s->mig_state.release = migrate_fd_release;
  97
  98     s->mig_state.blk = blk;
  99     s->mig_state.shared = inc;
 100
 101     s->state = MIG_STATE_ACTIVE;
 102     s->mon = NULL;
 103     s->bandwidth_limit = bandwidth_limit;
 104
 105     if (!detach) {
 106         migrate_fd_monitor_suspend(s, mon);
 107     }
 108
 109     migrate_fd_connect(s);
 110     return &s->mig_state;
 111
 112 err_after_open:
 113     pclose(f);
 114 err_after_alloc:
 115     qemu_free(s);
 116     return NULL;
 117 }
 118
 119 static void exec_accept_incoming_migration(void *opaque)
 120 {
 121     QEMUFile *f = opaque;
 122     int ret;
 123
 124     ret = qemu_loadvm_state(f);
 125     if (ret < 0) {
 126         fprintf(stderr, "load of migration failed\n");
 127         goto err;
 128     }
 129     qemu_announce_self();
 130     DPRINTF("successfully loaded vm state\n");
 131
 132     if (autostart)
 133         vm_start();
 134
 135 err:
 136     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 137     qemu_fclose(f);
 138 }
 139
 140 int exec_start_incoming_migration(const char *command)
 141 {
 142     QEMUFile *f;
 143
 144     DPRINTF("Attempting to start an incoming migration\n");
 145     f = qemu_popen_cmd(command, "r");
 146     if(f == NULL) {
 147         DPRINTF("Unable to apply qemu wrapper to popen file\n");
 148         return -errno;
 149     }
 150
 151     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 152                          exec_accept_incoming_migration, NULL, f);
 153
 154     return 0;
 155 }