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     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     if (fcntl(s->fd, F_SETFD, O_NONBLOCK) == -1) {
  77         dprintf("Unable to set nonblocking mode on file descriptor\n");
  78         goto err_after_open;
  79     }
  80
  81     s->opaque = qemu_popen(f, "w");
  82
  83     s->close = exec_close;
  84     s->get_error = file_errno;
  85     s->write = file_write;
  86     s->mig_state.cancel = migrate_fd_cancel;
  87     s->mig_state.get_status = migrate_fd_get_status;
  88     s->mig_state.release = migrate_fd_release;
  89
  90     s->state = MIG_STATE_ACTIVE;
  91     s->mon_resume = NULL;
  92     s->bandwidth_limit = bandwidth_limit;
  93
  94     if (!detach)
  95         migrate_fd_monitor_suspend(s);
  96
  97     migrate_fd_connect(s);
  98     return &s->mig_state;
  99
 100 err_after_open:
 101     pclose(f);
 102 err_after_alloc:
 103     qemu_free(s);
 104     return NULL;
 105 }
 106
 107 static void exec_accept_incoming_migration(void *opaque)
 108 {
 109     QEMUFile *f = opaque;
 110     int ret;
 111
 112     vm_stop(0); /* just in case */
 113     ret = qemu_loadvm_state(f);
 114     if (ret < 0) {
 115         fprintf(stderr, "load of migration failed\n");
 116         goto err;
 117     }
 118     qemu_announce_self();
 119     dprintf("successfully loaded vm state\n");
 120     /* we've successfully migrated, close the fd */
 121     qemu_set_fd_handler2(qemu_popen_fd(f), NULL, NULL, NULL, NULL);
 122     vm_start();
 123
 124 err:
 125     qemu_fclose(f);
 126 }
 127
 128 int exec_start_incoming_migration(const char *command)
 129 {
 130     QEMUFile *f;
 131
 132     dprintf("Attempting to start an incoming migration\n");
 133     f = qemu_popen_cmd(command, "r");
 134     if(f == NULL) {
 135         dprintf("Unable to apply qemu wrapper to popen file\n");
 136         return -errno;
 137     }
 138
 139     qemu_set_fd_handler2(qemu_popen_fd(f), NULL,
 140                          exec_accept_incoming_migration, NULL,
 141                          (void *)(unsigned long)f);
 142
 143     return 0;
 144 }