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