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(Monitor *mon,
  56                                               const char *command,
  57                                               int64_t bandwidth_limit,
  58                                               int detach,
  59                                               int blk,
  60                                               int inc)
  61 {
  62     FdMigrationState *s;
  63     FILE *f;
  64
  65     s = qemu_mallocz(sizeof(*s));
  66
  67     f = popen(command, "w");
  68     if (f == NULL) {
  69         DPRINTF("Unable to popen exec target\n");
  70         goto err_after_alloc;
  71     }
  72
  73     s->fd = fileno(f);
  74     if (s->fd == -1) {
  75         DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  76         goto err_after_open;
  77     }
  78
  79     socket_set_nonblock(s->fd);
  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->mig_state.blk = blk;
  91     s->mig_state.shared = inc;
  92
  93     s->state = MIG_STATE_ACTIVE;
  94     s->mon = NULL;
  95     s->bandwidth_limit = bandwidth_limit;
  96
  97     if (!detach) {
  98         migrate_fd_monitor_suspend(s, mon);
  99     }
 100
 101     migrate_fd_connect(s);
 102     return &s->mig_state;
 103
 104 err_after_open:
 105     pclose(f);
 106 err_after_alloc:
 107     qemu_free(s);
 108     return NULL;
 109 }
 110
 111 static void exec_accept_incoming_migration(void *opaque)
 112 {
 113     QEMUFile *f = opaque;
 114     int ret;
 115
 116     ret = qemu_loadvm_state(f);
 117     if (ret < 0) {
 118         fprintf(stderr, "load of migration failed\n");
 119         goto err;
 120     }
 121     qemu_announce_self();
 122     DPRINTF("successfully loaded vm state\n");
 123     /* we've successfully migrated, close the fd */
 124     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 125     if (autostart)
 126         vm_start();
 127
 128 err:
 129     qemu_fclose(f);
 130 }
 131
 132 int exec_start_incoming_migration(const char *command)
 133 {
 134     QEMUFile *f;
 135
 136     DPRINTF("Attempting to start an incoming migration\n");
 137     f = qemu_popen_cmd(command, "r");
 138     if(f == NULL) {
 139         DPRINTF("Unable to apply qemu wrapper to popen file\n");
 140         return -errno;
 141     }
 142
 143     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 144                          exec_accept_incoming_migration, NULL,
 145                          (void *)(unsigned long)f);
 146
 147     return 0;
 148 }