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 "buffered_file.h"
  21 #include "block.h"
  22 #include <sys/types.h>
  23 #include <sys/wait.h>
  24
  25 //#define DEBUG_MIGRATION_EXEC
  26
  27 #ifdef DEBUG_MIGRATION_EXEC
  28 #define DPRINTF(fmt, ...) \
  29     do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0)
  30 #else
  31 #define DPRINTF(fmt, ...) \
  32     do { } while (0)
  33 #endif
  34
  35 static int file_errno(MigrationState *s)
  36 {
  37     return errno;
  38 }
  39
  40 static int file_write(MigrationState *s, const void * buf, size_t size)
  41 {
  42     return write(s->fd, buf, size);
  43 }
  44
  45 static int exec_close(MigrationState *s)
  46 {
  47     int ret = 0;
  48     DPRINTF("exec_close\n");
  49     if (s->opaque) {
  50         ret = qemu_fclose(s->opaque);
  51         s->opaque = NULL;
  52         s->fd = -1;
  53         if (ret != -1 &&
  54             WIFEXITED(ret)
  55             && WEXITSTATUS(ret) == 0) {
  56             ret = 0;
  57         } else {
  58             ret = -1;
  59         }
  60     }
  61     return ret;
  62 }
  63
  64 MigrationState *exec_start_outgoing_migration(Monitor *mon,
  65                                               const char *command,
  66                                               int64_t bandwidth_limit,
  67                                               int detach,
  68                                               int blk,
  69                                               int inc)
  70 {
  71     MigrationState *s;
  72     FILE *f;
  73
  74     s = migrate_new(mon, bandwidth_limit, detach, blk, inc);
  75
  76     f = popen(command, "w");
  77     if (f == NULL) {
  78         DPRINTF("Unable to popen exec target\n");
  79         goto err_after_alloc;
  80     }
  81
  82     s->fd = fileno(f);
  83     if (s->fd == -1) {
  84         DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  85         goto err_after_open;
  86     }
  87
  88     socket_set_nonblock(s->fd);
  89
  90     s->opaque = qemu_popen(f, "w");
  91
  92     s->close = exec_close;
  93     s->get_error = file_errno;
  94     s->write = file_write;
  95
  96     migrate_fd_connect(s);
  97     return s;
  98
  99 err_after_open:
 100     pclose(f);
 101 err_after_alloc:
 102     g_free(s);
 103     return NULL;
 104 }
 105
 106 static void exec_accept_incoming_migration(void *opaque)
 107 {
 108     QEMUFile *f = opaque;
 109
 110     process_incoming_migration(f);
 111     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 112     qemu_fclose(f);
 113 }
 114
 115 int exec_start_incoming_migration(const char *command)
 116 {
 117     QEMUFile *f;
 118
 119     DPRINTF("Attempting to start an incoming migration\n");
 120     f = qemu_popen_cmd(command, "r");
 121     if(f == NULL) {
 122         DPRINTF("Unable to apply qemu wrapper to popen file\n");
 123         return -errno;
 124     }
 125
 126     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 127                          exec_accept_incoming_migration, NULL, f);
 128
 129     return 0;
 130 }