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 int exec_start_outgoing_migration(MigrationState *s, const char *command)
  65 {
  66     FILE *f;
  67
  68     f = popen(command, "w");
  69     if (f == NULL) {
  70         DPRINTF("Unable to popen exec target\n");
  71         goto err_after_popen;
  72     }
  73
  74     s->fd = fileno(f);
  75     if (s->fd == -1) {
  76         DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  77         goto err_after_open;
  78     }
  79
  80     socket_set_nonblock(s->fd);
  81
  82     s->opaque = qemu_popen(f, "w");
  83
  84     s->close = exec_close;
  85     s->get_error = file_errno;
  86     s->write = file_write;
  87
  88     migrate_fd_connect(s);
  89     return 0;
  90
  91 err_after_open:
  92     pclose(f);
  93 err_after_popen:
  94     return -1;
  95 }
  96
  97 static void exec_accept_incoming_migration(void *opaque)
  98 {
  99     QEMUFile *f = opaque;
 100
 101     process_incoming_migration(f);
 102     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 103     qemu_fclose(f);
 104 }
 105
 106 int exec_start_incoming_migration(const char *command)
 107 {
 108     QEMUFile *f;
 109
 110     DPRINTF("Attempting to start an incoming migration\n");
 111     f = qemu_popen_cmd(command, "r");
 112     if(f == NULL) {
 113         DPRINTF("Unable to apply qemu wrapper to popen file\n");
 114         return -errno;
 115     }
 116
 117     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 118                          exec_accept_incoming_migration, NULL, f);
 119
 120     return 0;
 121 }