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 >= 0 && !(WIFEXITED(ret) && WEXITSTATUS(ret) == 0)) {
  54             /* close succeeded, but non-zero exit code: */
  55             ret = -EIO; /* fake errno value */
  56         }
  57     }
  58     return ret;
  59 }
  60
  61 int exec_start_outgoing_migration(MigrationState *s, const char *command)
  62 {
  63     FILE *f;
  64
  65     f = popen(command, "w");
  66     if (f == NULL) {
  67         DPRINTF("Unable to popen exec target\n");
  68         goto err_after_popen;
  69     }
  70
  71     s->fd = fileno(f);
  72     if (s->fd == -1) {
  73         DPRINTF("Unable to retrieve file descriptor for popen'd handle\n");
  74         goto err_after_open;
  75     }
  76
  77     socket_set_nonblock(s->fd);
  78
  79     s->opaque = qemu_popen(f, "w");
  80
  81     s->close = exec_close;
  82     s->get_error = file_errno;
  83     s->write = file_write;
  84
  85     migrate_fd_connect(s);
  86     return 0;
  87
  88 err_after_open:
  89     pclose(f);
  90 err_after_popen:
  91     return -1;
  92 }
  93
  94 static void exec_accept_incoming_migration(void *opaque)
  95 {
  96     QEMUFile *f = opaque;
  97
  98     process_incoming_migration(f);
  99     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL, NULL, NULL, NULL);
 100     qemu_fclose(f);
 101 }
 102
 103 int exec_start_incoming_migration(const char *command)
 104 {
 105     QEMUFile *f;
 106
 107     DPRINTF("Attempting to start an incoming migration\n");
 108     f = qemu_popen_cmd(command, "r");
 109     if(f == NULL) {
 110         DPRINTF("Unable to apply qemu wrapper to popen file\n");
 111         return -errno;
 112     }
 113
 114     qemu_set_fd_handler2(qemu_stdio_fd(f), NULL,
 115                          exec_accept_incoming_migration, NULL, f);
 116
 117     return 0;
 118 }