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  * Contributions after 2012-01-13 are licensed under the terms of the
  15  * GNU GPL, version 2 or (at your option) any later version.
  16  */
  17
  18 #include "qemu-common.h"
  19 #include "qemu/sockets.h"
  20 #include "migration/migration.h"
  21 #include "migration/qemu-file.h"
  22 #include "block/block.h"
  23 #include <sys/types.h>
  24 #include <sys/wait.h>
  25
  26 //#define DEBUG_MIGRATION_EXEC
  27
  28 #ifdef DEBUG_MIGRATION_EXEC
  29 #define DPRINTF(fmt, ...) \
  30     do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0)
  31 #else
  32 #define DPRINTF(fmt, ...) \
  33     do { } while (0)
  34 #endif
  35
  36 static int file_errno(MigrationState *s)
  37 {
  38     return errno;
  39 }
  40
  41 static int file_write(MigrationState *s, const void * buf, size_t size)
  42 {
  43     return write(s->fd, buf, size);
  44 }
  45
  46 static int exec_close(MigrationState *s)
  47 {
  48     int ret = 0;
  49     DPRINTF("exec_close\n");
  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     return ret;
  58 }
  59
  60 void exec_start_outgoing_migration(MigrationState *s, const char *command, Error **errp)
  61 {
  62     FILE *f;
  63
  64     f = popen(command, "w");
  65     if (f == NULL) {
  66         error_setg_errno(errp, errno, "failed to popen the migration target");
  67         return;
  68     }
  69
  70     s->fd = fileno(f);
  71     assert(s->fd != -1);
  72
  73     s->opaque = qemu_popen(f, "w");
  74
  75     s->close = exec_close;
  76     s->get_error = file_errno;
  77     s->write = file_write;
  78
  79     migrate_fd_connect(s);
  80 }
  81
  82 static void exec_accept_incoming_migration(void *opaque)
  83 {
  84     QEMUFile *f = opaque;
  85
  86     qemu_set_fd_handler2(qemu_get_fd(f), NULL, NULL, NULL, NULL);
  87     process_incoming_migration(f);
  88 }
  89
  90 void exec_start_incoming_migration(const char *command, Error **errp)
  91 {
  92     QEMUFile *f;
  93
  94     DPRINTF("Attempting to start an incoming migration\n");
  95     f = qemu_popen_cmd(command, "r");
  96     if(f == NULL) {
  97         error_setg_errno(errp, errno, "failed to popen the migration source");
  98         return;
  99     }
 100
 101     qemu_set_fd_handler2(qemu_get_fd(f), NULL,
 102                          exec_accept_incoming_migration, NULL, f);
 103 }