migration/fd.c

   1 /*
   2  * QEMU live migration via generic fd
   3  *
   4  * Copyright Red Hat, Inc. 2009-2016
   5  *
   6  * Authors:
   7  *  Chris Lalancette <clalance@redhat.com>
   8  *  Daniel P. Berrange <berrange@redhat.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2.  See
  11  * the COPYING file in the top-level directory.
  12  *
  13  * Contributions after 2012-01-13 are licensed under the terms of the
  14  * GNU GPL, version 2 or (at your option) any later version.
  15  */
  16
  17 #include "qemu/osdep.h"
  18 #include "qapi/error.h"
  19 #include "channel.h"
  20 #include "fd.h"
  21 #include "migration.h"
  22 #include "monitor/monitor.h"
  23 #include "io/channel-file.h"
  24 #include "io/channel-util.h"
  25 #include "options.h"
  26 #include "trace.h"
  27
  28
  29 static struct FdOutgoingArgs {
  30     int fd;
  31 } outgoing_args;
  32
  33 int fd_args_get_fd(void)
  34 {
  35     return outgoing_args.fd;
  36 }
  37
  38 void fd_cleanup_outgoing_migration(void)
  39 {
  40     if (outgoing_args.fd > 0) {
  41         close(outgoing_args.fd);
  42         outgoing_args.fd = -1;
  43     }
  44 }
  45
  46 void fd_start_outgoing_migration(MigrationState *s, const char *fdname, Error **errp)
  47 {
  48     QIOChannel *ioc;
  49     int fd = monitor_get_fd(monitor_cur(), fdname, errp);
  50
  51     outgoing_args.fd = -1;
  52
  53     if (fd == -1) {
  54         return;
  55     }
  56
  57     trace_migration_fd_outgoing(fd);
  58     ioc = qio_channel_new_fd(fd, errp);
  59     if (!ioc) {
  60         close(fd);
  61         return;
  62     }
  63
  64     outgoing_args.fd = fd;
  65
  66     qio_channel_set_name(ioc, "migration-fd-outgoing");
  67     migration_channel_connect(s, ioc, NULL, NULL);
  68     object_unref(OBJECT(ioc));
  69 }
  70
  71 static gboolean fd_accept_incoming_migration(QIOChannel *ioc,
  72                                              GIOCondition condition,
  73                                              gpointer opaque)
  74 {
  75     migration_channel_process_incoming(ioc);
  76     object_unref(OBJECT(ioc));
  77     return G_SOURCE_REMOVE;
  78 }
  79
  80 void fd_start_incoming_migration(const char *fdname, Error **errp)
  81 {
  82     QIOChannel *ioc;
  83     int fd = monitor_fd_param(monitor_cur(), fdname, errp);
  84     if (fd == -1) {
  85         return;
  86     }
  87
  88     trace_migration_fd_incoming(fd);
  89
  90     ioc = qio_channel_new_fd(fd, errp);
  91     if (!ioc) {
  92         close(fd);
  93         return;
  94     }
  95
  96     qio_channel_set_name(ioc, "migration-fd-incoming");
  97     qio_channel_add_watch_full(ioc, G_IO_IN,
  98                                fd_accept_incoming_migration,
  99                                NULL, NULL,
 100                                g_main_context_get_thread_default());
 101
 102     if (migrate_multifd()) {
 103         int channels = migrate_multifd_channels();
 104
 105         while (channels--) {
 106             ioc = QIO_CHANNEL(qio_channel_file_new_fd(dup(fd)));
 107
 108             if (QIO_CHANNEL_FILE(ioc)->fd == -1) {
 109                 error_setg(errp, "Failed to duplicate fd %d", fd);
 110                 return;
 111             }
 112
 113             qio_channel_set_name(ioc, "migration-fd-incoming");
 114             qio_channel_add_watch_full(ioc, G_IO_IN,
 115                                        fd_accept_incoming_migration,
 116                                        NULL, NULL,
 117                                        g_main_context_get_thread_default());
 118         }
 119     }
 120 }