migration/colo-comm.c

   1 /*
   2  * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
   3  * (a.k.a. Fault Tolerance or Continuous Replication)
   4  *
   5  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
   6  * Copyright (c) 2016 FUJITSU LIMITED
   7  * Copyright (c) 2016 Intel Corporation
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or
  10  * later. See the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "migration/migration.h"
  16 #include "migration/colo.h"
  17 #include "migration/vmstate.h"
  18 #include "trace.h"
  19
  20 typedef struct {
  21      bool colo_requested;
  22 } COLOInfo;
  23
  24 static COLOInfo colo_info;
  25
  26 COLOMode get_colo_mode(void)
  27 {
  28     if (migration_in_colo_state()) {
  29         return COLO_MODE_PRIMARY;
  30     } else if (migration_incoming_in_colo_state()) {
  31         return COLO_MODE_SECONDARY;
  32     } else {
  33         return COLO_MODE_UNKNOWN;
  34     }
  35 }
  36
  37 static void colo_info_pre_save(void *opaque)
  38 {
  39     COLOInfo *s = opaque;
  40
  41     s->colo_requested = migrate_colo_enabled();
  42 }
  43
  44 static bool colo_info_need(void *opaque)
  45 {
  46    return migrate_colo_enabled();
  47 }
  48
  49 static const VMStateDescription colo_state = {
  50     .name = "COLOState",
  51     .version_id = 1,
  52     .minimum_version_id = 1,
  53     .pre_save = colo_info_pre_save,
  54     .needed = colo_info_need,
  55     .fields = (VMStateField[]) {
  56         VMSTATE_BOOL(colo_requested, COLOInfo),
  57         VMSTATE_END_OF_LIST()
  58     },
  59 };
  60
  61 void colo_info_init(void)
  62 {
  63     vmstate_register(NULL, 0, &colo_state, &colo_info);
  64 }
  65
  66 bool migration_incoming_enable_colo(void)
  67 {
  68     return colo_info.colo_requested;
  69 }
  70
  71 void migration_incoming_exit_colo(void)
  72 {
  73     colo_info.colo_requested = false;
  74 }