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/colo.h>
  16 #include "trace.h"
  17
  18 typedef struct {
  19      bool colo_requested;
  20 } COLOInfo;
  21
  22 static COLOInfo colo_info;
  23
  24 COLOMode get_colo_mode(void)
  25 {
  26     if (migration_in_colo_state()) {
  27         return COLO_MODE_PRIMARY;
  28     } else if (migration_incoming_in_colo_state()) {
  29         return COLO_MODE_SECONDARY;
  30     } else {
  31         return COLO_MODE_UNKNOWN;
  32     }
  33 }
  34
  35 static void colo_info_pre_save(void *opaque)
  36 {
  37     COLOInfo *s = opaque;
  38
  39     s->colo_requested = migrate_colo_enabled();
  40 }
  41
  42 static bool colo_info_need(void *opaque)
  43 {
  44    return migrate_colo_enabled();
  45 }
  46
  47 static const VMStateDescription colo_state = {
  48     .name = "COLOState",
  49     .version_id = 1,
  50     .minimum_version_id = 1,
  51     .pre_save = colo_info_pre_save,
  52     .needed = colo_info_need,
  53     .fields = (VMStateField[]) {
  54         VMSTATE_BOOL(colo_requested, COLOInfo),
  55         VMSTATE_END_OF_LIST()
  56     },
  57 };
  58
  59 void colo_info_init(void)
  60 {
  61     vmstate_register(NULL, 0, &colo_state, &colo_info);
  62 }
  63
  64 bool migration_incoming_enable_colo(void)
  65 {
  66     return colo_info.colo_requested;
  67 }
  68
  69 void migration_incoming_exit_colo(void)
  70 {
  71     colo_info.colo_requested = false;
  72 }