hw/arm/virt-acpi-build: don't save VirtGuestInfo on AcpiBuildState
[qemu.git] / migration / colo-failover.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 #include "qemu/osdep.h"
14 #include "migration/colo.h"
15 #include "migration/failover.h"
16 #include "qmp-commands.h"
17 #include "qapi/qmp/qerror.h"
18 #include "qemu/error-report.h"
19 #include "trace.h"
20
21 static QEMUBH *failover_bh;
22 static FailoverStatus failover_state;
23
24 static void colo_failover_bh(void *opaque)
25 {
26 int old_state;
27
28 qemu_bh_delete(failover_bh);
29 failover_bh = NULL;
30
31 old_state = failover_set_state(FAILOVER_STATUS_REQUIRE,
32 FAILOVER_STATUS_ACTIVE);
33 if (old_state != FAILOVER_STATUS_REQUIRE) {
34 error_report("Unknown error for failover, old_state = %s",
35 FailoverStatus_lookup[old_state]);
36 return;
37 }
38
39 colo_do_failover(NULL);
40 }
41
42 void failover_request_active(Error **errp)
43 {
44 if (failover_set_state(FAILOVER_STATUS_NONE,
45 FAILOVER_STATUS_REQUIRE) != FAILOVER_STATUS_NONE) {
46 error_setg(errp, "COLO failover is already actived");
47 return;
48 }
49 failover_bh = qemu_bh_new(colo_failover_bh, NULL);
50 qemu_bh_schedule(failover_bh);
51 }
52
53 void failover_init_state(void)
54 {
55 failover_state = FAILOVER_STATUS_NONE;
56 }
57
58 FailoverStatus failover_set_state(FailoverStatus old_state,
59 FailoverStatus new_state)
60 {
61 FailoverStatus old;
62
63 old = atomic_cmpxchg(&failover_state, old_state, new_state);
64 if (old == old_state) {
65 trace_colo_failover_set_state(FailoverStatus_lookup[new_state]);
66 }
67 return old;
68 }
69
70 FailoverStatus failover_get_state(void)
71 {
72 return atomic_read(&failover_state);
73 }
74
75 void qmp_x_colo_lost_heartbeat(Error **errp)
76 {
77 if (get_colo_mode() == COLO_MODE_UNKNOWN) {
78 error_setg(errp, QERR_FEATURE_DISABLED, "colo");
79 return;
80 }
81
82 failover_request_active(errp);
83 }