| 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 "qemu/main-loop.h" |
| 17 | #include "migration.h" |
| 18 | #include "qapi/error.h" |
| 19 | #include "qapi/qapi-commands-migration.h" |
| 20 | #include "qemu/error-report.h" |
| 21 | #include "trace.h" |
| 22 | |
| 23 | static QEMUBH *failover_bh; |
| 24 | static FailoverStatus failover_state; |
| 25 | |
| 26 | static void colo_failover_bh(void *opaque) |
| 27 | { |
| 28 | int old_state; |
| 29 | |
| 30 | qemu_bh_delete(failover_bh); |
| 31 | failover_bh = NULL; |
| 32 | |
| 33 | old_state = failover_set_state(FAILOVER_STATUS_REQUIRE, |
| 34 | FAILOVER_STATUS_ACTIVE); |
| 35 | if (old_state != FAILOVER_STATUS_REQUIRE) { |
| 36 | error_report("Unknown error for failover, old_state = %s", |
| 37 | FailoverStatus_str(old_state)); |
| 38 | return; |
| 39 | } |
| 40 | |
| 41 | colo_do_failover(); |
| 42 | } |
| 43 | |
| 44 | void failover_request_active(Error **errp) |
| 45 | { |
| 46 | if (failover_set_state(FAILOVER_STATUS_NONE, |
| 47 | FAILOVER_STATUS_REQUIRE) != FAILOVER_STATUS_NONE) { |
| 48 | error_setg(errp, "COLO failover is already activated"); |
| 49 | return; |
| 50 | } |
| 51 | failover_bh = qemu_bh_new(colo_failover_bh, NULL); |
| 52 | qemu_bh_schedule(failover_bh); |
| 53 | } |
| 54 | |
| 55 | void failover_init_state(void) |
| 56 | { |
| 57 | failover_state = FAILOVER_STATUS_NONE; |
| 58 | } |
| 59 | |
| 60 | FailoverStatus failover_set_state(FailoverStatus old_state, |
| 61 | FailoverStatus new_state) |
| 62 | { |
| 63 | FailoverStatus old; |
| 64 | |
| 65 | old = qatomic_cmpxchg(&failover_state, old_state, new_state); |
| 66 | if (old == old_state) { |
| 67 | trace_colo_failover_set_state(FailoverStatus_str(new_state)); |
| 68 | } |
| 69 | return old; |
| 70 | } |
| 71 | |
| 72 | FailoverStatus failover_get_state(void) |
| 73 | { |
| 74 | return qatomic_read(&failover_state); |
| 75 | } |
| 76 | |
| 77 | void qmp_x_colo_lost_heartbeat(Error **errp) |
| 78 | { |
| 79 | if (get_colo_mode() == COLO_MODE_NONE) { |
| 80 | error_setg(errp, "VM is not in COLO mode"); |
| 81 | return; |
| 82 | } |
| 83 | |
| 84 | failover_request_active(errp); |
| 85 | } |