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 "qapi/qmp/qerror.h" 21 #include "qemu/error-report.h" 22 #include "trace.h" 23 24 static QEMUBH *failover_bh; 25 static FailoverStatus failover_state; 26 27 static void colo_failover_bh(void *opaque) 28 { 29 int old_state; 30 31 qemu_bh_delete(failover_bh); 32 failover_bh = NULL; 33 34 old_state = failover_set_state(FAILOVER_STATUS_REQUIRE, 35 FAILOVER_STATUS_ACTIVE); 36 if (old_state != FAILOVER_STATUS_REQUIRE) { 37 error_report("Unknown error for failover, old_state = %s", 38 FailoverStatus_str(old_state)); 39 return; 40 } 41 42 colo_do_failover(); 43 } 44 45 void failover_request_active(Error **errp) 46 { 47 if (failover_set_state(FAILOVER_STATUS_NONE, 48 FAILOVER_STATUS_REQUIRE) != FAILOVER_STATUS_NONE) { 49 error_setg(errp, "COLO failover is already actived"); 50 return; 51 } 52 failover_bh = qemu_bh_new(colo_failover_bh, NULL); 53 qemu_bh_schedule(failover_bh); 54 } 55 56 void failover_init_state(void) 57 { 58 failover_state = FAILOVER_STATUS_NONE; 59 } 60 61 FailoverStatus failover_set_state(FailoverStatus old_state, 62 FailoverStatus new_state) 63 { 64 FailoverStatus old; 65 66 old = atomic_cmpxchg(&failover_state, old_state, new_state); 67 if (old == old_state) { 68 trace_colo_failover_set_state(FailoverStatus_str(new_state)); 69 } 70 return old; 71 } 72 73 FailoverStatus failover_get_state(void) 74 { 75 return atomic_read(&failover_state); 76 } 77 78 void qmp_x_colo_lost_heartbeat(Error **errp) 79 { 80 if (get_colo_mode() == COLO_MODE_NONE) { 81 error_setg(errp, QERR_FEATURE_DISABLED, "colo"); 82 return; 83 } 84 85 failover_request_active(errp); 86 } 87