COLO: Add 'x-colo-lost-heartbeat' command to trigger failover

We leave users to choose whatever heartbeat solution they want,
if the heartbeat is lost, or other errors they detect, they can use
experimental command 'x_colo_lost_heartbeat' to tell COLO to do failover,
COLO will do operations accordingly.

For example, if the command is sent to the Primary side,
the Primary side will exit COLO mode, does cleanup work,
and then, PVM will take over the service work. If sent to the Secondary side,
the Secondary side will run failover work, then takes over PVM's service work.

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Amit Shah <amit@amitshah.net>

diff --git a/docs/qmp-commands.txt b/docs/qmp-commands.txt
index 2e42929b6ea7a32e5aa18bf42377dd61b03e7295..a4732a570c8a23756a6eb8e55bf9f409af157a6f 100644 (file)
--- a/docs/qmp-commands.txt
+++ b/docs/qmp-commands.txt
@@ -554,6 +554,16 @@ Example:
 -> { "execute": "migrate_set_downtime", "arguments": { "value": 0.1 } }
 <- { "return": {} }
 
+x-colo-lost-heartbeat
+--------------------
+
+Tell COLO that heartbeat is lost, a failover or takeover is needed.
+
+Example:
+
+-> { "execute": "x-colo-lost-heartbeat" }
+<- { "return": {} }
+
 client_migrate_info
 -------------------
 

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 06bef470b99e3b856b3dc12d5b7b0b0b00f86c1d..88192817b259099b6bdebc23962ec612e049462a 100644 (file)
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1037,6 +1037,21 @@ STEXI
 @findex migrate_start_postcopy
 Switch in-progress migration to postcopy mode. Ignored after the end of
 migration (or once already in postcopy).
+ETEXI
+
+    {
+        .name       = "x_colo_lost_heartbeat",
+        .args_type  = "",
+        .params     = "",
+        .help       = "Tell COLO that heartbeat is lost,\n\t\t\t"
+                      "a failover or takeover is needed.",
+        .cmd = hmp_x_colo_lost_heartbeat,
+    },
+
+STEXI
+@item x_colo_lost_heartbeat
+@findex x_colo_lost_heartbeat
+Tell COLO that heartbeat is lost, a failover or takeover is needed.
 ETEXI
 
     {

diff --git a/hmp.c b/hmp.c
index f2b831a4a39eb8c8addf591587006626fce88717..00af4230bff59aa47c7c602010f68870403a0826 100644 (file)
--- a/hmp.c
+++ b/hmp.c
@@ -1451,6 +1451,14 @@ void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict)
     hmp_handle_error(mon, &err);
 }
 
+void hmp_x_colo_lost_heartbeat(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+
+    qmp_x_colo_lost_heartbeat(&err);
+    hmp_handle_error(mon, &err);
+}
+
 void hmp_set_password(Monitor *mon, const QDict *qdict)
 {
     const char *protocol  = qdict_get_str(qdict, "protocol");

diff --git a/hmp.h b/hmp.h
index 184769c13f6415557bd25a9c76f53f3db6824d34..05daf7cd5c28ee99564b0607466cf5fc8ec69021 100644 (file)
--- a/hmp.h
+++ b/hmp.h
@@ -72,6 +72,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict);
 void hmp_client_migrate_info(Monitor *mon, const QDict *qdict);
 void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict);
+void hmp_x_colo_lost_heartbeat(Monitor *mon, const QDict *qdict);
 void hmp_set_password(Monitor *mon, const QDict *qdict);
 void hmp_expire_password(Monitor *mon, const QDict *qdict);
 void hmp_eject(Monitor *mon, const QDict *qdict);

diff --git a/include/migration/colo.h b/include/migration/colo.h
index b40676c7481ab9edc6a63ef6c0622e0fe3352c4f..e9ac2c343af65252946a2a7ee8fe104ac7fdf5c5 100644 (file)
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -17,6 +17,7 @@
 #include "migration/migration.h"
 #include "qemu/coroutine_int.h"
 #include "qemu/thread.h"
+#include "qemu/main-loop.h"
 
 bool colo_supported(void);
 void colo_info_init(void);
@@ -29,4 +30,6 @@ bool migration_incoming_enable_colo(void);
 void migration_incoming_exit_colo(void);
 void *colo_process_incoming_thread(void *opaque);
 bool migration_incoming_in_colo_state(void);
+
+COLOMode get_colo_mode(void);
 #endif

diff --git a/include/migration/failover.h b/include/migration/failover.h
new file mode 100644 (file)
index 0000000..3274735
--- /dev/null
+++ b/include/migration/failover.h
@@ -0,0 +1,20 @@
+/*
+ *  COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ *  (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO.,LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_FAILOVER_H
+#define QEMU_FAILOVER_H
+
+#include "qemu-common.h"
+
+void failover_request_active(Error **errp);
+
+#endif

diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index 4bbe9ab31395b8e70371ad1f05fa2813bd036cfd..3f3e237142a0de9e4af5a0c230ffdf199298f6ef 100644 (file)
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -1,7 +1,7 @@
 common-obj-y += migration.o socket.o fd.o exec.o
 common-obj-y += tls.o
-common-obj-$(CONFIG_COLO) += colo.o
 common-obj-y += colo-comm.o
+common-obj-$(CONFIG_COLO) += colo.o colo-failover.o
 common-obj-y += vmstate.o
 common-obj-y += qemu-file.o
 common-obj-y += qemu-file-channel.o

diff --git a/migration/colo-comm.c b/migration/colo-comm.c
index bf44f764406aa8aebdd7c4535cd766be66f9457e..20b60ec3847981c39a0f2e4bebcdb7e4e6096aad 100644 (file)
--- a/migration/colo-comm.c
+++ b/migration/colo-comm.c
@@ -21,6 +21,17 @@ typedef struct {
 
 static COLOInfo colo_info;
 
+COLOMode get_colo_mode(void)
+{
+    if (migration_in_colo_state()) {
+        return COLO_MODE_PRIMARY;
+    } else if (migration_incoming_in_colo_state()) {
+        return COLO_MODE_SECONDARY;
+    } else {
+        return COLO_MODE_UNKNOWN;
+    }
+}
+
 static void colo_info_pre_save(void *opaque)
 {
     COLOInfo *s = opaque;

diff --git a/migration/colo-failover.c b/migration/colo-failover.c
new file mode 100644 (file)
index 0000000..e31fc10
--- /dev/null
+++ b/migration/colo-failover.c
@@ -0,0 +1,42 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "migration/colo.h"
+#include "migration/failover.h"
+#include "qmp-commands.h"
+#include "qapi/qmp/qerror.h"
+
+static QEMUBH *failover_bh;
+
+static void colo_failover_bh(void *opaque)
+{
+    qemu_bh_delete(failover_bh);
+    failover_bh = NULL;
+    /* TODO: Do failover work */
+}
+
+void failover_request_active(Error **errp)
+{
+    failover_bh = qemu_bh_new(colo_failover_bh, NULL);
+    qemu_bh_schedule(failover_bh);
+}
+
+void qmp_x_colo_lost_heartbeat(Error **errp)
+{
+    if (get_colo_mode() == COLO_MODE_UNKNOWN) {
+        error_setg(errp, QERR_FEATURE_DISABLED, "colo");
+        return;
+    }
+
+    failover_request_active(errp);
+}

diff --git a/migration/colo.c b/migration/colo.c
index a35cc5973174d49afae0dd018d00b0c2e2bb1a0f..12fa0b411157911d4e59498602cb40a569933642 100644 (file)
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -18,6 +18,7 @@
 #include "trace.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
+#include "migration/failover.h"
 
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 

diff --git a/qapi-schema.json b/qapi-schema.json
index 05fed9a2c0ce54dae8a812ad6b354cdbed45b16d..a18484115f6348538ed4f791ee1e31f65c461817 100644 (file)
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -823,6 +823,35 @@
             'vmstate-send', 'vmstate-size', 'vmstate-received',
             'vmstate-loaded' ] }
 
+##
+# @COLOMode
+#
+# The colo mode
+#
+# @unknown: unknown mode
+#
+# @primary: master side
+#
+# @secondary: slave side
+#
+# Since: 2.8
+##
+{ 'enum': 'COLOMode',
+  'data': [ 'unknown', 'primary', 'secondary'] }
+
+##
+# @x-colo-lost-heartbeat
+#
+# Tell qemu that heartbeat is lost, request it to do takeover procedures.
+# If this command is sent to the PVM, the Primary side will exit COLO mode.
+# If sent to the Secondary, the Secondary side will run failover work,
+# then takes over server operation to become the service VM.
+#
+# Since: 2.8
+##
+{ 'command': 'x-colo-lost-heartbeat' }
+
+##
 # @MouseInfo:
 #
 # Information about a mouse device.

diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
index 7b723954d5cb8dc64f58ba970334ad6ff9ebd689..7811764c4b28bc66b16a3f1d86b561c7b191322e 100644 (file)
--- a/stubs/migration-colo.c
+++ b/stubs/migration-colo.c
@@ -12,6 +12,7 @@
 
 #include "qemu/osdep.h"
 #include "migration/colo.h"
+#include "qmp-commands.h"
 
 bool colo_supported(void)
 {
@@ -36,3 +37,10 @@ void *colo_process_incoming_thread(void *opaque)
 {
     return NULL;
 }
+
+void qmp_x_colo_lost_heartbeat(Error **errp)
+{
+    error_setg(errp, "COLO is not supported, please rerun configure"
+                     " with --enable-colo option in order to support"
+                     " COLO feature");
+}