在 08/01/2014 10:43 PM, Dr. David Alan Gilbert 写道:
* Yang Hongyang (yanghy@xxxxxxxxxxxxxx) wrote:
migrate colo info to migration target to tell the target colo is
enabled.
If I understand this correctly this means that you send a 'colo info' device
information for migrations that don't have COLO enabled; that's bad because
it breaks migration unless the destination has it; I guess it's OK if you
were to guard it with a thing so it didn't do it for old machine-types.
You could use the QEMU_VM_COMMAND sections I've created for postcopy;
( http://lists.gnu.org/archive/html/qemu-devel/2014-07/msg00889.html ) and
add a QEMU_VM_CMD_COLO to indicate you want the destination to become an SVM,
then check the capability near the start of migration and send the command.
Thank you for the reference, I've read part of your Postcopy patches, but
haven't into detailed implementation. I will use QEMUSizedBuffer/QEMUFile in
next version. For QEMU_VM_COMMAND sections, can you separate it out so that I
can make use of it? Do you have a public git tree or something?
Or perhaps there's a way to add the colo-info device on the command line so it's
not always there.
Dave
Signed-off-by: Yang Hongyang <yanghy@xxxxxxxxxxxxxx>
---
Makefile.objs | 1 +
include/migration/migration-colo.h | 3 ++
migration-colo-comm.c | 68 ++++++++++++++++++++++++++++++++++++++
vl.c | 4 +++
4 files changed, 76 insertions(+)
create mode 100644 migration-colo-comm.c
diff --git a/Makefile.objs b/Makefile.objs
index cab5824..1836a68 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -50,6 +50,7 @@ common-obj-$(CONFIG_POSIX) += os-posix.o
common-obj-$(CONFIG_LINUX) += fsdev/
common-obj-y += migration.o migration-tcp.o
+common-obj-y += migration-colo-comm.o
common-obj-$(CONFIG_COLO) += migration-colo.o
common-obj-y += vmstate.o
common-obj-y += qemu-file.o
diff --git a/include/migration/migration-colo.h b/include/migration/migration-colo.h
index 35b384c..e3735d8 100644
--- a/include/migration/migration-colo.h
+++ b/include/migration/migration-colo.h
@@ -12,6 +12,9 @@
#define QEMU_MIGRATION_COLO_H
#include "qemu-common.h"
+#include "migration/migration.h"
+
+void colo_info_mig_init(void);
bool colo_supported(void);
diff --git a/migration-colo-comm.c b/migration-colo-comm.c
new file mode 100644
index 0000000..ccbc246
--- /dev/null
+++ b/migration-colo-comm.c
@@ -0,0 +1,68 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (C) 2014 FUJITSU LIMITED
+ *
+ * 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 <migration/migration-colo.h>
+
+#define DEBUG_COLO
+
+#ifdef DEBUG_COLO
+#define DPRINTF(fmt, ...) \
+ do { fprintf(stdout, "COLO: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+ do { } while (0)
+#endif
+
+static bool colo_requested;
+
+/* save */
+
+static bool migrate_use_colo(void)
+{
+ MigrationState *s = migrate_get_current();
+ return s->enabled_capabilities[MIGRATION_CAPABILITY_COLO];
+}
+
+static void colo_info_save(QEMUFile *f, void *opaque)
+{
+ qemu_put_byte(f, migrate_use_colo());
+}
+
+/* restore */
+
+static int colo_info_load(QEMUFile *f, void *opaque, int version_id)
+{
+ int value = qemu_get_byte(f);
+
+ if (value && !colo_supported()) {
+ fprintf(stderr, "COLO is not supported\n");
+ return -EINVAL;
+ }
+
+ if (value && !colo_requested) {
+ DPRINTF("COLO requested!\n");
+ }
+
+ colo_requested = value;
+
+ return 0;
+}
+
+static SaveVMHandlers savevm_colo_info_handlers = {
+ .save_state = colo_info_save,
+ .load_state = colo_info_load,
+};
+
+void colo_info_mig_init(void)
+{
+ register_savevm_live(NULL, "colo info", -1, 1,
+ &savevm_colo_info_handlers, NULL);
+}
diff --git a/vl.c b/vl.c
index fe451aa..1a282d8 100644
--- a/vl.c
+++ b/vl.c
@@ -89,6 +89,7 @@ int main(int argc, char **argv)
#include "sysemu/dma.h"
#include "audio/audio.h"
#include "migration/migration.h"
+#include "migration/migration-colo.h"
#include "sysemu/kvm.h"
#include "qapi/qmp/qjson.h"
#include "qemu/option.h"
@@ -4339,6 +4340,9 @@ int main(int argc, char **argv, char **envp)
blk_mig_init();
ram_mig_init();
+ if (colo_supported()) {
+ colo_info_mig_init();
+ }
/* open the virtual block devices */
if (snapshot)
--
1.9.1
--
Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK
.
--
Thanks,
Yang.
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