This is hook function to be called when a postcopy migration wants to
resume from a failure. For each module, it should provide its own
recovery logic before we switch to the postcopy-active state.
Signed-off-by: Peter Xu <pet...@redhat.com>
---
include/migration/register.h | 2 ++
migration/migration.c | 20 +++++++++++++++++++-
migration/savevm.c | 25 +++++++++++++++++++++++++
migration/savevm.h | 1 +
migration/trace-events | 1 +
5 files changed, 48 insertions(+), 1 deletion(-)
diff --git a/include/migration/register.h b/include/migration/register.h
index a0f1edd..b669362 100644
--- a/include/migration/register.h
+++ b/include/migration/register.h
@@ -41,6 +41,8 @@ typedef struct SaveVMHandlers {
LoadStateHandler *load_state;
int (*load_setup)(QEMUFile *f, void *opaque);
int (*load_cleanup)(void *opaque);
+ /* Called when postcopy migration wants to resume from failure */
+ int (*resume_prepare)(MigrationState *s, void *opaque);
} SaveVMHandlers;
int register_savevm_live(DeviceState *dev,
diff --git a/migration/migration.c b/migration/migration.c
index 62f91ce..6cb0ad3 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2150,7 +2150,25 @@ static bool postcopy_should_start(MigrationState *s)
/* Return zero if success, or <0 for error */
static int postcopy_do_resume(MigrationState *s)
{
- /* TODO: do the resume logic */
+ int ret;
+
+ /*
+ * Call all the resume_prepare() hooks, so that modules can be
+ * ready for the migration resume.
+ */
+ ret = qemu_savevm_state_resume_prepare(s);
+ if (ret) {
+ error_report("%s: resume_prepare() failure detected: %d",
+ __func__, ret);
+ return ret;
+ }
+
+ /*
+ * TODO: handshake with dest using MIG_CMD_RESUME,
+ * MIG_RP_MSG_RESUME_ACK, then switch source state to
+ * "postcopy-active"
+ */
+
return 0;
}
diff --git a/migration/savevm.c b/migration/savevm.c
index 02a67ac..08a4712 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1004,6 +1004,31 @@ void qemu_savevm_state_setup(QEMUFile *f)
}
}
+int qemu_savevm_state_resume_prepare(MigrationState *s)
+{
+ SaveStateEntry *se;
+ int ret;
+
+ trace_savevm_state_resume_prepare();
+
+ QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
+ if (!se->ops || !se->ops->resume_prepare) {
+ continue;
+ }
+ if (se->ops && se->ops->is_active) {
+ if (!se->ops->is_active(se->opaque)) {
+ continue;
+ }
+ }
+ ret = se->ops->resume_prepare(s, se->opaque);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
/*
* this function has three return values:
* negative: there was one error, and we have -errno.
diff --git a/migration/savevm.h b/migration/savevm.h
index a5f3879..3193f04 100644
--- a/migration/savevm.h
+++ b/migration/savevm.h
@@ -31,6 +31,7 @@
bool qemu_savevm_state_blocked(Error **errp);
void qemu_savevm_state_setup(QEMUFile *f);
+int qemu_savevm_state_resume_prepare(MigrationState *s);
void qemu_savevm_state_header(QEMUFile *f);
int qemu_savevm_state_iterate(QEMUFile *f, bool postcopy);
void qemu_savevm_state_cleanup(void);
diff --git a/migration/trace-events b/migration/trace-events
index 0b43fec..0fb2d1e 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -37,6 +37,7 @@ savevm_send_postcopy_run(void) ""
savevm_send_postcopy_resume(void) ""
savevm_send_recv_bitmap(char *name) "%s"
savevm_state_setup(void) ""
+savevm_state_resume_prepare(void) ""
savevm_state_header(void) ""
savevm_state_iterate(void) ""
savevm_state_cleanup(void) ""
--
2.7.4
