@@ -16,6 +16,7 @@
#define QEMU_MIGRATION_SNAPSHOT_H
#include "qapi/qapi-builtin-types.h"
+#include "qapi/qapi-types-run-state.h"
/**
* save_snapshot: Save an internal snapshot.
@@ -61,4 +62,10 @@ bool delete_snapshot(const char *name,
bool has_devices, strList *devices,
Error **errp);
+/**
+ * load_snapshot_resume: Restore runstate after loading snapshot.
+ * @state: state to restore
+ */
+void load_snapshot_resume(RunState state);
+
#endif
@@ -399,15 +399,17 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
void hmp_loadvm(Monitor *mon, const QDict *qdict)
{
- int saved_vm_running = runstate_is_running();
+ RunState saved_state = runstate_get();
+
const char *name = qdict_get_str(qdict, "name");
Error *err = NULL;
vm_stop(RUN_STATE_RESTORE_VM);
- if (load_snapshot(name, NULL, false, NULL, &err) && saved_vm_running) {
- vm_start();
+ if (load_snapshot(name, NULL, false, NULL, &err)) {
+ load_snapshot_resume(saved_state);
}
+
hmp_handle_error(mon, err);
}
@@ -3046,7 +3046,7 @@ bool save_snapshot(const char *name, bool overwrite, const char *vmstate,
QEMUSnapshotInfo sn1, *sn = &sn1;
int ret = -1, ret2;
QEMUFile *f;
- int saved_vm_running;
+ RunState saved_state = runstate_get();
uint64_t vm_state_size;
g_autoptr(GDateTime) now = g_date_time_new_now_local();
AioContext *aio_context;
@@ -3094,8 +3094,6 @@ bool save_snapshot(const char *name, bool overwrite, const char *vmstate,
}
aio_context = bdrv_get_aio_context(bs);
- saved_vm_running = runstate_is_running();
-
global_state_store();
vm_stop(RUN_STATE_SAVE_VM);
@@ -3163,9 +3161,7 @@ bool save_snapshot(const char *name, bool overwrite, const char *vmstate,
bdrv_drain_all_end();
- if (saved_vm_running) {
- vm_start();
- }
+ vm_resume(saved_state);
return ret == 0;
}
@@ -3339,6 +3335,14 @@ err_drain:
return false;
}
+void load_snapshot_resume(RunState state)
+{
+ vm_resume(state);
+ if (state == RUN_STATE_RUNNING && runstate_get() == RUN_STATE_SUSPENDED) {
+ qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
+ }
+}
+
bool delete_snapshot(const char *name, bool has_devices,
strList *devices, Error **errp)
{
@@ -3403,16 +3407,15 @@ static void snapshot_load_job_bh(void *opaque)
{
Job *job = opaque;
SnapshotJob *s = container_of(job, SnapshotJob, common);
- int orig_vm_running;
+ RunState orig_state = runstate_get();
job_progress_set_remaining(&s->common, 1);
- orig_vm_running = runstate_is_running();
vm_stop(RUN_STATE_RESTORE_VM);
s->ret = load_snapshot(s->tag, s->vmstate, true, s->devices, s->errp);
- if (s->ret && orig_vm_running) {
- vm_start();
+ if (s->ret) {
+ load_snapshot_resume(orig_state);
}
job_progress_update(&s->common, 1);
@@ -77,6 +77,7 @@ typedef struct {
static const RunStateTransition runstate_transitions_def[] = {
{ RUN_STATE_PRELAUNCH, RUN_STATE_INMIGRATE },
+ { RUN_STATE_PRELAUNCH, RUN_STATE_SUSPENDED },
{ RUN_STATE_DEBUG, RUN_STATE_RUNNING },
{ RUN_STATE_DEBUG, RUN_STATE_FINISH_MIGRATE },
@@ -132,6 +133,7 @@ static const RunStateTransition runstate_transitions_def[] = {
{ RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },
{ RUN_STATE_RESTORE_VM, RUN_STATE_PRELAUNCH },
+ { RUN_STATE_RESTORE_VM, RUN_STATE_SUSPENDED },
{ RUN_STATE_COLO, RUN_STATE_RUNNING },
{ RUN_STATE_COLO, RUN_STATE_PRELAUNCH },
@@ -150,6 +152,7 @@ static const RunStateTransition runstate_transitions_def[] = {
{ RUN_STATE_RUNNING, RUN_STATE_COLO},
{ RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },
+ { RUN_STATE_SAVE_VM, RUN_STATE_SUSPENDED },
{ RUN_STATE_SHUTDOWN, RUN_STATE_PAUSED },
{ RUN_STATE_SHUTDOWN, RUN_STATE_FINISH_MIGRATE },
@@ -163,6 +166,8 @@ static const RunStateTransition runstate_transitions_def[] = {
{ RUN_STATE_SUSPENDED, RUN_STATE_PRELAUNCH },
{ RUN_STATE_SUSPENDED, RUN_STATE_COLO},
{ RUN_STATE_SUSPENDED, RUN_STATE_PAUSED},
+ { RUN_STATE_SUSPENDED, RUN_STATE_SAVE_VM },
+ { RUN_STATE_SUSPENDED, RUN_STATE_RESTORE_VM },
{ RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
{ RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
@@ -2706,7 +2706,9 @@ void qmp_x_exit_preconfig(Error **errp)
qemu_machine_creation_done();
if (loadvm) {
+ RunState state = autostart ? RUN_STATE_RUNNING : runstate_get();
load_snapshot(loadvm, NULL, false, NULL, &error_fatal);
+ load_snapshot_resume(state);
}
if (replay_mode != REPLAY_MODE_NONE) {
replay_vmstate_init();
Restoring a snapshot can break a suspended guest. Snapshots suffer from the same suspended-state issues that affect live migration, plus they must handle an additional problematic scenario, which is that a running vm must remain running if it loads a suspended snapshot. Currently, after loading such a snapshot, the vm_start fails. The runstate is RUNNING, but the guest is not. To save, the vm_stop call now completely stops the suspended state, courtesy of a recent patch. Finish with vm_resume to leave the vm in the state it had prior to the save, correctly restoring the suspended state. To load, if the snapshot is not suspended, then vm_stop + vm_resume correctly handles all states, and leaves the vm in the state it had prior to the load. However, if the snapshot is suspended, restoration is trickier. First, call vm_resume to restore the state to suspended so the current state matches the saved state. Then, if the pre-load state is running, call wakeup to resume running. Prior to these changes, the vm_stop to RUN_STATE_SAVE_VM and RUN_STATE_RESTORE_VM did not change runstate if the current state was paused, suspended, or prelaunch, but now it does, so allow these transitions. Signed-off-by: Steve Sistare <steven.sistare@oracle.com> --- include/migration/snapshot.h | 7 +++++++ migration/migration-hmp-cmds.c | 8 +++++--- migration/savevm.c | 23 +++++++++++++---------- system/runstate.c | 5 +++++ system/vl.c | 2 ++ 5 files changed, 32 insertions(+), 13 deletions(-)