On 2/20/2024 2:33 AM, Peter Xu wrote:
> On Thu, Feb 08, 2024 at 10:54:03AM -0800, Steve Sistare wrote:
>> When migration for cpr is initiated, stop the vm and set state
>> RUN_STATE_FINISH_MIGRATE before ram is saved. This eliminates the
>> possibility of ram and device state being out of sync, and guarantees
>> that a guest in the suspended state remains suspended, because qmp_cont
>> rejects a cont command in the RUN_STATE_FINISH_MIGRATE state.
>>
>> Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
>> ---
>> include/migration/misc.h | 1 +
>> migration/migration.c | 32 +++++++++++++++++++++++++-------
>> 2 files changed, 26 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/migration/misc.h b/include/migration/misc.h
>> index 6dc234b..54c99a3 100644
>> --- a/include/migration/misc.h
>> +++ b/include/migration/misc.h
>> @@ -60,6 +60,7 @@ void migration_object_init(void);
>> void migration_shutdown(void);
>> bool migration_is_idle(void);
>> bool migration_is_active(MigrationState *);
>> +bool migrate_mode_is_cpr(MigrationState *);
>>
>> typedef enum MigrationEventType {
>> MIG_EVENT_PRECOPY_SETUP,
>> diff --git a/migration/migration.c b/migration/migration.c
>> index d1fce9e..fc5c587 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -1603,6 +1603,11 @@ bool migration_is_active(MigrationState *s)
>> s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
>> }
>>
>> +bool migrate_mode_is_cpr(MigrationState *s)
>> +{
>> + return s->parameters.mode == MIG_MODE_CPR_REBOOT;
>> +}
>> +
>> int migrate_init(MigrationState *s, Error **errp)
>> {
>> int ret;
>> @@ -2651,13 +2656,14 @@ static int
>> migration_completion_precopy(MigrationState *s,
>> bql_lock();
>> migration_downtime_start(s);
>>
>> - s->vm_old_state = runstate_get();
>> - global_state_store();
>> -
>> - ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE);
>> - trace_migration_completion_vm_stop(ret);
>> - if (ret < 0) {
>> - goto out_unlock;
>> + if (!migrate_mode_is_cpr(s)) {
>> + s->vm_old_state = runstate_get();
>> + global_state_store();
>> + ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE);
>> + trace_migration_completion_vm_stop(ret);
>> + if (ret < 0) {
>> + goto out_unlock;
>> + }
>> }
>>
>> ret = migration_maybe_pause(s, current_active_state,
>> @@ -3576,6 +3582,7 @@ void migrate_fd_connect(MigrationState *s, Error
>> *error_in)
>> Error *local_err = NULL;
>> uint64_t rate_limit;
>> bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED;
>> + int ret;
>>
>> /*
>> * If there's a previous error, free it and prepare for another one.
>> @@ -3651,6 +3658,17 @@ void migrate_fd_connect(MigrationState *s, Error
>> *error_in)
>> goto fail;
>> }
>>
>> + if (migrate_mode_is_cpr(s)) {
>> + s->vm_old_state = runstate_get();
>> + global_state_store();
>> + ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE);
>> + trace_migration_completion_vm_stop(ret);
>> + if (ret < 0) {
>> + error_setg(&local_err, "migration_stop_vm failed, error %d",
>> -ret);
>> + goto fail;
>> + }
>> + }
>
> Could we have a helper function for the shared codes?
Will do.
> How about postcopy? I know it's nonsense to enable postcopy for cpr.. but
> iiuc we don't yet forbid an user doing so. Maybe we should?
I will assert that mode != cpr in the postcopy path instead, to prevent any
nonsense.
- Steve
>> +
>> if (migrate_background_snapshot()) {
>> qemu_thread_create(&s->thread, "bg_snapshot",
>> bg_migration_thread, s, QEMU_THREAD_JOINABLE);
>> --
>> 1.8.3.1
>>
>
