Re: [Qemu-devel] [PATCH 1/1] vl: change QEMU state machine for system reset

[Paolo Bonzini <pbonzini@redhat.com>]

On 19/01/2016 08:59, Denis V. Lunev wrote:
> @@ -612,8 +617,10 @@ static const RunStateTransition runstate_transitions_def[] = {
>  
>      { RUN_STATE_FINISH_MIGRATE, RUN_STATE_RUNNING },
>      { RUN_STATE_FINISH_MIGRATE, RUN_STATE_POSTMIGRATE },
> +    { RUN_STATE_FINISH_MIGRATE, RUN_STATE_PRELAUNCH },
>  
>      { RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },
> +    { RUN_STATE_RESTORE_VM, RUN_STATE_PRELAUNCH },
>  
>      { RUN_STATE_RUNNING, RUN_STATE_DEBUG },
>      { RUN_STATE_RUNNING, RUN_STATE_INTERNAL_ERROR },
> @@ -627,20 +634,25 @@ static const RunStateTransition runstate_transitions_def[] = {
>      { RUN_STATE_RUNNING, RUN_STATE_GUEST_PANICKED },
>  
>      { RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },
> +    { RUN_STATE_SAVE_VM, RUN_STATE_PRELAUNCH },

This should not happen; thus I would remove this line.

>      { RUN_STATE_SHUTDOWN, RUN_STATE_PAUSED },
>      { RUN_STATE_SHUTDOWN, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_SHUTDOWN, RUN_STATE_PRELAUNCH },
>  
>      { RUN_STATE_DEBUG, RUN_STATE_SUSPENDED },
>      { RUN_STATE_RUNNING, RUN_STATE_SUSPENDED },
>      { RUN_STATE_SUSPENDED, RUN_STATE_RUNNING },
>      { RUN_STATE_SUSPENDED, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_SUSPENDED, RUN_STATE_PRELAUNCH },
>  
>      { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
>      { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_WATCHDOG, RUN_STATE_PRELAUNCH },
>  
>      { RUN_STATE_GUEST_PANICKED, RUN_STATE_RUNNING },
>      { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },
> +    { RUN_STATE_GUEST_PANICKED, RUN_STATE_PRELAUNCH },
>  
>      { RUN_STATE__MAX, RUN_STATE__MAX },
>  };
> @@ -1886,8 +1899,10 @@ static bool main_loop_should_exit(void)
>          cpu_synchronize_all_states();
>          qemu_system_reset(VMRESET_REPORT);
>          resume_all_vcpus();
> -        if (runstate_needs_reset()) {
> -            runstate_set(RUN_STATE_PAUSED);
> +        if (!runstate_check(RUN_STATE_RUNNING) &&
> +                !runstate_check(RUN_STATE_INMIGRATE) &&
> +                !runstate_check(RUN_STATE_SAVE_VM)) {

Since SAVE_VM should not happen here, I would leave this check out too.
 If it happens, the lack of a SAVE_VM->PRELAUNCH transition will cause
an assertion failure.

Thanks for the patch!

Paolo

> +            runstate_set(RUN_STATE_PRELAUNCH);
>          }
>      }
>      if (qemu_wakeup_requested()) {
>