Re: [Qemu-devel] [PATCH v13 4/8] add a new runstate: RUN_STATE_GUEST_PANICKED

[Hu Tao]

On Mon, Mar 04, 2013 at 10:40:15AM +0100, Paolo Bonzini wrote:
> Il 28/02/2013 13:13, Hu Tao ha scritto:
> > The guest will be in this state when it is panicked.
> > 
> > Signed-off-by: Wen Congyang <address@hidden>
> > Signed-off-by: Hu Tao <address@hidden>
> > ---
> >  migration.c      |  1 +
> >  qapi-schema.json |  6 +++++-
> >  qmp.c            |  3 ++-
> >  vl.c             | 11 ++++++++++-
> >  4 files changed, 18 insertions(+), 3 deletions(-)
> > 
> > diff --git a/migration.c b/migration.c
> > index c29830e..fa17b82 100644
> > --- a/migration.c
> > +++ b/migration.c
> > @@ -698,6 +698,7 @@ static void *buffered_file_thread(void *opaque)
> >                  int64_t start_time, end_time;
> >  
> >                  DPRINTF("done iterating\n");
> > +                save_run_state();
> >                  start_time = qemu_get_clock_ms(rt_clock);
> >                  qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
> >                  if (old_vm_running) {
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 28b070f..8f1d138 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -174,11 +174,15 @@
> >  # @suspended: guest is suspended (ACPI S3)
> >  #
> >  # @watchdog: the watchdog action is configured to pause and has been 
> > triggered
> > +#
> > +# @guest-panicked: the panicked action is configured to pause and has been
> > +# triggered.
> >  ##
> >  { 'enum': 'RunState',
> >    'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error', 'paused',
> >              'postmigrate', 'prelaunch', 'finish-migrate', 'restore-vm',
> > -            'running', 'save-vm', 'shutdown', 'suspended', 'watchdog' ] }
> > +            'running', 'save-vm', 'shutdown', 'suspended', 'watchdog',
> > +            'guest-panicked' ] }
> >  
> >  ##
> >  # @SnapshotInfo
> > diff --git a/qmp.c b/qmp.c
> > index 5f1bed1..f5027f6 100644
> > --- a/qmp.c
> > +++ b/qmp.c
> > @@ -150,7 +150,8 @@ void qmp_cont(Error **errp)
> >      Error *local_err = NULL;
> >  
> >      if (runstate_check(RUN_STATE_INTERNAL_ERROR) ||
> > -               runstate_check(RUN_STATE_SHUTDOWN)) {
> > +            runstate_check(RUN_STATE_SHUTDOWN) ||
> > +            runstate_check(RUN_STATE_GUEST_PANICKED)) {
> >          error_set(errp, QERR_RESET_REQUIRED);
> >          return;
> >      } else if (runstate_check(RUN_STATE_SUSPENDED)) {
> > diff --git a/vl.c b/vl.c
> > index 3d08e1a..51d4922 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -536,6 +536,7 @@ static const RunStateTransition 
> > runstate_transitions_def[] = {
> >  
> >      { RUN_STATE_INMIGRATE, RUN_STATE_RUNNING },
> >      { RUN_STATE_INMIGRATE, RUN_STATE_PAUSED },
> > +    { RUN_STATE_INMIGRATE, RUN_STATE_GUEST_PANICKED },
> 
> Is this a consequence of the first patch?

Yes.

> 
> >      { RUN_STATE_INTERNAL_ERROR, RUN_STATE_RUNNING },
> >      { RUN_STATE_INTERNAL_ERROR, RUN_STATE_FINISH_MIGRATE },
> > @@ -549,6 +550,7 @@ static const RunStateTransition 
> > runstate_transitions_def[] = {
> >      { RUN_STATE_POSTMIGRATE, RUN_STATE_RUNNING },
> >      { RUN_STATE_POSTMIGRATE, RUN_STATE_PAUSED },
> >      { RUN_STATE_POSTMIGRATE, RUN_STATE_FINISH_MIGRATE },
> > +    { RUN_STATE_POSTMIGRATE, RUN_STATE_GUEST_PANICKED },
> 
> Impossible.  GUEST_PANICKED requires an instruction to be executed in
> the guest, so it should first go to RUNNING.
> 
> >      { RUN_STATE_PRELAUNCH, RUN_STATE_RUNNING },
> >      { RUN_STATE_PRELAUNCH, RUN_STATE_FINISH_MIGRATE },
> > @@ -559,6 +561,7 @@ static const RunStateTransition 
> > runstate_transitions_def[] = {
> >  
> >      { RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },
> >      { RUN_STATE_RESTORE_VM, RUN_STATE_PAUSED },
> > +    { RUN_STATE_RESTORE_VM, RUN_STATE_GUEST_PANICKED },
> 
> Is it also for the first patch?

Yes.

> 
> >      { RUN_STATE_RUNNING, RUN_STATE_DEBUG },
> >      { RUN_STATE_RUNNING, RUN_STATE_INTERNAL_ERROR },
> > @@ -569,6 +572,7 @@ static const RunStateTransition 
> > runstate_transitions_def[] = {
> >      { RUN_STATE_RUNNING, RUN_STATE_SAVE_VM },
> >      { RUN_STATE_RUNNING, RUN_STATE_SHUTDOWN },
> >      { RUN_STATE_RUNNING, RUN_STATE_WATCHDOG },
> > +    { RUN_STATE_RUNNING, RUN_STATE_GUEST_PANICKED },
> 
> This one is obviously ok.
> 
> >      { RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },
> >  
> > @@ -583,6 +587,10 @@ static const RunStateTransition 
> > runstate_transitions_def[] = {
> >      { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
> >      { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
> >  
> > +    { RUN_STATE_GUEST_PANICKED, RUN_STATE_RUNNING },
> > +    { RUN_STATE_GUEST_PANICKED, RUN_STATE_PAUSED },
> > +    { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },
> 
> Like SHUTDOWN, it should go first to PAUSED and then to RUNNING.  A
> GUEST_PANICKED -> RUNNING transition is not possible.  You're seeing it
> because you lack the addition of GUEST_PANICKED here:
> 
>         if (runstate_check(RUN_STATE_INTERNAL_ERROR) ||
>             runstate_check(RUN_STATE_SHUTDOWN)) {
>             runstate_set(RUN_STATE_PAUSED);
>         }
> 
> I think you should first move the INTERNAL_ERROR || SHUTDOWN checks to a
> separate function, so that you can then add GUEST_PANICKED.

Will 

         if (runstate_check(RUN_STATE_INTERNAL_ERROR) ||
             runstate_check(RUN_STATE_SHUTDOWN) ||
             runstate_check(RUN_STATE_GUEST_PANICKED)) {
             runstate_set(RUN_STATE_PAUSED);
         }

be OK? Or I must be misunderstanding you.

> 
> Paolo
> 
> >      { RUN_STATE_MAX, RUN_STATE_MAX },
> >  };
> >  
> > @@ -2001,7 +2009,8 @@ static bool main_loop_should_exit(void)
> >          qemu_system_reset(VMRESET_REPORT);
> >          resume_all_vcpus();
> >          if (runstate_check(RUN_STATE_INTERNAL_ERROR) ||
> > -            runstate_check(RUN_STATE_SHUTDOWN)) {
> > +            runstate_check(RUN_STATE_SHUTDOWN) ||
> > +            runstate_check(RUN_STATE_GUEST_PANICKED)) {
> >              bdrv_iterate(iostatus_bdrv_it, NULL);
> >              vm_start();
> >          }
> >