Re: [Qemu-devel] [Qemu-ppc] [PATCH] pseries: Correct panic behaviour for pseries machine type

[David Gibson <david@gibson.dropbear.id.au>]

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On Thu, Jun 08, 2017 at 06:33:57AM +0200, Thomas Huth wrote:
> On 08.06.2017 02:18, David Gibson wrote:
> > On Wed, Jun 07, 2017 at 07:10:55PM +0200, Thomas Huth wrote:
> >> On 07.06.2017 16:34, Paolo Bonzini wrote:
> >>>
> >>>
> >>> On 07/06/2017 09:33, Thomas Huth wrote:
> >>>> On 07.06.2017 09:07, David Gibson wrote:
> >>>>> The pseries machine type doesn't usually use the 'pvpanic' device as such,
> >>>>> because it has a firmware/hypervisor facility with roughly the same
> >>>>> purpose.  The 'ibm,os-term' RTAS call notifies the hypervisor that the
> >>>>> guest has crashed.
> >>>>>
> >>>>> Our implementation of this call was sending a GUEST_PANICKED qmp event;
> >>>>> however, it was not doing the other usual panic actions, making its
> >>>>> behaviour different from pvpanic for no good reason.
> >>>>>
> >>>>> To correct this, we should call qemu_system_guest_panicked() rather than
> >>>>> directly sending the panic event.
> >>>>>
> >>>>> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> >>>>> ---
> >>>>>  hw/ppc/spapr_rtas.c | 7 ++-----
> >>>>>  1 file changed, 2 insertions(+), 5 deletions(-)
> >>>>>
> >>>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> >>>>> index 707c4d4..94a2799 100644
> >>>>> --- a/hw/ppc/spapr_rtas.c
> >>>>> +++ b/hw/ppc/spapr_rtas.c
> >>>>> @@ -293,12 +293,9 @@ static void rtas_ibm_os_term(PowerPCCPU *cpu,
> >>>>>                              target_ulong args,
> >>>>>                              uint32_t nret, target_ulong rets)
> >>>>>  {
> >>>>> -    target_ulong ret = 0;
> >>>>> +    qemu_system_guest_panicked(NULL);
> >>>>>  
> >>>>> -    qapi_event_send_guest_panicked(GUEST_PANIC_ACTION_PAUSE, false, NULL,
> >>>>> -                                   &error_abort);
> >>>>> -
> >>>>> -    rtas_st(rets, 0, ret);
> >>>>> +    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
> >>>>>  }
> >>>>>  
> >>>>>  static void rtas_set_power_level(PowerPCCPU *cpu, sPAPRMachineState *spapr,
> >>>>>
> >>>>
> >>>> If I get that qemu_system_guest_panicked() function right, it will stop
> >>>> the VM, won't it? That contradicts the LoPAPR spec that says that the
> >>>> RTAS call returns if the "ibm,extended-os-term" property is available in
> >>>> the device tree.
> >>>
> >>> It does return... but only after the user starts the guest again with
> >>> "cont".
> >>
> >> OK, I guess that's enough to say that the "ibm,extended-os-term"
> >> property can stay ... so I think the patch is fine as it is right now.
> > 
> > So.. can I have an R-b?
> 
> Reviewed-by: Thomas Huth <thuth@redhat.com>

Thanks.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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