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

[Thomas Huth <thuth@redhat.com>]

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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>


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