Re: [RFC PATCH v5 1/1] s390x: sigp: Reorder the SIGP STOP code

[Thomas Huth <thuth@redhat.com>]

On 18/01/2022 14.34, David Hildenbrand wrote:
> On 13.12.21 22:09, Eric Farman wrote:
>> Let's wait to mark the VCPU STOPPED until the possible
>> STORE STATUS operation is completed, so that we know the
>> CPU is fully stopped and done doing anything. (When we
>> also clear the possible sigp_order field for STOP orders.)
>>
>> Suggested-by: David Hildenbrand <david@redhat.com>
>> Signed-off-by: Eric Farman <farman@linux.ibm.com>
>> ---
>>   target/s390x/sigp.c | 12 ++++++++----
>>   1 file changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/target/s390x/sigp.c b/target/s390x/sigp.c
>> index 51c727834c..9dd977349a 100644
>> --- a/target/s390x/sigp.c
>> +++ b/target/s390x/sigp.c
>> @@ -139,7 +139,7 @@ static void sigp_stop_and_store_status(CPUState *cs, run_on_cpu_data arg)
>>       case S390_CPU_STATE_OPERATING:
>>           cpu->env.sigp_order = SIGP_STOP_STORE_STATUS;
>>           cpu_inject_stop(cpu);
>> -        /* store will be performed in do_stop_interrup() */
>> +        /* store will be performed in do_stop_interrupt() */
>>           break;
>>       case S390_CPU_STATE_STOPPED:
>>           /* already stopped, just store the status */
>> @@ -479,13 +479,17 @@ void do_stop_interrupt(CPUS390XState *env)
>>   {
>>       S390CPU *cpu = env_archcpu(env);
>>   
>> -    if (s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu) == 0) {
>> -        qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
>> -    }
>> +    /*
>> +     * Complete the STOP operation before exposing the CPU as
>> +     * STOPPED to the system.
>> +     */
>>       if (cpu->env.sigp_order == SIGP_STOP_STORE_STATUS) {
>>           s390_store_status(cpu, S390_STORE_STATUS_DEF_ADDR, true);
>>       }
>>       env->sigp_order = 0;
>> +    if (s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu) == 0) {
>> +        qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
>> +    }
>>       env->pending_int &= ~INTERRUPT_STOP;
>>   }
>>   
> 
> Reviewed-by: David Hildenbrand <david@redhat.com>
> 

Thanks, queued to my s390x-next branch now:

  https://gitlab.com/thuth/qemu/-/commits/s390x-next/

  Thomas