Re: [PATCH v9 01/10] s390x/cpus: Make absence of multithreading clear

[Pierre Morel <pmorel@linux.ibm.com>]

On 9/5/22 13:32, Nico Boehr wrote:
> Quoting Pierre Morel (2022-09-02 09:55:22)
>> S390x do not support multithreading in the guest.
>> Do not let admin falsely specify multithreading on QEMU
>> smp commandline.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   hw/s390x/s390-virtio-ccw.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 70229b102b..b5ca154e2f 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -86,6 +86,9 @@ static void s390_init_cpus(MachineState *machine)
>>       MachineClass *mc = MACHINE_GET_CLASS(machine);
>>       int i;
>>   
>> +    /* Explicitely do not support threads */
>            ^
>            Explicitly
> 
>> +    assert(machine->smp.threads == 1);
> 
> It might be nicer to give a better error message to the user.
> What do you think about something like (broken whitespace ahead):
> 
>      if (machine->smp.threads != 1) {if (machine->smp.threads != 1) {
>          error_setg(&error_fatal, "More than one thread specified, but multithreading unsupported");
>          return;
>      }
> 


OK, I think I wanted to do this and I changed my mind, obviously, I do 
not recall why.
I will do almost the same but after a look at error.h I will use 
error_report()/exit() instead of error_setg()/return as in:


+    /* Explicitly do not support threads */
+    if (machine->smp.threads != 1) {
+        error_report("More than one thread specified, but 
multithreading unsupported");
+        exit(1);
+    }


Thanks,

Regards,
Pierre

-- 
Pierre Morel
IBM Lab Boeblingen