Re: [Qemu-devel] [PATCH 8/8] [PATCH RFC v2] s390-qemu: cpu hotplug - Treat S390 cpus as devices

["Jason J. Herne" <jjherne@linux.vnet.ibm.com>]

On 06/08/2013 09:11 PM, Andreas Färber wrote:
>>   if (tcg_enabled() && !inited) {
>> >          inited = true;
>> >          s390x_translate_init();
>> >      }
>> >+
>> >+    smp_cpus += 1;
> Won't we need some form of locking?
>
> If we fiddle with a global CPU counter, we should do so in qom/cpu.c,
> not just in s390x code.
>

I've redesigned a lot of this to make it simpler and less intrusive. 
I'm almost ready to post the next revision but I'm hung up on this one 
thing.

I moved the smp_cpu increment to qom/cpu.c : cpu_common_realizefn. 
However this seems to break the user mode target because smp_cpus does 
not exist.  I tried wrapping the increment in a #ifndef CONFIG_USER_ONLY 
statement but it seems to have no effect.  I think the reason for that 
is because CONFIG_USER_ONLY is added to config-target.h which is not 
actually generated until after we compile qom/cpu.c.

...
   CC    qom/object.o
   CC    qom/container.o
   CC    qom/qom-qobject.o
   CC    qom/cpu.o
   CC    hw/core/qdev.o
   CC    hw/core/qdev-properties.o
   CC    hw/core/irq.o
   GEN   s390x-linux-user/config-target.h
   CC    s390x-linux-user/exec.o
...

Is there another place I should put the increment?


-- 
-- Jason J. Herne (jjherne@linux.vnet.ibm.com)