Re: [Qemu-devel] [PATCH v6 1/7] s390x/cpu: Cleanup init in preparation for hotplug

[Matthew Rosato <mjrosato@linux.vnet.ibm.com>]

On 02/22/2016 12:46 PM, Andreas Färber wrote:
> Am 22.02.2016 um 18:06 schrieb Matthew Rosato:
>> Ensure a valid cpu_model is set upfront by setting the
>> default value directly into the MachineState when none is
>> specified.  This is needed to ensure hotplugged CPUs share
>> the same cpu_model.
>>
>> Signed-off-by: Matthew Rosato <mjrosato@linux.vnet.ibm.com>
>> Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
>> ---
>>  hw/s390x/s390-virtio-ccw.c | 2 +-
>>  hw/s390x/s390-virtio.c     | 8 ++++----
>>  hw/s390x/s390-virtio.h     | 2 +-
>>  3 files changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 89f5d0d..b05ed8b 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -136,7 +136,7 @@ static void ccw_init(MachineState *machine)
>>      virtio_ccw_register_hcalls();
>>  
>>      /* init CPUs */
>> -    s390_init_cpus(machine->cpu_model);
>> +    s390_init_cpus(machine);
>>  
>>      if (kvm_enabled()) {
>>          kvm_s390_enable_css_support(s390_cpu_addr2state(0));
>> diff --git a/hw/s390x/s390-virtio.c b/hw/s390x/s390-virtio.c
>> index c320878..b576811 100644
>> --- a/hw/s390x/s390-virtio.c
>> +++ b/hw/s390x/s390-virtio.c
>> @@ -95,12 +95,12 @@ void s390_init_ipl_dev(const char *kernel_filename,
>>      qdev_init_nofail(dev);
>>  }
>>  
>> -void s390_init_cpus(const char *cpu_model)
>> +void s390_init_cpus(MachineState *machine)
>>  {
>>      int i;
>>  
>> -    if (cpu_model == NULL) {
>> -        cpu_model = "host";
>> +    if (machine->cpu_model == NULL) {
>> +        machine->cpu_model = "host";
> 
> When/why is cpu_model == NULL? Could you simply set it as a default in
> your machine's instance_init?
> 

Yes, we definitely did this in an earlier version. I'll set this during
machine instance_init.

Matt