Re: [Qemu-devel] block ais migration for machines <= 2.9

[Yi Min Zhao <zyimin@linux.vnet.ibm.com>]

在 2017/9/21 上午12:04, Dr. David Alan Gilbert 写道:
> * Christian Borntraeger (borntraeger@de.ibm.com) wrote:
>> Something like the following seems to do the tricks.
>> Needs proper patch description, review, full test with different kernel versions.....
> Without knowing anything about 'ais' - will this break migration from
> 2.10 -> 2.10+this fix?
I think it doesn't break. I will have a try later.
>
> Dave
>
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 1c7af39..2ff32ba 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -212,6 +212,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
>>       s390mc->cpu_model_allowed = true;
>>       s390mc->css_migration_enabled = true;
>>       s390mc->gs_allowed = true;
>> +    s390mc->ais_allowed = true;
>>       mc->init = ccw_init;
>>       mc->reset = s390_machine_reset;
>>       mc->hot_add_cpu = s390_hot_add_cpu;
>> @@ -305,6 +306,11 @@ bool gs_allowed(void)
>>       return false;
>>   }
>>   
>> +bool ais_allowed(void)
>> +{
>> +    return get_machine_class()->ais_allowed;
>> +}
>> +
>>   static char *machine_get_loadparm(Object *obj, Error **errp)
>>   {
>>       S390CcwMachineState *ms = S390_CCW_MACHINE(obj);
>> @@ -533,6 +539,7 @@ static void ccw_machine_2_9_class_options(MachineClass *mc)
>>       S390CcwMachineClass *s390mc = S390_MACHINE_CLASS(mc);
>>   
>>       s390mc->gs_allowed = false;
>> +    s390mc->ais_allowed = false;
>>       ccw_machine_2_10_class_options(mc);
>>       SET_MACHINE_COMPAT(mc, CCW_COMPAT_2_9);
>>       s390mc->css_migration_enabled = false;
>> diff --git a/include/hw/s390x/s390-virtio-ccw.h b/include/hw/s390x/s390-virtio-ccw.h
>> index 41a9d28..bba8660 100644
>> --- a/include/hw/s390x/s390-virtio-ccw.h
>> +++ b/include/hw/s390x/s390-virtio-ccw.h
>> @@ -41,6 +41,7 @@ typedef struct S390CcwMachineClass {
>>       bool cpu_model_allowed;
>>       bool css_migration_enabled;
>>       bool gs_allowed;
>> +    bool ais_allowed;
>>   } S390CcwMachineClass;
>>   
>>   /* runtime-instrumentation allowed by the machine */
>> @@ -49,6 +50,8 @@ bool ri_allowed(void);
>>   bool cpu_model_allowed(void);
>>   /* guarded-storage allowed by the machine */
>>   bool gs_allowed(void);
>> +/* ais allowed by the machine */
>> +bool ais_allowed(void);
>>   
>>   /**
>>    * Returns true if (vmstate based) migration of the channel subsystem
>> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
>> index c4c5791..531d474 100644
>> --- a/target/s390x/kvm.c
>> +++ b/target/s390x/kvm.c
>> @@ -309,7 +309,9 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
>>       }
>>   
>>       /* Try to enable AIS facility */
>> -    kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
>> +    if (ais_allowed()) {
>> +       kvm_vm_enable_cap(s, KVM_CAP_S390_AIS, 0);
>> +    }
>>   
>>       qemu_mutex_init(&qemu_sigp_mutex);
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
>