Re: [Qemu-devel] [PATCH v4 05/10] qom/cpu: move register_vmstate to common CPUClass.realizefn

[Chen Fan <chen.fan.fnst@cn.fujitsu.com>]

On 03/06/2015 04:53 PM, Igor Mammedov wrote:
> On Fri, 13 Feb 2015 18:25:28 +0800
> Zhu Guihua <zhugh.fnst@cn.fujitsu.com> wrote:
>
>> From: Gu Zheng <guz.fnst@cn.fujitsu.com>
>>
>> Move cpu vmstate register from cpu_exec_init into cpu_common_realizefn,
>> and use cc->get_arch_id as the instance id that suggested by Igor to
>> fix the migration issue.
>>
>> Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
>> Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
>> ---
>>   exec.c            | 25 ++++++++++++++++++-------
>>   include/qom/cpu.h |  2 ++
>>   qom/cpu.c         |  4 ++++
>>   3 files changed, 24 insertions(+), 7 deletions(-)
>>
>> diff --git a/exec.c b/exec.c
>> index 6dff7bc..8361591 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -513,10 +513,26 @@ void tcg_cpu_address_space_init(CPUState *cpu, AddressSpace *as)
>>   }
>>   #endif
>>   
>> +void cpu_vmstate_register(CPUState *cpu)
>> +{
>> +    CPUClass *cc = CPU_GET_CLASS(cpu);
>> +    int cpu_index = cc->get_arch_id(cpu) + max_cpus;
> Why do you add max_cpus here?
Adding max_cpus is to avoid cpu_index equals comat_index which would
cause migration fails,  this reason is that find_se() always compares 
instance_id
with se->instance_id or se->alias_id when do migration.

Thanks,
Chen

>
>> +    int compat_index = cc->get_compat_arch_id(cpu);
>> +
>> +    if (qdev_get_vmsd(DEVICE(cpu)) == NULL) {
>> +        vmstate_register_with_alias_id(NULL, cpu_index, &vmstate_cpu_common,
>> +                                       cpu, compat_index, 3);
>> +    }
>> +
>> +    if (cc->vmsd != NULL) {
>> +        vmstate_register_with_alias_id(NULL, cpu_index, cc->vmsd,
>> +                                       cpu, compat_index, 3);
>> +    }
>> +}
>> +
>>   void cpu_exec_init(CPUArchState *env)
>>   {
>>       CPUState *cpu = ENV_GET_CPU(env);
>> -    CPUClass *cc = CPU_GET_CLASS(cpu);
>>       CPUState *some_cpu;
>>       int cpu_index;
>>   
>> @@ -539,18 +555,13 @@ void cpu_exec_init(CPUArchState *env)
>>   #if defined(CONFIG_USER_ONLY)
>>       cpu_list_unlock();
>>   #endif
>> -    if (qdev_get_vmsd(DEVICE(cpu)) == NULL) {
>> -        vmstate_register(NULL, cpu_index, &vmstate_cpu_common, cpu);
>> -    }
>>   #if defined(CPU_SAVE_VERSION) && !defined(CONFIG_USER_ONLY)
>> +    CPUClass *cc = CPU_GET_CLASS(cpu);
>>       register_savevm(NULL, "cpu", cpu_index, CPU_SAVE_VERSION,
>>                       cpu_save, cpu_load, env);
>>       assert(cc->vmsd == NULL);
>>       assert(qdev_get_vmsd(DEVICE(cpu)) == NULL);
>>   #endif
>> -    if (cc->vmsd != NULL) {
>> -        vmstate_register(NULL, cpu_index, cc->vmsd, cpu);
>> -    }
>>   }
>>   
>>   #if defined(CONFIG_USER_ONLY)
>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
>> index 2e68dd2..d0a50e2 100644
>> --- a/include/qom/cpu.h
>> +++ b/include/qom/cpu.h
>> @@ -565,6 +565,8 @@ void cpu_interrupt(CPUState *cpu, int mask);
>>   
>>   #endif /* USER_ONLY */
>>   
>> +void cpu_vmstate_register(CPUState *cpu);
>> +
>>   #ifdef CONFIG_SOFTMMU
>>   static inline void cpu_unassigned_access(CPUState *cpu, hwaddr addr,
>>                                            bool is_write, bool is_exec,
>> diff --git a/qom/cpu.c b/qom/cpu.c
>> index 83d7766..8e37045 100644
>> --- a/qom/cpu.c
>> +++ b/qom/cpu.c
>> @@ -302,6 +302,10 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
>>   {
>>       CPUState *cpu = CPU(dev);
>>   
>> +#if !defined(CONFIG_USER_ONLY)
>> +    cpu_vmstate_register(cpu);
>> +#endif
>> +
>>       if (dev->hotplugged) {
>>           cpu_synchronize_post_init(cpu);
>>           cpu_resume(cpu);
> .
>