Re: [Qemu-devel] [RFC V2 02/10] qom/cpu: move register_vmstate to common CPUClass.realizefn

[Gu Zheng <guz.fnst@cn.fujitsu.com>]

Hi Igor,
On 09/09/2014 08:17 PM, Igor Mammedov wrote:

> On Thu, 28 Aug 2014 11:36:34 +0800
> Gu Zheng <guz.fnst@cn.fujitsu.com> wrote:
> 
>> Move cpu vmstate register from cpu_exec_init into cpu_common_realizefn,
>> apic vmstate register into x86_cpu_apic_realize. And use the
>> cc->get_arch_id as the instance id that suggested by Igor to
>> fix the migration issue.
>> Besides, also use cc->get_arch_id as the cpu index of HMP/QMP command output to
>> fix the index duplicated issue when hotadd a hot-removed cpu.
>>
>> v2:
>>  -fix the cpu index duplicated issue in the QMP/HMP command output.
>>
>> Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
> Please split CPU vmstate/APIC vmstate/QMP-monitor changes into separate patches.

Got it, it does need to be restructured.

> 
>> ---
>>  cpus.c                          |    4 +++-
>>  exec.c                          |   32 +++++++++++++++++++-------------
>>  hw/intc/apic_common.c           |    3 +--
>>  include/hw/i386/apic_internal.h |    2 ++
>>  include/qom/cpu.h               |    2 ++
>>  monitor.c                       |    4 +++-
>>  qom/cpu.c                       |    2 ++
>>  target-i386/cpu.c               |   10 ++++++++--
>>  8 files changed, 40 insertions(+), 19 deletions(-)
>>
>> diff --git a/cpus.c b/cpus.c
>> index 2b5c0bd..cce2744 100644
>> --- a/cpus.c
>> +++ b/cpus.c
>> @@ -1394,6 +1394,7 @@ CpuInfoList *qmp_query_cpus(Error **errp)
>>  {
>>      CpuInfoList *head = NULL, *cur_item = NULL;
>>      CPUState *cpu;
>> +    CPUClass *cc;
>>  
>>      CPU_FOREACH(cpu) {
>>          CpuInfoList *info;
>> @@ -1411,11 +1412,12 @@ CpuInfoList *qmp_query_cpus(Error **errp)
>>          CPUMIPSState *env = &mips_cpu->env;
>>  #endif
>>  
>> +        cc = CPU_GET_CLASS(cpu);
>>          cpu_synchronize_state(cpu);
>>  
>>          info = g_malloc0(sizeof(*info));
>>          info->value = g_malloc0(sizeof(*info->value));
>> -        info->value->CPU = cpu->cpu_index;
>> +        info->value->CPU = cc->get_arch_id(cpu);
>>          info->value->current = (cpu == first_cpu);
>>          info->value->halted = cpu->halted;
>>          info->value->thread_id = cpu->thread_id;
>> diff --git a/exec.c b/exec.c
>> index 5f9857c..c514492 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -473,10 +473,28 @@ 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);
>> +
>> +    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)
>> +    register_savevm(NULL, "cpu", cpu_index, CPU_SAVE_VERSION,
>> +                    cpu_save, cpu_load, cpu->env_ptr);
>> +    assert(cc->vmsd == NULL);
>> +    assert(qdev_get_vmsd(DEVICE(cpu)) == NULL);
>> +#endif
>> +    if (cc->vmsd != NULL) {
>> +        vmstate_register(NULL, cpu_index, cc->vmsd, cpu);
>> +    }
>> +}
>> +
>>  void cpu_exec_init(CPUArchState *env)
>>  {
>>      CPUState *cpu = ENV_GET_CPU(env);
>> -    CPUClass *cc = CPU_GET_CLASS(cpu);
>>      CPUState *some_cpu;
>>      int cpu_index;
>>  
>> @@ -499,18 +517,6 @@ 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)
>> -    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(TARGET_HAS_ICE)
>> diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
>> index ce3d903..029f67d 100644
>> --- a/hw/intc/apic_common.c
>> +++ b/hw/intc/apic_common.c
>> @@ -345,7 +345,7 @@ static int apic_dispatch_post_load(void *opaque, int version_id)
>>      return 0;
>>  }
>>  
>> -static const VMStateDescription vmstate_apic_common = {
>> +const VMStateDescription vmstate_apic_common = {
>>      .name = "apic",
>>      .version_id = 3,
>>      .minimum_version_id = 3,
>> @@ -391,7 +391,6 @@ static void apic_common_class_init(ObjectClass *klass, void *data)
>>      ICCDeviceClass *idc = ICC_DEVICE_CLASS(klass);
>>      DeviceClass *dc = DEVICE_CLASS(klass);
>>  
>> -    dc->vmsd = &vmstate_apic_common;
>>      dc->reset = apic_reset_common;
>>      dc->props = apic_properties_common;
>>      idc->realize = apic_common_realize;
>> diff --git a/include/hw/i386/apic_internal.h b/include/hw/i386/apic_internal.h
>> index 83e2a42..2c91609 100644
>> --- a/include/hw/i386/apic_internal.h
>> +++ b/include/hw/i386/apic_internal.h
>> @@ -23,6 +23,7 @@
>>  #include "exec/memory.h"
>>  #include "hw/cpu/icc_bus.h"
>>  #include "qemu/timer.h"
>> +#include "migration/vmstate.h"
>>  
>>  /* APIC Local Vector Table */
>>  #define APIC_LVT_TIMER                  0
>> @@ -136,6 +137,7 @@ typedef struct VAPICState {
>>  } QEMU_PACKED VAPICState;
>>  
>>  extern bool apic_report_tpr_access;
>> +extern const VMStateDescription vmstate_apic_common;
>>  
>>  void apic_report_irq_delivered(int delivered);
>>  bool apic_next_timer(APICCommonState *s, int64_t current_time);
>> diff --git a/include/qom/cpu.h b/include/qom/cpu.h
>> index 1aafbf5..bc32c9a 100644
>> --- a/include/qom/cpu.h
>> +++ b/include/qom/cpu.h
>> @@ -549,6 +549,8 @@ 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/monitor.c b/monitor.c
>> index 34cee74..55fd06c 100644
>> --- a/monitor.c
>> +++ b/monitor.c
>> @@ -1032,7 +1032,9 @@ static CPUArchState *mon_get_cpu(void)
>>  int monitor_get_cpu_index(void)
>>  {
>>      CPUState *cpu = ENV_GET_CPU(mon_get_cpu());
>> -    return cpu->cpu_index;
>> +    CPUClass *cc = CPU_GET_CLASS(cpu);
>> +
>> +    return cc->get_arch_id(cpu);
>>  }
>>  
>>  static void do_info_registers(Monitor *mon, const QDict *qdict)
>> diff --git a/qom/cpu.c b/qom/cpu.c
>> index b32dd0a..bf16590 100644
>> --- a/qom/cpu.c
>> +++ b/qom/cpu.c
>> @@ -301,6 +301,8 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
>>  {
>>      CPUState *cpu = CPU(dev);
>>  
>> +    cpu_vmstate_register(cpu);
>> +
>>      if (dev->hotplugged) {
>>          cpu_synchronize_post_init(cpu);
>>          notifier_list_notify(&cpu_added_notifiers, dev);
>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
>> index 217500c..2aa2b31 100644
>> --- a/target-i386/cpu.c
>> +++ b/target-i386/cpu.c
>> @@ -2662,11 +2662,17 @@ static void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
>>  
>>  static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
>>  {
>> -    if (cpu->apic_state == NULL) {
>> +    DeviceState *apic_state = cpu->apic_state;
>> +    CPUClass *cc = CPU_GET_CLASS(CPU(cpu));
>> +
>> +    if (apic_state == NULL) {
>>          return;
>>      }
>>  
>> -    if (qdev_init(cpu->apic_state)) {
>> +    vmstate_register(0, cc->get_arch_id(CPU(cpu)),
>> +            &vmstate_apic_common, apic_state);
> Why have you dropped generic dc->vmsd = &vmstate_apic_common from above
> and opencoded it here?

Because if dc->vmsd was set, it will be registered with a sequence instance
id in device_set_realized, which will break the instance rule (cc->get_arch_id),
so we hacked it here.
Any better solution is welcome.

Thanks,
Gu 

> 
> 
>> +
>> +    if (qdev_init(apic_state)) {
>>          error_setg(errp, "APIC device '%s' could not be initialized",
>>                     object_get_typename(OBJECT(cpu->apic_state)));
>>          return;
> 
> .
>