Re: [Qemu-devel] [RFC V2 04/10] x86: add x86_cpu_unrealizefn() for cpu apic remove

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 28 Aug 2014 11:36:36 +0800
Gu Zheng <guz.fnst@cn.fujitsu.com> wrote:

> From: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> 
> Implement x86_cpu_unrealizefn() for corresponding x86_cpu_realizefn(),
> which is mostly used to clean the apic related allocation and vmstates
> at here.
> 
> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
> ---
>  hw/i386/kvm/apic.c              |    8 +++++++
>  hw/intc/apic.c                  |   10 ++++++++
>  hw/intc/apic_common.c           |   23 +++++++++++++++++++-
>  include/hw/cpu/icc_bus.h        |    1 +
>  include/hw/i386/apic_internal.h |    1 +
>  target-i386/cpu-qom.h           |    1 +
>  target-i386/cpu.c               |   45 +++++++++++++++++++++++++++++++++++++++
>  7 files changed, 88 insertions(+), 1 deletions(-)
> 
> diff --git a/hw/i386/kvm/apic.c b/hw/i386/kvm/apic.c
> index e873b50..c95fb8a 100644
> --- a/hw/i386/kvm/apic.c
> +++ b/hw/i386/kvm/apic.c
> @@ -183,11 +183,19 @@ static void kvm_apic_realize(DeviceState *dev, Error **errp)
>      }
>  }
>  
> +static void kvm_apic_unrealize(DeviceState *dev, Error **errp)
> +{
> +    APICCommonState *s = APIC_COMMON(dev);
> +
> +    object_unparent(OBJECT(&s->io_memory));
> +}
> +
what will disable/destroy in kernel APIC?

>  static void kvm_apic_class_init(ObjectClass *klass, void *data)
>  {
>      APICCommonClass *k = APIC_COMMON_CLASS(klass);
>  
>      k->realize = kvm_apic_realize;
> +    k->unrealize = kvm_apic_unrealize;
>      k->set_base = kvm_apic_set_base;
>      k->set_tpr = kvm_apic_set_tpr;
>      k->get_tpr = kvm_apic_get_tpr;
> diff --git a/hw/intc/apic.c b/hw/intc/apic.c
> index 03ff9e9..6d38965 100644
> --- a/hw/intc/apic.c
> +++ b/hw/intc/apic.c
> @@ -885,11 +885,21 @@ static void apic_realize(DeviceState *dev, Error **errp)
>      msi_supported = true;
>  }
>  
> +static void apic_unrealize(DeviceState *dev, Error **errp)
> +{
> +    APICCommonState *s = APIC_COMMON(dev);
> +
> +    object_unparent(OBJECT(&s->io_memory));
> +    timer_free(s->timer);
> +    local_apics[s->idx] = NULL;
> +}
> +
>  static void apic_class_init(ObjectClass *klass, void *data)
>  {
>      APICCommonClass *k = APIC_COMMON_CLASS(klass);
>  
>      k->realize = apic_realize;
> +    k->unrealize = apic_unrealize;
>      k->set_base = apic_set_base;
>      k->set_tpr = apic_set_tpr;
>      k->get_tpr = apic_get_tpr;
> diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
> index 029f67d..8d17be1 100644
> --- a/hw/intc/apic_common.c
> +++ b/hw/intc/apic_common.c
> @@ -289,12 +289,13 @@ static int apic_load_old(QEMUFile *f, void *opaque, int version_id)
>      return 0;
>  }
>  
> +static int apic_no;
> +
some apic code still assumes that index in local_apics[] is APIC ID, so
apic_no and related stuff won't work with arbitrary CPU hotadd (i.e. arbitrary APIC ID)
to make it work the APICCommonState.idx should be dropped altogether and
replaced with apic_id.

I addition intc/apic.c is designed for APIC ID 8-bit max, we probably should add
some assert there so it wouldn't break silently when APIC ID goes above this
maximum.

>  static void apic_common_realize(DeviceState *dev, Error **errp)
>  {
>      APICCommonState *s = APIC_COMMON(dev);
>      APICCommonClass *info;
>      static DeviceState *vapic;
> -    static int apic_no;
>      static bool mmio_registered;
>  
>      if (apic_no >= MAX_APICS) {
> @@ -324,6 +325,25 @@ static void apic_common_realize(DeviceState *dev, Error **errp)
>  
>  }
>  
> +static void apic_common_unrealize(DeviceState *dev, Error **errp)
> +{
> +    APICCommonState *s = APIC_COMMON(dev);
> +    APICCommonClass *info = APIC_COMMON_GET_CLASS(s);
> +
> +    if (apic_no <= 0) {
> +        error_setg(errp, "%s exit failed.",
> +                   object_get_typename(OBJECT(dev)));
> +        return;
> +    }
> +    apic_no--;
> +
> +    info->unrealize(dev, errp);
> +
> +    if (apic_report_tpr_access && info->enable_tpr_reporting) {
> +        info->enable_tpr_reporting(s, false);
> +    }
what about unrealizing vapic?


> +}
> +
>  static void apic_dispatch_pre_save(void *opaque)
>  {
>      APICCommonState *s = APIC_COMMON(opaque);
> @@ -394,6 +414,7 @@ static void apic_common_class_init(ObjectClass *klass, void *data)
>      dc->reset = apic_reset_common;
>      dc->props = apic_properties_common;
>      idc->realize = apic_common_realize;
> +    idc->unrealize = apic_common_unrealize;
>      /*
>       * Reason: APIC and CPU need to be wired up by
>       * x86_cpu_apic_create()
> diff --git a/include/hw/cpu/icc_bus.h b/include/hw/cpu/icc_bus.h
> index 98a979f..75ed309 100644
> --- a/include/hw/cpu/icc_bus.h
> +++ b/include/hw/cpu/icc_bus.h
> @@ -67,6 +67,7 @@ typedef struct ICCDeviceClass {
>      /*< public >*/
>  
>      DeviceRealize realize;
> +    DeviceUnrealize unrealize;
>  } ICCDeviceClass;
>  
>  #define TYPE_ICC_DEVICE "icc-device"
> diff --git a/include/hw/i386/apic_internal.h b/include/hw/i386/apic_internal.h
> index 2c91609..6c9e390 100644
> --- a/include/hw/i386/apic_internal.h
> +++ b/include/hw/i386/apic_internal.h
> @@ -82,6 +82,7 @@ typedef struct APICCommonClass
>      ICCDeviceClass parent_class;
>  
>      DeviceRealize realize;
> +    DeviceUnrealize unrealize;
>      void (*set_base)(APICCommonState *s, uint64_t val);
>      void (*set_tpr)(APICCommonState *s, uint8_t val);
>      uint8_t (*get_tpr)(APICCommonState *s);
> diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
> index 71a1b97..2239105 100644
> --- a/target-i386/cpu-qom.h
> +++ b/target-i386/cpu-qom.h
> @@ -65,6 +65,7 @@ typedef struct X86CPUClass {
>      bool kvm_required;
>  
>      DeviceRealize parent_realize;
> +    DeviceUnrealize parent_unrealize;
>      void (*parent_reset)(CPUState *cpu);
>  } X86CPUClass;
>  
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index 5255ddb..72a94a6 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -2712,10 +2712,32 @@ static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
>          return;
>      }
>  }
> +
> +static void x86_cpu_apic_unrealize(X86CPU *cpu, Error **errp)
> +{
> +    Error *local_err = NULL;
> +
> +    if (cpu->apic_state == NULL) {
> +        return;
> +    }
> +
> +    object_property_set_bool(OBJECT(cpu->apic_state),
> +                             false, "realized", &local_err);
> +    if (local_err != NULL) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    vmstate_unregister(NULL, &vmstate_apic_common, cpu->apic_state);
this should be done by device_unrealize when APIC is being unrealized.

> +    object_unparent(OBJECT(cpu->apic_state));
> +}
>  #else
>  static void x86_cpu_apic_realize(X86CPU *cpu, Error **errp)
>  {
>  }
> +static void x86_cpu_apic_unrealize(X86CPU *cpu, Error **errp)
> +{
> +}
>  #endif
>  
>  static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
> @@ -2778,6 +2800,27 @@ out:
>      }
>  }
>  
> +static void x86_cpu_unrealizefn(DeviceState *dev, Error **errp)
> +{
> +    X86CPU *cpu = X86_CPU(dev);
> +    CPUClass *cc = CPU_GET_CLASS(dev);
> +    Error *local_err = NULL;
> +
> +    if (qdev_get_vmsd(DEVICE(cpu)) == NULL) {
> +        vmstate_unregister(NULL, &vmstate_cpu_common, cpu);
> +    }
> +
> +    if (cc->vmsd != NULL) {
> +        vmstate_unregister(NULL, cc->vmsd, cpu);
> +    }
I don't recall which variant x86cpu uses but it probably should be
one of above
or even better, make device_set_realized()->vmstate_[un]register*() work
wit x86cpu if possible.

> +
> +    x86_cpu_apic_unrealize(cpu, &local_err);
> +    if (local_err != NULL) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +}
> +
>  /* Enables contiguous-apic-ID mode, for compatibility */
>  static bool compat_apic_id_mode;
>  
> @@ -2957,7 +3000,9 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
>      DeviceClass *dc = DEVICE_CLASS(oc);
>  
>      xcc->parent_realize = dc->realize;
> +    xcc->parent_unrealize = dc->unrealize;
>      dc->realize = x86_cpu_realizefn;
> +    dc->unrealize = x86_cpu_unrealizefn;
>      dc->bus_type = TYPE_ICC_BUS;
>      dc->props = x86_cpu_properties;
>