[Qemu-devel] [RFC PATCH 0/3] cpu: add device_add foo-x86_64-cpu support

[Qemu-devel] [RFC PATCH 0/3] cpu: add device_add foo-x86_64-cpu support

[Gu Zheng]

This series is based on the previous patchset from Chen Fan:
https://lists.nongnu.org/archive/html/qemu-devel/2014-05/msg02360.html

This patches try to make cpu hotplug with device_add, and make
"-device foo-x86_64-cpu" available，also we can set apic-id
property with command line, if without setting apic-id property,
we offer the first unoccupied apic id as the default new apic id.
When hotplug cpu with device_add, additional check of APIC ID will be
done after cpu object initialization which was different from
'cpu_add' command that check 'ids' at the beginning.

Chen Fan (2):
  cpu: introduce CpuTopoInfo structure for argument simplification
  cpu: add device_add foo-x86_64-cpu support

Gu Zheng (1):
  qom/cpu: move register_vmstate to common CPUClass.realizefn

 exec.c                          |   32 ++++++++++-------
 hw/intc/apic_common.c           |    3 +-
 include/hw/i386/apic_internal.h |    3 +-
 include/qom/cpu.h               |    3 ++
 qdev-monitor.c                  |    1 +
 qom/cpu.c                       |    2 +
 target-i386/cpu.c               |   76 ++++++++++++++++++++++++++++++++++++--
 target-i386/topology.h          |   51 ++++++++++++++++++--------
 8 files changed, 135 insertions(+), 36 deletions(-)

-- 
1.7.7

[Qemu-devel] [RFC PATCH 1/3] cpu: introduce CpuTopoInfo structure for argument simplification

[Gu Zheng]

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
---
 target-i386/topology.h |   33 +++++++++++++++++----------------
 1 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/target-i386/topology.h b/target-i386/topology.h
index 07a6c5f..e9ff89c 100644
--- a/target-i386/topology.h
+++ b/target-i386/topology.h
@@ -47,6 +47,12 @@
  */
 typedef uint32_t apic_id_t;
 
+typedef struct X86CPUTopoInfo {
+    unsigned pkg_id;
+    unsigned core_id;
+    unsigned smt_id;
+} X86CPUTopoInfo;
+
 /* Return the bit width needed for 'count' IDs
  */
 static unsigned apicid_bitwidth_for_count(unsigned count)
@@ -92,13 +98,11 @@ static inline unsigned apicid_pkg_offset(unsigned nr_cores, unsigned nr_threads)
  */
 static inline apic_id_t apicid_from_topo_ids(unsigned nr_cores,
                                              unsigned nr_threads,
-                                             unsigned pkg_id,
-                                             unsigned core_id,
-                                             unsigned smt_id)
+                                             const X86CPUTopoInfo *topo)
 {
-    return (pkg_id  << apicid_pkg_offset(nr_cores, nr_threads)) |
-           (core_id << apicid_core_offset(nr_cores, nr_threads)) |
-           smt_id;
+    return (topo->pkg_id  << apicid_pkg_offset(nr_cores, nr_threads)) |
+           (topo->core_id << apicid_core_offset(nr_cores, nr_threads)) |
+           topo->smt_id;
 }
 
 /* Calculate thread/core/package IDs for a specific topology,
@@ -107,14 +111,12 @@ static inline apic_id_t apicid_from_topo_ids(unsigned nr_cores,
 static inline void x86_topo_ids_from_idx(unsigned nr_cores,
                                          unsigned nr_threads,
                                          unsigned cpu_index,
-                                         unsigned *pkg_id,
-                                         unsigned *core_id,
-                                         unsigned *smt_id)
+                                         X86CPUTopoInfo *topo)
 {
     unsigned core_index = cpu_index / nr_threads;
-    *smt_id = cpu_index % nr_threads;
-    *core_id = core_index % nr_cores;
-    *pkg_id = core_index / nr_cores;
+    topo->smt_id = cpu_index % nr_threads;
+    topo->core_id = core_index % nr_cores;
+    topo->pkg_id = core_index / nr_cores;
 }
 
 /* Make APIC ID for the CPU 'cpu_index'
@@ -125,10 +127,9 @@ static inline apic_id_t x86_apicid_from_cpu_idx(unsigned nr_cores,
                                                 unsigned nr_threads,
                                                 unsigned cpu_index)
 {
-    unsigned pkg_id, core_id, smt_id;
-    x86_topo_ids_from_idx(nr_cores, nr_threads, cpu_index,
-                          &pkg_id, &core_id, &smt_id);
-    return apicid_from_topo_ids(nr_cores, nr_threads, pkg_id, core_id, smt_id);
+    X86CPUTopoInfo topo;
+    x86_topo_ids_from_idx(nr_cores, nr_threads, cpu_index, &topo);
+    return apicid_from_topo_ids(nr_cores, nr_threads, &topo);
 }
 
 #endif /* TARGET_I386_TOPOLOGY_H */
-- 
1.7.7

Re: [Qemu-devel] [RFC PATCH 1/3] cpu: introduce CpuTopoInfo structure for argument simplification

[Gu Zheng]

Correct the author.
From: Chen Fan <chen.fan.fnst@cn.fujitsu.com>

On 06/27/2014 06:03 PM, Gu Zheng wrote:

> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
> ---
>  target-i386/topology.h |   33 +++++++++++++++++----------------
>  1 files changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/target-i386/topology.h b/target-i386/topology.h
> index 07a6c5f..e9ff89c 100644
> --- a/target-i386/topology.h
> +++ b/target-i386/topology.h
> @@ -47,6 +47,12 @@
>   */
>  typedef uint32_t apic_id_t;
>  
> +typedef struct X86CPUTopoInfo {
> +    unsigned pkg_id;
> +    unsigned core_id;
> +    unsigned smt_id;
> +} X86CPUTopoInfo;
> +
>  /* Return the bit width needed for 'count' IDs
>   */
>  static unsigned apicid_bitwidth_for_count(unsigned count)
> @@ -92,13 +98,11 @@ static inline unsigned apicid_pkg_offset(unsigned nr_cores, unsigned nr_threads)
>   */
>  static inline apic_id_t apicid_from_topo_ids(unsigned nr_cores,
>                                               unsigned nr_threads,
> -                                             unsigned pkg_id,
> -                                             unsigned core_id,
> -                                             unsigned smt_id)
> +                                             const X86CPUTopoInfo *topo)
>  {
> -    return (pkg_id  << apicid_pkg_offset(nr_cores, nr_threads)) |
> -           (core_id << apicid_core_offset(nr_cores, nr_threads)) |
> -           smt_id;
> +    return (topo->pkg_id  << apicid_pkg_offset(nr_cores, nr_threads)) |
> +           (topo->core_id << apicid_core_offset(nr_cores, nr_threads)) |
> +           topo->smt_id;
>  }
>  
>  /* Calculate thread/core/package IDs for a specific topology,
> @@ -107,14 +111,12 @@ static inline apic_id_t apicid_from_topo_ids(unsigned nr_cores,
>  static inline void x86_topo_ids_from_idx(unsigned nr_cores,
>                                           unsigned nr_threads,
>                                           unsigned cpu_index,
> -                                         unsigned *pkg_id,
> -                                         unsigned *core_id,
> -                                         unsigned *smt_id)
> +                                         X86CPUTopoInfo *topo)
>  {
>      unsigned core_index = cpu_index / nr_threads;
> -    *smt_id = cpu_index % nr_threads;
> -    *core_id = core_index % nr_cores;
> -    *pkg_id = core_index / nr_cores;
> +    topo->smt_id = cpu_index % nr_threads;
> +    topo->core_id = core_index % nr_cores;
> +    topo->pkg_id = core_index / nr_cores;
>  }
>  
>  /* Make APIC ID for the CPU 'cpu_index'
> @@ -125,10 +127,9 @@ static inline apic_id_t x86_apicid_from_cpu_idx(unsigned nr_cores,
>                                                  unsigned nr_threads,
>                                                  unsigned cpu_index)
>  {
> -    unsigned pkg_id, core_id, smt_id;
> -    x86_topo_ids_from_idx(nr_cores, nr_threads, cpu_index,
> -                          &pkg_id, &core_id, &smt_id);
> -    return apicid_from_topo_ids(nr_cores, nr_threads, pkg_id, core_id, smt_id);
> +    X86CPUTopoInfo topo;
> +    x86_topo_ids_from_idx(nr_cores, nr_threads, cpu_index, &topo);
> +    return apicid_from_topo_ids(nr_cores, nr_threads, &topo);
>  }
>  
>  #endif /* TARGET_I386_TOPOLOGY_H */

[Qemu-devel] [RFC PATCH 2/3] qom/cpu: move register_vmstate to common CPUClass.realizefn

[Gu Zheng]

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.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
---
 exec.c                          |   32 +++++++++++++++++++-------------
 hw/intc/apic_common.c           |    3 +--
 include/hw/i386/apic_internal.h |    3 ++-
 include/qom/cpu.h               |    2 ++
 qom/cpu.c                       |    2 ++
 target-i386/cpu.c               |   12 +++++++++---
 6 files changed, 35 insertions(+), 19 deletions(-)

diff --git a/exec.c b/exec.c
index 4e179a6..61ad996 100644
--- a/exec.c
+++ b/exec.c
@@ -468,10 +468,28 @@ 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;
 
@@ -494,18 +512,6 @@ 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..8a645cf 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
@@ -136,7 +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);
 void apic_enable_tpr_access_reporting(DeviceState *d, bool enable);
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 4b352a2..87eecd2 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -548,6 +548,8 @@ 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 fada2d4..5158343 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -296,6 +296,8 @@ 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 8983457..10f6d53 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2554,13 +2554,19 @@ 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);
+
+    if (qdev_init(apic_state)) {
         error_setg(errp, "APIC device '%s' could not be initialized",
-                   object_get_typename(OBJECT(cpu->apic_state)));
+            object_get_typename(OBJECT(cpu->apic_state)));
         return;
     }
 }
-- 
1.7.7

[Qemu-devel] [RFC PATCH 3/3] cpu: add device_add foo-x86_64-cpu support

[Gu Zheng]

From: Chen Fan <chen.fan.fnst@cn.fujitsu.com>

Add support to device_add foo-x86_64-cpu, and additional checks of
apic id are added into x86_cpuid_set_apic_id() and x86_cpu_apic_create()
for duplicate. Besides, in order to support "device/device_add foo-x86_64-cpu"
which without specified apic id, we add a new function get_free_apic_id() to
provide the first free apid id each time to avoid apic id duplicate.

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
---
 include/qom/cpu.h      |    1 +
 qdev-monitor.c         |    1 +
 target-i386/cpu.c      |   64 +++++++++++++++++++++++++++++++++++++++++++++++-
 target-i386/topology.h |   18 +++++++++++++
 4 files changed, 83 insertions(+), 1 deletions(-)

diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 87eecd2..87bd652 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -291,6 +291,7 @@ struct CPUState {
 QTAILQ_HEAD(CPUTailQ, CPUState);
 extern struct CPUTailQ cpus;
 #define CPU_NEXT(cpu) QTAILQ_NEXT(cpu, node)
+#define CPU_REMOVE(cpu) QTAILQ_REMOVE(&cpus, cpu, node)
 #define CPU_FOREACH(cpu) QTAILQ_FOREACH(cpu, &cpus, node)
 #define CPU_FOREACH_SAFE(cpu, next_cpu) \
     QTAILQ_FOREACH_SAFE(cpu, &cpus, node, next_cpu)
diff --git a/qdev-monitor.c b/qdev-monitor.c
index f87f3d8..48327c8 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -24,6 +24,7 @@
 #include "qmp-commands.h"
 #include "sysemu/arch_init.h"
 #include "qemu/config-file.h"
+#include "qom/object_interfaces.h"
 
 /*
  * Aliases were a bad idea from the start.  Let's keep them
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 10f6d53..b058b70 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -49,6 +49,7 @@
 #include "hw/i386/apic_internal.h"
 #endif
 
+#include "qom/object_interfaces.h"
 
 /* Cache topology CPUID constants: */
 
@@ -1550,6 +1551,7 @@ static void x86_cpuid_set_apic_id(Object *obj, Visitor *v, void *opaque,
     const int64_t max = UINT32_MAX;
     Error *error = NULL;
     int64_t value;
+    X86CPUTopoInfo topo;
 
     if (dev->realized) {
         error_setg(errp, "Attempt to set property '%s' on '%s' after "
@@ -1569,10 +1571,24 @@ static void x86_cpuid_set_apic_id(Object *obj, Visitor *v, void *opaque,
         return;
     }
 
+    if (value > x86_cpu_apic_id_from_index(max_cpus - 1)) {
+        error_setg(errp, "CPU with APIC ID %" PRIi64
+                   " is more than MAX APIC ID limits", value);
+        return;
+    }
+
+    x86_topo_ids_from_apic_id(smp_cores, smp_threads, value, &topo);
+    if (topo.smt_id >= smp_threads || topo.core_id >= smp_cores) {
+        error_setg(errp, "CPU with APIC ID %" PRIi64 " does not match "
+                   "topology configuration.", value);
+        return;
+    }
+
     if ((value != cpu->env.cpuid_apic_id) && cpu_exists(value)) {
         error_setg(errp, "CPU with APIC ID %" PRIi64 " exists", value);
         return;
     }
+
     cpu->env.cpuid_apic_id = value;
 }
 
@@ -1994,12 +2010,22 @@ out:
     return cpu;
 }
 
+static void x86_cpu_cpudef_instance_init(Object *obj)
+{
+    DeviceState *dev = DEVICE(obj);
+
+    dev->hotplugged = true;
+}
+
 static void x86_cpu_cpudef_class_init(ObjectClass *oc, void *data)
 {
     X86CPUDefinition *cpudef = data;
     X86CPUClass *xcc = X86_CPU_CLASS(oc);
+    DeviceClass *dc = DEVICE_CLASS(oc);
 
     xcc->cpu_def = cpudef;
+
+    dc->cannot_instantiate_with_device_add_yet = false;
 }
 
 static void x86_register_cpudef_type(X86CPUDefinition *def)
@@ -2008,6 +2034,8 @@ static void x86_register_cpudef_type(X86CPUDefinition *def)
     TypeInfo ti = {
         .name = typename,
         .parent = TYPE_X86_CPU,
+        .instance_size = sizeof(X86CPU),
+        .instance_init = x86_cpu_cpudef_instance_init,
         .class_init = x86_cpu_cpudef_class_init,
         .class_data = def,
     };
@@ -2544,8 +2572,17 @@ static void x86_cpu_apic_create(X86CPU *cpu, Error **errp)
         return;
     }
 
+    if (env->cpuid_apic_id > x86_cpu_apic_id_from_index(max_cpus - 1)) {
+        error_setg(errp, "CPU with APIC ID %" PRIi32
+                    " is more than MAX APIC ID:%" PRIi32,
+                    env->cpuid_apic_id,
+                    x86_cpu_apic_id_from_index(max_cpus - 1));
+        return;
+    }
+
     object_property_add_child(OBJECT(cpu), "apic",
                               OBJECT(cpu->apic_state), NULL);
+
     qdev_prop_set_uint8(cpu->apic_state, "id", env->cpuid_apic_id);
     /* TODO: convert to link<> */
     apic = APIC_COMMON(cpu->apic_state);
@@ -2681,6 +2718,21 @@ uint32_t x86_cpu_apic_id_from_index(unsigned int cpu_index)
     }
 }
 
+static uint32_t get_free_apic_id(void)
+{
+    int i;
+
+    for (i = 0; i < max_cpus; i++) {
+        uint32_t id = x86_cpu_apic_id_from_index(i);
+
+        if (!cpu_exists(id)) {
+            return id;
+        }
+    }
+
+    return x86_cpu_apic_id_from_index(max_cpus);
+}
+
 static void x86_cpu_initfn(Object *obj)
 {
     CPUState *cs = CPU(obj);
@@ -2688,7 +2740,9 @@ static void x86_cpu_initfn(Object *obj)
     X86CPUClass *xcc = X86_CPU_GET_CLASS(obj);
     CPUX86State *env = &cpu->env;
     static int inited;
+    uint32_t value;
 
+    value = get_free_apic_id();
     cs->env_ptr = env;
     cpu_exec_init(env);
 
@@ -2727,7 +2781,7 @@ static void x86_cpu_initfn(Object *obj)
                         NULL, NULL, (void *)cpu->filtered_features, NULL);
 
     cpu->hyperv_spinlock_attempts = HYPERV_SPINLOCK_NEVER_RETRY;
-    env->cpuid_apic_id = x86_cpu_apic_id_from_index(cs->cpu_index);
+    env->cpuid_apic_id = value;
 
     x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
 
@@ -2741,6 +2795,13 @@ static void x86_cpu_initfn(Object *obj)
     }
 }
 
+static void x86_cpu_finalizefn(Object *obj)
+{
+    CPUState *cs = CPU(obj);
+
+    CPU_REMOVE(cs);
+}
+
 static int64_t x86_cpu_get_arch_id(CPUState *cs)
 {
     X86CPU *cpu = X86_CPU(cs);
@@ -2841,6 +2902,7 @@ static const TypeInfo x86_cpu_type_info = {
     .parent = TYPE_CPU,
     .instance_size = sizeof(X86CPU),
     .instance_init = x86_cpu_initfn,
+    .instance_finalize = x86_cpu_finalizefn,
     .abstract = true,
     .class_size = sizeof(X86CPUClass),
     .class_init = x86_cpu_common_class_init,
diff --git a/target-i386/topology.h b/target-i386/topology.h
index e9ff89c..dcb4988 100644
--- a/target-i386/topology.h
+++ b/target-i386/topology.h
@@ -132,4 +132,22 @@ static inline apic_id_t x86_apicid_from_cpu_idx(unsigned nr_cores,
     return apicid_from_topo_ids(nr_cores, nr_threads, &topo);
 }
 
+/* Calculate CPU topology based on CPU APIC ID.
+ */
+static inline void x86_topo_ids_from_apic_id(unsigned nr_cores,
+                                             unsigned nr_threads,
+                                             apic_id_t apic_id,
+                                             X86CPUTopoInfo *topo)
+{
+    unsigned offset_mask;
+    topo->pkg_id = apic_id >> apicid_pkg_offset(nr_cores, nr_threads);
+
+    offset_mask = (1L << apicid_pkg_offset(nr_cores, nr_threads)) - 1;
+    topo->core_id = (apic_id & offset_mask)
+                     >> apicid_core_offset(nr_cores, nr_threads);
+
+    offset_mask = (1L << apicid_core_offset(nr_cores, nr_threads)) - 1;
+    topo->smt_id = apic_id & offset_mask;
+}
+
 #endif /* TARGET_I386_TOPOLOGY_H */
-- 
1.7.7