cpu: Introduce get_arch_id() method and override it for X86CPU

get_arch_id() adds possibility for generic code to get a guest-visible
CPU ID without accessing CPUArchState.
If derived classes don't override it, it will return cpu_index.

Override it on target-i386 in X86CPU to return the APIC ID.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: liguang <lig.fnst@cn.fujitsu.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

3 files changed, 18 insertions, 0 deletions

diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index ac93dcec66..1b4de17415 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -45,6 +45,7 @@ typedef struct CPUState CPUState;
  * instantiatable CPU type.
  * @reset: Callback to reset the #CPUState to its initial state.
  * @do_interrupt: Callback for interrupt handling.
+ * @get_arch_id: Callback for getting architecture-dependent CPU ID.
  * @vmsd: State description for migration.
  *
  * Represents a CPU family or model.
@@ -58,6 +59,7 @@ typedef struct CPUClass {
 
     void (*reset)(CPUState *cpu);
     void (*do_interrupt)(CPUState *cpu);
+    int64_t (*get_arch_id)(CPUState *cpu);
 
     const struct VMStateDescription *vmsd;
 } CPUClass;
diff --git a/qom/cpu.c b/qom/cpu.c
index 34fa8054b2..9a4457ba1b 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -78,6 +78,11 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
     }
 }
 
+static int64_t cpu_common_get_arch_id(CPUState *cpu)
+{
+    return cpu->cpu_index;
+}
+
 static void cpu_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -85,6 +90,7 @@ static void cpu_class_init(ObjectClass *klass, void *data)
 
     k->class_by_name = cpu_common_class_by_name;
     k->reset = cpu_common_reset;
+    k->get_arch_id = cpu_common_get_arch_id;
     dc->realize = cpu_common_realizefn;
     dc->no_user = 1;
 }
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index e2302d8b05..f34ba23dad 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2272,6 +2272,14 @@ static void x86_cpu_initfn(Object *obj)
     }
 }
 
+static int64_t x86_cpu_get_arch_id(CPUState *cs)
+{
+    X86CPU *cpu = X86_CPU(cs);
+    CPUX86State *env = &cpu->env;
+
+    return env->cpuid_apic_id;
+}
+
 static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
 {
     X86CPUClass *xcc = X86_CPU_CLASS(oc);
@@ -2286,6 +2294,8 @@ static void x86_cpu_common_class_init(ObjectClass *oc, void *data)
 
     cc->do_interrupt = x86_cpu_do_interrupt;
     cpu_class_set_vmsd(cc, &vmstate_x86_cpu);
+
+    cc->get_arch_id = x86_cpu_get_arch_id;
 }
 
 static const TypeInfo x86_cpu_type_info = {