[PATCH v2 1/2] cpus: Introduce cpu_is_of_type() helper

[Philippe Mathieu-Daudé]

Introduce a helper to check whether a vCPU instance is from
a certain QOM parent type.
We don't need to use the type-safe QOM cast macros and can
directly access the cached CPUClass (see commit 6fbdff87062
"cpu: cache CPUClass in CPUState for hot code paths").

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/core/cpu.h | 9 +++++++++
 cpu-common.c          | 5 +++++
 2 files changed, 14 insertions(+)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index c3ca0babcb3..d55d4802ceb 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -795,6 +795,15 @@ ObjectClass *cpu_class_by_name(const char *typename, const 
char *cpu_model);
  */
 char *cpu_model_from_type(const char *typename);
 
+/**
+ * cpu_is_of_type: Check if a CPU instance implement a QOM type
+ * @cpu: The CPU to be added to the list of CPUs.
+ * @typename: The CPU type.
+ *
+ * Returns: %true if @cpu is a QOM child of type @typename.
+ */
+bool cpu_is_of_type(CPUState *cpu, const char *typename);
+
 /**
  * cpu_create:
  * @typename: The CPU type.
diff --git a/cpu-common.c b/cpu-common.c
index 4248b2d727e..2541a81ef87 100644
--- a/cpu-common.c
+++ b/cpu-common.c
@@ -455,3 +455,8 @@ void cpu_breakpoint_remove_all(CPUState *cpu, int mask)
         }
     }
 }
+
+bool cpu_is_of_type(CPUState *cpu, const char *typename)
+{
+    return !!object_class_dynamic_cast((ObjectClass *)cpu->cc, typename);
+}
-- 
2.47.1