plugins: Free CPUPluginState before destroying vCPU state

cpu::plugin_state is allocated in cpu_common_initfn() when
the vCPU state is created. Release it in cpu_common_finalize()
when we are done.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240606124010.2460-3-philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240705084047.857176-29-alex.bennee@linaro.org>

hw/core/cpu-common.c

@@ -283,6 +283,11 @@ static void cpu_common_finalize(Object *obj)
 {
     CPUState *cpu = CPU(obj);
 
+#ifdef CONFIG_PLUGIN
+    if (tcg_enabled()) {
+        g_free(cpu->plugin_state);
+    }
+#endif
     g_array_free(cpu->gdb_regs, TRUE);
     qemu_lockcnt_destroy(&cpu->in_ioctl_lock);
     qemu_mutex_destroy(&cpu->work_mutex);

include/qemu/plugin.h

@@ -149,6 +149,9 @@ struct CPUPluginState {
 
 /**
  * qemu_plugin_create_vcpu_state: allocate plugin state
+ *
+ * The returned data must be released with g_free()
+ * when no longer required.
  */
 CPUPluginState *qemu_plugin_create_vcpu_state(void);