cpu: Add qemu_for_each_cpu()

Wrapper to avoid open-coded loops and to make CPUState iteration
independent of CPUArchState.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

include/qom/cpu.h

@@ -215,6 +215,15 @@ bool cpu_is_stopped(CPUState *cpu);
  */
 void run_on_cpu(CPUState *cpu, void (*func)(void *data), void *data);
 
+/**
+ * qemu_for_each_cpu:
+ * @func: The function to be executed.
+ * @data: Data to pass to the function.
+ *
+ * Executes @func for each CPU.
+ */
+void qemu_for_each_cpu(void (*func)(CPUState *cpu, void *data), void *data);
+
 /**
  * qemu_get_cpu:
  * @index: The CPUState@cpu_index value of the CPU to obtain.