port qemu-kvm's on_vcpu code

run_on_cpu allows to execute work on a given CPUState context.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/cpu-all.h b/cpu-all.h
index 52a1817..9efb8a9 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -821,6 +821,7 @@
 
 void cpu_single_step(CPUState *env, int enabled);
 void cpu_reset(CPUState *s);
+void run_on_cpu(CPUState *env, void (*func)(void *data), void *data);
 
 #define CPU_LOG_TB_OUT_ASM (1 << 0)
 #define CPU_LOG_TB_IN_ASM  (1 << 1)