cpus: Trace cpu_exec_start() and cpu_exec_end() calls

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

cpu-common.c

@@ -249,6 +249,8 @@ void end_exclusive(void)
 /* Wait for exclusive ops to finish, and begin cpu execution.  */
 void cpu_exec_start(CPUState *cpu)
 {
+    trace_cpu_exec_start(cpu->cpu_index);
+
     qatomic_set(&cpu->running, true);
 
     /* Write cpu->running before reading pending_cpus.  */
@@ -319,6 +321,7 @@ void cpu_exec_end(CPUState *cpu)
             }
         }
     }
+    trace_cpu_exec_end(cpu->cpu_index);
 }
 
 void async_safe_run_on_cpu(CPUState *cpu, run_on_cpu_func func,