[libvirt-users] how to read the libvirt log file

Hi folks, I need to trace how libvirt talk with qemu monitor, log everything when give command, but does anyone know what the format, and how to read the log file? for example: 2014-07-22 17:25:22.984+0000: 18571: debug : qemuMonitorIOProcess:356 : QEMU_MONITOR_IO_PROCESS: mon=0x7f733c000a40 buf={"timestamp": {"seconds": 1406049922, "microseconds": 983916}, "event": "STOP"} where to find the qemuMonitorIOProcess function, and what :356 means? Thanks very much! Best, Yuanzhen