| Specify tracing options. | 
 |  | 
 | @table @option | 
 | @item [enable=]@var{pattern} | 
 | Immediately enable events matching @var{pattern} | 
 | (either event name or a globbing pattern).  This option is only | 
 | available if QEMU has been compiled with the @var{simple}, @var{log} | 
 | or @var{ftrace} tracing backend.  To specify multiple events or patterns, | 
 | specify the @option{-trace} option multiple times. | 
 |  | 
 | Use @code{-trace help} to print a list of names of trace points. | 
 |  | 
 | @item events=@var{file} | 
 | Immediately enable events listed in @var{file}. | 
 | The file must contain one event name (as listed in the @file{trace-events-all} | 
 | file) per line; globbing patterns are accepted too.  This option is only | 
 | available if QEMU has been compiled with the @var{simple}, @var{log} or | 
 | @var{ftrace} tracing backend. | 
 |  | 
 | @item file=@var{file} | 
 | Log output traces to @var{file}. | 
 | This option is only available if QEMU has been compiled with | 
 | the @var{simple} tracing backend. | 
 | @end table |