On Thu, Jul 23, 2020 at 12:33:59AM -0500, Josh DuBois wrote:
> The simple trace backend is enabled / disabled with a call
> to st_set_trace_file_enabled().  When initializing tracing
> from the command-line, this must be enabled on startup.
> (Prior to db25d56c014aa1a9, command-line initialization of
> simple trace worked because every call to st_set_trace_file
> enabled tracing.)
> 
> Fixes: db25d56c014aa1a96319c663e0a60346a223b31e
> Signed-off-by: Josh DuBois <josh@joshdubois.com>
> ---
>  trace/control.c | 1 +
>  1 file changed, 1 insertion(+)

Thanks, applied to my tracing tree:
https://github.com/stefanha/qemu/commits/tracing

Stefan