[qemu-xen staging] trace/simple: Allow enabling simple traces from command line

[patchbot@xxxxxxx]

commit 1b7157be3a8c4300fc8044d40f4b2e64a152a1b4
Author:     Josh DuBois <duboisj@xxxxxxxxx>
AuthorDate: Thu Jul 23 00:33:59 2020 -0500
Commit:     Stefan Hajnoczi <stefanha@xxxxxxxxxx>
CommitDate: Wed Jul 29 16:39:56 2020 +0100

    trace/simple: Allow enabling simple traces from command line
    
    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@xxxxxxxxxxxxxx>
    Message-id: 20200723053359.256928-1-josh@xxxxxxxxxxxxxx
    Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
---
 trace/control.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/trace/control.c b/trace/control.c
index 2ffe000818..6558b5c906 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -225,6 +225,7 @@ void trace_init_file(const char *file)
 {
 #ifdef CONFIG_TRACE_SIMPLE
     st_set_trace_file(file);
+    st_set_trace_file_enabled(true);
 #elif defined CONFIG_TRACE_LOG
     /*
      * If both the simple and the log backends are enabled, "--trace file"
--
generated by git-patchbot for /home/xen/git/qemu-xen.git#staging