trace: convert stderr backend to log

[Also update .travis.yml --enable-trace-backends=stderr
--Stefan]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-id: 1452174932-28657-10-git-send-email-den@openvz.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

.travis.yml

@@ -78,7 +78,7 @@ matrix:
       compiler: gcc
     # All the trace backends (apart from dtrace)
     - env: TARGETS=i386-softmmu,x86_64-softmmu
-           EXTRA_CONFIG="--enable-trace-backends=stderr"
+           EXTRA_CONFIG="--enable-trace-backends=log"
       compiler: gcc
     - env: TARGETS=i386-softmmu,x86_64-softmmu
            EXTRA_CONFIG="--enable-trace-backends=simple"

configure

@@ -5445,8 +5445,8 @@ if have_backend "simple"; then
   # Set the appropriate trace file.
   trace_file="\"$trace_file-\" FMT_pid"
 fi
-if have_backend "stderr"; then
-  echo "CONFIG_TRACE_STDERR=y" >> $config_host_mak
+if have_backend "log"; then
+  echo "CONFIG_TRACE_LOG=y" >> $config_host_mak
 fi
 if have_backend "ust"; then
   echo "CONFIG_TRACE_UST=y" >> $config_host_mak

include/qemu/log.h

@@ -45,6 +45,7 @@ static inline bool qemu_log_separate(void)
 #define CPU_LOG_MMU        (1 << 12)
 #define CPU_LOG_TB_NOCHAIN (1 << 13)
 #define CPU_LOG_PAGE       (1 << 14)
+#define LOG_TRACE          (1 << 15)
 
 /* Returns true if a bit is set in the current loglevel mask
  */

scripts/tracetool/backend/log.py

@@ -25,6 +25,7 @@ def generate_h_begin(events):
         '#include <sys/types.h>',
         '#include <unistd.h>',
         '#include "trace/control.h"',
+        '#include "qemu/log.h"',
         '')
 
 
@@ -36,10 +37,10 @@ def generate_h(event):
     out('    if (trace_event_get_state(%(event_id)s)) {',
         '        struct timeval _now;',
         '        gettimeofday(&_now, NULL);',
-        '        fprintf(stderr, "%%d@%%zd.%%06zd:%(name)s " %(fmt)s "\\n",',
-        '                        getpid(),',
-        '                        (size_t)_now.tv_sec, (size_t)_now.tv_usec',
-        '                        %(argnames)s);',
+        '        qemu_log_mask(LOG_TRACE, "%%d@%%zd.%%06zd:%(name)s " %(fmt)s "\\n",',
+        '                      getpid(),',
+        '                      (size_t)_now.tv_sec, (size_t)_now.tv_usec',
+        '                      %(argnames)s);',
         '    }',
         event_id="TRACE_" + event.name.upper(),
         name=event.name,

trace/control.c

@@ -14,6 +14,9 @@
 #ifdef CONFIG_TRACE_FTRACE
 #include "trace/ftrace.h"
 #endif
+#ifdef CONFIG_TRACE_LOG
+#include "qemu/log.h"
+#endif
 #include "qemu/error-report.h"
 
 int trace_events_enabled_count;
@@ -174,6 +177,13 @@ void trace_init_file(const char *file)
 {
 #ifdef CONFIG_TRACE_SIMPLE
     st_set_trace_file(file);
+#elif defined CONFIG_TRACE_LOG
+    /* If both the simple and the log backends are enabled, "-trace file"
+     * only applies to the simple backend; use "-D" for the log backend.
+     */
+    if (file) {
+        qemu_set_log_filename(file);
+    }
 #else
     if (file) {
         fprintf(stderr, "error: -trace file=...: "

util/log.c

@@ -51,6 +51,9 @@ void qemu_log_mask(int mask, const char *fmt, ...)
 void do_qemu_set_log(int log_flags, bool use_own_buffers)
 {
     qemu_loglevel = log_flags;
+#ifdef CONFIG_TRACE_LOG
+    qemu_loglevel |= LOG_TRACE;
+#endif
     if (qemu_loglevel && !qemu_logfile) {
         if (logfilename) {
             qemu_logfile = fopen(logfilename, log_append ? "a" : "w");

vl.c

@@ -4115,6 +4115,8 @@ int main(int argc, char **argv, char **envp)
             exit(1);
         }
         qemu_set_log(mask);
+    } else {
+        qemu_set_log(0);
     }
 
     if (!trace_init_backends()) {