[Qemu-devel] [PATCH v8 05/14] trace: move backend-specific code into the trace/ directory

[Lluís]

Signed-off-by: Lluís Vilanova <address@hidden>
---
 Makefile          |    1 
 Makefile.objs     |    6 +
 scripts/tracetool |    2 
 simpletrace.c     |  355 -----------------------------------------------------
 simpletrace.h     |   48 -------
 trace/simple.c    |  355 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 trace/simple.h    |   48 +++++++
 vl.c              |    2 
 8 files changed, 410 insertions(+), 407 deletions(-)
 delete mode 100644 simpletrace.c
 delete mode 100644 simpletrace.h
 create mode 100644 trace/simple.c
 create mode 100644 trace/simple.h

diff --git a/Makefile b/Makefile
index 8606849..13be25a 100644
--- a/Makefile
+++ b/Makefile
@@ -209,6 +209,7 @@ clean:
        rm -Rf .libs
        rm -f slirp/*.o slirp/*.d audio/*.o audio/*.d block/*.o block/*.d 
net/*.o net/*.d fsdev/*.o fsdev/*.d ui/*.o ui/*.d qapi/*.o qapi/*.d qga/*.o 
qga/*.d
        rm -f qemu-img-cmds.h
+       rm -f trace/*.o trace/*.d
        rm -f trace.c trace.h trace.c-timestamp trace.h-timestamp
        rm -f trace-dtrace.dtrace trace-dtrace.dtrace-timestamp
        rm -f trace-dtrace.h trace-dtrace.h-timestamp
diff --git a/Makefile.objs b/Makefile.objs
index 833158b..4f8b0ed 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -372,16 +372,18 @@ trace-dtrace.lo: trace-dtrace.dtrace
        $(call quiet-command,$(LIBTOOL) --mode=compile --tag=CC dtrace -o $@ -G 
-s $<, "  lt GEN trace-dtrace.o")
 endif
 
-simpletrace.o: simpletrace.c $(GENERATED_HEADERS)
+trace/simple.o: trace/simple.c $(GENERATED_HEADERS)
 
 trace-obj-$(CONFIG_TRACE_DTRACE) += trace-dtrace.o
 ifneq ($(TRACE_BACKEND),dtrace)
 trace-obj-y = trace.o
 endif
 
-trace-obj-$(CONFIG_TRACE_SIMPLE) += simpletrace.o
+trace-nested-$(CONFIG_TRACE_SIMPLE) += simple.o
 trace-obj-$(CONFIG_TRACE_SIMPLE) += qemu-timer-common.o
 
+trace-obj-y += $(addprefix trace/, $(trace-nested-y))
+
 ######################################################################
 # smartcard
 
diff --git a/scripts/tracetool b/scripts/tracetool
index 2155a57..9ed4fae 100755
--- a/scripts/tracetool
+++ b/scripts/tracetool
@@ -158,7 +158,7 @@ linetoc_end_nop()
 linetoh_begin_simple()
 {
     cat <<EOF
-#include "simpletrace.h"
+#include "trace/simple.h"
 EOF
 
     simple_event_num=0
diff --git a/simpletrace.c b/simpletrace.c
deleted file mode 100644
index de355e9..0000000
--- a/simpletrace.c
+++ /dev/null
@@ -1,355 +0,0 @@
-/*
- * Simple trace backend
- *
- * Copyright IBM, Corp. 2010
- *
- * This work is licensed under the terms of the GNU GPL, version 2.  See
- * the COPYING file in the top-level directory.
- *
- */
-
-#include <stdlib.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <time.h>
-#include <signal.h>
-#include <pthread.h>
-#include "qemu-timer.h"
-#include "trace.h"
-
-/** Trace file header event ID */
-#define HEADER_EVENT_ID (~(uint64_t)0) /* avoids conflicting with 
TraceEventIDs */
-
-/** Trace file magic number */
-#define HEADER_MAGIC 0xf2b177cb0aa429b4ULL
-
-/** Trace file version number, bump if format changes */
-#define HEADER_VERSION 0
-
-/** Records were dropped event ID */
-#define DROPPED_EVENT_ID (~(uint64_t)0 - 1)
-
-/** Trace record is valid */
-#define TRACE_RECORD_VALID ((uint64_t)1 << 63)
-
-/** Trace buffer entry */
-typedef struct {
-    uint64_t event;
-    uint64_t timestamp_ns;
-    uint64_t x1;
-    uint64_t x2;
-    uint64_t x3;
-    uint64_t x4;
-    uint64_t x5;
-    uint64_t x6;
-} TraceRecord;
-
-enum {
-    TRACE_BUF_LEN = 4096,
-    TRACE_BUF_FLUSH_THRESHOLD = TRACE_BUF_LEN / 4,
-};
-
-/*
- * Trace records are written out by a dedicated thread.  The thread waits for
- * records to become available, writes them out, and then waits again.
- */
-static pthread_mutex_t trace_lock = PTHREAD_MUTEX_INITIALIZER;
-static pthread_cond_t trace_available_cond = PTHREAD_COND_INITIALIZER;
-static pthread_cond_t trace_empty_cond = PTHREAD_COND_INITIALIZER;
-static bool trace_available;
-static bool trace_writeout_enabled;
-
-static TraceRecord trace_buf[TRACE_BUF_LEN];
-static unsigned int trace_idx;
-static FILE *trace_fp;
-static char *trace_file_name = NULL;
-
-/**
- * Read a trace record from the trace buffer
- *
- * @idx         Trace buffer index
- * @record      Trace record to fill
- *
- * Returns false if the record is not valid.
- */
-static bool get_trace_record(unsigned int idx, TraceRecord *record)
-{
-    if (!(trace_buf[idx].event & TRACE_RECORD_VALID)) {
-        return false;
-    }
-
-    __sync_synchronize(); /* read memory barrier before accessing record */
-
-    *record = trace_buf[idx];
-    record->event &= ~TRACE_RECORD_VALID;
-    return true;
-}
-
-/**
- * Kick writeout thread
- *
- * @wait        Whether to wait for writeout thread to complete
- */
-static void flush_trace_file(bool wait)
-{
-    pthread_mutex_lock(&trace_lock);
-    trace_available = true;
-    pthread_cond_signal(&trace_available_cond);
-
-    if (wait) {
-        pthread_cond_wait(&trace_empty_cond, &trace_lock);
-    }
-
-    pthread_mutex_unlock(&trace_lock);
-}
-
-static void wait_for_trace_records_available(void)
-{
-    pthread_mutex_lock(&trace_lock);
-    while (!(trace_available && trace_writeout_enabled)) {
-        pthread_cond_signal(&trace_empty_cond);
-        pthread_cond_wait(&trace_available_cond, &trace_lock);
-    }
-    trace_available = false;
-    pthread_mutex_unlock(&trace_lock);
-}
-
-static void *writeout_thread(void *opaque)
-{
-    TraceRecord record;
-    unsigned int writeout_idx = 0;
-    unsigned int num_available, idx;
-    size_t unused __attribute__ ((unused));
-
-    for (;;) {
-        wait_for_trace_records_available();
-
-        num_available = trace_idx - writeout_idx;
-        if (num_available > TRACE_BUF_LEN) {
-            record = (TraceRecord){
-                .event = DROPPED_EVENT_ID,
-                .x1 = num_available,
-            };
-            unused = fwrite(&record, sizeof(record), 1, trace_fp);
-            writeout_idx += num_available;
-        }
-
-        idx = writeout_idx % TRACE_BUF_LEN;
-        while (get_trace_record(idx, &record)) {
-            trace_buf[idx].event = 0; /* clear valid bit */
-            unused = fwrite(&record, sizeof(record), 1, trace_fp);
-            idx = ++writeout_idx % TRACE_BUF_LEN;
-        }
-
-        fflush(trace_fp);
-    }
-    return NULL;
-}
-
-static void trace(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
-                  uint64_t x4, uint64_t x5, uint64_t x6)
-{
-    unsigned int idx;
-    uint64_t timestamp;
-
-    if (!trace_list[event].state) {
-        return;
-    }
-
-    timestamp = get_clock();
-
-    idx = __sync_fetch_and_add(&trace_idx, 1) % TRACE_BUF_LEN;
-    trace_buf[idx] = (TraceRecord){
-        .event = event,
-        .timestamp_ns = timestamp,
-        .x1 = x1,
-        .x2 = x2,
-        .x3 = x3,
-        .x4 = x4,
-        .x5 = x5,
-        .x6 = x6,
-    };
-    __sync_synchronize(); /* write barrier before marking as valid */
-    trace_buf[idx].event |= TRACE_RECORD_VALID;
-
-    if ((idx + 1) % TRACE_BUF_FLUSH_THRESHOLD == 0) {
-        flush_trace_file(false);
-    }
-}
-
-void trace0(TraceEventID event)
-{
-    trace(event, 0, 0, 0, 0, 0, 0);
-}
-
-void trace1(TraceEventID event, uint64_t x1)
-{
-    trace(event, x1, 0, 0, 0, 0, 0);
-}
-
-void trace2(TraceEventID event, uint64_t x1, uint64_t x2)
-{
-    trace(event, x1, x2, 0, 0, 0, 0);
-}
-
-void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3)
-{
-    trace(event, x1, x2, x3, 0, 0, 0);
-}
-
-void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4)
-{
-    trace(event, x1, x2, x3, x4, 0, 0);
-}
-
-void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5)
-{
-    trace(event, x1, x2, x3, x4, x5, 0);
-}
-
-void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5, uint64_t x6)
-{
-    trace(event, x1, x2, x3, x4, x5, x6);
-}
-
-void st_set_trace_file_enabled(bool enable)
-{
-    if (enable == !!trace_fp) {
-        return; /* no change */
-    }
-
-    /* Halt trace writeout */
-    flush_trace_file(true);
-    trace_writeout_enabled = false;
-    flush_trace_file(true);
-
-    if (enable) {
-        static const TraceRecord header = {
-            .event = HEADER_EVENT_ID,
-            .timestamp_ns = HEADER_MAGIC,
-            .x1 = HEADER_VERSION,
-        };
-
-        trace_fp = fopen(trace_file_name, "w");
-        if (!trace_fp) {
-            return;
-        }
-
-        if (fwrite(&header, sizeof header, 1, trace_fp) != 1) {
-            fclose(trace_fp);
-            trace_fp = NULL;
-            return;
-        }
-
-        /* Resume trace writeout */
-        trace_writeout_enabled = true;
-        flush_trace_file(false);
-    } else {
-        fclose(trace_fp);
-        trace_fp = NULL;
-    }
-}
-
-/**
- * Set the name of a trace file
- *
- * @file        The trace file name or NULL for the default name-<pid> set at
- *              config time
- */
-bool st_set_trace_file(const char *file)
-{
-    st_set_trace_file_enabled(false);
-
-    free(trace_file_name);
-
-    if (!file) {
-        if (asprintf(&trace_file_name, CONFIG_TRACE_FILE, getpid()) < 0) {
-            trace_file_name = NULL;
-            return false;
-        }
-    } else {
-        if (asprintf(&trace_file_name, "%s", file) < 0) {
-            trace_file_name = NULL;
-            return false;
-        }
-    }
-
-    st_set_trace_file_enabled(true);
-    return true;
-}
-
-void st_print_trace_file_status(FILE *stream, int (*stream_printf)(FILE 
*stream, const char *fmt, ...))
-{
-    stream_printf(stream, "Trace file \"%s\" %s.\n",
-                  trace_file_name, trace_fp ? "on" : "off");
-}
-
-void st_print_trace(FILE *stream, int (*stream_printf)(FILE *stream, const 
char *fmt, ...))
-{
-    unsigned int i;
-
-    for (i = 0; i < TRACE_BUF_LEN; i++) {
-        TraceRecord record;
-
-        if (!get_trace_record(i, &record)) {
-            continue;
-        }
-        stream_printf(stream, "Event %" PRIu64 " : %" PRIx64 " %" PRIx64
-                      " %" PRIx64 " %" PRIx64 " %" PRIx64 " %" PRIx64 "\n",
-                      record.event, record.x1, record.x2,
-                      record.x3, record.x4, record.x5,
-                      record.x6);
-    }
-}
-
-void st_print_trace_events(FILE *stream, int (*stream_printf)(FILE *stream, 
const char *fmt, ...))
-{
-    unsigned int i;
-
-    for (i = 0; i < NR_TRACE_EVENTS; i++) {
-        stream_printf(stream, "%s [Event ID %u] : state %u\n",
-                      trace_list[i].tp_name, i, trace_list[i].state);
-    }
-}
-
-bool st_change_trace_event_state(const char *name, bool enabled)
-{
-    unsigned int i;
-
-    for (i = 0; i < NR_TRACE_EVENTS; i++) {
-        if (!strcmp(trace_list[i].tp_name, name)) {
-            trace_list[i].state = enabled;
-            return true;
-        }
-    }
-    return false;
-}
-
-void st_flush_trace_buffer(void)
-{
-    flush_trace_file(true);
-}
-
-bool st_init(const char *file)
-{
-    pthread_t thread;
-    pthread_attr_t attr;
-    sigset_t set, oldset;
-    int ret;
-
-    pthread_attr_init(&attr);
-    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
-
-    sigfillset(&set);
-    pthread_sigmask(SIG_SETMASK, &set, &oldset);
-    ret = pthread_create(&thread, &attr, writeout_thread, NULL);
-    pthread_sigmask(SIG_SETMASK, &oldset, NULL);
-
-    if (ret != 0) {
-        return false;
-    }
-
-    atexit(st_flush_trace_buffer);
-    st_set_trace_file(file);
-    return true;
-}
diff --git a/simpletrace.h b/simpletrace.h
deleted file mode 100644
index 507dd87..0000000
--- a/simpletrace.h
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Simple trace backend
- *
- * Copyright IBM, Corp. 2010
- *
- * This work is licensed under the terms of the GNU GPL, version 2.  See
- * the COPYING file in the top-level directory.
- *
- */
-
-#ifndef SIMPLETRACE_H
-#define SIMPLETRACE_H
-
-#include <stdint.h>
-#include <stdbool.h>
-#include <stdio.h>
-
-#ifdef CONFIG_TRACE_SIMPLE
-typedef uint64_t TraceEventID;
-
-typedef struct {
-    const char *tp_name;
-    bool state;
-} TraceEvent;
-
-void trace0(TraceEventID event);
-void trace1(TraceEventID event, uint64_t x1);
-void trace2(TraceEventID event, uint64_t x1, uint64_t x2);
-void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3);
-void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4);
-void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5);
-void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5, uint64_t x6);
-void st_print_trace(FILE *stream, fprintf_function stream_printf);
-void st_print_trace_events(FILE *stream, fprintf_function stream_printf);
-bool st_change_trace_event_state(const char *tname, bool tstate);
-void st_print_trace_file_status(FILE *stream, fprintf_function stream_printf);
-void st_set_trace_file_enabled(bool enable);
-bool st_set_trace_file(const char *file);
-void st_flush_trace_buffer(void);
-bool st_init(const char *file);
-#else
-static inline bool st_init(const char *file)
-{
-    return true;
-}
-#endif /* !CONFIG_TRACE_SIMPLE */
-
-#endif /* SIMPLETRACE_H */
diff --git a/trace/simple.c b/trace/simple.c
new file mode 100644
index 0000000..de355e9
--- /dev/null
+++ b/trace/simple.c
@@ -0,0 +1,355 @@
+/*
+ * Simple trace backend
+ *
+ * Copyright IBM, Corp. 2010
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <time.h>
+#include <signal.h>
+#include <pthread.h>
+#include "qemu-timer.h"
+#include "trace.h"
+
+/** Trace file header event ID */
+#define HEADER_EVENT_ID (~(uint64_t)0) /* avoids conflicting with 
TraceEventIDs */
+
+/** Trace file magic number */
+#define HEADER_MAGIC 0xf2b177cb0aa429b4ULL
+
+/** Trace file version number, bump if format changes */
+#define HEADER_VERSION 0
+
+/** Records were dropped event ID */
+#define DROPPED_EVENT_ID (~(uint64_t)0 - 1)
+
+/** Trace record is valid */
+#define TRACE_RECORD_VALID ((uint64_t)1 << 63)
+
+/** Trace buffer entry */
+typedef struct {
+    uint64_t event;
+    uint64_t timestamp_ns;
+    uint64_t x1;
+    uint64_t x2;
+    uint64_t x3;
+    uint64_t x4;
+    uint64_t x5;
+    uint64_t x6;
+} TraceRecord;
+
+enum {
+    TRACE_BUF_LEN = 4096,
+    TRACE_BUF_FLUSH_THRESHOLD = TRACE_BUF_LEN / 4,
+};
+
+/*
+ * Trace records are written out by a dedicated thread.  The thread waits for
+ * records to become available, writes them out, and then waits again.
+ */
+static pthread_mutex_t trace_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t trace_available_cond = PTHREAD_COND_INITIALIZER;
+static pthread_cond_t trace_empty_cond = PTHREAD_COND_INITIALIZER;
+static bool trace_available;
+static bool trace_writeout_enabled;
+
+static TraceRecord trace_buf[TRACE_BUF_LEN];
+static unsigned int trace_idx;
+static FILE *trace_fp;
+static char *trace_file_name = NULL;
+
+/**
+ * Read a trace record from the trace buffer
+ *
+ * @idx         Trace buffer index
+ * @record      Trace record to fill
+ *
+ * Returns false if the record is not valid.
+ */
+static bool get_trace_record(unsigned int idx, TraceRecord *record)
+{
+    if (!(trace_buf[idx].event & TRACE_RECORD_VALID)) {
+        return false;
+    }
+
+    __sync_synchronize(); /* read memory barrier before accessing record */
+
+    *record = trace_buf[idx];
+    record->event &= ~TRACE_RECORD_VALID;
+    return true;
+}
+
+/**
+ * Kick writeout thread
+ *
+ * @wait        Whether to wait for writeout thread to complete
+ */
+static void flush_trace_file(bool wait)
+{
+    pthread_mutex_lock(&trace_lock);
+    trace_available = true;
+    pthread_cond_signal(&trace_available_cond);
+
+    if (wait) {
+        pthread_cond_wait(&trace_empty_cond, &trace_lock);
+    }
+
+    pthread_mutex_unlock(&trace_lock);
+}
+
+static void wait_for_trace_records_available(void)
+{
+    pthread_mutex_lock(&trace_lock);
+    while (!(trace_available && trace_writeout_enabled)) {
+        pthread_cond_signal(&trace_empty_cond);
+        pthread_cond_wait(&trace_available_cond, &trace_lock);
+    }
+    trace_available = false;
+    pthread_mutex_unlock(&trace_lock);
+}
+
+static void *writeout_thread(void *opaque)
+{
+    TraceRecord record;
+    unsigned int writeout_idx = 0;
+    unsigned int num_available, idx;
+    size_t unused __attribute__ ((unused));
+
+    for (;;) {
+        wait_for_trace_records_available();
+
+        num_available = trace_idx - writeout_idx;
+        if (num_available > TRACE_BUF_LEN) {
+            record = (TraceRecord){
+                .event = DROPPED_EVENT_ID,
+                .x1 = num_available,
+            };
+            unused = fwrite(&record, sizeof(record), 1, trace_fp);
+            writeout_idx += num_available;
+        }
+
+        idx = writeout_idx % TRACE_BUF_LEN;
+        while (get_trace_record(idx, &record)) {
+            trace_buf[idx].event = 0; /* clear valid bit */
+            unused = fwrite(&record, sizeof(record), 1, trace_fp);
+            idx = ++writeout_idx % TRACE_BUF_LEN;
+        }
+
+        fflush(trace_fp);
+    }
+    return NULL;
+}
+
+static void trace(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3,
+                  uint64_t x4, uint64_t x5, uint64_t x6)
+{
+    unsigned int idx;
+    uint64_t timestamp;
+
+    if (!trace_list[event].state) {
+        return;
+    }
+
+    timestamp = get_clock();
+
+    idx = __sync_fetch_and_add(&trace_idx, 1) % TRACE_BUF_LEN;
+    trace_buf[idx] = (TraceRecord){
+        .event = event,
+        .timestamp_ns = timestamp,
+        .x1 = x1,
+        .x2 = x2,
+        .x3 = x3,
+        .x4 = x4,
+        .x5 = x5,
+        .x6 = x6,
+    };
+    __sync_synchronize(); /* write barrier before marking as valid */
+    trace_buf[idx].event |= TRACE_RECORD_VALID;
+
+    if ((idx + 1) % TRACE_BUF_FLUSH_THRESHOLD == 0) {
+        flush_trace_file(false);
+    }
+}
+
+void trace0(TraceEventID event)
+{
+    trace(event, 0, 0, 0, 0, 0, 0);
+}
+
+void trace1(TraceEventID event, uint64_t x1)
+{
+    trace(event, x1, 0, 0, 0, 0, 0);
+}
+
+void trace2(TraceEventID event, uint64_t x1, uint64_t x2)
+{
+    trace(event, x1, x2, 0, 0, 0, 0);
+}
+
+void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3)
+{
+    trace(event, x1, x2, x3, 0, 0, 0);
+}
+
+void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4)
+{
+    trace(event, x1, x2, x3, x4, 0, 0);
+}
+
+void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5)
+{
+    trace(event, x1, x2, x3, x4, x5, 0);
+}
+
+void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5, uint64_t x6)
+{
+    trace(event, x1, x2, x3, x4, x5, x6);
+}
+
+void st_set_trace_file_enabled(bool enable)
+{
+    if (enable == !!trace_fp) {
+        return; /* no change */
+    }
+
+    /* Halt trace writeout */
+    flush_trace_file(true);
+    trace_writeout_enabled = false;
+    flush_trace_file(true);
+
+    if (enable) {
+        static const TraceRecord header = {
+            .event = HEADER_EVENT_ID,
+            .timestamp_ns = HEADER_MAGIC,
+            .x1 = HEADER_VERSION,
+        };
+
+        trace_fp = fopen(trace_file_name, "w");
+        if (!trace_fp) {
+            return;
+        }
+
+        if (fwrite(&header, sizeof header, 1, trace_fp) != 1) {
+            fclose(trace_fp);
+            trace_fp = NULL;
+            return;
+        }
+
+        /* Resume trace writeout */
+        trace_writeout_enabled = true;
+        flush_trace_file(false);
+    } else {
+        fclose(trace_fp);
+        trace_fp = NULL;
+    }
+}
+
+/**
+ * Set the name of a trace file
+ *
+ * @file        The trace file name or NULL for the default name-<pid> set at
+ *              config time
+ */
+bool st_set_trace_file(const char *file)
+{
+    st_set_trace_file_enabled(false);
+
+    free(trace_file_name);
+
+    if (!file) {
+        if (asprintf(&trace_file_name, CONFIG_TRACE_FILE, getpid()) < 0) {
+            trace_file_name = NULL;
+            return false;
+        }
+    } else {
+        if (asprintf(&trace_file_name, "%s", file) < 0) {
+            trace_file_name = NULL;
+            return false;
+        }
+    }
+
+    st_set_trace_file_enabled(true);
+    return true;
+}
+
+void st_print_trace_file_status(FILE *stream, int (*stream_printf)(FILE 
*stream, const char *fmt, ...))
+{
+    stream_printf(stream, "Trace file \"%s\" %s.\n",
+                  trace_file_name, trace_fp ? "on" : "off");
+}
+
+void st_print_trace(FILE *stream, int (*stream_printf)(FILE *stream, const 
char *fmt, ...))
+{
+    unsigned int i;
+
+    for (i = 0; i < TRACE_BUF_LEN; i++) {
+        TraceRecord record;
+
+        if (!get_trace_record(i, &record)) {
+            continue;
+        }
+        stream_printf(stream, "Event %" PRIu64 " : %" PRIx64 " %" PRIx64
+                      " %" PRIx64 " %" PRIx64 " %" PRIx64 " %" PRIx64 "\n",
+                      record.event, record.x1, record.x2,
+                      record.x3, record.x4, record.x5,
+                      record.x6);
+    }
+}
+
+void st_print_trace_events(FILE *stream, int (*stream_printf)(FILE *stream, 
const char *fmt, ...))
+{
+    unsigned int i;
+
+    for (i = 0; i < NR_TRACE_EVENTS; i++) {
+        stream_printf(stream, "%s [Event ID %u] : state %u\n",
+                      trace_list[i].tp_name, i, trace_list[i].state);
+    }
+}
+
+bool st_change_trace_event_state(const char *name, bool enabled)
+{
+    unsigned int i;
+
+    for (i = 0; i < NR_TRACE_EVENTS; i++) {
+        if (!strcmp(trace_list[i].tp_name, name)) {
+            trace_list[i].state = enabled;
+            return true;
+        }
+    }
+    return false;
+}
+
+void st_flush_trace_buffer(void)
+{
+    flush_trace_file(true);
+}
+
+bool st_init(const char *file)
+{
+    pthread_t thread;
+    pthread_attr_t attr;
+    sigset_t set, oldset;
+    int ret;
+
+    pthread_attr_init(&attr);
+    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+
+    sigfillset(&set);
+    pthread_sigmask(SIG_SETMASK, &set, &oldset);
+    ret = pthread_create(&thread, &attr, writeout_thread, NULL);
+    pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+
+    if (ret != 0) {
+        return false;
+    }
+
+    atexit(st_flush_trace_buffer);
+    st_set_trace_file(file);
+    return true;
+}
diff --git a/trace/simple.h b/trace/simple.h
new file mode 100644
index 0000000..77633ab
--- /dev/null
+++ b/trace/simple.h
@@ -0,0 +1,48 @@
+/*
+ * Simple trace backend
+ *
+ * Copyright IBM, Corp. 2010
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef TRACE_SIMPLE_H
+#define TRACE_SIMPLE_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+
+#ifdef CONFIG_TRACE_SIMPLE
+typedef uint64_t TraceEventID;
+
+typedef struct {
+    const char *tp_name;
+    bool state;
+} TraceEvent;
+
+void trace0(TraceEventID event);
+void trace1(TraceEventID event, uint64_t x1);
+void trace2(TraceEventID event, uint64_t x1, uint64_t x2);
+void trace3(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3);
+void trace4(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4);
+void trace5(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5);
+void trace6(TraceEventID event, uint64_t x1, uint64_t x2, uint64_t x3, 
uint64_t x4, uint64_t x5, uint64_t x6);
+void st_print_trace(FILE *stream, fprintf_function stream_printf);
+void st_print_trace_events(FILE *stream, fprintf_function stream_printf);
+bool st_change_trace_event_state(const char *tname, bool tstate);
+void st_print_trace_file_status(FILE *stream, fprintf_function stream_printf);
+void st_set_trace_file_enabled(bool enable);
+bool st_set_trace_file(const char *file);
+void st_flush_trace_buffer(void);
+bool st_init(const char *file);
+#else
+static inline bool st_init(const char *file)
+{
+    return true;
+}
+#endif /* !CONFIG_TRACE_SIMPLE */
+
+#endif /* TRACE_SIMPLE_H */
diff --git a/vl.c b/vl.c
index 8c7aaaa..145d738 100644
--- a/vl.c
+++ b/vl.c
@@ -156,7 +156,7 @@ int main(int argc, char **argv)
 #include "slirp/libslirp.h"
 
 #include "trace.h"
-#include "simpletrace.h"
+#include "trace/simple.h"
 #include "qemu-queue.h"
 #include "cpus.h"
 #include "arch_init.h"