Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

# gpg: Signature made Wed 03 Feb 2016 15:47:34 GMT using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/tracing-pull-request:
  log: add "-d trace:PATTERN"
  trace: switch default backend to "log"
  trace: convert stderr backend to log
  log: move qemu-log.c into util/ directory
  log: do not unnecessarily include qom/cpu.h
  trace: add "-trace help"
  trace: add "-trace enable=..."
  trace: no need to call trace_backend_init in different branches now
  trace: split trace_init_file out of trace_init_backends
  trace: split trace_init_events out of trace_init_backends
  trace: fix documentation
  trace: track enabled events in a separate array
  trace: count number of enabled events

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

57 files changed, 293 insertions, 137 deletions

diff --git a/.travis.yml b/.travis.yml
index 6ca0260..0428aed 100644
--- a/.travis.yml
+++ b/.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"
diff --git a/Makefile.objs b/Makefile.objs
index 06b95c7..fbcaa74 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -89,7 +89,6 @@ endif
 
 #######################################################################
 # Target-independent parts used in system and user emulation
-common-obj-y += qemu-log.o
 common-obj-y += tcg-runtime.o
 common-obj-y += hw/
 common-obj-y += qom/
diff --git a/bsd-user/main.c b/bsd-user/main.c
index 1ecaeb5..fefcfc1 100644
--- a/bsd-user/main.c
+++ b/bsd-user/main.c
@@ -33,6 +33,7 @@
 #include "tcg.h"
 #include "qemu/timer.h"
 #include "qemu/envlist.h"
+#include "exec/log.h"
 
 int singlestep;
 unsigned long mmap_min_addr;
diff --git a/configure b/configure
index 297bfc7..d4411a1 100755
--- a/configure
+++ b/configure
@@ -303,7 +303,7 @@ pkgversion=""
 pie=""
 zero_malloc=""
 qom_cast_debug="yes"
-trace_backends="nop"
+trace_backends="log"
 trace_file="trace"
 spice=""
 rbd=""
@@ -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
diff --git a/cpu-exec.c b/cpu-exec.c
index c459364..fd92452 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -27,6 +27,7 @@
 #include "exec/address-spaces.h"
 #include "qemu/rcu.h"
 #include "exec/tb-hash.h"
+#include "exec/log.h"
 #if defined(TARGET_I386) && !defined(CONFIG_USER_ONLY)
 #include "hw/i386/apic.h"
 #endif
diff --git a/exec.c b/exec.c
index 9e076bc..ab37360 100644
--- a/exec.c
+++ b/exec.c
@@ -52,6 +52,7 @@
 
 #include "exec/memory-internal.h"
 #include "exec/ram_addr.h"
+#include "exec/log.h"
 
 #include "qemu/range.h"
 #ifndef _WIN32
diff --git a/hw/acpi/cpu_hotplug.c b/hw/acpi/cpu_hotplug.c
index 2f99ec5..5a410a5 100644
--- a/hw/acpi/cpu_hotplug.c
+++ b/hw/acpi/cpu_hotplug.c
@@ -12,6 +12,7 @@
 #include "qemu/osdep.h"
 #include "hw/hw.h"
 #include "hw/acpi/cpu_hotplug.h"
+#include "qom/cpu.h"
 
 static uint64_t cpu_status_read(void *opaque, hwaddr addr, unsigned int size)
 {
diff --git a/hw/timer/a9gtimer.c b/hw/timer/a9gtimer.c
index c11a7bc..fa4602c 100644
--- a/hw/timer/a9gtimer.c
+++ b/hw/timer/a9gtimer.c
@@ -25,6 +25,7 @@
 #include "qemu/timer.h"
 #include "qemu/bitops.h"
 #include "qemu/log.h"
+#include "qom/cpu.h"
 
 #ifndef A9_GTIMER_ERR_DEBUG
 #define A9_GTIMER_ERR_DEBUG 0
diff --git a/include/exec/log.h b/include/exec/log.h
new file mode 100644
index 0000000..ba1c9b5
--- /dev/null
+++ b/include/exec/log.h
@@ -0,0 +1,60 @@
+#ifndef QEMU_EXEC_LOG_H
+#define QEMU_EXEC_LOG_H
+
+#include "qemu/log.h"
+#include "qom/cpu.h"
+#include "disas/disas.h"
+
+/* cpu_dump_state() logging functions: */
+/**
+ * log_cpu_state:
+ * @cpu: The CPU whose state is to be logged.
+ * @flags: Flags what to log.
+ *
+ * Logs the output of cpu_dump_state().
+ */
+static inline void log_cpu_state(CPUState *cpu, int flags)
+{
+    if (qemu_log_enabled()) {
+        cpu_dump_state(cpu, qemu_logfile, fprintf, flags);
+    }
+}
+
+/**
+ * log_cpu_state_mask:
+ * @mask: Mask when to log.
+ * @cpu: The CPU whose state is to be logged.
+ * @flags: Flags what to log.
+ *
+ * Logs the output of cpu_dump_state() if loglevel includes @mask.
+ */
+static inline void log_cpu_state_mask(int mask, CPUState *cpu, int flags)
+{
+    if (qemu_loglevel & mask) {
+        log_cpu_state(cpu, flags);
+    }
+}
+
+#ifdef NEED_CPU_H
+/* disas() and target_disas() to qemu_logfile: */
+static inline void log_target_disas(CPUState *cpu, target_ulong start,
+                                    target_ulong len, int flags)
+{
+    target_disas(qemu_logfile, cpu, start, len, flags);
+}
+
+static inline void log_disas(void *code, unsigned long size)
+{
+    disas(qemu_logfile, code, size);
+}
+
+#if defined(CONFIG_USER_ONLY)
+/* page_dump() output to the log file: */
+static inline void log_page_dump(void)
+{
+    page_dump(qemu_logfile);
+}
+#endif
+#endif
+
+#endif
diff --git a/include/qemu/log.h b/include/qemu/log.h
index d837d90..30817f7 100644
--- a/include/qemu/log.h
+++ b/include/qemu/log.h
@@ -5,10 +5,6 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include "qemu/compiler.h"
-#include "qom/cpu.h"
-#ifdef NEED_CPU_H
-#include "disas/disas.h"
-#endif
 
 /* Private global variables, don't use */
 extern FILE *qemu_logfile;
@@ -49,6 +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
  */
@@ -78,61 +75,6 @@ qemu_log_vprintf(const char *fmt, va_list va)
 void GCC_FMT_ATTR(2, 3) qemu_log_mask(int mask, const char *fmt, ...);
 
 
-/* Special cases: */
-
-/* cpu_dump_state() logging functions: */
-/**
- * log_cpu_state:
- * @cpu: The CPU whose state is to be logged.
- * @flags: Flags what to log.
- *
- * Logs the output of cpu_dump_state().
- */
-static inline void log_cpu_state(CPUState *cpu, int flags)
-{
-    if (qemu_log_enabled()) {
-        cpu_dump_state(cpu, qemu_logfile, fprintf, flags);
-    }
-}
-
-/**
- * log_cpu_state_mask:
- * @mask: Mask when to log.
- * @cpu: The CPU whose state is to be logged.
- * @flags: Flags what to log.
- *
- * Logs the output of cpu_dump_state() if loglevel includes @mask.
- */
-static inline void log_cpu_state_mask(int mask, CPUState *cpu, int flags)
-{
-    if (qemu_loglevel & mask) {
-        log_cpu_state(cpu, flags);
-    }
-}
-
-#ifdef NEED_CPU_H
-/* disas() and target_disas() to qemu_logfile: */
-static inline void log_target_disas(CPUState *cpu, target_ulong start,
-                                    target_ulong len, int flags)
-{
-    target_disas(qemu_logfile, cpu, start, len, flags);
-}
-
-static inline void log_disas(void *code, unsigned long size)
-{
-    disas(qemu_logfile, code, size);
-}
-
-#if defined(CONFIG_USER_ONLY)
-/* page_dump() output to the log file: */
-static inline void log_page_dump(void)
-{
-    page_dump(qemu_logfile);
-}
-#endif
-#endif
-
-
 /* Maintenance: */
 
 /* fflush() the log file */
diff --git a/linux-user/main.c b/linux-user/main.c
index f8d4577..e719a2d 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -28,6 +28,7 @@
 #include "qemu/timer.h"
 #include "qemu/envlist.h"
 #include "elf.h"
+#include "exec/log.h"
 
 char *exec_path;
 
diff --git a/qemu-io.c b/qemu-io.c
index d593f19..83c48f4 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -435,7 +435,7 @@ int main(int argc, char **argv)
             }
             break;
         case 'T':
-            if (!trace_init_backends(optarg, NULL)) {
+            if (!trace_init_backends()) {
                 exit(1); /* error message will have been printed */
             }
             break;
diff --git a/qemu-options.hx b/qemu-options.hx
index f31a240..733a194 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3544,7 +3544,7 @@ config files on @var{sysconfdir}, but won't make it skip the QEMU-provided confi
 files from @var{datadir}.
 ETEXI
 DEF("trace", HAS_ARG, QEMU_OPTION_trace,
-    "-trace [events=<file>][,file=<file>]\n"
+    "-trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
     "                specify tracing options\n",
     QEMU_ARCH_ALL)
 STEXI
@@ -3556,15 +3556,25 @@ HXCOMM HX does not support conditional compilation of text.
 Specify tracing options.
 
 @table @option
+@item [enable=]@var{pattern}
+Immediately enable events matching @var{pattern}.
+The file must contain one event name (as listed in the @file{trace-events} file)
+per line; globbing patterns are accepted too.  This option is only
+available if QEMU has been compiled with the @var{simple}, @var{stderr}
+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 @var{trace-events} file)
-per line.
-This option is only available if QEMU has been compiled with
-either @var{simple} or @var{stderr} tracing backend.
+The file must contain one event name (as listed in the @file{trace-events} file)
+per line; globbing patterns are accepted too.  This option is only
+available if QEMU has been compiled with the @var{simple}, @var{stderr} 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
diff --git a/qom/cpu.c b/qom/cpu.c
index 8f537a4..38dc713 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -23,6 +23,7 @@
 #include "sysemu/kvm.h"
 #include "qemu/notify.h"
 #include "qemu/log.h"
+#include "exec/log.h"
 #include "qemu/error-report.h"
 #include "sysemu/sysemu.h"
 
diff --git a/scripts/tracetool/backend/stderr.py b/scripts/tracetool/backend/log.py
index ca58054..a62c310 100644
--- a/scripts/tracetool/backend/stderr.py
+++ b/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,
diff --git a/scripts/tracetool/format/events_c.py b/scripts/tracetool/format/events_c.py
index 2d97fa3..2717ea3 100644
--- a/scripts/tracetool/format/events_c.py
+++ b/scripts/tracetool/format/events_c.py
@@ -27,7 +27,7 @@ def generate(events, backend):
     out('TraceEvent trace_events[TRACE_EVENT_COUNT] = {')
 
     for e in events:
-        out('    { .id = %(id)s, .name = \"%(name)s\", .sstate = %(sstate)s, .dstate = 0 },',
+        out('    { .id = %(id)s, .name = \"%(name)s\", .sstate = %(sstate)s },',
             id = "TRACE_" + e.name.upper(),
             name = e.name,
             sstate = "TRACE_%s_ENABLED" % e.name.upper())
diff --git a/target-alpha/translate.c b/target-alpha/translate.c
index 7d419d9..c96adbb 100644
--- a/target-alpha/translate.c
+++ b/target-alpha/translate.c
@@ -28,6 +28,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #undef ALPHA_DEBUG_DISAS
diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c
index 80f6c20..2af7d86 100644
--- a/target-arm/translate-a64.c
+++ b/target-arm/translate-a64.c
@@ -31,6 +31,7 @@
 
 #include "exec/helper-proto.h"
 #include "exec/helper-gen.h"
+#include "exec/log.h"
 
 #include "trace-tcg.h"
 
diff --git a/target-arm/translate.c b/target-arm/translate.c
index cff511b..3ec758a 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -32,6 +32,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define ENABLE_ARCH_4T    arm_dc_feature(s, ARM_FEATURE_V4T)
diff --git a/target-cris/translate.c b/target-cris/translate.c
index 295005f..0350cb5 100644
--- a/target-cris/translate.c
+++ b/target-cris/translate.c
@@ -35,6 +35,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define DISAS_CRIS 0
diff --git a/target-i386/seg_helper.c b/target-i386/seg_helper.c
index 4c7cab7..4f26941 100644
--- a/target-i386/seg_helper.c
+++ b/target-i386/seg_helper.c
@@ -23,6 +23,7 @@
 #include "qemu/log.h"
 #include "exec/helper-proto.h"
 #include "exec/cpu_ldst.h"
+#include "exec/log.h"
 
 //#define DEBUG_PCALL
 
diff --git a/target-i386/smm_helper.c b/target-i386/smm_helper.c
index b930421..e7bb5be 100644
--- a/target-i386/smm_helper.c
+++ b/target-i386/smm_helper.c
@@ -20,6 +20,7 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "exec/helper-proto.h"
+#include "exec/log.h"
 
 /* SMM support */
 
diff --git a/target-i386/translate.c b/target-i386/translate.c
index 957a92d..73a45c8 100644
--- a/target-i386/translate.c
+++ b/target-i386/translate.c
@@ -28,6 +28,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define PREFIX_REPZ   0x01
diff --git a/target-lm32/helper.c b/target-lm32/helper.c
index 3ebec68..655248f 100644
--- a/target-lm32/helper.c
+++ b/target-lm32/helper.c
@@ -22,6 +22,7 @@
 #include "qemu/host-utils.h"
 #include "sysemu/sysemu.h"
 #include "exec/semihost.h"
+#include "exec/log.h"
 
 int lm32_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
                               int mmu_idx)
diff --git a/target-lm32/translate.c b/target-lm32/translate.c
index 477d428..52fe562 100644
--- a/target-lm32/translate.c
+++ b/target-lm32/translate.c
@@ -29,6 +29,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define DISAS_LM32 1
diff --git a/target-m68k/translate.c b/target-m68k/translate.c
index 342c040..a402bd8 100644
--- a/target-m68k/translate.c
+++ b/target-m68k/translate.c
@@ -29,6 +29,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 //#define DEBUG_DISPATCH 1
diff --git a/target-microblaze/helper.c b/target-microblaze/helper.c
index 3b0fae8..4de6bdb 100644
--- a/target-microblaze/helper.c
+++ b/target-microblaze/helper.c
@@ -21,6 +21,7 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "qemu/host-utils.h"
+#include "exec/log.h"
 
 #define D(x)
 
diff --git a/target-microblaze/translate.c b/target-microblaze/translate.c
index 2e1293d..40be4ec 100644
--- a/target-microblaze/translate.c
+++ b/target-microblaze/translate.c
@@ -28,6 +28,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define SIM_COMPAT 0
diff --git a/target-mips/helper.c b/target-mips/helper.c
index f9c4c11..1004ede 100644
--- a/target-mips/helper.c
+++ b/target-mips/helper.c
@@ -21,6 +21,7 @@
 #include "cpu.h"
 #include "sysemu/kvm.h"
 #include "exec/cpu_ldst.h"
+#include "exec/log.h"
 
 enum {
     TLBRET_XI = -6,
diff --git a/target-mips/translate.c b/target-mips/translate.c
index 383d4b5..791866b 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -33,6 +33,7 @@
 #include "exec/semihost.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 #define MIPS_DEBUG_DISAS 0
 
diff --git a/target-moxie/translate.c b/target-moxie/translate.c
index 229ce3b..04ab278 100644
--- a/target-moxie/translate.c
+++ b/target-moxie/translate.c
@@ -31,6 +31,7 @@
 
 #include "exec/helper-proto.h"
 #include "exec/helper-gen.h"
+#include "exec/log.h"
 
 /* This is the state at translation time.  */
 typedef struct DisasContext {
diff --git a/target-openrisc/translate.c b/target-openrisc/translate.c
index 62890c2..b766b27 100644
--- a/target-openrisc/translate.c
+++ b/target-openrisc/translate.c
@@ -32,6 +32,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define OPENRISC_DISAS
diff --git a/target-ppc/mmu-hash32.c b/target-ppc/mmu-hash32.c
index b076d80..39abb2f 100644
--- a/target-ppc/mmu-hash32.c
+++ b/target-ppc/mmu-hash32.c
@@ -24,6 +24,7 @@
 #include "sysemu/kvm.h"
 #include "kvm_ppc.h"
 #include "mmu-hash32.h"
+#include "exec/log.h"
 
 //#define DEBUG_BAT
 
diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
index 6d110ee..9c58fbf 100644
--- a/target-ppc/mmu-hash64.c
+++ b/target-ppc/mmu-hash64.c
@@ -25,6 +25,7 @@
 #include "qemu/error-report.h"
 #include "kvm_ppc.h"
 #include "mmu-hash64.h"
+#include "exec/log.h"
 
 //#define DEBUG_SLB
 
diff --git a/target-ppc/mmu_helper.c b/target-ppc/mmu_helper.c
index de4e286..e5ec8d6 100644
--- a/target-ppc/mmu_helper.c
+++ b/target-ppc/mmu_helper.c
@@ -24,6 +24,7 @@
 #include "mmu-hash64.h"
 #include "mmu-hash32.h"
 #include "exec/cpu_ldst.h"
+#include "exec/log.h"
 
 //#define DEBUG_MMU
 //#define DEBUG_BATS
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 7db3145..0057bda 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -29,6 +29,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define CPU_SINGLE_STEP 0x1
diff --git a/target-s390x/translate.c b/target-s390x/translate.c
index 811928b..3087692 100644
--- a/target-s390x/translate.c
+++ b/target-s390x/translate.c
@@ -44,6 +44,7 @@ static TCGv_ptr cpu_env;
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 /* Information that (most) every instruction needs to manipulate.  */
diff --git a/target-sh4/helper.c b/target-sh4/helper.c
index 9d8b61c..6438338 100644
--- a/target-sh4/helper.c
+++ b/target-sh4/helper.c
@@ -19,6 +19,7 @@
 #include "qemu/osdep.h"
 
 #include "cpu.h"
+#include "exec/log.h"
 
 #if !defined(CONFIG_USER_ONLY)
 #include "hw/sh4/sh_intc.h"
diff --git a/target-sh4/translate.c b/target-sh4/translate.c
index 9de5659..3e4164b 100644
--- a/target-sh4/translate.c
+++ b/target-sh4/translate.c
@@ -29,6 +29,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 typedef struct DisasContext {
diff --git a/target-sparc/int32_helper.c b/target-sparc/int32_helper.c
index d4d6a4b..09afe13 100644
--- a/target-sparc/int32_helper.c
+++ b/target-sparc/int32_helper.c
@@ -21,6 +21,7 @@
 #include "cpu.h"
 #include "trace.h"
 #include "sysemu/sysemu.h"
+#include "exec/log.h"
 
 #define DEBUG_PCALL
 
diff --git a/target-sparc/int64_helper.c b/target-sparc/int64_helper.c
index ddef66b..aa876cd 100644
--- a/target-sparc/int64_helper.c
+++ b/target-sparc/int64_helper.c
@@ -20,6 +20,7 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "exec/helper-proto.h"
+#include "exec/log.h"
 #include "trace.h"
 
 #define DEBUG_PCALL
diff --git a/target-sparc/translate.c b/target-sparc/translate.c
index 747f94d..6726860 100644
--- a/target-sparc/translate.c
+++ b/target-sparc/translate.c
@@ -29,6 +29,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 #define DEBUG_DISAS
diff --git a/target-tilegx/translate.c b/target-tilegx/translate.c
index 2088f87..a5bb8d4 100644
--- a/target-tilegx/translate.c
+++ b/target-tilegx/translate.c
@@ -21,6 +21,7 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "qemu/log.h"
+#include "exec/log.h"
 #include "disas/disas.h"
 #include "tcg-op.h"
 #include "exec/cpu_ldst.h"
diff --git a/target-tricore/translate.c b/target-tricore/translate.c
index 2b07b86..e385fc7 100644
--- a/target-tricore/translate.c
+++ b/target-tricore/translate.c
@@ -28,6 +28,7 @@
 #include "exec/helper-gen.h"
 
 #include "tricore-opcodes.h"
+#include "exec/log.h"
 
 /*
  * TCG registers
diff --git a/target-unicore32/translate.c b/target-unicore32/translate.c
index 5db8f94..7dbfe3b 100644
--- a/target-unicore32/translate.c
+++ b/target-unicore32/translate.c
@@ -20,6 +20,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 /* internal defines */
diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index a8c1113..435ee03 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -43,6 +43,7 @@
 #include "exec/helper-gen.h"
 
 #include "trace-tcg.h"
+#include "exec/log.h"
 
 
 typedef struct DisasContext {
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 3ce02dc..be765ad 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -60,6 +60,7 @@
 #endif
 
 #include "elf.h"
+#include "exec/log.h"
 
 /* Forward declarations for functions declared in tcg-target.c and used here. */
 static void tcg_target_init(TCGContext *s);
diff --git a/trace/control-internal.h b/trace/control-internal.h
index 5a8df28..07cb1c1 100644
--- a/trace/control-internal.h
+++ b/trace/control-internal.h
@@ -14,6 +14,8 @@
 
 
 extern TraceEvent trace_events[];
+extern bool trace_events_dstate[];
+extern int trace_events_enabled_count;
 
 
 static inline TraceEventID trace_event_count(void)
@@ -51,17 +53,24 @@ static inline bool trace_event_get_state_static(TraceEvent *ev)
     return ev->sstate;
 }
 
+static inline bool trace_event_get_state_dynamic_by_id(int id)
+{
+    return unlikely(trace_events_enabled_count) && trace_events_dstate[id];
+}
+
 static inline bool trace_event_get_state_dynamic(TraceEvent *ev)
 {
-    assert(ev != NULL);
-    return ev->dstate;
+    int id = trace_event_get_id(ev);
+    return trace_event_get_state_dynamic_by_id(id);
 }
 
 static inline void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
 {
+    int id = trace_event_get_id(ev);
     assert(ev != NULL);
     assert(trace_event_get_state_static(ev));
-    ev->dstate = state;
+    trace_events_enabled_count += state - trace_events_dstate[id];
+    trace_events_dstate[id] = state;
 }
 
 #endif  /* TRACE__CONTROL_INTERNAL_H */
diff --git a/trace/control.c b/trace/control.c
index 995beb3..84ea840 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -14,8 +14,14 @@
 #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;
+bool trace_events_dstate[TRACE_EVENT_COUNT];
+
 TraceEvent *trace_event_name(const char *name)
 {
     assert(name != NULL);
@@ -85,7 +91,52 @@ TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
     return NULL;
 }
 
-static void trace_init_events(const char *fname)
+void trace_list_events(void)
+{
+    int i;
+    for (i = 0; i < trace_event_count(); i++) {
+        TraceEvent *res = trace_event_id(i);
+        fprintf(stderr, "%s\n", trace_event_get_name(res));
+    }
+}
+
+static void do_trace_enable_events(const char *line_buf)
+{
+    const bool enable = ('-' != line_buf[0]);
+    const char *line_ptr = enable ? line_buf : line_buf + 1;
+
+    if (trace_event_is_pattern(line_ptr)) {
+        TraceEvent *ev = NULL;
+        while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
+            if (trace_event_get_state_static(ev)) {
+                trace_event_set_state_dynamic(ev, enable);
+            }
+        }
+    } else {
+        TraceEvent *ev = trace_event_name(line_ptr);
+        if (ev == NULL) {
+            error_report("WARNING: trace event '%s' does not exist",
+                         line_ptr);
+        } else if (!trace_event_get_state_static(ev)) {
+            error_report("WARNING: trace event '%s' is not traceable",
+                         line_ptr);
+        } else {
+            trace_event_set_state_dynamic(ev, enable);
+        }
+    }
+}
+
+void trace_enable_events(const char *line_buf)
+{
+    if (is_help_option(line_buf)) {
+        trace_list_events();
+        exit(0);
+    } else {
+        do_trace_enable_events(line_buf);
+    }
+}
+
+void trace_init_events(const char *fname)
 {
     Location loc;
     FILE *fp;
@@ -111,27 +162,7 @@ static void trace_init_events(const char *fname)
             if ('#' == line_buf[0]) { /* skip commented lines */
                 continue;
             }
-            const bool enable = ('-' != line_buf[0]);
-            char *line_ptr = enable ? line_buf : line_buf + 1;
-            if (trace_event_is_pattern(line_ptr)) {
-                TraceEvent *ev = NULL;
-                while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
-                    if (trace_event_get_state_static(ev)) {
-                        trace_event_set_state_dynamic(ev, enable);
-                    }
-                }
-            } else {
-                TraceEvent *ev = trace_event_name(line_ptr);
-                if (ev == NULL) {
-                    error_report("WARNING: trace event '%s' does not exist",
-                                 line_ptr);
-                } else if (!trace_event_get_state_static(ev)) {
-                    error_report("WARNING: trace event '%s' is not traceable",
-                                 line_ptr);
-                } else {
-                    trace_event_set_state_dynamic(ev, enable);
-                }
-            }
+            trace_enable_events(line_buf);
         }
     }
     if (fclose(fp) != 0) {
@@ -142,17 +173,31 @@ static void trace_init_events(const char *fname)
     loc_pop(&loc);
 }
 
-bool trace_init_backends(const char *events, const char *file)
+void trace_init_file(const char *file)
 {
 #ifdef CONFIG_TRACE_SIMPLE
-    if (!st_init(file)) {
-        fprintf(stderr, "failed to initialize simple tracing backend.\n");
-        return false;
+    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=...: "
                 "option not supported by the selected tracing backends\n");
+        exit(1);
+    }
+#endif
+}
+
+bool trace_init_backends(void)
+{
+#ifdef CONFIG_TRACE_SIMPLE
+    if (!st_init()) {
+        fprintf(stderr, "failed to initialize simple tracing backend.\n");
         return false;
     }
 #endif
@@ -164,6 +209,5 @@ bool trace_init_backends(const char *events, const char *file)
     }
 #endif
 
-    trace_init_events(events);
     return true;
 }
diff --git a/trace/control.h b/trace/control.h
index da9bb6b..d5bc86e 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -104,7 +104,7 @@ static const char * trace_event_get_name(TraceEvent *ev);
  * As a down side, you must always use an immediate #TraceEventID value.
  */
 #define trace_event_get_state(id)                       \
-    ((id ##_ENABLED) && trace_event_get_state_dynamic(trace_event_id(id)))
+    ((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id))
 
 /**
  * trace_event_get_state_static:
@@ -150,8 +150,6 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 
 /**
  * trace_init_backends:
- * @events: Name of file with events to be enabled at startup; may be NULL.
- *          Corresponds to commandline option "-trace events=...".
  * @file:   Name of trace output file; may be NULL.
  *          Corresponds to commandline option "-trace file=...".
  *
@@ -159,7 +157,45 @@ static void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
  *
  * Returns: Whether the backends could be successfully initialized.
  */
-bool trace_init_backends(const char *events, const char *file);
+bool trace_init_backends(void);
+
+/**
+ * trace_init_events:
+ * @events: Name of file with events to be enabled at startup; may be NULL.
+ *          Corresponds to commandline option "-trace events=...".
+ *
+ * Read the list of enabled tracing events.
+ *
+ * Returns: Whether the backends could be successfully initialized.
+ */
+void trace_init_events(const char *file);
+
+/**
+ * trace_init_file:
+ * @file:   Name of trace output file; may be NULL.
+ *          Corresponds to commandline option "-trace file=...".
+ *
+ * Record the name of the output file for the tracing backend.
+ * Exits if no selected backend does not support specifying the
+ * output file, and a non-NULL file was passed.
+ */
+void trace_init_file(const char *file);
+
+/**
+ * trace_list_events:
+ *
+ * List all available events.
+ */
+void trace_list_events(void);
+
+/**
+ * trace_enable_events:
+ * @line_buf: A string with a glob pattern of events to be enabled or,
+ *            if the string starts with '-', disabled.
+ *
+ * Enable or disable matching events.
+ */
+void trace_enable_events(const char *line_buf);
 
 
 #include "trace/control-internal.h"
diff --git a/trace/event-internal.h b/trace/event-internal.h
index b2310d9..86f6a51 100644
--- a/trace/event-internal.h
+++ b/trace/event-internal.h
@@ -18,7 +18,6 @@
  * @id: Unique event identifier.
  * @name: Event name.
  * @sstate: Static tracing state.
- * @dstate: Dynamic tracing state.
  *
  * Opaque generic description of a tracing event.
  */
@@ -26,7 +25,6 @@ typedef struct TraceEvent {
     TraceEventID id;
     const char * name;
     const bool sstate;
-    bool dstate;
 } TraceEvent;
 
 
diff --git a/trace/simple.c b/trace/simple.c
index 56a624c..e8594cd 100644
--- a/trace/simple.c
+++ b/trace/simple.c
@@ -322,7 +322,7 @@ void st_set_trace_file_enabled(bool enable)
  * @file        The trace file name or NULL for the default name-<pid> set at
  *              config time
  */
-bool st_set_trace_file(const char *file)
+void st_set_trace_file(const char *file)
 {
     st_set_trace_file_enabled(false);
 
@@ -336,7 +336,6 @@ bool st_set_trace_file(const char *file)
     }
 
     st_set_trace_file_enabled(true);
-    return true;
 }
 
 void st_print_trace_file_status(FILE *stream, int (*stream_printf)(FILE *stream, const char *fmt, ...))
@@ -374,7 +373,7 @@ static GThread *trace_thread_create(GThreadFunc fn)
     return thread;
 }
 
-bool st_init(const char *file)
+bool st_init(void)
 {
     GThread *thread;
 
@@ -387,6 +386,5 @@ bool st_init(const char *file)
     }
 
     atexit(st_flush_trace_buffer);
-    st_set_trace_file(file);
     return true;
 }
diff --git a/trace/simple.h b/trace/simple.h
index 6997996..8d1a32e 100644
--- a/trace/simple.h
+++ b/trace/simple.h
@@ -20,8 +20,8 @@
 
 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);
-bool st_init(const char *file);
+void st_set_trace_file(const char *file);
+bool st_init(void);
 void st_flush_trace_buffer(void);
 
 typedef struct {
diff --git a/translate-all.c b/translate-all.c
index ab61fac..e9f409b 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -55,6 +55,7 @@
 #include "translate-all.h"
 #include "qemu/bitmap.h"
 #include "qemu/timer.h"
+#include "exec/log.h"
 
 //#define DEBUG_TB_INVALIDATE
 //#define DEBUG_FLUSH
diff --git a/util/Makefile.objs b/util/Makefile.objs
index 8620a80..a8a777e 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -31,3 +31,4 @@ util-obj-y += coroutine-$(CONFIG_COROUTINE_BACKEND).o
 util-obj-y += buffer.o
 util-obj-y += timed-average.o
 util-obj-y += base64.o
+util-obj-y += log.o
diff --git a/qemu-log.c b/util/log.c
index 901b930..46c88c9 100644
--- a/qemu-log.c
+++ b/util/log.c
@@ -19,6 +19,7 @@
 
 #include "qemu-common.h"
 #include "qemu/log.h"
+#include "trace/control.h"
 
 static char *logfilename;
 FILE *qemu_logfile;
@@ -51,6 +52,9 @@ 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");
@@ -151,6 +155,11 @@ int qemu_str_to_log_mask(const char *str)
             for (item = qemu_log_items; item->mask != 0; item++) {
                 mask |= item->mask;
             }
+#ifdef CONFIG_TRACE_LOG
+        } else if (strncmp(p, "trace:", 6) == 0 && p + 6 != p1) {
+            trace_enable_events(p + 6);
+            mask |= LOG_TRACE;
+#endif
         } else {
             for (item = qemu_log_items; item->mask != 0; item++) {
                 if (cmp1(p, p1 - p, item->name)) {
@@ -158,9 +167,9 @@ int qemu_str_to_log_mask(const char *str)
                 }
             }
             return 0;
+        found:
+            mask |= item->mask;
         }
-    found:
-        mask |= item->mask;
         if (*p1 != ',') {
             break;
         }
@@ -174,6 +183,10 @@ void qemu_print_log_usage(FILE *f)
     const QEMULogItem *item;
     fprintf(f, "Log items (comma separated):\n");
     for (item = qemu_log_items; item->mask != 0; item++) {
-        fprintf(f, "%-10s %s\n", item->name, item->help);
+        fprintf(f, "%-15s %s\n", item->name, item->help);
     }
+#ifdef CONFIG_TRACE_LOG
+    fprintf(f, "trace:PATTERN   enable trace events\n");
+    fprintf(f, "\nUse \"-d trace:help\" to get a list of trace events.\n\n");
+#endif
 }
diff --git a/vl.c b/vl.c
index f043009..a7d7c39 100644
--- a/vl.c
+++ b/vl.c
@@ -270,10 +270,14 @@ static QemuOptsList qemu_sandbox_opts = {
 
 static QemuOptsList qemu_trace_opts = {
     .name = "trace",
-    .implied_opt_name = "trace",
+    .implied_opt_name = "enable",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
     .desc = {
         {
+            .name = "enable",
+            .type = QEMU_OPT_STRING,
+        },
+        {
             .name = "events",
             .type = QEMU_OPT_STRING,
         },{
@@ -2988,8 +2992,7 @@ int main(int argc, char **argv, char **envp)
     bool userconfig = true;
     const char *log_mask = NULL;
     const char *log_file = NULL;
-    const char *trace_events = NULL;
-    const char *trace_file = NULL;
+    char *trace_file = NULL;
     ram_addr_t maxram_size;
     uint64_t ram_slots = 0;
     FILE *vmstate_dump_file = NULL;
@@ -3901,12 +3904,19 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_trace:
             {
                 opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
-                                               optarg, false);
+                                               optarg, true);
                 if (!opts) {
                     exit(1);
                 }
-                trace_events = qemu_opt_get(opts, "events");
-                trace_file = qemu_opt_get(opts, "file");
+                if (qemu_opt_get(opts, "enable")) {
+                    trace_enable_events(qemu_opt_get(opts, "enable"));
+                }
+                trace_init_events(qemu_opt_get(opts, "events"));
+                if (trace_file) {
+                    g_free(trace_file);
+                }
+                trace_file = g_strdup(qemu_opt_get(opts, "file"));
+                qemu_opts_del(opts);
                 break;
             }
             case QEMU_OPTION_readconfig:
@@ -4089,6 +4099,8 @@ int main(int argc, char **argv, char **envp)
         exit(0);
     }
 
+    trace_init_file(trace_file);
+
     /* Open the logfile at this point and set the log mask if necessary.
      */
     if (log_file) {
@@ -4103,12 +4115,12 @@ int main(int argc, char **argv, char **envp)
             exit(1);
         }
         qemu_set_log(mask);
+    } else {
+        qemu_set_log(0);
     }
 
-    if (!is_daemonized()) {
-        if (!trace_init_backends(trace_events, trace_file)) {
-            exit(1);
-        }
+    if (!trace_init_backends()) {
+        exit(1);
     }
 
     /* If no data_dir is specified then try to find it relative to the
@@ -4652,12 +4664,6 @@ int main(int argc, char **argv, char **envp)
 
     os_setup_post();
 
-    if (is_daemonized()) {
-        if (!trace_init_backends(trace_events, trace_file)) {
-            exit(1);
-        }
-    }
-
     main_loop();
     replay_disable_events();