This introduces a new tracing backend that targets the SystemTAP
implementation of DTrace userspace tracing. The core functionality
should be applicable and standard across any DTrace implementation
on Solaris, OS-X, *BSD, but the Makefile rules will likely need
some small additional changes to cope with OS specific build
requirements.
This backend builds a little differently from the other tracing
backends. Specifically there is no 'trace.c' file, because the
'dtrace' command line tool generates a '.o' file directly from
the dtrace probe definition file. The probe definition is usually
named with a '.d' extension but QEMU uses '.d' files for its
external makefile dependancy tracking, so this uses '.dtrace' as
the extension for the probe definition file.
The 'tracetool' program gains the ability to generate a trace.h
file for DTrace, and also to generate the trace.d file containing
the dtrace probe definition, and finally a qemu.stp file which is
a wrapper around the probe definition providing more convenient
access from SystemTAP scripts.
eg, instead of
probe process("qemu").mark("qemu_malloc") {
printf("Malloc %d %p\n", $arg1, $arg2);
}
The addition of qemu.stp to /usr/share/systemtap/tapset/
lets users write
probe qemu.qemu_malloc {
printf("Malloc %d %p\n", size, ptr);
}
In v2:
- Add check for 'dtrace' command in configure
- Comply with coding standards in generated code
- Misc fixes to tracetool
- Add more generated files to make clean target
- Mention 'dtrace' backend in configure help
Still todo in v3:
- Change process("qemu") statement so that it applies
to all 'qemu-system-XXX' binaries not just 'qemu'
* .gitignore: Ignore trace-dtrace.*
* Makefile: Extra rules for generating DTrace files
* Makefile.obj: Don't build trace.o for DTrace, use
trace-dtrace.o generated by 'dtrace' instead
* tracetool: Support for generating DTrace/SystemTAP
data files
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
.gitignore | 3 +
Makefile | 32 +++++++++++
Makefile.objs | 4 ++
configure | 12 ++++-
tracetool | 169 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
5 files changed, 209 insertions(+), 11 deletions(-)
diff --git a/.gitignore b/.gitignore
index a43e4d1..0d27afd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,9 @@ config-host.*
config-target.*
trace.h
trace.c
+trace-dtrace.h
+trace-dtrace.dtrace
+qemu.stp
*-timestamp
*-softmmu
*-darwin-user
diff --git a/Makefile b/Makefile
index 252c817..5aa85f6 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,9 @@
# Makefile for QEMU.
GENERATED_HEADERS = config-host.h trace.h
+ifeq ($(TRACE_BACKEND),dtrace)
+GENERATED_HEADERS += trace-dtrace.h
+endif
ifneq ($(wildcard config-host.mak),)
# Put the all: rule here so that config-host.mak can contain dependencies.
@@ -106,7 +109,11 @@ ui/vnc.o: QEMU_CFLAGS += $(VNC_TLS_CFLAGS)
bt-host.o: QEMU_CFLAGS += $(BLUEZ_CFLAGS)
+ifeq ($(TRACE_BACKEND),dtrace)
+trace.h: trace.h-timestamp trace-dtrace.h
+else
trace.h: trace.h-timestamp
+endif
trace.h-timestamp: $(SRC_PATH)/trace-events config-host.mak
$(call quiet-command,sh $(SRC_PATH)/tracetool --$(TRACE_BACKEND) -h <
$< > $@," GEN trace.h")
@cmp -s $@ trace.h || cp $@ trace.h
@@ -118,6 +125,23 @@ trace.c-timestamp: $(SRC_PATH)/trace-events config-host.mak
trace.o: trace.c $(GENERATED_HEADERS)
+trace-dtrace.h: trace-dtrace.dtrace
+ $(call quiet-command,dtrace -o $@ -h -s $<, " GEN trace-dtrace.h")
+
+# Normal practice is to name DTrace probe file with a '.d' extension
+# but that gets picked up by QEMU's Makefile as an external dependancy
+# rule file. So we use '.dtrace' instead
+trace-dtrace.dtrace: trace-dtrace.dtrace-timestamp
+trace-dtrace.dtrace-timestamp: $(SRC_PATH)/trace-events config-host.mak
+ $(call quiet-command,sh $(SRC_PATH)/tracetool --$(TRACE_BACKEND) -d <
$< > $@," GEN trace-dtrace.dtrace")
+ @cmp -s $@ trace-dtrace.dtrace || cp $@ trace-dtrace.dtrace
+ifdef CONFIG_LINUX
+ $(call quiet-command,sh $(SRC_PATH)/tracetool --$(TRACE_BACKEND) -s <
$< > qemu.stp," GEN qemu.stp")
+endif
+
+trace-dtrace.o: trace-dtrace.dtrace $(GENERATED_HEADERS)
+ $(call quiet-command,dtrace -o $@ -G -s $<, " GEN trace-dtrace.o")
+
simpletrace.o: simpletrace.c $(GENERATED_HEADERS)
version.o: $(SRC_PATH)/version.rc config-host.mak
@@ -154,6 +178,8 @@ clean:
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
rm -f qemu-img-cmds.h
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 qemu.stp
$(MAKE) -C tests clean
for d in $(ALL_SUBDIRS) libhw32 libhw64 libuser libdis libdis-user; do \
if test -d $$d; then $(MAKE) -C $$d $@ || exit 1; fi; \
@@ -214,6 +240,12 @@ ifneq ($(BLOBS),)
$(INSTALL_DATA) $(SRC_PATH)/pc-bios/$$x "$(DESTDIR)$(datadir)";
\
done
endif
+ifeq ($(TRACE_BACKEND),dtrace)
+ifdef CONFIG_LINUX
+ $(INSTALL_DIR) "$(DESTDIR)$(datadir)/../systemtap/tapset"
+ $(INSTALL_DATA) qemu.stp "$(DESTDIR)$(datadir)/../systemtap/tapset"
+endif
+endif
$(INSTALL_DIR) "$(DESTDIR)$(datadir)/keymaps"
set -e; for x in $(KEYMAPS); do \
$(INSTALL_DATA) $(SRC_PATH)/pc-bios/keymaps/$$x
"$(DESTDIR)$(datadir)/keymaps"; \
diff --git a/Makefile.objs b/Makefile.objs
index 816194a..ccecda0 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -273,10 +273,14 @@ libdis-$(CONFIG_SPARC_DIS) += sparc-dis.o
######################################################################
# trace
+ifeq ($(TRACE_BACKEND),dtrace)
+trace-obj-y = trace-dtrace.o
+else
trace-obj-y = trace.o
ifeq ($(TRACE_BACKEND),simple)
trace-obj-y += simpletrace.o
endif
+endif
vl.o: QEMU_CFLAGS+=$(GPROF_CFLAGS)
diff --git a/configure b/configure
index a079a49..92bb9c9 100755
--- a/configure
+++ b/configure
@@ -926,7 +926,7 @@ echo " --enable-docs enable documentation build"
echo " --disable-docs disable documentation build"
echo " --disable-vhost-net disable vhost-net acceleration support"
echo " --enable-vhost-net enable vhost-net acceleration support"
-echo " --trace-backend=B Trace backend nop simple ust"
+echo " --trace-backend=B Trace backend nop simple ust dtrace"
echo " --trace-file=NAME Full PATH,NAME of file to store traces"
echo " Default:trace-<pid>"
echo " --disable-spice disable spice"
@@ -2175,6 +2175,16 @@ EOF
exit 1
fi
fi
+
+##########################################
+# For 'dtrace' backend, test if 'dtrace' command is present
+if ! has 'dtrace' ; then
+ echo
+ echo "Error: dtrace command is not found in PATH $PATH"
+ echo
+ exit 1
+fi
+
##########################################
# End of CC checks
# After here, no more $cc or $ld runs
diff --git a/tracetool b/tracetool
index 7010858..047f16b 100755
--- a/tracetool
+++ b/tracetool
@@ -20,10 +20,13 @@ Backends:
--nop Tracing disabled
--simple Simple built-in backend
--ust LTTng User Space Tracing backend
+ --dtrace DTrace/SystemTAP backend
Output formats:
-h Generate .h file
-c Generate .c file
+ -d Generate .d file (DTrace only)
+ -s Generate .stp file (DTrace with SystemTAP only)
EOF
exit 1
}
@@ -46,8 +49,9 @@ get_args()
# Get the argument name list of a trace event
get_argnames()
{
- local nfields field name
+ local nfields field name sep
nfields=0
+ sep="$2"
for field in $(get_args "$1"); do
nfields=$((nfields + 1))
@@ -58,7 +62,7 @@ get_argnames()
name=${field%,}
test "$field" = "$name" && continue
- printf "%s" "$name, "
+ printf "%s%s " $name $sep
done
# Last argument name
@@ -73,7 +77,7 @@ get_argc()
{
local name argc
argc=0
- for name in $(get_argnames "$1"); do
+ for name in $(get_argnames "$1", ","); do
argc=$((argc + 1))
done
echo $argc
@@ -154,7 +158,7 @@ EOF
cast_args_to_uint64_t()
{
local arg
- for arg in $(get_argnames "$1"); do
+ for arg in $(get_argnames "$1", ","); do
printf "%s" "(uint64_t)(uintptr_t)$arg"
done
}
@@ -247,7 +251,7 @@ linetoh_ust()
local name args argnames
name=$(get_name "$1")
args=$(get_args "$1")
- argnames=$(get_argnames "$1")
+ argnames=$(get_argnames "$1", ",")
cat <<EOF
DECLARE_TRACE(ust_$name, TP_PROTO($args), TP_ARGS($argnames));
@@ -274,7 +278,7 @@ linetoc_ust()
local name args argnames fmt
name=$(get_name "$1")
args=$(get_args "$1")
- argnames=$(get_argnames "$1")
+ argnames=$(get_argnames "$1", ",")
fmt=$(get_fmt "$1")
cat <<EOF
@@ -306,6 +310,128 @@ EOF
echo "}"
}
+linetoh_begin_dtrace()
+{
+ cat <<EOF
+#include "trace-dtrace.h"
+EOF
+}
+
+linetoh_dtrace()
+{
+ local name args argnames state nameupper
+ name=$(get_name "$1")
+ args=$(get_args "$1")
+ argnames=$(get_argnames "$1", ",")
+ state=$(get_state "$1")
+ if [ "$state" = "0" ] ; then
+ name=${name##disable }
+ fi
+
+ nameupper=`echo $name | tr '[:lower:]' '[:upper:]'`
+
+ # Define an empty function for the trace event
+ cat <<EOF
+static inline void trace_$name($args) {
+ if (QEMU_${nameupper}_ENABLED()) {
+ QEMU_${nameupper}($argnames);
+ }
+}
+EOF
+}
+
+linetoh_end_dtrace()
+{
+ return
+}
+
+linetoc_begin_dtrace()
+{
+ return
+}
+
+linetoc_dtrace()
+{
+ # No need for function definitions in dtrace backend
+ return
+}
+
+linetoc_end_dtrace()
+{
+ return
+}
+
+linetod_begin_dtrace()
+{
+ cat <<EOF
+provider qemu {
+EOF
+}
+
+linetod_dtrace()
+{
+ local name args state
+ name=$(get_name "$1")
+ args=$(get_args "$1")
+ state=$(get_state "$1")
+ if [ "$state" = "0" ] ; then
+ name=${name##disable }
+ fi
+
+ # Define prototype for probe arguments
+ cat <<EOF
+ probe $name($args);
+EOF
+}
+
+linetod_end_dtrace()
+{
+ cat <<EOF
+};
+EOF
+}
+
+linetos_begin_dtrace()
+{
+ return
+}
+
+linetos_dtrace()
+{
+ local name args arglist state
+ name=$(get_name "$1")
+ args=$(get_args "$1")
+ arglist=$(get_argnames "$1", "")
+ state=$(get_state "$1")
+ if [ "$state" = "0" ] ; then
+ name=${name##disable }
+ fi
+
+ # Define prototype for probe arguments
+ cat <<EOF
+probe qemu.$name = process("qemu").mark("$name")
+{
+EOF
+
+ i=1
+ for arg in $arglist
+ do
+ cat <<EOF
+ $arg = \$arg$i;
+EOF
+ i="$((i+1))"
+ done
+
+ cat <<EOF
+}
+EOF
+}
+
+linetos_end_dtrace()
+{
+ return
+}
+
# Process stdin by calling begin, line, and end functions for the backend
convert()
{
@@ -324,9 +450,10 @@ convert()
disable=${str%%disable *}
echo
if test -z "$disable"; then
- # Pass the disabled state as an arg to lineto$1_simple().
- # For all other cases, call lineto$1_nop()
- if [ $backend = "simple" ]; then
+ # Pass the disabled state as an arg for the simple
+ # or DTrace backends which handle it dynamically.
+ # For all other backends, call lineto$1_nop()
+ if [ $backend = "simple" -o "$backend" = "dtrace" ]; then
"$process_line" "$str"
else
"lineto$1_nop" "${str##disable }"
@@ -360,9 +487,29 @@ tracetoc()
convert c
}
+tracetod()
+{
+ if [ $backend != "dtrace" ]; then
+ echo "DTrace probe generator not applicable to $backend backend"
+ exit 1
+ fi
+ echo "/* This file is autogenerated by tracetool, do not edit. */"
+ convert d
+}
+
+tracetos()
+{
+ if [ $backend != "dtrace" ]; then
+ echo "SystemTAP tapset generator not applicable to $backend backend"
+ exit 1
+ fi
+ echo "/* This file is autogenerated by tracetool, do not edit. */"
+ convert s
+}
+
# Choose backend
case "$1" in
-"--nop" | "--simple" | "--ust") backend="${1#--}" ;;
+"--nop" | "--simple" | "--ust" | "--dtrace") backend="${1#--}" ;;
*) usage ;;
esac
shift
@@ -370,6 +517,8 @@ shift
case "$1" in
"-h") tracetoh ;;
"-c") tracetoc ;;
+"-d") tracetod ;;
+"-s") tracetos ;;
"--check-backend") exit 0 ;; # used by ./configure to test for backend
*) usage ;;
esac
--
1.7.2.3
