[Qemu-devel] Add support for SystemTAP and DTrace tracing backends (v6)

[Qemu-devel] Add support for SystemTAP and DTrace tracing backends (v6)

[Daniel P. Berrange]

An update of the SystemTAP/DTrace patches from

  http://lists.gnu.org/archive/html/qemu-devel/2010-11/msg00563.html

The first patch contains the generic DTrace tracing backend support.
The second patch contains additional pieces for SystemTAP to generate
a tapset for each of the qemu-system-XXX binaries, to simplify life
for admins wanting to use the tracing backend.

Changed in v6:

 - Fix handling of probes with no-args in DTrace provider
 - Generate one tapset per target, for both system and user
   emulators
 - Re-write command line arg parsing in tracetool so it
   doesn't assume a particular ordering of args
 - Change '-s' to '--stap' in tracetool to avoid confusion
 - Pass full binary name into tracetool

[Qemu-devel] [PATCH 1/2] Add a DTrace tracing backend targetted for SystemTAP compatability

[Daniel P. Berrange]

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.

Example usage of a dtrace probe in systemtap looks like:

  probe process("qemu").mark("qemu_malloc") {
    printf("Malloc %d %p\n", $arg1, $arg2);
  }

* .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 data files

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 .gitignore    |    2 +
 Makefile      |   23 +++++++++++
 Makefile.objs |    4 ++
 configure     |   14 ++++++-
 tracetool     |  122 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
 5 files changed, 154 insertions(+), 11 deletions(-)

diff --git a/.gitignore b/.gitignore
index a43e4d1..3efb4ec 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,8 @@ config-host.*
 config-target.*
 trace.h
 trace.c
+trace-dtrace.h
+trace-dtrace.dtrace
 *-timestamp
 *-softmmu
 *-darwin-user
diff --git a/Makefile b/Makefile
index 02698e9..554ad97 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,9 @@
 # Makefile for QEMU.
 
 GENERATED_HEADERS = config-host.h trace.h qemu-options.def
+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.
@@ -108,7 +111,11 @@ 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
@@ -120,6 +127,20 @@ 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
+
+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
@@ -157,6 +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
 	$(MAKE) -C tests clean
 	for d in $(ALL_SUBDIRS) libhw32 libhw64 libuser libdis libdis-user; do \
 	if test -d $$d; then $(MAKE) -C $$d $@ || exit 1; fi; \
diff --git a/Makefile.objs b/Makefile.objs
index 15569af..23b17ce 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -286,11 +286,15 @@ libdis-$(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
 user-obj-y += qemu-timer-common.o
 endif
+endif
 
 vl.o: QEMU_CFLAGS+=$(GPROF_CFLAGS)
 
diff --git a/configure b/configure
index 7025d2b..f8dad3e 100755
--- a/configure
+++ b/configure
@@ -929,7 +929,7 @@ 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"
@@ -2193,6 +2193,18 @@ EOF
     exit 1
   fi
 fi
+
+##########################################
+# For 'dtrace' backend, test if 'dtrace' command is present
+if test "$trace_backend" = "dtrace"; then
+  if ! has 'dtrace' ; then
+    echo
+    echo "Error: dtrace command is not found in PATH $PATH"
+    echo
+    exit 1
+  fi
+fi
+
 ##########################################
 # End of CC checks
 # After here, no more $cc or $ld runs
diff --git a/tracetool b/tracetool
index 7010858..1ade103 100755
--- a/tracetool
+++ b/tracetool
@@ -20,10 +20,12 @@ 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)
 EOF
     exit 1
 }
@@ -46,8 +48,9 @@ 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 +61,7 @@ get_argnames()
         name=${field%,}
         test "$field" = "$name" && continue
 
-        printf "%s" "$name, "
+        printf "%s%s " $name $sep
     done
 
     # Last argument name
@@ -73,7 +76,7 @@ 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 +157,7 @@ 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 +250,7 @@ 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($argnames));
@@ -274,7 +277,7 @@ linetoc_ust()
     local name args argnames fmt
     name=$(get_name "$1")
     args=$(get_args "$1")
-    argnames=$(get_argnames "$1")
+    argnames=$(get_argnames "$1", ",")
     fmt=$(get_fmt "$1")
 
     cat <<EOF
@@ -306,6 +309,93 @@ 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=${name##disable }
+    fi
+
+    # DTrace provider syntax expects foo() for empty
+    # params, not foo(void)
+    if [ "$args" = "void" ]; then
+       args=""
+    fi
+
+    # Define prototype for probe arguments
+    cat <<EOF
+        probe $name($args);
+EOF
+}
+
+linetod_end_dtrace()
+{
+    cat <<EOF
+};
+EOF
+}
+
 # Process stdin by calling begin, line, and end functions for the backend
 convert()
 {
@@ -324,9 +414,10 @@ 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 +451,19 @@ 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
+}
+
 # Choose backend
 case "$1" in
-"--nop" | "--simple" | "--ust") backend="${1#--}" ;;
+"--nop" | "--simple" | "--ust" | "--dtrace") backend="${1#--}" ;;
 *) usage ;;
 esac
 shift
@@ -370,6 +471,7 @@ shift
 case "$1" in
 "-h") tracetoh ;;
 "-c") tracetoc ;;
+"-d") tracetod ;;
 "--check-backend") exit 0 ;; # used by ./configure to test for backend
 *) usage ;;
 esac
-- 
1.7.2.3

[Qemu-devel] [PATCH 2/2] Add support for generating a systemtap tapset static probes

[Daniel P. Berrange]

This introduces generation of a qemu.stp/qemu-system-XXX.stp
files which provides tapsets with friendly names for static
probes & their arguments. Instead of

    probe process("qemu").mark("qemu_malloc") {
        printf("Malloc %d %p\n", $arg1, $arg2);
    }

It is now possible todo

    probe qemu.system.i386.qemu_malloc {
        printf("Malloc %d %p\n", size, ptr);
    }

There is one tapset defined per target arch, for both
user and system emulators.

* Makefile.target: Generate stp files for each target
* tracetool: Support for generating systemtap tapsets
* configure: Check for whether systemtap is available
  with the DTrace backend

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 Makefile.target |   29 ++++++++++++-
 configure       |    7 +++
 tracetool       |  128 +++++++++++++++++++++++++++++++++++++++++++++++-------
 3 files changed, 146 insertions(+), 18 deletions(-)

diff --git a/Makefile.target b/Makefile.target
index 91e6e74..7c3671c 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -40,7 +40,27 @@ kvm.o kvm-all.o vhost.o vhost_net.o: QEMU_CFLAGS+=$(KVM_CFLAGS)
 config-target.h: config-target.h-timestamp
 config-target.h-timestamp: config-target.mak
 
-all: $(PROGS)
+ifdef CONFIG_SYSTEMTAP_TRACE
+stap: $(QEMU_PROG).stp
+
+ifdef CONFIG_USER_ONLY
+TARGET_TYPE=user
+else
+TARGET_TYPE=system
+endif
+
+$(QEMU_PROG).stp:
+	$(call quiet-command,sh $(SRC_PATH)/tracetool \
+		--$(TRACE_BACKEND) \
+		--binary $(bindir)/$(QEMU_PROG) \
+		--target-arch $(TARGET_ARCH) \
+		--target-type $(TARGET_TYPE) \
+		--stap < $(SRC_PATH)/trace-events > $(QEMU_PROG).stp,"  GEN   $(QEMU_PROG).stp")
+else
+stap:
+endif
+
+all: $(PROGS) stap
 
 # Dummy command so that make thinks it has done something
 	@true
@@ -340,6 +360,9 @@ clean:
 	rm -f *.o *.a *~ $(PROGS) nwfpe/*.o fpu/*.o
 	rm -f *.d */*.d tcg/*.o ide/*.o
 	rm -f hmp-commands.h qmp-commands.h gdbstub-xml.c
+ifdef CONFIG_SYSTEMTAP_TRACE
+	rm -f *.stp
+endif
 
 install: all
 ifneq ($(PROGS),)
@@ -348,6 +371,10 @@ ifneq ($(STRIP),)
 	$(STRIP) $(patsubst %,"$(DESTDIR)$(bindir)/%",$(PROGS))
 endif
 endif
+ifdef CONFIG_SYSTEMTAP_TRACE
+	$(INSTALL_DIR) "$(DESTDIR)$(datadir)/../systemtap/tapset"
+	$(INSTALL_DATA) $(QEMU_PROG).stp "$(DESTDIR)$(datadir)/../systemtap/tapset"
+endif
 
 # Include automatically generated dependency files
 -include $(wildcard *.d */*.d)
diff --git a/configure b/configure
index f8dad3e..2917874 100755
--- a/configure
+++ b/configure
@@ -2203,6 +2203,10 @@ if test "$trace_backend" = "dtrace"; then
     echo
     exit 1
   fi
+  trace_backend_stap="no"
+  if has 'stap' ; then
+    trace_backend_stap="yes"
+  fi
 fi
 
 ##########################################
@@ -2645,6 +2649,9 @@ fi
 if test "$trace_backend" = "simple"; then
   trace_file="\"$trace_file-%u\""
 fi
+if test "$trace_backend" = "dtrace" -a "$trace_backend_stap" = "yes" ; then
+  echo "CONFIG_SYSTEMTAP_TRACE=y" >> $config_host_mak
+fi
 echo "CONFIG_TRACE_FILE=$trace_file" >> $config_host_mak
 
 echo "TOOLS=$tools" >> $config_host_mak
diff --git a/tracetool b/tracetool
index 1ade103..fce491c 100755
--- a/tracetool
+++ b/tracetool
@@ -23,9 +23,16 @@ Backends:
   --dtrace  DTrace/SystemTAP backend
 
 Output formats:
-  -h    Generate .h file
-  -c    Generate .c file
-  -d    Generate .d file (DTrace only)
+  -h     Generate .h file
+  -c     Generate .c file
+  -d     Generate .d file (DTrace only)
+  --stap Generate .stp file (DTrace with SystemTAP only)
+
+Options:
+  --binary      [path]  Full path to QEMU binary
+  --target-arch [arch]  QEMU emulator target arch
+  --target-type [type]  QEMU emulator target type ('system' or 'user')
+
 EOF
     exit 1
 }
@@ -396,6 +403,51 @@ linetod_end_dtrace()
 EOF
 }
 
+linetostap_begin_dtrace()
+{
+    return
+}
+
+linetostap_dtrace()
+{
+    local i arg 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=${name##disable }
+    fi
+
+    # Define prototype for probe arguments
+    cat <<EOF
+probe qemu.$targettype.$targetarch.$name = process("$binary").mark("$name")
+{
+EOF
+
+    i=1
+    for arg in $arglist
+    do
+        # 'limit' is a reserved keyword
+        if [ "$arg" = "limit" ]; then
+          arg="_limit"
+        fi
+        cat <<EOF
+  $arg = \$arg$i;
+EOF
+	i="$((i+1))"
+    done
+
+    cat <<EOF
+}
+EOF
+}
+
+linetostap_end_dtrace()
+{
+    return
+}
+
 # Process stdin by calling begin, line, and end functions for the backend
 convert()
 {
@@ -461,19 +513,61 @@ tracetod()
     convert d
 }
 
-# Choose backend
-case "$1" in
-"--nop" | "--simple" | "--ust" | "--dtrace") backend="${1#--}" ;;
-*) usage ;;
-esac
-shift
-
-case "$1" in
-"-h") tracetoh ;;
-"-c") tracetoc ;;
-"-d") tracetod ;;
-"--check-backend") exit 0 ;; # used by ./configure to test for backend
-*) usage ;;
-esac
+tracetostap()
+{
+    if [ $backend != "dtrace" ]; then
+       echo "SystemTAP tapset generator not applicable to $backend backend"
+       exit 1
+    fi
+    if [ -z "$binary" ]; then
+       echo "--binary is required for SystemTAP tapset generator"
+       exit 1
+    fi
+    if [ -z "$targettype" ]; then
+       echo "--target-type is required for SystemTAP tapset generator"
+       exit 1
+    fi
+    if [ -z "$targetarch" ]; then
+       echo "--target-arch is required for SystemTAP tapset generator"
+       exit 1
+    fi
+    echo "/* This file is autogenerated by tracetool, do not edit. */"
+    convert stap
+}
+
+
+backend=
+output=
+binary=
+targettype=
+targetarch=
+
+
+until [ -z "$1" ]
+do
+  case "$1" in
+    "--nop" | "--simple" | "--ust" | "--dtrace") backend="${1#--}" ;;
+
+    "--binary") shift ; binary="$1" ;;
+    "--target-arch") shift ; targetarch="$1" ;;
+    "--target-type") shift ; targettype="$1" ;;
+
+    "-h" | "-c" | "-d") output="${1#-}" ;;
+    "--stap") output="${1#--}" ;;
+
+    "--check-backend") exit 0 ;; # used by ./configure to test for backend
+
+    *)
+      usage;;
+  esac
+  shift
+done
+
+if [ "$backend" = "" -o "$output" = "" ]; then
+  usage
+fi
+
+gen="traceto$output"
+"$gen"
 
 exit 0
-- 
1.7.2.3

Re: [Qemu-devel] [PATCH 1/2] Add a DTrace tracing backend targetted for SystemTAP compatability

[Stefan Hajnoczi]

On Fri, Nov 12, 2010 at 1:20 PM, Daniel P. Berrange <berrange@redhat.com> wrote:
> 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.
>
> Example usage of a dtrace probe in systemtap looks like:
>
>  probe process("qemu").mark("qemu_malloc") {
>    printf("Malloc %d %p\n", $arg1, $arg2);
>  }
>
> * .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 data files
>
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  .gitignore    |    2 +
>  Makefile      |   23 +++++++++++
>  Makefile.objs |    4 ++
>  configure     |   14 ++++++-
>  tracetool     |  122 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
>  5 files changed, 154 insertions(+), 11 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Re: [Qemu-devel] [PATCH 2/2] Add support for generating a systemtap tapset static probes

[Stefan Hajnoczi]

On Fri, Nov 12, 2010 at 1:20 PM, Daniel P. Berrange <berrange@redhat.com> wrote:
> This introduces generation of a qemu.stp/qemu-system-XXX.stp
> files which provides tapsets with friendly names for static
> probes & their arguments. Instead of
>
>    probe process("qemu").mark("qemu_malloc") {
>        printf("Malloc %d %p\n", $arg1, $arg2);
>    }
>
> It is now possible todo
>
>    probe qemu.system.i386.qemu_malloc {
>        printf("Malloc %d %p\n", size, ptr);
>    }
>
> There is one tapset defined per target arch, for both
> user and system emulators.
>
> * Makefile.target: Generate stp files for each target
> * tracetool: Support for generating systemtap tapsets
> * configure: Check for whether systemtap is available
>  with the DTrace backend
>
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  Makefile.target |   29 ++++++++++++-
>  configure       |    7 +++
>  tracetool       |  128 +++++++++++++++++++++++++++++++++++++++++++++++-------
>  3 files changed, 146 insertions(+), 18 deletions(-)

Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Re: [Qemu-devel] Add support for SystemTAP and DTrace tracing backends (v6)

[Stefan Hajnoczi]

On Fri, Nov 12, 2010 at 1:20 PM, Daniel P. Berrange <berrange@redhat.com> wrote:
> An update of the SystemTAP/DTrace patches from
>
>  http://lists.gnu.org/archive/html/qemu-devel/2010-11/msg00563.html
>
> The first patch contains the generic DTrace tracing backend support.
> The second patch contains additional pieces for SystemTAP to generate
> a tapset for each of the qemu-system-XXX binaries, to simplify life
> for admins wanting to use the tracing backend.
>
> Changed in v6:
>
>  - Fix handling of probes with no-args in DTrace provider
>  - Generate one tapset per target, for both system and user
>   emulators
>  - Re-write command line arg parsing in tracetool so it
>   doesn't assume a particular ordering of args
>  - Change '-s' to '--stap' in tracetool to avoid confusion
>  - Pass full binary name into tracetool

Both patches look good.  It would be nice to merge this.

Stefan