[Qemu-devel] [PULL 0/4] Tracing patches

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

This tracing pull request is long overdue for QEMU 1.5.

Eiichi Tsukata's ftrace backend makes it easy to correlate QEMU events with
host kernel events.  He also reports good performance.

Kazuya Saito's trace events make it easier to observe the KVM run loop.

The following changes since commit 8ca27ce2e1150486ea2db4116a03706b28294f16:

  Merge remote-tracking branch 'afaerber/qom-cpu' into staging (2013-05-02 10:57:01 -0500)

are available in the git repository at:


  git://github.com/stefanha/qemu.git tracing

for you to fetch changes up to e64dd5efb2c6d522a3bc9d096cd49a4e53f0ae10:

  trace: document ftrace backend (2013-05-03 13:58:09 +0200)

----------------------------------------------------------------
Eiichi Tsukata (2):
      trace: Add ftrace tracing backend
      trace: document ftrace backend

Kazuya Saito (2):
      kvm-all: add kvm_ioctl, kvm_vm_ioctl, kvm_vcpu_ioctl tracepoints
      kvm-all: add kvm_run_exit tracepoint

 configure                           |   8 +++
 docs/tracing.txt                    |  16 ++++++
 kvm-all.c                           |   5 ++
 scripts/tracetool/backend/ftrace.py |  54 +++++++++++++++++++
 trace-events                        |   7 +++
 trace/Makefile.objs                 |   1 +
 trace/ftrace.c                      | 102 ++++++++++++++++++++++++++++++++++++
 trace/ftrace.h                      |  10 ++++
 8 files changed, 203 insertions(+)
 create mode 100644 scripts/tracetool/backend/ftrace.py
 create mode 100644 trace/ftrace.c
 create mode 100644 trace/ftrace.h

-- 
1.8.1.4

[Qemu-devel] [PATCH 1/4] kvm-all: add kvm_ioctl, kvm_vm_ioctl, kvm_vcpu_ioctl tracepoints

[Stefan Hajnoczi]

From: Kazuya Saito <saito.kazuya@jp.fujitsu.com>

This patch adds tracepoints at ioctl to kvm. Tracing these ioctl is
useful for clarification whether the cause of troubles is qemu or kvm.

Signed-off-by: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 kvm-all.c    | 4 ++++
 trace-events | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/kvm-all.c b/kvm-all.c
index f6c0f4a..4f73b98 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -33,6 +33,7 @@
 #include "exec/memory.h"
 #include "exec/address-spaces.h"
 #include "qemu/event_notifier.h"
+#include "trace.h"
 
 /* This check must be after config-host.h is included */
 #ifdef CONFIG_EVENTFD
@@ -1687,6 +1688,7 @@ int kvm_ioctl(KVMState *s, int type, ...)
     arg = va_arg(ap, void *);
     va_end(ap);
 
+    trace_kvm_ioctl(type, arg);
     ret = ioctl(s->fd, type, arg);
     if (ret == -1) {
         ret = -errno;
@@ -1704,6 +1706,7 @@ int kvm_vm_ioctl(KVMState *s, int type, ...)
     arg = va_arg(ap, void *);
     va_end(ap);
 
+    trace_kvm_vm_ioctl(type, arg);
     ret = ioctl(s->vmfd, type, arg);
     if (ret == -1) {
         ret = -errno;
@@ -1721,6 +1724,7 @@ int kvm_vcpu_ioctl(CPUState *cpu, int type, ...)
     arg = va_arg(ap, void *);
     va_end(ap);
 
+    trace_kvm_vcpu_ioctl(cpu->cpu_index, type, arg);
     ret = ioctl(cpu->kvm_fd, type, arg);
     if (ret == -1) {
         ret = -errno;
diff --git a/trace-events b/trace-events
index 55e80be..d5bc7a5 100644
--- a/trace-events
+++ b/trace-events
@@ -1153,3 +1153,8 @@ virtio_ccw_new_device(int cssid, int ssid, int schid, int devno, const char *dev
 
 # migration.c
 migrate_set_state(int new_state) "new state %d"
+
+# kvm-all.c
+kvm_ioctl(int type, void *arg) "type %d, arg %p"
+kvm_vm_ioctl(int type, void *arg) "type %d, arg %p"
+kvm_vcpu_ioctl(int cpu_index, int type, void *arg) "cpu_index %d, type %d, arg %p"
-- 
1.8.1.4

Re: [Qemu-devel] [PATCH 1/4] kvm-all: add kvm_ioctl, kvm_vm_ioctl, kvm_vcpu_ioctl tracepoints

[Andreas Färber]

Am 03.05.2013 14:01, schrieb Stefan Hajnoczi:
> From: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
> 
> This patch adds tracepoints at ioctl to kvm. Tracing these ioctl is
> useful for clarification whether the cause of troubles is qemu or kvm.
> 
> Signed-off-by: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
>  kvm-all.c    | 4 ++++
>  trace-events | 5 +++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/kvm-all.c b/kvm-all.c
> index f6c0f4a..4f73b98 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -33,6 +33,7 @@
>  #include "exec/memory.h"
>  #include "exec/address-spaces.h"
>  #include "qemu/event_notifier.h"
> +#include "trace.h"
>  
>  /* This check must be after config-host.h is included */
>  #ifdef CONFIG_EVENTFD
> @@ -1687,6 +1688,7 @@ int kvm_ioctl(KVMState *s, int type, ...)
>      arg = va_arg(ap, void *);
>      va_end(ap);
>  
> +    trace_kvm_ioctl(type, arg);
>      ret = ioctl(s->fd, type, arg);
>      if (ret == -1) {
>          ret = -errno;
> @@ -1704,6 +1706,7 @@ int kvm_vm_ioctl(KVMState *s, int type, ...)
>      arg = va_arg(ap, void *);
>      va_end(ap);
>  
> +    trace_kvm_vm_ioctl(type, arg);
>      ret = ioctl(s->vmfd, type, arg);
>      if (ret == -1) {
>          ret = -errno;
> @@ -1721,6 +1724,7 @@ int kvm_vcpu_ioctl(CPUState *cpu, int type, ...)
>      arg = va_arg(ap, void *);
>      va_end(ap);
>  
> +    trace_kvm_vcpu_ioctl(cpu->cpu_index, type, arg);
>      ret = ioctl(cpu->kvm_fd, type, arg);
>      if (ret == -1) {
>          ret = -errno;
> diff --git a/trace-events b/trace-events
> index 55e80be..d5bc7a5 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1153,3 +1153,8 @@ virtio_ccw_new_device(int cssid, int ssid, int schid, int devno, const char *dev
>  
>  # migration.c
>  migrate_set_state(int new_state) "new state %d"
> +
> +# kvm-all.c
> +kvm_ioctl(int type, void *arg) "type %d, arg %p"
> +kvm_vm_ioctl(int type, void *arg) "type %d, arg %p"
> +kvm_vcpu_ioctl(int cpu_index, int type, void *arg) "cpu_index %d, type %d, arg %p"

Sorry that I'm just seeing this patch now (wasn't CC'ed), but I wonder
whether cpu_index is the best thing to trace here? Can we still change
trace event API or would we have to nack/change now?

CC'ing Igor since he just introduced a cpu_get_arch_id() and there's
also a kvm_arch_vcpu_id() introduced earlier by Eduardo.

Regards,
Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PATCH 1/4] kvm-all: add kvm_ioctl, kvm_vm_ioctl, kvm_vcpu_ioctl tracepoints

[Eduardo Habkost]

On Fri, May 03, 2013 at 02:12:14PM +0200, Andreas Färber wrote:
> Am 03.05.2013 14:01, schrieb Stefan Hajnoczi:
> > From: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
> > 
> > This patch adds tracepoints at ioctl to kvm. Tracing these ioctl is
> > useful for clarification whether the cause of troubles is qemu or kvm.
> > 
> > Signed-off-by: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
> > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >  kvm-all.c    | 4 ++++
> >  trace-events | 5 +++++
> >  2 files changed, 9 insertions(+)
> > 
> > diff --git a/kvm-all.c b/kvm-all.c
> > index f6c0f4a..4f73b98 100644
> > --- a/kvm-all.c
> > +++ b/kvm-all.c
> > @@ -33,6 +33,7 @@
> >  #include "exec/memory.h"
> >  #include "exec/address-spaces.h"
> >  #include "qemu/event_notifier.h"
> > +#include "trace.h"
> >  
> >  /* This check must be after config-host.h is included */
> >  #ifdef CONFIG_EVENTFD
> > @@ -1687,6 +1688,7 @@ int kvm_ioctl(KVMState *s, int type, ...)
> >      arg = va_arg(ap, void *);
> >      va_end(ap);
> >  
> > +    trace_kvm_ioctl(type, arg);
> >      ret = ioctl(s->fd, type, arg);
> >      if (ret == -1) {
> >          ret = -errno;
> > @@ -1704,6 +1706,7 @@ int kvm_vm_ioctl(KVMState *s, int type, ...)
> >      arg = va_arg(ap, void *);
> >      va_end(ap);
> >  
> > +    trace_kvm_vm_ioctl(type, arg);
> >      ret = ioctl(s->vmfd, type, arg);
> >      if (ret == -1) {
> >          ret = -errno;
> > @@ -1721,6 +1724,7 @@ int kvm_vcpu_ioctl(CPUState *cpu, int type, ...)
> >      arg = va_arg(ap, void *);
> >      va_end(ap);
> >  
> > +    trace_kvm_vcpu_ioctl(cpu->cpu_index, type, arg);
> >      ret = ioctl(cpu->kvm_fd, type, arg);
> >      if (ret == -1) {
> >          ret = -errno;
> > diff --git a/trace-events b/trace-events
> > index 55e80be..d5bc7a5 100644
> > --- a/trace-events
> > +++ b/trace-events
> > @@ -1153,3 +1153,8 @@ virtio_ccw_new_device(int cssid, int ssid, int schid, int devno, const char *dev
> >  
> >  # migration.c
> >  migrate_set_state(int new_state) "new state %d"
> > +
> > +# kvm-all.c
> > +kvm_ioctl(int type, void *arg) "type %d, arg %p"
> > +kvm_vm_ioctl(int type, void *arg) "type %d, arg %p"
> > +kvm_vcpu_ioctl(int cpu_index, int type, void *arg) "cpu_index %d, type %d, arg %p"
> 
> Sorry that I'm just seeing this patch now (wasn't CC'ed), but I wonder
> whether cpu_index is the best thing to trace here? Can we still change
> trace event API or would we have to nack/change now?
> 
> CC'ing Igor since he just introduced a cpu_get_arch_id() and there's
> also a kvm_arch_vcpu_id() introduced earlier by Eduardo.

Being kvm_vcpu_ioctl() a very low-level KVM function, I believe the KVM
VCPU "id" (the argument passed to KVM_CREATE_VCPU, that needs to be the
APIC ID on x86, and is returned by kvm_arch_vcpu_id()) is the best CPU
identifier to be included here.

cpu_index is the most ambiguous and least reliable CPU identifier we
have today. I wouldn't use it in any new code.

-- 
Eduardo

Re: [Qemu-devel] [PATCH 1/4] kvm-all: add kvm_ioctl, kvm_vm_ioctl, kvm_vcpu_ioctl tracepoints

[Stefan Hajnoczi]

On Fri, May 03, 2013 at 02:12:14PM +0200, Andreas Färber wrote:
> > +# kvm-all.c
> > +kvm_ioctl(int type, void *arg) "type %d, arg %p"
> > +kvm_vm_ioctl(int type, void *arg) "type %d, arg %p"
> > +kvm_vcpu_ioctl(int cpu_index, int type, void *arg) "cpu_index %d, type %d, arg %p"
> 
> Sorry that I'm just seeing this patch now (wasn't CC'ed), but I wonder
> whether cpu_index is the best thing to trace here? Can we still change
> trace event API or would we have to nack/change now?

Trace events are not stable.  We can change them.

STefan

[Qemu-devel] [PATCH 2/4] kvm-all: add kvm_run_exit tracepoint

[Stefan Hajnoczi]

From: Kazuya Saito <saito.kazuya@jp.fujitsu.com>

This patch enable us to know exit reason of KVM_RUN. It will help us
know where the trouble is caused.

Signed-off-by: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 kvm-all.c    | 1 +
 trace-events | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/kvm-all.c b/kvm-all.c
index 4f73b98..3a31602 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -1627,6 +1627,7 @@ int kvm_cpu_exec(CPUArchState *env)
             abort();
         }
 
+        trace_kvm_run_exit(cpu->cpu_index, run->exit_reason);
         switch (run->exit_reason) {
         case KVM_EXIT_IO:
             DPRINTF("handle_io\n");
diff --git a/trace-events b/trace-events
index d5bc7a5..17d75ab 100644
--- a/trace-events
+++ b/trace-events
@@ -1158,3 +1158,5 @@ migrate_set_state(int new_state) "new state %d"
 kvm_ioctl(int type, void *arg) "type %d, arg %p"
 kvm_vm_ioctl(int type, void *arg) "type %d, arg %p"
 kvm_vcpu_ioctl(int cpu_index, int type, void *arg) "cpu_index %d, type %d, arg %p"
+kvm_run_exit(int cpu_index, uint32_t reason) "cpu_index %d, reason %d"
+
-- 
1.8.1.4

[Qemu-devel] [PATCH 3/4] trace: Add ftrace tracing backend

[Stefan Hajnoczi]

From: Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>

This patch adds a ftrace tracing backend which sends trace event to
ftrace marker file. You can effectively compare qemu trace data and
kernel(especially, kvm.ko when using KVM) trace data.
The ftrace backend is restricted to Linux only.

To try out the ftrace backend:

 $ ./configure --trace-backend=ftrace
 $ make

if you use KVM, enable kvm events in ftrace:

 # sudo echo 1 > /sys/kernel/debug/tracing/events/kvm/enable

After running qemu by root user, you can get the trace:

 # cat /sys/kernel/debug/tracing/trace

Signed-off-by: Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 configure                           |   8 +++
 scripts/tracetool/backend/ftrace.py |  54 +++++++++++++++++++
 trace/Makefile.objs                 |   1 +
 trace/ftrace.c                      | 102 ++++++++++++++++++++++++++++++++++++
 trace/ftrace.h                      |  10 ++++
 5 files changed, 175 insertions(+)
 create mode 100644 scripts/tracetool/backend/ftrace.py
 create mode 100644 trace/ftrace.c
 create mode 100644 trace/ftrace.h

diff --git a/configure b/configure
index c4d85ba..e818e8b 100755
--- a/configure
+++ b/configure
@@ -4004,6 +4004,14 @@ if test "$trace_backend" = "dtrace"; then
     echo "CONFIG_TRACE_SYSTEMTAP=y" >> $config_host_mak
   fi
 fi
+if test "$trace_backend" = "ftrace"; then
+  if test "$linux" = "yes" ; then
+    echo "CONFIG_TRACE_FTRACE=y" >> $config_host_mak
+    trace_default=no
+  else
+    feature_not_found "ftrace(trace backend)"
+  fi
+fi
 echo "CONFIG_TRACE_FILE=$trace_file" >> $config_host_mak
 if test "$trace_default" = "yes"; then
   echo "CONFIG_TRACE_DEFAULT=y" >> $config_host_mak
diff --git a/scripts/tracetool/backend/ftrace.py b/scripts/tracetool/backend/ftrace.py
new file mode 100644
index 0000000..888c361
--- /dev/null
+++ b/scripts/tracetool/backend/ftrace.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Ftrace built-in backend.
+"""
+
+__author__     = "Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>"
+__copyright__  = "Copyright (C) 2013 Hitachi, Ltd."
+__license__    = "GPL version 2 or (at your option) any later version"
+
+__maintainer__ = "Stefan Hajnoczi"
+__email__      = "stefanha@redhat.com"
+
+
+from tracetool import out
+
+
+PUBLIC = True
+
+
+def c(events):
+    pass
+
+def h(events):
+    out('#include "trace/ftrace.h"',
+        '#include "trace/control.h"',
+        '',
+        )
+
+    for e in events:
+        argnames = ", ".join(e.args.names())
+        if len(e.args) > 0:
+            argnames = ", " + argnames
+
+        out('static inline void trace_%(name)s(%(args)s)',
+            '{',
+            '    char ftrace_buf[MAX_TRACE_STRLEN];',
+            '    int unused __attribute__ ((unused));',
+            '    int trlen;',
+            '    bool _state = trace_event_get_state(%(event_id)s);',
+            '    if (_state) {',
+            '        trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
+            '                         "%(name)s " %(fmt)s "\\n" %(argnames)s);',
+            '        trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
+            '        unused = write(trace_marker_fd, ftrace_buf, trlen);',
+            '    }',
+            '}',
+            name = e.name,
+            args = e.args,
+            event_id = "TRACE_" + e.name.upper(),
+            fmt = e.fmt.rstrip("\n"),
+            argnames = argnames,
+            )
diff --git a/trace/Makefile.objs b/trace/Makefile.objs
index a043072..3b88e49 100644
--- a/trace/Makefile.objs
+++ b/trace/Makefile.objs
@@ -76,5 +76,6 @@ endif
 util-obj-$(CONFIG_TRACE_DEFAULT) += default.o
 util-obj-$(CONFIG_TRACE_SIMPLE) += simple.o
 util-obj-$(CONFIG_TRACE_STDERR) += stderr.o
+util-obj-$(CONFIG_TRACE_FTRACE) += ftrace.o
 util-obj-y += control.o
 util-obj-y += generated-tracers.o
diff --git a/trace/ftrace.c b/trace/ftrace.c
new file mode 100644
index 0000000..46b7fdb
--- /dev/null
+++ b/trace/ftrace.c
@@ -0,0 +1,102 @@
+/*
+ * Ftrace trace backend
+ *
+ * Copyright (C) 2013 Hitachi, Ltd.
+ * Created by Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <limits.h>
+#include "trace.h"
+#include "trace/control.h"
+
+int trace_marker_fd;
+
+static int find_debugfs(char *debugfs)
+{
+    char type[100];
+    FILE *fp;
+
+    fp = fopen("/proc/mounts", "r");
+    if (fp == NULL) {
+        return 0;
+    }
+
+    while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
+                  debugfs, type) == 2) {
+        if (strcmp(type, "debugfs") == 0) {
+            break;
+        }
+    }
+    fclose(fp);
+
+    if (strcmp(type, "debugfs") != 0) {
+        return 0;
+    }
+    return 1;
+}
+
+void trace_print_events(FILE *stream, fprintf_function stream_printf)
+{
+    TraceEventID i;
+
+    for (i = 0; i < trace_event_count(); i++) {
+        TraceEvent *ev = trace_event_id(i);
+        stream_printf(stream, "%s [Event ID %u] : state %u\n",
+                      trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev));
+    }
+}
+
+void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state)
+{
+    ev->dstate = state;
+}
+
+bool trace_backend_init(const char *events, const char *file)
+{
+    char debugfs[PATH_MAX];
+    char path[PATH_MAX];
+    int debugfs_found;
+    int trace_fd = -1;
+
+    if (file) {
+        fprintf(stderr, "error: -trace file=...: "
+                "option not supported by the selected tracing backend\n");
+        return false;
+    }
+
+    debugfs_found = find_debugfs(debugfs);
+    if (debugfs_found) {
+        snprintf(path, PATH_MAX, "%s/tracing/tracing_on", debugfs);
+        trace_fd = open(path, O_WRONLY);
+        if (trace_fd < 0) {
+            perror("Could not open ftrace 'tracing_on' file");
+            return false;
+        } else {
+            if (write(trace_fd, "1", 1) < 0) {
+                perror("Could not write to 'tracing_on' file");
+                close(trace_fd);
+                return false;
+            }
+            close(trace_fd);
+        }
+        snprintf(path, PATH_MAX, "%s/tracing/trace_marker", debugfs);
+        trace_marker_fd = open(path, O_WRONLY);
+        if (trace_marker_fd < 0) {
+            perror("Could not open ftrace 'trace_marker' file");
+            return false;
+        }
+    } else {
+        fprintf(stderr, "debugfs is not mounted\n");
+        return false;
+    }
+
+    trace_backend_init_events(events);
+    return true;
+}
diff --git a/trace/ftrace.h b/trace/ftrace.h
new file mode 100644
index 0000000..94cb8d5
--- /dev/null
+++ b/trace/ftrace.h
@@ -0,0 +1,10 @@
+#ifndef TRACE_FTRACE_H
+#define TRACE_FTRACE_H
+
+#define MAX_TRACE_STRLEN 512
+#define _STR(x) #x
+#define STR(x) _STR(x)
+
+extern int trace_marker_fd;
+
+#endif /* ! TRACE_FTRACE_H */
-- 
1.8.1.4

[Qemu-devel] [PATCH 4/4] trace: document ftrace backend

[Stefan Hajnoczi]

From: Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>

Add documentation of ftrace backend.

Signed-off-by: Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 docs/tracing.txt | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/docs/tracing.txt b/docs/tracing.txt
index cf53c17..60ff9c5 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -175,6 +175,22 @@ unless you have specific needs for more advanced backends.
 The "simple" backend currently does not capture string arguments, it simply
 records the char* pointer value instead of the string that is pointed to.
 
+=== Ftrace ===
+
+The "ftrace" backend writes trace data to ftrace marker. This effectively
+sends trace events to ftrace ring buffer, and you can compare qemu trace
+data and kernel(especially kvm.ko when using KVM) trace data.
+
+if you use KVM, enable kvm events in ftrace:
+
+   # echo 1 > /sys/kernel/debug/tracing/events/kvm/enable
+
+After running qemu by root user, you can get the trace:
+
+   # cat /sys/kernel/debug/tracing/trace
+
+Restriction: "ftrace" backend is restricted to Linux only.
+
 ==== Monitor commands ====
 
 * trace-file on|off|flush|set <path>
-- 
1.8.1.4

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

The following changes since commit 411ad78115ebeb3411cf4b7622784b93dfabe259:

  Merge remote-tracking branch 'remotes/stefanberger/tags/pull-tpm-2017-12-15-1' into staging (2017-12-17 15:27:41 +0000)

are available in the Git repository at:

  git://github.com/stefanha/qemu.git tags/tracing-pull-request

for you to fetch changes up to 5c9522b358faf9688fd83cd0a881e1990bb84516:

  gdbstub: add tracing (2017-12-18 14:37:36 +0000)

----------------------------------------------------------------

----------------------------------------------------------------

Doug Gale (1):
  gdbstub: add tracing

Namhyung Kim (3):
  trace: Simplify find_debugfs()
  trace: Generalize searching for debugfs
  trace: Try using tracefs first

 gdbstub.c      | 113 +++++++++++++++++++++++++++++++++++++++------------------
 trace/ftrace.c |  33 ++++++++++-------
 trace-events   |  28 ++++++++++++++
 3 files changed, 125 insertions(+), 49 deletions(-)

-- 
2.14.3

Re: [Qemu-devel] [PULL 0/4] Tracing patches

[Peter Maydell]

On 18 December 2017 at 14:47, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> The following changes since commit 411ad78115ebeb3411cf4b7622784b93dfabe259:
>
>   Merge remote-tracking branch 'remotes/stefanberger/tags/pull-tpm-2017-12-15-1' into staging (2017-12-17 15:27:41 +0000)
>
> are available in the Git repository at:
>
>   git://github.com/stefanha/qemu.git tags/tracing-pull-request
>
> for you to fetch changes up to 5c9522b358faf9688fd83cd0a881e1990bb84516:
>
>   gdbstub: add tracing (2017-12-18 14:37:36 +0000)
>
> ----------------------------------------------------------------
>
> ----------------------------------------------------------------
>

Applied, thanks.

-- PMM

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

The following changes since commit 2ccede18bd24fce5db83fef3674563a1f256717b:

  Merge remote-tracking branch 'remotes/vivier/tags/m68k-for-2.9-pull-request' into staging (2017-01-16 12:41:35 +0000)

are available in the git repository at:

  git://github.com/stefanha/qemu.git tags/tracing-pull-request

for you to fetch changes up to a47e87151e785977d34e7b726495e7781860ca9f:

  trace: Add event "guest_cpu_exit" (2017-01-16 13:40:56 +0000)

----------------------------------------------------------------

----------------------------------------------------------------

Lluís Vilanova (3):
  trace: Lock vCPU list when initializing dynamic tracing state
  trace: Fix dynamic event state on vCPU hot-unplug
  trace: Add event "guest_cpu_exit"

Marc-André Lureau (1):
  trace-events: spelling fix

 trace/control.h        |  8 ++++++++
 qom/cpu.c              |  2 ++
 trace/control-target.c | 11 ++++++++++-
 trace/control.c        | 19 +++++++++++++++++++
 trace-events           |  8 +++++++-
 5 files changed, 46 insertions(+), 2 deletions(-)

-- 
2.9.3

Re: [Qemu-devel] [PULL 0/4] Tracing patches

[Peter Maydell]

On 16 January 2017 at 13:44, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> The following changes since commit 2ccede18bd24fce5db83fef3674563a1f256717b:
>
>   Merge remote-tracking branch 'remotes/vivier/tags/m68k-for-2.9-pull-request' into staging (2017-01-16 12:41:35 +0000)
>
> are available in the git repository at:
>
>   git://github.com/stefanha/qemu.git tags/tracing-pull-request
>
> for you to fetch changes up to a47e87151e785977d34e7b726495e7781860ca9f:
>
>   trace: Add event "guest_cpu_exit" (2017-01-16 13:40:56 +0000)
>
> ----------------------------------------------------------------
>
> ----------------------------------------------------------------
>

Applied, thanks.

-- PMM

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

The following changes since commit 9370a3bbc478f623dd21d783560629ea2064625b:

  Update version for v2.6.0-rc0 release (2016-03-30 19:25:40 +0100)

are available in the git repository at:

  git://github.com/stefanha/qemu.git tags/tracing-pull-request

for you to fetch changes up to a6d4953b6057dfc0b9b6b2d775231648fca3ca2b:

  trace-events: Fix typos (found by codespell) (2016-03-31 10:37:00 +0100)

----------------------------------------------------------------

----------------------------------------------------------------

Denis V. Lunev (2):
  trace: do not always call exit() in trace_enable_events
  log: move qemu_log_close/qemu_log_flush from header to log.c

Richard W.M. Jones (1):
  docs: Update documentation for stderr (now log) tracing backend.

Stefan Weil (1):
  trace-events: Fix typos (found by codespell)

 docs/tracing.txt   |  4 ++--
 include/qemu/log.h | 22 +++++-----------------
 trace-events       |  4 ++--
 trace/control.c    |  5 ++++-
 util/log.c         | 17 +++++++++++++++++
 5 files changed, 30 insertions(+), 22 deletions(-)

-- 
2.5.5

Re: [Qemu-devel] [PULL 0/4] Tracing patches

[Peter Maydell]

On 31 March 2016 at 13:35, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> The following changes since commit 9370a3bbc478f623dd21d783560629ea2064625b:
>
>   Update version for v2.6.0-rc0 release (2016-03-30 19:25:40 +0100)
>
> are available in the git repository at:
>
>   git://github.com/stefanha/qemu.git tags/tracing-pull-request
>
> for you to fetch changes up to a6d4953b6057dfc0b9b6b2d775231648fca3ca2b:
>
>   trace-events: Fix typos (found by codespell) (2016-03-31 10:37:00 +0100)

Applied, thanks.

-- PMM

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

The following changes since commit 38a762fec63fd5c035aae29ba9a77d357e21e4a7:

  Merge remote-tracking branch 'remotes/berrange/tags/pull-crypto-fixes-2015-12-23-1' into staging (2015-12-23 13:53:32 +0000)

are available in the git repository at:

  git://github.com/stefanha/qemu.git tags/tracing-pull-request

for you to fetch changes up to cef517ca4bf890ef5405aac1b95f75dcda043d6a:

  trace: add make dependencies on tracetool source (2016-01-07 16:59:56 +0800)

----------------------------------------------------------------

----------------------------------------------------------------

Mark Cave-Ayland (1):
  trace: fix PRIx64 constants in trace-events

Qinghua Jin (1):
  trace: reflect the file name change

Stefan Hajnoczi (2):
  trace: fix make foo-timestamp rules
  trace: add make dependencies on tracetool source

 trace-events        | 14 ++++++++------
 trace/Makefile.objs | 48 ++++++++++++++++++++++++++++--------------------
 2 files changed, 36 insertions(+), 26 deletions(-)

-- 
2.5.0

Re: [Qemu-devel] [PULL 0/4] Tracing patches

[Peter Maydell]

On 7 January 2016 at 09:13, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> The following changes since commit 38a762fec63fd5c035aae29ba9a77d357e21e4a7:
>
>   Merge remote-tracking branch 'remotes/berrange/tags/pull-crypto-fixes-2015-12-23-1' into staging (2015-12-23 13:53:32 +0000)
>
> are available in the git repository at:
>
>   git://github.com/stefanha/qemu.git tags/tracing-pull-request
>
> for you to fetch changes up to cef517ca4bf890ef5405aac1b95f75dcda043d6a:
>
>   trace: add make dependencies on tracetool source (2016-01-07 16:59:56 +0800)
>
> ----------------------------------------------------------------
>
> ----------------------------------------------------------------

Applied, thanks. (Hopefully this fixes the travis builds.)

-- PMM

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

The following changes since commit 0169c511554cb0014a00290b0d3d26c31a49818f:

  Merge remote-tracking branch 'qemu-kvm/uq/master' into staging (2014-01-24 15:52:44 -0800)

are available in the git repository at:


  git://github.com/stefanha/qemu.git tags/tracing-pull-request

for you to fetch changes up to 736ec1677f1ae7e64f2f3436ca3775c48f79678c:

  trace: fix simple trace "disable" keyword (2014-01-27 15:49:39 +0100)

----------------------------------------------------------------
Tracing pull request

----------------------------------------------------------------
Lluís Vilanova (1):
      trace: [simple] Do not include "trace/simple.h" in generated tracer headers

Michael Mueller (1):
      tracing: start trace processing thread in final child process

Stefan Hajnoczi (2):
      trace: add glib 2.32+ static GMutex support
      trace: fix simple trace "disable" keyword

 scripts/tracetool/backend/simple.py |  6 ++----
 trace/simple.c                      | 24 +++++++++++++++++-------
 vl.c                                | 12 ++++++++++--
 3 files changed, 29 insertions(+), 13 deletions(-)

-- 
1.8.4.2

Re: [Qemu-devel] [PULL 0/4] Tracing patches

[Peter Maydell]

On 27 January 2014 14:53, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> The following changes since commit 0169c511554cb0014a00290b0d3d26c31a49818f:
>
>   Merge remote-tracking branch 'qemu-kvm/uq/master' into staging (2014-01-24 15:52:44 -0800)
>
> are available in the git repository at:
>
>
>   git://github.com/stefanha/qemu.git tags/tracing-pull-request
>
> for you to fetch changes up to 736ec1677f1ae7e64f2f3436ca3775c48f79678c:
>
>   trace: fix simple trace "disable" keyword (2014-01-27 15:49:39 +0100)
>
> ----------------------------------------------------------------
> Tracing pull request
>

Applied, thanks.

-- PMM

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

The following changes since commit 6801038bc52d61f81ac8a25fbe392f1bad982887:

  target-mips: fix wrong microMIPS opcode encoding (2012-11-15 14:48:16 +0100)

are available in the git repository at:

  git://github.com/stefanha/qemu.git tracing

for you to fetch changes up to e94c4c9287392e9c4de5e9cc3a0fa40da959ccb5:

  trace: Remove "info trace" from documents (2012-11-16 13:35:48 +0100)

----------------------------------------------------------------
Daniel P. Berrange (1):
      Avoid all systemtap reserved words

Gerd Hoffmann (1):
      trace: allow disabling events in events file

Liming Wang (1):
      trace: Remove "info trace" from documents

Stefan Hajnoczi (1):
      trace: document '-' syntax for disabling events

 docs/tracing.txt                    | 13 ++++---------
 hmp-commands.hx                     |  7 -------
 scripts/tracetool/backend/dtrace.py | 11 ++++++++++-
 trace/control.c                     |  9 ++++++++-
 4 files changed, 22 insertions(+), 18 deletions(-)

-- 
1.8.0

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

Simpletrace v2 has landed:
 * Strings are now logged instead of their pointers
 * Variable-length arguments allow for >6 trace event arguments

Thanks to Harsh Prateek Bora for this improvement!

The following changes since commit dfe1ce5d80cba603bafaac91b239d683abe19cf7:

  Merge remote-tracking branch 'kwolf/for-anthony' into staging (2012-07-18 14:44:50 -0500)

are available in the git repository at:


  git://github.com/stefanha/qemu.git tracing

for you to fetch changes up to 90a147a275da3a432bdf00238ebf438eff1d2c1b:

  Update simpletrace.py for new log format (2012-07-19 11:34:33 +0100)

----------------------------------------------------------------
Alexey Kardashevskiy (1):
      trace: added ability to comment out events in the list

Harsh Prateek Bora (3):
      monitor: remove unused do_info_trace
      Simpletrace v2: Support multiple arguments, strings.
      Update simpletrace.py for new log format

 monitor.c                           |   16 ---
 scripts/simpletrace.py              |  116 +++++++++------
 scripts/tracetool/backend/simple.py |   90 +++++++++---
 trace/control.c                     |    3 +
 trace/simple.c                      |  271 ++++++++++++++++++++---------------
 trace/simple.h                      |   40 ++++--
 6 files changed, 340 insertions(+), 196 deletions(-)

-- 
1.7.10.4

Re: [Qemu-devel] [PULL 0/4] Tracing patches

[Harsh Bora]

On 07/19/2012 04:22 PM, Stefan Hajnoczi wrote:
> Simpletrace v2 has landed:
>   * Strings are now logged instead of their pointers
>   * Variable-length arguments allow for >6 trace event arguments
>
> Thanks to Harsh Prateek Bora for this improvement!

Thanks very much to Stefan Hajnoczi for his effective, detailed reviews 
without which it would have taken longer.

regards,
Harsh

>
> The following changes since commit dfe1ce5d80cba603bafaac91b239d683abe19cf7:
>
>    Merge remote-tracking branch 'kwolf/for-anthony' into staging (2012-07-18 14:44:50 -0500)
>
> are available in the git repository at:
>
>
>    git://github.com/stefanha/qemu.git tracing
>
> for you to fetch changes up to 90a147a275da3a432bdf00238ebf438eff1d2c1b:
>
>    Update simpletrace.py for new log format (2012-07-19 11:34:33 +0100)
>
> ----------------------------------------------------------------
> Alexey Kardashevskiy (1):
>        trace: added ability to comment out events in the list
>
> Harsh Prateek Bora (3):
>        monitor: remove unused do_info_trace
>        Simpletrace v2: Support multiple arguments, strings.
>        Update simpletrace.py for new log format
>
>   monitor.c                           |   16 ---
>   scripts/simpletrace.py              |  116 +++++++++------
>   scripts/tracetool/backend/simple.py |   90 +++++++++---
>   trace/control.c                     |    3 +
>   trace/simple.c                      |  271 ++++++++++++++++++++---------------
>   trace/simple.h                      |   40 ++++--
>   6 files changed, 340 insertions(+), 196 deletions(-)
>

[Qemu-devel] [PULL 0/4] Tracing patches

[Stefan Hajnoczi]

The following changes since commit d11cf8cc80d946dfc9a23597cd9a0bb1c487cfa7:

  etrax-dma: Remove bogus if statement (2011-10-03 10:20:13 +0200)

are available in the git repository at:
  ssh://repo.or.cz/srv/git/qemu/stefanha.git tracing

Michael Roth (1):
      hmp: re-enable trace-file command

Stefan Hajnoczi (3):
      trace: trace bdrv_open_common()
      trace: trace monitor qmp dispatch/completion
      trace: add arguments to bdrv_co_io_em() trace event

 block.c         |    4 +++-
 hmp-commands.hx |    2 +-
 monitor.c       |    7 +++++--
 trace-events    |    7 ++++++-
 4 files changed, 15 insertions(+), 5 deletions(-)

-- 
1.7.6.3

Re: [Qemu-devel] [PULL 0/4] Tracing patches

[Blue Swirl]

On Mon, Oct 3, 2011 at 11:30 AM, Stefan Hajnoczi
<stefanha@linux.vnet.ibm.com> wrote:
> The following changes since commit d11cf8cc80d946dfc9a23597cd9a0bb1c487cfa7:
>
>  etrax-dma: Remove bogus if statement (2011-10-03 10:20:13 +0200)
>
> are available in the git repository at:
>  ssh://repo.or.cz/srv/git/qemu/stefanha.git tracing

Thanks, pulled.

>
> Michael Roth (1):
>      hmp: re-enable trace-file command
>
> Stefan Hajnoczi (3):
>      trace: trace bdrv_open_common()
>      trace: trace monitor qmp dispatch/completion
>      trace: add arguments to bdrv_co_io_em() trace event
>
>  block.c         |    4 +++-
>  hmp-commands.hx |    2 +-
>  monitor.c       |    7 +++++--
>  trace-events    |    7 ++++++-
>  4 files changed, 15 insertions(+), 5 deletions(-)
>
> --
> 1.7.6.3
>
>