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

# gpg: Signature made Mon 05 Sep 2016 20:41:04 BST
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  trace: Avoid implicit bool->integer conversions
  trace: Remove 'trace_events_dstate_init'
  trace: add syslog tracing backend

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2016-09-06 12:41:24 +01:00
commit 30e7d092b2
8 changed files with 149 additions and 15 deletions

19
configure vendored
View File

@ -4191,6 +4191,18 @@ if compile_prog "" "" ; then
posix_madvise=yes
fi
##########################################
# check if we have posix_syslog
posix_syslog=no
cat > $TMPC << EOF
#include <syslog.h>
int main(void) { openlog("qemu", LOG_PID, LOG_DAEMON); syslog(LOG_INFO, "configure"); return 0; }
EOF
if compile_prog "" "" ; then
posix_syslog=yes
fi
##########################################
# check if trace backend exists
@ -5468,6 +5480,13 @@ if have_backend "ftrace"; then
feature_not_found "ftrace(trace backend)" "ftrace requires Linux"
fi
fi
if have_backend "syslog"; then
if test "$posix_syslog" = "yes" ; then
echo "CONFIG_TRACE_SYSLOG=y" >> $config_host_mak
else
feature_not_found "syslog(trace backend)" "syslog not available"
fi
fi
echo "CONFIG_TRACE_FILE=$trace_file" >> $config_host_mak
if test "$rdma" = "yes" ; then

View File

@ -192,6 +192,18 @@ After running qemu by root user, you can get the trace:
Restriction: "ftrace" backend is restricted to Linux only.
=== Syslog ===
The "syslog" backend sends trace events using the POSIX syslog API. The log
is opened specifying the LOG_DAEMON facility and LOG_PID option (so events
are tagged with the pid of the particular QEMU process that generated
them). All events are logged at LOG_INFO level.
NOTE: syslog may squash duplicate consecutive trace events and apply rate
limiting.
Restriction: "syslog" backend is restricted to POSIX compliant OS.
==== Monitor commands ====
* trace-file on|off|flush|set <path>

View File

@ -0,0 +1,45 @@
#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Syslog built-in backend.
"""
__author__ = "Paul Durrant <paul.durrant@citrix.com>"
__copyright__ = "Copyright 2016, Citrix Systems Inc."
__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 generate_h_begin(events):
out('#include <syslog.h>',
'#include "trace/control.h"',
'')
def generate_h(event):
argnames = ", ".join(event.args.names())
if len(event.args) > 0:
argnames = ", " + argnames
if "vcpu" in event.properties:
# already checked on the generic format code
cond = "true"
else:
cond = "trace_event_get_state(%s)" % ("TRACE_" + event.name.upper())
out(' if (%(cond)s) {',
' syslog(LOG_INFO, "%(name)s " %(fmt)s %(argnames)s);',
' }',
cond=cond,
name=event.name,
fmt=event.fmt.rstrip("\n"),
argnames=argnames)

View File

@ -11,13 +11,31 @@
#include "trace/control.h"
void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
{
trace_event_set_state_dynamic(ev, state);
}
void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
{
TraceEventID id;
bool state_pre;
assert(trace_event_get_state_static(ev));
id = trace_event_get_id(ev);
trace_events_enabled_count += state - trace_events_dstate[id];
trace_events_dstate[id] = state;
/*
* We ignore the "vcpu" property here, since there's no target code. Then
* dstate can only be 1 or 0.
*/
state_pre = trace_events_dstate[id];
if (state_pre != state) {
if (state) {
trace_events_enabled_count++;
trace_events_dstate[id] = 1;
} else {
trace_events_enabled_count--;
trace_events_dstate[id] = 0;
}
}
}
void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,

View File

@ -13,6 +13,27 @@
#include "translate-all.h"
void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
{
TraceEventID id = trace_event_get_id(ev);
bool state_pre;
assert(trace_event_get_state_static(ev));
/*
* We ignore the "vcpu" property here, since no vCPUs have been created
* yet. Then dstate can only be 1 or 0.
*/
state_pre = trace_events_dstate[id];
if (state_pre != state) {
if (state) {
trace_events_enabled_count++;
trace_events_dstate[id] = 1;
} else {
trace_events_enabled_count--;
trace_events_dstate[id] = 0;
}
}
}
void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
{
CPUState *vcpu;
@ -22,9 +43,18 @@ void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
trace_event_set_vcpu_state_dynamic(vcpu, ev, state);
}
} else {
/* Without the "vcpu" property, dstate can only be 1 or 0 */
TraceEventID id = trace_event_get_id(ev);
trace_events_enabled_count += state - trace_events_dstate[id];
trace_events_dstate[id] = state;
bool state_pre = trace_events_dstate[id];
if (state_pre != state) {
if (state) {
trace_events_enabled_count++;
trace_events_dstate[id] = 1;
} else {
trace_events_enabled_count--;
trace_events_dstate[id] = 0;
}
}
}
}

View File

@ -19,6 +19,9 @@
#ifdef CONFIG_TRACE_LOG
#include "qemu/log.h"
#endif
#ifdef CONFIG_TRACE_SYSLOG
#include <syslog.h>
#endif
#include "qapi/error.h"
#include "qemu/error-report.h"
#include "qemu/config-file.h"
@ -31,8 +34,6 @@ int trace_events_enabled_count;
* - true : Integral counting the number of vCPUs that have this event enabled.
*/
uint16_t trace_events_dstate[TRACE_EVENT_COUNT];
/* Marks events for late vCPU state init */
static bool trace_events_dstate_init[TRACE_EVENT_COUNT];
QemuOptsList qemu_trace_opts = {
.name = "trace",
@ -142,10 +143,7 @@ static void do_trace_enable_events(const char *line_buf)
TraceEvent *ev = NULL;
while ((ev = trace_event_pattern(line_ptr, ev)) != NULL) {
if (trace_event_get_state_static(ev)) {
/* start tracing */
trace_event_set_state_dynamic(ev, enable);
/* mark for late vCPU init */
trace_events_dstate_init[ev->id] = true;
trace_event_set_state_dynamic_init(ev, enable);
}
}
} else {
@ -157,10 +155,7 @@ static void do_trace_enable_events(const char *line_buf)
error_report("WARNING: trace event '%s' is not traceable",
line_ptr);
} else {
/* start tracing */
trace_event_set_state_dynamic(ev, enable);
/* mark for late vCPU init */
trace_events_dstate_init[ev->id] = true;
trace_event_set_state_dynamic_init(ev, enable);
}
}
}
@ -250,6 +245,10 @@ bool trace_init_backends(void)
}
#endif
#ifdef CONFIG_TRACE_SYSLOG
openlog(NULL, LOG_PID, LOG_DAEMON);
#endif
return true;
}
@ -277,7 +276,14 @@ void trace_init_vcpu_events(void)
while ((ev = trace_event_pattern("*", ev)) != NULL) {
if (trace_event_is_vcpu(ev) &&
trace_event_get_state_static(ev) &&
trace_events_dstate_init[ev->id]) {
trace_event_get_state_dynamic(ev)) {
TraceEventID id = trace_event_get_id(ev);
/* check preconditions */
assert(trace_events_dstate[id] == 1);
/* disable early-init state ... */
trace_events_dstate[id] = 0;
trace_events_enabled_count--;
/* ... and properly re-enable */
trace_event_set_state_dynamic(ev, true);
}
}

View File

@ -274,6 +274,9 @@ char *trace_opt_parse(const char *optarg);
*
* Re-synchronize initial event state with vCPUs (which can be created after
* trace_init_events()).
*
* Precondition: event states won't be changed between trace_enable_events() and
* trace_init_vcpu_events() (e.g., through QMP).
*/
void trace_init_vcpu_events(void);

View File

@ -29,5 +29,6 @@ typedef struct TraceEvent {
const bool sstate;
} TraceEvent;
void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state);
#endif /* TRACE__EVENT_INTERNAL_H */