From patchwork Mon Sep 5 19:42:47 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 666032 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3sSgVt3w9Yz9s3v for ; Tue, 6 Sep 2016 05:57:26 +1000 (AEST) Received: from localhost ([::1]:56787 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bh01D-00059j-3T for incoming@patchwork.ozlabs.org; Mon, 05 Sep 2016 15:57:23 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57532) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bgzoq-0003Ti-0G for qemu-devel@nongnu.org; Mon, 05 Sep 2016 15:44:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bgzok-0002DH-HE for qemu-devel@nongnu.org; Mon, 05 Sep 2016 15:44:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53356) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bgzok-0002DC-8l for qemu-devel@nongnu.org; Mon, 05 Sep 2016 15:44:30 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C03A580B22; Mon, 5 Sep 2016 19:44:29 +0000 (UTC) Received: from localhost (ovpn-112-28.ams2.redhat.com [10.36.112.28]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u85JiRb9001419; Mon, 5 Sep 2016 15:44:28 -0400 From: Stefan Hajnoczi To: Date: Mon, 5 Sep 2016 15:42:47 -0400 Message-Id: <1473104569-6973-2-git-send-email-stefanha@redhat.com> In-Reply-To: <1473104569-6973-1-git-send-email-stefanha@redhat.com> References: <1473104569-6973-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Mon, 05 Sep 2016 19:44:29 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 1/3] trace: add syslog tracing backend X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Paul Durrant , Stefan Hajnoczi Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Paul Durrant This patch adds a tracing backend which sends output using syslog(). The syslog backend is limited to POSIX compliant systems. openlog() is called with facility set to LOG_DAEMON, with the LOG_PID option. Trace events are logged at level LOG_INFO. Signed-off-by: Paul Durrant Message-id: 1470318254-29989-1-git-send-email-paul.durrant@citrix.com Cc: Stefan Hajnoczi Signed-off-by: Stefan Hajnoczi --- configure | 19 ++++++++++++++++ docs/tracing.txt | 12 ++++++++++ scripts/tracetool/backend/syslog.py | 45 +++++++++++++++++++++++++++++++++++++ trace/control.c | 7 ++++++ 4 files changed, 83 insertions(+) create mode 100644 scripts/tracetool/backend/syslog.py diff --git a/configure b/configure index 4b808f9..5a9bda1 100755 --- a/configure +++ b/configure @@ -4192,6 +4192,18 @@ if compile_prog "" "" ; then fi ########################################## +# check if we have posix_syslog + +posix_syslog=no +cat > $TMPC << EOF +#include +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 $python "$source_path/scripts/tracetool.py" "--backends=$trace_backends" --check-backends > /dev/null 2> /dev/null @@ -5468,6 +5480,13 @@ if have_backend "ftrace"; then feature_not_found "ftrace(trace backend)" "ftrace requires Linux" fi fi +if have_backend "syslog"; then + if test "$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 diff --git a/docs/tracing.txt b/docs/tracing.txt index 29f2f9a..e62444c 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -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 diff --git a/scripts/tracetool/backend/syslog.py b/scripts/tracetool/backend/syslog.py new file mode 100644 index 0000000..89019bc --- /dev/null +++ b/scripts/tracetool/backend/syslog.py @@ -0,0 +1,45 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +""" +Syslog built-in backend. +""" + +__author__ = "Paul Durrant " +__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 ', + '#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) diff --git a/trace/control.c b/trace/control.c index d173c09..b179cde 100644 --- a/trace/control.c +++ b/trace/control.c @@ -19,6 +19,9 @@ #ifdef CONFIG_TRACE_LOG #include "qemu/log.h" #endif +#ifdef CONFIG_TRACE_SYSLOG +#include +#endif #include "qapi/error.h" #include "qemu/error-report.h" #include "qemu/config-file.h" @@ -250,6 +253,10 @@ bool trace_init_backends(void) } #endif +#ifdef CONFIG_TRACE_SYSLOG + openlog(NULL, LOG_PID, LOG_DAEMON); +#endif + return true; }