From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O1KSq-0003ov-E5 for qemu-devel@nongnu.org; Mon, 12 Apr 2010 10:18:12 -0400 Received: from [140.186.70.92] (port=59068 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O1KSo-0003nu-8K for qemu-devel@nongnu.org; Mon, 12 Apr 2010 10:18:11 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O1KSm-00032P-DG for qemu-devel@nongnu.org; Mon, 12 Apr 2010 10:18:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:29782) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O1KSm-00032D-5p for qemu-devel@nongnu.org; Mon, 12 Apr 2010 10:18:08 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o3CEI7vv020730 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 12 Apr 2010 10:18:07 -0400 Date: Mon, 12 Apr 2010 15:18:00 +0100 From: "Daniel P. Berrange" Subject: Re: [Qemu-devel] Re: [libvirt] Libvirt debug API Message-ID: <20100412141800.GD9987@redhat.com> References: <4BBF2E93.3020508@redhat.com> <20100409142717.GA11875@redhat.com> <4BBF6EE6.5080803@redhat.com> <20100412124110.GA9987@redhat.com> <4BC326A2.7050909@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4BC326A2.7050909@redhat.com> Reply-To: "Daniel P. Berrange" List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Chris Lalancette Cc: Libvirt , Jiri Denemark , qemu-devel@nongnu.org On Mon, Apr 12, 2010 at 09:56:50AM -0400, Chris Lalancette wrote: > On 04/12/2010 08:41 AM, Daniel P. Berrange wrote: > >>> I don't think there's much to be gained from having an XML element to > >>> turn on/off use of these APIs. If an app doesn't want to use them, it > >>> can simply not link to libvirt-qemu.so > >> > >> The reason I wanted to do this was mostly for debug/support reasons. > >> That is, with this element in place we can easily tell from the dumpxml > >> output whether a person was using the "unreliable" API's, and thus we can > >> tell them to try and reproduce without that in place. > > > > That doesn't tell you whether they have actually used any API or not. > > It is also inconvenient if you start a guest without it, and only later > > realize you want to use the extra APIs. If we want to track the actual > > usage, then the first time a direct monitor command is issued, we should > > simply log a warning message. > > The problem with logging a message is that it is easy to lose it. What I'm > trying to avoid here is debugging somebody's setup for hours only to find > out that they did a "pci_del" behind libvirt's back. Maybe we can just make the > a read-only flag; it is ignored in the parsing, but > it is set by "GetXMLDesc" when it detects that the virDomainQemuInvokeMonitor > has been called. If the logging message is at level 'WARN' it will be included in syslog for libvirtd by default, which is basic support data always collected. The guest XML is a description of the guest configuration, which is not a place for ad-hoc flags related to API usage. Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|