From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57918) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wsmjj-0007gX-2Z for qemu-devel@nongnu.org; Fri, 06 Jun 2014 01:30:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Wsmjc-0003wp-P8 for qemu-devel@nongnu.org; Fri, 06 Jun 2014 01:30:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:25345) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wsmjc-0003we-BI for qemu-devel@nongnu.org; Fri, 06 Jun 2014 01:30:36 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s565UYNU030725 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 6 Jun 2014 01:30:35 -0400 Date: Fri, 6 Jun 2014 13:30:28 +0800 From: Amos Kong Message-ID: <20140606052801.GB6184@z.redhat.com> References: <538FA3C8.7000108@redhat.com> <20140605001214.GA2639@localhost.localdomain> <538FCDF2.4080409@redhat.com> <20140605020906.GA10963@T430.nay.redhat.com> <538FDC27.3020607@redhat.com> <87ppinesxp.fsf@blackfin.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87ppinesxp.fsf@blackfin.pond.sub.org> Subject: Re: [Qemu-devel] active block commit bug? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Fam Zheng , Jeff Cody , "qemu-devel@nongnu.org" On Thu, Jun 05, 2014 at 09:06:42AM +0200, Markus Armbruster wrote: > Eric Blake writes: > > > On 06/04/2014 08:09 PM, Fam Zheng wrote: > > > >>> Sounds like we have an off-by-one condition if empty files behave > >>> differently from other files. We ought to fix that bug (not that your > >>> normal guest will ever have a 0-length backing file, but this was what I > >>> was trying to use for libvirt's probing of whether active commit is > >>> supported) > >>> > >> > >> Yes, agreed, this special case is only going to make management confused. I > >> will send a patch to fix this. > > > > Thanks. > > > >> > >> Eric, is this a good way to probe the active commit? I was expecting full > >> instrospection of QMP could do it, but I don't know about the status of that > >> piece of work. Amos, any ideas? > > > > Introspection already missed qemu 2.0 when active commit was added; and > > we're close enough to soft freeze for 2.1 that I'm guessing it will miss > > 2.1 as well :( > > Almost certainly. It has non-trivial design issues. To have a chance > to make it into 2.x, it needs to be posted for review early in the 2.x > cycle. I already started to respin the new version, let's see the new version next week. > [...] -- Amos.