From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36985) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YOstC-0002Dy-ME for qemu-devel@nongnu.org; Fri, 20 Feb 2015 14:05:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YOst7-0002pk-LC for qemu-devel@nongnu.org; Fri, 20 Feb 2015 14:05:26 -0500 Received: from smtp3.mundo-r.com ([212.51.32.191]:64865 helo=smtp4.mundo-r.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YOst7-0002pe-Ev for qemu-devel@nongnu.org; Fri, 20 Feb 2015 14:05:21 -0500 Date: Fri, 20 Feb 2015 20:05:18 +0100 From: Alberto Garcia Message-ID: <20150220190518.GA2917@igalia.com> References: <54E77042.8010207@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54E77042.8010207@redhat.com> Subject: Re: [Qemu-devel] [PATCH 0/3] Support streaming to an intermediate layer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi On Fri, Feb 20, 2015 at 10:34:58AM -0700, Eric Blake wrote: > > I followed the proposed API from the wiki, which simply adds an > > additional 'top' parameter to block-stream specifying the image > > that data is written to: > > How does one learn whether qemu is new enough to support this > mode? Until we add QMP introspection, learning whether an optional > parameter exists requires attempting the command and seeing a > different error depending on whether the argument is recognized. Isn't it possible to just check the QEMU version number? If not, what's the recommended way to do it? Thanks, Berto