From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40305) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7o2E-0001g2-HF for qemu-devel@nongnu.org; Wed, 14 Mar 2012 09:14:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S7o1y-0002en-EJ for qemu-devel@nongnu.org; Wed, 14 Mar 2012 09:14:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40543) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7o1y-0002eg-6J for qemu-devel@nongnu.org; Wed, 14 Mar 2012 09:14:18 -0400 Date: Wed, 14 Mar 2012 15:14:10 +0200 From: Alon Levy Message-ID: <20120314131410.GE27659@garlic.redhat.com> References: <1331483977-18910-1-git-send-email-alevy@redhat.com> <1331494004-26177-1-git-send-email-alevy@redhat.com> <1331494004-26177-5-git-send-email-alevy@redhat.com> <20120313103555.0ae4b834@doriath.home> <20120313144514.GK27659@garlic.redhat.com> <4F605376.1050703@redhat.com> <20120314083713.GA26510@redhat.com> <20120314093258.4bdbc0a3@doriath.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120314093258.4bdbc0a3@doriath.home> Subject: Re: [Qemu-devel] [PATCH v2 4/5] console: pass Monitor to vga_hw_screen_dump/hw_vga_dump List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: aliguori@us.ibm.com, Gerd Hoffmann , qemu-devel@nongnu.org On Wed, Mar 14, 2012 at 09:32:58AM -0300, Luiz Capitulino wrote: > On Wed, 14 Mar 2012 08:37:13 +0000 > "Daniel P. Berrange" wrote: > > > > First, with this applied you will not know the size in advance. Also > > > one of the approaches discussed is to allow passing in a file handle. > > > That is a possible way to handle async screendumps too: just write to > > > the passed file handle and close it when done. Obvious drawback is that > > > this will not cover the classic way of specifying the output filename as > > > argument. > > As Daniel explains below, this is not a drawback and there's no problem > supporting multiple ways of returning the image. > > The real drawback of making this w/o async support is that you can't detect > errors. > You also can't detect when the writing is done (unless you continuously try to parse the file yourself..) > > This would not be a problem from libvirt's POV - we don't really want a > > file on disk anyway, nor do we want to pull the whole image into memory. > > Our ideal approach is to just have an pipe FD with QEMU, which we just > > incrementally read image data from, and forward to the client app via > > a libvirt stream object. >