From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:39423) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QO3EZ-0003EB-1m for qemu-devel@nongnu.org; Sun, 22 May 2011 03:38:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QO3EY-0002wp-4t for qemu-devel@nongnu.org; Sun, 22 May 2011 03:37:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32637) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QO3EX-0002wi-MO for qemu-devel@nongnu.org; Sun, 22 May 2011 03:37:54 -0400 Message-ID: <4DD8BD4C.3030109@redhat.com> Date: Sun, 22 May 2011 10:37:48 +0300 From: Avi Kivity MIME-Version: 1.0 References: <4DD51FDA.3010107@codemonkey.ws> <4DD520ED.8010606@redhat.com> <4DD5260A.1080309@codemonkey.ws> <4DD5272F.5000003@siemens.com> <4DD52848.6030102@codemonkey.ws> <4DD52910.4080106@siemens.com> <4DD52B0E.2080604@codemonkey.ws> <4DD52BF2.2080506@redhat.com> <20110519162706.GB27310@redhat.com> <4DD62D8E.2010605@redhat.com> <20110520115716.GN27310@redhat.com> In-Reply-To: <20110520115716.GN27310@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC] Memory API List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gleb Natapov Cc: Jan Kiszka , qemu-devel On 05/20/2011 02:57 PM, Gleb Natapov wrote: > On Fri, May 20, 2011 at 11:59:58AM +0300, Avi Kivity wrote: > > On 05/19/2011 07:27 PM, Gleb Natapov wrote: > > >> Think of how a window manager folds windows with priorities onto a > > >> flat framebuffer. > > >> > > >> You do a depth-first walk of the tree. For each child list, you > > >> iterate it from the lowest to highest priority, allowing later > > >> subregions override earlier subregions. > > >> > > >I do not think that window manager is a good analogy. Window can > > >overlap with only its siblings. In our memory tree each final node may > > >overlap with any other node in the tree. > > > > > > > Transparent windows. > > > No, still not that. Think about child windows that resides outside of its > parent windows on screen. In our memory region terms think about PCI BAR > is registered to overlap with RAM at address 0x1000 for instance. PCI > BAR memory region and RAM memory region are on very different branches > of the global tree. Right. But what's the problem with that? Which one takes precedence is determined by the priorities of the RAM subregion vs. the PCI bus subregion. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.