From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:48267)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <gleb@redhat.com>) id 1QN5ur-0000R8-0I
	for qemu-devel@nongnu.org; Thu, 19 May 2011 12:17:37 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <gleb@redhat.com>) id 1QN5up-0002XM-Pg
	for qemu-devel@nongnu.org; Thu, 19 May 2011 12:17:36 -0400
Received: from mx1.redhat.com ([209.132.183.28]:49732)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <gleb@redhat.com>) id 1QN5up-0002XA-IE
	for qemu-devel@nongnu.org; Thu, 19 May 2011 12:17:35 -0400
Date: Thu, 19 May 2011 19:17:31 +0300
From: Gleb Natapov <gleb@redhat.com>
Message-ID: <20110519161731.GA27310@redhat.com>
References: <4DD51A82.7060205@siemens.com> <4DD51B64.8000306@redhat.com>
	<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>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <4DD52BF2.2080506@redhat.com>
Subject: Re: [Qemu-devel] [RFC] Memory API
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Avi Kivity <avi@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>, qemu-devel <qemu-devel@nongnu.org>

On Thu, May 19, 2011 at 05:40:50PM +0300, Avi Kivity wrote:
> On 05/19/2011 05:37 PM, Anthony Liguori wrote:
> >
> >So....  do you do:
> >
> >isa_register_region(ISABus *bus, MemoryRegion *mr, int priority)
> >{
> >    chipset_register_region(bus->chipset, mr, priority + 1);
> >}
> >
> >I don't really understand how you can fold everything into one
> >table and not allow devices to override their parents using
> >priorities.
> 
> 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.
> 
And how you set those priorities in a sensible way? Why two device on a
PCI bus will want to register their memory region with anything but
highest priority? And if you let PCI subsystem to assign priorities how
it will coordinate with ISA subsystem/memory controller what priorities
to assign to get meaningful system?

--
			Gleb.