From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:42924) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QN62K-0001aH-7k for qemu-devel@nongnu.org; Thu, 19 May 2011 12:25:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QN62J-0004VU-8v for qemu-devel@nongnu.org; Thu, 19 May 2011 12:25:20 -0400 Received: from thoth.sbs.de ([192.35.17.2]:18216) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QN62I-0004Ut-SL for qemu-devel@nongnu.org; Thu, 19 May 2011 12:25:19 -0400 Message-ID: <4DD5446A.6030003@siemens.com> Date: Thu, 19 May 2011 18:25:14 +0200 From: Jan Kiszka MIME-Version: 1.0 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> <20110519161731.GA27310@redhat.com> In-Reply-To: <20110519161731.GA27310@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 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: Avi Kivity , qemu-devel On 2011-05-19 18:17, Gleb Natapov wrote: > 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? Priorities >default will only be used for explicit overlays, e.g. RAM over MMIO in PAM regions. Non-default priorities won't be assigned to normal PCI bars or any other device's region. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux