From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 7/9] register mmio slots Date: Tue, 23 Sep 2008 10:31:30 +0300 Message-ID: <48D89B52.6010006@redhat.com> References: <1221840506-22996-1-git-send-email-glommer@redhat.com> <1221840506-22996-8-git-send-email-glommer@redhat.com> <48D5431E.9090102@redhat.com> <20080922135530.GE3618@poweredge.glommer> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, aliguori@us.ibm.com To: Glauber Costa Return-path: Received: from mx2.redhat.com ([66.187.237.31]:34012 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753324AbYIWHcW (ORCPT ); Tue, 23 Sep 2008 03:32:22 -0400 In-Reply-To: <20080922135530.GE3618@poweredge.glommer> Sender: kvm-owner@vger.kernel.org List-ID: Glauber Costa wrote: > On Sat, Sep 20, 2008 at 11:38:22AM -0700, Avi Kivity wrote: > >> Glauber Costa wrote: >> >>> By analysing phys_offset, we know whether a region is an mmio region >>> or not. If it is, register it as so. We don't reuse the same slot >>> infrastructure already existant, because there is a relationship between >>> the slot number for kvm the kernel module, and the index in the slots vector >>> for libkvm. However, we can do best in the future and use only a single data structure >>> for both. >>> >>> >>> >> Why is kvm interested in emulated mmio regions, at all? >> > We don't need to. If the region is an mmio region, we do nothing (well, later on, I'm > coalescing the accesses). Oh no you don't. > But still, we need to keep track. Otherwise, qemu can (and it will) > try to register subsets of that memory, but without any indication that this is part of an mmio region > Why do we care? > Our algorithm will fail in this case, since we will then register a memory area we should have left blank. > So think of mmio in this case as a "please leave it blank". > Confused. If qemu knows about the mmio regions, surely it won't try to overlay them with RAM? -- error compiling committee.c: too many arguments to function