From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932355Ab2CYXZ7 (ORCPT ); Sun, 25 Mar 2012 19:25:59 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45371 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932323Ab2CYXZ6 (ORCPT ); Sun, 25 Mar 2012 19:25:58 -0400 Message-ID: <4F6FA972.9050103@zytor.com> Date: Sun, 25 Mar 2012 16:25:38 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.1) Gecko/20120209 Thunderbird/10.0.1 MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: Joerg Roedel , Avi Kivity , Marcelo Tosatti , Thomas Gleixner , Ingo Molnar , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC dontapply] kvm_para: add mmio word store hypercall References: <20120325220518.GA27879@redhat.com> In-Reply-To: <20120325220518.GA27879@redhat.com> X-Enigmail-Version: 1.3.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/25/2012 03:05 PM, Michael S. Tsirkin wrote: > We face a dilemma: IO mapped addresses are legacy, > so, for example, PCI express bridges waste 4K > of this space for each link, in effect limiting us > to 16 devices using this space. That is *only* if they are physical devices on PCIe links. For virtual devices you have no such limitation. What is the problem again? -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.