From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 1/9] pci-assign: Optionally enable 64bit BARs in guest Date: Tue, 31 Jan 2012 14:21:11 +0100 Message-ID: <4F27EAC7.50707@siemens.com> References: <20120128142104.25681.93072.stgit@bling.home> <20120128142139.25681.19080.stgit@bling.home> <4F27E15A.1090800@redhat.com> <4F27E25A.1060306@siemens.com> <4F27E3C2.5050204@redhat.com> <4F27E547.3000809@siemens.com> <4F27E83E.7080903@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Alex Williamson , "kvm@vger.kernel.org" , "shashidhar.patil@gmail.com" , "Michael S. Tsirkin" To: Avi Kivity Return-path: Received: from thoth.sbs.de ([192.35.17.2]:25120 "EHLO thoth.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754382Ab2AaNVS (ORCPT ); Tue, 31 Jan 2012 08:21:18 -0500 In-Reply-To: <4F27E83E.7080903@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2012-01-31 14:10, Avi Kivity wrote: > On 01/31/2012 02:57 PM, Jan Kiszka wrote: >>>>> Seems fine, but do we really need the option? If it doesn't work we >>>>> should treat it as an ordinary but and fix it. >>>> >>>> So far it's against the architecture of the emulated system: our current >>>> chipset predates 64 bit PCI. >>>> >>> >>> Then it should be enabled/disabled at the chipset level. >> >> Makes me wonder if we already do some filtering if the device supports >> 64 bit but the next bridge does not. >> > > Our 440fx does support 64-bit bars, so the question doesn't arise for > x86. Instead we violate the spec. If you mean by "our" the 440fx-qemu, not the real 440fx. That one does not even support >1GB RAM. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux