From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: [PATCH 2/3] qemu: make cirrus init value pci spec compliant Date: Thu, 8 Oct 2009 19:40:12 +0100 Message-ID: <20091008184011.GA6576@shareable.org> References: <20091008145241.GC12275@redhat.com> <4ACE0559.5040206@redhat.com> <20091008160623.GA13710@redhat.com> <4ACE0FC6.3050908@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Michael S. Tsirkin" , Anthony Liguori , "qemu-devel@nongnu.org" , kvm-devel To: Avi Kivity Return-path: Received: from mail2.shareable.org ([80.68.89.115]:36904 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932666AbZJHSlF (ORCPT ); Thu, 8 Oct 2009 14:41:05 -0400 Content-Disposition: inline In-Reply-To: <4ACE0FC6.3050908@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 10/08/2009 06:06 PM, Michael S. Tsirkin wrote: > >On Thu, Oct 08, 2009 at 05:29:29PM +0200, Avi Kivity wrote: > > > >>On 10/08/2009 04:52 PM, Michael S. Tsirkin wrote: > >> > >>>PCI memory should be disabled at reset, otherwise > >>>we might claim transactions at address 0. > >>>I/O should also be disabled, although for cirrus > >>>it is harmless to enable it as we do not > >>>have I/O bar. > >>> > >>>Note: need bios fix for this patch to work: > >>>currently pc-bios incorrently assumes that it does not > >>>need to enable i/o unless device has i/o bar. > >>> > >>>Signed-off-by: Michael S. Tsirkin > >> > >>This needs to be conditional on the machine type. Old machines must > >>retain this code for live migration to work (we need to live migrate the > >>bios, so we can't assume the bios fix is in during live migration from > >>older qemus). > >> > >No, if you migrate from older qemu you will be fine as command > >is enabled there on init. > > > > Right. No, I think Avi was right the first time. Migrating from an older qemu will be fine at first, but at the next reset _following_ migration, it'll be running the old BIOS on a new qemu and fail. -- Jamie