From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58836) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YH97z-00080d-96 for qemu-devel@nongnu.org; Fri, 30 Jan 2015 05:48:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YH97v-00023j-Hq for qemu-devel@nongnu.org; Fri, 30 Jan 2015 05:48:43 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43494) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YH97v-000230-9N for qemu-devel@nongnu.org; Fri, 30 Jan 2015 05:48:39 -0500 Date: Fri, 30 Jan 2015 10:48:33 +0000 From: "Daniel P. Berrange" Message-ID: <20150130104833.GC27572@redhat.com> References: <54CA6CF6.7090308@redhat.com> <54CA7BF5.8020800@redhat.com> <54CA8637.2080306@redhat.com> <54CA8E37.8070009@redhat.com> <20150130095456.GB27572@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] address order of virtio-mmio devices Reply-To: "Daniel P. Berrange" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: Laszlo Ersek , qemu devel list On Fri, Jan 30, 2015 at 10:29:46AM +0000, Peter Maydell wrote: > On 30 January 2015 at 09:54, Daniel P. Berrange wrote: > > While it is clear there is no solution that works correctly with all > > kernels, I hate to think that we're going to stick with an ordering > > that is clearly wrong for modern kernels, forever going forward. The > > aarch64 world is only just starting out, so on balance I think we > > should optimize for the future rather than the past, since that gives > > right behaviour for orders of magnitude more people in the long term. > > Yeah, I agree it's awkward. But I hate breaking people's > working setups, and we have no guarantee the kernel won't > change again in the future. > > You could try asking the kernel folk to revert that patch on > the basis that it breaks things... Might be worth a shot - the patch is only a month old. Or at least do a followup patch to put the ordering back the way it was, rather than plain revert Long term though it will be much better of AArch64 would just do PCI instead of MMIO bus. Then we have proper device addressing which we can control in a predictable manner that will be stable across hotplug and unplug and migration. I hear there's work on PCI for AArch64 but is there a near term ETA yet ? Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|