From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59667) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzMlB-0007kq-Vo for qemu-devel@nongnu.org; Tue, 24 Jun 2014 05:11:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzMl5-0008Nn-N9 for qemu-devel@nongnu.org; Tue, 24 Jun 2014 05:11:25 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:57263) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzMl5-0008Nb-Hl for qemu-devel@nongnu.org; Tue, 24 Jun 2014 05:11:19 -0400 Received: by mail-pa0-f46.google.com with SMTP id eu11so1052pac.5 for ; Tue, 24 Jun 2014 02:11:18 -0700 (PDT) Message-ID: <53A94091.2000406@ozlabs.ru> Date: Tue, 24 Jun 2014 19:10:41 +1000 From: Alexey Kardashevskiy MIME-Version: 1.0 References: <53A8366B.1020301@ozlabs.ru> <53A840C8.8060607@redhat.com> <53A89D98.3030708@ozlabs.ru> <53A9095B.3070803@redhat.com> <53A90E9C.2020300@ozlabs.ru> <87bnti202c.fsf@blackfin.pond.sub.org> In-Reply-To: <87bnti202c.fsf@blackfin.pond.sub.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] machines and versions - why so many? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Eduardo Habkost , "qemu-devel@nongnu.org" , Paul Mackerras , Paolo Bonzini , =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= , Alexander Graf On 06/24/2014 06:17 PM, Markus Armbruster wrote: > Alexey Kardashevskiy writes: > >> On 06/24/2014 03:15 PM, Paolo Bonzini wrote: >>> Il 23/06/2014 23:35, Alexey Kardashevskiy ha scritto: >>>> nec-usb-xhci is off for PC_COMPAT_1_3 because of what? PIIX emulation was >>>> broken in 1.3? Or nec-usb-xhci? >>> >>> nec-usb-xhci is not "off". >> >> Yes, my bad, I understood (but explained this wrong) that XHCI is enabled >> but without MSI. >> >> >>> >>> .driver = "nec-usb-xhci",\ >>> .property = "msi",\ >>> .value = "off",\ >>> >>> What's off is MSI (and MSI-X), because it wasn't implemented. >>> >>>> If it is the latter, why is the tweak limited by PC? >>> >>> Because at the time nobody cared about migration compatibility (even now >>> only pSeries is starting to care). >> >> >> "only pSeries"? There are plenty of x86 machines already and if it is not >> for migration support, then what are they all for? :) > > At the time, nobody *else* cared. Only PC did. Ah. Misinterpret. My bad. Ok. > > Back then gerd created a way to do the compatibility stuff without > getting into the other target's hair: compat_props. They've served us > well enough, but now that more targets get interested in migration, > their shortcomings start to hurt. Having to duplicate device > compatibility gunk in multiple places, all far away from the device, is > decidedly suboptimal. Better ideas welcome. I would suggest moving PC_COMPAT_X_Y things to platform-independent place but "[RFC v2 00/39] Convert PC machine-types to QOM classes" is already huge and complicated, and also "pseries" does not really need stuff below 1.6, may be it is not worth it... -- Alexey