From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:41121) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qwtvk-0000LQ-PX for qemu-devel@nongnu.org; Fri, 26 Aug 2011 06:46:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Qwtvj-0000k6-8l for qemu-devel@nongnu.org; Fri, 26 Aug 2011 06:46:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49112) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qwtvi-0000jw-MT for qemu-devel@nongnu.org; Fri, 26 Aug 2011 06:46:31 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p7QAkTqN001997 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 26 Aug 2011 06:46:29 -0400 Message-ID: <4E577983.50303@redhat.com> Date: Fri, 26 Aug 2011 12:46:27 +0200 From: Gerd Hoffmann MIME-Version: 1.0 References: <1314353480-14169-1-git-send-email-kraxel@redhat.com> <20110826102505.GI3944@redhat.com> In-Reply-To: <20110826102505.GI3944@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RfC PATCH] usb/vmstate: add parent dev path List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: qemu-devel@nongnu.org On 08/26/11 12:25, Daniel P. Berrange wrote: > On Fri, Aug 26, 2011 at 12:11:20PM +0200, Gerd Hoffmann wrote: >> ... to make vmstate id string truely unique with multiple host >> controllers, i.e. move from "1/usb-ptr" to "0000:00:01.3/1/usb-ptr" >> (usb tabled connected to piix3 uhci). >> >> Obvious problem with that is that it breaks migration from and to older >> versions, thats why it is RfC. I don't see any way to fix the issue >> without breaking though. So the question is how to deal with that best? > > How about keeping the original naming *only* for devices on the first > USB controller. Since it was impossible to start a QEMU process with > 2 USB controllers, Now it is, and we have a release (0.15) in the wild which supports it. > migration compatibility does not matter for the > naming of devices on the 2nd, 3rd, 4th.... controller. That would still break users which use usb 2.0 with qemu 0.15 today. cheers, Gerd