From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MQcfO-0001Y4-Rp for qemu-devel@nongnu.org; Tue, 14 Jul 2009 03:43:10 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MQcfJ-0001VU-BX for qemu-devel@nongnu.org; Tue, 14 Jul 2009 03:43:09 -0400 Received: from [199.232.76.173] (port=33016 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MQcfJ-0001VJ-83 for qemu-devel@nongnu.org; Tue, 14 Jul 2009 03:43:05 -0400 Received: from mx20.gnu.org ([199.232.41.8]:54857) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MQcfI-0003J5-Nt for qemu-devel@nongnu.org; Tue, 14 Jul 2009 03:43:04 -0400 Received: from mx2.redhat.com ([66.187.237.31]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MQcfH-0002J2-No for qemu-devel@nongnu.org; Tue, 14 Jul 2009 03:43:04 -0400 Message-ID: <4A5C3689.3070001@redhat.com> Date: Tue, 14 Jul 2009 09:40:57 +0200 From: Gerd Hoffmann MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 04/13] qdev: add generic qdev_device_add() References: <1247225179-5495-1-git-send-email-kraxel@redhat.com> <200907101823.07096.paul@codesourcery.com> <4A57A449.5000907@redhat.com> <200907102151.04322.paul@codesourcery.com> In-Reply-To: <200907102151.04322.paul@codesourcery.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Brook Cc: qemu-devel@nongnu.org On 07/10/09 22:51, Paul Brook wrote: >>> I think this is going in the wrong direction. The device tree provides us >>> with a standard way of identifying which bus to add a device to. We >>> should be removing uses of pci_create, not adding new ones. >> Why? >> >> Let me guess: Because pci bus numbers are guest-changeable and thus not >> stable? > > Because I don't think this code need to be bus specific. Parts of the problem are certainly bus-specific though, such as parsing bus addresses. > We also need to figure out the naming of multiple similar devices on the same > bus. Possibly your "device id" could be used to identify devices on a bus. > e.g. if we wanted two scsi adapters: > > -device lsi,bus=pci0,id=foo > -device lsi,bus=pci0,id=bar > -device scsi-disk,bus=pci0/foo/scsi > -device scsi-disk,bus=pci0/bar/scsi I think what we will see used in practice is: - either go with the defaults (i.e. don't specify a bus at all -> device is attached to the first (and often only) pci/scsi/usb/whatever bus. - or usage of ids to identify devices and busses. I think nobody will use stuff like -device scsi-disk,bus=/main-system-bus/i440FX-pcihost/pci/lsi/scsi in practice. cheers, Gerd