From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Brook Subject: Re: RFC qdev path semantics Date: Wed, 16 Jun 2010 12:45:27 +0100 Message-ID: <201006161245.27789.paul@codesourcery.com> References: <20100614054923.879.33717.stgit@localhost.localdomain> <4C18B786.1060105@siemens.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Cc: Markus Armbruster , Alex Williamson , qemu-devel@nongnu.org, chrisw@redhat.com, kvm@vger.kernel.org, kraxel@redhat.com, avi@redhat.com To: Jan Kiszka Return-path: Received: from mail.codesourcery.com ([38.113.113.100]:45451 "EHLO mail.codesourcery.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758647Ab0FPLpe (ORCPT ); Wed, 16 Jun 2010 07:45:34 -0400 In-Reply-To: <4C18B786.1060105@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: > Markus Armbruster wrote: > > A number of changes to qdev paths have been proposed in various threads. > > It's becoming harder to keep track of them, so let me sum them up in one > > place. Please correct me if I misrepresent your ideas. > > > > I'm going to describe the current state of things, and the proposed > > changes (marked with ###). > > > > > > The device tree has the main system bus as root. A child of a bus is a > > device. A child of a device is a bus. > > > > A qdev path consists of qdev path components separated by '/'. It > > resolves to a node in the device tree, either bus or device. > > > > The qdev path "/" resolves to the root, i.e. the main system bus. > > Another aspect: A path may start with an arbitrary bus name, not only > the system bus. Although this is ambiguous, we need to keep it for > addressing the bus itself due to existing client use. But, IMO, we > should at least start deprecating this for addressing elements below > that bus (e.g. "pci.0/e1000"). I think this would be better served by adding explicit aliases/IDs for those use-cases. i.e. define the global ID "pci.0" to be an alias for /i440FX-pcihost/pci Paul