From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Configuration vs. compat hints [was Re: [Qemu-devel] [PATCHv3 03/13] qemu: add routines to manage PCI capabilities] Date: Mon, 15 Jun 2009 18:11:28 +0300 Message-ID: <4A3664A0.6080105@redhat.com> References: <20090610150129.GC28601@redhat.com> <200906101624.30659.paul@codesourcery.com> <20090610174301.GC7416@shareable.org> <20090610182227.GN28601@redhat.com> <20090610192702.GH7416@shareable.org> <1244796209.16425.20.camel@blaa> <4A326B5C.5010501@codemonkey.ws> <1244821292.30522.56.camel@blaa> <4A327E4A.7010300@codemonkey.ws> <1244825303.26769.19.camel@blaa> <20090614095016.GA7560@redhat.com> <4A3617D4.5090405@redhat.com> <4A36424D.3080901@codemonkey.ws> <4A364698.1090402@redhat.com> <4A364A9B.9070001@codemonkey.ws> <4A364E32.4010808@redhat.com> <4A365078.5080209@codemonkey.ws> <4A36529D.4060200@redhat.com> <4A3663C6.3070801@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Michael S. Tsirkin" , Mark McLoughlin , Jamie Lokier , Carsten Otte , kvm@vger.kernel.org, Glauber Costa , Rusty Russell , qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org, Blue Swirl , Christian Borntraeger , Paul Brook To: Anthony Liguori Return-path: Received: from mx2.redhat.com ([66.187.237.31]:56589 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758436AbZFOPOJ (ORCPT ); Mon, 15 Jun 2009 11:14:09 -0400 In-Reply-To: <4A3663C6.3070801@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-ID: On 06/15/2009 06:07 PM, Anthony Liguori wrote: > Avi Kivity wrote: >> >> I'd object to any implicit addressing rules. If we have to say >> target=2,lun=7,street=8,city=9,state=99,zip=12345 instead of >> index=8345345235 so be it. > > The next observation is that while we expand the SCSI addressing, the > current propose flattens the PCI hierarchy (i.e. pci_addr=00:01.0). > > An alternative would be to either always expand or always flatten > addressing. I think the later has a lot of merit. Consider: > > -controller type=lsi1234,addr=00:01,name=blah > -controller-disk controller=blah,addr=00:01,name=sda > > -controller type=ide,addr=00.02,name=ide > -controller-disk controller=ide,addr=3,name=hdd > > -drive file=foo.img,controller-disk=sda > -drive file=bar.img,controller-disk=hdd > > This means that addr's format depends on the parent device node which > is a bit less explicit than the previous example. However, it is much > more consistent and easier to implement. Basically, when adding a > device to it's parent, you hand the parent the "addr" field and that > lets you say where you want to sit on the bus. I would prefer explicit names (pci_addr, lun, etc.) but would be okay with generic names too. There's value in sticking to well-understood names and address formats. -- error compiling committee.c: too many arguments to function