From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MFm8r-0006pS-EE for qemu-devel@nongnu.org; Sun, 14 Jun 2009 05:36:45 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MFm8m-0006p1-S7 for qemu-devel@nongnu.org; Sun, 14 Jun 2009 05:36:44 -0400 Received: from [199.232.76.173] (port=35216 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MFm8m-0006oy-Dg for qemu-devel@nongnu.org; Sun, 14 Jun 2009 05:36:40 -0400 Received: from mx20.gnu.org ([199.232.41.8]:52361) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MFm8m-0007fs-27 for qemu-devel@nongnu.org; Sun, 14 Jun 2009 05:36:40 -0400 Received: from mx2.redhat.com ([66.187.237.31]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MFm8k-0002Yy-M1 for qemu-devel@nongnu.org; Sun, 14 Jun 2009 05:36:38 -0400 Date: Sun, 14 Jun 2009 12:34:11 +0300 From: "Michael S. Tsirkin" Subject: Re: Configuration vs. compat hints [was Re: [Qemu-devel] [PATCHv3 03/13] qemu: add routines to manage PCI capabilities] Message-ID: <20090614093411.GA6959@redhat.com> References: <20090610145540.GI19375@poweredge.glommer> <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> <4A326C7E.3020309@codemonkey.ws> <1244822007.30522.68.camel@blaa> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1244822007.30522.68.camel@blaa> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark McLoughlin Cc: 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 , Avi Kivity On Fri, Jun 12, 2009 at 04:53:27PM +0100, Mark McLoughlin wrote: > On Fri, 2009-06-12 at 09:55 -0500, Anthony Liguori wrote: > > Mark McLoughlin wrote: > > > On Wed, 2009-06-10 at 20:27 +0100, Jamie Lokier wrote: > > > > > > = Solution - Separate configuration from compat hints = > > > > > > As I suggested before: > > > > > > - Allow the VM manager to dump compat hints; this would be an opaque > > > file format, more like the savevm format than a config file > > > > > > > How is compat hints different from a device tree? > > > > In my mind, that's what compat hints is. I don't see another sane way > > to implement it. > > A device tree with a different purpose than a config file. > > In its simplest form it could be a device tree with a version number for > each device[1]. > > The other obvious piece to add to it would be PCI addresses, so that > even if you remove a device, the addresses assigned to existing devices > don't change. Could you clarify this requirement please? If we want to remove a device from under a running guest, you need hotplug. So we can't just remove several lines from the config and hope that it'll work simply because the PCI address is stable. OTOH, if you reboot the guest, it's ok for addresses to change. > Cheers, > Mark. > > [1] - Adding such a per-device version number to the config file would > solve problem (2) > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html