From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [Qemu-devel] [PATCH 28/35] kvm: x86: Introduce kvmclock device to save/restore its state Date: Wed, 19 Jan 2011 10:54:10 -0600 Message-ID: <4D371732.5040901@linux.vnet.ibm.com> References: <4D2B6CB5.9050602@codemonkey.ws> <4D2B74D8.4080309@web.de> <4D2B8662.9060909@web.de> <4D2C60FB.7030009@linux.vnet.ibm.com> <4D2D80ED.8030405@redhat.com> <4D2D82EE.20002@siemens.com> <4D35A39A.8000801@siemens.com> <4D35ABF8.9050700@linux.vnet.ibm.com> <4D35B521.3090601@siemens.com> <4D35B6DD.1020005@linux.vnet.ibm.com> <4D35B963.7000605@siemens.com> <4D35BA22.7060602@linux.vnet.ibm.com> <4D35BD30.1060900@siemens.com> <4D35C1CE.10509@linux.vnet.ibm.com> <4D35C648.7050809@siemens.com> <4D35C92D.7030000@linux.vnet.ibm.com> <4D36B362.70202@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Gerd Hoffmann , "kvm@vger.kernel.org" , Jan Kiszka , Glauber Costa , Marcelo Tosatti , "qemu-devel@nongnu.org" , Avi Kivity To: Markus Armbruster Return-path: Received: from e3.ny.us.ibm.com ([32.97.182.143]:46029 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754413Ab1ASRLy (ORCPT ); Wed, 19 Jan 2011 12:11:54 -0500 Received: from d01dlp01.pok.ibm.com (d01dlp01.pok.ibm.com [9.56.224.56]) by e3.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p0JGprGJ023465 for ; Wed, 19 Jan 2011 11:52:52 -0500 Received: from d01relay07.pok.ibm.com (d01relay07.pok.ibm.com [9.56.227.147]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 68117729375 for ; Wed, 19 Jan 2011 11:54:19 -0500 (EST) Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay07.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p0JGsEfZ1286238 for ; Wed, 19 Jan 2011 11:54:14 -0500 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p0JGsD8U004341 for ; Wed, 19 Jan 2011 11:54:14 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 01/19/2011 07:11 AM, Markus Armbruster wrote: > Gerd Hoffmann writes: > > >> On 01/18/11 18:09, Anthony Liguori wrote: >> >>> On 01/18/2011 10:56 AM, Jan Kiszka wrote: >>> >>>> >>>>> The device model topology is 100% a hidden architectural detail. >>>>> >>>> This is true for the sysbus, it is obviously not the case for PCI and >>>> similarly discoverable buses. There we have a guest-explorable topology >>>> that is currently equivalent to the the qdev layout. >>>> >>> But we also don't do PCI passthrough so we really haven't even explored >>> how that maps in qdev. I don't know if qemu-kvm has attempted to >>> qdev-ify it. >>> >> It is qdev-ified. It is a normal pci device from qdev's point of view. >> >> BTW: is there any reason why (vfio-based) pci passthrough couldn't >> work with tcg? >> >> >>> The -device interface is a stable interface. Right now, you don't >>> specify any type of identifier of the pci bus when you create a PCI >>> device. It's implied in the interface. >>> >> Wrong. You can specify the bus you want attach the device to via >> bus=. This is true for *every* device, including all pci >> devices. If unspecified qdev uses the first bus it finds. >> >> As long as there is a single pci bus only there is simply no need to >> specify it, thats why nobody does that today. Once q35 finally >> arrives this will change of course. >> > As far as I know, libvirt does it already. > I think that's a bad idea from a forward compatibility perspective. Regards, Anthony Liguori