From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965980AbXDBVxs (ORCPT ); Mon, 2 Apr 2007 17:53:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965978AbXDBVxs (ORCPT ); Mon, 2 Apr 2007 17:53:48 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:44519 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965980AbXDBVxp (ORCPT ); Mon, 2 Apr 2007 17:53:45 -0400 Message-ID: <46117B62.9030902@us.ibm.com> Date: Mon, 02 Apr 2007 16:53:38 -0500 From: Anthony Liguori User-Agent: Thunderbird 1.5.0.10 (X11/20070307) MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Andi Kleen , Virtualization Mailing List , Jeff Garzik , "H. Peter Anvin" , Linux Kernel Mailing List , mathiasen@gmail.com, virtualization@lists.linux-foundation.org Subject: Re: A set of "standard" virtual devices? References: <4611652F.700@zytor.com> <200704022312.39195.ak@suse.de> <4611768D.1080801@garzik.org> <200704022336.43136.ak@suse.de> <461178D9.402@goop.org> In-Reply-To: <461178D9.402@goop.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jeremy Fitzhardinge wrote: > Andi Kleen wrote: >> The implementation wouldn't need to use PCI at all. There wouldn't >> even need to be PCI like registers internally. Just a pci device >> with an ID somewhere in sysfs. PCI with unique IDs >> is just a convenient and well established key into the driver module >> collection. Once you have the right driver it can do what it wants. > > But I understood hpa's suggestion to mean that there would be a standard > PCI interface for a hardware RNG, and a single linux driver for that > device, which all hypervisors would be expected to implement. But > that's only reasonable if the virtualization environment has some notion > of PCI to expose to the Linux guest. The actual PCI bus could paravirtualized. It's just a question of whether one reinvents a device discovery mechanism (like XenBus) or whether one piggy backs on existing mechanisms. Furthermore, in the future, I strongly suspect that HVM will become much more important for Xen than PV and since that already has a PCI bus it's not really that big of a deal. Regards, Anthony Liguori > J