From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965992AbXDBWMU (ORCPT ); Mon, 2 Apr 2007 18:12:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965993AbXDBWMU (ORCPT ); Mon, 2 Apr 2007 18:12:20 -0400 Received: from terminus.zytor.com ([192.83.249.54]:41653 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965992AbXDBWMT (ORCPT ); Mon, 2 Apr 2007 18:12:19 -0400 Message-ID: <46117F72.6020506@zytor.com> Date: Mon, 02 Apr 2007 15:10:58 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 1.5.0.9 (X11/20070212) MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Andi Kleen , Jeff Garzik , virtualization@lists.linux-foundation.org, Virtualization Mailing List , Linux Kernel Mailing List , mathiasen@gmail.com 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. > That is, of course, true, although "some notion of" is very broad, and one could also use this for detection and some hypervisor-specific communication for the actual I/O. However, one probably wants to think about what the heck one actually means with "virtualization" in the absence of a lot of this stuff. PCI is probably the closest thing we have to a lowest common denominator for device detection. -hpa