Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422729AbWHEESr (ORCPT ); Sat, 5 Aug 2006 00:18:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422733AbWHEESr (ORCPT ); Sat, 5 Aug 2006 00:18:47 -0400 Received: from stat9.steeleye.com ([209.192.50.41]:2739 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S1422729AbWHEESr (ORCPT ); Sat, 5 Aug 2006 00:18:47 -0400 Subject: Re: A proposal - binary From: James Bottomley To: Zachary Amsden Cc: Chris Wright , Greg KH , Linux Kernel Mailing List , Linus Torvalds , Andrew Morton , Christoph Hellwig , Rusty Russell , Jack Lo , virtualization@lists.osdl.org, xen-devel@lists.xensource.com, pazke@donpac.ru, Andi Kleen In-Reply-To: <44D3B0F0.2010409@vmware.com> References: <44D1CC7D.4010600@vmware.com> <20060803190605.GB14237@kroah.com> <44D24DD8.1080006@vmware.com> <20060803200136.GB28537@kroah.com> <20060804183448.GE11244@sequoia.sous-sol.org> <44D3B0F0.2010409@vmware.com> Content-Type: text/plain Date: Fri, 04 Aug 2006 21:30:08 -0400 Message-Id: <1154741408.3683.171.camel@mulgrave.il.steeleye.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-4.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1598 Lines: 31 On Fri, 2006-08-04 at 13:41 -0700, Zachary Amsden wrote: > Instead, what paravirt-ops promises long > term is a way to get rid of the sub-architecture layer altogether. > Sub-arches like Voyager and Visual workstation have some strange > initialization requirements, interrupt controllers, and SMP handling. > Exactly the kind of thing which paravirt_ops is being designed to > indirect for hypervisors. Well ... I agree that in principle it's possible to have a kernel that would run on both voyager and a generic x86 system and, I'll admit, I tried to go that route before creating the subarchitectures. However, in practice, I think the cost really becomes too high ... for voyager, it becomes necessary really to intercept almost the entirety of the the SMP API. The purpose of the subarchitecture interface wasn't to eventually have some API description that would allow voyager to co-exist with more normal x86 systems. It was to allow voyager to make use of generic x86 while being completely different at the x86 SMP level. I really don't think there'll ever be another x86 machine that's as different from the APIC approach as the voyager VIC/QIC is. thus, I think the actual x86 interface is much better described by mach-generic, which abstracts out the interfaces necessary to the more standard APIC based SMP systems. James - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/