Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030259AbWHDFio (ORCPT ); Fri, 4 Aug 2006 01:38:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030266AbWHDFio (ORCPT ); Fri, 4 Aug 2006 01:38:44 -0400 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:43392 "EHLO sous-sol.org") by vger.kernel.org with ESMTP id S1030259AbWHDFin (ORCPT ); Fri, 4 Aug 2006 01:38:43 -0400 Date: Thu, 3 Aug 2006 22:40:02 -0700 From: Chris Wright To: Andrew Morton Cc: Jeremy Fitzhardinge , greg@kroah.com, zach@vmware.com, linux-kernel@vger.kernel.org, torvalds@osdl.org, hch@infradead.org, rusty@rustcorp.com.au, jlo@vmware.com, xen-devel@lists.xensource.com, simon@xensource.com, ian.pratt@xensource.com, jeremy@goop.org Subject: Re: A proposal - binary Message-ID: <20060804054002.GC11244@sequoia.sous-sol.org> References: <44D1CC7D.4010600@vmware.com> <20060803190605.GB14237@kroah.com> <44D24DD8.1080006@vmware.com> <20060803200136.GB28537@kroah.com> <44D2B678.6060400@xensource.com> <20060803211850.3a01d0cc.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060803211850.3a01d0cc.akpm@osdl.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1263 Lines: 25 * Andrew Morton (akpm@osdl.org) wrote: > I must confess that I still don't "get" paravirtops. AFACIT the VMI > proposal, if it works, will make that whole layer simply go away. Which > is attractive. If it works. Paravirtops is simply a table of function which are populated by the hypervisor specific code at start-of-day. Some care is taken to patch up callsites which are performance sensitive. The main difference is the API vs. ABI distinction. In paravirt ops case, the ABI is defined at compile time from source. The VMI takes it one step further and fixes the ABI. That last step is a big one. There are two basic issues. 1) what is the interface between the kernel and the glue to a hypervisor. 2) how does one call from the kernel into the glue layer. Getting bogged down in #2, the details of the calling convention, is a distraction from the real issue, #1. We are trying to actually find an API that is useful for multiple projects. Paravirt_ops gives the flexibility to evolve the interface. - 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/