Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758781Ab2BJAVW (ORCPT ); Thu, 9 Feb 2012 19:21:22 -0500 Received: from ozlabs.org ([203.10.76.45]:51819 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758521Ab2BJAVS (ORCPT ); Thu, 9 Feb 2012 19:21:18 -0500 Date: Fri, 10 Feb 2012 11:21:12 +1100 From: David Gibson To: Joerg Roedel Cc: Benjamin Herrenschmidt , dwmw2@infradead.org, iommu@lists.linux-foundation.org, aik@ozlabs.ru, qemu-devel@nongnu.org, alex.williamson@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] Device isolation group infrastructure (v3) Message-ID: <20120210002112.GB10536@truffala.fritz.box> Mail-Followup-To: Joerg Roedel , Benjamin Herrenschmidt , dwmw2@infradead.org, iommu@lists.linux-foundation.org, aik@ozlabs.ru, qemu-devel@nongnu.org, alex.williamson@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <1328071614-8320-1-git-send-email-david@gibson.dropbear.id.au> <1328071614-8320-2-git-send-email-david@gibson.dropbear.id.au> <20120208152748.GD22598@amd.com> <1328737168.2903.35.camel@pasglop> <20120209112805.GN22598@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120209112805.GN22598@amd.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1590 Lines: 34 On Thu, Feb 09, 2012 at 12:28:05PM +0100, Joerg Roedel wrote: > On Thu, Feb 09, 2012 at 08:39:28AM +1100, Benjamin Herrenschmidt wrote: > > On Wed, 2012-02-08 at 16:27 +0100, Joerg Roedel wrote: > > > Again, device grouping is done by the IOMMU drivers, so this all > > > belongs > > > into the generic iommu-code rather than the driver core. > > > > Except that there isn't really a "generic iommu code"... discovery, > > initialization & matching of iommu vs. devices etc... that's all > > implemented in the arch specific iommu code. > > The whole point of moving the iommu drivers to drivers/iommu was to > factor out common code. We are not where we want to be yet but the goal > is to move more code to the generic part. > > For the group-code this means that the generic code should iterate over > all devices on a bus and build up group structures based on isolation > information provided by the arch specific code. And how exactly do you suggest it provide that information. I really can't see how an iommu driver would specify its isolation constraints generally enough, except in the form of code and then we're back to where we are now. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson -- 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/