From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Gibson Subject: Re: [PATCH 1/3] Device isolation group infrastructure (v3) Date: Fri, 10 Feb 2012 11:21:12 +1100 Message-ID: <20120210002112.GB10536@truffala.fritz.box> 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-Transfer-Encoding: 7bit Cc: kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, aik-sLpHqDYs0B2HXe+LvDLADg@public.gmane.org, Benjamin Herrenschmidt , qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Joerg Roedel Return-path: Content-Disposition: inline In-Reply-To: <20120209112805.GN22598-5C7GfCeVMHo@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: kvm.vger.kernel.org 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