From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756875Ab2IZPKz (ORCPT ); Wed, 26 Sep 2012 11:10:55 -0400 Received: from co1ehsobe002.messaging.microsoft.com ([216.32.180.185]:27701 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756565Ab2IZPKx (ORCPT ); Wed, 26 Sep 2012 11:10:53 -0400 X-Forefront-Antispam-Report: CIP:163.181.249.108;KIP:(null);UIP:(null);IPV:NLI;H:ausb3twp01.amd.com;RD:none;EFVD:NLI X-SpamScore: -8 X-BigFish: VPS-8(zz98dI179dNzz1202h1d1ah1d2ahzz15d4Iz2dh668h839h944hd25he5bhf0ah11b5h121eh1220h1288h12a5h12a9h12bdh137ah13b6h1155h) X-WSS-ID: 0MAYQ5Y-01-864-02 X-M-MSG: Date: Wed, 26 Sep 2012 17:10:44 +0200 From: "Roedel, Joerg" To: Alex Williamson CC: Florian Dazinger , , iommu Subject: Re: 3.6-rc7 boot crash + bisection Message-ID: <20120926151044.GE10549@amd.com> References: <20120924210348.5f50677b@brain.lan> <1348597970.28860.114.camel@bling.home> <20120925205420.0a07dea2@brain.lan> <1348602226.28860.132.camel@bling.home> <20120926132050.GB10549@amd.com> <1348670159.28860.183.camel@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1348670159.28860.183.camel@bling.home> User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 26, 2012 at 08:35:59AM -0600, Alex Williamson wrote: > Hmm, that throws a kink in iommu groups. So perhaps we need to make an > alias interface to iommu groups. Seems like this could just be an extra > parameter to iommu_group_get and iommu_group_add_device (empty in the > typical case). Then we have the problem of what's the type for an > alias? For AMI-Vi, it's a u16, but we need to be more generic than > that. Maybe iommu groups should just treat it as a void* so iommus can > use a pointer to some structure or a fixed value like a u16 bus:slot. > Thoughts? Good question. The iommu-groups are part of the IOMMU-API, with an interface to the IOMMU drivers and one to the users of IOMMU-API. So the alias handling itself should be a function of the interface to the IOMMU driver. In general the interface should not be bus specific. So a void pointer seems the only logical choice then. But I would not limit its scope to alias handling. How about making it a bus-private pointer where IOMMU driver store bus-specific information. That way we make sure that there is one struct per bus-type for this pointer, and not one structure per IOMMU driver. Joerg -- AMD Operating System Research Center Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach General Managers: Alberto Bozzo Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632