From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E179C433B4 for ; Thu, 22 Apr 2021 14:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A9C661425 for ; Thu, 22 Apr 2021 14:51:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237429AbhDVOwc (ORCPT ); Thu, 22 Apr 2021 10:52:32 -0400 Received: from mga14.intel.com ([192.55.52.115]:58050 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236019AbhDVOwb (ORCPT ); Thu, 22 Apr 2021 10:52:31 -0400 IronPort-SDR: eEF/14Cst16qjgmdqOckBhgIdgISUIsFeotAkwmtobMBz1c2bPO4yIRHB2SIPZfCavKYphmSu2 jpgz29AJ3vRg== X-IronPort-AV: E=McAfee;i="6200,9189,9962"; a="195455552" X-IronPort-AV: E=Sophos;i="5.82,242,1613462400"; d="scan'208";a="195455552" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Apr 2021 07:51:56 -0700 IronPort-SDR: 7ThSNZxN7/DzyQgxwuyvs2UwLBv5+Npjjt4tBmB3pqEMo2OeDtsP032DXqUh7QyXbL0WJvprKc ZQSHgHTKjOrQ== X-IronPort-AV: E=Sophos;i="5.82,242,1613462400"; d="scan'208";a="427976473" Received: from rlocatel-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.36.200]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Apr 2021 07:51:50 -0700 From: Jani Nikula To: Jason Gunthorpe , Arnd Bergmann Cc: Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , Zhenyu Wang , Alex Williamson , Kevin Tian , Cornelia Huck , Arnd Bergmann , Andrew Morton , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org, Zhenyu Wang , Zhi Wang Subject: Re: [PATCH] vfio/gvt: fix DRM_I915_GVT dependency on VFIO_MDEV In-Reply-To: <20210422135810.GG2047089@ziepe.ca> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20210422133547.1861063-1-arnd@kernel.org> <20210422135810.GG2047089@ziepe.ca> Date: Thu, 22 Apr 2021 17:51:47 +0300 Message-ID: <87sg3i74os.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cc: gvt list & maintainers On Thu, 22 Apr 2021, Jason Gunthorpe wrote: > On Thu, Apr 22, 2021 at 03:35:33PM +0200, Arnd Bergmann wrote: >> From: Arnd Bergmann >> >> The Kconfig dependency is incomplete since DRM_I915_GVT is a 'bool' >> symbol that depends on the 'tristate' VFIO_MDEV. This allows a >> configuration with VFIO_MDEV=m, DRM_I915_GVT=y and DRM_I915=y that >> causes a link failure: >> >> x86_64-linux-ld: drivers/gpu/drm/i915/gvt/gvt.o: in function `available_instances_show': >> gvt.c:(.text+0x67a): undefined reference to `mtype_get_parent_dev' >> x86_64-linux-ld: gvt.c:(.text+0x6a5): undefined reference to `mtype_get_type_group_id' >> x86_64-linux-ld: drivers/gpu/drm/i915/gvt/gvt.o: in function `description_show': >> gvt.c:(.text+0x76e): undefined reference to `mtype_get_parent_dev' >> x86_64-linux-ld: gvt.c:(.text+0x799): undefined reference to `mtype_get_type_group_id' >> >> Clarify the dependency by specifically disallowing the broken >> configuration. If VFIO_MDEV is built-in, it will work, but if >> VFIO_MDEV=m, the i915 driver cannot be built-in here. >> >> Fixes: 07e543f4f9d1 ("vfio/gvt: Make DRM_I915_GVT depend on VFIO_MDEV") >> Fixes: 9169cff168ff ("vfio/mdev: Correct the function signatures for the mdev_type_attributes") >> Signed-off-by: Arnd Bergmann >> --- >> drivers/gpu/drm/i915/Kconfig | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) > > Oh kconfig stuff like this makes my head hurt, thanks for finding it > > I also can't see an alternative to this ugly thing, besides having the > i915 guys properly modularize this code someday > > Reviewed-by: Jason Gunthorpe > > Jason -- Jani Nikula, Intel Open Source Graphics Center