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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 173FEC433E0 for ; Thu, 11 Feb 2021 08:54:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5C8F64E8B for ; Thu, 11 Feb 2021 08:54:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229793AbhBKIwb (ORCPT ); Thu, 11 Feb 2021 03:52:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229826AbhBKIuv (ORCPT ); Thu, 11 Feb 2021 03:50:51 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5885AC06178A; Thu, 11 Feb 2021 00:44:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=0+1wsL2U/UOf5qLOqr+WtO+GFHaK5njXOQm3ltdvYqE=; b=V1fNhX0SAT9Kjh0cdeZG8wqXkX 1dr6lym8yWshTHk5h/HgHIzmTu5KgT97LKBSxNERfoWWCRth1koQdUzZmIFkrlFwnmm3L/XuLStAF 1XBpOd5po9jwefEPsBCogZbQckL3Iz8f90uKszVdsFNItfvXdoiABsjbSgSRndyBpI52Bl1plAtL8 hEZvpGoe3DFi2Ypg83jw46CtCoiAF6jEGwVhfE+ZQk4In0S1BS5mwq6QHv34NDhx+MMyf3FEYFBfp dY4AX3pX4bcRnSNbe3RTJgdcR+zZNICik+T96AmP9al3B9SJOpQrHIE1u6i3qTHMByhimrcbhwlQJ sbs+uUSQ==; Received: from hch by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lA7aM-009zKa-9y; Thu, 11 Feb 2021 08:44:26 +0000 Date: Thu, 11 Feb 2021 08:44:26 +0000 From: Christoph Hellwig To: Alex Williamson Cc: Jason Gunthorpe , Max Gurtovoy , Cornelia Huck , Matthew Rosato , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, liranl@nvidia.com, oren@nvidia.com, tzahio@nvidia.com, leonro@nvidia.com, yarong@nvidia.com, aviadye@nvidia.com, shahafs@nvidia.com, artemp@nvidia.com, kwankhede@nvidia.com, ACurrid@nvidia.com, gmataev@nvidia.com, cjia@nvidia.com, yishaih@nvidia.com, aik@ozlabs.ru Subject: Re: [PATCH 8/9] vfio/pci: use x86 naming instead of igd Message-ID: <20210211084426.GB2378134@infradead.org> References: <20210202170659.1c62a9e8.cohuck@redhat.com> <20210202105455.5a358980@omen.home.shazbot.org> <20210202185017.GZ4247@nvidia.com> <20210202123723.6cc018b8@omen.home.shazbot.org> <20210202204432.GC4247@nvidia.com> <5e9ee84e-d950-c8d9-ac70-df042f7d8b47@nvidia.com> <20210202143013.06366e9d@omen.home.shazbot.org> <20210202230604.GD4247@nvidia.com> <20210202165923.53f76901@omen.home.shazbot.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210202165923.53f76901@omen.home.shazbot.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 02, 2021 at 04:59:23PM -0700, Alex Williamson wrote: > vfio-pci-igd support knows very little about the device, we're > effectively just exposing a firmware table and some of the host bridge > config space (read-only). So the idea that the host kernel needs to > have updated i915 support in order to expose the device to userspace > with these extra regions is a bit silly. On the other hand assuming the IGD scheme works for every device with an Intel Vendor ID and a VGA classcode that hangs off an Intel host bridge seems highly dangerous. Is this actually going to work for the new discreete Intel graphics? For the old i740? And if not what is the failure scenario?