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=-6.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 3EE72C433B4 for ; Tue, 4 May 2021 13:09:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0583B613C0 for ; Tue, 4 May 2021 13:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230411AbhEDNKB (ORCPT ); Tue, 4 May 2021 09:10:01 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:47076 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230373AbhEDNKA (ORCPT ); Tue, 4 May 2021 09:10:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620133745; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=I+a3Gqq/AQH86AQgX5MsIHGOIG8nweku9Ika1zopWOs=; b=iEs2gAMhE2W6/x498cBd6yOa91Xtm/M4uX+AzBs5brQVuZAiY2aYtU6huhz7gJgQcWLnBn Bck/PDb9X0G3lSceqCA9tswaBxEM2nSdUJpLN30DXB8Yc2Z7nhceXBRT8km0+cFZeXZqt5 ldfwmHw4p6tdWIAe4laKB5zlpJth9/k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-433-sAMffVlyOI2oanb_IGH7cQ-1; Tue, 04 May 2021 09:09:03 -0400 X-MC-Unique: sAMffVlyOI2oanb_IGH7cQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4102964157; Tue, 4 May 2021 13:09:01 +0000 (UTC) Received: from gondolin.fritz.box (ovpn-113-126.ams2.redhat.com [10.36.113.126]) by smtp.corp.redhat.com (Postfix) with ESMTP id 37B075D72F; Tue, 4 May 2021 13:08:53 +0000 (UTC) Date: Tue, 4 May 2021 15:08:51 +0200 From: Cornelia Huck To: Christoph Hellwig Cc: Greg Kroah-Hartman , qemu-devel@nongnu.org, Daniel Vetter , kvm@vger.kernel.org, David Airlie , Michael Ellerman , Greg Kurz , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Alex Williamson , Paul Mackerras , Jason Gunthorpe , linux-api@vger.kernel.org, qemu-ppc@nongnu.org, linuxppc-dev@lists.ozlabs.org Subject: Re: remove the nvlink2 pci_vfio subdriver v2 Message-ID: <20210504150851.54e278f8.cohuck@redhat.com> In-Reply-To: <20210504130039.GA7711@lst.de> References: <20210326061311.1497642-1-hch@lst.de> <20210504142236.76994047@bahia.lan> <20210504130039.GA7711@lst.de> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Tue, 4 May 2021 15:00:39 +0200 Christoph Hellwig wrote: > On Tue, May 04, 2021 at 02:59:07PM +0200, Greg Kroah-Hartman wrote: > > > Hi Christoph, > > > > > > FYI, these uapi changes break build of QEMU. > > > > What uapi changes? > > > > What exactly breaks? > > > > Why does QEMU require kernel driver stuff? > > Looks like it pull in the uapi struct definitions unconditionally > instead of having a local copy. We could fix that by just putting > them back, but to me this seems like a rather broken configuration > in qemu when it pulls in headers from the running/installed kernel > without any feature checks before using them. > It is not pulling them from the installed kernel, but from a development version to get new definitions. Removing things in the kernel requires workarounds in QEMU until it can remove those things as well. It is not a dumb update...