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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 376DAC3815B for ; Mon, 20 Apr 2020 08:29:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 111B221927 for ; Mon, 20 Apr 2020 08:29:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="d2qXA6v+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726183AbgDTI3N (ORCPT ); Mon, 20 Apr 2020 04:29:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725773AbgDTI3M (ORCPT ); Mon, 20 Apr 2020 04:29:12 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7033C061A0C; Mon, 20 Apr 2020 01:29:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=IqO0rH/XwB4jj2Xbm/MnV+bQAuc82OBA3N+hT9MUMh0=; b=d2qXA6v+SNk5E4HWTuJcwW6zBn DB1oSYdGQF1W4KKLZf9Ds+4wUNsRVg365/r3rjS/0JSpP8Vsh4xWwpOBUjf1/vp3uslgkQN80gG6h yMBJFQ1pwH9iKLSriw3RG73+stuI6syQo8t9T0BIp4KRaBcmjYmKuwg4LqryDDL2X2fYVyXIRkUl0 7WaB1Z+4BzMMXn3uzsNjSpRav6VqCOwDAi5ZAjUAwF/5JAuEDpOqmS86f2gPR940LS5e+0fOlAnMS Ml+O+FzmAu+Pqptaid6xzcjqQEpgnjNFfs9zpfvZ/LME9fc+V1v+1WJZLxJk1eX42+EGk5JwdGlGe /iRiWEhw==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jQRnh-0002G7-Jz; Mon, 20 Apr 2020 08:29:09 +0000 Date: Mon, 20 Apr 2020 01:29:09 -0700 From: Christoph Hellwig To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, Ard Biesheuvel , Richard Earnshaw , Sudeep Dutt , Ashutosh Dixit , Arnd Bergmann , Greg Kroah-Hartman , "David S. Miller" , Jason Wang , netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org Subject: Re: [PATCH v3] vhost: disable for OABI Message-ID: <20200420082909.GA28749@infradead.org> References: <20200416221902.5801-1-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200416221902.5801-1-mst@redhat.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 16, 2020 at 06:20:20PM -0400, Michael S. Tsirkin wrote: > vhost is currently broken on the some ARM configs. > > The reason is that that uses apcs-gnu which is the ancient OABI that is been > deprecated for a long time. > > Given that virtio support on such ancient systems is not needed in the > first place, let's just add something along the lines of > > depends on !ARM || AEABI > > to the virtio Kconfig declaration, and add a comment that it has to do > with struct member alignment. > > Note: we can't make VHOST and VHOST_RING themselves have > a dependency since these are selected. Add a new symbol for that. This description is horrible. The only interesting thing for ARM OABI is that it has some strange padding rules, but that isn't something that can't be handled. Please spend some time looking into the issue and add te proper __padded annotations, we've done that elsewhere in the kernel and it isn't too bad - in fact it helps understanding issues with implicit alignment. And even if you have a good reason not to fix vhost (which I think you don't have) this changelog is just utter crap, as it fails to mention what the problem with ARM OABI even is.