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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 69DD4C432C0 for ; Tue, 26 Nov 2019 10:02:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4036E2082F for ; Tue, 26 Nov 2019 10:02:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727730AbfKZKCS (ORCPT ); Tue, 26 Nov 2019 05:02:18 -0500 Received: from mx2.suse.de ([195.135.220.15]:51762 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727629AbfKZKCS (ORCPT ); Tue, 26 Nov 2019 05:02:18 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 5F9B7B38D; Tue, 26 Nov 2019 10:02:16 +0000 (UTC) Subject: Re: [PATCH v2 2/4] xen-pcifront: Align address of flags to size of unsigned long To: Fenghua Yu , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Andy Lutomirski , Peter Zijlstra , David Laight , Ashok Raj , Tony Luck , Ravi V Shankar Cc: linux-kernel , x86 References: <1574710984-208305-1-git-send-email-fenghua.yu@intel.com> <1574710984-208305-3-git-send-email-fenghua.yu@intel.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: Date: Tue, 26 Nov 2019 11:02:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <1574710984-208305-3-git-send-email-fenghua.yu@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25.11.19 20:43, Fenghua Yu wrote: > The address of "flags" is passed to atomic bitops which require the > address is aligned to size of unsigned long. > > Signed-off-by: Fenghua Yu > --- > include/xen/interface/io/pciif.h | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/include/xen/interface/io/pciif.h b/include/xen/interface/io/pciif.h > index d9922ae36eb5..639d5fb484a3 100644 > --- a/include/xen/interface/io/pciif.h > +++ b/include/xen/interface/io/pciif.h > @@ -103,8 +103,11 @@ struct xen_pcie_aer_op { > uint32_t devfn; > }; > struct xen_pci_sharedinfo { > - /* flags - XEN_PCIF_* */ > - uint32_t flags; > + /* flags - XEN_PCIF_*. Force alignment for atomic bit operations. */ > + union { > + uint32_t flags; > + unsigned long flags_alignment; > + }; > struct xen_pci_op op; > struct xen_pcie_aer_op aer_op; > }; > NAK. This is an interface definition for communication between Xen dom0 and guests via shared memory. It can't be changed. BTW: you should Cc: the maintainers for the files you are modifying. Juergen