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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 C0A1DC18E5A for ; Mon, 9 Mar 2020 18:11:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9EBF520873 for ; Mon, 9 Mar 2020 18:11:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JBRI00/u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726676AbgCISL3 (ORCPT ); Mon, 9 Mar 2020 14:11:29 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:35619 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726169AbgCISL3 (ORCPT ); Mon, 9 Mar 2020 14:11:29 -0400 Received: by mail-wr1-f66.google.com with SMTP id r7so12481194wro.2; Mon, 09 Mar 2020 11:11:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=zNpV6O5ivA3Si8ar1S1KuJt1ygXwnM2oG0rkigXm7x4=; b=JBRI00/uh/ses/SeUVzY3vSX8ROznzWZP4qPKV7MZj4CQI49MPIFIdWxymhBZNf25G U5ABL2tqMu5q6D4+VRuzsw3xJ3Zk78Hz32N4PO4mq8QicxYRnKldVHd4Bv2EWtuHElIm D4zJLQfi6Z0pr1ZUm3ATRftoOKcTGy05fA4GjXtkGq86+VLjW195R8zrexLTKdDm2LzU V0hb40PTXmizWfvwIbPlfbQyR9t1g83B8fSATcvUJ1Pw4A5ipW77owKqGYQqnBb+BX8r pnv8tqwqMU3Enn71hitKJBfh/4W/pRuQlJCyiqNKMURDn7HSQk2JIIhjA9sPkW2cwt7o nlMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=zNpV6O5ivA3Si8ar1S1KuJt1ygXwnM2oG0rkigXm7x4=; b=K4MHLUQOyFj/mVN/SszBwnY34SLs2lDn1pbfyBS4fmJwFPV4URtXePsQJO6SY66gX9 QIykdbhRygv554fOM6EX+6Xql9HTMwP7Qpw5rXs3WyKIwLE+9+MKHGX9/M6K0ehhBUAx J/vIXpSszhHjZhUxvu0s7V+bil9qo3Yd9Vt5DZqFkySudLGhxaw5kIgpC1L1YkOkWo20 zbyGPH0DPLR6v8WYU73IFz3DE2yzDEFC7C7Ebu0mpNgLn7sfv60ZYjWiD7RU1jeAuWx+ inUX2sxVX4nNm+tYFa0YtuUdUtJ4bXWaTNm/hxF361iJqgpbUpE4MtRGoHsPMW0XaJF0 qVxQ== X-Gm-Message-State: ANhLgQ0OFBv7Jfl04VNmOQQwk42xRzIgWzvwxnYEpOww6LkIiPpC5Hsb UnSeXwoY5YWsmeUDWLvHbT0= X-Google-Smtp-Source: ADFU+vscDulKO189yzGeCSJUrEBXThXgggVympv7I+OCNkEg2OD5wmtVBdAaUuoyClA2Y7GV3auAZA== X-Received: by 2002:adf:c40e:: with SMTP id v14mr4488963wrf.408.1583777487640; Mon, 09 Mar 2020 11:11:27 -0700 (PDT) Received: from jondnuc (IGLD-84-229-155-229.inter.net.il. [84.229.155.229]) by smtp.gmail.com with ESMTPSA id k2sm31501062wrn.57.2020.03.09.11.11.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Mar 2020 11:11:26 -0700 (PDT) Date: Mon, 9 Mar 2020 20:11:25 +0200 From: Jon Doron To: Vitaly Kuznetsov Cc: kvm@vger.kernel.org, linux-hyperv@vger.kernel.org Subject: Re: [PATCH v3 1/5] x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit Message-ID: <20200309181125.GA3755153@jondnuc> References: <20200306163909.1020369-1-arilou@gmail.com> <20200306163909.1020369-2-arilou@gmail.com> <87k13tcxrm.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <87k13tcxrm.fsf@vitty.brq.redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 09/03/2020, Vitaly Kuznetsov wrote: >Jon Doron writes: > >> Signed-off-by: Jon Doron >> --- >> include/uapi/linux/kvm.h | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h >> index 4b95f9a31a2f..24b7c48ccc6f 100644 >> --- a/include/uapi/linux/kvm.h >> +++ b/include/uapi/linux/kvm.h >> @@ -197,6 +197,7 @@ struct kvm_hyperv_exit { >> __u64 msg_page; >> } synic; >> struct { >> + __u32 pad; >> __u64 input; >> __u64 result; >> __u64 params[2]; > >This doesn't seem to be correct, __u64 get aligned at 8 byte boundary so >implicitly you now (pre-patch) have the following: > >struct kvm_hyperv_exit { > __u32 type; > __u32 pad1; > union { > struct { > __u32 msr; > __u32 pad2; > __u64 control; > __u64 evt_page; > __u64 msg_page; > } synic; > struct { > __u64 input; > __u64 result; > __u64 params[2]; > } hcall; > } u; >}; > >and the suggestion is only to make it explicit. Adding something before >'input' will actually break ABI. > >-- >Vitaly > Bah sorry guys :( not sure why this too so many iterations... will fix it right in next version.