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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 A4826C32792 for ; Tue, 1 Oct 2019 00:38:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73D6D20842 for ; Tue, 1 Oct 2019 00:38:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="iZrDDgQq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731193AbfJAAi5 (ORCPT ); Mon, 30 Sep 2019 20:38:57 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:58958 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726157AbfJAAi5 (ORCPT ); Mon, 30 Sep 2019 20:38:57 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x910TTPe027361; Tue, 1 Oct 2019 00:37:14 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2019-08-05; bh=an4qCn0lo1ONNRru8fvD6bTdRSkLm7X31qWqshOz5iE=; b=iZrDDgQq6Qf2betTNeLaM2uQNWpbpLwezSTLTDku8owqpZjAXbc/Zyq7fFyz8vU61yr+ 3jW26spVdX6Ag8zhzW6yDjhuDb6NBBAHBRvEINIAWV7ps2otD6lBKNCiJfyzMHTzJ5cG QpEGf4SCWgRXMc3iv+ZwFJZHO+GutBfgPmYNtYrnYZUcxd/pQDqusvpSN73n/2gg0nGQ a8KgW/5Z5Bd2VAL1HXQl6m5kPJ5SjatYzRC35Umu7mNi6saasgzeZxUVmSpyBE6jNt/z jfm/IorKE+b4v5WL1MaU8bGeaIdyWbpYENGrGiDS+9m+Le/Sr+nBUgEOZy4cNDtVnicT ow== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 2v9xxujj6a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Oct 2019 00:37:13 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x910SwGc040779; Tue, 1 Oct 2019 00:37:13 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 2vbqcyw423-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Oct 2019 00:37:12 +0000 Received: from abhmp0020.oracle.com (abhmp0020.oracle.com [141.146.116.26]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x910b5J5008743; Tue, 1 Oct 2019 00:37:08 GMT Received: from [10.191.5.100] (/10.191.5.100) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 30 Sep 2019 17:37:05 -0700 Subject: Re: [PATCH 1/3] KVM: X86: Add "nopvspin" parameter to disable PV spinlocks To: Vitaly Kuznetsov , linux-kernel@vger.kernel.org Cc: Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Paolo Bonzini , Radim Krcmar , Sean Christopherson , Wanpeng Li , Jim Mattson , Joerg Roedel , Peter Zijlstra , Will Deacon References: <1569759666-26904-1-git-send-email-zhenzhong.duan@oracle.com> <1569759666-26904-2-git-send-email-zhenzhong.duan@oracle.com> <87pnjh3i6i.fsf@vitty.brq.redhat.com> From: Zhenzhong Duan Organization: Oracle Corporation Message-ID: Date: Tue, 1 Oct 2019 08:36:58 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <87pnjh3i6i.fsf@vitty.brq.redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9396 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910010004 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9396 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910010004 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/9/30 23:41, Vitaly Kuznetsov wrote: > Zhenzhong Duan writes: > >> There are cases where a guest tries to switch spinlocks to bare metal >> behavior (e.g. by setting "xen_nopvspin" on XEN platform and >> "hv_nopvspin" on HYPER_V). >> >> That feature is missed on KVM, add a new parameter "nopvspin" to disable >> PV spinlocks for KVM guest. >> >> This new parameter is also intended to replace "xen_nopvspin" and >> "hv_nopvspin" in the future. > Any reason to not do it right now? We will probably need to have compat > code to support xen_nopvspin/hv_nopvspin too but emit a 'is deprecated' > warning. Sorry the description isn't clear, I'll fix it. I did the compat work in the other two patches. [PATCH 2/3] xen: Mark "xen_nopvspin" parameter obsolete and map it to "nopvspin" [PATCH 3/3] x86/hyperv: Mark "hv_nopvspin" parameter obsolete and map it to "nopvspin" > >> The global variable pvspin isn't defined as __initdata as it's used at >> runtime by XEN guest. >> >> Refactor the print stuff with pr_* which is preferred. > Please do it in a separate patch. Ok, I'll do that in v2. Thanks for review. Zhenzhong