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=-9.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B4E52C433DB for ; Mon, 22 Mar 2021 11:05:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8909C61983 for ; Mon, 22 Mar 2021 11:05:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230298AbhCVLFE (ORCPT ); Mon, 22 Mar 2021 07:05:04 -0400 Received: from mail-wr1-f41.google.com ([209.85.221.41]:40623 "EHLO mail-wr1-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230156AbhCVLEk (ORCPT ); Mon, 22 Mar 2021 07:04:40 -0400 Received: by mail-wr1-f41.google.com with SMTP id v11so16180455wro.7; Mon, 22 Mar 2021 04:04:39 -0700 (PDT) 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:content-transfer-encoding :in-reply-to; bh=PWWnDHWb0f6VWpKB3JAHyffSxPdrHA0WVJJCPyw/usc=; b=QS2i0VBc4msizGZn7kO+qmqW9uznZiSbxTvFXR+hQgYUksI7r8WIOqOXsthwm0mx4m qWEsTdOZWsliU28pBheKpSr5bVyCcWhmWOIcyeel+ac+2LXeyQuaBLFVm1f7Ku1/5VNx fQQZJ09n8pC/D2J1PKgEdtO2R8U1h3GULwa7OWM/S/JIuJ/YhMQguyoU9CDnzCZODW9M pbRkqkIvsmXIDpaI+JkrJ6MjwzOe9xSrZRyWuyP8VKm6gLp4zRIeLG3wlyR+lTCHmN7Z D+YIjRhN8Zg6uMowv9s2Vd4FRt8Q5K631ITelNrf6U8DxUVaWuHMHWOitic0fftuP7tp r7Yg== X-Gm-Message-State: AOAM533CO2nDLsleGyalQOzaRuepH/DI56bd1bRROA+16DZvD7G/d1pW KmLlL9WG8vr/U/Heeo86zp0= X-Google-Smtp-Source: ABdhPJzKfjNAAKkmny4+JhoyXbchQN4iBJ4d38/Ts+iZPYS2nOZ6TZ1yCyjmRv54v+IbOzZa76na4Q== X-Received: by 2002:a5d:6412:: with SMTP id z18mr17733482wru.214.1616411078811; Mon, 22 Mar 2021 04:04:38 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id s83sm16562582wms.16.2021.03.22.04.04.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Mar 2021 04:04:38 -0700 (PDT) Date: Mon, 22 Mar 2021 11:04:37 +0000 From: Wei Liu To: Xu Yihang Cc: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, johnny.chenyi@huawei.com, heying24@huawei.com, Wei Liu Subject: Re: [PATCH -next] x86: Fix unused variable 'msr_val' warning Message-ID: <20210322110437.ei3vfove4xqky3h5@liuwe-devbox-debian-v2> References: <20210322031713.23853-1-xuyihang@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210322031713.23853-1-xuyihang@huawei.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 22, 2021 at 11:17:13AM +0800, Xu Yihang wrote: > Fixes the following W=1 kernel build warning(s): > arch/x86/hyperv/hv_spinlock.c:28:16: warning: variable ‘msr_val’ set but not used [-Wunused-but-set-variable] > unsigned long msr_val; > > As Hypervisor Top-Level Functional Specification states in chapter 7.5 Virtual Processor Idle Sleep State, "A partition which possesses the AccessGuestIdleMsr privilege (refer to section 4.2.2) may trigger entry into the virtual processor idle sleep state through a read to the hypervisor-defined MSR HV_X64_MSR_GUEST_IDLE". That means only a read is necessary, msr_val is not uesed, so __maybe_unused should be added. > > Reference: > https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs > > Reported-by: Hulk Robot > Signed-off-by: Xu Yihang I modified the commit message a bit and queued this up for hyperv-next. Thanks. Wei.