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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 35B51C43461 for ; Mon, 17 May 2021 15:09:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10608610CB for ; Mon, 17 May 2021 15:09:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243283AbhEQPJe (ORCPT ); Mon, 17 May 2021 11:09:34 -0400 Received: from mga12.intel.com ([192.55.52.136]:52859 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242559AbhEQO7z (ORCPT ); Mon, 17 May 2021 10:59:55 -0400 IronPort-SDR: OqUwtqWNYDfdDO3uFAqmgaq9Xdf5evGw+DmvOrl/3Nhhf2GL1ufZIFiyFCbKMKt+9DBaAIRiWd omE2D+2yHPjw== X-IronPort-AV: E=McAfee;i="6200,9189,9987"; a="180080141" X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="180080141" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2021 07:50:26 -0700 IronPort-SDR: iIgpmFCjC+ba4PHw13ILGS1IQbgwQUXRhKvrLaJrySRFIcicr/hLb428X1DYTCkt3PCUMCgoEw kxVuVGQPc3IA== X-IronPort-AV: E=Sophos;i="5.82,307,1613462400"; d="scan'208";a="410852673" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.212.163.36]) ([10.212.163.36]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 May 2021 07:50:13 -0700 Subject: Re: [PATCH v6 08/16] KVM: x86/pmu: Add IA32_DS_AREA MSR emulation to support guest DS To: Peter Zijlstra , Like Xu Cc: Paolo Bonzini , Borislav Petkov , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , weijiang.yang@intel.com, Kan Liang , wei.w.wang@intel.com, eranian@google.com, liuxiangdong5@huawei.com, linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org References: <20210511024214.280733-1-like.xu@linux.intel.com> <20210511024214.280733-9-like.xu@linux.intel.com> From: Andi Kleen Message-ID: <3b13359c-5b7a-f103-74ff-1f57389db181@linux.intel.com> Date: Mon, 17 May 2021 07:50:02 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/17/2021 6:26 AM, Peter Zijlstra wrote: > On Tue, May 11, 2021 at 10:42:06AM +0800, Like Xu wrote: >> @@ -3897,6 +3898,8 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data) >> { >> struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); >> struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs; >> + struct debug_store *ds = __this_cpu_read(cpu_hw_events.ds); >> + struct kvm_pmu *pmu = (struct kvm_pmu *)data; > You can do without the cast, this is C, 'void *' silently casts to any > other pointer type. FWIW doing the C++ like casts for void * is fairly standard C coding style. I generally prefer it too for better documentation. K&R is written this way. -Andi (my last email on this topic to avoid any bike shedding)