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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 594FBC43217 for ; Thu, 20 Oct 2022 14:27:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230218AbiJTO1N (ORCPT ); Thu, 20 Oct 2022 10:27:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229670AbiJTO1H (ORCPT ); Thu, 20 Oct 2022 10:27:07 -0400 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D8CD1AFA87 for ; Thu, 20 Oct 2022 07:27:06 -0700 (PDT) Received: by mail-pj1-x1032.google.com with SMTP id ez6so2363468pjb.1 for ; Thu, 20 Oct 2022 07:27:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=5as7RvXmnpmdw2J8D5qzRuTt8iInwm4QklMlCoqT8xc=; b=j27ChnRsZvVCu6uPN8v6MUJfYY4YII6/shJfnYuumGcBsyqGBg77+FHzsgGrdDlnNa ZnFCjIqzMFIa5e8eFIH0V/QdekhZBbGzDhm9z/4ui+mENYaYGh4zgLHyLQGk4tqn2NjR 2hrqDcPJmVrShWIv/wXzs5tysV//YEBCk0GuL8AlDWPnJbGbNmIiA2r3SbfWjfwcws31 33T6GdhVyzV+oPccdsvefOM/kqT94JcavpQwiyhEMNLn+vwU9Un19XmDwfWPtadQHI76 fncVxyVVfNp9py+JAGWr+hiRcTGTPaXIMQCAwkOWizazXIKoaAvnii2ocHqu/Nl7NLre fF0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=5as7RvXmnpmdw2J8D5qzRuTt8iInwm4QklMlCoqT8xc=; b=KCI4pcqsWZJmK+WYTu+qLdv8B634ovrzoBfq5LWaEOeNEDtxTTBdo1s0wOfCHgZzlV BhoWNUGhPKa3XxxInS2XzSnt6+Gp2+f+AL2RoqkZYKG7OtdotwbEizHijnLC4POzJYye 71fjLkMRx6baGdWgd+Ud5nJ432E+VPg6JSq0mZcRt7ydTpgvi1kcNpHm9uRXmfmns1U0 Q8u792ofJlHogDs1hbSZ+5/px4WhoCdyTMCjnELZGghCUdTu34KHsKg2mzwu5gsxsxQ9 RmT2qkkhMLY4qRrHqsR3Ip+LMBzj/Z50lH7E/RYCZzFCHU9DvLfFQWDygza2nimS78hP QH4A== X-Gm-Message-State: ACrzQf0zlvTC8//RxHJLtsQcscgifOVwnQn5tvFthDWHLEh5EBIhyqi+ 26Yvk0X80B/n+W3gh5M+5gKZDQ== X-Google-Smtp-Source: AMsMyM6dgONGmly9i1g9cbunKT4jCzU6tIbYI+FDN89w9xHqsGAoFm5G+VheJmomUGkEYWEIAGyOkg== X-Received: by 2002:a17:90a:930b:b0:20b:a5d:35d6 with SMTP id p11-20020a17090a930b00b0020b0a5d35d6mr51575318pjo.146.1666276025901; Thu, 20 Oct 2022 07:27:05 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id 194-20020a6216cb000000b0053e199aa99bsm13217718pfw.220.2022.10.20.07.27.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 20 Oct 2022 07:27:05 -0700 (PDT) Date: Thu, 20 Oct 2022 14:27:01 +0000 From: Sean Christopherson To: Xiaoyao Li Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] KVM: x86: Fix the initial value of mcg_cap Message-ID: References: <20221020031615.890400-1-xiaoyao.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221020031615.890400-1-xiaoyao.li@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 20, 2022, Xiaoyao Li wrote: > vcpu->arch.mcg_cap represents the value of MSR_IA32_MCG_CAP. It's > set via ioctl(KVM_X86_SETUP_MCE) from userspace when exposing and > configuring MCE to guest. > > It's wrong to leave the default value as KVM_MAX_MCE_BANKS. Why? I agree it's an odd default, but the whole MCE API is odd. Functionally, I don't see anything that's broken by allowing the guest to access the MCx_CTL MSRs by default.