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=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 C492AC433E0 for ; Thu, 28 May 2020 15:40:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5DB62078C for ; Thu, 28 May 2020 15:40:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404537AbgE1Pkj (ORCPT ); Thu, 28 May 2020 11:40:39 -0400 Received: from mga03.intel.com ([134.134.136.65]:26482 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404383AbgE1Pkc (ORCPT ); Thu, 28 May 2020 11:40:32 -0400 IronPort-SDR: yoXXCkfH8taa2aIKmIuUYKwNICND5YJJmquQHwBVvrBd7RDb2naKMEi2KiDbkPwwqE64rsLyVi OXDHF/d9VfVQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2020 08:40:31 -0700 IronPort-SDR: KOgzxl9gfcD5mTiB9IER1X+pGcXi3LOqDn7qdHo+JXYQRMDr66UDPVTEEA0XGGPVoXmW+AzV5Z VfJukaq/kbrQ== X-IronPort-AV: E=Sophos;i="5.73,445,1583222400"; d="scan'208";a="267254410" Received: from xiaoyaol-mobl.ccr.corp.intel.com (HELO [10.249.174.96]) ([10.249.174.96]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 May 2020 08:40:29 -0700 Subject: Re: [PATCH] KVM: X86: Call kvm_x86_ops.cpuid_update() after CPUIDs fully updated To: Paolo Bonzini , Sean Christopherson , kvm@vger.kernel.org Cc: Vitaly Kuznetsov , Jim Mattson , linux-kernel@vger.kernel.org References: <20200528151927.14346-1-xiaoyao.li@intel.com> From: Xiaoyao Li Message-ID: <1f45de43-af43-24da-b7d3-00b9d2bd517c@intel.com> Date: Thu, 28 May 2020 23:40:26 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/28/2020 11:22 PM, Paolo Bonzini wrote: > On 28/05/20 17:19, Xiaoyao Li wrote: >> kvm_x86_ops.cpuid_update() is used to update vmx/svm settings based on >> updated CPUID settings. So it's supposed to be called after CPUIDs are >> fully updated, not in the middle stage. >> >> Signed-off-by: Xiaoyao Li > > Are you seeing anything bad happening from this? Not yet. IMO changing the order is more reasonable and less confusing. > Paolo > >> --- >> arch/x86/kvm/cpuid.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c >> index cd708b0b460a..753739bc1bf0 100644 >> --- a/arch/x86/kvm/cpuid.c >> +++ b/arch/x86/kvm/cpuid.c >> @@ -208,8 +208,11 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, >> vcpu->arch.cpuid_nent = cpuid->nent; >> cpuid_fix_nx_cap(vcpu); >> kvm_apic_set_version(vcpu); >> - kvm_x86_ops.cpuid_update(vcpu); >> r = kvm_update_cpuid(vcpu); >> + if (r) >> + goto out; >> + >> + kvm_x86_ops.cpuid_update(vcpu); >> >> out: >> vfree(cpuid_entries); >> @@ -231,8 +234,11 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, >> goto out; >> vcpu->arch.cpuid_nent = cpuid->nent; >> kvm_apic_set_version(vcpu); >> - kvm_x86_ops.cpuid_update(vcpu); >> r = kvm_update_cpuid(vcpu); >> + if (r) >> + goto out; >> + >> + kvm_x86_ops.cpuid_update(vcpu); >> out: >> return r; >> } >> >