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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 0766DC3F2D7 for ; Tue, 3 Mar 2020 00:01:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0488217F4 for ; Tue, 3 Mar 2020 00:01:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728057AbgCCABi (ORCPT ); Mon, 2 Mar 2020 19:01:38 -0500 Received: from mga03.intel.com ([134.134.136.65]:17170 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727273AbgCBX50 (ORCPT ); Mon, 2 Mar 2020 18:57:26 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Mar 2020 15:57:23 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,509,1574150400"; d="scan'208";a="243384771" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga006.jf.intel.com with ESMTP; 02 Mar 2020 15:57:23 -0800 From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaoyao Li Subject: [PATCH v2 49/66] KVM: x86: Do host CPUID at load time to mask KVM cpu caps Date: Mon, 2 Mar 2020 15:56:52 -0800 Message-Id: <20200302235709.27467-50-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200302235709.27467-1-sean.j.christopherson@intel.com> References: <20200302235709.27467-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mask kvm_cpu_caps based on host CPUID in preparation for overriding the CPUID results during KVM_GET_SUPPORTED_CPUID instead of doing the masking at runtime. Note, masking may or may not be necessary, e.g. the kernel rarely, if ever, sets real CPUID bits that are not supported by hardware. But, the code is cheap and only runs once at load, so an abundance of caution is warranted. No functional change intended. Reviewed-by: Vitaly Kuznetsov Signed-off-by: Sean Christopherson --- arch/x86/kvm/cpuid.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 49527dbcc90c..ec8e24b1c1a7 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -272,8 +272,16 @@ static __always_inline void cpuid_entry_mask(struct kvm_cpuid_entry2 *entry, static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask) { + const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32); + struct kvm_cpuid_entry2 entry; + reverse_cpuid_check(leaf); kvm_cpu_caps[leaf] &= mask; + + cpuid_count(cpuid.function, cpuid.index, + &entry.eax, &entry.ebx, &entry.ecx, &entry.edx); + + kvm_cpu_caps[leaf] &= *__cpuid_entry_get_reg(&entry, &cpuid); } void kvm_set_cpu_caps(void) -- 2.24.1