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 5B4D6C433F5 for ; Mon, 14 Feb 2022 10:31:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233034AbiBNKbZ (ORCPT ); Mon, 14 Feb 2022 05:31:25 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:37470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348051AbiBNKap (ORCPT ); Mon, 14 Feb 2022 05:30:45 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E397C9BF44; Mon, 14 Feb 2022 01:59:14 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BE1336077B; Mon, 14 Feb 2022 09:59:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8339EC340EF; Mon, 14 Feb 2022 09:59:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644832754; bh=ZUacl007zA4k+q0kyD4PfVFmSEOT8YIduCKetp5Er64=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xzO2GJlTUg3rekneT8kWb2am/aB3WjJDPNlyXp1ZB7yl+uKb7ndr4+ErY2igyb/YT YNWoc9Vd+FuTSgwS7RYiWSJOh4gln1xFW879juxSkETxa6fXmVhN0fyvUNsIuKiAzj y7UF5O+lRhP7VTuM3BqZr4RCDxKqXw7MYuVr2eK8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aaron Lewis , Jim Mattson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.16 072/203] KVM: x86: Report deprecated x87 features in supported CPUID Date: Mon, 14 Feb 2022 10:25:16 +0100 Message-Id: <20220214092512.726548643@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220214092510.221474733@linuxfoundation.org> References: <20220214092510.221474733@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jim Mattson [ Upstream commit e3bcfda012edd3564e12551b212afbd2521a1f68 ] CPUID.(EAX=7,ECX=0):EBX.FDP_EXCPTN_ONLY[bit 6] and CPUID.(EAX=7,ECX=0):EBX.ZERO_FCS_FDS[bit 13] are "defeature" bits. Unlike most of the other CPUID feature bits, these bits are clear if the features are present and set if the features are not present. These bits should be reported in KVM_GET_SUPPORTED_CPUID, because if these bits are set on hardware, they cannot be cleared in the guest CPUID. Doing so would claim guest support for a feature that the hardware doesn't support and that can't be efficiently emulated. Of course, any software (e.g WIN87EM.DLL) expecting these features to be present likely predates these CPUID feature bits and therefore doesn't know to check for them anyway. Aaron Lewis added the corresponding X86_FEATURE macros in commit cbb99c0f5887 ("x86/cpufeatures: Add FDP_EXCPTN_ONLY and ZERO_FCS_FDS"), with the intention of reporting these bits in KVM_GET_SUPPORTED_CPUID, but I was unable to find a proposed patch on the kvm list. Opportunistically reordered the CPUID_7_0_EBX capability bits from least to most significant. Cc: Aaron Lewis Signed-off-by: Jim Mattson Message-Id: <20220204001348.2844660-1-jmattson@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/cpuid.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index add8f58d686e3..bf18679757c70 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -532,12 +532,13 @@ void kvm_set_cpu_caps(void) ); kvm_cpu_cap_mask(CPUID_7_0_EBX, - F(FSGSBASE) | F(SGX) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | - F(BMI2) | F(ERMS) | F(INVPCID) | F(RTM) | 0 /*MPX*/ | F(RDSEED) | - F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | - F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | - F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | 0 /*INTEL_PT*/ - ); + F(FSGSBASE) | F(SGX) | F(BMI1) | F(HLE) | F(AVX2) | + F(FDP_EXCPTN_ONLY) | F(SMEP) | F(BMI2) | F(ERMS) | F(INVPCID) | + F(RTM) | F(ZERO_FCS_FDS) | 0 /*MPX*/ | F(AVX512F) | + F(AVX512DQ) | F(RDSEED) | F(ADX) | F(SMAP) | F(AVX512IFMA) | + F(CLFLUSHOPT) | F(CLWB) | 0 /*INTEL_PT*/ | F(AVX512PF) | + F(AVX512ER) | F(AVX512CD) | F(SHA_NI) | F(AVX512BW) | + F(AVX512VL)); kvm_cpu_cap_mask(CPUID_7_ECX, F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(RDPID) | -- 2.34.1