From nobody Thu Dec 18 05:18:22 2025 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 39995C77B76 for ; Thu, 20 Apr 2023 14:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232067AbjDTOQi (ORCPT ); Thu, 20 Apr 2023 10:16:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231962AbjDTOQV (ORCPT ); Thu, 20 Apr 2023 10:16:21 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 967FE5594; Thu, 20 Apr 2023 07:16:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1682000180; x=1713536180; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=/9rOO3Vbv54KntD8O0wgn+L44l9VgaKRnztR0QPc7F0=; b=FGLh1XN6L0CmuLbhgRPOwS0kpy2wfbadqE3Vrb+pdgG60Jx9yNssS98X TKHqfr5a4AwcdCr/ljmidxJ8209H29UESkdaNwNmzvCTSo092PF8PoOEz nWjmNf9I8JCLeBT9avg8JBQKSXr3whtGJXIxBqsfdkamiFbab2exkapZK GLRZhXykzXToKbj5/lBDTxlybZFUqY/1WxlHWHYuDHRxcYdUI12bV97Fp sjnoNBpc/cz3+XQ2RT1vqEJMVukI6OTJZ4Mcf0sclr0+Hc/FmXUKtex6E QklRIumkp76Ks6MjLrw/t+rDsEy3DA9m1Ufn8GFNg5W1D/mPHU9uGail6 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10686"; a="343217863" X-IronPort-AV: E=Sophos;i="5.99,212,1677571200"; d="scan'208";a="343217863" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Apr 2023 07:16:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10686"; a="816028909" X-IronPort-AV: E=Sophos;i="5.99,212,1677571200"; d="scan'208";a="816028909" Received: from arthur-vostro-3668.sh.intel.com ([10.238.200.53]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Apr 2023 07:16:13 -0700 From: Zeng Guang To: Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , H Peter Anvin , kvm@vger.kernel.org Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Gao Chao , Zeng Guang Subject: [PATCH 5/6] KVM: x86: Advertise LASS CPUID to user space Date: Thu, 20 Apr 2023 21:37:23 +0800 Message-Id: <20230420133724.11398-6-guang.zeng@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230420133724.11398-1-guang.zeng@intel.com> References: <20230420133724.11398-1-guang.zeng@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" LASS (Linear-address space separation) is an independent mechanism to enforce the mode-based protection that can prevent user-mode accesses to supervisor-mode addresses, and vice versa. Because the LASS protections are applied before paging, malicious software can not acquire any paging-based timing information to compromise the security of system. The CPUID bit definition to support LASS: CPUID.(EAX=3D07H.ECX=3D1):EAX.LASS[bit 6] Advertise LASS to user space to support LASS virtualization. Signed-off-by: Zeng Guang --- arch/x86/kvm/cpuid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index ba7f7abc8964..5facb8037140 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -663,8 +663,8 @@ void kvm_set_cpu_caps(void) kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD); =20 kvm_cpu_cap_mask(CPUID_7_1_EAX, - F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) | F(AMX_FP16) | - F(AVX_IFMA) + F(AVX_VNNI) | F(AVX512_BF16) | F(LASS) | F(CMPCCXADD) | + F(AMX_FP16) | F(AVX_IFMA) ); =20 kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX, --=20 2.27.0