From nobody Fri Sep 5 10:38:44 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 DD0EBEB64DC for ; Tue, 18 Jul 2023 14:01:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233224AbjGROBY (ORCPT ); Tue, 18 Jul 2023 10:01:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233129AbjGROA6 (ORCPT ); Tue, 18 Jul 2023 10:00:58 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 932AE1BCD; Tue, 18 Jul 2023 07:00:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689688840; x=1721224840; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=m7F+bfcxslqE8nz+gTY6bLsLBtHdYH/TwQh4VN2/phU=; b=a7Kd2CchCOKP65+qJTCKzfzpD0zqZ9gT8L3reqGMPzhj69T0DeKTEy3p az+/m5K8UeVr6ZIzB23ShZA6YBnw+KDQIOptty6tovheB3yrLH7fN1JIB DnNKY1ca7ytSyL6g3QUQSodsaCCSKvlS+kwREfTIzi+lfmTm4iocYoB3c V3M0mLGK7Qz/wjEG6cZqN1asaE5W2bUcXpjmHMX9NCevBRTIkjBAQ0R3Y bwW15ZebLst4ivfK9+GsxOhXxmAjiBSbuBk88UdEEnBZ0U6KKXnmWfwYo 9Jt8gIIRi5U+uRyoAaN7eVZanxLDRZs0ZrQrl5ckLabJUGxALjHp9kfFR g==; X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="363676209" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="363676209" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jul 2023 06:59:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="1054291208" X-IronPort-AV: E=Sophos;i="6.01,214,1684825200"; d="scan'208";a="1054291208" Received: from arthur-vostro-3668.sh.intel.com ([10.238.200.123]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jul 2023 06:59:02 -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, Zeng Guang Subject: [PATCH v2 8/8] KVM: x86: Advertise LASS CPUID to user space Date: Tue, 18 Jul 2023 21:18:44 +0800 Message-Id: <20230718131844.5706-9-guang.zeng@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230718131844.5706-1-guang.zeng@intel.com> References: <20230718131844.5706-1-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" Linear address space separation (LASS) 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 Tested-by: Xuelian Guo --- arch/x86/kvm/cpuid.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 0c9660a07b23..a7fafe99ffe4 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -646,9 +646,8 @@ 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(FZRM) | F(FSRS) | F(FSRC) | - F(AMX_FP16) | F(AVX_IFMA) + F(AVX_VNNI) | F(AVX512_BF16) | F(LASS) | F(CMPCCXADD) | + F(FZRM) | F(FSRS) | F(FSRC) | F(AMX_FP16) | F(AVX_IFMA) ); =20 kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX, --=20 2.27.0