From nobody Mon Feb 9 10:26:10 2026 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 06E4CC77B7E for ; Thu, 1 Jun 2023 15:06:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234940AbjFAPG2 (ORCPT ); Thu, 1 Jun 2023 11:06:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235334AbjFAPF2 (ORCPT ); Thu, 1 Jun 2023 11:05:28 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3BA810E9; Thu, 1 Jun 2023 08:04:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685631874; x=1717167874; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=Qobfjghbe5gi6AIkAjOe1SXmoivnNVnCI+24keSLXNs=; b=ahgAhLOD/8SwtU/IAVU21c2CbVTj02Be++UwKkW0PFxjGhsvipBbRzOc xsfTu8THe0sQ+ofqkGOVuoEwI3p3uoYUuGS82WVLpmzHsdAvCWVDXzrCq 8yAZNaJl8vWGrOA/xpOOd+386aShwmnsRLsCQuwd0ymMwEeNOv0/uvkke 43vQbHw8weCxf2UInOeWM09mqSuyJ9+efP6kwVLTI+tGdIR8qBdCxFWvH P1S0zFBq0HcCZhvJPDKVH7m91EvtMfdauxdJHnMxVt8BD33D2dcLqVdIe Lm2Bs52CBnSEtsoM04GxH4rUB/I9WsLwbicctXqXR3SGBu2U8TwBprnVS A==; X-IronPort-AV: E=McAfee;i="6600,9927,10728"; a="383853504" X-IronPort-AV: E=Sophos;i="6.00,210,1681196400"; d="scan'208";a="383853504" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2023 08:02:57 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10728"; a="657828278" X-IronPort-AV: E=Sophos;i="6.00,210,1681196400"; d="scan'208";a="657828278" Received: from arthur-vostro-3668.sh.intel.com ([10.238.200.123]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2023 08:02:54 -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 v1 6/6] KVM: x86: Advertise LASS CPUID to user space Date: Thu, 1 Jun 2023 22:23:09 +0800 Message-Id: <20230601142309.6307-7-guang.zeng@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230601142309.6307-1-guang.zeng@intel.com> References: <20230601142309.6307-1-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 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