From nobody Sun Sep 7 14:40:25 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 A21E6EB64DD for ; Wed, 19 Jul 2023 03:27:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231165AbjGSD1L (ORCPT ); Tue, 18 Jul 2023 23:27:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49374 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230505AbjGSD0f (ORCPT ); Tue, 18 Jul 2023 23:26:35 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF3BA2690; Tue, 18 Jul 2023 20:26:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689737167; x=1721273167; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=m7F+bfcxslqE8nz+gTY6bLsLBtHdYH/TwQh4VN2/phU=; b=lyWDkJqlf+4Py1HbNsJvZGid17t+6CMp/z0wOFKv80PI9DrDpJWajSFo UiYYv8VCoUUzeBXVOwAaNNfoO2aHKBau4DBRYBsAE1KxPmOCGNPfAB1kS DoNsX+GkDW9TNI3gsOrzmeJ92UbHrCo6TMZW5fd5GsoWNdoUzJki/SmBY uOvKQH8AqLAF36EyndG5cEqCnit0k0OLQhAq7SnMgkAOz8o8bhxRsGsfx +cbD65Rl3OcmP6DKGdPIoxBAGegUGvtVCvz6ch9gjr34FpLzjAAILyWxm BugxqO3uNCedslogV3RlJcJL0vx0ZOLyXyEe+bA/9qraR87K5QRKXKt/Z Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="346665883" X-IronPort-AV: E=Sophos;i="6.01,215,1684825200"; d="scan'208";a="346665883" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jul 2023 20:26:06 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10775"; a="813980304" X-IronPort-AV: E=Sophos;i="6.01,215,1684825200"; d="scan'208";a="813980304" Received: from arthur-vostro-3668.sh.intel.com ([10.238.200.123]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jul 2023 20:26:03 -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: Wed, 19 Jul 2023 10:45:58 +0800 Message-Id: <20230719024558.8539-9-guang.zeng@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230719024558.8539-1-guang.zeng@intel.com> References: <20230719024558.8539-1-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