From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 70D4F21DFA7B8 for ; Mon, 27 Mar 2017 00:02:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1490598144; x=1522134144; h=from:to:cc:subject:date:message-id; bh=DoWGuXmmyAeQ1EMq2rsmvMMHtZL3zpAeBSBjeXR1as4=; b=JIN7u1eZnKhs6Bi24ROA8791JZvoWWSsy5p7a7wiWCbNm56DF6/hDEWG 1Jq741Xo5XOMt2w90Wxcv50YOBVsyA==; Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Mar 2017 00:02:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,229,1486454400"; d="scan'208";a="79641160" Received: from jfan12-desk.ccr.corp.intel.com ([10.239.158.57]) by orsmga005.jf.intel.com with ESMTP; 27 Mar 2017 00:02:23 -0700 From: Jeff Fan To: edk2-devel@lists.01.org Cc: Feng Tian , Michael Kinney Date: Mon, 27 Mar 2017 15:02:21 +0800 Message-Id: <20170327070221.13228-1-jeff.fan@intel.com> X-Mailer: git-send-email 2.9.3.windows.2 Subject: [PATCH] UefiCpuPkg/MpLib.c: Add checking CR0 PG bit X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 27 Mar 2017 07:02:24 -0000 If CR0 PG bit is not set, it means paging is enabled on BSP. Thus, Execute Disable feature is not working actually. We cannot enable it on APs. Cc: Feng Tian Cc: Michael Kinney Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan --- UefiCpuPkg/Library/MpInitLib/MpLib.c | 38 +++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 14 deletions(-) diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c index 55fe812..bb93526 100644 --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c @@ -1,7 +1,7 @@ /** @file CPU MP Initialize Library common functions. - Copyright (c) 2016, Intel Corporation. All rights reserved.
+ Copyright (c) 2016 - 2017, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -18,8 +18,11 @@ EFI_GUID mCpuInitMpLibHobGuid = CPU_INIT_MP_LIB_HOB_GUID; /** The function will check if BSP Execute Disable is enabled. - DxeIpl may have enabled Execute Disable for BSP, - APs need to get the status and sync up the settings. + + DxeIpl may have enabled Execute Disable for BSP, APs need to + get the status and sync up the settings. + If BSP's CR0.Paging is not set, BSP execute Disble feature is + not working actually. @retval TRUE BSP Execute Disable is enabled. @retval FALSE BSP Execute Disable is not enabled. @@ -33,23 +36,30 @@ IsBspExecuteDisableEnabled ( CPUID_EXTENDED_CPU_SIG_EDX Edx; MSR_IA32_EFER_REGISTER EferMsr; BOOLEAN Enabled; + IA32_CR0 Cr0; Enabled = FALSE; - AsmCpuid (CPUID_EXTENDED_FUNCTION, &Eax, NULL, NULL, NULL); - if (Eax >= CPUID_EXTENDED_CPU_SIG) { - AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &Edx.Uint32); + Cr0.UintN = AsmReadCr0 (); + if (Cr0.Bits.PG != 0) { // - // CPUID 0x80000001 - // Bit 20: Execute Disable Bit available. + // If CR0 Paging bit is set // - if (Edx.Bits.NX != 0) { - EferMsr.Uint64 = AsmReadMsr64 (MSR_IA32_EFER); + AsmCpuid (CPUID_EXTENDED_FUNCTION, &Eax, NULL, NULL, NULL); + if (Eax >= CPUID_EXTENDED_CPU_SIG) { + AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &Edx.Uint32); // - // MSR 0xC0000080 - // Bit 11: Execute Disable Bit enable. + // CPUID 0x80000001 + // Bit 20: Execute Disable Bit available. // - if (EferMsr.Bits.NXE != 0) { - Enabled = TRUE; + if (Edx.Bits.NX != 0) { + EferMsr.Uint64 = AsmReadMsr64 (MSR_IA32_EFER); + // + // MSR 0xC0000080 + // Bit 11: Execute Disable Bit enable. + // + if (EferMsr.Bits.NXE != 0) { + Enabled = TRUE; + } } } } -- 2.9.3.windows.2