1 files changed, 91 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/ExecuteDisable.c b/UefiCpuPkg/Library/CpuCommonFeaturesLib/ExecuteDisable.c
new file mode 100644
index 0000000000..dd4293ee38
--- /dev/null
+++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/ExecuteDisable.c
@@ -0,0 +1,91 @@
+/** @file
+  Execute Disable feature.
+
+  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
+  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
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "CpuCommonFeatures.h"
+
+/**
+  Detects if Execute Disable feature supported on current processor.
+
+  @param[in]  ProcessorNumber  The index of the CPU executing this function.
+  @param[in]  CpuInfo          A pointer to the REGISTER_CPU_FEATURE_INFORMATION
+                               structure for the CPU executing this function.
+  @param[in]  ConfigData       A pointer to the configuration buffer returned
+                               by CPU_FEATURE_GET_CONFIG_DATA.  NULL if
+                               CPU_FEATURE_GET_CONFIG_DATA was not provided in
+                               RegisterCpuFeature().
+
+  @retval TRUE     Execute Disable feature is supported.
+  @retval FALSE    Execute Disable feature is not supported.
+
+  @note This service could be called by BSP/APs.
+**/
+BOOLEAN
+EFIAPI
+ExecuteDisableSupport (
+  IN UINTN                             ProcessorNumber,
+  IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
+  IN VOID                              *ConfigData  OPTIONAL
+  )
+{
+  UINT32                         Eax;
+  CPUID_EXTENDED_CPU_SIG_EDX     Edx;
+
+  AsmCpuid (CPUID_EXTENDED_FUNCTION, &Eax, NULL, NULL, NULL);
+  if (Eax <= CPUID_EXTENDED_FUNCTION) {
+    //
+    // Extended CPUID functions are not supported on this processor.
+    //
+    return FALSE;
+  }
+
+  AsmCpuid (CPUID_EXTENDED_CPU_SIG, NULL, NULL, NULL, &Edx.Uint32);
+  return (Edx.Bits.NX != 0);
+}
+
+/**
+  Initializes Execute Disable feature to specific state.
+
+  @param[in]  ProcessorNumber  The index of the CPU executing this function.
+  @param[in]  CpuInfo          A pointer to the REGISTER_CPU_FEATURE_INFORMATION
+                               structure for the CPU executing this function.
+  @param[in]  ConfigData       A pointer to the configuration buffer returned
+                               by CPU_FEATURE_GET_CONFIG_DATA.  NULL if
+                               CPU_FEATURE_GET_CONFIG_DATA was not provided in
+                               RegisterCpuFeature().
+  @param[in]  State            If TRUE, then the Execute Disable feature must be enabled.
+                               If FALSE, then the Execute Disable feature must be disabled.
+
+  @retval RETURN_SUCCESS       Execute Disable feature is initialized.
+
+  @note This service could be called by BSP only.
+**/
+RETURN_STATUS
+EFIAPI
+ExecuteDisableInitialize (
+  IN UINTN                             ProcessorNumber,
+  IN REGISTER_CPU_FEATURE_INFORMATION  *CpuInfo,
+  IN VOID                              *ConfigData,  OPTIONAL
+  IN BOOLEAN                           State
+  )
+{
+  CPU_REGISTER_TABLE_WRITE_FIELD (
+    ProcessorNumber,
+    Msr,
+    MSR_IA32_EFER,
+    MSR_IA32_EFER_REGISTER,
+    Bits.NXE,
+    (State) ? 1 : 0
+    );
+  return RETURN_SUCCESS;
+}