[PATCH v3 03/14] MdeModulePkg: Define the VariablePolicyHelperLib

["Michael Kubacki" <michael.kubacki@outlook.com>]

From: Bret Barkelew <brbarkel@microsoft.com>

https://bugzilla.tianocore.org/show_bug.cgi?id=2522

VariablePolicy is an updated interface to
replace VarLock and VarCheckProtocol.

Add the VariablePolicyHelperLib library, containing
several functions to help with the repetitive process
of creating a correctly structured and packed
VariablePolicy entry.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Bret Barkelew <brbarkel@microsoft.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
---
 MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c   | 404 ++++++++++++++++++++
 MdeModulePkg/Include/Library/VariablePolicyHelperLib.h                   | 164 ++++++++
 MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf |  35 ++
 MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.uni |  12 +
 MdeModulePkg/MdeModulePkg.dec                                            |   5 +
 MdeModulePkg/MdeModulePkg.dsc                                            |   2 +
 6 files changed, 622 insertions(+)

diff --git a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
new file mode 100644
index 000000000000..73f43a543929
--- /dev/null
+++ b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
@@ -0,0 +1,404 @@
+/** @file -- VariablePolicyHelperLib.c
+This library contains helper functions for marshalling and registering
+new policies with the VariablePolicy infrastructure.
+
+This library is currently written against VariablePolicy revision 0x00010000.
+
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+
+#include <Protocol/VariablePolicy.h>
+
+/**
+  This internal helper function populates the header structure,
+  all common fields, and takes care of fix-ups.
+
+  NOTE: Only use this internally. Assumes correctly-sized buffers.
+
+  @param[out] EntPtr      Pointer to the buffer to be populated.
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  LockPolicyType        LockPolicyType for the VariablePolicy.
+
+**/
+STATIC
+VOID
+PopulateCommonData (
+  OUT VARIABLE_POLICY_ENTRY   *EntPtr,
+  IN CONST  EFI_GUID          *Namespace,
+  IN        UINT32            MinSize,
+  IN        UINT32            MaxSize,
+  IN        UINT32            AttributesMustHave,
+  IN        UINT32            AttributesCantHave,
+  IN        UINT8             LockPolicyType
+  )
+{
+  EntPtr->Version             = VARIABLE_POLICY_ENTRY_REVISION;
+  CopyGuid (&EntPtr->Namespace, Namespace);
+  EntPtr->MinSize             = MinSize;
+  EntPtr->MaxSize             = MaxSize;
+  EntPtr->AttributesMustHave  = AttributesMustHave;
+  EntPtr->AttributesCantHave  = AttributesCantHave;
+  EntPtr->LockPolicyType      = LockPolicyType;
+
+  // NOTE: As a heler, fix up MaxSize for compatibility with the old model.
+  if (EntPtr->MaxSize == 0) {
+    EntPtr->MaxSize = VARIABLE_POLICY_NO_MAX_SIZE;
+  }
+
+  return;
+}
+
+
+/**
+  This helper function will allocate and populate a new VariablePolicy
+  structure for a policy that does not contain any sub-structures (such as
+  VARIABLE_LOCK_ON_VAR_STATE_POLICY).
+
+  NOTE: Caller will need to free structure once finished.
+
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  LockPolicyType        LockPolicyType for the VariablePolicy.
+  @param[out] NewEntry    If successful, will be set to a pointer to the allocated buffer containing the
+                          new policy.
+
+  @retval     EFI_SUCCESS             Operation completed successfully and structure is populated.
+  @retval     EFI_INVALID_PARAMETER   Namespace is NULL.
+  @retval     EFI_INVALID_PARAMETER   LockPolicyType is invalid for a basic structure.
+  @retval     EFI_BUFFER_TOO_SMALL    Finished structure would not fit in UINT16 size.
+  @retval     EFI_OUT_OF_RESOURCES    Could not allocate sufficient space for structure.
+
+**/
+EFI_STATUS
+EFIAPI
+CreateBasicVariablePolicy (
+  IN CONST  EFI_GUID          *Namespace,
+  IN CONST  CHAR16            *Name OPTIONAL,
+  IN        UINT32            MinSize,
+  IN        UINT32            MaxSize,
+  IN        UINT32            AttributesMustHave,
+  IN        UINT32            AttributesCantHave,
+  IN        UINT8             LockPolicyType,
+  OUT VARIABLE_POLICY_ENTRY   **NewEntry
+  )
+{
+  UINTN                   TotalSize;
+  UINTN                   NameSize;
+  VARIABLE_POLICY_ENTRY   *EntPtr;
+  CHAR16                  *CopyName;
+
+  // Check some initial invalid parameters for this function.
+  if (Namespace == NULL || NewEntry == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+  if (LockPolicyType != VARIABLE_POLICY_TYPE_NO_LOCK &&
+      LockPolicyType != VARIABLE_POLICY_TYPE_LOCK_NOW &&
+      LockPolicyType != VARIABLE_POLICY_TYPE_LOCK_ON_CREATE) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Now we've gotta determine the total size of the buffer required for
+  // the VariablePolicy structure.
+  TotalSize = sizeof (VARIABLE_POLICY_ENTRY);
+  if (Name != NULL) {
+    NameSize = StrnSizeS (Name, MAX_UINT16);
+    TotalSize += NameSize;
+  }
+  // Make sure the size fits within a VARIABLE_POLICY_ENTRY.Size.
+  ASSERT (TotalSize <= MAX_UINT16);
+  if (TotalSize > MAX_UINT16) {
+    return EFI_BUFFER_TOO_SMALL;
+  }
+
+  // Allocate a buffer to hold all the data. We're on the home stretch.
+  *NewEntry = AllocatePool (TotalSize);
+  if (*NewEntry == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // If we're still here, we're basically done.
+  // Copy the data and GET... OUT....
+  EntPtr = *NewEntry;
+  PopulateCommonData (
+    EntPtr,
+    Namespace,
+    MinSize,
+    MaxSize,
+    AttributesMustHave,
+    AttributesCantHave,
+    LockPolicyType
+    );
+  EntPtr->Size                = (UINT16) TotalSize;      // This is safe because we've already checked.
+  EntPtr->OffsetToName        = sizeof (VARIABLE_POLICY_ENTRY);
+  if (Name != NULL) {
+    CopyName = (CHAR16 *) ((UINT8 *) EntPtr + EntPtr->OffsetToName);
+    CopyMem (CopyName, Name, NameSize);
+  }
+
+  return EFI_SUCCESS;
+}
+
+
+/**
+  This helper function will allocate and populate a new VariablePolicy
+  structure for a policy with a lock type of VARIABLE_POLICY_TYPE_LOCK_ON_VAR_STATE.
+
+  NOTE: Caller will need to free structure once finished.
+
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  VarStateNamespace     Pointer to the EFI_GUID for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Namespace.
+  @param[in]  VarStateValue         Value for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Value.
+  @param[in]  VarStateName          Pointer to the CHAR16 array for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Name.
+  @param[out] NewEntry    If successful, will be set to a pointer to the allocated buffer containing the
+                          new policy.
+
+  @retval     EFI_SUCCESS             Operation completed successfully and structure is populated.
+  @retval     EFI_INVALID_PARAMETER   Namespace, VarStateNamespace, VarStateName is NULL.
+  @retval     EFI_BUFFER_TOO_SMALL    Finished structure would not fit in UINT16 size.
+  @retval     EFI_OUT_OF_RESOURCES    Could not allocate sufficient space for structure.
+
+**/
+EFI_STATUS
+EFIAPI
+CreateVarStateVariablePolicy (
+  IN CONST  EFI_GUID          *Namespace,
+  IN CONST  CHAR16            *Name OPTIONAL,
+  IN        UINT32            MinSize,
+  IN        UINT32            MaxSize,
+  IN        UINT32            AttributesMustHave,
+  IN        UINT32            AttributesCantHave,
+  IN CONST  EFI_GUID          *VarStateNamespace,
+  IN        UINT8             VarStateValue,
+  IN CONST  CHAR16            *VarStateName,
+  OUT VARIABLE_POLICY_ENTRY   **NewEntry
+  )
+{
+  UINTN                   TotalSize;
+  UINTN                   NameSize;
+  UINTN                   VarStateNameSize;
+  VARIABLE_POLICY_ENTRY   *EntPtr;
+  CHAR16                  *CopyName;
+  VARIABLE_LOCK_ON_VAR_STATE_POLICY *CopyPolicy;
+
+  // Check some initial invalid parameters for this function.
+  if (Namespace == NULL || VarStateNamespace == NULL ||
+      VarStateName == NULL || NewEntry == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Now we've gotta determine the total size of the buffer required for
+  // the VariablePolicy structure.
+  VarStateNameSize = StrnSizeS (VarStateName, MAX_UINT16);
+  TotalSize = sizeof (VARIABLE_POLICY_ENTRY) +
+                sizeof (VARIABLE_LOCK_ON_VAR_STATE_POLICY) +
+                VarStateNameSize;
+  if (Name != NULL) {
+    NameSize = StrnSizeS (Name, MAX_UINT16);
+    TotalSize += NameSize;
+  }
+  // Make sure the size fits within a VARIABLE_POLICY_ENTRY.Size.
+  ASSERT (TotalSize <= MAX_UINT16);
+  if (TotalSize > MAX_UINT16) {
+    return EFI_BUFFER_TOO_SMALL;
+  }
+
+  // Allocate a buffer to hold all the data. We're on the home stretch.
+  *NewEntry = AllocatePool (TotalSize);
+  if (*NewEntry == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  // If we're still here, we're basically done.
+  // Copy the data and GET... OUT....
+  EntPtr = *NewEntry;
+  PopulateCommonData (
+    EntPtr,
+    Namespace,
+    MinSize,
+    MaxSize,
+    AttributesMustHave,
+    AttributesCantHave,
+    VARIABLE_POLICY_TYPE_LOCK_ON_VAR_STATE
+    );
+  EntPtr->Size                = (UINT16) TotalSize;      // This is safe because we've already checked.
+  EntPtr->OffsetToName        = sizeof (VARIABLE_POLICY_ENTRY) +
+                                sizeof (VARIABLE_LOCK_ON_VAR_STATE_POLICY) +
+                                (UINT16) VarStateNameSize;
+
+  CopyPolicy = (VARIABLE_LOCK_ON_VAR_STATE_POLICY *) ((UINT8 *) EntPtr + sizeof (VARIABLE_POLICY_ENTRY));
+  CopyName = (CHAR16 *) ((UINT8 *) CopyPolicy + sizeof (VARIABLE_LOCK_ON_VAR_STATE_POLICY));
+  CopyGuid (&CopyPolicy->Namespace, VarStateNamespace);
+  CopyPolicy->Value = VarStateValue;
+  CopyMem (CopyName, VarStateName, VarStateNameSize);
+
+  if (Name != NULL) {
+    CopyName = (CHAR16 *) ((UINT8 *) EntPtr + EntPtr->OffsetToName);
+    CopyMem (CopyName, Name, NameSize);
+  }
+
+  return EFI_SUCCESS;
+}
+
+
+/**
+  This helper function does everything that CreateBasicVariablePolicy() does, but also
+  uses the passed in protocol to register the policy with the infrastructure.
+  Does not return a buffer, does not require the caller to free anything.
+
+  @param[in]  VariablePolicy  Pointer to a valid instance of the VariablePolicy protocol.
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  LockPolicyType        LockPolicyType for the VariablePolicy.
+
+  @retval     EFI_INVALID_PARAMETER VariablePolicy pointer is NULL.
+  @retval     EFI_STATUS            Status returned by CreateBasicVariablePolicy() or RegisterVariablePolicy().
+
+**/
+EFI_STATUS
+EFIAPI
+RegisterBasicVariablePolicy (
+  IN        EDKII_VARIABLE_POLICY_PROTOCOL  *VariablePolicy,
+  IN CONST  EFI_GUID                        *Namespace,
+  IN CONST  CHAR16                          *Name OPTIONAL,
+  IN        UINT32                          MinSize,
+  IN        UINT32                          MaxSize,
+  IN        UINT32                          AttributesMustHave,
+  IN        UINT32                          AttributesCantHave,
+  IN        UINT8                           LockPolicyType
+  )
+{
+  VARIABLE_POLICY_ENTRY   *NewEntry;
+  EFI_STATUS              Status;
+
+  // Check the simple things.
+  if (VariablePolicy == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Create the new entry and make sure that everything worked.
+  NewEntry = NULL;
+  Status = CreateBasicVariablePolicy (
+            Namespace,
+            Name,
+            MinSize,
+            MaxSize,
+            AttributesMustHave,
+            AttributesCantHave,
+            LockPolicyType,
+            &NewEntry
+            );
+
+  // If that was successful, attempt to register the new policy.
+  if (!EFI_ERROR (Status)) {
+    Status = VariablePolicy->RegisterVariablePolicy (NewEntry);
+  }
+
+  // If we allocated the buffer, free the buffer.
+  if (NewEntry != NULL) {
+    FreePool (NewEntry);
+  }
+
+  return Status;
+}
+
+
+/**
+  This helper function does everything that CreateBasicVariablePolicy() does, but also
+  uses the passed in protocol to register the policy with the infrastructure.
+  Does not return a buffer, does not require the caller to free anything.
+
+  @param[in]  VariablePolicy  Pointer to a valid instance of the VariablePolicy protocol.
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  VarStateNamespace     Pointer to the EFI_GUID for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Namespace.
+  @param[in]  VarStateName          Pointer to the CHAR16 array for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Name.
+  @param[in]  VarStateValue         Value for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Value.
+
+  @retval     EFI_INVALID_PARAMETER VariablePolicy pointer is NULL.
+  @retval     EFI_STATUS    Status returned by CreateBasicVariablePolicy() or RegisterVariablePolicy().
+
+**/
+EFI_STATUS
+EFIAPI
+RegisterVarStateVariablePolicy (
+  IN        EDKII_VARIABLE_POLICY_PROTOCOL  *VariablePolicy,
+  IN CONST  EFI_GUID                        *Namespace,
+  IN CONST  CHAR16                          *Name OPTIONAL,
+  IN        UINT32                          MinSize,
+  IN        UINT32                          MaxSize,
+  IN        UINT32                          AttributesMustHave,
+  IN        UINT32                          AttributesCantHave,
+  IN CONST  EFI_GUID                        *VarStateNamespace,
+  IN CONST  CHAR16                          *VarStateName,
+  IN        UINT8                           VarStateValue
+  )
+{
+  VARIABLE_POLICY_ENTRY   *NewEntry;
+  EFI_STATUS              Status;
+
+  // Check the simple things.
+  if (VariablePolicy == NULL) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Create the new entry and make sure that everything worked.
+  NewEntry = NULL;
+  Status =  CreateVarStateVariablePolicy (
+              Namespace,
+              Name,
+              MinSize,
+              MaxSize,
+              AttributesMustHave,
+              AttributesCantHave,
+              VarStateNamespace,
+              VarStateValue,
+              VarStateName,
+              &NewEntry
+              );
+
+  // If that was successful, attempt to register the new policy.
+  if (!EFI_ERROR (Status)) {
+    Status = VariablePolicy->RegisterVariablePolicy (NewEntry);
+  }
+
+  // If we allocated the buffer, free the buffer.
+  if (NewEntry != NULL) {
+    FreePool (NewEntry);
+  }
+
+  return Status;
+}
diff --git a/MdeModulePkg/Include/Library/VariablePolicyHelperLib.h b/MdeModulePkg/Include/Library/VariablePolicyHelperLib.h
new file mode 100644
index 000000000000..3b75e9786094
--- /dev/null
+++ b/MdeModulePkg/Include/Library/VariablePolicyHelperLib.h
@@ -0,0 +1,164 @@
+/** @file -- VariablePolicyHelperLib.h
+This library contains helper functions for marshalling and registering
+new policies with the VariablePolicy infrastructure.
+
+Copyright (c) Microsoft Corporation.
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _EDKII_VARIABLE_POLICY_HELPER_LIB_H_
+#define _EDKII_VARIABLE_POLICY_HELPER_LIB_H_
+
+#include <Protocol/VariablePolicy.h>
+
+/**
+  This helper function will allocate and populate a new VariablePolicy
+  structure for a policy that does not contain any sub-structures (such as
+  VARIABLE_LOCK_ON_VAR_STATE_POLICY).
+
+  NOTE: Caller will need to free structure once finished.
+
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  LockPolicyType        LockPolicyType for the VariablePolicy.
+  @param[out] NewEntry    If successful, will be set to a pointer to the allocated buffer containing the
+                          new policy.
+
+  @retval     EFI_SUCCESS             Operation completed successfully and structure is populated.
+  @retval     EFI_INVALID_PARAMETER   Namespace is NULL.
+  @retval     EFI_INVALID_PARAMETER   LockPolicyType is invalid for a basic structure.
+  @retval     EFI_BUFFER_TOO_SMALL    Finished structure would not fit in UINT16 size.
+  @retval     EFI_OUT_OF_RESOURCES    Could not allocate sufficient space for structure.
+
+**/
+EFI_STATUS
+EFIAPI
+CreateBasicVariablePolicy (
+  IN CONST  EFI_GUID          *Namespace,
+  IN CONST  CHAR16            *Name OPTIONAL,
+  IN        UINT32            MinSize,
+  IN        UINT32            MaxSize,
+  IN        UINT32            AttributesMustHave,
+  IN        UINT32            AttributesCantHave,
+  IN        UINT8             LockPolicyType,
+  OUT VARIABLE_POLICY_ENTRY   **NewEntry
+  );
+
+
+/**
+  This helper function will allocate and populate a new VariablePolicy
+  structure for a policy with a lock type of VARIABLE_POLICY_TYPE_LOCK_ON_VAR_STATE.
+
+  NOTE: Caller will need to free structure once finished.
+
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  VarStateNamespace     Pointer to the EFI_GUID for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Namespace.
+  @param[in]  VarStateValue         Value for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Value.
+  @param[in]  VarStateName          Pointer to the CHAR16 array for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Name.
+  @param[out] NewEntry    If successful, will be set to a pointer to the allocated buffer containing the
+                          new policy.
+
+  @retval     EFI_SUCCESS             Operation completed successfully and structure is populated.
+  @retval     EFI_INVALID_PARAMETER   Namespace, VarStateNamespace, VarStateName is NULL.
+  @retval     EFI_BUFFER_TOO_SMALL    Finished structure would not fit in UINT16 size.
+  @retval     EFI_OUT_OF_RESOURCES    Could not allocate sufficient space for structure.
+
+**/
+EFI_STATUS
+EFIAPI
+CreateVarStateVariablePolicy (
+  IN CONST  EFI_GUID          *Namespace,
+  IN CONST  CHAR16            *Name OPTIONAL,
+  IN        UINT32            MinSize,
+  IN        UINT32            MaxSize,
+  IN        UINT32            AttributesMustHave,
+  IN        UINT32            AttributesCantHave,
+  IN CONST  EFI_GUID          *VarStateNamespace,
+  IN        UINT8             VarStateValue,
+  IN CONST  CHAR16            *VarStateName,
+  OUT VARIABLE_POLICY_ENTRY   **NewEntry
+  );
+
+
+/**
+  This helper function does everything that CreateBasicVariablePolicy() does, but also
+  uses the passed in protocol to register the policy with the infrastructure.
+  Does not return a buffer, does not require the caller to free anything.
+
+  @param[in]  VariablePolicy  Pointer to a valid instance of the VariablePolicy protocol.
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  LockPolicyType        LockPolicyType for the VariablePolicy.
+
+  @retval     EFI_INVALID_PARAMETER VariablePolicy pointer is NULL.
+  @retval     EFI_STATUS            Status returned by CreateBasicVariablePolicy() or RegisterVariablePolicy().
+
+**/
+EFI_STATUS
+EFIAPI
+RegisterBasicVariablePolicy (
+  IN        EDKII_VARIABLE_POLICY_PROTOCOL  *VariablePolicy,
+  IN CONST  EFI_GUID                        *Namespace,
+  IN CONST  CHAR16                          *Name OPTIONAL,
+  IN        UINT32                          MinSize,
+  IN        UINT32                          MaxSize,
+  IN        UINT32                          AttributesMustHave,
+  IN        UINT32                          AttributesCantHave,
+  IN        UINT8                           LockPolicyType
+  );
+
+
+/**
+  This helper function does everything that CreateBasicVariablePolicy() does, but also
+  uses the passed in protocol to register the policy with the infrastructure.
+  Does not return a buffer, does not require the caller to free anything.
+
+  @param[in]  VariablePolicy  Pointer to a valid instance of the VariablePolicy protocol.
+  @param[in]  Namespace   Pointer to an EFI_GUID for the target variable namespace that this policy will protect.
+  @param[in]  Name        [Optional] If provided, a pointer to the CHAR16 array for the target variable name.
+                          Otherwise, will create a policy that targets an entire namespace.
+  @param[in]  MinSize     MinSize for the VariablePolicy.
+  @param[in]  MaxSize     MaxSize for the VariablePolicy.
+  @param[in]  AttributesMustHave    AttributesMustHave for the VariablePolicy.
+  @param[in]  AttributesCantHave    AttributesCantHave for the VariablePolicy.
+  @param[in]  VarStateNamespace     Pointer to the EFI_GUID for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Namespace.
+  @param[in]  VarStateName          Pointer to the CHAR16 array for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Name.
+  @param[in]  VarStateValue         Value for the VARIABLE_LOCK_ON_VAR_STATE_POLICY.Value.
+
+  @retval     EFI_INVALID_PARAMETER VariablePolicy pointer is NULL.
+  @retval     EFI_STATUS    Status returned by CreateBasicVariablePolicy() or RegisterVariablePolicy().
+
+**/
+EFI_STATUS
+EFIAPI
+RegisterVarStateVariablePolicy (
+  IN        EDKII_VARIABLE_POLICY_PROTOCOL  *VariablePolicy,
+  IN CONST  EFI_GUID                        *Namespace,
+  IN CONST  CHAR16                          *Name OPTIONAL,
+  IN        UINT32                          MinSize,
+  IN        UINT32                          MaxSize,
+  IN        UINT32                          AttributesMustHave,
+  IN        UINT32                          AttributesCantHave,
+  IN CONST  EFI_GUID                        *VarStateNamespace,
+  IN CONST  CHAR16                          *VarStateName,
+  IN        UINT8                           VarStateValue
+  );
+
+#endif // _EDKII_VARIABLE_POLICY_HELPER_LIB_H_
diff --git a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf
new file mode 100644
index 000000000000..506abf580e94
--- /dev/null
+++ b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf
@@ -0,0 +1,35 @@
+## @file VariablePolicyHelperLib.inf
+# This library contains helper functions for marshalling and registering
+# new policies with the VariablePolicy infrastructure.
+#
+# This library is currently written against VariablePolicy revision 0x00010000.
+#
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+
+[Defines]
+  INF_VERSION         = 0x00010017
+  BASE_NAME           = VariablePolicyHelperLib
+  # MODULE_UNI_FILE   = VariablePolicyHelperLib.uni
+  FILE_GUID           = B3C2206B-FDD1-4AED-8352-FC5EC34C5630
+  VERSION_STRING      = 1.0
+  MODULE_TYPE         = BASE
+  LIBRARY_CLASS       = VariablePolicyHelperLib
+
+
+[Sources]
+  VariablePolicyHelperLib.c
+
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  MemoryAllocationLib
+  BaseMemoryLib
diff --git a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.uni b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.uni
new file mode 100644
index 000000000000..39cbf11a4ce9
--- /dev/null
+++ b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.uni
@@ -0,0 +1,12 @@
+// /** @file
+// VariablePolicyHelperLib.uni
+//
+// Copyright (c) Microsoft Corporation.
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+
+#string STR_MODULE_ABSTRACT             #language en-US "Library containing helper functions for marshalling and registering new policies with the VariablePolicy infrastructure"
+
+#string STR_MODULE_DESCRIPTION          #language en-US "Library containing helper functions for marshalling and registering new policies with the VariablePolicy infrastructure"
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 31339741b840..2db37bd8ea9e 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -149,6 +149,11 @@ [LibraryClasses]
   #
   DisplayUpdateProgressLib|Include/Library/DisplayUpdateProgressLib.h
 
+  ##  @libraryclass  This library contains helper functions for marshalling and
+  #   registering new policies with the VariablePolicy infrastructure.
+  #
+  VariablePolicyHelperLib|Include/Library/VariablePolicyHelperLib.h
+
 [Guids]
   ## MdeModule package token space guid
   # Include/Guid/MdeModulePkgTokenSpace.h
diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
index 14b6ed536962..37795b9e4f58 100644
--- a/MdeModulePkg/MdeModulePkg.dsc
+++ b/MdeModulePkg/MdeModulePkg.dsc
@@ -99,6 +99,7 @@ [LibraryClasses]
   BmpSupportLib|MdeModulePkg/Library/BaseBmpSupportLib/BaseBmpSupportLib.inf
   SafeIntLib|MdePkg/Library/BaseSafeIntLib/BaseSafeIntLib.inf
   DisplayUpdateProgressLib|MdeModulePkg/Library/DisplayUpdateProgressLibGraphics/DisplayUpdateProgressLibGraphics.inf
+  VariablePolicyHelperLib|MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf
 
 [LibraryClasses.EBC.PEIM]
   IoLib|MdePkg/Library/PeiIoLibCpuIo/PeiIoLibCpuIo.inf
@@ -225,6 +226,7 @@ [Components]
   MdeModulePkg/Library/UefiHiiServicesLib/UefiHiiServicesLib.inf
   MdeModulePkg/Library/BaseHobLibNull/BaseHobLibNull.inf
   MdeModulePkg/Library/BaseMemoryAllocationLibNull/BaseMemoryAllocationLibNull.inf
+  MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf
 
   MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridgeDxe.inf
   MdeModulePkg/Bus/Pci/PciSioSerialDxe/PciSioSerialDxe.inf
-- 
2.16.3.windows.1