Re: [PATCH] UefiPayloadPkg: Add RNG support

["Ma, Maurice" <maurice.ma@intel.com>]

Hi,  Patrick

There is a BaseRngLib in MdePkg package already.  I am wondering why a new instance was created under UefiPayloadPkg in the patch.
Could we just reuse the same library in MdePkg?   
If not, what is the reason?   Can we try to enhance the library in MdePkg to address it if required?

Thanks
Maurice
> -----Original Message-----
> From: Patrick Rudolph <patrick.rudolph@9elements.com>
> Sent: Wednesday, January 20, 2021 7:52
> To: devel@edk2.groups.io
> Cc: Ma, Maurice <maurice.ma@intel.com>; Dong, Guo <guo.dong@intel.com>;
> You, Benjamin <benjamin.you@intel.com>
> Subject: [PATCH] UefiPayloadPkg: Add RNG support
> 
> Uses the RDRAND instruction if available and install EfiRngProtocol.
> The protocol may be used by iPXE or the Linux kernel to gather entropy.
> 
> Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
> ---
>  UefiPayloadPkg/Library/BaseRngLib/BaseRng.c      | 199
> ++++++++++++++++++++
>  UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf |  32 ++++
> UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni |  17 ++
>  UefiPayloadPkg/UefiPayloadPkg.dsc                |   8 +
>  UefiPayloadPkg/UefiPayloadPkg.fdf                |   4 +
>  5 files changed, 260 insertions(+)
> 
> diff --git a/UefiPayloadPkg/Library/BaseRngLib/BaseRng.c
> b/UefiPayloadPkg/Library/BaseRngLib/BaseRng.c
> new file mode 100644
> index 0000000000..1fe9e1dbe0
> --- /dev/null
> +++ b/UefiPayloadPkg/Library/BaseRngLib/BaseRng.c
> @@ -0,0 +1,199 @@
> +/** @file+  Random number generator services that uses RdRand instruction
> access+  to provide high-quality random numbers.++Copyright (c) 2015, Intel
> Corporation. All rights reserved.<BR>+SPDX-License-Identifier: BSD-2-Clause-
> Patent++**/++#include <Library/BaseLib.h>+#include
> <Library/DebugLib.h>+#include <Register/Intel/Cpuid.h>++STATIC BOOLEAN
> mHasRdRand;++//+// Bit mask used to determine if RdRand instruction is
> supported.+//+#define RDRAND_MASK                  BIT30++//+// Limited retry
> number when valid random data is returned.+// Uses the recommended value
> defined in Section 7.3.17 of "Intel 64 and IA-32+// Architectures Software
> Developer's Mannual".+//+#define RDRAND_RETRY_LIMIT           10++/**+  The
> constructor function checks whether or not RDRAND instruction is supported+
> by the host hardware.++  The constructor function checks whether or not
> RDRAND instruction is supported.+  It will always return RETURN_SUCCESS.++
> @retval RETURN_SUCCESS   The constructor always returns
> EFI_SUCCESS.++**/+RETURN_STATUS+EFIAPI+BaseRngLibConstructor (+
> VOID+  )+{+  UINT32  RegEax;+  UINT32  RegEcx;++  AsmCpuid
> (CPUID_SIGNATURE, &RegEax, NULL, NULL, NULL);+  if (RegEax < 1) {+
> mHasRdRand = FALSE;+    return RETURN_SUCCESS;+  }++  //+  // Determine
> RDRAND support by examining bit 30 of the ECX register returned by+  // CPUID.
> A value of 1 indicates that processor support RDRAND instruction.+  //+
> AsmCpuid (CPUID_VERSION_INFO, 0, 0, &RegEcx, 0);++  mHasRdRand =
> ((RegEcx & RDRAND_MASK) == RDRAND_MASK);++  return
> RETURN_SUCCESS;+}++/**+  Generates a 16-bit random number.++  if Rand is
> NULL, then ASSERT().++  @param[out] Rand     Buffer pointer to store the 16-bit
> random value.++  @retval TRUE         Random number generated successfully.+
> @retval FALSE        Failed to generate the random
> number.++**/+BOOLEAN+EFIAPI+GetRandomNumber16 (+  OUT     UINT16
> *Rand+  )+{+  UINT32  Index;++  ASSERT (Rand != NULL);++  if (mHasRdRand) {+
> //+    // A loop to fetch a 16 bit random value with a retry count limit.+    //+
> for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {+      if (AsmRdRand16
> (Rand)) {+        return TRUE;+      }+    }+  }++  return FALSE;+}++/**+  Generates a
> 32-bit random number.++  if Rand is NULL, then ASSERT().++  @param[out]
> Rand     Buffer pointer to store the 32-bit random value.++  @retval TRUE
> Random number generated successfully.+  @retval FALSE        Failed to generate
> the random number.++**/+BOOLEAN+EFIAPI+GetRandomNumber32 (+  OUT
> UINT32                    *Rand+  )+{+  UINT32  Index;++  ASSERT (Rand != NULL);++  if
> (mHasRdRand) {+    //+    // A loop to fetch a 32 bit random value with a retry
> count limit.+    //+    for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {+
> if (AsmRdRand32 (Rand)) {+        return TRUE;+      }+    }+  }++  return
> FALSE;+}++/**+  Generates a 64-bit random number.++  if Rand is NULL, then
> ASSERT().++  @param[out] Rand     Buffer pointer to store the 64-bit random
> value.++  @retval TRUE         Random number generated successfully.+  @retval
> FALSE        Failed to generate the random
> number.++**/+BOOLEAN+EFIAPI+GetRandomNumber64 (+  OUT     UINT64
> *Rand+  )+{+  UINT32  Index;++  ASSERT (Rand != NULL);++  if (mHasRdRand) {+
> //+    // A loop to fetch a 64 bit random value with a retry count limit.+    //+
> for (Index = 0; Index < RDRAND_RETRY_LIMIT; Index++) {+      if (AsmRdRand64
> (Rand)) {+        return TRUE;+      }+    }+  }++  return FALSE;+}++/**+  Generates a
> 128-bit random number.++  if Rand is NULL, then ASSERT().++  @param[out]
> Rand     Buffer pointer to store the 128-bit random value.++  @retval TRUE
> Random number generated successfully.+  @retval FALSE        Failed to generate
> the random number.++**/+BOOLEAN+EFIAPI+GetRandomNumber128 (+  OUT
> UINT64                    *Rand+  )+{+  ASSERT (Rand != NULL);++  //+  // Read first 64
> bits+  //+  if (!GetRandomNumber64 (Rand)) {+    return FALSE;+  }++  //+  //
> Read second 64 bits+  //+  return GetRandomNumber64 (++Rand);+}diff --git
> a/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf
> b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf
> new file mode 100644
> index 0000000000..67a91ccfff
> --- /dev/null
> +++ b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf
> @@ -0,0 +1,32 @@
> +## @file+#  Instance of RNG (Random Number Generator) Library.+#+#
> Copyright (c) 2020 9elements Agency GmbH.<BR>+#+#  SPDX-License-Identifier:
> BSD-2-Clause-Patent+#+##++[Defines]+  INF_VERSION                    =
> 0x00010005+  BASE_NAME                      = BaseRngLib+  MODULE_UNI_FILE
> = BaseRngLib.uni+  FILE_GUID                      = 05C48431-DE18-4550-931A-
> 3350E8551498+  MODULE_TYPE                    = BASE+  VERSION_STRING
> = 1.0+  LIBRARY_CLASS                  = RngLib+  CONSTRUCTOR                    =
> BaseRngLibConstructor++#+#  VALID_ARCHITECTURES           = IA32
> X64+#++[Sources.Ia32, Sources.X64]+  BaseRng.c++[Packages]+
> MdePkg/MdePkg.dec++[LibraryClasses]+  BaseLib+  DebugLibdiff --git
> a/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni
> b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni
> new file mode 100644
> index 0000000000..f3ed954c52
> --- /dev/null
> +++ b/UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.uni
> @@ -0,0 +1,17 @@
> +// /** @file+// Instance of RNG (Random Number Generator) Library.+//+//
> BaseRng Library that uses CPU RdRand instruction access to provide+// high-
> quality random numbers.+//+// Copyright (c) 2015, Intel Corporation. All rights
> reserved.<BR>+//+// SPDX-License-Identifier: BSD-2-Clause-Patent+//+//
> **/+++#string STR_MODULE_ABSTRACT             #language en-US "Instance of
> RNG Library"++#string STR_MODULE_DESCRIPTION          #language en-US
> "BaseRng Library that uses CPU RdRand instruction access to provide high-
> quality random numbers"+diff --git a/UefiPayloadPkg/UefiPayloadPkg.dsc
> b/UefiPayloadPkg/UefiPayloadPkg.dsc
> index ae62a9c4d6..78a475ea02 100644
> --- a/UefiPayloadPkg/UefiPayloadPkg.dsc
> +++ b/UefiPayloadPkg/UefiPayloadPkg.dsc
> @@ -494,6 +494,14 @@
>  !endif   UefiPayloadPkg/GraphicsOutputDxe/GraphicsOutputDxe.inf +  #+  #
> Random Number Generator+  #+
> SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf {+
> <LibraryClasses>+
> RngLib|UefiPayloadPkg/Library/BaseRngLib/BaseRngLib.inf+  }+   #-----------------
> -------------   #  Build the shell   #------------------------------diff --git
> a/UefiPayloadPkg/UefiPayloadPkg.fdf b/UefiPayloadPkg/UefiPayloadPkg.fdf
> index a97ace7395..57c06c8621 100644
> --- a/UefiPayloadPkg/UefiPayloadPkg.fdf
> +++ b/UefiPayloadPkg/UefiPayloadPkg.fdf
> @@ -169,6 +169,10 @@ INF
> MdeModulePkg/Bus/Usb/UsbBusDxe/UsbBusDxe.inf
>  INF MdeModulePkg/Bus/Usb/UsbKbDxe/UsbKbDxe.inf INF
> MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassStorageDxe.inf +#+#
> Random Number Generator+#+INF
> SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.inf  # # Shell--
> 2.26.2