Re: [PATCH] UefiCpuPkg: Fix SMM code hangs when InitPaging

["Ni, Ray" <ray.ni@intel.com>]

Reviewed-by: Ray Ni <ray.ni@intel.com>

> -----Original Message-----
> From: Liu, Zhiguang <zhiguang.liu@intel.com>
> Sent: Wednesday, January 4, 2023 1:41 PM
> To: devel@edk2.groups.io
> Cc: Liu, Zhiguang <zhiguang.liu@intel.com>; Ni, Ray <ray.ni@intel.com>; Kumar, Rahul R <rahul.r.kumar@intel.com>; Dong,
> Eric <eric.dong@intel.com>
> Subject: [PATCH] UefiCpuPkg: Fix SMM code hangs when InitPaging
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4246
> 
> In function InitPaging, NumberOfPml5Entries is calculated by below code
> NumberOfPml5Entries = (UINTN)LShiftU64 (1, SizeOfMemorySpace - 48);
> If the SizeOfMemorySpace is larger than 48, NumberOfPml5Entries will be
> larger than 1. However, this doesn't make sense if the hardware doesn't
> support 5 level page table.
> 
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Rahul Kumar <rahul1.kumar@intel.com>
> Signed-off-by: Eric Dong <eric.dong@intel.com>
> Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c
> index c1efda7126..c597b39b8c 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmProfile.c
> @@ -1,7 +1,7 @@
>  /** @file
>  Enable SMM profile.
> 
> -Copyright (c) 2012 - 2019, Intel Corporation. All rights reserved.<BR>
> +Copyright (c) 2012 - 2023, Intel Corporation. All rights reserved.<BR>
>  Copyright (c) 2017 - 2020, AMD Incorporated. All rights reserved.<BR>
> 
>  SPDX-License-Identifier: BSD-2-Clause-Patent
> @@ -587,15 +587,17 @@ InitPaging (
>      }
> 
>      SizeOfMemorySpace = HighBitSet64 (gPhyMask) + 1;
> +    ASSERT (SizeOfMemorySpace <= 52);
> +
>      //
> -    // Calculate the table entries of PML4E and PDPTE.
> +    // Calculate the table entries of PML5E, PML4E and PDPTE.
>      //
>      NumberOfPml5Entries = 1;
> -    if (SizeOfMemorySpace > 48) {
> +    if (Enable5LevelPaging && (SizeOfMemorySpace > 48)) {
>        NumberOfPml5Entries = (UINTN)LShiftU64 (1, SizeOfMemorySpace - 48);
> -      SizeOfMemorySpace   = 48;
>      }
> 
> +    SizeOfMemorySpace   = SizeOfMemorySpace > 48 ? 48 : SizeOfMemorySpace;
>      NumberOfPml4Entries = 1;
>      if (SizeOfMemorySpace > 39) {
>        NumberOfPml4Entries = (UINTN)LShiftU64 (1, SizeOfMemorySpace - 39);
> --
> 2.31.1.windows.1