Re: [PATCH] IntelSiliconPkg IntelVTdDxe: Fix flush cache issue

["Yao, Jiewen" <jiewen.yao@intel.com>]

That is good catch.
Thanks to fix it.

Reviewed-by: Jiewen.yao@intel.com

> -----Original Message-----
> From: Zeng, Star
> Sent: Wednesday, January 24, 2018 1:21 PM
> To: edk2-devel@lists.01.org
> Cc: Zeng, Star <star.zeng@intel.com>; Yao, Jiewen <jiewen.yao@intel.com>
> Subject: [PATCH] IntelSiliconPkg IntelVTdDxe: Fix flush cache issue
> 
> The patch fixes flush cache issue in
> CreateSecondLevelPagingEntryTable().
> 
> We found some video cards still not work even they have
> been added to the exception list.
> 
> In CreateSecondLevelPagingEntryTable(), the check
> "(BaseAddress >= MemoryLimit)" may be TRUE and "goto Done"
> will be executed, then the FlushPageTableMemory operations
> at the end of the function will be skipped.
> 
> Instead of "goto Done", this patch uses "break" to break
> the for loops, then the FlushPageTableMemory operations
> at the end of the function could have opportunity to be
> executed.
> 
> The patch also fixed a miscalculation for Lvl3End.
> 
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Star Zeng <star.zeng@intel.com>
> ---
>  IntelSiliconPkg/Feature/VTd/IntelVTdDxe/TranslationTable.c | 13
> +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/TranslationTable.c
> b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/TranslationTable.c
> index 7bdc4a5146bd..bce5a45105d2 100644
> --- a/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/TranslationTable.c
> +++ b/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/TranslationTable.c
> @@ -1,6 +1,6 @@
>  /** @file
> 
> -  Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
> +  Copyright (c) 2017 - 2018, 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
> @@ -226,7 +226,7 @@ CreateSecondLevelPagingEntryTable (
> 
>      Lvl3Start = RShiftU64 (BaseAddress, 30) & 0x1FF;
>      if (ALIGN_VALUE_LOW(BaseAddress + SIZE_1GB, SIZE_1GB) <=
> EndAddress) {
> -      Lvl3End = SIZE_4KB/sizeof(VTD_SECOND_LEVEL_PAGING_ENTRY);
> +      Lvl3End = SIZE_4KB/sizeof(VTD_SECOND_LEVEL_PAGING_ENTRY) - 1;
>      } else {
>        Lvl3End = RShiftU64 (EndAddress - 1, 30) & 0x1FF;
>      }
> @@ -252,16 +252,21 @@ CreateSecondLevelPagingEntryTable (
>          Lvl2PtEntry[Index2].Bits.PageSize = 1;
>          BaseAddress += SIZE_2MB;
>          if (BaseAddress >= MemoryLimit) {
> -          goto Done;
> +          break;
>          }
>        }
>        FlushPageTableMemory (VtdIndex, (UINTN)Lvl2PtEntry, SIZE_4KB);
> +      if (BaseAddress >= MemoryLimit) {
> +        break;
> +      }
>      }
>      FlushPageTableMemory (VtdIndex, (UINTN)&Lvl3PtEntry[Lvl3Start],
> (UINTN)&Lvl3PtEntry[Lvl3End + 1] - (UINTN)&Lvl3PtEntry[Lvl3Start]);
> +    if (BaseAddress >= MemoryLimit) {
> +      break;
> +    }
>    }
>    FlushPageTableMemory (VtdIndex, (UINTN)&Lvl4PtEntry[Lvl4Start],
> (UINTN)&Lvl4PtEntry[Lvl4End + 1] - (UINTN)&Lvl4PtEntry[Lvl4Start]);
> 
> -Done:
>    return SecondLevelPagingEntry;
>  }
> 
> --
> 2.7.0.windows.1