Re: [patch v2][edk2-stable201908] MdeModulePkg DxeCore: Fix for missing Memory Attributes Table (MAT) update

["Laszlo Ersek" <lersek@redhat.com>]

On 08/16/19 17:39, Liming Gao wrote:
> From: Mike Turner <miketur@microsoft.com>
> 
> The Fpdt driver (FirmwarePerformanceDxe) saves a memory address across
> reboots, and then does an AllocatePage for that memory address.
> If, on this boot, that memory comes from a Runtime memory bucket,
> the MAT table is not updated. This causes Windows to boot into Recovery.
> 
> This patch blocks the memory manager from changing the page
> from a special bucket to a different memory type.  Once the buckets are
> allocated, we freeze the memory ranges for the OS, and fragmenting
> the special buckets will cause errors resuming from hibernate (S4).
> 
> The references to S4 here are the use case that fails.  This
> failure is root caused to an inconsistent behavior of the
> core memory services themselves when type AllocateAddress is used.
> 
> The main issue is apparently with the UEFI memory map -- the UEFI memory
> map reflects the pre-allocated bins, but the actual allocations at fixed
> addresses may go out of sync with that. Everything else, such as:
> - EFI_MEMORY_ATTRIBUTES_TABLE (page protections) being out of sync,
> - S4 failing
> are just symptoms / consequences.
> 
> This patch is cherry pick from Project Mu:
> https://github.com/microsoft/mu_basecore/commit/a9be767d9be96af94016ebd391ea6f340920735a
> With the minor change,
> 1. Update commit message format to keep the message in 80 characters one line.
> 2. Remove // MU_CHANGE comments in source code.
> 3. Update comments style to follow edk2 style.
> 
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Cc: Dandan Bi <dandan.bi@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Liming Gao <liming.gao@intel.com>
> ---
> In v2, add more description for this issue. 
> 
>  MdeModulePkg/Core/Dxe/Mem/Page.c | 41 ++++++++++++++++++++++++++++++++++------
>  1 file changed, 35 insertions(+), 6 deletions(-)
> 
> diff --git a/MdeModulePkg/Core/Dxe/Mem/Page.c b/MdeModulePkg/Core/Dxe/Mem/Page.c
> index bd9e116aa5..1f0e3d94b9 100644
> --- a/MdeModulePkg/Core/Dxe/Mem/Page.c
> +++ b/MdeModulePkg/Core/Dxe/Mem/Page.c
> @@ -1265,12 +1265,13 @@ CoreInternalAllocatePages (
>    IN BOOLEAN                NeedGuard
>    )
>  {
> -  EFI_STATUS      Status;
> -  UINT64          Start;
> -  UINT64          NumberOfBytes;
> -  UINT64          End;
> -  UINT64          MaxAddress;
> -  UINTN           Alignment;
> +  EFI_STATUS       Status;
> +  UINT64           Start;
> +  UINT64           NumberOfBytes;
> +  UINT64           End;
> +  UINT64           MaxAddress;
> +  UINTN            Alignment;
> +  EFI_MEMORY_TYPE  CheckType;
>  
>    if ((UINT32)Type >= MaxAllocateType) {
>      return EFI_INVALID_PARAMETER;
> @@ -1321,6 +1322,7 @@ CoreInternalAllocatePages (
>    // if (Start + NumberOfBytes) rolls over 0 or
>    // if Start is above MAX_ALLOC_ADDRESS or
>    // if End is above MAX_ALLOC_ADDRESS,
> +  // if Start..End overlaps any tracked MemoryTypeStatistics range
>    // return EFI_NOT_FOUND.
>    //
>    if (Type == AllocateAddress) {
> @@ -1336,6 +1338,33 @@ CoreInternalAllocatePages (
>          (End > MaxAddress)) {
>        return EFI_NOT_FOUND;
>      }
> +
> +    //
> +    // A driver is allowed to call AllocatePages using an AllocateAddress type.  This type of
> +    // AllocatePage request the exact physical address if it is not used.  The existing code
> +    // will allow this request even in 'special' pages.  The problem with this is that the
> +    // reason to have 'special' pages for OS hibernate/resume is defeated as memory is
> +    // fragmented.
> +    //
> +
> +    for (CheckType = (EFI_MEMORY_TYPE) 0; CheckType < EfiMaxMemoryType; CheckType++) {
> +      if (MemoryType != CheckType &&
> +          mMemoryTypeStatistics[CheckType].Special &&
> +          mMemoryTypeStatistics[CheckType].NumberOfPages > 0) {
> +        if (Start >= mMemoryTypeStatistics[CheckType].BaseAddress &&
> +            Start <= mMemoryTypeStatistics[CheckType].MaximumAddress) {
> +          return EFI_NOT_FOUND;
> +        }
> +        if (End >= mMemoryTypeStatistics[CheckType].BaseAddress &&
> +            End <= mMemoryTypeStatistics[CheckType].MaximumAddress) {
> +          return EFI_NOT_FOUND;
> +        }
> +        if (Start < mMemoryTypeStatistics[CheckType].BaseAddress &&
> +            End   > mMemoryTypeStatistics[CheckType].MaximumAddress) {
> +          return EFI_NOT_FOUND;
> +        }
> +      }
> +    }
>    }
>  
>    if (Type == AllocateMaxAddress) {
> 

Acked-by: Laszlo Ersek <lersek@redhat.com>

Please wait for maintainer approval too.

Thanks
Laszlo