[edk2-devel] [PATCH 09/13] OvmfPkg/BaseMemEncryptSevLib: introduce MemEncryptSevClearMmioPageEncMask()

Laszlo Ersek lersek at redhat.com
Tue May 11 11:16:20 UTC 2021


On 05/07/21 22:38, Brijesh Singh wrote:
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
> 
> The MemEncryptSevClearMmioPageEncMask() helper can be used for clearing
> the memory encryption mask for the Mmio region.
> 
> The MemEncryptSevClearMmioPageEncMask() is a simplifies version of

(1) s/simplifies/simplified/

Reviewed-by: Laszlo Ersek <lersek at redhat.com>

Thanks
Laszlo

> MemEncryptSevClearPageEncMask() -- it does not flush the caches after
> clearing the page encryption mask.
> 
> Cc: James Bottomley <jejb at linux.ibm.com>
> Cc: Min Xu <min.m.xu at intel.com>
> Cc: Jiewen Yao <jiewen.yao at intel.com>
> Cc: Tom Lendacky <thomas.lendacky at amd.com>
> Cc: Jordan Justen <jordan.l.justen at intel.com>
> Cc: Ard Biesheuvel <ardb+tianocore at kernel.org>
> Cc: Laszlo Ersek <lersek at redhat.com>
> Cc: Erdem Aktas <erdemaktas at google.com>
> Signed-off-by: Brijesh Singh <brijesh.singh at amd.com>
> ---
>  OvmfPkg/Include/Library/MemEncryptSevLib.h    | 25 ++++++++++++++
>  .../BaseMemEncryptSevLib/X64/VirtualMemory.h  | 23 +++++++++++++
>  .../Ia32/MemEncryptSevLib.c                   | 31 +++++++++++++++++
>  .../X64/MemEncryptSevLib.c                    | 33 +++++++++++++++++++
>  .../X64/PeiDxeVirtualMemory.c                 | 33 +++++++++++++++++++
>  5 files changed, 145 insertions(+)
> 
> diff --git a/OvmfPkg/Include/Library/MemEncryptSevLib.h b/OvmfPkg/Include/Library/MemEncryptSevLib.h
> index 99f15a7d1271..b91490d5d44d 100644
> --- a/OvmfPkg/Include/Library/MemEncryptSevLib.h
> +++ b/OvmfPkg/Include/Library/MemEncryptSevLib.h
> @@ -203,4 +203,29 @@ MemEncryptSevGetAddressRangeState (
>    IN UINTN                    Length
>    );
>  
> +/**
> +  This function clears memory encryption bit for the MMIO region specified by
> +  BaseAddress and NumPages.
> +
> +  @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
> +                                      current CR3)
> +  @param[in]  BaseAddress             The physical address that is the start
> +                                      address of a MMIO region.
> +  @param[in]  NumPages                The number of pages from start memory
> +                                      region.
> +
> +  @retval RETURN_SUCCESS              The attributes were cleared for the
> +                                      memory region.
> +  @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
> +  @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
> +                                      is not supported
> +**/
> +RETURN_STATUS
> +EFIAPI
> +MemEncryptSevClearMmioPageEncMask (
> +  IN PHYSICAL_ADDRESS         Cr3BaseAddress,
> +  IN PHYSICAL_ADDRESS         BaseAddress,
> +  IN UINTN                    NumPages
> +  );
> +
>  #endif // _MEM_ENCRYPT_SEV_LIB_H_
> diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h
> index fe2a0b2826cd..8dc39e647b90 100644
> --- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h
> +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/VirtualMemory.h
> @@ -126,4 +126,27 @@ InternalMemEncryptSevGetAddressRangeState (
>    IN UINTN                    Length
>    );
>  
> +/**
> +  This function clears memory encryption bit for the MMIO region specified by
> +  PhysicalAddress and Length.
> +
> +  @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
> +                                      current CR3)
> +  @param[in]  PhysicalAddress         The physical address that is the start
> +                                      address of a MMIO region.
> +  @param[in]  Length                  The length of memory region
> +
> +  @retval RETURN_SUCCESS              The attributes were cleared for the
> +                                      memory region.
> +  @retval RETURN_INVALID_PARAMETER    Length is zero.
> +  @retval RETURN_UNSUPPORTED          Clearing the memory encyrption attribute
> +                                      is not supported
> +**/
> +RETURN_STATUS
> +EFIAPI
> +InternalMemEncryptSevClearMmioPageEncMask (
> +  IN  PHYSICAL_ADDRESS        Cr3BaseAddress,
> +  IN  PHYSICAL_ADDRESS        PhysicalAddress,
> +  IN  UINTN                   Length
> +  );
>  #endif
> diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c b/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
> index 12a5bf495bd7..169d3118e44f 100644
> --- a/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
> +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c
> @@ -111,3 +111,34 @@ MemEncryptSevGetAddressRangeState (
>    //
>    return MemEncryptSevAddressRangeEncrypted;
>  }
> +
> +/**
> +  This function clears memory encryption bit for the MMIO region specified by
> +  BaseAddress and NumPages.
> +
> +  @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
> +                                      current CR3)
> +  @param[in]  BaseAddress             The physical address that is the start
> +                                      address of a MMIO region.
> +  @param[in]  NumPages                The number of pages from start memory
> +                                      region.
> +
> +  @retval RETURN_SUCCESS              The attributes were cleared for the
> +                                      memory region.
> +  @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
> +  @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
> +                                      is not supported
> +**/
> +RETURN_STATUS
> +EFIAPI
> +MemEncryptSevClearMmioPageEncMask (
> +  IN PHYSICAL_ADDRESS         Cr3BaseAddress,
> +  IN PHYSICAL_ADDRESS         BaseAddress,
> +  IN UINTN                    NumPages
> +  )
> +{
> +  //
> +  // Memory encryption bit is not accessible in 32-bit mode
> +  //
> +  return RETURN_UNSUPPORTED;
> +}
> diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c
> index 4fea6a6be0ac..a2bf698bcde7 100644
> --- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c
> +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/MemEncryptSevLib.c
> @@ -118,3 +118,36 @@ MemEncryptSevGetAddressRangeState (
>             Length
>             );
>  }
> +
> +/**
> +  This function clears memory encryption bit for the mmio region specified by
> +  BaseAddress and NumPages.
> +
> +  @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
> +                                      current CR3)
> +  @param[in]  BaseAddress             The physical address that is the start
> +                                      address of a mmio region.
> +  @param[in]  NumPages                The number of pages from start memory
> +                                      region.
> +
> +  @retval RETURN_SUCCESS              The attributes were cleared for the
> +                                      memory region.
> +  @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
> +  @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
> +                                      is not supported
> +**/
> +RETURN_STATUS
> +EFIAPI
> +MemEncryptSevClearMmioPageEncMask (
> +  IN PHYSICAL_ADDRESS         Cr3BaseAddress,
> +  IN PHYSICAL_ADDRESS         BaseAddress,
> +  IN UINTN                    NumPages
> +  )
> +{
> +  return InternalMemEncryptSevClearMmioPageEncMask (
> +           Cr3BaseAddress,
> +           BaseAddress,
> +           EFI_PAGES_TO_SIZE (NumPages)
> +           );
> +
> +}
> diff --git a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
> index d3455e812bd1..a18d336a8789 100644
> --- a/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
> +++ b/OvmfPkg/Library/BaseMemEncryptSevLib/X64/PeiDxeVirtualMemory.c
> @@ -891,3 +891,36 @@ InternalMemEncryptSevSetMemoryEncrypted (
>             Flush
>             );
>  }
> +
> +/**
> +  This function clears memory encryption bit for the MMIO region specified by
> +  PhysicalAddress and Length.
> +
> +  @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
> +                                      current CR3)
> +  @param[in]  PhysicalAddress         The physical address that is the start
> +                                      address of a MMIO region.
> +  @param[in]  Length                  The length of memory region
> +
> +  @retval RETURN_SUCCESS              The attributes were cleared for the
> +                                      memory region.
> +  @retval RETURN_INVALID_PARAMETER    Length is zero.
> +  @retval RETURN_UNSUPPORTED          Clearing the memory encyrption attribute
> +                                      is not supported
> +**/
> +RETURN_STATUS
> +EFIAPI
> +InternalMemEncryptSevClearMmioPageEncMask (
> +  IN  PHYSICAL_ADDRESS        Cr3BaseAddress,
> +  IN  PHYSICAL_ADDRESS        PhysicalAddress,
> +  IN  UINTN                   Length
> +  )
> +{
> +  return SetMemoryEncDec (
> +           Cr3BaseAddress,
> +           PhysicalAddress,
> +           Length,
> +           ClearCBit,
> +           FALSE
> +           );
> +}
> 



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