Re: [edk2-devel] [PATCH v3 02/11] UefiCpuPkg/VmgExitLib: Add interfaces to set/read GHCB ValidBitmap bits

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

Ray, Eric, can one of you please ACK this patch? I've reviewed it
already, but your ACK would be appreciated, process-wise. I intend to
merge the series on Thursday at the latest (Nov 5th).

Thank you.
Laszlo

On 10/29/20 15:17, Lendacky, Thomas wrote:
> From: Tom Lendacky <thomas.lendacky@amd.com>
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3008
> 
> In upcoming patches, the setting of the bits in the GHCB ValidBitmap will
> be performed in multiple places. In order to reduce code duplication, add
> an interface, VmgSetOffsetValid(), to VmgExitLib library to perform this
> function. Also, to keep management of the ValidBitmap within the library,
> add an inteface, VmgIsOffsetValid(), to return whether the bit in the
> ValidBitmap is set for a specified offset.
> 
> The new VmgSetOffsetValid() function is a VOID function and will be an
> empty function in the VmgExitLibNull implementation of the VmgExitLib
> library.
> 
> The new VmgIsOffsetValid() function returns a BOOLEAN to indicate if the
> offset is valid. This will always return FALSE in the VmgExitLibNull
> implementation of the VmgExitLib library.
> 
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Rahul Kumar <rahul1.kumar@intel.com>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
>  UefiCpuPkg/Include/Library/VmgExitLib.h            | 37 +++++++++++++++++
>  UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c | 42 ++++++++++++++++++++
>  2 files changed, 79 insertions(+)
> 
> diff --git a/UefiCpuPkg/Include/Library/VmgExitLib.h b/UefiCpuPkg/Include/Library/VmgExitLib.h
> index 45fc27d35e29..07e8af6450b9 100644
> --- a/UefiCpuPkg/Include/Library/VmgExitLib.h
> +++ b/UefiCpuPkg/Include/Library/VmgExitLib.h
> @@ -74,6 +74,43 @@ VmgDone (
>    IN OUT GHCB                *Ghcb
>    );
>  
> +/**
> +  Marks a specified offset as valid in the GHCB.
> +
> +  The ValidBitmap area represents the areas of the GHCB that have been marked
> +  valid. Set the bit in ValidBitmap for the input offset.
> +
> +  @param[in, out]  Ghcb       A pointer to the GHCB
> +  @param[in]       Offset     Qword offset in the GHCB to mark valid
> +
> +**/
> +VOID
> +EFIAPI
> +VmgSetOffsetValid (
> +  IN OUT GHCB                *Ghcb,
> +  IN     GHCB_REGISTER       Offset
> +  );
> +
> +/**
> +  Checks if a specified offset is valid in the GHCB.
> +
> +  The ValidBitmap area represents the areas of the GHCB that have been marked
> +  valid. Return whether the bit in the ValidBitmap is set for the input offset.
> +
> +  @param[in]  Ghcb            A pointer to the GHCB
> +  @param[in]  Offset          Qword offset in the GHCB to mark valid
> +
> +  @retval TRUE                Offset is marked valid in the GHCB
> +  @retval FALSE               Offset is not marked valid in the GHCB
> +
> +**/
> +BOOLEAN
> +EFIAPI
> +VmgIsOffsetValid (
> +  IN GHCB                    *Ghcb,
> +  IN GHCB_REGISTER           Offset
> +  );
> +
>  /**
>    Handle a #VC exception.
>  
> diff --git a/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c
> index bb265e1700d2..b47e282aff82 100644
> --- a/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c
> +++ b/UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c
> @@ -89,6 +89,48 @@ VmgDone (
>  {
>  }
>  
> +/**
> +  Marks a field at the specified offset as valid in the GHCB.
> +
> +  The ValidBitmap area represents the areas of the GHCB that have been marked
> +  valid. Set the bit in ValidBitmap for the input offset.
> +
> +  @param[in, out] Ghcb    Pointer to the Guest-Hypervisor Communication Block
> +  @param[in]      Offset  Qword offset in the GHCB to mark valid
> +
> +**/
> +VOID
> +EFIAPI
> +VmgSetOffsetValid (
> +  IN OUT GHCB                *Ghcb,
> +  IN     GHCB_REGISTER       Offset
> +  )
> +{
> +}
> +
> +/**
> +  Checks if a specified offset is valid in the GHCB.
> +
> +  The ValidBitmap area represents the areas of the GHCB that have been marked
> +  valid. Return whether the bit in the ValidBitmap is set for the input offset.
> +
> +  @param[in]  Ghcb            A pointer to the GHCB
> +  @param[in]  Offset          Qword offset in the GHCB to mark valid
> +
> +  @retval TRUE                Offset is marked valid in the GHCB
> +  @retval FALSE               Offset is not marked valid in the GHCB
> +
> +**/
> +BOOLEAN
> +EFIAPI
> +VmgIsOffsetValid (
> +  IN GHCB                    *Ghcb,
> +  IN GHCB_REGISTER           Offset
> +  )
> +{
> +  return FALSE;
> +}
> +
>  /**
>    Handle a #VC exception.
>  
>