From 8a7ca9923ec9d1071280f702e8bf59503a974621 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Fri, 6 Nov 2020 11:53:04 -0600 Subject: UefiCpuPkg/VmgExitLib: Add interfaces to set/read GHCB ValidBitmap bits 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 Cc: Ray Ni Cc: Laszlo Ersek Cc: Rahul Kumar Acked-by: Eric Dong Reviewed-by: Laszlo Ersek Signed-off-by: Tom Lendacky Message-Id: <0bcb2373f8c6e0171ae277d3d7c2eb284621355e.1604685192.git.thomas.lendacky@amd.com> --- UefiCpuPkg/Include/Library/VmgExitLib.h | 37 +++++++++++++++++++ UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c | 42 ++++++++++++++++++++++ 2 files changed, 79 insertions(+) (limited to 'UefiCpuPkg') diff --git a/UefiCpuPkg/Include/Library/VmgExitLib.h b/UefiCpuPkg/Include/Library/VmgExitLib.h index 45fc27d35e..07e8af6450 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 bb265e1700..b47e282aff 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. -- cgit v1.2.3