RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
In TDX IA32_ERER is RO to host VMM. It could not be changed. PcdIa32EferChangeAllowed is added in MdeModulePkg.dec and it is to be set to FALSE in Tdx guest. Cc: Jian J Wang <[email protected]> Cc: Hao A Wu <[email protected]> Cc: Brijesh Singh <[email protected]> Cc: Erdem Aktas <[email protected]> Cc: James Bottomley <[email protected]> Cc: Jiewen Yao <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Gerd Hoffmann <[email protected]> Acked-by: Gerd Hoffmann <[email protected]> Signed-off-by: Min Xu <[email protected]> --- MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf | 1 + MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c | 7 +++++++ MdeModulePkg/MdeModulePkg.dec | 5 +++++ 3 files changed, 13 insertions(+) diff --git a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf index 19b8a4c8aefa..106b679b6bd0 100644 --- a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf +++ b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf @@ -117,6 +117,7 @@ gEfiMdeModulePkgTokenSpaceGuid.PcdUse5LevelPageTable ## SOMETIMES_CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbBase ## CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbSize ## CONSUMES + gEfiMdeModulePkgTokenSpaceGuid.PcdIa32EferChangeAllowed ## CONSUMES [Pcd.IA32,Pcd.X64,Pcd.ARM,Pcd.AARCH64] gEfiMdeModulePkgTokenSpaceGuid.PcdSetNxForStack ## SOMETIMES_CONSUMES diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c index 0700f310b203..5c647c74e773 100644 --- a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c +++ b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c @@ -159,6 +159,13 @@ IsEnableNonExecNeeded ( return FALSE; } + // + // Intel TDX sets this flag to FALSE. + // + if (!PcdGetBool (PcdIa32EferChangeAllowed)) { + return FALSE; + } + // // XD flag (BIT63) in page table entry is only valid if IA32_EFER.NXE is set. // Features controlled by Following PCDs need this feature to be enabled. diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec index 463e889e9a68..453f2a74b11d 100644 --- a/MdeModulePkg/MdeModulePkg.dec +++ b/MdeModulePkg/MdeModulePkg.dec @@ -2138,6 +2138,11 @@ # @Prompt GHCB Pool Size gEfiMdeModulePkgTokenSpaceGuid.PcdGhcbSize|0|UINT64|0x00030008 + ## This dynamic PCD indicates if IA32_EFER can be changed. The default value is TRUE but in + # Intel TDX change of IA32_EFER is not allowed. + # @Prompt The flag which indicates if IA32_EFER is allowed to be changed. + gEfiMdeModulePkgTokenSpaceGuid.PcdIa32EferChangeAllowed|TRUE|BOOLEAN|0x00030009 + [PcdsDynamicEx] ## This dynamic PCD enables the default variable setting. # Its value is the default store ID value. The default value is zero as Standard default. -- 2.29.2.windows.2 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#84726): https://edk2.groups.io/g/devel/message/84726 Mute This Topic: https://groups.io/mt/87696592/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
