BIOS uses TE with a null root entry table to block VT-d engine access to block any DMA traffic in pre-memory phase.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2867 Cc: Ray Ni <ray...@intel.com> Cc: Rangasai V Chaganty <rangasai.v.chaga...@intel.com> Signed-off-by: Sheng Wei <w.sh...@intel.com> --- .../PlatformVTdInfoSamplePei/PlatformVTdInfoSamplePei.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/PlatformVTdInfoSamplePei/PlatformVTdInfoSamplePei.c b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/PlatformVTdInfoSamplePei/PlatformVTdInfoSamplePei.c index 6f6c14f7a9..1399f4238d 100644 --- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/PlatformVTdInfoSamplePei/PlatformVTdInfoSamplePei.c +++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/PlatformVTdInfoSamplePei/PlatformVTdInfoSamplePei.c @@ -164,6 +164,17 @@ EFI_PEI_PPI_DESCRIPTOR mPlatformVTdNoIgdInfoSampleDesc = { &mPlatformVTdNoIgdSample }; +EFI_GUID gVTdNullRootEntryTableGuid = { 0x3de0593f, 0x6e3e, 0x4542, { 0xa1, 0xcb, 0xcb, 0xb2, 0xdb, 0xeb, 0xd8, 0xff }}; + +// BIOS uses TE with a null root entry table to block VT-d engine access to block any DMA traffic in pre-memory phase. +UINT64 mNullRootEntryTable = 0xFED20000; + +EFI_PEI_PPI_DESCRIPTOR mPlatformNullRootEntryTableDesc = { + (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST), + &gVTdNullRootEntryTableGuid, + &mNullRootEntryTable +}; + /** Initialize VTd register. Initialize the VTd hardware unit which has INCLUDE_PCI_ALL set @@ -349,6 +360,11 @@ PlatformVTdInfoSampleInitialize ( Status = PeiServicesNotifyPpi (&mSiliconInitializedNotifyList); InitGlobalVtd (); + Status = PeiServicesInstallPpi (&mPlatformNullRootEntryTableDesc); + if (EFI_ERROR (Status)) { + DEBUG ((DEBUG_ERROR , "Failed to install the NullRootEntryTable ppi - %r\n", Status)); + } + Status = PeiServicesInstallPpi (&mPlatformVTdNoIgdInfoSampleDesc); ASSERT_EFI_ERROR (Status); } else { -- 2.16.2.windows.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#63441): https://edk2.groups.io/g/devel/message/63441 Mute This Topic: https://groups.io/mt/75861787/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
