RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429
Host VMM may inject OptionRom which is untrusted in Td guest. So PCI OptionRom needs to be ignored if it is Td guest. According to "Table 20. ACPI 2.0 & 3.0 QWORD Address Space Descriptor Usage" PI spec 1.7, type-specific flags can be set to 0 when Address Translation Offset == 6 to skip device option ROM. Cc: Michael D Kinney <[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]> Signed-off-by: Min Xu <[email protected]> --- .../IncompatiblePciDeviceSupport.c | 46 +++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/OvmfPkg/IncompatiblePciDeviceSupportDxe/IncompatiblePciDeviceSupport.c b/OvmfPkg/IncompatiblePciDeviceSupportDxe/IncompatiblePciDeviceSupport.c index f5c03bdf6dd6..2d385d26ef28 100644 --- a/OvmfPkg/IncompatiblePciDeviceSupportDxe/IncompatiblePciDeviceSupport.c +++ b/OvmfPkg/IncompatiblePciDeviceSupportDxe/IncompatiblePciDeviceSupport.c @@ -71,6 +71,40 @@ STATIC CONST EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR mMmio64Configuration = { // use probed BAR size }; +// +// mOptionRomConfiguration is present only in Td guest. +// Host VMM can inject option ROM which is untrusted in Td guest, +// so PCI option ROM needs to be ignored. +// According to "Table 20. ACPI 2.0 & 3.0 QWORD Address Space Descriptor Usage" +// PI spec 1.7, type-specific flags can be set to 0 when +// Address Translation Offset == 6 to skip device option ROM. +// +STATIC CONST EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR mOptionRomConfiguration = { + ACPI_ADDRESS_SPACE_DESCRIPTOR, // Desc + (UINT16)( // Len + sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) - + OFFSET_OF ( + EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR, + ResType + ) + ), + ACPI_ADDRESS_SPACE_TYPE_MEM, // ResType + 0, // GenFlag + 0, // Disable option roms SpecificFlag + 64, // AddrSpaceGranularity: + // aperture selection hint + // for BAR allocation + MAX_UINT64, // AddrRangeMin + MAX_UINT64, // AddrRangeMax: + // no special alignment + // for affected BARs + 6, // AddrTranslationOffset: + // hint covers all + // eligible BARs + 0 // AddrLen: + // use probed BAR size +}; + STATIC CONST EFI_ACPI_END_TAG_DESCRIPTOR mEndDesc = { ACPI_END_TAG_DESCRIPTOR, // Desc 0 // Checksum: to be ignored @@ -227,6 +261,13 @@ CheckDevice ( // Length = sizeof mMmio64Configuration + sizeof mEndDesc; + // + // In Td guest OptionRom is not allowed. + // + if (TdIsEnabled ()) { + Length += sizeof mOptionRomConfiguration; + } + *Configuration = AllocateZeroPool (Length); if (*Configuration == NULL) { @@ -245,6 +286,11 @@ CheckDevice ( CopyMem (Ptr, &mMmio64Configuration, sizeof mMmio64Configuration); Length = sizeof mMmio64Configuration; + if (TdIsEnabled ()) { + CopyMem (Ptr + Length, &mOptionRomConfiguration, sizeof mOptionRomConfiguration); + Length += sizeof mOptionRomConfiguration; + } + CopyMem (Ptr + Length, &mEndDesc, sizeof mEndDesc); return EFI_SUCCESS; -- 2.29.2.windows.2 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#87516): https://edk2.groups.io/g/devel/message/87516 Mute This Topic: https://groups.io/mt/89743610/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
