TDVF Overview | |
------------- | |
<b>Intel Trust Domain Extension (TDX)</b> is Intel Architecture extension | |
to provide trusted, isolated VM execution by removing CSP software | |
(hypervisor etc) from the TCB. <b>TDX Virtual Firmware (TDVF)</b> is an | |
EDK II based project to enable UEFI support for TDX based Virtual | |
Machines. It provides the capability to launch a TD. | |
The <b>Intel? TDX Virtual Firmware Design Guide</b> is at | |
https://www.intel.com/content/dam/develop/external/us/en/documents/tdx-virtual-firmware-design-guide-rev-1.01.pdf. | |
More information can be found at: | |
https://www.intel.com/content/www/us/en/developer/articles/technical/intel-trust-domain-extensions.html | |
Configurations and Features | |
---------------------------- | |
There are 2 configurations for TDVF. | |
<b>Config-A:</b> | |
- Merge the *basic* TDVF feature to existing OvmfX64Pkg.dsc. (Align | |
with existing SEV) | |
- Threat model: VMM is NOT out of TCB. (We don?t make things worse) | |
- The OvmfX64Pkg.dsc includes SEV/TDX/normal OVMF basic boot capability. | |
The final binary can run on SEV/TDX/normal OVMF. | |
- No changes to existing OvmfPkgX64 image layout. | |
- No need to remove features if they exist today. | |
- PEI phase is NOT skipped in either Td or Non-Td. | |
- RTMR based measurement is supported. | |
- External inputs from Host VMM are measured, such as TdHob, CFV. | |
- Other external inputs are measured, such as FW_CFG data, os loader, | |
initrd, etc. | |
<b>Config-B:</b> | |
- Add a standalone IntelTdx.dsc to a TDX specific directory for a *full* | |
feature TDVF.(Align with existing SEV) | |
- Threat model: VMM is out of TCB. (We need necessary change to prevent | |
attack from VMM) | |
- IntelTdx.dsc includes TDX/normal OVMF basic boot capability. The final | |
binary can run on TDX/normal OVMF. | |
- It might eventually merge with AmdSev.dsc, but NOT at this point of | |
time. And we don?t know when it will happen. We need sync with AMD in | |
the community after both of us think the solutions are mature to merge. | |
- Need to add necessary security feature as mandatory requirement, such | |
as RTMR based Trusted Boot support. | |
- Need to measure the external input from Host VMM, such as TdHob, CFV. | |
- Need to measure other external input, such as FW_CFG data, os loader, | |
initrd, etc. | |
- Need to remove unnecessary attack surfaces, such as network stack. | |
Build | |
------ | |
- Build the TDVF (Config-A) target: | |
`cd /path/to/edk2` | |
`source edksetup.sh` | |
`build.sh -p OvmfPkg/OvmfPkgX64.dsc -a X64 -t GCC5` | |
- Build the TDVF (Config-B) target: | |
`cd /path/to/edk2` | |
`set PACKAGES_PATH=/path/to/edk2/OvmfPkg` | |
`source edksetup.sh` | |
`build.sh -p OvmfPkg/IntelTdx/IntelTdxX64.dsc -a X64 -t GCC5` | |
Usage | |
----- | |
Assuming TDX-QEMU/TDX-KVM are already built, one can start a TD virtual | |
machine as [launching-td-guest](https://github.com/intel/qemu-tdx/blob/tdx-qemu-upstream-rfc-v3/docs/system/i386/tdx.rst#launching-a-td-tdx-vm): | |
`qemu_system_x86 \` | |
` -machine ...,confidential-guest-support=tdx0 \` | |
` -object tdx-guest,id=tdx0,[sept-ve-disable=off] \` | |
` -drive if=pflash,format=raw,unit=0,file=/path/to/OVMF_CODE.fd \` | |
` -drive if=pflash,format=raw,unit=1,file=/path/to/OVMF_VARS.fd \` | |
Note: | |
TDX-QEMU/TDX-KVM are still in upstreaming progress. Please refer to: | |
- kvm : https://github.com/intel/tdx/tree/kvm-upstream | |
- qemu : https://github.com/intel/qemu-tdx/blob/tdx-qemu-upstream-rfc-v3 | |
Once above 2 upstreaming are completed a minimum qemu/kvm version will be updated here. |