| 1 | TDVF Overview
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| 2 | -------------
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| 3 |
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| 4 | <b>Intel Trust Domain Extension (TDX)</b> is Intel Architecture extension
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| 5 | to provide trusted, isolated VM execution by removing CSP software
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| 6 | (hypervisor etc) from the TCB. <b>TDX Virtual Firmware (TDVF)</b> is an
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| 7 | EDK II based project to enable UEFI support for TDX based Virtual
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| 8 | Machines. It provides the capability to launch a TD.
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| 9 |
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| 10 | The <b>Intel? TDX Virtual Firmware Design Guide</b> is at
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| 11 | https://www.intel.com/content/dam/develop/external/us/en/documents/tdx-virtual-firmware-design-guide-rev-1.01.pdf.
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| 12 |
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| 13 | More information can be found at:
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| 14 | https://www.intel.com/content/www/us/en/developer/articles/technical/intel-trust-domain-extensions.html
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| 15 |
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| 16 |
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| 17 | Configurations and Features
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| 18 | ----------------------------
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| 19 |
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| 20 | There are 2 configurations for TDVF.
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| 21 |
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| 22 | <b>Config-A:</b>
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| 23 | - Merge the *basic* TDVF feature to existing OvmfX64Pkg.dsc. (Align
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| 24 | with existing SEV)
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| 25 | - Threat model: VMM is NOT out of TCB. (We don?t make things worse)
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| 26 | - The OvmfX64Pkg.dsc includes SEV/TDX/normal OVMF basic boot capability.
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| 27 | The final binary can run on SEV/TDX/normal OVMF.
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| 28 | - No changes to existing OvmfPkgX64 image layout.
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| 29 | - No need to remove features if they exist today.
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| 30 | - PEI phase is NOT skipped in either Td or Non-Td.
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| 31 | - RTMR based measurement is supported.
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| 32 | - External inputs from Host VMM are measured, such as TdHob, CFV.
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| 33 | - Other external inputs are measured, such as FW_CFG data, os loader,
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| 34 | initrd, etc.
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| 35 |
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| 36 | <b>Config-B:</b>
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| 37 | - Add a standalone IntelTdx.dsc to a TDX specific directory for a *full*
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| 38 | feature TDVF.(Align with existing SEV)
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| 39 | - Threat model: VMM is out of TCB. (We need necessary change to prevent
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| 40 | attack from VMM)
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| 41 | - IntelTdx.dsc includes TDX/normal OVMF basic boot capability. The final
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| 42 | binary can run on TDX/normal OVMF.
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| 43 | - It might eventually merge with AmdSev.dsc, but NOT at this point of
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| 44 | time. And we don?t know when it will happen. We need sync with AMD in
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| 45 | the community after both of us think the solutions are mature to merge.
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| 46 | - Need to add necessary security feature as mandatory requirement, such
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| 47 | as RTMR based Trusted Boot support.
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| 48 | - Need to measure the external input from Host VMM, such as TdHob, CFV.
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| 49 | - Need to measure other external input, such as FW_CFG data, os loader,
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| 50 | initrd, etc.
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| 51 | - Need to remove unnecessary attack surfaces, such as network stack.
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| 52 |
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| 53 | Build
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| 54 | ------
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| 55 | - Build the TDVF (Config-A) target:
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| 56 | `cd /path/to/edk2`
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| 57 | `source edksetup.sh`
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| 58 | `build.sh -p OvmfPkg/OvmfPkgX64.dsc -a X64 -t GCC5`
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| 59 |
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| 60 | - Build the TDVF (Config-B) target:
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| 61 | `cd /path/to/edk2`
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| 62 | `set PACKAGES_PATH=/path/to/edk2/OvmfPkg`
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| 63 | `source edksetup.sh`
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| 64 | `build.sh -p OvmfPkg/IntelTdx/IntelTdxX64.dsc -a X64 -t GCC5`
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| 65 |
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| 66 | Usage
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| 67 | -----
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| 68 |
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| 69 | Assuming TDX-QEMU/TDX-KVM are already built, one can start a TD virtual
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| 70 | 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):
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| 71 |
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| 72 | `qemu_system_x86 \`
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| 73 | ` -machine ...,confidential-guest-support=tdx0 \`
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| 74 | ` -object tdx-guest,id=tdx0,[sept-ve-disable=off] \`
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| 75 | ` -drive if=pflash,format=raw,unit=0,file=/path/to/OVMF_CODE.fd \`
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| 76 | ` -drive if=pflash,format=raw,unit=1,file=/path/to/OVMF_VARS.fd \`
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| 77 |
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| 78 | Note:
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| 79 | TDX-QEMU/TDX-KVM are still in upstreaming progress. Please refer to:
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| 80 | - kvm : https://github.com/intel/tdx/tree/kvm-upstream
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| 81 | - qemu : https://github.com/intel/qemu-tdx/blob/tdx-qemu-upstream-rfc-v3
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| 82 |
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| 83 | Once above 2 upstreaming are completed a minimum qemu/kvm version will be updated here.
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