OvmfPkg/IntelTdx: Update TDVF README

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4756

There are below updates in this patch:
1. Rename README to README.md so that it can be show as markdown
   document.
2. Update some information about TDVF.
2. Fix some typo.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

1 files changed, 38 insertions, 26 deletions

diff --git a/OvmfPkg/IntelTdx/README b/OvmfPkg/IntelTdx/README.md
index 7307ede78f..c168167c12 100644
--- a/OvmfPkg/IntelTdx/README
+++ b/OvmfPkg/IntelTdx/README.md
@@ -1,13 +1,13 @@
 TDVF Overview

 -------------

 

-<b>Intel Trust Domain Extension (TDX)</b> is Intel Architecture extension

+**Intel Trust Domain Extension (TDX)** 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

+(hypervisor etc) from the TCB. **TDX Virtual Firmware (TDVF)** 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

+The **Intel TDX Virtual Firmware Design Guide** 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:

@@ -19,49 +19,61 @@ Configurations and Features
 

 There are 2 configurations for TDVF.

 

-<b>Config-A:</b>

- - Merge the *basic* TDVF feature to existing OvmfX64Pkg.dsc. (Align

+**Config-A:**

+ - Merge the *basic* TDVF feature to existing **OvmfPkgX64.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.

+ - Threat model: VMM is **NOT** out of TCB. (We don't make things worse)

+ - The OvmfPkgX64.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.

+ - PEI phase is **NOT** skipped in either TD or Non-TD.

+ - RTMR based measurement (CC_MEASUREMENT) is supported as an optional requirement.

  - 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)

+**Config-B:**

+ - Add a standalone **IntelTdxX64.dsc** to a TDX specific directory

+   (**OvmfPkg/IntelTdx**) 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

+ - IntelTdxX64.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

+   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,

+ - RTMR based measurement (CC_MEASUREMENT) is supported as a mandatory requirement.

+ - 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.

- - Need to remove unnecessary attack surfaces, such as network stack.

+ - PEI phase is skipped to remove unnecessary attack surface.

+ - DXE FV is split into 2 FVs (DXEFV & NCCFV) to remove the unnecessary attack

+   surface in a TD guest..

+   - When launching a TD guest, only drivers in DXEFV are loaded.

+   - When launching a Non-TD guest, dirvers in both DXEFV and NCCFV are

+     loaded.

 

 Build

 ------

 - Build the TDVF (Config-A) target:

-`cd /path/to/edk2`

-`source edksetup.sh`

-`build.sh -p OvmfPkg/OvmfPkgX64.dsc -a X64 -t GCC5`

+```

+cd /path/to/edk2

+source edksetup.sh

+

+## without CC_MEASUREMENT enabled

+build -p OvmfPkg/OvmfPkgX64.dsc -a X64 -t GCC5 -b RELEASE

+

+## CC_MEASUREMENT enabled

+build -p OvmfPkg/OvmfPkgX64.dsc -a X64 -t GCC5 -D CC_MEASUREMENT_ENABLE=TRUE -b RELEASE

+```

 

 - 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`

+```

+cd /path/to/edk2

+source edksetup.sh

+build -p OvmfPkg/IntelTdx/IntelTdxX64.dsc -a X64 -t GCC5 -b RELEASE

+```

 

 Usage

 -----