docs: add PIID reference for manifest

Author: burgerdev

docs/docs/architecture/components/manifest.md

@@ -305,6 +305,59 @@ Attributes specifies various attested properties of the TDX VM and is documented
 
 The extended features available mask (`XFAM`) determines the set of extended features available for use by the guest and is documented in Section 3.4.2 (`XFAM`) in the [TDX ABI Spec].
 
+### `ReferenceValues.tdx.AllowedPIIDs`
+
+These are matched against the `PIID` field from the PCK certificate, as documented in section 1.3.5 of the [SGX PCK Spec].
+If the list is empty or null, all PIIDs are accepted.
+
+In case hardware is operated by you instead of a third party, or you are able to gain physical access to the hardware to audit it,
+you can obtain the PIID with the following steps:
+
+1. Install and run Intel's [`PCKIDRetrievalTool`].
+   This should place a CSV file in your working directory.
+2. Retrieve the following fields from the CSV file:
+   - `EncryptedPPID`
+   - `PCE_ID`
+   - `CPUSVN`
+   - `PCE ISVSVN`
+3. Use these values to [request a PCK certificate from Intel PCS](https://api.portal.trustedservices.intel.com/content/documentation.html#pcs-certificate-v4).
+   Note that the response contains intermediate certificates in the `SGX-PCK-Certificate-Issuer-Chain` header that are required to verify the PCK certificate's signature.
+4. Verify that the PCK certificate chains back to Intel's root, for example with `openssl verify`.
+5. Parse the PCK certificate to find the SGX extension address:
+
+   ```sh
+   openssl asn1parse -in pck.pem
+   ```
+
+   Example output, showing the extension address `624` right after its ASN.1 OID:
+
+   ```txt
+     613:d=5  hl=2 l=   9 prim: OBJECT            :1.2.840.113741.1.13.1
+     624:d=5  hl=4 l= 554 prim: OCTET STRING      [HEX DUMP]: [...]
+   ```
+
+6. Parse the SGX extension to find the PIID:
+
+   ```sh
+   openssl asn1parse -in pck.pem --strparse $ADDRESS
+   ```
+
+   Example output with `ADDRESS=624`, showing the PIID right after its ASN.1 OID:
+
+   ```txt
+     454:d=2  hl=2 l=  10 prim: OBJECT            :1.2.840.113741.1.13.1.6
+     466:d=2  hl=2 l=  16 prim: OCTET STRING      [HEX DUMP]:E90210702A2CC5AD9764F29DDC8FDE8C
+   ```
+
+   Copy the value shown after `[HEX DUMP]` into the `AllowedPIIDs` field.
+
+:::warning
+
+The EncryptedPPID must be retrieved from a machine by physically accessing it.
+If you retrieve this value via a remote channel, your traffic could already be redirected to a hostile environment that allows an attacker physical access.
+
+:::
+
 ## `WorkloadOwnerKeyDigests` {#workload-owner-key-digests}
 
 A list of workload owner public key digests.
@@ -330,3 +383,5 @@ Doing the same for the `SeedshareOwnerKeys` field makes Coordinator recovery and
 [`snphost`]: https://github.com/virtee/snphost
 [SEV ABI Spec]: https://www.amd.com/content/dam/amd/en/documents/developer/56860.pdf
 [TDX ABI Spec]: https://cdrdv2.intel.com/v1/dl/getContent/733579
+[SGX PCK Spec]: https://api.trustedservices.intel.com/documents/Intel_SGX_PCK_Certificate_CRL_Spec-1.5.pdf
+[`PCKIDRetrievalTool`]: https://github.com/intel/confidential-computing.tee.dcap/blob/717f2a91ca732c3309b0c59d21757463133eb440/tools/PCKRetrievalTool/README.txt

tools/vale/styles/config/vocabularies/edgeless/accept.txt

@@ -119,8 +119,10 @@ paravisor
 passthrough
 PCIe?
 PCRs?
+PIIDs?
 plaintext
 podman
+PPID
 precalculator
 protobuf
 proxied