fix(migtd-hash): reconstruct IGVM CFV pages by GPA - #1026
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The legacy extractor counted populated CFV pages, copied that many payload pages from the serialized IGVM stream, and appended zero padding. After IGVM payload ordering became sparse, this shifted or omitted enrolled policy files and produced offline RTMR values that did not match runtime memory. The issue was previously hidden because generated IGVMs happened to serialize populated CFV pages contiguously in GPA order. Place each PageData payload at its declared GPA, preserve gaps, and reject pages extending beyond the configuration volume. Assisted-by: GitHub Copilot CLI:GPT-5.6 Sol Signed-off-by: Haitao Huang <haitaohuang@microsoft.com>
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Problem
The legacy IGVM configuration-volume extractor counts populated CFV pages, copies that many payload pages from the serialized IGVM stream, and pads the remainder with zeroes. This assumes payloads are serialized contiguously in GPA order.
That assumption was previously hidden because generated IGVMs happened to use that layout. With sparse or reordered page payloads, enrolled policy and issuer-chain files can be shifted or omitted from the reconstructed CFV, causing offline RTMR1/RTMR2 and TDINFO measurements to differ from runtime memory.
Fix
Parse IGVM
PageDatadirectives and place each payload at its declared guest physical address relative to the CFV base. Preserve sparse gaps and reject pages that extend past the configuration-volume range.This fix is independent of the proposed one-hash TCB mapping work and applies directly to the existing
migtd-hashIGVM measurement path.Validation
cargo test -p migtd-hashcargo fmt -- --checkcargo check