Refactor SandboxMemoryLayout#1455
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Pull request overview
This PR refactors SandboxMemoryLayout to remove derived/stored offset fields and instead compute layout addresses/offsets on demand, with the goal of simplifying snapshot serialization and reducing layout-related bugs.
Changes:
- Replace stored layout-derived fields (PEB offsets, heap/init offsets, etc.) with accessor methods and store only configuration-derived sizes.
- Switch PEB initialization to build a
HyperlightPEBstruct and serialize it viabytemuckrather than manually writing individualu64fields. - Add
bytemuck::Pod/Zeroablederives forGuestMemoryRegion/HyperlightPEBand add a unit test validating round-trip byte serialization.
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Copilot reviewed 6 out of 7 changed files in this pull request and generated 1 comment.
Show a summary per file
| File | Description |
|---|---|
| src/hyperlight_host/src/sandbox/uninitialized_evolve.rs | Update PEB address access to the new peb_address() accessor. |
| src/hyperlight_host/src/mem/mgr.rs | Use new SandboxMemoryLayout size fields (input_data_size/output_data_size) instead of pulling from config. |
| src/hyperlight_host/src/mem/layout.rs | Remove derived fields and compute offsets via methods; refactor PEB writing to struct + bytemuck serialization. |
| src/hyperlight_host/src/hypervisor/hyperlight_vm/x86_64.rs | Update test to use peb_address() accessor. |
| src/hyperlight_host/Cargo.toml | Add bytemuck dependency for host-side PEB serialization. |
| src/hyperlight_common/src/mem.rs | Mark PEB-related structs as Pod/Zeroable and add serialization round-trip unit test. |
| Cargo.lock | Lockfile update to include bytemuck in the dependency graph. |
Signed-off-by: Ludvig Liljenberg <4257730+ludfjig@users.noreply.github.com>
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jprendes
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May 14, 2026
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LGTM
Very clean refactor, thanks!
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This PR removes derived fields from SandboxMemoryLayout, with the primary goal to help simplify future snapshot serialization and prevent a whole category of bugs. Note that the added
bytemuckcrate dep is already a transitive dep of hyperlight-common, so I'm not adding anything new. I filed #1454 to fix this, but not in scope for this PR