1.8: vmbfs: Implement SaveRestore (#4072) - #4125
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Steven Malis (smalis-msft) wants to merge 1 commit into
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1.8: vmbfs: Implement SaveRestore (#4072)#4125Steven Malis (smalis-msft) wants to merge 1 commit into
Steven Malis (smalis-msft) wants to merge 1 commit into
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The hope is this will fix some UEFI flakiness, as our UEFI is not tolerant of vmbfs getting revoked and reoffered, which is the fallback behavior for vmbus devices that don't implement SaveRestore. (cherry picked from commit 59dd998)
Steven Malis (smalis-msft)
added
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release_1.8.2607
Steven Malis (smalis-msft)
enabled auto-merge (squash)
July 31, 2026 17:20
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Pull request overview
Backport to release/1.8.2607 adding Save/Restore support to the vmbfs VMBus device so it can be restored without revoke/reoffer fallback behavior (intended to reduce UEFI flakiness).
Changes:
- Implement
SaveRestoreSimpleVmbusDeviceforVmbfsDeviceand advertise support viasupports_save_restore(). - Add a protobuf-encoded saved-state payload (mesh) to persist the channel state across save/restore.
- Add the
meshdependency forvmbfsand updateCargo.lockaccordingly.
Reviewed changes
Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| vm/devices/vmbus/vmbfs/src/lib.rs | Adds Save/Restore support and defines the saved-state protobuf payload. |
| vm/devices/vmbus/vmbfs/Cargo.toml | Adds mesh dependency required for the saved-state encoding. |
| Cargo.lock | Records the new mesh dependency for the vmbfs crate. |
Comment on lines
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| fn save_open(&mut self, runner: &Self::Runner) -> state::SavedState { | ||
| let Self::Runner { | ||
| state, | ||
| pipe: _, | ||
| buf: _, | ||
| } = runner; | ||
| state::SavedState { | ||
| state: match state { | ||
| State::VersionRequest => state::State::VersionRequest, | ||
| State::Ready => state::State::Ready, | ||
| }, | ||
| } | ||
| } |
Comment on lines
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| #[async_trait] | ||
| impl SimpleVmbusDevice for VmbfsDevice { | ||
| type SavedState = SavedStateNotSupported; | ||
| type SavedState = save_restore::state::SavedState; |
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Backport of #4072 to
release/1.8.2607.The cherry-pick of 59dd998 applied cleanly onto
release/1.8.2607with no conflicts and no manual edits.Original PR: #4072
This backport PR was created by an AI agent (GitHub Copilot) on behalf of Steven Malis (@smalis-msft).