Upstream PR 3058 TCG Plugin Monitor

Upstream PR #3058 — TCG plugin and monitor interaction

Upstream work · Actionable research · Research and retired work

Current disposition — November 1, 2026

Reviewed: November 1, 2026. Fork source: b7140848 (full SHA b71408480a3a979a9c584663e1d1f400904c8bb7). Latest stable checked: v0.8.136-0-g458730bf5373, September 30, source 458730bf5373f1f0d027450fef7443e3af7a3ae1. GitHub state, branch recommendation, source presence and release availability are separate facts. See current status and release versus main.

Current field	November 1, 2026 observation
GitHub source	Upstream #3058
GitHub state / draft	Open / No
Current head	885319c94a4aa47783d7b85973314b32d551d5ea
Originally reviewed head	c59a5f59999303b450f6de806e8d028050889b2b
Last metadata update (UTC)	2026-10-20T21:11:48Z
Head versus original review	Changed head and verified proposal-source changes; historical review needs the update described below.
Current action	Re-review new locking, callback context and unload sequence.
Fork/release availability	This upstream proposal’s GitHub state does not establish full fork/release inclusion. The historical overlap below is scoped to its recorded fork baseline; use the current feature register for delivered fork behavior.

The head changed from c59a5f59999303b450f6de806e8d028050889b2b to 885319c94a4aa47783d7b85973314b32d551d5ea (October 20). New commits add plugin locking, unregister commands before unload, dispatch asynchronously in safe vCPU context, release plugin.lock before invoking the callback, and allow register reads during callback execution. A successful monitor dispatch still does not prove the callback ran or the guest reached its measurement phase; reset/uninstall and queued-command lifetimes require review at this head.

Source-change record: original-to-current comparison. The branch diverged/rebased; comparison-wide unrelated upstream changes are not all proposal changes.

This refresh checked GitHub identity/state and the specific source boundaries named above. It did not rerun native games, XISO timings or integration qualification. Historical performance claims remain attached to their original heads.

Historical review — September 21, 2026

The review below is preserved as written, including its original state, head, fork baseline and proposed handoff. Its present-tense statements apply to that dated review; the current disposition above governs today’s action.

← Upstream Work

Field	Value
Upstream PR	xemu-project/xemu#3058
State at 2026-09-21 audit	Open
Reviewed upstream head	c59a5f59999303b450f6de806e8d028050889b2b
Last upstream update seen	2026-09-19
Reviewed upstream base	f9b14039e5bb56ae2d8f028e31e7cc19f13f7e12
Fork baseline	82d04d84bdb3de956f20c3537e1da2cece0e8da2
Relationship	Supports downstream profiling workflow
Related fork work	Diagnostic counters and bounded performance protocol
Contribution priority	Medium
Upstream contact status	No comment posted by this audit.

Summary

This feature can constrain TCG instrumentation to a repeatable workload phase instead of collecting boot, loading, and cleanup together.

Upstream scope

The PR adds interaction between the TCG plugin system and monitor controls.

Corresponding fork work

The fork’s profiling method requires explicit admission, measurement boundaries, schema identity, and uninstrumented acceptance. Cause counters already distinguish diagnostics from performance qualification.

Difference that must remain explicit

Monitor acknowledgment does not prove the guest reached the intended phase. Instrumentation itself can perturb timing and must not silently remain enabled.

Transferable regression and review cases

• Start/stop commands are acknowledged and reflected in plugin state.
• Repeated start/stop leaves no stale callbacks or duplicate collection.
• Guest-side phase markers and host monitor timestamps align.
• Disabled instrumentation performs no logging/locking/clock work.
• Final acceptance uses an uninstrumented build.

Suggested upstream handoff

Offer the bounded-measurement and disabled-path rules rather than an implementation patch.

Claims this page does not support

• It does not prove the upstream branch merges cleanly with current upstream.
• It does not prove a native correctness or performance result unless a linked exact-head run says so.
• It does not transfer favorable performance percentages between hardware, renderers, games, or source heads.
• It does not authorize posting a comment or review upstream.

Before sending anything upstream

• Refresh the PR state, head SHA, description, changed files, and newest review comments.
• Recheck the corresponding fork implementation on current main.
• Run or cite the narrow regression on an exact source state.
• Verify every public link and remove private paths, captures, game data, credentials, and internal logs.
• Phrase source concerns as source concerns and reproductions as reproductions.
• State the uncovered behavior and evidence limit.
• Add the posted URL and upstream response to this page.

Tracking log

Date	Upstream head	Action	Result
2026-09-21	c59a5f599993	Fork/upstream source comparison recorded	Handoff prepared; nothing posted

References

• Upstream PR #3058
• Fork repository
• Upstream Work
• Pull Request Lessons