Upstream PR 2999 Required Vulkan Features

Upstream PR #2999 — Enable required Vulkan features and buffer usage

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 #2999
GitHub state / draft	Open / No
Current head	bf3f610d0518dccbc6f9ad158c5d71f826dd3bcb
Originally reviewed head	bf3f610d0518dccbc6f9ad158c5d71f826dd3bcb
Last metadata update (UTC)	2026-10-18T20:59:12Z
Head versus original review	Same recorded head; metadata/state updates do not indicate a new proposal-code head.
Current action	Review feature query/enablement separately from #3000.
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.

Still open. Required feature enablement, including shader-demote capability, is distinct from supported compiler target selection in merged #3000. The transfer-source usage part overlaps fork #104; that overlap does not establish the rest of the feature-negotiation chain.

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#2999
State at 2026-09-21 audit	Open
Reviewed upstream head	bf3f610d0518dccbc6f9ad158c5d71f826dd3bcb
Last upstream update seen	2026-09-06
Reviewed upstream base	f9b14039e5bb56ae2d8f028e31e7cc19f13f7e12
Fork baseline	82d04d84bdb3de956f20c3537e1da2cece0e8da2
Relationship	One direct overlap plus separate feature-negotiation work
Related fork work	Mainkill1/xemu#104
Contribution priority	High
Upstream contact status	No comment posted by this audit.

Summary

The transfer-source usage fix overlaps directly with fork #104. Shader-demote feature negotiation is a separate responsibility.

Upstream scope

The PR enables Vulkan features and buffer usage that renderer paths already assume, including shader-demote behavior and transfer-source use.

Corresponding fork work

Fork #104 adds VK_BUFFER_USAGE_TRANSFER_SRC_BIT for the relevant compute-destination buffer and repairs invalid depth and block-compressed buffer-to-image copy layout/alignment.

Difference that must remain explicit

The buffer-usage correction does not validate the shader-demote feature chain. Device feature query, enablement, SPIR-V capabilities, compiler target, and shader path must agree independently.

Transferable regression and review cases

• The relevant buffer is created with every usage required by later commands.
• BC copies cover tiny mip levels and required block alignment.
• Unsupported demote capability selects a valid fallback or rejects the route before pipeline creation.
• Enabled device features match generated SPIR-V capabilities and selected target environment.

Suggested upstream handoff

Offer #104’s transfer-source and BC/depth copy regressions. Explicitly exclude shader-demote negotiation from the claimed overlap.

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	bf3f610d0518	Fork/upstream source comparison recorded	Handoff prepared; nothing posted

References

• Upstream PR #2999
• Fork repository
• Upstream Work
• Pull Request Lessons