QEMU Model Verification

Audit workflow

For a non-trivial task that writes to the workspace, use only the needed entries under .oh-my-qemu/<task-slug>/: audit.md (baseline, plan, decisions, evidence, verification, and gaps), commands.md (redacted commands, working directories, and results), logs/ (decisive build, test, and runtime output), scripts/ (probes, parsers, and harnesses), and output/ (generated deliverables, third-party dependencies, and non-QEMU binaries). Keep QEMU's own build tree at source-root builds/build-<target>/, never an unqualified build/. In a Git worktree, add .agents/, .oh-my-qemu/, and builds/ to the file from git rev-parse --git-path info/exclude before writing artifacts or configuring QEMU; preserve existing entries and avoid duplicates. Never stage or commit these paths; stage source only when the user explicitly requests that separate action. At handoff, reconcile git status --short with the baseline and report the task directory, build directory, source changes, pre-existing changes, and unresolved gaps.

QEMU upstream boundary

QEMU's official GitLab and mailing lists are upstream channels. A patch becomes an upstream contribution when it is sent to the maintainers selected through MAINTAINERS. Do not prepare or send agent-generated code, documentation, commit messages, or patches for upstream submission; see the checked-out tree's docs/devel/code-provenance.rst. Research, debugging, analysis, local experiments, verification, and workflow guidance remain allowed. Local branches, commits, patch files, pushes, and pull requests are not by themselves upstream contributions; perform those Git actions only when requested.

Evidence ladder

Given one falsifiable claim and existing evidence, report PASS, FAIL, or INCONCLUSIVE without inventing evidence. Use the lowest rung that proves the claim; a boot banner alone does not prove device correctness:

1. Static inspection: source/docs establish a fact.
2. Build: the touched target compiles.
3. Unit/qtest: register, IRQ, timer, memory, or board contract holds.
4. Trace/log: the expected runtime path executes and the bad path does not.
5. Boot smoke: firmware/kernel reaches a named milestone.
6. Workload: guest output proves the modeled hardware was consumed.
7. Replay/reproduction: the failure is deterministic or captured.

Evidence provenance

Derive every expected marker, status value, count, or numeric bound from the same evidence class as the artifact under test: register contract, model source, or a checked-in test. Record the source and re-derive it when the test, image, or model changes. A stale literal is a known false-negative source (an old SHUTDOWN status, a DTB without required properties); do not edit an expected literal to force a pass until its provenance is restored.

Record and compare hashes of the QEMU binary/build directory, images, DTB, and machine options. Verify the device-tree properties the claim depends on (MSI: msi-parent and an ITS node; timers/interrupts: controller and clock properties) and decode the DTB when in doubt; a stale DTB is a known false negative, not model evidence.

Claim and acceptance criteria

Record one claim per gate in the claim record template: claim, gate, expected values with provenance, inputs and hashes, evidence paths, verdict, proves and does-not-prove, next blocker.

INCONCLUSIVE sufficiency

A verdict is sufficient only when it names the evidence that would change it. INCONCLUSIVE must state the gate, evidence collected, missing evidence, and the next narrow command that could obtain it.

Reviewer claims

Treat external review findings, human or agent, as hypotheses. Verify each against the checked-out code and QOM semantics with file:line, classify it as pre-existing or introduced by the change set, and reject unsupported debug surfaces (for example a -global override unreachable from normal machine or guest paths) as proof. Record the classification and evidence: claim review.

First divergence

For numeric mismatches, localize the first diverging slice: compare slice by slice against a reference model or expected trace, capture trace/GDB state at the first difference, and check whether banked or multiple address spaces hide the difference.

Failure classification

Classify before changing model code: environment/toolchain/build directory; stale image; boot ABI; board topology; device register/IRQ/timer/DMA semantics; TCG frontend/backend; guest/application. Usually only topology, model-semantics, and TCG categories justify source changes.

Register model structure check

Reconstruct the register-framework decision from current evidence (workspace policy, compatible explicit user direction, maintained nearby convention, with RegisterInfo as the fallback default) and verify the implementation matches it. Register offsets, field macros, backing storage, framework tables, and register-local callbacks must live in the device .c file, not a header or board file. Report FAIL when current evidence does not justify the implementation or a record contradicts it; do not fail only because no historical record exists. Record the decision in audit.md; a successful build, boot, or probe does not override this check.

Device and board checklist

Use the qemu-peripheral-modeling and qemu-board-modeling checklists when installed; otherwise verify directly: reset state, read/write masks and reserved bits, W1C/status clear, IRQ raise/clear route, virtual-clock timer, DMA guest-memory effect, machine creation, memory-map probes, reset after dirty state.

Trace validation

• count events and inspect semantic summaries; check skipped or unknown descriptor counts;
• verify command-memory and DMA ranges, and that the running image is the one intended;
• correlate trace milestones with UART or workload output.

Reporting format

PASS|FAIL|INCONCLUSIVE: <gate>
Command: <exact command>
Artifacts: <paths under .oh-my-qemu/<task-slug>/>
Evidence: <decisive lines or summary>
Proves / does not prove: <claim> / <remaining gap>

Upstream references

• QEMU code provenance and AI policy: docs/devel/code-provenance.rst.
• Testing overview: docs/devel/testing/main.rst.
• QTest docs: docs/devel/testing/qtest.rst.
• Tracing: docs/devel/tracing.rst.
• Replay: docs/system/replay.rst.

Paths can differ between QEMU versions; locate them in the checked-out tree.