ctos — QEMU NMI pin → taken SError Diagram

ADR-083 opt-in

Pin QEMU v10.0.0 (7c949c53) + TYPE_NMI→SError patch
CTOS_REQUIRE_TAKEN_SERROR=1 requires bare el0: serror
Tip ~6ec1f4e — documentation aid, not Live status
Opt-in taken path (qemu-smoke, Pinned QEMU, QMP inject, Standing EL0, el0: serror): CTOS_QEMU + CTOS_REQUIRE_TAKEN_SERROR=1 until serial shows el0: serror.

Stock path unchanged

Distro QEMU: inject-nmi → machine does not provide NMIs
el0: serror-park stays Verified on default CI/Docker
Do not force multi-minute QEMU compile on every PR
Stock park path (qemu-smoke, Stock QEMU, Standing EL0, el0: serror-park): Distro QEMU still lacks TYPE_NMI; el0: serror-park stays Verified.

Explicit non-claims

FEAT_NMI / FIQ / BRK are not async SError
Umbrella EL0 isolated remains non-claim (ADR-055)
CloudAgent HELD — agent-box proof; amd64 workstation intent only
Honesty boundary (TYPE_NMI patch, Pinned QEMU, el0: serror, el0: serror-park): Patch raises async SError via TYPE_NMI. Not FEAT_NMI. Not EL0 isolated.