[Enrique Saurez (esaurez)]

Part of #1103 (SL2.15), in #1076. Does not close the SL2.16/SL2.18 work in that issue.

Adds the Linux real-VM restore-exclusion gate and its platform-aware consolidated-suite registration. This sync replays only the seven owned commits from historical fork 2a0451d4ed1e27445bcd4615e7c0878c291edca5 through original remote head 970046d4d03517658808275c673eb9abadeeabab onto already-published PR #1455 source 1148a7487995e02f3a39c6cf384f5d6d825f40ce. The resulting head is 27994d47a389f64ee51ae37d9b05cc4de30d471a, tree ee150f1db1803556772e8d0ee21452a0a8368ab8.

The selected producer's actual source lower is 8d6cbce4e649ae2dc6a9275f61541135171bd854. PR #1455's mutable base subsequently advanced to e976e5c307f396807854ebfe6cff0efb289ba754; that newer lower is not imported or qualified here. The PR's existing base branch, Draft state, labels and actual native-stack membership are preserved.

Rebase onto feature/nvx-refactor

#1455 and #1453 merged, so the branch now holds only its seven own commits, rebased onto cfdb452f29c898cd39c4691b9a12fabc14ca1bca as 48847d006a..d6b70447d5d0fd8843332a51a32e9b5884255e73 (tree 42a22938a69b48491420690142c8ff383df9138e). git range-diff 1148a74879..27994d47a3 cfdb452f29..d6b70447d5 reports all seven patches identical, and the rebase resolved no conflicts. The inherited #1454 and #1455 commits are dropped because they landed in the base. Since the base holds #1455's third commit, which moves VmDir into the private host::vm_directory below both host::snapshot and host::vm, the known host-module cycle below no longer applies. check_test_changes.py --base origin/feature/nvx-refactor reports the same 4 changed existing test items and 36 added items as the accounting below.

Rechecked on Windows at d6b70447: the 16 RuntimeAdapterSuiteTests, Ruff lint and format of both changed Python files, Pyright of runtime_adapter_tests.py for Windows and Linux, and the runtime adapter's rustfmt and Clippy with -D warnings for the host feature on Windows and on x86_64-unknown-linux-musl. CI runs the remaining gates, including the Linux real-VM gate.

Exact owned-change preservation

The seven original commits (89e324b8, 32c63815, 673f9252, 32834506, 7be6836f, 794cafb7, 970046d4) replay cleanly. Every individual source patch and the aggregate own-range patch are byte-identical; only commit ancestry and the current-session trailers change. All six final gate/runner/inventory/documentation blobs exactly match original 970046.

In particular, tests/runtime-adapter/tests/vm_clone.rs remains Git blob c7e6ab682f5575003e79bcdb3451f2e110a721e1: all four gate oracles, both retained regressions, FIFO synchronization, helper rendezvous and assertions are unchanged. The entire nvx-rs subtree exactly matches selected producer 1148; no production permission implementation, restore API, native source/pin, guest/kernel input, lock storage or fallback is added by this sync. Native remains 14dc4116ec7e57567633c4b7b07892aca3a58522.

Inherited privacy finding: fixed by adopting existing producer logic

Finding 4531202369 is valid on the old 970046/2a0451 source: both APIs directly used the legacy capture validator, whose Linux private_file_problem deliberately returns no per-file refusal.

Published producer 1148 already fixes this at the snapshot boundary. Its existing check_openvmm first preserves legacy validation and then calls strict check_file on each manifest.bin, memory.bin and state.bin. On Linux, that refuses a different effective UID or any mode bits in 0077; both Snapshot::open and finish_capture call this same boundary. Windows keeps its owner-only ACL/reparse checks. The legacy template validator and generic Linux private-file policy are unchanged.

Existing regressions cover shared permissions for all artifacts through opening and finishing, including the finalizer's per-artifact 0640 refusal followed by restored 0600, links, FIFOs and sockets; Windows covers shared ACLs and reparse entries through both APIs. The root-only foreign-owner mutation regression remains explicitly ignored: source inspection establishes the common UID guard, not a falsely claimed privileged execution.

Platform-aware inventory, already corrected before this sync

Finding 4530276205 was already addressed by original 794cafb7 plus 970046d4, not a second new unfixed bug. scenarios.txt accepts TARGET TEST [linux|windows]; unqualified entries run on both. The restore-exclusion gate is explicitly linux, matching its Rust cfg, and is excluded on Windows.

Malformed lines, unknown qualifiers and global duplicate target/test pairs fail before filtering. The same selected list drives strict Cargo/libtest inventory, exact --include-ignored execution and counts. Missing/unlisted tests and ignored tests in the library or unnamed targets remain errors. No discovery-based omission, suppressed failure or weakened Rust assertion is introduced.

Existing-test accounting

Existing asset	Disposition retained unchanged by the sync
RuntimeAdapterSuiteTests.test_scenarios_refuse_other_lines	Keeps malformed/duplicate/empty-inventory checks; distinguishes unknown qualifiers and checks both platforms, including off-platform duplicates
RuntimeAdapterSuiteTests.test_the_adapter_s_readme_lists_its_scenarios	Keeps exact documentation/inventory correspondence for both platforms, including module-qualified names and documented qualifiers
tests/runtime-adapter/scenarios.txt	Documents the optional qualifier and adds only the exact Linux-only restore gate
read_scenarios in scripts/nvx_tools/runtime_adapter_tests.py	Adds explicit selection while retaining visible parse/duplicate failures and strict downstream inventory/execution checks

Three focused Python tests retain platform/order selection, identical check-only/execution/count selection and unexpected/ignored-test failures. No existing Rust test is rewritten or retired. Exact-parent accounting reports 4 existing-test asset changes and 36 added test items: the original 33 Rust items plus 3 Python tests.

Measured own delta remains 11 core lines and 1 counted non-test Python file, with the exact original 510 added Rust test lines. The complete own range touches 6 files; this sync adds no source changes beyond replaying it.

Current prepared-source checks

Both fresh private checkouts have real Git metadata and exact native source/Cargo files at 14dc4116ec7e57567633c4b7b07892aca3a58522. verify preceded every Cargo command. Rust formatting for both crates and the adapter's cargo build --locked --features host passed on both hosts.

Actual platform	Exact-head focused snapshot tests	Actual platform-selected compile/list inventory
Linux/MSHV	cargo test --locked --lib --manifest-path nvx-rs/Cargo.toml -- host::snapshot::: 99 passed, 1 root-only ownership test ignored	python3 scripts/nvx.py test-runtime-adapter --backend mshv --check-only: 157 scenarios / 11 targets, Linux gate included
Windows/WHP	cargo test --locked --lib --manifest-path nvx-rs\Cargo.toml -- host::snapshot::: 97 passed, 0 ignored	python scripts\nvx.py test-runtime-adapter --backend whp --check-only: 156 scenarios / 11 targets, Linux gate excluded

These are actual prepared-source compilations, privacy-regression executions and Cargo/libtest-list inventory checks, not inherited parent receipts or mocked discovery. Check-only runs execute no VM scenario. Windows MSVC setup and all Cargo descendants ran in the same cmd.exe environment; private targets/caches and fresh physical/commit-memory/disk admission were used on both hosts.

At this exact head, the preserved Python RuntimeAdapterSuiteTests pass (16 tests), along with affected-file Ruff 0.15.22 lint/format, Pyright 1.1.411 for Linux and Windows (0 type errors/warnings), targeted compileall, test layout, Markdown links and exact-parent test accounting.

Known inherited quality failure: canonical 1148 has a host-module dependency cycle (snapshot/capture imports vm, while vm imports snapshot). The independently classified PR #1455 CI run 42913894943 fails host_modules::the_children_of_host_depend_on_one_another_without_cycles on both hosts (21 passed, 1 failed, exit 101) on the actual 1148/8d6 merge source, not merely because its mutable base moved. This sync preserves that exact producer subtree; it neither patches, suppresses nor allowlists the failure, and claims neither all-quality nor full-CI green. Producer repair is separate work.

Original hardware proof stays bound to original 7be

All four cases passed on Linux/MSHV at original gate head 7be6836f5d9bf465588810a19bb488e8a91f5ee9, tree bea48db54d9f4b32da44e20ec2e3c23a506c4469:

Case	Actual historical outcome at 7be
Concurrent live restores under one caller-owned file lock, including view creation/removal	Four complete Activate/Start/Ping/Stop lifecycles with overlapping VMMs
Unlocked memory-file link addition during restore startup	Native generation-change error, non-success exit and no ready connection
Controller killed before the VMM connects restore-ready	Verified SIGKILL, native readiness-connect error and VMM exit
Link change after the authenticated VMM connects restore-ready	Exact ready event and complete lifecycle

The native artifact_open record and blocking --log-file FIFO still provide the ordering boundary. The capability pipe is written/closed before spawn; the nonblocking FIFO reader stays owned until VMM reaping, and the link helper waits until its PID/start identity is recorded. No production hook, synthetic VMM or fallback is used.

Both openvmm_reads_none_of_the_host_s_input_until_the_repair_acknowledges_the_restore and a_clone_reads_no_more_of_its_disks_than_its_root_needs passed in that same original invocation. Original hardware, software-matrix and scoped-review receipts remain historical evidence only, retained under D:\copilot\nvx-slim-1076\runs\sl215-20261110 and the original handoffs.

No VM/hardware scenario, KVM/WHP hardware gate, native/kernel/guest rebuild, broad matrix, MSRV or new manual logical review was run solely for this unchanged replay. No future lower/producer graph is qualified. Copilot review and full CI remain separate from these focused checks; a request's admission, pending state or Draft skip is not a verdict.

This pull request is ready for review on feature/nvx-refactor; its review threads are answered and resolved.

[Copilot]

🟡 Changes recommended

The Linux-only test is absent from the scenario inventory, causing the runner to fail before executing any scenarios; registration must be platform-aware to avoid breaking Windows.

1 open issue

• Register the Linux-only restore exclusion test in runtime scenarios · New

What changed in this PR

Adds the Linux restore-exclusion gate for SL2.15, validating caller-owned snapshot locking before production restore work in SL2.16.

Changes:

• Exercises concurrent hard-linked restores under a caller-owned file lock.
• Checks restore failure after an unlocked link change or controller death before readiness.
• Verifies that a link change after the authenticated readiness connection still permits the full adapter lifecycle.

File	Description
tests/​runtime-adapter/​tests/​vm_clone.rs	Adds a Linux-only real-VM test covering four restore-exclusion cases, with synchronization and process cleanup helpers.

_{Review effort: Balanced}

[github-actions]

This pull request changes existing tests

It modifies or removes 4 existing test asset(s), listed below. Review each with care: a change to a test can hide a regression that the test caught. See doc/contribute.md#changes-to-existing-tests.

Test code

Change	What	Before	After
modified test	def RuntimeAdapterSuiteTests.test_scenarios_refuse_other_lines in scripts/test_nvx_tools.py	scripts/test_nvx_tools.py:21038	scripts/test_nvx_tools.py:21038
modified test	def RuntimeAdapterSuiteTests.test_the_adapter_s_readme_lists_its_scenarios in scripts/test_nvx_tools.py	scripts/test_nvx_tools.py:21051	scripts/test_nvx_tools.py:21090

Test data

Change	What	Before	After
modified file	tests/runtime-adapter/scenarios.txt	tests/runtime-adapter/scenarios.txt	tests/runtime-adapter/scenarios.txt

End-to-end tests

Change	What	Before	After
modified helper	def read_scenarios in scripts/nvx_tools/runtime_adapter_tests.py	scripts/nvx_tools/runtime_adapter_tests.py:79	scripts/nvx_tools/runtime_adapter_tests.py:80

Relocated unchanged: 0; added: 36. Compared the merge base cfdb452f29c8 with d6b70447d5d0.

[Copilot]

🟡 Changes recommended

Linux validation omits ownership and permission checks for manifest, RAM, and saved-state files in both Snapshot::open() and finish_capture(), allowing shared-permission files that violate the private-snapshot contract.

2 open issues

• Restore private-file checks for all snapshot artifacts on Linux · New
• Register the Linux-only restore exclusion test in runtime scenarios

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Real-VM ordering and controller-death guarantees need maintainer validation on the reviewed head because hardware evidence covers only a historical revision.

2 open issues

• Restore private-file checks for all snapshot artifacts on Linux
• Register the Linux-only restore exclusion test in runtime scenarios

_{Review effort: Balanced}