Replace PVH with ACPI-free Linux direct boot - #106
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Pedro Henrique Penna (ppenna) wants to merge 3 commits into
Open
Pedro Henrique Penna (ppenna) wants to merge 3 commits into
Pedro Henrique Penna (ppenna) wants to merge 3 commits into
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Complete the NVX side of the PVH replacement and pin the matching OpenVMM implementation. - disable CONFIG_PVH while retaining MP parsing, local APIC, IOAPIC, and virtio-mmio prerequisites - replace Xen entry-note checks with the Linux MP-table boot contract - pass the NVX ACPI-free kernel and initramfs into focused OpenVMM hardware tests so 1, 2, 4, and 8-vCPU coverage uses an MP-capable guest - build OpenVMM with the fat-LTO single-codegen-unit microvm-release profile and stage stripped Linux binaries with separate debug information - emit the readiness marker before diagnostic banner bytes to reduce timed port-I/O exits after all guest initialization work is complete - update runtime, benchmark, release, CI, and validation terminology - document the Linux direct boot layout, snapshot contract, build flow, and measured acceptance criteria Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Pedro Henrique Penna (ppenna)
September 18, 2026 05:04
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Copilot review overview
🟡 Changes recommended
OpenVMM CI jobs do not fetch the newly required NVX guest artifacts and will fail before tests run.
Get a fresh assessment by requesting another Copilot review.
Review effort: Balanced
Findings: 1
Open (8)
What changed in this PR
Replaces PVH boot with ACPI-free Linux direct boot using Intel MP tables and aligns NVX tooling, tests, kernel configuration, and documentation.
Changes:
- Pins the OpenVMM direct-boot implementation and disables kernel PVH support.
- Adds optimized runtime staging and uses NVX guest artifacts in OpenVMM tests.
- Updates readiness output, snapshot terminology, and design documentation.
| File | Description |
|---|---|
alpine/init |
Emits readiness before diagnostics. |
doc/build.md |
Documents optimized builds and debug artifacts. |
doc/ci.md |
Updates CI test-layer documentation. |
doc/design/code-ownership-map.md |
Revises loader and test ownership. |
doc/design/cold-boot.md |
Documents direct MP-table boot. |
doc/design/configuration-boundary.md |
Defines the new boot layout. |
doc/design/current-limits.md |
Updates snapshot limitations. |
doc/design/goals.md |
Revises platform goals and ABI terminology. |
doc/design/integrated-implementation-status.md |
Records direct-boot implementation status. |
doc/design/machine-and-device-abi.md |
Updates machine-contract diagrams. |
doc/design/sandbox-filesystem-and-agent-architecture.md |
Replaces PVH terminology. |
doc/design/snapshot-and-restore.md |
Updates memory-map and boot wording. |
doc/design/validation.md |
Documents NVX-backed OpenVMM tests. |
doc/direct-boot-plan.md |
Adds the migration plan and acceptance criteria. |
doc/run.md |
Updates runtime and compatibility guidance. |
kernel/config-microvm |
Disables CONFIG_PVH. |
openvmm |
Pins the direct-boot OpenVMM revision. |
scripts/nvx.py |
Builds and stages optimized OpenVMM binaries. |
scripts/nvx_tools/benchmark.py |
Renames kernel artifact descriptions. |
scripts/nvx_tools/build.py |
Validates direct-boot kernel prerequisites. |
scripts/nvx_tools/ci.py |
Supplies NVX artifacts to OpenVMM tests. |
scripts/nvx_tools/microvm_tests.py |
Updates kernel terminology. |
scripts/nvx_tools/release.py |
Verifies direct-boot kernel settings. |
scripts/nvx_tools/sandbox_lifecycle.py |
Updates kernel terminology. |
scripts/test_nvx_tools.py |
Updates build and CI unit tests. |
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| kernel = require_file( | ||
| artifact_path("vmlinux"), | ||
| "microVM Linux direct kernel", | ||
| ) | ||
| initrd = require_file( |
| _native_initramfs() | ||
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| def _install_openvmm_release(source: Path) -> None: |
| ) | ||
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| def _assert_direct_boot_kernel_config(path: Path) -> None: |
| build/initramfs.cpio.gz | ||
| build/initramfs.cpio.gz.packages.json | ||
| openvmm/target/release/openvmm[.exe] | ||
| openvmm/target/release/openvmm.dbg # Linux only |
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| can execute concurrently. `openvmm-tests` uses OpenVMM's Linux-direct kernel | ||
| and initrd artifacts and exercises Linux MP-table lifecycle, TTRPC, and snapshot | ||
| contracts without restoring NVX guest artifacts. `nvx-microvm-tests` consumes | ||
| the NVX Linux kernel and Alpine initramfs and exercises Linux, SMP, virtio, |
| | Workload namespace and root construction | [`alpine/nvx-container-launch`](../../alpine/nvx-container-launch) and [`alpine/nvx-container-enter`](../../alpine/nvx-container-enter) | | ||
| | Guest workload, scratch quiesce, and post-restore CPU/RAM repair | [`alpine/nvx-snapshot`](../../alpine/nvx-snapshot) and [`alpine/nvx-init-agent`](../../alpine/nvx-init-agent) | | ||
| | Self-contained OpenVMM control-plane tests | [`guest_test_pvh`](../../openvmm/guest_test_pvh), [`vmm_tests/tests/tests/x86_64/microvm.rs`](../../openvmm/vmm_tests/vmm_tests/tests/tests/x86_64/microvm.rs), and [`vmm_tests/tests/tests/ttrpc.rs`](../../openvmm/vmm_tests/vmm_tests/tests/tests/ttrpc.rs) | | ||
| | Self-contained OpenVMM control-plane tests | [`vmm_tests/tests/tests/x86_64/microvm.rs`](../../openvmm/vmm_tests/vmm_tests/tests/tests/x86_64/microvm.rs) and [`vmm_tests/tests/tests/ttrpc.rs`](../../openvmm/vmm_tests/vmm_tests/tests/tests/ttrpc.rs) | |
| - exposing no ACPI or SMBIOS data; | ||
| - using Intel MP 1.4 tables for processor and IOAPIC discovery; | ||
| - retaining fixed command-line virtio-mmio discovery and the allowlisted | ||
| microVM device model; and |
| ## 2. Extract shared MP-table construction | ||
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| Move MP-table construction from | ||
| [`vm/loader/src/pvh.rs`](../openvmm/vm/loader/src/pvh.rs) into a protocol-neutral |
Pedro Henrique Penna (ppenna)
marked this pull request as ready for review
September 18, 2026 13:10
Make OpenVMM hardware-test jobs depend on and download the shared NVX kernel and initramfs, add regression coverage for the workflow contract, and pin the clippy-clean OpenVMM head. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot started reviewing on behalf of
Pedro Henrique Penna (ppenna)
September 18, 2026 14:25
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Copilot review overview
🟡 Changes recommended
The MSHV release path still bypasses the new optimized profile and stripped-binary staging.
Get a fresh assessment by requesting another Copilot review.
Review effort: Balanced
Findings: 1
Open (11)
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| "build", | ||
| "--profile", | ||
| OPENVMM_MICROVM_RELEASE_PROFILE, |
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| `build-openvmm` uses the `microvm-release` profile: fat LTO with one codegen | ||
| unit. Linux builds retain separate debug information in `openvmm.dbg` and | ||
| stage a stripped runtime binary. Windows builds stage the linker-produced | ||
| executable and PDB. |
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| all later command-line mutation and extraction sites that currently match only | ||
| - every microVM configuration requires `LoadMode::Linux` with `MpTable`; | ||
| - `LoadMode::Pvh` is removed from the configuration enum; | ||
| - the microVM command-line validator reads the `LoadMode::Linux` command line; | ||
| wire field is required when Linux-direct replaces PVH as the default. Update |
Resolve the CI workflow conflict by retaining the shared guest-artifact handoff, align artifact downloads with v8, and make Windows curl retries effective through CURL_HOME configuration. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot started reviewing on behalf of
Pedro Henrique Penna (ppenna)
September 18, 2026 14:29
View session
Contributor
There was a problem hiding this comment.
Copilot review overview
🟡 Changes recommended
The musl runtime bypasses the optimized staging path, and focused OpenVMM testing no longer exercises snapshot restore.
Get a fresh assessment by requesting another Copilot review.
Review effort: Balanced
Findings: 1
Open (12)
| OPENVMM_MICROVM_TEST_FILTER = ( | ||
| "test(openvmm_microvm_test_pvh_x64_phase_1_lifecycle) + " | ||
| "test(test_ttrpc_microvm_pvh_snapshot)" | ||
| "test(test_ttrpc_microvm_linux_direct_lifecycle_and_snapshot)" |
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Dependency
Depends on nanvix/openvmm#80.
Summary
CONFIG_PVHand validate MP parsing, APIC/IOAPIC, and virtio-mmio kernel prerequisitesmicrovm-releaseprofilenr_cpus=<capacity>for fresh boots while retaining version-3 snapshot compatibilityHardware validation
Bare-metal hosts:
prometheus32prometheus30prometheus28Passed on all three backends:
nvx.py test-microvmscenario setPerformance acceptance
Each path used one warmup. KVM/WHP retained 30 interleaved samples per vCPU count; MSHV retained 60.
All cold-start and peak-RSS gates pass without widening thresholds.
Local validation
cargo xtask fmt --fixpass