ci: add kernel binary size checks by benhillis · Pull Request #3144 · microsoft/openvmm

benhillis · 2026-03-27T18:14:47Z

Add size regression checks for OpenHCL kernel binaries in the OSS CI pipeline, matching the pattern used for the usermode openvmm_hcl binary.

On post-merge CI, kernel baselines are published as artifacts. On PRs, the current kernel is compared against the baseline using xtask verify-size (50 KiB tolerance).

Kernel variants checked:

x64 Main kernel
x64 CVM kernel
aarch64 Main kernel

Copilot

Pull request overview

Adds OpenHCL kernel binary size regression checks to the OSS GitHub CI, mirroring the existing openvmm_hcl (usermode) size-check pattern by publishing merge baselines and comparing PR outputs against them via xtask verify-size.

Changes:

Introduces a new kernel baseline artifact publisher node (artifact_openhcl_kernel_sizecheck) and a CI job node to publish kernel baselines on post-merge CI.
Adds a PR job node to download the last-merge baseline artifact and run xtask verify-size for kernel variants (x64 main, x64 CVM, aarch64 main).
Wires the new baseline publishing + PR comparison jobs into the checkin_gates pipeline and regenerates openvmm-ci.yaml accordingly.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
flowey/flowey_lib_hvlite/src/lib.rs	Exposes the new kernel sizecheck artifact module.
flowey/flowey_lib_hvlite/src/artifact_openhcl_kernel_sizecheck.rs	New node to copy the resolved kernel binary into an artifact directory for publishing.
flowey/flowey_lib_hvlite/src/_jobs/mod.rs	Registers the new job nodes for kernel baseline publish + PR size verification.
flowey/flowey_lib_hvlite/src/_jobs/check_openhcl_kernel_size.rs	New PR job to fetch last-merge baseline artifact and run `xtask verify-size` against the currently resolved kernel.
flowey/flowey_lib_hvlite/src/_jobs/build_and_publish_openhcl_kernel_baseline.rs	New CI job to resolve the kernel binary and publish it as a baseline artifact.
flowey/flowey_hvlite/src/pipelines/checkin_gates.rs	Adds kernel baseline publishing (CI) and kernel verify-size jobs (PR) to the pipeline graph.
.github/workflows/openvmm-ci.yaml	Regenerated workflow to publish the new kernel baseline artifacts from CI jobs.

Copilot

Pull request overview

Copilot reviewed 7 out of 8 changed files in this pull request and generated 2 comments.

benhillis · 2026-03-30T22:47:41Z

Still looking at this, don't think I want one runner per kernel type.

Copilot

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 3 comments.

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Address review feedback on PR microsoft#3144: 1. Replace overly broad wildcard fallback with explicit match arms: - (Err, Err): both unparseable → raw file size comparison (e.g. aarch64 Image) - (Err, Ok) or (Ok, Err): mismatched formats → error with file path context 2. Fix integer division truncation in raw size comparison: - Use div_ceil when computing KiB differences for the threshold check - This prevents up to 1023 bytes from silently slipping through the 50 KiB tolerance Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Extend the existing openhcl binary size check infrastructure to also compare kernel binaries between PRs and the last successful main merge. Kernels checked per architecture: - x64: Main, CVM - aarch64: Main The kernel baselines are included in the existing per-arch openhcl-baseline artifact (alongside the usermode binary), and the comparisons run in the existing 'verify openhcl binary size' jobs. No new CI jobs, artifacts, or files are added.

Address review feedback on PR microsoft#3144: 1. Replace overly broad wildcard fallback with explicit match arms: - (Err, Err): both unparseable → raw file size comparison (e.g. aarch64 Image) - (Err, Ok) or (Ok, Err): mismatched formats → error with file path context 2. Fix integer division truncation in raw size comparison: - Use div_ceil when computing KiB differences for the threshold check - This prevents up to 1023 bytes from silently slipping through the 50 KiB tolerance Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 2 comments.

Address review feedback on PR microsoft#3144: 1. Replace overly broad wildcard fallback with explicit match arms: - (Err, Err): both unparseable → raw file size comparison (e.g. aarch64 Image) - (Err, Ok) or (Ok, Err): mismatched formats → error with file path context 2. Fix integer division truncation in raw size comparison: - Use div_ceil when computing KiB differences for the threshold check - This prevents up to 1023 bytes from silently slipping through the 50 KiB tolerance Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Address review feedback on PR microsoft#3144: 1. Replace overly broad wildcard fallback with explicit match arms: - (Err, Err): both unparseable → raw file size comparison (e.g. aarch64 Image) - (Err, Ok) or (Ok, Err): mismatched formats → error with file path context 2. Fix integer division truncation in raw size comparison: - Use div_ceil when computing KiB differences for the threshold check - This prevents up to 1023 bytes from silently slipping through the 50 KiB tolerance Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Address review feedback on PR microsoft#3144: 1. Replace overly broad wildcard fallback with explicit match arms: - (Err, Err): both unparseable → raw file size comparison (e.g. aarch64 Image) - (Err, Ok) or (Ok, Err): mismatched formats → error with file path context 2. Fix integer division truncation in raw size comparison: - Use div_ceil when computing KiB differences for the threshold check - This prevents up to 1023 bytes from silently slipping through the 50 KiB tolerance Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

benhillis requested a review from a team as a code owner March 27, 2026 18:14

Copilot AI review requested due to automatic review settings March 27, 2026 18:14

benhillis requested a review from a team as a code owner March 27, 2026 18:14

benhillis changed the title ~~ci: add kernel binary size checks to OSS CI~~ ci: add kernel binary size checks Mar 27, 2026

Copilot started reviewing on behalf of benhillis March 27, 2026 18:19 View session

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benhillis force-pushed the kernel_size_check branch 2 times, most recently from 5d5100d to 44a963e Compare March 30, 2026 22:40

Copilot AI review requested due to automatic review settings March 30, 2026 22:40

Copilot started reviewing on behalf of benhillis March 30, 2026 22:41 View session

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Comment thread flowey/flowey_lib_hvlite/src/_jobs/check_openhcl_kernel_size.rs Outdated

Comment thread flowey/flowey_lib_hvlite/src/_jobs/build_and_publish_openhcl_kernel_baseline.rs Outdated

benhillis force-pushed the kernel_size_check branch from 44a963e to 2386d79 Compare March 30, 2026 23:07

benhillis requested a review from Copilot March 30, 2026 23:08

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Comment thread flowey/flowey_lib_hvlite/src/artifact_openvmm_hcl_sizecheck.rs

Comment thread flowey/flowey_lib_hvlite/src/_jobs/check_openvmm_hcl_size.rs Outdated

Comment thread .github/workflows/openvmm-pr.yaml

benhillis force-pushed the kernel_size_check branch from 2386d79 to c125586 Compare March 30, 2026 23:43

benhillis added the CI Improvements or additions to our CI setup outside of flowey label Apr 6, 2026

Copilot AI review requested due to automatic review settings April 7, 2026 21:26

benhillis force-pushed the kernel_size_check branch from c125586 to ecbe39c Compare April 7, 2026 21:26

Copilot started reviewing on behalf of benhillis April 7, 2026 21:27 View session

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Comment thread xtask/src/tasks/verify_size.rs Outdated

Comment thread xtask/src/tasks/verify_size.rs Outdated

Copilot AI review requested due to automatic review settings April 20, 2026 17:18

benhillis force-pushed the kernel_size_check branch from 4c80c97 to 5f88248 Compare April 20, 2026 17:18

Copilot started reviewing on behalf of benhillis April 20, 2026 17:19 View session

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Comment thread xtask/src/tasks/verify_size.rs Outdated

Comment thread flowey/flowey_lib_hvlite/src/artifact_openvmm_hcl_sizecheck.rs Outdated

benhillis force-pushed the kernel_size_check branch from 5f88248 to daf6193 Compare April 20, 2026 17:31

benhillis requested a review from Copilot April 20, 2026 17:36

Copilot started reviewing on behalf of benhillis April 20, 2026 17:37 View session

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Comment thread xtask/src/tasks/verify_size.rs

Comment thread flowey/flowey_lib_hvlite/src/artifact_openvmm_hcl_sizecheck.rs

Comment thread flowey/flowey_lib_hvlite/src/_jobs/check_openvmm_hcl_size.rs

benhillis force-pushed the kernel_size_check branch from daf6193 to 62ff083 Compare April 20, 2026 17:59

benhillis requested a review from Copilot April 20, 2026 18:24

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Comment thread xtask/src/tasks/verify_size.rs Outdated

Comment thread xtask/src/tasks/verify_size.rs Outdated

Comment thread xtask/src/tasks/verify_size.rs

benhillis force-pushed the kernel_size_check branch from 62ff083 to 7abd4f4 Compare April 20, 2026 19:49

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benhillis commented Mar 27, 2026

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