guide: document standalone OpenVMM releases

Guide/src/SUMMARY.md

@@ -61,7 +61,8 @@
   - [Coding Conventions](./dev_guide/contrib/code.md)
   - [Save State](./dev_guide/contrib/save-state.md)
   - [Snapshot Format](./dev_guide/snapshot_format.md)
-  - [Releases & Code Flow](./dev_guide/contrib/release.md)
+  - [OpenVMM Release Model and Support](./dev_guide/contrib/openvmm_release.md)
+  - [OpenHCL Release Management](./dev_guide/contrib/release.md)
   - [Submitting Changes](./dev_guide/contrib/pr.md)
   - [Code Review Process](./dev_guide/contrib/code_review.md)
   - [Guide Updates](./dev_guide/contrib/guide.md)

Guide/src/dev_guide/contrib/openvmm_release.md

@@ -0,0 +1,329 @@
+# OpenVMM Release Model and Support
+
+This page describes standalone OpenVMM releases, support policy, source-build
+identity, and the maintainer release runbook. OpenVMM versions are independent
+from OpenHCL servicing versions.
+
+## One repository, two products
+
+OpenVMM and OpenHCL share a repository and substantial code, but they are
+separate products with different release and support policies.
+
+| Product | Release and support model |
+| --- | --- |
+| OpenVMM | Cross-platform Virtual Machine Monitor. Continuous development on `main`, with standalone releases identified by OpenVMM-specific tags. |
+| OpenHCL | Paravisor built on OpenVMM. Releases and in-market servicing use selected long-lived release branches. |
+
+```admonish note title="See also"
+[OpenHCL Release Management](./release.md) describes the OpenHCL release
+branch and backport process.
+```
+
+## Pre-1.0 cadence and support
+
+Before `1.0`, maintainers target approximately one OpenVMM release per month
+from a healthy `main` commit. A release may be delayed or skipped when the
+candidate does not meet the quality bar. Calendar months are not encoded into
+the product version.
+
+Normal releases advance the minor version:
+
+```text
+0.1.0
+0.2.0
+0.3.0
+```
+
+Patch releases advance the patch version:
+
+```text
+0.2.1
+0.2.2
+```
+
+Only the newest OpenVMM release is supported initially. A supported release
+receives a patch only for a security issue or release-blocking regression.
+Once a newer normal release ships, the previous line leaves normal support.
+
+Before `1.0`, normal minor releases may make breaking changes to APIs,
+command-line behavior, device models, snapshot formats, and other interfaces.
+Breaking changes should be intentional and documented in the release notes,
+with migration guidance when practical. Patch releases correct the currently
+supported minor line and should not intentionally introduce breaking changes.
+
+## Release tags
+
+Git tags are the only source of public OpenVMM semantic versions. There is no
+checked-in OpenVMM product-version file.
+
+Release tags use:
+
+```text
+openvmm-vMAJOR.MINOR.PATCH
+```
+
+Examples:
+
+```text
+openvmm-v0.1.0
+openvmm-v0.1.1
+openvmm-v0.2.0
+```
+
+Tags must contain exactly three canonical unsigned numeric components.
+Prerelease suffixes, build metadata, leading zeroes, and additional components
+are rejected.
+
+Normal `MAJOR.MINOR.0` tags must point to commits reachable from `main`. A
+patch tag must descend from its immediate predecessor. For example,
+`openvmm-v0.2.2` must descend from `openvmm-v0.2.1`.
+
+More than one `openvmm-v*` tag on the same commit is an error. After Git checks
+out a tagged commit, the source identity cannot determine which of several tags
+the caller intended. Selecting the highest version could therefore make a
+checkout of an older tag report a newer version. Each release commit must have
+exactly one OpenVMM release tag. Pushed release tags are immutable.
+
+## Build identity
+
+```admonish note
+The source-identity versioning described here is under development. It is the
+intended model, not current behavior: today `openvmm --version` reports the
+Cargo package version. Treat this section as planned until the implementation
+lands.
+```
+
+OpenVMM resolves its displayed version from source identity:
+
+| Source state | Displayed version |
+| --- | --- |
+| Clean exact `openvmm-v0.2.0` tag | `0.2.0` |
+| Dirty exact tag | `0.2.0+dirty` |
+| Clean untagged Git checkout | `0.0.0-dev+g012345678` |
+| Dirty untagged Git checkout | `0.0.0-dev+g012345678.dirty` |
+| No usable Git or generated release metadata | `0.0.0-dev` |
+
+The `g` prefix follows the `git describe` convention and identifies the
+following nine characters as an abbreviated Git commit ID. It is not part of
+the commit ID.
+
+More than one OpenVMM release tag on `HEAD` fails the build rather than
+selecting an arbitrary version.
+
+`openvmm --version` prints the concise displayed version. The full source
+revision remains available as separate embedded build information.
+
+A copied or exported source tree may contain neither Git metadata nor generated
+release metadata. Examples include GitHub's automatic source archives and
+metadata-free vendored source trees. Such a build warns that `0.0.0-dev` is not
+an official release identity. The official OpenVMM source archive described
+below instead includes generated release metadata and retains the exact release
+identity without Git.
+
+Windows numeric version resources use `MAJOR.MINOR.PATCH.0` for an official
+release and `0.0.0.0` for a development build.
+
+### Independent version spaces
+
+The OpenVMM product version is independent from:
+
+- internal Cargo crate versions;
+- OpenHCL release and servicing versions;
+- distribution package versions;
+- CI build counters;
+- source revision identifiers.
+
+Build and distribution systems may record package versions, build IDs, and
+source revisions as additional metadata. They must not present those values as
+the OpenVMM product version.
+
+## Release assets
+
+The initial release contains nine archives plus a separate `SHA256SUMS`
+checksum file:
+
+- `openvmm-<VERSION>-windows-x64.zip`;
+- `openvmm-<VERSION>-windows-x64-symbols.zip`;
+- `openvmm-<VERSION>-windows-arm64.zip`;
+- `openvmm-<VERSION>-windows-arm64-symbols.zip`;
+- `openvmm-<VERSION>-linux-x64-musl.tar.gz`;
+- `openvmm-<VERSION>-linux-x64-musl-symbols.tar.gz`;
+- `openvmm-<VERSION>-linux-arm64-musl.tar.gz`;
+- `openvmm-<VERSION>-linux-arm64-musl-symbols.tar.gz`;
+- `openvmm-<VERSION>-source.tar.gz`;
+- `SHA256SUMS`.
+
+Runtime archives contain the runnable binary and `LICENSE`. Symbol archives
+contain the matching debug symbols and `LICENSE`. Linux runtime binaries retain
+executable permissions.
+
+`SHA256SUMS` covers all nine archives. Every archive and `SHA256SUMS` receives a
+public GitHub build provenance attestation before the release is published.
+
+```admonish warning title="Windows signing is not implemented"
+The public release workflow does not Authenticode-sign Windows artifacts. Do
+not describe downloaded Windows executables as signed.
+```
+
+## Building a release from source
+
+A real Git checkout with the exact release tag available derives its version
+directly from Git:
+
+```bash
+git clone https://github.com/microsoft/openvmm.git
+cd openvmm
+git checkout openvmm-v0.2.0
+```
+
+Once the release automation lands, each release will also publish an official
+attested source archive. The archive will contain `.openvmm-release.json` at
+its root, recording the metadata schema, release version, release tag, and full
+source revision. Builds from this archive retain the exact release identity
+without a `.git` directory.
+
+```admonish warning title="Use the official source archive"
+GitHub's automatic "Source code (zip)" and "Source code (tar.gz)" links omit Git
+metadata and do not preserve the OpenVMM release identity. They are convenience
+snapshots, not supported version-preserving build inputs. Use a real checkout of
+the release tag or `openvmm-<VERSION>-source.tar.gz`.
+```
+
+## Normal release runbook
+
+```admonish note
+The tag-triggered release automation described below is under development. Do
+not create a public OpenVMM release tag until that implementation has landed.
+```
+
+Tag creation is the release decision. A successful workflow publishes
+automatically after building, packaging, checksumming, and attesting every
+asset. There is no separate manual approval or draft-review phase.
+
+### 1. Select the release
+
+Choose a healthy commit already on `main`. Confirm that:
+
+- required changes are merged;
+- required CI checks pass;
+- the next normal version follows the release sequence;
+- the version has not already been released;
+- the commit is suitable for public release.
+
+Do not create the tag while required changes or checks are outstanding.
+
+### 2. Create and push the tag
+
+Update local `main`, confirm the working tree is clean, and create an annotated
+tag. For example:
+
+```bash
+git switch main
+git pull --ff-only
+git status --short
+version="0.2.0"
+tag="openvmm-v${version}"
+git tag -a "${tag}" -m "OpenVMM ${version}"
+git push origin "${tag}"
+```
+
+Do not move, delete, or recreate a pushed release tag.
+
+### 3. Monitor automatic publication
+
+The tag starts the OpenVMM release workflow. The workflow:
+
+1. validates the tag and commit topology;
+2. builds Windows x64, Windows ARM64, Linux musl x64, and Linux musl ARM64;
+3. creates separate runtime and symbol archives;
+4. creates the official source archive;
+5. creates `SHA256SUMS`;
+6. attests every archive and the checksum file;
+7. publishes a non-draft GitHub Release with generated notes.
+
+If a build, packaging, checksum, or attestation step fails, no public release
+is created. The same immutable tag may be rerun after a pipeline or
+infrastructure failure when no release was published.
+
+If a public release already exists, the workflow refuses to replace its assets.
+Correct a bad published release with a new version rather than mutating it.
+
+### 4. Confirm the release
+
+After the workflow succeeds, confirm that:
+
+- the release page points to the intended tag and revision;
+- all four targets have separate runtime and symbol archives;
+- the official source archive is present;
+- every runtime and symbol archive contains `LICENSE`;
+- `SHA256SUMS` covers all nine archives;
+- every archive and `SHA256SUMS` has a provenance attestation;
+- generated notes cover the intended pull requests;
+- Windows assets are not described as signed;
+- the release is presented as the newest supported OpenVMM release.
+
+After downloading all assets into one directory, verify the checksums:
+
+```bash
+sha256sum -c SHA256SUMS
+```
+
+Verify an asset's provenance with the GitHub CLI:
+
+```bash
+gh attestation verify path/to/<ASSET> --repo microsoft/openvmm
+```
+
+Smoke-test runnable archives on compatible hosts where practical. At minimum,
+confirm that the executable starts and reports the expected version.
+
+## Patch release runbook
+
+OpenVMM does not create a release branch for every normal release. Create a
+patch branch only when the currently supported release requires a security or
+release-blocking fix.
+
+1. Implement and merge the fix into `main`.
+2. Create a temporary patch branch from the currently supported release tag.
+3. Cherry-pick the fix onto that branch.
+4. Validate the branch and the affected release artifacts.
+5. Tag the corrected commit with the next patch version.
+6. Push the tag and monitor the normal automatic release workflow.
+
+For example:
+
+```bash
+git switch main
+git pull --ff-only
+git switch -c patch/openvmm-0.2.x openvmm-v0.2.0
+git cherry-pick <FIX_COMMIT>
+git tag -a openvmm-v0.2.1 -m "OpenVMM 0.2.1"
+git push origin openvmm-v0.2.1
+```
+
+Further patches must branch from or include their immediate predecessor. For
+example, `openvmm-v0.2.2` must descend from `openvmm-v0.2.1`.
+
+The patch branch is not a new general development branch. New work continues
+on `main`, and the older line leaves support when the next normal release
+ships.
+
+## How fixes flow
+
+Shared fixes always land in `main` first.
+
+For OpenHCL, maintainers cherry-pick a fix to each live OpenHCL release branch
+that requires it.
+
+For OpenVMM, the fix ships in the next normal release unless the currently
+supported release qualifies for an on-demand patch.
+
+## Future policy
+
+The project may later designate selected releases for longer support, but no
+LTS policy exists yet. Before supporting multiple OpenVMM lines or publishing
+`1.0.0`, maintainers must document the compatibility, deprecation,
+support-window, and servicing commitments.
+
+Public nightly releases are deferred until a concrete consumer requires them.
+Ordinary CI artifacts remain available for engineering use.