BSD 3-Clause License

Copyright (c) 2026, The Open-IOV Project
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its
   contributors may be used to endorse or promote products derived from
   this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

---

Note on the license change
==========================

Open-IOV is distributed under the BSD 3-Clause License. This is a deliberate
choice for a project whose mission is *adversarial interoperability*: the
widest possible reuse, including in commercial products, is a feature, not an
accident. A permissive license lets hardware vendors, hypervisor vendors,
integrators and other open source projects adopt, ship and co-develop this
software without license friction, which is exactly how an independent,
durable IP block for GPU virtualization should spread.

Contributions are accepted under the same terms (inbound = outbound).

Mixed licensing: kernel modules are GPL-2.0
===========================================

The Linux kernel exports many of the interfaces this project depends on
(VFIO, mdev, IOMMU, workqueue and DMA internals) under `EXPORT_SYMBOL_GPL`.
To use those symbols legally, **kernel modules may be licensed GPL-2.0**.
The policy is therefore:

| Component | License | Why |
|---|---|---|
| `kernel/**` (e.g. `open-iov-vfio.ko`) | **GPL-2.0** (`MODULE_LICENSE("GPL v2")`) | Uses GPL-only kernel exports (VFIO/mdev/IOMMU). |
| `userspace/**`, `tools/**`, `scripts/**`, `config/**`, `docs/**` | **BSD-3-Clause** | No GPL-only interfaces; maximize reuse. |
| Third-party imports (vendor firmware, submodules, study material) | their own terms | Used for interoperability study; not relicensed. |

**Per-file SPDX identifiers always govern.** If a file carries
`SPDX-License-Identifier: GPL-2.0` it is GPL-2.0, even if it lives outside
`kernel/`. Otherwise the project default is BSD-3-Clause.

This split is intentional and stable: it gives the kernel side a clean legal
footing and keeps every reusable, vendor-facing, embeddable part of the
project permissive.

Third-party components
======================

* Vendor firmware images and third-party software referenced by this project
  are **not** covered by this license; they keep their own terms and are used
  for interoperability study. See `docs/09-reference/legal-and-licensing.md`.
* Linux kernel headers are used under their own license (GPL-2.0) and are not
  redistributed by this project.