# Contributing to Cloud Hypervisor

Cloud Hypervisor is an open source project licensed under the [Apache v2 License](https://opensource.org/licenses/Apache-2.0) and the [BSD 3 Clause](https://opensource.org/licenses/BSD-3-Clause) license.

## Coding Style

We follow the [Rust Style](https://github.com/rust-dev-tools/fmt-rfcs/blob/master/guide/guide.md)
convention and enforce it through the Continuous Integration (CI) process calling into `rustfmt`
for each submitted Pull Request (PR).

## Certificate of Origin

In order to get a clear contribution chain of trust we use the [signed-off-by language](https://01.org/community/signed-process)
used by the Linux kernel project.

## Patch format

Beside the signed-off-by footer, we expect each patch to comply with the following format:

```
<component>: Change summary

More detailed explanation of your changes: Why and how.
Wrap it to 72 characters.
See http://chris.beams.io/posts/git-commit/
for some more good pieces of advice.

Signed-off-by: <contributor@foo.com>
```

For example:

```
vm-virtio: Reset underlying device on driver request
    
If the driver triggers a reset by writing zero into the status register
then reset the underlying device if supported. A device reset also
requires resetting various aspects of the queue.
    
In order to be able to do a subsequent reactivate it is required to
reclaim certain resources (interrupt and queue EventFDs.) If a device
reset is requested by the driver but the underlying device does not
support it then generate an error as the driver would not be able to
configure it anyway.
    
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
```

## Pull requests

Cloud Hypervisor uses the “fork-and-pull” development model. Follow these steps if
you want to merge your changes to `cloud-hypervisor`:

1. Fork the [cloud-hypervisor](https://github.com/cloud-hypervisor/cloud-hypervisor) project
   into your github organization.
2. Within your fork, create a branch for your contribution.
3. [Create a pull request](https://help.github.com/articles/creating-a-pull-request-from-a-fork/)
   against the master branch of the Cloud Hypervisor repository.
4. Add reviewers to your pull request and then work with your reviewers to address
   any comments and obtain minimum of 2 [maintainers](MAINTAINERS.md) approvals.
   To update your pull request amend existing commits whenever applicable and
   then push the new changes to your pull request branch.
5. Once the pull request is approved, one of the maintainers will merge it.

## Issue tracking

If you have a problem, please let us know. We recommend using
[github issues](https://github.com/cloud-hypervisor/cloud-hypervisor/issues/new) for formally
reporting and documenting them.

To quickly and informally bring something up to us, you can also reach out on [Slack](https://cloud-hypervisor.slack.com).

## Closing issues

You can either close issues manually by adding the fixing commit SHA1 to the issue
comments or by adding the `Fixes` keyword to your commit message:

```
serial: Set terminal in raw mode
    
In order to have proper output from the serial, we need to setup the
terminal in raw mode. When the VM is shutting down, it is also the
VMM responsibility to set the terminal back into canonical mode if we
don't want to get any weird behavior from the shell.
    
Fixes #88
	
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
```

Then, after the correspoding PR is merged, Github will automatically close that issue when parsing the
[commit message](https://help.github.com/articles/closing-issues-via-commit-messages/).