devices: port vhost-user-net from cloud-hypervisor

This is the cloud-hypervisor vhost-user-net code, modified just enough
to compile as part of crosvm.  There is currently no way to run crosvm
with a vhost-user-net device, and even if there were, it wouldn't work
without some further fixes.

1 files changed, 30 insertions, 0 deletions

diff --git a/vhost_rs/src/vsock.rs b/vhost_rs/src/vsock.rs
new file mode 100644
index 0000000..399b7a3
--- /dev/null
+++ b/vhost_rs/src/vsock.rs
@@ -0,0 +1,30 @@
+// Copyright (C) 2019 Alibaba Cloud Computing. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0 or BSD-3-Clause
+//
+// Portions Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Portions Copyright 2017 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE-BSD file.
+
+//! Trait to control vhost-vsock backend drivers.
+
+use crate::backend::VhostBackend;
+use crate::Result;
+
+/// Trait to control vhost-vsock backend drivers.
+pub trait VhostVsock: VhostBackend {
+    /// Set the CID for the guest.
+    /// This number is used for routing all data destined for running in the guest.
+    /// Each guest on a hypervisor must have an unique CID.
+    ///
+    /// # Arguments
+    /// * `cid` - CID to assign to the guest
+    fn set_guest_cid(&mut self, cid: u64) -> Result<()>;
+
+    /// Tell the VHOST driver to start performing data transfer.
+    fn start(&mut self) -> Result<()>;
+
+    /// Tell the VHOST driver to stop performing data transfer.
+    fn stop(&mut self) -> Result<()>;
+}