vm-virtio, virtio-devices: Split device implementation from virt queues

Split the generic virtio code (queues and device type) from the
VirtioDevice trait, transport and device implementations.

This also simplifies the feature handling in vhost_user_backend as the
vm-virtio crate is no longer has any features.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

virtio-devices/src/lib.rs

@@ -0,0 +1,123 @@
+// 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-3-Clause file.
+//
+// Copyright © 2019 Intel Corporation
+//
+// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
+
+//! Implements virtio devices, queues, and transport mechanisms.
+
+extern crate arc_swap;
+extern crate epoll;
+#[macro_use]
+extern crate log;
+#[cfg(feature = "pci_support")]
+extern crate pci;
+extern crate serde;
+#[macro_use]
+extern crate serde_derive;
+extern crate serde_json;
+extern crate vhost_rs;
+extern crate virtio_bindings;
+extern crate vm_device;
+extern crate vm_memory;
+
+use std::io;
+
+#[macro_use]
+mod device;
+pub mod block;
+mod console;
+mod iommu;
+pub mod mem;
+pub mod net;
+pub mod net_util;
+mod pmem;
+mod rng;
+pub mod transport;
+pub mod vhost_user;
+pub mod vsock;
+
+pub use self::block::*;
+pub use self::console::*;
+pub use self::device::*;
+pub use self::iommu::*;
+pub use self::mem::*;
+pub use self::net::*;
+pub use self::net_util::*;
+pub use self::pmem::*;
+pub use self::rng::*;
+pub use self::vsock::*;
+use vm_virtio::{queue::*, VirtioDeviceType};
+
+const DEVICE_INIT: u32 = 0x00;
+const DEVICE_ACKNOWLEDGE: u32 = 0x01;
+const DEVICE_DRIVER: u32 = 0x02;
+const DEVICE_DRIVER_OK: u32 = 0x04;
+const DEVICE_FEATURES_OK: u32 = 0x08;
+const DEVICE_FAILED: u32 = 0x80;
+
+const VIRTIO_F_VERSION_1: u32 = 32;
+const VIRTIO_F_IOMMU_PLATFORM: u32 = 33;
+const VIRTIO_F_IN_ORDER: u32 = 35;
+
+#[allow(dead_code)]
+const INTERRUPT_STATUS_USED_RING: u32 = 0x1;
+#[allow(dead_code)]
+const INTERRUPT_STATUS_CONFIG_CHANGED: u32 = 0x2;
+#[cfg(feature = "pci_support")]
+const VIRTIO_MSI_NO_VECTOR: u16 = 0xffff;
+
+#[derive(Debug)]
+pub enum ActivateError {
+    EpollCtl(std::io::Error),
+    BadActivate,
+    /// Queue number is not correct
+    BadQueueNum,
+    /// Failed to clone Kill event
+    CloneKillEventFd,
+    /// Failed to create Vhost-user interrupt eventfd
+    VhostIrqCreate,
+    /// Failed to setup vhost-user daemon.
+    VhostUserSetup(vhost_user::Error),
+    /// Failed to setup vhost-user daemon.
+    VhostUserNetSetup(vhost_user::Error),
+    /// Failed to setup vhost-user daemon.
+    VhostUserBlkSetup(vhost_user::Error),
+    /// Failed to reset vhost-user daemon.
+    VhostUserReset(vhost_user::Error),
+}
+
+pub type ActivateResult = std::result::Result<(), ActivateError>;
+
+pub type DeviceEventT = u16;
+
+#[derive(Debug)]
+pub enum Error {
+    FailedReadingQueue {
+        event_type: &'static str,
+        underlying: io::Error,
+    },
+    FailedReadTap,
+    FailedSignalingUsedQueue(io::Error),
+    PayloadExpected,
+    UnknownEvent {
+        device: &'static str,
+        event: DeviceEventT,
+    },
+    IoError(io::Error),
+    RegisterListener(io::Error),
+    UnregisterListener(io::Error),
+    EpollCreateFd(io::Error),
+    EpollCtl(io::Error),
+    EpollWait(io::Error),
+    FailedSignalingDriver(io::Error),
+    VhostUserUpdateMemory(vhost_user::Error),
+    EventfdError(io::Error),
+    SetShmRegionsNotSupported,
+    EpollHander(String),
+    NoMemoryConfigured,
+}