devices, vm-device: Move BusDevice and Bus into vm-device

This removes the dependency of the pci crate on the devices crate which
now only contains the device implementations themselves.

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

devices/src/lib.rs

@@ -25,12 +25,8 @@ extern crate vmm_sys_util;
 extern crate serde_derive;
 extern crate serde_json;
 
-use std::fs::File;
-use std::io;
-
 #[cfg(feature = "acpi")]
 mod acpi;
-mod bus;
 #[cfg(target_arch = "aarch64")]
 pub mod gic;
 pub mod interrupt_controller;
@@ -40,45 +36,6 @@ pub mod legacy;
 
 #[cfg(feature = "acpi")]
 pub use self::acpi::{AcpiGEDDevice, AcpiPMTimerDevice, AcpiShutdownDevice};
-pub use self::bus::{Bus, BusDevice, Error as BusError};
-
-pub type DeviceEventT = u16;
-
-/// The payload is used to handle events where the internal state of the VirtIO device
-/// needs to be changed.
-pub enum EpollHandlerPayload {
-    /// DrivePayload(disk_image)
-    DrivePayload(File),
-    /// Events that do not need a payload.
-    Empty,
-}
-
-type Result<T> = std::result::Result<T, Error>;
-
-pub trait EpollHandler: Send {
-    fn handle_event(
-        &mut self,
-        device_event: DeviceEventT,
-        event_flags: u32,
-        payload: EpollHandlerPayload,
-    ) -> Result<()>;
-}
-
-#[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),
-}
 
 bitflags! {
     pub struct HotPlugNotificationFlags: u8 {