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diff --git a/devices/src/irqchip/mod.rs b/devices/src/irqchip/mod.rs
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+// Copyright 2020 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 file.
+
+mod kvm;
+pub use self::kvm::KvmKernelIrqChip;
+
+use std::marker::{Send, Sized};
+
+use hypervisor::{IrqRoute, Vcpu};
+use sys_util::{EventFd, Result};
+
+/// Trait that abstracts interactions with interrupt controllers.
+///
+/// Each VM will have one IrqChip instance which is responsible for routing IRQ lines and
+/// registering IRQ events. Depending on the implementation, the IrqChip may interact with an
+/// underlying hypervisor API or emulate devices in userspace.
+///
+/// This trait is generic over a Vcpu type because some IrqChip implementations can support
+/// multiple hypervisors with a single implementation.
+pub trait IrqChip<V: Vcpu>: Send + Sized {
+    /// Add a vcpu to the irq chip.
+    fn add_vcpu(&mut self, vcpu_id: usize, vcpu: V) -> Result<()>;
+
+    /// Register an event that can trigger an interrupt for a particular GSI.
+    fn register_irq_event(
+        &mut self,
+        irq: u32,
+        irq_event: &EventFd,
+        resample_event: Option<&EventFd>,
+    ) -> Result<()>;
+
+    /// Unregister an event for a particular GSI.
+    fn unregister_irq_event(
+        &mut self,
+        irq: u32,
+        irq_event: &EventFd,
+        resample_event: Option<&EventFd>,
+    ) -> Result<()>;
+
+    /// Route an IRQ line to an interrupt controller, or to a particular MSI vector.
+    fn route_irq(&mut self, route: IrqRoute) -> Result<()>;
+
+    /// Return a vector of all registered irq numbers and their associated events.  To be used by
+    /// the main thread to wait for irq events to be triggered.
+    fn irq_event_tokens(&self) -> Result<Vec<(u32, EventFd)>>;
+
+    /// Either assert or deassert an IRQ line.  Sends to either an interrupt controller, or does
+    /// a send_msi if the irq is associated with an MSI.
+    fn service_irq(&mut self, irq: u32, level: bool) -> Result<()>;
+
+    /// Broadcast an end of interrupt.
+    fn broadcast_eoi(&mut self, vector: u8) -> Result<()>;
+
+    /// Return true if there is a pending interrupt for the specified vcpu.
+    fn interrupt_requested(&self, vcpu_id: usize) -> bool;
+
+    /// Check if the specified vcpu has any pending interrupts. Returns None for no interrupts,
+    /// otherwise Some(u32) should be the injected interrupt vector.
+    fn get_external_interrupt(&mut self, vcpu_id: usize) -> Result<Option<u32>>;
+
+    /// Attempt to clone this IrqChip instance.
+    fn try_clone(&self) -> Result<Self>;
+}