1 files changed, 122 insertions, 0 deletions
diff --git a/devices/src/irqchip/kvm/mod.rs b/devices/src/irqchip/kvm/mod.rs
new file mode 100644
index 0000000..56794a3
--- /dev/null
+++ b/devices/src/irqchip/kvm/mod.rs
@@ -0,0 +1,122 @@
+// 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.
+
+use hypervisor::kvm::{KvmVcpu, KvmVm};
+use hypervisor::IrqRoute;
+use std::sync::Arc;
+use sync::Mutex;
+use sys_util::{EventFd, Result};
+
+use crate::IrqChip;
+
+/// IrqChip implementation where the entire IrqChip is emulated by KVM.
+///
+/// This implementation will use the KVM API to create and configure the in-kernel irqchip.
+pub struct KvmKernelIrqChip {
+    _vm: KvmVm,
+    vcpus: Arc<Mutex<Vec<Option<KvmVcpu>>>>,
+}
+
+impl KvmKernelIrqChip {
+    /// Construct a new KvmKernelIrqchip.
+    pub fn new(vm: KvmVm, num_vcpus: usize) -> Result<KvmKernelIrqChip> {
+        Ok(KvmKernelIrqChip {
+            _vm: vm,
+            vcpus: Arc::new(Mutex::new((0..num_vcpus).map(|_| None).collect())),
+        })
+    }
+}
+
+/// This IrqChip only works with Kvm so we only implement it for KvmVcpu.
+impl IrqChip<KvmVcpu> for KvmKernelIrqChip {
+    /// Add a vcpu to the irq chip.
+    fn add_vcpu(&mut self, vcpu_id: usize, vcpu: KvmVcpu) -> Result<()> {
+        self.vcpus.lock().insert(vcpu_id, Some(vcpu));
+        Ok(())
+    }
+
+    /// 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<()> {
+        unimplemented!("register_irq_event for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// Unregister an event for a particular GSI.
+    fn unregister_irq_event(
+        &mut self,
+        _irq: u32,
+        _irq_event: &EventFd,
+        _resample_event: Option<&EventFd>,
+    ) -> Result<()> {
+        unimplemented!("unregister_irq_event for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// Route an IRQ line to an interrupt controller, or to a particular MSI vector.
+    fn route_irq(&mut self, _route: IrqRoute) -> Result<()> {
+        unimplemented!("route_irq for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// 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)>> {
+        unimplemented!("irq_event_tokens for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// 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<()> {
+        unimplemented!("service_irq for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// Broadcast an end of interrupt.
+    fn broadcast_eoi(&mut self, _vector: u8) -> Result<()> {
+        unimplemented!("broadcast_eoi for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// Return true if there is a pending interrupt for the specified vcpu.
+    fn interrupt_requested(&self, _vcpu_id: usize) -> bool {
+        unimplemented!("interrupt_requested for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// 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>> {
+        unimplemented!("get_external_interrupt for KvmKernelIrqChip is not yet implemented");
+    }
+
+    /// Attempt to clone this IrqChip instance.
+    fn try_clone(&self) -> Result<Self> {
+        unimplemented!("try_clone for KvmKernelIrqChip is not yet implemented");
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use hypervisor::kvm::{Kvm, KvmVm};
+    use sys_util::GuestMemory;
+
+    use crate::irqchip::{IrqChip, KvmKernelIrqChip};
+    #[cfg(any(target_arch = "arm", target_arch = "aarch64"))]
+    use hypervisor::VmAarch64;
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    use hypervisor::VmX86_64;
+
+    #[test]
+    fn create_kvm_kernel_irqchip() {
+        let kvm = Kvm::new().expect("failed to instantiate Kvm");
+        let mem = GuestMemory::new(&[]).unwrap();
+        let vm = KvmVm::new(&kvm, mem).expect("failed to instantiate vm");
+        let vcpu = vm.create_vcpu(0).expect("failed to instantiate vcpu");
+
+        let mut chip =
+            KvmKernelIrqChip::new(vm, 1).expect("failed to instantiate KvmKernelIrqChip");
+
+        chip.add_vcpu(0, vcpu).expect("failed to add vcpu");
+    }
+}