hypervisor: arch: Introduce riscv64 AIA

Introduce definitions, traits relate to RISC-V AIA (Advanced Interrupt
Architecutre) construction.

Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>

hypervisor/src/arch/riscv64/aia.rs

@@ -0,0 +1,65 @@
+// Copyright © 2024 Institute of Software, CAS. All rights reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+
+use std::any::Any;
+use std::result;
+
+use thiserror::Error;
+
+use crate::{AiaState, HypervisorDeviceError, HypervisorVmError};
+
+/// Errors thrown while setting up the VAIA.
+#[derive(Debug, Error)]
+pub enum Error {
+    /// Error while calling KVM ioctl for setting up the global interrupt controller.
+    #[error("Failed creating AIA device: {0}")]
+    CreateAia(HypervisorVmError),
+    /// Error while setting device attributes for the AIA.
+    #[error("Failed setting device attributes for the AIA: {0}")]
+    SetDeviceAttribute(HypervisorDeviceError),
+    /// Error while getting device attributes for the AIA.
+    #[error("Failed getting device attributes for the AIA: {0}")]
+    GetDeviceAttribute(HypervisorDeviceError),
+}
+pub type Result<T> = result::Result<T, Error>;
+
+#[derive(Debug)]
+pub struct VaiaConfig {
+    pub vcpu_count: u64,
+    pub aplic_addr: u64,
+    pub aplic_size: u64,
+    pub imsic_addr: u64,
+    pub imsic_size: u64,
+    pub nr_irqs: u32,
+}
+
+/// Hypervisor agnostic interface for a virtualized AIA
+pub trait Vaia: Send + Sync {
+    /// Returns the compatibility property of APLIC
+    fn aplic_compatibility(&self) -> &str;
+
+    /// Returns an array with APLIC device properties
+    fn aplic_properties(&self) -> [u64; 4];
+
+    /// Returns the compatibility property of IMSIC
+    fn imsic_compatibility(&self) -> &str;
+
+    /// Returns an array with IMSIC device properties
+    fn imsic_properties(&self) -> [u64; 4];
+
+    /// Returns the number of vCPUs this AIA handles
+    fn vcpu_count(&self) -> u64;
+
+    /// Returns whether the AIA device is MSI compatible or not
+    fn msi_compatible(&self) -> bool;
+
+    /// Downcast the trait object to its concrete type.
+    fn as_any_concrete_mut(&mut self) -> &mut dyn Any;
+
+    /// Save the state of AiaImsics.
+    fn state(&self) -> Result<AiaState>;
+
+    /// Restore the state of AiaImsics.
+    fn set_state(&mut self, state: &AiaState) -> Result<()>;
+}