refactor: move arch specific Kvm code into modules

src/snapshot-editor/src/edit_vmstate.rs

@@ -99,7 +99,7 @@ mod tests {
         const KVM_REG_SIZE_U32: u64 = 0x20000000000000;
 
         use vmm::arch::aarch64::regs::Aarch64RegisterRef;
-        use vmm::vstate::vcpu::aarch64::VcpuState;
+        use vmm::arch::aarch64::vcpu::VcpuState;
 
         let vcpu_state = VcpuState {
             regs: {
@@ -158,7 +158,7 @@ mod tests {
         const KVM_REG_SIZE_U32: u64 = 0x20000000000000;
 
         use vmm::arch::aarch64::regs::Aarch64RegisterRef;
-        use vmm::vstate::vcpu::aarch64::VcpuState;
+        use vmm::arch::aarch64::vcpu::VcpuState;
 
         let vcpu_state = VcpuState {
             regs: {

src/vmm/src/arch/aarch64/kvm.rs

@@ -0,0 +1,64 @@
+// Copyright 2025 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+use std::convert::Infallible;
+
+use kvm_ioctls::Kvm as KvmFd;
+
+use crate::cpu_config::templates::KvmCapability;
+
+/// ['Kvm'] initialization can't fail for Aarch64
+pub type KvmArchError = Infallible;
+
+/// Optional capabilities.
+#[derive(Debug, Default)]
+pub struct OptionalCapabilities {
+    /// KVM_CAP_COUNTER_OFFSET
+    pub counter_offset: bool,
+}
+
+/// Struct with kvm fd and kvm associated parameters.
+#[derive(Debug)]
+pub struct Kvm {
+    /// KVM fd.
+    pub fd: KvmFd,
+    /// Maximum number of memory slots allowed by KVM.
+    pub max_memslots: usize,
+    /// Additional capabilities that were specified in cpu template.
+    pub kvm_cap_modifiers: Vec<KvmCapability>,
+}
+
+impl Kvm {
+    pub(crate) const DEFAULT_CAPABILITIES: [u32; 7] = [
+        kvm_bindings::KVM_CAP_IOEVENTFD,
+        kvm_bindings::KVM_CAP_IRQFD,
+        kvm_bindings::KVM_CAP_USER_MEMORY,
+        kvm_bindings::KVM_CAP_ARM_PSCI_0_2,
+        kvm_bindings::KVM_CAP_DEVICE_CTRL,
+        kvm_bindings::KVM_CAP_MP_STATE,
+        kvm_bindings::KVM_CAP_ONE_REG,
+    ];
+
+    /// Initialize [`Kvm`] type for Aarch64 architecture
+    pub fn init_arch(
+        fd: KvmFd,
+        max_memslots: usize,
+        kvm_cap_modifiers: Vec<KvmCapability>,
+    ) -> Result<Self, KvmArchError> {
+        Ok(Self {
+            fd,
+            max_memslots,
+            kvm_cap_modifiers,
+        })
+    }
+
+    /// Returns struct with optional capabilities statuses.
+    pub fn optional_capabilities(&self) -> OptionalCapabilities {
+        OptionalCapabilities {
+            counter_offset: self
+                .fd
+                .check_extension_raw(kvm_bindings::KVM_CAP_COUNTER_OFFSET.into())
+                != 0,
+        }
+    }
+}

src/vmm/src/arch/aarch64/mod.rs

@@ -5,12 +5,16 @@ pub(crate) mod cache_info;
 mod fdt;
 /// Module for the global interrupt controller configuration.
 pub mod gic;
+/// Architecture specific KVM-related code
+pub mod kvm;
 /// Layout for this aarch64 system.
 pub mod layout;
 /// Logic for configuring aarch64 registers.
 pub mod regs;
-/// Helper methods for VcpuFd.
+/// Architecture specific vCPU code
 pub mod vcpu;
+/// Architecture specific VM state code
+pub mod vm;
 
 use std::cmp::min;
 use std::collections::HashMap;