hypervisor: add a function to return hypervisor type

Signed-off-by: Wei Liu <liuwe@microsoft.com>

hypervisor/src/hypervisor.rs

@@ -12,6 +12,7 @@ use crate::arch::x86::CpuIdEntry;
 #[cfg(feature = "tdx")]
 use crate::kvm::TdxCapabilities;
 use crate::vm::Vm;
+use crate::HypervisorType;
 use std::sync::Arc;
 use thiserror::Error;
 
@@ -82,6 +83,10 @@ pub type Result<T> = std::result::Result<T, HypervisorError>;
 /// This crate provides a hypervisor-agnostic interfaces
 ///
 pub trait Hypervisor: Send + Sync {
+    ///
+    /// Returns the type of the hypervisor
+    ///
+    fn hypervisor_type(&self) -> HypervisorType;
     ///
     /// Create a Vm using the underlying hypervisor
     /// Return a hypervisor-agnostic Vm trait object

hypervisor/src/kvm/mod.rs

@@ -21,6 +21,7 @@ use crate::cpu;
 use crate::hypervisor;
 use crate::vec_with_array_field;
 use crate::vm::{self, InterruptSourceConfig, VmOps};
+use crate::HypervisorType;
 #[cfg(target_arch = "aarch64")]
 use crate::{arm64_core_reg_id, offset__of};
 use kvm_ioctls::{NoDatamatch, VcpuFd, VmFd};
@@ -924,6 +925,12 @@ impl KvmHypervisor {
 /// let vm = hypervisor.create_vm().expect("new VM fd creation failed");
 ///
 impl hypervisor::Hypervisor for KvmHypervisor {
+    ///
+    /// Returns the type of the hypervisor
+    ///
+    fn hypervisor_type(&self) -> HypervisorType {
+        HypervisorType::Kvm
+    }
     /// Create a KVM vm object of a specific VM type and return the object as Vm trait object
     /// Example
     /// # extern crate hypervisor;

hypervisor/src/lib.rs

@@ -61,6 +61,12 @@ pub use vm::{
     Vm, VmOps,
 };
 
+#[derive(Debug, Copy, Clone)]
+pub enum HypervisorType {
+    Kvm,
+    Mshv,
+}
+
 pub fn new() -> std::result::Result<Arc<dyn Hypervisor>, HypervisorError> {
     #[cfg(feature = "kvm")]
     let hv = kvm::KvmHypervisor::new()?;

hypervisor/src/mshv/mod.rs

@@ -12,6 +12,7 @@ use crate::cpu::Vcpu;
 use crate::hypervisor;
 use crate::vec_with_array_field;
 use crate::vm::{self, InterruptSourceConfig, VmOps};
+use crate::HypervisorType;
 pub use mshv_bindings::*;
 use mshv_ioctls::{set_registers_64, Mshv, NoDatamatch, VcpuFd, VmFd};
 use std::any::Any;
@@ -191,6 +192,12 @@ impl MshvHypervisor {
 /// let vm = hypervisor.create_vm().expect("new VM fd creation failed");
 ///
 impl hypervisor::Hypervisor for MshvHypervisor {
+    ///
+    /// Returns the type of the hypervisor
+    ///
+    fn hypervisor_type(&self) -> HypervisorType {
+        HypervisorType::Mshv
+    }
     /// Create a mshv vm object and return the object as Vm trait object
     /// Example
     /// # extern crate hypervisor;