feat(tdx): select KvmVmType::TDX when TDX is enabled

Signed-off-by: Changyuan Lyu <changyuanl@google.com>

Author: Lencerf

alioth/src/hv/kvm/vm/vm_x86_64.rs

@@ -68,9 +68,13 @@ impl VmArch {
 
 impl KvmVm {
     pub fn determine_vm_type(config: &VmConfig) -> KvmVmType {
-        match &config.coco {
-            Some(Coco::AmdSnp { .. }) => KvmVmType::SNP,
-            _ => KvmVmType::DEFAULT,
+        let Some(coco) = &config.coco else {
+            return KvmVmType::DEFAULT;
+        };
+        match coco {
+            Coco::AmdSev { .. } => KvmVmType::DEFAULT,
+            Coco::AmdSnp { .. } => KvmVmType::SNP,
+            Coco::IntelTdx { .. } => KvmVmType::TDX,
         }
     }
 

alioth/src/hv/kvm/vm/vm_x86_64_test.rs

@@ -14,7 +14,12 @@
 
 use rstest::rstest;
 
+use crate::arch::sev::{SevPolicy, SnpPolicy};
+use crate::arch::tdx::TdAttr;
+use crate::hv::kvm::vm::KvmVm;
 use crate::hv::kvm::vm::x86_64::translate_msi_addr;
+use crate::hv::{Coco, VmConfig};
+use crate::sys::kvm::KvmVmType;
 
 #[rstest]
 #[case(0, 0)]
@@ -26,3 +31,33 @@ fn test_translate_msi_addr(#[case] addr: u64, #[case] expected: u64) {
     let (lo, hi) = translate_msi_addr(addr as u32, (addr >> 32) as u32);
     assert_eq!((lo as u64) | ((hi as u64) << 32), expected);
 }
+
+#[rstest]
+#[case(VmConfig { coco: None }, KvmVmType::DEFAULT)]
+#[case(
+    VmConfig {
+        coco: Some(Coco::AmdSev {
+            policy: SevPolicy(0x5)
+        })
+    },
+    KvmVmType::DEFAULT
+)]
+#[case(
+    VmConfig {
+        coco: Some(Coco::AmdSnp {
+            policy: SnpPolicy(0x30000)
+        })
+    },
+    KvmVmType::SNP
+)]
+#[case(
+    VmConfig {
+        coco: Some(Coco::IntelTdx {
+            attr: TdAttr::empty()
+        })
+    },
+    KvmVmType::TDX
+)]
+fn test_determine_vm_type(#[case] config: VmConfig, #[case] vm_type: KvmVmType) {
+    assert_eq!(KvmVm::determine_vm_type(&config), vm_type)
+}