diff --git a/tdx-tdcall/src/tdx.rs b/tdx-tdcall/src/tdx.rs
index 4cd246bf..141adb70 100644
--- a/tdx-tdcall/src/tdx.rs
+++ b/tdx-tdcall/src/tdx.rs
@@ -37,6 +37,7 @@ pub struct TdInfo {
     pub attributes: u64,
     pub max_vcpus: u32,
     pub num_vcpus: u32,
+    pub vcpu_index: u32,
     pub rsvd: [u64; 3],
 }
 
@@ -504,6 +505,7 @@ pub fn tdcall_get_td_info() -> Result<TdInfo, TdCallError> {
         attributes: args.rdx,
         max_vcpus: (args.r8 >> 32) as u32,
         num_vcpus: args.r8 as u32,
+        vcpu_index: args.r9 as u32,
         ..Default::default()
     };
 
@@ -700,7 +702,7 @@ mod tests {
     fn test_struct_size_alignment() {
         assert_eq!(align_of::<TdxDigest>(), 64);
         assert_eq!(size_of::<TdxDigest>(), 64);
-        assert_eq!(size_of::<TdInfo>(), 48);
+        assert_eq!(size_of::<TdInfo>(), 56);
         assert_eq!(size_of::<TdVeInfo>(), 48);
     }