diff --git a/src/lib.rs b/src/lib.rs
index aff7ac8..89c2173 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -61,6 +61,8 @@ numeric_enum! {
         HWrite = HYPER_CALL_CODE_PRIVILEGED_MASK | 0x12,
         /// Duplicate current gaddrspace to a new one, return its EPTP list index.
         HDupGas = HYPER_CALL_CODE_PRIVILEGED_MASK | 0x13,
+        /// Just a benchmark hypercall for VM call overhead measurement.
+        HBenchVMCall = HYPER_CALL_CODE_PRIVILEGED_MASK | 0xff,
     }
 }
 
@@ -87,6 +89,7 @@ impl core::fmt::Debug for HyperCallCode {
             HyperCallCode::HIVCDt => write!(f, "HIVCDt {:#x}", *self as u32),
             HyperCallCode::HIVCSHMAt => write!(f, "HIVCSHMAt {:#x}", *self as u32),
             HyperCallCode::HClearGuestAreas => write!(f, "HClearGuestAreas {:#x}", *self as u32),
+            HyperCallCode::HBenchVMCall => write!(f, "HBenchVMCall {:#x}", *self as u32),
         }?;
         write!(f, ")")
     }