fix(aarch64): drop fds in unit tests before asserts

If test need to drop fd, it needs to do that before assert
checks. Otherwise if assert fails, the IO safety error will
occur instead of the assertion error.

Signed-off-by: Egor Lazarchuk <[email protected]>

Author: ShadowCurse

src/vmm/src/arch/aarch64/vcpu.rs

@@ -532,13 +532,16 @@ mod tests {
         unsafe { libc::close(vm.fd().as_raw_fd()) };
 
         let err = KvmVcpu::new(0, &vm);
+
+        // dropping vm would double close the gic fd, so leak it
+        // do the drop before assertion. Otherwise if assert fails,
+        // we get IO runtime error instead of assert error.
+        std::mem::forget(vm);
+
         assert_eq!(
             err.err().unwrap().to_string(),
             "Error creating vcpu: Bad file descriptor (os error 9)".to_string()
         );
-
-        // dropping vm would double close the gic fd, so leak it
-        std::mem::forget(vm);
     }
 
     #[test]
@@ -574,6 +577,12 @@ mod tests {
             &vcpu_config,
             &optional_capabilities,
         );
+
+        // dropping vcpu would double close the gic fd, so leak it
+        // do the drop before assertion. Otherwise if assert fails,
+        // we get IO runtime error instead of assert error.
+        std::mem::forget(vcpu);
+
         assert_eq!(
             err.unwrap_err(),
             KvmVcpuError::ConfigureRegisters(VcpuArchError::SetOneReg(
@@ -582,9 +591,6 @@ mod tests {
                 kvm_ioctls::Error::new(9)
             ))
         );
-
-        // dropping vcpu would double close the gic fd, so leak it
-        std::mem::forget(vcpu);
     }
 
     #[test]
@@ -780,9 +786,12 @@ mod tests {
         assert!(matches!(res, Err(VcpuArchError::GetMp(_))), "{:?}", res);
 
         let res = vcpu.set_mpstate(kvm_mp_state::default());
-        assert!(matches!(res, Err(VcpuArchError::SetMp(_))), "{:?}", res);
 
         // dropping vcpu would double close the fd, so leak it
+        // do the drop before assertion. Otherwise if assert fails,
+        // we get IO runtime error instead of assert error.
         std::mem::forget(vcpu);
+
+        assert!(matches!(res, Err(VcpuArchError::SetMp(_))), "{:?}", res);
     }
 }