refactor(builder): address comments

Signed-off-by: tommady <tommady@users.noreply.github.com>

src/vmm/src/builder.rs

@@ -152,7 +152,7 @@ impl std::convert::From<linux_loader::cmdline::Error> for StartMicrovmError {
 pub mod aarch64 {
     use super::*;
 
-    fn attach_legacy_devices_aarch64(
+    fn attach_legacy_devices(
         event_manager: &mut EventManager,
         vmm: &mut Vmm,
         cmdline: &mut LoaderKernelCmdline,
@@ -222,7 +222,8 @@ pub mod aarch64 {
 
         let vcpu_config = VcpuConfig {
             vcpu_count: vm_config.vcpu_count,
-            smt: vm_config.smt,
+            // smt does not exist on aarch64
+            smt: false,
             cpu_config,
         };
 
@@ -642,8 +643,7 @@ pub fn build_microvm_for_boot(
     }
 
     #[cfg(target_arch = "aarch64")]
-    aarch::attach_legacy_devices_aarch64(event_manager, &mut vmm, &mut boot_cmdline)
-        .map_err(Internal)?;
+    aarch::attach_legacy_devices(event_manager, &mut vmm, &mut boot_cmdline).map_err(Internal)?;
 
     attach_vmgenid_device(&mut vmm)?;