rust/qemu-api: Use device_class_set_props_n

This means we can update declare_properties to drop the
zero terminator at the end of the array as well.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Lei Yang <leiyang@redhat.com>
Link: https://lore.kernel.org/r/20241218134251.4724-18-richard.henderson@linaro.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust/qemu-api/src/device_class.rs

@@ -7,7 +7,6 @@
 use crate::{
     bindings::{self, DeviceClass, DeviceState, Error, ObjectClass, Property, VMStateDescription},
     prelude::*,
-    zeroable::Zeroable,
 };
 
 /// Trait providing the contents of [`DeviceClass`].
@@ -31,7 +30,7 @@ pub trait DeviceImpl {
     /// device.  Not a `const` because referencing statics in constants
     /// is unstable until Rust 1.83.0.
     fn properties() -> &'static [Property] {
-        &[Zeroable::ZERO; 1]
+        &[]
     }
 
     /// A `VMStateDescription` providing the migration format for the device
@@ -87,7 +86,10 @@ fn vmsd() -> Option<&'static VMStateDescription> {
         if let Some(vmsd) = <T as DeviceImpl>::vmsd() {
             dc.vmsd = vmsd;
         }
-        bindings::device_class_set_props(dc, <T as DeviceImpl>::properties().as_ptr());
+        let prop = <T as DeviceImpl>::properties();
+        if !prop.is_empty() {
+            bindings::device_class_set_props_n(dc, prop.as_ptr(), prop.len());
+        }
     }
 }
 
@@ -134,7 +136,7 @@ macro_rules! define_property {
 macro_rules! declare_properties {
     ($ident:ident, $($prop:expr),*$(,)*) => {
         pub static $ident: [$crate::bindings::Property; {
-            let mut len = 1;
+            let mut len = 0;
             $({
                 _ = stringify!($prop);
                 len += 1;
@@ -142,7 +144,6 @@ macro_rules! declare_properties {
             len
         }] = [
             $($prop),*,
-            $crate::zeroable::Zeroable::ZERO,
         ];
     };
 }