> +/// Trait providing the contents of [`ResettablePhases`].
> +pub trait ResettablePhasesImpl {
> + /// If not None, this is called when the object enters reset. It
> + /// can reset local state of the object, but it must not do anything that
> + /// has a side-effect on other objects, such as raising or lowering a
> + /// [`qemu_irq`] line or reading or writing guest memory. It takes the
> + /// reset's type as argument.
> + const ENTER: Option<fn(&Self, ResetType)> = None;
> +
> + /// If not None, this is called when the object for entry into reset,
> once
> + /// every object in the system which is being reset has had its
> + /// @phases.enter method called. At this point devices can do actions
Maybe s/@phases.enter/ResettablePhasesImpl::ENTER/?
> + /// that affect other objects.
> + ///
> + /// If in doubt, implement this method.
> + const HOLD: Option<fn(&Self, ResetType)> = None;
> +
> + /// If not None, this phase is called when the object leaves the reset
> + /// state. Actions affecting other objects are permitted.
> + const EXIT: Option<fn(&Self, ResetType)> = None;
> +}
> +
...
> impl<T> ClassInitImpl<DeviceClass> for T
> where
> - T: ClassInitImpl<ObjectClass> + DeviceImpl,
> + T: ClassInitImpl<ObjectClass> + ClassInitImpl<ResettableClass> +
> DeviceImpl,
This constraint requires each device to explicitly implement
ResettablePhasesImpl,
even the device doesn't want to do anything for reset.
So what about the following changes:
* Define 3-Phases methods in DeviceImpl.
* Implement ResettablePhasesImpl for all devices by passing their 3-Phases
methods to ResettablePhasesImpl's.
Then device doesn't need to implement this reset trait if unnecessary.
For example:
--- a/rust/qemu-api/src/qdev.rs
+++ b/rust/qemu-api/src/qdev.rs
@@ -84,7 +84,7 @@ pub trait ResettablePhasesImpl {
}
/// Trait providing the contents of [`DeviceClass`].
-pub trait DeviceImpl: ObjectImpl + ResettablePhasesImpl {
+pub trait DeviceImpl: ObjectImpl {
/// _Realization_ is the second stage of device creation. It contains
/// all operations that depend on device properties and can fail (note:
/// this is not yet supported for Rust devices).
@@ -106,6 +106,18 @@ fn properties() -> &'static [Property] {
fn vmsd() -> Option<&'static VMStateDescription> {
None
}
+
+ const RESET_ENTER: Option<fn(&Self, ResetType)> = None;
+ const RESET_HOLD: Option<fn(&Self, ResetType)> = None;
+ const RESET_EXIT: Option<fn(&Self, ResetType)> = None;
+}
+
+impl<T> ResettablePhasesImpl for T
+where T: DeviceImpl
+{
+ const ENTER: Option<fn(&Self, ResetType)> = T::RESET_ENTER;
+ const HOLD: Option<fn(&Self, ResetType)> = T::RESET_HOLD;
+ const EXIT: Option<fn(&Self, ResetType)> = T::RESET_EXIT;
}
/// # Safety
---
Though this way add duplicate methods, it reduces the burden on the
device developer.
Regards,
Zhao
> {
> fn class_init(dc: &mut DeviceClass) {
> if <T as DeviceImpl>::REALIZE.is_some() {
> dc.realize = Some(rust_realize_fn::<T>);
> }
> - if <T as DeviceImpl>::RESET.is_some() {
> - unsafe {
> - bindings::device_class_set_legacy_reset(dc,
> Some(rust_reset_fn::<T>));
> - }
> - }
> if let Some(vmsd) = <T as DeviceImpl>::vmsd() {
> dc.vmsd = vmsd;
> }
> @@ -99,6 +162,7 @@ fn class_init(dc: &mut DeviceClass) {
> }
> }
>
> + ResettableClass::interface_init::<T, DeviceState>(dc);
> <T as ClassInitImpl<ObjectClass>>::class_init(&mut dc.parent_class);
> }
> }
