rust: Fix the typos in doc

These typos are found by "cargo spellcheck". Though it outputs a lot of
noise and false positives, there still are some real typos.

Signed-off-by: Zhao Liu <zhao1.liu@int

rust: Fix the typos in doc

These typos are found by "cargo spellcheck". Though it outputs a lot of
noise and false positives, there still are some real typos.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250520152750.2542612-6-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: enable clippy::ptr_cast_constness

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.co

rust: enable clippy::ptr_cast_constness

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: fix TODO about zeroability of classes

The proposed suggestion is not correct. First it is not necessary for
*all* classes to be Zeroable, only for Rust-defined ones; classes
defined in C

rust: qom: fix TODO about zeroability of classes

The proposed suggestion is not correct. First it is not necessary for
*all* classes to be Zeroable, only for Rust-defined ones; classes
defined in C never implement ObjectImpl.

Second, the parent class field need not be Zeroable. For example,
ChardevClass's chr_write and chr_be_event fields cannot be NULL,
therefore ChardevClass cannot be Zeroable. However, char_class_init()
initializes them, therefore ChardevClass could be subclassed by Rust code.

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: use std::ffi instead of std::os::raw

This is allowed since Rust 1.64.0.

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-of

rust: use std::ffi instead of std::os::raw

This is allowed since Rust 1.64.0.

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

qom: Constify TypeInfo::interfaces

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20250424194905.82506-6-philmd@

qom: Constify TypeInfo::interfaces

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20250424194905.82506-6-philmd@linaro.org>

show more ...

qom: Constify TypeInfo::class_data

All callers now correctly expect a const class data.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@l

qom: Constify TypeInfo::class_data

All callers now correctly expect a const class data.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250424194905.82506-5-philmd@linaro.org>

show more ...

qom: Have class_init() take a const data argument

Mechanical change using gsed, then style manually adapted
to pass checkpatch.pl script.

Suggested-by: Richard Henderson <richard.henderson@linaro.o

qom: Have class_init() take a const data argument

Mechanical change using gsed, then style manually adapted
to pass checkpatch.pl script.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250424194905.82506-4-philmd@linaro.org>

show more ...

qom: Have class_base_init() take a const data argument

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <2025042419

qom: Have class_base_init() take a const data argument

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250424194905.82506-3-philmd@linaro.org>

show more ...

rust: qom: remove operations on &mut

The dubious casts of mutable references to objects are not used
anymore: the wrappers for qdev_init_clock_in and for IRQ and MMIO
initialization can be called di

rust: qom: remove operations on &mut

The dubious casts of mutable references to objects are not used
anymore: the wrappers for qdev_init_clock_in and for IRQ and MMIO
initialization can be called directly on the subclasses, without
casts, plus they take a shared reference so they can just use
"upcast()" instead of "upcast_mut()". Remove them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: wrap Object with Opaque<>

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust: qom: get rid of ClassInitImpl

Complete the conversion from the ClassInitImpl trait to class_init() methods.
This will provide more freedom to split the qemu_api crate in separate parts.

Revie

rust: qom: get rid of ClassInitImpl

Complete the conversion from the ClassInitImpl trait to class_init() methods.
This will provide more freedom to split the qemu_api crate in separate parts.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: add ObjectImpl::CLASS_INIT

As shown in the PL011 device, the orphan rules required a manual
implementation of ClassInitImpl for anything not in the qemu_api crate;
this gets in the way of

rust: qom: add ObjectImpl::CLASS_INIT

As shown in the PL011 device, the orphan rules required a manual
implementation of ClassInitImpl for anything not in the qemu_api crate;
this gets in the way of moving system emulation-specific code (including
DeviceClass, which as a blanket ClassInitImpl<DeviceClass> implementation)
into its own crate.

Make ClassInitImpl optional, at the cost of having to specify the CLASS_INIT
member by hand in every implementation of ObjectImpl. The next commits will
get rid of it, replacing all the "impl<T> ClassInitImpl<Class> for T" blocks
with a generic class_init<T> method on Class.

Right now the definition is always the same, but do not provide a default
as that will not be true once ClassInitImpl goes away.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: add IsA bounds to QOM implementation traits

Check that the right bounds are provided to the qom_isa! macro
whenever the class is defined to implement a certain class.
This removes the need to

rust: add IsA bounds to QOM implementation traits

Check that the right bounds are provided to the qom_isa! macro
whenever the class is defined to implement a certain class.
This removes the need to add IsA<> bounds together with the
*Impl trait bounds.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: allow initializing interface vtables

Unlike regular classes, interface vtables can only be obtained via
object_class_dynamic_cast. Provide a wrapper that allows accessing
the vtable and

rust: qom: allow initializing interface vtables

Unlike regular classes, interface vtables can only be obtained via
object_class_dynamic_cast. Provide a wrapper that allows accessing
the vtable and pass it to a ClassInitImpl implementation, for example
ClassInitImpl<ResettableClass>.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: add object creation functionality

The basic object lifecycle test can now be implemented using safe code!

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzi

rust: qom: add object creation functionality

The basic object lifecycle test can now be implemented using safe code!

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: add reference counting functionality

Add a smart pointer that allows to add and remove references from
QOM objects. It's important to note that while all QOM objects have a
reference cou

rust: qom: add reference counting functionality

Add a smart pointer that allows to add and remove references from
QOM objects. It's important to note that while all QOM objects have a
reference count, in practice not all of them have their lifetime guarded
by it. Embedded objects, specifically, are confined to the lifetime of
the owner.

When writing Rust bindings this is important, because embedded objects are
*never* used through the "Owned<>" smart pointer that is introduced here.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: prefer NonNull::new to assertions

Do not use new_unchecked; the effect is the same, but the
code is easier to read and unsafe regions become smaller.
Likewise, NonNull::new can be used instead

rust: prefer NonNull::new to assertions

Do not use new_unchecked; the effect is the same, but the
code is easier to read and unsafe regions become smaller.
Likewise, NonNull::new can be used instead of assertion and
followed by as_ref() or as_mut() instead of dereferencing the
pointer.

Suggested-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: make INSTANCE_POST_INIT take a shared reference

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

rust: qom: automatically use Drop trait to implement instance_finalize

Replace the customizable INSTANCE_FINALIZE with a generic function
that drops the Rust object.

Reviewed-by: Zhao Liu <zhao1.li

rust: qom: automatically use Drop trait to implement instance_finalize

Replace the customizable INSTANCE_FINALIZE with a generic function
that drops the Rust object.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: add ParentField

Add a type that, together with the C function object_deinit, ensures the
correct drop order for QOM objects relative to their superclasses.

Right now it is not possible t

rust: qom: add ParentField

Add a type that, together with the C function object_deinit, ensures the
correct drop order for QOM objects relative to their superclasses.

Right now it is not possible to implement the Drop trait for QOM classes
that are defined in Rust, as the drop() function would not be called when
the object goes away; instead what is called is ObjectImpl::INSTANCE_FINALIZE.
It would be nice for INSTANCE_FINALIZE to just drop the object, but this has
a problem: suppose you have

pub struct MySuperclass {
parent: DeviceState,
field: Box<MyData>,
...
}

impl Drop for MySuperclass {
...
}

pub struct MySubclass {
parent: MySuperclass,
...
}

and an instance_finalize implementation that is like

unsafe extern "C" fn drop_object<T: ObjectImpl>(obj: *mut Object) {
unsafe { std::ptr::drop_in_place(obj.cast::<T>()) }
}

When instance_finalize is called for MySubclass, it will walk the struct's
list of fields and call the drop method for MySuperclass. Then, object_deinit
recurses to the superclass and calls the same drop method again. This
will cause double-freeing of the Box<Data>.

What's happening here is that QOM wants to control the drop order of
MySuperclass and MySubclass's fields. To do so, the parent field must
be marked ManuallyDrop<>, which is quite ugly. Instead, add a wrapper
type ParentField<> that is specific to QOM. This hides the implementation
detail of *what* is special about the ParentField, and will also be easy
to check in the #[derive(Object)] macro.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: add initial subset of methods on Object

Add an example of implementing instance methods and converting the
result back to a Rust type. In this case the returned types are a
string (actua

rust: qom: add initial subset of methods on Object

Add an example of implementing instance methods and converting the
result back to a Rust type. In this case the returned types are a
string (actually a Cow<str>; but that's transparent as long as it derefs
to &str) and a QOM class.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: add casting functionality

Add traits that let client cast typecast safely between object types.
In particular, an upcast is compile-time guaranteed to succeed, and a
YOLO C-style downcast

rust: qom: add casting functionality

Add traits that let client cast typecast safely between object types.
In particular, an upcast is compile-time guaranteed to succeed, and a
YOLO C-style downcast must be marked as unsafe.

The traits are based on an IsA<> trait that declares what
is a subclass of what, which is an idea taken from glib-rs
(https://docs.rs/glib/latest/glib/object/trait.IsA.html).
The four primitives are also taken from there
(https://docs.rs/glib/latest/glib/object/trait.Cast.html). However,
the implementation of casting itself is a bit different and uses the
Deref trait.

This removes some pointer arithmetic from the pl011 device; it is also a
prerequisite for the definition of methods, so that they can be invoked
on all subclass structs. This will use the IsA<> trait to detect the
structs that support the methods.

glib also has a "monadic" casting trait which could be implemented on
Option (as in https://docs.rs/glib/latest/glib/object/trait.CastNone.html)
and perhaps even Result. For now I'm leaving it out, as the patch is
already big enough and the benefit seems debatable.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: re-export C types from qemu-api submodules

Long term we do not want device code to use "bindings" at all, so make it
possible to get the relevant types from the other modules of qemu-api.

Rev

rust: re-export C types from qemu-api submodules

Long term we do not want device code to use "bindings" at all, so make it
possible to get the relevant types from the other modules of qemu-api.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: rename qemu-api modules to follow C code a bit more

A full match would mean calling them qom::object and hw::core::qdev. For now,
keep the names shorter but still a bit easier to find.

Revie

rust: rename qemu-api modules to follow C code a bit more

A full match would mean calling them qom::object and hw::core::qdev. For now,
keep the names shorter but still a bit easier to find.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...

rust: qom: add possibility of overriding unparent

Add a blanket definition of ClassInitImpl<ObjectClass> that thunks
ObjectImpl::UNPARENT and overrides it in ObjectClass if it is not
None.

ClassIni

rust: qom: add possibility of overriding unparent

Add a blanket definition of ClassInitImpl<ObjectClass> that thunks
ObjectImpl::UNPARENT and overrides it in ObjectClass if it is not
None.

ClassInitImpl<DeviceClass> can now call its superclass's ClassInitImpl,
so that the C and Rust hierarchies match more closely.

This is mostly done as an example of implementing the metaclass
hierarchy under ClassInitImpl.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

show more ...