Commit graph

15 commits

Author SHA1 Message Date
Paolo Bonzini
6dd818fbbb rust: qom: put class_init together from multiple ClassInitImpl<>
Parameterize the implementation of ClassInitImpl so that it is
possible to call up the chain of implementations, one superclass at
a time starting at ClassInitImpl<Self::Class>.

In order to avoid having to implement (for example)
ClassInitImpl<PL011Class>, also remove the dummy PL011Class and
PL011LuminaryClass structs and specify the same ObjectType::Class as
the superclass.  In the future this default behavior can be handled by
a procedural macro, by looking at the first field in the struct.

Note that the new trait is safe: the calls are started by
rust_class_init<>(), which is not public and can convert the class
pointer to a Rust reference.

Since CLASS_BASE_INIT applies to the type that is being defined,
and only to it, move it to ObjectImpl.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-19 19:36:37 +01:00
Paolo Bonzini
166e8a1fd1 rust: qom: change the parent type to an associated type
Avoid duplicated code to retrieve the QOM type strings from the
Rust type.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-11 15:57:19 +01:00
Paolo Bonzini
7bd8e3ef63 rust: qom: split ObjectType from ObjectImpl trait
Define a separate trait for fields that also applies to classes that are
defined by C code.  This makes it possible to add metadata to core classes,
which has multiple uses:

- it makes it possible to access the parent struct's TYPE_* for types
  that are defined in Rust code, and to avoid repeating it in every subclass

- implementors of ObjectType will be allowed to implement the IsA<> trait and
  therefore to perform typesafe casts from one class to another.

- in the future, an ObjectType could be created with Foo::new() in a type-safe
  manner, without having to pass a TYPE_* constant.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-11 15:56:54 +01:00
Paolo Bonzini
1f9d52c938 rust: qom: move bridge for TypeInfo functions out of pl011
Allow the ObjectImpl trait to expose Rust functions that avoid raw
pointers (though INSTANCE_INIT for example is still unsafe).
ObjectImpl::TYPE_INFO adds thunks around the functions in
ObjectImpl.

While at it, document `TypeInfo`.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-11 10:32:15 +01:00
Paolo Bonzini
f75fb90ff2 rust: qdev: move bridge for realize and reset functions out of pl011
Allow the DeviceImpl trait to expose safe Rust functions.
rust_device_class_init<> adds thunks around the functions
in DeviceImpl.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-10 18:49:26 +01:00
Paolo Bonzini
c6c4f3e0d9 rust: qom: move ClassInitImpl to the instance side
Put all traits on the instance struct, which makes it possible to reuse
class structs if no new virtual methods or class fields are added.
This is almost always the case for devices (because they are leaf
classes), which is the primary use case for Rust.

This is also simpler: soon we will find the implemented methods without
macros, and this removes the need to go from the class struct to the
instance struct to find the implementation of the *Impl traits.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-10 18:49:26 +01:00
Paolo Bonzini
3701fb22df rust: qom: convert type_info! macro to an associated const
type_info! is only used in the definition of ObjectImpl::TYPE_INFO, and
in fact in all of them.  Pull type_info!'s definition into the ObjectImpl
trait, thus simplifying the external interface of qemu_api::definitions.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-10 18:49:26 +01:00
Paolo Bonzini
93ea0896ea rust: qom: rename Class trait to ClassInitImpl
While at it, document it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-10 18:49:26 +01:00
Paolo Bonzini
b2a4854508 rust: qom: add default definitions for ObjectImpl
Remove a bunch of duplicate const definitions.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-12-10 18:49:26 +01:00
Paolo Bonzini
9f7d4520d6 rust: use std::os::raw instead of core::ffi
core::ffi::c_* types were introduced in Rust 1.64.0.  Use the older types
in std::os::raw, which are now aliases of the types in core::ffi.  There is
no need to compile QEMU as no_std, so this is acceptable as long as we support
a version of Debian with Rust 1.63.0.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:16 +01:00
Paolo Bonzini
e90d470733 rust: cleanup module_init!, use it from #[derive(Object)]
Remove the duplicate code by using the module_init! macro; at the same time,
simplify how module_init! is used, by taking inspiration from the implementation
of #[derive(Object)].

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:15 +01:00
Paolo Bonzini
4f7521916d rust: modernize link_section usage for ELF platforms
Some newer ABI implementations do not provide .ctors; and while
some linkers rewrite .ctors into .init_array, not all of them do.
Use the newer .init_array ABI, which works more reliably, and
apply it to all non-Apple, non-Windows platforms.

This is similar to how the ctor crate operates; without this change,
"#[derive(Object)]" does not work on Fedora 41.

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:15 +01:00
Paolo Bonzini
2eb6274d12 rust: remove uses of #[no_mangle]
Mangled symbols do not cause any issue; disabling mangling is only useful if
C headers reference the Rust function, which is not the case here.

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:15 +01:00
Paolo Bonzini
00ed18de35 rust: do not use --no-size_t-is-usize
This is not necessary and makes it harder to write code that is
portable between 32- and 64-bit systems: it adds extra casts even
though size_of, align_of or offset_of already return the right type.

Reviewed-by: Junjie Mao <junjie.mao@hotmail.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-11-05 14:18:15 +01:00
Manos Pitsidianakis
5a5110d290 rust: add crate to expose bindings and interfaces
Add rust/qemu-api, which exposes rust-bindgen generated FFI bindings and
provides some declaration macros for symbols visible to the rest of
QEMU.

Co-authored-by: Junjie Mao <junjie.mao@intel.com>
Co-authored-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Link: https://lore.kernel.org/r/0fb23fbe211761b263aacec03deaf85c0cc39995.1727961605.git.manos.pitsidianakis@linaro.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-10-11 12:32:17 +02:00