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authorStefan Hajnoczi <stefanha@redhat.com>2024-12-12 18:40:32 -0500
committerStefan Hajnoczi <stefanha@redhat.com>2024-12-12 18:40:32 -0500
commit1eec82cc06cd68b6ffaf13ba8337fac0080c7bce (patch)
tree25f66000339cca55497068c9f826d8c877185558 /rust/qemu-api/src/device_class.rs
parent2a1823456c3ab500a90c3fe0cfcc5fc6f560282b (diff)
parent166e8a1fd15bfa527b25fc15ca315e572c0556d2 (diff)
downloadfocaccia-qemu-1eec82cc06cd68b6ffaf13ba8337fac0080c7bce.tar.gz
focaccia-qemu-1eec82cc06cd68b6ffaf13ba8337fac0080c7bce.zip
Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging
* rust: better integration with clippy, rustfmt and rustdoc
* rust: interior mutability types
* rust: add a bit operations module
* rust: first part of QOM rework
* kvm: remove unnecessary #ifdef
* clock: small cleanups, improve handling of Clock lifetimes

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# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
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* tag 'for-upstream' of https://gitlab.com/bonzini/qemu: (49 commits)
  rust: qom: change the parent type to an associated type
  rust: qom: split ObjectType from ObjectImpl trait
  rust: qom: move bridge for TypeInfo functions out of pl011
  rust: qdev: move bridge for realize and reset functions out of pl011
  rust: qdev: move device_class_init! body to generic function, ClassInitImpl implementation to macro
  rust: qom: move ClassInitImpl to the instance side
  rust: qom: convert type_info! macro to an associated const
  rust: qom: rename Class trait to ClassInitImpl
  rust: qom: add default definitions for ObjectImpl
  rust: add a bit operation module
  rust: add bindings for interrupt sources
  rust: define prelude
  rust: cell: add BQL-enforcing RefCell variant
  rust: cell: add BQL-enforcing Cell variant
  bql: check that the BQL is not dropped within marked sections
  qom/object: Remove type_register()
  script/codeconverter/qom_type_info: Deprecate MakeTypeRegisterStatic and MakeTypeRegisterNotStatic
  ui: Replace type_register() with type_register_static()
  target/xtensa: Replace type_register() with type_register_static()
  target/sparc: Replace type_register() with type_register_static()
  ...

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'rust/qemu-api/src/device_class.rs')
-rw-r--r--rust/qemu-api/src/device_class.rs126
1 files changed, 103 insertions, 23 deletions
diff --git a/rust/qemu-api/src/device_class.rs b/rust/qemu-api/src/device_class.rs
index 0ba798d3e3..03d03feee8 100644
--- a/rust/qemu-api/src/device_class.rs
+++ b/rust/qemu-api/src/device_class.rs
@@ -2,32 +2,112 @@
 // Author(s): Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
 // SPDX-License-Identifier: GPL-2.0-or-later
 
-use std::ffi::CStr;
+use std::{ffi::CStr, os::raw::c_void};
 
-use crate::bindings;
+use crate::{
+    bindings::{self, DeviceClass, DeviceState, Error, ObjectClass, Property, VMStateDescription},
+    prelude::*,
+    zeroable::Zeroable,
+};
+
+/// Trait providing the contents of [`DeviceClass`].
+pub trait DeviceImpl {
+    /// _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).
+    ///
+    /// If not `None`, the parent class's `realize` method is overridden
+    /// with the function pointed to by `REALIZE`.
+    const REALIZE: Option<fn(&mut Self)> = None;
+
+    /// If not `None`, the parent class's `reset` method is overridden
+    /// with the function pointed to by `RESET`.
+    ///
+    /// Rust does not yet support the three-phase reset protocol; this is
+    /// usually okay for leaf classes.
+    const RESET: Option<fn(&mut Self)> = None;
+
+    /// An array providing the properties that the user can set on the
+    /// 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
+    /// Not a `const` because referencing statics in constants is unstable
+    /// until Rust 1.83.0.
+    fn vmsd() -> Option<&'static VMStateDescription> {
+        None
+    }
+}
+
+/// # Safety
+///
+/// This function is only called through the QOM machinery and
+/// the `impl_device_class!` macro.
+/// We expect the FFI user of this function to pass a valid pointer that
+/// can be downcasted to type `T`. We also expect the device is
+/// readable/writeable from one thread at any time.
+unsafe extern "C" fn rust_realize_fn<T: DeviceImpl>(dev: *mut DeviceState, _errp: *mut *mut Error) {
+    assert!(!dev.is_null());
+    let state = dev.cast::<T>();
+    T::REALIZE.unwrap()(unsafe { &mut *state });
+}
+
+/// # Safety
+///
+/// We expect the FFI user of this function to pass a valid pointer that
+/// can be downcasted to type `T`. We also expect the device is
+/// readable/writeable from one thread at any time.
+unsafe extern "C" fn rust_reset_fn<T: DeviceImpl>(dev: *mut DeviceState) {
+    assert!(!dev.is_null());
+    let state = dev.cast::<T>();
+    T::RESET.unwrap()(unsafe { &mut *state });
+}
+
+/// # Safety
+///
+/// We expect the FFI user of this function to pass a valid pointer that
+/// can be downcasted to type `DeviceClass`, because `T` implements
+/// `DeviceImpl`.
+pub unsafe extern "C" fn rust_device_class_init<T: DeviceImpl>(
+    klass: *mut ObjectClass,
+    _: *mut c_void,
+) {
+    let mut dc = ::core::ptr::NonNull::new(klass.cast::<DeviceClass>()).unwrap();
+    unsafe {
+        let dc = dc.as_mut();
+        if <T as DeviceImpl>::REALIZE.is_some() {
+            dc.realize = Some(rust_realize_fn::<T>);
+        }
+        if <T as DeviceImpl>::RESET.is_some() {
+            bindings::device_class_set_legacy_reset(dc, Some(rust_reset_fn::<T>));
+        }
+        if let Some(vmsd) = <T as DeviceImpl>::vmsd() {
+            dc.vmsd = vmsd;
+        }
+        bindings::device_class_set_props(dc, <T as DeviceImpl>::properties().as_ptr());
+    }
+}
 
 #[macro_export]
-macro_rules! device_class_init {
-    ($func:ident, props => $props:ident, realize_fn => $realize_fn:expr, legacy_reset_fn => $legacy_reset_fn:expr, vmsd => $vmsd:ident$(,)*) => {
-        pub unsafe extern "C" fn $func(
-            klass: *mut $crate::bindings::ObjectClass,
-            _: *mut ::std::os::raw::c_void,
-        ) {
-            let mut dc =
-                ::core::ptr::NonNull::new(klass.cast::<$crate::bindings::DeviceClass>()).unwrap();
-            unsafe {
-                dc.as_mut().realize = $realize_fn;
-                dc.as_mut().vmsd = &$vmsd;
-                $crate::bindings::device_class_set_legacy_reset(dc.as_mut(), $legacy_reset_fn);
-                $crate::bindings::device_class_set_props(dc.as_mut(), $props.as_ptr());
-            }
+macro_rules! impl_device_class {
+    ($type:ty) => {
+        impl $crate::definitions::ClassInitImpl for $type {
+            const CLASS_INIT: Option<
+                unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut ::std::os::raw::c_void),
+            > = Some($crate::device_class::rust_device_class_init::<$type>);
+            const CLASS_BASE_INIT: Option<
+                unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut ::std::os::raw::c_void),
+            > = None;
         }
     };
 }
 
 #[macro_export]
 macro_rules! define_property {
-    ($name:expr, $state:ty, $field:ident, $prop:expr, $type:expr, default = $defval:expr$(,)*) => {
+    ($name:expr, $state:ty, $field:ident, $prop:expr, $type:ty, default = $defval:expr$(,)*) => {
         $crate::bindings::Property {
             // use associated function syntax for type checking
             name: ::std::ffi::CStr::as_ptr($name),
@@ -38,7 +118,7 @@ macro_rules! define_property {
             ..$crate::zeroable::Zeroable::ZERO
         }
     };
-    ($name:expr, $state:ty, $field:ident, $prop:expr, $type:expr$(,)*) => {
+    ($name:expr, $state:ty, $field:ident, $prop:expr, $type:ty$(,)*) => {
         $crate::bindings::Property {
             // use associated function syntax for type checking
             name: ::std::ffi::CStr::as_ptr($name),
@@ -67,8 +147,8 @@ macro_rules! declare_properties {
     };
 }
 
-// workaround until we can use --generate-cstr in bindgen.
-pub const TYPE_DEVICE: &CStr =
-    unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_DEVICE) };
-pub const TYPE_SYS_BUS_DEVICE: &CStr =
-    unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_SYS_BUS_DEVICE) };
+unsafe impl ObjectType for bindings::DeviceState {
+    type Class = bindings::DeviceClass;
+    const TYPE_NAME: &'static CStr =
+        unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_DEVICE) };
+}