diff --git a/MAINTAINERS b/MAINTAINERS index f09029560b64..de583a169148 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3291,6 +3291,12 @@ F: hw/core/register.c F: include/hw/register.h F: include/hw/registerfields.h +Rust +M: Manos Pitsidianakis +S: Maintained +F: rust/qemu-api +F: rust/rustfmt.toml + SLIRP M: Samuel Thibault S: Maintained diff --git a/rust/meson.build b/rust/meson.build index e69de29bb2d1..4a58d106b1dd 100644 --- a/rust/meson.build +++ b/rust/meson.build @@ -0,0 +1 @@ +subdir('qemu-api') diff --git a/rust/qemu-api/.gitignore b/rust/qemu-api/.gitignore new file mode 100644 index 000000000000..b9e7e004c867 --- /dev/null +++ b/rust/qemu-api/.gitignore @@ -0,0 +1,2 @@ +# Ignore generated bindings file overrides. +src/bindings.rs diff --git a/rust/qemu-api/Cargo.lock b/rust/qemu-api/Cargo.lock new file mode 100644 index 000000000000..e9c51a243a85 --- /dev/null +++ b/rust/qemu-api/Cargo.lock @@ -0,0 +1,7 @@ +# This file is automatically @generated by Cargo. +# It is not intended for manual editing. +version = 3 + +[[package]] +name = "qemu_api" +version = "0.1.0" diff --git a/rust/qemu-api/Cargo.toml b/rust/qemu-api/Cargo.toml new file mode 100644 index 000000000000..3677def3fe2b --- /dev/null +++ b/rust/qemu-api/Cargo.toml @@ -0,0 +1,26 @@ +[package] +name = "qemu_api" +version = "0.1.0" +edition = "2021" +authors = ["Manos Pitsidianakis "] +license = "GPL-2.0-or-later" +readme = "README.md" +homepage = "https://www.qemu.org" +description = "Rust bindings for QEMU" +repository = "https://gitlab.com/qemu-project/qemu/" +resolver = "2" +publish = false +keywords = [] +categories = [] + +[dependencies] + +[features] +default = [] +allocator = [] + +# Do not include in any global workspace +[workspace] + +[lints.rust] +unexpected_cfgs = { level = "warn", check-cfg = ['cfg(MESON)', 'cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)'] } diff --git a/rust/qemu-api/README.md b/rust/qemu-api/README.md new file mode 100644 index 000000000000..7588fa29ef37 --- /dev/null +++ b/rust/qemu-api/README.md @@ -0,0 +1,17 @@ +# QEMU bindings and API wrappers + +This library exports helper Rust types, Rust macros and C FFI bindings for internal QEMU APIs. + +The C bindings can be generated with `bindgen`, using this build target: + +```console +$ ninja bindings.rs +``` + +## Generate Rust documentation + +To generate docs for this crate, including private items: + +```sh +cargo doc --no-deps --document-private-items +``` diff --git a/rust/qemu-api/build.rs b/rust/qemu-api/build.rs new file mode 100644 index 000000000000..419b154c2d26 --- /dev/null +++ b/rust/qemu-api/build.rs @@ -0,0 +1,14 @@ +// Copyright 2024, Linaro Limited +// Author(s): Manos Pitsidianakis +// SPDX-License-Identifier: GPL-2.0-or-later + +use std::path::Path; + +fn main() { + if !Path::new("src/bindings.rs").exists() { + panic!( + "No generated C bindings found! Either build them manually with bindgen or with meson \ + (`ninja bindings.rs`) and copy them to src/bindings.rs, or build through meson." + ); + } +} diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build new file mode 100644 index 000000000000..439ef73c29e1 --- /dev/null +++ b/rust/qemu-api/meson.build @@ -0,0 +1,21 @@ +_qemu_api_rs = static_library( + 'qemu_api', + structured_sources( + [ + 'src/lib.rs', + 'src/definitions.rs', + 'src/device_class.rs', + ], + {'.' : bindings_rs}, + ), + override_options: ['rust_std=2021', 'build.rust_std=2021'], + rust_abi: 'rust', + rust_args: rustc_args + [ + '--cfg', 'MESON', + # '--cfg', 'feature="allocator"', + ], +) + +qemu_api = declare_dependency( + link_with: _qemu_api_rs, +) diff --git a/rust/qemu-api/src/definitions.rs b/rust/qemu-api/src/definitions.rs new file mode 100644 index 000000000000..60bd3f8aaa65 --- /dev/null +++ b/rust/qemu-api/src/definitions.rs @@ -0,0 +1,97 @@ +// Copyright 2024, Linaro Limited +// Author(s): Manos Pitsidianakis +// SPDX-License-Identifier: GPL-2.0-or-later + +//! Definitions required by QEMU when registering a device. + +use ::core::ffi::{c_void, CStr}; + +use crate::bindings::{Object, ObjectClass, TypeInfo}; + +/// Trait a type must implement to be registered with QEMU. +pub trait ObjectImpl { + type Class; + const TYPE_INFO: TypeInfo; + const TYPE_NAME: &'static CStr; + const PARENT_TYPE_NAME: Option<&'static CStr>; + const ABSTRACT: bool; + const INSTANCE_INIT: Option; + const INSTANCE_POST_INIT: Option; + const INSTANCE_FINALIZE: Option; +} + +pub trait Class { + const CLASS_INIT: Option; + const CLASS_BASE_INIT: Option< + unsafe extern "C" fn(klass: *mut ObjectClass, data: *mut c_void), + >; +} + +#[macro_export] +macro_rules! module_init { + ($func:expr, $type:expr) => { + #[used] + #[cfg_attr(target_os = "linux", link_section = ".ctors")] + #[cfg_attr(target_os = "macos", link_section = "__DATA,__mod_init_func")] + #[cfg_attr(target_os = "windows", link_section = ".CRT$XCU")] + pub static LOAD_MODULE: extern "C" fn() = { + extern "C" fn __load() { + unsafe { + $crate::bindings::register_module_init(Some($func), $type); + } + } + + __load + }; + }; + (qom: $func:ident => $body:block) => { + // NOTE: To have custom identifiers for the ctor func we need to either supply + // them directly as a macro argument or create them with a proc macro. + #[used] + #[cfg_attr(target_os = "linux", link_section = ".ctors")] + #[cfg_attr(target_os = "macos", link_section = "__DATA,__mod_init_func")] + #[cfg_attr(target_os = "windows", link_section = ".CRT$XCU")] + pub static LOAD_MODULE: extern "C" fn() = { + extern "C" fn __load() { + #[no_mangle] + unsafe extern "C" fn $func() { + $body + } + + unsafe { + $crate::bindings::register_module_init( + Some($func), + $crate::bindings::module_init_type::MODULE_INIT_QOM, + ); + } + } + + __load + }; + }; +} + +#[macro_export] +macro_rules! type_info { + ($t:ty) => { + $crate::bindings::TypeInfo { + name: <$t as $crate::definitions::ObjectImpl>::TYPE_NAME.as_ptr(), + parent: if let Some(pname) = <$t as $crate::definitions::ObjectImpl>::PARENT_TYPE_NAME { + pname.as_ptr() + } else { + ::core::ptr::null_mut() + }, + instance_size: ::core::mem::size_of::<$t>() as $crate::bindings::size_t, + instance_align: ::core::mem::align_of::<$t>() as $crate::bindings::size_t, + instance_init: <$t as $crate::definitions::ObjectImpl>::INSTANCE_INIT, + instance_post_init: <$t as $crate::definitions::ObjectImpl>::INSTANCE_POST_INIT, + instance_finalize: <$t as $crate::definitions::ObjectImpl>::INSTANCE_FINALIZE, + abstract_: <$t as $crate::definitions::ObjectImpl>::ABSTRACT, + class_size: ::core::mem::size_of::<<$t as $crate::definitions::ObjectImpl>::Class>() as $crate::bindings::size_t, + class_init: <<$t as $crate::definitions::ObjectImpl>::Class as $crate::definitions::Class>::CLASS_INIT, + class_base_init: <<$t as $crate::definitions::ObjectImpl>::Class as $crate::definitions::Class>::CLASS_BASE_INIT, + class_data: ::core::ptr::null_mut(), + interfaces: ::core::ptr::null_mut(), + }; + } +} diff --git a/rust/qemu-api/src/device_class.rs b/rust/qemu-api/src/device_class.rs new file mode 100644 index 000000000000..1ea95beb78db --- /dev/null +++ b/rust/qemu-api/src/device_class.rs @@ -0,0 +1,128 @@ +// Copyright 2024, Linaro Limited +// Author(s): Manos Pitsidianakis +// SPDX-License-Identifier: GPL-2.0-or-later + +use std::sync::OnceLock; + +use crate::bindings::Property; + +#[macro_export] +macro_rules! device_class_init { + ($func:ident, props => $props:ident, realize_fn => $realize_fn:expr, legacy_reset_fn => $legacy_reset_fn:expr, vmsd => $vmsd:ident$(,)*) => { + #[no_mangle] + pub unsafe extern "C" fn $func( + klass: *mut $crate::bindings::ObjectClass, + _: *mut ::core::ffi::c_void, + ) { + let mut dc = + ::core::ptr::NonNull::new(klass.cast::<$crate::bindings::DeviceClass>()).unwrap(); + 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(), $props.as_mut_ptr()); + } + }; +} + +#[macro_export] +macro_rules! define_property { + ($name:expr, $state:ty, $field:expr, $prop:expr, $type:expr, default = $defval:expr$(,)*) => { + $crate::bindings::Property { + name: { + #[used] + static _TEMP: &::core::ffi::CStr = $name; + _TEMP.as_ptr() + }, + info: $prop, + offset: ::core::mem::offset_of!($state, $field) + .try_into() + .expect("Could not fit offset value to type"), + bitnr: 0, + bitmask: 0, + set_default: true, + defval: $crate::bindings::Property__bindgen_ty_1 { u: $defval.into() }, + arrayoffset: 0, + arrayinfo: ::core::ptr::null(), + arrayfieldsize: 0, + link_type: ::core::ptr::null(), + } + }; + ($name:expr, $state:ty, $field:expr, $prop:expr, $type:expr$(,)*) => { + $crate::bindings::Property { + name: { + #[used] + static _TEMP: &::core::ffi::CStr = $name; + _TEMP.as_ptr() + }, + info: $prop, + offset: ::core::mem::offset_of!($state, $field) + .try_into() + .expect("Could not fit offset value to type"), + bitnr: 0, + bitmask: 0, + set_default: false, + defval: $crate::bindings::Property__bindgen_ty_1 { i: 0 }, + arrayoffset: 0, + arrayinfo: ::core::ptr::null(), + arrayfieldsize: 0, + link_type: ::core::ptr::null(), + } + }; +} + +#[repr(C)] +pub struct Properties(pub OnceLock<[Property; N]>, pub fn() -> [Property; N]); + +impl Properties { + pub fn as_mut_ptr(&mut self) -> *mut Property { + _ = self.0.get_or_init(self.1); + self.0.get_mut().unwrap().as_mut_ptr() + } +} + +#[macro_export] +macro_rules! declare_properties { + ($ident:ident, $($prop:expr),*$(,)*) => { + + const fn _calc_prop_len() -> usize { + let mut len = 1; + $({ + _ = stringify!($prop); + len += 1; + })* + len + } + const PROP_LEN: usize = _calc_prop_len(); + + fn _make_properties() -> [$crate::bindings::Property; PROP_LEN] { + [ + $($prop),*, + unsafe { ::core::mem::MaybeUninit::<$crate::bindings::Property>::zeroed().assume_init() }, + ] + } + + #[no_mangle] + pub static mut $ident: $crate::device_class::Properties = $crate::device_class::Properties(::std::sync::OnceLock::new(), _make_properties); + }; +} + +#[macro_export] +macro_rules! vm_state_description { + ($(#[$outer:meta])* + $name:ident, + $(name: $vname:expr,)* + $(unmigratable: $um_val:expr,)* + ) => { + #[used] + $(#[$outer])* + pub static $name: $crate::bindings::VMStateDescription = $crate::bindings::VMStateDescription { + $(name: { + #[used] + static VMSTATE_NAME: &::core::ffi::CStr = $vname; + $vname.as_ptr() + },)* + unmigratable: true, + ..unsafe { ::core::mem::MaybeUninit::<$crate::bindings::VMStateDescription>::zeroed().assume_init() } + }; + } +} diff --git a/rust/qemu-api/src/lib.rs b/rust/qemu-api/src/lib.rs new file mode 100644 index 000000000000..e72fb4b4bb13 --- /dev/null +++ b/rust/qemu-api/src/lib.rs @@ -0,0 +1,166 @@ +// Copyright 2024, Linaro Limited +// Author(s): Manos Pitsidianakis +// SPDX-License-Identifier: GPL-2.0-or-later + +#![cfg_attr(not(MESON), doc = include_str!("../README.md"))] + +#[allow( + dead_code, + improper_ctypes_definitions, + improper_ctypes, + non_camel_case_types, + non_snake_case, + non_upper_case_globals, + unsafe_op_in_unsafe_fn, + clippy::missing_const_for_fn, + clippy::too_many_arguments, + clippy::approx_constant, + clippy::use_self, + clippy::useless_transmute, + clippy::missing_safety_doc, +)] +#[rustfmt::skip] +pub mod bindings; + +unsafe impl Send for bindings::Property {} +unsafe impl Sync for bindings::Property {} +unsafe impl Sync for bindings::TypeInfo {} +unsafe impl Sync for bindings::VMStateDescription {} + +pub mod definitions; +pub mod device_class; + +#[cfg(test)] +mod tests; + +use std::alloc::{GlobalAlloc, Layout}; + +#[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] +extern "C" { + fn g_aligned_alloc0( + n_blocks: bindings::gsize, + n_block_bytes: bindings::gsize, + alignment: bindings::gsize, + ) -> bindings::gpointer; + fn g_aligned_free(mem: bindings::gpointer); +} + +#[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] +extern "C" { + fn qemu_memalign(alignment: usize, size: usize) -> *mut ::core::ffi::c_void; + fn qemu_vfree(ptr: *mut ::core::ffi::c_void); +} + +extern "C" { + fn g_malloc0(n_bytes: bindings::gsize) -> bindings::gpointer; + fn g_free(mem: bindings::gpointer); +} + +/// An allocator that uses the same allocator as QEMU in C. +/// +/// It is enabled by default with the `allocator` feature. +/// +/// To set it up manually as a global allocator in your crate: +/// +/// ```ignore +/// use qemu_api::QemuAllocator; +/// +/// #[global_allocator] +/// static GLOBAL: QemuAllocator = QemuAllocator::new(); +/// ``` +#[derive(Clone, Copy, Debug)] +#[repr(C)] +pub struct QemuAllocator { + _unused: [u8; 0], +} + +#[cfg_attr(all(feature = "allocator", not(test)), global_allocator)] +pub static GLOBAL: QemuAllocator = QemuAllocator::new(); + +impl QemuAllocator { + // From the glibc documentation, on GNU systems, malloc guarantees 16-byte + // alignment on 64-bit systems and 8-byte alignment on 32-bit systems. See + // https://www.gnu.org/software/libc/manual/html_node/Malloc-Examples.html. + // This alignment guarantee also applies to Windows and Android. On Darwin + // and OpenBSD, the alignment is 16 bytes on both 64-bit and 32-bit systems. + #[cfg(all( + target_pointer_width = "32", + not(any(target_os = "macos", target_os = "openbsd")) + ))] + pub const DEFAULT_ALIGNMENT_BYTES: Option = Some(8); + #[cfg(all( + target_pointer_width = "64", + not(any(target_os = "macos", target_os = "openbsd")) + ))] + pub const DEFAULT_ALIGNMENT_BYTES: Option = Some(16); + #[cfg(all( + any(target_pointer_width = "32", target_pointer_width = "64"), + any(target_os = "macos", target_os = "openbsd") + ))] + pub const DEFAULT_ALIGNMENT_BYTES: Option = Some(16); + #[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))] + pub const DEFAULT_ALIGNMENT_BYTES: Option = None; + + pub const fn new() -> Self { + Self { _unused: [] } + } +} + +impl Default for QemuAllocator { + fn default() -> Self { + Self::new() + } +} + +// Sanity check. +const _: [(); 8] = [(); ::core::mem::size_of::<*mut ::core::ffi::c_void>()]; + +unsafe impl GlobalAlloc for QemuAllocator { + unsafe fn alloc(&self, layout: Layout) -> *mut u8 { + if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) + { + // SAFETY: g_malloc0() is safe to call. + unsafe { g_malloc0(layout.size().try_into().unwrap()).cast::() } + } else { + #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] + { + // SAFETY: g_aligned_alloc0() is safe to call. + unsafe { + g_aligned_alloc0( + layout.size().try_into().unwrap(), + 1, + layout.align().try_into().unwrap(), + ) + .cast::() + } + } + #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] + { + // SAFETY: qemu_memalign() is safe to call. + unsafe { qemu_memalign(layout.align(), layout.size()).cast::() } + } + } + } + + unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) { + if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) + { + // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid + // glib-allocated pointer, so `g_free`ing is safe. + unsafe { g_free(ptr.cast::<_>()) } + } else { + #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] + { + // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned + // glib-allocated pointer, so `g_aligned_free`ing is safe. + unsafe { g_aligned_free(ptr.cast::<_>()) } + } + #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] + { + // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned + // glib-allocated pointer, so `qemu_vfree`ing is safe. + unsafe { qemu_vfree(ptr.cast::<_>()) } + } + } + } +} diff --git a/rust/qemu-api/src/tests.rs b/rust/qemu-api/src/tests.rs new file mode 100644 index 000000000000..df54edbd4e27 --- /dev/null +++ b/rust/qemu-api/src/tests.rs @@ -0,0 +1,49 @@ +// Copyright 2024, Linaro Limited +// Author(s): Manos Pitsidianakis +// SPDX-License-Identifier: GPL-2.0-or-later + +use crate::{ + bindings::*, declare_properties, define_property, device_class_init, vm_state_description, +}; + +#[test] +fn test_device_decl_macros() { + // Test that macros can compile. + vm_state_description! { + VMSTATE, + name: c"name", + unmigratable: true, + } + + #[repr(C)] + pub struct DummyState { + pub char_backend: CharBackend, + pub migrate_clock: bool, + } + + declare_properties! { + DUMMY_PROPERTIES, + define_property!( + c"chardev", + DummyState, + char_backend, + unsafe { &qdev_prop_chr }, + CharBackend + ), + define_property!( + c"migrate-clk", + DummyState, + migrate_clock, + unsafe { &qdev_prop_bool }, + bool + ), + } + + device_class_init! { + dummy_class_init, + props => DUMMY_PROPERTIES, + realize_fn => None, + reset_fn => None, + vmsd => VMSTATE, + } +} diff --git a/rust/rustfmt.toml b/rust/rustfmt.toml new file mode 100644 index 000000000000..ebecb99fe09e --- /dev/null +++ b/rust/rustfmt.toml @@ -0,0 +1,7 @@ +edition = "2021" +format_generated_files = false +format_code_in_doc_comments = true +format_strings = true +imports_granularity = "Crate" +group_imports = "StdExternalCrate" +wrap_comments = true