1 // Copyright 2024, Linaro Limited 2 // Author(s): Manos Pitsidianakis <manos.pitsidianakis@linaro.org> 3 // SPDX-License-Identifier: GPL-2.0-or-later 4 5 #![cfg_attr(not(MESON), doc = include_str!("../README.md"))] 6 7 #[allow( 8 dead_code, 9 improper_ctypes_definitions, 10 improper_ctypes, 11 non_camel_case_types, 12 non_snake_case, 13 non_upper_case_globals, 14 unsafe_op_in_unsafe_fn, 15 clippy::missing_const_for_fn, 16 clippy::too_many_arguments, 17 clippy::approx_constant, 18 clippy::use_self, 19 clippy::useless_transmute, 20 clippy::missing_safety_doc, 21 )] 22 #[rustfmt::skip] 23 pub mod bindings; 24 25 unsafe impl Send for bindings::Property {} 26 unsafe impl Sync for bindings::Property {} 27 unsafe impl Sync for bindings::TypeInfo {} 28 unsafe impl Sync for bindings::VMStateDescription {} 29 unsafe impl Sync for bindings::VMStateField {} 30 unsafe impl Sync for bindings::VMStateInfo {} 31 32 pub mod c_str; 33 pub mod definitions; 34 pub mod device_class; 35 pub mod vmstate; 36 pub mod zeroable; 37 38 use std::{ 39 alloc::{GlobalAlloc, Layout}, 40 os::raw::c_void, 41 }; 42 43 #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] 44 extern "C" { 45 fn g_aligned_alloc0( 46 n_blocks: bindings::gsize, 47 n_block_bytes: bindings::gsize, 48 alignment: bindings::gsize, 49 ) -> bindings::gpointer; 50 fn g_aligned_free(mem: bindings::gpointer); 51 } 52 53 #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] 54 extern "C" { 55 fn qemu_memalign(alignment: usize, size: usize) -> *mut c_void; 56 fn qemu_vfree(ptr: *mut c_void); 57 } 58 59 extern "C" { 60 fn g_malloc0(n_bytes: bindings::gsize) -> bindings::gpointer; 61 fn g_free(mem: bindings::gpointer); 62 } 63 64 /// An allocator that uses the same allocator as QEMU in C. 65 /// 66 /// It is enabled by default with the `allocator` feature. 67 /// 68 /// To set it up manually as a global allocator in your crate: 69 /// 70 /// ```ignore 71 /// use qemu_api::QemuAllocator; 72 /// 73 /// #[global_allocator] 74 /// static GLOBAL: QemuAllocator = QemuAllocator::new(); 75 /// ``` 76 #[derive(Clone, Copy, Debug)] 77 #[repr(C)] 78 pub struct QemuAllocator { 79 _unused: [u8; 0], 80 } 81 82 #[cfg_attr(all(feature = "allocator", not(test)), global_allocator)] 83 pub static GLOBAL: QemuAllocator = QemuAllocator::new(); 84 85 impl QemuAllocator { 86 // From the glibc documentation, on GNU systems, malloc guarantees 16-byte 87 // alignment on 64-bit systems and 8-byte alignment on 32-bit systems. See 88 // https://www.gnu.org/software/libc/manual/html_node/Malloc-Examples.html. 89 // This alignment guarantee also applies to Windows and Android. On Darwin 90 // and OpenBSD, the alignment is 16 bytes on both 64-bit and 32-bit systems. 91 #[cfg(all( 92 target_pointer_width = "32", 93 not(any(target_os = "macos", target_os = "openbsd")) 94 ))] 95 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(8); 96 #[cfg(all( 97 target_pointer_width = "64", 98 not(any(target_os = "macos", target_os = "openbsd")) 99 ))] 100 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16); 101 #[cfg(all( 102 any(target_pointer_width = "32", target_pointer_width = "64"), 103 any(target_os = "macos", target_os = "openbsd") 104 ))] 105 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = Some(16); 106 #[cfg(not(any(target_pointer_width = "32", target_pointer_width = "64")))] 107 pub const DEFAULT_ALIGNMENT_BYTES: Option<usize> = None; 108 109 pub const fn new() -> Self { 110 Self { _unused: [] } 111 } 112 } 113 114 impl Default for QemuAllocator { 115 fn default() -> Self { 116 Self::new() 117 } 118 } 119 120 // Sanity check. 121 const _: [(); 8] = [(); ::core::mem::size_of::<*mut c_void>()]; 122 123 unsafe impl GlobalAlloc for QemuAllocator { 124 unsafe fn alloc(&self, layout: Layout) -> *mut u8 { 125 if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) 126 { 127 // SAFETY: g_malloc0() is safe to call. 128 unsafe { g_malloc0(layout.size().try_into().unwrap()).cast::<u8>() } 129 } else { 130 #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] 131 { 132 // SAFETY: g_aligned_alloc0() is safe to call. 133 unsafe { 134 g_aligned_alloc0( 135 layout.size().try_into().unwrap(), 136 1, 137 layout.align().try_into().unwrap(), 138 ) 139 .cast::<u8>() 140 } 141 } 142 #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] 143 { 144 // SAFETY: qemu_memalign() is safe to call. 145 unsafe { qemu_memalign(layout.align(), layout.size()).cast::<u8>() } 146 } 147 } 148 } 149 150 unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) { 151 if matches!(Self::DEFAULT_ALIGNMENT_BYTES, Some(default) if default.checked_rem(layout.align()) == Some(0)) 152 { 153 // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid 154 // glib-allocated pointer, so `g_free`ing is safe. 155 unsafe { g_free(ptr.cast::<_>()) } 156 } else { 157 #[cfg(HAVE_GLIB_WITH_ALIGNED_ALLOC)] 158 { 159 // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned 160 // glib-allocated pointer, so `g_aligned_free`ing is safe. 161 unsafe { g_aligned_free(ptr.cast::<_>()) } 162 } 163 #[cfg(not(HAVE_GLIB_WITH_ALIGNED_ALLOC))] 164 { 165 // SAFETY: `ptr` must have been allocated by Self::alloc thus a valid aligned 166 // glib-allocated pointer, so `qemu_vfree`ing is safe. 167 unsafe { qemu_vfree(ptr.cast::<_>()) } 168 } 169 } 170 } 171 } 172