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