From 590faa03ee64b4221d1be39949190e82e361efb7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 17 Jan 2025 18:14:25 +0100 Subject: rust: bindings for MemoryRegionOps Reviewed-by: Zhao Liu Signed-off-by: Paolo Bonzini --- rust/qemu-api/src/memory.rs | 191 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 rust/qemu-api/src/memory.rs (limited to 'rust/qemu-api/src/memory.rs') diff --git a/rust/qemu-api/src/memory.rs b/rust/qemu-api/src/memory.rs new file mode 100644 index 0000000..963d689 --- /dev/null +++ b/rust/qemu-api/src/memory.rs @@ -0,0 +1,191 @@ +// Copyright 2024 Red Hat, Inc. +// Author(s): Paolo Bonzini +// SPDX-License-Identifier: GPL-2.0-or-later + +//! Bindings for `MemoryRegion` and `MemoryRegionOps` + +use std::{ + ffi::{CStr, CString}, + marker::{PhantomData, PhantomPinned}, + os::raw::{c_uint, c_void}, + ptr::addr_of, +}; + +pub use bindings::hwaddr; + +use crate::{ + bindings::{self, device_endian, memory_region_init_io}, + callbacks::FnCall, + prelude::*, + zeroable::Zeroable, +}; + +pub struct MemoryRegionOps( + bindings::MemoryRegionOps, + // Note: quite often you'll see PhantomData mentioned when discussing + // covariance and contravariance; you don't need any of those to understand + // this usage of PhantomData. Quite simply, MemoryRegionOps *logically* + // holds callbacks that take an argument of type &T, except the type is erased + // before the callback is stored in the bindings::MemoryRegionOps field. + // The argument of PhantomData is a function pointer in order to represent + // that relationship; while that will also provide desirable and safe variance + // for T, variance is not the point but just a consequence. + PhantomData, +); + +// SAFETY: When a *const T is passed to the callbacks, the call itself +// is done in a thread-safe manner. The invocation is okay as long as +// T itself is `Sync`. +unsafe impl Sync for MemoryRegionOps {} + +#[derive(Clone)] +pub struct MemoryRegionOpsBuilder(bindings::MemoryRegionOps, PhantomData); + +unsafe extern "C" fn memory_region_ops_read_cb FnCall<(&'a T, hwaddr, u32), u64>>( + opaque: *mut c_void, + addr: hwaddr, + size: c_uint, +) -> u64 { + F::call((unsafe { &*(opaque.cast::()) }, addr, size)) +} + +unsafe extern "C" fn memory_region_ops_write_cb FnCall<(&'a T, hwaddr, u64, u32)>>( + opaque: *mut c_void, + addr: hwaddr, + data: u64, + size: c_uint, +) { + F::call((unsafe { &*(opaque.cast::()) }, addr, data, size)) +} + +impl MemoryRegionOpsBuilder { + #[must_use] + pub const fn read FnCall<(&'a T, hwaddr, u32), u64>>(mut self, _f: &F) -> Self { + self.0.read = Some(memory_region_ops_read_cb::); + self + } + + #[must_use] + pub const fn write FnCall<(&'a T, hwaddr, u64, u32)>>(mut self, _f: &F) -> Self { + self.0.write = Some(memory_region_ops_write_cb::); + self + } + + #[must_use] + pub const fn big_endian(mut self) -> Self { + self.0.endianness = device_endian::DEVICE_BIG_ENDIAN; + self + } + + #[must_use] + pub const fn little_endian(mut self) -> Self { + self.0.endianness = device_endian::DEVICE_LITTLE_ENDIAN; + self + } + + #[must_use] + pub const fn native_endian(mut self) -> Self { + self.0.endianness = device_endian::DEVICE_NATIVE_ENDIAN; + self + } + + #[must_use] + pub const fn valid_sizes(mut self, min: u32, max: u32) -> Self { + self.0.valid.min_access_size = min; + self.0.valid.max_access_size = max; + self + } + + #[must_use] + pub const fn valid_unaligned(mut self) -> Self { + self.0.valid.unaligned = true; + self + } + + #[must_use] + pub const fn impl_sizes(mut self, min: u32, max: u32) -> Self { + self.0.impl_.min_access_size = min; + self.0.impl_.max_access_size = max; + self + } + + #[must_use] + pub const fn impl_unaligned(mut self) -> Self { + self.0.impl_.unaligned = true; + self + } + + #[must_use] + pub const fn build(self) -> MemoryRegionOps { + MemoryRegionOps::(self.0, PhantomData) + } + + #[must_use] + pub const fn new() -> Self { + Self(bindings::MemoryRegionOps::ZERO, PhantomData) + } +} + +impl Default for MemoryRegionOpsBuilder { + fn default() -> Self { + Self::new() + } +} + +/// A safe wrapper around [`bindings::MemoryRegion`]. Compared to the +/// underlying C struct it is marked as pinned because the QOM tree +/// contains a pointer to it. +pub struct MemoryRegion { + inner: bindings::MemoryRegion, + _pin: PhantomPinned, +} + +impl MemoryRegion { + // inline to ensure that it is not included in tests, which only + // link to hwcore and qom. FIXME: inlining is actually the opposite + // of what we want, since this is the type-erased version of the + // init_io function below. Look into splitting the qemu_api crate. + #[inline(always)] + unsafe fn do_init_io( + slot: *mut bindings::MemoryRegion, + owner: *mut Object, + ops: &'static bindings::MemoryRegionOps, + name: &'static str, + size: u64, + ) { + unsafe { + let cstr = CString::new(name).unwrap(); + memory_region_init_io( + slot, + owner.cast::(), + ops, + owner.cast::(), + cstr.as_ptr(), + size, + ); + } + } + + pub fn init_io>( + &mut self, + owner: *mut T, + ops: &'static MemoryRegionOps, + name: &'static str, + size: u64, + ) { + unsafe { + Self::do_init_io(&mut self.inner, owner.cast::(), &ops.0, name, size); + } + } + + pub(crate) const fn as_mut_ptr(&self) -> *mut bindings::MemoryRegion { + addr_of!(self.inner) as *mut _ + } +} + +unsafe impl ObjectType for MemoryRegion { + type Class = bindings::MemoryRegionClass; + const TYPE_NAME: &'static CStr = + unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_MEMORY_REGION) }; +} +qom_isa!(MemoryRegion: Object); -- cgit v1.1 From d015d4cbb4d16cf8adc8c10cbd2d0a45f014dad1 Mon Sep 17 00:00:00 2001 From: Zhao Liu Date: Sat, 25 Jan 2025 20:51:32 +0800 Subject: rust: add bindings for memattrs The MemTxAttrs structure contains bitfield members, and bindgen is unable to generate an equivalent macro definition for MEMTXATTRS_UNSPECIFIED. Therefore, manually define a global constant variable MEMTXATTRS_UNSPECIFIED to support calls from Rust code. Signed-off-by: Zhao Liu Link: https://lore.kernel.org/r/20250125125137.1223277-6-zhao1.liu@intel.com Signed-off-by: Paolo Bonzini --- rust/qemu-api/src/memory.rs | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'rust/qemu-api/src/memory.rs') diff --git a/rust/qemu-api/src/memory.rs b/rust/qemu-api/src/memory.rs index 963d689..682951a 100644 --- a/rust/qemu-api/src/memory.rs +++ b/rust/qemu-api/src/memory.rs @@ -2,7 +2,7 @@ // Author(s): Paolo Bonzini // SPDX-License-Identifier: GPL-2.0-or-later -//! Bindings for `MemoryRegion` and `MemoryRegionOps` +//! Bindings for `MemoryRegion`, `MemoryRegionOps` and `MemTxAttrs` use std::{ ffi::{CStr, CString}, @@ -11,7 +11,7 @@ use std::{ ptr::addr_of, }; -pub use bindings::hwaddr; +pub use bindings::{hwaddr, MemTxAttrs}; use crate::{ bindings::{self, device_endian, memory_region_init_io}, @@ -189,3 +189,15 @@ unsafe impl ObjectType for MemoryRegion { unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_MEMORY_REGION) }; } qom_isa!(MemoryRegion: Object); + +/// A special `MemTxAttrs` constant, used to indicate that no memory +/// attributes are specified. +/// +/// Bus masters which don't specify any attributes will get this, +/// which has all attribute bits clear except the topmost one +/// (so that we can distinguish "all attributes deliberately clear" +/// from "didn't specify" if necessary). +pub const MEMTXATTRS_UNSPECIFIED: MemTxAttrs = MemTxAttrs { + unspecified: true, + ..Zeroable::ZERO +}; -- cgit v1.1