From: Zhao Liu <zhao1....@intel.com> Define HPETFwEntry structure with the same memory layout as hpet_fw_entry in C.
Further, define the global hpet_cfg variable in Rust which is the same as the C version. This hpet_cfg variable in Rust will replace the C version one and allows both Rust code and C code to access it. The Rust version of hpet_cfg is self-contained, avoiding unsafe access to C code. Signed-off-by: Zhao Liu <zhao1....@intel.com> Link: https://lore.kernel.org/r/20250210030051.2562726-8-zhao1....@intel.com Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- rust/Cargo.lock | 8 ++++ rust/Cargo.toml | 1 + rust/hw/meson.build | 1 + rust/hw/timer/hpet/Cargo.toml | 18 ++++++++ rust/hw/timer/hpet/meson.build | 18 ++++++++ rust/hw/timer/hpet/src/fw_cfg.rs | 71 ++++++++++++++++++++++++++++++++ rust/hw/timer/hpet/src/lib.rs | 10 +++++ rust/hw/timer/meson.build | 1 + rust/qemu-api/src/zeroable.rs | 6 ++- 9 files changed, 132 insertions(+), 2 deletions(-) create mode 100644 rust/hw/timer/hpet/Cargo.toml create mode 100644 rust/hw/timer/hpet/meson.build create mode 100644 rust/hw/timer/hpet/src/fw_cfg.rs create mode 100644 rust/hw/timer/hpet/src/lib.rs create mode 100644 rust/hw/timer/meson.build diff --git a/rust/Cargo.lock b/rust/Cargo.lock index c0c6069247a..79e142723b8 100644 --- a/rust/Cargo.lock +++ b/rust/Cargo.lock @@ -37,6 +37,14 @@ version = "1.12.0" source = "registry+https://github.com/rust-lang/crates.io-index"; checksum = "3dca9240753cf90908d7e4aac30f630662b02aebaa1b58a3cadabdb23385b58b" +[[package]] +name = "hpet" +version = "0.1.0" +dependencies = [ + "qemu_api", + "qemu_api_macros", +] + [[package]] name = "itertools" version = "0.11.0" diff --git a/rust/Cargo.toml b/rust/Cargo.toml index 5b0cb559286..5041d6291fd 100644 --- a/rust/Cargo.toml +++ b/rust/Cargo.toml @@ -4,6 +4,7 @@ members = [ "qemu-api-macros", "qemu-api", "hw/char/pl011", + "hw/timer/hpet", ] [workspace.lints.rust] diff --git a/rust/hw/meson.build b/rust/hw/meson.build index 860196645e7..9749d4adfc9 100644 --- a/rust/hw/meson.build +++ b/rust/hw/meson.build @@ -1 +1,2 @@ subdir('char') +subdir('timer') diff --git a/rust/hw/timer/hpet/Cargo.toml b/rust/hw/timer/hpet/Cargo.toml new file mode 100644 index 00000000000..147f216e725 --- /dev/null +++ b/rust/hw/timer/hpet/Cargo.toml @@ -0,0 +1,18 @@ +[package] +name = "hpet" +version = "0.1.0" +edition = "2021" +authors = ["Zhao Liu <zhao1....@intel.com>"] +license = "GPL-2.0-or-later" +description = "IA-PC High Precision Event Timer emulation in Rust" +rust-version = "1.63.0" + +[lib] +crate-type = ["staticlib"] + +[dependencies] +qemu_api = { path = "../../../qemu-api" } +qemu_api_macros = { path = "../../../qemu-api-macros" } + +[lints] +workspace = true diff --git a/rust/hw/timer/hpet/meson.build b/rust/hw/timer/hpet/meson.build new file mode 100644 index 00000000000..c2d7c0532ca --- /dev/null +++ b/rust/hw/timer/hpet/meson.build @@ -0,0 +1,18 @@ +_libhpet_rs = static_library( + 'hpet', + files('src/lib.rs'), + override_options: ['rust_std=2021', 'build.rust_std=2021'], + rust_abi: 'rust', + dependencies: [ + qemu_api, + qemu_api_macros, + ], +) + +rust_devices_ss.add(when: 'CONFIG_X_HPET_RUST', if_true: [declare_dependency( + link_whole: [_libhpet_rs], + # Putting proc macro crates in `dependencies` is necessary for Meson to find + # them when compiling the root per-target static rust lib. + dependencies: [qemu_api_macros], + variables: {'crate': 'hpet'}, +)]) diff --git a/rust/hw/timer/hpet/src/fw_cfg.rs b/rust/hw/timer/hpet/src/fw_cfg.rs new file mode 100644 index 00000000000..849e277d483 --- /dev/null +++ b/rust/hw/timer/hpet/src/fw_cfg.rs @@ -0,0 +1,71 @@ +// Copyright (C) 2024 Intel Corporation. +// Author(s): Zhao Liu <zhai1....@intel.com> +// SPDX-License-Identifier: GPL-2.0-or-later + +#![allow(dead_code)] + +use std::ptr::addr_of_mut; + +use qemu_api::{cell::bql_locked, impl_zeroable, zeroable::Zeroable}; + +/// Each `HPETState` represents a Event Timer Block. The v1 spec supports +/// up to 8 blocks. QEMU only uses 1 block (in PC machine). +const HPET_MAX_NUM_EVENT_TIMER_BLOCK: usize = 8; + +#[repr(C, packed)] +#[derive(Copy, Clone, Default)] +pub struct HPETFwEntry { + pub event_timer_block_id: u32, + pub address: u64, + pub min_tick: u16, + pub page_prot: u8, +} +impl_zeroable!(HPETFwEntry); + +#[repr(C, packed)] +#[derive(Copy, Clone, Default)] +pub struct HPETFwConfig { + pub count: u8, + pub hpet: [HPETFwEntry; HPET_MAX_NUM_EVENT_TIMER_BLOCK], +} +impl_zeroable!(HPETFwConfig); + +#[allow(non_upper_case_globals)] +#[no_mangle] +pub static mut hpet_fw_cfg: HPETFwConfig = HPETFwConfig { + count: u8::MAX, + ..Zeroable::ZERO +}; + +impl HPETFwConfig { + pub(crate) fn assign_hpet_id() -> usize { + assert!(bql_locked()); + // SAFETY: all accesses go through these methods, which guarantee + // that the accesses are protected by the BQL. + let mut fw_cfg = unsafe { *addr_of_mut!(hpet_fw_cfg) }; + + if fw_cfg.count == u8::MAX { + // first instance + fw_cfg.count = 0; + } + + if fw_cfg.count == 8 { + // TODO: Add error binding: error_setg() + panic!("Only 8 instances of HPET is allowed"); + } + + let id: usize = fw_cfg.count.into(); + fw_cfg.count += 1; + id + } + + pub(crate) fn update_hpet_cfg(hpet_id: usize, timer_block_id: u32, address: u64) { + assert!(bql_locked()); + // SAFETY: all accesses go through these methods, which guarantee + // that the accesses are protected by the BQL. + let mut fw_cfg = unsafe { *addr_of_mut!(hpet_fw_cfg) }; + + fw_cfg.hpet[hpet_id].event_timer_block_id = timer_block_id; + fw_cfg.hpet[hpet_id].address = address; + } +} diff --git a/rust/hw/timer/hpet/src/lib.rs b/rust/hw/timer/hpet/src/lib.rs new file mode 100644 index 00000000000..44e9f3fb8ab --- /dev/null +++ b/rust/hw/timer/hpet/src/lib.rs @@ -0,0 +1,10 @@ +// Copyright (C) 2024 Intel Corporation. +// Author(s): Zhao Liu <zhai1....@intel.com> +// SPDX-License-Identifier: GPL-2.0-or-later + +//! # HPET QEMU Device Model +//! +//! This library implements a device model for the IA-PC HPET (High +//! Precision Event Timers) device in QEMU. + +pub mod fw_cfg; diff --git a/rust/hw/timer/meson.build b/rust/hw/timer/meson.build new file mode 100644 index 00000000000..22a84f15536 --- /dev/null +++ b/rust/hw/timer/meson.build @@ -0,0 +1 @@ +subdir('hpet') diff --git a/rust/qemu-api/src/zeroable.rs b/rust/qemu-api/src/zeroable.rs index 9f009606b1a..cd424e6ea05 100644 --- a/rust/qemu-api/src/zeroable.rs +++ b/rust/qemu-api/src/zeroable.rs @@ -56,6 +56,7 @@ pub unsafe trait Zeroable: Default { /// ## Differences with `core::mem::zeroed` /// /// `const_zero` zeroes padding bits, while `core::mem::zeroed` doesn't +#[macro_export] macro_rules! const_zero { // This macro to produce a type-generic zero constant is taken from the // const_zero crate (v0.1.1): @@ -77,10 +78,11 @@ union TypeAsBytes { } /// A wrapper to implement the `Zeroable` trait through the `const_zero` macro. +#[macro_export] macro_rules! impl_zeroable { ($type:ty) => { - unsafe impl Zeroable for $type { - const ZERO: Self = unsafe { const_zero!($type) }; + unsafe impl $crate::zeroable::Zeroable for $type { + const ZERO: Self = unsafe { $crate::const_zero!($type) }; } }; } -- 2.48.1
