summary refs log tree commit diff stats
path: root/rust/qemu-api/src (follow)
Commit message (Collapse)AuthorAgeFilesLines
...
* rust: qom: rename Class trait to ClassInitImplPaolo Bonzini2024-12-101-3/+22
| | | | | | While at it, document it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: qom: add default definitions for ObjectImplPaolo Bonzini2024-12-101-4/+4
| | | | | | Remove a bunch of duplicate const definitions. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: add a bit operation modulePaolo Bonzini2024-12-103-0/+122
| | | | | | | | | | | | | | | | | | | The bindgen supports `static inline` function binding since v0.64.0 as an experimental feature (`--wrap-static-fns`), and stabilizes it after v0.70.0. But the oldest version of bindgen supported by QEMU is v0.60.1, so there's no way to generate the binding for deposit64() which is `static inline` (in include/qemu/bitops.h). Instead, implement it by hand in Rust and make it available for all unsigned types through an IntegerExt trait. Since it only involves bit operations, the Rust version of the code is almost identical to the original C version, but it applies to more types than just u64. Signed-off-by: Zhao Liu <zhao1.liu@intel.com> Co-authored-by: Zhao Liu <zhao1.liu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: add bindings for interrupt sourcesPaolo Bonzini2024-12-103-0/+120
| | | | | | | | | | | | | | | The InterruptSource bindings let us call qemu_set_irq() and sysbus_init_irq() as safe code. Interrupt sources, qemu_irq in C code, are pointers to IRQState objects. They are QOM link properties and can be written to outside the control of the device (i.e. from a shared reference); therefore they must be interior-mutable in Rust. Since thread-safety is provided by the BQL, what we want here is the newly-introduced BqlCell. A pointer to the contents of the BqlCell (an IRQState**, or equivalently qemu_irq*) is then passed to the C sysbus_init_irq function. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: define preludePaolo Bonzini2024-12-102-0/+11
| | | | | | | | Add a module that will contain frequently used traits and occasionally structs. They can be included quickly with "use qemu_api::prelude::*". Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: cell: add BQL-enforcing RefCell variantPaolo Bonzini2024-12-101-10/+534
| | | | | | | | | | | | | | | Similar to the existing BqlCell, introduce a custom interior mutability primitive that resembles RefCell but accounts for QEMU's threading model. Borrowing the RefCell requires proving that the BQL is held, and attempting to access without the BQL is a runtime panic. Almost all of the code was taken from Rust's standard library, while removing unstable features and probably-unnecessary functionality that amounts to 60% of the original code. A lot of what's left is documentation, as well as unit tests in the form of doctests. These are not yet integrated in "make check" but can be run with "cargo test --doc". Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: cell: add BQL-enforcing Cell variantPaolo Bonzini2024-12-102-0/+299
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | QEMU objects usually have their pointer shared with the "outside world" very early in their lifetime, for example when they create their MemoryRegions. Because at this point it is not valid anymore to create a &mut reference to the device, individual parts of the device struct must be made mutable in a controlled manner. QEMU's Big Lock (BQL) effectively turns multi-threaded code into single-threaded code while device code runs, as long as the BQL is not released while the device is borrowed (because C code could sneak in and mutate the device). We can then introduce custom interior mutability primitives that are semantically similar to the standard library's (single-threaded) Cell and RefCell, but account for QEMU's threading model. Accessing the "BqlCell" or borrowing the "BqlRefCell" requires proving that the BQL is held, and attempting to access without the BQL is a runtime panic, similar to RefCell's already-borrowed panic. With respect to naming I also considered omitting the "Bql" prefix or moving it to the module, e.g. qemu_api::bql::{Cell, RefCell}. However, this could easily lead to mistakes and confusion; for example rustc could suggest the wrong import, leading to subtle bugs. As a start introduce the an equivalent of Cell. Almost all of the code was taken from Rust's standard library, while removing unstable features and probably-unnecessary functionality that constitute a large of the original code. A lot of what's left is documentation, as well as unit tests in the form of doctests. These are not yet integrated in "make check" but can be run with "cargo test --doc". Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust/qemu-api: Fix fragment-specifiers in define_property macroJunjie Mao2024-12-101-2/+2
| | | | | | | | | | | | | | | | | | For the matcher of macro, "expr" is used for expressions, while "ident" is used for variable/function names, and "ty" matches types. In define_property macro, $field is a member name of type $state, so it should be defined as "ident", though offset_of! doesn't complain about this. $type is the type of $field, since it is not used in the macro, so that no type mismatch error is triggered either. Fix fragment-specifiers of $field and $type. Signed-off-by: Junjie Mao <junjie.mao@hotmail.com> Co-developed-by: Zhao Liu <zhao1.liu@intel.com> Signed-off-by: Zhao Liu <zhao1.liu@intel.com> Link: https://lore.kernel.org/r/20241017143245.1248589-2-zhao1.liu@intel.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: fix doc test syntaxPaolo Bonzini2024-12-101-3/+3
| | | | | | | Allow "cargo test --doc" to pass. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: build: establish a baseline of lints across all cratesPaolo Bonzini2024-12-101-3/+3
| | | | | | | | | | | | | | | | Many lints that default to allow can be helpful in detecting bugs or keeping the code style homogeneous. Add them liberally, though perhaps not as liberally as in hw/char/pl011/src/lib.rs. In particular, enabling entire groups can be problematic because of bitrot when new links are added in the future. For Clippy, this is actually a feature that is only present in Cargo 1.74.0 but, since we are not using Cargo to *build* QEMU, only developers will need a new-enough cargo and only to run tools such as clippy. The requirement does not apply to distros that are building QEMU. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: allow using build-root bindings.rs from cargoPaolo Bonzini2024-12-102-22/+29
| | | | | | | | | | | | | | Right now, using cargo with QEMU requires copying by hand the bindings.rs to the source tree. Instead, we can use an include file to escape the cage of cargo's mandated source directory structure. By running cargo within meson's "devenv" and adding a MESON_BUILD_ROOT environment variable, it is easy for build.rs to find the file. However, the file must be symlinked into cargo's output directory for rust-analyzer to find it. Suggested-by: Junjie Mao <junjie.mao@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: do not use --generate-cstrPaolo Bonzini2024-11-051-0/+10
| | | | | | | | --generate-cstr is a good idea and generally the right thing to do, but it is not available in Debian 12 and Ubuntu 22.04. Work around the absence. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: do not use MaybeUninit::zeroed()Paolo Bonzini2024-11-051-14/+77
| | | | | | | | | | | | MaybeUninit::zeroed() is handy but is not available as a "const" function until Rust 1.75.0. Remove the default implementation of Zeroable::ZERO, and write by hand the definitions for those types that need it. It may be possible to add automatic implementation of the trait, via a procedural macro and/or a trick similar to offset_of!, but do it the easy way for now. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: introduce alternative implementation of offset_of!Junjie Mao2024-11-054-9/+174
| | | | | | | | | | | | | | | | | | | | | offset_of! was stabilized in Rust 1.77.0. Use an alternative implemenation that was found on the Rust forums, and whose author agreed to license as MIT for use in QEMU. The alternative allows only one level of field access, but apart from this can be used just by replacing core::mem::offset_of! with qemu_api::offset_of!. The actual implementation of offset_of! is done in a declarative macro, but for simplicity and to avoid introducing an extra level of indentation, the trigger is a procedural macro #[derive(offsets)]. The procedural macro is perhaps a bit overengineered, but it helps introducing some idioms that will be useful in the future as well. Signed-off-by: Junjie Mao <junjie.mao@hotmail.com> Co-developed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: introduce a c_str macroPaolo Bonzini2024-11-053-1/+55
| | | | | | | | | This allows CStr constants to be defined easily on Rust 1.63.0, while checking that there are no embedded NULs. c"" literals were only stabilized in Rust 1.77.0. Reviewed-by: Zhao Liu <zhao1.liu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: use std::os::raw instead of core::ffiPaolo Bonzini2024-11-054-13/+16
| | | | | | | | | | core::ffi::c_* types were introduced in Rust 1.64.0. Use the older types in std::os::raw, which are now aliases of the types in core::ffi. There is no need to compile QEMU as no_std, so this is acceptable as long as we support a version of Debian with Rust 1.63.0. Reviewed-by: Zhao Liu <zhao1.liu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: add definitions for vmstateManos Pitsidianakis2024-11-053-21/+363
| | | | | | | | | | | | | | | | | | | | | | | Add a new qemu_api module, `vmstate`. Declare a bunch of Rust macros declared that are equivalent in spirit to the C macros in include/migration/vmstate.h. For example the Rust of equivalent of the C macro: VMSTATE_UINT32(field_name, struct_name) is: vmstate_uint32!(field_name, StructName) This breathtaking development will allow us to reach feature parity between the Rust and C pl011 implementations. Extracted from a patch by Manos Pitsidianakis (https://lore.kernel.org/qemu-devel/20241024-rust-round-2-v1-4-051e7a25b978@linaro.org/). Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: provide safe wrapper for MaybeUninit::zeroed()Paolo Bonzini2024-11-053-4/+28
| | | | | | | | | | | | | | MaybeUninit::zeroed() is handy, but it introduces unsafe (and has a pretty heavy syntax in general). Introduce a trait that provides the same functionality while staying within safe Rust. In addition, MaybeUninit::zeroed() is not available as a "const" function until Rust 1.75.0, so this also prepares for having handwritten implementations of the trait until we can assume that version. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: make properties array immutablePaolo Bonzini2024-11-051-34/+8
| | | | | | | | | | | | | | | Now that device_class_set_props() takes a const pointer, the only part of "define_property!" that needs to be non-const is the call to try_into(). This in turn will only break if offset_of returns a value with the most significant bit set (i.e. a struct size that is >=2^31 or >= 2^63, respectively on 32- and 64-bit system), which is impossible. Just use a cast and clean everything up to remove the run-time initialization. This also removes a use of OnceLock, which was only stabilized in 1.70.0. Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: clean up define_property macroPaolo Bonzini2024-11-051-24/+7
| | | | | | | | | Use the "struct update" syntax to initialize most of the fields to zero, and simplify the handmade type-checking of $name. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: cleanup module_init!, use it from #[derive(Object)]Paolo Bonzini2024-11-051-38/+27
| | | | | | | | | | Remove the duplicate code by using the module_init! macro; at the same time, simplify how module_init! is used, by taking inspiration from the implementation of #[derive(Object)]. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: build integration test for the qemu_api cratePaolo Bonzini2024-11-052-52/+0
| | | | | | | | | | | | Adjust the integration test to compile with a subset of QEMU object files, and make it actually create an object of the class it defines. Follow the Rust filesystem conventions, where tests go in tests/ if they use the library in the same way any other code would. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: modernize link_section usage for ELF platformsPaolo Bonzini2024-11-051-4/+10
| | | | | | | | | | | | | | | Some newer ABI implementations do not provide .ctors; and while some linkers rewrite .ctors into .init_array, not all of them do. Use the newer .init_array ABI, which works more reliably, and apply it to all non-Apple, non-Windows platforms. This is similar to how the ctor crate operates; without this change, "#[derive(Object)]" does not work on Fedora 41. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Zhao Liu <zhao1.liu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: remove uses of #[no_mangle]Paolo Bonzini2024-11-052-3/+0
| | | | | | | | | | Mangled symbols do not cause any issue; disabling mangling is only useful if C headers reference the Rust function, which is not the case here. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Zhao Liu <zhao1.liu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: do not use --no-size_t-is-usizePaolo Bonzini2024-11-051-3/+3
| | | | | | | | | | | This is not necessary and makes it harder to write code that is portable between 32- and 64-bit systems: it adds extra casts even though size_of, align_of or offset_of already return the right type. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Zhao Liu <zhao1.liu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* meson: pass rustc_args when building all cratesPaolo Bonzini2024-11-051-4/+6
| | | | | | | | | rustc_args is needed to smooth the difference in warnings between the various versions of rustc. Always include those arguments. Reviewed-by: Junjie Mao <junjie.mao@hotmail.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* rust: add crate to expose bindings and interfacesManos Pitsidianakis2024-10-114-0/+440
Add rust/qemu-api, which exposes rust-bindgen generated FFI bindings and provides some declaration macros for symbols visible to the rest of QEMU. Co-authored-by: Junjie Mao <junjie.mao@intel.com> Co-authored-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Junjie Mao <junjie.mao@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org> Link: https://lore.kernel.org/r/0fb23fbe211761b263aacec03deaf85c0cc39995.1727961605.git.manos.pitsidianakis@linaro.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>