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authorStefan Hajnoczi <stefanha@redhat.com>2025-02-10 10:23:03 -0500
committerStefan Hajnoczi <stefanha@redhat.com>2025-02-10 10:23:03 -0500
commit9c72ba3af2587d2e2870ea0f92aa20de336a86f2 (patch)
tree8c48a7ae252af795fb6b60c61070ec76e0a02199
parent852712695749c0ad23cca1d9983f225b14371933 (diff)
parent476d6e4c9c4965734d6f47ee299ac9f84440a9b3 (diff)
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Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging
* tcg/optimize: optimize TSTNE using smask and zmask * target/i386: fix exceptions for 0 * Inf + QNaN * rust: cleanups to the configuration and the warnings * rust: add developer docs # -----BEGIN PGP SIGNATURE----- # # iQFIBAABCAAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmep0nsUHHBib256aW5p # QHJlZGhhdC5jb20ACgkQv/vSX3jHroN0aggAo8mKY4c7LGLF+5xGM1W/ZLxaBrMN # 4/LGMV3UJJq+OIEb+e7ThtfyHzcAsYXdO2SIMJ6ffW58ukmwM1SycA8WUjG3JMya # m05dVnI//D/G7iqYgyNlsiTbqazdr3P/Ha0ty10l9K9dL3SjB3Nm3xLD4XnD3tzM # U+0yXrn1ngMZ3Y1knTuWwjoH7JT5QftwGCVZ5aeq0KlSAvWb8M8jupYFunLBcZ0z # LkFSWXbxhw9HRkI+Lp6c2IjIBDEd7267tEfnXf+d29ykVnrdyIWgyYw08/Un72i+ # C5hNEUMiwcD7preTYX5YqDcxSASG1zWNFzEWGhTphMWf1O60f2PIXMWX5g== # =0KKa # -----END PGP SIGNATURE----- # gpg: Signature made Mon 10 Feb 2025 05:18:35 EST # gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83 # gpg: issuer "pbonzini@redhat.com" # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full] # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full] # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * tag 'for-upstream' of https://gitlab.com/bonzini/qemu: rust: restrict missing_const_for_fn to qemu_api crate rust: pl011: use default set of lints tcg/optimize: optimize TSTNE using smask and zmask tests/tcg/x86_64/fma: Test some x86 fused-multiply-add cases target/i386: Do not raise Invalid for 0 * Inf + QNaN rust: add clippy configuration file rust: add docs rust: include rust_version in Cargo.toml rust: remove unnecessary Cargo.toml metadata Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
-rw-r--r--docs/devel/index-process.rst1
-rw-r--r--docs/devel/rust.rst430
-rw-r--r--fpu/softfloat-parts.c.inc5
-rw-r--r--include/fpu/softfloat-types.h16
-rw-r--r--rust/Cargo.toml1
-rw-r--r--rust/clippy.toml2
-rw-r--r--rust/hw/char/pl011/Cargo.toml4
-rw-r--r--rust/hw/char/pl011/README.md31
-rw-r--r--rust/hw/char/pl011/src/device_class.rs1
-rw-r--r--rust/hw/char/pl011/src/lib.rs23
-rw-r--r--rust/qemu-api-macros/Cargo.toml4
-rw-r--r--rust/qemu-api-macros/README.md1
-rw-r--r--rust/qemu-api/Cargo.toml1
-rw-r--r--rust/qemu-api/src/lib.rs1
-rw-r--r--target/i386/tcg/fpu_helper.c5
-rw-r--r--tcg/optimize.c13
-rw-r--r--tests/tcg/x86_64/Makefile.target1
-rw-r--r--tests/tcg/x86_64/fma.c109
18 files changed, 581 insertions, 68 deletions
diff --git a/docs/devel/index-process.rst b/docs/devel/index-process.rst
index 362f97e..cb7c664 100644
--- a/docs/devel/index-process.rst
+++ b/docs/devel/index-process.rst
@@ -17,3 +17,4 @@ Notes about how to interact with the community and how and where to submit patch
stable-process
submitting-a-pull-request
secure-coding-practices
+ rust
diff --git a/docs/devel/rust.rst b/docs/devel/rust.rst
new file mode 100644
index 0000000..390aae4
--- /dev/null
+++ b/docs/devel/rust.rst
@@ -0,0 +1,430 @@
+.. |msrv| replace:: 1.63.0
+
+Rust in QEMU
+============
+
+Rust in QEMU is a project to enable using the Rust programming language
+to add new functionality to QEMU.
+
+Right now, the focus is on making it possible to write devices that inherit
+from ``SysBusDevice`` in `*safe*`__ Rust. Later, it may become possible
+to write other kinds of devices (e.g. PCI devices that can do DMA),
+complete boards, or backends (e.g. block device formats).
+
+__ https://doc.rust-lang.org/nomicon/meet-safe-and-unsafe.html
+
+Building the Rust in QEMU code
+------------------------------
+
+The Rust in QEMU code is included in the emulators via Meson. Meson
+invokes rustc directly, building static libraries that are then linked
+together with the C code. This is completely automatic when you run
+``make`` or ``ninja``.
+
+However, QEMU's build system also tries to be easy to use for people who
+are accustomed to the more "normal" Cargo-based development workflow.
+In particular:
+
+* the set of warnings and lints that are used to build QEMU always
+ comes from the ``rust/Cargo.toml`` workspace file
+
+* it is also possible to use ``cargo`` for common Rust-specific coding
+ tasks, in particular to invoke ``clippy``, ``rustfmt`` and ``rustdoc``.
+
+To this end, QEMU includes a ``build.rs`` build script that picks up
+generated sources from QEMU's build directory and puts it in Cargo's
+output directory (typically ``rust/target/``). A vanilla invocation
+of Cargo will complain that it cannot find the generated sources,
+which can be fixed in different ways:
+
+* by using special shorthand targets in the QEMU build directory::
+
+ make clippy
+ make rustfmt
+ make rustdoc
+
+* by invoking ``cargo`` through the Meson `development environment`__
+ feature::
+
+ pyvenv/bin/meson devenv -w ../rust cargo clippy --tests
+ pyvenv/bin/meson devenv -w ../rust cargo fmt
+
+ If you are going to use ``cargo`` repeatedly, ``pyvenv/bin/meson devenv``
+ will enter a shell where commands like ``cargo clippy`` just work.
+
+__ https://mesonbuild.com/Commands.html#devenv
+
+* by pointing the ``MESON_BUILD_ROOT`` to the top of your QEMU build
+ tree. This third method is useful if you are using ``rust-analyzer``;
+ you can set the environment variable through the
+ ``rust-analyzer.cargo.extraEnv`` setting.
+
+As shown above, you can use the ``--tests`` option as usual to operate on test
+code. Note however that you cannot *build* or run tests via ``cargo``, because
+they need support C code from QEMU that Cargo does not know about. Tests can
+be run via ``meson test`` or ``make``::
+
+ make check-rust
+
+Building Rust code with ``--enable-modules`` is not supported yet.
+
+Supported tools
+'''''''''''''''
+
+QEMU supports rustc version 1.63.0 and newer. Notably, the following features
+are missing:
+
+* ``core::ffi`` (1.64.0). Use ``std::os::raw`` and ``std::ffi`` instead.
+
+* ``cast_mut()``/``cast_const()`` (1.65.0). Use ``as`` instead.
+
+* "let ... else" (1.65.0). Use ``if let`` instead. This is currently patched
+ in QEMU's vendored copy of the bilge crate.
+
+* Generic Associated Types (1.65.0)
+
+* ``CStr::from_bytes_with_nul()`` as a ``const`` function (1.72.0).
+
+* "Return position ``impl Trait`` in Traits" (1.75.0, blocker for including
+ the pinned-init create).
+
+* ``MaybeUninit::zeroed()`` as a ``const`` function (1.75.0). QEMU's
+ ``Zeroable`` trait can be implemented without ``MaybeUninit::zeroed()``,
+ so this would be just a cleanup.
+
+* ``c"" literals`` (stable in 1.77.0). QEMU provides a ``c_str!()`` macro
+ to define ``CStr`` constants easily
+
+* ``offset_of!`` (stable in 1.77.0). QEMU uses ``offset_of!()`` heavily; it
+ provides a replacement in the ``qemu_api`` crate, but it does not support
+ lifetime parameters and therefore ``&'a Something`` fields in the struct
+ may have to be replaced by ``NonNull<Something>``. *Nested* ``offset_of!``
+ was only stabilized in Rust 1.82.0, but it is not used.
+
+* inline const expression (stable in 1.79.0), currently worked around with
+ associated constants in the ``FnCall`` trait.
+
+* associated constants have to be explicitly marked ``'static`` (`changed in
+ 1.81.0`__)
+
+* ``&raw`` (stable in 1.82.0). Use ``addr_of!`` and ``addr_of_mut!`` instead,
+ though hopefully the need for raw pointers will go down over time.
+
+* ``new_uninit`` (stable in 1.82.0). This is used internally by the ``pinned_init``
+ crate, which is planned for inclusion in QEMU, but it can be easily patched
+ out.
+
+* referencing statics in constants (stable in 1.83.0). For now use a const
+ function; this is an important limitation for QEMU's migration stream
+ architecture (VMState). Right now, VMState lacks type safety because
+ it is hard to place the ``VMStateField`` definitions in traits.
+
+* associated const equality would be nice to have for some users of
+ ``callbacks::FnCall``, but is still experimental. ``ASSERT_IS_SOME``
+ replaces it.
+
+__ https://github.com/rust-lang/rust/pull/125258
+
+It is expected that QEMU will advance its minimum supported version of
+rustc to 1.77.0 as soon as possible; as of January 2025, blockers
+for that right now are Debian bookworm and 32-bit MIPS processors.
+This unfortunately means that references to statics in constants will
+remain an issue.
+
+QEMU also supports version 0.60.x of bindgen, which is missing option
+``--generate-cstr``. This option requires version 0.66.x and will
+be adopted as soon as supporting these older versions is not necessary
+anymore.
+
+Writing Rust code in QEMU
+-------------------------
+
+Right now QEMU includes three crates:
+
+* ``qemu_api`` for bindings to C code and useful functionality
+
+* ``qemu_api_macros`` defines several procedural macros that are useful when
+ writing C code
+
+* ``pl011`` (under ``rust/hw/char/pl011``) is the sample device that is being
+ used to further develop ``qemu_api`` and ``qemu_api_macros``. It is a functional
+ replacement for the ``hw/char/pl011.c`` file.
+
+This section explains how to work with them.
+
+Status
+''''''
+
+Modules of ``qemu_api`` can be defined as:
+
+- *complete*: ready for use in new devices; if applicable, the API supports the
+ full functionality available in C
+
+- *stable*: ready for production use, the API is safe and should not undergo
+ major changes
+
+- *proof of concept*: the API is subject to change but allows working with safe
+ Rust
+
+- *initial*: the API is in its initial stages; it requires large amount of
+ unsafe code; it might have soundness or type-safety issues
+
+The status of the modules is as follows:
+
+================ ======================
+module status
+================ ======================
+``assertions`` stable
+``bitops`` complete
+``callbacks`` complete
+``cell`` stable
+``c_str`` complete
+``irq`` complete
+``module`` complete
+``offset_of`` stable
+``qdev`` stable
+``qom`` stable
+``sysbus`` stable
+``vmstate`` proof of concept
+``zeroable`` stable
+================ ======================
+
+.. note::
+ API stability is not a promise, if anything because the C APIs are not a stable
+ interface either. Also, ``unsafe`` interfaces may be replaced by safe interfaces
+ later.
+
+Common pitfalls
+'''''''''''''''
+
+Rust has very strict rules with respect to how you get an exclusive (``&mut``)
+reference; failure to respect those rules is a source of undefined behavior.
+In particular, even if a value is loaded from a raw mutable pointer (``*mut``),
+it *cannot* be casted to ``&mut`` unless the value was stored to the ``*mut``
+from a mutable reference. Furthermore, it is undefined behavior if any
+shared reference was created between the store to the ``*mut`` and the load::
+
+ let mut p: u32 = 42;
+ let p_mut = &mut p; // 1
+ let p_raw = p_mut as *mut u32; // 2
+
+ // p_raw keeps the mutable reference "alive"
+
+ let p_shared = &p; // 3
+ println!("access from &u32: {}", *p_shared);
+
+ // Bring back the mutable reference, its lifetime overlaps
+ // with that of a shared reference.
+ let p_mut = unsafe { &mut *p_raw }; // 4
+ println!("access from &mut 32: {}", *p_mut);
+
+ println!("access from &u32: {}", *p_shared); // 5
+
+These rules can be tested with `MIRI`__, for example.
+
+__ https://github.com/rust-lang/miri
+
+Almost all Rust code in QEMU will involve QOM objects, and pointers to these
+objects are *shared*, for example because they are part of the QOM composition
+tree. This creates exactly the above scenario:
+
+1. a QOM object is created
+
+2. a ``*mut`` is created, for example as the opaque value for a ``MemoryRegion``
+
+3. the QOM object is placed in the composition tree
+
+4. a memory access dereferences the opaque value to a ``&mut``
+
+5. but the shared reference is still present in the composition tree
+
+Because of this, QOM objects should almost always use ``&self`` instead
+of ``&mut self``; access to internal fields must use *interior mutability*
+to go from a shared reference to a ``&mut``.
+
+Whenever C code provides you with an opaque ``void *``, avoid converting it
+to a Rust mutable reference, and use a shared reference instead. Rust code
+will then have to use QEMU's ``BqlRefCell`` and ``BqlCell`` type, which
+enforce that locking rules for the "Big QEMU Lock" are respected. These cell
+types are also known to the ``vmstate`` crate, which is able to "look inside"
+them when building an in-memory representation of a ``struct``s layout.
+Note that the same is not true of a ``RefCell`` or ``Mutex``.
+
+In the future, similar cell types might also be provided for ``AioContext``-based
+locking as well.
+
+Writing bindings to C code
+''''''''''''''''''''''''''
+
+Here are some things to keep in mind when working on the ``qemu_api`` crate.
+
+**Look at existing code**
+ Very often, similar idioms in C code correspond to similar tricks in
+ Rust bindings. If the C code uses ``offsetof``, look at qdev properties
+ or ``vmstate``. If the C code has a complex const struct, look at
+ ``MemoryRegion``. Reuse existing patterns for handling lifetimes;
+ for example use ``&T`` for QOM objects that do not need a reference
+ count (including those that can be embedded in other objects) and
+ ``Owned<T>`` for those that need it.
+
+**Use the type system**
+ Bindings often will need access information that is specific to a type
+ (either a builtin one or a user-defined one) in order to pass it to C
+ functions. Put them in a trait and access it through generic parameters.
+ The ``vmstate`` module has examples of how to retrieve type information
+ for the fields of a Rust ``struct``.
+
+**Prefer unsafe traits to unsafe functions**
+ Unsafe traits are much easier to prove correct than unsafe functions.
+ They are an excellent place to store metadata that can later be accessed
+ by generic functions. C code usually places metadata in global variables;
+ in Rust, they can be stored in traits and then turned into ``static``
+ variables. Often, unsafe traits can be generated by procedural macros.
+
+**Document limitations due to old Rust versions**
+ If you need to settle for an inferior solution because of the currently
+ supported set of Rust versions, document it in the source and in this
+ file. This ensures that it can be fixed when the minimum supported
+ version is bumped.
+
+**Keep locking in mind**.
+ When marking a type ``Sync``, be careful of whether it needs the big
+ QEMU lock. Use ``BqlCell`` and ``BqlRefCell`` for interior data,
+ or assert ``bql_locked()``.
+
+**Don't be afraid of complexity, but document and isolate it**
+ It's okay to be tricky; device code is written more often than bindings
+ code and it's important that it is idiomatic. However, you should strive
+ to isolate any tricks in a place (for example a ``struct``, a trait
+ or a macro) where it can be documented and tested. If needed, include
+ toy versions of the code in the documentation.
+
+Writing procedural macros
+'''''''''''''''''''''''''
+
+By conventions, procedural macros are split in two functions, one
+returning ``Result<proc_macro2::TokenStream, MacroError>` with the body of
+the procedural macro, and the second returning ``proc_macro::TokenStream``
+which is the actual procedural macro. The former's name is the same as
+the latter with the ``_or_error`` suffix. The code for the latter is more
+or less fixed; it follows the following template, which is fixed apart
+from the type after ``as`` in the invocation of ``parse_macro_input!``::
+
+ #[proc_macro_derive(Object)]
+ pub fn derive_object(input: TokenStream) -> TokenStream {
+ let input = parse_macro_input!(input as DeriveInput);
+ let expanded = derive_object_or_error(input).unwrap_or_else(Into::into);
+
+ TokenStream::from(expanded)
+ }
+
+The ``qemu_api_macros`` crate has utility functions to examine a
+``DeriveInput`` and perform common checks (e.g. looking for a struct
+with named fields). These functions return ``Result<..., MacroError>``
+and can be used easily in the procedural macro function::
+
+ fn derive_object_or_error(input: DeriveInput) ->
+ Result<proc_macro2::TokenStream, MacroError>
+ {
+ is_c_repr(&input, "#[derive(Object)]")?;
+
+ let name = &input.ident;
+ let parent = &get_fields(&input, "#[derive(Object)]")?[0].ident;
+ ...
+ }
+
+Use procedural macros with care. They are mostly useful for two purposes:
+
+* Performing consistency checks; for example ``#[derive(Object)]`` checks
+ that the structure has ``#[repr[C])`` and that the type of the first field
+ is consistent with the ``ObjectType`` declaration.
+
+* Extracting information from Rust source code into traits, typically based
+ on types and attributes. For example, ``#[derive(TryInto)]`` builds an
+ implementation of ``TryFrom``, and it uses the ``#[repr(...)]`` attribute
+ as the ``TryFrom`` source and error types.
+
+Procedural macros can be hard to debug and test; if the code generation
+exceeds a few lines of code, it may be worthwhile to delegate work to
+"regular" declarative (``macro_rules!``) macros and write unit tests for
+those instead.
+
+
+Coding style
+''''''''''''
+
+Code should pass clippy and be formatted with rustfmt.
+
+Right now, only the nightly version of ``rustfmt`` is supported. This
+might change in the future. While CI checks for correct formatting via
+``cargo fmt --check``, maintainers can fix this for you when applying patches.
+
+It is expected that ``qemu_api`` provides full ``rustdoc`` documentation for
+bindings that are in their final shape or close.
+
+Adding dependencies
+-------------------
+
+Generally, the set of dependent crates is kept small. Think twice before
+adding a new external crate, especially if it comes with a large set of
+dependencies itself. Sometimes QEMU only needs a small subset of the
+functionality; see for example QEMU's ``assertions`` or ``c_str`` modules.
+
+On top of this recommendation, adding external crates to QEMU is a
+slightly complicated process, mostly due to the need to teach Meson how
+to build them. While Meson has initial support for parsing ``Cargo.lock``
+files, it is still highly experimental and is therefore not used.
+
+Therefore, external crates must be added as subprojects for Meson to
+learn how to build them, as well as to the relevant ``Cargo.toml`` files.
+The versions specified in ``rust/Cargo.lock`` must be the same as the
+subprojects; note that the ``rust/`` directory forms a Cargo `workspace`__,
+and therefore there is a single lock file for the whole build.
+
+__ https://doc.rust-lang.org/cargo/reference/workspaces.html#virtual-workspace
+
+Choose a version of the crate that works with QEMU's minimum supported
+Rust version (|msrv|).
+
+Second, a new ``wrap`` file must be added to teach Meson how to download the
+crate. The wrap file must be named ``NAME-SEMVER-rs.wrap``, where ``NAME``
+is the name of the crate and ``SEMVER`` is the version up to and including the
+first non-zero number. For example, a crate with version ``0.2.3`` will use
+``0.2`` for its ``SEMVER``, while a crate with version ``1.0.84`` will use ``1``.
+
+Third, the Meson rules to build the crate must be added at
+``subprojects/NAME-SEMVER-rs/meson.build``. Generally this includes:
+
+* ``subproject`` and ``dependency`` lines for all dependent crates
+
+* a ``static_library`` or ``rust.proc_macro`` line to perform the actual build
+
+* ``declare_dependency`` and a ``meson.override_dependency`` lines to expose
+ the result to QEMU and to other subprojects
+
+Remember to add ``native: true`` to ``dependency``, ``static_library`` and
+``meson.override_dependency`` for dependencies of procedural macros.
+If a crate is needed in both procedural macros and QEMU binaries, everything
+apart from ``subproject`` must be duplicated to build both native and
+non-native versions of the crate.
+
+It's important to specify the right compiler options. These include:
+
+* the language edition (which can be found in the ``Cargo.toml`` file)
+
+* the ``--cfg`` (which have to be "reverse engineered" from the ``build.rs``
+ file of the crate).
+
+* usually, a ``--cap-lints allow`` argument to hide warnings from rustc
+ or clippy.
+
+After every change to the ``meson.build`` file you have to update the patched
+version with ``meson subprojects update --reset ``NAME-SEMVER-rs``. This might
+be automated in the future.
+
+Also, after every change to the ``meson.build`` file it is strongly suggested to
+do a dummy change to the ``.wrap`` file (for example adding a comment like
+``# version 2``), which will help Meson notice that the subproject is out of date.
+
+As a last step, add the new subproject to ``scripts/archive-source.sh``,
+``scripts/make-release`` and ``subprojects/.gitignore``.
diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index fee05d0..73621f4 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -126,7 +126,8 @@ static FloatPartsN *partsN(pick_nan_muladd)(FloatPartsN *a, FloatPartsN *b,
float_raise(float_flag_invalid | float_flag_invalid_snan, s);
}
- if (infzero) {
+ if (infzero &&
+ !(s->float_infzeronan_rule & float_infzeronan_suppress_invalid)) {
/* This is (0 * inf) + NaN or (inf * 0) + NaN */
float_raise(float_flag_invalid | float_flag_invalid_imz, s);
}
@@ -144,7 +145,7 @@ static FloatPartsN *partsN(pick_nan_muladd)(FloatPartsN *a, FloatPartsN *b,
* Inf * 0 + NaN -- some implementations return the
* default NaN here, and some return the input NaN.
*/
- switch (s->float_infzeronan_rule) {
+ switch (s->float_infzeronan_rule & ~float_infzeronan_suppress_invalid) {
case float_infzeronan_dnan_never:
break;
case float_infzeronan_dnan_always:
diff --git a/include/fpu/softfloat-types.h b/include/fpu/softfloat-types.h
index 616c290..2e43d1d 100644
--- a/include/fpu/softfloat-types.h
+++ b/include/fpu/softfloat-types.h
@@ -280,11 +280,21 @@ typedef enum __attribute__((__packed__)) {
/* No propagation rule specified */
float_infzeronan_none = 0,
/* Result is never the default NaN (so always the input NaN) */
- float_infzeronan_dnan_never,
+ float_infzeronan_dnan_never = 1,
/* Result is always the default NaN */
- float_infzeronan_dnan_always,
+ float_infzeronan_dnan_always = 2,
/* Result is the default NaN if the input NaN is quiet */
- float_infzeronan_dnan_if_qnan,
+ float_infzeronan_dnan_if_qnan = 3,
+ /*
+ * Don't raise Invalid for 0 * Inf + NaN. Default is to raise.
+ * IEEE 754-2008 section 7.2 makes it implementation defined whether
+ * 0 * Inf + QNaN raises Invalid or not. Note that 0 * Inf + SNaN will
+ * raise the Invalid flag for the SNaN anyway.
+ *
+ * This is a flag which can be ORed in with any of the above
+ * DNaN behaviour options.
+ */
+ float_infzeronan_suppress_invalid = (1 << 7),
} FloatInfZeroNaNRule;
/*
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 5b6b6ca..5b0cb55 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -52,7 +52,6 @@ empty_structs_with_brackets = "deny"
ignored_unit_patterns = "deny"
implicit_clone = "deny"
macro_use_imports = "deny"
-missing_const_for_fn = "deny"
missing_safety_doc = "deny"
multiple_crate_versions = "deny"
mut_mut = "deny"
diff --git a/rust/clippy.toml b/rust/clippy.toml
new file mode 100644
index 0000000..5d190f9
--- /dev/null
+++ b/rust/clippy.toml
@@ -0,0 +1,2 @@
+doc-valid-idents = ["PrimeCell", ".."]
+msrv = "1.63.0"
diff --git a/rust/hw/char/pl011/Cargo.toml b/rust/hw/char/pl011/Cargo.toml
index 58f3e85..f2296ca 100644
--- a/rust/hw/char/pl011/Cargo.toml
+++ b/rust/hw/char/pl011/Cargo.toml
@@ -4,14 +4,12 @@ version = "0.1.0"
edition = "2021"
authors = ["Manos Pitsidianakis <manos.pitsidianakis@linaro.org>"]
license = "GPL-2.0-or-later"
-readme = "README.md"
-homepage = "https://www.qemu.org"
description = "pl011 device model for QEMU"
-repository = "https://gitlab.com/epilys/rust-for-qemu"
resolver = "2"
publish = false
keywords = []
categories = []
+rust-version = "1.63.0"
[lib]
crate-type = ["staticlib"]
diff --git a/rust/hw/char/pl011/README.md b/rust/hw/char/pl011/README.md
deleted file mode 100644
index cd7dea3..0000000
--- a/rust/hw/char/pl011/README.md
+++ /dev/null
@@ -1,31 +0,0 @@
-# PL011 QEMU Device Model
-
-This library implements a device model for the PrimeCell® UART (PL011)
-device in QEMU.
-
-## Build static lib
-
-Host build target must be explicitly specified:
-
-```sh
-cargo build --target x86_64-unknown-linux-gnu
-```
-
-Replace host target triplet if necessary.
-
-## Generate Rust documentation
-
-To generate docs for this crate, including private items:
-
-```sh
-cargo doc --no-deps --document-private-items --target x86_64-unknown-linux-gnu
-```
-
-To include direct dependencies like `bilge` (bitmaps for register types):
-
-```sh
-cargo tree --depth 1 -e normal --prefix none \
- | cut -d' ' -f1 \
- | xargs printf -- '-p %s\n' \
- | xargs cargo doc --no-deps --document-private-items --target x86_64-unknown-linux-gnu
-```
diff --git a/rust/hw/char/pl011/src/device_class.rs b/rust/hw/char/pl011/src/device_class.rs
index 8a157a6..dbef93f 100644
--- a/rust/hw/char/pl011/src/device_class.rs
+++ b/rust/hw/char/pl011/src/device_class.rs
@@ -12,7 +12,6 @@ use qemu_api::{
use crate::device::{PL011Registers, PL011State};
-#[allow(clippy::missing_const_for_fn)]
extern "C" fn pl011_clock_needed(opaque: *mut c_void) -> bool {
let state = NonNull::new(opaque).unwrap().cast::<PL011State>();
unsafe { state.as_ref().migrate_clock }
diff --git a/rust/hw/char/pl011/src/lib.rs b/rust/hw/char/pl011/src/lib.rs
index e2df458..3c72f12 100644
--- a/rust/hw/char/pl011/src/lib.rs
+++ b/rust/hw/char/pl011/src/lib.rs
@@ -1,29 +1,18 @@
// Copyright 2024, Linaro Limited
// Author(s): Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
// SPDX-License-Identifier: GPL-2.0-or-later
-//
-// PL011 QEMU Device Model
-//
-// This library implements a device model for the PrimeCell® UART (PL011)
-// device in QEMU.
-//
-#![doc = include_str!("../README.md")]
+
+//! PL011 QEMU Device Model
+//!
+//! This library implements a device model for the PrimeCell® UART (PL011)
+//! device in QEMU.
+//!
//! # Library crate
//!
//! See [`PL011State`](crate::device::PL011State) for the device model type and
//! the [`registers`] module for register types.
-#![deny(
- clippy::correctness,
- clippy::suspicious,
- clippy::complexity,
- clippy::perf,
- clippy::cargo,
- clippy::nursery,
- clippy::style
-)]
#![allow(clippy::upper_case_acronyms)]
-#![allow(clippy::result_unit_err)]
use qemu_api::c_str;
diff --git a/rust/qemu-api-macros/Cargo.toml b/rust/qemu-api-macros/Cargo.toml
index 5a27b52..89dee1c 100644
--- a/rust/qemu-api-macros/Cargo.toml
+++ b/rust/qemu-api-macros/Cargo.toml
@@ -4,14 +4,12 @@ version = "0.1.0"
edition = "2021"
authors = ["Manos Pitsidianakis <manos.pitsidianakis@linaro.org>"]
license = "GPL-2.0-or-later"
-readme = "README.md"
-homepage = "https://www.qemu.org"
description = "Rust bindings for QEMU - Utility macros"
-repository = "https://gitlab.com/qemu-project/qemu/"
resolver = "2"
publish = false
keywords = []
categories = []
+rust-version = "1.63.0"
[lib]
proc-macro = true
diff --git a/rust/qemu-api-macros/README.md b/rust/qemu-api-macros/README.md
deleted file mode 100644
index f60f54a..0000000
--- a/rust/qemu-api-macros/README.md
+++ /dev/null
@@ -1 +0,0 @@
-# `qemu-api-macros` - Utility macros for defining QEMU devices
diff --git a/rust/qemu-api/Cargo.toml b/rust/qemu-api/Cargo.toml
index 4aa22f3..a51dd14 100644
--- a/rust/qemu-api/Cargo.toml
+++ b/rust/qemu-api/Cargo.toml
@@ -12,6 +12,7 @@ resolver = "2"
publish = false
keywords = []
categories = []
+rust-version = "1.63.0"
[dependencies]
qemu_api_macros = { path = "../qemu-api-macros" }
diff --git a/rust/qemu-api/src/lib.rs b/rust/qemu-api/src/lib.rs
index 83c6a98..3cf9371 100644
--- a/rust/qemu-api/src/lib.rs
+++ b/rust/qemu-api/src/lib.rs
@@ -3,6 +3,7 @@
// SPDX-License-Identifier: GPL-2.0-or-later
#![cfg_attr(not(MESON), doc = include_str!("../README.md"))]
+#![deny(clippy::missing_const_for_fn)]
#[rustfmt::skip]
pub mod bindings;
diff --git a/target/i386/tcg/fpu_helper.c b/target/i386/tcg/fpu_helper.c
index 3d764bc..de6d0b2 100644
--- a/target/i386/tcg/fpu_helper.c
+++ b/target/i386/tcg/fpu_helper.c
@@ -178,8 +178,11 @@ void cpu_init_fp_statuses(CPUX86State *env)
* "Fused-Multiply-ADD (FMA) Numeric Behavior" the NaN handling is
* specified -- for 0 * inf + NaN the input NaN is selected, and if
* there are multiple input NaNs they are selected in the order a, b, c.
+ * We also do not raise Invalid for the 0 * inf + (Q)NaN case.
*/
- set_float_infzeronan_rule(float_infzeronan_dnan_never, &env->sse_status);
+ set_float_infzeronan_rule(float_infzeronan_dnan_never |
+ float_infzeronan_suppress_invalid,
+ &env->sse_status);
set_float_3nan_prop_rule(float_3nan_prop_abc, &env->sse_status);
/* Default NaN: sign bit set, most significant frac bit set */
set_float_default_nan_pattern(0b11000000, &env->fp_status);
diff --git a/tcg/optimize.c b/tcg/optimize.c
index 8c6303e..bca11cc 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -766,6 +766,7 @@ static int do_constant_folding_cond1(OptContext *ctx, TCGOp *op, TCGArg dest,
TCGArg *p1, TCGArg *p2, TCGArg *pcond)
{
TCGCond cond;
+ TempOptInfo *i1;
bool swap;
int r;
@@ -783,19 +784,21 @@ static int do_constant_folding_cond1(OptContext *ctx, TCGOp *op, TCGArg dest,
return -1;
}
+ i1 = arg_info(*p1);
+
/*
* TSTNE x,x -> NE x,0
- * TSTNE x,-1 -> NE x,0
+ * TSTNE x,i -> NE x,0 if i includes all nonzero bits of x
*/
- if (args_are_copies(*p1, *p2) || arg_is_const_val(*p2, -1)) {
+ if (args_are_copies(*p1, *p2) ||
+ (arg_is_const(*p2) && (i1->z_mask & ~arg_info(*p2)->val) == 0)) {
*p2 = arg_new_constant(ctx, 0);
*pcond = tcg_tst_eqne_cond(cond);
return -1;
}
- /* TSTNE x,sign -> LT x,0 */
- if (arg_is_const_val(*p2, (ctx->type == TCG_TYPE_I32
- ? INT32_MIN : INT64_MIN))) {
+ /* TSTNE x,i -> LT x,0 if i only includes sign bit copies */
+ if (arg_is_const(*p2) && (arg_info(*p2)->val & ~i1->s_mask) == 0) {
*p2 = arg_new_constant(ctx, 0);
*pcond = tcg_tst_ltge_cond(cond);
return -1;
diff --git a/tests/tcg/x86_64/Makefile.target b/tests/tcg/x86_64/Makefile.target
index d6dff55..be20fc6 100644
--- a/tests/tcg/x86_64/Makefile.target
+++ b/tests/tcg/x86_64/Makefile.target
@@ -18,6 +18,7 @@ X86_64_TESTS += adox
X86_64_TESTS += test-1648
X86_64_TESTS += test-2175
X86_64_TESTS += cross-modifying-code
+X86_64_TESTS += fma
TESTS=$(MULTIARCH_TESTS) $(X86_64_TESTS) test-x86_64
else
TESTS=$(MULTIARCH_TESTS)
diff --git a/tests/tcg/x86_64/fma.c b/tests/tcg/x86_64/fma.c
new file mode 100644
index 0000000..09c622e
--- /dev/null
+++ b/tests/tcg/x86_64/fma.c
@@ -0,0 +1,109 @@
+/*
+ * Test some fused multiply add corner cases.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <inttypes.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+/*
+ * Perform one "n * m + a" operation using the vfmadd insn and return
+ * the result; on return *mxcsr_p is set to the bottom 6 bits of MXCSR
+ * (the Flag bits). If ftz is true then we set MXCSR.FTZ while doing
+ * the operation.
+ * We print the operation and its results to stdout.
+ */
+static uint64_t do_fmadd(uint64_t n, uint64_t m, uint64_t a,
+ bool ftz, uint32_t *mxcsr_p)
+{
+ uint64_t r;
+ uint32_t mxcsr = 0;
+ uint32_t ftz_bit = ftz ? (1 << 15) : 0;
+ uint32_t saved_mxcsr = 0;
+
+ asm volatile("stmxcsr %[saved_mxcsr]\n"
+ "stmxcsr %[mxcsr]\n"
+ "andl $0xffff7fc0, %[mxcsr]\n"
+ "orl %[ftz_bit], %[mxcsr]\n"
+ "ldmxcsr %[mxcsr]\n"
+ "movq %[a], %%xmm0\n"
+ "movq %[m], %%xmm1\n"
+ "movq %[n], %%xmm2\n"
+ /* xmm0 = xmm0 + xmm2 * xmm1 */
+ "vfmadd231sd %%xmm1, %%xmm2, %%xmm0\n"
+ "movq %%xmm0, %[r]\n"
+ "stmxcsr %[mxcsr]\n"
+ "ldmxcsr %[saved_mxcsr]\n"
+ : [r] "=r" (r), [mxcsr] "=m" (mxcsr),
+ [saved_mxcsr] "=m" (saved_mxcsr)
+ : [n] "r" (n), [m] "r" (m), [a] "r" (a),
+ [ftz_bit] "r" (ftz_bit)
+ : "xmm0", "xmm1", "xmm2");
+ *mxcsr_p = mxcsr & 0x3f;
+ printf("vfmadd132sd 0x%" PRIx64 " 0x%" PRIx64 " 0x%" PRIx64
+ " = 0x%" PRIx64 " MXCSR flags 0x%" PRIx32 "\n",
+ n, m, a, r, *mxcsr_p);
+ return r;
+}
+
+typedef struct testdata {
+ /* Input n, m, a */
+ uint64_t n;
+ uint64_t m;
+ uint64_t a;
+ bool ftz;
+ /* Expected result */
+ uint64_t expected_r;
+ /* Expected low 6 bits of MXCSR (the Flag bits) */
+ uint32_t expected_mxcsr;
+} testdata;
+
+static testdata tests[] = {
+ { 0, 0x7ff0000000000000, 0x7ff000000000aaaa, false, /* 0 * Inf + SNaN */
+ 0x7ff800000000aaaa, 1 }, /* Should be QNaN and does raise Invalid */
+ { 0, 0x7ff0000000000000, 0x7ff800000000aaaa, false, /* 0 * Inf + QNaN */
+ 0x7ff800000000aaaa, 0 }, /* Should be QNaN and does *not* raise Invalid */
+ /*
+ * These inputs give a result which is tiny before rounding but which
+ * becomes non-tiny after rounding. x86 is a "detect tininess after
+ * rounding" architecture, so it should give a non-denormal result and
+ * not set the Underflow flag (only the Precision flag for an inexact
+ * result).
+ */
+ { 0x3fdfffffffffffff, 0x001fffffffffffff, 0x801fffffffffffff, false,
+ 0x8010000000000000, 0x20 },
+ /*
+ * Flushing of denormal outputs to zero should also happen after
+ * rounding, so setting FTZ should not affect the result or the flags.
+ * QEMU currently does not emulate this correctly because we do the
+ * flush-to-zero check before rounding, so we incorrectly produce a
+ * zero result and set Underflow as well as Precision.
+ */
+#ifdef ENABLE_FAILING_TESTS
+ { 0x3fdfffffffffffff, 0x001fffffffffffff, 0x801fffffffffffff, true,
+ 0x8010000000000000, 0x20 }, /* Enabling FTZ shouldn't change flags */
+#endif
+};
+
+int main(void)
+{
+ bool passed = true;
+ for (int i = 0; i < ARRAY_SIZE(tests); i++) {
+ uint32_t mxcsr;
+ uint64_t r = do_fmadd(tests[i].n, tests[i].m, tests[i].a,
+ tests[i].ftz, &mxcsr);
+ if (r != tests[i].expected_r) {
+ printf("expected result 0x%" PRIx64 "\n", tests[i].expected_r);
+ passed = false;
+ }
+ if (mxcsr != tests[i].expected_mxcsr) {
+ printf("expected MXCSR flags 0x%x\n", tests[i].expected_mxcsr);
+ passed = false;
+ }
+ }
+ return passed ? 0 : 1;
+}