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>
An extra benefit of workspaces is that they allow to place lint level
settings in a single Cargo.toml; the settings are then inherited by
packages in the workspace.
Correspondingly, teach rustc_args.py to get the unexpected_cfgs
configuration from the workspace Cargo.toml.
Note that it is still possible to allow or deny warnings per crate or
module, via the #![] attribute syntax. The rust/qemu-api/src/bindings.rs
file is an example.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
Workspaces allows tracking dependencies for multiple crates at once,
by having a single Cargo.lock file at the top of the rust/ tree.
Because QEMU's Cargo.lock files have to be synchronized with the versions
of crates in subprojects/, using a workspace avoids the need to copy
over the Cargo.lock file when adding a new device (and thus a new crate)
under rust/hw/.
In addition, workspaces let cargo download and build dependencies just
once. While right now we have one leaf crate (hw/char/pl011), this
will not be the case once more devices are added.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The next commit will introduce a new build.rs dependency for rust/qemu-api,
version_check. Before adding it, ensure that all dependencies are
synchronized between the Meson- and cargo-based build systems.
Note that it's not clear whether in the long term we'll use Cargo for
anything; it seems that the three main uses (clippy, rustfmt, rustdoc)
can all be invoked manually---either via glue code in QEMU, or by
extending Meson to gain the relevant functionality. However, for
the time being we're stuck with Cargo so it should at least look at
the same code as the rest of the build system.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
