Generalize timer_and_addr() to decode all registers into a single enum
HPETRegister, and use the TryInto derive to separate valid and
invalid values.
The main advantage lies in checking that all registers are enumerated
in the "match" statements.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.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.liu@intel.com>
Link: https://lore.kernel.org/r/20250210030051.2562726-8-zhao1.liu@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
missing_const_for_fn is not necessarily useful or good. For example in
a private API you can always add const later, and in a public API
it can be unnecessarily restrictive to annotate everything with const
(blocking further improvements to the API).
Nevertheless, QEMU turns it on because qemu_api uses const quite
aggressively and therefore it can be handy to have as much as possible
annotated with const. Outside qemu_api though, not so much: devices
are self contained consumers and if there is nothing that could use
their functions in const contexts that were not anticipated.
Since missing_const_for_fn can be a bit noisy and trigger on trivial
functions that no one would ever call in const context, do not
turn it on everywhere and only keep it in qemu_api as a special case.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add traits that let client cast typecast safely between object types.
In particular, an upcast is compile-time guaranteed to succeed, and a
YOLO C-style downcast must be marked as unsafe.
The traits are based on an IsA<> trait that declares what
is a subclass of what, which is an idea taken from glib-rs
(https://docs.rs/glib/latest/glib/object/trait.IsA.html).
The four primitives are also taken from there
(https://docs.rs/glib/latest/glib/object/trait.Cast.html). However,
the implementation of casting itself is a bit different and uses the
Deref trait.
This removes some pointer arithmetic from the pl011 device; it is also a
prerequisite for the definition of methods, so that they can be invoked
on all subclass structs. This will use the IsA<> trait to detect the
structs that support the methods.
glib also has a "monadic" casting trait which could be implemented on
Option (as in https://docs.rs/glib/latest/glib/object/trait.CastNone.html)
and perhaps even Result. For now I'm leaving it out, as the patch is
already big enough and the benefit seems debatable.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
Make Cargo use unknown_lints = "allow" as well. This is more future
proof as we might add new lints to rust/Cargo.toml that are not supported
by older versions of rustc or clippy.
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>
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>
