rust: do not use --generate-cstr

--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:

rust: do not use --generate-cstr

--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>

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rust: do not use MaybeUninit::zeroed()

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

rust: do not use MaybeUninit::zeroed()

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>

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rust: introduce alternative implementation of offset_of!

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 lic

rust: introduce alternative implementation of offset_of!

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>

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rust: introduce a c_str macro

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.

Revi

rust: introduce a c_str macro

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>

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rust: use std::os::raw instead of core::ffi

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 n

rust: use std::os::raw instead of core::ffi

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>

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rust: add definitions for vmstate

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 exa

rust: add definitions for vmstate

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>

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rust: provide safe wrapper for MaybeUninit::zeroed()

MaybeUninit::zeroed() is handy, but it introduces unsafe (and has a
pretty heavy syntax in general). Introduce a trait that provides the
same fu

rust: provide safe wrapper for MaybeUninit::zeroed()

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>

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rust: make properties array immutable

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

rust: make properties array immutable

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>

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rust: clean up define_property macro

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@h

rust: clean up define_property macro

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>

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rust: cleanup module_init!, use it from #[derive(Object)]

Remove the duplicate code by using the module_init! macro; at the same time,
simplify how module_init! is used, by taking inspiration from t

rust: cleanup module_init!, use it from #[derive(Object)]

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>

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rust: build integration test for the qemu_api crate

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

rust: build integration test for the qemu_api crate

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>

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rust: modernize link_section usage for ELF platforms

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 .

rust: modernize link_section usage for ELF platforms

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>

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rust: remove uses of #[no_mangle]

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

rust: remove uses of #[no_mangle]

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>

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rust: do not use --no-size_t-is-usize

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 of

rust: do not use --no-size_t-is-usize

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>

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meson: pass rustc_args when building all crates

rustc_args is needed to smooth the difference in warnings between the various
versions of rustc. Always include those arguments.

Reviewed-by: Junjie

meson: pass rustc_args when building all crates

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>

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rust: add crate to expose bindings and interfaces

Add rust/qemu-api, which exposes rust-bindgen generated FFI bindings and
provides some declaration macros for symbols visible to the rest of
QEMU.

rust: add crate to expose bindings and interfaces

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>

show more ...