Hi
On Tue, Aug 26, 2025 at 6:56 PM Manos Pitsidianakis <
manos.pitsidiana...@linaro.org> wrote:
> On Tue, Aug 26, 2025 at 5:44 PM Paolo Bonzini <pbonz...@redhat.com> wrote:
> >
> > On 8/26/25 16:04, marcandre.lur...@redhat.com wrote:
> > > From: Marc-André Lureau <marcandre.lur...@redhat.com>
> > >
> > > Hi,
> > >
> > > qemu-api is providing bindings for various internal libraries.
> Instead, the
> > > bindings requirements should match the various libraries and use the
> minimal set
> > > of dependencies.
> > >
> > > An initial Rust-only "common" crate is introduced, then "util" (for
> libqemuutil,
> > > without bql), "migration" (so it doesn't depend on bql), "bql", "qom"
> (arguably,
> > > bql shouldn't be required?), and "chardev", "system", "hwcore".
> Finally the
> > > qemu-api crates are renamed and repurposed.
> > >
> > > This involves a lot of code churn, so hopefully it can be reviewed and
> merged
> > > early and iterated upon :)
> >
> > The one comment that I would like to handle before merging, is that I'd
> > prefer to keep the preludes and, in fact, even add more exports to them
> > since they can now be chosen per-crate. Ideally, many of the crates
> > you've crated would be accessed through many "use xyz::prelude::*"
> > statements.
>
> I kind of agree with this sentiment. What this series basically does
> is unwrapping most modules to standalone crates. Semantically, they
> make sense to be their own crates just like they made sense being
> their own modules before). But I'm not sure what developer benefit
>
Indeed, that's the point. The benefit is that you can compile and link only
what you need, just like how qemu code and libraries are organized. Modules
become quickly tangled between each other if you don't do it.
> this brings, it's like splitting Rust's std crate to separate crates
> (ergonomically speaking). Big crates like tokio split implementation
> to crates and then re-export them under tokio::* to ease compilation
> parallelism which we should definitely try to do as well. However in
> our case our Rust wrappers are very small. Let's do this if they ever
> end up growing unwieldy.
>
It will become difficult to manage. It's already hard to know which type
comes from which library/header. Better to do the split early imho. It was
nice to have a single crate in the early days, but we should prepare to
scale up now.
> > Also, if I understood correctly the split util/errno.rs can move to
> > common/. While it has a dependency on libc, it doesn't need bindgen.
> >
> > There's a bunch of code duplication for the various bindings.rs and
> > build.rs files, which is not ideal but shouldn't grow much more than
> > this. I wonder if, later, common code across build.rs could be written
> > just once by adding a new crate (e.g. "qemu_meson") to the workspace,
> > that can be used as a build-dependency.
> >
> > Paolo
> >
> > > Marc-André Lureau (18):
> > > rust: remove unused global qemu "allocator"
> > > rust: add workspace authors
> > > rust: split Rust-only "common" crate
> > > rust: split "util" crate
> > > rust: move vmstate_clock!() to qdev module
> > > rust: move VMState handling to QOM module
> > > rust: move Cell vmstate impl
> > > rust: split "migration" crate
> > > rust: split "bql" crate
> > > rust: split "qom" crate
> > > rust: split "chardev" crate
> > > rust: split "system" crate
> > > rust: split "hwcore" crate
> > > rust: rename qemu_api_macros -> qemu_macros
> > > rust/hpet: drop now unneeded qemu_api dep
> > > rust/pl011: drop dependency on qemu_api
> > > rust: repurpose qemu_api -> tests
> > > docs: update rust.rst
> > >
> > > MAINTAINERS | 12 +-
> > > docs/devel/rust.rst | 51 +--
> > > meson.build | 4 -
> > > rust/bql/wrapper.h | 27 ++
> > > rust/chardev/wrapper.h | 28 ++
> > > rust/hw/char/pl011/wrapper.h | 51 +++
> > > rust/hw/core/wrapper.h | 32 ++
> > > rust/{qemu-api => migration}/wrapper.h | 20 --
> > > rust/qom/wrapper.h | 27 ++
> > > rust/system/wrapper.h | 29 ++
> > > rust/util/wrapper.h | 32 ++
> > > rust/Cargo.lock | 127 ++++++-
> > > rust/Cargo.toml | 16 +-
> > > rust/bits/Cargo.toml | 2 +-
> > > rust/bits/meson.build | 2 +-
> > > rust/bits/src/lib.rs | 4 +-
> > > rust/{qemu-api => bql}/Cargo.toml | 13 +-
> > > rust/{qemu-api => bql}/build.rs | 2 +-
> > > rust/bql/meson.build | 52 +++
> > > rust/bql/src/bindings.rs | 25 ++
> > > rust/{qemu-api => bql}/src/cell.rs | 333
> +++---------------
> > > rust/bql/src/lib.rs | 29 ++
> > > rust/chardev/Cargo.toml | 24 ++
> > > rust/chardev/build.rs | 43 +++
> > > rust/chardev/meson.build | 54 +++
> > > rust/chardev/src/bindings.rs | 36 ++
> > > rust/{qemu-api => chardev}/src/chardev.rs | 35 +-
> > > rust/chardev/src/lib.rs | 4 +
> > > rust/common/Cargo.toml | 16 +
> > > rust/common/meson.build | 32 ++
> > > rust/{qemu-api => common}/src/assertions.rs | 16 +-
> > > rust/{qemu-api => common}/src/bitops.rs | 1 -
> > > rust/{qemu-api => common}/src/callbacks.rs | 12 +-
> > > rust/common/src/lib.rs | 17 +
> > > rust/common/src/opaque.rs | 240 +++++++++++++
> > > rust/{qemu-api => common}/src/uninit.rs | 2 +-
> > > rust/common/src/zeroable.rs | 18 +
> > > rust/hw/char/pl011/Cargo.toml | 11 +-
> > > rust/hw/char/pl011/build.rs | 43 +++
> > > rust/hw/char/pl011/meson.build | 39 +-
> > > rust/hw/char/pl011/src/bindings.rs | 27 ++
> > > rust/hw/char/pl011/src/device.rs | 49 +--
> > > rust/hw/char/pl011/src/lib.rs | 1 +
> > > rust/hw/char/pl011/src/registers.rs | 4 +-
> > > rust/hw/core/Cargo.toml | 26 ++
> > > rust/hw/core/build.rs | 43 +++
> > > rust/{qemu-api => hw/core}/meson.build | 86 ++---
> > > rust/hw/core/src/bindings.rs | 41 +++
> > > rust/{qemu-api => hw/core}/src/irq.rs | 18 +-
> > > rust/hw/core/src/lib.rs | 12 +
> > > rust/{qemu-api => hw/core}/src/qdev.rs | 81 +++--
> > > rust/{qemu-api => hw/core}/src/sysbus.rs | 28 +-
> > > rust/{qemu-api => hw/core}/tests/tests.rs | 29 +-
> > > rust/hw/timer/hpet/Cargo.toml | 10 +-
> > > rust/hw/timer/hpet/meson.build | 12 +-
> > > rust/hw/timer/hpet/src/device.rs | 56 ++-
> > > rust/hw/timer/hpet/src/fw_cfg.rs | 6 +-
> > > rust/meson.build | 12 +-
> > > rust/migration/Cargo.toml | 21 ++
> > > rust/migration/build.rs | 43 +++
> > > rust/migration/meson.build | 57 +++
> > > rust/migration/src/bindings.rs | 48 +++
> > > rust/migration/src/lib.rs | 4 +
> > > rust/{qemu-api => migration}/src/vmstate.rs | 166 ++++-----
> > > rust/qemu-api/.gitignore | 2 -
> > > rust/qemu-api/README.md | 19 -
> > > rust/qemu-api/src/lib.rs | 170 ---------
> > > rust/qemu-api/src/prelude.rs | 31 --
> > > rust/qemu-api/src/zeroable.rs | 37 --
> > > .../Cargo.toml | 2 +-
> > > .../meson.build | 10 +-
> > > .../src/bits.rs | 0
> > > .../src/lib.rs | 20 +-
> > > .../src/tests.rs | 8 +-
> > > rust/qom/Cargo.toml | 23 ++
> > > rust/qom/build.rs | 43 +++
> > > rust/qom/meson.build | 61 ++++
> > > rust/qom/src/bindings.rs | 25 ++
> > > rust/qom/src/lib.rs | 4 +
> > > rust/{qemu-api => qom}/src/qom.rs | 27 +-
> > > rust/qom/tests/tests.rs | 47 +++
> > > rust/system/Cargo.toml | 22 ++
> > > rust/system/build.rs | 43 +++
> > > rust/system/meson.build | 57 +++
> > > rust/{qemu-api => system}/src/bindings.rs | 33 +-
> > > rust/system/src/lib.rs | 4 +
> > > rust/{qemu-api => system}/src/memory.rs | 20 +-
> > > rust/tests/Cargo.toml | 30 ++
> > > rust/tests/meson.build | 14 +
> > > .../tests/vmstate_tests.rs | 18 +-
> > > rust/util/Cargo.toml | 23 ++
> > > rust/util/build.rs | 43 +++
> > > rust/util/meson.build | 61 ++++
> > > rust/util/src/bindings.rs | 25 ++
> > > rust/{qemu-api => util}/src/errno.rs | 11 +-
> > > rust/{qemu-api => util}/src/error.rs | 6 +-
> > > rust/util/src/lib.rs | 10 +
> > > rust/{qemu-api => util}/src/log.rs | 12 +-
> > > rust/{qemu-api => util}/src/module.rs | 2 +-
> > > rust/{qemu-api => util}/src/timer.rs | 12 +-
> > > 100 files changed, 2372 insertions(+), 1044 deletions(-)
> > > create mode 100644 rust/bql/wrapper.h
> > > create mode 100644 rust/chardev/wrapper.h
> > > create mode 100644 rust/hw/char/pl011/wrapper.h
> > > create mode 100644 rust/hw/core/wrapper.h
> > > rename rust/{qemu-api => migration}/wrapper.h (77%)
> > > create mode 100644 rust/qom/wrapper.h
> > > create mode 100644 rust/system/wrapper.h
> > > create mode 100644 rust/util/wrapper.h
> > > rename rust/{qemu-api => bql}/Cargo.toml (52%)
> > > rename rust/{qemu-api => bql}/build.rs (96%)
> > > create mode 100644 rust/bql/meson.build
> > > create mode 100644 rust/bql/src/bindings.rs
> > > rename rust/{qemu-api => bql}/src/cell.rs (70%)
> > > create mode 100644 rust/bql/src/lib.rs
> > > create mode 100644 rust/chardev/Cargo.toml
> > > create mode 100644 rust/chardev/build.rs
> > > create mode 100644 rust/chardev/meson.build
> > > create mode 100644 rust/chardev/src/bindings.rs
> > > rename rust/{qemu-api => chardev}/src/chardev.rs (91%)
> > > create mode 100644 rust/chardev/src/lib.rs
> > > create mode 100644 rust/common/Cargo.toml
> > > create mode 100644 rust/common/meson.build
> > > rename rust/{qemu-api => common}/src/assertions.rs (92%)
> > > rename rust/{qemu-api => common}/src/bitops.rs (98%)
> > > rename rust/{qemu-api => common}/src/callbacks.rs (97%)
> > > create mode 100644 rust/common/src/lib.rs
> > > create mode 100644 rust/common/src/opaque.rs
> > > rename rust/{qemu-api => common}/src/uninit.rs (98%)
> > > create mode 100644 rust/common/src/zeroable.rs
> > > create mode 100644 rust/hw/char/pl011/build.rs
> > > create mode 100644 rust/hw/char/pl011/src/bindings.rs
> > > create mode 100644 rust/hw/core/Cargo.toml
> > > create mode 100644 rust/hw/core/build.rs
> > > rename rust/{qemu-api => hw/core}/meson.build (52%)
> > > create mode 100644 rust/hw/core/src/bindings.rs
> > > rename rust/{qemu-api => hw/core}/src/irq.rs (92%)
> > > create mode 100644 rust/hw/core/src/lib.rs
> > > rename rust/{qemu-api => hw/core}/src/qdev.rs (86%)
> > > rename rust/{qemu-api => hw/core}/src/sysbus.rs (87%)
> > > rename rust/{qemu-api => hw/core}/tests/tests.rs (88%)
> > > create mode 100644 rust/migration/Cargo.toml
> > > create mode 100644 rust/migration/build.rs
> > > create mode 100644 rust/migration/meson.build
> > > create mode 100644 rust/migration/src/bindings.rs
> > > create mode 100644 rust/migration/src/lib.rs
> > > rename rust/{qemu-api => migration}/src/vmstate.rs (80%)
> > > delete mode 100644 rust/qemu-api/.gitignore
> > > delete mode 100644 rust/qemu-api/README.md
> > > delete mode 100644 rust/qemu-api/src/lib.rs
> > > delete mode 100644 rust/qemu-api/src/prelude.rs
> > > delete mode 100644 rust/qemu-api/src/zeroable.rs
> > > rename rust/{qemu-api-macros => qemu-macros}/Cargo.toml (94%)
> > > rename rust/{qemu-api-macros => qemu-macros}/meson.build (63%)
> > > rename rust/{qemu-api-macros => qemu-macros}/src/bits.rs (100%)
> > > rename rust/{qemu-api-macros => qemu-macros}/src/lib.rs (91%)
> > > rename rust/{qemu-api-macros => qemu-macros}/src/tests.rs (93%)
> > > create mode 100644 rust/qom/Cargo.toml
> > > create mode 100644 rust/qom/build.rs
> > > create mode 100644 rust/qom/meson.build
> > > create mode 100644 rust/qom/src/bindings.rs
> > > create mode 100644 rust/qom/src/lib.rs
> > > rename rust/{qemu-api => qom}/src/qom.rs (98%)
> > > create mode 100644 rust/qom/tests/tests.rs
> > > create mode 100644 rust/system/Cargo.toml
> > > create mode 100644 rust/system/build.rs
> > > create mode 100644 rust/system/meson.build
> > > rename rust/{qemu-api => system}/src/bindings.rs (56%)
> > > create mode 100644 rust/system/src/lib.rs
> > > rename rust/{qemu-api => system}/src/memory.rs (95%)
> > > create mode 100644 rust/tests/Cargo.toml
> > > create mode 100644 rust/tests/meson.build
> > > rename rust/{qemu-api => tests}/tests/vmstate_tests.rs (96%)
> > > create mode 100644 rust/util/Cargo.toml
> > > create mode 100644 rust/util/build.rs
> > > create mode 100644 rust/util/meson.build
> > > create mode 100644 rust/util/src/bindings.rs
> > > rename rust/{qemu-api => util}/src/errno.rs (98%)
> > > rename rust/{qemu-api => util}/src/error.rs (98%)
> > > create mode 100644 rust/util/src/lib.rs
> > > rename rust/{qemu-api => util}/src/log.rs (93%)
> > > rename rust/{qemu-api => util}/src/module.rs (97%)
> > > rename rust/{qemu-api => util}/src/timer.rs (93%)
> > >
> >
>
>
