[PATCH 0/2] trace: add Rust DTrace/SystemTap SDT support

[Stefan Hajnoczi <stefanha@redhat.com>]

This series adds SDT probe support so that SystemTap, GDB, etc can trace QEMU's
Rust code when compiled with `./configure --enable-trace-backends=dtrace`.

The dtrace(1) tool that generates the .o and C header file does not support
Rust. Use the probe crate (https://crates.io/crates/probe), which takes care of
emitting SDT probes, and extend tracetool to emit code for the trace events.

While SDT is cross-platform, the probe crate currently only supports Linux
(SystemTap). On other platforms the crate is a nop - it compiles but does
nothing. Future changes to the probe crate may add support for other operating
systems like FreeBSD, macOS, etc without much needed in the way of QEMU code
changes.

Josh: I CCed you just to let you know that QEMU will use the probes
crate. There is no need to review the code unless you want to.

Based-on: <20251106215606.36598-1-stefanha@redhat.com>

Stefan Hajnoczi (2):
  subprojects: add probe crate
  tracetool: add Rust DTrace/SystemTap SDT support

 rust/Cargo.lock                               |  6 ++
 rust/hw/char/pl011/meson.build                |  1 +
 rust/hw/timer/hpet/meson.build                |  1 +
 rust/meson.build                              |  2 +
 rust/trace/Cargo.toml                         |  1 +
 rust/trace/meson.build                        |  2 +-
 scripts/archive-source.sh                     |  1 +
 scripts/make-release                          |  2 +-
 scripts/tracetool/__init__.py                 |  1 +
 scripts/tracetool/backend/dtrace.py           | 32 +++++++++
 scripts/tracetool/format/rs.py                | 27 ++++++--
 subprojects/.gitignore                        |  1 +
 .../packagefiles/probe-0.5-rs/meson.build     | 22 +++++++
 subprojects/probe-0.5-rs.wrap                 |  7 ++
 tests/tracetool/dtrace.rs                     | 65 +++++++++++++++++++
 tests/tracetool/ftrace.rs                     | 21 ++++++
 tests/tracetool/log.rs                        | 21 ++++++
 tests/tracetool/simple.rs                     | 21 ++++++
 tests/tracetool/syslog.rs                     | 21 ++++++
 tests/tracetool/tracetool-test.py             |  2 +-
 20 files changed, 250 insertions(+), 7 deletions(-)
 create mode 100644 subprojects/packagefiles/probe-0.5-rs/meson.build
 create mode 100644 subprojects/probe-0.5-rs.wrap
 create mode 100644 tests/tracetool/dtrace.rs

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2.51.1