From 54140102d2e57bd2e34823e4537d2191cdcd5f08 Mon Sep 17 00:00:00 2001 From: Tanish Desai Date: Mon, 29 Sep 2025 17:49:31 +0200 Subject: rust: add trace crate The trace crate is a minimal container for dependencies of tracepoints (so that they do not have to be imported in all the crates that use tracepoints); it also contains a macro called "include_trace!" that is able to find the right include file from the trace/ directory. [Write commit message, add #[allow()]. - Paolo] Signed-off-by: Tanish Desai Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini Message-ID: <20250929154938.594389-10-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi --- rust/trace/src/lib.rs | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 rust/trace/src/lib.rs (limited to 'rust/trace/src/lib.rs') diff --git a/rust/trace/src/lib.rs b/rust/trace/src/lib.rs new file mode 100644 index 0000000000..0955461573 --- /dev/null +++ b/rust/trace/src/lib.rs @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +//! This crate provides macros that aid in using QEMU's tracepoint +//! functionality. + +#[macro_export] +/// Define the trace-points from the named directory (which should have slashes +/// replaced by underscore characters) as functions in a module called `trace`. +/// +/// ```ignore +/// ::trace::include_trace!("hw_char"); +/// // ... +/// trace::trace_pl011_read_fifo_rx_full(); +/// ``` +macro_rules! include_trace { + ($name:literal) => { + #[allow( + clippy::ptr_as_ptr, + clippy::cast_lossless, + clippy::used_underscore_binding + )] + mod trace { + #[cfg(not(MESON))] + include!(concat!( + env!("MESON_BUILD_ROOT"), + "/trace/trace-", + $name, + ".rs" + )); + + #[cfg(MESON)] + include!(concat!("@MESON_BUILD_ROOT@/trace/trace-", $name, ".rs")); + } + }; +} -- cgit 1.4.1 From 1461752f0fa4bcd7e60d51fe47e3430f8a81cdd8 Mon Sep 17 00:00:00 2001 From: Tanish Desai Date: Mon, 29 Sep 2025 17:49:38 +0200 Subject: tracetool/syslog: add Rust support The syslog backend needs the syslog function from libc and the LOG_INFO enum value; they are re-exported as "::trace::syslog" and "::trace::LOG_INFO" so that device crates do not all have to add the libc dependency, but otherwise there is nothing special. Signed-off-by: Tanish Desai Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini Message-ID: <20250929154938.594389-17-pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi --- rust/Cargo.lock | 3 +++ rust/trace/Cargo.toml | 3 +++ rust/trace/src/lib.rs | 4 ++++ scripts/tracetool/backend/syslog.py | 7 ++++++- tests/tracetool/syslog.rs | 40 +++++++++++++++++++++++++++++++++++++ tests/tracetool/tracetool-test.py | 2 +- 6 files changed, 57 insertions(+), 2 deletions(-) create mode 100644 tests/tracetool/syslog.rs (limited to 'rust/trace/src/lib.rs') diff --git a/rust/Cargo.lock b/rust/Cargo.lock index f84a3dd076..444ef516a7 100644 --- a/rust/Cargo.lock +++ b/rust/Cargo.lock @@ -262,6 +262,9 @@ dependencies = [ [[package]] name = "trace" version = "0.1.0" +dependencies = [ + "libc", +] [[package]] name = "unicode-ident" diff --git a/rust/trace/Cargo.toml b/rust/trace/Cargo.toml index 13ac0b33d6..fc81bce580 100644 --- a/rust/trace/Cargo.toml +++ b/rust/trace/Cargo.toml @@ -12,5 +12,8 @@ license.workspace = true repository.workspace = true rust-version.workspace = true +[dependencies] +libc = { workspace = true } + [lints] workspace = true diff --git a/rust/trace/src/lib.rs b/rust/trace/src/lib.rs index 0955461573..e03bce43c4 100644 --- a/rust/trace/src/lib.rs +++ b/rust/trace/src/lib.rs @@ -3,6 +3,10 @@ //! This crate provides macros that aid in using QEMU's tracepoint //! functionality. +#[doc(hidden)] +/// Re-exported item to avoid adding libc as a dependency everywhere. +pub use libc::{syslog, LOG_INFO}; + #[macro_export] /// Define the trace-points from the named directory (which should have slashes /// replaced by underscore characters) as functions in a module called `trace`. diff --git a/scripts/tracetool/backend/syslog.py b/scripts/tracetool/backend/syslog.py index 177414d56a..12b826593d 100644 --- a/scripts/tracetool/backend/syslog.py +++ b/scripts/tracetool/backend/syslog.py @@ -12,7 +12,7 @@ __maintainer__ = "Stefan Hajnoczi" __email__ = "stefanha@redhat.com" -from tracetool import out +from tracetool import out, expand_format_string PUBLIC = True @@ -38,6 +38,11 @@ def generate_h(event, group): fmt=event.fmt.rstrip("\n"), argnames=argnames) +def generate_rs(event, group): + out(' let format_string = c"%(fmt)s";', + ' unsafe {::trace::syslog(::trace::LOG_INFO, format_string.as_ptr() as *const c_char, %(args)s);}', + fmt=expand_format_string(event.fmt), + args=event.args.rust_call_varargs()) def generate_h_backend_dstate(event, group): out(' trace_event_get_state_dynamic_by_id(%(event_id)s) || \\', diff --git a/tests/tracetool/syslog.rs b/tests/tracetool/syslog.rs new file mode 100644 index 0000000000..9d3675a0b5 --- /dev/null +++ b/tests/tracetool/syslog.rs @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// This file is @generated by tracetool, do not edit. + +#[allow(unused_imports)] +use std::ffi::c_char; +#[allow(unused_imports)] +use util::bindings; + +#[inline(always)] +fn trace_event_state_is_enabled(dstate: u16) -> bool { + (unsafe { trace_events_enabled_count }) != 0 && dstate != 0 +} + +extern "C" { + static mut trace_events_enabled_count: u32; +} +extern "C" { + static mut _TRACE_TEST_BLAH_DSTATE: u16; + static mut _TRACE_TEST_WIBBLE_DSTATE: u16; +} + +#[inline(always)] +#[allow(dead_code)] +pub fn trace_test_blah(_context: *mut (), _filename: &std::ffi::CStr) +{ + if trace_event_state_is_enabled(unsafe { _TRACE_TEST_BLAH_DSTATE}) { + let format_string = c"Blah context=%p filename=%s"; + unsafe {::trace::syslog(::trace::LOG_INFO, format_string.as_ptr() as *const c_char, _context /* as *mut () */, _filename.as_ptr());} + } +} + +#[inline(always)] +#[allow(dead_code)] +pub fn trace_test_wibble(_context: *mut (), _value: std::ffi::c_int) +{ + if trace_event_state_is_enabled(unsafe { _TRACE_TEST_WIBBLE_DSTATE}) { + let format_string = c"Wibble context=%p value=%d"; + unsafe {::trace::syslog(::trace::LOG_INFO, format_string.as_ptr() as *const c_char, _context /* as *mut () */, _value /* as std::ffi::c_int */);} + } +} diff --git a/tests/tracetool/tracetool-test.py b/tests/tracetool/tracetool-test.py index 3341fb18f9..786083ad7f 100755 --- a/tests/tracetool/tracetool-test.py +++ b/tests/tracetool/tracetool-test.py @@ -14,7 +14,7 @@ def get_formats(backend): "c", "h", ] - if backend in {"ftrace", "log", "simple"}: + if backend in {"ftrace", "log", "simple", "syslog"}: formats += ["rs"] if backend == "dtrace": formats += [ -- cgit 1.4.1