A qemu_log_mask!() macro is provided which expects similar arguments as the C
version. However, the formatting works as one would expect from Rust.
To maximize code reuse the macro is just a thin wrapper around qemu_log().
Also, just the bare minimum of logging masks is provided which should suffice
for the current use case of Rust in QEMU.
Signed-off-by: Bernhard Beschow <shen...@gmail.com>
---
docs/devel/rust.rst | 1 +
rust/wrapper.h | 2 ++
rust/qemu-api/meson.build | 1 +
rust/qemu-api/src/lib.rs | 1 +
rust/qemu-api/src/log.rs | 55 +++++++++++++++++++++++++++++++++++++++
5 files changed, 60 insertions(+)
create mode 100644 rust/qemu-api/src/log.rs
diff --git a/docs/devel/rust.rst b/docs/devel/rust.rst
index 88bdec1eb2..bc50216dc6 100644
--- a/docs/devel/rust.rst
+++ b/docs/devel/rust.rst
@@ -187,6 +187,7 @@ module status
``c_str`` complete
``errno`` complete
``irq`` complete
+``log`` proof of concept
``memory`` stable
``module`` complete
``offset_of`` stable
diff --git a/rust/wrapper.h b/rust/wrapper.h
index d4fec54657..9518face53 100644
--- a/rust/wrapper.h
+++ b/rust/wrapper.h
@@ -48,6 +48,8 @@ typedef enum memory_order {
#endif /* __CLANG_STDATOMIC_H */
#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/log-for-trace.h"
#include "qemu/module.h"
#include "qemu-io.h"
#include "system/system.h"
diff --git a/rust/qemu-api/meson.build b/rust/qemu-api/meson.build
index 858685ddd4..112f6735a9 100644
--- a/rust/qemu-api/meson.build
+++ b/rust/qemu-api/meson.build
@@ -26,6 +26,7 @@ _qemu_api_rs = static_library(
'src/c_str.rs',
'src/errno.rs',
'src/irq.rs',
+ 'src/log.rs',
'src/memory.rs',
'src/module.rs',
'src/offset_of.rs',
diff --git a/rust/qemu-api/src/lib.rs b/rust/qemu-api/src/lib.rs
index 05f38b51d3..b54989a243 100644
--- a/rust/qemu-api/src/lib.rs
+++ b/rust/qemu-api/src/lib.rs
@@ -21,6 +21,7 @@
pub mod chardev;
pub mod errno;
pub mod irq;
+pub mod log;
pub mod memory;
pub mod module;
pub mod offset_of;
diff --git a/rust/qemu-api/src/log.rs b/rust/qemu-api/src/log.rs
new file mode 100644
index 0000000000..3103a86efa
--- /dev/null
+++ b/rust/qemu-api/src/log.rs
@@ -0,0 +1,55 @@
+// Copyright 2025 Bernhard Beschow <shen...@gmail.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+pub use crate::bindings::{LOG_GUEST_ERROR, LOG_INVALID_MEM, LOG_UNIMP};
+
+/// A macro to log messages conditionally based on a provided mask.
+///
+/// The `qemu_log_mask` macro checks whether the given mask matches the
+/// current log level and, if so, formats and logs the message.
+///
+/// # Parameters
+///
+/// - `$mask`: The log mask to check. This should be an integer value
+/// indicating the log level mask.
+/// - `$fmt`: A format string following the syntax and rules of the `format!`
+/// macro. It specifies the structure of the log message.
+/// - `$args`: Optional arguments to be interpolated into the format string.
+///
+/// # Example
+///
+/// ```
+/// use qemu_api::log::LOG_GUEST_ERROR;
+///
+/// qemu_log_mask!(
+/// LOG_GUEST_ERROR,
+/// "Address 0x{error_address:x} out of range\n"
+/// );
+/// ```
+///
+/// It is also possible to use printf style:
+///
+/// ```
+/// use qemu_api::log::LOG_GUEST_ERROR;
+///
+/// qemu_log_mask!(
+/// LOG_GUEST_ERROR,
+/// "Address 0x{:x} out of range\n",
+/// error_address
+/// );
+/// ```
+#[macro_export]
+macro_rules! qemu_log_mask {
+ ($mask:expr, $fmt:expr $(, $args:expr)*) => {{
+ if unsafe {
+ (::qemu_api::bindings::qemu_loglevel & ($mask as
std::os::raw::c_int)) != 0
+ } {
+ let formatted_string = format!($fmt, $($args),*);
+ let c_string = std::ffi::CString::new(formatted_string).unwrap();
+
+ unsafe {
+ ::qemu_api::bindings::qemu_log(c_string.as_ptr());
+ }
+ }
+ }};
+}
--
2.49.0
