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authorStefan Hajnoczi <stefanha@redhat.com>2025-07-14 09:36:57 -0400
committerStefan Hajnoczi <stefanha@redhat.com>2025-07-14 09:36:57 -0400
commitb92b39af4219df4250f121f64d215506909c7404 (patch)
treed112c017e3c77df7341e5fe28072571ad9ecceb8 /rust/qemu-api/src
parent6fae7ce1488e3f5bdcc1747564ea68e7f6f0e931 (diff)
parent5d21ee453ad8e3f95f75e542cb3b35c5bb7cf23a (diff)
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Merge tag 'for-upstream' of https://gitlab.com/bonzini/qemu into staging
* rust: miscellaneous fixes * rust: qemu-api-macros: cleanup and add unit tests for TryInto * rust: log: implement io::Write, avoid memory allocations when logging constant strings * target/i386: fix usage of properties whenever accelerators change the default (e.g. vendor) * target/i386: add support for TDVMCALL_SETUP_EVENT_NOTIFY_INTERRUPT * target/i386: add support for booting an SEV VM from an IGVM file * target/i386: unify cache model descriptions between CPUID 2, CPUID 4 and AMD specific CPUID 0x80000006 * target/i386: introduce cache models for recent Intel CPU models * target/i386: mark some 0x80000000-0x80000008 bits as reserved on Intel * target/i386: cleanups # -----BEGIN PGP SIGNATURE----- # # iQFIBAABCgAyFiEE8TM4V0tmI4mGbHaCv/vSX3jHroMFAmh0v+sUHHBib256aW5p # QHJlZGhhdC5jb20ACgkQv/vSX3jHroOQUQf8CTsCnl2xYrnrkVfSVj6kuAE+JYD6 # oLSXsOEG4yrVknuhwIfVsqNScmleJCdz85ej7CZxy3vzzgjLfmy7nwifKEIKku7E # XO/Q3HbB898MnzqceQRmwe1AzELoj1Lave215CPhUBo60LCRPwaIZsiHprnNZgXi # TyHlmywDVRjyFLtKkx3El0dnLAhFqPWeGh81CD5lPLZZJ+Wt2FuAw2zqSOGB2ztM # FkJmunFJiaTItjyCN/uNvBSbDKecAHgCXvSCVNG3+I4U2R0gK1lcwm3TRo7yKia+ # HUHGa3UEXoIqlRfXdX6zuc8tW1/u6SPv+8WX53t204PAeSWDUrtIe9jZ4A== # =y4/a # -----END PGP SIGNATURE----- # gpg: Signature made Mon 14 Jul 2025 04:29:31 EDT # gpg: using RSA key F13338574B662389866C7682BFFBD25F78C7AE83 # gpg: issuer "pbonzini@redhat.com" # gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full] # gpg: aka "Paolo Bonzini <pbonzini@redhat.com>" [full] # Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4 E2F7 7E15 100C CD36 69B1 # Subkey fingerprint: F133 3857 4B66 2389 866C 7682 BFFB D25F 78C7 AE83 * tag 'for-upstream' of https://gitlab.com/bonzini/qemu: (77 commits) i386/cpu: Honor maximum value for CPUID.8000001DH.EAX[25:14] i386/cpu: Fix overflow of cache topology fields in CPUID.04H i386/cpu: Fix cpu number overflow in CPUID.01H.EBX[23:16] i386/cpu: Fix number of addressable IDs field for CPUID.01H.EBX[23:16] i386/cpu: Reorder CPUID leaves in cpu_x86_cpuid() tests/vm: bump FreeBSD image to 14.3 tests/functional: test_x86_cpu_model_versions: remove dead tests i386/cpu: Mark CPUID 0x80000008 ECX bits[0:7] & [12:15] as reserved for Intel/Zhaoxin i386/cpu: Mark CPUID 0x80000007[EBX] as reserved for Intel i386/cpu: Mark EBX/ECX/EDX in CPUID 0x80000000 leaf as reserved for Intel i386/cpu: Enable 0x1f leaf for YongFeng by default i386/cpu: Enable 0x1f leaf for SapphireRapids by default i386/cpu: Enable 0x1f leaf for GraniteRapids by default i386/cpu: Enable 0x1f leaf for SierraForest by default i386/cpu: Enable 0x1f leaf for SierraForest by default i386/cpu: Add a "x-force-cpuid-0x1f" property i386/cpu: Introduce cache model for YongFeng i386/cpu: Introduce cache model for SapphireRapids i386/cpu: Introduce cache model for GraniteRapids i386/cpu: Introduce cache model for SierraForest ... Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'rust/qemu-api/src')
-rw-r--r--rust/qemu-api/src/bindings.rs1
-rw-r--r--rust/qemu-api/src/log.rs92
2 files changed, 85 insertions, 8 deletions
diff --git a/rust/qemu-api/src/bindings.rs b/rust/qemu-api/src/bindings.rs
index 057de4b..3cdad0f 100644
--- a/rust/qemu-api/src/bindings.rs
+++ b/rust/qemu-api/src/bindings.rs
@@ -6,6 +6,7 @@
non_camel_case_types,
non_snake_case,
non_upper_case_globals,
+ unnecessary_transmutes,
unsafe_op_in_unsafe_fn,
clippy::pedantic,
clippy::restriction,
diff --git a/rust/qemu-api/src/log.rs b/rust/qemu-api/src/log.rs
index d6c3d6c..a441b8c 100644
--- a/rust/qemu-api/src/log.rs
+++ b/rust/qemu-api/src/log.rs
@@ -3,6 +3,13 @@
//! Bindings for QEMU's logging infrastructure
+use std::{
+ io::{self, Write},
+ ptr::NonNull,
+};
+
+use crate::{bindings, errno};
+
#[repr(u32)]
/// Represents specific error categories within QEMU's logging system.
///
@@ -11,11 +18,82 @@
pub enum Log {
/// Log invalid access caused by the guest.
/// Corresponds to `LOG_GUEST_ERROR` in the C implementation.
- GuestError = crate::bindings::LOG_GUEST_ERROR,
+ GuestError = bindings::LOG_GUEST_ERROR,
/// Log guest access of unimplemented functionality.
/// Corresponds to `LOG_UNIMP` in the C implementation.
- Unimp = crate::bindings::LOG_UNIMP,
+ Unimp = bindings::LOG_UNIMP,
+}
+
+/// A RAII guard for QEMU's logging infrastructure. Creating the guard
+/// locks the log file, and dropping it (letting it go out of scope) unlocks
+/// the file.
+///
+/// As long as the guard lives, it can be written to using [`std::io::Write`].
+///
+/// The locking is recursive, therefore owning a guard does not prevent
+/// using [`log_mask_ln!()`](crate::log_mask_ln).
+pub struct LogGuard(NonNull<bindings::FILE>);
+
+impl LogGuard {
+ /// Return a RAII guard that writes to QEMU's logging infrastructure.
+ /// The log file is locked while the guard exists, ensuring that there
+ /// is no tearing of the messages.
+ ///
+ /// Return `None` if the log file is closed and could not be opened.
+ /// Do *not* use `unwrap()` on the result; failure can be handled simply
+ /// by not logging anything.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use qemu_api::log::LogGuard;
+ /// # use std::io::Write;
+ /// if let Some(mut log) = LogGuard::new() {
+ /// writeln!(log, "test");
+ /// }
+ /// ```
+ pub fn new() -> Option<Self> {
+ let f = unsafe { bindings::qemu_log_trylock() }.cast();
+ NonNull::new(f).map(Self)
+ }
+
+ /// Writes a formatted string into the log, returning any error encountered.
+ ///
+ /// This method is primarily used by the
+ /// [`log_mask_ln!()`](crate::log_mask_ln) macro, and it is rare for it
+ /// to be called explicitly. It is public because it is the only way to
+ /// examine the error, which `log_mask_ln!()` ignores
+ ///
+ /// Unlike `log_mask_ln!()`, it does *not* append a newline at the end.
+ pub fn log_fmt(args: std::fmt::Arguments) -> io::Result<()> {
+ if let Some(mut log) = Self::new() {
+ log.write_fmt(args)?;
+ }
+ Ok(())
+ }
+}
+
+impl Write for LogGuard {
+ fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
+ let ret = unsafe {
+ bindings::rust_fwrite(bytes.as_ptr().cast(), 1, bytes.len(), self.0.as_ptr())
+ };
+ errno::into_io_result(ret)
+ }
+
+ fn flush(&mut self) -> io::Result<()> {
+ // Do nothing, dropping the guard takes care of flushing
+ Ok(())
+ }
+}
+
+impl Drop for LogGuard {
+ fn drop(&mut self) {
+ unsafe {
+ bindings::qemu_log_unlock(self.0.as_ptr());
+ }
+ }
}
/// A macro to log messages conditionally based on a provided mask.
@@ -24,6 +102,8 @@ pub enum Log {
/// log level and, if so, formats and logs the message. It is the Rust
/// counterpart of the `qemu_log_mask()` macro in the C implementation.
///
+/// Errors from writing to the log are ignored.
+///
/// # Parameters
///
/// - `$mask`: A log level mask. This should be a variant of the `Log` enum.
@@ -62,12 +142,8 @@ macro_rules! log_mask_ln {
if unsafe {
(::qemu_api::bindings::qemu_loglevel & ($mask as std::os::raw::c_int)) != 0
} {
- let formatted_string = format!("{}\n", format_args!($fmt $($args)*));
- let c_string = std::ffi::CString::new(formatted_string).unwrap();
-
- unsafe {
- ::qemu_api::bindings::qemu_log(c_string.as_ptr());
- }
+ _ = ::qemu_api::log::LogGuard::log_fmt(
+ format_args!("{}\n", format_args!($fmt $($args)*)));
}
}};
}