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From: "Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>
To: qemu-devel@nongnu.org
Cc: "Daniel Henrique Barboza" <daniel.barboza@oss.qualcomm.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Pierrick Bouvier" <pierrick.bouvier@oss.qualcomm.com>,
	"Mohamed Mediouni" <mohamed@unpredictable.fr>,
	"Alexander Graf" <agraf@csgraf.de>,
	qemu-ppc@nongnu.org, qemu-riscv@nongnu.org, kvm@vger.kernel.org,
	"Richard Henderson" <richard.henderson@linaro.org>,
	qemu-arm@nongnu.org,
	"Magnus Kulke" <magnuskulke@linux.microsoft.com>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	"Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>,
	"Philippe Mathieu-Daudé" <philmd@mailo.com>,
	"Zhao Liu" <zhao1.liu@intel.com>
Subject: [PATCH 08/16] cpus: Slightly improve *run_on_cpu() docstrings
Date: Thu, 13 Aug 2026 20:16:31 +0200	[thread overview]
Message-ID: <20260813181640.6537-9-philmd@oss.qualcomm.com> (raw)
In-Reply-To: <20260813181640.6537-1-philmd@oss.qualcomm.com>

Be a bit more precise mentioning BQL use and blocking calls.

Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
---
 include/hw/core/cpu.h | 36 ++++++++++++++++++++----------------
 1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 183ef9f4ef2..d610f87abd3 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -908,36 +908,40 @@ void do_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data,
                    QemuMutex *mutex);
 
 /**
- * run_on_cpu:
+ * run_on_cpu - Execute a function on a vCPU and wait for completion
  * @cpu: The vCPU to run on.
  * @func: The function to be executed.
  * @data: Data to pass to the function.
  *
- * Schedules the function @func for execution on the vCPU @cpu.
+ * Schedules the function @func for execution on the vCPU @cpu and
+ * block until it completes.
+ *
+ * Note: The caller must hold the BQL.
  */
 void run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data);
 
 /**
- * async_run_on_cpu:
- * @cpu: The vCPU to run on.
- * @func: The function to be executed.
- * @data: Data to pass to the function.
- *
- * Schedules the function @func for execution on the vCPU @cpu asynchronously.
- */
-void async_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data);
-
-/**
- * async_safe_run_on_cpu:
+ * async_run_on_cpu - Queue a function for execution on a vCPU
  * @cpu: The vCPU to run on.
  * @func: The function to be executed.
  * @data: Data to pass to the function.
  *
  * Schedules the function @func for execution on the vCPU @cpu asynchronously,
- * while all other vCPUs are sleeping.
+ * then return immediately without waiting.
  *
- * Unlike run_on_cpu and async_run_on_cpu, the function is run outside the
- * BQL.
+ * Note: The vCPU will hold the BQL when executing @func.
+ */
+void async_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data);
+
+/**
+ * async_safe_run_on_cpu - Queue a function to run with other vCPUs paused
+ * @cpu: The vCPU to run on.
+ * @func: The function to be executed.
+ * @data: Data to pass to the function.
+ *
+ * Schedules the function @func for execution on the vCPU @cpu asynchronously.
+ * Unlike async_run_on_cpu(), all other vCPUs are paused while @func executes,
+ * ensuring @cpu has exclusive access to shared state.
  */
 void async_safe_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data);
 
-- 
2.53.0


  parent reply	other threads:[~2026-08-13 18:17 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-13 18:16 [PATCH 00/16] cpus: Improvements around BQL locking, improving docstring Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 01/16] accel: Label outer / inner vCPU execution loops Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 02/16] cpus: Improve qemu_cpu_kick_self() docstring Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 03/16] cpus: Rename cpu_stop_current() -> qemu_cpu_stop_self() Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 04/16] cpus: Rename qemu_cpu_stop() to qemu_cpu_ack_stop_request() Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 05/16] cpus: Improve cpu_pause() docstring Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 06/16] cpus: Improve cpu_exit() docstring Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 07/16] cpus: Document process_queued_cpu_work*() runs on current vCPU Philippe Mathieu-Daudé
2026-08-13 18:16 ` Philippe Mathieu-Daudé [this message]
2026-08-13 18:16 ` [PATCH 09/16] accel/tcg: Use RUN_ON_CPU_NULL for tcg_commit() callbacks Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 10/16] accel/kvm: Clarify use of @r variable in vcpu thread loop Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 11/16] accel/kvm: Consistently return CPU halt state from process_async_events Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 12/16] target/arm/hvf: Move flush_cpu_state() into the inner vCPU loop Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 13/16] target/arm/hvf: Lock BQL outside of the vCPU inner execution loop Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 14/16] target/i386/hvf: " Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 15/16] target/arm/powerctl: Move BQL assertions to async work context Philippe Mathieu-Daudé
2026-08-13 18:16 ` [PATCH 16/16] target/arm/whpx: Fix argument order typo in memory access error message Philippe Mathieu-Daudé

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