[RFC,3/7] accel/tcg: Implement tcg_get_cpus_queue()

Commit Message

Philippe Mathieu-Daudé Jan. 6, 2025, 8:02 p.m. UTC

Use a specific vCPUs queue for our unique software accelerator.
Register the AccelOpsClass::get_cpus_queue() handler.

Signed-off-by: Philippe Mathieu-Daudé <[e-mail]>
---
 accel/tcg/tcg-accel-ops.h | 10 ++++++++++
 accel/tcg/tcg-accel-ops.c |  8 ++++++++
 2 files changed, 18 insertions(+)

Patch

diff --git a/accel/tcg/tcg-accel-ops.h b/accel/tcg/tcg-accel-ops.h
index 6feeb3f3e9b..7b1d6288742 100644
--- a/accel/tcg/tcg-accel-ops.h
+++ b/accel/tcg/tcg-accel-ops.h
@@ -13,10 +13,20 @@ 
 #define TCG_ACCEL_OPS_H
 
 #include "system/cpus.h"
+#include "hw/core/cpu.h"
 
 void tcg_cpu_destroy(CPUState *cpu);
 int tcg_cpu_exec(CPUState *cpu);
 void tcg_handle_interrupt(CPUState *cpu, int mask);
 void tcg_cpu_init_cflags(CPUState *cpu, bool parallel);
 
+#ifdef CONFIG_USER_ONLY
+#define tcg_cpus_queue cpus_queue
+#else
+/* Guard with qemu_cpu_list_lock */
+extern CPUTailQ tcg_cpus_queue;
+#endif
+
+#define CPU_FOREACH_TCG(cpu) QTAILQ_FOREACH_RCU(cpu, &tcg_cpus_queue, node)
+
 #endif /* TCG_ACCEL_OPS_H */
diff --git a/accel/tcg/tcg-accel-ops.c b/accel/tcg/tcg-accel-ops.c
index 6e3f1fa92b2..1fb077f7b38 100644
--- a/accel/tcg/tcg-accel-ops.c
+++ b/accel/tcg/tcg-accel-ops.c
@@ -47,6 +47,13 @@ 
 
 /* common functionality among all TCG variants */
 
+CPUTailQ tcg_cpus_queue = QTAILQ_HEAD_INITIALIZER(tcg_cpus_queue);
+
+static CPUTailQ *tcg_get_cpus_queue(void)
+{
+    return &tcg_cpus_queue;
+}
+
 void tcg_cpu_init_cflags(CPUState *cpu, bool parallel)
 {
     uint32_t cflags;
@@ -199,6 +206,7 @@  static inline void tcg_remove_all_breakpoints(CPUState *cpu)
 
 static void tcg_accel_ops_init(AccelOpsClass *ops)
 {
+    ops->get_cpus_queue = tcg_get_cpus_queue;
     if (qemu_tcg_mttcg_enabled()) {
         ops->create_vcpu_thread = mttcg_start_vcpu_thread;
         ops->kick_vcpu_thread = mttcg_kick_vcpu_thread;