1 files changed, 20 insertions, 2 deletions

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index b01a0cffd6..fb788ca110 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -422,6 +422,15 @@ struct qemu_work_item;
  * valid under cpu_list_lock.
  * @created: Indicates whether the CPU thread has been successfully created.
  * @halt_cond: condition variable sleeping threads can wait on.
+ * @exit_request: Another thread requests the CPU to call qemu_process_cpu_events().
+ *   Should be read only by CPU thread with load-acquire, to synchronize with
+ *   other threads' store-release operation.
+ *
+ *   In some cases, accelerator-specific code will write exit_request from
+ *   within the same thread, to "bump" the effect of qemu_cpu_kick() to
+ *   the one provided by cpu_exit(), especially when processing interrupt
+ *   flags.  In this case, the write and read happen in the same thread
+ *   and the write therefore can use qemu_atomic_set().
  * @interrupt_request: Indicates a pending interrupt request.
  *   Only used by system emulation.
  * @halted: Nonzero if the CPU is in suspended state.
@@ -495,7 +504,6 @@ struct CPUState {
     bool exit_request;
     int exclusive_context_count;
     uint32_t cflags_next_tb;
-    /* updates protected by BQL */
     uint32_t interrupt_request;
     int singlestep_enabled;
     int64_t icount_budget;
@@ -830,7 +838,8 @@ bool qemu_cpu_is_self(CPUState *cpu);
  * qemu_cpu_kick:
  * @cpu: The vCPU to kick.
  *
- * Kicks @cpu's thread.
+ * Kicks @cpu's thread to exit the accelerator.  For accelerators that
+ * can do that, the target vCPU thread will try not to take the BQL.
  */
 void qemu_cpu_kick(CPUState *cpu);
 
@@ -1136,6 +1145,15 @@ AddressSpace *cpu_get_address_space(CPUState *cpu, int asidx);
 G_NORETURN void cpu_abort(CPUState *cpu, const char *fmt, ...)
     G_GNUC_PRINTF(2, 3);
 
+/**
+ * qemu_process_cpu_events:
+ * @cpu: CPU that left the execution loop
+ *
+ * Perform accelerator-independent work after the CPU has left
+ * the inner execution loop.
+ */
+void qemu_process_cpu_events(CPUState *cpu);
+
 /* $(top_srcdir)/cpu.c */
 void cpu_class_init_props(DeviceClass *dc);
 void cpu_exec_class_post_init(CPUClass *cc);