[Qemu-devel] [RFC PATCH V2 2/3] cpus: add a tcg_executing flag.

[fred.konrad@greensocs.com]

From: KONRAD Frederic <fred.konrad@greensocs.com>

This flag indicates if the VCPU is currently executing TCG code.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>

Changes V1 -> V2:
  * do both tcg_executing = 0 or 1 in cpu_exec().
---
 cpu-exec.c        | 2 ++
 include/qom/cpu.h | 3 +++
 qom/cpu.c         | 1 +
 3 files changed, 6 insertions(+)

diff --git a/cpu-exec.c b/cpu-exec.c
index 75694f3..2fdf89d 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -371,6 +371,7 @@ int cpu_exec(CPUState *cpu)
         cpu->halted = 0;
     }
 
+    cpu->tcg_executing = 1;
     current_cpu = cpu;
 
     /* As long as current_cpu is null, up to the assignment just above,
@@ -583,5 +584,6 @@ int cpu_exec(CPUState *cpu)
 
     /* fail safe : never use current_cpu outside cpu_exec() */
     current_cpu = NULL;
+    cpu->tcg_executing = 0;
     return ret;
 }
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index efa9624..a2de536 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -226,6 +226,7 @@ struct kvm_run;
  * @stopped: Indicates the CPU has been artificially stopped.
  * @tcg_exit_req: Set to force TCG to stop executing linked TBs for this
  *           CPU and return to its top level loop.
+ * @tcg_executing: This TCG thread is in cpu_exec().
  * @singlestep_enabled: Flags for single-stepping.
  * @icount_extra: Instructions until next timer event.
  * @icount_decr: Number of cycles left, with interrupt flag in high bit.
@@ -322,6 +323,8 @@ struct CPUState {
        (absolute value) offset as small as possible.  This reduces code
        size, especially for hosts without large memory offsets.  */
     volatile sig_atomic_t tcg_exit_req;
+
+    volatile int tcg_executing;
 };
 
 QTAILQ_HEAD(CPUTailQ, CPUState);
diff --git a/qom/cpu.c b/qom/cpu.c
index 4e12598..62663e5 100644
--- a/qom/cpu.c
+++ b/qom/cpu.c
@@ -249,6 +249,7 @@ static void cpu_common_reset(CPUState *cpu)
     cpu->icount_decr.u32 = 0;
     cpu->can_do_io = 0;
     cpu->exception_index = -1;
+    cpu->tcg_executing = 0;
     memset(cpu->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof(void *));
 }
 
-- 
1.9.0