[Qemu-devel] [RFC PATCH V6 09/18] cpu: add a tcg_executing flag.

[fred . konrad]

From: KONRAD Frederic <address@hidden>

We need to know whether any other VCPU is executing code or not it's possible
with this flag.

Signed-off-by: KONRAD Frederic <address@hidden>
---
 cpu-exec.c        | 1 +
 cpus.c            | 1 +
 include/qom/cpu.h | 3 +++
 qom/cpu.c         | 1 +
 4 files changed, 6 insertions(+)

diff --git a/cpu-exec.c b/cpu-exec.c
index 0644383..de256d6 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -390,6 +390,7 @@ int cpu_exec(CPUArchState *env)
         cpu->halted = 0;
     }
 
+    cpu->tcg_executing = 1;
     current_cpu = cpu;
 
     rcu_read_lock();
diff --git a/cpus.c b/cpus.c
index 2541c56..0291620 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1377,6 +1377,7 @@ static int tcg_cpu_exec(CPUArchState *env)
     }
     qemu_mutex_unlock_iothread();
     ret = cpu_exec(env);
+    cpu->tcg_executing = 0;
     qemu_mutex_lock_iothread();
 #ifdef CONFIG_PROFILER
     tcg_time += profile_getclock() - ti;
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index af3c9e4..1464afa 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -222,6 +222,7 @@ 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.
@@ -315,6 +316,8 @@ 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 108bfa2..ff41a4c 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