From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>

introduce kvm_dirty_ring_enabled to show if kvm-reaper is working.
dirtyrate thread could use it to check if calculation can base on
dirty ring feature.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
 accel/kvm/kvm-all.c  | 5 +++++
 include/sysemu/kvm.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index c7ec538850..2e96b77b31 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2293,6 +2293,11 @@ bool kvm_vcpu_id_is_valid(int vcpu_id)
     return vcpu_id >= 0 && vcpu_id < kvm_max_vcpu_id(s);
 }
 
+bool kvm_dirty_ring_enabled(void)
+{
+    return kvm_state->kvm_dirty_ring_size ? true : false;
+}
+
 static int kvm_init(MachineState *ms)
 {
     MachineClass *mc = MACHINE_GET_CLASS(ms);
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index a1ab1ee12d..7b22aeb6ae 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -547,4 +547,5 @@ bool kvm_cpu_check_are_resettable(void);
 
 bool kvm_arch_cpu_check_are_resettable(void);
 
+bool kvm_dirty_ring_enabled(void);
 #endif
-- 
2.24.3