KVM: introduce dirty_pages and kvm_dirty_ring_enabled

dirty_pages is used to calculate dirtyrate via dirty ring, when
enabled, kvm-reaper will increase the dirty pages after gfns
being dirtied.

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

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Message-Id: <fee5fb2ab17ec2159405fc54a3cff8e02322f816.1624040308.git.huangy81@chinatelecom.cn>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index db8d83b137..eecd8031cf 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -469,6 +469,7 @@ int kvm_init_vcpu(CPUState *cpu, Error **errp)
     cpu->kvm_fd = ret;
     cpu->kvm_state = s;
     cpu->vcpu_dirty = true;
+    cpu->dirty_pages = 0;
 
     mmap_size = kvm_ioctl(s, KVM_GET_VCPU_MMAP_SIZE, 0);
     if (mmap_size < 0) {
@@ -743,6 +744,7 @@ static uint32_t kvm_dirty_ring_reap_one(KVMState *s, CPUState *cpu)
         count++;
     }
     cpu->kvm_fetch_index = fetch;
+    cpu->dirty_pages += count;
 
     return count;
 }
@@ -2296,6 +2298,11 @@ 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);