[PULL 02/20] KVM: introduce dirty_pages and kvm_dirty_ring_enabled

[Juan Quintela <quintela@xxxxxxxxxx>]

From: Hyman Huang(黄勇) <huangy81@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Message-Id: <fee5fb2ab17ec2159405fc54a3cff8e02322f816.1624040308.git.huangy81@xxxxxxxxxxxxxxx>
Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>
Reviewed-by: Juan Quintela <quintela@xxxxxxxxxx>
Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx>
---
 include/hw/core/cpu.h  | 1 +
 include/sysemu/kvm.h   | 1 +
 accel/kvm/kvm-all.c    | 7 +++++++
 accel/stubs/kvm-stub.c | 5 +++++
 4 files changed, 14 insertions(+)

diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 1a10497af3..e948e81f1a 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -381,6 +381,7 @@ struct CPUState {
     struct kvm_run *kvm_run;
     struct kvm_dirty_gfn *kvm_dirty_gfns;
     uint32_t kvm_fetch_index;
+    uint64_t dirty_pages;
 
     /* Used for events with 'vcpu' and *without* the 'disabled' properties */
     DECLARE_BITMAP(trace_dstate_delayed, CPU_TRACE_DSTATE_MAX_EVENTS);
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
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);
diff --git a/accel/stubs/kvm-stub.c b/accel/stubs/kvm-stub.c
index 5b1d00a222..5319573e00 100644
--- a/accel/stubs/kvm-stub.c
+++ b/accel/stubs/kvm-stub.c
@@ -147,4 +147,9 @@ bool kvm_arm_supports_user_irq(void)
 {
     return false;
 }
+
+bool kvm_dirty_ring_enabled(void)
+{
+    return false;
+}
 #endif
-- 
2.33.1