KVM: Add dirty-ring-size property

[mirror_qemu.git] / accel / kvm / kvm-all.c

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index df9fbf59a6451dc9ce24342d2f34c70889aca94e..5afe15ae663089dd766fa9ec3fbd2e6a85f12da3 100644 (file)
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -126,6 +126,8 @@ struct KVMState
         KVMMemoryListener *ml;
         AddressSpace *as;
     } *as;
+    uint64_t kvm_dirty_ring_bytes;  /* Size of the per-vcpu dirty ring */
+    uint32_t kvm_dirty_ring_size;   /* Number of dirty GFNs per ring */
 };
 
 KVMState *kvm_state;
@@ -3182,6 +3184,42 @@ bool kvm_kernel_irqchip_split(void)
     return kvm_state->kernel_irqchip_split == ON_OFF_AUTO_ON;
 }
 
+static void kvm_get_dirty_ring_size(Object *obj, Visitor *v,
+                                    const char *name, void *opaque,
+                                    Error **errp)
+{
+    KVMState *s = KVM_STATE(obj);
+    uint32_t value = s->kvm_dirty_ring_size;
+
+    visit_type_uint32(v, name, &value, errp);
+}
+
+static void kvm_set_dirty_ring_size(Object *obj, Visitor *v,
+                                    const char *name, void *opaque,
+                                    Error **errp)
+{
+    KVMState *s = KVM_STATE(obj);
+    Error *error = NULL;
+    uint32_t value;
+
+    if (s->fd != -1) {
+        error_setg(errp, "Cannot set properties after the accelerator has been initialized");
+        return;
+    }
+
+    visit_type_uint32(v, name, &value, &error);
+    if (error) {
+        error_propagate(errp, error);
+        return;
+    }
+    if (value & (value - 1)) {
+        error_setg(errp, "dirty-ring-size must be a power of two.");
+        return;
+    }
+
+    s->kvm_dirty_ring_size = value;
+}
+
 static void kvm_accel_instance_init(Object *obj)
 {
     KVMState *s = KVM_STATE(obj);
@@ -3191,6 +3229,8 @@ static void kvm_accel_instance_init(Object *obj)
     s->kvm_shadow_mem = -1;
     s->kernel_irqchip_allowed = true;
     s->kernel_irqchip_split = ON_OFF_AUTO_AUTO;
+    /* KVM dirty ring is by default off */
+    s->kvm_dirty_ring_size = 0;
 }
 
 static void kvm_accel_class_init(ObjectClass *oc, void *data)
@@ -3212,6 +3252,12 @@ static void kvm_accel_class_init(ObjectClass *oc, void *data)
         NULL, NULL);
     object_class_property_set_description(oc, "kvm-shadow-mem",
         "KVM shadow MMU size");
+
+    object_class_property_add(oc, "dirty-ring-size", "uint32",
+        kvm_get_dirty_ring_size, kvm_set_dirty_ring_size,
+        NULL, NULL);
+    object_class_property_set_description(oc, "dirty-ring-size",
+        "Size of KVM dirty page ring buffer (default: 0, i.e. use bitmap)");
 }
 
 static const TypeInfo kvm_accel_type = {