KVM: MMU: audit: replace mmu audit tracepoint with jump-label
The tracepoint is only used to audit mmu code, it should not be exposed to
user, let us replace it with jump-label.
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/mmu_audit.c b/arch/x86/kvm/mmu_audit.c
index 746ec25..5df6736 100644
--- a/arch/x86/kvm/mmu_audit.c
+++ b/arch/x86/kvm/mmu_audit.c
@@ -224,30 +224,29 @@
mmu_spte_walk(vcpu, audit_spte);
}
-static void kvm_mmu_audit(void *ignore, struct kvm_vcpu *vcpu, int point)
+static bool mmu_audit;
+static struct jump_label_key mmu_audit_key;
+
+static void kvm_mmu_audit(struct kvm_vcpu *vcpu, int point)
{
static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10);
- if (!__ratelimit(&ratelimit_state))
- return;
+ if (static_branch((&mmu_audit_key))) {
+ if (!__ratelimit(&ratelimit_state))
+ return;
- vcpu->kvm->arch.audit_point = point;
- audit_all_active_sps(vcpu->kvm);
- audit_vcpu_spte(vcpu);
+ vcpu->kvm->arch.audit_point = point;
+ audit_all_active_sps(vcpu->kvm);
+ audit_vcpu_spte(vcpu);
+ }
}
-static bool mmu_audit;
-
static void mmu_audit_enable(void)
{
- int ret;
-
if (mmu_audit)
return;
- ret = register_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);
- WARN_ON(ret);
-
+ jump_label_inc(&mmu_audit_key);
mmu_audit = true;
}
@@ -256,8 +255,7 @@
if (!mmu_audit)
return;
- unregister_trace_kvm_mmu_audit(kvm_mmu_audit, NULL);
- tracepoint_synchronize_unregister();
+ jump_label_dec(&mmu_audit_key);
mmu_audit = false;
}