KVM: x86: release time_page on vcpu destruction

Not releasing the time_page causes a leak of that page or the compound
page it is situated in.

Cc: stable@kernel.org
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

arch/x86/kvm/x86.c

@@ -4159,6 +4159,11 @@ EXPORT_SYMBOL_GPL(kvm_put_guest_fpu);
 
 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 {
+	if (vcpu->arch.time_page) {
+		kvm_release_page_dirty(vcpu->arch.time_page);
+		vcpu->arch.time_page = NULL;
+	}
+
 	kvm_x86_ops->vcpu_free(vcpu);
 }