KVM: arm64: Hide kvm_mmu_wp_memory_region()

We needn't expose the function as it's only used by mmu.c since it
was introduced by commit c6473555 ("KVM: arm: Add initial dirty
page locking support").
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210316041126.81860-2-gshan@redhat.com

arch/arm64/include/asm/kvm_host.h

@@ -632,7 +632,6 @@ void kvm_arm_resume_guest(struct kvm *kvm);
 	})
 
 void force_vm_exit(const cpumask_t *mask);
-void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
 
 int handle_exit(struct kvm_vcpu *vcpu, int exception_index);
 void handle_exit_early(struct kvm_vcpu *vcpu, int exception_index);

arch/arm64/kvm/mmu.c

@@ -555,7 +555,7 @@ static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_
  * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
  * serializing operations for VM memory regions.
  */
-void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
+static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
 {
 	struct kvm_memslots *slots = kvm_memslots(kvm);
 	struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);