KVM: x86/mmu: Move kvm_mmu_available_pages() into mmu.c

Move kvm_mmu_available_pages() from mmu.h to mmu.c, it has a single
caller and has no business being exposed via mmu.h.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622202034.15093-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu.h

@@ -64,15 +64,6 @@ bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu);
 int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
 				u64 fault_address, char *insn, int insn_len);
 
-static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm)
-{
-	if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages)
-		return kvm->arch.n_max_mmu_pages -
-			kvm->arch.n_used_mmu_pages;
-
-	return 0;
-}
-
 static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu)
 {
 	if (likely(vcpu->arch.mmu->root_hpa != INVALID_PAGE))

arch/x86/kvm/mmu/mmu.c

@@ -2853,6 +2853,15 @@ static unsigned long kvm_mmu_zap_oldest_mmu_pages(struct kvm *kvm,
 	return total_zapped;
 }
 
+static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm)
+{
+	if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages)
+		return kvm->arch.n_max_mmu_pages -
+			kvm->arch.n_used_mmu_pages;
+
+	return 0;
+}
+
 static int make_mmu_pages_available(struct kvm_vcpu *vcpu)
 {
 	unsigned long avail = kvm_mmu_available_pages(vcpu->kvm);