KVM: arm64: Add kvm_uninit_stage2_mmu()

Add kvm_uninit_stage2_mmu() and move kvm_free_stage2_pgd() into it. A
future commit will add some more things to do inside of
kvm_uninit_stage2_mmu().

Signed-off-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Link: https://lore.kernel.org/r/20230426172330.1439644-9-ricarkol@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

Author: Ricardo Koller

arch/arm64/include/asm/kvm_mmu.h

@@ -172,6 +172,7 @@ void __init free_hyp_pgds(void);
 
 void stage2_unmap_vm(struct kvm *kvm);
 int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type);
+void kvm_uninit_stage2_mmu(struct kvm *kvm);
 void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu);
 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 			  phys_addr_t pa, unsigned long size, bool writable);

arch/arm64/kvm/mmu.c

@@ -790,6 +790,11 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
 	return err;
 }
 
+void kvm_uninit_stage2_mmu(struct kvm *kvm)
+{
+	kvm_free_stage2_pgd(&kvm->arch.mmu);
+}
+
 static void stage2_unmap_memslot(struct kvm *kvm,
 				 struct kvm_memory_slot *memslot)
 {
@@ -1893,7 +1898,7 @@ void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
 
 void kvm_arch_flush_shadow_all(struct kvm *kvm)
 {
-	kvm_free_stage2_pgd(&kvm->arch.mmu);
+	kvm_uninit_stage2_mmu(kvm);
 }
 
 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,