KVM: arm64: Introduce addr_is_memory()

Introduce a helper usable in nVHE protected mode to check whether a
physical address is in a RAM region or not.
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210809152448.1810400-16-qperret@google.com

arch/arm64/kvm/hyp/include/nvhe/mem_protect.h

@@ -51,6 +51,7 @@ extern const u8 pkvm_hyp_id;
 int __pkvm_prot_finalize(void);
 int __pkvm_mark_hyp(phys_addr_t start, phys_addr_t end);
 
+bool addr_is_memory(phys_addr_t phys);
 int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
 int host_stage2_set_owner_locked(phys_addr_t addr, u64 size, u8 owner_id);
 int kvm_host_prepare_stage2(void *pgt_pool_base);

arch/arm64/kvm/hyp/nvhe/mem_protect.c

@@ -197,6 +197,13 @@ static bool find_mem_range(phys_addr_t addr, struct kvm_mem_range *range)
 	return false;
 }
 
+bool addr_is_memory(phys_addr_t phys)
+{
+	struct kvm_mem_range range;
+
+	return find_mem_range(phys, &range);
+}
+
 static bool range_is_memory(u64 start, u64 end)
 {
 	struct kvm_mem_range r1, r2;