KVM: arm64: Convert kvm_phys_addr_ioremap() to generic page-table API

Convert kvm_phys_addr_ioremap() to use kvm_pgtable_stage2_map() instead
of stage2_set_pte().
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-8-will@kernel.org

arch/arm64/kvm/mmu.c

@@ -1154,35 +1154,33 @@ static int stage2_pudp_test_and_clear_young(pud_t *pud)
 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 			  phys_addr_t pa, unsigned long size, bool writable)
 {
-	phys_addr_t addr, end;
+	phys_addr_t addr;
 	int ret = 0;
-	unsigned long pfn;
 	struct kvm_mmu_memory_cache cache = { 0, __GFP_ZERO, NULL, };
+	struct kvm_pgtable *pgt = kvm->arch.mmu.pgt;
+	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_DEVICE |
+				     KVM_PGTABLE_PROT_R |
+				     (writable ? KVM_PGTABLE_PROT_W : 0);
 
-	end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
-	pfn = __phys_to_pfn(pa);
-
-	for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
-		pte_t pte = kvm_pfn_pte(pfn, PAGE_S2_DEVICE);
-
-		if (writable)
-			pte = kvm_s2pte_mkwrite(pte);
+	size += offset_in_page(guest_ipa);
+	guest_ipa &= PAGE_MASK;
 
+	for (addr = guest_ipa; addr < guest_ipa + size; addr += PAGE_SIZE) {
 		ret = kvm_mmu_topup_memory_cache(&cache,
 						 kvm_mmu_cache_min_pages(kvm));
 		if (ret)
-			goto out;
+			break;
+
 		spin_lock(&kvm->mmu_lock);
-		ret = stage2_set_pte(&kvm->arch.mmu, &cache, addr, &pte,
-				     KVM_S2PTE_FLAG_IS_IOMAP);
+		ret = kvm_pgtable_stage2_map(pgt, addr, PAGE_SIZE, pa, prot,
+					     &cache);
 		spin_unlock(&kvm->mmu_lock);
 		if (ret)
-			goto out;
+			break;
 
-		pfn++;
+		pa += PAGE_SIZE;
 	}
 
-out:
 	kvm_mmu_free_memory_cache(&cache);
 	return ret;
 }