ANDROID: KVM: arm64: Deprecate lazy pte mappings for hyp modules

Remove the lazy PTE mapping functionality for vendor modules
since we now support donating memory through the ff-a lend
interface.

Bug: 352480558
Bug: 278749606
Bug: 381963586
Change-Id: I632d937cda52d8869b1157063d24dc86ee53085f
Signed-off-by: Sebastian Ene <sebastianene@google.com>

arch/arm64/include/asm/kvm_pgtable.h

@@ -941,27 +941,4 @@ enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
  */
 void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
 				phys_addr_t addr, size_t size);
-
-/**
- * kvm_pgtable_stage2_get_pages() - Raise the refcount for each entry and unmap them.
- *
- * @pgt:	Page-table structure initialised by kvm_pgtable_*_init()
- *		or a similar initialiser.
- * @addr:	Input address for the start of the walk.
- * @size:	Size of the range.
- * @mc:		Cache of pre-allocated and zeroed memory from which to allocate
- *		page-table pages.
- */
-int kvm_pgtable_stage2_get_pages(struct kvm_pgtable *pgt, u64 addr, u64 size, void *mc);
-
-/**
- * kvm_pgtable_stage2_put_pages() - Drop the refcount for each entry. This is the
- *			     opposite of kvm_pgtable_get_pages().
- *
- * @pgt:	Page-table structure initialised by kvm_pgtable_*_init()
- *		or a similar initialiser.
- * @addr:	Input address for the start of the walk.
- * @size:	Size of the range.
- */
-int kvm_pgtable_stage2_put_pages(struct kvm_pgtable *pgt, u64 addr, u64 size);
 #endif	/* __ARM64_KVM_PGTABLE_H__ */

arch/arm64/include/asm/kvm_pkvm_module.h

@@ -95,12 +95,14 @@ struct pkvm_sglist_page {
  *				allows to apply this prot on a range of
  *				contiguous memory.
  * @host_stage2_enable_lazy_pte:
+ *				DEPRECATED
  *				Unmap a range of memory from the host stage-2,
  *				leaving the pages host ownership intact. The
  *				pages will be remapped lazily (subject to the
  *				usual ownership checks) in response to a
  *				faulting access from the host.
  * @host_stage2_disable_lazy_pte:
+ *				DEPRECATED
  *				This is the opposite function of
  *				host_stage2_enable_lazy_pte. Must be called once
  *				the module is done with the region.

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

@@ -78,7 +78,6 @@ int __pkvm_guest_relinquish_to_host(struct pkvm_hyp_vcpu *vcpu,
 				    u64 ipa, u64 *ppa);
 int __pkvm_use_dma(u64 phys_addr, size_t size, struct pkvm_hyp_vcpu *hyp_vcpu);
 int __pkvm_unuse_dma(u64 phys_addr, size_t size, struct pkvm_hyp_vcpu *hyp_vcpu);
-int __pkvm_host_lazy_pte(u64 pfn, u64 nr_pages, bool enable);
 u64 __pkvm_ptdump_get_config(pkvm_handle_t handle, enum pkvm_ptdump_ops op);
 u64 __pkvm_ptdump_walk_range(pkvm_handle_t handle, struct pkvm_ptdump_log_hdr *log_hva);
 

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

@@ -1779,45 +1779,6 @@ unlock:
 	return ret;
 }
 
-int __pkvm_host_lazy_pte(u64 pfn, u64 nr_pages, bool enable)
-{
-	u64 size, end, addr = hyp_pfn_to_phys(pfn);
-	struct memblock_region *reg;
-	struct kvm_mem_range range;
-	int ret;
-
-	if (check_shl_overflow(nr_pages, PAGE_SHIFT, &size) ||
-	    check_add_overflow(addr, size, &end))
-		return -EINVAL;
-
-	/* Reject MMIO regions */
-	reg = find_mem_range(addr, &range);
-	if (!reg || !is_in_mem_range(end - 1, &range))
-		return -EPERM;
-
-	host_lock_component();
-
-	ret = ___host_check_page_state_range(addr, size, PKVM_PAGE_OWNED, reg, true);
-	if (ret)
-		goto unlock;
-
-	if (enable) {
-		ret = kvm_pgtable_stage2_get_pages(&host_mmu.pgt, addr, size,
-						   &host_s2_pool);
-	} else {
-		ret = kvm_pgtable_stage2_put_pages(&host_mmu.pgt, addr, size);
-		if (ret)
-			goto unlock;
-
-		WARN_ON(host_stage2_idmap_locked(addr, size, PKVM_HOST_MEM_PROT, false));
-	}
-
-unlock:
-	host_unlock_component();
-
-	return ret;
-}
-
 int hyp_pin_shared_mem(void *from, void *to)
 {
 	u64 cur, start = ALIGN_DOWN((u64)from, PAGE_SIZE);

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

@@ -116,12 +116,20 @@ static void tracing_mod_hyp_printk(u8 fmt_id, u64 a, u64 b, u64 c, u64 d)
 
 static int host_stage2_enable_lazy_pte(u64 pfn, u64 nr_pages)
 {
-	return __pkvm_host_lazy_pte(pfn, nr_pages, true);
+	/*
+	 * Deprecating the lazy PTE functionality as now the
+	 * host can unmap on FF-A lend.
+	 */
+	WARN_ON(1);
+
+	return -EPERM;
 }
 
 static int host_stage2_disable_lazy_pte(u64 pfn, u64 nr_pages)
 {
-	return __pkvm_host_lazy_pte(pfn, nr_pages, false);
+	WARN_ON(1);
+
+	return -EPERM;
 }
 
 static int __hyp_smp_processor_id(void)

arch/arm64/kvm/hyp/pgtable.c

@@ -1263,66 +1263,6 @@ int kvm_pgtable_stage2_annotate(struct kvm_pgtable *pgt, u64 addr, u64 size,
 	return ret;
 }
 
-static int stage2_get_pages_walker(const struct kvm_pgtable_visit_ctx *ctx,
-				   enum kvm_pgtable_walk_flags visit)
-{
-	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
-	struct stage2_map_data *data = ctx->arg;
-	int ret;
-
-	ret = stage2_map_walk_leaf(ctx, data);
-	if (ret)
-		return ret;
-
-	if (ctx->level == KVM_PGTABLE_LAST_LEVEL)
-		mm_ops->get_page(ctx->ptep);
-
-	return 0;
-}
-
-int kvm_pgtable_stage2_get_pages(struct kvm_pgtable *pgt, u64 addr, u64 size,
-				 void *mc)
-{
-	struct stage2_map_data map_data = {
-		.phys		= KVM_PHYS_INVALID,
-		.mmu		= pgt->mmu,
-		.memcache	= mc,
-		.force_pte	= true,
-	};
-	struct kvm_pgtable_walker walker = {
-		.cb		= stage2_get_pages_walker,
-		.flags		= KVM_PGTABLE_WALK_LEAF,
-		.arg		= &map_data,
-	};
-
-	return kvm_pgtable_walk(pgt, addr, size, &walker);
-}
-
-static int stage2_put_pages_walker(const struct kvm_pgtable_visit_ctx *ctx,
-				   enum kvm_pgtable_walk_flags visit)
-{
-	struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
-
-	/* get_pages has force_pte */
-	if (WARN_ON(ctx->level != KVM_PGTABLE_LAST_LEVEL))
-		return -EINVAL;
-
-	mm_ops->put_page(ctx->ptep);
-
-	return 0;
-}
-
-int kvm_pgtable_stage2_put_pages(struct kvm_pgtable *pgt, u64 addr, u64 size)
-{
-	struct kvm_pgtable_walker walker = {
-		.cb		= stage2_put_pages_walker,
-		.flags		= KVM_PGTABLE_WALK_LEAF,
-		.arg		= pgt->mmu,
-	};
-
-	return kvm_pgtable_walk(pgt, addr, size, &walker);
-}
-
 static int stage2_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
 			       enum kvm_pgtable_walk_flags visit)
 {