mmu.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
   4 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
   5 */
   6
   7#include <linux/acpi.h>
   8#include <linux/mman.h>
   9#include <linux/kvm_host.h>
  10#include <linux/io.h>
  11#include <linux/hugetlb.h>
  12#include <linux/sched/signal.h>
  13#include <trace/events/kvm.h>
  14#include <asm/acpi.h>
  15#include <asm/pgalloc.h>
  16#include <asm/cacheflush.h>
  17#include <asm/kvm_arm.h>
  18#include <asm/kvm_mmu.h>
  19#include <asm/kvm_pgtable.h>
  20#include <asm/kvm_pkvm.h>
  21#include <asm/kvm_asm.h>
  22#include <asm/kvm_emulate.h>
  23#include <asm/virt.h>
  24
  25#include "trace.h"
  26
  27static struct kvm_pgtable *hyp_pgtable;
  28static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
  29
  30static unsigned long __ro_after_init hyp_idmap_start;
  31static unsigned long __ro_after_init hyp_idmap_end;
  32static phys_addr_t __ro_after_init hyp_idmap_vector;
  33
  34u32 __ro_after_init __hyp_va_bits;
  35
  36static unsigned long __ro_after_init io_map_base;
  37
  38#define KVM_PGT_FN(fn)		(!is_protected_kvm_enabled() ? fn : p ## fn)
  39
  40static phys_addr_t __stage2_range_addr_end(phys_addr_t addr, phys_addr_t end,
  41					   phys_addr_t size)
  42{
  43	phys_addr_t boundary = ALIGN_DOWN(addr + size, size);
  44
  45	return (boundary - 1 < end - 1) ? boundary : end;
  46}
  47
  48static phys_addr_t stage2_range_addr_end(phys_addr_t addr, phys_addr_t end)
  49{
  50	phys_addr_t size = kvm_granule_size(KVM_PGTABLE_MIN_BLOCK_LEVEL);
  51
  52	return __stage2_range_addr_end(addr, end, size);
  53}
  54
  55/*
  56 * Release kvm_mmu_lock periodically if the memory region is large. Otherwise,
  57 * we may see kernel panics with CONFIG_DETECT_HUNG_TASK,
  58 * CONFIG_LOCKUP_DETECTOR, CONFIG_LOCKDEP. Additionally, holding the lock too
  59 * long will also starve other vCPUs. We have to also make sure that the page
  60 * tables are not freed while we released the lock.
  61 */
  62static int stage2_apply_range(struct kvm_s2_mmu *mmu, phys_addr_t addr,
  63			      phys_addr_t end,
  64			      int (*fn)(struct kvm_pgtable *, u64, u64),
  65			      bool resched)
  66{
  67	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
  68	int ret;
  69	u64 next;
  70
  71	do {
  72		struct kvm_pgtable *pgt = mmu->pgt;
  73		if (!pgt)
  74			return -EINVAL;
  75
  76		next = stage2_range_addr_end(addr, end);
  77		ret = fn(pgt, addr, next - addr);
  78		if (ret)
  79			break;
  80
  81		if (resched && next != end)
  82			cond_resched_rwlock_write(&kvm->mmu_lock);
  83	} while (addr = next, addr != end);
  84
  85	return ret;
  86}
  87
  88#define stage2_apply_range_resched(mmu, addr, end, fn)			\
  89	stage2_apply_range(mmu, addr, end, fn, true)
  90
  91/*
  92 * Get the maximum number of page-tables pages needed to split a range
  93 * of blocks into PAGE_SIZE PTEs. It assumes the range is already
  94 * mapped at level 2, or at level 1 if allowed.
  95 */
  96static int kvm_mmu_split_nr_page_tables(u64 range)
  97{
  98	int n = 0;
  99
 100	if (KVM_PGTABLE_MIN_BLOCK_LEVEL < 2)
 101		n += DIV_ROUND_UP(range, PUD_SIZE);
 102	n += DIV_ROUND_UP(range, PMD_SIZE);
 103	return n;
 104}
 105
 106static bool need_split_memcache_topup_or_resched(struct kvm *kvm)
 107{
 108	struct kvm_mmu_memory_cache *cache;
 109	u64 chunk_size, min;
 110
 111	if (need_resched() || rwlock_needbreak(&kvm->mmu_lock))
 112		return true;
 113
 114	chunk_size = kvm->arch.mmu.split_page_chunk_size;
 115	min = kvm_mmu_split_nr_page_tables(chunk_size);
 116	cache = &kvm->arch.mmu.split_page_cache;
 117	return kvm_mmu_memory_cache_nr_free_objects(cache) < min;
 118}
 119
 120static int kvm_mmu_split_huge_pages(struct kvm *kvm, phys_addr_t addr,
 121				    phys_addr_t end)
 122{
 123	struct kvm_mmu_memory_cache *cache;
 124	struct kvm_pgtable *pgt;
 125	int ret, cache_capacity;
 126	u64 next, chunk_size;
 127
 128	lockdep_assert_held_write(&kvm->mmu_lock);
 129
 130	chunk_size = kvm->arch.mmu.split_page_chunk_size;
 131	cache_capacity = kvm_mmu_split_nr_page_tables(chunk_size);
 132
 133	if (chunk_size == 0)
 134		return 0;
 135
 136	cache = &kvm->arch.mmu.split_page_cache;
 137
 138	do {
 139		if (need_split_memcache_topup_or_resched(kvm)) {
 140			write_unlock(&kvm->mmu_lock);
 141			cond_resched();
 142			/* Eager page splitting is best-effort. */
 143			ret = __kvm_mmu_topup_memory_cache(cache,
 144							   cache_capacity,
 145							   cache_capacity);
 146			write_lock(&kvm->mmu_lock);
 147			if (ret)
 148				break;
 149		}
 150
 151		pgt = kvm->arch.mmu.pgt;
 152		if (!pgt)
 153			return -EINVAL;
 154
 155		next = __stage2_range_addr_end(addr, end, chunk_size);
 156		ret = KVM_PGT_FN(kvm_pgtable_stage2_split)(pgt, addr, next - addr, cache);
 157		if (ret)
 158			break;
 159	} while (addr = next, addr != end);
 160
 161	return ret;
 162}
 163
 164static bool memslot_is_logging(struct kvm_memory_slot *memslot)
 165{
 166	return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
 167}
 168
 169/**
 170 * kvm_arch_flush_remote_tlbs() - flush all VM TLB entries for v7/8
 171 * @kvm:	pointer to kvm structure.
 172 *
 173 * Interface to HYP function to flush all VM TLB entries
 174 */
 175int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
 176{
 177	if (is_protected_kvm_enabled())
 178		kvm_call_hyp_nvhe(__pkvm_tlb_flush_vmid, kvm->arch.pkvm.handle);
 179	else
 180		kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
 181	return 0;
 182}
 183
 184int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm,
 185				      gfn_t gfn, u64 nr_pages)
 186{
 187	u64 size = nr_pages << PAGE_SHIFT;
 188	u64 addr = gfn << PAGE_SHIFT;
 189
 190	if (is_protected_kvm_enabled())
 191		kvm_call_hyp_nvhe(__pkvm_tlb_flush_vmid, kvm->arch.pkvm.handle);
 192	else
 193		kvm_tlb_flush_vmid_range(&kvm->arch.mmu, addr, size);
 194	return 0;
 195}
 196
 197static void *stage2_memcache_zalloc_page(void *arg)
 198{
 199	struct kvm_mmu_memory_cache *mc = arg;
 200	void *virt;
 201
 202	/* Allocated with __GFP_ZERO, so no need to zero */
 203	virt = kvm_mmu_memory_cache_alloc(mc);
 204	if (virt)
 205		kvm_account_pgtable_pages(virt, 1);
 206	return virt;
 207}
 208
 209static void *kvm_host_zalloc_pages_exact(size_t size)
 210{
 211	return alloc_pages_exact(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
 212}
 213
 214static void *kvm_s2_zalloc_pages_exact(size_t size)
 215{
 216	void *virt = kvm_host_zalloc_pages_exact(size);
 217
 218	if (virt)
 219		kvm_account_pgtable_pages(virt, (size >> PAGE_SHIFT));
 220	return virt;
 221}
 222
 223static void kvm_s2_free_pages_exact(void *virt, size_t size)
 224{
 225	kvm_account_pgtable_pages(virt, -(size >> PAGE_SHIFT));
 226	free_pages_exact(virt, size);
 227}
 228
 229static struct kvm_pgtable_mm_ops kvm_s2_mm_ops;
 230
 231static void stage2_free_unlinked_table_rcu_cb(struct rcu_head *head)
 232{
 233	struct page *page = container_of(head, struct page, rcu_head);
 234	void *pgtable = page_to_virt(page);
 235	s8 level = page_private(page);
 236
 237	KVM_PGT_FN(kvm_pgtable_stage2_free_unlinked)(&kvm_s2_mm_ops, pgtable, level);
 238}
 239
 240static void stage2_free_unlinked_table(void *addr, s8 level)
 241{
 242	struct page *page = virt_to_page(addr);
 243
 244	set_page_private(page, (unsigned long)level);
 245	call_rcu(&page->rcu_head, stage2_free_unlinked_table_rcu_cb);
 246}
 247
 248static void kvm_host_get_page(void *addr)
 249{
 250	get_page(virt_to_page(addr));
 251}
 252
 253static void kvm_host_put_page(void *addr)
 254{
 255	put_page(virt_to_page(addr));
 256}
 257
 258static void kvm_s2_put_page(void *addr)
 259{
 260	struct page *p = virt_to_page(addr);
 261	/* Dropping last refcount, the page will be freed */
 262	if (page_count(p) == 1)
 263		kvm_account_pgtable_pages(addr, -1);
 264	put_page(p);
 265}
 266
 267static int kvm_host_page_count(void *addr)
 268{
 269	return page_count(virt_to_page(addr));
 270}
 271
 272static phys_addr_t kvm_host_pa(void *addr)
 273{
 274	return __pa(addr);
 275}
 276
 277static void *kvm_host_va(phys_addr_t phys)
 278{
 279	return __va(phys);
 280}
 281
 282static void clean_dcache_guest_page(void *va, size_t size)
 283{
 284	__clean_dcache_guest_page(va, size);
 285}
 286
 287static void invalidate_icache_guest_page(void *va, size_t size)
 288{
 289	__invalidate_icache_guest_page(va, size);
 290}
 291
 292/*
 293 * Unmapping vs dcache management:
 294 *
 295 * If a guest maps certain memory pages as uncached, all writes will
 296 * bypass the data cache and go directly to RAM.  However, the CPUs
 297 * can still speculate reads (not writes) and fill cache lines with
 298 * data.
 299 *
 300 * Those cache lines will be *clean* cache lines though, so a
 301 * clean+invalidate operation is equivalent to an invalidate
 302 * operation, because no cache lines are marked dirty.
 303 *
 304 * Those clean cache lines could be filled prior to an uncached write
 305 * by the guest, and the cache coherent IO subsystem would therefore
 306 * end up writing old data to disk.
 307 *
 308 * This is why right after unmapping a page/section and invalidating
 309 * the corresponding TLBs, we flush to make sure the IO subsystem will
 310 * never hit in the cache.
 311 *
 312 * This is all avoided on systems that have ARM64_HAS_STAGE2_FWB, as
 313 * we then fully enforce cacheability of RAM, no matter what the guest
 314 * does.
 315 */
 316/**
 317 * __unmap_stage2_range -- Clear stage2 page table entries to unmap a range
 318 * @mmu:   The KVM stage-2 MMU pointer
 319 * @start: The intermediate physical base address of the range to unmap
 320 * @size:  The size of the area to unmap
 321 * @may_block: Whether or not we are permitted to block
 322 *
 323 * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
 324 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
 325 * destroying the VM), otherwise another faulting VCPU may come in and mess
 326 * with things behind our backs.
 327 */
 328static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size,
 329				 bool may_block)
 330{
 331	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
 332	phys_addr_t end = start + size;
 333
 334	lockdep_assert_held_write(&kvm->mmu_lock);
 335	WARN_ON(size & ~PAGE_MASK);
 336	WARN_ON(stage2_apply_range(mmu, start, end, KVM_PGT_FN(kvm_pgtable_stage2_unmap),
 337				   may_block));
 338}
 339
 340void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start,
 341			    u64 size, bool may_block)
 342{
 343	__unmap_stage2_range(mmu, start, size, may_block);
 344}
 345
 346void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
 347{
 348	stage2_apply_range_resched(mmu, addr, end, KVM_PGT_FN(kvm_pgtable_stage2_flush));
 349}
 350
 351static void stage2_flush_memslot(struct kvm *kvm,
 352				 struct kvm_memory_slot *memslot)
 353{
 354	phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
 355	phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
 356
 357	kvm_stage2_flush_range(&kvm->arch.mmu, addr, end);
 358}
 359
 360/**
 361 * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
 362 * @kvm: The struct kvm pointer
 363 *
 364 * Go through the stage 2 page tables and invalidate any cache lines
 365 * backing memory already mapped to the VM.
 366 */
 367static void stage2_flush_vm(struct kvm *kvm)
 368{
 369	struct kvm_memslots *slots;
 370	struct kvm_memory_slot *memslot;
 371	int idx, bkt;
 372
 373	idx = srcu_read_lock(&kvm->srcu);
 374	write_lock(&kvm->mmu_lock);
 375
 376	slots = kvm_memslots(kvm);
 377	kvm_for_each_memslot(memslot, bkt, slots)
 378		stage2_flush_memslot(kvm, memslot);
 379
 380	kvm_nested_s2_flush(kvm);
 381
 382	write_unlock(&kvm->mmu_lock);
 383	srcu_read_unlock(&kvm->srcu, idx);
 384}
 385
 386/**
 387 * free_hyp_pgds - free Hyp-mode page tables
 388 */
 389void __init free_hyp_pgds(void)
 390{
 391	mutex_lock(&kvm_hyp_pgd_mutex);
 392	if (hyp_pgtable) {
 393		kvm_pgtable_hyp_destroy(hyp_pgtable);
 394		kfree(hyp_pgtable);
 395		hyp_pgtable = NULL;
 396	}
 397	mutex_unlock(&kvm_hyp_pgd_mutex);
 398}
 399
 400static bool kvm_host_owns_hyp_mappings(void)
 401{
 402	if (is_kernel_in_hyp_mode())
 403		return false;
 404
 405	if (static_branch_likely(&kvm_protected_mode_initialized))
 406		return false;
 407
 408	/*
 409	 * This can happen at boot time when __create_hyp_mappings() is called
 410	 * after the hyp protection has been enabled, but the static key has
 411	 * not been flipped yet.
 412	 */
 413	if (!hyp_pgtable && is_protected_kvm_enabled())
 414		return false;
 415
 416	WARN_ON(!hyp_pgtable);
 417
 418	return true;
 419}
 420
 421int __create_hyp_mappings(unsigned long start, unsigned long size,
 422			  unsigned long phys, enum kvm_pgtable_prot prot)
 423{
 424	int err;
 425
 426	if (WARN_ON(!kvm_host_owns_hyp_mappings()))
 427		return -EINVAL;
 428
 429	mutex_lock(&kvm_hyp_pgd_mutex);
 430	err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot);
 431	mutex_unlock(&kvm_hyp_pgd_mutex);
 432
 433	return err;
 434}
 435
 436static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
 437{
 438	if (!is_vmalloc_addr(kaddr)) {
 439		BUG_ON(!virt_addr_valid(kaddr));
 440		return __pa(kaddr);
 441	} else {
 442		return page_to_phys(vmalloc_to_page(kaddr)) +
 443		       offset_in_page(kaddr);
 444	}
 445}
 446
 447struct hyp_shared_pfn {
 448	u64 pfn;
 449	int count;
 450	struct rb_node node;
 451};
 452
 453static DEFINE_MUTEX(hyp_shared_pfns_lock);
 454static struct rb_root hyp_shared_pfns = RB_ROOT;
 455
 456static struct hyp_shared_pfn *find_shared_pfn(u64 pfn, struct rb_node ***node,
 457					      struct rb_node **parent)
 458{
 459	struct hyp_shared_pfn *this;
 460
 461	*node = &hyp_shared_pfns.rb_node;
 462	*parent = NULL;
 463	while (**node) {
 464		this = container_of(**node, struct hyp_shared_pfn, node);
 465		*parent = **node;
 466		if (this->pfn < pfn)
 467			*node = &((**node)->rb_left);
 468		else if (this->pfn > pfn)
 469			*node = &((**node)->rb_right);
 470		else
 471			return this;
 472	}
 473
 474	return NULL;
 475}
 476
 477static int share_pfn_hyp(u64 pfn)
 478{
 479	struct rb_node **node, *parent;
 480	struct hyp_shared_pfn *this;
 481	int ret = 0;
 482
 483	mutex_lock(&hyp_shared_pfns_lock);
 484	this = find_shared_pfn(pfn, &node, &parent);
 485	if (this) {
 486		this->count++;
 487		goto unlock;
 488	}
 489
 490	this = kzalloc(sizeof(*this), GFP_KERNEL);
 491	if (!this) {
 492		ret = -ENOMEM;
 493		goto unlock;
 494	}
 495
 496	this->pfn = pfn;
 497	this->count = 1;
 498	rb_link_node(&this->node, parent, node);
 499	rb_insert_color(&this->node, &hyp_shared_pfns);
 500	ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn);
 501unlock:
 502	mutex_unlock(&hyp_shared_pfns_lock);
 503
 504	return ret;
 505}
 506
 507static int unshare_pfn_hyp(u64 pfn)
 508{
 509	struct rb_node **node, *parent;
 510	struct hyp_shared_pfn *this;
 511	int ret = 0;
 512
 513	mutex_lock(&hyp_shared_pfns_lock);
 514	this = find_shared_pfn(pfn, &node, &parent);
 515	if (WARN_ON(!this)) {
 516		ret = -ENOENT;
 517		goto unlock;
 518	}
 519
 520	this->count--;
 521	if (this->count)
 522		goto unlock;
 523
 524	rb_erase(&this->node, &hyp_shared_pfns);
 525	kfree(this);
 526	ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn);
 527unlock:
 528	mutex_unlock(&hyp_shared_pfns_lock);
 529
 530	return ret;
 531}
 532
 533int kvm_share_hyp(void *from, void *to)
 534{
 535	phys_addr_t start, end, cur;
 536	u64 pfn;
 537	int ret;
 538
 539	if (is_kernel_in_hyp_mode())
 540		return 0;
 541
 542	/*
 543	 * The share hcall maps things in the 'fixed-offset' region of the hyp
 544	 * VA space, so we can only share physically contiguous data-structures
 545	 * for now.
 546	 */
 547	if (is_vmalloc_or_module_addr(from) || is_vmalloc_or_module_addr(to))
 548		return -EINVAL;
 549
 550	if (kvm_host_owns_hyp_mappings())
 551		return create_hyp_mappings(from, to, PAGE_HYP);
 552
 553	start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
 554	end = PAGE_ALIGN(__pa(to));
 555	for (cur = start; cur < end; cur += PAGE_SIZE) {
 556		pfn = __phys_to_pfn(cur);
 557		ret = share_pfn_hyp(pfn);
 558		if (ret)
 559			return ret;
 560	}
 561
 562	return 0;
 563}
 564
 565void kvm_unshare_hyp(void *from, void *to)
 566{
 567	phys_addr_t start, end, cur;
 568	u64 pfn;
 569
 570	if (is_kernel_in_hyp_mode() || kvm_host_owns_hyp_mappings() || !from)
 571		return;
 572
 573	start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
 574	end = PAGE_ALIGN(__pa(to));
 575	for (cur = start; cur < end; cur += PAGE_SIZE) {
 576		pfn = __phys_to_pfn(cur);
 577		WARN_ON(unshare_pfn_hyp(pfn));
 578	}
 579}
 580
 581/**
 582 * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
 583 * @from:	The virtual kernel start address of the range
 584 * @to:		The virtual kernel end address of the range (exclusive)
 585 * @prot:	The protection to be applied to this range
 586 *
 587 * The same virtual address as the kernel virtual address is also used
 588 * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
 589 * physical pages.
 590 */
 591int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
 592{
 593	phys_addr_t phys_addr;
 594	unsigned long virt_addr;
 595	unsigned long start = kern_hyp_va((unsigned long)from);
 596	unsigned long end = kern_hyp_va((unsigned long)to);
 597
 598	if (is_kernel_in_hyp_mode())
 599		return 0;
 600
 601	if (!kvm_host_owns_hyp_mappings())
 602		return -EPERM;
 603
 604	start = start & PAGE_MASK;
 605	end = PAGE_ALIGN(end);
 606
 607	for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
 608		int err;
 609
 610		phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
 611		err = __create_hyp_mappings(virt_addr, PAGE_SIZE, phys_addr,
 612					    prot);
 613		if (err)
 614			return err;
 615	}
 616
 617	return 0;
 618}
 619
 620static int __hyp_alloc_private_va_range(unsigned long base)
 621{
 622	lockdep_assert_held(&kvm_hyp_pgd_mutex);
 623
 624	if (!PAGE_ALIGNED(base))
 625		return -EINVAL;
 626
 627	/*
 628	 * Verify that BIT(VA_BITS - 1) hasn't been flipped by
 629	 * allocating the new area, as it would indicate we've
 630	 * overflowed the idmap/IO address range.
 631	 */
 632	if ((base ^ io_map_base) & BIT(VA_BITS - 1))
 633		return -ENOMEM;
 634
 635	io_map_base = base;
 636
 637	return 0;
 638}
 639
 640/**
 641 * hyp_alloc_private_va_range - Allocates a private VA range.
 642 * @size:	The size of the VA range to reserve.
 643 * @haddr:	The hypervisor virtual start address of the allocation.
 644 *
 645 * The private virtual address (VA) range is allocated below io_map_base
 646 * and aligned based on the order of @size.
 647 *
 648 * Return: 0 on success or negative error code on failure.
 649 */
 650int hyp_alloc_private_va_range(size_t size, unsigned long *haddr)
 651{
 652	unsigned long base;
 653	int ret = 0;
 654
 655	mutex_lock(&kvm_hyp_pgd_mutex);
 656
 657	/*
 658	 * This assumes that we have enough space below the idmap
 659	 * page to allocate our VAs. If not, the check in
 660	 * __hyp_alloc_private_va_range() will kick. A potential
 661	 * alternative would be to detect that overflow and switch
 662	 * to an allocation above the idmap.
 663	 *
 664	 * The allocated size is always a multiple of PAGE_SIZE.
 665	 */
 666	size = PAGE_ALIGN(size);
 667	base = io_map_base - size;
 668	ret = __hyp_alloc_private_va_range(base);
 669
 670	mutex_unlock(&kvm_hyp_pgd_mutex);
 671
 672	if (!ret)
 673		*haddr = base;
 674
 675	return ret;
 676}
 677
 678static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
 679					unsigned long *haddr,
 680					enum kvm_pgtable_prot prot)
 681{
 682	unsigned long addr;
 683	int ret = 0;
 684
 685	if (!kvm_host_owns_hyp_mappings()) {
 686		addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
 687					 phys_addr, size, prot);
 688		if (IS_ERR_VALUE(addr))
 689			return addr;
 690		*haddr = addr;
 691
 692		return 0;
 693	}
 694
 695	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
 696	ret = hyp_alloc_private_va_range(size, &addr);
 697	if (ret)
 698		return ret;
 699
 700	ret = __create_hyp_mappings(addr, size, phys_addr, prot);
 701	if (ret)
 702		return ret;
 703
 704	*haddr = addr + offset_in_page(phys_addr);
 705	return ret;
 706}
 707
 708int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr)
 709{
 710	unsigned long base;
 711	size_t size;
 712	int ret;
 713
 714	mutex_lock(&kvm_hyp_pgd_mutex);
 715	/*
 716	 * Efficient stack verification using the NVHE_STACK_SHIFT bit implies
 717	 * an alignment of our allocation on the order of the size.
 718	 */
 719	size = NVHE_STACK_SIZE * 2;
 720	base = ALIGN_DOWN(io_map_base - size, size);
 721
 722	ret = __hyp_alloc_private_va_range(base);
 723
 724	mutex_unlock(&kvm_hyp_pgd_mutex);
 725
 726	if (ret) {
 727		kvm_err("Cannot allocate hyp stack guard page\n");
 728		return ret;
 729	}
 730
 731	/*
 732	 * Since the stack grows downwards, map the stack to the page
 733	 * at the higher address and leave the lower guard page
 734	 * unbacked.
 735	 *
 736	 * Any valid stack address now has the NVHE_STACK_SHIFT bit as 1
 737	 * and addresses corresponding to the guard page have the
 738	 * NVHE_STACK_SHIFT bit as 0 - this is used for overflow detection.
 739	 */
 740	ret = __create_hyp_mappings(base + NVHE_STACK_SIZE, NVHE_STACK_SIZE,
 741				    phys_addr, PAGE_HYP);
 742	if (ret)
 743		kvm_err("Cannot map hyp stack\n");
 744
 745	*haddr = base + size;
 746
 747	return ret;
 748}
 749
 750/**
 751 * create_hyp_io_mappings - Map IO into both kernel and HYP
 752 * @phys_addr:	The physical start address which gets mapped
 753 * @size:	Size of the region being mapped
 754 * @kaddr:	Kernel VA for this mapping
 755 * @haddr:	HYP VA for this mapping
 756 */
 757int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 758			   void __iomem **kaddr,
 759			   void __iomem **haddr)
 760{
 761	unsigned long addr;
 762	int ret;
 763
 764	if (is_protected_kvm_enabled())
 765		return -EPERM;
 766
 767	*kaddr = ioremap(phys_addr, size);
 768	if (!*kaddr)
 769		return -ENOMEM;
 770
 771	if (is_kernel_in_hyp_mode()) {
 772		*haddr = *kaddr;
 773		return 0;
 774	}
 775
 776	ret = __create_hyp_private_mapping(phys_addr, size,
 777					   &addr, PAGE_HYP_DEVICE);
 778	if (ret) {
 779		iounmap(*kaddr);
 780		*kaddr = NULL;
 781		*haddr = NULL;
 782		return ret;
 783	}
 784
 785	*haddr = (void __iomem *)addr;
 786	return 0;
 787}
 788
 789/**
 790 * create_hyp_exec_mappings - Map an executable range into HYP
 791 * @phys_addr:	The physical start address which gets mapped
 792 * @size:	Size of the region being mapped
 793 * @haddr:	HYP VA for this mapping
 794 */
 795int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
 796			     void **haddr)
 797{
 798	unsigned long addr;
 799	int ret;
 800
 801	BUG_ON(is_kernel_in_hyp_mode());
 802
 803	ret = __create_hyp_private_mapping(phys_addr, size,
 804					   &addr, PAGE_HYP_EXEC);
 805	if (ret) {
 806		*haddr = NULL;
 807		return ret;
 808	}
 809
 810	*haddr = (void *)addr;
 811	return 0;
 812}
 813
 814static struct kvm_pgtable_mm_ops kvm_user_mm_ops = {
 815	/* We shouldn't need any other callback to walk the PT */
 816	.phys_to_virt		= kvm_host_va,
 817};
 818
 819static int get_user_mapping_size(struct kvm *kvm, u64 addr)
 820{
 821	struct kvm_pgtable pgt = {
 822		.pgd		= (kvm_pteref_t)kvm->mm->pgd,
 823		.ia_bits	= vabits_actual,
 824		.start_level	= (KVM_PGTABLE_LAST_LEVEL -
 825				   ARM64_HW_PGTABLE_LEVELS(pgt.ia_bits) + 1),
 826		.mm_ops		= &kvm_user_mm_ops,
 827	};
 828	unsigned long flags;
 829	kvm_pte_t pte = 0;	/* Keep GCC quiet... */
 830	s8 level = S8_MAX;
 831	int ret;
 832
 833	/*
 834	 * Disable IRQs so that we hazard against a concurrent
 835	 * teardown of the userspace page tables (which relies on
 836	 * IPI-ing threads).
 837	 */
 838	local_irq_save(flags);
 839	ret = kvm_pgtable_get_leaf(&pgt, addr, &pte, &level);
 840	local_irq_restore(flags);
 841
 842	if (ret)
 843		return ret;
 844
 845	/*
 846	 * Not seeing an error, but not updating level? Something went
 847	 * deeply wrong...
 848	 */
 849	if (WARN_ON(level > KVM_PGTABLE_LAST_LEVEL))
 850		return -EFAULT;
 851	if (WARN_ON(level < KVM_PGTABLE_FIRST_LEVEL))
 852		return -EFAULT;
 853
 854	/* Oops, the userspace PTs are gone... Replay the fault */
 855	if (!kvm_pte_valid(pte))
 856		return -EAGAIN;
 857
 858	return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(level));
 859}
 860
 861static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = {
 862	.zalloc_page		= stage2_memcache_zalloc_page,
 863	.zalloc_pages_exact	= kvm_s2_zalloc_pages_exact,
 864	.free_pages_exact	= kvm_s2_free_pages_exact,
 865	.free_unlinked_table	= stage2_free_unlinked_table,
 866	.get_page		= kvm_host_get_page,
 867	.put_page		= kvm_s2_put_page,
 868	.page_count		= kvm_host_page_count,
 869	.phys_to_virt		= kvm_host_va,
 870	.virt_to_phys		= kvm_host_pa,
 871	.dcache_clean_inval_poc	= clean_dcache_guest_page,
 872	.icache_inval_pou	= invalidate_icache_guest_page,
 873};
 874
 875static int kvm_init_ipa_range(struct kvm_s2_mmu *mmu, unsigned long type)
 876{
 877	u32 kvm_ipa_limit = get_kvm_ipa_limit();
 878	u64 mmfr0, mmfr1;
 879	u32 phys_shift;
 880
 881	if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
 882		return -EINVAL;
 883
 884	phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
 885	if (is_protected_kvm_enabled()) {
 886		phys_shift = kvm_ipa_limit;
 887	} else if (phys_shift) {
 888		if (phys_shift > kvm_ipa_limit ||
 889		    phys_shift < ARM64_MIN_PARANGE_BITS)
 890			return -EINVAL;
 891	} else {
 892		phys_shift = KVM_PHYS_SHIFT;
 893		if (phys_shift > kvm_ipa_limit) {
 894			pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n",
 895				     current->comm);
 896			return -EINVAL;
 897		}
 898	}
 899
 900	mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
 901	mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
 902	mmu->vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift);
 903
 904	return 0;
 905}
 906
 907/*
 908 * Assume that @pgt is valid and unlinked from the KVM MMU to free the
 909 * page-table without taking the kvm_mmu_lock and without performing any
 910 * TLB invalidations.
 911 *
 912 * Also, the range of addresses can be large enough to cause need_resched
 913 * warnings, for instance on CONFIG_PREEMPT_NONE kernels. Hence, invoke
 914 * cond_resched() periodically to prevent hogging the CPU for a long time
 915 * and schedule something else, if required.
 916 */
 917static void stage2_destroy_range(struct kvm_pgtable *pgt, phys_addr_t addr,
 918				   phys_addr_t end)
 919{
 920	u64 next;
 921
 922	do {
 923		next = stage2_range_addr_end(addr, end);
 924		KVM_PGT_FN(kvm_pgtable_stage2_destroy_range)(pgt, addr,
 925							     next - addr);
 926		if (next != end)
 927			cond_resched();
 928	} while (addr = next, addr != end);
 929}
 930
 931static void kvm_stage2_destroy(struct kvm_pgtable *pgt)
 932{
 933	unsigned int ia_bits = VTCR_EL2_IPA(pgt->mmu->vtcr);
 934
 935	stage2_destroy_range(pgt, 0, BIT(ia_bits));
 936	KVM_PGT_FN(kvm_pgtable_stage2_destroy_pgd)(pgt);
 937}
 938
 939/**
 940 * kvm_init_stage2_mmu - Initialise a S2 MMU structure
 941 * @kvm:	The pointer to the KVM structure
 942 * @mmu:	The pointer to the s2 MMU structure
 943 * @type:	The machine type of the virtual machine
 944 *
 945 * Allocates only the stage-2 HW PGD level table(s).
 946 * Note we don't need locking here as this is only called in two cases:
 947 *
 948 * - when the VM is created, which can't race against anything
 949 *
 950 * - when secondary kvm_s2_mmu structures are initialised for NV
 951 *   guests, and the caller must hold kvm->lock as this is called on a
 952 *   per-vcpu basis.
 953 */
 954int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type)
 955{
 956	int cpu, err;
 957	struct kvm_pgtable *pgt;
 958
 959	/*
 960	 * If we already have our page tables in place, and that the
 961	 * MMU context is the canonical one, we have a bug somewhere,
 962	 * as this is only supposed to ever happen once per VM.
 963	 *
 964	 * Otherwise, we're building nested page tables, and that's
 965	 * probably because userspace called KVM_ARM_VCPU_INIT more
 966	 * than once on the same vcpu. Since that's actually legal,
 967	 * don't kick a fuss and leave gracefully.
 968	 */
 969	if (mmu->pgt != NULL) {
 970		if (kvm_is_nested_s2_mmu(kvm, mmu))
 971			return 0;
 972
 973		kvm_err("kvm_arch already initialized?\n");
 974		return -EINVAL;
 975	}
 976
 977	err = kvm_init_ipa_range(mmu, type);
 978	if (err)
 979		return err;
 980
 981	pgt = kzalloc(sizeof(*pgt), GFP_KERNEL_ACCOUNT);
 982	if (!pgt)
 983		return -ENOMEM;
 984
 985	mmu->arch = &kvm->arch;
 986	err = KVM_PGT_FN(kvm_pgtable_stage2_init)(pgt, mmu, &kvm_s2_mm_ops);
 987	if (err)
 988		goto out_free_pgtable;
 989
 990	mmu->pgt = pgt;
 991	if (is_protected_kvm_enabled())
 992		return 0;
 993
 994	mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran));
 995	if (!mmu->last_vcpu_ran) {
 996		err = -ENOMEM;
 997		goto out_destroy_pgtable;
 998	}
 999
1000	for_each_possible_cpu(cpu)
1001		*per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1;
1002
1003	 /* The eager page splitting is disabled by default */
1004	mmu->split_page_chunk_size = KVM_ARM_EAGER_SPLIT_CHUNK_SIZE_DEFAULT;
1005	mmu->split_page_cache.gfp_zero = __GFP_ZERO;
1006
1007	mmu->pgd_phys = __pa(pgt->pgd);
1008
1009	if (kvm_is_nested_s2_mmu(kvm, mmu))
1010		kvm_init_nested_s2_mmu(mmu);
1011
1012	return 0;
1013
1014out_destroy_pgtable:
1015	kvm_stage2_destroy(pgt);
1016out_free_pgtable:
1017	kfree(pgt);
1018	return err;
1019}
1020
1021void kvm_uninit_stage2_mmu(struct kvm *kvm)
1022{
1023	kvm_free_stage2_pgd(&kvm->arch.mmu);
1024	kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache);
1025}
1026
1027static void stage2_unmap_memslot(struct kvm *kvm,
1028				 struct kvm_memory_slot *memslot)
1029{
1030	hva_t hva = memslot->userspace_addr;
1031	phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
1032	phys_addr_t size = PAGE_SIZE * memslot->npages;
1033	hva_t reg_end = hva + size;
1034
1035	/*
1036	 * A memory region could potentially cover multiple VMAs, and any holes
1037	 * between them, so iterate over all of them to find out if we should
1038	 * unmap any of them.
1039	 *
1040	 *     +--------------------------------------------+
1041	 * +---------------+----------------+   +----------------+
1042	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
1043	 * +---------------+----------------+   +----------------+
1044	 *     |               memory region                |
1045	 *     +--------------------------------------------+
1046	 */
1047	do {
1048		struct vm_area_struct *vma;
1049		hva_t vm_start, vm_end;
1050
1051		vma = find_vma_intersection(current->mm, hva, reg_end);
1052		if (!vma)
1053			break;
1054
1055		/*
1056		 * Take the intersection of this VMA with the memory region
1057		 */
1058		vm_start = max(hva, vma->vm_start);
1059		vm_end = min(reg_end, vma->vm_end);
1060
1061		if (!(vma->vm_flags & VM_PFNMAP)) {
1062			gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
1063			kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, vm_end - vm_start, true);
1064		}
1065		hva = vm_end;
1066	} while (hva < reg_end);
1067}
1068
1069/**
1070 * stage2_unmap_vm - Unmap Stage-2 RAM mappings
1071 * @kvm: The struct kvm pointer
1072 *
1073 * Go through the memregions and unmap any regular RAM
1074 * backing memory already mapped to the VM.
1075 */
1076void stage2_unmap_vm(struct kvm *kvm)
1077{
1078	struct kvm_memslots *slots;
1079	struct kvm_memory_slot *memslot;
1080	int idx, bkt;
1081
1082	idx = srcu_read_lock(&kvm->srcu);
1083	mmap_read_lock(current->mm);
1084	write_lock(&kvm->mmu_lock);
1085
1086	slots = kvm_memslots(kvm);
1087	kvm_for_each_memslot(memslot, bkt, slots)
1088		stage2_unmap_memslot(kvm, memslot);
1089
1090	kvm_nested_s2_unmap(kvm, true);
1091
1092	write_unlock(&kvm->mmu_lock);
1093	mmap_read_unlock(current->mm);
1094	srcu_read_unlock(&kvm->srcu, idx);
1095}
1096
1097void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
1098{
1099	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
1100	struct kvm_pgtable *pgt = NULL;
1101
1102	write_lock(&kvm->mmu_lock);
1103	pgt = mmu->pgt;
1104	if (pgt) {
1105		mmu->pgd_phys = 0;
1106		mmu->pgt = NULL;
1107		free_percpu(mmu->last_vcpu_ran);
1108	}
1109
1110	if (kvm_is_nested_s2_mmu(kvm, mmu))
1111		kvm_init_nested_s2_mmu(mmu);
1112
1113	write_unlock(&kvm->mmu_lock);
1114
1115	if (pgt) {
1116		kvm_stage2_destroy(pgt);
1117		kfree(pgt);
1118	}
1119}
1120
1121static void hyp_mc_free_fn(void *addr, void *mc)
1122{
1123	struct kvm_hyp_memcache *memcache = mc;
1124
1125	if (memcache->flags & HYP_MEMCACHE_ACCOUNT_STAGE2)
1126		kvm_account_pgtable_pages(addr, -1);
1127
1128	free_page((unsigned long)addr);
1129}
1130
1131static void *hyp_mc_alloc_fn(void *mc)
1132{
1133	struct kvm_hyp_memcache *memcache = mc;
1134	void *addr;
1135
1136	addr = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
1137	if (addr && memcache->flags & HYP_MEMCACHE_ACCOUNT_STAGE2)
1138		kvm_account_pgtable_pages(addr, 1);
1139
1140	return addr;
1141}
1142
1143void free_hyp_memcache(struct kvm_hyp_memcache *mc)
1144{
1145	if (!is_protected_kvm_enabled())
1146		return;
1147
1148	kfree(mc->mapping);
1149	__free_hyp_memcache(mc, hyp_mc_free_fn, kvm_host_va, mc);
1150}
1151
1152int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
1153{
1154	if (!is_protected_kvm_enabled())
1155		return 0;
1156
1157	if (!mc->mapping) {
1158		mc->mapping = kzalloc(sizeof(struct pkvm_mapping), GFP_KERNEL_ACCOUNT);
1159		if (!mc->mapping)
1160			return -ENOMEM;
1161	}
1162
1163	return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn,
1164				    kvm_host_pa, mc);
1165}
1166
1167/**
1168 * kvm_phys_addr_ioremap - map a device range to guest IPA
1169 *
1170 * @kvm:	The KVM pointer
1171 * @guest_ipa:	The IPA at which to insert the mapping
1172 * @pa:		The physical address of the device
1173 * @size:	The size of the mapping
1174 * @writable:   Whether or not to create a writable mapping
1175 */
1176int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
1177			  phys_addr_t pa, unsigned long size, bool writable)
1178{
1179	phys_addr_t addr;
1180	int ret = 0;
1181	struct kvm_mmu_memory_cache cache = { .gfp_zero = __GFP_ZERO };
1182	struct kvm_s2_mmu *mmu = &kvm->arch.mmu;
1183	struct kvm_pgtable *pgt = mmu->pgt;
1184	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_DEVICE |
1185				     KVM_PGTABLE_PROT_R |
1186				     (writable ? KVM_PGTABLE_PROT_W : 0);
1187
1188	if (is_protected_kvm_enabled())
1189		return -EPERM;
1190
1191	size += offset_in_page(guest_ipa);
1192	guest_ipa &= PAGE_MASK;
1193
1194	for (addr = guest_ipa; addr < guest_ipa + size; addr += PAGE_SIZE) {
1195		ret = kvm_mmu_topup_memory_cache(&cache,
1196						 kvm_mmu_cache_min_pages(mmu));
1197		if (ret)
1198			break;
1199
1200		write_lock(&kvm->mmu_lock);
1201		ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, addr, PAGE_SIZE,
1202				 pa, prot, &cache, 0);
1203		write_unlock(&kvm->mmu_lock);
1204		if (ret)
1205			break;
1206
1207		pa += PAGE_SIZE;
1208	}
1209
1210	kvm_mmu_free_memory_cache(&cache);
1211	return ret;
1212}
1213
1214/**
1215 * kvm_stage2_wp_range() - write protect stage2 memory region range
1216 * @mmu:        The KVM stage-2 MMU pointer
1217 * @addr:	Start address of range
1218 * @end:	End address of range
1219 */
1220void kvm_stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
1221{
1222	stage2_apply_range_resched(mmu, addr, end, KVM_PGT_FN(kvm_pgtable_stage2_wrprotect));
1223}
1224
1225/**
1226 * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1227 * @kvm:	The KVM pointer
1228 * @slot:	The memory slot to write protect
1229 *
1230 * Called to start logging dirty pages after memory region
1231 * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1232 * all present PUD, PMD and PTEs are write protected in the memory region.
1233 * Afterwards read of dirty page log can be called.
1234 *
1235 * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1236 * serializing operations for VM memory regions.
1237 */
1238static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
1239{
1240	struct kvm_memslots *slots = kvm_memslots(kvm);
1241	struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1242	phys_addr_t start, end;
1243
1244	if (WARN_ON_ONCE(!memslot))
1245		return;
1246
1247	start = memslot->base_gfn << PAGE_SHIFT;
1248	end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
1249
1250	write_lock(&kvm->mmu_lock);
1251	kvm_stage2_wp_range(&kvm->arch.mmu, start, end);
1252	kvm_nested_s2_wp(kvm);
1253	write_unlock(&kvm->mmu_lock);
1254	kvm_flush_remote_tlbs_memslot(kvm, memslot);
1255}
1256
1257/**
1258 * kvm_mmu_split_memory_region() - split the stage 2 blocks into PAGE_SIZE
1259 *				   pages for memory slot
1260 * @kvm:	The KVM pointer
1261 * @slot:	The memory slot to split
1262 *
1263 * Acquires kvm->mmu_lock. Called with kvm->slots_lock mutex acquired,
1264 * serializing operations for VM memory regions.
1265 */
1266static void kvm_mmu_split_memory_region(struct kvm *kvm, int slot)
1267{
1268	struct kvm_memslots *slots;
1269	struct kvm_memory_slot *memslot;
1270	phys_addr_t start, end;
1271
1272	lockdep_assert_held(&kvm->slots_lock);
1273
1274	slots = kvm_memslots(kvm);
1275	memslot = id_to_memslot(slots, slot);
1276
1277	start = memslot->base_gfn << PAGE_SHIFT;
1278	end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
1279
1280	write_lock(&kvm->mmu_lock);
1281	kvm_mmu_split_huge_pages(kvm, start, end);
1282	write_unlock(&kvm->mmu_lock);
1283}
1284
1285/*
1286 * kvm_arch_mmu_enable_log_dirty_pt_masked() - enable dirty logging for selected pages.
1287 * @kvm:	The KVM pointer
1288 * @slot:	The memory slot associated with mask
1289 * @gfn_offset:	The gfn offset in memory slot
1290 * @mask:	The mask of pages at offset 'gfn_offset' in this memory
1291 *		slot to enable dirty logging on
1292 *
1293 * Writes protect selected pages to enable dirty logging, and then
1294 * splits them to PAGE_SIZE. Caller must acquire kvm->mmu_lock.
1295 */
1296void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
1297		struct kvm_memory_slot *slot,
1298		gfn_t gfn_offset, unsigned long mask)
1299{
1300	phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
1301	phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
1302	phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
1303
1304	lockdep_assert_held_write(&kvm->mmu_lock);
1305
1306	kvm_stage2_wp_range(&kvm->arch.mmu, start, end);
1307
1308	/*
1309	 * Eager-splitting is done when manual-protect is set.  We
1310	 * also check for initially-all-set because we can avoid
1311	 * eager-splitting if initially-all-set is false.
1312	 * Initially-all-set equal false implies that huge-pages were
1313	 * already split when enabling dirty logging: no need to do it
1314	 * again.
1315	 */
1316	if (kvm_dirty_log_manual_protect_and_init_set(kvm))
1317		kvm_mmu_split_huge_pages(kvm, start, end);
1318
1319	kvm_nested_s2_wp(kvm);
1320}
1321
1322static void kvm_send_hwpoison_signal(unsigned long address, short lsb)
1323{
1324	send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current);
1325}
1326
1327static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot,
1328					       unsigned long hva,
1329					       unsigned long map_size)
1330{
1331	gpa_t gpa_start;
1332	hva_t uaddr_start, uaddr_end;
1333	size_t size;
1334
1335	/* The memslot and the VMA are guaranteed to be aligned to PAGE_SIZE */
1336	if (map_size == PAGE_SIZE)
1337		return true;
1338
1339	/* pKVM only supports PMD_SIZE huge-mappings */
1340	if (is_protected_kvm_enabled() && map_size != PMD_SIZE)
1341		return false;
1342
1343	size = memslot->npages * PAGE_SIZE;
1344
1345	gpa_start = memslot->base_gfn << PAGE_SHIFT;
1346
1347	uaddr_start = memslot->userspace_addr;
1348	uaddr_end = uaddr_start + size;
1349
1350	/*
1351	 * Pages belonging to memslots that don't have the same alignment
1352	 * within a PMD/PUD for userspace and IPA cannot be mapped with stage-2
1353	 * PMD/PUD entries, because we'll end up mapping the wrong pages.
1354	 *
1355	 * Consider a layout like the following:
1356	 *
1357	 *    memslot->userspace_addr:
1358	 *    +-----+--------------------+--------------------+---+
1359	 *    |abcde|fgh  Stage-1 block  |    Stage-1 block tv|xyz|
1360	 *    +-----+--------------------+--------------------+---+
1361	 *
1362	 *    memslot->base_gfn << PAGE_SHIFT:
1363	 *      +---+--------------------+--------------------+-----+
1364	 *      |abc|def  Stage-2 block  |    Stage-2 block   |tvxyz|
1365	 *      +---+--------------------+--------------------+-----+
1366	 *
1367	 * If we create those stage-2 blocks, we'll end up with this incorrect
1368	 * mapping:
1369	 *   d -> f
1370	 *   e -> g
1371	 *   f -> h
1372	 */
1373	if ((gpa_start & (map_size - 1)) != (uaddr_start & (map_size - 1)))
1374		return false;
1375
1376	/*
1377	 * Next, let's make sure we're not trying to map anything not covered
1378	 * by the memslot. This means we have to prohibit block size mappings
1379	 * for the beginning and end of a non-block aligned and non-block sized
1380	 * memory slot (illustrated by the head and tail parts of the
1381	 * userspace view above containing pages 'abcde' and 'xyz',
1382	 * respectively).
1383	 *
1384	 * Note that it doesn't matter if we do the check using the
1385	 * userspace_addr or the base_gfn, as both are equally aligned (per
1386	 * the check above) and equally sized.
1387	 */
1388	return (hva & ~(map_size - 1)) >= uaddr_start &&
1389	       (hva & ~(map_size - 1)) + map_size <= uaddr_end;
1390}
1391
1392/*
1393 * Check if the given hva is backed by a transparent huge page (THP) and
1394 * whether it can be mapped using block mapping in stage2. If so, adjust
1395 * the stage2 PFN and IPA accordingly. Only PMD_SIZE THPs are currently
1396 * supported. This will need to be updated to support other THP sizes.
1397 *
1398 * Returns the size of the mapping.
1399 */
1400static long
1401transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot,
1402			    unsigned long hva, kvm_pfn_t *pfnp,
1403			    phys_addr_t *ipap)
1404{
1405	kvm_pfn_t pfn = *pfnp;
1406
1407	/*
1408	 * Make sure the adjustment is done only for THP pages. Also make
1409	 * sure that the HVA and IPA are sufficiently aligned and that the
1410	 * block map is contained within the memslot.
1411	 */
1412	if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) {
1413		int sz = get_user_mapping_size(kvm, hva);
1414
1415		if (sz < 0)
1416			return sz;
1417
1418		if (sz < PMD_SIZE)
1419			return PAGE_SIZE;
1420
1421		*ipap &= PMD_MASK;
1422		pfn &= ~(PTRS_PER_PMD - 1);
1423		*pfnp = pfn;
1424
1425		return PMD_SIZE;
1426	}
1427
1428	/* Use page mapping if we cannot use block mapping. */
1429	return PAGE_SIZE;
1430}
1431
1432static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva)
1433{
1434	unsigned long pa;
1435
1436	if (is_vm_hugetlb_page(vma) && !(vma->vm_flags & VM_PFNMAP))
1437		return huge_page_shift(hstate_vma(vma));
1438
1439	if (!(vma->vm_flags & VM_PFNMAP))
1440		return PAGE_SHIFT;
1441
1442	VM_BUG_ON(is_vm_hugetlb_page(vma));
1443
1444	pa = (vma->vm_pgoff << PAGE_SHIFT) + (hva - vma->vm_start);
1445
1446#ifndef __PAGETABLE_PMD_FOLDED
1447	if ((hva & (PUD_SIZE - 1)) == (pa & (PUD_SIZE - 1)) &&
1448	    ALIGN_DOWN(hva, PUD_SIZE) >= vma->vm_start &&
1449	    ALIGN(hva, PUD_SIZE) <= vma->vm_end)
1450		return PUD_SHIFT;
1451#endif
1452
1453	if ((hva & (PMD_SIZE - 1)) == (pa & (PMD_SIZE - 1)) &&
1454	    ALIGN_DOWN(hva, PMD_SIZE) >= vma->vm_start &&
1455	    ALIGN(hva, PMD_SIZE) <= vma->vm_end)
1456		return PMD_SHIFT;
1457
1458	return PAGE_SHIFT;
1459}
1460
1461/*
1462 * The page will be mapped in stage 2 as Normal Cacheable, so the VM will be
1463 * able to see the page's tags and therefore they must be initialised first. If
1464 * PG_mte_tagged is set, tags have already been initialised.
1465 *
1466 * Must be called with kvm->mmu_lock held to ensure the memory remains mapped
1467 * while the tags are zeroed.
1468 */
1469static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
1470			      unsigned long size)
1471{
1472	unsigned long i, nr_pages = size >> PAGE_SHIFT;
1473	struct page *page = pfn_to_page(pfn);
1474	struct folio *folio = page_folio(page);
1475
1476	if (!kvm_has_mte(kvm))
1477		return;
1478
1479	if (folio_test_hugetlb(folio)) {
1480		/* Hugetlb has MTE flags set on head page only */
1481		if (folio_try_hugetlb_mte_tagging(folio)) {
1482			for (i = 0; i < nr_pages; i++, page++)
1483				mte_clear_page_tags(page_address(page));
1484			folio_set_hugetlb_mte_tagged(folio);
1485		}
1486		return;
1487	}
1488
1489	for (i = 0; i < nr_pages; i++, page++) {
1490		if (try_page_mte_tagging(page)) {
1491			mte_clear_page_tags(page_address(page));
1492			set_page_mte_tagged(page);
1493		}
1494	}
1495}
1496
1497static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
1498{
1499	return vma->vm_flags & VM_MTE_ALLOWED;
1500}
1501
1502static bool kvm_vma_is_cacheable(struct vm_area_struct *vma)
1503{
1504	switch (FIELD_GET(PTE_ATTRINDX_MASK, pgprot_val(vma->vm_page_prot))) {
1505	case MT_NORMAL_NC:
1506	case MT_DEVICE_nGnRnE:
1507	case MT_DEVICE_nGnRE:
1508		return false;
1509	default:
1510		return true;
1511	}
1512}
1513
1514static int prepare_mmu_memcache(struct kvm_vcpu *vcpu, bool topup_memcache,
1515				void **memcache)
1516{
1517	int min_pages;
1518
1519	if (!is_protected_kvm_enabled())
1520		*memcache = &vcpu->arch.mmu_page_cache;
1521	else
1522		*memcache = &vcpu->arch.pkvm_memcache;
1523
1524	if (!topup_memcache)
1525		return 0;
1526
1527	min_pages = kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu);
1528
1529	if (!is_protected_kvm_enabled())
1530		return kvm_mmu_topup_memory_cache(*memcache, min_pages);
1531
1532	return topup_hyp_memcache(*memcache, min_pages);
1533}
1534
1535/*
1536 * Potentially reduce shadow S2 permissions to match the guest's own S2. For
1537 * exec faults, we'd only reach this point if the guest actually allowed it (see
1538 * kvm_s2_handle_perm_fault).
1539 *
1540 * Also encode the level of the original translation in the SW bits of the leaf
1541 * entry as a proxy for the span of that translation. This will be retrieved on
1542 * TLB invalidation from the guest and used to limit the invalidation scope if a
1543 * TTL hint or a range isn't provided.
1544 */
1545static void adjust_nested_fault_perms(struct kvm_s2_trans *nested,
1546				      enum kvm_pgtable_prot *prot,
1547				      bool *writable)
1548{
1549	*writable &= kvm_s2_trans_writable(nested);
1550	if (!kvm_s2_trans_readable(nested))
1551		*prot &= ~KVM_PGTABLE_PROT_R;
1552
1553	*prot |= kvm_encode_nested_level(nested);
1554}
1555
1556static void adjust_nested_exec_perms(struct kvm *kvm,
1557				     struct kvm_s2_trans *nested,
1558				     enum kvm_pgtable_prot *prot)
1559{
1560	if (!kvm_s2_trans_exec_el0(kvm, nested))
1561		*prot &= ~KVM_PGTABLE_PROT_UX;
1562	if (!kvm_s2_trans_exec_el1(kvm, nested))
1563		*prot &= ~KVM_PGTABLE_PROT_PX;
1564}
1565
1566static int gmem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1567		      struct kvm_s2_trans *nested,
1568		      struct kvm_memory_slot *memslot, bool is_perm)
1569{
1570	bool write_fault, exec_fault, writable;
1571	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED;
1572	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
1573	struct kvm_pgtable *pgt = vcpu->arch.hw_mmu->pgt;
1574	unsigned long mmu_seq;
1575	struct page *page;
1576	struct kvm *kvm = vcpu->kvm;
1577	void *memcache;
1578	kvm_pfn_t pfn;
1579	gfn_t gfn;
1580	int ret;
1581
1582	ret = prepare_mmu_memcache(vcpu, true, &memcache);
1583	if (ret)
1584		return ret;
1585
1586	if (nested)
1587		gfn = kvm_s2_trans_output(nested) >> PAGE_SHIFT;
1588	else
1589		gfn = fault_ipa >> PAGE_SHIFT;
1590
1591	write_fault = kvm_is_write_fault(vcpu);
1592	exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
1593
1594	VM_WARN_ON_ONCE(write_fault && exec_fault);
1595
1596	mmu_seq = kvm->mmu_invalidate_seq;
1597	/* Pairs with the smp_wmb() in kvm_mmu_invalidate_end(). */
1598	smp_rmb();
1599
1600	ret = kvm_gmem_get_pfn(kvm, memslot, gfn, &pfn, &page, NULL);
1601	if (ret) {
1602		kvm_prepare_memory_fault_exit(vcpu, fault_ipa, PAGE_SIZE,
1603					      write_fault, exec_fault, false);
1604		return ret;
1605	}
1606
1607	writable = !(memslot->flags & KVM_MEM_READONLY);
1608
1609	if (nested)
1610		adjust_nested_fault_perms(nested, &prot, &writable);
1611
1612	if (writable)
1613		prot |= KVM_PGTABLE_PROT_W;
1614
1615	if (exec_fault || cpus_have_final_cap(ARM64_HAS_CACHE_DIC))
1616		prot |= KVM_PGTABLE_PROT_X;
1617
1618	if (nested)
1619		adjust_nested_exec_perms(kvm, nested, &prot);
1620
1621	kvm_fault_lock(kvm);
1622	if (mmu_invalidate_retry(kvm, mmu_seq)) {
1623		ret = -EAGAIN;
1624		goto out_unlock;
1625	}
1626
1627	ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, fault_ipa, PAGE_SIZE,
1628						 __pfn_to_phys(pfn), prot,
1629						 memcache, flags);
1630
1631out_unlock:
1632	kvm_release_faultin_page(kvm, page, !!ret, writable);
1633	kvm_fault_unlock(kvm);
1634
1635	if (writable && !ret)
1636		mark_page_dirty_in_slot(kvm, memslot, gfn);
1637
1638	return ret != -EAGAIN ? ret : 0;
1639}
1640
1641static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1642			  struct kvm_s2_trans *nested,
1643			  struct kvm_memory_slot *memslot, unsigned long hva,
1644			  bool fault_is_perm)
1645{
1646	int ret = 0;
1647	bool topup_memcache;
1648	bool write_fault, writable;
1649	bool exec_fault, mte_allowed, is_vma_cacheable;
1650	bool s2_force_noncacheable = false, vfio_allow_any_uc = false;
1651	unsigned long mmu_seq;
1652	phys_addr_t ipa = fault_ipa;
1653	struct kvm *kvm = vcpu->kvm;
1654	struct vm_area_struct *vma;
1655	short vma_shift;
1656	void *memcache;
1657	gfn_t gfn;
1658	kvm_pfn_t pfn;
1659	bool logging_active = memslot_is_logging(memslot);
1660	bool force_pte = logging_active;
1661	long vma_pagesize, fault_granule;
1662	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
1663	struct kvm_pgtable *pgt;
1664	struct page *page;
1665	vm_flags_t vm_flags;
1666	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED;
1667
1668	if (fault_is_perm)
1669		fault_granule = kvm_vcpu_trap_get_perm_fault_granule(vcpu);
1670	write_fault = kvm_is_write_fault(vcpu);
1671	exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
1672	VM_WARN_ON_ONCE(write_fault && exec_fault);
1673
1674	/*
1675	 * Permission faults just need to update the existing leaf entry,
1676	 * and so normally don't require allocations from the memcache. The
1677	 * only exception to this is when dirty logging is enabled at runtime
1678	 * and a write fault needs to collapse a block entry into a table.
1679	 */
1680	topup_memcache = !fault_is_perm || (logging_active && write_fault);
1681	ret = prepare_mmu_memcache(vcpu, topup_memcache, &memcache);
1682	if (ret)
1683		return ret;
1684
1685	/*
1686	 * Let's check if we will get back a huge page backed by hugetlbfs, or
1687	 * get block mapping for device MMIO region.
1688	 */
1689	mmap_read_lock(current->mm);
1690	vma = vma_lookup(current->mm, hva);
1691	if (unlikely(!vma)) {
1692		kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
1693		mmap_read_unlock(current->mm);
1694		return -EFAULT;
1695	}
1696
1697	if (force_pte)
1698		vma_shift = PAGE_SHIFT;
1699	else
1700		vma_shift = get_vma_page_shift(vma, hva);
1701
1702	switch (vma_shift) {
1703#ifndef __PAGETABLE_PMD_FOLDED
1704	case PUD_SHIFT:
1705		if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE))
1706			break;
1707		fallthrough;
1708#endif
1709	case CONT_PMD_SHIFT:
1710		vma_shift = PMD_SHIFT;
1711		fallthrough;
1712	case PMD_SHIFT:
1713		if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE))
1714			break;
1715		fallthrough;
1716	case CONT_PTE_SHIFT:
1717		vma_shift = PAGE_SHIFT;
1718		force_pte = true;
1719		fallthrough;
1720	case PAGE_SHIFT:
1721		break;
1722	default:
1723		WARN_ONCE(1, "Unknown vma_shift %d", vma_shift);
1724	}
1725
1726	vma_pagesize = 1UL << vma_shift;
1727
1728	if (nested) {
1729		unsigned long max_map_size;
1730
1731		max_map_size = force_pte ? PAGE_SIZE : PUD_SIZE;
1732
1733		ipa = kvm_s2_trans_output(nested);
1734
1735		/*
1736		 * If we're about to create a shadow stage 2 entry, then we
1737		 * can only create a block mapping if the guest stage 2 page
1738		 * table uses at least as big a mapping.
1739		 */
1740		max_map_size = min(kvm_s2_trans_size(nested), max_map_size);
1741
1742		/*
1743		 * Be careful that if the mapping size falls between
1744		 * two host sizes, take the smallest of the two.
1745		 */
1746		if (max_map_size >= PMD_SIZE && max_map_size < PUD_SIZE)
1747			max_map_size = PMD_SIZE;
1748		else if (max_map_size >= PAGE_SIZE && max_map_size < PMD_SIZE)
1749			max_map_size = PAGE_SIZE;
1750
1751		force_pte = (max_map_size == PAGE_SIZE);
1752		vma_pagesize = min_t(long, vma_pagesize, max_map_size);
1753	}
1754
1755	/*
1756	 * Both the canonical IPA and fault IPA must be aligned to the
1757	 * mapping size to ensure we find the right PFN and lay down the
1758	 * mapping in the right place.
1759	 */
1760	fault_ipa = ALIGN_DOWN(fault_ipa, vma_pagesize);
1761	ipa = ALIGN_DOWN(ipa, vma_pagesize);
1762
1763	gfn = ipa >> PAGE_SHIFT;
1764	mte_allowed = kvm_vma_mte_allowed(vma);
1765
1766	vfio_allow_any_uc = vma->vm_flags & VM_ALLOW_ANY_UNCACHED;
1767
1768	vm_flags = vma->vm_flags;
1769
1770	is_vma_cacheable = kvm_vma_is_cacheable(vma);
1771
1772	/* Don't use the VMA after the unlock -- it may have vanished */
1773	vma = NULL;
1774
1775	/*
1776	 * Read mmu_invalidate_seq so that KVM can detect if the results of
1777	 * vma_lookup() or __kvm_faultin_pfn() become stale prior to
1778	 * acquiring kvm->mmu_lock.
1779	 *
1780	 * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs
1781	 * with the smp_wmb() in kvm_mmu_invalidate_end().
1782	 */
1783	mmu_seq = kvm->mmu_invalidate_seq;
1784	mmap_read_unlock(current->mm);
1785
1786	pfn = __kvm_faultin_pfn(memslot, gfn, write_fault ? FOLL_WRITE : 0,
1787				&writable, &page);
1788	if (pfn == KVM_PFN_ERR_HWPOISON) {
1789		kvm_send_hwpoison_signal(hva, vma_shift);
1790		return 0;
1791	}
1792	if (is_error_noslot_pfn(pfn))
1793		return -EFAULT;
1794
1795	/*
1796	 * Check if this is non-struct page memory PFN, and cannot support
1797	 * CMOs. It could potentially be unsafe to access as cacheable.
1798	 */
1799	if (vm_flags & (VM_PFNMAP | VM_MIXEDMAP) && !pfn_is_map_memory(pfn)) {
1800		if (is_vma_cacheable) {
1801			/*
1802			 * Whilst the VMA owner expects cacheable mapping to this
1803			 * PFN, hardware also has to support the FWB and CACHE DIC
1804			 * features.
1805			 *
1806			 * ARM64 KVM relies on kernel VA mapping to the PFN to
1807			 * perform cache maintenance as the CMO instructions work on
1808			 * virtual addresses. VM_PFNMAP region are not necessarily
1809			 * mapped to a KVA and hence the presence of hardware features
1810			 * S2FWB and CACHE DIC are mandatory to avoid the need for
1811			 * cache maintenance.
1812			 */
1813			if (!kvm_supports_cacheable_pfnmap())
1814				ret = -EFAULT;
1815		} else {
1816			/*
1817			 * If the page was identified as device early by looking at
1818			 * the VMA flags, vma_pagesize is already representing the
1819			 * largest quantity we can map.  If instead it was mapped
1820			 * via __kvm_faultin_pfn(), vma_pagesize is set to PAGE_SIZE
1821			 * and must not be upgraded.
1822			 *
1823			 * In both cases, we don't let transparent_hugepage_adjust()
1824			 * change things at the last minute.
1825			 */
1826			s2_force_noncacheable = true;
1827		}
1828	} else if (logging_active && !write_fault) {
1829		/*
1830		 * Only actually map the page as writable if this was a write
1831		 * fault.
1832		 */
1833		writable = false;
1834	}
1835
1836	if (exec_fault && s2_force_noncacheable)
1837		ret = -ENOEXEC;
1838
1839	if (ret) {
1840		kvm_release_page_unused(page);
1841		return ret;
1842	}
1843
1844	if (nested)
1845		adjust_nested_fault_perms(nested, &prot, &writable);
1846
1847	kvm_fault_lock(kvm);
1848	pgt = vcpu->arch.hw_mmu->pgt;
1849	if (mmu_invalidate_retry(kvm, mmu_seq)) {
1850		ret = -EAGAIN;
1851		goto out_unlock;
1852	}
1853
1854	/*
1855	 * If we are not forced to use page mapping, check if we are
1856	 * backed by a THP and thus use block mapping if possible.
1857	 */
1858	if (vma_pagesize == PAGE_SIZE && !(force_pte || s2_force_noncacheable)) {
1859		if (fault_is_perm && fault_granule > PAGE_SIZE)
1860			vma_pagesize = fault_granule;
1861		else
1862			vma_pagesize = transparent_hugepage_adjust(kvm, memslot,
1863								   hva, &pfn,
1864								   &fault_ipa);
1865
1866		if (vma_pagesize < 0) {
1867			ret = vma_pagesize;
1868			goto out_unlock;
1869		}
1870	}
1871
1872	if (!fault_is_perm && !s2_force_noncacheable && kvm_has_mte(kvm)) {
1873		/* Check the VMM hasn't introduced a new disallowed VMA */
1874		if (mte_allowed) {
1875			sanitise_mte_tags(kvm, pfn, vma_pagesize);
1876		} else {
1877			ret = -EFAULT;
1878			goto out_unlock;
1879		}
1880	}
1881
1882	if (writable)
1883		prot |= KVM_PGTABLE_PROT_W;
1884
1885	if (exec_fault)
1886		prot |= KVM_PGTABLE_PROT_X;
1887
1888	if (s2_force_noncacheable) {
1889		if (vfio_allow_any_uc)
1890			prot |= KVM_PGTABLE_PROT_NORMAL_NC;
1891		else
1892			prot |= KVM_PGTABLE_PROT_DEVICE;
1893	} else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) {
1894		prot |= KVM_PGTABLE_PROT_X;
1895	}
1896
1897	if (nested)
1898		adjust_nested_exec_perms(kvm, nested, &prot);
1899
1900	/*
1901	 * Under the premise of getting a FSC_PERM fault, we just need to relax
1902	 * permissions only if vma_pagesize equals fault_granule. Otherwise,
1903	 * kvm_pgtable_stage2_map() should be called to change block size.
1904	 */
1905	if (fault_is_perm && vma_pagesize == fault_granule) {
1906		/*
1907		 * Drop the SW bits in favour of those stored in the
1908		 * PTE, which will be preserved.
1909		 */
1910		prot &= ~KVM_NV_GUEST_MAP_SZ;
1911		ret = KVM_PGT_FN(kvm_pgtable_stage2_relax_perms)(pgt, fault_ipa, prot, flags);
1912	} else {
1913		ret = KVM_PGT_FN(kvm_pgtable_stage2_map)(pgt, fault_ipa, vma_pagesize,
1914					     __pfn_to_phys(pfn), prot,
1915					     memcache, flags);
1916	}
1917
1918out_unlock:
1919	kvm_release_faultin_page(kvm, page, !!ret, writable);
1920	kvm_fault_unlock(kvm);
1921
1922	/* Mark the page dirty only if the fault is handled successfully */
1923	if (writable && !ret)
1924		mark_page_dirty_in_slot(kvm, memslot, gfn);
1925
1926	return ret != -EAGAIN ? ret : 0;
1927}
1928
1929/* Resolve the access fault by making the page young again. */
1930static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
1931{
1932	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED;
1933	struct kvm_s2_mmu *mmu;
1934
1935	trace_kvm_access_fault(fault_ipa);
1936
1937	read_lock(&vcpu->kvm->mmu_lock);
1938	mmu = vcpu->arch.hw_mmu;
1939	KVM_PGT_FN(kvm_pgtable_stage2_mkyoung)(mmu->pgt, fault_ipa, flags);
1940	read_unlock(&vcpu->kvm->mmu_lock);
1941}
1942
1943/*
1944 * Returns true if the SEA should be handled locally within KVM if the abort
1945 * is caused by a kernel memory allocation (e.g. stage-2 table memory).
1946 */
1947static bool host_owns_sea(struct kvm_vcpu *vcpu, u64 esr)
1948{
1949	/*
1950	 * Without FEAT_RAS HCR_EL2.TEA is RES0, meaning any external abort
1951	 * taken from a guest EL to EL2 is due to a host-imposed access (e.g.
1952	 * stage-2 PTW).
1953	 */
1954	if (!cpus_have_final_cap(ARM64_HAS_RAS_EXTN))
1955		return true;
1956
1957	/* KVM owns the VNCR when the vCPU isn't in a nested context. */
1958	if (is_hyp_ctxt(vcpu) && !kvm_vcpu_trap_is_iabt(vcpu) && (esr & ESR_ELx_VNCR))
1959		return true;
1960
1961	/*
1962	 * Determining if an external abort during a table walk happened at
1963	 * stage-2 is only possible with S1PTW is set. Otherwise, since KVM
1964	 * sets HCR_EL2.TEA, SEAs due to a stage-1 walk (i.e. accessing the
1965	 * PA of the stage-1 descriptor) can reach here and are reported
1966	 * with a TTW ESR value.
1967	 */
1968	return (esr_fsc_is_sea_ttw(esr) && (esr & ESR_ELx_S1PTW));
1969}
1970
1971int kvm_handle_guest_sea(struct kvm_vcpu *vcpu)
1972{
1973	struct kvm *kvm = vcpu->kvm;
1974	struct kvm_run *run = vcpu->run;
1975	u64 esr = kvm_vcpu_get_esr(vcpu);
1976	u64 esr_mask = ESR_ELx_EC_MASK	|
1977		       ESR_ELx_IL	|
1978		       ESR_ELx_FnV	|
1979		       ESR_ELx_EA	|
1980		       ESR_ELx_CM	|
1981		       ESR_ELx_WNR	|
1982		       ESR_ELx_FSC;
1983	u64 ipa;
1984
1985	/*
1986	 * Give APEI the opportunity to claim the abort before handling it
1987	 * within KVM. apei_claim_sea() expects to be called with IRQs enabled.
1988	 */
1989	lockdep_assert_irqs_enabled();
1990	if (apei_claim_sea(NULL) == 0)
1991		return 1;
1992
1993	if (host_owns_sea(vcpu, esr) ||
1994	    !test_bit(KVM_ARCH_FLAG_EXIT_SEA, &vcpu->kvm->arch.flags))
1995		return kvm_inject_serror(vcpu);
1996
1997	/* ESR_ELx.SET is RES0 when FEAT_RAS isn't implemented. */
1998	if (kvm_has_ras(kvm))
1999		esr_mask |= ESR_ELx_SET_MASK;
2000
2001	/*
2002	 * Exit to userspace, and provide faulting guest virtual and physical
2003	 * addresses in case userspace wants to emulate SEA to guest by
2004	 * writing to FAR_ELx and HPFAR_ELx registers.
2005	 */
2006	memset(&run->arm_sea, 0, sizeof(run->arm_sea));
2007	run->exit_reason = KVM_EXIT_ARM_SEA;
2008	run->arm_sea.esr = esr & esr_mask;
2009
2010	if (!(esr & ESR_ELx_FnV))
2011		run->arm_sea.gva = kvm_vcpu_get_hfar(vcpu);
2012
2013	ipa = kvm_vcpu_get_fault_ipa(vcpu);
2014	if (ipa != INVALID_GPA) {
2015		run->arm_sea.flags |= KVM_EXIT_ARM_SEA_FLAG_GPA_VALID;
2016		run->arm_sea.gpa = ipa;
2017	}
2018
2019	return 0;
2020}
2021
2022/**
2023 * kvm_handle_guest_abort - handles all 2nd stage aborts
2024 * @vcpu:	the VCPU pointer
2025 *
2026 * Any abort that gets to the host is almost guaranteed to be caused by a
2027 * missing second stage translation table entry, which can mean that either the
2028 * guest simply needs more memory and we must allocate an appropriate page or it
2029 * can mean that the guest tried to access I/O memory, which is emulated by user
2030 * space. The distinction is based on the IPA causing the fault and whether this
2031 * memory region has been registered as standard RAM by user space.
2032 */
2033int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
2034{
2035	struct kvm_s2_trans nested_trans, *nested = NULL;
2036	unsigned long esr;
2037	phys_addr_t fault_ipa; /* The address we faulted on */
2038	phys_addr_t ipa; /* Always the IPA in the L1 guest phys space */
2039	struct kvm_memory_slot *memslot;
2040	unsigned long hva;
2041	bool is_iabt, write_fault, writable;
2042	gfn_t gfn;
2043	int ret, idx;
2044
2045	if (kvm_vcpu_abt_issea(vcpu))
2046		return kvm_handle_guest_sea(vcpu);
2047
2048	esr = kvm_vcpu_get_esr(vcpu);
2049
2050	/*
2051	 * The fault IPA should be reliable at this point as we're not dealing
2052	 * with an SEA.
2053	 */
2054	ipa = fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
2055	if (KVM_BUG_ON(ipa == INVALID_GPA, vcpu->kvm))
2056		return -EFAULT;
2057
2058	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
2059
2060	if (esr_fsc_is_translation_fault(esr)) {
2061		/* Beyond sanitised PARange (which is the IPA limit) */
2062		if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit())) {
2063			kvm_inject_size_fault(vcpu);
2064			return 1;
2065		}
2066
2067		/* Falls between the IPA range and the PARange? */
2068		if (fault_ipa >= BIT_ULL(VTCR_EL2_IPA(vcpu->arch.hw_mmu->vtcr))) {
2069			fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
2070
2071			return kvm_inject_sea(vcpu, is_iabt, fault_ipa);
2072		}
2073	}
2074
2075	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu),
2076			      kvm_vcpu_get_hfar(vcpu), fault_ipa);
2077
2078	/* Check the stage-2 fault is trans. fault or write fault */
2079	if (!esr_fsc_is_translation_fault(esr) &&
2080	    !esr_fsc_is_permission_fault(esr) &&
2081	    !esr_fsc_is_access_flag_fault(esr)) {
2082		kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
2083			kvm_vcpu_trap_get_class(vcpu),
2084			(unsigned long)kvm_vcpu_trap_get_fault(vcpu),
2085			(unsigned long)kvm_vcpu_get_esr(vcpu));
2086		return -EFAULT;
2087	}
2088
2089	idx = srcu_read_lock(&vcpu->kvm->srcu);
2090
2091	/*
2092	 * We may have faulted on a shadow stage 2 page table if we are
2093	 * running a nested guest.  In this case, we have to resolve the L2
2094	 * IPA to the L1 IPA first, before knowing what kind of memory should
2095	 * back the L1 IPA.
2096	 *
2097	 * If the shadow stage 2 page table walk faults, then we simply inject
2098	 * this to the guest and carry on.
2099	 *
2100	 * If there are no shadow S2 PTs because S2 is disabled, there is
2101	 * nothing to walk and we treat it as a 1:1 before going through the
2102	 * canonical translation.
2103	 */
2104	if (kvm_is_nested_s2_mmu(vcpu->kvm,vcpu->arch.hw_mmu) &&
2105	    vcpu->arch.hw_mmu->nested_stage2_enabled) {
2106		u32 esr;
2107
2108		ret = kvm_walk_nested_s2(vcpu, fault_ipa, &nested_trans);
2109		if (ret == -EAGAIN) {
2110			ret = 1;
2111			goto out_unlock;
2112		}
2113
2114		if (ret) {
2115			esr = kvm_s2_trans_esr(&nested_trans);
2116			kvm_inject_s2_fault(vcpu, esr);
2117			goto out_unlock;
2118		}
2119
2120		ret = kvm_s2_handle_perm_fault(vcpu, &nested_trans);
2121		if (ret) {
2122			esr = kvm_s2_trans_esr(&nested_trans);
2123			kvm_inject_s2_fault(vcpu, esr);
2124			goto out_unlock;
2125		}
2126
2127		ipa = kvm_s2_trans_output(&nested_trans);
2128		nested = &nested_trans;
2129	}
2130
2131	gfn = ipa >> PAGE_SHIFT;
2132	memslot = gfn_to_memslot(vcpu->kvm, gfn);
2133	hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
2134	write_fault = kvm_is_write_fault(vcpu);
2135	if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
2136		/*
2137		 * The guest has put either its instructions or its page-tables
2138		 * somewhere it shouldn't have. Userspace won't be able to do
2139		 * anything about this (there's no syndrome for a start), so
2140		 * re-inject the abort back into the guest.
2141		 */
2142		if (is_iabt) {
2143			ret = -ENOEXEC;
2144			goto out;
2145		}
2146
2147		if (kvm_vcpu_abt_iss1tw(vcpu)) {
2148			ret = kvm_inject_sea_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
2149			goto out_unlock;
2150		}
2151
2152		/*
2153		 * Check for a cache maintenance operation. Since we
2154		 * ended-up here, we know it is outside of any memory
2155		 * slot. But we can't find out if that is for a device,
2156		 * or if the guest is just being stupid. The only thing
2157		 * we know for sure is that this range cannot be cached.
2158		 *
2159		 * So let's assume that the guest is just being
2160		 * cautious, and skip the instruction.
2161		 */
2162		if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) {
2163			kvm_incr_pc(vcpu);
2164			ret = 1;
2165			goto out_unlock;
2166		}
2167
2168		/*
2169		 * The IPA is reported as [MAX:12], so we need to
2170		 * complement it with the bottom 12 bits from the
2171		 * faulting VA. This is always 12 bits, irrespective
2172		 * of the page size.
2173		 */
2174		ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
2175		ret = io_mem_abort(vcpu, ipa);
2176		goto out_unlock;
2177	}
2178
2179	/* Userspace should not be able to register out-of-bounds IPAs */
2180	VM_BUG_ON(ipa >= kvm_phys_size(vcpu->arch.hw_mmu));
2181
2182	if (esr_fsc_is_access_flag_fault(esr)) {
2183		handle_access_fault(vcpu, fault_ipa);
2184		ret = 1;
2185		goto out_unlock;
2186	}
2187
2188	VM_WARN_ON_ONCE(kvm_vcpu_trap_is_permission_fault(vcpu) &&
2189			!write_fault && !kvm_vcpu_trap_is_exec_fault(vcpu));
2190
2191	if (kvm_slot_has_gmem(memslot))
2192		ret = gmem_abort(vcpu, fault_ipa, nested, memslot,
2193				 esr_fsc_is_permission_fault(esr));
2194	else
2195		ret = user_mem_abort(vcpu, fault_ipa, nested, memslot, hva,
2196				     esr_fsc_is_permission_fault(esr));
2197	if (ret == 0)
2198		ret = 1;
2199out:
2200	if (ret == -ENOEXEC)
2201		ret = kvm_inject_sea_iabt(vcpu, kvm_vcpu_get_hfar(vcpu));
2202out_unlock:
2203	srcu_read_unlock(&vcpu->kvm->srcu, idx);
2204	return ret;
2205}
2206
2207bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
2208{
2209	if (!kvm->arch.mmu.pgt)
2210		return false;
2211
2212	__unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT,
2213			     (range->end - range->start) << PAGE_SHIFT,
2214			     range->may_block);
2215
2216	kvm_nested_s2_unmap(kvm, range->may_block);
2217	return false;
2218}
2219
2220bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
2221{
2222	u64 size = (range->end - range->start) << PAGE_SHIFT;
2223
2224	if (!kvm->arch.mmu.pgt)
2225		return false;
2226
2227	return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
2228						   range->start << PAGE_SHIFT,
2229						   size, true);
2230	/*
2231	 * TODO: Handle nested_mmu structures here using the reverse mapping in
2232	 * a later version of patch series.
2233	 */
2234}
2235
2236bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
2237{
2238	u64 size = (range->end - range->start) << PAGE_SHIFT;
2239
2240	if (!kvm->arch.mmu.pgt)
2241		return false;
2242
2243	return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
2244						   range->start << PAGE_SHIFT,
2245						   size, false);
2246}
2247
2248phys_addr_t kvm_mmu_get_httbr(void)
2249{
2250	return __pa(hyp_pgtable->pgd);
2251}
2252
2253phys_addr_t kvm_get_idmap_vector(void)
2254{
2255	return hyp_idmap_vector;
2256}
2257
2258static int kvm_map_idmap_text(void)
2259{
2260	unsigned long size = hyp_idmap_end - hyp_idmap_start;
2261	int err = __create_hyp_mappings(hyp_idmap_start, size, hyp_idmap_start,
2262					PAGE_HYP_EXEC);
2263	if (err)
2264		kvm_err("Failed to idmap %lx-%lx\n",
2265			hyp_idmap_start, hyp_idmap_end);
2266
2267	return err;
2268}
2269
2270static void *kvm_hyp_zalloc_page(void *arg)
2271{
2272	return (void *)get_zeroed_page(GFP_KERNEL);
2273}
2274
2275static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = {
2276	.zalloc_page		= kvm_hyp_zalloc_page,
2277	.get_page		= kvm_host_get_page,
2278	.put_page		= kvm_host_put_page,
2279	.phys_to_virt		= kvm_host_va,
2280	.virt_to_phys		= kvm_host_pa,
2281};
2282
2283int __init kvm_mmu_init(u32 *hyp_va_bits)
2284{
2285	int err;
2286	u32 idmap_bits;
2287	u32 kernel_bits;
2288
2289	hyp_idmap_start = __pa_symbol(__hyp_idmap_text_start);
2290	hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE);
2291	hyp_idmap_end = __pa_symbol(__hyp_idmap_text_end);
2292	hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE);
2293	hyp_idmap_vector = __pa_symbol(__kvm_hyp_init);
2294
2295	/*
2296	 * We rely on the linker script to ensure at build time that the HYP
2297	 * init code does not cross a page boundary.
2298	 */
2299	BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
2300
2301	/*
2302	 * The ID map is always configured for 48 bits of translation, which
2303	 * may be fewer than the number of VA bits used by the regular kernel
2304	 * stage 1, when VA_BITS=52.
2305	 *
2306	 * At EL2, there is only one TTBR register, and we can't switch between
2307	 * translation tables *and* update TCR_EL2.T0SZ at the same time. Bottom
2308	 * line: we need to use the extended range with *both* our translation
2309	 * tables.
2310	 *
2311	 * So use the maximum of the idmap VA bits and the regular kernel stage
2312	 * 1 VA bits to assure that the hypervisor can both ID map its code page
2313	 * and map any kernel memory.
2314	 */
2315	idmap_bits = IDMAP_VA_BITS;
2316	kernel_bits = vabits_actual;
2317	*hyp_va_bits = max(idmap_bits, kernel_bits);
2318
2319	kvm_debug("Using %u-bit virtual addresses at EL2\n", *hyp_va_bits);
2320	kvm_debug("IDMAP page: %lx\n", hyp_idmap_start);
2321	kvm_debug("HYP VA range: %lx:%lx\n",
2322		  kern_hyp_va(PAGE_OFFSET),
2323		  kern_hyp_va((unsigned long)high_memory - 1));
2324
2325	if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
2326	    hyp_idmap_start <  kern_hyp_va((unsigned long)high_memory - 1) &&
2327	    hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
2328		/*
2329		 * The idmap page is intersecting with the VA space,
2330		 * it is not safe to continue further.
2331		 */
2332		kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
2333		err = -EINVAL;
2334		goto out;
2335	}
2336
2337	hyp_pgtable = kzalloc(sizeof(*hyp_pgtable), GFP_KERNEL);
2338	if (!hyp_pgtable) {
2339		kvm_err("Hyp mode page-table not allocated\n");
2340		err = -ENOMEM;
2341		goto out;
2342	}
2343
2344	err = kvm_pgtable_hyp_init(hyp_pgtable, *hyp_va_bits, &kvm_hyp_mm_ops);
2345	if (err)
2346		goto out_free_pgtable;
2347
2348	err = kvm_map_idmap_text();
2349	if (err)
2350		goto out_destroy_pgtable;
2351
2352	io_map_base = hyp_idmap_start;
2353	__hyp_va_bits = *hyp_va_bits;
2354	return 0;
2355
2356out_destroy_pgtable:
2357	kvm_pgtable_hyp_destroy(hyp_pgtable);
2358out_free_pgtable:
2359	kfree(hyp_pgtable);
2360	hyp_pgtable = NULL;
2361out:
2362	return err;
2363}
2364
2365void kvm_arch_commit_memory_region(struct kvm *kvm,
2366				   struct kvm_memory_slot *old,
2367				   const struct kvm_memory_slot *new,
2368				   enum kvm_mr_change change)
2369{
2370	bool log_dirty_pages = new && new->flags & KVM_MEM_LOG_DIRTY_PAGES;
2371
2372	/*
2373	 * At this point memslot has been committed and there is an
2374	 * allocated dirty_bitmap[], dirty pages will be tracked while the
2375	 * memory slot is write protected.
2376	 */
2377	if (log_dirty_pages) {
2378
2379		if (change == KVM_MR_DELETE)
2380			return;
2381
2382		/*
2383		 * Huge and normal pages are write-protected and split
2384		 * on either of these two cases:
2385		 *
2386		 * 1. with initial-all-set: gradually with CLEAR ioctls,
2387		 */
2388		if (kvm_dirty_log_manual_protect_and_init_set(kvm))
2389			return;
2390		/*
2391		 * or
2392		 * 2. without initial-all-set: all in one shot when
2393		 *    enabling dirty logging.
2394		 */
2395		kvm_mmu_wp_memory_region(kvm, new->id);
2396		kvm_mmu_split_memory_region(kvm, new->id);
2397	} else {
2398		/*
2399		 * Free any leftovers from the eager page splitting cache. Do
2400		 * this when deleting, moving, disabling dirty logging, or
2401		 * creating the memslot (a nop). Doing it for deletes makes
2402		 * sure we don't leak memory, and there's no need to keep the
2403		 * cache around for any of the other cases.
2404		 */
2405		kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache);
2406	}
2407}
2408
2409int kvm_arch_prepare_memory_region(struct kvm *kvm,
2410				   const struct kvm_memory_slot *old,
2411				   struct kvm_memory_slot *new,
2412				   enum kvm_mr_change change)
2413{
2414	hva_t hva, reg_end;
2415	int ret = 0;
2416
2417	if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
2418			change != KVM_MR_FLAGS_ONLY)
2419		return 0;
2420
2421	/*
2422	 * Prevent userspace from creating a memory region outside of the IPA
2423	 * space addressable by the KVM guest IPA space.
2424	 */
2425	if ((new->base_gfn + new->npages) > (kvm_phys_size(&kvm->arch.mmu) >> PAGE_SHIFT))
2426		return -EFAULT;
2427
2428	/*
2429	 * Only support guest_memfd backed memslots with mappable memory, since
2430	 * there aren't any CoCo VMs that support only private memory on arm64.
2431	 */
2432	if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new))
2433		return -EINVAL;
2434
2435	hva = new->userspace_addr;
2436	reg_end = hva + (new->npages << PAGE_SHIFT);
2437
2438	mmap_read_lock(current->mm);
2439	/*
2440	 * A memory region could potentially cover multiple VMAs, and any holes
2441	 * between them, so iterate over all of them.
2442	 *
2443	 *     +--------------------------------------------+
2444	 * +---------------+----------------+   +----------------+
2445	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
2446	 * +---------------+----------------+   +----------------+
2447	 *     |               memory region                |
2448	 *     +--------------------------------------------+
2449	 */
2450	do {
2451		struct vm_area_struct *vma;
2452
2453		vma = find_vma_intersection(current->mm, hva, reg_end);
2454		if (!vma)
2455			break;
2456
2457		if (kvm_has_mte(kvm) && !kvm_vma_mte_allowed(vma)) {
2458			ret = -EINVAL;
2459			break;
2460		}
2461
2462		if (vma->vm_flags & VM_PFNMAP) {
2463			/* IO region dirty page logging not allowed */
2464			if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
2465				ret = -EINVAL;
2466				break;
2467			}
2468
2469			/*
2470			 * Cacheable PFNMAP is allowed only if the hardware
2471			 * supports it.
2472			 */
2473			if (kvm_vma_is_cacheable(vma) && !kvm_supports_cacheable_pfnmap()) {
2474				ret = -EINVAL;
2475				break;
2476			}
2477		}
2478		hva = min(reg_end, vma->vm_end);
2479	} while (hva < reg_end);
2480
2481	mmap_read_unlock(current->mm);
2482	return ret;
2483}
2484
2485void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
2486{
2487}
2488
2489void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
2490{
2491}
2492
2493void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
2494				   struct kvm_memory_slot *slot)
2495{
2496	gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
2497	phys_addr_t size = slot->npages << PAGE_SHIFT;
2498
2499	write_lock(&kvm->mmu_lock);
2500	kvm_stage2_unmap_range(&kvm->arch.mmu, gpa, size, true);
2501	kvm_nested_s2_unmap(kvm, true);
2502	write_unlock(&kvm->mmu_lock);
2503}
2504
2505/*
2506 * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
2507 *
2508 * Main problems:
2509 * - S/W ops are local to a CPU (not broadcast)
2510 * - We have line migration behind our back (speculation)
2511 * - System caches don't support S/W at all (damn!)
2512 *
2513 * In the face of the above, the best we can do is to try and convert
2514 * S/W ops to VA ops. Because the guest is not allowed to infer the
2515 * S/W to PA mapping, it can only use S/W to nuke the whole cache,
2516 * which is a rather good thing for us.
2517 *
2518 * Also, it is only used when turning caches on/off ("The expected
2519 * usage of the cache maintenance instructions that operate by set/way
2520 * is associated with the cache maintenance instructions associated
2521 * with the powerdown and powerup of caches, if this is required by
2522 * the implementation.").
2523 *
2524 * We use the following policy:
2525 *
2526 * - If we trap a S/W operation, we enable VM trapping to detect
2527 *   caches being turned on/off, and do a full clean.
2528 *
2529 * - We flush the caches on both caches being turned on and off.
2530 *
2531 * - Once the caches are enabled, we stop trapping VM ops.
2532 */
2533void kvm_set_way_flush(struct kvm_vcpu *vcpu)
2534{
2535	unsigned long hcr = *vcpu_hcr(vcpu);
2536
2537	/*
2538	 * If this is the first time we do a S/W operation
2539	 * (i.e. HCR_TVM not set) flush the whole memory, and set the
2540	 * VM trapping.
2541	 *
2542	 * Otherwise, rely on the VM trapping to wait for the MMU +
2543	 * Caches to be turned off. At that point, we'll be able to
2544	 * clean the caches again.
2545	 */
2546	if (!(hcr & HCR_TVM)) {
2547		trace_kvm_set_way_flush(*vcpu_pc(vcpu),
2548					vcpu_has_cache_enabled(vcpu));
2549		stage2_flush_vm(vcpu->kvm);
2550		*vcpu_hcr(vcpu) = hcr | HCR_TVM;
2551	}
2552}
2553
2554void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
2555{
2556	bool now_enabled = vcpu_has_cache_enabled(vcpu);
2557
2558	/*
2559	 * If switching the MMU+caches on, need to invalidate the caches.
2560	 * If switching it off, need to clean the caches.
2561	 * Clean + invalidate does the trick always.
2562	 */
2563	if (now_enabled != was_enabled)
2564		stage2_flush_vm(vcpu->kvm);
2565
2566	/* Caches are now on, stop trapping VM ops (until a S/W op) */
2567	if (now_enabled)
2568		*vcpu_hcr(vcpu) &= ~HCR_TVM;
2569
2570	trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
2571}