Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1883 insertions, 0 deletions

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
new file mode 100644
index 000000000..54ccdcc2d
--- /dev/null
+++ b/arch/arm64/kvm/mmu.c
@@ -0,0 +1,1883 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ */
+
+#include <linux/mman.h>
+#include <linux/kvm_host.h>
+#include <linux/io.h>
+#include <linux/hugetlb.h>
+#include <linux/sched/signal.h>
+#include <trace/events/kvm.h>
+#include <asm/pgalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+#include <asm/kvm_pgtable.h>
+#include <asm/kvm_ras.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+#include <asm/virt.h>
+
+#include "trace.h"
+
+static struct kvm_pgtable *hyp_pgtable;
+static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
+
+static unsigned long hyp_idmap_start;
+static unsigned long hyp_idmap_end;
+static phys_addr_t hyp_idmap_vector;
+
+static unsigned long io_map_base;
+
+static phys_addr_t stage2_range_addr_end(phys_addr_t addr, phys_addr_t end)
+{
+	phys_addr_t size = kvm_granule_size(KVM_PGTABLE_MIN_BLOCK_LEVEL);
+	phys_addr_t boundary = ALIGN_DOWN(addr + size, size);
+
+	return (boundary - 1 < end - 1) ? boundary : end;
+}
+
+/*
+ * Release kvm_mmu_lock periodically if the memory region is large. Otherwise,
+ * we may see kernel panics with CONFIG_DETECT_HUNG_TASK,
+ * CONFIG_LOCKUP_DETECTOR, CONFIG_LOCKDEP. Additionally, holding the lock too
+ * long will also starve other vCPUs. We have to also make sure that the page
+ * tables are not freed while we released the lock.
+ */
+static int stage2_apply_range(struct kvm *kvm, phys_addr_t addr,
+			      phys_addr_t end,
+			      int (*fn)(struct kvm_pgtable *, u64, u64),
+			      bool resched)
+{
+	int ret;
+	u64 next;
+
+	do {
+		struct kvm_pgtable *pgt = kvm->arch.mmu.pgt;
+		if (!pgt)
+			return -EINVAL;
+
+		next = stage2_range_addr_end(addr, end);
+		ret = fn(pgt, addr, next - addr);
+		if (ret)
+			break;
+
+		if (resched && next != end)
+			cond_resched_rwlock_write(&kvm->mmu_lock);
+	} while (addr = next, addr != end);
+
+	return ret;
+}
+
+#define stage2_apply_range_resched(kvm, addr, end, fn)			\
+	stage2_apply_range(kvm, addr, end, fn, true)
+
+static bool memslot_is_logging(struct kvm_memory_slot *memslot)
+{
+	return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
+}
+
+/**
+ * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
+ * @kvm:	pointer to kvm structure.
+ *
+ * Interface to HYP function to flush all VM TLB entries
+ */
+void kvm_flush_remote_tlbs(struct kvm *kvm)
+{
+	++kvm->stat.generic.remote_tlb_flush_requests;
+	kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
+}
+
+static bool kvm_is_device_pfn(unsigned long pfn)
+{
+	return !pfn_is_map_memory(pfn);
+}
+
+static void *stage2_memcache_zalloc_page(void *arg)
+{
+	struct kvm_mmu_memory_cache *mc = arg;
+	void *virt;
+
+	/* Allocated with __GFP_ZERO, so no need to zero */
+	virt = kvm_mmu_memory_cache_alloc(mc);
+	if (virt)
+		kvm_account_pgtable_pages(virt, 1);
+	return virt;
+}
+
+static void *kvm_host_zalloc_pages_exact(size_t size)
+{
+	return alloc_pages_exact(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
+}
+
+static void *kvm_s2_zalloc_pages_exact(size_t size)
+{
+	void *virt = kvm_host_zalloc_pages_exact(size);
+
+	if (virt)
+		kvm_account_pgtable_pages(virt, (size >> PAGE_SHIFT));
+	return virt;
+}
+
+static void kvm_s2_free_pages_exact(void *virt, size_t size)
+{
+	kvm_account_pgtable_pages(virt, -(size >> PAGE_SHIFT));
+	free_pages_exact(virt, size);
+}
+
+static void kvm_host_get_page(void *addr)
+{
+	get_page(virt_to_page(addr));
+}
+
+static void kvm_host_put_page(void *addr)
+{
+	put_page(virt_to_page(addr));
+}
+
+static void kvm_s2_put_page(void *addr)
+{
+	struct page *p = virt_to_page(addr);
+	/* Dropping last refcount, the page will be freed */
+	if (page_count(p) == 1)
+		kvm_account_pgtable_pages(addr, -1);
+	put_page(p);
+}
+
+static int kvm_host_page_count(void *addr)
+{
+	return page_count(virt_to_page(addr));
+}
+
+static phys_addr_t kvm_host_pa(void *addr)
+{
+	return __pa(addr);
+}
+
+static void *kvm_host_va(phys_addr_t phys)
+{
+	return __va(phys);
+}
+
+static void clean_dcache_guest_page(void *va, size_t size)
+{
+	__clean_dcache_guest_page(va, size);
+}
+
+static void invalidate_icache_guest_page(void *va, size_t size)
+{
+	__invalidate_icache_guest_page(va, size);
+}
+
+/*
+ * Unmapping vs dcache management:
+ *
+ * If a guest maps certain memory pages as uncached, all writes will
+ * bypass the data cache and go directly to RAM.  However, the CPUs
+ * can still speculate reads (not writes) and fill cache lines with
+ * data.
+ *
+ * Those cache lines will be *clean* cache lines though, so a
+ * clean+invalidate operation is equivalent to an invalidate
+ * operation, because no cache lines are marked dirty.
+ *
+ * Those clean cache lines could be filled prior to an uncached write
+ * by the guest, and the cache coherent IO subsystem would therefore
+ * end up writing old data to disk.
+ *
+ * This is why right after unmapping a page/section and invalidating
+ * the corresponding TLBs, we flush to make sure the IO subsystem will
+ * never hit in the cache.
+ *
+ * This is all avoided on systems that have ARM64_HAS_STAGE2_FWB, as
+ * we then fully enforce cacheability of RAM, no matter what the guest
+ * does.
+ */
+/**
+ * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
+ * @mmu:   The KVM stage-2 MMU pointer
+ * @start: The intermediate physical base address of the range to unmap
+ * @size:  The size of the area to unmap
+ * @may_block: Whether or not we are permitted to block
+ *
+ * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
+ * be called while holding mmu_lock (unless for freeing the stage2 pgd before
+ * destroying the VM), otherwise another faulting VCPU may come in and mess
+ * with things behind our backs.
+ */
+static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size,
+				 bool may_block)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
+	phys_addr_t end = start + size;
+
+	lockdep_assert_held_write(&kvm->mmu_lock);
+	WARN_ON(size & ~PAGE_MASK);
+	WARN_ON(stage2_apply_range(kvm, start, end, kvm_pgtable_stage2_unmap,
+				   may_block));
+}
+
+static void unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size)
+{
+	__unmap_stage2_range(mmu, start, size, true);
+}
+
+static void stage2_flush_memslot(struct kvm *kvm,
+				 struct kvm_memory_slot *memslot)
+{
+	phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
+	phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
+
+	stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_flush);
+}
+
+/**
+ * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
+ * @kvm: The struct kvm pointer
+ *
+ * Go through the stage 2 page tables and invalidate any cache lines
+ * backing memory already mapped to the VM.
+ */
+static void stage2_flush_vm(struct kvm *kvm)
+{
+	struct kvm_memslots *slots;
+	struct kvm_memory_slot *memslot;
+	int idx, bkt;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	write_lock(&kvm->mmu_lock);
+
+	slots = kvm_memslots(kvm);
+	kvm_for_each_memslot(memslot, bkt, slots)
+		stage2_flush_memslot(kvm, memslot);
+
+	write_unlock(&kvm->mmu_lock);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
+/**
+ * free_hyp_pgds - free Hyp-mode page tables
+ */
+void free_hyp_pgds(void)
+{
+	mutex_lock(&kvm_hyp_pgd_mutex);
+	if (hyp_pgtable) {
+		kvm_pgtable_hyp_destroy(hyp_pgtable);
+		kfree(hyp_pgtable);
+		hyp_pgtable = NULL;
+	}
+	mutex_unlock(&kvm_hyp_pgd_mutex);
+}
+
+static bool kvm_host_owns_hyp_mappings(void)
+{
+	if (is_kernel_in_hyp_mode())
+		return false;
+
+	if (static_branch_likely(&kvm_protected_mode_initialized))
+		return false;
+
+	/*
+	 * This can happen at boot time when __create_hyp_mappings() is called
+	 * after the hyp protection has been enabled, but the static key has
+	 * not been flipped yet.
+	 */
+	if (!hyp_pgtable && is_protected_kvm_enabled())
+		return false;
+
+	WARN_ON(!hyp_pgtable);
+
+	return true;
+}
+
+int __create_hyp_mappings(unsigned long start, unsigned long size,
+			  unsigned long phys, enum kvm_pgtable_prot prot)
+{
+	int err;
+
+	if (WARN_ON(!kvm_host_owns_hyp_mappings()))
+		return -EINVAL;
+
+	mutex_lock(&kvm_hyp_pgd_mutex);
+	err = kvm_pgtable_hyp_map(hyp_pgtable, start, size, phys, prot);
+	mutex_unlock(&kvm_hyp_pgd_mutex);
+
+	return err;
+}
+
+static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
+{
+	if (!is_vmalloc_addr(kaddr)) {
+		BUG_ON(!virt_addr_valid(kaddr));
+		return __pa(kaddr);
+	} else {
+		return page_to_phys(vmalloc_to_page(kaddr)) +
+		       offset_in_page(kaddr);
+	}
+}
+
+struct hyp_shared_pfn {
+	u64 pfn;
+	int count;
+	struct rb_node node;
+};
+
+static DEFINE_MUTEX(hyp_shared_pfns_lock);
+static struct rb_root hyp_shared_pfns = RB_ROOT;
+
+static struct hyp_shared_pfn *find_shared_pfn(u64 pfn, struct rb_node ***node,
+					      struct rb_node **parent)
+{
+	struct hyp_shared_pfn *this;
+
+	*node = &hyp_shared_pfns.rb_node;
+	*parent = NULL;
+	while (**node) {
+		this = container_of(**node, struct hyp_shared_pfn, node);
+		*parent = **node;
+		if (this->pfn < pfn)
+			*node = &((**node)->rb_left);
+		else if (this->pfn > pfn)
+			*node = &((**node)->rb_right);
+		else
+			return this;
+	}
+
+	return NULL;
+}
+
+static int share_pfn_hyp(u64 pfn)
+{
+	struct rb_node **node, *parent;
+	struct hyp_shared_pfn *this;
+	int ret = 0;
+
+	mutex_lock(&hyp_shared_pfns_lock);
+	this = find_shared_pfn(pfn, &node, &parent);
+	if (this) {
+		this->count++;
+		goto unlock;
+	}
+
+	this = kzalloc(sizeof(*this), GFP_KERNEL);
+	if (!this) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	this->pfn = pfn;
+	this->count = 1;
+	rb_link_node(&this->node, parent, node);
+	rb_insert_color(&this->node, &hyp_shared_pfns);
+	ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn, 1);
+unlock:
+	mutex_unlock(&hyp_shared_pfns_lock);
+
+	return ret;
+}
+
+static int unshare_pfn_hyp(u64 pfn)
+{
+	struct rb_node **node, *parent;
+	struct hyp_shared_pfn *this;
+	int ret = 0;
+
+	mutex_lock(&hyp_shared_pfns_lock);
+	this = find_shared_pfn(pfn, &node, &parent);
+	if (WARN_ON(!this)) {
+		ret = -ENOENT;
+		goto unlock;
+	}
+
+	this->count--;
+	if (this->count)
+		goto unlock;
+
+	rb_erase(&this->node, &hyp_shared_pfns);
+	kfree(this);
+	ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn, 1);
+unlock:
+	mutex_unlock(&hyp_shared_pfns_lock);
+
+	return ret;
+}
+
+int kvm_share_hyp(void *from, void *to)
+{
+	phys_addr_t start, end, cur;
+	u64 pfn;
+	int ret;
+
+	if (is_kernel_in_hyp_mode())
+		return 0;
+
+	/*
+	 * The share hcall maps things in the 'fixed-offset' region of the hyp
+	 * VA space, so we can only share physically contiguous data-structures
+	 * for now.
+	 */
+	if (is_vmalloc_or_module_addr(from) || is_vmalloc_or_module_addr(to))
+		return -EINVAL;
+
+	if (kvm_host_owns_hyp_mappings())
+		return create_hyp_mappings(from, to, PAGE_HYP);
+
+	start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
+	end = PAGE_ALIGN(__pa(to));
+	for (cur = start; cur < end; cur += PAGE_SIZE) {
+		pfn = __phys_to_pfn(cur);
+		ret = share_pfn_hyp(pfn);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+void kvm_unshare_hyp(void *from, void *to)
+{
+	phys_addr_t start, end, cur;
+	u64 pfn;
+
+	if (is_kernel_in_hyp_mode() || kvm_host_owns_hyp_mappings() || !from)
+		return;
+
+	start = ALIGN_DOWN(__pa(from), PAGE_SIZE);
+	end = PAGE_ALIGN(__pa(to));
+	for (cur = start; cur < end; cur += PAGE_SIZE) {
+		pfn = __phys_to_pfn(cur);
+		WARN_ON(unshare_pfn_hyp(pfn));
+	}
+}
+
+/**
+ * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
+ * @from:	The virtual kernel start address of the range
+ * @to:		The virtual kernel end address of the range (exclusive)
+ * @prot:	The protection to be applied to this range
+ *
+ * The same virtual address as the kernel virtual address is also used
+ * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
+ * physical pages.
+ */
+int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot)
+{
+	phys_addr_t phys_addr;
+	unsigned long virt_addr;
+	unsigned long start = kern_hyp_va((unsigned long)from);
+	unsigned long end = kern_hyp_va((unsigned long)to);
+
+	if (is_kernel_in_hyp_mode())
+		return 0;
+
+	if (!kvm_host_owns_hyp_mappings())
+		return -EPERM;
+
+	start = start & PAGE_MASK;
+	end = PAGE_ALIGN(end);
+
+	for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
+		int err;
+
+		phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
+		err = __create_hyp_mappings(virt_addr, PAGE_SIZE, phys_addr,
+					    prot);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+
+/**
+ * hyp_alloc_private_va_range - Allocates a private VA range.
+ * @size:	The size of the VA range to reserve.
+ * @haddr:	The hypervisor virtual start address of the allocation.
+ *
+ * The private virtual address (VA) range is allocated below io_map_base
+ * and aligned based on the order of @size.
+ *
+ * Return: 0 on success or negative error code on failure.
+ */
+int hyp_alloc_private_va_range(size_t size, unsigned long *haddr)
+{
+	unsigned long base;
+	int ret = 0;
+
+	mutex_lock(&kvm_hyp_pgd_mutex);
+
+	/*
+	 * This assumes that we have enough space below the idmap
+	 * page to allocate our VAs. If not, the check below will
+	 * kick. A potential alternative would be to detect that
+	 * overflow and switch to an allocation above the idmap.
+	 *
+	 * The allocated size is always a multiple of PAGE_SIZE.
+	 */
+	base = io_map_base - PAGE_ALIGN(size);
+
+	/* Align the allocation based on the order of its size */
+	base = ALIGN_DOWN(base, PAGE_SIZE << get_order(size));
+
+	/*
+	 * Verify that BIT(VA_BITS - 1) hasn't been flipped by
+	 * allocating the new area, as it would indicate we've
+	 * overflowed the idmap/IO address range.
+	 */
+	if ((base ^ io_map_base) & BIT(VA_BITS - 1))
+		ret = -ENOMEM;
+	else
+		*haddr = io_map_base = base;
+
+	mutex_unlock(&kvm_hyp_pgd_mutex);
+
+	return ret;
+}
+
+static int __create_hyp_private_mapping(phys_addr_t phys_addr, size_t size,
+					unsigned long *haddr,
+					enum kvm_pgtable_prot prot)
+{
+	unsigned long addr;
+	int ret = 0;
+
+	if (!kvm_host_owns_hyp_mappings()) {
+		addr = kvm_call_hyp_nvhe(__pkvm_create_private_mapping,
+					 phys_addr, size, prot);
+		if (IS_ERR_VALUE(addr))
+			return addr;
+		*haddr = addr;
+
+		return 0;
+	}
+
+	size = PAGE_ALIGN(size + offset_in_page(phys_addr));
+	ret = hyp_alloc_private_va_range(size, &addr);
+	if (ret)
+		return ret;
+
+	ret = __create_hyp_mappings(addr, size, phys_addr, prot);
+	if (ret)
+		return ret;
+
+	*haddr = addr + offset_in_page(phys_addr);
+	return ret;
+}
+
+/**
+ * create_hyp_io_mappings - Map IO into both kernel and HYP
+ * @phys_addr:	The physical start address which gets mapped
+ * @size:	Size of the region being mapped
+ * @kaddr:	Kernel VA for this mapping
+ * @haddr:	HYP VA for this mapping
+ */
+int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
+			   void __iomem **kaddr,
+			   void __iomem **haddr)
+{
+	unsigned long addr;
+	int ret;
+
+	if (is_protected_kvm_enabled())
+		return -EPERM;
+
+	*kaddr = ioremap(phys_addr, size);
+	if (!*kaddr)
+		return -ENOMEM;
+
+	if (is_kernel_in_hyp_mode()) {
+		*haddr = *kaddr;
+		return 0;
+	}
+
+	ret = __create_hyp_private_mapping(phys_addr, size,
+					   &addr, PAGE_HYP_DEVICE);
+	if (ret) {
+		iounmap(*kaddr);
+		*kaddr = NULL;
+		*haddr = NULL;
+		return ret;
+	}
+
+	*haddr = (void __iomem *)addr;
+	return 0;
+}
+
+/**
+ * create_hyp_exec_mappings - Map an executable range into HYP
+ * @phys_addr:	The physical start address which gets mapped
+ * @size:	Size of the region being mapped
+ * @haddr:	HYP VA for this mapping
+ */
+int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
+			     void **haddr)
+{
+	unsigned long addr;
+	int ret;
+
+	BUG_ON(is_kernel_in_hyp_mode());
+
+	ret = __create_hyp_private_mapping(phys_addr, size,
+					   &addr, PAGE_HYP_EXEC);
+	if (ret) {
+		*haddr = NULL;
+		return ret;
+	}
+
+	*haddr = (void *)addr;
+	return 0;
+}
+
+static struct kvm_pgtable_mm_ops kvm_user_mm_ops = {
+	/* We shouldn't need any other callback to walk the PT */
+	.phys_to_virt		= kvm_host_va,
+};
+
+static int get_user_mapping_size(struct kvm *kvm, u64 addr)
+{
+	struct kvm_pgtable pgt = {
+		.pgd		= (kvm_pte_t *)kvm->mm->pgd,
+		.ia_bits	= VA_BITS,
+		.start_level	= (KVM_PGTABLE_MAX_LEVELS -
+				   CONFIG_PGTABLE_LEVELS),
+		.mm_ops		= &kvm_user_mm_ops,
+	};
+	unsigned long flags;
+	kvm_pte_t pte = 0;	/* Keep GCC quiet... */
+	u32 level = ~0;
+	int ret;
+
+	/*
+	 * Disable IRQs so that we hazard against a concurrent
+	 * teardown of the userspace page tables (which relies on
+	 * IPI-ing threads).
+	 */
+	local_irq_save(flags);
+	ret = kvm_pgtable_get_leaf(&pgt, addr, &pte, &level);
+	local_irq_restore(flags);
+
+	if (ret)
+		return ret;
+
+	/*
+	 * Not seeing an error, but not updating level? Something went
+	 * deeply wrong...
+	 */
+	if (WARN_ON(level >= KVM_PGTABLE_MAX_LEVELS))
+		return -EFAULT;
+
+	/* Oops, the userspace PTs are gone... Replay the fault */
+	if (!kvm_pte_valid(pte))
+		return -EAGAIN;
+
+	return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(level));
+}
+
+static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = {
+	.zalloc_page		= stage2_memcache_zalloc_page,
+	.zalloc_pages_exact	= kvm_s2_zalloc_pages_exact,
+	.free_pages_exact	= kvm_s2_free_pages_exact,
+	.get_page		= kvm_host_get_page,
+	.put_page		= kvm_s2_put_page,
+	.page_count		= kvm_host_page_count,
+	.phys_to_virt		= kvm_host_va,
+	.virt_to_phys		= kvm_host_pa,
+	.dcache_clean_inval_poc	= clean_dcache_guest_page,
+	.icache_inval_pou	= invalidate_icache_guest_page,
+};
+
+/**
+ * kvm_init_stage2_mmu - Initialise a S2 MMU structure
+ * @kvm:	The pointer to the KVM structure
+ * @mmu:	The pointer to the s2 MMU structure
+ *
+ * Allocates only the stage-2 HW PGD level table(s).
+ * Note we don't need locking here as this is only called when the VM is
+ * created, which can only be done once.
+ */
+int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu)
+{
+	int cpu, err;
+	struct kvm_pgtable *pgt;
+
+	if (mmu->pgt != NULL) {
+		kvm_err("kvm_arch already initialized?\n");
+		return -EINVAL;
+	}
+
+	pgt = kzalloc(sizeof(*pgt), GFP_KERNEL_ACCOUNT);
+	if (!pgt)
+		return -ENOMEM;
+
+	mmu->arch = &kvm->arch;
+	err = kvm_pgtable_stage2_init(pgt, mmu, &kvm_s2_mm_ops);
+	if (err)
+		goto out_free_pgtable;
+
+	mmu->last_vcpu_ran = alloc_percpu(typeof(*mmu->last_vcpu_ran));
+	if (!mmu->last_vcpu_ran) {
+		err = -ENOMEM;
+		goto out_destroy_pgtable;
+	}
+
+	for_each_possible_cpu(cpu)
+		*per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1;
+
+	mmu->pgt = pgt;
+	mmu->pgd_phys = __pa(pgt->pgd);
+	return 0;
+
+out_destroy_pgtable:
+	kvm_pgtable_stage2_destroy(pgt);
+out_free_pgtable:
+	kfree(pgt);
+	return err;
+}
+
+static void stage2_unmap_memslot(struct kvm *kvm,
+				 struct kvm_memory_slot *memslot)
+{
+	hva_t hva = memslot->userspace_addr;
+	phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
+	phys_addr_t size = PAGE_SIZE * memslot->npages;
+	hva_t reg_end = hva + size;
+
+	/*
+	 * A memory region could potentially cover multiple VMAs, and any holes
+	 * between them, so iterate over all of them to find out if we should
+	 * unmap any of them.
+	 *
+	 *     +--------------------------------------------+
+	 * +---------------+----------------+   +----------------+
+	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
+	 * +---------------+----------------+   +----------------+
+	 *     |               memory region                |
+	 *     +--------------------------------------------+
+	 */
+	do {
+		struct vm_area_struct *vma;
+		hva_t vm_start, vm_end;
+
+		vma = find_vma_intersection(current->mm, hva, reg_end);
+		if (!vma)
+			break;
+
+		/*
+		 * Take the intersection of this VMA with the memory region
+		 */
+		vm_start = max(hva, vma->vm_start);
+		vm_end = min(reg_end, vma->vm_end);
+
+		if (!(vma->vm_flags & VM_PFNMAP)) {
+			gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
+			unmap_stage2_range(&kvm->arch.mmu, gpa, vm_end - vm_start);
+		}
+		hva = vm_end;
+	} while (hva < reg_end);
+}
+
+/**
+ * stage2_unmap_vm - Unmap Stage-2 RAM mappings
+ * @kvm: The struct kvm pointer
+ *
+ * Go through the memregions and unmap any regular RAM
+ * backing memory already mapped to the VM.
+ */
+void stage2_unmap_vm(struct kvm *kvm)
+{
+	struct kvm_memslots *slots;
+	struct kvm_memory_slot *memslot;
+	int idx, bkt;
+
+	idx = srcu_read_lock(&kvm->srcu);
+	mmap_read_lock(current->mm);
+	write_lock(&kvm->mmu_lock);
+
+	slots = kvm_memslots(kvm);
+	kvm_for_each_memslot(memslot, bkt, slots)
+		stage2_unmap_memslot(kvm, memslot);
+
+	write_unlock(&kvm->mmu_lock);
+	mmap_read_unlock(current->mm);
+	srcu_read_unlock(&kvm->srcu, idx);
+}
+
+void kvm_free_stage2_pgd(struct kvm_s2_mmu *mmu)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
+	struct kvm_pgtable *pgt = NULL;
+
+	write_lock(&kvm->mmu_lock);
+	pgt = mmu->pgt;
+	if (pgt) {
+		mmu->pgd_phys = 0;
+		mmu->pgt = NULL;
+		free_percpu(mmu->last_vcpu_ran);
+	}
+	write_unlock(&kvm->mmu_lock);
+
+	if (pgt) {
+		kvm_pgtable_stage2_destroy(pgt);
+		kfree(pgt);
+	}
+}
+
+/**
+ * kvm_phys_addr_ioremap - map a device range to guest IPA
+ *
+ * @kvm:	The KVM pointer
+ * @guest_ipa:	The IPA at which to insert the mapping
+ * @pa:		The physical address of the device
+ * @size:	The size of the mapping
+ * @writable:   Whether or not to create a writable mapping
+ */
+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;
+	int ret = 0;
+	struct kvm_mmu_memory_cache cache = { .gfp_zero = __GFP_ZERO };
+	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);
+
+	if (is_protected_kvm_enabled())
+		return -EPERM;
+
+	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)
+			break;
+
+		write_lock(&kvm->mmu_lock);
+		ret = kvm_pgtable_stage2_map(pgt, addr, PAGE_SIZE, pa, prot,
+					     &cache);
+		write_unlock(&kvm->mmu_lock);
+		if (ret)
+			break;
+
+		pa += PAGE_SIZE;
+	}
+
+	kvm_mmu_free_memory_cache(&cache);
+	return ret;
+}
+
+/**
+ * stage2_wp_range() - write protect stage2 memory region range
+ * @mmu:        The KVM stage-2 MMU pointer
+ * @addr:	Start address of range
+ * @end:	End address of range
+ */
+static void stage2_wp_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
+	stage2_apply_range_resched(kvm, addr, end, kvm_pgtable_stage2_wrprotect);
+}
+
+/**
+ * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
+ * @kvm:	The KVM pointer
+ * @slot:	The memory slot to write protect
+ *
+ * Called to start logging dirty pages after memory region
+ * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
+ * all present PUD, PMD and PTEs are write protected in the memory region.
+ * Afterwards read of dirty page log can be called.
+ *
+ * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
+ * serializing operations for VM memory regions.
+ */
+static void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
+{
+	struct kvm_memslots *slots = kvm_memslots(kvm);
+	struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
+	phys_addr_t start, end;
+
+	if (WARN_ON_ONCE(!memslot))
+		return;
+
+	start = memslot->base_gfn << PAGE_SHIFT;
+	end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
+
+	write_lock(&kvm->mmu_lock);
+	stage2_wp_range(&kvm->arch.mmu, start, end);
+	write_unlock(&kvm->mmu_lock);
+	kvm_flush_remote_tlbs(kvm);
+}
+
+/**
+ * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
+ * @kvm:	The KVM pointer
+ * @slot:	The memory slot associated with mask
+ * @gfn_offset:	The gfn offset in memory slot
+ * @mask:	The mask of dirty pages at offset 'gfn_offset' in this memory
+ *		slot to be write protected
+ *
+ * Walks bits set in mask write protects the associated pte's. Caller must
+ * acquire kvm_mmu_lock.
+ */
+static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
+		struct kvm_memory_slot *slot,
+		gfn_t gfn_offset, unsigned long mask)
+{
+	phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
+	phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
+	phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
+
+	stage2_wp_range(&kvm->arch.mmu, start, end);
+}
+
+/*
+ * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
+ * dirty pages.
+ *
+ * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
+ * enable dirty logging for them.
+ */
+void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
+		struct kvm_memory_slot *slot,
+		gfn_t gfn_offset, unsigned long mask)
+{
+	kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
+}
+
+static void kvm_send_hwpoison_signal(unsigned long address, short lsb)
+{
+	send_sig_mceerr(BUS_MCEERR_AR, (void __user *)address, lsb, current);
+}
+
+static bool fault_supports_stage2_huge_mapping(struct kvm_memory_slot *memslot,
+					       unsigned long hva,
+					       unsigned long map_size)
+{
+	gpa_t gpa_start;
+	hva_t uaddr_start, uaddr_end;
+	size_t size;
+
+	/* The memslot and the VMA are guaranteed to be aligned to PAGE_SIZE */
+	if (map_size == PAGE_SIZE)
+		return true;
+
+	size = memslot->npages * PAGE_SIZE;
+
+	gpa_start = memslot->base_gfn << PAGE_SHIFT;
+
+	uaddr_start = memslot->userspace_addr;
+	uaddr_end = uaddr_start + size;
+
+	/*
+	 * Pages belonging to memslots that don't have the same alignment
+	 * within a PMD/PUD for userspace and IPA cannot be mapped with stage-2
+	 * PMD/PUD entries, because we'll end up mapping the wrong pages.
+	 *
+	 * Consider a layout like the following:
+	 *
+	 *    memslot->userspace_addr:
+	 *    +-----+--------------------+--------------------+---+
+	 *    |abcde|fgh  Stage-1 block  |    Stage-1 block tv|xyz|
+	 *    +-----+--------------------+--------------------+---+
+	 *
+	 *    memslot->base_gfn << PAGE_SHIFT:
+	 *      +---+--------------------+--------------------+-----+
+	 *      |abc|def  Stage-2 block  |    Stage-2 block   |tvxyz|
+	 *      +---+--------------------+--------------------+-----+
+	 *
+	 * If we create those stage-2 blocks, we'll end up with this incorrect
+	 * mapping:
+	 *   d -> f
+	 *   e -> g
+	 *   f -> h
+	 */
+	if ((gpa_start & (map_size - 1)) != (uaddr_start & (map_size - 1)))
+		return false;
+
+	/*
+	 * Next, let's make sure we're not trying to map anything not covered
+	 * by the memslot. This means we have to prohibit block size mappings
+	 * for the beginning and end of a non-block aligned and non-block sized
+	 * memory slot (illustrated by the head and tail parts of the
+	 * userspace view above containing pages 'abcde' and 'xyz',
+	 * respectively).
+	 *
+	 * Note that it doesn't matter if we do the check using the
+	 * userspace_addr or the base_gfn, as both are equally aligned (per
+	 * the check above) and equally sized.
+	 */
+	return (hva & ~(map_size - 1)) >= uaddr_start &&
+	       (hva & ~(map_size - 1)) + map_size <= uaddr_end;
+}
+
+/*
+ * Check if the given hva is backed by a transparent huge page (THP) and
+ * whether it can be mapped using block mapping in stage2. If so, adjust
+ * the stage2 PFN and IPA accordingly. Only PMD_SIZE THPs are currently
+ * supported. This will need to be updated to support other THP sizes.
+ *
+ * Returns the size of the mapping.
+ */
+static long
+transparent_hugepage_adjust(struct kvm *kvm, struct kvm_memory_slot *memslot,
+			    unsigned long hva, kvm_pfn_t *pfnp,
+			    phys_addr_t *ipap)
+{
+	kvm_pfn_t pfn = *pfnp;
+
+	/*
+	 * Make sure the adjustment is done only for THP pages. Also make
+	 * sure that the HVA and IPA are sufficiently aligned and that the
+	 * block map is contained within the memslot.
+	 */
+	if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE)) {
+		int sz = get_user_mapping_size(kvm, hva);
+
+		if (sz < 0)
+			return sz;
+
+		if (sz < PMD_SIZE)
+			return PAGE_SIZE;
+
+		/*
+		 * The address we faulted on is backed by a transparent huge
+		 * page.  However, because we map the compound huge page and
+		 * not the individual tail page, we need to transfer the
+		 * refcount to the head page.  We have to be careful that the
+		 * THP doesn't start to split while we are adjusting the
+		 * refcounts.
+		 *
+		 * We are sure this doesn't happen, because mmu_invalidate_retry
+		 * was successful and we are holding the mmu_lock, so if this
+		 * THP is trying to split, it will be blocked in the mmu
+		 * notifier before touching any of the pages, specifically
+		 * before being able to call __split_huge_page_refcount().
+		 *
+		 * We can therefore safely transfer the refcount from PG_tail
+		 * to PG_head and switch the pfn from a tail page to the head
+		 * page accordingly.
+		 */
+		*ipap &= PMD_MASK;
+		kvm_release_pfn_clean(pfn);
+		pfn &= ~(PTRS_PER_PMD - 1);
+		get_page(pfn_to_page(pfn));
+		*pfnp = pfn;
+
+		return PMD_SIZE;
+	}
+
+	/* Use page mapping if we cannot use block mapping. */
+	return PAGE_SIZE;
+}
+
+static int get_vma_page_shift(struct vm_area_struct *vma, unsigned long hva)
+{
+	unsigned long pa;
+
+	if (is_vm_hugetlb_page(vma) && !(vma->vm_flags & VM_PFNMAP))
+		return huge_page_shift(hstate_vma(vma));
+
+	if (!(vma->vm_flags & VM_PFNMAP))
+		return PAGE_SHIFT;
+
+	VM_BUG_ON(is_vm_hugetlb_page(vma));
+
+	pa = (vma->vm_pgoff << PAGE_SHIFT) + (hva - vma->vm_start);
+
+#ifndef __PAGETABLE_PMD_FOLDED
+	if ((hva & (PUD_SIZE - 1)) == (pa & (PUD_SIZE - 1)) &&
+	    ALIGN_DOWN(hva, PUD_SIZE) >= vma->vm_start &&
+	    ALIGN(hva, PUD_SIZE) <= vma->vm_end)
+		return PUD_SHIFT;
+#endif
+
+	if ((hva & (PMD_SIZE - 1)) == (pa & (PMD_SIZE - 1)) &&
+	    ALIGN_DOWN(hva, PMD_SIZE) >= vma->vm_start &&
+	    ALIGN(hva, PMD_SIZE) <= vma->vm_end)
+		return PMD_SHIFT;
+
+	return PAGE_SHIFT;
+}
+
+/*
+ * The page will be mapped in stage 2 as Normal Cacheable, so the VM will be
+ * able to see the page's tags and therefore they must be initialised first. If
+ * PG_mte_tagged is set, tags have already been initialised.
+ *
+ * The race in the test/set of the PG_mte_tagged flag is handled by:
+ * - preventing VM_SHARED mappings in a memslot with MTE preventing two VMs
+ *   racing to santise the same page
+ * - mmap_lock protects between a VM faulting a page in and the VMM performing
+ *   an mprotect() to add VM_MTE
+ */
+static int sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
+			     unsigned long size)
+{
+	unsigned long i, nr_pages = size >> PAGE_SHIFT;
+	struct page *page;
+
+	if (!kvm_has_mte(kvm))
+		return 0;
+
+	/*
+	 * pfn_to_online_page() is used to reject ZONE_DEVICE pages
+	 * that may not support tags.
+	 */
+	page = pfn_to_online_page(pfn);
+
+	if (!page)
+		return -EFAULT;
+
+	for (i = 0; i < nr_pages; i++, page++) {
+		if (!page_mte_tagged(page)) {
+			mte_clear_page_tags(page_address(page));
+			set_page_mte_tagged(page);
+		}
+	}
+
+	return 0;
+}
+
+static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
+			  struct kvm_memory_slot *memslot, unsigned long hva,
+			  unsigned long fault_status)
+{
+	int ret = 0;
+	bool write_fault, writable, force_pte = false;
+	bool exec_fault;
+	bool device = false;
+	bool shared;
+	unsigned long mmu_seq;
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
+	struct vm_area_struct *vma;
+	short vma_shift;
+	gfn_t gfn;
+	kvm_pfn_t pfn;
+	bool logging_active = memslot_is_logging(memslot);
+	bool use_read_lock = false;
+	unsigned long fault_level = kvm_vcpu_trap_get_fault_level(vcpu);
+	long vma_pagesize, fault_granule;
+	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
+	struct kvm_pgtable *pgt;
+
+	fault_granule = 1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(fault_level);
+	write_fault = kvm_is_write_fault(vcpu);
+	exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
+	VM_BUG_ON(write_fault && exec_fault);
+
+	if (fault_status == FSC_PERM && !write_fault && !exec_fault) {
+		kvm_err("Unexpected L2 read permission error\n");
+		return -EFAULT;
+	}
+
+	/*
+	 * Permission faults just need to update the existing leaf entry,
+	 * and so normally don't require allocations from the memcache. The
+	 * only exception to this is when dirty logging is enabled at runtime
+	 * and a write fault needs to collapse a block entry into a table.
+	 */
+	if (fault_status != FSC_PERM ||
+	    (logging_active && write_fault)) {
+		ret = kvm_mmu_topup_memory_cache(memcache,
+						 kvm_mmu_cache_min_pages(kvm));
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Let's check if we will get back a huge page backed by hugetlbfs, or
+	 * get block mapping for device MMIO region.
+	 */
+	mmap_read_lock(current->mm);
+	vma = vma_lookup(current->mm, hva);
+	if (unlikely(!vma)) {
+		kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
+		mmap_read_unlock(current->mm);
+		return -EFAULT;
+	}
+
+	/*
+	 * logging_active is guaranteed to never be true for VM_PFNMAP
+	 * memslots.
+	 */
+	if (logging_active) {
+		force_pte = true;
+		vma_shift = PAGE_SHIFT;
+		use_read_lock = (fault_status == FSC_PERM && write_fault &&
+				 fault_granule == PAGE_SIZE);
+	} else {
+		vma_shift = get_vma_page_shift(vma, hva);
+	}
+
+	shared = (vma->vm_flags & VM_SHARED);
+
+	switch (vma_shift) {
+#ifndef __PAGETABLE_PMD_FOLDED
+	case PUD_SHIFT:
+		if (fault_supports_stage2_huge_mapping(memslot, hva, PUD_SIZE))
+			break;
+		fallthrough;
+#endif
+	case CONT_PMD_SHIFT:
+		vma_shift = PMD_SHIFT;
+		fallthrough;
+	case PMD_SHIFT:
+		if (fault_supports_stage2_huge_mapping(memslot, hva, PMD_SIZE))
+			break;
+		fallthrough;
+	case CONT_PTE_SHIFT:
+		vma_shift = PAGE_SHIFT;
+		force_pte = true;
+		fallthrough;
+	case PAGE_SHIFT:
+		break;
+	default:
+		WARN_ONCE(1, "Unknown vma_shift %d", vma_shift);
+	}
+
+	vma_pagesize = 1UL << vma_shift;
+	if (vma_pagesize == PMD_SIZE || vma_pagesize == PUD_SIZE)
+		fault_ipa &= ~(vma_pagesize - 1);
+
+	gfn = fault_ipa >> PAGE_SHIFT;
+
+	/*
+	 * Read mmu_invalidate_seq so that KVM can detect if the results of
+	 * vma_lookup() or __gfn_to_pfn_memslot() become stale prior to
+	 * acquiring kvm->mmu_lock.
+	 *
+	 * Rely on mmap_read_unlock() for an implicit smp_rmb(), which pairs
+	 * with the smp_wmb() in kvm_mmu_invalidate_end().
+	 */
+	mmu_seq = vcpu->kvm->mmu_invalidate_seq;
+	mmap_read_unlock(current->mm);
+
+	pfn = __gfn_to_pfn_memslot(memslot, gfn, false, NULL,
+				   write_fault, &writable, NULL);
+	if (pfn == KVM_PFN_ERR_HWPOISON) {
+		kvm_send_hwpoison_signal(hva, vma_shift);
+		return 0;
+	}
+	if (is_error_noslot_pfn(pfn))
+		return -EFAULT;
+
+	if (kvm_is_device_pfn(pfn)) {
+		/*
+		 * If the page was identified as device early by looking at
+		 * the VMA flags, vma_pagesize is already representing the
+		 * largest quantity we can map.  If instead it was mapped
+		 * via gfn_to_pfn_prot(), vma_pagesize is set to PAGE_SIZE
+		 * and must not be upgraded.
+		 *
+		 * In both cases, we don't let transparent_hugepage_adjust()
+		 * change things at the last minute.
+		 */
+		device = true;
+	} else if (logging_active && !write_fault) {
+		/*
+		 * Only actually map the page as writable if this was a write
+		 * fault.
+		 */
+		writable = false;
+	}
+
+	if (exec_fault && device)
+		return -ENOEXEC;
+
+	/*
+	 * To reduce MMU contentions and enhance concurrency during dirty
+	 * logging dirty logging, only acquire read lock for permission
+	 * relaxation.
+	 */
+	if (use_read_lock)
+		read_lock(&kvm->mmu_lock);
+	else
+		write_lock(&kvm->mmu_lock);
+	pgt = vcpu->arch.hw_mmu->pgt;
+	if (mmu_invalidate_retry(kvm, mmu_seq))
+		goto out_unlock;
+
+	/*
+	 * If we are not forced to use page mapping, check if we are
+	 * backed by a THP and thus use block mapping if possible.
+	 */
+	if (vma_pagesize == PAGE_SIZE && !(force_pte || device)) {
+		if (fault_status == FSC_PERM && fault_granule > PAGE_SIZE)
+			vma_pagesize = fault_granule;
+		else
+			vma_pagesize = transparent_hugepage_adjust(kvm, memslot,
+								   hva, &pfn,
+								   &fault_ipa);
+
+		if (vma_pagesize < 0) {
+			ret = vma_pagesize;
+			goto out_unlock;
+		}
+	}
+
+	if (fault_status != FSC_PERM && !device && kvm_has_mte(kvm)) {
+		/* Check the VMM hasn't introduced a new VM_SHARED VMA */
+		if (!shared)
+			ret = sanitise_mte_tags(kvm, pfn, vma_pagesize);
+		else
+			ret = -EFAULT;
+		if (ret)
+			goto out_unlock;
+	}
+
+	if (writable)
+		prot |= KVM_PGTABLE_PROT_W;
+
+	if (exec_fault)
+		prot |= KVM_PGTABLE_PROT_X;
+
+	if (device)
+		prot |= KVM_PGTABLE_PROT_DEVICE;
+	else if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC))
+		prot |= KVM_PGTABLE_PROT_X;
+
+	/*
+	 * Under the premise of getting a FSC_PERM fault, we just need to relax
+	 * permissions only if vma_pagesize equals fault_granule. Otherwise,
+	 * kvm_pgtable_stage2_map() should be called to change block size.
+	 */
+	if (fault_status == FSC_PERM && vma_pagesize == fault_granule) {
+		ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot);
+	} else {
+		WARN_ONCE(use_read_lock, "Attempted stage-2 map outside of write lock\n");
+
+		ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize,
+					     __pfn_to_phys(pfn), prot,
+					     memcache);
+	}
+
+	/* Mark the page dirty only if the fault is handled successfully */
+	if (writable && !ret) {
+		kvm_set_pfn_dirty(pfn);
+		mark_page_dirty_in_slot(kvm, memslot, gfn);
+	}
+
+out_unlock:
+	if (use_read_lock)
+		read_unlock(&kvm->mmu_lock);
+	else
+		write_unlock(&kvm->mmu_lock);
+	kvm_set_pfn_accessed(pfn);
+	kvm_release_pfn_clean(pfn);
+	return ret != -EAGAIN ? ret : 0;
+}
+
+/* Resolve the access fault by making the page young again. */
+static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
+{
+	pte_t pte;
+	kvm_pte_t kpte;
+	struct kvm_s2_mmu *mmu;
+
+	trace_kvm_access_fault(fault_ipa);
+
+	write_lock(&vcpu->kvm->mmu_lock);
+	mmu = vcpu->arch.hw_mmu;
+	kpte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
+	write_unlock(&vcpu->kvm->mmu_lock);
+
+	pte = __pte(kpte);
+	if (pte_valid(pte))
+		kvm_set_pfn_accessed(pte_pfn(pte));
+}
+
+/**
+ * kvm_handle_guest_abort - handles all 2nd stage aborts
+ * @vcpu:	the VCPU pointer
+ *
+ * Any abort that gets to the host is almost guaranteed to be caused by a
+ * missing second stage translation table entry, which can mean that either the
+ * guest simply needs more memory and we must allocate an appropriate page or it
+ * can mean that the guest tried to access I/O memory, which is emulated by user
+ * space. The distinction is based on the IPA causing the fault and whether this
+ * memory region has been registered as standard RAM by user space.
+ */
+int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
+{
+	unsigned long fault_status;
+	phys_addr_t fault_ipa;
+	struct kvm_memory_slot *memslot;
+	unsigned long hva;
+	bool is_iabt, write_fault, writable;
+	gfn_t gfn;
+	int ret, idx;
+
+	fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
+
+	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
+	is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
+
+	if (fault_status == FSC_FAULT) {
+		/* Beyond sanitised PARange (which is the IPA limit) */
+		if (fault_ipa >= BIT_ULL(get_kvm_ipa_limit())) {
+			kvm_inject_size_fault(vcpu);
+			return 1;
+		}
+
+		/* Falls between the IPA range and the PARange? */
+		if (fault_ipa >= BIT_ULL(vcpu->arch.hw_mmu->pgt->ia_bits)) {
+			fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
+
+			if (is_iabt)
+				kvm_inject_pabt(vcpu, fault_ipa);
+			else
+				kvm_inject_dabt(vcpu, fault_ipa);
+			return 1;
+		}
+	}
+
+	/* Synchronous External Abort? */
+	if (kvm_vcpu_abt_issea(vcpu)) {
+		/*
+		 * For RAS the host kernel may handle this abort.
+		 * There is no need to pass the error into the guest.
+		 */
+		if (kvm_handle_guest_sea(fault_ipa, kvm_vcpu_get_esr(vcpu)))
+			kvm_inject_vabt(vcpu);
+
+		return 1;
+	}
+
+	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_esr(vcpu),
+			      kvm_vcpu_get_hfar(vcpu), fault_ipa);
+
+	/* Check the stage-2 fault is trans. fault or write fault */
+	if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
+	    fault_status != FSC_ACCESS) {
+		kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
+			kvm_vcpu_trap_get_class(vcpu),
+			(unsigned long)kvm_vcpu_trap_get_fault(vcpu),
+			(unsigned long)kvm_vcpu_get_esr(vcpu));
+		return -EFAULT;
+	}
+
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
+
+	gfn = fault_ipa >> PAGE_SHIFT;
+	memslot = gfn_to_memslot(vcpu->kvm, gfn);
+	hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
+	write_fault = kvm_is_write_fault(vcpu);
+	if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
+		/*
+		 * The guest has put either its instructions or its page-tables
+		 * somewhere it shouldn't have. Userspace won't be able to do
+		 * anything about this (there's no syndrome for a start), so
+		 * re-inject the abort back into the guest.
+		 */
+		if (is_iabt) {
+			ret = -ENOEXEC;
+			goto out;
+		}
+
+		if (kvm_vcpu_abt_iss1tw(vcpu)) {
+			kvm_inject_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
+			ret = 1;
+			goto out_unlock;
+		}
+
+		/*
+		 * Check for a cache maintenance operation. Since we
+		 * ended-up here, we know it is outside of any memory
+		 * slot. But we can't find out if that is for a device,
+		 * or if the guest is just being stupid. The only thing
+		 * we know for sure is that this range cannot be cached.
+		 *
+		 * So let's assume that the guest is just being
+		 * cautious, and skip the instruction.
+		 */
+		if (kvm_is_error_hva(hva) && kvm_vcpu_dabt_is_cm(vcpu)) {
+			kvm_incr_pc(vcpu);
+			ret = 1;
+			goto out_unlock;
+		}
+
+		/*
+		 * The IPA is reported as [MAX:12], so we need to
+		 * complement it with the bottom 12 bits from the
+		 * faulting VA. This is always 12 bits, irrespective
+		 * of the page size.
+		 */
+		fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
+		ret = io_mem_abort(vcpu, fault_ipa);
+		goto out_unlock;
+	}
+
+	/* Userspace should not be able to register out-of-bounds IPAs */
+	VM_BUG_ON(fault_ipa >= kvm_phys_size(vcpu->kvm));
+
+	if (fault_status == FSC_ACCESS) {
+		handle_access_fault(vcpu, fault_ipa);
+		ret = 1;
+		goto out_unlock;
+	}
+
+	ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
+	if (ret == 0)
+		ret = 1;
+out:
+	if (ret == -ENOEXEC) {
+		kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
+		ret = 1;
+	}
+out_unlock:
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
+	return ret;
+}
+
+bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+	if (!kvm->arch.mmu.pgt)
+		return false;
+
+	__unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT,
+			     (range->end - range->start) << PAGE_SHIFT,
+			     range->may_block);
+
+	return false;
+}
+
+bool kvm_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+	kvm_pfn_t pfn = pte_pfn(range->pte);
+	int ret;
+
+	if (!kvm->arch.mmu.pgt)
+		return false;
+
+	WARN_ON(range->end - range->start != 1);
+
+	ret = sanitise_mte_tags(kvm, pfn, PAGE_SIZE);
+	if (ret)
+		return false;
+
+	/*
+	 * We've moved a page around, probably through CoW, so let's treat
+	 * it just like a translation fault and the map handler will clean
+	 * the cache to the PoC.
+	 *
+	 * The MMU notifiers will have unmapped a huge PMD before calling
+	 * ->change_pte() (which in turn calls kvm_set_spte_gfn()) and
+	 * therefore we never need to clear out a huge PMD through this
+	 * calling path and a memcache is not required.
+	 */
+	kvm_pgtable_stage2_map(kvm->arch.mmu.pgt, range->start << PAGE_SHIFT,
+			       PAGE_SIZE, __pfn_to_phys(pfn),
+			       KVM_PGTABLE_PROT_R, NULL);
+
+	return false;
+}
+
+bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+	u64 size = (range->end - range->start) << PAGE_SHIFT;
+	kvm_pte_t kpte;
+	pte_t pte;
+
+	if (!kvm->arch.mmu.pgt)
+		return false;
+
+	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
+
+	kpte = kvm_pgtable_stage2_mkold(kvm->arch.mmu.pgt,
+					range->start << PAGE_SHIFT);
+	pte = __pte(kpte);
+	return pte_valid(pte) && pte_young(pte);
+}
+
+bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+	if (!kvm->arch.mmu.pgt)
+		return false;
+
+	return kvm_pgtable_stage2_is_young(kvm->arch.mmu.pgt,
+					   range->start << PAGE_SHIFT);
+}
+
+phys_addr_t kvm_mmu_get_httbr(void)
+{
+	return __pa(hyp_pgtable->pgd);
+}
+
+phys_addr_t kvm_get_idmap_vector(void)
+{
+	return hyp_idmap_vector;
+}
+
+static int kvm_map_idmap_text(void)
+{
+	unsigned long size = hyp_idmap_end - hyp_idmap_start;
+	int err = __create_hyp_mappings(hyp_idmap_start, size, hyp_idmap_start,
+					PAGE_HYP_EXEC);
+	if (err)
+		kvm_err("Failed to idmap %lx-%lx\n",
+			hyp_idmap_start, hyp_idmap_end);
+
+	return err;
+}
+
+static void *kvm_hyp_zalloc_page(void *arg)
+{
+	return (void *)get_zeroed_page(GFP_KERNEL);
+}
+
+static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = {
+	.zalloc_page		= kvm_hyp_zalloc_page,
+	.get_page		= kvm_host_get_page,
+	.put_page		= kvm_host_put_page,
+	.phys_to_virt		= kvm_host_va,
+	.virt_to_phys		= kvm_host_pa,
+};
+
+int kvm_mmu_init(u32 *hyp_va_bits)
+{
+	int err;
+
+	hyp_idmap_start = __pa_symbol(__hyp_idmap_text_start);
+	hyp_idmap_start = ALIGN_DOWN(hyp_idmap_start, PAGE_SIZE);
+	hyp_idmap_end = __pa_symbol(__hyp_idmap_text_end);
+	hyp_idmap_end = ALIGN(hyp_idmap_end, PAGE_SIZE);
+	hyp_idmap_vector = __pa_symbol(__kvm_hyp_init);
+
+	/*
+	 * We rely on the linker script to ensure at build time that the HYP
+	 * init code does not cross a page boundary.
+	 */
+	BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
+
+	*hyp_va_bits = 64 - ((idmap_t0sz & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET);
+	kvm_debug("Using %u-bit virtual addresses at EL2\n", *hyp_va_bits);
+	kvm_debug("IDMAP page: %lx\n", hyp_idmap_start);
+	kvm_debug("HYP VA range: %lx:%lx\n",
+		  kern_hyp_va(PAGE_OFFSET),
+		  kern_hyp_va((unsigned long)high_memory - 1));
+
+	if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
+	    hyp_idmap_start <  kern_hyp_va((unsigned long)high_memory - 1) &&
+	    hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
+		/*
+		 * The idmap page is intersecting with the VA space,
+		 * it is not safe to continue further.
+		 */
+		kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	hyp_pgtable = kzalloc(sizeof(*hyp_pgtable), GFP_KERNEL);
+	if (!hyp_pgtable) {
+		kvm_err("Hyp mode page-table not allocated\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = kvm_pgtable_hyp_init(hyp_pgtable, *hyp_va_bits, &kvm_hyp_mm_ops);
+	if (err)
+		goto out_free_pgtable;
+
+	err = kvm_map_idmap_text();
+	if (err)
+		goto out_destroy_pgtable;
+
+	io_map_base = hyp_idmap_start;
+	return 0;
+
+out_destroy_pgtable:
+	kvm_pgtable_hyp_destroy(hyp_pgtable);
+out_free_pgtable:
+	kfree(hyp_pgtable);
+	hyp_pgtable = NULL;
+out:
+	return err;
+}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm,
+				   struct kvm_memory_slot *old,
+				   const struct kvm_memory_slot *new,
+				   enum kvm_mr_change change)
+{
+	/*
+	 * At this point memslot has been committed and there is an
+	 * allocated dirty_bitmap[], dirty pages will be tracked while the
+	 * memory slot is write protected.
+	 */
+	if (change != KVM_MR_DELETE && new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
+		/*
+		 * If we're with initial-all-set, we don't need to write
+		 * protect any pages because they're all reported as dirty.
+		 * Huge pages and normal pages will be write protect gradually.
+		 */
+		if (!kvm_dirty_log_manual_protect_and_init_set(kvm)) {
+			kvm_mmu_wp_memory_region(kvm, new->id);
+		}
+	}
+}
+
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+				   const struct kvm_memory_slot *old,
+				   struct kvm_memory_slot *new,
+				   enum kvm_mr_change change)
+{
+	hva_t hva, reg_end;
+	int ret = 0;
+
+	if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
+			change != KVM_MR_FLAGS_ONLY)
+		return 0;
+
+	/*
+	 * Prevent userspace from creating a memory region outside of the IPA
+	 * space addressable by the KVM guest IPA space.
+	 */
+	if ((new->base_gfn + new->npages) > (kvm_phys_size(kvm) >> PAGE_SHIFT))
+		return -EFAULT;
+
+	hva = new->userspace_addr;
+	reg_end = hva + (new->npages << PAGE_SHIFT);
+
+	mmap_read_lock(current->mm);
+	/*
+	 * A memory region could potentially cover multiple VMAs, and any holes
+	 * between them, so iterate over all of them.
+	 *
+	 *     +--------------------------------------------+
+	 * +---------------+----------------+   +----------------+
+	 * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
+	 * +---------------+----------------+   +----------------+
+	 *     |               memory region                |
+	 *     +--------------------------------------------+
+	 */
+	do {
+		struct vm_area_struct *vma;
+
+		vma = find_vma_intersection(current->mm, hva, reg_end);
+		if (!vma)
+			break;
+
+		/*
+		 * VM_SHARED mappings are not allowed with MTE to avoid races
+		 * when updating the PG_mte_tagged page flag, see
+		 * sanitise_mte_tags for more details.
+		 */
+		if (kvm_has_mte(kvm) && vma->vm_flags & VM_SHARED) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (vma->vm_flags & VM_PFNMAP) {
+			/* IO region dirty page logging not allowed */
+			if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
+				ret = -EINVAL;
+				break;
+			}
+		}
+		hva = min(reg_end, vma->vm_end);
+	} while (hva < reg_end);
+
+	mmap_read_unlock(current->mm);
+	return ret;
+}
+
+void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
+{
+}
+
+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);
+}
+
+void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
+				   struct kvm_memory_slot *slot)
+{
+	gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
+	phys_addr_t size = slot->npages << PAGE_SHIFT;
+
+	write_lock(&kvm->mmu_lock);
+	unmap_stage2_range(&kvm->arch.mmu, gpa, size);
+	write_unlock(&kvm->mmu_lock);
+}
+
+/*
+ * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
+ *
+ * Main problems:
+ * - S/W ops are local to a CPU (not broadcast)
+ * - We have line migration behind our back (speculation)
+ * - System caches don't support S/W at all (damn!)
+ *
+ * In the face of the above, the best we can do is to try and convert
+ * S/W ops to VA ops. Because the guest is not allowed to infer the
+ * S/W to PA mapping, it can only use S/W to nuke the whole cache,
+ * which is a rather good thing for us.
+ *
+ * Also, it is only used when turning caches on/off ("The expected
+ * usage of the cache maintenance instructions that operate by set/way
+ * is associated with the cache maintenance instructions associated
+ * with the powerdown and powerup of caches, if this is required by
+ * the implementation.").
+ *
+ * We use the following policy:
+ *
+ * - If we trap a S/W operation, we enable VM trapping to detect
+ *   caches being turned on/off, and do a full clean.
+ *
+ * - We flush the caches on both caches being turned on and off.
+ *
+ * - Once the caches are enabled, we stop trapping VM ops.
+ */
+void kvm_set_way_flush(struct kvm_vcpu *vcpu)
+{
+	unsigned long hcr = *vcpu_hcr(vcpu);
+
+	/*
+	 * If this is the first time we do a S/W operation
+	 * (i.e. HCR_TVM not set) flush the whole memory, and set the
+	 * VM trapping.
+	 *
+	 * Otherwise, rely on the VM trapping to wait for the MMU +
+	 * Caches to be turned off. At that point, we'll be able to
+	 * clean the caches again.
+	 */
+	if (!(hcr & HCR_TVM)) {
+		trace_kvm_set_way_flush(*vcpu_pc(vcpu),
+					vcpu_has_cache_enabled(vcpu));
+		stage2_flush_vm(vcpu->kvm);
+		*vcpu_hcr(vcpu) = hcr | HCR_TVM;
+	}
+}
+
+void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
+{
+	bool now_enabled = vcpu_has_cache_enabled(vcpu);
+
+	/*
+	 * If switching the MMU+caches on, need to invalidate the caches.
+	 * If switching it off, need to clean the caches.
+	 * Clean + invalidate does the trick always.
+	 */
+	if (now_enabled != was_enabled)
+		stage2_flush_vm(vcpu->kvm);
+
+	/* Caches are now on, stop trapping VM ops (until a S/W op) */
+	if (now_enabled)
+		*vcpu_hcr(vcpu) &= ~HCR_TVM;
+
+	trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
+}