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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/arm64/kvm/mmu.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/mmu.c')
-rw-r--r--arch/arm64/kvm/mmu.c2158
1 files changed, 2158 insertions, 0 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
new file mode 100644
index 0000000000..482280fe22
--- /dev/null
+++ b/arch/arm64/kvm/mmu.c
@@ -0,0 +1,2158 @@
+// 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 __ro_after_init hyp_idmap_start;
+static unsigned long __ro_after_init hyp_idmap_end;
+static phys_addr_t __ro_after_init hyp_idmap_vector;
+
+static unsigned long __ro_after_init io_map_base;
+
+static phys_addr_t __stage2_range_addr_end(phys_addr_t addr, phys_addr_t end,
+ phys_addr_t size)
+{
+ phys_addr_t boundary = ALIGN_DOWN(addr + size, size);
+
+ return (boundary - 1 < end - 1) ? boundary : end;
+}
+
+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);
+
+ return __stage2_range_addr_end(addr, end, size);
+}
+
+/*
+ * 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_s2_mmu *mmu, phys_addr_t addr,
+ phys_addr_t end,
+ int (*fn)(struct kvm_pgtable *, u64, u64),
+ bool resched)
+{
+ struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
+ int ret;
+ u64 next;
+
+ do {
+ struct kvm_pgtable *pgt = 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(mmu, addr, end, fn) \
+ stage2_apply_range(mmu, addr, end, fn, true)
+
+/*
+ * Get the maximum number of page-tables pages needed to split a range
+ * of blocks into PAGE_SIZE PTEs. It assumes the range is already
+ * mapped at level 2, or at level 1 if allowed.
+ */
+static int kvm_mmu_split_nr_page_tables(u64 range)
+{
+ int n = 0;
+
+ if (KVM_PGTABLE_MIN_BLOCK_LEVEL < 2)
+ n += DIV_ROUND_UP(range, PUD_SIZE);
+ n += DIV_ROUND_UP(range, PMD_SIZE);
+ return n;
+}
+
+static bool need_split_memcache_topup_or_resched(struct kvm *kvm)
+{
+ struct kvm_mmu_memory_cache *cache;
+ u64 chunk_size, min;
+
+ if (need_resched() || rwlock_needbreak(&kvm->mmu_lock))
+ return true;
+
+ chunk_size = kvm->arch.mmu.split_page_chunk_size;
+ min = kvm_mmu_split_nr_page_tables(chunk_size);
+ cache = &kvm->arch.mmu.split_page_cache;
+ return kvm_mmu_memory_cache_nr_free_objects(cache) < min;
+}
+
+static int kvm_mmu_split_huge_pages(struct kvm *kvm, phys_addr_t addr,
+ phys_addr_t end)
+{
+ struct kvm_mmu_memory_cache *cache;
+ struct kvm_pgtable *pgt;
+ int ret, cache_capacity;
+ u64 next, chunk_size;
+
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ chunk_size = kvm->arch.mmu.split_page_chunk_size;
+ cache_capacity = kvm_mmu_split_nr_page_tables(chunk_size);
+
+ if (chunk_size == 0)
+ return 0;
+
+ cache = &kvm->arch.mmu.split_page_cache;
+
+ do {
+ if (need_split_memcache_topup_or_resched(kvm)) {
+ write_unlock(&kvm->mmu_lock);
+ cond_resched();
+ /* Eager page splitting is best-effort. */
+ ret = __kvm_mmu_topup_memory_cache(cache,
+ cache_capacity,
+ cache_capacity);
+ write_lock(&kvm->mmu_lock);
+ if (ret)
+ break;
+ }
+
+ pgt = kvm->arch.mmu.pgt;
+ if (!pgt)
+ return -EINVAL;
+
+ next = __stage2_range_addr_end(addr, end, chunk_size);
+ ret = kvm_pgtable_stage2_split(pgt, addr, next - addr, cache);
+ if (ret)
+ break;
+ } while (addr = next, addr != end);
+
+ return ret;
+}
+
+static bool memslot_is_logging(struct kvm_memory_slot *memslot)
+{
+ return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
+}
+
+/**
+ * kvm_arch_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
+ */
+int kvm_arch_flush_remote_tlbs(struct kvm *kvm)
+{
+ kvm_call_hyp(__kvm_tlb_flush_vmid, &kvm->arch.mmu);
+ return 0;
+}
+
+int kvm_arch_flush_remote_tlbs_range(struct kvm *kvm,
+ gfn_t gfn, u64 nr_pages)
+{
+ kvm_tlb_flush_vmid_range(&kvm->arch.mmu,
+ gfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT);
+ return 0;
+}
+
+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 struct kvm_pgtable_mm_ops kvm_s2_mm_ops;
+
+static void stage2_free_unlinked_table_rcu_cb(struct rcu_head *head)
+{
+ struct page *page = container_of(head, struct page, rcu_head);
+ void *pgtable = page_to_virt(page);
+ u32 level = page_private(page);
+
+ kvm_pgtable_stage2_free_unlinked(&kvm_s2_mm_ops, pgtable, level);
+}
+
+static void stage2_free_unlinked_table(void *addr, u32 level)
+{
+ struct page *page = virt_to_page(addr);
+
+ set_page_private(page, (unsigned long)level);
+ call_rcu(&page->rcu_head, stage2_free_unlinked_table_rcu_cb);
+}
+
+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(mmu, 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->arch.mmu, 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 __init 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;
+}
+
+static int __hyp_alloc_private_va_range(unsigned long base)
+{
+ lockdep_assert_held(&kvm_hyp_pgd_mutex);
+
+ if (!PAGE_ALIGNED(base))
+ return -EINVAL;
+
+ /*
+ * 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))
+ return -ENOMEM;
+
+ io_map_base = base;
+
+ 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 in
+ * __hyp_alloc_private_va_range() 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.
+ */
+ size = PAGE_ALIGN(size);
+ base = io_map_base - size;
+ ret = __hyp_alloc_private_va_range(base);
+
+ mutex_unlock(&kvm_hyp_pgd_mutex);
+
+ if (!ret)
+ *haddr = base;
+
+ 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;
+}
+
+int create_hyp_stack(phys_addr_t phys_addr, unsigned long *haddr)
+{
+ unsigned long base;
+ size_t size;
+ int ret;
+
+ mutex_lock(&kvm_hyp_pgd_mutex);
+ /*
+ * Efficient stack verification using the PAGE_SHIFT bit implies
+ * an alignment of our allocation on the order of the size.
+ */
+ size = PAGE_SIZE * 2;
+ base = ALIGN_DOWN(io_map_base - size, size);
+
+ ret = __hyp_alloc_private_va_range(base);
+
+ mutex_unlock(&kvm_hyp_pgd_mutex);
+
+ if (ret) {
+ kvm_err("Cannot allocate hyp stack guard page\n");
+ return ret;
+ }
+
+ /*
+ * Since the stack grows downwards, map the stack to the page
+ * at the higher address and leave the lower guard page
+ * unbacked.
+ *
+ * Any valid stack address now has the PAGE_SHIFT bit as 1
+ * and addresses corresponding to the guard page have the
+ * PAGE_SHIFT bit as 0 - this is used for overflow detection.
+ */
+ ret = __create_hyp_mappings(base + PAGE_SIZE, PAGE_SIZE, phys_addr,
+ PAGE_HYP);
+ if (ret)
+ kvm_err("Cannot map hyp stack\n");
+
+ *haddr = base + size;
+
+ 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_pteref_t)kvm->mm->pgd,
+ .ia_bits = vabits_actual,
+ .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,
+ .free_unlinked_table = stage2_free_unlinked_table,
+ .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
+ * @type: The machine type of the virtual machine
+ *
+ * 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, unsigned long type)
+{
+ u32 kvm_ipa_limit = get_kvm_ipa_limit();
+ int cpu, err;
+ struct kvm_pgtable *pgt;
+ u64 mmfr0, mmfr1;
+ u32 phys_shift;
+
+ if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
+ return -EINVAL;
+
+ phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
+ if (is_protected_kvm_enabled()) {
+ phys_shift = kvm_ipa_limit;
+ } else if (phys_shift) {
+ if (phys_shift > kvm_ipa_limit ||
+ phys_shift < ARM64_MIN_PARANGE_BITS)
+ return -EINVAL;
+ } else {
+ phys_shift = KVM_PHYS_SHIFT;
+ if (phys_shift > kvm_ipa_limit) {
+ pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n",
+ current->comm);
+ return -EINVAL;
+ }
+ }
+
+ mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
+ mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
+ kvm->arch.vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift);
+
+ 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;
+
+ /* The eager page splitting is disabled by default */
+ mmu->split_page_chunk_size = KVM_ARM_EAGER_SPLIT_CHUNK_SIZE_DEFAULT;
+ mmu->split_page_cache.gfp_zero = __GFP_ZERO;
+
+ 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;
+}
+
+void kvm_uninit_stage2_mmu(struct kvm *kvm)
+{
+ kvm_free_stage2_pgd(&kvm->arch.mmu);
+ kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache);
+}
+
+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);
+ }
+}
+
+static void hyp_mc_free_fn(void *addr, void *unused)
+{
+ free_page((unsigned long)addr);
+}
+
+static void *hyp_mc_alloc_fn(void *unused)
+{
+ return (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
+}
+
+void free_hyp_memcache(struct kvm_hyp_memcache *mc)
+{
+ if (is_protected_kvm_enabled())
+ __free_hyp_memcache(mc, hyp_mc_free_fn,
+ kvm_host_va, NULL);
+}
+
+int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)
+{
+ if (!is_protected_kvm_enabled())
+ return 0;
+
+ return __topup_hyp_memcache(mc, min_pages, hyp_mc_alloc_fn,
+ kvm_host_pa, NULL);
+}
+
+/**
+ * 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, 0);
+ 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)
+{
+ stage2_apply_range_resched(mmu, 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_memslot(kvm, memslot);
+}
+
+/**
+ * kvm_mmu_split_memory_region() - split the stage 2 blocks into PAGE_SIZE
+ * pages for memory slot
+ * @kvm: The KVM pointer
+ * @slot: The memory slot to split
+ *
+ * Acquires kvm->mmu_lock. Called with kvm->slots_lock mutex acquired,
+ * serializing operations for VM memory regions.
+ */
+static void kvm_mmu_split_memory_region(struct kvm *kvm, int slot)
+{
+ struct kvm_memslots *slots;
+ struct kvm_memory_slot *memslot;
+ phys_addr_t start, end;
+
+ lockdep_assert_held(&kvm->slots_lock);
+
+ slots = kvm_memslots(kvm);
+ memslot = id_to_memslot(slots, slot);
+
+ start = memslot->base_gfn << PAGE_SHIFT;
+ end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
+
+ write_lock(&kvm->mmu_lock);
+ kvm_mmu_split_huge_pages(kvm, start, end);
+ write_unlock(&kvm->mmu_lock);
+}
+
+/*
+ * kvm_arch_mmu_enable_log_dirty_pt_masked() - enable dirty logging for selected pages.
+ * @kvm: The KVM pointer
+ * @slot: The memory slot associated with mask
+ * @gfn_offset: The gfn offset in memory slot
+ * @mask: The mask of pages at offset 'gfn_offset' in this memory
+ * slot to enable dirty logging on
+ *
+ * Writes protect selected pages to enable dirty logging, and then
+ * splits them to PAGE_SIZE. Caller must acquire kvm->mmu_lock.
+ */
+void kvm_arch_mmu_enable_log_dirty_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;
+
+ lockdep_assert_held_write(&kvm->mmu_lock);
+
+ stage2_wp_range(&kvm->arch.mmu, start, end);
+
+ /*
+ * Eager-splitting is done when manual-protect is set. We
+ * also check for initially-all-set because we can avoid
+ * eager-splitting if initially-all-set is false.
+ * Initially-all-set equal false implies that huge-pages were
+ * already split when enabling dirty logging: no need to do it
+ * again.
+ */
+ if (kvm_dirty_log_manual_protect_and_init_set(kvm))
+ kvm_mmu_split_huge_pages(kvm, start, end);
+}
+
+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 void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn,
+ unsigned long size)
+{
+ unsigned long i, nr_pages = size >> PAGE_SHIFT;
+ struct page *page = pfn_to_page(pfn);
+
+ if (!kvm_has_mte(kvm))
+ return;
+
+ for (i = 0; i < nr_pages; i++, page++) {
+ if (try_page_mte_tagging(page)) {
+ mte_clear_page_tags(page_address(page));
+ set_page_mte_tagged(page);
+ }
+ }
+}
+
+static bool kvm_vma_mte_allowed(struct vm_area_struct *vma)
+{
+ return vma->vm_flags & VM_MTE_ALLOWED;
+}
+
+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, mte_allowed;
+ bool device = false;
+ 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);
+ 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 == ESR_ELx_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 != ESR_ELx_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;
+ } else {
+ vma_shift = get_vma_page_shift(vma, hva);
+ }
+
+ 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;
+ mte_allowed = kvm_vma_mte_allowed(vma);
+
+ /* Don't use the VMA after the unlock -- it may have vanished */
+ vma = NULL;
+
+ /*
+ * 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, 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;
+
+ read_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 == ESR_ELx_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 != ESR_ELx_FSC_PERM && !device && kvm_has_mte(kvm)) {
+ /* Check the VMM hasn't introduced a new disallowed VMA */
+ if (mte_allowed) {
+ sanitise_mte_tags(kvm, pfn, vma_pagesize);
+ } else {
+ ret = -EFAULT;
+ 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 == ESR_ELx_FSC_PERM && vma_pagesize == fault_granule)
+ ret = kvm_pgtable_stage2_relax_perms(pgt, fault_ipa, prot);
+ else
+ ret = kvm_pgtable_stage2_map(pgt, fault_ipa, vma_pagesize,
+ __pfn_to_phys(pfn), prot,
+ memcache,
+ KVM_PGTABLE_WALK_HANDLE_FAULT |
+ KVM_PGTABLE_WALK_SHARED);
+
+ /* 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:
+ read_unlock(&kvm->mmu_lock);
+ 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)
+{
+ kvm_pte_t pte;
+ struct kvm_s2_mmu *mmu;
+
+ trace_kvm_access_fault(fault_ipa);
+
+ read_lock(&vcpu->kvm->mmu_lock);
+ mmu = vcpu->arch.hw_mmu;
+ pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
+ read_unlock(&vcpu->kvm->mmu_lock);
+
+ if (kvm_pte_valid(pte))
+ kvm_set_pfn_accessed(kvm_pte_to_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 == ESR_ELx_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 != ESR_ELx_FSC_FAULT &&
+ fault_status != ESR_ELx_FSC_PERM &&
+ fault_status != ESR_ELx_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 == ESR_ELx_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->arg.pte);
+
+ if (!kvm->arch.mmu.pgt)
+ return false;
+
+ WARN_ON(range->end - range->start != 1);
+
+ /*
+ * If the page isn't tagged, defer to user_mem_abort() for sanitising
+ * the MTE tags. The S2 pte should have been unmapped by
+ * mmu_notifier_invalidate_range_end().
+ */
+ if (kvm_has_mte(kvm) && !page_mte_tagged(pfn_to_page(pfn)))
+ 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, 0);
+
+ return false;
+}
+
+bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ u64 size = (range->end - range->start) << PAGE_SHIFT;
+
+ if (!kvm->arch.mmu.pgt)
+ return false;
+
+ return kvm_pgtable_stage2_test_clear_young(kvm->arch.mmu.pgt,
+ range->start << PAGE_SHIFT,
+ size, true);
+}
+
+bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
+{
+ u64 size = (range->end - range->start) << PAGE_SHIFT;
+
+ if (!kvm->arch.mmu.pgt)
+ return false;
+
+ return kvm_pgtable_stage2_test_clear_young(kvm->arch.mmu.pgt,
+ range->start << PAGE_SHIFT,
+ size, false);
+}
+
+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 __init kvm_mmu_init(u32 *hyp_va_bits)
+{
+ int err;
+ u32 idmap_bits;
+ u32 kernel_bits;
+
+ 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);
+
+ /*
+ * The ID map may be configured to use an extended virtual address
+ * range. This is only the case if system RAM is out of range for the
+ * currently configured page size and VA_BITS_MIN, in which case we will
+ * also need the extended virtual range for the HYP ID map, or we won't
+ * be able to enable the EL2 MMU.
+ *
+ * However, in some cases the ID map may be configured for fewer than
+ * the number of VA bits used by the regular kernel stage 1. This
+ * happens when VA_BITS=52 and the kernel image is placed in PA space
+ * below 48 bits.
+ *
+ * At EL2, there is only one TTBR register, and we can't switch between
+ * translation tables *and* update TCR_EL2.T0SZ at the same time. Bottom
+ * line: we need to use the extended range with *both* our translation
+ * tables.
+ *
+ * So use the maximum of the idmap VA bits and the regular kernel stage
+ * 1 VA bits to assure that the hypervisor can both ID map its code page
+ * and map any kernel memory.
+ */
+ idmap_bits = 64 - ((idmap_t0sz & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET);
+ kernel_bits = vabits_actual;
+ *hyp_va_bits = max(idmap_bits, kernel_bits);
+
+ 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)
+{
+ bool log_dirty_pages = new && new->flags & KVM_MEM_LOG_DIRTY_PAGES;
+
+ /*
+ * 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 (log_dirty_pages) {
+
+ if (change == KVM_MR_DELETE)
+ return;
+
+ /*
+ * Huge and normal pages are write-protected and split
+ * on either of these two cases:
+ *
+ * 1. with initial-all-set: gradually with CLEAR ioctls,
+ */
+ if (kvm_dirty_log_manual_protect_and_init_set(kvm))
+ return;
+ /*
+ * or
+ * 2. without initial-all-set: all in one shot when
+ * enabling dirty logging.
+ */
+ kvm_mmu_wp_memory_region(kvm, new->id);
+ kvm_mmu_split_memory_region(kvm, new->id);
+ } else {
+ /*
+ * Free any leftovers from the eager page splitting cache. Do
+ * this when deleting, moving, disabling dirty logging, or
+ * creating the memslot (a nop). Doing it for deletes makes
+ * sure we don't leak memory, and there's no need to keep the
+ * cache around for any of the other cases.
+ */
+ kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache);
+ }
+}
+
+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;
+
+ if (kvm_has_mte(kvm) && !kvm_vma_mte_allowed(vma)) {
+ 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_uninit_stage2_mmu(kvm);
+}
+
+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);
+}