v4.19.13 snapshot.
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
new file mode 100644
index 0000000..911c7de
--- /dev/null
+++ b/arch/s390/mm/gmap.c
@@ -0,0 +1,2639 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KVM guest address space mapping code
+ *
+ * Copyright IBM Corp. 2007, 2016, 2018
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ * David Hildenbrand <david@redhat.com>
+ * Janosch Frank <frankja@linux.vnet.ibm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/swapops.h>
+#include <linux/ksm.h>
+#include <linux/mman.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/gmap.h>
+#include <asm/tlb.h>
+
+#define GMAP_SHADOW_FAKE_TABLE 1ULL
+
+/**
+ * gmap_alloc - allocate and initialize a guest address space
+ * @mm: pointer to the parent mm_struct
+ * @limit: maximum address of the gmap address space
+ *
+ * Returns a guest address space structure.
+ */
+static struct gmap *gmap_alloc(unsigned long limit)
+{
+ struct gmap *gmap;
+ struct page *page;
+ unsigned long *table;
+ unsigned long etype, atype;
+
+ if (limit < _REGION3_SIZE) {
+ limit = _REGION3_SIZE - 1;
+ atype = _ASCE_TYPE_SEGMENT;
+ etype = _SEGMENT_ENTRY_EMPTY;
+ } else if (limit < _REGION2_SIZE) {
+ limit = _REGION2_SIZE - 1;
+ atype = _ASCE_TYPE_REGION3;
+ etype = _REGION3_ENTRY_EMPTY;
+ } else if (limit < _REGION1_SIZE) {
+ limit = _REGION1_SIZE - 1;
+ atype = _ASCE_TYPE_REGION2;
+ etype = _REGION2_ENTRY_EMPTY;
+ } else {
+ limit = -1UL;
+ atype = _ASCE_TYPE_REGION1;
+ etype = _REGION1_ENTRY_EMPTY;
+ }
+ gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
+ if (!gmap)
+ goto out;
+ INIT_LIST_HEAD(&gmap->crst_list);
+ INIT_LIST_HEAD(&gmap->children);
+ INIT_LIST_HEAD(&gmap->pt_list);
+ INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL);
+ INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC);
+ INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC);
+ spin_lock_init(&gmap->guest_table_lock);
+ spin_lock_init(&gmap->shadow_lock);
+ atomic_set(&gmap->ref_count, 1);
+ page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+ if (!page)
+ goto out_free;
+ page->index = 0;
+ list_add(&page->lru, &gmap->crst_list);
+ table = (unsigned long *) page_to_phys(page);
+ crst_table_init(table, etype);
+ gmap->table = table;
+ gmap->asce = atype | _ASCE_TABLE_LENGTH |
+ _ASCE_USER_BITS | __pa(table);
+ gmap->asce_end = limit;
+ return gmap;
+
+out_free:
+ kfree(gmap);
+out:
+ return NULL;
+}
+
+/**
+ * gmap_create - create a guest address space
+ * @mm: pointer to the parent mm_struct
+ * @limit: maximum size of the gmap address space
+ *
+ * Returns a guest address space structure.
+ */
+struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit)
+{
+ struct gmap *gmap;
+ unsigned long gmap_asce;
+
+ gmap = gmap_alloc(limit);
+ if (!gmap)
+ return NULL;
+ gmap->mm = mm;
+ spin_lock(&mm->context.lock);
+ list_add_rcu(&gmap->list, &mm->context.gmap_list);
+ if (list_is_singular(&mm->context.gmap_list))
+ gmap_asce = gmap->asce;
+ else
+ gmap_asce = -1UL;
+ WRITE_ONCE(mm->context.gmap_asce, gmap_asce);
+ spin_unlock(&mm->context.lock);
+ return gmap;
+}
+EXPORT_SYMBOL_GPL(gmap_create);
+
+static void gmap_flush_tlb(struct gmap *gmap)
+{
+ if (MACHINE_HAS_IDTE)
+ __tlb_flush_idte(gmap->asce);
+ else
+ __tlb_flush_global();
+}
+
+static void gmap_radix_tree_free(struct radix_tree_root *root)
+{
+ struct radix_tree_iter iter;
+ unsigned long indices[16];
+ unsigned long index;
+ void __rcu **slot;
+ int i, nr;
+
+ /* A radix tree is freed by deleting all of its entries */
+ index = 0;
+ do {
+ nr = 0;
+ radix_tree_for_each_slot(slot, root, &iter, index) {
+ indices[nr] = iter.index;
+ if (++nr == 16)
+ break;
+ }
+ for (i = 0; i < nr; i++) {
+ index = indices[i];
+ radix_tree_delete(root, index);
+ }
+ } while (nr > 0);
+}
+
+static void gmap_rmap_radix_tree_free(struct radix_tree_root *root)
+{
+ struct gmap_rmap *rmap, *rnext, *head;
+ struct radix_tree_iter iter;
+ unsigned long indices[16];
+ unsigned long index;
+ void __rcu **slot;
+ int i, nr;
+
+ /* A radix tree is freed by deleting all of its entries */
+ index = 0;
+ do {
+ nr = 0;
+ radix_tree_for_each_slot(slot, root, &iter, index) {
+ indices[nr] = iter.index;
+ if (++nr == 16)
+ break;
+ }
+ for (i = 0; i < nr; i++) {
+ index = indices[i];
+ head = radix_tree_delete(root, index);
+ gmap_for_each_rmap_safe(rmap, rnext, head)
+ kfree(rmap);
+ }
+ } while (nr > 0);
+}
+
+/**
+ * gmap_free - free a guest address space
+ * @gmap: pointer to the guest address space structure
+ *
+ * No locks required. There are no references to this gmap anymore.
+ */
+static void gmap_free(struct gmap *gmap)
+{
+ struct page *page, *next;
+
+ /* Flush tlb of all gmaps (if not already done for shadows) */
+ if (!(gmap_is_shadow(gmap) && gmap->removed))
+ gmap_flush_tlb(gmap);
+ /* Free all segment & region tables. */
+ list_for_each_entry_safe(page, next, &gmap->crst_list, lru)
+ __free_pages(page, CRST_ALLOC_ORDER);
+ gmap_radix_tree_free(&gmap->guest_to_host);
+ gmap_radix_tree_free(&gmap->host_to_guest);
+
+ /* Free additional data for a shadow gmap */
+ if (gmap_is_shadow(gmap)) {
+ /* Free all page tables. */
+ list_for_each_entry_safe(page, next, &gmap->pt_list, lru)
+ page_table_free_pgste(page);
+ gmap_rmap_radix_tree_free(&gmap->host_to_rmap);
+ /* Release reference to the parent */
+ gmap_put(gmap->parent);
+ }
+
+ kfree(gmap);
+}
+
+/**
+ * gmap_get - increase reference counter for guest address space
+ * @gmap: pointer to the guest address space structure
+ *
+ * Returns the gmap pointer
+ */
+struct gmap *gmap_get(struct gmap *gmap)
+{
+ atomic_inc(&gmap->ref_count);
+ return gmap;
+}
+EXPORT_SYMBOL_GPL(gmap_get);
+
+/**
+ * gmap_put - decrease reference counter for guest address space
+ * @gmap: pointer to the guest address space structure
+ *
+ * If the reference counter reaches zero the guest address space is freed.
+ */
+void gmap_put(struct gmap *gmap)
+{
+ if (atomic_dec_return(&gmap->ref_count) == 0)
+ gmap_free(gmap);
+}
+EXPORT_SYMBOL_GPL(gmap_put);
+
+/**
+ * gmap_remove - remove a guest address space but do not free it yet
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_remove(struct gmap *gmap)
+{
+ struct gmap *sg, *next;
+ unsigned long gmap_asce;
+
+ /* Remove all shadow gmaps linked to this gmap */
+ if (!list_empty(&gmap->children)) {
+ spin_lock(&gmap->shadow_lock);
+ list_for_each_entry_safe(sg, next, &gmap->children, list) {
+ list_del(&sg->list);
+ gmap_put(sg);
+ }
+ spin_unlock(&gmap->shadow_lock);
+ }
+ /* Remove gmap from the pre-mm list */
+ spin_lock(&gmap->mm->context.lock);
+ list_del_rcu(&gmap->list);
+ if (list_empty(&gmap->mm->context.gmap_list))
+ gmap_asce = 0;
+ else if (list_is_singular(&gmap->mm->context.gmap_list))
+ gmap_asce = list_first_entry(&gmap->mm->context.gmap_list,
+ struct gmap, list)->asce;
+ else
+ gmap_asce = -1UL;
+ WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce);
+ spin_unlock(&gmap->mm->context.lock);
+ synchronize_rcu();
+ /* Put reference */
+ gmap_put(gmap);
+}
+EXPORT_SYMBOL_GPL(gmap_remove);
+
+/**
+ * gmap_enable - switch primary space to the guest address space
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_enable(struct gmap *gmap)
+{
+ S390_lowcore.gmap = (unsigned long) gmap;
+}
+EXPORT_SYMBOL_GPL(gmap_enable);
+
+/**
+ * gmap_disable - switch back to the standard primary address space
+ * @gmap: pointer to the guest address space structure
+ */
+void gmap_disable(struct gmap *gmap)
+{
+ S390_lowcore.gmap = 0UL;
+}
+EXPORT_SYMBOL_GPL(gmap_disable);
+
+/**
+ * gmap_get_enabled - get a pointer to the currently enabled gmap
+ *
+ * Returns a pointer to the currently enabled gmap. 0 if none is enabled.
+ */
+struct gmap *gmap_get_enabled(void)
+{
+ return (struct gmap *) S390_lowcore.gmap;
+}
+EXPORT_SYMBOL_GPL(gmap_get_enabled);
+
+/*
+ * gmap_alloc_table is assumed to be called with mmap_sem held
+ */
+static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
+ unsigned long init, unsigned long gaddr)
+{
+ struct page *page;
+ unsigned long *new;
+
+ /* since we dont free the gmap table until gmap_free we can unlock */
+ page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+ if (!page)
+ return -ENOMEM;
+ new = (unsigned long *) page_to_phys(page);
+ crst_table_init(new, init);
+ spin_lock(&gmap->guest_table_lock);
+ if (*table & _REGION_ENTRY_INVALID) {
+ list_add(&page->lru, &gmap->crst_list);
+ *table = (unsigned long) new | _REGION_ENTRY_LENGTH |
+ (*table & _REGION_ENTRY_TYPE_MASK);
+ page->index = gaddr;
+ page = NULL;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ if (page)
+ __free_pages(page, CRST_ALLOC_ORDER);
+ return 0;
+}
+
+/**
+ * __gmap_segment_gaddr - find virtual address from segment pointer
+ * @entry: pointer to a segment table entry in the guest address space
+ *
+ * Returns the virtual address in the guest address space for the segment
+ */
+static unsigned long __gmap_segment_gaddr(unsigned long *entry)
+{
+ struct page *page;
+ unsigned long offset, mask;
+
+ offset = (unsigned long) entry / sizeof(unsigned long);
+ offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
+ mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
+ page = virt_to_page((void *)((unsigned long) entry & mask));
+ return page->index + offset;
+}
+
+/**
+ * __gmap_unlink_by_vmaddr - unlink a single segment via a host address
+ * @gmap: pointer to the guest address space structure
+ * @vmaddr: address in the host process address space
+ *
+ * Returns 1 if a TLB flush is required
+ */
+static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr)
+{
+ unsigned long *entry;
+ int flush = 0;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ spin_lock(&gmap->guest_table_lock);
+ entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT);
+ if (entry) {
+ flush = (*entry != _SEGMENT_ENTRY_EMPTY);
+ *entry = _SEGMENT_ENTRY_EMPTY;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ return flush;
+}
+
+/**
+ * __gmap_unmap_by_gaddr - unmap a single segment via a guest address
+ * @gmap: pointer to the guest address space structure
+ * @gaddr: address in the guest address space
+ *
+ * Returns 1 if a TLB flush is required
+ */
+static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long vmaddr;
+
+ vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host,
+ gaddr >> PMD_SHIFT);
+ return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0;
+}
+
+/**
+ * gmap_unmap_segment - unmap segment from the guest address space
+ * @gmap: pointer to the guest address space structure
+ * @to: address in the guest address space
+ * @len: length of the memory area to unmap
+ *
+ * Returns 0 if the unmap succeeded, -EINVAL if not.
+ */
+int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
+{
+ unsigned long off;
+ int flush;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ if ((to | len) & (PMD_SIZE - 1))
+ return -EINVAL;
+ if (len == 0 || to + len < to)
+ return -EINVAL;
+
+ flush = 0;
+ down_write(&gmap->mm->mmap_sem);
+ for (off = 0; off < len; off += PMD_SIZE)
+ flush |= __gmap_unmap_by_gaddr(gmap, to + off);
+ up_write(&gmap->mm->mmap_sem);
+ if (flush)
+ gmap_flush_tlb(gmap);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gmap_unmap_segment);
+
+/**
+ * gmap_map_segment - map a segment to the guest address space
+ * @gmap: pointer to the guest address space structure
+ * @from: source address in the parent address space
+ * @to: target address in the guest address space
+ * @len: length of the memory area to map
+ *
+ * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not.
+ */
+int gmap_map_segment(struct gmap *gmap, unsigned long from,
+ unsigned long to, unsigned long len)
+{
+ unsigned long off;
+ int flush;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ if ((from | to | len) & (PMD_SIZE - 1))
+ return -EINVAL;
+ if (len == 0 || from + len < from || to + len < to ||
+ from + len - 1 > TASK_SIZE_MAX || to + len - 1 > gmap->asce_end)
+ return -EINVAL;
+
+ flush = 0;
+ down_write(&gmap->mm->mmap_sem);
+ for (off = 0; off < len; off += PMD_SIZE) {
+ /* Remove old translation */
+ flush |= __gmap_unmap_by_gaddr(gmap, to + off);
+ /* Store new translation */
+ if (radix_tree_insert(&gmap->guest_to_host,
+ (to + off) >> PMD_SHIFT,
+ (void *) from + off))
+ break;
+ }
+ up_write(&gmap->mm->mmap_sem);
+ if (flush)
+ gmap_flush_tlb(gmap);
+ if (off >= len)
+ return 0;
+ gmap_unmap_segment(gmap, to, len);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(gmap_map_segment);
+
+/**
+ * __gmap_translate - translate a guest address to a user space address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ *
+ * Returns user space address which corresponds to the guest address or
+ * -EFAULT if no such mapping exists.
+ * This function does not establish potentially missing page table entries.
+ * The mmap_sem of the mm that belongs to the address space must be held
+ * when this function gets called.
+ *
+ * Note: Can also be called for shadow gmaps.
+ */
+unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long vmaddr;
+
+ vmaddr = (unsigned long)
+ radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT);
+ /* Note: guest_to_host is empty for a shadow gmap */
+ return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT;
+}
+EXPORT_SYMBOL_GPL(__gmap_translate);
+
+/**
+ * gmap_translate - translate a guest address to a user space address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ *
+ * Returns user space address which corresponds to the guest address or
+ * -EFAULT if no such mapping exists.
+ * This function does not establish potentially missing page table entries.
+ */
+unsigned long gmap_translate(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long rc;
+
+ down_read(&gmap->mm->mmap_sem);
+ rc = __gmap_translate(gmap, gaddr);
+ up_read(&gmap->mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_translate);
+
+/**
+ * gmap_unlink - disconnect a page table from the gmap shadow tables
+ * @gmap: pointer to guest mapping meta data structure
+ * @table: pointer to the host page table
+ * @vmaddr: vm address associated with the host page table
+ */
+void gmap_unlink(struct mm_struct *mm, unsigned long *table,
+ unsigned long vmaddr)
+{
+ struct gmap *gmap;
+ int flush;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ flush = __gmap_unlink_by_vmaddr(gmap, vmaddr);
+ if (flush)
+ gmap_flush_tlb(gmap);
+ }
+ rcu_read_unlock();
+}
+
+static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *old, pmd_t new,
+ unsigned long gaddr);
+
+/**
+ * gmap_link - set up shadow page tables to connect a host to a guest address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ * @vmaddr: vm address
+ *
+ * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
+ * if the vm address is already mapped to a different guest segment.
+ * The mmap_sem of the mm that belongs to the address space must be held
+ * when this function gets called.
+ */
+int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
+{
+ struct mm_struct *mm;
+ unsigned long *table;
+ spinlock_t *ptl;
+ pgd_t *pgd;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ u64 unprot;
+ int rc;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ /* Create higher level tables in the gmap page table */
+ table = gmap->table;
+ if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
+ table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
+ if ((*table & _REGION_ENTRY_INVALID) &&
+ gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
+ gaddr & _REGION1_MASK))
+ return -ENOMEM;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ }
+ if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
+ table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
+ if ((*table & _REGION_ENTRY_INVALID) &&
+ gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
+ gaddr & _REGION2_MASK))
+ return -ENOMEM;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ }
+ if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
+ table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
+ if ((*table & _REGION_ENTRY_INVALID) &&
+ gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
+ gaddr & _REGION3_MASK))
+ return -ENOMEM;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ }
+ table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
+ /* Walk the parent mm page table */
+ mm = gmap->mm;
+ pgd = pgd_offset(mm, vmaddr);
+ VM_BUG_ON(pgd_none(*pgd));
+ p4d = p4d_offset(pgd, vmaddr);
+ VM_BUG_ON(p4d_none(*p4d));
+ pud = pud_offset(p4d, vmaddr);
+ VM_BUG_ON(pud_none(*pud));
+ /* large puds cannot yet be handled */
+ if (pud_large(*pud))
+ return -EFAULT;
+ pmd = pmd_offset(pud, vmaddr);
+ VM_BUG_ON(pmd_none(*pmd));
+ /* Are we allowed to use huge pages? */
+ if (pmd_large(*pmd) && !gmap->mm->context.allow_gmap_hpage_1m)
+ return -EFAULT;
+ /* Link gmap segment table entry location to page table. */
+ rc = radix_tree_preload(GFP_KERNEL);
+ if (rc)
+ return rc;
+ ptl = pmd_lock(mm, pmd);
+ spin_lock(&gmap->guest_table_lock);
+ if (*table == _SEGMENT_ENTRY_EMPTY) {
+ rc = radix_tree_insert(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT, table);
+ if (!rc) {
+ if (pmd_large(*pmd)) {
+ *table = (pmd_val(*pmd) &
+ _SEGMENT_ENTRY_HARDWARE_BITS_LARGE)
+ | _SEGMENT_ENTRY_GMAP_UC;
+ } else
+ *table = pmd_val(*pmd) &
+ _SEGMENT_ENTRY_HARDWARE_BITS;
+ }
+ } else if (*table & _SEGMENT_ENTRY_PROTECT &&
+ !(pmd_val(*pmd) & _SEGMENT_ENTRY_PROTECT)) {
+ unprot = (u64)*table;
+ unprot &= ~_SEGMENT_ENTRY_PROTECT;
+ unprot |= _SEGMENT_ENTRY_GMAP_UC;
+ gmap_pmdp_xchg(gmap, (pmd_t *)table, __pmd(unprot), gaddr);
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ spin_unlock(ptl);
+ radix_tree_preload_end();
+ return rc;
+}
+
+/**
+ * gmap_fault - resolve a fault on a guest address
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: guest address
+ * @fault_flags: flags to pass down to handle_mm_fault()
+ *
+ * Returns 0 on success, -ENOMEM for out of memory conditions, and -EFAULT
+ * if the vm address is already mapped to a different guest segment.
+ */
+int gmap_fault(struct gmap *gmap, unsigned long gaddr,
+ unsigned int fault_flags)
+{
+ unsigned long vmaddr;
+ int rc;
+ bool unlocked;
+
+ down_read(&gmap->mm->mmap_sem);
+
+retry:
+ unlocked = false;
+ vmaddr = __gmap_translate(gmap, gaddr);
+ if (IS_ERR_VALUE(vmaddr)) {
+ rc = vmaddr;
+ goto out_up;
+ }
+ if (fixup_user_fault(current, gmap->mm, vmaddr, fault_flags,
+ &unlocked)) {
+ rc = -EFAULT;
+ goto out_up;
+ }
+ /*
+ * In the case that fixup_user_fault unlocked the mmap_sem during
+ * faultin redo __gmap_translate to not race with a map/unmap_segment.
+ */
+ if (unlocked)
+ goto retry;
+
+ rc = __gmap_link(gmap, gaddr, vmaddr);
+out_up:
+ up_read(&gmap->mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_fault);
+
+/*
+ * this function is assumed to be called with mmap_sem held
+ */
+void __gmap_zap(struct gmap *gmap, unsigned long gaddr)
+{
+ unsigned long vmaddr;
+ spinlock_t *ptl;
+ pte_t *ptep;
+
+ /* Find the vm address for the guest address */
+ vmaddr = (unsigned long) radix_tree_lookup(&gmap->guest_to_host,
+ gaddr >> PMD_SHIFT);
+ if (vmaddr) {
+ vmaddr |= gaddr & ~PMD_MASK;
+ /* Get pointer to the page table entry */
+ ptep = get_locked_pte(gmap->mm, vmaddr, &ptl);
+ if (likely(ptep))
+ ptep_zap_unused(gmap->mm, vmaddr, ptep, 0);
+ pte_unmap_unlock(ptep, ptl);
+ }
+}
+EXPORT_SYMBOL_GPL(__gmap_zap);
+
+void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
+{
+ unsigned long gaddr, vmaddr, size;
+ struct vm_area_struct *vma;
+
+ down_read(&gmap->mm->mmap_sem);
+ for (gaddr = from; gaddr < to;
+ gaddr = (gaddr + PMD_SIZE) & PMD_MASK) {
+ /* Find the vm address for the guest address */
+ vmaddr = (unsigned long)
+ radix_tree_lookup(&gmap->guest_to_host,
+ gaddr >> PMD_SHIFT);
+ if (!vmaddr)
+ continue;
+ vmaddr |= gaddr & ~PMD_MASK;
+ /* Find vma in the parent mm */
+ vma = find_vma(gmap->mm, vmaddr);
+ if (!vma)
+ continue;
+ /*
+ * We do not discard pages that are backed by
+ * hugetlbfs, so we don't have to refault them.
+ */
+ if (is_vm_hugetlb_page(vma))
+ continue;
+ size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
+ zap_page_range(vma, vmaddr, size);
+ }
+ up_read(&gmap->mm->mmap_sem);
+}
+EXPORT_SYMBOL_GPL(gmap_discard);
+
+static LIST_HEAD(gmap_notifier_list);
+static DEFINE_SPINLOCK(gmap_notifier_lock);
+
+/**
+ * gmap_register_pte_notifier - register a pte invalidation callback
+ * @nb: pointer to the gmap notifier block
+ */
+void gmap_register_pte_notifier(struct gmap_notifier *nb)
+{
+ spin_lock(&gmap_notifier_lock);
+ list_add_rcu(&nb->list, &gmap_notifier_list);
+ spin_unlock(&gmap_notifier_lock);
+}
+EXPORT_SYMBOL_GPL(gmap_register_pte_notifier);
+
+/**
+ * gmap_unregister_pte_notifier - remove a pte invalidation callback
+ * @nb: pointer to the gmap notifier block
+ */
+void gmap_unregister_pte_notifier(struct gmap_notifier *nb)
+{
+ spin_lock(&gmap_notifier_lock);
+ list_del_rcu(&nb->list);
+ spin_unlock(&gmap_notifier_lock);
+ synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(gmap_unregister_pte_notifier);
+
+/**
+ * gmap_call_notifier - call all registered invalidation callbacks
+ * @gmap: pointer to guest mapping meta data structure
+ * @start: start virtual address in the guest address space
+ * @end: end virtual address in the guest address space
+ */
+static void gmap_call_notifier(struct gmap *gmap, unsigned long start,
+ unsigned long end)
+{
+ struct gmap_notifier *nb;
+
+ list_for_each_entry(nb, &gmap_notifier_list, list)
+ nb->notifier_call(gmap, start, end);
+}
+
+/**
+ * gmap_table_walk - walk the gmap page tables
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @level: page table level to stop at
+ *
+ * Returns a table entry pointer for the given guest address and @level
+ * @level=0 : returns a pointer to a page table table entry (or NULL)
+ * @level=1 : returns a pointer to a segment table entry (or NULL)
+ * @level=2 : returns a pointer to a region-3 table entry (or NULL)
+ * @level=3 : returns a pointer to a region-2 table entry (or NULL)
+ * @level=4 : returns a pointer to a region-1 table entry (or NULL)
+ *
+ * Returns NULL if the gmap page tables could not be walked to the
+ * requested level.
+ *
+ * Note: Can also be called for shadow gmaps.
+ */
+static inline unsigned long *gmap_table_walk(struct gmap *gmap,
+ unsigned long gaddr, int level)
+{
+ unsigned long *table;
+
+ if ((gmap->asce & _ASCE_TYPE_MASK) + 4 < (level * 4))
+ return NULL;
+ if (gmap_is_shadow(gmap) && gmap->removed)
+ return NULL;
+ if (gaddr & (-1UL << (31 + ((gmap->asce & _ASCE_TYPE_MASK) >> 2)*11)))
+ return NULL;
+ table = gmap->table;
+ switch (gmap->asce & _ASCE_TYPE_MASK) {
+ case _ASCE_TYPE_REGION1:
+ table += (gaddr & _REGION1_INDEX) >> _REGION1_SHIFT;
+ if (level == 4)
+ break;
+ if (*table & _REGION_ENTRY_INVALID)
+ return NULL;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ /* Fallthrough */
+ case _ASCE_TYPE_REGION2:
+ table += (gaddr & _REGION2_INDEX) >> _REGION2_SHIFT;
+ if (level == 3)
+ break;
+ if (*table & _REGION_ENTRY_INVALID)
+ return NULL;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ /* Fallthrough */
+ case _ASCE_TYPE_REGION3:
+ table += (gaddr & _REGION3_INDEX) >> _REGION3_SHIFT;
+ if (level == 2)
+ break;
+ if (*table & _REGION_ENTRY_INVALID)
+ return NULL;
+ table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+ /* Fallthrough */
+ case _ASCE_TYPE_SEGMENT:
+ table += (gaddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT;
+ if (level == 1)
+ break;
+ if (*table & _REGION_ENTRY_INVALID)
+ return NULL;
+ table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN);
+ table += (gaddr & _PAGE_INDEX) >> _PAGE_SHIFT;
+ }
+ return table;
+}
+
+/**
+ * gmap_pte_op_walk - walk the gmap page table, get the page table lock
+ * and return the pte pointer
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @ptl: pointer to the spinlock pointer
+ *
+ * Returns a pointer to the locked pte for a guest address, or NULL
+ */
+static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr,
+ spinlock_t **ptl)
+{
+ unsigned long *table;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ /* Walk the gmap page table, lock and get pte pointer */
+ table = gmap_table_walk(gmap, gaddr, 1); /* get segment pointer */
+ if (!table || *table & _SEGMENT_ENTRY_INVALID)
+ return NULL;
+ return pte_alloc_map_lock(gmap->mm, (pmd_t *) table, gaddr, ptl);
+}
+
+/**
+ * gmap_pte_op_fixup - force a page in and connect the gmap page table
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @vmaddr: address in the host process address space
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ *
+ * Returns 0 if the caller can retry __gmap_translate (might fail again),
+ * -ENOMEM if out of memory and -EFAULT if anything goes wrong while fixing
+ * up or connecting the gmap page table.
+ */
+static int gmap_pte_op_fixup(struct gmap *gmap, unsigned long gaddr,
+ unsigned long vmaddr, int prot)
+{
+ struct mm_struct *mm = gmap->mm;
+ unsigned int fault_flags;
+ bool unlocked = false;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ fault_flags = (prot == PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
+ if (fixup_user_fault(current, mm, vmaddr, fault_flags, &unlocked))
+ return -EFAULT;
+ if (unlocked)
+ /* lost mmap_sem, caller has to retry __gmap_translate */
+ return 0;
+ /* Connect the page tables */
+ return __gmap_link(gmap, gaddr, vmaddr);
+}
+
+/**
+ * gmap_pte_op_end - release the page table lock
+ * @ptl: pointer to the spinlock pointer
+ */
+static void gmap_pte_op_end(spinlock_t *ptl)
+{
+ if (ptl)
+ spin_unlock(ptl);
+}
+
+/**
+ * gmap_pmd_op_walk - walk the gmap tables, get the guest table lock
+ * and return the pmd pointer
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ *
+ * Returns a pointer to the pmd for a guest address, or NULL
+ */
+static inline pmd_t *gmap_pmd_op_walk(struct gmap *gmap, unsigned long gaddr)
+{
+ pmd_t *pmdp;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ spin_lock(&gmap->guest_table_lock);
+ pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1);
+
+ if (!pmdp || pmd_none(*pmdp)) {
+ spin_unlock(&gmap->guest_table_lock);
+ return NULL;
+ }
+
+ /* 4k page table entries are locked via the pte (pte_alloc_map_lock). */
+ if (!pmd_large(*pmdp))
+ spin_unlock(&gmap->guest_table_lock);
+ return pmdp;
+}
+
+/**
+ * gmap_pmd_op_end - release the guest_table_lock if needed
+ * @gmap: pointer to the guest mapping meta data structure
+ * @pmdp: pointer to the pmd
+ */
+static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp)
+{
+ if (pmd_large(*pmdp))
+ spin_unlock(&gmap->guest_table_lock);
+}
+
+/*
+ * gmap_protect_pmd - remove access rights to memory and set pmd notification bits
+ * @pmdp: pointer to the pmd to be protected
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bits: notification bits to set
+ *
+ * Returns:
+ * 0 if successfully protected
+ * -EAGAIN if a fixup is needed
+ * -EINVAL if unsupported notifier bits have been specified
+ *
+ * Expected to be called with sg->mm->mmap_sem in read and
+ * guest_table_lock held.
+ */
+static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr,
+ pmd_t *pmdp, int prot, unsigned long bits)
+{
+ int pmd_i = pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID;
+ int pmd_p = pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT;
+ pmd_t new = *pmdp;
+
+ /* Fixup needed */
+ if ((pmd_i && (prot != PROT_NONE)) || (pmd_p && (prot == PROT_WRITE)))
+ return -EAGAIN;
+
+ if (prot == PROT_NONE && !pmd_i) {
+ pmd_val(new) |= _SEGMENT_ENTRY_INVALID;
+ gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
+ }
+
+ if (prot == PROT_READ && !pmd_p) {
+ pmd_val(new) &= ~_SEGMENT_ENTRY_INVALID;
+ pmd_val(new) |= _SEGMENT_ENTRY_PROTECT;
+ gmap_pmdp_xchg(gmap, pmdp, new, gaddr);
+ }
+
+ if (bits & GMAP_NOTIFY_MPROT)
+ pmd_val(*pmdp) |= _SEGMENT_ENTRY_GMAP_IN;
+
+ /* Shadow GMAP protection needs split PMDs */
+ if (bits & GMAP_NOTIFY_SHADOW)
+ return -EINVAL;
+
+ return 0;
+}
+
+/*
+ * gmap_protect_pte - remove access rights to memory and set pgste bits
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @pmdp: pointer to the pmd associated with the pte
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bits: notification bits to set
+ *
+ * Returns 0 if successfully protected, -ENOMEM if out of memory and
+ * -EAGAIN if a fixup is needed.
+ *
+ * Expected to be called with sg->mm->mmap_sem in read
+ */
+static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
+ pmd_t *pmdp, int prot, unsigned long bits)
+{
+ int rc;
+ pte_t *ptep;
+ spinlock_t *ptl = NULL;
+ unsigned long pbits = 0;
+
+ if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
+ return -EAGAIN;
+
+ ptep = pte_alloc_map_lock(gmap->mm, pmdp, gaddr, &ptl);
+ if (!ptep)
+ return -ENOMEM;
+
+ pbits |= (bits & GMAP_NOTIFY_MPROT) ? PGSTE_IN_BIT : 0;
+ pbits |= (bits & GMAP_NOTIFY_SHADOW) ? PGSTE_VSIE_BIT : 0;
+ /* Protect and unlock. */
+ rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, pbits);
+ gmap_pte_op_end(ptl);
+ return rc;
+}
+
+/*
+ * gmap_protect_range - remove access rights to memory and set pgste bits
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @len: size of area
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bits: pgste notification bits to set
+ *
+ * Returns 0 if successfully protected, -ENOMEM if out of memory and
+ * -EFAULT if gaddr is invalid (or mapping for shadows is missing).
+ *
+ * Called with sg->mm->mmap_sem in read.
+ */
+static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
+ unsigned long len, int prot, unsigned long bits)
+{
+ unsigned long vmaddr, dist;
+ pmd_t *pmdp;
+ int rc;
+
+ BUG_ON(gmap_is_shadow(gmap));
+ while (len) {
+ rc = -EAGAIN;
+ pmdp = gmap_pmd_op_walk(gmap, gaddr);
+ if (pmdp) {
+ if (!pmd_large(*pmdp)) {
+ rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
+ bits);
+ if (!rc) {
+ len -= PAGE_SIZE;
+ gaddr += PAGE_SIZE;
+ }
+ } else {
+ rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot,
+ bits);
+ if (!rc) {
+ dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK);
+ len = len < dist ? 0 : len - dist;
+ gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE;
+ }
+ }
+ gmap_pmd_op_end(gmap, pmdp);
+ }
+ if (rc) {
+ if (rc == -EINVAL)
+ return rc;
+
+ /* -EAGAIN, fixup of userspace mm and gmap */
+ vmaddr = __gmap_translate(gmap, gaddr);
+ if (IS_ERR_VALUE(vmaddr))
+ return vmaddr;
+ rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, prot);
+ if (rc)
+ return rc;
+ }
+ }
+ return 0;
+}
+
+/**
+ * gmap_mprotect_notify - change access rights for a range of ptes and
+ * call the notifier if any pte changes again
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @len: size of area
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ *
+ * Returns 0 if for each page in the given range a gmap mapping exists,
+ * the new access rights could be set and the notifier could be armed.
+ * If the gmap mapping is missing for one or more pages -EFAULT is
+ * returned. If no memory could be allocated -ENOMEM is returned.
+ * This function establishes missing page table entries.
+ */
+int gmap_mprotect_notify(struct gmap *gmap, unsigned long gaddr,
+ unsigned long len, int prot)
+{
+ int rc;
+
+ if ((gaddr & ~PAGE_MASK) || (len & ~PAGE_MASK) || gmap_is_shadow(gmap))
+ return -EINVAL;
+ if (!MACHINE_HAS_ESOP && prot == PROT_READ)
+ return -EINVAL;
+ down_read(&gmap->mm->mmap_sem);
+ rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT);
+ up_read(&gmap->mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_mprotect_notify);
+
+/**
+ * gmap_read_table - get an unsigned long value from a guest page table using
+ * absolute addressing, without marking the page referenced.
+ * @gmap: pointer to guest mapping meta data structure
+ * @gaddr: virtual address in the guest address space
+ * @val: pointer to the unsigned long value to return
+ *
+ * Returns 0 if the value was read, -ENOMEM if out of memory and -EFAULT
+ * if reading using the virtual address failed. -EINVAL if called on a gmap
+ * shadow.
+ *
+ * Called with gmap->mm->mmap_sem in read.
+ */
+int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val)
+{
+ unsigned long address, vmaddr;
+ spinlock_t *ptl;
+ pte_t *ptep, pte;
+ int rc;
+
+ if (gmap_is_shadow(gmap))
+ return -EINVAL;
+
+ while (1) {
+ rc = -EAGAIN;
+ ptep = gmap_pte_op_walk(gmap, gaddr, &ptl);
+ if (ptep) {
+ pte = *ptep;
+ if (pte_present(pte) && (pte_val(pte) & _PAGE_READ)) {
+ address = pte_val(pte) & PAGE_MASK;
+ address += gaddr & ~PAGE_MASK;
+ *val = *(unsigned long *) address;
+ pte_val(*ptep) |= _PAGE_YOUNG;
+ /* Do *NOT* clear the _PAGE_INVALID bit! */
+ rc = 0;
+ }
+ gmap_pte_op_end(ptl);
+ }
+ if (!rc)
+ break;
+ vmaddr = __gmap_translate(gmap, gaddr);
+ if (IS_ERR_VALUE(vmaddr)) {
+ rc = vmaddr;
+ break;
+ }
+ rc = gmap_pte_op_fixup(gmap, gaddr, vmaddr, PROT_READ);
+ if (rc)
+ break;
+ }
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_read_table);
+
+/**
+ * gmap_insert_rmap - add a rmap to the host_to_rmap radix tree
+ * @sg: pointer to the shadow guest address space structure
+ * @vmaddr: vm address associated with the rmap
+ * @rmap: pointer to the rmap structure
+ *
+ * Called with the sg->guest_table_lock
+ */
+static inline void gmap_insert_rmap(struct gmap *sg, unsigned long vmaddr,
+ struct gmap_rmap *rmap)
+{
+ void __rcu **slot;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ slot = radix_tree_lookup_slot(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
+ if (slot) {
+ rmap->next = radix_tree_deref_slot_protected(slot,
+ &sg->guest_table_lock);
+ radix_tree_replace_slot(&sg->host_to_rmap, slot, rmap);
+ } else {
+ rmap->next = NULL;
+ radix_tree_insert(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT,
+ rmap);
+ }
+}
+
+/**
+ * gmap_protect_rmap - restrict access rights to memory (RO) and create an rmap
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow gmap
+ * @paddr: address in the parent guest address space
+ * @len: length of the memory area to protect
+ *
+ * Returns 0 if successfully protected and the rmap was created, -ENOMEM
+ * if out of memory and -EFAULT if paddr is invalid.
+ */
+static int gmap_protect_rmap(struct gmap *sg, unsigned long raddr,
+ unsigned long paddr, unsigned long len)
+{
+ struct gmap *parent;
+ struct gmap_rmap *rmap;
+ unsigned long vmaddr;
+ spinlock_t *ptl;
+ pte_t *ptep;
+ int rc;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ parent = sg->parent;
+ while (len) {
+ vmaddr = __gmap_translate(parent, paddr);
+ if (IS_ERR_VALUE(vmaddr))
+ return vmaddr;
+ rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
+ if (!rmap)
+ return -ENOMEM;
+ rmap->raddr = raddr;
+ rc = radix_tree_preload(GFP_KERNEL);
+ if (rc) {
+ kfree(rmap);
+ return rc;
+ }
+ rc = -EAGAIN;
+ ptep = gmap_pte_op_walk(parent, paddr, &ptl);
+ if (ptep) {
+ spin_lock(&sg->guest_table_lock);
+ rc = ptep_force_prot(parent->mm, paddr, ptep, PROT_READ,
+ PGSTE_VSIE_BIT);
+ if (!rc)
+ gmap_insert_rmap(sg, vmaddr, rmap);
+ spin_unlock(&sg->guest_table_lock);
+ gmap_pte_op_end(ptl);
+ }
+ radix_tree_preload_end();
+ if (rc) {
+ kfree(rmap);
+ rc = gmap_pte_op_fixup(parent, paddr, vmaddr, PROT_READ);
+ if (rc)
+ return rc;
+ continue;
+ }
+ paddr += PAGE_SIZE;
+ len -= PAGE_SIZE;
+ }
+ return 0;
+}
+
+#define _SHADOW_RMAP_MASK 0x7
+#define _SHADOW_RMAP_REGION1 0x5
+#define _SHADOW_RMAP_REGION2 0x4
+#define _SHADOW_RMAP_REGION3 0x3
+#define _SHADOW_RMAP_SEGMENT 0x2
+#define _SHADOW_RMAP_PGTABLE 0x1
+
+/**
+ * gmap_idte_one - invalidate a single region or segment table entry
+ * @asce: region or segment table *origin* + table-type bits
+ * @vaddr: virtual address to identify the table entry to flush
+ *
+ * The invalid bit of a single region or segment table entry is set
+ * and the associated TLB entries depending on the entry are flushed.
+ * The table-type of the @asce identifies the portion of the @vaddr
+ * that is used as the invalidation index.
+ */
+static inline void gmap_idte_one(unsigned long asce, unsigned long vaddr)
+{
+ asm volatile(
+ " .insn rrf,0xb98e0000,%0,%1,0,0"
+ : : "a" (asce), "a" (vaddr) : "cc", "memory");
+}
+
+/**
+ * gmap_unshadow_page - remove a page from a shadow page table
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void gmap_unshadow_page(struct gmap *sg, unsigned long raddr)
+{
+ unsigned long *table;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ table = gmap_table_walk(sg, raddr, 0); /* get page table pointer */
+ if (!table || *table & _PAGE_INVALID)
+ return;
+ gmap_call_notifier(sg, raddr, raddr + _PAGE_SIZE - 1);
+ ptep_unshadow_pte(sg->mm, raddr, (pte_t *) table);
+}
+
+/**
+ * __gmap_unshadow_pgt - remove all entries from a shadow page table
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ * @pgt: pointer to the start of a shadow page table
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void __gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr,
+ unsigned long *pgt)
+{
+ int i;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ for (i = 0; i < _PAGE_ENTRIES; i++, raddr += _PAGE_SIZE)
+ pgt[i] = _PAGE_INVALID;
+}
+
+/**
+ * gmap_unshadow_pgt - remove a shadow page table from a segment entry
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: address in the shadow guest address space
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void gmap_unshadow_pgt(struct gmap *sg, unsigned long raddr)
+{
+ unsigned long sto, *ste, *pgt;
+ struct page *page;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ ste = gmap_table_walk(sg, raddr, 1); /* get segment pointer */
+ if (!ste || !(*ste & _SEGMENT_ENTRY_ORIGIN))
+ return;
+ gmap_call_notifier(sg, raddr, raddr + _SEGMENT_SIZE - 1);
+ sto = (unsigned long) (ste - ((raddr & _SEGMENT_INDEX) >> _SEGMENT_SHIFT));
+ gmap_idte_one(sto | _ASCE_TYPE_SEGMENT, raddr);
+ pgt = (unsigned long *)(*ste & _SEGMENT_ENTRY_ORIGIN);
+ *ste = _SEGMENT_ENTRY_EMPTY;
+ __gmap_unshadow_pgt(sg, raddr, pgt);
+ /* Free page table */
+ page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ page_table_free_pgste(page);
+}
+
+/**
+ * __gmap_unshadow_sgt - remove all entries from a shadow segment table
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ * @sgt: pointer to the start of a shadow segment table
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void __gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr,
+ unsigned long *sgt)
+{
+ unsigned long *pgt;
+ struct page *page;
+ int i;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ for (i = 0; i < _CRST_ENTRIES; i++, raddr += _SEGMENT_SIZE) {
+ if (!(sgt[i] & _SEGMENT_ENTRY_ORIGIN))
+ continue;
+ pgt = (unsigned long *)(sgt[i] & _REGION_ENTRY_ORIGIN);
+ sgt[i] = _SEGMENT_ENTRY_EMPTY;
+ __gmap_unshadow_pgt(sg, raddr, pgt);
+ /* Free page table */
+ page = pfn_to_page(__pa(pgt) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ page_table_free_pgste(page);
+ }
+}
+
+/**
+ * gmap_unshadow_sgt - remove a shadow segment table from a region-3 entry
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ *
+ * Called with the shadow->guest_table_lock
+ */
+static void gmap_unshadow_sgt(struct gmap *sg, unsigned long raddr)
+{
+ unsigned long r3o, *r3e, *sgt;
+ struct page *page;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ r3e = gmap_table_walk(sg, raddr, 2); /* get region-3 pointer */
+ if (!r3e || !(*r3e & _REGION_ENTRY_ORIGIN))
+ return;
+ gmap_call_notifier(sg, raddr, raddr + _REGION3_SIZE - 1);
+ r3o = (unsigned long) (r3e - ((raddr & _REGION3_INDEX) >> _REGION3_SHIFT));
+ gmap_idte_one(r3o | _ASCE_TYPE_REGION3, raddr);
+ sgt = (unsigned long *)(*r3e & _REGION_ENTRY_ORIGIN);
+ *r3e = _REGION3_ENTRY_EMPTY;
+ __gmap_unshadow_sgt(sg, raddr, sgt);
+ /* Free segment table */
+ page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ __free_pages(page, CRST_ALLOC_ORDER);
+}
+
+/**
+ * __gmap_unshadow_r3t - remove all entries from a shadow region-3 table
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: address in the shadow guest address space
+ * @r3t: pointer to the start of a shadow region-3 table
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void __gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr,
+ unsigned long *r3t)
+{
+ unsigned long *sgt;
+ struct page *page;
+ int i;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION3_SIZE) {
+ if (!(r3t[i] & _REGION_ENTRY_ORIGIN))
+ continue;
+ sgt = (unsigned long *)(r3t[i] & _REGION_ENTRY_ORIGIN);
+ r3t[i] = _REGION3_ENTRY_EMPTY;
+ __gmap_unshadow_sgt(sg, raddr, sgt);
+ /* Free segment table */
+ page = pfn_to_page(__pa(sgt) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+}
+
+/**
+ * gmap_unshadow_r3t - remove a shadow region-3 table from a region-2 entry
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void gmap_unshadow_r3t(struct gmap *sg, unsigned long raddr)
+{
+ unsigned long r2o, *r2e, *r3t;
+ struct page *page;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ r2e = gmap_table_walk(sg, raddr, 3); /* get region-2 pointer */
+ if (!r2e || !(*r2e & _REGION_ENTRY_ORIGIN))
+ return;
+ gmap_call_notifier(sg, raddr, raddr + _REGION2_SIZE - 1);
+ r2o = (unsigned long) (r2e - ((raddr & _REGION2_INDEX) >> _REGION2_SHIFT));
+ gmap_idte_one(r2o | _ASCE_TYPE_REGION2, raddr);
+ r3t = (unsigned long *)(*r2e & _REGION_ENTRY_ORIGIN);
+ *r2e = _REGION2_ENTRY_EMPTY;
+ __gmap_unshadow_r3t(sg, raddr, r3t);
+ /* Free region 3 table */
+ page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ __free_pages(page, CRST_ALLOC_ORDER);
+}
+
+/**
+ * __gmap_unshadow_r2t - remove all entries from a shadow region-2 table
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ * @r2t: pointer to the start of a shadow region-2 table
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void __gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr,
+ unsigned long *r2t)
+{
+ unsigned long *r3t;
+ struct page *page;
+ int i;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION2_SIZE) {
+ if (!(r2t[i] & _REGION_ENTRY_ORIGIN))
+ continue;
+ r3t = (unsigned long *)(r2t[i] & _REGION_ENTRY_ORIGIN);
+ r2t[i] = _REGION2_ENTRY_EMPTY;
+ __gmap_unshadow_r3t(sg, raddr, r3t);
+ /* Free region 3 table */
+ page = pfn_to_page(__pa(r3t) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+}
+
+/**
+ * gmap_unshadow_r2t - remove a shadow region-2 table from a region-1 entry
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ *
+ * Called with the sg->guest_table_lock
+ */
+static void gmap_unshadow_r2t(struct gmap *sg, unsigned long raddr)
+{
+ unsigned long r1o, *r1e, *r2t;
+ struct page *page;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ r1e = gmap_table_walk(sg, raddr, 4); /* get region-1 pointer */
+ if (!r1e || !(*r1e & _REGION_ENTRY_ORIGIN))
+ return;
+ gmap_call_notifier(sg, raddr, raddr + _REGION1_SIZE - 1);
+ r1o = (unsigned long) (r1e - ((raddr & _REGION1_INDEX) >> _REGION1_SHIFT));
+ gmap_idte_one(r1o | _ASCE_TYPE_REGION1, raddr);
+ r2t = (unsigned long *)(*r1e & _REGION_ENTRY_ORIGIN);
+ *r1e = _REGION1_ENTRY_EMPTY;
+ __gmap_unshadow_r2t(sg, raddr, r2t);
+ /* Free region 2 table */
+ page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ __free_pages(page, CRST_ALLOC_ORDER);
+}
+
+/**
+ * __gmap_unshadow_r1t - remove all entries from a shadow region-1 table
+ * @sg: pointer to the shadow guest address space structure
+ * @raddr: rmap address in the shadow guest address space
+ * @r1t: pointer to the start of a shadow region-1 table
+ *
+ * Called with the shadow->guest_table_lock
+ */
+static void __gmap_unshadow_r1t(struct gmap *sg, unsigned long raddr,
+ unsigned long *r1t)
+{
+ unsigned long asce, *r2t;
+ struct page *page;
+ int i;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ asce = (unsigned long) r1t | _ASCE_TYPE_REGION1;
+ for (i = 0; i < _CRST_ENTRIES; i++, raddr += _REGION1_SIZE) {
+ if (!(r1t[i] & _REGION_ENTRY_ORIGIN))
+ continue;
+ r2t = (unsigned long *)(r1t[i] & _REGION_ENTRY_ORIGIN);
+ __gmap_unshadow_r2t(sg, raddr, r2t);
+ /* Clear entry and flush translation r1t -> r2t */
+ gmap_idte_one(asce, raddr);
+ r1t[i] = _REGION1_ENTRY_EMPTY;
+ /* Free region 2 table */
+ page = pfn_to_page(__pa(r2t) >> PAGE_SHIFT);
+ list_del(&page->lru);
+ __free_pages(page, CRST_ALLOC_ORDER);
+ }
+}
+
+/**
+ * gmap_unshadow - remove a shadow page table completely
+ * @sg: pointer to the shadow guest address space structure
+ *
+ * Called with sg->guest_table_lock
+ */
+static void gmap_unshadow(struct gmap *sg)
+{
+ unsigned long *table;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ if (sg->removed)
+ return;
+ sg->removed = 1;
+ gmap_call_notifier(sg, 0, -1UL);
+ gmap_flush_tlb(sg);
+ table = (unsigned long *)(sg->asce & _ASCE_ORIGIN);
+ switch (sg->asce & _ASCE_TYPE_MASK) {
+ case _ASCE_TYPE_REGION1:
+ __gmap_unshadow_r1t(sg, 0, table);
+ break;
+ case _ASCE_TYPE_REGION2:
+ __gmap_unshadow_r2t(sg, 0, table);
+ break;
+ case _ASCE_TYPE_REGION3:
+ __gmap_unshadow_r3t(sg, 0, table);
+ break;
+ case _ASCE_TYPE_SEGMENT:
+ __gmap_unshadow_sgt(sg, 0, table);
+ break;
+ }
+}
+
+/**
+ * gmap_find_shadow - find a specific asce in the list of shadow tables
+ * @parent: pointer to the parent gmap
+ * @asce: ASCE for which the shadow table is created
+ * @edat_level: edat level to be used for the shadow translation
+ *
+ * Returns the pointer to a gmap if a shadow table with the given asce is
+ * already available, ERR_PTR(-EAGAIN) if another one is just being created,
+ * otherwise NULL
+ */
+static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
+ int edat_level)
+{
+ struct gmap *sg;
+
+ list_for_each_entry(sg, &parent->children, list) {
+ if (sg->orig_asce != asce || sg->edat_level != edat_level ||
+ sg->removed)
+ continue;
+ if (!sg->initialized)
+ return ERR_PTR(-EAGAIN);
+ atomic_inc(&sg->ref_count);
+ return sg;
+ }
+ return NULL;
+}
+
+/**
+ * gmap_shadow_valid - check if a shadow guest address space matches the
+ * given properties and is still valid
+ * @sg: pointer to the shadow guest address space structure
+ * @asce: ASCE for which the shadow table is requested
+ * @edat_level: edat level to be used for the shadow translation
+ *
+ * Returns 1 if the gmap shadow is still valid and matches the given
+ * properties, the caller can continue using it. Returns 0 otherwise, the
+ * caller has to request a new shadow gmap in this case.
+ *
+ */
+int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level)
+{
+ if (sg->removed)
+ return 0;
+ return sg->orig_asce == asce && sg->edat_level == edat_level;
+}
+EXPORT_SYMBOL_GPL(gmap_shadow_valid);
+
+/**
+ * gmap_shadow - create/find a shadow guest address space
+ * @parent: pointer to the parent gmap
+ * @asce: ASCE for which the shadow table is created
+ * @edat_level: edat level to be used for the shadow translation
+ *
+ * The pages of the top level page table referred by the asce parameter
+ * will be set to read-only and marked in the PGSTEs of the kvm process.
+ * The shadow table will be removed automatically on any change to the
+ * PTE mapping for the source table.
+ *
+ * Returns a guest address space structure, ERR_PTR(-ENOMEM) if out of memory,
+ * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
+ * parent gmap table could not be protected.
+ */
+struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
+ int edat_level)
+{
+ struct gmap *sg, *new;
+ unsigned long limit;
+ int rc;
+
+ BUG_ON(parent->mm->context.allow_gmap_hpage_1m);
+ BUG_ON(gmap_is_shadow(parent));
+ spin_lock(&parent->shadow_lock);
+ sg = gmap_find_shadow(parent, asce, edat_level);
+ spin_unlock(&parent->shadow_lock);
+ if (sg)
+ return sg;
+ /* Create a new shadow gmap */
+ limit = -1UL >> (33 - (((asce & _ASCE_TYPE_MASK) >> 2) * 11));
+ if (asce & _ASCE_REAL_SPACE)
+ limit = -1UL;
+ new = gmap_alloc(limit);
+ if (!new)
+ return ERR_PTR(-ENOMEM);
+ new->mm = parent->mm;
+ new->parent = gmap_get(parent);
+ new->orig_asce = asce;
+ new->edat_level = edat_level;
+ new->initialized = false;
+ spin_lock(&parent->shadow_lock);
+ /* Recheck if another CPU created the same shadow */
+ sg = gmap_find_shadow(parent, asce, edat_level);
+ if (sg) {
+ spin_unlock(&parent->shadow_lock);
+ gmap_free(new);
+ return sg;
+ }
+ if (asce & _ASCE_REAL_SPACE) {
+ /* only allow one real-space gmap shadow */
+ list_for_each_entry(sg, &parent->children, list) {
+ if (sg->orig_asce & _ASCE_REAL_SPACE) {
+ spin_lock(&sg->guest_table_lock);
+ gmap_unshadow(sg);
+ spin_unlock(&sg->guest_table_lock);
+ list_del(&sg->list);
+ gmap_put(sg);
+ break;
+ }
+ }
+ }
+ atomic_set(&new->ref_count, 2);
+ list_add(&new->list, &parent->children);
+ if (asce & _ASCE_REAL_SPACE) {
+ /* nothing to protect, return right away */
+ new->initialized = true;
+ spin_unlock(&parent->shadow_lock);
+ return new;
+ }
+ spin_unlock(&parent->shadow_lock);
+ /* protect after insertion, so it will get properly invalidated */
+ down_read(&parent->mm->mmap_sem);
+ rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN,
+ ((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE,
+ PROT_READ, GMAP_NOTIFY_SHADOW);
+ up_read(&parent->mm->mmap_sem);
+ spin_lock(&parent->shadow_lock);
+ new->initialized = true;
+ if (rc) {
+ list_del(&new->list);
+ gmap_free(new);
+ new = ERR_PTR(rc);
+ }
+ spin_unlock(&parent->shadow_lock);
+ return new;
+}
+EXPORT_SYMBOL_GPL(gmap_shadow);
+
+/**
+ * gmap_shadow_r2t - create an empty shadow region 2 table
+ * @sg: pointer to the shadow guest address space structure
+ * @saddr: faulting address in the shadow gmap
+ * @r2t: parent gmap address of the region 2 table to get shadowed
+ * @fake: r2t references contiguous guest memory block, not a r2t
+ *
+ * The r2t parameter specifies the address of the source table. The
+ * four pages of the source table are made read-only in the parent gmap
+ * address space. A write to the source table area @r2t will automatically
+ * remove the shadow r2 table and all of its decendents.
+ *
+ * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
+ * shadow table structure is incomplete, -ENOMEM if out of memory and
+ * -EFAULT if an address in the parent gmap could not be resolved.
+ *
+ * Called with sg->mm->mmap_sem in read.
+ */
+int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
+ int fake)
+{
+ unsigned long raddr, origin, offset, len;
+ unsigned long *s_r2t, *table;
+ struct page *page;
+ int rc;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ /* Allocate a shadow region second table */
+ page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+ if (!page)
+ return -ENOMEM;
+ page->index = r2t & _REGION_ENTRY_ORIGIN;
+ if (fake)
+ page->index |= GMAP_SHADOW_FAKE_TABLE;
+ s_r2t = (unsigned long *) page_to_phys(page);
+ /* Install shadow region second table */
+ spin_lock(&sg->guest_table_lock);
+ table = gmap_table_walk(sg, saddr, 4); /* get region-1 pointer */
+ if (!table) {
+ rc = -EAGAIN; /* Race with unshadow */
+ goto out_free;
+ }
+ if (!(*table & _REGION_ENTRY_INVALID)) {
+ rc = 0; /* Already established */
+ goto out_free;
+ } else if (*table & _REGION_ENTRY_ORIGIN) {
+ rc = -EAGAIN; /* Race with shadow */
+ goto out_free;
+ }
+ crst_table_init(s_r2t, _REGION2_ENTRY_EMPTY);
+ /* mark as invalid as long as the parent table is not protected */
+ *table = (unsigned long) s_r2t | _REGION_ENTRY_LENGTH |
+ _REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID;
+ if (sg->edat_level >= 1)
+ *table |= (r2t & _REGION_ENTRY_PROTECT);
+ list_add(&page->lru, &sg->crst_list);
+ if (fake) {
+ /* nothing to protect for fake tables */
+ *table &= ~_REGION_ENTRY_INVALID;
+ spin_unlock(&sg->guest_table_lock);
+ return 0;
+ }
+ spin_unlock(&sg->guest_table_lock);
+ /* Make r2t read-only in parent gmap page table */
+ raddr = (saddr & _REGION1_MASK) | _SHADOW_RMAP_REGION1;
+ origin = r2t & _REGION_ENTRY_ORIGIN;
+ offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
+ len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
+ rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
+ spin_lock(&sg->guest_table_lock);
+ if (!rc) {
+ table = gmap_table_walk(sg, saddr, 4);
+ if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
+ (unsigned long) s_r2t)
+ rc = -EAGAIN; /* Race with unshadow */
+ else
+ *table &= ~_REGION_ENTRY_INVALID;
+ } else {
+ gmap_unshadow_r2t(sg, raddr);
+ }
+ spin_unlock(&sg->guest_table_lock);
+ return rc;
+out_free:
+ spin_unlock(&sg->guest_table_lock);
+ __free_pages(page, CRST_ALLOC_ORDER);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_shadow_r2t);
+
+/**
+ * gmap_shadow_r3t - create a shadow region 3 table
+ * @sg: pointer to the shadow guest address space structure
+ * @saddr: faulting address in the shadow gmap
+ * @r3t: parent gmap address of the region 3 table to get shadowed
+ * @fake: r3t references contiguous guest memory block, not a r3t
+ *
+ * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
+ * shadow table structure is incomplete, -ENOMEM if out of memory and
+ * -EFAULT if an address in the parent gmap could not be resolved.
+ *
+ * Called with sg->mm->mmap_sem in read.
+ */
+int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
+ int fake)
+{
+ unsigned long raddr, origin, offset, len;
+ unsigned long *s_r3t, *table;
+ struct page *page;
+ int rc;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ /* Allocate a shadow region second table */
+ page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+ if (!page)
+ return -ENOMEM;
+ page->index = r3t & _REGION_ENTRY_ORIGIN;
+ if (fake)
+ page->index |= GMAP_SHADOW_FAKE_TABLE;
+ s_r3t = (unsigned long *) page_to_phys(page);
+ /* Install shadow region second table */
+ spin_lock(&sg->guest_table_lock);
+ table = gmap_table_walk(sg, saddr, 3); /* get region-2 pointer */
+ if (!table) {
+ rc = -EAGAIN; /* Race with unshadow */
+ goto out_free;
+ }
+ if (!(*table & _REGION_ENTRY_INVALID)) {
+ rc = 0; /* Already established */
+ goto out_free;
+ } else if (*table & _REGION_ENTRY_ORIGIN) {
+ rc = -EAGAIN; /* Race with shadow */
+ }
+ crst_table_init(s_r3t, _REGION3_ENTRY_EMPTY);
+ /* mark as invalid as long as the parent table is not protected */
+ *table = (unsigned long) s_r3t | _REGION_ENTRY_LENGTH |
+ _REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID;
+ if (sg->edat_level >= 1)
+ *table |= (r3t & _REGION_ENTRY_PROTECT);
+ list_add(&page->lru, &sg->crst_list);
+ if (fake) {
+ /* nothing to protect for fake tables */
+ *table &= ~_REGION_ENTRY_INVALID;
+ spin_unlock(&sg->guest_table_lock);
+ return 0;
+ }
+ spin_unlock(&sg->guest_table_lock);
+ /* Make r3t read-only in parent gmap page table */
+ raddr = (saddr & _REGION2_MASK) | _SHADOW_RMAP_REGION2;
+ origin = r3t & _REGION_ENTRY_ORIGIN;
+ offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
+ len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
+ rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
+ spin_lock(&sg->guest_table_lock);
+ if (!rc) {
+ table = gmap_table_walk(sg, saddr, 3);
+ if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
+ (unsigned long) s_r3t)
+ rc = -EAGAIN; /* Race with unshadow */
+ else
+ *table &= ~_REGION_ENTRY_INVALID;
+ } else {
+ gmap_unshadow_r3t(sg, raddr);
+ }
+ spin_unlock(&sg->guest_table_lock);
+ return rc;
+out_free:
+ spin_unlock(&sg->guest_table_lock);
+ __free_pages(page, CRST_ALLOC_ORDER);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_shadow_r3t);
+
+/**
+ * gmap_shadow_sgt - create a shadow segment table
+ * @sg: pointer to the shadow guest address space structure
+ * @saddr: faulting address in the shadow gmap
+ * @sgt: parent gmap address of the segment table to get shadowed
+ * @fake: sgt references contiguous guest memory block, not a sgt
+ *
+ * Returns: 0 if successfully shadowed or already shadowed, -EAGAIN if the
+ * shadow table structure is incomplete, -ENOMEM if out of memory and
+ * -EFAULT if an address in the parent gmap could not be resolved.
+ *
+ * Called with sg->mm->mmap_sem in read.
+ */
+int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
+ int fake)
+{
+ unsigned long raddr, origin, offset, len;
+ unsigned long *s_sgt, *table;
+ struct page *page;
+ int rc;
+
+ BUG_ON(!gmap_is_shadow(sg) || (sgt & _REGION3_ENTRY_LARGE));
+ /* Allocate a shadow segment table */
+ page = alloc_pages(GFP_KERNEL, CRST_ALLOC_ORDER);
+ if (!page)
+ return -ENOMEM;
+ page->index = sgt & _REGION_ENTRY_ORIGIN;
+ if (fake)
+ page->index |= GMAP_SHADOW_FAKE_TABLE;
+ s_sgt = (unsigned long *) page_to_phys(page);
+ /* Install shadow region second table */
+ spin_lock(&sg->guest_table_lock);
+ table = gmap_table_walk(sg, saddr, 2); /* get region-3 pointer */
+ if (!table) {
+ rc = -EAGAIN; /* Race with unshadow */
+ goto out_free;
+ }
+ if (!(*table & _REGION_ENTRY_INVALID)) {
+ rc = 0; /* Already established */
+ goto out_free;
+ } else if (*table & _REGION_ENTRY_ORIGIN) {
+ rc = -EAGAIN; /* Race with shadow */
+ goto out_free;
+ }
+ crst_table_init(s_sgt, _SEGMENT_ENTRY_EMPTY);
+ /* mark as invalid as long as the parent table is not protected */
+ *table = (unsigned long) s_sgt | _REGION_ENTRY_LENGTH |
+ _REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID;
+ if (sg->edat_level >= 1)
+ *table |= sgt & _REGION_ENTRY_PROTECT;
+ list_add(&page->lru, &sg->crst_list);
+ if (fake) {
+ /* nothing to protect for fake tables */
+ *table &= ~_REGION_ENTRY_INVALID;
+ spin_unlock(&sg->guest_table_lock);
+ return 0;
+ }
+ spin_unlock(&sg->guest_table_lock);
+ /* Make sgt read-only in parent gmap page table */
+ raddr = (saddr & _REGION3_MASK) | _SHADOW_RMAP_REGION3;
+ origin = sgt & _REGION_ENTRY_ORIGIN;
+ offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * PAGE_SIZE;
+ len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * PAGE_SIZE - offset;
+ rc = gmap_protect_rmap(sg, raddr, origin + offset, len);
+ spin_lock(&sg->guest_table_lock);
+ if (!rc) {
+ table = gmap_table_walk(sg, saddr, 2);
+ if (!table || (*table & _REGION_ENTRY_ORIGIN) !=
+ (unsigned long) s_sgt)
+ rc = -EAGAIN; /* Race with unshadow */
+ else
+ *table &= ~_REGION_ENTRY_INVALID;
+ } else {
+ gmap_unshadow_sgt(sg, raddr);
+ }
+ spin_unlock(&sg->guest_table_lock);
+ return rc;
+out_free:
+ spin_unlock(&sg->guest_table_lock);
+ __free_pages(page, CRST_ALLOC_ORDER);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_shadow_sgt);
+
+/**
+ * gmap_shadow_lookup_pgtable - find a shadow page table
+ * @sg: pointer to the shadow guest address space structure
+ * @saddr: the address in the shadow aguest address space
+ * @pgt: parent gmap address of the page table to get shadowed
+ * @dat_protection: if the pgtable is marked as protected by dat
+ * @fake: pgt references contiguous guest memory block, not a pgtable
+ *
+ * Returns 0 if the shadow page table was found and -EAGAIN if the page
+ * table was not found.
+ *
+ * Called with sg->mm->mmap_sem in read.
+ */
+int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
+ unsigned long *pgt, int *dat_protection,
+ int *fake)
+{
+ unsigned long *table;
+ struct page *page;
+ int rc;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ spin_lock(&sg->guest_table_lock);
+ table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
+ if (table && !(*table & _SEGMENT_ENTRY_INVALID)) {
+ /* Shadow page tables are full pages (pte+pgste) */
+ page = pfn_to_page(*table >> PAGE_SHIFT);
+ *pgt = page->index & ~GMAP_SHADOW_FAKE_TABLE;
+ *dat_protection = !!(*table & _SEGMENT_ENTRY_PROTECT);
+ *fake = !!(page->index & GMAP_SHADOW_FAKE_TABLE);
+ rc = 0;
+ } else {
+ rc = -EAGAIN;
+ }
+ spin_unlock(&sg->guest_table_lock);
+ return rc;
+
+}
+EXPORT_SYMBOL_GPL(gmap_shadow_pgt_lookup);
+
+/**
+ * gmap_shadow_pgt - instantiate a shadow page table
+ * @sg: pointer to the shadow guest address space structure
+ * @saddr: faulting address in the shadow gmap
+ * @pgt: parent gmap address of the page table to get shadowed
+ * @fake: pgt references contiguous guest memory block, not a pgtable
+ *
+ * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
+ * shadow table structure is incomplete, -ENOMEM if out of memory,
+ * -EFAULT if an address in the parent gmap could not be resolved and
+ *
+ * Called with gmap->mm->mmap_sem in read
+ */
+int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
+ int fake)
+{
+ unsigned long raddr, origin;
+ unsigned long *s_pgt, *table;
+ struct page *page;
+ int rc;
+
+ BUG_ON(!gmap_is_shadow(sg) || (pgt & _SEGMENT_ENTRY_LARGE));
+ /* Allocate a shadow page table */
+ page = page_table_alloc_pgste(sg->mm);
+ if (!page)
+ return -ENOMEM;
+ page->index = pgt & _SEGMENT_ENTRY_ORIGIN;
+ if (fake)
+ page->index |= GMAP_SHADOW_FAKE_TABLE;
+ s_pgt = (unsigned long *) page_to_phys(page);
+ /* Install shadow page table */
+ spin_lock(&sg->guest_table_lock);
+ table = gmap_table_walk(sg, saddr, 1); /* get segment pointer */
+ if (!table) {
+ rc = -EAGAIN; /* Race with unshadow */
+ goto out_free;
+ }
+ if (!(*table & _SEGMENT_ENTRY_INVALID)) {
+ rc = 0; /* Already established */
+ goto out_free;
+ } else if (*table & _SEGMENT_ENTRY_ORIGIN) {
+ rc = -EAGAIN; /* Race with shadow */
+ goto out_free;
+ }
+ /* mark as invalid as long as the parent table is not protected */
+ *table = (unsigned long) s_pgt | _SEGMENT_ENTRY |
+ (pgt & _SEGMENT_ENTRY_PROTECT) | _SEGMENT_ENTRY_INVALID;
+ list_add(&page->lru, &sg->pt_list);
+ if (fake) {
+ /* nothing to protect for fake tables */
+ *table &= ~_SEGMENT_ENTRY_INVALID;
+ spin_unlock(&sg->guest_table_lock);
+ return 0;
+ }
+ spin_unlock(&sg->guest_table_lock);
+ /* Make pgt read-only in parent gmap page table (not the pgste) */
+ raddr = (saddr & _SEGMENT_MASK) | _SHADOW_RMAP_SEGMENT;
+ origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK;
+ rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE);
+ spin_lock(&sg->guest_table_lock);
+ if (!rc) {
+ table = gmap_table_walk(sg, saddr, 1);
+ if (!table || (*table & _SEGMENT_ENTRY_ORIGIN) !=
+ (unsigned long) s_pgt)
+ rc = -EAGAIN; /* Race with unshadow */
+ else
+ *table &= ~_SEGMENT_ENTRY_INVALID;
+ } else {
+ gmap_unshadow_pgt(sg, raddr);
+ }
+ spin_unlock(&sg->guest_table_lock);
+ return rc;
+out_free:
+ spin_unlock(&sg->guest_table_lock);
+ page_table_free_pgste(page);
+ return rc;
+
+}
+EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
+
+/**
+ * gmap_shadow_page - create a shadow page mapping
+ * @sg: pointer to the shadow guest address space structure
+ * @saddr: faulting address in the shadow gmap
+ * @pte: pte in parent gmap address space to get shadowed
+ *
+ * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
+ * shadow table structure is incomplete, -ENOMEM if out of memory and
+ * -EFAULT if an address in the parent gmap could not be resolved.
+ *
+ * Called with sg->mm->mmap_sem in read.
+ */
+int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
+{
+ struct gmap *parent;
+ struct gmap_rmap *rmap;
+ unsigned long vmaddr, paddr;
+ spinlock_t *ptl;
+ pte_t *sptep, *tptep;
+ int prot;
+ int rc;
+
+ BUG_ON(!gmap_is_shadow(sg));
+ parent = sg->parent;
+ prot = (pte_val(pte) & _PAGE_PROTECT) ? PROT_READ : PROT_WRITE;
+
+ rmap = kzalloc(sizeof(*rmap), GFP_KERNEL);
+ if (!rmap)
+ return -ENOMEM;
+ rmap->raddr = (saddr & PAGE_MASK) | _SHADOW_RMAP_PGTABLE;
+
+ while (1) {
+ paddr = pte_val(pte) & PAGE_MASK;
+ vmaddr = __gmap_translate(parent, paddr);
+ if (IS_ERR_VALUE(vmaddr)) {
+ rc = vmaddr;
+ break;
+ }
+ rc = radix_tree_preload(GFP_KERNEL);
+ if (rc)
+ break;
+ rc = -EAGAIN;
+ sptep = gmap_pte_op_walk(parent, paddr, &ptl);
+ if (sptep) {
+ spin_lock(&sg->guest_table_lock);
+ /* Get page table pointer */
+ tptep = (pte_t *) gmap_table_walk(sg, saddr, 0);
+ if (!tptep) {
+ spin_unlock(&sg->guest_table_lock);
+ gmap_pte_op_end(ptl);
+ radix_tree_preload_end();
+ break;
+ }
+ rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
+ if (rc > 0) {
+ /* Success and a new mapping */
+ gmap_insert_rmap(sg, vmaddr, rmap);
+ rmap = NULL;
+ rc = 0;
+ }
+ gmap_pte_op_end(ptl);
+ spin_unlock(&sg->guest_table_lock);
+ }
+ radix_tree_preload_end();
+ if (!rc)
+ break;
+ rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot);
+ if (rc)
+ break;
+ }
+ kfree(rmap);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_shadow_page);
+
+/**
+ * gmap_shadow_notify - handle notifications for shadow gmap
+ *
+ * Called with sg->parent->shadow_lock.
+ */
+static void gmap_shadow_notify(struct gmap *sg, unsigned long vmaddr,
+ unsigned long gaddr)
+{
+ struct gmap_rmap *rmap, *rnext, *head;
+ unsigned long start, end, bits, raddr;
+
+ BUG_ON(!gmap_is_shadow(sg));
+
+ spin_lock(&sg->guest_table_lock);
+ if (sg->removed) {
+ spin_unlock(&sg->guest_table_lock);
+ return;
+ }
+ /* Check for top level table */
+ start = sg->orig_asce & _ASCE_ORIGIN;
+ end = start + ((sg->orig_asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE;
+ if (!(sg->orig_asce & _ASCE_REAL_SPACE) && gaddr >= start &&
+ gaddr < end) {
+ /* The complete shadow table has to go */
+ gmap_unshadow(sg);
+ spin_unlock(&sg->guest_table_lock);
+ list_del(&sg->list);
+ gmap_put(sg);
+ return;
+ }
+ /* Remove the page table tree from on specific entry */
+ head = radix_tree_delete(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT);
+ gmap_for_each_rmap_safe(rmap, rnext, head) {
+ bits = rmap->raddr & _SHADOW_RMAP_MASK;
+ raddr = rmap->raddr ^ bits;
+ switch (bits) {
+ case _SHADOW_RMAP_REGION1:
+ gmap_unshadow_r2t(sg, raddr);
+ break;
+ case _SHADOW_RMAP_REGION2:
+ gmap_unshadow_r3t(sg, raddr);
+ break;
+ case _SHADOW_RMAP_REGION3:
+ gmap_unshadow_sgt(sg, raddr);
+ break;
+ case _SHADOW_RMAP_SEGMENT:
+ gmap_unshadow_pgt(sg, raddr);
+ break;
+ case _SHADOW_RMAP_PGTABLE:
+ gmap_unshadow_page(sg, raddr);
+ break;
+ }
+ kfree(rmap);
+ }
+ spin_unlock(&sg->guest_table_lock);
+}
+
+/**
+ * ptep_notify - call all invalidation callbacks for a specific pte.
+ * @mm: pointer to the process mm_struct
+ * @addr: virtual address in the process address space
+ * @pte: pointer to the page table entry
+ * @bits: bits from the pgste that caused the notify call
+ *
+ * This function is assumed to be called with the page table lock held
+ * for the pte to notify.
+ */
+void ptep_notify(struct mm_struct *mm, unsigned long vmaddr,
+ pte_t *pte, unsigned long bits)
+{
+ unsigned long offset, gaddr = 0;
+ unsigned long *table;
+ struct gmap *gmap, *sg, *next;
+
+ offset = ((unsigned long) pte) & (255 * sizeof(pte_t));
+ offset = offset * (PAGE_SIZE / sizeof(pte_t));
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ spin_lock(&gmap->guest_table_lock);
+ table = radix_tree_lookup(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (table)
+ gaddr = __gmap_segment_gaddr(table) + offset;
+ spin_unlock(&gmap->guest_table_lock);
+ if (!table)
+ continue;
+
+ if (!list_empty(&gmap->children) && (bits & PGSTE_VSIE_BIT)) {
+ spin_lock(&gmap->shadow_lock);
+ list_for_each_entry_safe(sg, next,
+ &gmap->children, list)
+ gmap_shadow_notify(sg, vmaddr, gaddr);
+ spin_unlock(&gmap->shadow_lock);
+ }
+ if (bits & PGSTE_IN_BIT)
+ gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(ptep_notify);
+
+static void pmdp_notify_gmap(struct gmap *gmap, pmd_t *pmdp,
+ unsigned long gaddr)
+{
+ pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_IN;
+ gmap_call_notifier(gmap, gaddr, gaddr + HPAGE_SIZE - 1);
+}
+
+/**
+ * gmap_pmdp_xchg - exchange a gmap pmd with another
+ * @gmap: pointer to the guest address space structure
+ * @pmdp: pointer to the pmd entry
+ * @new: replacement entry
+ * @gaddr: the affected guest address
+ *
+ * This function is assumed to be called with the guest_table_lock
+ * held.
+ */
+static void gmap_pmdp_xchg(struct gmap *gmap, pmd_t *pmdp, pmd_t new,
+ unsigned long gaddr)
+{
+ gaddr &= HPAGE_MASK;
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ pmd_val(new) &= ~_SEGMENT_ENTRY_GMAP_IN;
+ if (MACHINE_HAS_TLB_GUEST)
+ __pmdp_idte(gaddr, (pmd_t *)pmdp, IDTE_GUEST_ASCE, gmap->asce,
+ IDTE_GLOBAL);
+ else if (MACHINE_HAS_IDTE)
+ __pmdp_idte(gaddr, (pmd_t *)pmdp, 0, 0, IDTE_GLOBAL);
+ else
+ __pmdp_csp(pmdp);
+ *pmdp = new;
+}
+
+static void gmap_pmdp_clear(struct mm_struct *mm, unsigned long vmaddr,
+ int purge)
+{
+ pmd_t *pmdp;
+ struct gmap *gmap;
+ unsigned long gaddr;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ spin_lock(&gmap->guest_table_lock);
+ pmdp = (pmd_t *)radix_tree_delete(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (pmdp) {
+ gaddr = __gmap_segment_gaddr((unsigned long *)pmdp);
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ WARN_ON(pmd_val(*pmdp) & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
+ _SEGMENT_ENTRY_GMAP_UC));
+ if (purge)
+ __pmdp_csp(pmdp);
+ pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ }
+ rcu_read_unlock();
+}
+
+/**
+ * gmap_pmdp_invalidate - invalidate all affected guest pmd entries without
+ * flushing
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_invalidate(struct mm_struct *mm, unsigned long vmaddr)
+{
+ gmap_pmdp_clear(mm, vmaddr, 0);
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_invalidate);
+
+/**
+ * gmap_pmdp_csp - csp all affected guest pmd entries
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_csp(struct mm_struct *mm, unsigned long vmaddr)
+{
+ gmap_pmdp_clear(mm, vmaddr, 1);
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_csp);
+
+/**
+ * gmap_pmdp_idte_local - invalidate and clear a guest pmd entry
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_idte_local(struct mm_struct *mm, unsigned long vmaddr)
+{
+ unsigned long *entry, gaddr;
+ struct gmap *gmap;
+ pmd_t *pmdp;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ spin_lock(&gmap->guest_table_lock);
+ entry = radix_tree_delete(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (entry) {
+ pmdp = (pmd_t *)entry;
+ gaddr = __gmap_segment_gaddr(entry);
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
+ _SEGMENT_ENTRY_GMAP_UC));
+ if (MACHINE_HAS_TLB_GUEST)
+ __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
+ gmap->asce, IDTE_LOCAL);
+ else if (MACHINE_HAS_IDTE)
+ __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_LOCAL);
+ *entry = _SEGMENT_ENTRY_EMPTY;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_idte_local);
+
+/**
+ * gmap_pmdp_idte_global - invalidate and clear a guest pmd entry
+ * @mm: pointer to the process mm_struct
+ * @vmaddr: virtual address in the process address space
+ */
+void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr)
+{
+ unsigned long *entry, gaddr;
+ struct gmap *gmap;
+ pmd_t *pmdp;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) {
+ spin_lock(&gmap->guest_table_lock);
+ entry = radix_tree_delete(&gmap->host_to_guest,
+ vmaddr >> PMD_SHIFT);
+ if (entry) {
+ pmdp = (pmd_t *)entry;
+ gaddr = __gmap_segment_gaddr(entry);
+ pmdp_notify_gmap(gmap, pmdp, gaddr);
+ WARN_ON(*entry & ~(_SEGMENT_ENTRY_HARDWARE_BITS_LARGE |
+ _SEGMENT_ENTRY_GMAP_UC));
+ if (MACHINE_HAS_TLB_GUEST)
+ __pmdp_idte(gaddr, pmdp, IDTE_GUEST_ASCE,
+ gmap->asce, IDTE_GLOBAL);
+ else if (MACHINE_HAS_IDTE)
+ __pmdp_idte(gaddr, pmdp, 0, 0, IDTE_GLOBAL);
+ else
+ __pmdp_csp(pmdp);
+ *entry = _SEGMENT_ENTRY_EMPTY;
+ }
+ spin_unlock(&gmap->guest_table_lock);
+ }
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(gmap_pmdp_idte_global);
+
+/**
+ * gmap_test_and_clear_dirty_pmd - test and reset segment dirty status
+ * @gmap: pointer to guest address space
+ * @pmdp: pointer to the pmd to be tested
+ * @gaddr: virtual address in the guest address space
+ *
+ * This function is assumed to be called with the guest_table_lock
+ * held.
+ */
+bool gmap_test_and_clear_dirty_pmd(struct gmap *gmap, pmd_t *pmdp,
+ unsigned long gaddr)
+{
+ if (pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID)
+ return false;
+
+ /* Already protected memory, which did not change is clean */
+ if (pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT &&
+ !(pmd_val(*pmdp) & _SEGMENT_ENTRY_GMAP_UC))
+ return false;
+
+ /* Clear UC indication and reset protection */
+ pmd_val(*pmdp) &= ~_SEGMENT_ENTRY_GMAP_UC;
+ gmap_protect_pmd(gmap, gaddr, pmdp, PROT_READ, 0);
+ return true;
+}
+
+/**
+ * gmap_sync_dirty_log_pmd - set bitmap based on dirty status of segment
+ * @gmap: pointer to guest address space
+ * @bitmap: dirty bitmap for this pmd
+ * @gaddr: virtual address in the guest address space
+ * @vmaddr: virtual address in the host address space
+ *
+ * This function is assumed to be called with the guest_table_lock
+ * held.
+ */
+void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long bitmap[4],
+ unsigned long gaddr, unsigned long vmaddr)
+{
+ int i;
+ pmd_t *pmdp;
+ pte_t *ptep;
+ spinlock_t *ptl;
+
+ pmdp = gmap_pmd_op_walk(gmap, gaddr);
+ if (!pmdp)
+ return;
+
+ if (pmd_large(*pmdp)) {
+ if (gmap_test_and_clear_dirty_pmd(gmap, pmdp, gaddr))
+ bitmap_fill(bitmap, _PAGE_ENTRIES);
+ } else {
+ for (i = 0; i < _PAGE_ENTRIES; i++, vmaddr += PAGE_SIZE) {
+ ptep = pte_alloc_map_lock(gmap->mm, pmdp, vmaddr, &ptl);
+ if (!ptep)
+ continue;
+ if (ptep_test_and_clear_uc(gmap->mm, vmaddr, ptep))
+ set_bit(i, bitmap);
+ spin_unlock(ptl);
+ }
+ }
+ gmap_pmd_op_end(gmap, pmdp);
+}
+EXPORT_SYMBOL_GPL(gmap_sync_dirty_log_pmd);
+
+static inline void thp_split_mm(struct mm_struct *mm)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ struct vm_area_struct *vma;
+ unsigned long addr;
+
+ for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) {
+ for (addr = vma->vm_start;
+ addr < vma->vm_end;
+ addr += PAGE_SIZE)
+ follow_page(vma, addr, FOLL_SPLIT);
+ vma->vm_flags &= ~VM_HUGEPAGE;
+ vma->vm_flags |= VM_NOHUGEPAGE;
+ }
+ mm->def_flags |= VM_NOHUGEPAGE;
+#endif
+}
+
+/*
+ * Remove all empty zero pages from the mapping for lazy refaulting
+ * - This must be called after mm->context.has_pgste is set, to avoid
+ * future creation of zero pages
+ * - This must be called after THP was enabled
+ */
+static int __zap_zero_pages(pmd_t *pmd, unsigned long start,
+ unsigned long end, struct mm_walk *walk)
+{
+ unsigned long addr;
+
+ for (addr = start; addr != end; addr += PAGE_SIZE) {
+ pte_t *ptep;
+ spinlock_t *ptl;
+
+ ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+ if (is_zero_pfn(pte_pfn(*ptep)))
+ ptep_xchg_direct(walk->mm, addr, ptep, __pte(_PAGE_INVALID));
+ pte_unmap_unlock(ptep, ptl);
+ }
+ return 0;
+}
+
+static inline void zap_zero_pages(struct mm_struct *mm)
+{
+ struct mm_walk walk = { .pmd_entry = __zap_zero_pages };
+
+ walk.mm = mm;
+ walk_page_range(0, TASK_SIZE, &walk);
+}
+
+/*
+ * switch on pgstes for its userspace process (for kvm)
+ */
+int s390_enable_sie(void)
+{
+ struct mm_struct *mm = current->mm;
+
+ /* Do we have pgstes? if yes, we are done */
+ if (mm_has_pgste(mm))
+ return 0;
+ /* Fail if the page tables are 2K */
+ if (!mm_alloc_pgste(mm))
+ return -EINVAL;
+ down_write(&mm->mmap_sem);
+ mm->context.has_pgste = 1;
+ /* split thp mappings and disable thp for future mappings */
+ thp_split_mm(mm);
+ zap_zero_pages(mm);
+ up_write(&mm->mmap_sem);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s390_enable_sie);
+
+/*
+ * Enable storage key handling from now on and initialize the storage
+ * keys with the default key.
+ */
+static int __s390_enable_skey_pte(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ /* Clear storage key */
+ ptep_zap_key(walk->mm, addr, pte);
+ return 0;
+}
+
+static int __s390_enable_skey_hugetlb(pte_t *pte, unsigned long addr,
+ unsigned long hmask, unsigned long next,
+ struct mm_walk *walk)
+{
+ pmd_t *pmd = (pmd_t *)pte;
+ unsigned long start, end;
+ struct page *page = pmd_page(*pmd);
+
+ /*
+ * The write check makes sure we do not set a key on shared
+ * memory. This is needed as the walker does not differentiate
+ * between actual guest memory and the process executable or
+ * shared libraries.
+ */
+ if (pmd_val(*pmd) & _SEGMENT_ENTRY_INVALID ||
+ !(pmd_val(*pmd) & _SEGMENT_ENTRY_WRITE))
+ return 0;
+
+ start = pmd_val(*pmd) & HPAGE_MASK;
+ end = start + HPAGE_SIZE - 1;
+ __storage_key_init_range(start, end);
+ set_bit(PG_arch_1, &page->flags);
+ return 0;
+}
+
+int s390_enable_skey(void)
+{
+ struct mm_walk walk = {
+ .hugetlb_entry = __s390_enable_skey_hugetlb,
+ .pte_entry = __s390_enable_skey_pte,
+ };
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ int rc = 0;
+
+ down_write(&mm->mmap_sem);
+ if (mm_uses_skeys(mm))
+ goto out_up;
+
+ mm->context.uses_skeys = 1;
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (ksm_madvise(vma, vma->vm_start, vma->vm_end,
+ MADV_UNMERGEABLE, &vma->vm_flags)) {
+ mm->context.uses_skeys = 0;
+ rc = -ENOMEM;
+ goto out_up;
+ }
+ }
+ mm->def_flags &= ~VM_MERGEABLE;
+
+ walk.mm = mm;
+ walk_page_range(0, TASK_SIZE, &walk);
+
+out_up:
+ up_write(&mm->mmap_sem);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(s390_enable_skey);
+
+/*
+ * Reset CMMA state, make all pages stable again.
+ */
+static int __s390_reset_cmma(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ ptep_zap_unused(walk->mm, addr, pte, 1);
+ return 0;
+}
+
+void s390_reset_cmma(struct mm_struct *mm)
+{
+ struct mm_walk walk = { .pte_entry = __s390_reset_cmma };
+
+ down_write(&mm->mmap_sem);
+ walk.mm = mm;
+ walk_page_range(0, TASK_SIZE, &walk);
+ up_write(&mm->mmap_sem);
+}
+EXPORT_SYMBOL_GPL(s390_reset_cmma);