| // 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/pagewalk.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 <linux/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); |
| refcount_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) |
| { |
| refcount_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 (refcount_dec_and_test(&gmap->ref_count)) |
| 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_lock 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; |
| mmap_write_lock(gmap->mm); |
| for (off = 0; off < len; off += PMD_SIZE) |
| flush |= __gmap_unmap_by_gaddr(gmap, to + off); |
| mmap_write_unlock(gmap->mm); |
| 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; |
| mmap_write_lock(gmap->mm); |
| 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; |
| } |
| mmap_write_unlock(gmap->mm); |
| 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_lock 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; |
| |
| mmap_read_lock(gmap->mm); |
| rc = __gmap_translate(gmap, gaddr); |
| mmap_read_unlock(gmap->mm); |
| 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_lock 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; |
| |
| mmap_read_lock(gmap->mm); |
| |
| retry: |
| unlocked = false; |
| vmaddr = __gmap_translate(gmap, gaddr); |
| if (IS_ERR_VALUE(vmaddr)) { |
| rc = vmaddr; |
| goto out_up; |
| } |
| if (fixup_user_fault(gmap->mm, vmaddr, fault_flags, |
| &unlocked)) { |
| rc = -EFAULT; |
| goto out_up; |
| } |
| /* |
| * In the case that fixup_user_fault unlocked the mmap_lock 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: |
| mmap_read_unlock(gmap->mm); |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(gmap_fault); |
| |
| /* |
| * this function is assumed to be called with mmap_lock 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; |
| |
| mmap_read_lock(gmap->mm); |
| 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); |
| } |
| mmap_read_unlock(gmap->mm); |
| } |
| 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) |
| { |
| const int asce_type = gmap->asce & _ASCE_TYPE_MASK; |
| unsigned long *table = gmap->table; |
| |
| if (gmap_is_shadow(gmap) && gmap->removed) |
| return NULL; |
| |
| if (WARN_ON_ONCE(level > (asce_type >> 2) + 1)) |
| return NULL; |
| |
| if (asce_type != _ASCE_TYPE_REGION1 && |
| gaddr & (-1UL << (31 + (asce_type >> 2) * 11))) |
| return NULL; |
| |
| switch (asce_type) { |
| 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(mm, vmaddr, fault_flags, &unlocked)) |
| return -EFAULT; |
| if (unlocked) |
| /* lost mmap_lock, 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)); |
| pmdp = (pmd_t *) gmap_table_walk(gmap, gaddr, 1); |
| if (!pmdp) |
| return NULL; |
| |
| /* without huge pages, there is no need to take the table lock */ |
| if (!gmap->mm->context.allow_gmap_hpage_1m) |
| return pmd_none(*pmdp) ? NULL : pmdp; |
| |
| spin_lock(&gmap->guest_table_lock); |
| if (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_lock 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_lock 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_lock 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; |
| mmap_read_lock(gmap->mm); |
| rc = gmap_protect_range(gmap, gaddr, len, prot, GMAP_NOTIFY_MPROT); |
| mmap_read_unlock(gmap->mm); |
| 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_lock 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); |
| refcount_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; |
| } |
| } |
| } |
| refcount_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 */ |
| mmap_read_lock(parent->mm); |
| rc = gmap_protect_range(parent, asce & _ASCE_ORIGIN, |
| ((asce & _ASCE_TABLE_LENGTH) + 1) * PAGE_SIZE, |
| PROT_READ, GMAP_NOTIFY_SHADOW); |
| mmap_read_unlock(parent->mm); |
| 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_lock 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_lock 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 */ |
| goto out_free; |
| } |
| 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_lock 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_lock 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_lock 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_lock 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. |
| */ |
| static 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); |
| |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| static int thp_split_walk_pmd_entry(pmd_t *pmd, unsigned long addr, |
| unsigned long end, struct mm_walk *walk) |
| { |
| struct vm_area_struct *vma = walk->vma; |
| |
| split_huge_pmd(vma, pmd, addr); |
| return 0; |
| } |
| |
| static const struct mm_walk_ops thp_split_walk_ops = { |
| .pmd_entry = thp_split_walk_pmd_entry, |
| }; |
| |
| static inline void thp_split_mm(struct mm_struct *mm) |
| { |
| struct vm_area_struct *vma; |
| |
| for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) { |
| vma->vm_flags &= ~VM_HUGEPAGE; |
| vma->vm_flags |= VM_NOHUGEPAGE; |
| walk_page_vma(vma, &thp_split_walk_ops, NULL); |
| } |
| mm->def_flags |= VM_NOHUGEPAGE; |
| } |
| #else |
| static inline void thp_split_mm(struct mm_struct *mm) |
| { |
| } |
| #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
| |
| /* |
| * 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 const struct mm_walk_ops zap_zero_walk_ops = { |
| .pmd_entry = __zap_zero_pages, |
| }; |
| |
| /* |
| * 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; |
| mmap_write_lock(mm); |
| mm->context.has_pgste = 1; |
| /* split thp mappings and disable thp for future mappings */ |
| thp_split_mm(mm); |
| walk_page_range(mm, 0, TASK_SIZE, &zap_zero_walk_ops, NULL); |
| mmap_write_unlock(mm); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(s390_enable_sie); |
| |
| int gmap_mark_unmergeable(void) |
| { |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| int ret; |
| |
| for (vma = mm->mmap; vma; vma = vma->vm_next) { |
| ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, |
| MADV_UNMERGEABLE, &vma->vm_flags); |
| if (ret) |
| return ret; |
| } |
| mm->def_flags &= ~VM_MERGEABLE; |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(gmap_mark_unmergeable); |
| |
| /* |
| * 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; |
| } |
| |
| static const struct mm_walk_ops enable_skey_walk_ops = { |
| .hugetlb_entry = __s390_enable_skey_hugetlb, |
| .pte_entry = __s390_enable_skey_pte, |
| }; |
| |
| int s390_enable_skey(void) |
| { |
| struct mm_struct *mm = current->mm; |
| int rc = 0; |
| |
| mmap_write_lock(mm); |
| if (mm_uses_skeys(mm)) |
| goto out_up; |
| |
| mm->context.uses_skeys = 1; |
| rc = gmap_mark_unmergeable(); |
| if (rc) { |
| mm->context.uses_skeys = 0; |
| goto out_up; |
| } |
| walk_page_range(mm, 0, TASK_SIZE, &enable_skey_walk_ops, NULL); |
| |
| out_up: |
| mmap_write_unlock(mm); |
| 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; |
| } |
| |
| static const struct mm_walk_ops reset_cmma_walk_ops = { |
| .pte_entry = __s390_reset_cmma, |
| }; |
| |
| void s390_reset_cmma(struct mm_struct *mm) |
| { |
| mmap_write_lock(mm); |
| walk_page_range(mm, 0, TASK_SIZE, &reset_cmma_walk_ops, NULL); |
| mmap_write_unlock(mm); |
| } |
| EXPORT_SYMBOL_GPL(s390_reset_cmma); |
| |
| /* |
| * make inaccessible pages accessible again |
| */ |
| static int __s390_reset_acc(pte_t *ptep, unsigned long addr, |
| unsigned long next, struct mm_walk *walk) |
| { |
| pte_t pte = READ_ONCE(*ptep); |
| |
| if (pte_present(pte)) |
| WARN_ON_ONCE(uv_destroy_page(pte_val(pte) & PAGE_MASK)); |
| return 0; |
| } |
| |
| static const struct mm_walk_ops reset_acc_walk_ops = { |
| .pte_entry = __s390_reset_acc, |
| }; |
| |
| #include <linux/sched/mm.h> |
| void s390_reset_acc(struct mm_struct *mm) |
| { |
| if (!mm_is_protected(mm)) |
| return; |
| /* |
| * we might be called during |
| * reset: we walk the pages and clear |
| * close of all kvm file descriptors: we walk the pages and clear |
| * exit of process on fd closure: vma already gone, do nothing |
| */ |
| if (!mmget_not_zero(mm)) |
| return; |
| mmap_read_lock(mm); |
| walk_page_range(mm, 0, TASK_SIZE, &reset_acc_walk_ops, NULL); |
| mmap_read_unlock(mm); |
| mmput(mm); |
| } |
| EXPORT_SYMBOL_GPL(s390_reset_acc); |