diff options
Diffstat (limited to 'arch/s390/mm/gmap.c')
| -rw-r--r-- | arch/s390/mm/gmap.c | 1574 |
1 files changed, 1500 insertions, 74 deletions
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c index 063c721ec0dc..2ce6bb3bab32 100644 --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -20,14 +20,16 @@ #include <asm/gmap.h> #include <asm/tlb.h> +#define GMAP_SHADOW_FAKE_TABLE 1ULL + /** - * gmap_alloc - allocate a guest address space + * 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. */ -struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit) +static struct gmap *gmap_alloc(unsigned long limit) { struct gmap *gmap; struct page *page; @@ -55,10 +57,14 @@ struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit) 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); - gmap->mm = mm; + spin_lock_init(&gmap->shadow_lock); + atomic_set(&gmap->ref_count, 1); page = alloc_pages(GFP_KERNEL, 2); if (!page) goto out_free; @@ -70,9 +76,6 @@ struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit) gmap->asce = atype | _ASCE_TABLE_LENGTH | _ASCE_USER_BITS | __pa(table); gmap->asce_end = limit; - down_write(&mm->mmap_sem); - list_add(&gmap->list, &mm->context.gmap_list); - up_write(&mm->mmap_sem); return gmap; out_free: @@ -80,7 +83,28 @@ out_free: out: return NULL; } -EXPORT_SYMBOL_GPL(gmap_alloc); + +/** + * 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; + + gmap = gmap_alloc(limit); + if (!gmap) + return NULL; + gmap->mm = mm; + spin_lock(&mm->context.gmap_lock); + list_add_rcu(&gmap->list, &mm->context.gmap_list); + spin_unlock(&mm->context.gmap_lock); + return gmap; +} +EXPORT_SYMBOL_GPL(gmap_create); static void gmap_flush_tlb(struct gmap *gmap) { @@ -114,31 +138,117 @@ static void gmap_radix_tree_free(struct radix_tree_root *root) } 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 **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. */ -void gmap_free(struct gmap *gmap) +static void gmap_free(struct gmap *gmap) { struct page *page, *next; - /* Flush tlb. */ - if (MACHINE_HAS_IDTE) - __tlb_flush_idte(gmap->asce); - else - __tlb_flush_global(); - + /* 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, 2); gmap_radix_tree_free(&gmap->guest_to_host); gmap_radix_tree_free(&gmap->host_to_guest); - down_write(&gmap->mm->mmap_sem); - list_del(&gmap->list); - up_write(&gmap->mm->mmap_sem); + + /* 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); } -EXPORT_SYMBOL_GPL(gmap_free); + +/** + * 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; + + /* 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.gmap_lock); + list_del_rcu(&gmap->list); + spin_unlock(&gmap->mm->context.gmap_lock); + synchronize_rcu(); + /* Put reference */ + gmap_put(gmap); +} +EXPORT_SYMBOL_GPL(gmap_remove); /** * gmap_enable - switch primary space to the guest address space @@ -160,6 +270,17 @@ void gmap_disable(struct gmap *gmap) } 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 */ @@ -175,7 +296,7 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table, return -ENOMEM; new = (unsigned long *) page_to_phys(page); crst_table_init(new, init); - spin_lock(&gmap->mm->page_table_lock); + 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 | @@ -183,7 +304,7 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table, page->index = gaddr; page = NULL; } - spin_unlock(&gmap->mm->page_table_lock); + spin_unlock(&gmap->guest_table_lock); if (page) __free_pages(page, 2); return 0; @@ -219,6 +340,7 @@ 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) { @@ -258,6 +380,7 @@ 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) @@ -289,6 +412,7 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from, 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 || @@ -326,6 +450,8 @@ EXPORT_SYMBOL_GPL(gmap_map_segment); * 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) { @@ -333,6 +459,7 @@ unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr) 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); @@ -369,11 +496,13 @@ void gmap_unlink(struct mm_struct *mm, unsigned long *table, struct gmap *gmap; int flush; - list_for_each_entry(gmap, &mm->context.gmap_list, list) { + 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(); } /** @@ -397,6 +526,7 @@ int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr) pmd_t *pmd; 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) { @@ -552,116 +682,1412 @@ static LIST_HEAD(gmap_notifier_list); static DEFINE_SPINLOCK(gmap_notifier_lock); /** - * gmap_register_ipte_notifier - register a pte invalidation callback + * gmap_register_pte_notifier - register a pte invalidation callback * @nb: pointer to the gmap notifier block */ -void gmap_register_ipte_notifier(struct gmap_notifier *nb) +void gmap_register_pte_notifier(struct gmap_notifier *nb) { spin_lock(&gmap_notifier_lock); - list_add(&nb->list, &gmap_notifier_list); + list_add_rcu(&nb->list, &gmap_notifier_list); spin_unlock(&gmap_notifier_lock); } -EXPORT_SYMBOL_GPL(gmap_register_ipte_notifier); +EXPORT_SYMBOL_GPL(gmap_register_pte_notifier); /** - * gmap_unregister_ipte_notifier - remove a pte invalidation callback + * gmap_unregister_pte_notifier - remove a pte invalidation callback * @nb: pointer to the gmap notifier block */ -void gmap_unregister_ipte_notifier(struct gmap_notifier *nb) +void gmap_unregister_pte_notifier(struct gmap_notifier *nb) { spin_lock(&gmap_notifier_lock); - list_del_init(&nb->list); + 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 >> 53) & 0x7ff; + 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 >> 42) & 0x7ff; + 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 >> 31) & 0x7ff; + 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 >> 20) & 0x7ff; + if (level == 1) + break; + if (*table & _REGION_ENTRY_INVALID) + return NULL; + table = (unsigned long *)(*table & _SEGMENT_ENTRY_ORIGIN); + table += (gaddr >> 12) & 0xff; + } + 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 + * + * Note: Can also be called for shadow gmaps. + */ +static pte_t *gmap_pte_op_walk(struct gmap *gmap, unsigned long gaddr, + spinlock_t **ptl) +{ + unsigned long *table; + + if (gmap_is_shadow(gmap)) + spin_lock(&gmap->guest_table_lock); + /* 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) { + if (gmap_is_shadow(gmap)) + spin_unlock(&gmap->guest_table_lock); + return NULL; + } + if (gmap_is_shadow(gmap)) { + *ptl = &gmap->guest_table_lock; + return pte_offset_map((pmd_t *) table, gaddr); + } + 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); } -EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier); /** - * gmap_ipte_notify - mark a range of ptes for invalidation notification + * gmap_pte_op_end - release the page table lock + * @ptl: pointer to the spinlock pointer + */ +static void gmap_pte_op_end(spinlock_t *ptl) +{ + spin_unlock(ptl); +} + +/* + * 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 for each page in the given range a gmap mapping exists and - * the invalidation notification could be set. 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. + * 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. + * + * Note: Can also be called for shadow gmaps. */ -int gmap_ipte_notify(struct gmap *gmap, unsigned long gaddr, unsigned long len) +static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr, + unsigned long len, int prot, unsigned long bits) { - unsigned long addr; + unsigned long vmaddr; spinlock_t *ptl; pte_t *ptep; - bool unlocked; - int rc = 0; + int rc; + + while (len) { + rc = -EAGAIN; + ptep = gmap_pte_op_walk(gmap, gaddr, &ptl); + if (ptep) { + rc = ptep_force_prot(gmap->mm, gaddr, ptep, prot, bits); + gmap_pte_op_end(ptl); + } + if (rc) { + 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; + continue; + } + gaddr += PAGE_SIZE; + len -= PAGE_SIZE; + } + 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)) + 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); - while (len) { - unlocked = false; - /* Convert gmap address and connect the page tables */ - addr = __gmap_translate(gmap, gaddr); - if (IS_ERR_VALUE(addr)) { - rc = addr; + rc = gmap_protect_range(gmap, gaddr, len, prot, PGSTE_IN_BIT); + 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. + * + * 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; + + 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; } - /* Get the page mapped */ - if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE, - &unlocked)) { - rc = -EFAULT; + 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 **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(slot, rmap); + } else { + rmap->next = NULL; + radix_tree_insert(&sg->host_to_rmap, vmaddr >> PAGE_SHIFT, + rmap); + } +} + +/** + * gmap_protect_rmap - modify access rights to memory 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 + * @prot: indicates access rights: none, read-only or read-write + * + * 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, int prot) +{ + 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, + PGSTE_VSIE_BIT); + if (!rc) + gmap_insert_rmap(sg, vmaddr, rmap); + spin_unlock(&sg->guest_table_lock); + gmap_pte_op_end(ptl); } - /* While trying to map mmap_sem got unlocked. Let us retry */ - if (unlocked) + radix_tree_preload_end(); + if (rc) { + kfree(rmap); + rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot); + if (rc) + return rc; continue; - rc = __gmap_link(gmap, gaddr, addr); + } + 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 + (1UL << 12) - 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 < 256; i++, raddr += 1UL << 12) + 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 + (1UL << 20) - 1); + sto = (unsigned long) (ste - ((raddr >> 20) & 0x7ff)); + 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 asce, *pgt; + struct page *page; + int i; + + BUG_ON(!gmap_is_shadow(sg)); + asce = (unsigned long) sgt | _ASCE_TYPE_SEGMENT; + for (i = 0; i < 2048; i++, raddr += 1UL << 20) { + 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 + (1UL << 31) - 1); + r3o = (unsigned long) (r3e - ((raddr >> 31) & 0x7ff)); + 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, 2); +} + +/** + * __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 asce, *sgt; + struct page *page; + int i; + + BUG_ON(!gmap_is_shadow(sg)); + asce = (unsigned long) r3t | _ASCE_TYPE_REGION3; + for (i = 0; i < 2048; i++, raddr += 1UL << 31) { + 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, 2); + } +} + +/** + * 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 + (1UL << 42) - 1); + r2o = (unsigned long) (r2e - ((raddr >> 42) & 0x7ff)); + 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, 2); +} + +/** + * __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 asce, *r3t; + struct page *page; + int i; + + BUG_ON(!gmap_is_shadow(sg)); + asce = (unsigned long) r2t | _ASCE_TYPE_REGION2; + for (i = 0; i < 2048; i++, raddr += 1UL << 42) { + 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, 2); + } +} + +/** + * 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 + (1UL << 53) - 1); + r1o = (unsigned long) (r1e - ((raddr >> 53) & 0x7ff)); + 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, 2); +} + +/** + * __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 < 2048; i++, raddr += 1UL << 53) { + 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, 2); + } +} + +/** + * 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(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) * 4096, + PROT_READ, PGSTE_VSIE_BIT); + 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, 2); + 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 & 0xffe0000000000000UL) | _SHADOW_RMAP_REGION1; + origin = r2t & _REGION_ENTRY_ORIGIN; + offset = ((r2t & _REGION_ENTRY_OFFSET) >> 6) * 4096; + len = ((r2t & _REGION_ENTRY_LENGTH) + 1) * 4096 - offset; + rc = gmap_protect_rmap(sg, raddr, origin + offset, len, PROT_READ); + 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, 2); + 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, 2); + 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 & 0xfffffc0000000000UL) | _SHADOW_RMAP_REGION2; + origin = r3t & _REGION_ENTRY_ORIGIN; + offset = ((r3t & _REGION_ENTRY_OFFSET) >> 6) * 4096; + len = ((r3t & _REGION_ENTRY_LENGTH) + 1) * 4096 - offset; + rc = gmap_protect_rmap(sg, raddr, origin + offset, len, PROT_READ); + 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, 2); + 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, 2); + 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 & 0xffffffff80000000UL) | _SHADOW_RMAP_REGION3; + origin = sgt & _REGION_ENTRY_ORIGIN; + offset = ((sgt & _REGION_ENTRY_OFFSET) >> 6) * 4096; + len = ((sgt & _REGION_ENTRY_LENGTH) + 1) * 4096 - offset; + rc = gmap_protect_rmap(sg, raddr, origin + offset, len, PROT_READ); + 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, 2); + 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 & 0xfffffffffff00000UL) | _SHADOW_RMAP_SEGMENT; + origin = pgt & _SEGMENT_ENTRY_ORIGIN & PAGE_MASK; + rc = gmap_protect_rmap(sg, raddr, origin, PAGE_SIZE, PROT_READ); + 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; - /* Walk the process page table, lock and get pte pointer */ - ptep = get_locked_pte(gmap->mm, addr, &ptl); - VM_BUG_ON(!ptep); - /* Set notification bit in the pgste of the pte */ - if ((pte_val(*ptep) & (_PAGE_INVALID | _PAGE_PROTECT)) == 0) { - ptep_set_notify(gmap->mm, addr, ptep); - gaddr += PAGE_SIZE; - len -= PAGE_SIZE; + 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); } - pte_unmap_unlock(ptep, ptl); + radix_tree_preload_end(); + if (!rc) + break; + rc = gmap_pte_op_fixup(parent, paddr, vmaddr, prot); + if (rc) + break; } - up_read(&gmap->mm->mmap_sem); + kfree(rmap); return rc; } -EXPORT_SYMBOL_GPL(gmap_ipte_notify); +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 offset, pte_t *pte) +{ + struct gmap_rmap *rmap, *rnext, *head; + unsigned long gaddr, start, end, bits, raddr; + unsigned long *table; + + BUG_ON(!gmap_is_shadow(sg)); + spin_lock(&sg->parent->guest_table_lock); + table = radix_tree_lookup(&sg->parent->host_to_guest, + vmaddr >> PMD_SHIFT); + gaddr = table ? __gmap_segment_gaddr(table) + offset : 0; + spin_unlock(&sg->parent->guest_table_lock); + if (!table) + return; + + 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) * 4096; + 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 >> 12); + 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) +void ptep_notify(struct mm_struct *mm, unsigned long vmaddr, + pte_t *pte, unsigned long bits) { unsigned long offset, gaddr; unsigned long *table; - struct gmap_notifier *nb; - struct gmap *gmap; + struct gmap *gmap, *sg, *next; offset = ((unsigned long) pte) & (255 * sizeof(pte_t)); offset = offset * (4096 / sizeof(pte_t)); - spin_lock(&gmap_notifier_lock); - list_for_each_entry(gmap, &mm->context.gmap_list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) { + 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, offset, pte); + spin_unlock(&gmap->shadow_lock); + } + if (!(bits & PGSTE_IN_BIT)) + continue; + spin_lock(&gmap->guest_table_lock); table = radix_tree_lookup(&gmap->host_to_guest, vmaddr >> PMD_SHIFT); - if (!table) - continue; - gaddr = __gmap_segment_gaddr(table) + offset; - list_for_each_entry(nb, &gmap_notifier_list, list) - nb->notifier_call(gmap, gaddr); + if (table) + gaddr = __gmap_segment_gaddr(table) + offset; + spin_unlock(&gmap->guest_table_lock); + if (table) + gmap_call_notifier(gmap, gaddr, gaddr + PAGE_SIZE - 1); } - spin_unlock(&gmap_notifier_lock); + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(ptep_notify); |