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2707 lines
77 KiB
2707 lines
77 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* KVM guest address space mapping code |
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* |
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* Copyright IBM Corp. 2007, 2020 |
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* Author(s): Martin Schwidefsky <[email protected]> |
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* David Hildenbrand <[email protected]> |
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* Janosch Frank <[email protected]> |
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*/ |
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|
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#include <linux/kernel.h> |
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#include <linux/pagewalk.h> |
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#include <linux/swap.h> |
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#include <linux/smp.h> |
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#include <linux/spinlock.h> |
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#include <linux/slab.h> |
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#include <linux/swapops.h> |
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#include <linux/ksm.h> |
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#include <linux/mman.h> |
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#include <linux/pgtable.h> |
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|
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#include <asm/pgalloc.h> |
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#include <asm/gmap.h> |
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#include <asm/tlb.h> |
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|
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#define GMAP_SHADOW_FAKE_TABLE 1ULL |
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|
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/** |
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* gmap_alloc - allocate and initialize a guest address space |
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* @limit: maximum address of the gmap address space |
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* |
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* Returns a guest address space structure. |
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*/ |
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static struct gmap *gmap_alloc(unsigned long limit) |
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{ |
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struct gmap *gmap; |
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struct page *page; |
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unsigned long *table; |
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unsigned long etype, atype; |
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|
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if (limit < _REGION3_SIZE) { |
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limit = _REGION3_SIZE - 1; |
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atype = _ASCE_TYPE_SEGMENT; |
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etype = _SEGMENT_ENTRY_EMPTY; |
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} else if (limit < _REGION2_SIZE) { |
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limit = _REGION2_SIZE - 1; |
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atype = _ASCE_TYPE_REGION3; |
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etype = _REGION3_ENTRY_EMPTY; |
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} else if (limit < _REGION1_SIZE) { |
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limit = _REGION1_SIZE - 1; |
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atype = _ASCE_TYPE_REGION2; |
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etype = _REGION2_ENTRY_EMPTY; |
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} else { |
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limit = -1UL; |
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atype = _ASCE_TYPE_REGION1; |
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etype = _REGION1_ENTRY_EMPTY; |
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} |
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gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL_ACCOUNT); |
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if (!gmap) |
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goto out; |
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INIT_LIST_HEAD(&gmap->crst_list); |
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INIT_LIST_HEAD(&gmap->children); |
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INIT_LIST_HEAD(&gmap->pt_list); |
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INIT_RADIX_TREE(&gmap->guest_to_host, GFP_KERNEL_ACCOUNT); |
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INIT_RADIX_TREE(&gmap->host_to_guest, GFP_ATOMIC | __GFP_ACCOUNT); |
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INIT_RADIX_TREE(&gmap->host_to_rmap, GFP_ATOMIC | __GFP_ACCOUNT); |
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spin_lock_init(&gmap->guest_table_lock); |
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spin_lock_init(&gmap->shadow_lock); |
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refcount_set(&gmap->ref_count, 1); |
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page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER); |
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if (!page) |
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goto out_free; |
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page->index = 0; |
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list_add(&page->lru, &gmap->crst_list); |
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table = (unsigned long *) page_to_phys(page); |
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crst_table_init(table, etype); |
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gmap->table = table; |
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gmap->asce = atype | _ASCE_TABLE_LENGTH | |
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_ASCE_USER_BITS | __pa(table); |
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gmap->asce_end = limit; |
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return gmap; |
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|
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out_free: |
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kfree(gmap); |
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out: |
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return NULL; |
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} |
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|
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/** |
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* gmap_create - create a guest address space |
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* @mm: pointer to the parent mm_struct |
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* @limit: maximum size of the gmap address space |
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* |
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* Returns a guest address space structure. |
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*/ |
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struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit) |
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{ |
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struct gmap *gmap; |
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unsigned long gmap_asce; |
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|
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gmap = gmap_alloc(limit); |
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if (!gmap) |
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return NULL; |
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gmap->mm = mm; |
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spin_lock(&mm->context.lock); |
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list_add_rcu(&gmap->list, &mm->context.gmap_list); |
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if (list_is_singular(&mm->context.gmap_list)) |
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gmap_asce = gmap->asce; |
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else |
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gmap_asce = -1UL; |
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WRITE_ONCE(mm->context.gmap_asce, gmap_asce); |
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spin_unlock(&mm->context.lock); |
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return gmap; |
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} |
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EXPORT_SYMBOL_GPL(gmap_create); |
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|
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static void gmap_flush_tlb(struct gmap *gmap) |
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{ |
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if (MACHINE_HAS_IDTE) |
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__tlb_flush_idte(gmap->asce); |
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else |
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__tlb_flush_global(); |
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} |
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|
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static void gmap_radix_tree_free(struct radix_tree_root *root) |
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{ |
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struct radix_tree_iter iter; |
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unsigned long indices[16]; |
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unsigned long index; |
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void __rcu **slot; |
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int i, nr; |
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|
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/* A radix tree is freed by deleting all of its entries */ |
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index = 0; |
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do { |
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nr = 0; |
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radix_tree_for_each_slot(slot, root, &iter, index) { |
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indices[nr] = iter.index; |
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if (++nr == 16) |
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break; |
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} |
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for (i = 0; i < nr; i++) { |
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index = indices[i]; |
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radix_tree_delete(root, index); |
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} |
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} while (nr > 0); |
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} |
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|
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static void gmap_rmap_radix_tree_free(struct radix_tree_root *root) |
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{ |
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struct gmap_rmap *rmap, *rnext, *head; |
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struct radix_tree_iter iter; |
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unsigned long indices[16]; |
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unsigned long index; |
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void __rcu **slot; |
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int i, nr; |
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|
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/* A radix tree is freed by deleting all of its entries */ |
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index = 0; |
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do { |
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nr = 0; |
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radix_tree_for_each_slot(slot, root, &iter, index) { |
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indices[nr] = iter.index; |
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if (++nr == 16) |
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break; |
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} |
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for (i = 0; i < nr; i++) { |
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index = indices[i]; |
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head = radix_tree_delete(root, index); |
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gmap_for_each_rmap_safe(rmap, rnext, head) |
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kfree(rmap); |
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} |
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} while (nr > 0); |
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} |
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|
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/** |
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* gmap_free - free a guest address space |
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* @gmap: pointer to the guest address space structure |
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* |
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* No locks required. There are no references to this gmap anymore. |
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*/ |
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static void gmap_free(struct gmap *gmap) |
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{ |
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struct page *page, *next; |
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|
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/* Flush tlb of all gmaps (if not already done for shadows) */ |
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if (!(gmap_is_shadow(gmap) && gmap->removed)) |
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gmap_flush_tlb(gmap); |
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/* Free all segment & region tables. */ |
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list_for_each_entry_safe(page, next, &gmap->crst_list, lru) |
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__free_pages(page, CRST_ALLOC_ORDER); |
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gmap_radix_tree_free(&gmap->guest_to_host); |
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gmap_radix_tree_free(&gmap->host_to_guest); |
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|
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/* Free additional data for a shadow gmap */ |
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if (gmap_is_shadow(gmap)) { |
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/* Free all page tables. */ |
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list_for_each_entry_safe(page, next, &gmap->pt_list, lru) |
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page_table_free_pgste(page); |
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gmap_rmap_radix_tree_free(&gmap->host_to_rmap); |
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/* Release reference to the parent */ |
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gmap_put(gmap->parent); |
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} |
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|
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kfree(gmap); |
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} |
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|
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/** |
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* gmap_get - increase reference counter for guest address space |
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* @gmap: pointer to the guest address space structure |
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* |
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* Returns the gmap pointer |
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*/ |
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struct gmap *gmap_get(struct gmap *gmap) |
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{ |
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refcount_inc(&gmap->ref_count); |
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return gmap; |
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} |
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EXPORT_SYMBOL_GPL(gmap_get); |
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|
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/** |
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* gmap_put - decrease reference counter for guest address space |
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* @gmap: pointer to the guest address space structure |
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* |
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* If the reference counter reaches zero the guest address space is freed. |
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*/ |
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void gmap_put(struct gmap *gmap) |
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{ |
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if (refcount_dec_and_test(&gmap->ref_count)) |
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gmap_free(gmap); |
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} |
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EXPORT_SYMBOL_GPL(gmap_put); |
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|
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/** |
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* gmap_remove - remove a guest address space but do not free it yet |
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* @gmap: pointer to the guest address space structure |
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*/ |
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void gmap_remove(struct gmap *gmap) |
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{ |
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struct gmap *sg, *next; |
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unsigned long gmap_asce; |
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|
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/* Remove all shadow gmaps linked to this gmap */ |
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if (!list_empty(&gmap->children)) { |
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spin_lock(&gmap->shadow_lock); |
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list_for_each_entry_safe(sg, next, &gmap->children, list) { |
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list_del(&sg->list); |
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gmap_put(sg); |
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} |
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spin_unlock(&gmap->shadow_lock); |
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} |
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/* Remove gmap from the pre-mm list */ |
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spin_lock(&gmap->mm->context.lock); |
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list_del_rcu(&gmap->list); |
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if (list_empty(&gmap->mm->context.gmap_list)) |
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gmap_asce = 0; |
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else if (list_is_singular(&gmap->mm->context.gmap_list)) |
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gmap_asce = list_first_entry(&gmap->mm->context.gmap_list, |
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struct gmap, list)->asce; |
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else |
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gmap_asce = -1UL; |
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WRITE_ONCE(gmap->mm->context.gmap_asce, gmap_asce); |
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spin_unlock(&gmap->mm->context.lock); |
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synchronize_rcu(); |
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/* Put reference */ |
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gmap_put(gmap); |
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} |
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EXPORT_SYMBOL_GPL(gmap_remove); |
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|
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/** |
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* gmap_enable - switch primary space to the guest address space |
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* @gmap: pointer to the guest address space structure |
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*/ |
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void gmap_enable(struct gmap *gmap) |
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{ |
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S390_lowcore.gmap = (unsigned long) gmap; |
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} |
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EXPORT_SYMBOL_GPL(gmap_enable); |
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|
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/** |
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* gmap_disable - switch back to the standard primary address space |
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* @gmap: pointer to the guest address space structure |
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*/ |
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void gmap_disable(struct gmap *gmap) |
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{ |
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S390_lowcore.gmap = 0UL; |
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} |
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EXPORT_SYMBOL_GPL(gmap_disable); |
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|
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/** |
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* gmap_get_enabled - get a pointer to the currently enabled gmap |
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* |
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* Returns a pointer to the currently enabled gmap. 0 if none is enabled. |
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*/ |
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struct gmap *gmap_get_enabled(void) |
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{ |
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return (struct gmap *) S390_lowcore.gmap; |
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} |
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EXPORT_SYMBOL_GPL(gmap_get_enabled); |
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/* |
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* gmap_alloc_table is assumed to be called with mmap_lock held |
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*/ |
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static int gmap_alloc_table(struct gmap *gmap, unsigned long *table, |
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unsigned long init, unsigned long gaddr) |
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{ |
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struct page *page; |
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unsigned long *new; |
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|
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/* since we dont free the gmap table until gmap_free we can unlock */ |
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page = alloc_pages(GFP_KERNEL_ACCOUNT, CRST_ALLOC_ORDER); |
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if (!page) |
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return -ENOMEM; |
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new = (unsigned long *) page_to_phys(page); |
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crst_table_init(new, init); |
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spin_lock(&gmap->guest_table_lock); |
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if (*table & _REGION_ENTRY_INVALID) { |
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list_add(&page->lru, &gmap->crst_list); |
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*table = (unsigned long) new | _REGION_ENTRY_LENGTH | |
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(*table & _REGION_ENTRY_TYPE_MASK); |
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page->index = gaddr; |
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page = NULL; |
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} |
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spin_unlock(&gmap->guest_table_lock); |
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if (page) |
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__free_pages(page, CRST_ALLOC_ORDER); |
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return 0; |
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} |
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|
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/** |
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* __gmap_segment_gaddr - find virtual address from segment pointer |
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* @entry: pointer to a segment table entry in the guest address space |
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* |
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* Returns the virtual address in the guest address space for the segment |
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*/ |
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static unsigned long __gmap_segment_gaddr(unsigned long *entry) |
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{ |
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struct page *page; |
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unsigned long offset, mask; |
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offset = (unsigned long) entry / sizeof(unsigned long); |
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offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE; |
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mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); |
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page = virt_to_page((void *)((unsigned long) entry & mask)); |
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return page->index + offset; |
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} |
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|
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/** |
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* __gmap_unlink_by_vmaddr - unlink a single segment via a host address |
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* @gmap: pointer to the guest address space structure |
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* @vmaddr: address in the host process address space |
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* |
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* Returns 1 if a TLB flush is required |
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*/ |
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static int __gmap_unlink_by_vmaddr(struct gmap *gmap, unsigned long vmaddr) |
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{ |
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unsigned long *entry; |
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int flush = 0; |
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|
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BUG_ON(gmap_is_shadow(gmap)); |
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spin_lock(&gmap->guest_table_lock); |
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entry = radix_tree_delete(&gmap->host_to_guest, vmaddr >> PMD_SHIFT); |
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if (entry) { |
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flush = (*entry != _SEGMENT_ENTRY_EMPTY); |
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*entry = _SEGMENT_ENTRY_EMPTY; |
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} |
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spin_unlock(&gmap->guest_table_lock); |
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return flush; |
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} |
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|
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/** |
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* __gmap_unmap_by_gaddr - unmap a single segment via a guest address |
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* @gmap: pointer to the guest address space structure |
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* @gaddr: address in the guest address space |
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* |
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* Returns 1 if a TLB flush is required |
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*/ |
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static int __gmap_unmap_by_gaddr(struct gmap *gmap, unsigned long gaddr) |
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{ |
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unsigned long vmaddr; |
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|
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vmaddr = (unsigned long) radix_tree_delete(&gmap->guest_to_host, |
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gaddr >> PMD_SHIFT); |
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return vmaddr ? __gmap_unlink_by_vmaddr(gmap, vmaddr) : 0; |
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} |
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|
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/** |
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* gmap_unmap_segment - unmap segment from the guest address space |
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* @gmap: pointer to the guest address space structure |
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* @to: address in the guest address space |
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* @len: length of the memory area to unmap |
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* |
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* Returns 0 if the unmap succeeded, -EINVAL if not. |
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*/ |
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int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len) |
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{ |
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unsigned long off; |
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int flush; |
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|
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BUG_ON(gmap_is_shadow(gmap)); |
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if ((to | len) & (PMD_SIZE - 1)) |
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return -EINVAL; |
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if (len == 0 || to + len < to) |
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return -EINVAL; |
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|
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flush = 0; |
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mmap_write_lock(gmap->mm); |
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for (off = 0; off < len; off += PMD_SIZE) |
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flush |= __gmap_unmap_by_gaddr(gmap, to + off); |
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mmap_write_unlock(gmap->mm); |
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if (flush) |
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gmap_flush_tlb(gmap); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(gmap_unmap_segment); |
|
|
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/** |
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* gmap_map_segment - map a segment to the guest address space |
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* @gmap: pointer to the guest address space structure |
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* @from: source address in the parent address space |
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* @to: target address in the guest address space |
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* @len: length of the memory area to map |
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* |
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* Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not. |
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*/ |
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int gmap_map_segment(struct gmap *gmap, unsigned long from, |
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unsigned long to, unsigned long len) |
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{ |
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unsigned long off; |
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int flush; |
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|
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BUG_ON(gmap_is_shadow(gmap)); |
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if ((from | to | len) & (PMD_SIZE - 1)) |
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return -EINVAL; |
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if (len == 0 || from + len < from || to + len < to || |
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from + len - 1 > TASK_SIZE_MAX || to + len - 1 > gmap->asce_end) |
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return -EINVAL; |
|
|
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flush = 0; |
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mmap_write_lock(gmap->mm); |
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for (off = 0; off < len; off += PMD_SIZE) { |
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/* Remove old translation */ |
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flush |= __gmap_unmap_by_gaddr(gmap, to + off); |
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/* Store new translation */ |
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if (radix_tree_insert(&gmap->guest_to_host, |
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(to + off) >> PMD_SHIFT, |
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(void *) from + off)) |
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break; |
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} |
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mmap_write_unlock(gmap->mm); |
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if (flush) |
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gmap_flush_tlb(gmap); |
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if (off >= len) |
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return 0; |
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gmap_unmap_segment(gmap, to, len); |
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return -ENOMEM; |
|
} |
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EXPORT_SYMBOL_GPL(gmap_map_segment); |
|
|
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/** |
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* __gmap_translate - translate a guest address to a user space address |
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* @gmap: pointer to guest mapping meta data structure |
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* @gaddr: guest address |
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* |
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* Returns user space address which corresponds to the guest address or |
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* -EFAULT if no such mapping exists. |
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* This function does not establish potentially missing page table entries. |
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* The mmap_lock of the mm that belongs to the address space must be held |
|
* when this function gets called. |
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* |
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* Note: Can also be called for shadow gmaps. |
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*/ |
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unsigned long __gmap_translate(struct gmap *gmap, unsigned long gaddr) |
|
{ |
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unsigned long vmaddr; |
|
|
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vmaddr = (unsigned long) |
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radix_tree_lookup(&gmap->guest_to_host, gaddr >> PMD_SHIFT); |
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/* Note: guest_to_host is empty for a shadow gmap */ |
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return vmaddr ? (vmaddr | (gaddr & ~PMD_MASK)) : -EFAULT; |
|
} |
|
EXPORT_SYMBOL_GPL(__gmap_translate); |
|
|
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/** |
|
* gmap_translate - translate a guest address to a user space address |
|
* @gmap: pointer to guest mapping meta data structure |
|
* @gaddr: guest address |
|
* |
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* Returns user space address which corresponds to the guest address or |
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* -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) |
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{ |
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unsigned long rc; |
|
|
|
mmap_read_lock(gmap->mm); |
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rc = __gmap_translate(gmap, gaddr); |
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mmap_read_unlock(gmap->mm); |
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return rc; |
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} |
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EXPORT_SYMBOL_GPL(gmap_translate); |
|
|
|
/** |
|
* gmap_unlink - disconnect a page table from the gmap shadow tables |
|
* @mm: pointer to the parent mm_struct |
|
* @table: pointer to the host page table |
|
* @vmaddr: vm address associated with the host page table |
|
*/ |
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void gmap_unlink(struct mm_struct *mm, unsigned long *table, |
|
unsigned long vmaddr) |
|
{ |
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struct gmap *gmap; |
|
int flush; |
|
|
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rcu_read_lock(); |
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list_for_each_entry_rcu(gmap, &mm->context.gmap_list, list) { |
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flush = __gmap_unlink_by_vmaddr(gmap, vmaddr); |
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if (flush) |
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gmap_flush_tlb(gmap); |
|
} |
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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 |
|
* |
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* 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_ACCOUNT); |
|
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_ACCOUNT); |
|
if (!rmap) |
|
return -ENOMEM; |
|
rmap->raddr = raddr; |
|
rc = radix_tree_preload(GFP_KERNEL_ACCOUNT); |
|
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_ACCOUNT, 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_ACCOUNT, 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_ACCOUNT, 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_pgt_lookup - 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_ACCOUNT); |
|
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_ACCOUNT); |
|
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 |
|
* @vmaddr: 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);
|
|
|