gmap.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 *  KVM guest address space mapping code
  4 *
  5 *    Copyright IBM Corp. 2007, 2016
  6 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  7 */
  8
  9#ifndef _ASM_S390_GMAP_H
 10#define _ASM_S390_GMAP_H
 11
 12#include <linux/radix-tree.h>
 13#include <linux/refcount.h>
 14
 15/* Generic bits for GMAP notification on DAT table entry changes. */
 16#define GMAP_NOTIFY_SHADOW	0x2
 17#define GMAP_NOTIFY_MPROT	0x1
 18
 19/* Status bits only for huge segment entries */
 20#define _SEGMENT_ENTRY_GMAP_IN		0x0800	/* invalidation notify bit */
 21#define _SEGMENT_ENTRY_GMAP_UC		0x0002	/* dirty (migration) */
 22
 23/**
 24 * struct gmap_struct - guest address space
 25 * @list: list head for the mm->context gmap list
 26 * @mm: pointer to the parent mm_struct
 27 * @guest_to_host: radix tree with guest to host address translation
 28 * @host_to_guest: radix tree with pointer to segment table entries
 29 * @guest_table_lock: spinlock to protect all entries in the guest page table
 30 * @ref_count: reference counter for the gmap structure
 31 * @table: pointer to the page directory
 32 * @asce: address space control element for gmap page table
 33 * @pfault_enabled: defines if pfaults are applicable for the guest
 34 * @guest_handle: protected virtual machine handle for the ultravisor
 35 * @host_to_rmap: radix tree with gmap_rmap lists
 36 * @children: list of shadow gmap structures
 37 * @shadow_lock: spinlock to protect the shadow gmap list
 38 * @parent: pointer to the parent gmap for shadow guest address spaces
 39 * @orig_asce: ASCE for which the shadow page table has been created
 40 * @edat_level: edat level to be used for the shadow translation
 41 * @removed: flag to indicate if a shadow guest address space has been removed
 42 * @initialized: flag to indicate if a shadow guest address space can be used
 43 */
 44struct gmap {
 45	struct list_head list;
 46	struct mm_struct *mm;
 47	struct radix_tree_root guest_to_host;
 48	struct radix_tree_root host_to_guest;
 49	spinlock_t guest_table_lock;
 50	refcount_t ref_count;
 51	unsigned long *table;
 52	unsigned long asce;
 53	unsigned long asce_end;
 54	void *private;
 55	bool pfault_enabled;
 56	/* only set for protected virtual machines */
 57	unsigned long guest_handle;
 58	/* Additional data for shadow guest address spaces */
 59	struct radix_tree_root host_to_rmap;
 60	struct list_head children;
 61	spinlock_t shadow_lock;
 62	struct gmap *parent;
 63	unsigned long orig_asce;
 64	int edat_level;
 65	bool removed;
 66	bool initialized;
 67};
 68
 69/**
 70 * struct gmap_rmap - reverse mapping for shadow page table entries
 71 * @next: pointer to next rmap in the list
 72 * @raddr: virtual rmap address in the shadow guest address space
 73 */
 74struct gmap_rmap {
 75	struct gmap_rmap *next;
 76	unsigned long raddr;
 77};
 78
 79#define gmap_for_each_rmap(pos, head) \
 80	for (pos = (head); pos; pos = pos->next)
 81
 82#define gmap_for_each_rmap_safe(pos, n, head) \
 83	for (pos = (head); n = pos ? pos->next : NULL, pos; pos = n)
 84
 85/**
 86 * struct gmap_notifier - notify function block for page invalidation
 87 * @notifier_call: address of callback function
 88 */
 89struct gmap_notifier {
 90	struct list_head list;
 91	struct rcu_head rcu;
 92	void (*notifier_call)(struct gmap *gmap, unsigned long start,
 93			      unsigned long end);
 94};
 95
 96static inline int gmap_is_shadow(struct gmap *gmap)
 97{
 98	return !!gmap->parent;
 99}
100
101struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit);
102void gmap_remove(struct gmap *gmap);
103struct gmap *gmap_get(struct gmap *gmap);
104void gmap_put(struct gmap *gmap);
105void gmap_free(struct gmap *gmap);
106struct gmap *gmap_alloc(unsigned long limit);
107
108int gmap_map_segment(struct gmap *gmap, unsigned long from,
109		     unsigned long to, unsigned long len);
110int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
111unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
112int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
113void __gmap_zap(struct gmap *, unsigned long gaddr);
114void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
115
116int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
117
118void gmap_unshadow(struct gmap *sg);
119int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
120		    int fake);
121int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
122		    int fake);
123int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
124		    int fake);
125int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
126		    int fake);
127int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
128
129void gmap_register_pte_notifier(struct gmap_notifier *);
130void gmap_unregister_pte_notifier(struct gmap_notifier *);
131
132int gmap_protect_one(struct gmap *gmap, unsigned long gaddr, int prot, unsigned long bits);
133
134void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
135			     unsigned long gaddr, unsigned long vmaddr);
136int s390_replace_asce(struct gmap *gmap);
137void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns);
138int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
139			    unsigned long end, bool interruptible);
140unsigned long *gmap_table_walk(struct gmap *gmap, unsigned long gaddr, int level);
141
142/**
143 * s390_uv_destroy_range - Destroy a range of pages in the given mm.
144 * @mm: the mm on which to operate on
145 * @start: the start of the range
146 * @end: the end of the range
147 *
148 * This function will call cond_sched, so it should not generate stalls, but
149 * it will otherwise only return when it completed.
150 */
151static inline void s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
152					 unsigned long end)
153{
154	(void)__s390_uv_destroy_range(mm, start, end, false);
155}
156
157/**
158 * s390_uv_destroy_range_interruptible - Destroy a range of pages in the
159 * given mm, but stop when a fatal signal is received.
160 * @mm: the mm on which to operate on
161 * @start: the start of the range
162 * @end: the end of the range
163 *
164 * This function will call cond_sched, so it should not generate stalls. If
165 * a fatal signal is received, it will return with -EINTR immediately,
166 * without finishing destroying the whole range. Upon successful
167 * completion, 0 is returned.
168 */
169static inline int s390_uv_destroy_range_interruptible(struct mm_struct *mm, unsigned long start,
170						      unsigned long end)
171{
172	return __s390_uv_destroy_range(mm, start, end, true);
173}
174#endif /* _ASM_S390_GMAP_H */