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 0x8000 /* invalidation notify bit */
21 #define _SEGMENT_ENTRY_GMAP_UC 0x4000 /* dirty (migration) */
22
23 /**
24 * struct gmap_struct - guest address space
25 * @list: list head for the mm->context gmap list
26 * @crst_list: list of all crst tables used in the guest address space
27 * @mm: pointer to the parent mm_struct
28 * @guest_to_host: radix tree with guest to host address translation
29 * @host_to_guest: radix tree with pointer to segment table entries
30 * @guest_table_lock: spinlock to protect all entries in the guest page table
31 * @ref_count: reference counter for the gmap structure
32 * @table: pointer to the page directory
33 * @asce: address space control element for gmap page table
34 * @pfault_enabled: defines if pfaults are applicable for the guest
35 * @guest_handle: protected virtual machine handle for the ultravisor
36 * @host_to_rmap: radix tree with gmap_rmap lists
37 * @children: list of shadow gmap structures
38 * @pt_list: list of all page tables used in the shadow guest address space
39 * @shadow_lock: spinlock to protect the shadow gmap list
40 * @parent: pointer to the parent gmap for shadow guest address spaces
41 * @orig_asce: ASCE for which the shadow page table has been created
42 * @edat_level: edat level to be used for the shadow translation
43 * @removed: flag to indicate if a shadow guest address space has been removed
44 * @initialized: flag to indicate if a shadow guest address space can be used
45 */
46 struct gmap {
47 struct list_head list;
48 struct list_head crst_list;
49 struct mm_struct *mm;
50 struct radix_tree_root guest_to_host;
51 struct radix_tree_root host_to_guest;
52 spinlock_t guest_table_lock;
53 refcount_t ref_count;
54 unsigned long *table;
55 unsigned long asce;
56 unsigned long asce_end;
57 void *private;
58 bool pfault_enabled;
59 /* only set for protected virtual machines */
60 unsigned long guest_handle;
61 /* Additional data for shadow guest address spaces */
62 struct radix_tree_root host_to_rmap;
63 struct list_head children;
64 struct list_head pt_list;
65 spinlock_t shadow_lock;
66 struct gmap *parent;
67 unsigned long orig_asce;
68 int edat_level;
69 bool removed;
70 bool initialized;
71 };
72
73 /**
74 * struct gmap_rmap - reverse mapping for shadow page table entries
75 * @next: pointer to next rmap in the list
76 * @raddr: virtual rmap address in the shadow guest address space
77 */
78 struct gmap_rmap {
79 struct gmap_rmap *next;
80 unsigned long raddr;
81 };
82
83 #define gmap_for_each_rmap(pos, head) \
84 for (pos = (head); pos; pos = pos->next)
85
86 #define gmap_for_each_rmap_safe(pos, n, head) \
87 for (pos = (head); n = pos ? pos->next : NULL, pos; pos = n)
88
89 /**
90 * struct gmap_notifier - notify function block for page invalidation
91 * @notifier_call: address of callback function
92 */
93 struct gmap_notifier {
94 struct list_head list;
95 struct rcu_head rcu;
96 void (*notifier_call)(struct gmap *gmap, unsigned long start,
97 unsigned long end);
98 };
99
gmap_is_shadow(struct gmap * gmap)100 static inline int gmap_is_shadow(struct gmap *gmap)
101 {
102 return !!gmap->parent;
103 }
104
105 struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit);
106 void gmap_remove(struct gmap *gmap);
107 struct gmap *gmap_get(struct gmap *gmap);
108 void gmap_put(struct gmap *gmap);
109
110 void gmap_enable(struct gmap *gmap);
111 void gmap_disable(struct gmap *gmap);
112 struct gmap *gmap_get_enabled(void);
113 int gmap_map_segment(struct gmap *gmap, unsigned long from,
114 unsigned long to, unsigned long len);
115 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
116 unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
117 unsigned long gmap_translate(struct gmap *, unsigned long gaddr);
118 int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
119 int gmap_fault(struct gmap *, unsigned long gaddr, unsigned int fault_flags);
120 void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
121 void __gmap_zap(struct gmap *, unsigned long gaddr);
122 void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
123
124 int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
125
126 struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
127 int edat_level);
128 int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level);
129 int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
130 int fake);
131 int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
132 int fake);
133 int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
134 int fake);
135 int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
136 int fake);
137 int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
138 unsigned long *pgt, int *dat_protection, int *fake);
139 int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
140
141 void gmap_register_pte_notifier(struct gmap_notifier *);
142 void gmap_unregister_pte_notifier(struct gmap_notifier *);
143
144 int gmap_mprotect_notify(struct gmap *, unsigned long start,
145 unsigned long len, int prot);
146
147 void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
148 unsigned long gaddr, unsigned long vmaddr);
149 int s390_disable_cow_sharing(void);
150 void s390_unlist_old_asce(struct gmap *gmap);
151 int s390_replace_asce(struct gmap *gmap);
152 void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns);
153 int __s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
154 unsigned long end, bool interruptible);
155
156 /**
157 * s390_uv_destroy_range - Destroy a range of pages in the given mm.
158 * @mm: the mm on which to operate on
159 * @start: the start of the range
160 * @end: the end of the range
161 *
162 * This function will call cond_sched, so it should not generate stalls, but
163 * it will otherwise only return when it completed.
164 */
s390_uv_destroy_range(struct mm_struct * mm,unsigned long start,unsigned long end)165 static inline void s390_uv_destroy_range(struct mm_struct *mm, unsigned long start,
166 unsigned long end)
167 {
168 (void)__s390_uv_destroy_range(mm, start, end, false);
169 }
170
171 /**
172 * s390_uv_destroy_range_interruptible - Destroy a range of pages in the
173 * given mm, but stop when a fatal signal is received.
174 * @mm: the mm on which to operate on
175 * @start: the start of the range
176 * @end: the end of the range
177 *
178 * This function will call cond_sched, so it should not generate stalls. If
179 * a fatal signal is received, it will return with -EINTR immediately,
180 * without finishing destroying the whole range. Upon successful
181 * completion, 0 is returned.
182 */
s390_uv_destroy_range_interruptible(struct mm_struct * mm,unsigned long start,unsigned long end)183 static inline int s390_uv_destroy_range_interruptible(struct mm_struct *mm, unsigned long start,
184 unsigned long end)
185 {
186 return __s390_uv_destroy_range(mm, start, end, true);
187 }
188 #endif /* _ASM_S390_GMAP_H */
189