xref: /linux/arch/s390/include/asm/gmap.h (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
1 /*
2  *  KVM guest address space mapping code
3  *
4  *    Copyright IBM Corp. 2007, 2016
5  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
6  */
7 
8 #ifndef _ASM_S390_GMAP_H
9 #define _ASM_S390_GMAP_H
10 
11 /**
12  * struct gmap_struct - guest address space
13  * @list: list head for the mm->context gmap list
14  * @crst_list: list of all crst tables used in the guest address space
15  * @mm: pointer to the parent mm_struct
16  * @guest_to_host: radix tree with guest to host address translation
17  * @host_to_guest: radix tree with pointer to segment table entries
18  * @guest_table_lock: spinlock to protect all entries in the guest page table
19  * @ref_count: reference counter for the gmap structure
20  * @table: pointer to the page directory
21  * @asce: address space control element for gmap page table
22  * @pfault_enabled: defines if pfaults are applicable for the guest
23  * @host_to_rmap: radix tree with gmap_rmap lists
24  * @children: list of shadow gmap structures
25  * @pt_list: list of all page tables used in the shadow guest address space
26  * @shadow_lock: spinlock to protect the shadow gmap list
27  * @parent: pointer to the parent gmap for shadow guest address spaces
28  * @orig_asce: ASCE for which the shadow page table has been created
29  * @edat_level: edat level to be used for the shadow translation
30  * @removed: flag to indicate if a shadow guest address space has been removed
31  * @initialized: flag to indicate if a shadow guest address space can be used
32  */
33 struct gmap {
34 	struct list_head list;
35 	struct list_head crst_list;
36 	struct mm_struct *mm;
37 	struct radix_tree_root guest_to_host;
38 	struct radix_tree_root host_to_guest;
39 	spinlock_t guest_table_lock;
40 	atomic_t ref_count;
41 	unsigned long *table;
42 	unsigned long asce;
43 	unsigned long asce_end;
44 	void *private;
45 	bool pfault_enabled;
46 	/* Additional data for shadow guest address spaces */
47 	struct radix_tree_root host_to_rmap;
48 	struct list_head children;
49 	struct list_head pt_list;
50 	spinlock_t shadow_lock;
51 	struct gmap *parent;
52 	unsigned long orig_asce;
53 	int edat_level;
54 	bool removed;
55 	bool initialized;
56 };
57 
58 /**
59  * struct gmap_rmap - reverse mapping for shadow page table entries
60  * @next: pointer to next rmap in the list
61  * @raddr: virtual rmap address in the shadow guest address space
62  */
63 struct gmap_rmap {
64 	struct gmap_rmap *next;
65 	unsigned long raddr;
66 };
67 
68 #define gmap_for_each_rmap(pos, head) \
69 	for (pos = (head); pos; pos = pos->next)
70 
71 #define gmap_for_each_rmap_safe(pos, n, head) \
72 	for (pos = (head); n = pos ? pos->next : NULL, pos; pos = n)
73 
74 /**
75  * struct gmap_notifier - notify function block for page invalidation
76  * @notifier_call: address of callback function
77  */
78 struct gmap_notifier {
79 	struct list_head list;
80 	struct rcu_head rcu;
81 	void (*notifier_call)(struct gmap *gmap, unsigned long start,
82 			      unsigned long end);
83 };
84 
85 static inline int gmap_is_shadow(struct gmap *gmap)
86 {
87 	return !!gmap->parent;
88 }
89 
90 struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit);
91 void gmap_remove(struct gmap *gmap);
92 struct gmap *gmap_get(struct gmap *gmap);
93 void gmap_put(struct gmap *gmap);
94 
95 void gmap_enable(struct gmap *gmap);
96 void gmap_disable(struct gmap *gmap);
97 struct gmap *gmap_get_enabled(void);
98 int gmap_map_segment(struct gmap *gmap, unsigned long from,
99 		     unsigned long to, unsigned long len);
100 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
101 unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
102 unsigned long gmap_translate(struct gmap *, unsigned long gaddr);
103 int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
104 int gmap_fault(struct gmap *, unsigned long gaddr, unsigned int fault_flags);
105 void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
106 void __gmap_zap(struct gmap *, unsigned long gaddr);
107 void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
108 
109 int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
110 
111 struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
112 			 int edat_level);
113 int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level);
114 int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
115 		    int fake);
116 int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
117 		    int fake);
118 int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
119 		    int fake);
120 int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
121 		    int fake);
122 int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
123 			   unsigned long *pgt, int *dat_protection, int *fake);
124 int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
125 
126 void gmap_register_pte_notifier(struct gmap_notifier *);
127 void gmap_unregister_pte_notifier(struct gmap_notifier *);
128 void gmap_pte_notify(struct mm_struct *, unsigned long addr, pte_t *,
129 		     unsigned long bits);
130 
131 int gmap_mprotect_notify(struct gmap *, unsigned long start,
132 			 unsigned long len, int prot);
133 
134 #endif /* _ASM_S390_GMAP_H */
135