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 */
 46struct 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 */
 78struct 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 */
 93struct 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
100static inline int gmap_is_shadow(struct gmap *gmap)
101{
102	return !!gmap->parent;
103}
104
105struct gmap *gmap_create(struct mm_struct *mm, unsigned long limit);
106void gmap_remove(struct gmap *gmap);
107struct gmap *gmap_get(struct gmap *gmap);
108void gmap_put(struct gmap *gmap);
109
110void gmap_enable(struct gmap *gmap);
111void gmap_disable(struct gmap *gmap);
112struct gmap *gmap_get_enabled(void);
113int gmap_map_segment(struct gmap *gmap, unsigned long from,
114		     unsigned long to, unsigned long len);
115int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len);
116unsigned long __gmap_translate(struct gmap *, unsigned long gaddr);
117unsigned long gmap_translate(struct gmap *, unsigned long gaddr);
118int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr);
119int gmap_fault(struct gmap *, unsigned long gaddr, unsigned int fault_flags);
120void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
121void __gmap_zap(struct gmap *, unsigned long gaddr);
122void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
123
124int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
125
126struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
127			 int edat_level);
128int gmap_shadow_valid(struct gmap *sg, unsigned long asce, int edat_level);
129int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
130		    int fake);
131int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
132		    int fake);
133int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
134		    int fake);
135int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,
136		    int fake);
137int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
138			   unsigned long *pgt, int *dat_protection, int *fake);
139int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
140
141void gmap_register_pte_notifier(struct gmap_notifier *);
142void gmap_unregister_pte_notifier(struct gmap_notifier *);
143
144int gmap_mprotect_notify(struct gmap *, unsigned long start,
145			 unsigned long len, int prot);
146
147void gmap_sync_dirty_log_pmd(struct gmap *gmap, unsigned long dirty_bitmap[4],
148			     unsigned long gaddr, unsigned long vmaddr);
149int gmap_mark_unmergeable(void);
150void s390_unlist_old_asce(struct gmap *gmap);
151int s390_replace_asce(struct gmap *gmap);
152void s390_uv_destroy_pfns(unsigned long count, unsigned long *pfns);
153int __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 */
165static 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 */
183static 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 */