1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * KVM guest address space mapping code
4 *
5 * Copyright IBM Corp. 2007, 2016, 2025
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 * Claudio Imbrenda <imbrenda@linux.ibm.com>
8 */
9
10 #ifndef ARCH_KVM_S390_GMAP_H
11 #define ARCH_KVM_S390_GMAP_H
12
13 #include "dat.h"
14
15 /**
16 * enum gmap_flags - Flags of a gmap.
17 *
18 * @GMAP_FLAG_SHADOW: The gmap is a vsie shadow gmap.
19 * @GMAP_FLAG_OWNS_PAGETABLES: The gmap owns all dat levels; normally 1, is 0
20 * only for ucontrol per-cpu gmaps, since they
21 * share the page tables with the main gmap.
22 * @GMAP_FLAG_IS_UCONTROL: The gmap is ucontrol (main gmap or per-cpu gmap).
23 * @GMAP_FLAG_ALLOW_HPAGE_1M: 1M hugepages are allowed for this gmap,
24 * independently of the page size used by userspace.
25 * @GMAP_FLAG_ALLOW_HPAGE_2G: 2G hugepages are allowed for this gmap,
26 * independently of the page size used by userspace.
27 * @GMAP_FLAG_PFAULT_ENABLED: Pfault is enabled for the gmap.
28 * @GMAP_FLAG_USES_SKEYS: If the guest uses storage keys.
29 * @GMAP_FLAG_USES_CMM: Whether the guest uses CMMA.
30 * @GMAP_FLAG_EXPORT_ON_UNMAP: Whether to export guest pages when unmapping.
31 */
32 enum gmap_flags {
33 GMAP_FLAG_SHADOW = 0,
34 GMAP_FLAG_OWNS_PAGETABLES,
35 GMAP_FLAG_IS_UCONTROL,
36 GMAP_FLAG_ALLOW_HPAGE_1M,
37 GMAP_FLAG_ALLOW_HPAGE_2G,
38 GMAP_FLAG_PFAULT_ENABLED,
39 GMAP_FLAG_USES_SKEYS,
40 GMAP_FLAG_USES_CMM,
41 GMAP_FLAG_EXPORT_ON_UNMAP,
42 };
43
44 /**
45 * struct gmap_struct - Guest address space.
46 *
47 * @flags: GMAP_FLAG_* flags.
48 * @edat_level: The edat level of this shadow gmap.
49 * @kvm: The vm.
50 * @asce: The ASCE used by this gmap.
51 * @list: List head used in children gmaps for the children gmap list.
52 * @children_lock: Protects children and scb_users.
53 * @children: List of child gmaps of this gmap.
54 * @scb_users: List of vsie_scb that use this shadow gmap.
55 * @parent: Parent gmap of a child gmap.
56 * @guest_asce: Original ASCE of this shadow gmap.
57 * @host_to_rmap_lock: Protects host_to_rmap.
58 * @host_to_rmap: Radix tree mapping host addresses to guest addresses.
59 */
60 struct gmap {
61 unsigned long flags;
62 unsigned char edat_level;
63 bool invalidated;
64 struct kvm *kvm;
65 union asce asce;
66 struct list_head list;
67 spinlock_t children_lock; /* Protects: children, scb_users */
68 struct list_head children;
69 struct list_head scb_users;
70 struct gmap *parent;
71 union asce guest_asce;
72 spinlock_t host_to_rmap_lock; /* Protects host_to_rmap */
73 struct radix_tree_root host_to_rmap;
74 refcount_t refcount;
75 };
76
77 struct gmap_cache {
78 struct list_head list;
79 struct gmap *gmap;
80 };
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 int s390_replace_asce(struct gmap *gmap);
86 bool _gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end, bool hint);
87 bool gmap_age_gfn(struct gmap *gmap, gfn_t start, gfn_t end);
88 bool gmap_unmap_gfn_range(struct gmap *gmap, struct kvm_memory_slot *slot, gfn_t start, gfn_t end);
89 int gmap_try_fixup_minor(struct gmap *gmap, struct guest_fault *fault);
90 struct gmap *gmap_new(struct kvm *kvm, gfn_t limit);
91 struct gmap *gmap_new_child(struct gmap *parent, gfn_t limit);
92 void gmap_remove_child(struct gmap *child);
93 void gmap_dispose(struct gmap *gmap);
94 int gmap_link(struct kvm_s390_mmu_cache *mc, struct gmap *gmap, struct guest_fault *fault);
95 void gmap_sync_dirty_log(struct gmap *gmap, gfn_t start, gfn_t end);
96 int gmap_set_limit(struct gmap *gmap, gfn_t limit);
97 int gmap_ucas_translate(struct kvm_s390_mmu_cache *mc, struct gmap *gmap, gpa_t *gaddr);
98 int gmap_ucas_map(struct gmap *gmap, gfn_t p_gfn, gfn_t c_gfn, unsigned long count);
99 void gmap_ucas_unmap(struct gmap *gmap, gfn_t c_gfn, unsigned long count);
100 int gmap_enable_skeys(struct gmap *gmap);
101 int gmap_pv_destroy_range(struct gmap *gmap, gfn_t start, gfn_t end, bool interruptible);
102 int gmap_insert_rmap(struct gmap *sg, gfn_t p_gfn, gfn_t r_gfn, int level);
103 int gmap_protect_rmap(struct kvm_s390_mmu_cache *mc, struct gmap *sg, gfn_t p_gfn, gfn_t r_gfn,
104 kvm_pfn_t pfn, int level, bool wr);
105 void gmap_set_cmma_all_dirty(struct gmap *gmap);
106 void _gmap_handle_vsie_unshadow_event(struct gmap *parent, gfn_t gfn);
107 struct gmap *gmap_create_shadow(struct kvm_s390_mmu_cache *mc, struct gmap *gmap,
108 union asce asce, int edat_level);
109 void gmap_split_huge_pages(struct gmap *gmap);
110
uses_skeys(struct gmap * gmap)111 static inline bool uses_skeys(struct gmap *gmap)
112 {
113 return test_bit(GMAP_FLAG_USES_SKEYS, &gmap->flags);
114 }
115
uses_cmm(struct gmap * gmap)116 static inline bool uses_cmm(struct gmap *gmap)
117 {
118 return test_bit(GMAP_FLAG_USES_CMM, &gmap->flags);
119 }
120
pfault_enabled(struct gmap * gmap)121 static inline bool pfault_enabled(struct gmap *gmap)
122 {
123 return test_bit(GMAP_FLAG_PFAULT_ENABLED, &gmap->flags);
124 }
125
is_ucontrol(struct gmap * gmap)126 static inline bool is_ucontrol(struct gmap *gmap)
127 {
128 return test_bit(GMAP_FLAG_IS_UCONTROL, &gmap->flags);
129 }
130
is_shadow(struct gmap * gmap)131 static inline bool is_shadow(struct gmap *gmap)
132 {
133 return test_bit(GMAP_FLAG_SHADOW, &gmap->flags);
134 }
135
owns_page_tables(struct gmap * gmap)136 static inline bool owns_page_tables(struct gmap *gmap)
137 {
138 return test_bit(GMAP_FLAG_OWNS_PAGETABLES, &gmap->flags);
139 }
140
gmap_put(struct gmap * gmap)141 static inline struct gmap *gmap_put(struct gmap *gmap)
142 {
143 if (refcount_dec_and_test(&gmap->refcount))
144 gmap_dispose(gmap);
145 return NULL;
146 }
147
gmap_get(struct gmap * gmap)148 static inline void gmap_get(struct gmap *gmap)
149 {
150 WARN_ON_ONCE(unlikely(!refcount_inc_not_zero(&gmap->refcount)));
151 }
152
gmap_handle_vsie_unshadow_event(struct gmap * parent,gfn_t gfn)153 static inline void gmap_handle_vsie_unshadow_event(struct gmap *parent, gfn_t gfn)
154 {
155 scoped_guard(spinlock, &parent->children_lock)
156 _gmap_handle_vsie_unshadow_event(parent, gfn);
157 }
158
gmap_mkold_prefix(struct gmap * gmap,gfn_t gfn,gfn_t end)159 static inline bool gmap_mkold_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end)
160 {
161 return _gmap_unmap_prefix(gmap, gfn, end, true);
162 }
163
gmap_unmap_prefix(struct gmap * gmap,gfn_t gfn,gfn_t end)164 static inline bool gmap_unmap_prefix(struct gmap *gmap, gfn_t gfn, gfn_t end)
165 {
166 return _gmap_unmap_prefix(gmap, gfn, end, false);
167 }
168
_gmap_ptep_xchg(struct gmap * gmap,union pte * ptep,union pte newpte,union pgste pgste,gfn_t gfn,bool needs_lock)169 static inline union pgste _gmap_ptep_xchg(struct gmap *gmap, union pte *ptep, union pte newpte,
170 union pgste pgste, gfn_t gfn, bool needs_lock)
171 {
172 lockdep_assert_held(&gmap->kvm->mmu_lock);
173 if (!needs_lock)
174 lockdep_assert_held(&gmap->children_lock);
175 else
176 lockdep_assert_not_held(&gmap->children_lock);
177
178 if (pgste.prefix_notif && (newpte.h.p || newpte.h.i)) {
179 pgste.prefix_notif = 0;
180 gmap_unmap_prefix(gmap, gfn, gfn + 1);
181 }
182 if (pgste.vsie_notif && (ptep->h.p != newpte.h.p || newpte.h.i)) {
183 pgste.vsie_notif = 0;
184 if (needs_lock)
185 gmap_handle_vsie_unshadow_event(gmap, gfn);
186 else
187 _gmap_handle_vsie_unshadow_event(gmap, gfn);
188 }
189 if (!ptep->s.d && newpte.s.d && !newpte.s.s)
190 SetPageDirty(pfn_to_page(newpte.h.pfra));
191 return __dat_ptep_xchg(ptep, pgste, newpte, gfn, gmap->asce, uses_skeys(gmap));
192 }
193
gmap_ptep_xchg(struct gmap * gmap,union pte * ptep,union pte newpte,union pgste pgste,gfn_t gfn)194 static inline union pgste gmap_ptep_xchg(struct gmap *gmap, union pte *ptep, union pte newpte,
195 union pgste pgste, gfn_t gfn)
196 {
197 return _gmap_ptep_xchg(gmap, ptep, newpte, pgste, gfn, true);
198 }
199
_gmap_crstep_xchg_atomic(struct gmap * gmap,union crste * crstep,union crste oldcrste,union crste newcrste,gfn_t gfn,bool needs_lock)200 static inline bool __must_check _gmap_crstep_xchg_atomic(struct gmap *gmap, union crste *crstep,
201 union crste oldcrste, union crste newcrste,
202 gfn_t gfn, bool needs_lock)
203 {
204 unsigned long align = is_pmd(newcrste) ? _PAGE_ENTRIES : _PAGE_ENTRIES * _CRST_ENTRIES;
205
206 if (KVM_BUG_ON(crstep->h.tt != oldcrste.h.tt || newcrste.h.tt != oldcrste.h.tt, gmap->kvm))
207 return true;
208
209 lockdep_assert_held(&gmap->kvm->mmu_lock);
210 if (!needs_lock)
211 lockdep_assert_held(&gmap->children_lock);
212
213 gfn = ALIGN_DOWN(gfn, align);
214 if (crste_prefix(oldcrste) && (newcrste.h.p || newcrste.h.i || !crste_prefix(newcrste))) {
215 newcrste.s.fc1.prefix_notif = 0;
216 gmap_unmap_prefix(gmap, gfn, gfn + align);
217 }
218 if (crste_leaf(oldcrste) && oldcrste.s.fc1.vsie_notif &&
219 (newcrste.h.p || newcrste.h.i || !newcrste.s.fc1.vsie_notif)) {
220 newcrste.s.fc1.vsie_notif = 0;
221 if (needs_lock)
222 gmap_handle_vsie_unshadow_event(gmap, gfn);
223 else
224 _gmap_handle_vsie_unshadow_event(gmap, gfn);
225 }
226 if (!oldcrste.s.fc1.d && newcrste.s.fc1.d && !newcrste.s.fc1.s)
227 SetPageDirty(phys_to_page(crste_origin_large(newcrste)));
228 return dat_crstep_xchg_atomic(crstep, oldcrste, newcrste, gfn, gmap->asce);
229 }
230
gmap_crstep_xchg_atomic(struct gmap * gmap,union crste * crstep,union crste oldcrste,union crste newcrste,gfn_t gfn)231 static inline bool __must_check gmap_crstep_xchg_atomic(struct gmap *gmap, union crste *crstep,
232 union crste oldcrste, union crste newcrste,
233 gfn_t gfn)
234 {
235 return _gmap_crstep_xchg_atomic(gmap, crstep, oldcrste, newcrste, gfn, true);
236 }
237
238 /**
239 * gmap_is_shadow_valid() - check if a shadow guest address space matches the
240 * given properties and is still valid.
241 * @sg: Pointer to the shadow guest address space structure.
242 * @asce: ASCE for which the shadow table is requested.
243 * @edat_level: Edat level to be used for the shadow translation.
244 *
245 * Return: true if the gmap shadow is still valid and matches the given
246 * properties and the caller can continue using it; false otherwise, the
247 * caller has to request a new shadow gmap in this case.
248 */
gmap_is_shadow_valid(struct gmap * sg,union asce asce,int edat_level)249 static inline bool gmap_is_shadow_valid(struct gmap *sg, union asce asce, int edat_level)
250 {
251 return sg->guest_asce.val == asce.val && sg->edat_level == edat_level;
252 }
253
254 #endif /* ARCH_KVM_S390_GMAP_H */
255