1 /*
2 * gaccess.h - access guest memory
3 *
4 * Copyright IBM Corp. 2008
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License (version 2 only)
8 * as published by the Free Software Foundation.
9 *
10 * Author(s): Carsten Otte <cotte@de.ibm.com>
11 */
12
13 #ifndef __KVM_S390_GACCESS_H
14 #define __KVM_S390_GACCESS_H
15
16 #include <linux/compiler.h>
17 #include <linux/kvm_host.h>
18 #include <asm/uaccess.h>
19
__guestaddr_to_user(struct kvm_vcpu * vcpu,unsigned long guestaddr)20 static inline void __user *__guestaddr_to_user(struct kvm_vcpu *vcpu,
21 unsigned long guestaddr)
22 {
23 unsigned long prefix = vcpu->arch.sie_block->prefix;
24 unsigned long origin = vcpu->kvm->arch.guest_origin;
25 unsigned long memsize = vcpu->kvm->arch.guest_memsize;
26
27 if (guestaddr < 2 * PAGE_SIZE)
28 guestaddr += prefix;
29 else if ((guestaddr >= prefix) && (guestaddr < prefix + 2 * PAGE_SIZE))
30 guestaddr -= prefix;
31
32 if (guestaddr > memsize)
33 return (void __user __force *) ERR_PTR(-EFAULT);
34
35 guestaddr += origin;
36
37 return (void __user *) guestaddr;
38 }
39
get_guest_u64(struct kvm_vcpu * vcpu,unsigned long guestaddr,u64 * result)40 static inline int get_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
41 u64 *result)
42 {
43 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
44
45 BUG_ON(guestaddr & 7);
46
47 if (IS_ERR((void __force *) uptr))
48 return PTR_ERR((void __force *) uptr);
49
50 return get_user(*result, (unsigned long __user *) uptr);
51 }
52
get_guest_u32(struct kvm_vcpu * vcpu,unsigned long guestaddr,u32 * result)53 static inline int get_guest_u32(struct kvm_vcpu *vcpu, unsigned long guestaddr,
54 u32 *result)
55 {
56 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
57
58 BUG_ON(guestaddr & 3);
59
60 if (IS_ERR((void __force *) uptr))
61 return PTR_ERR((void __force *) uptr);
62
63 return get_user(*result, (u32 __user *) uptr);
64 }
65
get_guest_u16(struct kvm_vcpu * vcpu,unsigned long guestaddr,u16 * result)66 static inline int get_guest_u16(struct kvm_vcpu *vcpu, unsigned long guestaddr,
67 u16 *result)
68 {
69 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
70
71 BUG_ON(guestaddr & 1);
72
73 if (IS_ERR(uptr))
74 return PTR_ERR(uptr);
75
76 return get_user(*result, (u16 __user *) uptr);
77 }
78
get_guest_u8(struct kvm_vcpu * vcpu,unsigned long guestaddr,u8 * result)79 static inline int get_guest_u8(struct kvm_vcpu *vcpu, unsigned long guestaddr,
80 u8 *result)
81 {
82 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
83
84 if (IS_ERR((void __force *) uptr))
85 return PTR_ERR((void __force *) uptr);
86
87 return get_user(*result, (u8 __user *) uptr);
88 }
89
put_guest_u64(struct kvm_vcpu * vcpu,unsigned long guestaddr,u64 value)90 static inline int put_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
91 u64 value)
92 {
93 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
94
95 BUG_ON(guestaddr & 7);
96
97 if (IS_ERR((void __force *) uptr))
98 return PTR_ERR((void __force *) uptr);
99
100 return put_user(value, (u64 __user *) uptr);
101 }
102
put_guest_u32(struct kvm_vcpu * vcpu,unsigned long guestaddr,u32 value)103 static inline int put_guest_u32(struct kvm_vcpu *vcpu, unsigned long guestaddr,
104 u32 value)
105 {
106 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
107
108 BUG_ON(guestaddr & 3);
109
110 if (IS_ERR((void __force *) uptr))
111 return PTR_ERR((void __force *) uptr);
112
113 return put_user(value, (u32 __user *) uptr);
114 }
115
put_guest_u16(struct kvm_vcpu * vcpu,unsigned long guestaddr,u16 value)116 static inline int put_guest_u16(struct kvm_vcpu *vcpu, unsigned long guestaddr,
117 u16 value)
118 {
119 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
120
121 BUG_ON(guestaddr & 1);
122
123 if (IS_ERR((void __force *) uptr))
124 return PTR_ERR((void __force *) uptr);
125
126 return put_user(value, (u16 __user *) uptr);
127 }
128
put_guest_u8(struct kvm_vcpu * vcpu,unsigned long guestaddr,u8 value)129 static inline int put_guest_u8(struct kvm_vcpu *vcpu, unsigned long guestaddr,
130 u8 value)
131 {
132 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
133
134 if (IS_ERR((void __force *) uptr))
135 return PTR_ERR((void __force *) uptr);
136
137 return put_user(value, (u8 __user *) uptr);
138 }
139
140
__copy_to_guest_slow(struct kvm_vcpu * vcpu,unsigned long guestdest,const void * from,unsigned long n)141 static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu,
142 unsigned long guestdest,
143 const void *from, unsigned long n)
144 {
145 int rc;
146 unsigned long i;
147 const u8 *data = from;
148
149 for (i = 0; i < n; i++) {
150 rc = put_guest_u8(vcpu, guestdest++, *(data++));
151 if (rc < 0)
152 return rc;
153 }
154 return 0;
155 }
156
copy_to_guest(struct kvm_vcpu * vcpu,unsigned long guestdest,const void * from,unsigned long n)157 static inline int copy_to_guest(struct kvm_vcpu *vcpu, unsigned long guestdest,
158 const void *from, unsigned long n)
159 {
160 unsigned long prefix = vcpu->arch.sie_block->prefix;
161 unsigned long origin = vcpu->kvm->arch.guest_origin;
162 unsigned long memsize = vcpu->kvm->arch.guest_memsize;
163
164 if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
165 goto slowpath;
166
167 if ((guestdest < prefix) && (guestdest + n > prefix))
168 goto slowpath;
169
170 if ((guestdest < prefix + 2 * PAGE_SIZE)
171 && (guestdest + n > prefix + 2 * PAGE_SIZE))
172 goto slowpath;
173
174 if (guestdest < 2 * PAGE_SIZE)
175 guestdest += prefix;
176 else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
177 guestdest -= prefix;
178
179 if (guestdest + n > memsize)
180 return -EFAULT;
181
182 if (guestdest + n < guestdest)
183 return -EFAULT;
184
185 guestdest += origin;
186
187 return copy_to_user((void __user *) guestdest, from, n);
188 slowpath:
189 return __copy_to_guest_slow(vcpu, guestdest, from, n);
190 }
191
__copy_from_guest_slow(struct kvm_vcpu * vcpu,void * to,unsigned long guestsrc,unsigned long n)192 static inline int __copy_from_guest_slow(struct kvm_vcpu *vcpu, void *to,
193 unsigned long guestsrc,
194 unsigned long n)
195 {
196 int rc;
197 unsigned long i;
198 u8 *data = to;
199
200 for (i = 0; i < n; i++) {
201 rc = get_guest_u8(vcpu, guestsrc++, data++);
202 if (rc < 0)
203 return rc;
204 }
205 return 0;
206 }
207
copy_from_guest(struct kvm_vcpu * vcpu,void * to,unsigned long guestsrc,unsigned long n)208 static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to,
209 unsigned long guestsrc, unsigned long n)
210 {
211 unsigned long prefix = vcpu->arch.sie_block->prefix;
212 unsigned long origin = vcpu->kvm->arch.guest_origin;
213 unsigned long memsize = vcpu->kvm->arch.guest_memsize;
214
215 if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
216 goto slowpath;
217
218 if ((guestsrc < prefix) && (guestsrc + n > prefix))
219 goto slowpath;
220
221 if ((guestsrc < prefix + 2 * PAGE_SIZE)
222 && (guestsrc + n > prefix + 2 * PAGE_SIZE))
223 goto slowpath;
224
225 if (guestsrc < 2 * PAGE_SIZE)
226 guestsrc += prefix;
227 else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
228 guestsrc -= prefix;
229
230 if (guestsrc + n > memsize)
231 return -EFAULT;
232
233 if (guestsrc + n < guestsrc)
234 return -EFAULT;
235
236 guestsrc += origin;
237
238 return copy_from_user(to, (void __user *) guestsrc, n);
239 slowpath:
240 return __copy_from_guest_slow(vcpu, to, guestsrc, n);
241 }
242
copy_to_guest_absolute(struct kvm_vcpu * vcpu,unsigned long guestdest,const void * from,unsigned long n)243 static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu,
244 unsigned long guestdest,
245 const void *from, unsigned long n)
246 {
247 unsigned long origin = vcpu->kvm->arch.guest_origin;
248 unsigned long memsize = vcpu->kvm->arch.guest_memsize;
249
250 if (guestdest + n > memsize)
251 return -EFAULT;
252
253 if (guestdest + n < guestdest)
254 return -EFAULT;
255
256 guestdest += origin;
257
258 return copy_to_user((void __user *) guestdest, from, n);
259 }
260
copy_from_guest_absolute(struct kvm_vcpu * vcpu,void * to,unsigned long guestsrc,unsigned long n)261 static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to,
262 unsigned long guestsrc,
263 unsigned long n)
264 {
265 unsigned long origin = vcpu->kvm->arch.guest_origin;
266 unsigned long memsize = vcpu->kvm->arch.guest_memsize;
267
268 if (guestsrc + n > memsize)
269 return -EFAULT;
270
271 if (guestsrc + n < guestsrc)
272 return -EFAULT;
273
274 guestsrc += origin;
275
276 return copy_from_user(to, (void __user *) guestsrc, n);
277 }
278 #endif
279