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1/*
2 * access guest memory
3 *
4 * Copyright IBM Corp. 2008, 2014
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 <linux/uaccess.h>
19#include <linux/ptrace.h>
20#include "kvm-s390.h"
21
22/**
23 * kvm_s390_real_to_abs - convert guest real address to guest absolute address
24 * @vcpu - guest virtual cpu
25 * @gra - guest real address
26 *
27 * Returns the guest absolute address that corresponds to the passed guest real
28 * address @gra of a virtual guest cpu by applying its prefix.
29 */
30static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
31 unsigned long gra)
32{
33 unsigned long prefix = kvm_s390_get_prefix(vcpu);
34
35 if (gra < 2 * PAGE_SIZE)
36 gra += prefix;
37 else if (gra >= prefix && gra < prefix + 2 * PAGE_SIZE)
38 gra -= prefix;
39 return gra;
40}
41
42/**
43 * kvm_s390_logical_to_effective - convert guest logical to effective address
44 * @vcpu: guest virtual cpu
45 * @ga: guest logical address
46 *
47 * Convert a guest vcpu logical address to a guest vcpu effective address by
48 * applying the rules of the vcpu's addressing mode defined by PSW bits 31
49 * and 32 (extendended/basic addressing mode).
50 *
51 * Depending on the vcpu's addressing mode the upper 40 bits (24 bit addressing
52 * mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing mode)
53 * of @ga will be zeroed and the remaining bits will be returned.
54 */
55static inline unsigned long kvm_s390_logical_to_effective(struct kvm_vcpu *vcpu,
56 unsigned long ga)
57{
58 psw_t *psw = &vcpu->arch.sie_block->gpsw;
59
60 if (psw_bits(*psw).eaba == PSW_AMODE_64BIT)
61 return ga;
62 if (psw_bits(*psw).eaba == PSW_AMODE_31BIT)
63 return ga & ((1UL << 31) - 1);
64 return ga & ((1UL << 24) - 1);
65}
66
67/*
68 * put_guest_lc, read_guest_lc and write_guest_lc are guest access functions
69 * which shall only be used to access the lowcore of a vcpu.
70 * These functions should be used for e.g. interrupt handlers where no
71 * guest memory access protection facilities, like key or low address
72 * protection, are applicable.
73 * At a later point guest vcpu lowcore access should happen via pinned
74 * prefix pages, so that these pages can be accessed directly via the
75 * kernel mapping. All of these *_lc functions can be removed then.
76 */
77
78/**
79 * put_guest_lc - write a simple variable to a guest vcpu's lowcore
80 * @vcpu: virtual cpu
81 * @x: value to copy to guest
82 * @gra: vcpu's destination guest real address
83 *
84 * Copies a simple value from kernel space to a guest vcpu's lowcore.
85 * The size of the variable may be 1, 2, 4 or 8 bytes. The destination
86 * must be located in the vcpu's lowcore. Otherwise the result is undefined.
87 *
88 * Returns zero on success or -EFAULT on error.
89 *
90 * Note: an error indicates that either the kernel is out of memory or
91 * the guest memory mapping is broken. In any case the best solution
92 * would be to terminate the guest.
93 * It is wrong to inject a guest exception.
94 */
95#define put_guest_lc(vcpu, x, gra) \
96({ \
97 struct kvm_vcpu *__vcpu = (vcpu); \
98 __typeof__(*(gra)) __x = (x); \
99 unsigned long __gpa; \
100 \
101 __gpa = (unsigned long)(gra); \
102 __gpa += kvm_s390_get_prefix(__vcpu); \
103 kvm_write_guest(__vcpu->kvm, __gpa, &__x, sizeof(__x)); \
104})
105
106/**
107 * write_guest_lc - copy data from kernel space to guest vcpu's lowcore
108 * @vcpu: virtual cpu
109 * @gra: vcpu's source guest real address
110 * @data: source address in kernel space
111 * @len: number of bytes to copy
112 *
113 * Copy data from kernel space to guest vcpu's lowcore. The entire range must
114 * be located within the vcpu's lowcore, otherwise the result is undefined.
115 *
116 * Returns zero on success or -EFAULT on error.
117 *
118 * Note: an error indicates that either the kernel is out of memory or
119 * the guest memory mapping is broken. In any case the best solution
120 * would be to terminate the guest.
121 * It is wrong to inject a guest exception.
122 */
123static inline __must_check
124int write_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
125 unsigned long len)
126{
127 unsigned long gpa = gra + kvm_s390_get_prefix(vcpu);
128
129 return kvm_write_guest(vcpu->kvm, gpa, data, len);
130}
131
132/**
133 * read_guest_lc - copy data from guest vcpu's lowcore to kernel space
134 * @vcpu: virtual cpu
135 * @gra: vcpu's source guest real address
136 * @data: destination address in kernel space
137 * @len: number of bytes to copy
138 *
139 * Copy data from guest vcpu's lowcore to kernel space. The entire range must
140 * be located within the vcpu's lowcore, otherwise the result is undefined.
141 *
142 * Returns zero on success or -EFAULT on error.
143 *
144 * Note: an error indicates that either the kernel is out of memory or
145 * the guest memory mapping is broken. In any case the best solution
146 * would be to terminate the guest.
147 * It is wrong to inject a guest exception.
148 */
149static inline __must_check
150int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
151 unsigned long len)
152{
153 unsigned long gpa = gra + kvm_s390_get_prefix(vcpu);
154
155 return kvm_read_guest(vcpu->kvm, gpa, data, len);
156}
157
158enum gacc_mode {
159 GACC_FETCH,
160 GACC_STORE,
161 GACC_IFETCH,
162};
163
164int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,
165 ar_t ar, unsigned long *gpa, enum gacc_mode mode);
166int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
167 unsigned long length, enum gacc_mode mode);
168
169int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
170 unsigned long len, enum gacc_mode mode);
171
172int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
173 void *data, unsigned long len, enum gacc_mode mode);
174
175/**
176 * write_guest - copy data from kernel space to guest space
177 * @vcpu: virtual cpu
178 * @ga: guest address
179 * @ar: access register
180 * @data: source address in kernel space
181 * @len: number of bytes to copy
182 *
183 * Copy @len bytes from @data (kernel space) to @ga (guest address).
184 * In order to copy data to guest space the PSW of the vcpu is inspected:
185 * If DAT is off data will be copied to guest real or absolute memory.
186 * If DAT is on data will be copied to the address space as specified by
187 * the address space bits of the PSW:
188 * Primary, secondary, home space or access register mode.
189 * The addressing mode of the PSW is also inspected, so that address wrap
190 * around is taken into account for 24-, 31- and 64-bit addressing mode,
191 * if the to be copied data crosses page boundaries in guest address space.
192 * In addition also low address and DAT protection are inspected before
193 * copying any data (key protection is currently not implemented).
194 *
195 * This function modifies the 'struct kvm_s390_pgm_info pgm' member of @vcpu.
196 * In case of an access exception (e.g. protection exception) pgm will contain
197 * all data necessary so that a subsequent call to 'kvm_s390_inject_prog_vcpu()'
198 * will inject a correct exception into the guest.
199 * If no access exception happened, the contents of pgm are undefined when
200 * this function returns.
201 *
202 * Returns: - zero on success
203 * - a negative value if e.g. the guest mapping is broken or in
204 * case of out-of-memory. In this case the contents of pgm are
205 * undefined. Also parts of @data may have been copied to guest
206 * space.
207 * - a positive value if an access exception happened. In this case
208 * the returned value is the program interruption code and the
209 * contents of pgm may be used to inject an exception into the
210 * guest. No data has been copied to guest space.
211 *
212 * Note: in case an access exception is recognized no data has been copied to
213 * guest space (this is also true, if the to be copied data would cross
214 * one or more page boundaries in guest space).
215 * Therefore this function may be used for nullifying and suppressing
216 * instruction emulation.
217 * It may also be used for terminating instructions, if it is undefined
218 * if data has been changed in guest space in case of an exception.
219 */
220static inline __must_check
221int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
222 unsigned long len)
223{
224 return access_guest(vcpu, ga, ar, data, len, GACC_STORE);
225}
226
227/**
228 * read_guest - copy data from guest space to kernel space
229 * @vcpu: virtual cpu
230 * @ga: guest address
231 * @ar: access register
232 * @data: destination address in kernel space
233 * @len: number of bytes to copy
234 *
235 * Copy @len bytes from @ga (guest address) to @data (kernel space).
236 *
237 * The behaviour of read_guest is identical to write_guest, except that
238 * data will be copied from guest space to kernel space.
239 */
240static inline __must_check
241int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
242 unsigned long len)
243{
244 return access_guest(vcpu, ga, ar, data, len, GACC_FETCH);
245}
246
247/**
248 * read_guest_instr - copy instruction data from guest space to kernel space
249 * @vcpu: virtual cpu
250 * @data: destination address in kernel space
251 * @len: number of bytes to copy
252 *
253 * Copy @len bytes from the current psw address (guest space) to @data (kernel
254 * space).
255 *
256 * The behaviour of read_guest_instr is identical to read_guest, except that
257 * instruction data will be read from primary space when in home-space or
258 * address-space mode.
259 */
260static inline __must_check
261int read_guest_instr(struct kvm_vcpu *vcpu, void *data, unsigned long len)
262{
263 return access_guest(vcpu, vcpu->arch.sie_block->gpsw.addr, 0, data, len,
264 GACC_IFETCH);
265}
266
267/**
268 * write_guest_abs - copy data from kernel space to guest space absolute
269 * @vcpu: virtual cpu
270 * @gpa: guest physical (absolute) address
271 * @data: source address in kernel space
272 * @len: number of bytes to copy
273 *
274 * Copy @len bytes from @data (kernel space) to @gpa (guest absolute address).
275 * It is up to the caller to ensure that the entire guest memory range is
276 * valid memory before calling this function.
277 * Guest low address and key protection are not checked.
278 *
279 * Returns zero on success or -EFAULT on error.
280 *
281 * If an error occurs data may have been copied partially to guest memory.
282 */
283static inline __must_check
284int write_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data,
285 unsigned long len)
286{
287 return kvm_write_guest(vcpu->kvm, gpa, data, len);
288}
289
290/**
291 * read_guest_abs - copy data from guest space absolute to kernel space
292 * @vcpu: virtual cpu
293 * @gpa: guest physical (absolute) address
294 * @data: destination address in kernel space
295 * @len: number of bytes to copy
296 *
297 * Copy @len bytes from @gpa (guest absolute address) to @data (kernel space).
298 * It is up to the caller to ensure that the entire guest memory range is
299 * valid memory before calling this function.
300 * Guest key protection is not checked.
301 *
302 * Returns zero on success or -EFAULT on error.
303 *
304 * If an error occurs data may have been copied partially to kernel space.
305 */
306static inline __must_check
307int read_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data,
308 unsigned long len)
309{
310 return kvm_read_guest(vcpu->kvm, gpa, data, len);
311}
312
313/**
314 * write_guest_real - copy data from kernel space to guest space real
315 * @vcpu: virtual cpu
316 * @gra: guest real address
317 * @data: source address in kernel space
318 * @len: number of bytes to copy
319 *
320 * Copy @len bytes from @data (kernel space) to @gra (guest real address).
321 * It is up to the caller to ensure that the entire guest memory range is
322 * valid memory before calling this function.
323 * Guest low address and key protection are not checked.
324 *
325 * Returns zero on success or -EFAULT on error.
326 *
327 * If an error occurs data may have been copied partially to guest memory.
328 */
329static inline __must_check
330int write_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
331 unsigned long len)
332{
333 return access_guest_real(vcpu, gra, data, len, 1);
334}
335
336/**
337 * read_guest_real - copy data from guest space real to kernel space
338 * @vcpu: virtual cpu
339 * @gra: guest real address
340 * @data: destination address in kernel space
341 * @len: number of bytes to copy
342 *
343 * Copy @len bytes from @gra (guest real address) to @data (kernel space).
344 * It is up to the caller to ensure that the entire guest memory range is
345 * valid memory before calling this function.
346 * Guest key protection is not checked.
347 *
348 * Returns zero on success or -EFAULT on error.
349 *
350 * If an error occurs data may have been copied partially to kernel space.
351 */
352static inline __must_check
353int read_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
354 unsigned long len)
355{
356 return access_guest_real(vcpu, gra, data, len, 0);
357}
358
359void ipte_lock(struct kvm_vcpu *vcpu);
360void ipte_unlock(struct kvm_vcpu *vcpu);
361int ipte_lock_held(struct kvm_vcpu *vcpu);
362int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra);
363
364int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *shadow,
365 unsigned long saddr);
366
367#endif /* __KVM_S390_GACCESS_H */
1/*
2 * access.h - access guest memory
3 *
4 * Copyright IBM Corp. 2008,2009
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#include "kvm-s390.h"
20
21static inline void __user *__guestaddr_to_user(struct kvm_vcpu *vcpu,
22 unsigned long guestaddr)
23{
24 unsigned long prefix = vcpu->arch.sie_block->prefix;
25
26 if (guestaddr < 2 * PAGE_SIZE)
27 guestaddr += prefix;
28 else if ((guestaddr >= prefix) && (guestaddr < prefix + 2 * PAGE_SIZE))
29 guestaddr -= prefix;
30
31 return (void __user *) gmap_fault(guestaddr, vcpu->arch.gmap);
32}
33
34static inline int get_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
35 u64 *result)
36{
37 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
38
39 BUG_ON(guestaddr & 7);
40
41 if (IS_ERR((void __force *) uptr))
42 return PTR_ERR((void __force *) uptr);
43
44 return get_user(*result, (unsigned long __user *) uptr);
45}
46
47static inline int get_guest_u32(struct kvm_vcpu *vcpu, unsigned long guestaddr,
48 u32 *result)
49{
50 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
51
52 BUG_ON(guestaddr & 3);
53
54 if (IS_ERR((void __force *) uptr))
55 return PTR_ERR((void __force *) uptr);
56
57 return get_user(*result, (u32 __user *) uptr);
58}
59
60static inline int get_guest_u16(struct kvm_vcpu *vcpu, unsigned long guestaddr,
61 u16 *result)
62{
63 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
64
65 BUG_ON(guestaddr & 1);
66
67 if (IS_ERR(uptr))
68 return PTR_ERR(uptr);
69
70 return get_user(*result, (u16 __user *) uptr);
71}
72
73static inline int get_guest_u8(struct kvm_vcpu *vcpu, unsigned long guestaddr,
74 u8 *result)
75{
76 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
77
78 if (IS_ERR((void __force *) uptr))
79 return PTR_ERR((void __force *) uptr);
80
81 return get_user(*result, (u8 __user *) uptr);
82}
83
84static inline int put_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
85 u64 value)
86{
87 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
88
89 BUG_ON(guestaddr & 7);
90
91 if (IS_ERR((void __force *) uptr))
92 return PTR_ERR((void __force *) uptr);
93
94 return put_user(value, (u64 __user *) uptr);
95}
96
97static inline int put_guest_u32(struct kvm_vcpu *vcpu, unsigned long guestaddr,
98 u32 value)
99{
100 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
101
102 BUG_ON(guestaddr & 3);
103
104 if (IS_ERR((void __force *) uptr))
105 return PTR_ERR((void __force *) uptr);
106
107 return put_user(value, (u32 __user *) uptr);
108}
109
110static inline int put_guest_u16(struct kvm_vcpu *vcpu, unsigned long guestaddr,
111 u16 value)
112{
113 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
114
115 BUG_ON(guestaddr & 1);
116
117 if (IS_ERR((void __force *) uptr))
118 return PTR_ERR((void __force *) uptr);
119
120 return put_user(value, (u16 __user *) uptr);
121}
122
123static inline int put_guest_u8(struct kvm_vcpu *vcpu, unsigned long guestaddr,
124 u8 value)
125{
126 void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
127
128 if (IS_ERR((void __force *) uptr))
129 return PTR_ERR((void __force *) uptr);
130
131 return put_user(value, (u8 __user *) uptr);
132}
133
134
135static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu,
136 unsigned long guestdest,
137 void *from, unsigned long n)
138{
139 int rc;
140 unsigned long i;
141 u8 *data = from;
142
143 for (i = 0; i < n; i++) {
144 rc = put_guest_u8(vcpu, guestdest++, *(data++));
145 if (rc < 0)
146 return rc;
147 }
148 return 0;
149}
150
151static inline int __copy_to_guest_fast(struct kvm_vcpu *vcpu,
152 unsigned long guestdest,
153 void *from, unsigned long n)
154{
155 int r;
156 void __user *uptr;
157 unsigned long size;
158
159 if (guestdest + n < guestdest)
160 return -EFAULT;
161
162 /* simple case: all within one segment table entry? */
163 if ((guestdest & PMD_MASK) == ((guestdest+n) & PMD_MASK)) {
164 uptr = (void __user *) gmap_fault(guestdest, vcpu->arch.gmap);
165
166 if (IS_ERR((void __force *) uptr))
167 return PTR_ERR((void __force *) uptr);
168
169 r = copy_to_user(uptr, from, n);
170
171 if (r)
172 r = -EFAULT;
173
174 goto out;
175 }
176
177 /* copy first segment */
178 uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
179
180 if (IS_ERR((void __force *) uptr))
181 return PTR_ERR((void __force *) uptr);
182
183 size = PMD_SIZE - (guestdest & ~PMD_MASK);
184
185 r = copy_to_user(uptr, from, size);
186
187 if (r) {
188 r = -EFAULT;
189 goto out;
190 }
191 from += size;
192 n -= size;
193 guestdest += size;
194
195 /* copy full segments */
196 while (n >= PMD_SIZE) {
197 uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
198
199 if (IS_ERR((void __force *) uptr))
200 return PTR_ERR((void __force *) uptr);
201
202 r = copy_to_user(uptr, from, PMD_SIZE);
203
204 if (r) {
205 r = -EFAULT;
206 goto out;
207 }
208 from += PMD_SIZE;
209 n -= PMD_SIZE;
210 guestdest += PMD_SIZE;
211 }
212
213 /* copy the tail segment */
214 if (n) {
215 uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
216
217 if (IS_ERR((void __force *) uptr))
218 return PTR_ERR((void __force *) uptr);
219
220 r = copy_to_user(uptr, from, n);
221
222 if (r)
223 r = -EFAULT;
224 }
225out:
226 return r;
227}
228
229static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu,
230 unsigned long guestdest,
231 void *from, unsigned long n)
232{
233 return __copy_to_guest_fast(vcpu, guestdest, from, n);
234}
235
236static inline int copy_to_guest(struct kvm_vcpu *vcpu, unsigned long guestdest,
237 void *from, unsigned long n)
238{
239 unsigned long prefix = vcpu->arch.sie_block->prefix;
240
241 if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
242 goto slowpath;
243
244 if ((guestdest < prefix) && (guestdest + n > prefix))
245 goto slowpath;
246
247 if ((guestdest < prefix + 2 * PAGE_SIZE)
248 && (guestdest + n > prefix + 2 * PAGE_SIZE))
249 goto slowpath;
250
251 if (guestdest < 2 * PAGE_SIZE)
252 guestdest += prefix;
253 else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
254 guestdest -= prefix;
255
256 return __copy_to_guest_fast(vcpu, guestdest, from, n);
257slowpath:
258 return __copy_to_guest_slow(vcpu, guestdest, from, n);
259}
260
261static inline int __copy_from_guest_slow(struct kvm_vcpu *vcpu, void *to,
262 unsigned long guestsrc,
263 unsigned long n)
264{
265 int rc;
266 unsigned long i;
267 u8 *data = to;
268
269 for (i = 0; i < n; i++) {
270 rc = get_guest_u8(vcpu, guestsrc++, data++);
271 if (rc < 0)
272 return rc;
273 }
274 return 0;
275}
276
277static inline int __copy_from_guest_fast(struct kvm_vcpu *vcpu, void *to,
278 unsigned long guestsrc,
279 unsigned long n)
280{
281 int r;
282 void __user *uptr;
283 unsigned long size;
284
285 if (guestsrc + n < guestsrc)
286 return -EFAULT;
287
288 /* simple case: all within one segment table entry? */
289 if ((guestsrc & PMD_MASK) == ((guestsrc+n) & PMD_MASK)) {
290 uptr = (void __user *) gmap_fault(guestsrc, vcpu->arch.gmap);
291
292 if (IS_ERR((void __force *) uptr))
293 return PTR_ERR((void __force *) uptr);
294
295 r = copy_from_user(to, uptr, n);
296
297 if (r)
298 r = -EFAULT;
299
300 goto out;
301 }
302
303 /* copy first segment */
304 uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
305
306 if (IS_ERR((void __force *) uptr))
307 return PTR_ERR((void __force *) uptr);
308
309 size = PMD_SIZE - (guestsrc & ~PMD_MASK);
310
311 r = copy_from_user(to, uptr, size);
312
313 if (r) {
314 r = -EFAULT;
315 goto out;
316 }
317 to += size;
318 n -= size;
319 guestsrc += size;
320
321 /* copy full segments */
322 while (n >= PMD_SIZE) {
323 uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
324
325 if (IS_ERR((void __force *) uptr))
326 return PTR_ERR((void __force *) uptr);
327
328 r = copy_from_user(to, uptr, PMD_SIZE);
329
330 if (r) {
331 r = -EFAULT;
332 goto out;
333 }
334 to += PMD_SIZE;
335 n -= PMD_SIZE;
336 guestsrc += PMD_SIZE;
337 }
338
339 /* copy the tail segment */
340 if (n) {
341 uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
342
343 if (IS_ERR((void __force *) uptr))
344 return PTR_ERR((void __force *) uptr);
345
346 r = copy_from_user(to, uptr, n);
347
348 if (r)
349 r = -EFAULT;
350 }
351out:
352 return r;
353}
354
355static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to,
356 unsigned long guestsrc,
357 unsigned long n)
358{
359 return __copy_from_guest_fast(vcpu, to, guestsrc, n);
360}
361
362static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to,
363 unsigned long guestsrc, unsigned long n)
364{
365 unsigned long prefix = vcpu->arch.sie_block->prefix;
366
367 if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
368 goto slowpath;
369
370 if ((guestsrc < prefix) && (guestsrc + n > prefix))
371 goto slowpath;
372
373 if ((guestsrc < prefix + 2 * PAGE_SIZE)
374 && (guestsrc + n > prefix + 2 * PAGE_SIZE))
375 goto slowpath;
376
377 if (guestsrc < 2 * PAGE_SIZE)
378 guestsrc += prefix;
379 else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
380 guestsrc -= prefix;
381
382 return __copy_from_guest_fast(vcpu, to, guestsrc, n);
383slowpath:
384 return __copy_from_guest_slow(vcpu, to, guestsrc, n);
385}
386#endif