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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 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
21/* Convert real to absolute address by applying the prefix of the CPU */
22static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
23 unsigned long gaddr)
24{
25 unsigned long prefix = vcpu->arch.sie_block->prefix;
26 if (gaddr < 2 * PAGE_SIZE)
27 gaddr += prefix;
28 else if (gaddr >= prefix && gaddr < prefix + 2 * PAGE_SIZE)
29 gaddr -= prefix;
30 return gaddr;
31}
32
33static inline void __user *__gptr_to_uptr(struct kvm_vcpu *vcpu,
34 void __user *gptr,
35 int prefixing)
36{
37 unsigned long gaddr = (unsigned long) gptr;
38 unsigned long uaddr;
39
40 if (prefixing)
41 gaddr = kvm_s390_real_to_abs(vcpu, gaddr);
42 uaddr = gmap_fault(gaddr, vcpu->arch.gmap);
43 if (IS_ERR_VALUE(uaddr))
44 uaddr = -EFAULT;
45 return (void __user *)uaddr;
46}
47
48#define get_guest(vcpu, x, gptr) \
49({ \
50 __typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
51 int __mask = sizeof(__typeof__(*(gptr))) - 1; \
52 int __ret; \
53 \
54 if (IS_ERR((void __force *)__uptr)) { \
55 __ret = PTR_ERR((void __force *)__uptr); \
56 } else { \
57 BUG_ON((unsigned long)__uptr & __mask); \
58 __ret = get_user(x, __uptr); \
59 } \
60 __ret; \
61})
62
63#define put_guest(vcpu, x, gptr) \
64({ \
65 __typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
66 int __mask = sizeof(__typeof__(*(gptr))) - 1; \
67 int __ret; \
68 \
69 if (IS_ERR((void __force *)__uptr)) { \
70 __ret = PTR_ERR((void __force *)__uptr); \
71 } else { \
72 BUG_ON((unsigned long)__uptr & __mask); \
73 __ret = put_user(x, __uptr); \
74 } \
75 __ret; \
76})
77
78static inline int __copy_guest(struct kvm_vcpu *vcpu, unsigned long to,
79 unsigned long from, unsigned long len,
80 int to_guest, int prefixing)
81{
82 unsigned long _len, rc;
83 void __user *uptr;
84
85 while (len) {
86 uptr = to_guest ? (void __user *)to : (void __user *)from;
87 uptr = __gptr_to_uptr(vcpu, uptr, prefixing);
88 if (IS_ERR((void __force *)uptr))
89 return -EFAULT;
90 _len = PAGE_SIZE - ((unsigned long)uptr & (PAGE_SIZE - 1));
91 _len = min(_len, len);
92 if (to_guest)
93 rc = copy_to_user((void __user *) uptr, (void *)from, _len);
94 else
95 rc = copy_from_user((void *)to, (void __user *)uptr, _len);
96 if (rc)
97 return -EFAULT;
98 len -= _len;
99 from += _len;
100 to += _len;
101 }
102 return 0;
103}
104
105#define copy_to_guest(vcpu, to, from, size) \
106 __copy_guest(vcpu, to, (unsigned long)from, size, 1, 1)
107#define copy_from_guest(vcpu, to, from, size) \
108 __copy_guest(vcpu, (unsigned long)to, from, size, 0, 1)
109#define copy_to_guest_absolute(vcpu, to, from, size) \
110 __copy_guest(vcpu, to, (unsigned long)from, size, 1, 0)
111#define copy_from_guest_absolute(vcpu, to, from, size) \
112 __copy_guest(vcpu, (unsigned long)to, from, size, 0, 0)
113
114#endif /* __KVM_S390_GACCESS_H */