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