linux/arch/s390/kvm/gaccess.h
Thomas Huth 732e563373 KVM: s390: Helper for converting real addresses to absolute
Added a separate helper function that translates guest real addresses
to guest absolute addresses by applying the prefix of the guest CPU.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-09-24 19:12:20 +02:00

115 lines
3.1 KiB
C

/*
* access guest memory
*
* Copyright IBM Corp. 2008, 2009
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (version 2 only)
* as published by the Free Software Foundation.
*
* Author(s): Carsten Otte <cotte@de.ibm.com>
*/
#ifndef __KVM_S390_GACCESS_H
#define __KVM_S390_GACCESS_H
#include <linux/compiler.h>
#include <linux/kvm_host.h>
#include <asm/uaccess.h>
#include "kvm-s390.h"
/* Convert real to absolute address by applying the prefix of the CPU */
static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
unsigned long gaddr)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
if (gaddr < 2 * PAGE_SIZE)
gaddr += prefix;
else if (gaddr >= prefix && gaddr < prefix + 2 * PAGE_SIZE)
gaddr -= prefix;
return gaddr;
}
static inline void __user *__gptr_to_uptr(struct kvm_vcpu *vcpu,
void __user *gptr,
int prefixing)
{
unsigned long gaddr = (unsigned long) gptr;
unsigned long uaddr;
if (prefixing)
gaddr = kvm_s390_real_to_abs(vcpu, gaddr);
uaddr = gmap_fault(gaddr, vcpu->arch.gmap);
if (IS_ERR_VALUE(uaddr))
uaddr = -EFAULT;
return (void __user *)uaddr;
}
#define get_guest(vcpu, x, gptr) \
({ \
__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
int __mask = sizeof(__typeof__(*(gptr))) - 1; \
int __ret; \
\
if (IS_ERR((void __force *)__uptr)) { \
__ret = PTR_ERR((void __force *)__uptr); \
} else { \
BUG_ON((unsigned long)__uptr & __mask); \
__ret = get_user(x, __uptr); \
} \
__ret; \
})
#define put_guest(vcpu, x, gptr) \
({ \
__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
int __mask = sizeof(__typeof__(*(gptr))) - 1; \
int __ret; \
\
if (IS_ERR((void __force *)__uptr)) { \
__ret = PTR_ERR((void __force *)__uptr); \
} else { \
BUG_ON((unsigned long)__uptr & __mask); \
__ret = put_user(x, __uptr); \
} \
__ret; \
})
static inline int __copy_guest(struct kvm_vcpu *vcpu, unsigned long to,
unsigned long from, unsigned long len,
int to_guest, int prefixing)
{
unsigned long _len, rc;
void __user *uptr;
while (len) {
uptr = to_guest ? (void __user *)to : (void __user *)from;
uptr = __gptr_to_uptr(vcpu, uptr, prefixing);
if (IS_ERR((void __force *)uptr))
return -EFAULT;
_len = PAGE_SIZE - ((unsigned long)uptr & (PAGE_SIZE - 1));
_len = min(_len, len);
if (to_guest)
rc = copy_to_user((void __user *) uptr, (void *)from, _len);
else
rc = copy_from_user((void *)to, (void __user *)uptr, _len);
if (rc)
return -EFAULT;
len -= _len;
from += _len;
to += _len;
}
return 0;
}
#define copy_to_guest(vcpu, to, from, size) \
__copy_guest(vcpu, to, (unsigned long)from, size, 1, 1)
#define copy_from_guest(vcpu, to, from, size) \
__copy_guest(vcpu, (unsigned long)to, from, size, 0, 1)
#define copy_to_guest_absolute(vcpu, to, from, size) \
__copy_guest(vcpu, to, (unsigned long)from, size, 1, 0)
#define copy_from_guest_absolute(vcpu, to, from, size) \
__copy_guest(vcpu, (unsigned long)to, from, size, 0, 0)
#endif /* __KVM_S390_GACCESS_H */