linux/arch/s390/kvm/gaccess.h
Carsten Otte 092670cd90 [S390] Use gmap translation for accessing guest memory
This patch removes kvm-s390 internal assumption of a linear mapping
of guest address space to user space. Previously, guest memory was
translated to user addresses using a fixed offset (gmsor). The new
code uses gmap_fault to resolve guest addresses.

Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-07-24 10:48:21 +02:00

387 lines
8.6 KiB
C

/*
* access.h - 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"
static inline void __user *__guestaddr_to_user(struct kvm_vcpu *vcpu,
unsigned long guestaddr)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
if (guestaddr < 2 * PAGE_SIZE)
guestaddr += prefix;
else if ((guestaddr >= prefix) && (guestaddr < prefix + 2 * PAGE_SIZE))
guestaddr -= prefix;
return (void __user *) gmap_fault(guestaddr, vcpu->arch.gmap);
}
static inline int get_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u64 *result)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
BUG_ON(guestaddr & 7);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
return get_user(*result, (unsigned long __user *) uptr);
}
static inline int get_guest_u32(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u32 *result)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
BUG_ON(guestaddr & 3);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
return get_user(*result, (u32 __user *) uptr);
}
static inline int get_guest_u16(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u16 *result)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
BUG_ON(guestaddr & 1);
if (IS_ERR(uptr))
return PTR_ERR(uptr);
return get_user(*result, (u16 __user *) uptr);
}
static inline int get_guest_u8(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u8 *result)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
return get_user(*result, (u8 __user *) uptr);
}
static inline int put_guest_u64(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u64 value)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
BUG_ON(guestaddr & 7);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
return put_user(value, (u64 __user *) uptr);
}
static inline int put_guest_u32(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u32 value)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
BUG_ON(guestaddr & 3);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
return put_user(value, (u32 __user *) uptr);
}
static inline int put_guest_u16(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u16 value)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
BUG_ON(guestaddr & 1);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
return put_user(value, (u16 __user *) uptr);
}
static inline int put_guest_u8(struct kvm_vcpu *vcpu, unsigned long guestaddr,
u8 value)
{
void __user *uptr = __guestaddr_to_user(vcpu, guestaddr);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
return put_user(value, (u8 __user *) uptr);
}
static inline int __copy_to_guest_slow(struct kvm_vcpu *vcpu,
unsigned long guestdest,
void *from, unsigned long n)
{
int rc;
unsigned long i;
u8 *data = from;
for (i = 0; i < n; i++) {
rc = put_guest_u8(vcpu, guestdest++, *(data++));
if (rc < 0)
return rc;
}
return 0;
}
static inline int __copy_to_guest_fast(struct kvm_vcpu *vcpu,
unsigned long guestdest,
void *from, unsigned long n)
{
int r;
void __user *uptr;
unsigned long size;
if (guestdest + n < guestdest)
return -EFAULT;
/* simple case: all within one segment table entry? */
if ((guestdest & PMD_MASK) == ((guestdest+n) & PMD_MASK)) {
uptr = (void __user *) gmap_fault(guestdest, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
r = copy_to_user(uptr, from, n);
if (r)
r = -EFAULT;
goto out;
}
/* copy first segment */
uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
size = PMD_SIZE - (guestdest & ~PMD_MASK);
r = copy_to_user(uptr, from, size);
if (r) {
r = -EFAULT;
goto out;
}
from += size;
n -= size;
guestdest += size;
/* copy full segments */
while (n >= PMD_SIZE) {
uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
r = copy_to_user(uptr, from, PMD_SIZE);
if (r) {
r = -EFAULT;
goto out;
}
from += PMD_SIZE;
n -= PMD_SIZE;
guestdest += PMD_SIZE;
}
/* copy the tail segment */
if (n) {
uptr = (void __user *)gmap_fault(guestdest, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
r = copy_to_user(uptr, from, n);
if (r)
r = -EFAULT;
}
out:
return r;
}
static inline int copy_to_guest_absolute(struct kvm_vcpu *vcpu,
unsigned long guestdest,
void *from, unsigned long n)
{
return __copy_to_guest_fast(vcpu, guestdest, from, n);
}
static inline int copy_to_guest(struct kvm_vcpu *vcpu, unsigned long guestdest,
void *from, unsigned long n)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
if ((guestdest < 2 * PAGE_SIZE) && (guestdest + n > 2 * PAGE_SIZE))
goto slowpath;
if ((guestdest < prefix) && (guestdest + n > prefix))
goto slowpath;
if ((guestdest < prefix + 2 * PAGE_SIZE)
&& (guestdest + n > prefix + 2 * PAGE_SIZE))
goto slowpath;
if (guestdest < 2 * PAGE_SIZE)
guestdest += prefix;
else if ((guestdest >= prefix) && (guestdest < prefix + 2 * PAGE_SIZE))
guestdest -= prefix;
return __copy_to_guest_fast(vcpu, guestdest, from, n);
slowpath:
return __copy_to_guest_slow(vcpu, guestdest, from, n);
}
static inline int __copy_from_guest_slow(struct kvm_vcpu *vcpu, void *to,
unsigned long guestsrc,
unsigned long n)
{
int rc;
unsigned long i;
u8 *data = to;
for (i = 0; i < n; i++) {
rc = get_guest_u8(vcpu, guestsrc++, data++);
if (rc < 0)
return rc;
}
return 0;
}
static inline int __copy_from_guest_fast(struct kvm_vcpu *vcpu, void *to,
unsigned long guestsrc,
unsigned long n)
{
int r;
void __user *uptr;
unsigned long size;
if (guestsrc + n < guestsrc)
return -EFAULT;
/* simple case: all within one segment table entry? */
if ((guestsrc & PMD_MASK) == ((guestsrc+n) & PMD_MASK)) {
uptr = (void __user *) gmap_fault(guestsrc, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
r = copy_from_user(to, uptr, n);
if (r)
r = -EFAULT;
goto out;
}
/* copy first segment */
uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
size = PMD_SIZE - (guestsrc & ~PMD_MASK);
r = copy_from_user(to, uptr, size);
if (r) {
r = -EFAULT;
goto out;
}
to += size;
n -= size;
guestsrc += size;
/* copy full segments */
while (n >= PMD_SIZE) {
uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
r = copy_from_user(to, uptr, PMD_SIZE);
if (r) {
r = -EFAULT;
goto out;
}
to += PMD_SIZE;
n -= PMD_SIZE;
guestsrc += PMD_SIZE;
}
/* copy the tail segment */
if (n) {
uptr = (void __user *)gmap_fault(guestsrc, vcpu->arch.gmap);
if (IS_ERR((void __force *) uptr))
return PTR_ERR((void __force *) uptr);
r = copy_from_user(to, uptr, n);
if (r)
r = -EFAULT;
}
out:
return r;
}
static inline int copy_from_guest_absolute(struct kvm_vcpu *vcpu, void *to,
unsigned long guestsrc,
unsigned long n)
{
return __copy_from_guest_fast(vcpu, to, guestsrc, n);
}
static inline int copy_from_guest(struct kvm_vcpu *vcpu, void *to,
unsigned long guestsrc, unsigned long n)
{
unsigned long prefix = vcpu->arch.sie_block->prefix;
if ((guestsrc < 2 * PAGE_SIZE) && (guestsrc + n > 2 * PAGE_SIZE))
goto slowpath;
if ((guestsrc < prefix) && (guestsrc + n > prefix))
goto slowpath;
if ((guestsrc < prefix + 2 * PAGE_SIZE)
&& (guestsrc + n > prefix + 2 * PAGE_SIZE))
goto slowpath;
if (guestsrc < 2 * PAGE_SIZE)
guestsrc += prefix;
else if ((guestsrc >= prefix) && (guestsrc < prefix + 2 * PAGE_SIZE))
guestsrc -= prefix;
return __copy_from_guest_fast(vcpu, to, guestsrc, n);
slowpath:
return __copy_from_guest_slow(vcpu, to, guestsrc, n);
}
#endif