/*
* access guest memory
*
* Copyright IBM Corp. 2008, 2014
*
* 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 <linux/uaccess.h>
#include <linux/ptrace.h>
#include "kvm-s390.h"
/**
* kvm_s390_real_to_abs - convert guest real address to guest absolute address
* @vcpu - guest virtual cpu
* @gra - guest real address
*
* Returns the guest absolute address that corresponds to the passed guest real
* address @gra of a virtual guest cpu by applying its prefix.
*/
static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
unsigned long gra)
{
unsigned long prefix = kvm_s390_get_prefix(vcpu);
if (gra < 2 * PAGE_SIZE)
gra += prefix;
else if (gra >= prefix && gra < prefix + 2 * PAGE_SIZE)
gra -= prefix;
return gra;
}
/**
* kvm_s390_logical_to_effective - convert guest logical to effective address
* @vcpu: guest virtual cpu
* @ga: guest logical address
*
* Convert a guest vcpu logical address to a guest vcpu effective address by
* applying the rules of the vcpu's addressing mode defined by PSW bits 31
* and 32 (extendended/basic addressing mode).
*
* Depending on the vcpu's addressing mode the upper 40 bits (24 bit addressing
* mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing mode)
* of @ga will be zeroed and the remaining bits will be returned.
*/
static inline unsigned long kvm_s390_logical_to_effective(struct kvm_vcpu *vcpu,
unsigned long ga)
{
psw_t *psw = &vcpu->arch.sie_block->gpsw;
if (psw_bits(*psw).eaba == PSW_AMODE_64BIT)
return ga;
if (psw_bits(*psw).eaba == PSW_AMODE_31BIT)
return ga & ((1UL << 31) - 1);
return ga & ((1UL << 24) - 1);
}
/*
* put_guest_lc, read_guest_lc and write_guest_lc are guest access functions
* which shall only be used to access the lowcore of a vcpu.
* These functions should be used for e.g. interrupt handlers where no
* guest memory access protection facilities, like key or low address
* protection, are applicable.
* At a later point guest vcpu lowcore access should happen via pinned
* prefix pages, so that these pages can be accessed directly via the
* kernel mapping. All of these *_lc functions can be removed then.
*/
/**
* put_guest_lc - write a simple variable to a guest vcpu's lowcore
* @vcpu: virtual cpu
* @x: value to copy to guest
* @gra: vcpu's destination guest real address
*
* Copies a simple value from kernel space to a guest vcpu's lowcore.
* The size of the variable may be 1, 2, 4 or 8 bytes. The destination
* must be located in the vcpu's lowcore. Otherwise the result is undefined.
*
* Returns zero on success or -EFAULT on error.
*
* Note: an error indicates that either the kernel is out of memory or
* the guest memory mapping is broken. In any case the best solution
* would be to terminate the guest.
* It is wrong to inject a guest exception.
*/
#define put_guest_lc(vcpu, x, gra) \
({ \
struct kvm_vcpu *__vcpu = (vcpu); \
__typeof__(*(gra)) __x = (x); \
unsigned long __gpa; \
\
__gpa = (unsigned long)(gra); \
__gpa += kvm_s390_get_prefix(__vcpu); \
kvm_write_guest(__vcpu->kvm, __gpa, &__x, sizeof(__x)); \
})
/**
* write_guest_lc - copy data from kernel space to guest vcpu's lowcore
* @vcpu: virtual cpu
* @gra: vcpu's source guest real address
* @data: source address in kernel space
* @len: number of bytes to copy
*
* Copy data from kernel space to guest vcpu's lowcore. The entire range must
* be located within the vcpu's lowcore, otherwise the result is undefined.
*
* Returns zero on success or -EFAULT on error.
*
* Note: an error indicates that either the kernel is out of memory or
* the guest memory mapping is broken. In any case the best solution
* would be to terminate the guest.
* It is wrong to inject a guest exception.
*/
static inline __must_check
int write_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
unsigned long len)
{
unsigned long gpa = gra + kvm_s390_get_prefix(vcpu);
return kvm_write_guest(vcpu->kvm, gpa, data, len);
}
/**
* read_guest_lc - copy data from guest vcpu's lowcore to kernel space
* @vcpu: virtual cpu
* @gra: vcpu's source guest real address
* @data: destination address in kernel space
* @len: number of bytes to copy
*
* Copy data from guest vcpu's lowcore to kernel space. The entire range must
* be located within the vcpu's lowcore, otherwise the result is undefined.
*
* Returns zero on success or -EFAULT on error.
*
* Note: an error indicates that either the kernel is out of memory or
* the guest memory mapping is broken. In any case the best solution
* would be to terminate the guest.
* It is wrong to inject a guest exception.
*/
static inline __must_check
int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
unsigned long len)
{
unsigned long gpa = gra + kvm_s390_get_prefix(vcpu);
return kvm_read_guest(vcpu->kvm, gpa, data, len);
}
int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,
ar_t ar, unsigned long *gpa, int write);
int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, ar_t ar,
unsigned long length, int is_write);
int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
unsigned long len, int write);
int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
void *data, unsigned long len, int write);
/**
* write_guest - copy data from kernel space to guest space
* @vcpu: virtual cpu
* @ga: guest address
* @ar: access register
* @data: source address in kernel space
* @len: number of bytes to copy
*
* Copy @len bytes from @data (kernel space) to @ga (guest address).
* In order to copy data to guest space the PSW of the vcpu is inspected:
* If DAT is off data will be copied to guest real or absolute memory.
* If DAT is on data will be copied to the address space as specified by
* the address space bits of the PSW:
* Primary, secondary, home space or access register mode.
* The addressing mode of the PSW is also inspected, so that address wrap
* around is taken into account for 24-, 31- and 64-bit addressing mode,
* if the to be copied data crosses page boundaries in guest address space.
* In addition also low address and DAT protection are inspected before
* copying any data (key protection is currently not implemented).
*
* This function modifies the 'struct kvm_s390_pgm_info pgm' member of @vcpu.
* In case of an access exception (e.g. protection exception) pgm will contain
* all data necessary so that a subsequent call to 'kvm_s390_inject_prog_vcpu()'
* will inject a correct exception into the guest.
* If no access exception happened, the contents of pgm are undefined when
* this function returns.
*
* Returns: - zero on success
* - a negative value if e.g. the guest mapping is broken or in
* case of out-of-memory. In this case the contents of pgm are
* undefined. Also parts of @data may have been copied to guest
* space.
* - a positive value if an access exception happened. In this case
* the returned value is the program interruption code and the
* contents of pgm may be used to inject an exception into the
* guest. No data has been copied to guest space.
*
* Note: in case an access exception is recognized no data has been copied to
* guest space (this is also true, if the to be copied data would cross
* one or more page boundaries in guest space).
* Therefore this function may be used for nullifying and suppressing
* instruction emulation.
* It may also be used for terminating instructions, if it is undefined
* if data has been changed in guest space in case of an exception.
*/
static inline __must_check
int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
unsigned long len)
{
return access_guest(vcpu, ga, ar, data, len, 1);
}
/**
* read_guest - copy data from guest space to kernel space
* @vcpu: virtual cpu
* @ga: guest address
* @ar: access register
* @data: destination address in kernel space
* @len: number of bytes to copy
*
* Copy @len bytes from @ga (guest address) to @data (kernel space).
*
* The behaviour of read_guest is identical to write_guest, except that
* data will be copied from guest space to kernel space.
*/
static inline __must_check
int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, ar_t ar, void *data,
unsigned long len)
{
return access_guest(vcpu, ga, ar, data, len, 0);
}
/**
* write_guest_abs - copy data from kernel space to guest space absolute
* @vcpu: virtual cpu
* @gpa: guest physical (absolute) address
* @data: source address in kernel space
* @len: number of bytes to copy
*
* Copy @len bytes from @data (kernel space) to @gpa (guest absolute address).
* It is up to the caller to ensure that the entire guest memory range is
* valid memory before calling this function.
* Guest low address and key protection are not checked.
*
* Returns zero on success or -EFAULT on error.
*
* If an error occurs data may have been copied partially to guest memory.
*/
static inline __must_check
int write_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data,
unsigned long len)
{
return kvm_write_guest(vcpu->kvm, gpa, data, len);
}
/**
* read_guest_abs - copy data from guest space absolute to kernel space
* @vcpu: virtual cpu
* @gpa: guest physical (absolute) address
* @data: destination address in kernel space
* @len: number of bytes to copy
*
* Copy @len bytes from @gpa (guest absolute address) to @data (kernel space).
* It is up to the caller to ensure that the entire guest memory range is
* valid memory before calling this function.
* Guest key protection is not checked.
*
* Returns zero on success or -EFAULT on error.
*
* If an error occurs data may have been copied partially to kernel space.
*/
static inline __must_check
int read_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data,
unsigned long len)
{
return kvm_read_guest(vcpu->kvm, gpa, data, len);
}
/**
* write_guest_real - copy data from kernel space to guest space real
* @vcpu: virtual cpu
* @gra: guest real address
* @data: source address in kernel space
* @len: number of bytes to copy
*
* Copy @len bytes from @data (kernel space) to @gra (guest real address).
* It is up to the caller to ensure that the entire guest memory range is
* valid memory before calling this function.
* Guest low address and key protection are not checked.
*
* Returns zero on success or -EFAULT on error.
*
* If an error occurs data may have been copied partially to guest memory.
*/
static inline __must_check
int write_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
unsigned long len)
{
return access_guest_real(vcpu, gra, data, len, 1);
}
/**
* read_guest_real - copy data from guest space real to kernel space
* @vcpu: virtual cpu
* @gra: guest real address
* @data: destination address in kernel space
* @len: number of bytes to copy
*
* Copy @len bytes from @gra (guest real address) to @data (kernel space).
* It is up to the caller to ensure that the entire guest memory range is
* valid memory before calling this function.
* Guest key protection is not checked.
*
* Returns zero on success or -EFAULT on error.
*
* If an error occurs data may have been copied partially to kernel space.
*/
static inline __must_check
int read_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
unsigned long len)
{
return access_guest_real(vcpu, gra, data, len, 0);
}
void ipte_lock(struct kvm_vcpu *vcpu);
void ipte_unlock(struct kvm_vcpu *vcpu);
int ipte_lock_held(struct kvm_vcpu *vcpu);
int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra);
#endif /* __KVM_S390_GACCESS_H */