335 lines
12 KiB
C
335 lines
12 KiB
C
/*
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* access guest memory
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*
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* Copyright IBM Corp. 2008, 2014
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License (version 2 only)
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* as published by the Free Software Foundation.
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*
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* Author(s): Carsten Otte <cotte@de.ibm.com>
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*/
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#ifndef __KVM_S390_GACCESS_H
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#define __KVM_S390_GACCESS_H
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#include <linux/compiler.h>
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#include <linux/kvm_host.h>
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#include <linux/uaccess.h>
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#include <linux/ptrace.h>
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#include "kvm-s390.h"
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/**
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* kvm_s390_real_to_abs - convert guest real address to guest absolute address
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* @vcpu - guest virtual cpu
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* @gra - guest real address
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*
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* Returns the guest absolute address that corresponds to the passed guest real
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* address @gra of a virtual guest cpu by applying its prefix.
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*/
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static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu,
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unsigned long gra)
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{
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unsigned long prefix = kvm_s390_get_prefix(vcpu);
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if (gra < 2 * PAGE_SIZE)
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gra += prefix;
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else if (gra >= prefix && gra < prefix + 2 * PAGE_SIZE)
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gra -= prefix;
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return gra;
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}
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/**
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* kvm_s390_logical_to_effective - convert guest logical to effective address
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* @vcpu: guest virtual cpu
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* @ga: guest logical address
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*
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* Convert a guest vcpu logical address to a guest vcpu effective address by
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* applying the rules of the vcpu's addressing mode defined by PSW bits 31
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* and 32 (extendended/basic addressing mode).
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*
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* Depending on the vcpu's addressing mode the upper 40 bits (24 bit addressing
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* mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing mode)
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* of @ga will be zeroed and the remaining bits will be returned.
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*/
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static inline unsigned long kvm_s390_logical_to_effective(struct kvm_vcpu *vcpu,
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unsigned long ga)
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{
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psw_t *psw = &vcpu->arch.sie_block->gpsw;
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if (psw_bits(*psw).eaba == PSW_AMODE_64BIT)
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return ga;
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if (psw_bits(*psw).eaba == PSW_AMODE_31BIT)
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return ga & ((1UL << 31) - 1);
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return ga & ((1UL << 24) - 1);
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}
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/*
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* put_guest_lc, read_guest_lc and write_guest_lc are guest access functions
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* which shall only be used to access the lowcore of a vcpu.
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* These functions should be used for e.g. interrupt handlers where no
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* guest memory access protection facilities, like key or low address
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* protection, are applicable.
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* At a later point guest vcpu lowcore access should happen via pinned
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* prefix pages, so that these pages can be accessed directly via the
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* kernel mapping. All of these *_lc functions can be removed then.
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*/
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/**
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* put_guest_lc - write a simple variable to a guest vcpu's lowcore
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* @vcpu: virtual cpu
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* @x: value to copy to guest
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* @gra: vcpu's destination guest real address
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*
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* Copies a simple value from kernel space to a guest vcpu's lowcore.
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* The size of the variable may be 1, 2, 4 or 8 bytes. The destination
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* must be located in the vcpu's lowcore. Otherwise the result is undefined.
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*
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* Returns zero on success or -EFAULT on error.
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*
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* Note: an error indicates that either the kernel is out of memory or
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* the guest memory mapping is broken. In any case the best solution
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* would be to terminate the guest.
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* It is wrong to inject a guest exception.
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*/
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#define put_guest_lc(vcpu, x, gra) \
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({ \
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struct kvm_vcpu *__vcpu = (vcpu); \
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__typeof__(*(gra)) __x = (x); \
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unsigned long __gpa; \
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\
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__gpa = (unsigned long)(gra); \
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__gpa += kvm_s390_get_prefix(__vcpu); \
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kvm_write_guest(__vcpu->kvm, __gpa, &__x, sizeof(__x)); \
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})
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/**
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* write_guest_lc - copy data from kernel space to guest vcpu's lowcore
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* @vcpu: virtual cpu
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* @gra: vcpu's source guest real address
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* @data: source address in kernel space
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* @len: number of bytes to copy
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*
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* Copy data from kernel space to guest vcpu's lowcore. The entire range must
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* be located within the vcpu's lowcore, otherwise the result is undefined.
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*
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* Returns zero on success or -EFAULT on error.
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*
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* Note: an error indicates that either the kernel is out of memory or
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* the guest memory mapping is broken. In any case the best solution
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* would be to terminate the guest.
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* It is wrong to inject a guest exception.
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*/
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static inline __must_check
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int write_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
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unsigned long len)
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{
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unsigned long gpa = gra + kvm_s390_get_prefix(vcpu);
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return kvm_write_guest(vcpu->kvm, gpa, data, len);
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}
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/**
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* read_guest_lc - copy data from guest vcpu's lowcore to kernel space
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* @vcpu: virtual cpu
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* @gra: vcpu's source guest real address
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* @data: destination address in kernel space
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* @len: number of bytes to copy
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*
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* Copy data from guest vcpu's lowcore to kernel space. The entire range must
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* be located within the vcpu's lowcore, otherwise the result is undefined.
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*
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* Returns zero on success or -EFAULT on error.
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*
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* Note: an error indicates that either the kernel is out of memory or
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* the guest memory mapping is broken. In any case the best solution
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* would be to terminate the guest.
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* It is wrong to inject a guest exception.
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*/
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static inline __must_check
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int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
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unsigned long len)
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{
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unsigned long gpa = gra + kvm_s390_get_prefix(vcpu);
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return kvm_read_guest(vcpu->kvm, gpa, data, len);
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}
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int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva,
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unsigned long *gpa, int write);
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int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
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unsigned long len, int write);
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int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
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void *data, unsigned long len, int write);
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/**
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* write_guest - copy data from kernel space to guest space
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* @vcpu: virtual cpu
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* @ga: guest address
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* @data: source address in kernel space
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* @len: number of bytes to copy
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*
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* Copy @len bytes from @data (kernel space) to @ga (guest address).
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* In order to copy data to guest space the PSW of the vcpu is inspected:
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* If DAT is off data will be copied to guest real or absolute memory.
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* If DAT is on data will be copied to the address space as specified by
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* the address space bits of the PSW:
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* Primary, secondory or home space (access register mode is currently not
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* implemented).
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* The addressing mode of the PSW is also inspected, so that address wrap
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* around is taken into account for 24-, 31- and 64-bit addressing mode,
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* if the to be copied data crosses page boundaries in guest address space.
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* In addition also low address and DAT protection are inspected before
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* copying any data (key protection is currently not implemented).
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*
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* This function modifies the 'struct kvm_s390_pgm_info pgm' member of @vcpu.
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* In case of an access exception (e.g. protection exception) pgm will contain
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* all data necessary so that a subsequent call to 'kvm_s390_inject_prog_vcpu()'
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* will inject a correct exception into the guest.
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* If no access exception happened, the contents of pgm are undefined when
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* this function returns.
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*
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* Returns: - zero on success
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* - a negative value if e.g. the guest mapping is broken or in
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* case of out-of-memory. In this case the contents of pgm are
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* undefined. Also parts of @data may have been copied to guest
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* space.
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* - a positive value if an access exception happened. In this case
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* the returned value is the program interruption code and the
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* contents of pgm may be used to inject an exception into the
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* guest. No data has been copied to guest space.
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*
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* Note: in case an access exception is recognized no data has been copied to
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* guest space (this is also true, if the to be copied data would cross
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* one or more page boundaries in guest space).
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* Therefore this function may be used for nullifying and suppressing
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* instruction emulation.
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* It may also be used for terminating instructions, if it is undefined
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* if data has been changed in guest space in case of an exception.
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*/
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static inline __must_check
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int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
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unsigned long len)
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{
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return access_guest(vcpu, ga, data, len, 1);
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}
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/**
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* read_guest - copy data from guest space to kernel space
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* @vcpu: virtual cpu
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* @ga: guest address
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* @data: destination address in kernel space
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* @len: number of bytes to copy
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*
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* Copy @len bytes from @ga (guest address) to @data (kernel space).
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*
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* The behaviour of read_guest is identical to write_guest, except that
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* data will be copied from guest space to kernel space.
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*/
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static inline __must_check
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int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, void *data,
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unsigned long len)
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{
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return access_guest(vcpu, ga, data, len, 0);
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}
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/**
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* write_guest_abs - copy data from kernel space to guest space absolute
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* @vcpu: virtual cpu
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* @gpa: guest physical (absolute) address
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* @data: source address in kernel space
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* @len: number of bytes to copy
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*
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* Copy @len bytes from @data (kernel space) to @gpa (guest absolute address).
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* It is up to the caller to ensure that the entire guest memory range is
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* valid memory before calling this function.
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* Guest low address and key protection are not checked.
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*
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* Returns zero on success or -EFAULT on error.
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*
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* If an error occurs data may have been copied partially to guest memory.
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*/
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static inline __must_check
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int write_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data,
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unsigned long len)
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{
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return kvm_write_guest(vcpu->kvm, gpa, data, len);
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}
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/**
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* read_guest_abs - copy data from guest space absolute to kernel space
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* @vcpu: virtual cpu
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* @gpa: guest physical (absolute) address
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* @data: destination address in kernel space
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* @len: number of bytes to copy
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*
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* Copy @len bytes from @gpa (guest absolute address) to @data (kernel space).
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* It is up to the caller to ensure that the entire guest memory range is
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* valid memory before calling this function.
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* Guest key protection is not checked.
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*
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* Returns zero on success or -EFAULT on error.
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*
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* If an error occurs data may have been copied partially to kernel space.
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*/
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static inline __must_check
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int read_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data,
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unsigned long len)
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{
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return kvm_read_guest(vcpu->kvm, gpa, data, len);
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}
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/**
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* write_guest_real - copy data from kernel space to guest space real
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* @vcpu: virtual cpu
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* @gra: guest real address
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* @data: source address in kernel space
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* @len: number of bytes to copy
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*
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* Copy @len bytes from @data (kernel space) to @gra (guest real address).
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* It is up to the caller to ensure that the entire guest memory range is
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* valid memory before calling this function.
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* Guest low address and key protection are not checked.
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*
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* Returns zero on success or -EFAULT on error.
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*
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* If an error occurs data may have been copied partially to guest memory.
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*/
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static inline __must_check
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int write_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
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unsigned long len)
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{
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return access_guest_real(vcpu, gra, data, len, 1);
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}
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/**
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* read_guest_real - copy data from guest space real to kernel space
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* @vcpu: virtual cpu
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* @gra: guest real address
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* @data: destination address in kernel space
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* @len: number of bytes to copy
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*
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* Copy @len bytes from @gra (guest real address) to @data (kernel space).
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* It is up to the caller to ensure that the entire guest memory range is
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* valid memory before calling this function.
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* Guest key protection is not checked.
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*
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* Returns zero on success or -EFAULT on error.
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*
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* If an error occurs data may have been copied partially to kernel space.
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*/
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static inline __must_check
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int read_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data,
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unsigned long len)
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{
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return access_guest_real(vcpu, gra, data, len, 0);
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}
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void ipte_lock(struct kvm_vcpu *vcpu);
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void ipte_unlock(struct kvm_vcpu *vcpu);
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int ipte_lock_held(struct kvm_vcpu *vcpu);
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int kvm_s390_check_low_addr_protection(struct kvm_vcpu *vcpu, unsigned long ga);
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#endif /* __KVM_S390_GACCESS_H */
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