/* * 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 */ #ifndef __KVM_S390_GACCESS_H #define __KVM_S390_GACCESS_H #include #include #include #include #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; } /** * 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); } 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) /* * 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 += __vcpu->arch.sie_block->prefix; \ 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 + vcpu->arch.sie_block->prefix; 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 + vcpu->arch.sie_block->prefix; return kvm_read_guest(vcpu->kvm, gpa, data, len); } int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, 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 * @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, secondory or home space (access register mode is currently not * implemented). * 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, void *data, unsigned long len) { return access_guest(vcpu, ga, data, len, 1); } /** * read_guest - copy data from guest space to kernel space * @vcpu: virtual cpu * @ga: guest address * @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, void *data, unsigned long len) { return access_guest(vcpu, ga, 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); } #endif /* __KVM_S390_GACCESS_H */