1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * access guest memory 4 * 5 * Copyright IBM Corp. 2008, 2014 6 * 7 * Author(s): Carsten Otte <cotte@de.ibm.com> 8 */ 9 10 #ifndef __KVM_S390_GACCESS_H 11 #define __KVM_S390_GACCESS_H 12 13 #include <linux/compiler.h> 14 #include <linux/kvm_host.h> 15 #include <linux/uaccess.h> 16 #include <linux/ptrace.h> 17 #include "kvm-s390.h" 18 19 /** 20 * kvm_s390_real_to_abs - convert guest real address to guest absolute address 21 * @vcpu - guest virtual cpu 22 * @gra - guest real address 23 * 24 * Returns the guest absolute address that corresponds to the passed guest real 25 * address @gra of a virtual guest cpu by applying its prefix. 26 */ 27 static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu, 28 unsigned long gra) 29 { 30 unsigned long prefix = kvm_s390_get_prefix(vcpu); 31 32 if (gra < 2 * PAGE_SIZE) 33 gra += prefix; 34 else if (gra >= prefix && gra < prefix + 2 * PAGE_SIZE) 35 gra -= prefix; 36 return gra; 37 } 38 39 /** 40 * kvm_s390_logical_to_effective - convert guest logical to effective address 41 * @vcpu: guest virtual cpu 42 * @ga: guest logical address 43 * 44 * Convert a guest vcpu logical address to a guest vcpu effective address by 45 * applying the rules of the vcpu's addressing mode defined by PSW bits 31 46 * and 32 (extendended/basic addressing mode). 47 * 48 * Depending on the vcpu's addressing mode the upper 40 bits (24 bit addressing 49 * mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing mode) 50 * of @ga will be zeroed and the remaining bits will be returned. 51 */ 52 static inline unsigned long kvm_s390_logical_to_effective(struct kvm_vcpu *vcpu, 53 unsigned long ga) 54 { 55 psw_t *psw = &vcpu->arch.sie_block->gpsw; 56 57 if (psw_bits(*psw).eaba == PSW_BITS_AMODE_64BIT) 58 return ga; 59 if (psw_bits(*psw).eaba == PSW_BITS_AMODE_31BIT) 60 return ga & ((1UL << 31) - 1); 61 return ga & ((1UL << 24) - 1); 62 } 63 64 /* 65 * put_guest_lc, read_guest_lc and write_guest_lc are guest access functions 66 * which shall only be used to access the lowcore of a vcpu. 67 * These functions should be used for e.g. interrupt handlers where no 68 * guest memory access protection facilities, like key or low address 69 * protection, are applicable. 70 * At a later point guest vcpu lowcore access should happen via pinned 71 * prefix pages, so that these pages can be accessed directly via the 72 * kernel mapping. All of these *_lc functions can be removed then. 73 */ 74 75 /** 76 * put_guest_lc - write a simple variable to a guest vcpu's lowcore 77 * @vcpu: virtual cpu 78 * @x: value to copy to guest 79 * @gra: vcpu's destination guest real address 80 * 81 * Copies a simple value from kernel space to a guest vcpu's lowcore. 82 * The size of the variable may be 1, 2, 4 or 8 bytes. The destination 83 * must be located in the vcpu's lowcore. Otherwise the result is undefined. 84 * 85 * Returns zero on success or -EFAULT on error. 86 * 87 * Note: an error indicates that either the kernel is out of memory or 88 * the guest memory mapping is broken. In any case the best solution 89 * would be to terminate the guest. 90 * It is wrong to inject a guest exception. 91 */ 92 #define put_guest_lc(vcpu, x, gra) \ 93 ({ \ 94 struct kvm_vcpu *__vcpu = (vcpu); \ 95 __typeof__(*(gra)) __x = (x); \ 96 unsigned long __gpa; \ 97 \ 98 __gpa = (unsigned long)(gra); \ 99 __gpa += kvm_s390_get_prefix(__vcpu); \ 100 kvm_write_guest(__vcpu->kvm, __gpa, &__x, sizeof(__x)); \ 101 }) 102 103 /** 104 * write_guest_lc - copy data from kernel space to guest vcpu's lowcore 105 * @vcpu: virtual cpu 106 * @gra: vcpu's source guest real address 107 * @data: source address in kernel space 108 * @len: number of bytes to copy 109 * 110 * Copy data from kernel space to guest vcpu's lowcore. The entire range must 111 * be located within the vcpu's lowcore, otherwise the result is undefined. 112 * 113 * Returns zero on success or -EFAULT on error. 114 * 115 * Note: an error indicates that either the kernel is out of memory or 116 * the guest memory mapping is broken. In any case the best solution 117 * would be to terminate the guest. 118 * It is wrong to inject a guest exception. 119 */ 120 static inline __must_check 121 int write_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 122 unsigned long len) 123 { 124 unsigned long gpa = gra + kvm_s390_get_prefix(vcpu); 125 126 return kvm_write_guest(vcpu->kvm, gpa, data, len); 127 } 128 129 /** 130 * read_guest_lc - copy data from guest vcpu's lowcore to kernel space 131 * @vcpu: virtual cpu 132 * @gra: vcpu's source guest real address 133 * @data: destination address in kernel space 134 * @len: number of bytes to copy 135 * 136 * Copy data from guest vcpu's lowcore to kernel space. The entire range must 137 * be located within the vcpu's lowcore, otherwise the result is undefined. 138 * 139 * Returns zero on success or -EFAULT on error. 140 * 141 * Note: an error indicates that either the kernel is out of memory or 142 * the guest memory mapping is broken. In any case the best solution 143 * would be to terminate the guest. 144 * It is wrong to inject a guest exception. 145 */ 146 static inline __must_check 147 int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 148 unsigned long len) 149 { 150 unsigned long gpa = gra + kvm_s390_get_prefix(vcpu); 151 152 return kvm_read_guest(vcpu->kvm, gpa, data, len); 153 } 154 155 enum gacc_mode { 156 GACC_FETCH, 157 GACC_STORE, 158 GACC_IFETCH, 159 }; 160 161 int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, 162 u8 ar, unsigned long *gpa, enum gacc_mode mode); 163 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar, 164 unsigned long length, enum gacc_mode mode); 165 166 int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 167 unsigned long len, enum gacc_mode mode); 168 169 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, 170 void *data, unsigned long len, enum gacc_mode mode); 171 172 /** 173 * write_guest - copy data from kernel space to guest space 174 * @vcpu: virtual cpu 175 * @ga: guest address 176 * @ar: access register 177 * @data: source address in kernel space 178 * @len: number of bytes to copy 179 * 180 * Copy @len bytes from @data (kernel space) to @ga (guest address). 181 * In order to copy data to guest space the PSW of the vcpu is inspected: 182 * If DAT is off data will be copied to guest real or absolute memory. 183 * If DAT is on data will be copied to the address space as specified by 184 * the address space bits of the PSW: 185 * Primary, secondary, home space or access register mode. 186 * The addressing mode of the PSW is also inspected, so that address wrap 187 * around is taken into account for 24-, 31- and 64-bit addressing mode, 188 * if the to be copied data crosses page boundaries in guest address space. 189 * In addition also low address and DAT protection are inspected before 190 * copying any data (key protection is currently not implemented). 191 * 192 * This function modifies the 'struct kvm_s390_pgm_info pgm' member of @vcpu. 193 * In case of an access exception (e.g. protection exception) pgm will contain 194 * all data necessary so that a subsequent call to 'kvm_s390_inject_prog_vcpu()' 195 * will inject a correct exception into the guest. 196 * If no access exception happened, the contents of pgm are undefined when 197 * this function returns. 198 * 199 * Returns: - zero on success 200 * - a negative value if e.g. the guest mapping is broken or in 201 * case of out-of-memory. In this case the contents of pgm are 202 * undefined. Also parts of @data may have been copied to guest 203 * space. 204 * - a positive value if an access exception happened. In this case 205 * the returned value is the program interruption code and the 206 * contents of pgm may be used to inject an exception into the 207 * guest. No data has been copied to guest space. 208 * 209 * Note: in case an access exception is recognized no data has been copied to 210 * guest space (this is also true, if the to be copied data would cross 211 * one or more page boundaries in guest space). 212 * Therefore this function may be used for nullifying and suppressing 213 * instruction emulation. 214 * It may also be used for terminating instructions, if it is undefined 215 * if data has been changed in guest space in case of an exception. 216 */ 217 static inline __must_check 218 int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 219 unsigned long len) 220 { 221 return access_guest(vcpu, ga, ar, data, len, GACC_STORE); 222 } 223 224 /** 225 * read_guest - copy data from guest space to kernel space 226 * @vcpu: virtual cpu 227 * @ga: guest address 228 * @ar: access register 229 * @data: destination address in kernel space 230 * @len: number of bytes to copy 231 * 232 * Copy @len bytes from @ga (guest address) to @data (kernel space). 233 * 234 * The behaviour of read_guest is identical to write_guest, except that 235 * data will be copied from guest space to kernel space. 236 */ 237 static inline __must_check 238 int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 239 unsigned long len) 240 { 241 return access_guest(vcpu, ga, ar, data, len, GACC_FETCH); 242 } 243 244 /** 245 * read_guest_instr - copy instruction data from guest space to kernel space 246 * @vcpu: virtual cpu 247 * @ga: guest address 248 * @data: destination address in kernel space 249 * @len: number of bytes to copy 250 * 251 * Copy @len bytes from the given address (guest space) to @data (kernel 252 * space). 253 * 254 * The behaviour of read_guest_instr is identical to read_guest, except that 255 * instruction data will be read from primary space when in home-space or 256 * address-space mode. 257 */ 258 static inline __must_check 259 int read_guest_instr(struct kvm_vcpu *vcpu, unsigned long ga, void *data, 260 unsigned long len) 261 { 262 return access_guest(vcpu, ga, 0, data, len, GACC_IFETCH); 263 } 264 265 /** 266 * write_guest_abs - copy data from kernel space to guest space absolute 267 * @vcpu: virtual cpu 268 * @gpa: guest physical (absolute) address 269 * @data: source address in kernel space 270 * @len: number of bytes to copy 271 * 272 * Copy @len bytes from @data (kernel space) to @gpa (guest absolute address). 273 * It is up to the caller to ensure that the entire guest memory range is 274 * valid memory before calling this function. 275 * Guest low address and key protection are not checked. 276 * 277 * Returns zero on success or -EFAULT on error. 278 * 279 * If an error occurs data may have been copied partially to guest memory. 280 */ 281 static inline __must_check 282 int write_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data, 283 unsigned long len) 284 { 285 return kvm_write_guest(vcpu->kvm, gpa, data, len); 286 } 287 288 /** 289 * read_guest_abs - copy data from guest space absolute to kernel space 290 * @vcpu: virtual cpu 291 * @gpa: guest physical (absolute) address 292 * @data: destination address in kernel space 293 * @len: number of bytes to copy 294 * 295 * Copy @len bytes from @gpa (guest absolute address) to @data (kernel space). 296 * It is up to the caller to ensure that the entire guest memory range is 297 * valid memory before calling this function. 298 * Guest key protection is not checked. 299 * 300 * Returns zero on success or -EFAULT on error. 301 * 302 * If an error occurs data may have been copied partially to kernel space. 303 */ 304 static inline __must_check 305 int read_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data, 306 unsigned long len) 307 { 308 return kvm_read_guest(vcpu->kvm, gpa, data, len); 309 } 310 311 /** 312 * write_guest_real - copy data from kernel space to guest space real 313 * @vcpu: virtual cpu 314 * @gra: guest real address 315 * @data: source address in kernel space 316 * @len: number of bytes to copy 317 * 318 * Copy @len bytes from @data (kernel space) to @gra (guest real address). 319 * It is up to the caller to ensure that the entire guest memory range is 320 * valid memory before calling this function. 321 * Guest low address and key protection are not checked. 322 * 323 * Returns zero on success or -EFAULT on error. 324 * 325 * If an error occurs data may have been copied partially to guest memory. 326 */ 327 static inline __must_check 328 int write_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 329 unsigned long len) 330 { 331 return access_guest_real(vcpu, gra, data, len, 1); 332 } 333 334 /** 335 * read_guest_real - copy data from guest space real to kernel space 336 * @vcpu: virtual cpu 337 * @gra: guest real address 338 * @data: destination address in kernel space 339 * @len: number of bytes to copy 340 * 341 * Copy @len bytes from @gra (guest real address) to @data (kernel space). 342 * It is up to the caller to ensure that the entire guest memory range is 343 * valid memory before calling this function. 344 * Guest key protection is not checked. 345 * 346 * Returns zero on success or -EFAULT on error. 347 * 348 * If an error occurs data may have been copied partially to kernel space. 349 */ 350 static inline __must_check 351 int read_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 352 unsigned long len) 353 { 354 return access_guest_real(vcpu, gra, data, len, 0); 355 } 356 357 void ipte_lock(struct kvm_vcpu *vcpu); 358 void ipte_unlock(struct kvm_vcpu *vcpu); 359 int ipte_lock_held(struct kvm_vcpu *vcpu); 360 int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra); 361 362 int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *shadow, 363 unsigned long saddr); 364 365 #endif /* __KVM_S390_GACCESS_H */ 366