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 * @prefix - guest prefix 22 * @gra - guest real address 23 * 24 * Returns the guest absolute address that corresponds to the passed guest real 25 * address @gra of by applying the given prefix. 26 */ 27 static inline unsigned long _kvm_s390_real_to_abs(u32 prefix, unsigned long gra) 28 { 29 if (gra < 2 * PAGE_SIZE) 30 gra += prefix; 31 else if (gra >= prefix && gra < prefix + 2 * PAGE_SIZE) 32 gra -= prefix; 33 return gra; 34 } 35 36 /** 37 * kvm_s390_real_to_abs - convert guest real address to guest absolute address 38 * @vcpu - guest virtual cpu 39 * @gra - guest real address 40 * 41 * Returns the guest absolute address that corresponds to the passed guest real 42 * address @gra of a virtual guest cpu by applying its prefix. 43 */ 44 static inline unsigned long kvm_s390_real_to_abs(struct kvm_vcpu *vcpu, 45 unsigned long gra) 46 { 47 return _kvm_s390_real_to_abs(kvm_s390_get_prefix(vcpu), gra); 48 } 49 50 /** 51 * _kvm_s390_logical_to_effective - convert guest logical to effective address 52 * @psw: psw of the guest 53 * @ga: guest logical address 54 * 55 * Convert a guest logical address to an effective address by applying the 56 * rules of the addressing mode defined by bits 31 and 32 of the given PSW 57 * (extendended/basic addressing mode). 58 * 59 * Depending on the addressing mode, the upper 40 bits (24 bit addressing 60 * mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing 61 * mode) of @ga will be zeroed and the remaining bits will be returned. 62 */ 63 static inline unsigned long _kvm_s390_logical_to_effective(psw_t *psw, 64 unsigned long ga) 65 { 66 if (psw_bits(*psw).eaba == PSW_BITS_AMODE_64BIT) 67 return ga; 68 if (psw_bits(*psw).eaba == PSW_BITS_AMODE_31BIT) 69 return ga & ((1UL << 31) - 1); 70 return ga & ((1UL << 24) - 1); 71 } 72 73 /** 74 * kvm_s390_logical_to_effective - convert guest logical to effective address 75 * @vcpu: guest virtual cpu 76 * @ga: guest logical address 77 * 78 * Convert a guest vcpu logical address to a guest vcpu effective address by 79 * applying the rules of the vcpu's addressing mode defined by PSW bits 31 80 * and 32 (extendended/basic addressing mode). 81 * 82 * Depending on the vcpu's addressing mode the upper 40 bits (24 bit addressing 83 * mode), 33 bits (31 bit addressing mode) or no bits (64 bit addressing mode) 84 * of @ga will be zeroed and the remaining bits will be returned. 85 */ 86 static inline unsigned long kvm_s390_logical_to_effective(struct kvm_vcpu *vcpu, 87 unsigned long ga) 88 { 89 return _kvm_s390_logical_to_effective(&vcpu->arch.sie_block->gpsw, ga); 90 } 91 92 /* 93 * put_guest_lc, read_guest_lc and write_guest_lc are guest access functions 94 * which shall only be used to access the lowcore of a vcpu. 95 * These functions should be used for e.g. interrupt handlers where no 96 * guest memory access protection facilities, like key or low address 97 * protection, are applicable. 98 * At a later point guest vcpu lowcore access should happen via pinned 99 * prefix pages, so that these pages can be accessed directly via the 100 * kernel mapping. All of these *_lc functions can be removed then. 101 */ 102 103 /** 104 * put_guest_lc - write a simple variable to a guest vcpu's lowcore 105 * @vcpu: virtual cpu 106 * @x: value to copy to guest 107 * @gra: vcpu's destination guest real address 108 * 109 * Copies a simple value from kernel space to a guest vcpu's lowcore. 110 * The size of the variable may be 1, 2, 4 or 8 bytes. The destination 111 * must be located in 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 #define put_guest_lc(vcpu, x, gra) \ 121 ({ \ 122 struct kvm_vcpu *__vcpu = (vcpu); \ 123 __typeof__(*(gra)) __x = (x); \ 124 unsigned long __gpa; \ 125 \ 126 __gpa = (unsigned long)(gra); \ 127 __gpa += kvm_s390_get_prefix(__vcpu); \ 128 kvm_write_guest(__vcpu->kvm, __gpa, &__x, sizeof(__x)); \ 129 }) 130 131 /** 132 * write_guest_lc - copy data from kernel space to guest vcpu's lowcore 133 * @vcpu: virtual cpu 134 * @gra: vcpu's source guest real address 135 * @data: source address in kernel space 136 * @len: number of bytes to copy 137 * 138 * Copy data from kernel space to guest vcpu's lowcore. The entire range must 139 * be located within the vcpu's lowcore, otherwise the result is undefined. 140 * 141 * Returns zero on success or -EFAULT on error. 142 * 143 * Note: an error indicates that either the kernel is out of memory or 144 * the guest memory mapping is broken. In any case the best solution 145 * would be to terminate the guest. 146 * It is wrong to inject a guest exception. 147 */ 148 static inline __must_check 149 int write_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 150 unsigned long len) 151 { 152 unsigned long gpa = gra + kvm_s390_get_prefix(vcpu); 153 154 return kvm_write_guest(vcpu->kvm, gpa, data, len); 155 } 156 157 /** 158 * read_guest_lc - copy data from guest vcpu's lowcore to kernel space 159 * @vcpu: virtual cpu 160 * @gra: vcpu's source guest real address 161 * @data: destination address in kernel space 162 * @len: number of bytes to copy 163 * 164 * Copy data from guest vcpu's lowcore to kernel space. The entire range must 165 * be located within the vcpu's lowcore, otherwise the result is undefined. 166 * 167 * Returns zero on success or -EFAULT on error. 168 * 169 * Note: an error indicates that either the kernel is out of memory or 170 * the guest memory mapping is broken. In any case the best solution 171 * would be to terminate the guest. 172 * It is wrong to inject a guest exception. 173 */ 174 static inline __must_check 175 int read_guest_lc(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 176 unsigned long len) 177 { 178 unsigned long gpa = gra + kvm_s390_get_prefix(vcpu); 179 180 return kvm_read_guest(vcpu->kvm, gpa, data, len); 181 } 182 183 enum gacc_mode { 184 GACC_FETCH, 185 GACC_STORE, 186 GACC_IFETCH, 187 }; 188 189 int guest_translate_address_with_key(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar, 190 unsigned long *gpa, enum gacc_mode mode, 191 u8 access_key); 192 193 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar, 194 unsigned long length, enum gacc_mode mode, u8 access_key); 195 196 int check_gpa_range(struct kvm *kvm, unsigned long gpa, unsigned long length, 197 enum gacc_mode mode, u8 access_key); 198 199 int access_guest_abs_with_key(struct kvm *kvm, gpa_t gpa, void *data, 200 unsigned long len, enum gacc_mode mode, u8 access_key); 201 202 int access_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, 203 void *data, unsigned long len, enum gacc_mode mode, 204 u8 access_key); 205 206 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, 207 void *data, unsigned long len, enum gacc_mode mode); 208 209 /** 210 * write_guest_with_key - copy data from kernel space to guest space 211 * @vcpu: virtual cpu 212 * @ga: guest address 213 * @ar: access register 214 * @data: source address in kernel space 215 * @len: number of bytes to copy 216 * @access_key: access key the storage key needs to match 217 * 218 * Copy @len bytes from @data (kernel space) to @ga (guest address). 219 * In order to copy data to guest space the PSW of the vcpu is inspected: 220 * If DAT is off data will be copied to guest real or absolute memory. 221 * If DAT is on data will be copied to the address space as specified by 222 * the address space bits of the PSW: 223 * Primary, secondary, home space or access register mode. 224 * The addressing mode of the PSW is also inspected, so that address wrap 225 * around is taken into account for 24-, 31- and 64-bit addressing mode, 226 * if the to be copied data crosses page boundaries in guest address space. 227 * In addition low address, DAT and key protection checks are performed before 228 * copying any data. 229 * 230 * This function modifies the 'struct kvm_s390_pgm_info pgm' member of @vcpu. 231 * In case of an access exception (e.g. protection exception) pgm will contain 232 * all data necessary so that a subsequent call to 'kvm_s390_inject_prog_vcpu()' 233 * will inject a correct exception into the guest. 234 * If no access exception happened, the contents of pgm are undefined when 235 * this function returns. 236 * 237 * Returns: - zero on success 238 * - a negative value if e.g. the guest mapping is broken or in 239 * case of out-of-memory. In this case the contents of pgm are 240 * undefined. Also parts of @data may have been copied to guest 241 * space. 242 * - a positive value if an access exception happened. In this case 243 * the returned value is the program interruption code and the 244 * contents of pgm may be used to inject an exception into the 245 * guest. No data has been copied to guest space. 246 * 247 * Note: in case an access exception is recognized no data has been copied to 248 * guest space (this is also true, if the to be copied data would cross 249 * one or more page boundaries in guest space). 250 * Therefore this function may be used for nullifying and suppressing 251 * instruction emulation. 252 * It may also be used for terminating instructions, if it is undefined 253 * if data has been changed in guest space in case of an exception. 254 */ 255 static inline __must_check 256 int write_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, 257 void *data, unsigned long len, u8 access_key) 258 { 259 return access_guest_with_key(vcpu, ga, ar, data, len, GACC_STORE, 260 access_key); 261 } 262 263 /** 264 * write_guest - copy data from kernel space to guest space 265 * @vcpu: virtual cpu 266 * @ga: guest address 267 * @ar: access register 268 * @data: source address in kernel space 269 * @len: number of bytes to copy 270 * 271 * The behaviour of write_guest is identical to write_guest_with_key, except 272 * that the PSW access key is used instead of an explicit argument. 273 */ 274 static inline __must_check 275 int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 276 unsigned long len) 277 { 278 u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key; 279 280 return write_guest_with_key(vcpu, ga, ar, data, len, access_key); 281 } 282 283 /** 284 * read_guest_with_key - copy data from guest space to kernel space 285 * @vcpu: virtual cpu 286 * @ga: guest address 287 * @ar: access register 288 * @data: destination address in kernel space 289 * @len: number of bytes to copy 290 * @access_key: access key the storage key needs to match 291 * 292 * Copy @len bytes from @ga (guest address) to @data (kernel space). 293 * 294 * The behaviour of read_guest_with_key is identical to write_guest_with_key, 295 * except that data will be copied from guest space to kernel space. 296 */ 297 static inline __must_check 298 int read_guest_with_key(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, 299 void *data, unsigned long len, u8 access_key) 300 { 301 return access_guest_with_key(vcpu, ga, ar, data, len, GACC_FETCH, 302 access_key); 303 } 304 305 /** 306 * read_guest - copy data from guest space to kernel space 307 * @vcpu: virtual cpu 308 * @ga: guest address 309 * @ar: access register 310 * @data: destination address in kernel space 311 * @len: number of bytes to copy 312 * 313 * Copy @len bytes from @ga (guest address) to @data (kernel space). 314 * 315 * The behaviour of read_guest is identical to read_guest_with_key, except 316 * that the PSW access key is used instead of an explicit argument. 317 */ 318 static inline __must_check 319 int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 320 unsigned long len) 321 { 322 u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key; 323 324 return read_guest_with_key(vcpu, ga, ar, data, len, access_key); 325 } 326 327 /** 328 * read_guest_instr - copy instruction data from guest space to kernel space 329 * @vcpu: virtual cpu 330 * @ga: guest address 331 * @data: destination address in kernel space 332 * @len: number of bytes to copy 333 * 334 * Copy @len bytes from the given address (guest space) to @data (kernel 335 * space). 336 * 337 * The behaviour of read_guest_instr is identical to read_guest, except that 338 * instruction data will be read from primary space when in home-space or 339 * address-space mode. 340 */ 341 static inline __must_check 342 int read_guest_instr(struct kvm_vcpu *vcpu, unsigned long ga, void *data, 343 unsigned long len) 344 { 345 u8 access_key = psw_bits(vcpu->arch.sie_block->gpsw).key; 346 347 return access_guest_with_key(vcpu, ga, 0, data, len, GACC_IFETCH, 348 access_key); 349 } 350 351 /** 352 * write_guest_abs - copy data from kernel space to guest space absolute 353 * @vcpu: virtual cpu 354 * @gpa: guest physical (absolute) address 355 * @data: source address in kernel space 356 * @len: number of bytes to copy 357 * 358 * Copy @len bytes from @data (kernel space) to @gpa (guest absolute address). 359 * It is up to the caller to ensure that the entire guest memory range is 360 * valid memory before calling this function. 361 * Guest low address and key protection are not checked. 362 * 363 * Returns zero on success or -EFAULT on error. 364 * 365 * If an error occurs data may have been copied partially to guest memory. 366 */ 367 static inline __must_check 368 int write_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data, 369 unsigned long len) 370 { 371 return kvm_write_guest(vcpu->kvm, gpa, data, len); 372 } 373 374 /** 375 * read_guest_abs - copy data from guest space absolute to kernel space 376 * @vcpu: virtual cpu 377 * @gpa: guest physical (absolute) address 378 * @data: destination address in kernel space 379 * @len: number of bytes to copy 380 * 381 * Copy @len bytes from @gpa (guest absolute address) to @data (kernel space). 382 * It is up to the caller to ensure that the entire guest memory range is 383 * valid memory before calling this function. 384 * Guest key protection is not checked. 385 * 386 * Returns zero on success or -EFAULT on error. 387 * 388 * If an error occurs data may have been copied partially to kernel space. 389 */ 390 static inline __must_check 391 int read_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data, 392 unsigned long len) 393 { 394 return kvm_read_guest(vcpu->kvm, gpa, data, len); 395 } 396 397 /** 398 * write_guest_real - copy data from kernel space to guest space real 399 * @vcpu: virtual cpu 400 * @gra: guest real address 401 * @data: source address in kernel space 402 * @len: number of bytes to copy 403 * 404 * Copy @len bytes from @data (kernel space) to @gra (guest real address). 405 * It is up to the caller to ensure that the entire guest memory range is 406 * valid memory before calling this function. 407 * Guest low address and key protection are not checked. 408 * 409 * Returns zero on success or -EFAULT on error. 410 * 411 * If an error occurs data may have been copied partially to guest memory. 412 */ 413 static inline __must_check 414 int write_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 415 unsigned long len) 416 { 417 return access_guest_real(vcpu, gra, data, len, 1); 418 } 419 420 /** 421 * read_guest_real - copy data from guest space real to kernel space 422 * @vcpu: virtual cpu 423 * @gra: guest real address 424 * @data: destination address in kernel space 425 * @len: number of bytes to copy 426 * 427 * Copy @len bytes from @gra (guest real address) to @data (kernel space). 428 * It is up to the caller to ensure that the entire guest memory range is 429 * valid memory before calling this function. 430 * Guest key protection is not checked. 431 * 432 * Returns zero on success or -EFAULT on error. 433 * 434 * If an error occurs data may have been copied partially to kernel space. 435 */ 436 static inline __must_check 437 int read_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 438 unsigned long len) 439 { 440 return access_guest_real(vcpu, gra, data, len, 0); 441 } 442 443 void ipte_lock(struct kvm_vcpu *vcpu); 444 void ipte_unlock(struct kvm_vcpu *vcpu); 445 int ipte_lock_held(struct kvm_vcpu *vcpu); 446 int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra); 447 448 /* MVPG PEI indication bits */ 449 #define PEI_DAT_PROT 2 450 #define PEI_NOT_PTE 4 451 452 int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *shadow, 453 unsigned long saddr, unsigned long *datptr); 454 455 #endif /* __KVM_S390_GACCESS_H */ 456