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(struct kvm_vcpu *vcpu, unsigned long gva, 190 u8 ar, unsigned long *gpa, enum gacc_mode mode); 191 int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar, 192 unsigned long length, enum gacc_mode mode); 193 194 int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 195 unsigned long len, enum gacc_mode mode); 196 197 int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, 198 void *data, unsigned long len, enum gacc_mode mode); 199 200 /** 201 * write_guest - copy data from kernel space to guest space 202 * @vcpu: virtual cpu 203 * @ga: guest address 204 * @ar: access register 205 * @data: source address in kernel space 206 * @len: number of bytes to copy 207 * 208 * Copy @len bytes from @data (kernel space) to @ga (guest address). 209 * In order to copy data to guest space the PSW of the vcpu is inspected: 210 * If DAT is off data will be copied to guest real or absolute memory. 211 * If DAT is on data will be copied to the address space as specified by 212 * the address space bits of the PSW: 213 * Primary, secondary, home space or access register mode. 214 * The addressing mode of the PSW is also inspected, so that address wrap 215 * around is taken into account for 24-, 31- and 64-bit addressing mode, 216 * if the to be copied data crosses page boundaries in guest address space. 217 * In addition also low address and DAT protection are inspected before 218 * copying any data (key protection is currently not implemented). 219 * 220 * This function modifies the 'struct kvm_s390_pgm_info pgm' member of @vcpu. 221 * In case of an access exception (e.g. protection exception) pgm will contain 222 * all data necessary so that a subsequent call to 'kvm_s390_inject_prog_vcpu()' 223 * will inject a correct exception into the guest. 224 * If no access exception happened, the contents of pgm are undefined when 225 * this function returns. 226 * 227 * Returns: - zero on success 228 * - a negative value if e.g. the guest mapping is broken or in 229 * case of out-of-memory. In this case the contents of pgm are 230 * undefined. Also parts of @data may have been copied to guest 231 * space. 232 * - a positive value if an access exception happened. In this case 233 * the returned value is the program interruption code and the 234 * contents of pgm may be used to inject an exception into the 235 * guest. No data has been copied to guest space. 236 * 237 * Note: in case an access exception is recognized no data has been copied to 238 * guest space (this is also true, if the to be copied data would cross 239 * one or more page boundaries in guest space). 240 * Therefore this function may be used for nullifying and suppressing 241 * instruction emulation. 242 * It may also be used for terminating instructions, if it is undefined 243 * if data has been changed in guest space in case of an exception. 244 */ 245 static inline __must_check 246 int write_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 247 unsigned long len) 248 { 249 return access_guest(vcpu, ga, ar, data, len, GACC_STORE); 250 } 251 252 /** 253 * read_guest - copy data from guest space to kernel space 254 * @vcpu: virtual cpu 255 * @ga: guest address 256 * @ar: access register 257 * @data: destination address in kernel space 258 * @len: number of bytes to copy 259 * 260 * Copy @len bytes from @ga (guest address) to @data (kernel space). 261 * 262 * The behaviour of read_guest is identical to write_guest, except that 263 * data will be copied from guest space to kernel space. 264 */ 265 static inline __must_check 266 int read_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data, 267 unsigned long len) 268 { 269 return access_guest(vcpu, ga, ar, data, len, GACC_FETCH); 270 } 271 272 /** 273 * read_guest_instr - copy instruction data from guest space to kernel space 274 * @vcpu: virtual cpu 275 * @ga: guest address 276 * @data: destination address in kernel space 277 * @len: number of bytes to copy 278 * 279 * Copy @len bytes from the given address (guest space) to @data (kernel 280 * space). 281 * 282 * The behaviour of read_guest_instr is identical to read_guest, except that 283 * instruction data will be read from primary space when in home-space or 284 * address-space mode. 285 */ 286 static inline __must_check 287 int read_guest_instr(struct kvm_vcpu *vcpu, unsigned long ga, void *data, 288 unsigned long len) 289 { 290 return access_guest(vcpu, ga, 0, data, len, GACC_IFETCH); 291 } 292 293 /** 294 * write_guest_abs - copy data from kernel space to guest space absolute 295 * @vcpu: virtual cpu 296 * @gpa: guest physical (absolute) address 297 * @data: source address in kernel space 298 * @len: number of bytes to copy 299 * 300 * Copy @len bytes from @data (kernel space) to @gpa (guest absolute address). 301 * It is up to the caller to ensure that the entire guest memory range is 302 * valid memory before calling this function. 303 * Guest low address and key protection are not checked. 304 * 305 * Returns zero on success or -EFAULT on error. 306 * 307 * If an error occurs data may have been copied partially to guest memory. 308 */ 309 static inline __must_check 310 int write_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data, 311 unsigned long len) 312 { 313 return kvm_write_guest(vcpu->kvm, gpa, data, len); 314 } 315 316 /** 317 * read_guest_abs - copy data from guest space absolute to kernel space 318 * @vcpu: virtual cpu 319 * @gpa: guest physical (absolute) address 320 * @data: destination address in kernel space 321 * @len: number of bytes to copy 322 * 323 * Copy @len bytes from @gpa (guest absolute address) to @data (kernel space). 324 * It is up to the caller to ensure that the entire guest memory range is 325 * valid memory before calling this function. 326 * Guest key protection is not checked. 327 * 328 * Returns zero on success or -EFAULT on error. 329 * 330 * If an error occurs data may have been copied partially to kernel space. 331 */ 332 static inline __must_check 333 int read_guest_abs(struct kvm_vcpu *vcpu, unsigned long gpa, void *data, 334 unsigned long len) 335 { 336 return kvm_read_guest(vcpu->kvm, gpa, data, len); 337 } 338 339 /** 340 * write_guest_real - copy data from kernel space to guest space real 341 * @vcpu: virtual cpu 342 * @gra: guest real address 343 * @data: source address in kernel space 344 * @len: number of bytes to copy 345 * 346 * Copy @len bytes from @data (kernel space) to @gra (guest real address). 347 * It is up to the caller to ensure that the entire guest memory range is 348 * valid memory before calling this function. 349 * Guest low address and key protection are not checked. 350 * 351 * Returns zero on success or -EFAULT on error. 352 * 353 * If an error occurs data may have been copied partially to guest memory. 354 */ 355 static inline __must_check 356 int write_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 357 unsigned long len) 358 { 359 return access_guest_real(vcpu, gra, data, len, 1); 360 } 361 362 /** 363 * read_guest_real - copy data from guest space real to kernel space 364 * @vcpu: virtual cpu 365 * @gra: guest real address 366 * @data: destination address in kernel space 367 * @len: number of bytes to copy 368 * 369 * Copy @len bytes from @gra (guest real address) to @data (kernel space). 370 * It is up to the caller to ensure that the entire guest memory range is 371 * valid memory before calling this function. 372 * Guest key protection is not checked. 373 * 374 * Returns zero on success or -EFAULT on error. 375 * 376 * If an error occurs data may have been copied partially to kernel space. 377 */ 378 static inline __must_check 379 int read_guest_real(struct kvm_vcpu *vcpu, unsigned long gra, void *data, 380 unsigned long len) 381 { 382 return access_guest_real(vcpu, gra, data, len, 0); 383 } 384 385 void ipte_lock(struct kvm_vcpu *vcpu); 386 void ipte_unlock(struct kvm_vcpu *vcpu); 387 int ipte_lock_held(struct kvm_vcpu *vcpu); 388 int kvm_s390_check_low_addr_prot_real(struct kvm_vcpu *vcpu, unsigned long gra); 389 390 /* MVPG PEI indication bits */ 391 #define PEI_DAT_PROT 2 392 #define PEI_NOT_PTE 4 393 394 int kvm_s390_shadow_fault(struct kvm_vcpu *vcpu, struct gmap *shadow, 395 unsigned long saddr, unsigned long *datptr); 396 397 #endif /* __KVM_S390_GACCESS_H */ 398