1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2021 Google LLC 4 * Author: Fuad Tabba <tabba@google.com> 5 */ 6 7 #include <linux/irqchip/arm-gic-v3.h> 8 9 #include <asm/kvm_asm.h> 10 #include <asm/kvm_mmu.h> 11 12 #include <hyp/adjust_pc.h> 13 14 #include <nvhe/fixed_config.h> 15 16 #include "../../sys_regs.h" 17 18 /* 19 * Copies of the host's CPU features registers holding sanitized values at hyp. 20 */ 21 u64 id_aa64pfr0_el1_sys_val; 22 u64 id_aa64pfr1_el1_sys_val; 23 u64 id_aa64isar0_el1_sys_val; 24 u64 id_aa64isar1_el1_sys_val; 25 u64 id_aa64isar2_el1_sys_val; 26 u64 id_aa64mmfr0_el1_sys_val; 27 u64 id_aa64mmfr1_el1_sys_val; 28 u64 id_aa64mmfr2_el1_sys_val; 29 u64 id_aa64smfr0_el1_sys_val; 30 31 /* 32 * Inject an unknown/undefined exception to an AArch64 guest while most of its 33 * sysregs are live. 34 */ 35 static void inject_undef64(struct kvm_vcpu *vcpu) 36 { 37 u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); 38 39 *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR); 40 *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR); 41 42 kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC); 43 44 __kvm_adjust_pc(vcpu); 45 46 write_sysreg_el1(esr, SYS_ESR); 47 write_sysreg_el1(read_sysreg_el2(SYS_ELR), SYS_ELR); 48 write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR); 49 write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR); 50 } 51 52 /* 53 * Returns the restricted features values of the feature register based on the 54 * limitations in restrict_fields. 55 * A feature id field value of 0b0000 does not impose any restrictions. 56 * Note: Use only for unsigned feature field values. 57 */ 58 static u64 get_restricted_features_unsigned(u64 sys_reg_val, 59 u64 restrict_fields) 60 { 61 u64 value = 0UL; 62 u64 mask = GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0); 63 64 /* 65 * According to the Arm Architecture Reference Manual, feature fields 66 * use increasing values to indicate increases in functionality. 67 * Iterate over the restricted feature fields and calculate the minimum 68 * unsigned value between the one supported by the system, and what the 69 * value is being restricted to. 70 */ 71 while (sys_reg_val && restrict_fields) { 72 value |= min(sys_reg_val & mask, restrict_fields & mask); 73 sys_reg_val &= ~mask; 74 restrict_fields &= ~mask; 75 mask <<= ARM64_FEATURE_FIELD_BITS; 76 } 77 78 return value; 79 } 80 81 /* 82 * Functions that return the value of feature id registers for protected VMs 83 * based on allowed features, system features, and KVM support. 84 */ 85 86 static u64 get_pvm_id_aa64pfr0(const struct kvm_vcpu *vcpu) 87 { 88 u64 set_mask = 0; 89 u64 allow_mask = PVM_ID_AA64PFR0_ALLOW; 90 91 set_mask |= get_restricted_features_unsigned(id_aa64pfr0_el1_sys_val, 92 PVM_ID_AA64PFR0_RESTRICT_UNSIGNED); 93 94 return (id_aa64pfr0_el1_sys_val & allow_mask) | set_mask; 95 } 96 97 static u64 get_pvm_id_aa64pfr1(const struct kvm_vcpu *vcpu) 98 { 99 const struct kvm *kvm = (const struct kvm *)kern_hyp_va(vcpu->kvm); 100 u64 allow_mask = PVM_ID_AA64PFR1_ALLOW; 101 102 if (!kvm_has_mte(kvm)) 103 allow_mask &= ~ARM64_FEATURE_MASK(ID_AA64PFR1_EL1_MTE); 104 105 return id_aa64pfr1_el1_sys_val & allow_mask; 106 } 107 108 static u64 get_pvm_id_aa64zfr0(const struct kvm_vcpu *vcpu) 109 { 110 /* 111 * No support for Scalable Vectors, therefore, hyp has no sanitized 112 * copy of the feature id register. 113 */ 114 BUILD_BUG_ON(PVM_ID_AA64ZFR0_ALLOW != 0ULL); 115 return 0; 116 } 117 118 static u64 get_pvm_id_aa64dfr0(const struct kvm_vcpu *vcpu) 119 { 120 /* 121 * No support for debug, including breakpoints, and watchpoints, 122 * therefore, pKVM has no sanitized copy of the feature id register. 123 */ 124 BUILD_BUG_ON(PVM_ID_AA64DFR0_ALLOW != 0ULL); 125 return 0; 126 } 127 128 static u64 get_pvm_id_aa64dfr1(const struct kvm_vcpu *vcpu) 129 { 130 /* 131 * No support for debug, therefore, hyp has no sanitized copy of the 132 * feature id register. 133 */ 134 BUILD_BUG_ON(PVM_ID_AA64DFR1_ALLOW != 0ULL); 135 return 0; 136 } 137 138 static u64 get_pvm_id_aa64afr0(const struct kvm_vcpu *vcpu) 139 { 140 /* 141 * No support for implementation defined features, therefore, hyp has no 142 * sanitized copy of the feature id register. 143 */ 144 BUILD_BUG_ON(PVM_ID_AA64AFR0_ALLOW != 0ULL); 145 return 0; 146 } 147 148 static u64 get_pvm_id_aa64afr1(const struct kvm_vcpu *vcpu) 149 { 150 /* 151 * No support for implementation defined features, therefore, hyp has no 152 * sanitized copy of the feature id register. 153 */ 154 BUILD_BUG_ON(PVM_ID_AA64AFR1_ALLOW != 0ULL); 155 return 0; 156 } 157 158 static u64 get_pvm_id_aa64isar0(const struct kvm_vcpu *vcpu) 159 { 160 return id_aa64isar0_el1_sys_val & PVM_ID_AA64ISAR0_ALLOW; 161 } 162 163 static u64 get_pvm_id_aa64isar1(const struct kvm_vcpu *vcpu) 164 { 165 u64 allow_mask = PVM_ID_AA64ISAR1_ALLOW; 166 167 if (!vcpu_has_ptrauth(vcpu)) 168 allow_mask &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_APA) | 169 ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_API) | 170 ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPA) | 171 ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPI)); 172 173 return id_aa64isar1_el1_sys_val & allow_mask; 174 } 175 176 static u64 get_pvm_id_aa64isar2(const struct kvm_vcpu *vcpu) 177 { 178 u64 allow_mask = PVM_ID_AA64ISAR2_ALLOW; 179 180 if (!vcpu_has_ptrauth(vcpu)) 181 allow_mask &= ~(ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_APA3) | 182 ARM64_FEATURE_MASK(ID_AA64ISAR2_EL1_GPA3)); 183 184 return id_aa64isar2_el1_sys_val & allow_mask; 185 } 186 187 static u64 get_pvm_id_aa64mmfr0(const struct kvm_vcpu *vcpu) 188 { 189 u64 set_mask; 190 191 set_mask = get_restricted_features_unsigned(id_aa64mmfr0_el1_sys_val, 192 PVM_ID_AA64MMFR0_RESTRICT_UNSIGNED); 193 194 return (id_aa64mmfr0_el1_sys_val & PVM_ID_AA64MMFR0_ALLOW) | set_mask; 195 } 196 197 static u64 get_pvm_id_aa64mmfr1(const struct kvm_vcpu *vcpu) 198 { 199 return id_aa64mmfr1_el1_sys_val & PVM_ID_AA64MMFR1_ALLOW; 200 } 201 202 static u64 get_pvm_id_aa64mmfr2(const struct kvm_vcpu *vcpu) 203 { 204 return id_aa64mmfr2_el1_sys_val & PVM_ID_AA64MMFR2_ALLOW; 205 } 206 207 /* Read a sanitized cpufeature ID register by its encoding */ 208 u64 pvm_read_id_reg(const struct kvm_vcpu *vcpu, u32 id) 209 { 210 switch (id) { 211 case SYS_ID_AA64PFR0_EL1: 212 return get_pvm_id_aa64pfr0(vcpu); 213 case SYS_ID_AA64PFR1_EL1: 214 return get_pvm_id_aa64pfr1(vcpu); 215 case SYS_ID_AA64ZFR0_EL1: 216 return get_pvm_id_aa64zfr0(vcpu); 217 case SYS_ID_AA64DFR0_EL1: 218 return get_pvm_id_aa64dfr0(vcpu); 219 case SYS_ID_AA64DFR1_EL1: 220 return get_pvm_id_aa64dfr1(vcpu); 221 case SYS_ID_AA64AFR0_EL1: 222 return get_pvm_id_aa64afr0(vcpu); 223 case SYS_ID_AA64AFR1_EL1: 224 return get_pvm_id_aa64afr1(vcpu); 225 case SYS_ID_AA64ISAR0_EL1: 226 return get_pvm_id_aa64isar0(vcpu); 227 case SYS_ID_AA64ISAR1_EL1: 228 return get_pvm_id_aa64isar1(vcpu); 229 case SYS_ID_AA64ISAR2_EL1: 230 return get_pvm_id_aa64isar2(vcpu); 231 case SYS_ID_AA64MMFR0_EL1: 232 return get_pvm_id_aa64mmfr0(vcpu); 233 case SYS_ID_AA64MMFR1_EL1: 234 return get_pvm_id_aa64mmfr1(vcpu); 235 case SYS_ID_AA64MMFR2_EL1: 236 return get_pvm_id_aa64mmfr2(vcpu); 237 default: 238 /* Unhandled ID register, RAZ */ 239 return 0; 240 } 241 } 242 243 static u64 read_id_reg(const struct kvm_vcpu *vcpu, 244 struct sys_reg_desc const *r) 245 { 246 return pvm_read_id_reg(vcpu, reg_to_encoding(r)); 247 } 248 249 /* Handler to RAZ/WI sysregs */ 250 static bool pvm_access_raz_wi(struct kvm_vcpu *vcpu, struct sys_reg_params *p, 251 const struct sys_reg_desc *r) 252 { 253 if (!p->is_write) 254 p->regval = 0; 255 256 return true; 257 } 258 259 /* 260 * Accessor for AArch32 feature id registers. 261 * 262 * The value of these registers is "unknown" according to the spec if AArch32 263 * isn't supported. 264 */ 265 static bool pvm_access_id_aarch32(struct kvm_vcpu *vcpu, 266 struct sys_reg_params *p, 267 const struct sys_reg_desc *r) 268 { 269 if (p->is_write) { 270 inject_undef64(vcpu); 271 return false; 272 } 273 274 /* 275 * No support for AArch32 guests, therefore, pKVM has no sanitized copy 276 * of AArch32 feature id registers. 277 */ 278 BUILD_BUG_ON(FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_EL1), 279 PVM_ID_AA64PFR0_RESTRICT_UNSIGNED) > ID_AA64PFR0_EL1_ELx_64BIT_ONLY); 280 281 return pvm_access_raz_wi(vcpu, p, r); 282 } 283 284 /* 285 * Accessor for AArch64 feature id registers. 286 * 287 * If access is allowed, set the regval to the protected VM's view of the 288 * register and return true. 289 * Otherwise, inject an undefined exception and return false. 290 */ 291 static bool pvm_access_id_aarch64(struct kvm_vcpu *vcpu, 292 struct sys_reg_params *p, 293 const struct sys_reg_desc *r) 294 { 295 if (p->is_write) { 296 inject_undef64(vcpu); 297 return false; 298 } 299 300 p->regval = read_id_reg(vcpu, r); 301 return true; 302 } 303 304 static bool pvm_gic_read_sre(struct kvm_vcpu *vcpu, 305 struct sys_reg_params *p, 306 const struct sys_reg_desc *r) 307 { 308 /* pVMs only support GICv3. 'nuf said. */ 309 if (!p->is_write) 310 p->regval = ICC_SRE_EL1_DIB | ICC_SRE_EL1_DFB | ICC_SRE_EL1_SRE; 311 312 return true; 313 } 314 315 /* Mark the specified system register as an AArch32 feature id register. */ 316 #define AARCH32(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch32 } 317 318 /* Mark the specified system register as an AArch64 feature id register. */ 319 #define AARCH64(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch64 } 320 321 /* 322 * sys_reg_desc initialiser for architecturally unallocated cpufeature ID 323 * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2 324 * (1 <= crm < 8, 0 <= Op2 < 8). 325 */ 326 #define ID_UNALLOCATED(crm, op2) { \ 327 Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2), \ 328 .access = pvm_access_id_aarch64, \ 329 } 330 331 /* Mark the specified system register as Read-As-Zero/Write-Ignored */ 332 #define RAZ_WI(REG) { SYS_DESC(REG), .access = pvm_access_raz_wi } 333 334 /* Mark the specified system register as not being handled in hyp. */ 335 #define HOST_HANDLED(REG) { SYS_DESC(REG), .access = NULL } 336 337 /* 338 * Architected system registers. 339 * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 340 * 341 * NOTE: Anything not explicitly listed here is *restricted by default*, i.e., 342 * it will lead to injecting an exception into the guest. 343 */ 344 static const struct sys_reg_desc pvm_sys_reg_descs[] = { 345 /* Cache maintenance by set/way operations are restricted. */ 346 347 /* Debug and Trace Registers are restricted. */ 348 349 /* AArch64 mappings of the AArch32 ID registers */ 350 /* CRm=1 */ 351 AARCH32(SYS_ID_PFR0_EL1), 352 AARCH32(SYS_ID_PFR1_EL1), 353 AARCH32(SYS_ID_DFR0_EL1), 354 AARCH32(SYS_ID_AFR0_EL1), 355 AARCH32(SYS_ID_MMFR0_EL1), 356 AARCH32(SYS_ID_MMFR1_EL1), 357 AARCH32(SYS_ID_MMFR2_EL1), 358 AARCH32(SYS_ID_MMFR3_EL1), 359 360 /* CRm=2 */ 361 AARCH32(SYS_ID_ISAR0_EL1), 362 AARCH32(SYS_ID_ISAR1_EL1), 363 AARCH32(SYS_ID_ISAR2_EL1), 364 AARCH32(SYS_ID_ISAR3_EL1), 365 AARCH32(SYS_ID_ISAR4_EL1), 366 AARCH32(SYS_ID_ISAR5_EL1), 367 AARCH32(SYS_ID_MMFR4_EL1), 368 AARCH32(SYS_ID_ISAR6_EL1), 369 370 /* CRm=3 */ 371 AARCH32(SYS_MVFR0_EL1), 372 AARCH32(SYS_MVFR1_EL1), 373 AARCH32(SYS_MVFR2_EL1), 374 ID_UNALLOCATED(3,3), 375 AARCH32(SYS_ID_PFR2_EL1), 376 AARCH32(SYS_ID_DFR1_EL1), 377 AARCH32(SYS_ID_MMFR5_EL1), 378 ID_UNALLOCATED(3,7), 379 380 /* AArch64 ID registers */ 381 /* CRm=4 */ 382 AARCH64(SYS_ID_AA64PFR0_EL1), 383 AARCH64(SYS_ID_AA64PFR1_EL1), 384 ID_UNALLOCATED(4,2), 385 ID_UNALLOCATED(4,3), 386 AARCH64(SYS_ID_AA64ZFR0_EL1), 387 ID_UNALLOCATED(4,5), 388 ID_UNALLOCATED(4,6), 389 ID_UNALLOCATED(4,7), 390 AARCH64(SYS_ID_AA64DFR0_EL1), 391 AARCH64(SYS_ID_AA64DFR1_EL1), 392 ID_UNALLOCATED(5,2), 393 ID_UNALLOCATED(5,3), 394 AARCH64(SYS_ID_AA64AFR0_EL1), 395 AARCH64(SYS_ID_AA64AFR1_EL1), 396 ID_UNALLOCATED(5,6), 397 ID_UNALLOCATED(5,7), 398 AARCH64(SYS_ID_AA64ISAR0_EL1), 399 AARCH64(SYS_ID_AA64ISAR1_EL1), 400 AARCH64(SYS_ID_AA64ISAR2_EL1), 401 ID_UNALLOCATED(6,3), 402 ID_UNALLOCATED(6,4), 403 ID_UNALLOCATED(6,5), 404 ID_UNALLOCATED(6,6), 405 ID_UNALLOCATED(6,7), 406 AARCH64(SYS_ID_AA64MMFR0_EL1), 407 AARCH64(SYS_ID_AA64MMFR1_EL1), 408 AARCH64(SYS_ID_AA64MMFR2_EL1), 409 ID_UNALLOCATED(7,3), 410 ID_UNALLOCATED(7,4), 411 ID_UNALLOCATED(7,5), 412 ID_UNALLOCATED(7,6), 413 ID_UNALLOCATED(7,7), 414 415 /* Scalable Vector Registers are restricted. */ 416 417 RAZ_WI(SYS_ERRIDR_EL1), 418 RAZ_WI(SYS_ERRSELR_EL1), 419 RAZ_WI(SYS_ERXFR_EL1), 420 RAZ_WI(SYS_ERXCTLR_EL1), 421 RAZ_WI(SYS_ERXSTATUS_EL1), 422 RAZ_WI(SYS_ERXADDR_EL1), 423 RAZ_WI(SYS_ERXMISC0_EL1), 424 RAZ_WI(SYS_ERXMISC1_EL1), 425 426 /* Performance Monitoring Registers are restricted. */ 427 428 /* Limited Ordering Regions Registers are restricted. */ 429 430 HOST_HANDLED(SYS_ICC_SGI1R_EL1), 431 HOST_HANDLED(SYS_ICC_ASGI1R_EL1), 432 HOST_HANDLED(SYS_ICC_SGI0R_EL1), 433 { SYS_DESC(SYS_ICC_SRE_EL1), .access = pvm_gic_read_sre, }, 434 435 HOST_HANDLED(SYS_CCSIDR_EL1), 436 HOST_HANDLED(SYS_CLIDR_EL1), 437 HOST_HANDLED(SYS_CSSELR_EL1), 438 HOST_HANDLED(SYS_CTR_EL0), 439 440 /* Performance Monitoring Registers are restricted. */ 441 442 /* Activity Monitoring Registers are restricted. */ 443 444 HOST_HANDLED(SYS_CNTP_TVAL_EL0), 445 HOST_HANDLED(SYS_CNTP_CTL_EL0), 446 HOST_HANDLED(SYS_CNTP_CVAL_EL0), 447 448 /* Performance Monitoring Registers are restricted. */ 449 }; 450 451 /* 452 * Checks that the sysreg table is unique and in-order. 453 * 454 * Returns 0 if the table is consistent, or 1 otherwise. 455 */ 456 int kvm_check_pvm_sysreg_table(void) 457 { 458 unsigned int i; 459 460 for (i = 1; i < ARRAY_SIZE(pvm_sys_reg_descs); i++) { 461 if (cmp_sys_reg(&pvm_sys_reg_descs[i-1], &pvm_sys_reg_descs[i]) >= 0) 462 return 1; 463 } 464 465 return 0; 466 } 467 468 /* 469 * Handler for protected VM MSR, MRS or System instruction execution. 470 * 471 * Returns true if the hypervisor has handled the exit, and control should go 472 * back to the guest, or false if it hasn't, to be handled by the host. 473 */ 474 bool kvm_handle_pvm_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code) 475 { 476 const struct sys_reg_desc *r; 477 struct sys_reg_params params; 478 unsigned long esr = kvm_vcpu_get_esr(vcpu); 479 int Rt = kvm_vcpu_sys_get_rt(vcpu); 480 481 params = esr_sys64_to_params(esr); 482 params.regval = vcpu_get_reg(vcpu, Rt); 483 484 r = find_reg(¶ms, pvm_sys_reg_descs, ARRAY_SIZE(pvm_sys_reg_descs)); 485 486 /* Undefined (RESTRICTED). */ 487 if (r == NULL) { 488 inject_undef64(vcpu); 489 return true; 490 } 491 492 /* Handled by the host (HOST_HANDLED) */ 493 if (r->access == NULL) 494 return false; 495 496 /* Handled by hyp: skip instruction if instructed to do so. */ 497 if (r->access(vcpu, ¶ms, r)) 498 __kvm_skip_instr(vcpu); 499 500 if (!params.is_write) 501 vcpu_set_reg(vcpu, Rt, params.regval); 502 503 return true; 504 } 505 506 /* 507 * Handler for protected VM restricted exceptions. 508 * 509 * Inject an undefined exception into the guest and return true to indicate that 510 * the hypervisor has handled the exit, and control should go back to the guest. 511 */ 512 bool kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu, u64 *exit_code) 513 { 514 inject_undef64(vcpu); 515 return true; 516 } 517