1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * handling interprocessor communication 4 * 5 * Copyright IBM Corp. 2008, 2013 6 * 7 * Author(s): Carsten Otte <cotte@de.ibm.com> 8 * Christian Borntraeger <borntraeger@de.ibm.com> 9 * Christian Ehrhardt <ehrhardt@de.ibm.com> 10 */ 11 12 #include <linux/kvm.h> 13 #include <linux/kvm_host.h> 14 #include <linux/slab.h> 15 #include <asm/sigp.h> 16 #include "gaccess.h" 17 #include "kvm-s390.h" 18 #include "trace.h" 19 20 static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu, 21 u64 *reg) 22 { 23 const bool stopped = kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED); 24 int rc; 25 int ext_call_pending; 26 27 ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu); 28 if (!stopped && !ext_call_pending) 29 rc = SIGP_CC_ORDER_CODE_ACCEPTED; 30 else { 31 *reg &= 0xffffffff00000000UL; 32 if (ext_call_pending) 33 *reg |= SIGP_STATUS_EXT_CALL_PENDING; 34 if (stopped) 35 *reg |= SIGP_STATUS_STOPPED; 36 rc = SIGP_CC_STATUS_STORED; 37 } 38 39 VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id, 40 rc); 41 return rc; 42 } 43 44 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu, 45 struct kvm_vcpu *dst_vcpu) 46 { 47 struct kvm_s390_irq irq = { 48 .type = KVM_S390_INT_EMERGENCY, 49 .u.emerg.code = vcpu->vcpu_id, 50 }; 51 int rc = 0; 52 53 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); 54 if (!rc) 55 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x", 56 dst_vcpu->vcpu_id); 57 58 return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED; 59 } 60 61 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu) 62 { 63 return __inject_sigp_emergency(vcpu, dst_vcpu); 64 } 65 66 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu, 67 struct kvm_vcpu *dst_vcpu, 68 u16 asn, u64 *reg) 69 { 70 const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT; 71 u16 p_asn, s_asn; 72 psw_t *psw; 73 bool idle; 74 75 idle = is_vcpu_idle(vcpu); 76 psw = &dst_vcpu->arch.sie_block->gpsw; 77 p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff; /* Primary ASN */ 78 s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff; /* Secondary ASN */ 79 80 /* Inject the emergency signal? */ 81 if (!is_vcpu_stopped(vcpu) 82 || (psw->mask & psw_int_mask) != psw_int_mask 83 || (idle && psw->addr != 0) 84 || (!idle && (asn == p_asn || asn == s_asn))) { 85 return __inject_sigp_emergency(vcpu, dst_vcpu); 86 } else { 87 *reg &= 0xffffffff00000000UL; 88 *reg |= SIGP_STATUS_INCORRECT_STATE; 89 return SIGP_CC_STATUS_STORED; 90 } 91 } 92 93 static int __sigp_external_call(struct kvm_vcpu *vcpu, 94 struct kvm_vcpu *dst_vcpu, u64 *reg) 95 { 96 struct kvm_s390_irq irq = { 97 .type = KVM_S390_INT_EXTERNAL_CALL, 98 .u.extcall.code = vcpu->vcpu_id, 99 }; 100 int rc; 101 102 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); 103 if (rc == -EBUSY) { 104 *reg &= 0xffffffff00000000UL; 105 *reg |= SIGP_STATUS_EXT_CALL_PENDING; 106 return SIGP_CC_STATUS_STORED; 107 } else if (rc == 0) { 108 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x", 109 dst_vcpu->vcpu_id); 110 } 111 112 return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED; 113 } 114 115 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu) 116 { 117 struct kvm_s390_irq irq = { 118 .type = KVM_S390_SIGP_STOP, 119 }; 120 int rc; 121 122 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); 123 if (rc == -EBUSY) 124 rc = SIGP_CC_BUSY; 125 else if (rc == 0) 126 VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x", 127 dst_vcpu->vcpu_id); 128 129 return rc; 130 } 131 132 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu, 133 struct kvm_vcpu *dst_vcpu, u64 *reg) 134 { 135 struct kvm_s390_irq irq = { 136 .type = KVM_S390_SIGP_STOP, 137 .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS, 138 }; 139 int rc; 140 141 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); 142 if (rc == -EBUSY) 143 rc = SIGP_CC_BUSY; 144 else if (rc == 0) 145 VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x", 146 dst_vcpu->vcpu_id); 147 148 return rc; 149 } 150 151 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter, 152 u64 *status_reg) 153 { 154 *status_reg &= 0xffffffff00000000UL; 155 156 /* Reject set arch order, with czam we're always in z/Arch mode. */ 157 *status_reg |= SIGP_STATUS_INVALID_PARAMETER; 158 return SIGP_CC_STATUS_STORED; 159 } 160 161 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu, 162 u32 address, u64 *reg) 163 { 164 struct kvm_s390_irq irq = { 165 .type = KVM_S390_SIGP_SET_PREFIX, 166 .u.prefix.address = address & 0x7fffe000u, 167 }; 168 int rc; 169 170 /* 171 * Make sure the new value is valid memory. We only need to check the 172 * first page, since address is 8k aligned and memory pieces are always 173 * at least 1MB aligned and have at least a size of 1MB. 174 */ 175 if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) { 176 *reg &= 0xffffffff00000000UL; 177 *reg |= SIGP_STATUS_INVALID_PARAMETER; 178 return SIGP_CC_STATUS_STORED; 179 } 180 181 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq); 182 if (rc == -EBUSY) { 183 *reg &= 0xffffffff00000000UL; 184 *reg |= SIGP_STATUS_INCORRECT_STATE; 185 return SIGP_CC_STATUS_STORED; 186 } 187 188 return rc; 189 } 190 191 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu, 192 struct kvm_vcpu *dst_vcpu, 193 u32 addr, u64 *reg) 194 { 195 int rc; 196 197 if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) { 198 *reg &= 0xffffffff00000000UL; 199 *reg |= SIGP_STATUS_INCORRECT_STATE; 200 return SIGP_CC_STATUS_STORED; 201 } 202 203 addr &= 0x7ffffe00; 204 rc = kvm_s390_store_status_unloaded(dst_vcpu, addr); 205 if (rc == -EFAULT) { 206 *reg &= 0xffffffff00000000UL; 207 *reg |= SIGP_STATUS_INVALID_PARAMETER; 208 rc = SIGP_CC_STATUS_STORED; 209 } 210 return rc; 211 } 212 213 static int __sigp_sense_running(struct kvm_vcpu *vcpu, 214 struct kvm_vcpu *dst_vcpu, u64 *reg) 215 { 216 int rc; 217 218 if (!test_kvm_facility(vcpu->kvm, 9)) { 219 *reg &= 0xffffffff00000000UL; 220 *reg |= SIGP_STATUS_INVALID_ORDER; 221 return SIGP_CC_STATUS_STORED; 222 } 223 224 if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) { 225 /* running */ 226 rc = SIGP_CC_ORDER_CODE_ACCEPTED; 227 } else { 228 /* not running */ 229 *reg &= 0xffffffff00000000UL; 230 *reg |= SIGP_STATUS_NOT_RUNNING; 231 rc = SIGP_CC_STATUS_STORED; 232 } 233 234 VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x", 235 dst_vcpu->vcpu_id, rc); 236 237 return rc; 238 } 239 240 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu, 241 struct kvm_vcpu *dst_vcpu, u8 order_code) 242 { 243 struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int; 244 /* handle (RE)START in user space */ 245 int rc = -EOPNOTSUPP; 246 247 /* make sure we don't race with STOP irq injection */ 248 spin_lock(&li->lock); 249 if (kvm_s390_is_stop_irq_pending(dst_vcpu)) 250 rc = SIGP_CC_BUSY; 251 spin_unlock(&li->lock); 252 253 return rc; 254 } 255 256 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu, 257 struct kvm_vcpu *dst_vcpu, u8 order_code) 258 { 259 /* handle (INITIAL) CPU RESET in user space */ 260 return -EOPNOTSUPP; 261 } 262 263 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu, 264 struct kvm_vcpu *dst_vcpu) 265 { 266 /* handle unknown orders in user space */ 267 return -EOPNOTSUPP; 268 } 269 270 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code, 271 u16 cpu_addr, u32 parameter, u64 *status_reg) 272 { 273 int rc; 274 struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr); 275 276 if (!dst_vcpu) 277 return SIGP_CC_NOT_OPERATIONAL; 278 279 /* 280 * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders 281 * are processed asynchronously. Until the affected VCPU finishes 282 * its work and calls back into KVM to clear the (RESTART or STOP) 283 * interrupt, we need to return any new non-reset orders "busy". 284 * 285 * This is important because a single VCPU could issue: 286 * 1) SIGP STOP $DESTINATION 287 * 2) SIGP SENSE $DESTINATION 288 * 289 * If the SIGP SENSE would not be rejected as "busy", it could 290 * return an incorrect answer as to whether the VCPU is STOPPED 291 * or OPERATING. 292 */ 293 if (order_code != SIGP_INITIAL_CPU_RESET && 294 order_code != SIGP_CPU_RESET) { 295 /* 296 * Lockless check. Both SIGP STOP and SIGP (RE)START 297 * properly synchronize everything while processing 298 * their orders, while the guest cannot observe a 299 * difference when issuing other orders from two 300 * different VCPUs. 301 */ 302 if (kvm_s390_is_stop_irq_pending(dst_vcpu) || 303 kvm_s390_is_restart_irq_pending(dst_vcpu)) 304 return SIGP_CC_BUSY; 305 } 306 307 switch (order_code) { 308 case SIGP_SENSE: 309 vcpu->stat.instruction_sigp_sense++; 310 rc = __sigp_sense(vcpu, dst_vcpu, status_reg); 311 break; 312 case SIGP_EXTERNAL_CALL: 313 vcpu->stat.instruction_sigp_external_call++; 314 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg); 315 break; 316 case SIGP_EMERGENCY_SIGNAL: 317 vcpu->stat.instruction_sigp_emergency++; 318 rc = __sigp_emergency(vcpu, dst_vcpu); 319 break; 320 case SIGP_STOP: 321 vcpu->stat.instruction_sigp_stop++; 322 rc = __sigp_stop(vcpu, dst_vcpu); 323 break; 324 case SIGP_STOP_AND_STORE_STATUS: 325 vcpu->stat.instruction_sigp_stop_store_status++; 326 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg); 327 break; 328 case SIGP_STORE_STATUS_AT_ADDRESS: 329 vcpu->stat.instruction_sigp_store_status++; 330 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter, 331 status_reg); 332 break; 333 case SIGP_SET_PREFIX: 334 vcpu->stat.instruction_sigp_prefix++; 335 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg); 336 break; 337 case SIGP_COND_EMERGENCY_SIGNAL: 338 vcpu->stat.instruction_sigp_cond_emergency++; 339 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter, 340 status_reg); 341 break; 342 case SIGP_SENSE_RUNNING: 343 vcpu->stat.instruction_sigp_sense_running++; 344 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg); 345 break; 346 case SIGP_START: 347 vcpu->stat.instruction_sigp_start++; 348 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code); 349 break; 350 case SIGP_RESTART: 351 vcpu->stat.instruction_sigp_restart++; 352 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code); 353 break; 354 case SIGP_INITIAL_CPU_RESET: 355 vcpu->stat.instruction_sigp_init_cpu_reset++; 356 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code); 357 break; 358 case SIGP_CPU_RESET: 359 vcpu->stat.instruction_sigp_cpu_reset++; 360 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code); 361 break; 362 default: 363 vcpu->stat.instruction_sigp_unknown++; 364 rc = __prepare_sigp_unknown(vcpu, dst_vcpu); 365 } 366 367 if (rc == -EOPNOTSUPP) 368 VCPU_EVENT(vcpu, 4, 369 "sigp order %u -> cpu %x: handled in user space", 370 order_code, dst_vcpu->vcpu_id); 371 372 return rc; 373 } 374 375 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code, 376 u16 cpu_addr) 377 { 378 if (!vcpu->kvm->arch.user_sigp) 379 return 0; 380 381 switch (order_code) { 382 case SIGP_SENSE: 383 case SIGP_EXTERNAL_CALL: 384 case SIGP_EMERGENCY_SIGNAL: 385 case SIGP_COND_EMERGENCY_SIGNAL: 386 case SIGP_SENSE_RUNNING: 387 return 0; 388 /* update counters as we're directly dropping to user space */ 389 case SIGP_STOP: 390 vcpu->stat.instruction_sigp_stop++; 391 break; 392 case SIGP_STOP_AND_STORE_STATUS: 393 vcpu->stat.instruction_sigp_stop_store_status++; 394 break; 395 case SIGP_STORE_STATUS_AT_ADDRESS: 396 vcpu->stat.instruction_sigp_store_status++; 397 break; 398 case SIGP_STORE_ADDITIONAL_STATUS: 399 vcpu->stat.instruction_sigp_store_adtl_status++; 400 break; 401 case SIGP_SET_PREFIX: 402 vcpu->stat.instruction_sigp_prefix++; 403 break; 404 case SIGP_START: 405 vcpu->stat.instruction_sigp_start++; 406 break; 407 case SIGP_RESTART: 408 vcpu->stat.instruction_sigp_restart++; 409 break; 410 case SIGP_INITIAL_CPU_RESET: 411 vcpu->stat.instruction_sigp_init_cpu_reset++; 412 break; 413 case SIGP_CPU_RESET: 414 vcpu->stat.instruction_sigp_cpu_reset++; 415 break; 416 default: 417 vcpu->stat.instruction_sigp_unknown++; 418 } 419 VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace", 420 order_code, cpu_addr); 421 422 return 1; 423 } 424 425 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu) 426 { 427 int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4; 428 int r3 = vcpu->arch.sie_block->ipa & 0x000f; 429 u32 parameter; 430 u16 cpu_addr = vcpu->run->s.regs.gprs[r3]; 431 u8 order_code; 432 int rc; 433 434 /* sigp in userspace can exit */ 435 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE) 436 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP); 437 438 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL); 439 if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr)) 440 return -EOPNOTSUPP; 441 442 if (r1 % 2) 443 parameter = vcpu->run->s.regs.gprs[r1]; 444 else 445 parameter = vcpu->run->s.regs.gprs[r1 + 1]; 446 447 trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter); 448 switch (order_code) { 449 case SIGP_SET_ARCHITECTURE: 450 vcpu->stat.instruction_sigp_arch++; 451 rc = __sigp_set_arch(vcpu, parameter, 452 &vcpu->run->s.regs.gprs[r1]); 453 break; 454 default: 455 rc = handle_sigp_dst(vcpu, order_code, cpu_addr, 456 parameter, 457 &vcpu->run->s.regs.gprs[r1]); 458 } 459 460 if (rc < 0) 461 return rc; 462 463 kvm_s390_set_psw_cc(vcpu, rc); 464 return 0; 465 } 466 467 /* 468 * Handle SIGP partial execution interception. 469 * 470 * This interception will occur at the source cpu when a source cpu sends an 471 * external call to a target cpu and the target cpu has the WAIT bit set in 472 * its cpuflags. Interception will occur after the interrupt indicator bits at 473 * the target cpu have been set. All error cases will lead to instruction 474 * interception, therefore nothing is to be checked or prepared. 475 */ 476 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu) 477 { 478 int r3 = vcpu->arch.sie_block->ipa & 0x000f; 479 u16 cpu_addr = vcpu->run->s.regs.gprs[r3]; 480 struct kvm_vcpu *dest_vcpu; 481 u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL); 482 483 if (order_code == SIGP_EXTERNAL_CALL) { 484 trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr); 485 486 dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr); 487 BUG_ON(dest_vcpu == NULL); 488 489 kvm_s390_vcpu_wakeup(dest_vcpu); 490 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED); 491 return 0; 492 } 493 494 return -EOPNOTSUPP; 495 } 496