1/* 2 * interrupt.c - handling kvm guest interrupts 3 * 4 * Copyright IBM Corp. 2008 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License (version 2 only) 8 * as published by the Free Software Foundation. 9 * 10 * Author(s): Carsten Otte <cotte@de.ibm.com> 11 */ 12 13#include <linux/interrupt.h> 14#include <linux/kvm_host.h> 15#include <linux/hrtimer.h> 16#include <linux/signal.h> 17#include <linux/slab.h> 18#include <asm/asm-offsets.h> 19#include <asm/uaccess.h> 20#include "kvm-s390.h" 21#include "gaccess.h" 22 23static int psw_extint_disabled(struct kvm_vcpu *vcpu) 24{ 25 return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT); 26} 27 28static int psw_interrupts_disabled(struct kvm_vcpu *vcpu) 29{ 30 if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER) || 31 (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_IO) || 32 (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT)) 33 return 0; 34 return 1; 35} 36 37static int __interrupt_is_deliverable(struct kvm_vcpu *vcpu, 38 struct kvm_s390_interrupt_info *inti) 39{ 40 switch (inti->type) { 41 case KVM_S390_INT_EMERGENCY: 42 if (psw_extint_disabled(vcpu)) 43 return 0; 44 if (vcpu->arch.sie_block->gcr[0] & 0x4000ul) 45 return 1; 46 return 0; 47 case KVM_S390_INT_SERVICE: 48 if (psw_extint_disabled(vcpu)) 49 return 0; 50 if (vcpu->arch.sie_block->gcr[0] & 0x200ul) 51 return 1; 52 return 0; 53 case KVM_S390_INT_VIRTIO: 54 if (psw_extint_disabled(vcpu)) 55 return 0; 56 if (vcpu->arch.sie_block->gcr[0] & 0x200ul) 57 return 1; 58 return 0; 59 case KVM_S390_PROGRAM_INT: 60 case KVM_S390_SIGP_STOP: 61 case KVM_S390_SIGP_SET_PREFIX: 62 case KVM_S390_RESTART: 63 return 1; 64 default: 65 BUG(); 66 } 67 return 0; 68} 69 70static void __set_cpu_idle(struct kvm_vcpu *vcpu) 71{ 72 BUG_ON(vcpu->vcpu_id > KVM_MAX_VCPUS - 1); 73 atomic_set_mask(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags); 74 set_bit(vcpu->vcpu_id, vcpu->arch.local_int.float_int->idle_mask); 75} 76 77static void __unset_cpu_idle(struct kvm_vcpu *vcpu) 78{ 79 BUG_ON(vcpu->vcpu_id > KVM_MAX_VCPUS - 1); 80 atomic_clear_mask(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags); 81 clear_bit(vcpu->vcpu_id, vcpu->arch.local_int.float_int->idle_mask); 82} 83 84static void __reset_intercept_indicators(struct kvm_vcpu *vcpu) 85{ 86 atomic_clear_mask(CPUSTAT_ECALL_PEND | 87 CPUSTAT_IO_INT | CPUSTAT_EXT_INT | CPUSTAT_STOP_INT, 88 &vcpu->arch.sie_block->cpuflags); 89 vcpu->arch.sie_block->lctl = 0x0000; 90} 91 92static void __set_cpuflag(struct kvm_vcpu *vcpu, u32 flag) 93{ 94 atomic_set_mask(flag, &vcpu->arch.sie_block->cpuflags); 95} 96 97static void __set_intercept_indicator(struct kvm_vcpu *vcpu, 98 struct kvm_s390_interrupt_info *inti) 99{ 100 switch (inti->type) { 101 case KVM_S390_INT_EMERGENCY: 102 case KVM_S390_INT_SERVICE: 103 case KVM_S390_INT_VIRTIO: 104 if (psw_extint_disabled(vcpu)) 105 __set_cpuflag(vcpu, CPUSTAT_EXT_INT); 106 else 107 vcpu->arch.sie_block->lctl |= LCTL_CR0; 108 break; 109 case KVM_S390_SIGP_STOP: 110 __set_cpuflag(vcpu, CPUSTAT_STOP_INT); 111 break; 112 default: 113 BUG(); 114 } 115} 116 117static void __do_deliver_interrupt(struct kvm_vcpu *vcpu, 118 struct kvm_s390_interrupt_info *inti) 119{ 120 const unsigned short table[] = { 2, 4, 4, 6 }; 121 int rc, exception = 0; 122 123 switch (inti->type) { 124 case KVM_S390_INT_EMERGENCY: 125 VCPU_EVENT(vcpu, 4, "%s", "interrupt: sigp emerg"); 126 vcpu->stat.deliver_emergency_signal++; 127 rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1201); 128 if (rc == -EFAULT) 129 exception = 1; 130 131 rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW, 132 &vcpu->arch.sie_block->gpsw, sizeof(psw_t)); 133 if (rc == -EFAULT) 134 exception = 1; 135 136 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw, 137 __LC_EXT_NEW_PSW, sizeof(psw_t)); 138 if (rc == -EFAULT) 139 exception = 1; 140 break; 141 142 case KVM_S390_INT_SERVICE: 143 VCPU_EVENT(vcpu, 4, "interrupt: sclp parm:%x", 144 inti->ext.ext_params); 145 vcpu->stat.deliver_service_signal++; 146 rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2401); 147 if (rc == -EFAULT) 148 exception = 1; 149 150 rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW, 151 &vcpu->arch.sie_block->gpsw, sizeof(psw_t)); 152 if (rc == -EFAULT) 153 exception = 1; 154 155 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw, 156 __LC_EXT_NEW_PSW, sizeof(psw_t)); 157 if (rc == -EFAULT) 158 exception = 1; 159 160 rc = put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params); 161 if (rc == -EFAULT) 162 exception = 1; 163 break; 164 165 case KVM_S390_INT_VIRTIO: 166 VCPU_EVENT(vcpu, 4, "interrupt: virtio parm:%x,parm64:%llx", 167 inti->ext.ext_params, inti->ext.ext_params2); 168 vcpu->stat.deliver_virtio_interrupt++; 169 rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2603); 170 if (rc == -EFAULT) 171 exception = 1; 172 173 rc = put_guest_u16(vcpu, __LC_CPU_ADDRESS, 0x0d00); 174 if (rc == -EFAULT) 175 exception = 1; 176 177 rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW, 178 &vcpu->arch.sie_block->gpsw, sizeof(psw_t)); 179 if (rc == -EFAULT) 180 exception = 1; 181 182 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw, 183 __LC_EXT_NEW_PSW, sizeof(psw_t)); 184 if (rc == -EFAULT) 185 exception = 1; 186 187 rc = put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params); 188 if (rc == -EFAULT) 189 exception = 1; 190 191 rc = put_guest_u64(vcpu, __LC_EXT_PARAMS2, 192 inti->ext.ext_params2); 193 if (rc == -EFAULT) 194 exception = 1; 195 break; 196 197 case KVM_S390_SIGP_STOP: 198 VCPU_EVENT(vcpu, 4, "%s", "interrupt: cpu stop"); 199 vcpu->stat.deliver_stop_signal++; 200 __set_intercept_indicator(vcpu, inti); 201 break; 202 203 case KVM_S390_SIGP_SET_PREFIX: 204 VCPU_EVENT(vcpu, 4, "interrupt: set prefix to %x", 205 inti->prefix.address); 206 vcpu->stat.deliver_prefix_signal++; 207 vcpu->arch.sie_block->prefix = inti->prefix.address; 208 vcpu->arch.sie_block->ihcpu = 0xffff; 209 break; 210 211 case KVM_S390_RESTART: 212 VCPU_EVENT(vcpu, 4, "%s", "interrupt: cpu restart"); 213 vcpu->stat.deliver_restart_signal++; 214 rc = copy_to_guest(vcpu, offsetof(struct _lowcore, 215 restart_old_psw), &vcpu->arch.sie_block->gpsw, sizeof(psw_t)); 216 if (rc == -EFAULT) 217 exception = 1; 218 219 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw, 220 offsetof(struct _lowcore, restart_psw), sizeof(psw_t)); 221 if (rc == -EFAULT) 222 exception = 1; 223 break; 224 225 case KVM_S390_PROGRAM_INT: 226 VCPU_EVENT(vcpu, 4, "interrupt: pgm check code:%x, ilc:%x", 227 inti->pgm.code, 228 table[vcpu->arch.sie_block->ipa >> 14]); 229 vcpu->stat.deliver_program_int++; 230 rc = put_guest_u16(vcpu, __LC_PGM_INT_CODE, inti->pgm.code); 231 if (rc == -EFAULT) 232 exception = 1; 233 234 rc = put_guest_u16(vcpu, __LC_PGM_ILC, 235 table[vcpu->arch.sie_block->ipa >> 14]); 236 if (rc == -EFAULT) 237 exception = 1; 238 239 rc = copy_to_guest(vcpu, __LC_PGM_OLD_PSW, 240 &vcpu->arch.sie_block->gpsw, sizeof(psw_t)); 241 if (rc == -EFAULT) 242 exception = 1; 243 244 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw, 245 __LC_PGM_NEW_PSW, sizeof(psw_t)); 246 if (rc == -EFAULT) 247 exception = 1; 248 break; 249 250 default: 251 BUG(); 252 } 253 if (exception) { 254 printk("kvm: The guest lowcore is not mapped during interrupt " 255 "delivery, killing userspace\n"); 256 do_exit(SIGKILL); 257 } 258} 259 260static int __try_deliver_ckc_interrupt(struct kvm_vcpu *vcpu) 261{ 262 int rc, exception = 0; 263 264 if (psw_extint_disabled(vcpu)) 265 return 0; 266 if (!(vcpu->arch.sie_block->gcr[0] & 0x800ul)) 267 return 0; 268 rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1004); 269 if (rc == -EFAULT) 270 exception = 1; 271 rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW, 272 &vcpu->arch.sie_block->gpsw, sizeof(psw_t)); 273 if (rc == -EFAULT) 274 exception = 1; 275 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw, 276 __LC_EXT_NEW_PSW, sizeof(psw_t)); 277 if (rc == -EFAULT) 278 exception = 1; 279 if (exception) { 280 printk("kvm: The guest lowcore is not mapped during interrupt " 281 "delivery, killing userspace\n"); 282 do_exit(SIGKILL); 283 } 284 return 1; 285} 286 287static int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu) 288{ 289 struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int; 290 struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int; 291 struct kvm_s390_interrupt_info *inti; 292 int rc = 0; 293 294 if (atomic_read(&li->active)) { 295 spin_lock_bh(&li->lock); 296 list_for_each_entry(inti, &li->list, list) 297 if (__interrupt_is_deliverable(vcpu, inti)) { 298 rc = 1; 299 break; 300 } 301 spin_unlock_bh(&li->lock); 302 } 303 304 if ((!rc) && atomic_read(&fi->active)) { 305 spin_lock(&fi->lock); 306 list_for_each_entry(inti, &fi->list, list) 307 if (__interrupt_is_deliverable(vcpu, inti)) { 308 rc = 1; 309 break; 310 } 311 spin_unlock(&fi->lock); 312 } 313 314 if ((!rc) && (vcpu->arch.sie_block->ckc < 315 get_clock() + vcpu->arch.sie_block->epoch)) { 316 if ((!psw_extint_disabled(vcpu)) && 317 (vcpu->arch.sie_block->gcr[0] & 0x800ul)) 318 rc = 1; 319 } 320 321 return rc; 322} 323 324int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) 325{ 326 return 0; 327} 328 329int kvm_s390_handle_wait(struct kvm_vcpu *vcpu) 330{ 331 u64 now, sltime; 332 DECLARE_WAITQUEUE(wait, current); 333 334 vcpu->stat.exit_wait_state++; 335 if (kvm_cpu_has_interrupt(vcpu)) 336 return 0; 337 338 __set_cpu_idle(vcpu); 339 spin_lock_bh(&vcpu->arch.local_int.lock); 340 vcpu->arch.local_int.timer_due = 0; 341 spin_unlock_bh(&vcpu->arch.local_int.lock); 342 343 if (psw_interrupts_disabled(vcpu)) { 344 VCPU_EVENT(vcpu, 3, "%s", "disabled wait"); 345 __unset_cpu_idle(vcpu); 346 return -EOPNOTSUPP; /* disabled wait */ 347 } 348 349 if (psw_extint_disabled(vcpu) || 350 (!(vcpu->arch.sie_block->gcr[0] & 0x800ul))) { 351 VCPU_EVENT(vcpu, 3, "%s", "enabled wait w/o timer"); 352 goto no_timer; 353 } 354 355 now = get_clock() + vcpu->arch.sie_block->epoch; 356 if (vcpu->arch.sie_block->ckc < now) { 357 __unset_cpu_idle(vcpu); 358 return 0; 359 } 360 361 sltime = ((vcpu->arch.sie_block->ckc - now)*125)>>9; 362 363 hrtimer_start(&vcpu->arch.ckc_timer, ktime_set (0, sltime) , HRTIMER_MODE_REL); 364 VCPU_EVENT(vcpu, 5, "enabled wait via clock comparator: %llx ns", sltime); 365no_timer: 366 spin_lock(&vcpu->arch.local_int.float_int->lock); 367 spin_lock_bh(&vcpu->arch.local_int.lock); 368 add_wait_queue(&vcpu->arch.local_int.wq, &wait); 369 while (list_empty(&vcpu->arch.local_int.list) && 370 list_empty(&vcpu->arch.local_int.float_int->list) && 371 (!vcpu->arch.local_int.timer_due) && 372 !signal_pending(current)) { 373 set_current_state(TASK_INTERRUPTIBLE); 374 spin_unlock_bh(&vcpu->arch.local_int.lock); 375 spin_unlock(&vcpu->arch.local_int.float_int->lock); 376 vcpu_put(vcpu); 377 schedule(); 378 vcpu_load(vcpu); 379 spin_lock(&vcpu->arch.local_int.float_int->lock); 380 spin_lock_bh(&vcpu->arch.local_int.lock); 381 } 382 __unset_cpu_idle(vcpu); 383 __set_current_state(TASK_RUNNING); 384 remove_wait_queue(&vcpu->arch.local_int.wq, &wait); 385 spin_unlock_bh(&vcpu->arch.local_int.lock); 386 spin_unlock(&vcpu->arch.local_int.float_int->lock); 387 hrtimer_try_to_cancel(&vcpu->arch.ckc_timer); 388 return 0; 389} 390 391void kvm_s390_tasklet(unsigned long parm) 392{ 393 struct kvm_vcpu *vcpu = (struct kvm_vcpu *) parm; 394 395 spin_lock(&vcpu->arch.local_int.lock); 396 vcpu->arch.local_int.timer_due = 1; 397 if (waitqueue_active(&vcpu->arch.local_int.wq)) 398 wake_up_interruptible(&vcpu->arch.local_int.wq); 399 spin_unlock(&vcpu->arch.local_int.lock); 400} 401 402/* 403 * low level hrtimer wake routine. Because this runs in hardirq context 404 * we schedule a tasklet to do the real work. 405 */ 406enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer) 407{ 408 struct kvm_vcpu *vcpu; 409 410 vcpu = container_of(timer, struct kvm_vcpu, arch.ckc_timer); 411 tasklet_schedule(&vcpu->arch.tasklet); 412 413 return HRTIMER_NORESTART; 414} 415 416void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu) 417{ 418 struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int; 419 struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int; 420 struct kvm_s390_interrupt_info *n, *inti = NULL; 421 int deliver; 422 423 __reset_intercept_indicators(vcpu); 424 if (atomic_read(&li->active)) { 425 do { 426 deliver = 0; 427 spin_lock_bh(&li->lock); 428 list_for_each_entry_safe(inti, n, &li->list, list) { 429 if (__interrupt_is_deliverable(vcpu, inti)) { 430 list_del(&inti->list); 431 deliver = 1; 432 break; 433 } 434 __set_intercept_indicator(vcpu, inti); 435 } 436 if (list_empty(&li->list)) 437 atomic_set(&li->active, 0); 438 spin_unlock_bh(&li->lock); 439 if (deliver) { 440 __do_deliver_interrupt(vcpu, inti); 441 kfree(inti); 442 } 443 } while (deliver); 444 } 445 446 if ((vcpu->arch.sie_block->ckc < 447 get_clock() + vcpu->arch.sie_block->epoch)) 448 __try_deliver_ckc_interrupt(vcpu); 449 450 if (atomic_read(&fi->active)) { 451 do { 452 deliver = 0; 453 spin_lock(&fi->lock); 454 list_for_each_entry_safe(inti, n, &fi->list, list) { 455 if (__interrupt_is_deliverable(vcpu, inti)) { 456 list_del(&inti->list); 457 deliver = 1; 458 break; 459 } 460 __set_intercept_indicator(vcpu, inti); 461 } 462 if (list_empty(&fi->list)) 463 atomic_set(&fi->active, 0); 464 spin_unlock(&fi->lock); 465 if (deliver) { 466 __do_deliver_interrupt(vcpu, inti); 467 kfree(inti); 468 } 469 } while (deliver); 470 } 471} 472 473int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code) 474{ 475 struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int; 476 struct kvm_s390_interrupt_info *inti; 477 478 inti = kzalloc(sizeof(*inti), GFP_KERNEL); 479 if (!inti) 480 return -ENOMEM; 481 482 inti->type = KVM_S390_PROGRAM_INT; 483 inti->pgm.code = code; 484 485 VCPU_EVENT(vcpu, 3, "inject: program check %d (from kernel)", code); 486 spin_lock_bh(&li->lock); 487 list_add(&inti->list, &li->list); 488 atomic_set(&li->active, 1); 489 BUG_ON(waitqueue_active(&li->wq)); 490 spin_unlock_bh(&li->lock); 491 return 0; 492} 493 494int kvm_s390_inject_vm(struct kvm *kvm, 495 struct kvm_s390_interrupt *s390int) 496{ 497 struct kvm_s390_local_interrupt *li; 498 struct kvm_s390_float_interrupt *fi; 499 struct kvm_s390_interrupt_info *inti; 500 int sigcpu; 501 502 inti = kzalloc(sizeof(*inti), GFP_KERNEL); 503 if (!inti) 504 return -ENOMEM; 505 506 switch (s390int->type) { 507 case KVM_S390_INT_VIRTIO: 508 VM_EVENT(kvm, 5, "inject: virtio parm:%x,parm64:%llx", 509 s390int->parm, s390int->parm64); 510 inti->type = s390int->type; 511 inti->ext.ext_params = s390int->parm; 512 inti->ext.ext_params2 = s390int->parm64; 513 break; 514 case KVM_S390_INT_SERVICE: 515 VM_EVENT(kvm, 5, "inject: sclp parm:%x", s390int->parm); 516 inti->type = s390int->type; 517 inti->ext.ext_params = s390int->parm; 518 break; 519 case KVM_S390_PROGRAM_INT: 520 case KVM_S390_SIGP_STOP: 521 case KVM_S390_INT_EMERGENCY: 522 default: 523 kfree(inti); 524 return -EINVAL; 525 } 526 527 mutex_lock(&kvm->lock); 528 fi = &kvm->arch.float_int; 529 spin_lock(&fi->lock); 530 list_add_tail(&inti->list, &fi->list); 531 atomic_set(&fi->active, 1); 532 sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS); 533 if (sigcpu == KVM_MAX_VCPUS) { 534 do { 535 sigcpu = fi->next_rr_cpu++; 536 if (sigcpu == KVM_MAX_VCPUS) 537 sigcpu = fi->next_rr_cpu = 0; 538 } while (fi->local_int[sigcpu] == NULL); 539 } 540 li = fi->local_int[sigcpu]; 541 spin_lock_bh(&li->lock); 542 atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags); 543 if (waitqueue_active(&li->wq)) 544 wake_up_interruptible(&li->wq); 545 spin_unlock_bh(&li->lock); 546 spin_unlock(&fi->lock); 547 mutex_unlock(&kvm->lock); 548 return 0; 549} 550 551int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu, 552 struct kvm_s390_interrupt *s390int) 553{ 554 struct kvm_s390_local_interrupt *li; 555 struct kvm_s390_interrupt_info *inti; 556 557 inti = kzalloc(sizeof(*inti), GFP_KERNEL); 558 if (!inti) 559 return -ENOMEM; 560 561 switch (s390int->type) { 562 case KVM_S390_PROGRAM_INT: 563 if (s390int->parm & 0xffff0000) { 564 kfree(inti); 565 return -EINVAL; 566 } 567 inti->type = s390int->type; 568 inti->pgm.code = s390int->parm; 569 VCPU_EVENT(vcpu, 3, "inject: program check %d (from user)", 570 s390int->parm); 571 break; 572 case KVM_S390_SIGP_SET_PREFIX: 573 inti->prefix.address = s390int->parm; 574 inti->type = s390int->type; 575 VCPU_EVENT(vcpu, 3, "inject: set prefix to %x (from user)", 576 s390int->parm); 577 break; 578 case KVM_S390_SIGP_STOP: 579 case KVM_S390_RESTART: 580 case KVM_S390_INT_EMERGENCY: 581 VCPU_EVENT(vcpu, 3, "inject: type %x", s390int->type); 582 inti->type = s390int->type; 583 break; 584 case KVM_S390_INT_VIRTIO: 585 case KVM_S390_INT_SERVICE: 586 default: 587 kfree(inti); 588 return -EINVAL; 589 } 590 591 mutex_lock(&vcpu->kvm->lock); 592 li = &vcpu->arch.local_int; 593 spin_lock_bh(&li->lock); 594 if (inti->type == KVM_S390_PROGRAM_INT) 595 list_add(&inti->list, &li->list); 596 else 597 list_add_tail(&inti->list, &li->list); 598 atomic_set(&li->active, 1); 599 if (inti->type == KVM_S390_SIGP_STOP) 600 li->action_bits |= ACTION_STOP_ON_STOP; 601 atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags); 602 if (waitqueue_active(&li->wq)) 603 wake_up_interruptible(&vcpu->arch.local_int.wq); 604 spin_unlock_bh(&li->lock); 605 mutex_unlock(&vcpu->kvm->lock); 606 return 0; 607} 608