1 /* 2 * 8253/8254 interval timer emulation 3 * 4 * Copyright (c) 2003-2004 Fabrice Bellard 5 * Copyright (c) 2006 Intel Corporation 6 * Copyright (c) 2007 Keir Fraser, XenSource Inc 7 * Copyright (c) 2008 Intel Corporation 8 * Copyright 2009 Red Hat, Inc. and/or its affiliates. 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a copy 11 * of this software and associated documentation files (the "Software"), to deal 12 * in the Software without restriction, including without limitation the rights 13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 14 * copies of the Software, and to permit persons to whom the Software is 15 * furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 26 * THE SOFTWARE. 27 * 28 * Authors: 29 * Sheng Yang <sheng.yang@intel.com> 30 * Based on QEMU and Xen. 31 */ 32 33 #define pr_fmt(fmt) "pit: " fmt 34 35 #include <linux/kvm_host.h> 36 #include <linux/slab.h> 37 38 #include "irq.h" 39 #include "i8254.h" 40 41 #ifndef CONFIG_X86_64 42 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) 43 #else 44 #define mod_64(x, y) ((x) % (y)) 45 #endif 46 47 #define RW_STATE_LSB 1 48 #define RW_STATE_MSB 2 49 #define RW_STATE_WORD0 3 50 #define RW_STATE_WORD1 4 51 52 /* Compute with 96 bit intermediate result: (a*b)/c */ 53 static u64 muldiv64(u64 a, u32 b, u32 c) 54 { 55 union { 56 u64 ll; 57 struct { 58 u32 low, high; 59 } l; 60 } u, res; 61 u64 rl, rh; 62 63 u.ll = a; 64 rl = (u64)u.l.low * (u64)b; 65 rh = (u64)u.l.high * (u64)b; 66 rh += (rl >> 32); 67 res.l.high = div64_u64(rh, c); 68 res.l.low = div64_u64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c); 69 return res.ll; 70 } 71 72 static void pit_set_gate(struct kvm *kvm, int channel, u32 val) 73 { 74 struct kvm_kpit_channel_state *c = 75 &kvm->arch.vpit->pit_state.channels[channel]; 76 77 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 78 79 switch (c->mode) { 80 default: 81 case 0: 82 case 4: 83 /* XXX: just disable/enable counting */ 84 break; 85 case 1: 86 case 2: 87 case 3: 88 case 5: 89 /* Restart counting on rising edge. */ 90 if (c->gate < val) 91 c->count_load_time = ktime_get(); 92 break; 93 } 94 95 c->gate = val; 96 } 97 98 static int pit_get_gate(struct kvm *kvm, int channel) 99 { 100 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 101 102 return kvm->arch.vpit->pit_state.channels[channel].gate; 103 } 104 105 static s64 __kpit_elapsed(struct kvm *kvm) 106 { 107 s64 elapsed; 108 ktime_t remaining; 109 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; 110 111 if (!ps->pit_timer.period) 112 return 0; 113 114 /* 115 * The Counter does not stop when it reaches zero. In 116 * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to 117 * the highest count, either FFFF hex for binary counting 118 * or 9999 for BCD counting, and continues counting. 119 * Modes 2 and 3 are periodic; the Counter reloads 120 * itself with the initial count and continues counting 121 * from there. 122 */ 123 remaining = hrtimer_get_remaining(&ps->pit_timer.timer); 124 elapsed = ps->pit_timer.period - ktime_to_ns(remaining); 125 elapsed = mod_64(elapsed, ps->pit_timer.period); 126 127 return elapsed; 128 } 129 130 static s64 kpit_elapsed(struct kvm *kvm, struct kvm_kpit_channel_state *c, 131 int channel) 132 { 133 if (channel == 0) 134 return __kpit_elapsed(kvm); 135 136 return ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time)); 137 } 138 139 static int pit_get_count(struct kvm *kvm, int channel) 140 { 141 struct kvm_kpit_channel_state *c = 142 &kvm->arch.vpit->pit_state.channels[channel]; 143 s64 d, t; 144 int counter; 145 146 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 147 148 t = kpit_elapsed(kvm, c, channel); 149 d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); 150 151 switch (c->mode) { 152 case 0: 153 case 1: 154 case 4: 155 case 5: 156 counter = (c->count - d) & 0xffff; 157 break; 158 case 3: 159 /* XXX: may be incorrect for odd counts */ 160 counter = c->count - (mod_64((2 * d), c->count)); 161 break; 162 default: 163 counter = c->count - mod_64(d, c->count); 164 break; 165 } 166 return counter; 167 } 168 169 static int pit_get_out(struct kvm *kvm, int channel) 170 { 171 struct kvm_kpit_channel_state *c = 172 &kvm->arch.vpit->pit_state.channels[channel]; 173 s64 d, t; 174 int out; 175 176 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 177 178 t = kpit_elapsed(kvm, c, channel); 179 d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC); 180 181 switch (c->mode) { 182 default: 183 case 0: 184 out = (d >= c->count); 185 break; 186 case 1: 187 out = (d < c->count); 188 break; 189 case 2: 190 out = ((mod_64(d, c->count) == 0) && (d != 0)); 191 break; 192 case 3: 193 out = (mod_64(d, c->count) < ((c->count + 1) >> 1)); 194 break; 195 case 4: 196 case 5: 197 out = (d == c->count); 198 break; 199 } 200 201 return out; 202 } 203 204 static void pit_latch_count(struct kvm *kvm, int channel) 205 { 206 struct kvm_kpit_channel_state *c = 207 &kvm->arch.vpit->pit_state.channels[channel]; 208 209 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 210 211 if (!c->count_latched) { 212 c->latched_count = pit_get_count(kvm, channel); 213 c->count_latched = c->rw_mode; 214 } 215 } 216 217 static void pit_latch_status(struct kvm *kvm, int channel) 218 { 219 struct kvm_kpit_channel_state *c = 220 &kvm->arch.vpit->pit_state.channels[channel]; 221 222 WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock)); 223 224 if (!c->status_latched) { 225 /* TODO: Return NULL COUNT (bit 6). */ 226 c->status = ((pit_get_out(kvm, channel) << 7) | 227 (c->rw_mode << 4) | 228 (c->mode << 1) | 229 c->bcd); 230 c->status_latched = 1; 231 } 232 } 233 234 static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian) 235 { 236 struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state, 237 irq_ack_notifier); 238 int value; 239 240 spin_lock(&ps->inject_lock); 241 value = atomic_dec_return(&ps->pit_timer.pending); 242 if (value < 0) 243 /* spurious acks can be generated if, for example, the 244 * PIC is being reset. Handle it gracefully here 245 */ 246 atomic_inc(&ps->pit_timer.pending); 247 else if (value > 0) 248 /* in this case, we had multiple outstanding pit interrupts 249 * that we needed to inject. Reinject 250 */ 251 queue_kthread_work(&ps->pit->worker, &ps->pit->expired); 252 ps->irq_ack = 1; 253 spin_unlock(&ps->inject_lock); 254 } 255 256 void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu) 257 { 258 struct kvm_pit *pit = vcpu->kvm->arch.vpit; 259 struct hrtimer *timer; 260 261 if (!kvm_vcpu_is_bsp(vcpu) || !pit) 262 return; 263 264 timer = &pit->pit_state.pit_timer.timer; 265 if (hrtimer_cancel(timer)) 266 hrtimer_start_expires(timer, HRTIMER_MODE_ABS); 267 } 268 269 static void destroy_pit_timer(struct kvm_pit *pit) 270 { 271 hrtimer_cancel(&pit->pit_state.pit_timer.timer); 272 flush_kthread_work(&pit->expired); 273 } 274 275 static bool kpit_is_periodic(struct kvm_timer *ktimer) 276 { 277 struct kvm_kpit_state *ps = container_of(ktimer, struct kvm_kpit_state, 278 pit_timer); 279 return ps->is_periodic; 280 } 281 282 static struct kvm_timer_ops kpit_ops = { 283 .is_periodic = kpit_is_periodic, 284 }; 285 286 static void pit_do_work(struct kthread_work *work) 287 { 288 struct kvm_pit *pit = container_of(work, struct kvm_pit, expired); 289 struct kvm *kvm = pit->kvm; 290 struct kvm_vcpu *vcpu; 291 int i; 292 struct kvm_kpit_state *ps = &pit->pit_state; 293 int inject = 0; 294 295 /* Try to inject pending interrupts when 296 * last one has been acked. 297 */ 298 spin_lock(&ps->inject_lock); 299 if (ps->irq_ack) { 300 ps->irq_ack = 0; 301 inject = 1; 302 } 303 spin_unlock(&ps->inject_lock); 304 if (inject) { 305 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1); 306 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0); 307 308 /* 309 * Provides NMI watchdog support via Virtual Wire mode. 310 * The route is: PIT -> PIC -> LVT0 in NMI mode. 311 * 312 * Note: Our Virtual Wire implementation is simplified, only 313 * propagating PIT interrupts to all VCPUs when they have set 314 * LVT0 to NMI delivery. Other PIC interrupts are just sent to 315 * VCPU0, and only if its LVT0 is in EXTINT mode. 316 */ 317 if (kvm->arch.vapics_in_nmi_mode > 0) 318 kvm_for_each_vcpu(i, vcpu, kvm) 319 kvm_apic_nmi_wd_deliver(vcpu); 320 } 321 } 322 323 static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) 324 { 325 struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer); 326 struct kvm_pit *pt = ktimer->kvm->arch.vpit; 327 328 if (ktimer->reinject || !atomic_read(&ktimer->pending)) { 329 atomic_inc(&ktimer->pending); 330 queue_kthread_work(&pt->worker, &pt->expired); 331 } 332 333 if (ktimer->t_ops->is_periodic(ktimer)) { 334 hrtimer_add_expires_ns(&ktimer->timer, ktimer->period); 335 return HRTIMER_RESTART; 336 } else 337 return HRTIMER_NORESTART; 338 } 339 340 static void create_pit_timer(struct kvm *kvm, u32 val, int is_period) 341 { 342 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; 343 struct kvm_timer *pt = &ps->pit_timer; 344 s64 interval; 345 346 if (!irqchip_in_kernel(kvm) || ps->flags & KVM_PIT_FLAGS_HPET_LEGACY) 347 return; 348 349 interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ); 350 351 pr_debug("create pit timer, interval is %llu nsec\n", interval); 352 353 /* TODO The new value only affected after the retriggered */ 354 hrtimer_cancel(&pt->timer); 355 flush_kthread_work(&ps->pit->expired); 356 pt->period = interval; 357 ps->is_periodic = is_period; 358 359 pt->timer.function = pit_timer_fn; 360 pt->t_ops = &kpit_ops; 361 pt->kvm = ps->pit->kvm; 362 363 atomic_set(&pt->pending, 0); 364 ps->irq_ack = 1; 365 366 hrtimer_start(&pt->timer, ktime_add_ns(ktime_get(), interval), 367 HRTIMER_MODE_ABS); 368 } 369 370 static void pit_load_count(struct kvm *kvm, int channel, u32 val) 371 { 372 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; 373 374 WARN_ON(!mutex_is_locked(&ps->lock)); 375 376 pr_debug("load_count val is %d, channel is %d\n", val, channel); 377 378 /* 379 * The largest possible initial count is 0; this is equivalent 380 * to 216 for binary counting and 104 for BCD counting. 381 */ 382 if (val == 0) 383 val = 0x10000; 384 385 ps->channels[channel].count = val; 386 387 if (channel != 0) { 388 ps->channels[channel].count_load_time = ktime_get(); 389 return; 390 } 391 392 /* Two types of timer 393 * mode 1 is one shot, mode 2 is period, otherwise del timer */ 394 switch (ps->channels[0].mode) { 395 case 0: 396 case 1: 397 /* FIXME: enhance mode 4 precision */ 398 case 4: 399 create_pit_timer(kvm, val, 0); 400 break; 401 case 2: 402 case 3: 403 create_pit_timer(kvm, val, 1); 404 break; 405 default: 406 destroy_pit_timer(kvm->arch.vpit); 407 } 408 } 409 410 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start) 411 { 412 u8 saved_mode; 413 if (hpet_legacy_start) { 414 /* save existing mode for later reenablement */ 415 saved_mode = kvm->arch.vpit->pit_state.channels[0].mode; 416 kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */ 417 pit_load_count(kvm, channel, val); 418 kvm->arch.vpit->pit_state.channels[0].mode = saved_mode; 419 } else { 420 pit_load_count(kvm, channel, val); 421 } 422 } 423 424 static inline struct kvm_pit *dev_to_pit(struct kvm_io_device *dev) 425 { 426 return container_of(dev, struct kvm_pit, dev); 427 } 428 429 static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev) 430 { 431 return container_of(dev, struct kvm_pit, speaker_dev); 432 } 433 434 static inline int pit_in_range(gpa_t addr) 435 { 436 return ((addr >= KVM_PIT_BASE_ADDRESS) && 437 (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH)); 438 } 439 440 static int pit_ioport_write(struct kvm_io_device *this, 441 gpa_t addr, int len, const void *data) 442 { 443 struct kvm_pit *pit = dev_to_pit(this); 444 struct kvm_kpit_state *pit_state = &pit->pit_state; 445 struct kvm *kvm = pit->kvm; 446 int channel, access; 447 struct kvm_kpit_channel_state *s; 448 u32 val = *(u32 *) data; 449 if (!pit_in_range(addr)) 450 return -EOPNOTSUPP; 451 452 val &= 0xff; 453 addr &= KVM_PIT_CHANNEL_MASK; 454 455 mutex_lock(&pit_state->lock); 456 457 if (val != 0) 458 pr_debug("write addr is 0x%x, len is %d, val is 0x%x\n", 459 (unsigned int)addr, len, val); 460 461 if (addr == 3) { 462 channel = val >> 6; 463 if (channel == 3) { 464 /* Read-Back Command. */ 465 for (channel = 0; channel < 3; channel++) { 466 s = &pit_state->channels[channel]; 467 if (val & (2 << channel)) { 468 if (!(val & 0x20)) 469 pit_latch_count(kvm, channel); 470 if (!(val & 0x10)) 471 pit_latch_status(kvm, channel); 472 } 473 } 474 } else { 475 /* Select Counter <channel>. */ 476 s = &pit_state->channels[channel]; 477 access = (val >> 4) & KVM_PIT_CHANNEL_MASK; 478 if (access == 0) { 479 pit_latch_count(kvm, channel); 480 } else { 481 s->rw_mode = access; 482 s->read_state = access; 483 s->write_state = access; 484 s->mode = (val >> 1) & 7; 485 if (s->mode > 5) 486 s->mode -= 4; 487 s->bcd = val & 1; 488 } 489 } 490 } else { 491 /* Write Count. */ 492 s = &pit_state->channels[addr]; 493 switch (s->write_state) { 494 default: 495 case RW_STATE_LSB: 496 pit_load_count(kvm, addr, val); 497 break; 498 case RW_STATE_MSB: 499 pit_load_count(kvm, addr, val << 8); 500 break; 501 case RW_STATE_WORD0: 502 s->write_latch = val; 503 s->write_state = RW_STATE_WORD1; 504 break; 505 case RW_STATE_WORD1: 506 pit_load_count(kvm, addr, s->write_latch | (val << 8)); 507 s->write_state = RW_STATE_WORD0; 508 break; 509 } 510 } 511 512 mutex_unlock(&pit_state->lock); 513 return 0; 514 } 515 516 static int pit_ioport_read(struct kvm_io_device *this, 517 gpa_t addr, int len, void *data) 518 { 519 struct kvm_pit *pit = dev_to_pit(this); 520 struct kvm_kpit_state *pit_state = &pit->pit_state; 521 struct kvm *kvm = pit->kvm; 522 int ret, count; 523 struct kvm_kpit_channel_state *s; 524 if (!pit_in_range(addr)) 525 return -EOPNOTSUPP; 526 527 addr &= KVM_PIT_CHANNEL_MASK; 528 if (addr == 3) 529 return 0; 530 531 s = &pit_state->channels[addr]; 532 533 mutex_lock(&pit_state->lock); 534 535 if (s->status_latched) { 536 s->status_latched = 0; 537 ret = s->status; 538 } else if (s->count_latched) { 539 switch (s->count_latched) { 540 default: 541 case RW_STATE_LSB: 542 ret = s->latched_count & 0xff; 543 s->count_latched = 0; 544 break; 545 case RW_STATE_MSB: 546 ret = s->latched_count >> 8; 547 s->count_latched = 0; 548 break; 549 case RW_STATE_WORD0: 550 ret = s->latched_count & 0xff; 551 s->count_latched = RW_STATE_MSB; 552 break; 553 } 554 } else { 555 switch (s->read_state) { 556 default: 557 case RW_STATE_LSB: 558 count = pit_get_count(kvm, addr); 559 ret = count & 0xff; 560 break; 561 case RW_STATE_MSB: 562 count = pit_get_count(kvm, addr); 563 ret = (count >> 8) & 0xff; 564 break; 565 case RW_STATE_WORD0: 566 count = pit_get_count(kvm, addr); 567 ret = count & 0xff; 568 s->read_state = RW_STATE_WORD1; 569 break; 570 case RW_STATE_WORD1: 571 count = pit_get_count(kvm, addr); 572 ret = (count >> 8) & 0xff; 573 s->read_state = RW_STATE_WORD0; 574 break; 575 } 576 } 577 578 if (len > sizeof(ret)) 579 len = sizeof(ret); 580 memcpy(data, (char *)&ret, len); 581 582 mutex_unlock(&pit_state->lock); 583 return 0; 584 } 585 586 static int speaker_ioport_write(struct kvm_io_device *this, 587 gpa_t addr, int len, const void *data) 588 { 589 struct kvm_pit *pit = speaker_to_pit(this); 590 struct kvm_kpit_state *pit_state = &pit->pit_state; 591 struct kvm *kvm = pit->kvm; 592 u32 val = *(u32 *) data; 593 if (addr != KVM_SPEAKER_BASE_ADDRESS) 594 return -EOPNOTSUPP; 595 596 mutex_lock(&pit_state->lock); 597 pit_state->speaker_data_on = (val >> 1) & 1; 598 pit_set_gate(kvm, 2, val & 1); 599 mutex_unlock(&pit_state->lock); 600 return 0; 601 } 602 603 static int speaker_ioport_read(struct kvm_io_device *this, 604 gpa_t addr, int len, void *data) 605 { 606 struct kvm_pit *pit = speaker_to_pit(this); 607 struct kvm_kpit_state *pit_state = &pit->pit_state; 608 struct kvm *kvm = pit->kvm; 609 unsigned int refresh_clock; 610 int ret; 611 if (addr != KVM_SPEAKER_BASE_ADDRESS) 612 return -EOPNOTSUPP; 613 614 /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */ 615 refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1; 616 617 mutex_lock(&pit_state->lock); 618 ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(kvm, 2) | 619 (pit_get_out(kvm, 2) << 5) | (refresh_clock << 4)); 620 if (len > sizeof(ret)) 621 len = sizeof(ret); 622 memcpy(data, (char *)&ret, len); 623 mutex_unlock(&pit_state->lock); 624 return 0; 625 } 626 627 void kvm_pit_reset(struct kvm_pit *pit) 628 { 629 int i; 630 struct kvm_kpit_channel_state *c; 631 632 mutex_lock(&pit->pit_state.lock); 633 pit->pit_state.flags = 0; 634 for (i = 0; i < 3; i++) { 635 c = &pit->pit_state.channels[i]; 636 c->mode = 0xff; 637 c->gate = (i != 2); 638 pit_load_count(pit->kvm, i, 0); 639 } 640 mutex_unlock(&pit->pit_state.lock); 641 642 atomic_set(&pit->pit_state.pit_timer.pending, 0); 643 pit->pit_state.irq_ack = 1; 644 } 645 646 static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask) 647 { 648 struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier); 649 650 if (!mask) { 651 atomic_set(&pit->pit_state.pit_timer.pending, 0); 652 pit->pit_state.irq_ack = 1; 653 } 654 } 655 656 static const struct kvm_io_device_ops pit_dev_ops = { 657 .read = pit_ioport_read, 658 .write = pit_ioport_write, 659 }; 660 661 static const struct kvm_io_device_ops speaker_dev_ops = { 662 .read = speaker_ioport_read, 663 .write = speaker_ioport_write, 664 }; 665 666 /* Caller must hold slots_lock */ 667 struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags) 668 { 669 struct kvm_pit *pit; 670 struct kvm_kpit_state *pit_state; 671 struct pid *pid; 672 pid_t pid_nr; 673 int ret; 674 675 pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL); 676 if (!pit) 677 return NULL; 678 679 pit->irq_source_id = kvm_request_irq_source_id(kvm); 680 if (pit->irq_source_id < 0) { 681 kfree(pit); 682 return NULL; 683 } 684 685 mutex_init(&pit->pit_state.lock); 686 mutex_lock(&pit->pit_state.lock); 687 spin_lock_init(&pit->pit_state.inject_lock); 688 689 pid = get_pid(task_tgid(current)); 690 pid_nr = pid_vnr(pid); 691 put_pid(pid); 692 693 init_kthread_worker(&pit->worker); 694 pit->worker_task = kthread_run(kthread_worker_fn, &pit->worker, 695 "kvm-pit/%d", pid_nr); 696 if (IS_ERR(pit->worker_task)) { 697 mutex_unlock(&pit->pit_state.lock); 698 kvm_free_irq_source_id(kvm, pit->irq_source_id); 699 kfree(pit); 700 return NULL; 701 } 702 init_kthread_work(&pit->expired, pit_do_work); 703 704 kvm->arch.vpit = pit; 705 pit->kvm = kvm; 706 707 pit_state = &pit->pit_state; 708 pit_state->pit = pit; 709 hrtimer_init(&pit_state->pit_timer.timer, 710 CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 711 pit_state->irq_ack_notifier.gsi = 0; 712 pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq; 713 kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); 714 pit_state->pit_timer.reinject = true; 715 mutex_unlock(&pit->pit_state.lock); 716 717 kvm_pit_reset(pit); 718 719 pit->mask_notifier.func = pit_mask_notifer; 720 kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); 721 722 kvm_iodevice_init(&pit->dev, &pit_dev_ops); 723 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, KVM_PIT_BASE_ADDRESS, 724 KVM_PIT_MEM_LENGTH, &pit->dev); 725 if (ret < 0) 726 goto fail; 727 728 if (flags & KVM_PIT_SPEAKER_DUMMY) { 729 kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops); 730 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 731 KVM_SPEAKER_BASE_ADDRESS, 4, 732 &pit->speaker_dev); 733 if (ret < 0) 734 goto fail_unregister; 735 } 736 737 return pit; 738 739 fail_unregister: 740 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev); 741 742 fail: 743 kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier); 744 kvm_unregister_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); 745 kvm_free_irq_source_id(kvm, pit->irq_source_id); 746 kthread_stop(pit->worker_task); 747 kfree(pit); 748 return NULL; 749 } 750 751 void kvm_free_pit(struct kvm *kvm) 752 { 753 struct hrtimer *timer; 754 755 if (kvm->arch.vpit) { 756 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev); 757 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, 758 &kvm->arch.vpit->speaker_dev); 759 kvm_unregister_irq_mask_notifier(kvm, 0, 760 &kvm->arch.vpit->mask_notifier); 761 kvm_unregister_irq_ack_notifier(kvm, 762 &kvm->arch.vpit->pit_state.irq_ack_notifier); 763 mutex_lock(&kvm->arch.vpit->pit_state.lock); 764 timer = &kvm->arch.vpit->pit_state.pit_timer.timer; 765 hrtimer_cancel(timer); 766 flush_kthread_work(&kvm->arch.vpit->expired); 767 kthread_stop(kvm->arch.vpit->worker_task); 768 kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id); 769 mutex_unlock(&kvm->arch.vpit->pit_state.lock); 770 kfree(kvm->arch.vpit); 771 } 772 } 773