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