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 #include "x86.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->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->timer); 125 elapsed = ps->period - ktime_to_ns(remaining); 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->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->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.timer; 265 mutex_lock(&pit->pit_state.lock); 266 if (hrtimer_cancel(timer)) 267 hrtimer_start_expires(timer, HRTIMER_MODE_ABS); 268 mutex_unlock(&pit->pit_state.lock); 269 } 270 271 static void destroy_pit_timer(struct kvm_pit *pit) 272 { 273 hrtimer_cancel(&pit->pit_state.timer); 274 flush_kthread_work(&pit->expired); 275 } 276 277 static void pit_do_work(struct kthread_work *work) 278 { 279 struct kvm_pit *pit = container_of(work, struct kvm_pit, expired); 280 struct kvm *kvm = pit->kvm; 281 struct kvm_vcpu *vcpu; 282 int i; 283 struct kvm_kpit_state *ps = &pit->pit_state; 284 int inject = 0; 285 286 /* Try to inject pending interrupts when 287 * last one has been acked. 288 */ 289 spin_lock(&ps->inject_lock); 290 if (ps->irq_ack) { 291 ps->irq_ack = 0; 292 inject = 1; 293 } 294 spin_unlock(&ps->inject_lock); 295 if (inject) { 296 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1, false); 297 kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0, false); 298 299 /* 300 * Provides NMI watchdog support via Virtual Wire mode. 301 * The route is: PIT -> PIC -> LVT0 in NMI mode. 302 * 303 * Note: Our Virtual Wire implementation is simplified, only 304 * propagating PIT interrupts to all VCPUs when they have set 305 * LVT0 to NMI delivery. Other PIC interrupts are just sent to 306 * VCPU0, and only if its LVT0 is in EXTINT mode. 307 */ 308 if (atomic_read(&kvm->arch.vapics_in_nmi_mode) > 0) 309 kvm_for_each_vcpu(i, vcpu, kvm) 310 kvm_apic_nmi_wd_deliver(vcpu); 311 } 312 } 313 314 static enum hrtimer_restart pit_timer_fn(struct hrtimer *data) 315 { 316 struct kvm_kpit_state *ps = container_of(data, struct kvm_kpit_state, timer); 317 struct kvm_pit *pt = ps->kvm->arch.vpit; 318 319 if (ps->reinject || !atomic_read(&ps->pending)) { 320 atomic_inc(&ps->pending); 321 queue_kthread_work(&pt->worker, &pt->expired); 322 } 323 324 if (ps->is_periodic) { 325 hrtimer_add_expires_ns(&ps->timer, ps->period); 326 return HRTIMER_RESTART; 327 } else 328 return HRTIMER_NORESTART; 329 } 330 331 static void create_pit_timer(struct kvm *kvm, u32 val, int is_period) 332 { 333 struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state; 334 s64 interval; 335 336 if (!irqchip_in_kernel(kvm) || ps->flags & KVM_PIT_FLAGS_HPET_LEGACY) 337 return; 338 339 interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ); 340 341 pr_debug("create pit timer, interval is %llu nsec\n", interval); 342 343 /* TODO The new value only affected after the retriggered */ 344 hrtimer_cancel(&ps->timer); 345 flush_kthread_work(&ps->pit->expired); 346 ps->period = interval; 347 ps->is_periodic = is_period; 348 349 ps->timer.function = pit_timer_fn; 350 ps->kvm = ps->pit->kvm; 351 352 atomic_set(&ps->pending, 0); 353 ps->irq_ack = 1; 354 355 /* 356 * Do not allow the guest to program periodic timers with small 357 * interval, since the hrtimers are not throttled by the host 358 * scheduler. 359 */ 360 if (ps->is_periodic) { 361 s64 min_period = min_timer_period_us * 1000LL; 362 363 if (ps->period < min_period) { 364 pr_info_ratelimited( 365 "kvm: requested %lld ns " 366 "i8254 timer period limited to %lld ns\n", 367 ps->period, min_period); 368 ps->period = min_period; 369 } 370 } 371 372 hrtimer_start(&ps->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 create_pit_timer(kvm, val, 0); 406 break; 407 case 2: 408 case 3: 409 create_pit_timer(kvm, val, 1); 410 break; 411 default: 412 destroy_pit_timer(kvm->arch.vpit); 413 } 414 } 415 416 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start) 417 { 418 u8 saved_mode; 419 if (hpet_legacy_start) { 420 /* save existing mode for later reenablement */ 421 saved_mode = kvm->arch.vpit->pit_state.channels[0].mode; 422 kvm->arch.vpit->pit_state.channels[0].mode = 0xff; /* disable timer */ 423 pit_load_count(kvm, channel, val); 424 kvm->arch.vpit->pit_state.channels[0].mode = saved_mode; 425 } else { 426 pit_load_count(kvm, channel, val); 427 } 428 } 429 430 static inline struct kvm_pit *dev_to_pit(struct kvm_io_device *dev) 431 { 432 return container_of(dev, struct kvm_pit, dev); 433 } 434 435 static inline struct kvm_pit *speaker_to_pit(struct kvm_io_device *dev) 436 { 437 return container_of(dev, struct kvm_pit, speaker_dev); 438 } 439 440 static inline int pit_in_range(gpa_t addr) 441 { 442 return ((addr >= KVM_PIT_BASE_ADDRESS) && 443 (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH)); 444 } 445 446 static int pit_ioport_write(struct kvm_vcpu *vcpu, 447 struct kvm_io_device *this, 448 gpa_t addr, int len, const void *data) 449 { 450 struct kvm_pit *pit = dev_to_pit(this); 451 struct kvm_kpit_state *pit_state = &pit->pit_state; 452 struct kvm *kvm = pit->kvm; 453 int channel, access; 454 struct kvm_kpit_channel_state *s; 455 u32 val = *(u32 *) data; 456 if (!pit_in_range(addr)) 457 return -EOPNOTSUPP; 458 459 val &= 0xff; 460 addr &= KVM_PIT_CHANNEL_MASK; 461 462 mutex_lock(&pit_state->lock); 463 464 if (val != 0) 465 pr_debug("write addr is 0x%x, len is %d, val is 0x%x\n", 466 (unsigned int)addr, len, val); 467 468 if (addr == 3) { 469 channel = val >> 6; 470 if (channel == 3) { 471 /* Read-Back Command. */ 472 for (channel = 0; channel < 3; channel++) { 473 s = &pit_state->channels[channel]; 474 if (val & (2 << channel)) { 475 if (!(val & 0x20)) 476 pit_latch_count(kvm, channel); 477 if (!(val & 0x10)) 478 pit_latch_status(kvm, channel); 479 } 480 } 481 } else { 482 /* Select Counter <channel>. */ 483 s = &pit_state->channels[channel]; 484 access = (val >> 4) & KVM_PIT_CHANNEL_MASK; 485 if (access == 0) { 486 pit_latch_count(kvm, channel); 487 } else { 488 s->rw_mode = access; 489 s->read_state = access; 490 s->write_state = access; 491 s->mode = (val >> 1) & 7; 492 if (s->mode > 5) 493 s->mode -= 4; 494 s->bcd = val & 1; 495 } 496 } 497 } else { 498 /* Write Count. */ 499 s = &pit_state->channels[addr]; 500 switch (s->write_state) { 501 default: 502 case RW_STATE_LSB: 503 pit_load_count(kvm, addr, val); 504 break; 505 case RW_STATE_MSB: 506 pit_load_count(kvm, addr, val << 8); 507 break; 508 case RW_STATE_WORD0: 509 s->write_latch = val; 510 s->write_state = RW_STATE_WORD1; 511 break; 512 case RW_STATE_WORD1: 513 pit_load_count(kvm, addr, s->write_latch | (val << 8)); 514 s->write_state = RW_STATE_WORD0; 515 break; 516 } 517 } 518 519 mutex_unlock(&pit_state->lock); 520 return 0; 521 } 522 523 static int pit_ioport_read(struct kvm_vcpu *vcpu, 524 struct kvm_io_device *this, 525 gpa_t addr, int len, void *data) 526 { 527 struct kvm_pit *pit = dev_to_pit(this); 528 struct kvm_kpit_state *pit_state = &pit->pit_state; 529 struct kvm *kvm = pit->kvm; 530 int ret, count; 531 struct kvm_kpit_channel_state *s; 532 if (!pit_in_range(addr)) 533 return -EOPNOTSUPP; 534 535 addr &= KVM_PIT_CHANNEL_MASK; 536 if (addr == 3) 537 return 0; 538 539 s = &pit_state->channels[addr]; 540 541 mutex_lock(&pit_state->lock); 542 543 if (s->status_latched) { 544 s->status_latched = 0; 545 ret = s->status; 546 } else if (s->count_latched) { 547 switch (s->count_latched) { 548 default: 549 case RW_STATE_LSB: 550 ret = s->latched_count & 0xff; 551 s->count_latched = 0; 552 break; 553 case RW_STATE_MSB: 554 ret = s->latched_count >> 8; 555 s->count_latched = 0; 556 break; 557 case RW_STATE_WORD0: 558 ret = s->latched_count & 0xff; 559 s->count_latched = RW_STATE_MSB; 560 break; 561 } 562 } else { 563 switch (s->read_state) { 564 default: 565 case RW_STATE_LSB: 566 count = pit_get_count(kvm, addr); 567 ret = count & 0xff; 568 break; 569 case RW_STATE_MSB: 570 count = pit_get_count(kvm, addr); 571 ret = (count >> 8) & 0xff; 572 break; 573 case RW_STATE_WORD0: 574 count = pit_get_count(kvm, addr); 575 ret = count & 0xff; 576 s->read_state = RW_STATE_WORD1; 577 break; 578 case RW_STATE_WORD1: 579 count = pit_get_count(kvm, addr); 580 ret = (count >> 8) & 0xff; 581 s->read_state = RW_STATE_WORD0; 582 break; 583 } 584 } 585 586 if (len > sizeof(ret)) 587 len = sizeof(ret); 588 memcpy(data, (char *)&ret, len); 589 590 mutex_unlock(&pit_state->lock); 591 return 0; 592 } 593 594 static int speaker_ioport_write(struct kvm_vcpu *vcpu, 595 struct kvm_io_device *this, 596 gpa_t addr, int len, const void *data) 597 { 598 struct kvm_pit *pit = speaker_to_pit(this); 599 struct kvm_kpit_state *pit_state = &pit->pit_state; 600 struct kvm *kvm = pit->kvm; 601 u32 val = *(u32 *) data; 602 if (addr != KVM_SPEAKER_BASE_ADDRESS) 603 return -EOPNOTSUPP; 604 605 mutex_lock(&pit_state->lock); 606 pit_state->speaker_data_on = (val >> 1) & 1; 607 pit_set_gate(kvm, 2, val & 1); 608 mutex_unlock(&pit_state->lock); 609 return 0; 610 } 611 612 static int speaker_ioport_read(struct kvm_vcpu *vcpu, 613 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.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.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 struct pid *pid; 682 pid_t pid_nr; 683 int ret; 684 685 pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL); 686 if (!pit) 687 return NULL; 688 689 pit->irq_source_id = kvm_request_irq_source_id(kvm); 690 if (pit->irq_source_id < 0) { 691 kfree(pit); 692 return NULL; 693 } 694 695 mutex_init(&pit->pit_state.lock); 696 mutex_lock(&pit->pit_state.lock); 697 spin_lock_init(&pit->pit_state.inject_lock); 698 699 pid = get_pid(task_tgid(current)); 700 pid_nr = pid_vnr(pid); 701 put_pid(pid); 702 703 init_kthread_worker(&pit->worker); 704 pit->worker_task = kthread_run(kthread_worker_fn, &pit->worker, 705 "kvm-pit/%d", pid_nr); 706 if (IS_ERR(pit->worker_task)) { 707 mutex_unlock(&pit->pit_state.lock); 708 kvm_free_irq_source_id(kvm, pit->irq_source_id); 709 kfree(pit); 710 return NULL; 711 } 712 init_kthread_work(&pit->expired, pit_do_work); 713 714 kvm->arch.vpit = pit; 715 pit->kvm = kvm; 716 717 pit_state = &pit->pit_state; 718 pit_state->pit = pit; 719 hrtimer_init(&pit_state->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 720 pit_state->irq_ack_notifier.gsi = 0; 721 pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq; 722 kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); 723 pit_state->reinject = true; 724 mutex_unlock(&pit->pit_state.lock); 725 726 kvm_pit_reset(pit); 727 728 pit->mask_notifier.func = pit_mask_notifer; 729 kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier); 730 731 kvm_iodevice_init(&pit->dev, &pit_dev_ops); 732 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, KVM_PIT_BASE_ADDRESS, 733 KVM_PIT_MEM_LENGTH, &pit->dev); 734 if (ret < 0) 735 goto fail; 736 737 if (flags & KVM_PIT_SPEAKER_DUMMY) { 738 kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops); 739 ret = kvm_io_bus_register_dev(kvm, KVM_PIO_BUS, 740 KVM_SPEAKER_BASE_ADDRESS, 4, 741 &pit->speaker_dev); 742 if (ret < 0) 743 goto fail_unregister; 744 } 745 746 return pit; 747 748 fail_unregister: 749 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &pit->dev); 750 751 fail: 752 kvm_unregister_irq_mask_notifier(kvm, 0, &pit->mask_notifier); 753 kvm_unregister_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier); 754 kvm_free_irq_source_id(kvm, pit->irq_source_id); 755 kthread_stop(pit->worker_task); 756 kfree(pit); 757 return NULL; 758 } 759 760 void kvm_free_pit(struct kvm *kvm) 761 { 762 struct hrtimer *timer; 763 764 if (kvm->arch.vpit) { 765 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, &kvm->arch.vpit->dev); 766 kvm_io_bus_unregister_dev(kvm, KVM_PIO_BUS, 767 &kvm->arch.vpit->speaker_dev); 768 kvm_unregister_irq_mask_notifier(kvm, 0, 769 &kvm->arch.vpit->mask_notifier); 770 kvm_unregister_irq_ack_notifier(kvm, 771 &kvm->arch.vpit->pit_state.irq_ack_notifier); 772 mutex_lock(&kvm->arch.vpit->pit_state.lock); 773 timer = &kvm->arch.vpit->pit_state.timer; 774 hrtimer_cancel(timer); 775 flush_kthread_work(&kvm->arch.vpit->expired); 776 kthread_stop(kvm->arch.vpit->worker_task); 777 kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id); 778 mutex_unlock(&kvm->arch.vpit->pit_state.lock); 779 kfree(kvm->arch.vpit); 780 } 781 } 782