SAFE public projects git trees. - safe/jmp/linux-2.6/blob - arch/x86/kvm/i8254.c

   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  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25  * THE SOFTWARE.
  26  *
  27  * Authors:
  28  *   Sheng Yang <sheng.yang@intel.com>
  29  *   Based on QEMU and Xen.
  30  */
  31
  32 #include <linux/kvm_host.h>
  33
  34 #include "irq.h"
  35 #include "i8254.h"
  36
  37 #ifndef CONFIG_X86_64
  38 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
  39 #else
  40 #define mod_64(x, y) ((x) % (y))
  41 #endif
  42
  43 #define RW_STATE_LSB 1
  44 #define RW_STATE_MSB 2
  45 #define RW_STATE_WORD0 3
  46 #define RW_STATE_WORD1 4
  47
  48 /* Compute with 96 bit intermediate result: (a*b)/c */
  49 static u64 muldiv64(u64 a, u32 b, u32 c)
  50 {
  51         union {
  52                 u64 ll;
  53                 struct {
  54                         u32 low, high;
  55                 } l;
  56         } u, res;
  57         u64 rl, rh;
  58
  59         u.ll = a;
  60         rl = (u64)u.l.low * (u64)b;
  61         rh = (u64)u.l.high * (u64)b;
  62         rh += (rl >> 32);
  63         res.l.high = div64_u64(rh, c);
  64         res.l.low = div64_u64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c);
  65         return res.ll;
  66 }
  67
  68 static void pit_set_gate(struct kvm *kvm, int channel, u32 val)
  69 {
  70         struct kvm_kpit_channel_state *c =
  71                 &kvm->arch.vpit->pit_state.channels[channel];
  72
  73         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
  74
  75         switch (c->mode) {
  76         default:
  77         case 0:
  78         case 4:
  79                 /* XXX: just disable/enable counting */
  80                 break;
  81         case 1:
  82         case 2:
  83         case 3:
  84         case 5:
  85                 /* Restart counting on rising edge. */
  86                 if (c->gate < val)
  87                         c->count_load_time = ktime_get();
  88                 break;
  89         }
  90
  91         c->gate = val;
  92 }
  93
  94 static int pit_get_gate(struct kvm *kvm, int channel)
  95 {
  96         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
  97
  98         return kvm->arch.vpit->pit_state.channels[channel].gate;
  99 }
 100
 101 static s64 __kpit_elapsed(struct kvm *kvm)
 102 {
 103         s64 elapsed;
 104         ktime_t remaining;
 105         struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
 106
 107         remaining = hrtimer_expires_remaining(&ps->pit_timer.timer);
 108         if (ktime_to_ns(remaining) < 0)
 109                 remaining = ktime_set(0, 0);
 110
 111         elapsed = ps->pit_timer.period;
 112         if (ktime_to_ns(remaining) <= ps->pit_timer.period)
 113                 elapsed = ps->pit_timer.period - ktime_to_ns(remaining);
 114
 115         return elapsed;
 116 }
 117
 118 static s64 kpit_elapsed(struct kvm *kvm, struct kvm_kpit_channel_state *c,
 119                         int channel)
 120 {
 121         if (channel == 0)
 122                 return __kpit_elapsed(kvm);
 123
 124         return ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
 125 }
 126
 127 static int pit_get_count(struct kvm *kvm, int channel)
 128 {
 129         struct kvm_kpit_channel_state *c =
 130                 &kvm->arch.vpit->pit_state.channels[channel];
 131         s64 d, t;
 132         int counter;
 133
 134         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
 135
 136         t = kpit_elapsed(kvm, c, channel);
 137         d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
 138
 139         switch (c->mode) {
 140         case 0:
 141         case 1:
 142         case 4:
 143         case 5:
 144                 counter = (c->count - d) & 0xffff;
 145                 break;
 146         case 3:
 147                 /* XXX: may be incorrect for odd counts */
 148                 counter = c->count - (mod_64((2 * d), c->count));
 149                 break;
 150         default:
 151                 counter = c->count - mod_64(d, c->count);
 152                 break;
 153         }
 154         return counter;
 155 }
 156
 157 static int pit_get_out(struct kvm *kvm, int channel)
 158 {
 159         struct kvm_kpit_channel_state *c =
 160                 &kvm->arch.vpit->pit_state.channels[channel];
 161         s64 d, t;
 162         int out;
 163
 164         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
 165
 166         t = kpit_elapsed(kvm, c, channel);
 167         d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
 168
 169         switch (c->mode) {
 170         default:
 171         case 0:
 172                 out = (d >= c->count);
 173                 break;
 174         case 1:
 175                 out = (d < c->count);
 176                 break;
 177         case 2:
 178                 out = ((mod_64(d, c->count) == 0) && (d != 0));
 179                 break;
 180         case 3:
 181                 out = (mod_64(d, c->count) < ((c->count + 1) >> 1));
 182                 break;
 183         case 4:
 184         case 5:
 185                 out = (d == c->count);
 186                 break;
 187         }
 188
 189         return out;
 190 }
 191
 192 static void pit_latch_count(struct kvm *kvm, int channel)
 193 {
 194         struct kvm_kpit_channel_state *c =
 195                 &kvm->arch.vpit->pit_state.channels[channel];
 196
 197         WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
 198
 199         if (!c->count_latched) {
 200                 c->latched_count = pit_get_count(kvm, channel);
 201                 c->count_latched = c->rw_mode;
 202         }
 203 }
 204
 205 static void pit_latch_status(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->status_latched) {
 213                 /* TODO: Return NULL COUNT (bit 6). */
 214                 c->status = ((pit_get_out(kvm, channel) << 7) |
 215                                 (c->rw_mode << 4) |
 216                                 (c->mode << 1) |
 217                                 c->bcd);
 218                 c->status_latched = 1;
 219         }
 220 }
 221
 222 int pit_has_pending_timer(struct kvm_vcpu *vcpu)
 223 {
 224         struct kvm_pit *pit = vcpu->kvm->arch.vpit;
 225
 226         if (pit && vcpu->vcpu_id == 0 && pit->pit_state.irq_ack)
 227                 return atomic_read(&pit->pit_state.pit_timer.pending);
 228         return 0;
 229 }
 230
 231 static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
 232 {
 233         struct kvm_kpit_state *ps = container_of(kian, struct kvm_kpit_state,
 234                                                  irq_ack_notifier);
 235         spin_lock(&ps->inject_lock);
 236         if (atomic_dec_return(&ps->pit_timer.pending) < 0)
 237                 atomic_inc(&ps->pit_timer.pending);
 238         ps->irq_ack = 1;
 239         spin_unlock(&ps->inject_lock);
 240 }
 241
 242 void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
 243 {
 244         struct kvm_pit *pit = vcpu->kvm->arch.vpit;
 245         struct hrtimer *timer;
 246
 247         if (vcpu->vcpu_id != 0 || !pit)
 248                 return;
 249
 250         timer = &pit->pit_state.pit_timer.timer;
 251         if (hrtimer_cancel(timer))
 252                 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 253 }
 254
 255 static void destroy_pit_timer(struct kvm_timer *pt)
 256 {
 257         pr_debug("pit: execute del timer!\n");
 258         hrtimer_cancel(&pt->timer);
 259 }
 260
 261 static bool kpit_is_periodic(struct kvm_timer *ktimer)
 262 {
 263         struct kvm_kpit_state *ps = container_of(ktimer, struct kvm_kpit_state,
 264                                                  pit_timer);
 265         return ps->is_periodic;
 266 }
 267
 268 struct kvm_timer_ops kpit_ops = {
 269         .is_periodic = kpit_is_periodic,
 270 };
 271
 272 static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
 273 {
 274         struct kvm_timer *pt = &ps->pit_timer;
 275         s64 interval;
 276
 277         interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
 278
 279         pr_debug("pit: create pit timer, interval is %llu nsec\n", interval);
 280
 281         /* TODO The new value only affected after the retriggered */
 282         hrtimer_cancel(&pt->timer);
 283         pt->period = (is_period == 0) ? 0 : interval;
 284         ps->is_periodic = is_period;
 285
 286         pt->timer.function = kvm_timer_fn;
 287         pt->t_ops = &kpit_ops;
 288         pt->kvm = ps->pit->kvm;
 289         pt->vcpu_id = 0;
 290
 291         atomic_set(&pt->pending, 0);
 292         ps->irq_ack = 1;
 293
 294         hrtimer_start(&pt->timer, ktime_add_ns(ktime_get(), interval),
 295                       HRTIMER_MODE_ABS);
 296 }
 297
 298 static void pit_load_count(struct kvm *kvm, int channel, u32 val)
 299 {
 300         struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
 301
 302         WARN_ON(!mutex_is_locked(&ps->lock));
 303
 304         pr_debug("pit: load_count val is %d, channel is %d\n", val, channel);
 305
 306         /*
 307          * Though spec said the state of 8254 is undefined after power-up,
 308          * seems some tricky OS like Windows XP depends on IRQ0 interrupt
 309          * when booting up.
 310          * So here setting initialize rate for it, and not a specific number
 311          */
 312         if (val == 0)
 313                 val = 0x10000;
 314
 315         ps->channels[channel].count = val;
 316
 317         if (channel != 0) {
 318                 ps->channels[channel].count_load_time = ktime_get();
 319                 return;
 320         }
 321
 322         /* Two types of timer
 323          * mode 1 is one shot, mode 2 is period, otherwise del timer */
 324         switch (ps->channels[0].mode) {
 325         case 1:
 326         /* FIXME: enhance mode 4 precision */
 327         case 4:
 328                 create_pit_timer(ps, val, 0);
 329                 break;
 330         case 2:
 331         case 3:
 332                 create_pit_timer(ps, val, 1);
 333                 break;
 334         default:
 335                 destroy_pit_timer(&ps->pit_timer);
 336         }
 337 }
 338
 339 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val)
 340 {
 341         mutex_lock(&kvm->arch.vpit->pit_state.lock);
 342         pit_load_count(kvm, channel, val);
 343         mutex_unlock(&kvm->arch.vpit->pit_state.lock);
 344 }
 345
 346 static void pit_ioport_write(struct kvm_io_device *this,
 347                              gpa_t addr, int len, const void *data)
 348 {
 349         struct kvm_pit *pit = (struct kvm_pit *)this->private;
 350         struct kvm_kpit_state *pit_state = &pit->pit_state;
 351         struct kvm *kvm = pit->kvm;
 352         int channel, access;
 353         struct kvm_kpit_channel_state *s;
 354         u32 val = *(u32 *) data;
 355
 356         val  &= 0xff;
 357         addr &= KVM_PIT_CHANNEL_MASK;
 358
 359         mutex_lock(&pit_state->lock);
 360
 361         if (val != 0)
 362                 pr_debug("pit: write addr is 0x%x, len is %d, val is 0x%x\n",
 363                           (unsigned int)addr, len, val);
 364
 365         if (addr == 3) {
 366                 channel = val >> 6;
 367                 if (channel == 3) {
 368                         /* Read-Back Command. */
 369                         for (channel = 0; channel < 3; channel++) {
 370                                 s = &pit_state->channels[channel];
 371                                 if (val & (2 << channel)) {
 372                                         if (!(val & 0x20))
 373                                                 pit_latch_count(kvm, channel);
 374                                         if (!(val & 0x10))
 375                                                 pit_latch_status(kvm, channel);
 376                                 }
 377                         }
 378                 } else {
 379                         /* Select Counter <channel>. */
 380                         s = &pit_state->channels[channel];
 381                         access = (val >> 4) & KVM_PIT_CHANNEL_MASK;
 382                         if (access == 0) {
 383                                 pit_latch_count(kvm, channel);
 384                         } else {
 385                                 s->rw_mode = access;
 386                                 s->read_state = access;
 387                                 s->write_state = access;
 388                                 s->mode = (val >> 1) & 7;
 389                                 if (s->mode > 5)
 390                                         s->mode -= 4;
 391                                 s->bcd = val & 1;
 392                         }
 393                 }
 394         } else {
 395                 /* Write Count. */
 396                 s = &pit_state->channels[addr];
 397                 switch (s->write_state) {
 398                 default:
 399                 case RW_STATE_LSB:
 400                         pit_load_count(kvm, addr, val);
 401                         break;
 402                 case RW_STATE_MSB:
 403                         pit_load_count(kvm, addr, val << 8);
 404                         break;
 405                 case RW_STATE_WORD0:
 406                         s->write_latch = val;
 407                         s->write_state = RW_STATE_WORD1;
 408                         break;
 409                 case RW_STATE_WORD1:
 410                         pit_load_count(kvm, addr, s->write_latch | (val << 8));
 411                         s->write_state = RW_STATE_WORD0;
 412                         break;
 413                 }
 414         }
 415
 416         mutex_unlock(&pit_state->lock);
 417 }
 418
 419 static void pit_ioport_read(struct kvm_io_device *this,
 420                             gpa_t addr, int len, void *data)
 421 {
 422         struct kvm_pit *pit = (struct kvm_pit *)this->private;
 423         struct kvm_kpit_state *pit_state = &pit->pit_state;
 424         struct kvm *kvm = pit->kvm;
 425         int ret, count;
 426         struct kvm_kpit_channel_state *s;
 427
 428         addr &= KVM_PIT_CHANNEL_MASK;
 429         s = &pit_state->channels[addr];
 430
 431         mutex_lock(&pit_state->lock);
 432
 433         if (s->status_latched) {
 434                 s->status_latched = 0;
 435                 ret = s->status;
 436         } else if (s->count_latched) {
 437                 switch (s->count_latched) {
 438                 default:
 439                 case RW_STATE_LSB:
 440                         ret = s->latched_count & 0xff;
 441                         s->count_latched = 0;
 442                         break;
 443                 case RW_STATE_MSB:
 444                         ret = s->latched_count >> 8;
 445                         s->count_latched = 0;
 446                         break;
 447                 case RW_STATE_WORD0:
 448                         ret = s->latched_count & 0xff;
 449                         s->count_latched = RW_STATE_MSB;
 450                         break;
 451                 }
 452         } else {
 453                 switch (s->read_state) {
 454                 default:
 455                 case RW_STATE_LSB:
 456                         count = pit_get_count(kvm, addr);
 457                         ret = count & 0xff;
 458                         break;
 459                 case RW_STATE_MSB:
 460                         count = pit_get_count(kvm, addr);
 461                         ret = (count >> 8) & 0xff;
 462                         break;
 463                 case RW_STATE_WORD0:
 464                         count = pit_get_count(kvm, addr);
 465                         ret = count & 0xff;
 466                         s->read_state = RW_STATE_WORD1;
 467                         break;
 468                 case RW_STATE_WORD1:
 469                         count = pit_get_count(kvm, addr);
 470                         ret = (count >> 8) & 0xff;
 471                         s->read_state = RW_STATE_WORD0;
 472                         break;
 473                 }
 474         }
 475
 476         if (len > sizeof(ret))
 477                 len = sizeof(ret);
 478         memcpy(data, (char *)&ret, len);
 479
 480         mutex_unlock(&pit_state->lock);
 481 }
 482
 483 static int pit_in_range(struct kvm_io_device *this, gpa_t addr,
 484                         int len, int is_write)
 485 {
 486         return ((addr >= KVM_PIT_BASE_ADDRESS) &&
 487                 (addr < KVM_PIT_BASE_ADDRESS + KVM_PIT_MEM_LENGTH));
 488 }
 489
 490 static void speaker_ioport_write(struct kvm_io_device *this,
 491                                  gpa_t addr, int len, const void *data)
 492 {
 493         struct kvm_pit *pit = (struct kvm_pit *)this->private;
 494         struct kvm_kpit_state *pit_state = &pit->pit_state;
 495         struct kvm *kvm = pit->kvm;
 496         u32 val = *(u32 *) data;
 497
 498         mutex_lock(&pit_state->lock);
 499         pit_state->speaker_data_on = (val >> 1) & 1;
 500         pit_set_gate(kvm, 2, val & 1);
 501         mutex_unlock(&pit_state->lock);
 502 }
 503
 504 static void speaker_ioport_read(struct kvm_io_device *this,
 505                                 gpa_t addr, int len, void *data)
 506 {
 507         struct kvm_pit *pit = (struct kvm_pit *)this->private;
 508         struct kvm_kpit_state *pit_state = &pit->pit_state;
 509         struct kvm *kvm = pit->kvm;
 510         unsigned int refresh_clock;
 511         int ret;
 512
 513         /* Refresh clock toggles at about 15us. We approximate as 2^14ns. */
 514         refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1;
 515
 516         mutex_lock(&pit_state->lock);
 517         ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(kvm, 2) |
 518                 (pit_get_out(kvm, 2) << 5) | (refresh_clock << 4));
 519         if (len > sizeof(ret))
 520                 len = sizeof(ret);
 521         memcpy(data, (char *)&ret, len);
 522         mutex_unlock(&pit_state->lock);
 523 }
 524
 525 static int speaker_in_range(struct kvm_io_device *this, gpa_t addr,
 526                             int len, int is_write)
 527 {
 528         return (addr == KVM_SPEAKER_BASE_ADDRESS);
 529 }
 530
 531 void kvm_pit_reset(struct kvm_pit *pit)
 532 {
 533         int i;
 534         struct kvm_kpit_channel_state *c;
 535
 536         mutex_lock(&pit->pit_state.lock);
 537         for (i = 0; i < 3; i++) {
 538                 c = &pit->pit_state.channels[i];
 539                 c->mode = 0xff;
 540                 c->gate = (i != 2);
 541                 pit_load_count(pit->kvm, i, 0);
 542         }
 543         mutex_unlock(&pit->pit_state.lock);
 544
 545         atomic_set(&pit->pit_state.pit_timer.pending, 0);
 546         pit->pit_state.irq_ack = 1;
 547 }
 548
 549 static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask)
 550 {
 551         struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier);
 552
 553         if (!mask) {
 554                 atomic_set(&pit->pit_state.pit_timer.pending, 0);
 555                 pit->pit_state.irq_ack = 1;
 556         }
 557 }
 558
 559 struct kvm_pit *kvm_create_pit(struct kvm *kvm)
 560 {
 561         struct kvm_pit *pit;
 562         struct kvm_kpit_state *pit_state;
 563
 564         pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL);
 565         if (!pit)
 566                 return NULL;
 567
 568         pit->irq_source_id = kvm_request_irq_source_id(kvm);
 569         if (pit->irq_source_id < 0) {
 570                 kfree(pit);
 571                 return NULL;
 572         }
 573
 574         mutex_init(&pit->pit_state.lock);
 575         mutex_lock(&pit->pit_state.lock);
 576         spin_lock_init(&pit->pit_state.inject_lock);
 577
 578         /* Initialize PIO device */
 579         pit->dev.read = pit_ioport_read;
 580         pit->dev.write = pit_ioport_write;
 581         pit->dev.in_range = pit_in_range;
 582         pit->dev.private = pit;
 583         kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
 584
 585         pit->speaker_dev.read = speaker_ioport_read;
 586         pit->speaker_dev.write = speaker_ioport_write;
 587         pit->speaker_dev.in_range = speaker_in_range;
 588         pit->speaker_dev.private = pit;
 589         kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
 590
 591         kvm->arch.vpit = pit;
 592         pit->kvm = kvm;
 593
 594         pit_state = &pit->pit_state;
 595         pit_state->pit = pit;
 596         hrtimer_init(&pit_state->pit_timer.timer,
 597                      CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 598         pit_state->irq_ack_notifier.gsi = 0;
 599         pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq;
 600         kvm_register_irq_ack_notifier(kvm, &pit_state->irq_ack_notifier);
 601         pit_state->pit_timer.reinject = true;
 602         mutex_unlock(&pit->pit_state.lock);
 603
 604         kvm_pit_reset(pit);
 605
 606         pit->mask_notifier.func = pit_mask_notifer;
 607         kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
 608
 609         return pit;
 610 }
 611
 612 void kvm_free_pit(struct kvm *kvm)
 613 {
 614         struct hrtimer *timer;
 615
 616         if (kvm->arch.vpit) {
 617                 kvm_unregister_irq_mask_notifier(kvm, 0,
 618                                                &kvm->arch.vpit->mask_notifier);
 619                 mutex_lock(&kvm->arch.vpit->pit_state.lock);
 620                 timer = &kvm->arch.vpit->pit_state.pit_timer.timer;
 621                 hrtimer_cancel(timer);
 622                 kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id);
 623                 mutex_unlock(&kvm->arch.vpit->pit_state.lock);
 624                 kfree(kvm->arch.vpit);
 625         }
 626 }
 627
 628 static void __inject_pit_timer_intr(struct kvm *kvm)
 629 {
 630         struct kvm_vcpu *vcpu;
 631         int i;
 632
 633         mutex_lock(&kvm->lock);
 634         kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1);
 635         kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0);
 636         mutex_unlock(&kvm->lock);
 637
 638         /*
 639          * Provides NMI watchdog support via Virtual Wire mode.
 640          * The route is: PIT -> PIC -> LVT0 in NMI mode.
 641          *
 642          * Note: Our Virtual Wire implementation is simplified, only
 643          * propagating PIT interrupts to all VCPUs when they have set
 644          * LVT0 to NMI delivery. Other PIC interrupts are just sent to
 645          * VCPU0, and only if its LVT0 is in EXTINT mode.
 646          */
 647         if (kvm->arch.vapics_in_nmi_mode > 0)
 648                 for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 649                         vcpu = kvm->vcpus[i];
 650                         if (vcpu)
 651                                 kvm_apic_nmi_wd_deliver(vcpu);
 652                 }
 653 }
 654
 655 void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu)
 656 {
 657         struct kvm_pit *pit = vcpu->kvm->arch.vpit;
 658         struct kvm *kvm = vcpu->kvm;
 659         struct kvm_kpit_state *ps;
 660
 661         if (vcpu && pit) {
 662                 int inject = 0;
 663                 ps = &pit->pit_state;
 664
 665                 /* Try to inject pending interrupts when
 666                  * last one has been acked.
 667                  */
 668                 spin_lock(&ps->inject_lock);
 669                 if (atomic_read(&ps->pit_timer.pending) && ps->irq_ack) {
 670                         ps->irq_ack = 0;
 671                         inject = 1;
 672                 }
 673                 spin_unlock(&ps->inject_lock);
 674                 if (inject)
 675                         __inject_pit_timer_intr(kvm);
 676         }
 677 }