virt/kvm/ioapic.c

   1 /*
   2  *  Copyright (C) 2001  MandrakeSoft S.A.
   3  *  Copyright 2010 Red Hat, Inc. and/or its affiliates.
   4  *
   5  *    MandrakeSoft S.A.
   6  *    43, rue d'Aboukir
   7  *    75002 Paris - France
   8  *    http://www.linux-mandrake.com/
   9  *    http://www.mandrakesoft.com/
  10  *
  11  *  This library is free software; you can redistribute it and/or
  12  *  modify it under the terms of the GNU Lesser General Public
  13  *  License as published by the Free Software Foundation; either
  14  *  version 2 of the License, or (at your option) any later version.
  15  *
  16  *  This library is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  *  Lesser General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU Lesser General Public
  22  *  License along with this library; if not, write to the Free Software
  23  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  24  *
  25  *  Yunhong Jiang <yunhong.jiang@intel.com>
  26  *  Yaozu (Eddie) Dong <eddie.dong@intel.com>
  27  *  Based on Xen 3.1 code.
  28  */
  29
  30 #include <linux/kvm_host.h>
  31 #include <linux/kvm.h>
  32 #include <linux/mm.h>
  33 #include <linux/highmem.h>
  34 #include <linux/smp.h>
  35 #include <linux/hrtimer.h>
  36 #include <linux/io.h>
  37 #include <linux/slab.h>
  38 #include <linux/export.h>
  39 #include <asm/processor.h>
  40 #include <asm/page.h>
  41 #include <asm/current.h>
  42 #include <trace/events/kvm.h>
  43
  44 #include "ioapic.h"
  45 #include "lapic.h"
  46 #include "irq.h"
  47
  48 #if 0
  49 #define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
  50 #else
  51 #define ioapic_debug(fmt, arg...)
  52 #endif
  53 static int ioapic_deliver(struct kvm_ioapic *vioapic, int irq,
  54                 bool line_status);
  55
  56 static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
  57                                           unsigned long addr,
  58                                           unsigned long length)
  59 {
  60         unsigned long result = 0;
  61
  62         switch (ioapic->ioregsel) {
  63         case IOAPIC_REG_VERSION:
  64                 result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
  65                           | (IOAPIC_VERSION_ID & 0xff));
  66                 break;
  67
  68         case IOAPIC_REG_APIC_ID:
  69         case IOAPIC_REG_ARB_ID:
  70                 result = ((ioapic->id & 0xf) << 24);
  71                 break;
  72
  73         default:
  74                 {
  75                         u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
  76                         u64 redir_content;
  77
  78                         if (redir_index < IOAPIC_NUM_PINS)
  79                                 redir_content =
  80                                         ioapic->redirtbl[redir_index].bits;
  81                         else
  82                                 redir_content = ~0ULL;
  83
  84                         result = (ioapic->ioregsel & 0x1) ?
  85                             (redir_content >> 32) & 0xffffffff :
  86                             redir_content & 0xffffffff;
  87                         break;
  88                 }
  89         }
  90
  91         return result;
  92 }
  93
  94 static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
  95 {
  96         ioapic->rtc_status.pending_eoi = 0;
  97         bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS);
  98 }
  99
 100 static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
 101 {
 102         bool new_val, old_val;
 103         struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
 104         union kvm_ioapic_redirect_entry *e;
 105
 106         e = &ioapic->redirtbl[RTC_GSI];
 107         if (!kvm_apic_match_dest(vcpu, NULL, 0, e->fields.dest_id,
 108                                 e->fields.dest_mode))
 109                 return;
 110
 111         new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
 112         old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
 113
 114         if (new_val == old_val)
 115                 return;
 116
 117         if (new_val) {
 118                 __set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
 119                 ioapic->rtc_status.pending_eoi++;
 120         } else {
 121                 __clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
 122                 ioapic->rtc_status.pending_eoi--;
 123         }
 124
 125         WARN_ON(ioapic->rtc_status.pending_eoi < 0);
 126 }
 127
 128 void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
 129 {
 130         struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
 131
 132         spin_lock(&ioapic->lock);
 133         __rtc_irq_eoi_tracking_restore_one(vcpu);
 134         spin_unlock(&ioapic->lock);
 135 }
 136
 137 static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
 138 {
 139         struct kvm_vcpu *vcpu;
 140         int i;
 141
 142         if (RTC_GSI >= IOAPIC_NUM_PINS)
 143                 return;
 144
 145         rtc_irq_eoi_tracking_reset(ioapic);
 146         kvm_for_each_vcpu(i, vcpu, ioapic->kvm)
 147             __rtc_irq_eoi_tracking_restore_one(vcpu);
 148 }
 149
 150 static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu)
 151 {
 152         if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map))
 153                 --ioapic->rtc_status.pending_eoi;
 154
 155         WARN_ON(ioapic->rtc_status.pending_eoi < 0);
 156 }
 157
 158 static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
 159 {
 160         if (ioapic->rtc_status.pending_eoi > 0)
 161                 return true; /* coalesced */
 162
 163         return false;
 164 }
 165
 166 static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx,
 167                 bool line_status)
 168 {
 169         union kvm_ioapic_redirect_entry *pent;
 170         int injected = -1;
 171
 172         pent = &ioapic->redirtbl[idx];
 173
 174         if (!pent->fields.mask) {
 175                 injected = ioapic_deliver(ioapic, idx, line_status);
 176                 if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
 177                         pent->fields.remote_irr = 1;
 178         }
 179
 180         return injected;
 181 }
 182
 183 static void update_handled_vectors(struct kvm_ioapic *ioapic)
 184 {
 185         DECLARE_BITMAP(handled_vectors, 256);
 186         int i;
 187
 188         memset(handled_vectors, 0, sizeof(handled_vectors));
 189         for (i = 0; i < IOAPIC_NUM_PINS; ++i)
 190                 __set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
 191         memcpy(ioapic->handled_vectors, handled_vectors,
 192                sizeof(handled_vectors));
 193         smp_wmb();
 194 }
 195
 196 void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
 197                         u32 *tmr)
 198 {
 199         struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
 200         union kvm_ioapic_redirect_entry *e;
 201         int index;
 202
 203         spin_lock(&ioapic->lock);
 204         for (index = 0; index < IOAPIC_NUM_PINS; index++) {
 205                 e = &ioapic->redirtbl[index];
 206                 if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
 207                     kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
 208                     index == RTC_GSI) {
 209                         if (kvm_apic_match_dest(vcpu, NULL, 0,
 210                                 e->fields.dest_id, e->fields.dest_mode)) {
 211                                 __set_bit(e->fields.vector,
 212                                         (unsigned long *)eoi_exit_bitmap);
 213                                 if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG)
 214                                         __set_bit(e->fields.vector,
 215                                                 (unsigned long *)tmr);
 216                         }
 217                 }
 218         }
 219         spin_unlock(&ioapic->lock);
 220 }
 221
 222 #ifdef CONFIG_X86
 223 void kvm_vcpu_request_scan_ioapic(struct kvm *kvm)
 224 {
 225         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 226
 227         if (!ioapic)
 228                 return;
 229         kvm_make_scan_ioapic_request(kvm);
 230 }
 231 #else
 232 void kvm_vcpu_request_scan_ioapic(struct kvm *kvm)
 233 {
 234         return;
 235 }
 236 #endif
 237
 238 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
 239 {
 240         unsigned index;
 241         bool mask_before, mask_after;
 242         union kvm_ioapic_redirect_entry *e;
 243
 244         switch (ioapic->ioregsel) {
 245         case IOAPIC_REG_VERSION:
 246                 /* Writes are ignored. */
 247                 break;
 248
 249         case IOAPIC_REG_APIC_ID:
 250                 ioapic->id = (val >> 24) & 0xf;
 251                 break;
 252
 253         case IOAPIC_REG_ARB_ID:
 254                 break;
 255
 256         default:
 257                 index = (ioapic->ioregsel - 0x10) >> 1;
 258
 259                 ioapic_debug("change redir index %x val %x\n", index, val);
 260                 if (index >= IOAPIC_NUM_PINS)
 261                         return;
 262                 e = &ioapic->redirtbl[index];
 263                 mask_before = e->fields.mask;
 264                 if (ioapic->ioregsel & 1) {
 265                         e->bits &= 0xffffffff;
 266                         e->bits |= (u64) val << 32;
 267                 } else {
 268                         e->bits &= ~0xffffffffULL;
 269                         e->bits |= (u32) val;
 270                         e->fields.remote_irr = 0;
 271                 }
 272                 update_handled_vectors(ioapic);
 273                 mask_after = e->fields.mask;
 274                 if (mask_before != mask_after)
 275                         kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
 276                 if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
 277                     && ioapic->irr & (1 << index))
 278                         ioapic_service(ioapic, index, false);
 279                 kvm_vcpu_request_scan_ioapic(ioapic->kvm);
 280                 break;
 281         }
 282 }
 283
 284 static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq, bool line_status)
 285 {
 286         union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
 287         struct kvm_lapic_irq irqe;
 288         int ret;
 289
 290         ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
 291                      "vector=%x trig_mode=%x\n",
 292                      entry->fields.dest_id, entry->fields.dest_mode,
 293                      entry->fields.delivery_mode, entry->fields.vector,
 294                      entry->fields.trig_mode);
 295
 296         irqe.dest_id = entry->fields.dest_id;
 297         irqe.vector = entry->fields.vector;
 298         irqe.dest_mode = entry->fields.dest_mode;
 299         irqe.trig_mode = entry->fields.trig_mode;
 300         irqe.delivery_mode = entry->fields.delivery_mode << 8;
 301         irqe.level = 1;
 302         irqe.shorthand = 0;
 303
 304         if (irq == RTC_GSI && line_status) {
 305                 BUG_ON(ioapic->rtc_status.pending_eoi != 0);
 306                 ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
 307                                 ioapic->rtc_status.dest_map);
 308                 ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
 309         } else
 310                 ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);
 311
 312         return ret;
 313 }
 314
 315 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 316                        int level, bool line_status)
 317 {
 318         u32 old_irr;
 319         u32 mask = 1 << irq;
 320         union kvm_ioapic_redirect_entry entry;
 321         int ret, irq_level;
 322
 323         BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
 324
 325         spin_lock(&ioapic->lock);
 326         old_irr = ioapic->irr;
 327         irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
 328                                          irq_source_id, level);
 329         entry = ioapic->redirtbl[irq];
 330         irq_level ^= entry.fields.polarity;
 331         if (!irq_level) {
 332                 ioapic->irr &= ~mask;
 333                 ret = 1;
 334         } else {
 335                 int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 336
 337                 if (irq == RTC_GSI && line_status &&
 338                         rtc_irq_check_coalesced(ioapic)) {
 339                         ret = 0; /* coalesced */
 340                         goto out;
 341                 }
 342                 ioapic->irr |= mask;
 343                 if ((edge && old_irr != ioapic->irr) ||
 344                     (!edge && !entry.fields.remote_irr))
 345                         ret = ioapic_service(ioapic, irq, line_status);
 346                 else
 347                         ret = 0; /* report coalesced interrupt */
 348         }
 349 out:
 350         trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 351         spin_unlock(&ioapic->lock);
 352
 353         return ret;
 354 }
 355
 356 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
 357 {
 358         int i;
 359
 360         spin_lock(&ioapic->lock);
 361         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 362                 __clear_bit(irq_source_id, &ioapic->irq_states[i]);
 363         spin_unlock(&ioapic->lock);
 364 }
 365
 366 static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
 367                         struct kvm_ioapic *ioapic, int vector, int trigger_mode)
 368 {
 369         int i;
 370
 371         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 372                 union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
 373
 374                 if (ent->fields.vector != vector)
 375                         continue;
 376
 377                 if (i == RTC_GSI)
 378                         rtc_irq_eoi(ioapic, vcpu);
 379                 /*
 380                  * We are dropping lock while calling ack notifiers because ack
 381                  * notifier callbacks for assigned devices call into IOAPIC
 382                  * recursively. Since remote_irr is cleared only after call
 383                  * to notifiers if the same vector will be delivered while lock
 384                  * is dropped it will be put into irr and will be delivered
 385                  * after ack notifier returns.
 386                  */
 387                 spin_unlock(&ioapic->lock);
 388                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
 389                 spin_lock(&ioapic->lock);
 390
 391                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
 392                         continue;
 393
 394                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 395                 ent->fields.remote_irr = 0;
 396                 if (!ent->fields.mask && (ioapic->irr & (1 << i)))
 397                         ioapic_service(ioapic, i, false);
 398         }
 399 }
 400
 401 bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
 402 {
 403         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 404         smp_rmb();
 405         return test_bit(vector, ioapic->handled_vectors);
 406 }
 407
 408 void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
 409 {
 410         struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
 411
 412         spin_lock(&ioapic->lock);
 413         __kvm_ioapic_update_eoi(vcpu, ioapic, vector, trigger_mode);
 414         spin_unlock(&ioapic->lock);
 415 }
 416
 417 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 418 {
 419         return container_of(dev, struct kvm_ioapic, dev);
 420 }
 421
 422 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 423 {
 424         return ((addr >= ioapic->base_address &&
 425                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 426 }
 427
 428 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 429                             void *val)
 430 {
 431         struct kvm_ioapic *ioapic = to_ioapic(this);
 432         u32 result;
 433         if (!ioapic_in_range(ioapic, addr))
 434                 return -EOPNOTSUPP;
 435
 436         ioapic_debug("addr %lx\n", (unsigned long)addr);
 437         ASSERT(!(addr & 0xf));  /* check alignment */
 438
 439         addr &= 0xff;
 440         spin_lock(&ioapic->lock);
 441         switch (addr) {
 442         case IOAPIC_REG_SELECT:
 443                 result = ioapic->ioregsel;
 444                 break;
 445
 446         case IOAPIC_REG_WINDOW:
 447                 result = ioapic_read_indirect(ioapic, addr, len);
 448                 break;
 449
 450         default:
 451                 result = 0;
 452                 break;
 453         }
 454         spin_unlock(&ioapic->lock);
 455
 456         switch (len) {
 457         case 8:
 458                 *(u64 *) val = result;
 459                 break;
 460         case 1:
 461         case 2:
 462         case 4:
 463                 memcpy(val, (char *)&result, len);
 464                 break;
 465         default:
 466                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 467         }
 468         return 0;
 469 }
 470
 471 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 472                              const void *val)
 473 {
 474         struct kvm_ioapic *ioapic = to_ioapic(this);
 475         u32 data;
 476         if (!ioapic_in_range(ioapic, addr))
 477                 return -EOPNOTSUPP;
 478
 479         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 480                      (void*)addr, len, val);
 481         ASSERT(!(addr & 0xf));  /* check alignment */
 482
 483         switch (len) {
 484         case 8:
 485         case 4:
 486                 data = *(u32 *) val;
 487                 break;
 488         case 2:
 489                 data = *(u16 *) val;
 490                 break;
 491         case 1:
 492                 data = *(u8  *) val;
 493                 break;
 494         default:
 495                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 496                 return 0;
 497         }
 498
 499         addr &= 0xff;
 500         spin_lock(&ioapic->lock);
 501         switch (addr) {
 502         case IOAPIC_REG_SELECT:
 503                 ioapic->ioregsel = data & 0xFF; /* 8-bit register */
 504                 break;
 505
 506         case IOAPIC_REG_WINDOW:
 507                 ioapic_write_indirect(ioapic, data);
 508                 break;
 509 #ifdef  CONFIG_IA64
 510         case IOAPIC_REG_EOI:
 511                 __kvm_ioapic_update_eoi(NULL, ioapic, data, IOAPIC_LEVEL_TRIG);
 512                 break;
 513 #endif
 514
 515         default:
 516                 break;
 517         }
 518         spin_unlock(&ioapic->lock);
 519         return 0;
 520 }
 521
 522 static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 523 {
 524         int i;
 525
 526         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 527                 ioapic->redirtbl[i].fields.mask = 1;
 528         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 529         ioapic->ioregsel = 0;
 530         ioapic->irr = 0;
 531         ioapic->id = 0;
 532         rtc_irq_eoi_tracking_reset(ioapic);
 533         update_handled_vectors(ioapic);
 534 }
 535
 536 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 537         .read     = ioapic_mmio_read,
 538         .write    = ioapic_mmio_write,
 539 };
 540
 541 int kvm_ioapic_init(struct kvm *kvm)
 542 {
 543         struct kvm_ioapic *ioapic;
 544         int ret;
 545
 546         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 547         if (!ioapic)
 548                 return -ENOMEM;
 549         spin_lock_init(&ioapic->lock);
 550         kvm->arch.vioapic = ioapic;
 551         kvm_ioapic_reset(ioapic);
 552         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 553         ioapic->kvm = kvm;
 554         mutex_lock(&kvm->slots_lock);
 555         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
 556                                       IOAPIC_MEM_LENGTH, &ioapic->dev);
 557         mutex_unlock(&kvm->slots_lock);
 558         if (ret < 0) {
 559                 kvm->arch.vioapic = NULL;
 560                 kfree(ioapic);
 561         }
 562
 563         return ret;
 564 }
 565
 566 void kvm_ioapic_destroy(struct kvm *kvm)
 567 {
 568         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 569
 570         if (ioapic) {
 571                 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 572                 kvm->arch.vioapic = NULL;
 573                 kfree(ioapic);
 574         }
 575 }
 576
 577 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 578 {
 579         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 580         if (!ioapic)
 581                 return -EINVAL;
 582
 583         spin_lock(&ioapic->lock);
 584         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
 585         spin_unlock(&ioapic->lock);
 586         return 0;
 587 }
 588
 589 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 590 {
 591         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 592         if (!ioapic)
 593                 return -EINVAL;
 594
 595         spin_lock(&ioapic->lock);
 596         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 597         update_handled_vectors(ioapic);
 598         kvm_vcpu_request_scan_ioapic(kvm);
 599         kvm_rtc_eoi_tracking_restore_all(ioapic);
 600         spin_unlock(&ioapic->lock);
 601         return 0;
 602 }