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
  55 static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
  56                                           unsigned long addr,
  57                                           unsigned long length)
  58 {
  59         unsigned long result = 0;
  60
  61         switch (ioapic->ioregsel) {
  62         case IOAPIC_REG_VERSION:
  63                 result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
  64                           | (IOAPIC_VERSION_ID & 0xff));
  65                 break;
  66
  67         case IOAPIC_REG_APIC_ID:
  68         case IOAPIC_REG_ARB_ID:
  69                 result = ((ioapic->id & 0xf) << 24);
  70                 break;
  71
  72         default:
  73                 {
  74                         u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
  75                         u64 redir_content;
  76
  77                         ASSERT(redir_index < IOAPIC_NUM_PINS);
  78
  79                         redir_content = ioapic->redirtbl[redir_index].bits;
  80                         result = (ioapic->ioregsel & 0x1) ?
  81                             (redir_content >> 32) & 0xffffffff :
  82                             redir_content & 0xffffffff;
  83                         break;
  84                 }
  85         }
  86
  87         return result;
  88 }
  89
  90 static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
  91 {
  92         union kvm_ioapic_redirect_entry *pent;
  93         int injected = -1;
  94
  95         pent = &ioapic->redirtbl[idx];
  96
  97         if (!pent->fields.mask) {
  98                 injected = ioapic_deliver(ioapic, idx);
  99                 if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
 100                         pent->fields.remote_irr = 1;
 101         }
 102
 103         return injected;
 104 }
 105
 106 static void update_handled_vectors(struct kvm_ioapic *ioapic)
 107 {
 108         DECLARE_BITMAP(handled_vectors, 256);
 109         int i;
 110
 111         memset(handled_vectors, 0, sizeof(handled_vectors));
 112         for (i = 0; i < IOAPIC_NUM_PINS; ++i)
 113                 __set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
 114         memcpy(ioapic->handled_vectors, handled_vectors,
 115                sizeof(handled_vectors));
 116         smp_wmb();
 117 }
 118
 119 void kvm_ioapic_calculate_eoi_exitmap(struct kvm_vcpu *vcpu,
 120                                         u64 *eoi_exit_bitmap)
 121 {
 122         struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
 123         union kvm_ioapic_redirect_entry *e;
 124         struct kvm_lapic_irq irqe;
 125         int index;
 126
 127         spin_lock(&ioapic->lock);
 128         /* traverse ioapic entry to set eoi exit bitmap*/
 129         for (index = 0; index < IOAPIC_NUM_PINS; index++) {
 130                 e = &ioapic->redirtbl[index];
 131                 if (!e->fields.mask &&
 132                         (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
 133                          kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC,
 134                                  index))) {
 135                         irqe.dest_id = e->fields.dest_id;
 136                         irqe.vector = e->fields.vector;
 137                         irqe.dest_mode = e->fields.dest_mode;
 138                         irqe.delivery_mode = e->fields.delivery_mode << 8;
 139                         kvm_calculate_eoi_exitmap(vcpu, &irqe, eoi_exit_bitmap);
 140                 }
 141         }
 142         spin_unlock(&ioapic->lock);
 143 }
 144 EXPORT_SYMBOL_GPL(kvm_ioapic_calculate_eoi_exitmap);
 145
 146 void kvm_ioapic_make_eoibitmap_request(struct kvm *kvm)
 147 {
 148         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 149
 150         if (!kvm_apic_vid_enabled(kvm) || !ioapic)
 151                 return;
 152         kvm_make_update_eoibitmap_request(kvm);
 153 }
 154
 155 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
 156 {
 157         unsigned index;
 158         bool mask_before, mask_after;
 159         union kvm_ioapic_redirect_entry *e;
 160
 161         switch (ioapic->ioregsel) {
 162         case IOAPIC_REG_VERSION:
 163                 /* Writes are ignored. */
 164                 break;
 165
 166         case IOAPIC_REG_APIC_ID:
 167                 ioapic->id = (val >> 24) & 0xf;
 168                 break;
 169
 170         case IOAPIC_REG_ARB_ID:
 171                 break;
 172
 173         default:
 174                 index = (ioapic->ioregsel - 0x10) >> 1;
 175
 176                 ioapic_debug("change redir index %x val %x\n", index, val);
 177                 if (index >= IOAPIC_NUM_PINS)
 178                         return;
 179                 e = &ioapic->redirtbl[index];
 180                 mask_before = e->fields.mask;
 181                 if (ioapic->ioregsel & 1) {
 182                         e->bits &= 0xffffffff;
 183                         e->bits |= (u64) val << 32;
 184                 } else {
 185                         e->bits &= ~0xffffffffULL;
 186                         e->bits |= (u32) val;
 187                         e->fields.remote_irr = 0;
 188                 }
 189                 update_handled_vectors(ioapic);
 190                 mask_after = e->fields.mask;
 191                 if (mask_before != mask_after)
 192                         kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
 193                 if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
 194                     && ioapic->irr & (1 << index))
 195                         ioapic_service(ioapic, index);
 196                 kvm_ioapic_make_eoibitmap_request(ioapic->kvm);
 197                 break;
 198         }
 199 }
 200
 201 static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
 202 {
 203         union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
 204         struct kvm_lapic_irq irqe;
 205
 206         ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
 207                      "vector=%x trig_mode=%x\n",
 208                      entry->fields.dest_id, entry->fields.dest_mode,
 209                      entry->fields.delivery_mode, entry->fields.vector,
 210                      entry->fields.trig_mode);
 211
 212         irqe.dest_id = entry->fields.dest_id;
 213         irqe.vector = entry->fields.vector;
 214         irqe.dest_mode = entry->fields.dest_mode;
 215         irqe.trig_mode = entry->fields.trig_mode;
 216         irqe.delivery_mode = entry->fields.delivery_mode << 8;
 217         irqe.level = 1;
 218         irqe.shorthand = 0;
 219
 220         return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe);
 221 }
 222
 223 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 224                        int level)
 225 {
 226         u32 old_irr;
 227         u32 mask = 1 << irq;
 228         union kvm_ioapic_redirect_entry entry;
 229         int ret, irq_level;
 230
 231         BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
 232
 233         spin_lock(&ioapic->lock);
 234         old_irr = ioapic->irr;
 235         irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
 236                                          irq_source_id, level);
 237         entry = ioapic->redirtbl[irq];
 238         irq_level ^= entry.fields.polarity;
 239         if (!irq_level) {
 240                 ioapic->irr &= ~mask;
 241                 ret = 1;
 242         } else {
 243                 int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 244                 ioapic->irr |= mask;
 245                 if ((edge && old_irr != ioapic->irr) ||
 246                     (!edge && !entry.fields.remote_irr))
 247                         ret = ioapic_service(ioapic, irq);
 248                 else
 249                         ret = 0; /* report coalesced interrupt */
 250         }
 251         trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 252         spin_unlock(&ioapic->lock);
 253
 254         return ret;
 255 }
 256
 257 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
 258 {
 259         int i;
 260
 261         spin_lock(&ioapic->lock);
 262         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 263                 __clear_bit(irq_source_id, &ioapic->irq_states[i]);
 264         spin_unlock(&ioapic->lock);
 265 }
 266
 267 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
 268                                      int trigger_mode)
 269 {
 270         int i;
 271
 272         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 273                 union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
 274
 275                 if (ent->fields.vector != vector)
 276                         continue;
 277
 278                 /*
 279                  * We are dropping lock while calling ack notifiers because ack
 280                  * notifier callbacks for assigned devices call into IOAPIC
 281                  * recursively. Since remote_irr is cleared only after call
 282                  * to notifiers if the same vector will be delivered while lock
 283                  * is dropped it will be put into irr and will be delivered
 284                  * after ack notifier returns.
 285                  */
 286                 spin_unlock(&ioapic->lock);
 287                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
 288                 spin_lock(&ioapic->lock);
 289
 290                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
 291                         continue;
 292
 293                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 294                 ent->fields.remote_irr = 0;
 295                 if (!ent->fields.mask && (ioapic->irr & (1 << i)))
 296                         ioapic_service(ioapic, i);
 297         }
 298 }
 299
 300 bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
 301 {
 302         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 303         smp_rmb();
 304         return test_bit(vector, ioapic->handled_vectors);
 305 }
 306
 307 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 308 {
 309         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 310
 311         spin_lock(&ioapic->lock);
 312         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
 313         spin_unlock(&ioapic->lock);
 314 }
 315
 316 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 317 {
 318         return container_of(dev, struct kvm_ioapic, dev);
 319 }
 320
 321 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 322 {
 323         return ((addr >= ioapic->base_address &&
 324                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 325 }
 326
 327 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 328                             void *val)
 329 {
 330         struct kvm_ioapic *ioapic = to_ioapic(this);
 331         u32 result;
 332         if (!ioapic_in_range(ioapic, addr))
 333                 return -EOPNOTSUPP;
 334
 335         ioapic_debug("addr %lx\n", (unsigned long)addr);
 336         ASSERT(!(addr & 0xf));  /* check alignment */
 337
 338         addr &= 0xff;
 339         spin_lock(&ioapic->lock);
 340         switch (addr) {
 341         case IOAPIC_REG_SELECT:
 342                 result = ioapic->ioregsel;
 343                 break;
 344
 345         case IOAPIC_REG_WINDOW:
 346                 result = ioapic_read_indirect(ioapic, addr, len);
 347                 break;
 348
 349         default:
 350                 result = 0;
 351                 break;
 352         }
 353         spin_unlock(&ioapic->lock);
 354
 355         switch (len) {
 356         case 8:
 357                 *(u64 *) val = result;
 358                 break;
 359         case 1:
 360         case 2:
 361         case 4:
 362                 memcpy(val, (char *)&result, len);
 363                 break;
 364         default:
 365                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 366         }
 367         return 0;
 368 }
 369
 370 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 371                              const void *val)
 372 {
 373         struct kvm_ioapic *ioapic = to_ioapic(this);
 374         u32 data;
 375         if (!ioapic_in_range(ioapic, addr))
 376                 return -EOPNOTSUPP;
 377
 378         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 379                      (void*)addr, len, val);
 380         ASSERT(!(addr & 0xf));  /* check alignment */
 381
 382         switch (len) {
 383         case 8:
 384         case 4:
 385                 data = *(u32 *) val;
 386                 break;
 387         case 2:
 388                 data = *(u16 *) val;
 389                 break;
 390         case 1:
 391                 data = *(u8  *) val;
 392                 break;
 393         default:
 394                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 395                 return 0;
 396         }
 397
 398         addr &= 0xff;
 399         spin_lock(&ioapic->lock);
 400         switch (addr) {
 401         case IOAPIC_REG_SELECT:
 402                 ioapic->ioregsel = data & 0xFF; /* 8-bit register */
 403                 break;
 404
 405         case IOAPIC_REG_WINDOW:
 406                 ioapic_write_indirect(ioapic, data);
 407                 break;
 408 #ifdef  CONFIG_IA64
 409         case IOAPIC_REG_EOI:
 410                 __kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);
 411                 break;
 412 #endif
 413
 414         default:
 415                 break;
 416         }
 417         spin_unlock(&ioapic->lock);
 418         return 0;
 419 }
 420
 421 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 422 {
 423         int i;
 424
 425         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 426                 ioapic->redirtbl[i].fields.mask = 1;
 427         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 428         ioapic->ioregsel = 0;
 429         ioapic->irr = 0;
 430         ioapic->id = 0;
 431         update_handled_vectors(ioapic);
 432 }
 433
 434 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 435         .read     = ioapic_mmio_read,
 436         .write    = ioapic_mmio_write,
 437 };
 438
 439 int kvm_ioapic_init(struct kvm *kvm)
 440 {
 441         struct kvm_ioapic *ioapic;
 442         int ret;
 443
 444         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 445         if (!ioapic)
 446                 return -ENOMEM;
 447         spin_lock_init(&ioapic->lock);
 448         kvm->arch.vioapic = ioapic;
 449         kvm_ioapic_reset(ioapic);
 450         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 451         ioapic->kvm = kvm;
 452         mutex_lock(&kvm->slots_lock);
 453         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
 454                                       IOAPIC_MEM_LENGTH, &ioapic->dev);
 455         mutex_unlock(&kvm->slots_lock);
 456         if (ret < 0) {
 457                 kvm->arch.vioapic = NULL;
 458                 kfree(ioapic);
 459         }
 460
 461         return ret;
 462 }
 463
 464 void kvm_ioapic_destroy(struct kvm *kvm)
 465 {
 466         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 467
 468         if (ioapic) {
 469                 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 470                 kvm->arch.vioapic = NULL;
 471                 kfree(ioapic);
 472         }
 473 }
 474
 475 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 476 {
 477         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 478         if (!ioapic)
 479                 return -EINVAL;
 480
 481         spin_lock(&ioapic->lock);
 482         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
 483         spin_unlock(&ioapic->lock);
 484         return 0;
 485 }
 486
 487 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 488 {
 489         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 490         if (!ioapic)
 491                 return -EINVAL;
 492
 493         spin_lock(&ioapic->lock);
 494         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 495         update_handled_vectors(ioapic);
 496         kvm_ioapic_make_eoibitmap_request(kvm);
 497         spin_unlock(&ioapic->lock);
 498         return 0;
 499 }