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                         if (redir_index < IOAPIC_NUM_PINS)
  78                                 redir_content =
  79                                         ioapic->redirtbl[redir_index].bits;
  80                         else
  81                                 redir_content = ~0ULL;
  82
  83                         result = (ioapic->ioregsel & 0x1) ?
  84                             (redir_content >> 32) & 0xffffffff :
  85                             redir_content & 0xffffffff;
  86                         break;
  87                 }
  88         }
  89
  90         return result;
  91 }
  92
  93 static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
  94 {
  95         union kvm_ioapic_redirect_entry *pent;
  96         int injected = -1;
  97
  98         pent = &ioapic->redirtbl[idx];
  99
 100         if (!pent->fields.mask) {
 101                 injected = ioapic_deliver(ioapic, idx);
 102                 if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
 103                         pent->fields.remote_irr = 1;
 104         }
 105
 106         return injected;
 107 }
 108
 109 static void update_handled_vectors(struct kvm_ioapic *ioapic)
 110 {
 111         DECLARE_BITMAP(handled_vectors, 256);
 112         int i;
 113
 114         memset(handled_vectors, 0, sizeof(handled_vectors));
 115         for (i = 0; i < IOAPIC_NUM_PINS; ++i)
 116                 __set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
 117         memcpy(ioapic->handled_vectors, handled_vectors,
 118                sizeof(handled_vectors));
 119         smp_wmb();
 120 }
 121
 122 void kvm_ioapic_calculate_eoi_exitmap(struct kvm_vcpu *vcpu,
 123                                         u64 *eoi_exit_bitmap)
 124 {
 125         struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
 126         union kvm_ioapic_redirect_entry *e;
 127         struct kvm_lapic_irq irqe;
 128         int index;
 129
 130         spin_lock(&ioapic->lock);
 131         /* traverse ioapic entry to set eoi exit bitmap*/
 132         for (index = 0; index < IOAPIC_NUM_PINS; index++) {
 133                 e = &ioapic->redirtbl[index];
 134                 if (!e->fields.mask &&
 135                         (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
 136                          kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC,
 137                                  index))) {
 138                         irqe.dest_id = e->fields.dest_id;
 139                         irqe.vector = e->fields.vector;
 140                         irqe.dest_mode = e->fields.dest_mode;
 141                         irqe.delivery_mode = e->fields.delivery_mode << 8;
 142                         kvm_calculate_eoi_exitmap(vcpu, &irqe, eoi_exit_bitmap);
 143                 }
 144         }
 145         spin_unlock(&ioapic->lock);
 146 }
 147 EXPORT_SYMBOL_GPL(kvm_ioapic_calculate_eoi_exitmap);
 148
 149 void kvm_ioapic_make_eoibitmap_request(struct kvm *kvm)
 150 {
 151         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 152
 153         if (!kvm_apic_vid_enabled(kvm) || !ioapic)
 154                 return;
 155         kvm_make_update_eoibitmap_request(kvm);
 156 }
 157
 158 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
 159 {
 160         unsigned index;
 161         bool mask_before, mask_after;
 162         union kvm_ioapic_redirect_entry *e;
 163
 164         switch (ioapic->ioregsel) {
 165         case IOAPIC_REG_VERSION:
 166                 /* Writes are ignored. */
 167                 break;
 168
 169         case IOAPIC_REG_APIC_ID:
 170                 ioapic->id = (val >> 24) & 0xf;
 171                 break;
 172
 173         case IOAPIC_REG_ARB_ID:
 174                 break;
 175
 176         default:
 177                 index = (ioapic->ioregsel - 0x10) >> 1;
 178
 179                 ioapic_debug("change redir index %x val %x\n", index, val);
 180                 if (index >= IOAPIC_NUM_PINS)
 181                         return;
 182                 e = &ioapic->redirtbl[index];
 183                 mask_before = e->fields.mask;
 184                 if (ioapic->ioregsel & 1) {
 185                         e->bits &= 0xffffffff;
 186                         e->bits |= (u64) val << 32;
 187                 } else {
 188                         e->bits &= ~0xffffffffULL;
 189                         e->bits |= (u32) val;
 190                         e->fields.remote_irr = 0;
 191                 }
 192                 update_handled_vectors(ioapic);
 193                 mask_after = e->fields.mask;
 194                 if (mask_before != mask_after)
 195                         kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
 196                 if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
 197                     && ioapic->irr & (1 << index))
 198                         ioapic_service(ioapic, index);
 199                 kvm_ioapic_make_eoibitmap_request(ioapic->kvm);
 200                 break;
 201         }
 202 }
 203
 204 static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
 205 {
 206         union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
 207         struct kvm_lapic_irq irqe;
 208
 209         ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
 210                      "vector=%x trig_mode=%x\n",
 211                      entry->fields.dest_id, entry->fields.dest_mode,
 212                      entry->fields.delivery_mode, entry->fields.vector,
 213                      entry->fields.trig_mode);
 214
 215         irqe.dest_id = entry->fields.dest_id;
 216         irqe.vector = entry->fields.vector;
 217         irqe.dest_mode = entry->fields.dest_mode;
 218         irqe.trig_mode = entry->fields.trig_mode;
 219         irqe.delivery_mode = entry->fields.delivery_mode << 8;
 220         irqe.level = 1;
 221         irqe.shorthand = 0;
 222
 223         return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe);
 224 }
 225
 226 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 227                        int level)
 228 {
 229         u32 old_irr;
 230         u32 mask = 1 << irq;
 231         union kvm_ioapic_redirect_entry entry;
 232         int ret, irq_level;
 233
 234         BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
 235
 236         spin_lock(&ioapic->lock);
 237         old_irr = ioapic->irr;
 238         irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
 239                                          irq_source_id, level);
 240         entry = ioapic->redirtbl[irq];
 241         irq_level ^= entry.fields.polarity;
 242         if (!irq_level) {
 243                 ioapic->irr &= ~mask;
 244                 ret = 1;
 245         } else {
 246                 int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 247                 ioapic->irr |= mask;
 248                 if ((edge && old_irr != ioapic->irr) ||
 249                     (!edge && !entry.fields.remote_irr))
 250                         ret = ioapic_service(ioapic, irq);
 251                 else
 252                         ret = 0; /* report coalesced interrupt */
 253         }
 254         trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 255         spin_unlock(&ioapic->lock);
 256
 257         return ret;
 258 }
 259
 260 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
 261 {
 262         int i;
 263
 264         spin_lock(&ioapic->lock);
 265         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 266                 __clear_bit(irq_source_id, &ioapic->irq_states[i]);
 267         spin_unlock(&ioapic->lock);
 268 }
 269
 270 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
 271                                      int trigger_mode)
 272 {
 273         int i;
 274
 275         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 276                 union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
 277
 278                 if (ent->fields.vector != vector)
 279                         continue;
 280
 281                 /*
 282                  * We are dropping lock while calling ack notifiers because ack
 283                  * notifier callbacks for assigned devices call into IOAPIC
 284                  * recursively. Since remote_irr is cleared only after call
 285                  * to notifiers if the same vector will be delivered while lock
 286                  * is dropped it will be put into irr and will be delivered
 287                  * after ack notifier returns.
 288                  */
 289                 spin_unlock(&ioapic->lock);
 290                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
 291                 spin_lock(&ioapic->lock);
 292
 293                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
 294                         continue;
 295
 296                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 297                 ent->fields.remote_irr = 0;
 298                 if (!ent->fields.mask && (ioapic->irr & (1 << i)))
 299                         ioapic_service(ioapic, i);
 300         }
 301 }
 302
 303 bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
 304 {
 305         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 306         smp_rmb();
 307         return test_bit(vector, ioapic->handled_vectors);
 308 }
 309
 310 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 311 {
 312         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 313
 314         spin_lock(&ioapic->lock);
 315         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
 316         spin_unlock(&ioapic->lock);
 317 }
 318
 319 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 320 {
 321         return container_of(dev, struct kvm_ioapic, dev);
 322 }
 323
 324 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 325 {
 326         return ((addr >= ioapic->base_address &&
 327                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 328 }
 329
 330 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 331                             void *val)
 332 {
 333         struct kvm_ioapic *ioapic = to_ioapic(this);
 334         u32 result;
 335         if (!ioapic_in_range(ioapic, addr))
 336                 return -EOPNOTSUPP;
 337
 338         ioapic_debug("addr %lx\n", (unsigned long)addr);
 339         ASSERT(!(addr & 0xf));  /* check alignment */
 340
 341         addr &= 0xff;
 342         spin_lock(&ioapic->lock);
 343         switch (addr) {
 344         case IOAPIC_REG_SELECT:
 345                 result = ioapic->ioregsel;
 346                 break;
 347
 348         case IOAPIC_REG_WINDOW:
 349                 result = ioapic_read_indirect(ioapic, addr, len);
 350                 break;
 351
 352         default:
 353                 result = 0;
 354                 break;
 355         }
 356         spin_unlock(&ioapic->lock);
 357
 358         switch (len) {
 359         case 8:
 360                 *(u64 *) val = result;
 361                 break;
 362         case 1:
 363         case 2:
 364         case 4:
 365                 memcpy(val, (char *)&result, len);
 366                 break;
 367         default:
 368                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 369         }
 370         return 0;
 371 }
 372
 373 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 374                              const void *val)
 375 {
 376         struct kvm_ioapic *ioapic = to_ioapic(this);
 377         u32 data;
 378         if (!ioapic_in_range(ioapic, addr))
 379                 return -EOPNOTSUPP;
 380
 381         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 382                      (void*)addr, len, val);
 383         ASSERT(!(addr & 0xf));  /* check alignment */
 384
 385         switch (len) {
 386         case 8:
 387         case 4:
 388                 data = *(u32 *) val;
 389                 break;
 390         case 2:
 391                 data = *(u16 *) val;
 392                 break;
 393         case 1:
 394                 data = *(u8  *) val;
 395                 break;
 396         default:
 397                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 398                 return 0;
 399         }
 400
 401         addr &= 0xff;
 402         spin_lock(&ioapic->lock);
 403         switch (addr) {
 404         case IOAPIC_REG_SELECT:
 405                 ioapic->ioregsel = data & 0xFF; /* 8-bit register */
 406                 break;
 407
 408         case IOAPIC_REG_WINDOW:
 409                 ioapic_write_indirect(ioapic, data);
 410                 break;
 411 #ifdef  CONFIG_IA64
 412         case IOAPIC_REG_EOI:
 413                 __kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);
 414                 break;
 415 #endif
 416
 417         default:
 418                 break;
 419         }
 420         spin_unlock(&ioapic->lock);
 421         return 0;
 422 }
 423
 424 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 425 {
 426         int i;
 427
 428         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 429                 ioapic->redirtbl[i].fields.mask = 1;
 430         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 431         ioapic->ioregsel = 0;
 432         ioapic->irr = 0;
 433         ioapic->id = 0;
 434         update_handled_vectors(ioapic);
 435 }
 436
 437 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 438         .read     = ioapic_mmio_read,
 439         .write    = ioapic_mmio_write,
 440 };
 441
 442 int kvm_ioapic_init(struct kvm *kvm)
 443 {
 444         struct kvm_ioapic *ioapic;
 445         int ret;
 446
 447         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 448         if (!ioapic)
 449                 return -ENOMEM;
 450         spin_lock_init(&ioapic->lock);
 451         kvm->arch.vioapic = ioapic;
 452         kvm_ioapic_reset(ioapic);
 453         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 454         ioapic->kvm = kvm;
 455         mutex_lock(&kvm->slots_lock);
 456         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
 457                                       IOAPIC_MEM_LENGTH, &ioapic->dev);
 458         mutex_unlock(&kvm->slots_lock);
 459         if (ret < 0) {
 460                 kvm->arch.vioapic = NULL;
 461                 kfree(ioapic);
 462         }
 463
 464         return ret;
 465 }
 466
 467 void kvm_ioapic_destroy(struct kvm *kvm)
 468 {
 469         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 470
 471         if (ioapic) {
 472                 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 473                 kvm->arch.vioapic = NULL;
 474                 kfree(ioapic);
 475         }
 476 }
 477
 478 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 479 {
 480         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 481         if (!ioapic)
 482                 return -EINVAL;
 483
 484         spin_lock(&ioapic->lock);
 485         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
 486         spin_unlock(&ioapic->lock);
 487         return 0;
 488 }
 489
 490 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 491 {
 492         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 493         if (!ioapic)
 494                 return -EINVAL;
 495
 496         spin_lock(&ioapic->lock);
 497         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 498         update_handled_vectors(ioapic);
 499         kvm_ioapic_make_eoibitmap_request(kvm);
 500         spin_unlock(&ioapic->lock);
 501         return 0;
 502 }