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 <asm/processor.h>
  39 #include <asm/page.h>
  40 #include <asm/current.h>
  41 #include <trace/events/kvm.h>
  42
  43 #include "ioapic.h"
  44 #include "lapic.h"
  45 #include "irq.h"
  46
  47 #if 0
  48 #define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
  49 #else
  50 #define ioapic_debug(fmt, arg...)
  51 #endif
  52 static int ioapic_deliver(struct kvm_ioapic *vioapic, int irq);
  53
  54 static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
  55                                           unsigned long addr,
  56                                           unsigned long length)
  57 {
  58         unsigned long result = 0;
  59
  60         switch (ioapic->ioregsel) {
  61         case IOAPIC_REG_VERSION:
  62                 result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
  63                           | (IOAPIC_VERSION_ID & 0xff));
  64                 break;
  65
  66         case IOAPIC_REG_APIC_ID:
  67         case IOAPIC_REG_ARB_ID:
  68                 result = ((ioapic->id & 0xf) << 24);
  69                 break;
  70
  71         default:
  72                 {
  73                         u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
  74                         u64 redir_content;
  75
  76                         ASSERT(redir_index < IOAPIC_NUM_PINS);
  77
  78                         redir_content = ioapic->redirtbl[redir_index].bits;
  79                         result = (ioapic->ioregsel & 0x1) ?
  80                             (redir_content >> 32) & 0xffffffff :
  81                             redir_content & 0xffffffff;
  82                         break;
  83                 }
  84         }
  85
  86         return result;
  87 }
  88
  89 static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
  90 {
  91         union kvm_ioapic_redirect_entry *pent;
  92         int injected = -1;
  93
  94         pent = &ioapic->redirtbl[idx];
  95
  96         if (!pent->fields.mask) {
  97                 injected = ioapic_deliver(ioapic, idx);
  98                 if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
  99                         pent->fields.remote_irr = 1;
 100         }
 101
 102         return injected;
 103 }
 104
 105 static void update_handled_vectors(struct kvm_ioapic *ioapic)
 106 {
 107         DECLARE_BITMAP(handled_vectors, 256);
 108         int i;
 109
 110         memset(handled_vectors, 0, sizeof(handled_vectors));
 111         for (i = 0; i < IOAPIC_NUM_PINS; ++i)
 112                 __set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
 113         memcpy(ioapic->handled_vectors, handled_vectors,
 114                sizeof(handled_vectors));
 115         smp_wmb();
 116 }
 117
 118 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
 119 {
 120         unsigned index;
 121         bool mask_before, mask_after;
 122         union kvm_ioapic_redirect_entry *e;
 123
 124         switch (ioapic->ioregsel) {
 125         case IOAPIC_REG_VERSION:
 126                 /* Writes are ignored. */
 127                 break;
 128
 129         case IOAPIC_REG_APIC_ID:
 130                 ioapic->id = (val >> 24) & 0xf;
 131                 break;
 132
 133         case IOAPIC_REG_ARB_ID:
 134                 break;
 135
 136         default:
 137                 index = (ioapic->ioregsel - 0x10) >> 1;
 138
 139                 ioapic_debug("change redir index %x val %x\n", index, val);
 140                 if (index >= IOAPIC_NUM_PINS)
 141                         return;
 142                 e = &ioapic->redirtbl[index];
 143                 mask_before = e->fields.mask;
 144                 if (ioapic->ioregsel & 1) {
 145                         e->bits &= 0xffffffff;
 146                         e->bits |= (u64) val << 32;
 147                 } else {
 148                         e->bits &= ~0xffffffffULL;
 149                         e->bits |= (u32) val;
 150                         e->fields.remote_irr = 0;
 151                 }
 152                 update_handled_vectors(ioapic);
 153                 mask_after = e->fields.mask;
 154                 if (mask_before != mask_after)
 155                         kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
 156                 if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
 157                     && ioapic->irr & (1 << index))
 158                         ioapic_service(ioapic, index);
 159                 break;
 160         }
 161 }
 162
 163 static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
 164 {
 165         union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
 166         struct kvm_lapic_irq irqe;
 167
 168         ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
 169                      "vector=%x trig_mode=%x\n",
 170                      entry->fields.dest_id, entry->fields.dest_mode,
 171                      entry->fields.delivery_mode, entry->fields.vector,
 172                      entry->fields.trig_mode);
 173
 174         irqe.dest_id = entry->fields.dest_id;
 175         irqe.vector = entry->fields.vector;
 176         irqe.dest_mode = entry->fields.dest_mode;
 177         irqe.trig_mode = entry->fields.trig_mode;
 178         irqe.delivery_mode = entry->fields.delivery_mode << 8;
 179         irqe.level = 1;
 180         irqe.shorthand = 0;
 181
 182 #ifdef CONFIG_X86
 183         /* Always delivery PIT interrupt to vcpu 0 */
 184         if (irq == 0) {
 185                 irqe.dest_mode = 0; /* Physical mode. */
 186                 /* need to read apic_id from apic regiest since
 187                  * it can be rewritten */
 188                 irqe.dest_id = ioapic->kvm->bsp_vcpu_id;
 189         }
 190 #endif
 191         return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe);
 192 }
 193
 194 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 195                        int level)
 196 {
 197         u32 old_irr;
 198         u32 mask = 1 << irq;
 199         union kvm_ioapic_redirect_entry entry;
 200         int ret, irq_level;
 201
 202         BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
 203
 204         spin_lock(&ioapic->lock);
 205         old_irr = ioapic->irr;
 206         irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
 207                                          irq_source_id, level);
 208         entry = ioapic->redirtbl[irq];
 209         irq_level ^= entry.fields.polarity;
 210         if (!irq_level) {
 211                 ioapic->irr &= ~mask;
 212                 ret = 1;
 213         } else {
 214                 int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 215                 ioapic->irr |= mask;
 216                 if ((edge && old_irr != ioapic->irr) ||
 217                     (!edge && !entry.fields.remote_irr))
 218                         ret = ioapic_service(ioapic, irq);
 219                 else
 220                         ret = 0; /* report coalesced interrupt */
 221         }
 222         trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 223         spin_unlock(&ioapic->lock);
 224
 225         return ret;
 226 }
 227
 228 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
 229 {
 230         int i;
 231
 232         spin_lock(&ioapic->lock);
 233         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 234                 __clear_bit(irq_source_id, &ioapic->irq_states[i]);
 235         spin_unlock(&ioapic->lock);
 236 }
 237
 238 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
 239                                      int trigger_mode)
 240 {
 241         int i;
 242
 243         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 244                 union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
 245
 246                 if (ent->fields.vector != vector)
 247                         continue;
 248
 249                 /*
 250                  * We are dropping lock while calling ack notifiers because ack
 251                  * notifier callbacks for assigned devices call into IOAPIC
 252                  * recursively. Since remote_irr is cleared only after call
 253                  * to notifiers if the same vector will be delivered while lock
 254                  * is dropped it will be put into irr and will be delivered
 255                  * after ack notifier returns.
 256                  */
 257                 spin_unlock(&ioapic->lock);
 258                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
 259                 spin_lock(&ioapic->lock);
 260
 261                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
 262                         continue;
 263
 264                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 265                 ent->fields.remote_irr = 0;
 266                 if (!ent->fields.mask && (ioapic->irr & (1 << i)))
 267                         ioapic_service(ioapic, i);
 268         }
 269 }
 270
 271 bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
 272 {
 273         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 274         smp_rmb();
 275         return test_bit(vector, ioapic->handled_vectors);
 276 }
 277
 278 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 279 {
 280         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 281
 282         spin_lock(&ioapic->lock);
 283         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
 284         spin_unlock(&ioapic->lock);
 285 }
 286
 287 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 288 {
 289         return container_of(dev, struct kvm_ioapic, dev);
 290 }
 291
 292 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 293 {
 294         return ((addr >= ioapic->base_address &&
 295                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 296 }
 297
 298 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 299                             void *val)
 300 {
 301         struct kvm_ioapic *ioapic = to_ioapic(this);
 302         u32 result;
 303         if (!ioapic_in_range(ioapic, addr))
 304                 return -EOPNOTSUPP;
 305
 306         ioapic_debug("addr %lx\n", (unsigned long)addr);
 307         ASSERT(!(addr & 0xf));  /* check alignment */
 308
 309         addr &= 0xff;
 310         spin_lock(&ioapic->lock);
 311         switch (addr) {
 312         case IOAPIC_REG_SELECT:
 313                 result = ioapic->ioregsel;
 314                 break;
 315
 316         case IOAPIC_REG_WINDOW:
 317                 result = ioapic_read_indirect(ioapic, addr, len);
 318                 break;
 319
 320         default:
 321                 result = 0;
 322                 break;
 323         }
 324         spin_unlock(&ioapic->lock);
 325
 326         switch (len) {
 327         case 8:
 328                 *(u64 *) val = result;
 329                 break;
 330         case 1:
 331         case 2:
 332         case 4:
 333                 memcpy(val, (char *)&result, len);
 334                 break;
 335         default:
 336                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 337         }
 338         return 0;
 339 }
 340
 341 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 342                              const void *val)
 343 {
 344         struct kvm_ioapic *ioapic = to_ioapic(this);
 345         u32 data;
 346         if (!ioapic_in_range(ioapic, addr))
 347                 return -EOPNOTSUPP;
 348
 349         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 350                      (void*)addr, len, val);
 351         ASSERT(!(addr & 0xf));  /* check alignment */
 352
 353         switch (len) {
 354         case 8:
 355         case 4:
 356                 data = *(u32 *) val;
 357                 break;
 358         case 2:
 359                 data = *(u16 *) val;
 360                 break;
 361         case 1:
 362                 data = *(u8  *) val;
 363                 break;
 364         default:
 365                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 366                 return 0;
 367         }
 368
 369         addr &= 0xff;
 370         spin_lock(&ioapic->lock);
 371         switch (addr) {
 372         case IOAPIC_REG_SELECT:
 373                 ioapic->ioregsel = data & 0xFF; /* 8-bit register */
 374                 break;
 375
 376         case IOAPIC_REG_WINDOW:
 377                 ioapic_write_indirect(ioapic, data);
 378                 break;
 379 #ifdef  CONFIG_IA64
 380         case IOAPIC_REG_EOI:
 381                 __kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);
 382                 break;
 383 #endif
 384
 385         default:
 386                 break;
 387         }
 388         spin_unlock(&ioapic->lock);
 389         return 0;
 390 }
 391
 392 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 393 {
 394         int i;
 395
 396         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 397                 ioapic->redirtbl[i].fields.mask = 1;
 398         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 399         ioapic->ioregsel = 0;
 400         ioapic->irr = 0;
 401         ioapic->id = 0;
 402         update_handled_vectors(ioapic);
 403 }
 404
 405 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 406         .read     = ioapic_mmio_read,
 407         .write    = ioapic_mmio_write,
 408 };
 409
 410 int kvm_ioapic_init(struct kvm *kvm)
 411 {
 412         struct kvm_ioapic *ioapic;
 413         int ret;
 414
 415         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 416         if (!ioapic)
 417                 return -ENOMEM;
 418         spin_lock_init(&ioapic->lock);
 419         kvm->arch.vioapic = ioapic;
 420         kvm_ioapic_reset(ioapic);
 421         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 422         ioapic->kvm = kvm;
 423         mutex_lock(&kvm->slots_lock);
 424         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
 425                                       IOAPIC_MEM_LENGTH, &ioapic->dev);
 426         mutex_unlock(&kvm->slots_lock);
 427         if (ret < 0) {
 428                 kvm->arch.vioapic = NULL;
 429                 kfree(ioapic);
 430         }
 431
 432         return ret;
 433 }
 434
 435 void kvm_ioapic_destroy(struct kvm *kvm)
 436 {
 437         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 438
 439         if (ioapic) {
 440                 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 441                 kvm->arch.vioapic = NULL;
 442                 kfree(ioapic);
 443         }
 444 }
 445
 446 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 447 {
 448         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 449         if (!ioapic)
 450                 return -EINVAL;
 451
 452         spin_lock(&ioapic->lock);
 453         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
 454         spin_unlock(&ioapic->lock);
 455         return 0;
 456 }
 457
 458 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 459 {
 460         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 461         if (!ioapic)
 462                 return -EINVAL;
 463
 464         spin_lock(&ioapic->lock);
 465         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 466         update_handled_vectors(ioapic);
 467         spin_unlock(&ioapic->lock);
 468         return 0;
 469 }