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->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 level)
 195 {
 196         u32 old_irr;
 197         u32 mask = 1 << irq;
 198         union kvm_ioapic_redirect_entry entry;
 199         int ret = 1;
 200
 201         spin_lock(&ioapic->lock);
 202         old_irr = ioapic->irr;
 203         if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
 204                 entry = ioapic->redirtbl[irq];
 205                 level ^= entry.fields.polarity;
 206                 if (!level)
 207                         ioapic->irr &= ~mask;
 208                 else {
 209                         int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 210                         ioapic->irr |= mask;
 211                         if ((edge && old_irr != ioapic->irr) ||
 212                             (!edge && !entry.fields.remote_irr))
 213                                 ret = ioapic_service(ioapic, irq);
 214                         else
 215                                 ret = 0; /* report coalesced interrupt */
 216                 }
 217                 trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 218         }
 219         spin_unlock(&ioapic->lock);
 220
 221         return ret;
 222 }
 223
 224 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
 225                                      int trigger_mode)
 226 {
 227         int i;
 228
 229         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 230                 union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
 231
 232                 if (ent->fields.vector != vector)
 233                         continue;
 234
 235                 /*
 236                  * We are dropping lock while calling ack notifiers because ack
 237                  * notifier callbacks for assigned devices call into IOAPIC
 238                  * recursively. Since remote_irr is cleared only after call
 239                  * to notifiers if the same vector will be delivered while lock
 240                  * is dropped it will be put into irr and will be delivered
 241                  * after ack notifier returns.
 242                  */
 243                 spin_unlock(&ioapic->lock);
 244                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
 245                 spin_lock(&ioapic->lock);
 246
 247                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
 248                         continue;
 249
 250                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 251                 ent->fields.remote_irr = 0;
 252                 if (!ent->fields.mask && (ioapic->irr & (1 << i)))
 253                         ioapic_service(ioapic, i);
 254         }
 255 }
 256
 257 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 258 {
 259         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 260
 261         smp_rmb();
 262         if (!test_bit(vector, ioapic->handled_vectors))
 263                 return;
 264         spin_lock(&ioapic->lock);
 265         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
 266         spin_unlock(&ioapic->lock);
 267 }
 268
 269 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 270 {
 271         return container_of(dev, struct kvm_ioapic, dev);
 272 }
 273
 274 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 275 {
 276         return ((addr >= ioapic->base_address &&
 277                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 278 }
 279
 280 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 281                             void *val)
 282 {
 283         struct kvm_ioapic *ioapic = to_ioapic(this);
 284         u32 result;
 285         if (!ioapic_in_range(ioapic, addr))
 286                 return -EOPNOTSUPP;
 287
 288         ioapic_debug("addr %lx\n", (unsigned long)addr);
 289         ASSERT(!(addr & 0xf));  /* check alignment */
 290
 291         addr &= 0xff;
 292         spin_lock(&ioapic->lock);
 293         switch (addr) {
 294         case IOAPIC_REG_SELECT:
 295                 result = ioapic->ioregsel;
 296                 break;
 297
 298         case IOAPIC_REG_WINDOW:
 299                 result = ioapic_read_indirect(ioapic, addr, len);
 300                 break;
 301
 302         default:
 303                 result = 0;
 304                 break;
 305         }
 306         spin_unlock(&ioapic->lock);
 307
 308         switch (len) {
 309         case 8:
 310                 *(u64 *) val = result;
 311                 break;
 312         case 1:
 313         case 2:
 314         case 4:
 315                 memcpy(val, (char *)&result, len);
 316                 break;
 317         default:
 318                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 319         }
 320         return 0;
 321 }
 322
 323 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 324                              const void *val)
 325 {
 326         struct kvm_ioapic *ioapic = to_ioapic(this);
 327         u32 data;
 328         if (!ioapic_in_range(ioapic, addr))
 329                 return -EOPNOTSUPP;
 330
 331         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 332                      (void*)addr, len, val);
 333         ASSERT(!(addr & 0xf));  /* check alignment */
 334
 335         if (len == 4 || len == 8)
 336                 data = *(u32 *) val;
 337         else {
 338                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 339                 return 0;
 340         }
 341
 342         addr &= 0xff;
 343         spin_lock(&ioapic->lock);
 344         switch (addr) {
 345         case IOAPIC_REG_SELECT:
 346                 ioapic->ioregsel = data;
 347                 break;
 348
 349         case IOAPIC_REG_WINDOW:
 350                 ioapic_write_indirect(ioapic, data);
 351                 break;
 352 #ifdef  CONFIG_IA64
 353         case IOAPIC_REG_EOI:
 354                 __kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);
 355                 break;
 356 #endif
 357
 358         default:
 359                 break;
 360         }
 361         spin_unlock(&ioapic->lock);
 362         return 0;
 363 }
 364
 365 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 366 {
 367         int i;
 368
 369         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 370                 ioapic->redirtbl[i].fields.mask = 1;
 371         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 372         ioapic->ioregsel = 0;
 373         ioapic->irr = 0;
 374         ioapic->id = 0;
 375         update_handled_vectors(ioapic);
 376 }
 377
 378 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 379         .read     = ioapic_mmio_read,
 380         .write    = ioapic_mmio_write,
 381 };
 382
 383 int kvm_ioapic_init(struct kvm *kvm)
 384 {
 385         struct kvm_ioapic *ioapic;
 386         int ret;
 387
 388         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 389         if (!ioapic)
 390                 return -ENOMEM;
 391         spin_lock_init(&ioapic->lock);
 392         kvm->arch.vioapic = ioapic;
 393         kvm_ioapic_reset(ioapic);
 394         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 395         ioapic->kvm = kvm;
 396         mutex_lock(&kvm->slots_lock);
 397         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 398         mutex_unlock(&kvm->slots_lock);
 399         if (ret < 0) {
 400                 kvm->arch.vioapic = NULL;
 401                 kfree(ioapic);
 402         }
 403
 404         return ret;
 405 }
 406
 407 void kvm_ioapic_destroy(struct kvm *kvm)
 408 {
 409         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 410
 411         if (ioapic) {
 412                 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 413                 kvm->arch.vioapic = NULL;
 414                 kfree(ioapic);
 415         }
 416 }
 417
 418 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 419 {
 420         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 421         if (!ioapic)
 422                 return -EINVAL;
 423
 424         spin_lock(&ioapic->lock);
 425         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
 426         spin_unlock(&ioapic->lock);
 427         return 0;
 428 }
 429
 430 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 431 {
 432         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 433         if (!ioapic)
 434                 return -EINVAL;
 435
 436         spin_lock(&ioapic->lock);
 437         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 438         update_handled_vectors(ioapic);
 439         spin_unlock(&ioapic->lock);
 440         return 0;
 441 }