virt/kvm/ioapic.c

   1 /*
   2  *  Copyright (C) 2001  MandrakeSoft S.A.
   3  *
   4  *    MandrakeSoft S.A.
   5  *    43, rue d'Aboukir
   6  *    75002 Paris - France
   7  *    http://www.linux-mandrake.com/
   8  *    http://www.mandrakesoft.com/
   9  *
  10  *  This library is free software; you can redistribute it and/or
  11  *  modify it under the terms of the GNU Lesser General Public
  12  *  License as published by the Free Software Foundation; either
  13  *  version 2 of the License, or (at your option) any later version.
  14  *
  15  *  This library is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  Lesser General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU Lesser General Public
  21  *  License along with this library; if not, write to the Free Software
  22  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  23  *
  24  *  Yunhong Jiang <yunhong.jiang@intel.com>
  25  *  Yaozu (Eddie) Dong <eddie.dong@intel.com>
  26  *  Based on Xen 3.1 code.
  27  */
  28
  29 #include <linux/kvm_host.h>
  30 #include <linux/kvm.h>
  31 #include <linux/mm.h>
  32 #include <linux/highmem.h>
  33 #include <linux/smp.h>
  34 #include <linux/hrtimer.h>
  35 #include <linux/io.h>
  36 #include <linux/slab.h>
  37 #include <asm/processor.h>
  38 #include <asm/page.h>
  39 #include <asm/current.h>
  40 #include <trace/events/kvm.h>
  41
  42 #include "ioapic.h"
  43 #include "lapic.h"
  44 #include "irq.h"
  45
  46 #if 0
  47 #define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
  48 #else
  49 #define ioapic_debug(fmt, arg...)
  50 #endif
  51 static int ioapic_deliver(struct kvm_ioapic *vioapic, int irq);
  52
  53 static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
  54                                           unsigned long addr,
  55                                           unsigned long length)
  56 {
  57         unsigned long result = 0;
  58
  59         switch (ioapic->ioregsel) {
  60         case IOAPIC_REG_VERSION:
  61                 result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
  62                           | (IOAPIC_VERSION_ID & 0xff));
  63                 break;
  64
  65         case IOAPIC_REG_APIC_ID:
  66         case IOAPIC_REG_ARB_ID:
  67                 result = ((ioapic->id & 0xf) << 24);
  68                 break;
  69
  70         default:
  71                 {
  72                         u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
  73                         u64 redir_content;
  74
  75                         ASSERT(redir_index < IOAPIC_NUM_PINS);
  76
  77                         redir_content = ioapic->redirtbl[redir_index].bits;
  78                         result = (ioapic->ioregsel & 0x1) ?
  79                             (redir_content >> 32) & 0xffffffff :
  80                             redir_content & 0xffffffff;
  81                         break;
  82                 }
  83         }
  84
  85         return result;
  86 }
  87
  88 static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
  89 {
  90         union kvm_ioapic_redirect_entry *pent;
  91         int injected = -1;
  92
  93         pent = &ioapic->redirtbl[idx];
  94
  95         if (!pent->fields.mask) {
  96                 injected = ioapic_deliver(ioapic, idx);
  97                 if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
  98                         pent->fields.remote_irr = 1;
  99         }
 100
 101         return injected;
 102 }
 103
 104 static void update_handled_vectors(struct kvm_ioapic *ioapic)
 105 {
 106         DECLARE_BITMAP(handled_vectors, 256);
 107         int i;
 108
 109         memset(handled_vectors, 0, sizeof(handled_vectors));
 110         for (i = 0; i < IOAPIC_NUM_PINS; ++i)
 111                 __set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
 112         memcpy(ioapic->handled_vectors, handled_vectors,
 113                sizeof(handled_vectors));
 114         smp_wmb();
 115 }
 116
 117 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
 118 {
 119         unsigned index;
 120         bool mask_before, mask_after;
 121         union kvm_ioapic_redirect_entry *e;
 122
 123         switch (ioapic->ioregsel) {
 124         case IOAPIC_REG_VERSION:
 125                 /* Writes are ignored. */
 126                 break;
 127
 128         case IOAPIC_REG_APIC_ID:
 129                 ioapic->id = (val >> 24) & 0xf;
 130                 break;
 131
 132         case IOAPIC_REG_ARB_ID:
 133                 break;
 134
 135         default:
 136                 index = (ioapic->ioregsel - 0x10) >> 1;
 137
 138                 ioapic_debug("change redir index %x val %x\n", index, val);
 139                 if (index >= IOAPIC_NUM_PINS)
 140                         return;
 141                 e = &ioapic->redirtbl[index];
 142                 mask_before = e->fields.mask;
 143                 if (ioapic->ioregsel & 1) {
 144                         e->bits &= 0xffffffff;
 145                         e->bits |= (u64) val << 32;
 146                 } else {
 147                         e->bits &= ~0xffffffffULL;
 148                         e->bits |= (u32) val;
 149                         e->fields.remote_irr = 0;
 150                 }
 151                 update_handled_vectors(ioapic);
 152                 mask_after = e->fields.mask;
 153                 if (mask_before != mask_after)
 154                         kvm_fire_mask_notifiers(ioapic->kvm, index, mask_after);
 155                 if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
 156                     && ioapic->irr & (1 << index))
 157                         ioapic_service(ioapic, index);
 158                 break;
 159         }
 160 }
 161
 162 static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
 163 {
 164         union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
 165         struct kvm_lapic_irq irqe;
 166
 167         ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
 168                      "vector=%x trig_mode=%x\n",
 169                      entry->fields.dest, entry->fields.dest_mode,
 170                      entry->fields.delivery_mode, entry->fields.vector,
 171                      entry->fields.trig_mode);
 172
 173         irqe.dest_id = entry->fields.dest_id;
 174         irqe.vector = entry->fields.vector;
 175         irqe.dest_mode = entry->fields.dest_mode;
 176         irqe.trig_mode = entry->fields.trig_mode;
 177         irqe.delivery_mode = entry->fields.delivery_mode << 8;
 178         irqe.level = 1;
 179         irqe.shorthand = 0;
 180
 181 #ifdef CONFIG_X86
 182         /* Always delivery PIT interrupt to vcpu 0 */
 183         if (irq == 0) {
 184                 irqe.dest_mode = 0; /* Physical mode. */
 185                 /* need to read apic_id from apic regiest since
 186                  * it can be rewritten */
 187                 irqe.dest_id = ioapic->kvm->bsp_vcpu->vcpu_id;
 188         }
 189 #endif
 190         return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe);
 191 }
 192
 193 int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
 194 {
 195         u32 old_irr;
 196         u32 mask = 1 << irq;
 197         union kvm_ioapic_redirect_entry entry;
 198         int ret = 1;
 199
 200         spin_lock(&ioapic->lock);
 201         old_irr = ioapic->irr;
 202         if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
 203                 entry = ioapic->redirtbl[irq];
 204                 level ^= entry.fields.polarity;
 205                 if (!level)
 206                         ioapic->irr &= ~mask;
 207                 else {
 208                         int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 209                         ioapic->irr |= mask;
 210                         if ((edge && old_irr != ioapic->irr) ||
 211                             (!edge && !entry.fields.remote_irr))
 212                                 ret = ioapic_service(ioapic, irq);
 213                         else
 214                                 ret = 0; /* report coalesced interrupt */
 215                 }
 216                 trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 217         }
 218         spin_unlock(&ioapic->lock);
 219
 220         return ret;
 221 }
 222
 223 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
 224                                      int trigger_mode)
 225 {
 226         int i;
 227
 228         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 229                 union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
 230
 231                 if (ent->fields.vector != vector)
 232                         continue;
 233
 234                 /*
 235                  * We are dropping lock while calling ack notifiers because ack
 236                  * notifier callbacks for assigned devices call into IOAPIC
 237                  * recursively. Since remote_irr is cleared only after call
 238                  * to notifiers if the same vector will be delivered while lock
 239                  * is dropped it will be put into irr and will be delivered
 240                  * after ack notifier returns.
 241                  */
 242                 spin_unlock(&ioapic->lock);
 243                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
 244                 spin_lock(&ioapic->lock);
 245
 246                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
 247                         continue;
 248
 249                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 250                 ent->fields.remote_irr = 0;
 251                 if (!ent->fields.mask && (ioapic->irr & (1 << i)))
 252                         ioapic_service(ioapic, i);
 253         }
 254 }
 255
 256 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 257 {
 258         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 259
 260         smp_rmb();
 261         if (!test_bit(vector, ioapic->handled_vectors))
 262                 return;
 263         spin_lock(&ioapic->lock);
 264         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
 265         spin_unlock(&ioapic->lock);
 266 }
 267
 268 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 269 {
 270         return container_of(dev, struct kvm_ioapic, dev);
 271 }
 272
 273 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 274 {
 275         return ((addr >= ioapic->base_address &&
 276                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 277 }
 278
 279 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 280                             void *val)
 281 {
 282         struct kvm_ioapic *ioapic = to_ioapic(this);
 283         u32 result;
 284         if (!ioapic_in_range(ioapic, addr))
 285                 return -EOPNOTSUPP;
 286
 287         ioapic_debug("addr %lx\n", (unsigned long)addr);
 288         ASSERT(!(addr & 0xf));  /* check alignment */
 289
 290         addr &= 0xff;
 291         spin_lock(&ioapic->lock);
 292         switch (addr) {
 293         case IOAPIC_REG_SELECT:
 294                 result = ioapic->ioregsel;
 295                 break;
 296
 297         case IOAPIC_REG_WINDOW:
 298                 result = ioapic_read_indirect(ioapic, addr, len);
 299                 break;
 300
 301         default:
 302                 result = 0;
 303                 break;
 304         }
 305         spin_unlock(&ioapic->lock);
 306
 307         switch (len) {
 308         case 8:
 309                 *(u64 *) val = result;
 310                 break;
 311         case 1:
 312         case 2:
 313         case 4:
 314                 memcpy(val, (char *)&result, len);
 315                 break;
 316         default:
 317                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 318         }
 319         return 0;
 320 }
 321
 322 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 323                              const void *val)
 324 {
 325         struct kvm_ioapic *ioapic = to_ioapic(this);
 326         u32 data;
 327         if (!ioapic_in_range(ioapic, addr))
 328                 return -EOPNOTSUPP;
 329
 330         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 331                      (void*)addr, len, val);
 332         ASSERT(!(addr & 0xf));  /* check alignment */
 333
 334         if (len == 4 || len == 8)
 335                 data = *(u32 *) val;
 336         else {
 337                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 338                 return 0;
 339         }
 340
 341         addr &= 0xff;
 342         spin_lock(&ioapic->lock);
 343         switch (addr) {
 344         case IOAPIC_REG_SELECT:
 345                 ioapic->ioregsel = data;
 346                 break;
 347
 348         case IOAPIC_REG_WINDOW:
 349                 ioapic_write_indirect(ioapic, data);
 350                 break;
 351 #ifdef  CONFIG_IA64
 352         case IOAPIC_REG_EOI:
 353                 __kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);
 354                 break;
 355 #endif
 356
 357         default:
 358                 break;
 359         }
 360         spin_unlock(&ioapic->lock);
 361         return 0;
 362 }
 363
 364 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 365 {
 366         int i;
 367
 368         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 369                 ioapic->redirtbl[i].fields.mask = 1;
 370         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 371         ioapic->ioregsel = 0;
 372         ioapic->irr = 0;
 373         ioapic->id = 0;
 374         update_handled_vectors(ioapic);
 375 }
 376
 377 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 378         .read     = ioapic_mmio_read,
 379         .write    = ioapic_mmio_write,
 380 };
 381
 382 int kvm_ioapic_init(struct kvm *kvm)
 383 {
 384         struct kvm_ioapic *ioapic;
 385         int ret;
 386
 387         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 388         if (!ioapic)
 389                 return -ENOMEM;
 390         spin_lock_init(&ioapic->lock);
 391         kvm->arch.vioapic = ioapic;
 392         kvm_ioapic_reset(ioapic);
 393         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 394         ioapic->kvm = kvm;
 395         mutex_lock(&kvm->slots_lock);
 396         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 397         mutex_unlock(&kvm->slots_lock);
 398         if (ret < 0) {
 399                 kvm->arch.vioapic = NULL;
 400                 kfree(ioapic);
 401         }
 402
 403         return ret;
 404 }
 405
 406 void kvm_ioapic_destroy(struct kvm *kvm)
 407 {
 408         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 409
 410         if (ioapic) {
 411                 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 412                 kvm->arch.vioapic = NULL;
 413                 kfree(ioapic);
 414         }
 415 }
 416
 417 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 418 {
 419         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 420         if (!ioapic)
 421                 return -EINVAL;
 422
 423         spin_lock(&ioapic->lock);
 424         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
 425         spin_unlock(&ioapic->lock);
 426         return 0;
 427 }
 428
 429 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 430 {
 431         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 432         if (!ioapic)
 433                 return -EINVAL;
 434
 435         spin_lock(&ioapic->lock);
 436         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 437         update_handled_vectors(ioapic);
 438         spin_unlock(&ioapic->lock);
 439         return 0;
 440 }