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 = 1;
 201
 202         spin_lock(&ioapic->lock);
 203         old_irr = ioapic->irr;
 204         if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
 205                 int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
 206                                                      irq_source_id, level);
 207                 entry = ioapic->redirtbl[irq];
 208                 irq_level ^= entry.fields.polarity;
 209                 if (!irq_level)
 210                         ioapic->irr &= ~mask;
 211                 else {
 212                         int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 213                         ioapic->irr |= mask;
 214                         if ((edge && old_irr != ioapic->irr) ||
 215                             (!edge && !entry.fields.remote_irr))
 216                                 ret = ioapic_service(ioapic, irq);
 217                         else
 218                                 ret = 0; /* report coalesced interrupt */
 219                 }
 220                 trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 221         }
 222         spin_unlock(&ioapic->lock);
 223
 224         return ret;
 225 }
 226
 227 void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
 228 {
 229         int i;
 230
 231         spin_lock(&ioapic->lock);
 232         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 233                 __clear_bit(irq_source_id, &ioapic->irq_states[i]);
 234         spin_unlock(&ioapic->lock);
 235 }
 236
 237 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
 238                                      int trigger_mode)
 239 {
 240         int i;
 241
 242         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 243                 union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
 244
 245                 if (ent->fields.vector != vector)
 246                         continue;
 247
 248                 /*
 249                  * We are dropping lock while calling ack notifiers because ack
 250                  * notifier callbacks for assigned devices call into IOAPIC
 251                  * recursively. Since remote_irr is cleared only after call
 252                  * to notifiers if the same vector will be delivered while lock
 253                  * is dropped it will be put into irr and will be delivered
 254                  * after ack notifier returns.
 255                  */
 256                 spin_unlock(&ioapic->lock);
 257                 kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
 258                 spin_lock(&ioapic->lock);
 259
 260                 if (trigger_mode != IOAPIC_LEVEL_TRIG)
 261                         continue;
 262
 263                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 264                 ent->fields.remote_irr = 0;
 265                 if (!ent->fields.mask && (ioapic->irr & (1 << i)))
 266                         ioapic_service(ioapic, i);
 267         }
 268 }
 269
 270 bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
 271 {
 272         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 273         smp_rmb();
 274         return test_bit(vector, ioapic->handled_vectors);
 275 }
 276
 277 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 278 {
 279         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 280
 281         spin_lock(&ioapic->lock);
 282         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
 283         spin_unlock(&ioapic->lock);
 284 }
 285
 286 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 287 {
 288         return container_of(dev, struct kvm_ioapic, dev);
 289 }
 290
 291 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 292 {
 293         return ((addr >= ioapic->base_address &&
 294                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 295 }
 296
 297 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 298                             void *val)
 299 {
 300         struct kvm_ioapic *ioapic = to_ioapic(this);
 301         u32 result;
 302         if (!ioapic_in_range(ioapic, addr))
 303                 return -EOPNOTSUPP;
 304
 305         ioapic_debug("addr %lx\n", (unsigned long)addr);
 306         ASSERT(!(addr & 0xf));  /* check alignment */
 307
 308         addr &= 0xff;
 309         spin_lock(&ioapic->lock);
 310         switch (addr) {
 311         case IOAPIC_REG_SELECT:
 312                 result = ioapic->ioregsel;
 313                 break;
 314
 315         case IOAPIC_REG_WINDOW:
 316                 result = ioapic_read_indirect(ioapic, addr, len);
 317                 break;
 318
 319         default:
 320                 result = 0;
 321                 break;
 322         }
 323         spin_unlock(&ioapic->lock);
 324
 325         switch (len) {
 326         case 8:
 327                 *(u64 *) val = result;
 328                 break;
 329         case 1:
 330         case 2:
 331         case 4:
 332                 memcpy(val, (char *)&result, len);
 333                 break;
 334         default:
 335                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 336         }
 337         return 0;
 338 }
 339
 340 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 341                              const void *val)
 342 {
 343         struct kvm_ioapic *ioapic = to_ioapic(this);
 344         u32 data;
 345         if (!ioapic_in_range(ioapic, addr))
 346                 return -EOPNOTSUPP;
 347
 348         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 349                      (void*)addr, len, val);
 350         ASSERT(!(addr & 0xf));  /* check alignment */
 351
 352         switch (len) {
 353         case 8:
 354         case 4:
 355                 data = *(u32 *) val;
 356                 break;
 357         case 2:
 358                 data = *(u16 *) val;
 359                 break;
 360         case 1:
 361                 data = *(u8  *) val;
 362                 break;
 363         default:
 364                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 365                 return 0;
 366         }
 367
 368         addr &= 0xff;
 369         spin_lock(&ioapic->lock);
 370         switch (addr) {
 371         case IOAPIC_REG_SELECT:
 372                 ioapic->ioregsel = data & 0xFF; /* 8-bit register */
 373                 break;
 374
 375         case IOAPIC_REG_WINDOW:
 376                 ioapic_write_indirect(ioapic, data);
 377                 break;
 378 #ifdef  CONFIG_IA64
 379         case IOAPIC_REG_EOI:
 380                 __kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);
 381                 break;
 382 #endif
 383
 384         default:
 385                 break;
 386         }
 387         spin_unlock(&ioapic->lock);
 388         return 0;
 389 }
 390
 391 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 392 {
 393         int i;
 394
 395         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 396                 ioapic->redirtbl[i].fields.mask = 1;
 397         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 398         ioapic->ioregsel = 0;
 399         ioapic->irr = 0;
 400         ioapic->id = 0;
 401         update_handled_vectors(ioapic);
 402 }
 403
 404 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 405         .read     = ioapic_mmio_read,
 406         .write    = ioapic_mmio_write,
 407 };
 408
 409 int kvm_ioapic_init(struct kvm *kvm)
 410 {
 411         struct kvm_ioapic *ioapic;
 412         int ret;
 413
 414         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 415         if (!ioapic)
 416                 return -ENOMEM;
 417         spin_lock_init(&ioapic->lock);
 418         kvm->arch.vioapic = ioapic;
 419         kvm_ioapic_reset(ioapic);
 420         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 421         ioapic->kvm = kvm;
 422         mutex_lock(&kvm->slots_lock);
 423         ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
 424                                       IOAPIC_MEM_LENGTH, &ioapic->dev);
 425         mutex_unlock(&kvm->slots_lock);
 426         if (ret < 0) {
 427                 kvm->arch.vioapic = NULL;
 428                 kfree(ioapic);
 429         }
 430
 431         return ret;
 432 }
 433
 434 void kvm_ioapic_destroy(struct kvm *kvm)
 435 {
 436         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 437
 438         if (ioapic) {
 439                 kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
 440                 kvm->arch.vioapic = NULL;
 441                 kfree(ioapic);
 442         }
 443 }
 444
 445 int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 446 {
 447         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 448         if (!ioapic)
 449                 return -EINVAL;
 450
 451         spin_lock(&ioapic->lock);
 452         memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
 453         spin_unlock(&ioapic->lock);
 454         return 0;
 455 }
 456
 457 int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 458 {
 459         struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
 460         if (!ioapic)
 461                 return -EINVAL;
 462
 463         spin_lock(&ioapic->lock);
 464         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
 465         update_handled_vectors(ioapic);
 466         spin_unlock(&ioapic->lock);
 467         return 0;
 468 }