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