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 = ioapic->irr;
 181         u32 mask = 1 << irq;
 182         union kvm_ioapic_redirect_entry entry;
 183         int ret = 1;
 184
 185         if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
 186                 entry = ioapic->redirtbl[irq];
 187                 level ^= entry.fields.polarity;
 188                 if (!level)
 189                         ioapic->irr &= ~mask;
 190                 else {
 191                         int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
 192                         ioapic->irr |= mask;
 193                         if ((edge && old_irr != ioapic->irr) ||
 194                             (!edge && !entry.fields.remote_irr))
 195                                 ret = ioapic_service(ioapic, irq);
 196                         else
 197                                 ret = 0; /* report coalesced interrupt */
 198                 }
 199                 trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 200         }
 201         return ret;
 202 }
 203
 204 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int pin,
 205                                     int trigger_mode)
 206 {
 207         union kvm_ioapic_redirect_entry *ent;
 208
 209         ent = &ioapic->redirtbl[pin];
 210
 211         kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);
 212
 213         if (trigger_mode == IOAPIC_LEVEL_TRIG) {
 214                 ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
 215                 ent->fields.remote_irr = 0;
 216                 if (!ent->fields.mask && (ioapic->irr & (1 << pin)))
 217                         ioapic_service(ioapic, pin);
 218         }
 219 }
 220
 221 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 222 {
 223         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 224         int i;
 225
 226         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 227                 if (ioapic->redirtbl[i].fields.vector == vector)
 228                         __kvm_ioapic_update_eoi(ioapic, i, trigger_mode);
 229 }
 230
 231 static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
 232 {
 233         return container_of(dev, struct kvm_ioapic, dev);
 234 }
 235
 236 static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
 237 {
 238         return ((addr >= ioapic->base_address &&
 239                  (addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
 240 }
 241
 242 static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
 243                             void *val)
 244 {
 245         struct kvm_ioapic *ioapic = to_ioapic(this);
 246         u32 result;
 247         if (!ioapic_in_range(ioapic, addr))
 248                 return -EOPNOTSUPP;
 249
 250         ioapic_debug("addr %lx\n", (unsigned long)addr);
 251         ASSERT(!(addr & 0xf));  /* check alignment */
 252
 253         mutex_lock(&ioapic->kvm->irq_lock);
 254         addr &= 0xff;
 255         switch (addr) {
 256         case IOAPIC_REG_SELECT:
 257                 result = ioapic->ioregsel;
 258                 break;
 259
 260         case IOAPIC_REG_WINDOW:
 261                 result = ioapic_read_indirect(ioapic, addr, len);
 262                 break;
 263
 264         default:
 265                 result = 0;
 266                 break;
 267         }
 268         switch (len) {
 269         case 8:
 270                 *(u64 *) val = result;
 271                 break;
 272         case 1:
 273         case 2:
 274         case 4:
 275                 memcpy(val, (char *)&result, len);
 276                 break;
 277         default:
 278                 printk(KERN_WARNING "ioapic: wrong length %d\n", len);
 279         }
 280         mutex_unlock(&ioapic->kvm->irq_lock);
 281         return 0;
 282 }
 283
 284 static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
 285                              const void *val)
 286 {
 287         struct kvm_ioapic *ioapic = to_ioapic(this);
 288         u32 data;
 289         if (!ioapic_in_range(ioapic, addr))
 290                 return -EOPNOTSUPP;
 291
 292         ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
 293                      (void*)addr, len, val);
 294         ASSERT(!(addr & 0xf));  /* check alignment */
 295
 296         mutex_lock(&ioapic->kvm->irq_lock);
 297         if (len == 4 || len == 8)
 298                 data = *(u32 *) val;
 299         else {
 300                 printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
 301                 goto unlock;
 302         }
 303
 304         addr &= 0xff;
 305         switch (addr) {
 306         case IOAPIC_REG_SELECT:
 307                 ioapic->ioregsel = data;
 308                 break;
 309
 310         case IOAPIC_REG_WINDOW:
 311                 ioapic_write_indirect(ioapic, data);
 312                 break;
 313 #ifdef  CONFIG_IA64
 314         case IOAPIC_REG_EOI:
 315                 kvm_ioapic_update_eoi(ioapic->kvm, data, IOAPIC_LEVEL_TRIG);
 316                 break;
 317 #endif
 318
 319         default:
 320                 break;
 321         }
 322 unlock:
 323         mutex_unlock(&ioapic->kvm->irq_lock);
 324         return 0;
 325 }
 326
 327 void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 328 {
 329         int i;
 330
 331         for (i = 0; i < IOAPIC_NUM_PINS; i++)
 332                 ioapic->redirtbl[i].fields.mask = 1;
 333         ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
 334         ioapic->ioregsel = 0;
 335         ioapic->irr = 0;
 336         ioapic->id = 0;
 337 }
 338
 339 static const struct kvm_io_device_ops ioapic_mmio_ops = {
 340         .read     = ioapic_mmio_read,
 341         .write    = ioapic_mmio_write,
 342 };
 343
 344 int kvm_ioapic_init(struct kvm *kvm)
 345 {
 346         struct kvm_ioapic *ioapic;
 347         int ret;
 348
 349         ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 350         if (!ioapic)
 351                 return -ENOMEM;
 352         kvm->arch.vioapic = ioapic;
 353         kvm_ioapic_reset(ioapic);
 354         kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
 355         ioapic->kvm = kvm;
 356         ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev);
 357         if (ret < 0)
 358                 kfree(ioapic);
 359
 360         return ret;
 361 }
 362