hw/intc/ioapic.c

   1 /*
   2  *  ioapic.c IOAPIC emulation logic
   3  *
   4  *  Copyright (c) 2004-2005 Fabrice Bellard
   5  *
   6  *  Split the ioapic logic from apic.c
   7  *  Xiantao Zhang <xiantao.zhang@intel.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include "qemu/osdep.h"
  24 #include "qemu/error-report.h"
  25 #include "monitor/monitor.h"
  26 #include "hw/hw.h"
  27 #include "hw/i386/pc.h"
  28 #include "hw/i386/apic.h"
  29 #include "hw/i386/ioapic.h"
  30 #include "hw/i386/ioapic_internal.h"
  31 #include "include/hw/pci/msi.h"
  32 #include "sysemu/kvm.h"
  33 #include "target/i386/cpu.h"
  34 #include "hw/i386/apic-msidef.h"
  35 #include "hw/i386/x86-iommu.h"
  36 #include "trace.h"
  37
  38 //#define DEBUG_IOAPIC
  39
  40 #ifdef DEBUG_IOAPIC
  41 #define DPRINTF(fmt, ...)                                       \
  42     do { printf("ioapic: " fmt , ## __VA_ARGS__); } while (0)
  43 #else
  44 #define DPRINTF(fmt, ...)
  45 #endif
  46
  47 #define APIC_DELIVERY_MODE_SHIFT 8
  48 #define APIC_POLARITY_SHIFT 14
  49 #define APIC_TRIG_MODE_SHIFT 15
  50
  51 static IOAPICCommonState *ioapics[MAX_IOAPICS];
  52
  53 /* global variable from ioapic_common.c */
  54 extern int ioapic_no;
  55
  56 struct ioapic_entry_info {
  57     /* fields parsed from IOAPIC entries */
  58     uint8_t masked;
  59     uint8_t trig_mode;
  60     uint16_t dest_idx;
  61     uint8_t dest_mode;
  62     uint8_t delivery_mode;
  63     uint8_t vector;
  64
  65     /* MSI message generated from above parsed fields */
  66     uint32_t addr;
  67     uint32_t data;
  68 };
  69
  70 static void ioapic_entry_parse(uint64_t entry, struct ioapic_entry_info *info)
  71 {
  72     memset(info, 0, sizeof(*info));
  73     info->masked = (entry >> IOAPIC_LVT_MASKED_SHIFT) & 1;
  74     info->trig_mode = (entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1;
  75     /*
  76      * By default, this would be dest_id[8] + reserved[8]. When IR
  77      * is enabled, this would be interrupt_index[15] +
  78      * interrupt_format[1]. This field never means anything, but
  79      * only used to generate corresponding MSI.
  80      */
  81     info->dest_idx = (entry >> IOAPIC_LVT_DEST_IDX_SHIFT) & 0xffff;
  82     info->dest_mode = (entry >> IOAPIC_LVT_DEST_MODE_SHIFT) & 1;
  83     info->delivery_mode = (entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) \
  84         & IOAPIC_DM_MASK;
  85     if (info->delivery_mode == IOAPIC_DM_EXTINT) {
  86         info->vector = pic_read_irq(isa_pic);
  87     } else {
  88         info->vector = entry & IOAPIC_VECTOR_MASK;
  89     }
  90
  91     info->addr = APIC_DEFAULT_ADDRESS | \
  92         (info->dest_idx << MSI_ADDR_DEST_IDX_SHIFT) | \
  93         (info->dest_mode << MSI_ADDR_DEST_MODE_SHIFT);
  94     info->data = (info->vector << MSI_DATA_VECTOR_SHIFT) | \
  95         (info->trig_mode << MSI_DATA_TRIGGER_SHIFT) | \
  96         (info->delivery_mode << MSI_DATA_DELIVERY_MODE_SHIFT);
  97 }
  98
  99 static void ioapic_service(IOAPICCommonState *s)
 100 {
 101     AddressSpace *ioapic_as = PC_MACHINE(qdev_get_machine())->ioapic_as;
 102     struct ioapic_entry_info info;
 103     uint8_t i;
 104     uint32_t mask;
 105     uint64_t entry;
 106
 107     for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 108         mask = 1 << i;
 109         if (s->irr & mask) {
 110             int coalesce = 0;
 111
 112             entry = s->ioredtbl[i];
 113             ioapic_entry_parse(entry, &info);
 114             if (!info.masked) {
 115                 if (info.trig_mode == IOAPIC_TRIGGER_EDGE) {
 116                     s->irr &= ~mask;
 117                 } else {
 118                     coalesce = s->ioredtbl[i] & IOAPIC_LVT_REMOTE_IRR;
 119                     trace_ioapic_set_remote_irr(i);
 120                     s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;
 121                 }
 122
 123                 if (coalesce) {
 124                     /* We are level triggered interrupts, and the
 125                      * guest should be still working on previous one,
 126                      * so skip it. */
 127                     continue;
 128                 }
 129
 130 #ifdef CONFIG_KVM
 131                 if (kvm_irqchip_is_split()) {
 132                     if (info.trig_mode == IOAPIC_TRIGGER_EDGE) {
 133                         kvm_set_irq(kvm_state, i, 1);
 134                         kvm_set_irq(kvm_state, i, 0);
 135                     } else {
 136                         kvm_set_irq(kvm_state, i, 1);
 137                     }
 138                     continue;
 139                 }
 140 #endif
 141
 142                 /* No matter whether IR is enabled, we translate
 143                  * the IOAPIC message into a MSI one, and its
 144                  * address space will decide whether we need a
 145                  * translation. */
 146                 stl_le_phys(ioapic_as, info.addr, info.data);
 147             }
 148         }
 149     }
 150 }
 151
 152 static void ioapic_set_irq(void *opaque, int vector, int level)
 153 {
 154     IOAPICCommonState *s = opaque;
 155
 156     /* ISA IRQs map to GSI 1-1 except for IRQ0 which maps
 157      * to GSI 2.  GSI maps to ioapic 1-1.  This is not
 158      * the cleanest way of doing it but it should work. */
 159
 160     DPRINTF("%s: %s vec %x\n", __func__, level ? "raise" : "lower", vector);
 161     if (vector == 0) {
 162         vector = 2;
 163     }
 164     if (vector >= 0 && vector < IOAPIC_NUM_PINS) {
 165         uint32_t mask = 1 << vector;
 166         uint64_t entry = s->ioredtbl[vector];
 167
 168         if (((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1) ==
 169             IOAPIC_TRIGGER_LEVEL) {
 170             /* level triggered */
 171             if (level) {
 172                 s->irr |= mask;
 173                 if (!(entry & IOAPIC_LVT_REMOTE_IRR)) {
 174                     ioapic_service(s);
 175                 }
 176             } else {
 177                 s->irr &= ~mask;
 178             }
 179         } else {
 180             /* According to the 82093AA manual, we must ignore edge requests
 181              * if the input pin is masked. */
 182             if (level && !(entry & IOAPIC_LVT_MASKED)) {
 183                 s->irr |= mask;
 184                 ioapic_service(s);
 185             }
 186         }
 187     }
 188 }
 189
 190 static void ioapic_update_kvm_routes(IOAPICCommonState *s)
 191 {
 192 #ifdef CONFIG_KVM
 193     int i;
 194
 195     if (kvm_irqchip_is_split()) {
 196         for (i = 0; i < IOAPIC_NUM_PINS; i++) {
 197             MSIMessage msg;
 198             struct ioapic_entry_info info;
 199             ioapic_entry_parse(s->ioredtbl[i], &info);
 200             msg.address = info.addr;
 201             msg.data = info.data;
 202             kvm_irqchip_update_msi_route(kvm_state, i, msg, NULL);
 203         }
 204         kvm_irqchip_commit_routes(kvm_state);
 205     }
 206 #endif
 207 }
 208
 209 #ifdef CONFIG_KVM
 210 static void ioapic_iec_notifier(void *private, bool global,
 211                                 uint32_t index, uint32_t mask)
 212 {
 213     IOAPICCommonState *s = (IOAPICCommonState *)private;
 214     /* For simplicity, we just update all the routes */
 215     ioapic_update_kvm_routes(s);
 216 }
 217 #endif
 218
 219 void ioapic_eoi_broadcast(int vector)
 220 {
 221     IOAPICCommonState *s;
 222     uint64_t entry;
 223     int i, n;
 224
 225     trace_ioapic_eoi_broadcast(vector);
 226
 227     for (i = 0; i < MAX_IOAPICS; i++) {
 228         s = ioapics[i];
 229         if (!s) {
 230             continue;
 231         }
 232         for (n = 0; n < IOAPIC_NUM_PINS; n++) {
 233             entry = s->ioredtbl[n];
 234             if ((entry & IOAPIC_LVT_REMOTE_IRR)
 235                 && (entry & IOAPIC_VECTOR_MASK) == vector) {
 236                 trace_ioapic_clear_remote_irr(n, vector);
 237                 s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR;
 238                 if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) {
 239                     ioapic_service(s);
 240                 }
 241             }
 242         }
 243     }
 244 }
 245
 246 void ioapic_dump_state(Monitor *mon, const QDict *qdict)
 247 {
 248     int i;
 249
 250     for (i = 0; i < MAX_IOAPICS; i++) {
 251         if (ioapics[i] != 0) {
 252             ioapic_print_redtbl(mon, ioapics[i]);
 253         }
 254     }
 255 }
 256
 257 static uint64_t
 258 ioapic_mem_read(void *opaque, hwaddr addr, unsigned int size)
 259 {
 260     IOAPICCommonState *s = opaque;
 261     int index;
 262     uint32_t val = 0;
 263
 264     addr &= 0xff;
 265
 266     switch (addr) {
 267     case IOAPIC_IOREGSEL:
 268         val = s->ioregsel;
 269         break;
 270     case IOAPIC_IOWIN:
 271         if (size != 4) {
 272             break;
 273         }
 274         switch (s->ioregsel) {
 275         case IOAPIC_REG_ID:
 276         case IOAPIC_REG_ARB:
 277             val = s->id << IOAPIC_ID_SHIFT;
 278             break;
 279         case IOAPIC_REG_VER:
 280             val = s->version |
 281                 ((IOAPIC_NUM_PINS - 1) << IOAPIC_VER_ENTRIES_SHIFT);
 282             break;
 283         default:
 284             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
 285             if (index >= 0 && index < IOAPIC_NUM_PINS) {
 286                 if (s->ioregsel & 1) {
 287                     val = s->ioredtbl[index] >> 32;
 288                 } else {
 289                     val = s->ioredtbl[index] & 0xffffffff;
 290                 }
 291             }
 292         }
 293         DPRINTF("read: %08x = %08x\n", s->ioregsel, val);
 294         break;
 295     }
 296
 297     trace_ioapic_mem_read(addr, size, val);
 298
 299     return val;
 300 }
 301
 302 /*
 303  * This is to satisfy the hack in Linux kernel. One hack of it is to
 304  * simulate clearing the Remote IRR bit of IOAPIC entry using the
 305  * following:
 306  *
 307  * "For IO-APIC's with EOI register, we use that to do an explicit EOI.
 308  * Otherwise, we simulate the EOI message manually by changing the trigger
 309  * mode to edge and then back to level, with RTE being masked during
 310  * this."
 311  *
 312  * (See linux kernel __eoi_ioapic_pin() comment in commit c0205701)
 313  *
 314  * This is based on the assumption that, Remote IRR bit will be
 315  * cleared by IOAPIC hardware when configured as edge-triggered
 316  * interrupts.
 317  *
 318  * Without this, level-triggered interrupts in IR mode might fail to
 319  * work correctly.
 320  */
 321 static inline void
 322 ioapic_fix_edge_remote_irr(uint64_t *entry)
 323 {
 324     if (!(*entry & IOAPIC_LVT_TRIGGER_MODE)) {
 325         /* Edge-triggered interrupts, make sure remote IRR is zero */
 326         *entry &= ~((uint64_t)IOAPIC_LVT_REMOTE_IRR);
 327     }
 328 }
 329
 330 static void
 331 ioapic_mem_write(void *opaque, hwaddr addr, uint64_t val,
 332                  unsigned int size)
 333 {
 334     IOAPICCommonState *s = opaque;
 335     int index;
 336
 337     addr &= 0xff;
 338     trace_ioapic_mem_write(addr, size, val);
 339
 340     switch (addr) {
 341     case IOAPIC_IOREGSEL:
 342         s->ioregsel = val;
 343         break;
 344     case IOAPIC_IOWIN:
 345         if (size != 4) {
 346             break;
 347         }
 348         DPRINTF("write: %08x = %08" PRIx64 "\n", s->ioregsel, val);
 349         switch (s->ioregsel) {
 350         case IOAPIC_REG_ID:
 351             s->id = (val >> IOAPIC_ID_SHIFT) & IOAPIC_ID_MASK;
 352             break;
 353         case IOAPIC_REG_VER:
 354         case IOAPIC_REG_ARB:
 355             break;
 356         default:
 357             index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
 358             if (index >= 0 && index < IOAPIC_NUM_PINS) {
 359                 uint64_t ro_bits = s->ioredtbl[index] & IOAPIC_RO_BITS;
 360                 if (s->ioregsel & 1) {
 361                     s->ioredtbl[index] &= 0xffffffff;
 362                     s->ioredtbl[index] |= (uint64_t)val << 32;
 363                 } else {
 364                     s->ioredtbl[index] &= ~0xffffffffULL;
 365                     s->ioredtbl[index] |= val;
 366                 }
 367                 /* restore RO bits */
 368                 s->ioredtbl[index] &= IOAPIC_RW_BITS;
 369                 s->ioredtbl[index] |= ro_bits;
 370                 ioapic_fix_edge_remote_irr(&s->ioredtbl[index]);
 371                 ioapic_service(s);
 372             }
 373         }
 374         break;
 375     case IOAPIC_EOI:
 376         /* Explicit EOI is only supported for IOAPIC version 0x20 */
 377         if (size != 4 || s->version != 0x20) {
 378             break;
 379         }
 380         ioapic_eoi_broadcast(val);
 381         break;
 382     }
 383
 384     ioapic_update_kvm_routes(s);
 385 }
 386
 387 static const MemoryRegionOps ioapic_io_ops = {
 388     .read = ioapic_mem_read,
 389     .write = ioapic_mem_write,
 390     .endianness = DEVICE_NATIVE_ENDIAN,
 391 };
 392
 393 static void ioapic_machine_done_notify(Notifier *notifier, void *data)
 394 {
 395 #ifdef CONFIG_KVM
 396     IOAPICCommonState *s = container_of(notifier, IOAPICCommonState,
 397                                         machine_done);
 398
 399     if (kvm_irqchip_is_split()) {
 400         X86IOMMUState *iommu = x86_iommu_get_default();
 401         if (iommu) {
 402             /* Register this IOAPIC with IOMMU IEC notifier, so that
 403              * when there are IR invalidates, we can be notified to
 404              * update kernel IR cache. */
 405             x86_iommu_iec_register_notifier(iommu, ioapic_iec_notifier, s);
 406         }
 407     }
 408 #endif
 409 }
 410
 411 #define IOAPIC_VER_DEF 0x20
 412
 413 static void ioapic_realize(DeviceState *dev, Error **errp)
 414 {
 415     IOAPICCommonState *s = IOAPIC_COMMON(dev);
 416
 417     if (s->version != 0x11 && s->version != 0x20) {
 418         error_report("IOAPIC only supports version 0x11 or 0x20 "
 419                      "(default: 0x%x).", IOAPIC_VER_DEF);
 420         exit(1);
 421     }
 422
 423     memory_region_init_io(&s->io_memory, OBJECT(s), &ioapic_io_ops, s,
 424                           "ioapic", 0x1000);
 425
 426     qdev_init_gpio_in(dev, ioapic_set_irq, IOAPIC_NUM_PINS);
 427
 428     ioapics[ioapic_no] = s;
 429     s->machine_done.notify = ioapic_machine_done_notify;
 430     qemu_add_machine_init_done_notifier(&s->machine_done);
 431 }
 432
 433 static Property ioapic_properties[] = {
 434     DEFINE_PROP_UINT8("version", IOAPICCommonState, version, IOAPIC_VER_DEF),
 435     DEFINE_PROP_END_OF_LIST(),
 436 };
 437
 438 static void ioapic_class_init(ObjectClass *klass, void *data)
 439 {
 440     IOAPICCommonClass *k = IOAPIC_COMMON_CLASS(klass);
 441     DeviceClass *dc = DEVICE_CLASS(klass);
 442
 443     k->realize = ioapic_realize;
 444     /*
 445      * If APIC is in kernel, we need to update the kernel cache after
 446      * migration, otherwise first 24 gsi routes will be invalid.
 447      */
 448     k->post_load = ioapic_update_kvm_routes;
 449     dc->reset = ioapic_reset_common;
 450     dc->props = ioapic_properties;
 451     /*
 452      * FIXME: Set only because we are not sure yet if this device
 453      * will be outside the q35 sysbus whitelist.
 454      */
 455     dc->user_creatable = true;
 456 }
 457
 458 static const TypeInfo ioapic_info = {
 459     .name          = "ioapic",
 460     .parent        = TYPE_IOAPIC_COMMON,
 461     .instance_size = sizeof(IOAPICCommonState),
 462     .class_init    = ioapic_class_init,
 463 };
 464
 465 static void ioapic_register_types(void)
 466 {
 467     type_register_static(&ioapic_info);
 468 }
 469
 470 type_init(ioapic_register_types)