hw/kvmvapic.c

   1 /*
   2  * TPR optimization for 32-bit Windows guests (XP and Server 2003)
   3  *
   4  * Copyright (C) 2007-2008 Qumranet Technologies
   5  * Copyright (C) 2012      Jan Kiszka, Siemens AG
   6  *
   7  * This work is licensed under the terms of the GNU GPL version 2, or
   8  * (at your option) any later version. See the COPYING file in the
   9  * top-level directory.
  10  */
  11 #include "sysemu/sysemu.h"
  12 #include "sysemu/cpus.h"
  13 #include "sysemu/kvm.h"
  14 #include "apic_internal.h"
  15
  16 #define APIC_DEFAULT_ADDRESS    0xfee00000
  17
  18 #define VAPIC_IO_PORT           0x7e
  19
  20 #define VAPIC_CPU_SHIFT         7
  21
  22 #define ROM_BLOCK_SIZE          512
  23 #define ROM_BLOCK_MASK          (~(ROM_BLOCK_SIZE - 1))
  24
  25 typedef enum VAPICMode {
  26     VAPIC_INACTIVE = 0,
  27     VAPIC_ACTIVE   = 1,
  28     VAPIC_STANDBY  = 2,
  29 } VAPICMode;
  30
  31 typedef struct VAPICHandlers {
  32     uint32_t set_tpr;
  33     uint32_t set_tpr_eax;
  34     uint32_t get_tpr[8];
  35     uint32_t get_tpr_stack;
  36 } QEMU_PACKED VAPICHandlers;
  37
  38 typedef struct GuestROMState {
  39     char signature[8];
  40     uint32_t vaddr;
  41     uint32_t fixup_start;
  42     uint32_t fixup_end;
  43     uint32_t vapic_vaddr;
  44     uint32_t vapic_size;
  45     uint32_t vcpu_shift;
  46     uint32_t real_tpr_addr;
  47     VAPICHandlers up;
  48     VAPICHandlers mp;
  49 } QEMU_PACKED GuestROMState;
  50
  51 typedef struct VAPICROMState {
  52     SysBusDevice busdev;
  53     MemoryRegion io;
  54     MemoryRegion rom;
  55     uint32_t state;
  56     uint32_t rom_state_paddr;
  57     uint32_t rom_state_vaddr;
  58     uint32_t vapic_paddr;
  59     uint32_t real_tpr_addr;
  60     GuestROMState rom_state;
  61     size_t rom_size;
  62     bool rom_mapped_writable;
  63 } VAPICROMState;
  64
  65 #define TPR_INSTR_ABS_MODRM             0x1
  66 #define TPR_INSTR_MATCH_MODRM_REG       0x2
  67
  68 typedef struct TPRInstruction {
  69     uint8_t opcode;
  70     uint8_t modrm_reg;
  71     unsigned int flags;
  72     TPRAccess access;
  73     size_t length;
  74     off_t addr_offset;
  75 } TPRInstruction;
  76
  77 /* must be sorted by length, shortest first */
  78 static const TPRInstruction tpr_instr[] = {
  79     { /* mov abs to eax */
  80         .opcode = 0xa1,
  81         .access = TPR_ACCESS_READ,
  82         .length = 5,
  83         .addr_offset = 1,
  84     },
  85     { /* mov eax to abs */
  86         .opcode = 0xa3,
  87         .access = TPR_ACCESS_WRITE,
  88         .length = 5,
  89         .addr_offset = 1,
  90     },
  91     { /* mov r32 to r/m32 */
  92         .opcode = 0x89,
  93         .flags = TPR_INSTR_ABS_MODRM,
  94         .access = TPR_ACCESS_WRITE,
  95         .length = 6,
  96         .addr_offset = 2,
  97     },
  98     { /* mov r/m32 to r32 */
  99         .opcode = 0x8b,
 100         .flags = TPR_INSTR_ABS_MODRM,
 101         .access = TPR_ACCESS_READ,
 102         .length = 6,
 103         .addr_offset = 2,
 104     },
 105     { /* push r/m32 */
 106         .opcode = 0xff,
 107         .modrm_reg = 6,
 108         .flags = TPR_INSTR_ABS_MODRM | TPR_INSTR_MATCH_MODRM_REG,
 109         .access = TPR_ACCESS_READ,
 110         .length = 6,
 111         .addr_offset = 2,
 112     },
 113     { /* mov imm32, r/m32 (c7/0) */
 114         .opcode = 0xc7,
 115         .modrm_reg = 0,
 116         .flags = TPR_INSTR_ABS_MODRM | TPR_INSTR_MATCH_MODRM_REG,
 117         .access = TPR_ACCESS_WRITE,
 118         .length = 10,
 119         .addr_offset = 2,
 120     },
 121 };
 122
 123 static void read_guest_rom_state(VAPICROMState *s)
 124 {
 125     cpu_physical_memory_rw(s->rom_state_paddr, (void *)&s->rom_state,
 126                            sizeof(GuestROMState), 0);
 127 }
 128
 129 static void write_guest_rom_state(VAPICROMState *s)
 130 {
 131     cpu_physical_memory_rw(s->rom_state_paddr, (void *)&s->rom_state,
 132                            sizeof(GuestROMState), 1);
 133 }
 134
 135 static void update_guest_rom_state(VAPICROMState *s)
 136 {
 137     read_guest_rom_state(s);
 138
 139     s->rom_state.real_tpr_addr = cpu_to_le32(s->real_tpr_addr);
 140     s->rom_state.vcpu_shift = cpu_to_le32(VAPIC_CPU_SHIFT);
 141
 142     write_guest_rom_state(s);
 143 }
 144
 145 static int find_real_tpr_addr(VAPICROMState *s, CPUX86State *env)
 146 {
 147     hwaddr paddr;
 148     target_ulong addr;
 149
 150     if (s->state == VAPIC_ACTIVE) {
 151         return 0;
 152     }
 153     /*
 154      * If there is no prior TPR access instruction we could analyze (which is
 155      * the case after resume from hibernation), we need to scan the possible
 156      * virtual address space for the APIC mapping.
 157      */
 158     for (addr = 0xfffff000; addr >= 0x80000000; addr -= TARGET_PAGE_SIZE) {
 159         paddr = cpu_get_phys_page_debug(env, addr);
 160         if (paddr != APIC_DEFAULT_ADDRESS) {
 161             continue;
 162         }
 163         s->real_tpr_addr = addr + 0x80;
 164         update_guest_rom_state(s);
 165         return 0;
 166     }
 167     return -1;
 168 }
 169
 170 static uint8_t modrm_reg(uint8_t modrm)
 171 {
 172     return (modrm >> 3) & 7;
 173 }
 174
 175 static bool is_abs_modrm(uint8_t modrm)
 176 {
 177     return (modrm & 0xc7) == 0x05;
 178 }
 179
 180 static bool opcode_matches(uint8_t *opcode, const TPRInstruction *instr)
 181 {
 182     return opcode[0] == instr->opcode &&
 183         (!(instr->flags & TPR_INSTR_ABS_MODRM) || is_abs_modrm(opcode[1])) &&
 184         (!(instr->flags & TPR_INSTR_MATCH_MODRM_REG) ||
 185          modrm_reg(opcode[1]) == instr->modrm_reg);
 186 }
 187
 188 static int evaluate_tpr_instruction(VAPICROMState *s, CPUX86State *env,
 189                                     target_ulong *pip, TPRAccess access)
 190 {
 191     const TPRInstruction *instr;
 192     target_ulong ip = *pip;
 193     uint8_t opcode[2];
 194     uint32_t real_tpr_addr;
 195     int i;
 196
 197     if ((ip & 0xf0000000ULL) != 0x80000000ULL &&
 198         (ip & 0xf0000000ULL) != 0xe0000000ULL) {
 199         return -1;
 200     }
 201
 202     /*
 203      * Early Windows 2003 SMP initialization contains a
 204      *
 205      *   mov imm32, r/m32
 206      *
 207      * instruction that is patched by TPR optimization. The problem is that
 208      * RSP, used by the patched instruction, is zero, so the guest gets a
 209      * double fault and dies.
 210      */
 211     if (env->regs[R_ESP] == 0) {
 212         return -1;
 213     }
 214
 215     if (kvm_enabled() && !kvm_irqchip_in_kernel()) {
 216         /*
 217          * KVM without kernel-based TPR access reporting will pass an IP that
 218          * points after the accessing instruction. So we need to look backward
 219          * to find the reason.
 220          */
 221         for (i = 0; i < ARRAY_SIZE(tpr_instr); i++) {
 222             instr = &tpr_instr[i];
 223             if (instr->access != access) {
 224                 continue;
 225             }
 226             if (cpu_memory_rw_debug(env, ip - instr->length, opcode,
 227                                     sizeof(opcode), 0) < 0) {
 228                 return -1;
 229             }
 230             if (opcode_matches(opcode, instr)) {
 231                 ip -= instr->length;
 232                 goto instruction_ok;
 233             }
 234         }
 235         return -1;
 236     } else {
 237         if (cpu_memory_rw_debug(env, ip, opcode, sizeof(opcode), 0) < 0) {
 238             return -1;
 239         }
 240         for (i = 0; i < ARRAY_SIZE(tpr_instr); i++) {
 241             instr = &tpr_instr[i];
 242             if (opcode_matches(opcode, instr)) {
 243                 goto instruction_ok;
 244             }
 245         }
 246         return -1;
 247     }
 248
 249 instruction_ok:
 250     /*
 251      * Grab the virtual TPR address from the instruction
 252      * and update the cached values.
 253      */
 254     if (cpu_memory_rw_debug(env, ip + instr->addr_offset,
 255                             (void *)&real_tpr_addr,
 256                             sizeof(real_tpr_addr), 0) < 0) {
 257         return -1;
 258     }
 259     real_tpr_addr = le32_to_cpu(real_tpr_addr);
 260     if ((real_tpr_addr & 0xfff) != 0x80) {
 261         return -1;
 262     }
 263     s->real_tpr_addr = real_tpr_addr;
 264     update_guest_rom_state(s);
 265
 266     *pip = ip;
 267     return 0;
 268 }
 269
 270 static int update_rom_mapping(VAPICROMState *s, CPUX86State *env, target_ulong ip)
 271 {
 272     hwaddr paddr;
 273     uint32_t rom_state_vaddr;
 274     uint32_t pos, patch, offset;
 275
 276     /* nothing to do if already activated */
 277     if (s->state == VAPIC_ACTIVE) {
 278         return 0;
 279     }
 280
 281     /* bail out if ROM init code was not executed (missing ROM?) */
 282     if (s->state == VAPIC_INACTIVE) {
 283         return -1;
 284     }
 285
 286     /* find out virtual address of the ROM */
 287     rom_state_vaddr = s->rom_state_paddr + (ip & 0xf0000000);
 288     paddr = cpu_get_phys_page_debug(env, rom_state_vaddr);
 289     if (paddr == -1) {
 290         return -1;
 291     }
 292     paddr += rom_state_vaddr & ~TARGET_PAGE_MASK;
 293     if (paddr != s->rom_state_paddr) {
 294         return -1;
 295     }
 296     read_guest_rom_state(s);
 297     if (memcmp(s->rom_state.signature, "kvm aPiC", 8) != 0) {
 298         return -1;
 299     }
 300     s->rom_state_vaddr = rom_state_vaddr;
 301
 302     /* fixup addresses in ROM if needed */
 303     if (rom_state_vaddr == le32_to_cpu(s->rom_state.vaddr)) {
 304         return 0;
 305     }
 306     for (pos = le32_to_cpu(s->rom_state.fixup_start);
 307          pos < le32_to_cpu(s->rom_state.fixup_end);
 308          pos += 4) {
 309         cpu_physical_memory_rw(paddr + pos - s->rom_state.vaddr,
 310                                (void *)&offset, sizeof(offset), 0);
 311         offset = le32_to_cpu(offset);
 312         cpu_physical_memory_rw(paddr + offset, (void *)&patch,
 313                                sizeof(patch), 0);
 314         patch = le32_to_cpu(patch);
 315         patch += rom_state_vaddr - le32_to_cpu(s->rom_state.vaddr);
 316         patch = cpu_to_le32(patch);
 317         cpu_physical_memory_rw(paddr + offset, (void *)&patch,
 318                                sizeof(patch), 1);
 319     }
 320     read_guest_rom_state(s);
 321     s->vapic_paddr = paddr + le32_to_cpu(s->rom_state.vapic_vaddr) -
 322         le32_to_cpu(s->rom_state.vaddr);
 323
 324     return 0;
 325 }
 326
 327 /*
 328  * Tries to read the unique processor number from the Kernel Processor Control
 329  * Region (KPCR) of 32-bit Windows XP and Server 2003. Returns -1 if the KPCR
 330  * cannot be accessed or is considered invalid. This also ensures that we are
 331  * not patching the wrong guest.
 332  */
 333 static int get_kpcr_number(CPUX86State *env)
 334 {
 335     struct kpcr {
 336         uint8_t  fill1[0x1c];
 337         uint32_t self;
 338         uint8_t  fill2[0x31];
 339         uint8_t  number;
 340     } QEMU_PACKED kpcr;
 341
 342     if (cpu_memory_rw_debug(env, env->segs[R_FS].base,
 343                             (void *)&kpcr, sizeof(kpcr), 0) < 0 ||
 344         kpcr.self != env->segs[R_FS].base) {
 345         return -1;
 346     }
 347     return kpcr.number;
 348 }
 349
 350 static int vapic_enable(VAPICROMState *s, CPUX86State *env)
 351 {
 352     int cpu_number = get_kpcr_number(env);
 353     hwaddr vapic_paddr;
 354     static const uint8_t enabled = 1;
 355
 356     if (cpu_number < 0) {
 357         return -1;
 358     }
 359     vapic_paddr = s->vapic_paddr +
 360         (((hwaddr)cpu_number) << VAPIC_CPU_SHIFT);
 361     cpu_physical_memory_rw(vapic_paddr + offsetof(VAPICState, enabled),
 362                            (void *)&enabled, sizeof(enabled), 1);
 363     apic_enable_vapic(env->apic_state, vapic_paddr);
 364
 365     s->state = VAPIC_ACTIVE;
 366
 367     return 0;
 368 }
 369
 370 static void patch_byte(CPUX86State *env, target_ulong addr, uint8_t byte)
 371 {
 372     cpu_memory_rw_debug(env, addr, &byte, 1, 1);
 373 }
 374
 375 static void patch_call(VAPICROMState *s, CPUX86State *env, target_ulong ip,
 376                        uint32_t target)
 377 {
 378     uint32_t offset;
 379
 380     offset = cpu_to_le32(target - ip - 5);
 381     patch_byte(env, ip, 0xe8); /* call near */
 382     cpu_memory_rw_debug(env, ip + 1, (void *)&offset, sizeof(offset), 1);
 383 }
 384
 385 static void patch_instruction(VAPICROMState *s, X86CPU *cpu, target_ulong ip)
 386 {
 387     CPUState *cs = CPU(cpu);
 388     CPUX86State *env = &cpu->env;
 389     VAPICHandlers *handlers;
 390     uint8_t opcode[2];
 391     uint32_t imm32;
 392     target_ulong current_pc = 0;
 393     target_ulong current_cs_base = 0;
 394     int current_flags = 0;
 395
 396     if (smp_cpus == 1) {
 397         handlers = &s->rom_state.up;
 398     } else {
 399         handlers = &s->rom_state.mp;
 400     }
 401
 402     if (!kvm_enabled()) {
 403         cpu_restore_state(env, env->mem_io_pc);
 404         cpu_get_tb_cpu_state(env, &current_pc, &current_cs_base,
 405                              &current_flags);
 406     }
 407
 408     pause_all_vcpus();
 409
 410     cpu_memory_rw_debug(env, ip, opcode, sizeof(opcode), 0);
 411
 412     switch (opcode[0]) {
 413     case 0x89: /* mov r32 to r/m32 */
 414         patch_byte(env, ip, 0x50 + modrm_reg(opcode[1]));  /* push reg */
 415         patch_call(s, env, ip + 1, handlers->set_tpr);
 416         break;
 417     case 0x8b: /* mov r/m32 to r32 */
 418         patch_byte(env, ip, 0x90);
 419         patch_call(s, env, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]);
 420         break;
 421     case 0xa1: /* mov abs to eax */
 422         patch_call(s, env, ip, handlers->get_tpr[0]);
 423         break;
 424     case 0xa3: /* mov eax to abs */
 425         patch_call(s, env, ip, handlers->set_tpr_eax);
 426         break;
 427     case 0xc7: /* mov imm32, r/m32 (c7/0) */
 428         patch_byte(env, ip, 0x68);  /* push imm32 */
 429         cpu_memory_rw_debug(env, ip + 6, (void *)&imm32, sizeof(imm32), 0);
 430         cpu_memory_rw_debug(env, ip + 1, (void *)&imm32, sizeof(imm32), 1);
 431         patch_call(s, env, ip + 5, handlers->set_tpr);
 432         break;
 433     case 0xff: /* push r/m32 */
 434         patch_byte(env, ip, 0x50); /* push eax */
 435         patch_call(s, env, ip + 1, handlers->get_tpr_stack);
 436         break;
 437     default:
 438         abort();
 439     }
 440
 441     resume_all_vcpus();
 442
 443     if (!kvm_enabled()) {
 444         cs->current_tb = NULL;
 445         tb_gen_code(env, current_pc, current_cs_base, current_flags, 1);
 446         cpu_resume_from_signal(env, NULL);
 447     }
 448 }
 449
 450 void vapic_report_tpr_access(DeviceState *dev, CPUState *cs, target_ulong ip,
 451                              TPRAccess access)
 452 {
 453     VAPICROMState *s = DO_UPCAST(VAPICROMState, busdev.qdev, dev);
 454     X86CPU *cpu = X86_CPU(cs);
 455     CPUX86State *env = &cpu->env;
 456
 457     cpu_synchronize_state(env);
 458
 459     if (evaluate_tpr_instruction(s, env, &ip, access) < 0) {
 460         if (s->state == VAPIC_ACTIVE) {
 461             vapic_enable(s, env);
 462         }
 463         return;
 464     }
 465     if (update_rom_mapping(s, env, ip) < 0) {
 466         return;
 467     }
 468     if (vapic_enable(s, env) < 0) {
 469         return;
 470     }
 471     patch_instruction(s, cpu, ip);
 472 }
 473
 474 typedef struct VAPICEnableTPRReporting {
 475     DeviceState *apic;
 476     bool enable;
 477 } VAPICEnableTPRReporting;
 478
 479 static void vapic_do_enable_tpr_reporting(void *data)
 480 {
 481     VAPICEnableTPRReporting *info = data;
 482
 483     apic_enable_tpr_access_reporting(info->apic, info->enable);
 484 }
 485
 486 static void vapic_enable_tpr_reporting(bool enable)
 487 {
 488     VAPICEnableTPRReporting info = {
 489         .enable = enable,
 490     };
 491     X86CPU *cpu;
 492     CPUX86State *env;
 493
 494     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 495         cpu = x86_env_get_cpu(env);
 496         info.apic = env->apic_state;
 497         run_on_cpu(CPU(cpu), vapic_do_enable_tpr_reporting, &info);
 498     }
 499 }
 500
 501 static void vapic_reset(DeviceState *dev)
 502 {
 503     VAPICROMState *s = DO_UPCAST(VAPICROMState, busdev.qdev, dev);
 504
 505     if (s->state == VAPIC_ACTIVE) {
 506         s->state = VAPIC_STANDBY;
 507     }
 508     vapic_enable_tpr_reporting(false);
 509 }
 510
 511 /*
 512  * Set the IRQ polling hypercalls to the supported variant:
 513  *  - vmcall if using KVM in-kernel irqchip
 514  *  - 32-bit VAPIC port write otherwise
 515  */
 516 static int patch_hypercalls(VAPICROMState *s)
 517 {
 518     hwaddr rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
 519     static const uint8_t vmcall_pattern[] = { /* vmcall */
 520         0xb8, 0x1, 0, 0, 0, 0xf, 0x1, 0xc1
 521     };
 522     static const uint8_t outl_pattern[] = { /* nop; outl %eax,0x7e */
 523         0xb8, 0x1, 0, 0, 0, 0x90, 0xe7, 0x7e
 524     };
 525     uint8_t alternates[2];
 526     const uint8_t *pattern;
 527     const uint8_t *patch;
 528     int patches = 0;
 529     off_t pos;
 530     uint8_t *rom;
 531
 532     rom = g_malloc(s->rom_size);
 533     cpu_physical_memory_rw(rom_paddr, rom, s->rom_size, 0);
 534
 535     for (pos = 0; pos < s->rom_size - sizeof(vmcall_pattern); pos++) {
 536         if (kvm_irqchip_in_kernel()) {
 537             pattern = outl_pattern;
 538             alternates[0] = outl_pattern[7];
 539             alternates[1] = outl_pattern[7];
 540             patch = &vmcall_pattern[5];
 541         } else {
 542             pattern = vmcall_pattern;
 543             alternates[0] = vmcall_pattern[7];
 544             alternates[1] = 0xd9; /* AMD's VMMCALL */
 545             patch = &outl_pattern[5];
 546         }
 547         if (memcmp(rom + pos, pattern, 7) == 0 &&
 548             (rom[pos + 7] == alternates[0] || rom[pos + 7] == alternates[1])) {
 549             cpu_physical_memory_rw(rom_paddr + pos + 5, (uint8_t *)patch,
 550                                    3, 1);
 551             /*
 552              * Don't flush the tb here. Under ordinary conditions, the patched
 553              * calls are miles away from the current IP. Under malicious
 554              * conditions, the guest could trick us to crash.
 555              */
 556         }
 557     }
 558
 559     g_free(rom);
 560
 561     if (patches != 0 && patches != 2) {
 562         return -1;
 563     }
 564
 565     return 0;
 566 }
 567
 568 /*
 569  * For TCG mode or the time KVM honors read-only memory regions, we need to
 570  * enable write access to the option ROM so that variables can be updated by
 571  * the guest.
 572  */
 573 static void vapic_map_rom_writable(VAPICROMState *s)
 574 {
 575     hwaddr rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
 576     MemoryRegionSection section;
 577     MemoryRegion *as;
 578     size_t rom_size;
 579     uint8_t *ram;
 580
 581     as = sysbus_address_space(&s->busdev);
 582
 583     if (s->rom_mapped_writable) {
 584         memory_region_del_subregion(as, &s->rom);
 585         memory_region_destroy(&s->rom);
 586     }
 587
 588     /* grab RAM memory region (region @rom_paddr may still be pc.rom) */
 589     section = memory_region_find(as, 0, 1);
 590
 591     /* read ROM size from RAM region */
 592     ram = memory_region_get_ram_ptr(section.mr);
 593     rom_size = ram[rom_paddr + 2] * ROM_BLOCK_SIZE;
 594     s->rom_size = rom_size;
 595
 596     /* We need to round to avoid creating subpages
 597      * from which we cannot run code. */
 598     rom_size += rom_paddr & ~TARGET_PAGE_MASK;
 599     rom_paddr &= TARGET_PAGE_MASK;
 600     rom_size = TARGET_PAGE_ALIGN(rom_size);
 601
 602     memory_region_init_alias(&s->rom, "kvmvapic-rom", section.mr, rom_paddr,
 603                              rom_size);
 604     memory_region_add_subregion_overlap(as, rom_paddr, &s->rom, 1000);
 605     s->rom_mapped_writable = true;
 606 }
 607
 608 static int vapic_prepare(VAPICROMState *s)
 609 {
 610     vapic_map_rom_writable(s);
 611
 612     if (patch_hypercalls(s) < 0) {
 613         return -1;
 614     }
 615
 616     vapic_enable_tpr_reporting(true);
 617
 618     return 0;
 619 }
 620
 621 static void vapic_write(void *opaque, hwaddr addr, uint64_t data,
 622                         unsigned int size)
 623 {
 624     CPUX86State *env = cpu_single_env;
 625     hwaddr rom_paddr;
 626     VAPICROMState *s = opaque;
 627
 628     cpu_synchronize_state(env);
 629
 630     /*
 631      * The VAPIC supports two PIO-based hypercalls, both via port 0x7E.
 632      *  o 16-bit write access:
 633      *    Reports the option ROM initialization to the hypervisor. Written
 634      *    value is the offset of the state structure in the ROM.
 635      *  o 8-bit write access:
 636      *    Reactivates the VAPIC after a guest hibernation, i.e. after the
 637      *    option ROM content has been re-initialized by a guest power cycle.
 638      *  o 32-bit write access:
 639      *    Poll for pending IRQs, considering the current VAPIC state.
 640      */
 641     switch (size) {
 642     case 2:
 643         if (s->state == VAPIC_INACTIVE) {
 644             rom_paddr = (env->segs[R_CS].base + env->eip) & ROM_BLOCK_MASK;
 645             s->rom_state_paddr = rom_paddr + data;
 646
 647             s->state = VAPIC_STANDBY;
 648         }
 649         if (vapic_prepare(s) < 0) {
 650             s->state = VAPIC_INACTIVE;
 651             break;
 652         }
 653         break;
 654     case 1:
 655         if (kvm_enabled()) {
 656             /*
 657              * Disable triggering instruction in ROM by writing a NOP.
 658              *
 659              * We cannot do this in TCG mode as the reported IP is not
 660              * accurate.
 661              */
 662             pause_all_vcpus();
 663             patch_byte(env, env->eip - 2, 0x66);
 664             patch_byte(env, env->eip - 1, 0x90);
 665             resume_all_vcpus();
 666         }
 667
 668         if (s->state == VAPIC_ACTIVE) {
 669             break;
 670         }
 671         if (update_rom_mapping(s, env, env->eip) < 0) {
 672             break;
 673         }
 674         if (find_real_tpr_addr(s, env) < 0) {
 675             break;
 676         }
 677         vapic_enable(s, env);
 678         break;
 679     default:
 680     case 4:
 681         if (!kvm_irqchip_in_kernel()) {
 682             apic_poll_irq(env->apic_state);
 683         }
 684         break;
 685     }
 686 }
 687
 688 static const MemoryRegionOps vapic_ops = {
 689     .write = vapic_write,
 690     .endianness = DEVICE_NATIVE_ENDIAN,
 691 };
 692
 693 static int vapic_init(SysBusDevice *dev)
 694 {
 695     VAPICROMState *s = FROM_SYSBUS(VAPICROMState, dev);
 696
 697     memory_region_init_io(&s->io, &vapic_ops, s, "kvmvapic", 2);
 698     sysbus_add_io(dev, VAPIC_IO_PORT, &s->io);
 699     sysbus_init_ioports(dev, VAPIC_IO_PORT, 2);
 700
 701     option_rom[nb_option_roms].name = "kvmvapic.bin";
 702     option_rom[nb_option_roms].bootindex = -1;
 703     nb_option_roms++;
 704
 705     return 0;
 706 }
 707
 708 static void do_vapic_enable(void *data)
 709 {
 710     VAPICROMState *s = data;
 711
 712     vapic_enable(s, first_cpu);
 713 }
 714
 715 static int vapic_post_load(void *opaque, int version_id)
 716 {
 717     VAPICROMState *s = opaque;
 718     uint8_t *zero;
 719
 720     /*
 721      * The old implementation of qemu-kvm did not provide the state
 722      * VAPIC_STANDBY. Reconstruct it.
 723      */
 724     if (s->state == VAPIC_INACTIVE && s->rom_state_paddr != 0) {
 725         s->state = VAPIC_STANDBY;
 726     }
 727
 728     if (s->state != VAPIC_INACTIVE) {
 729         if (vapic_prepare(s) < 0) {
 730             return -1;
 731         }
 732     }
 733     if (s->state == VAPIC_ACTIVE) {
 734         if (smp_cpus == 1) {
 735             run_on_cpu(ENV_GET_CPU(first_cpu), do_vapic_enable, s);
 736         } else {
 737             zero = g_malloc0(s->rom_state.vapic_size);
 738             cpu_physical_memory_rw(s->vapic_paddr, zero,
 739                                    s->rom_state.vapic_size, 1);
 740             g_free(zero);
 741         }
 742     }
 743
 744     return 0;
 745 }
 746
 747 static const VMStateDescription vmstate_handlers = {
 748     .name = "kvmvapic-handlers",
 749     .version_id = 1,
 750     .minimum_version_id = 1,
 751     .minimum_version_id_old = 1,
 752     .fields = (VMStateField[]) {
 753         VMSTATE_UINT32(set_tpr, VAPICHandlers),
 754         VMSTATE_UINT32(set_tpr_eax, VAPICHandlers),
 755         VMSTATE_UINT32_ARRAY(get_tpr, VAPICHandlers, 8),
 756         VMSTATE_UINT32(get_tpr_stack, VAPICHandlers),
 757         VMSTATE_END_OF_LIST()
 758     }
 759 };
 760
 761 static const VMStateDescription vmstate_guest_rom = {
 762     .name = "kvmvapic-guest-rom",
 763     .version_id = 1,
 764     .minimum_version_id = 1,
 765     .minimum_version_id_old = 1,
 766     .fields = (VMStateField[]) {
 767         VMSTATE_UNUSED(8),     /* signature */
 768         VMSTATE_UINT32(vaddr, GuestROMState),
 769         VMSTATE_UINT32(fixup_start, GuestROMState),
 770         VMSTATE_UINT32(fixup_end, GuestROMState),
 771         VMSTATE_UINT32(vapic_vaddr, GuestROMState),
 772         VMSTATE_UINT32(vapic_size, GuestROMState),
 773         VMSTATE_UINT32(vcpu_shift, GuestROMState),
 774         VMSTATE_UINT32(real_tpr_addr, GuestROMState),
 775         VMSTATE_STRUCT(up, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
 776         VMSTATE_STRUCT(mp, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
 777         VMSTATE_END_OF_LIST()
 778     }
 779 };
 780
 781 static const VMStateDescription vmstate_vapic = {
 782     .name = "kvm-tpr-opt",      /* compatible with qemu-kvm VAPIC */
 783     .version_id = 1,
 784     .minimum_version_id = 1,
 785     .minimum_version_id_old = 1,
 786     .post_load = vapic_post_load,
 787     .fields = (VMStateField[]) {
 788         VMSTATE_STRUCT(rom_state, VAPICROMState, 0, vmstate_guest_rom,
 789                        GuestROMState),
 790         VMSTATE_UINT32(state, VAPICROMState),
 791         VMSTATE_UINT32(real_tpr_addr, VAPICROMState),
 792         VMSTATE_UINT32(rom_state_vaddr, VAPICROMState),
 793         VMSTATE_UINT32(vapic_paddr, VAPICROMState),
 794         VMSTATE_UINT32(rom_state_paddr, VAPICROMState),
 795         VMSTATE_END_OF_LIST()
 796     }
 797 };
 798
 799 static void vapic_class_init(ObjectClass *klass, void *data)
 800 {
 801     SysBusDeviceClass *sc = SYS_BUS_DEVICE_CLASS(klass);
 802     DeviceClass *dc = DEVICE_CLASS(klass);
 803
 804     dc->no_user = 1;
 805     dc->reset   = vapic_reset;
 806     dc->vmsd    = &vmstate_vapic;
 807     sc->init    = vapic_init;
 808 }
 809
 810 static const TypeInfo vapic_type = {
 811     .name          = "kvmvapic",
 812     .parent        = TYPE_SYS_BUS_DEVICE,
 813     .instance_size = sizeof(VAPICROMState),
 814     .class_init    = vapic_class_init,
 815 };
 816
 817 static void vapic_register(void)
 818 {
 819     type_register_static(&vapic_type);
 820 }
 821
 822 type_init(vapic_register);