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.h"
  12 #include "cpus.h"
  13 #include "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     target_phys_addr_t 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     target_phys_addr_t 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     target_phys_addr_t 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         (((target_phys_addr_t)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, CPUX86State *env, target_ulong ip)
 386 {
 387     target_phys_addr_t paddr;
 388     VAPICHandlers *handlers;
 389     uint8_t opcode[2];
 390     uint32_t imm32;
 391
 392     if (smp_cpus == 1) {
 393         handlers = &s->rom_state.up;
 394     } else {
 395         handlers = &s->rom_state.mp;
 396     }
 397
 398     pause_all_vcpus();
 399
 400     cpu_memory_rw_debug(env, ip, opcode, sizeof(opcode), 0);
 401
 402     switch (opcode[0]) {
 403     case 0x89: /* mov r32 to r/m32 */
 404         patch_byte(env, ip, 0x50 + modrm_reg(opcode[1]));  /* push reg */
 405         patch_call(s, env, ip + 1, handlers->set_tpr);
 406         break;
 407     case 0x8b: /* mov r/m32 to r32 */
 408         patch_byte(env, ip, 0x90);
 409         patch_call(s, env, ip + 1, handlers->get_tpr[modrm_reg(opcode[1])]);
 410         break;
 411     case 0xa1: /* mov abs to eax */
 412         patch_call(s, env, ip, handlers->get_tpr[0]);
 413         break;
 414     case 0xa3: /* mov eax to abs */
 415         patch_call(s, env, ip, handlers->set_tpr_eax);
 416         break;
 417     case 0xc7: /* mov imm32, r/m32 (c7/0) */
 418         patch_byte(env, ip, 0x68);  /* push imm32 */
 419         cpu_memory_rw_debug(env, ip + 6, (void *)&imm32, sizeof(imm32), 0);
 420         cpu_memory_rw_debug(env, ip + 1, (void *)&imm32, sizeof(imm32), 1);
 421         patch_call(s, env, ip + 5, handlers->set_tpr);
 422         break;
 423     case 0xff: /* push r/m32 */
 424         patch_byte(env, ip, 0x50); /* push eax */
 425         patch_call(s, env, ip + 1, handlers->get_tpr_stack);
 426         break;
 427     default:
 428         abort();
 429     }
 430
 431     resume_all_vcpus();
 432
 433     paddr = cpu_get_phys_page_debug(env, ip);
 434     paddr += ip & ~TARGET_PAGE_MASK;
 435     tb_invalidate_phys_page_range(paddr, paddr + 1, 1);
 436 }
 437
 438 void vapic_report_tpr_access(DeviceState *dev, void *cpu, target_ulong ip,
 439                              TPRAccess access)
 440 {
 441     VAPICROMState *s = DO_UPCAST(VAPICROMState, busdev.qdev, dev);
 442     CPUX86State *env = cpu;
 443
 444     cpu_synchronize_state(env);
 445
 446     if (evaluate_tpr_instruction(s, env, &ip, access) < 0) {
 447         if (s->state == VAPIC_ACTIVE) {
 448             vapic_enable(s, env);
 449         }
 450         return;
 451     }
 452     if (update_rom_mapping(s, env, ip) < 0) {
 453         return;
 454     }
 455     if (vapic_enable(s, env) < 0) {
 456         return;
 457     }
 458     patch_instruction(s, env, ip);
 459 }
 460
 461 typedef struct VAPICEnableTPRReporting {
 462     DeviceState *apic;
 463     bool enable;
 464 } VAPICEnableTPRReporting;
 465
 466 static void vapic_do_enable_tpr_reporting(void *data)
 467 {
 468     VAPICEnableTPRReporting *info = data;
 469
 470     apic_enable_tpr_access_reporting(info->apic, info->enable);
 471 }
 472
 473 static void vapic_enable_tpr_reporting(bool enable)
 474 {
 475     VAPICEnableTPRReporting info = {
 476         .enable = enable,
 477     };
 478     CPUX86State *env;
 479
 480     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 481         info.apic = env->apic_state;
 482         run_on_cpu(env, vapic_do_enable_tpr_reporting, &info);
 483     }
 484 }
 485
 486 static void vapic_reset(DeviceState *dev)
 487 {
 488     VAPICROMState *s = DO_UPCAST(VAPICROMState, busdev.qdev, dev);
 489
 490     if (s->state == VAPIC_ACTIVE) {
 491         s->state = VAPIC_STANDBY;
 492     }
 493     vapic_enable_tpr_reporting(false);
 494 }
 495
 496 /*
 497  * Set the IRQ polling hypercalls to the supported variant:
 498  *  - vmcall if using KVM in-kernel irqchip
 499  *  - 32-bit VAPIC port write otherwise
 500  */
 501 static int patch_hypercalls(VAPICROMState *s)
 502 {
 503     target_phys_addr_t rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
 504     static const uint8_t vmcall_pattern[] = { /* vmcall */
 505         0xb8, 0x1, 0, 0, 0, 0xf, 0x1, 0xc1
 506     };
 507     static const uint8_t outl_pattern[] = { /* nop; outl %eax,0x7e */
 508         0xb8, 0x1, 0, 0, 0, 0x90, 0xe7, 0x7e
 509     };
 510     uint8_t alternates[2];
 511     const uint8_t *pattern;
 512     const uint8_t *patch;
 513     int patches = 0;
 514     off_t pos;
 515     uint8_t *rom;
 516
 517     rom = g_malloc(s->rom_size);
 518     cpu_physical_memory_rw(rom_paddr, rom, s->rom_size, 0);
 519
 520     for (pos = 0; pos < s->rom_size - sizeof(vmcall_pattern); pos++) {
 521         if (kvm_irqchip_in_kernel()) {
 522             pattern = outl_pattern;
 523             alternates[0] = outl_pattern[7];
 524             alternates[1] = outl_pattern[7];
 525             patch = &vmcall_pattern[5];
 526         } else {
 527             pattern = vmcall_pattern;
 528             alternates[0] = vmcall_pattern[7];
 529             alternates[1] = 0xd9; /* AMD's VMMCALL */
 530             patch = &outl_pattern[5];
 531         }
 532         if (memcmp(rom + pos, pattern, 7) == 0 &&
 533             (rom[pos + 7] == alternates[0] || rom[pos + 7] == alternates[1])) {
 534             cpu_physical_memory_rw(rom_paddr + pos + 5, (uint8_t *)patch,
 535                                    3, 1);
 536             /*
 537              * Don't flush the tb here. Under ordinary conditions, the patched
 538              * calls are miles away from the current IP. Under malicious
 539              * conditions, the guest could trick us to crash.
 540              */
 541         }
 542     }
 543
 544     g_free(rom);
 545
 546     if (patches != 0 && patches != 2) {
 547         return -1;
 548     }
 549
 550     return 0;
 551 }
 552
 553 /*
 554  * For TCG mode or the time KVM honors read-only memory regions, we need to
 555  * enable write access to the option ROM so that variables can be updated by
 556  * the guest.
 557  */
 558 static void vapic_map_rom_writable(VAPICROMState *s)
 559 {
 560     target_phys_addr_t rom_paddr = s->rom_state_paddr & ROM_BLOCK_MASK;
 561     MemoryRegionSection section;
 562     MemoryRegion *as;
 563     size_t rom_size;
 564     uint8_t *ram;
 565
 566     as = sysbus_address_space(&s->busdev);
 567
 568     if (s->rom_mapped_writable) {
 569         memory_region_del_subregion(as, &s->rom);
 570         memory_region_destroy(&s->rom);
 571     }
 572
 573     /* grab RAM memory region (region @rom_paddr may still be pc.rom) */
 574     section = memory_region_find(as, 0, 1);
 575
 576     /* read ROM size from RAM region */
 577     ram = memory_region_get_ram_ptr(section.mr);
 578     rom_size = ram[rom_paddr + 2] * ROM_BLOCK_SIZE;
 579     s->rom_size = rom_size;
 580
 581     /* We need to round to avoid creating subpages
 582      * from which we cannot run code. */
 583     rom_size += rom_paddr & ~TARGET_PAGE_MASK;
 584     rom_paddr &= TARGET_PAGE_MASK;
 585     rom_size = TARGET_PAGE_ALIGN(rom_size);
 586
 587     memory_region_init_alias(&s->rom, "kvmvapic-rom", section.mr, rom_paddr,
 588                              rom_size);
 589     memory_region_add_subregion_overlap(as, rom_paddr, &s->rom, 1000);
 590     s->rom_mapped_writable = true;
 591 }
 592
 593 static int vapic_prepare(VAPICROMState *s)
 594 {
 595     vapic_map_rom_writable(s);
 596
 597     if (patch_hypercalls(s) < 0) {
 598         return -1;
 599     }
 600
 601     vapic_enable_tpr_reporting(true);
 602
 603     return 0;
 604 }
 605
 606 static void vapic_write(void *opaque, target_phys_addr_t addr, uint64_t data,
 607                         unsigned int size)
 608 {
 609     CPUX86State *env = cpu_single_env;
 610     target_phys_addr_t rom_paddr;
 611     VAPICROMState *s = opaque;
 612
 613     cpu_synchronize_state(env);
 614
 615     /*
 616      * The VAPIC supports two PIO-based hypercalls, both via port 0x7E.
 617      *  o 16-bit write access:
 618      *    Reports the option ROM initialization to the hypervisor. Written
 619      *    value is the offset of the state structure in the ROM.
 620      *  o 8-bit write access:
 621      *    Reactivates the VAPIC after a guest hibernation, i.e. after the
 622      *    option ROM content has been re-initialized by a guest power cycle.
 623      *  o 32-bit write access:
 624      *    Poll for pending IRQs, considering the current VAPIC state.
 625      */
 626     switch (size) {
 627     case 2:
 628         if (s->state == VAPIC_INACTIVE) {
 629             rom_paddr = (env->segs[R_CS].base + env->eip) & ROM_BLOCK_MASK;
 630             s->rom_state_paddr = rom_paddr + data;
 631
 632             s->state = VAPIC_STANDBY;
 633         }
 634         if (vapic_prepare(s) < 0) {
 635             s->state = VAPIC_INACTIVE;
 636             break;
 637         }
 638         break;
 639     case 1:
 640         if (kvm_enabled()) {
 641             /*
 642              * Disable triggering instruction in ROM by writing a NOP.
 643              *
 644              * We cannot do this in TCG mode as the reported IP is not
 645              * accurate.
 646              */
 647             pause_all_vcpus();
 648             patch_byte(env, env->eip - 2, 0x66);
 649             patch_byte(env, env->eip - 1, 0x90);
 650             resume_all_vcpus();
 651         }
 652
 653         if (s->state == VAPIC_ACTIVE) {
 654             break;
 655         }
 656         if (update_rom_mapping(s, env, env->eip) < 0) {
 657             break;
 658         }
 659         if (find_real_tpr_addr(s, env) < 0) {
 660             break;
 661         }
 662         vapic_enable(s, env);
 663         break;
 664     default:
 665     case 4:
 666         if (!kvm_irqchip_in_kernel()) {
 667             apic_poll_irq(env->apic_state);
 668         }
 669         break;
 670     }
 671 }
 672
 673 static const MemoryRegionOps vapic_ops = {
 674     .write = vapic_write,
 675     .endianness = DEVICE_NATIVE_ENDIAN,
 676 };
 677
 678 static int vapic_init(SysBusDevice *dev)
 679 {
 680     VAPICROMState *s = FROM_SYSBUS(VAPICROMState, dev);
 681
 682     memory_region_init_io(&s->io, &vapic_ops, s, "kvmvapic", 2);
 683     sysbus_add_io(dev, VAPIC_IO_PORT, &s->io);
 684     sysbus_init_ioports(dev, VAPIC_IO_PORT, 2);
 685
 686     option_rom[nb_option_roms].name = "kvmvapic.bin";
 687     option_rom[nb_option_roms].bootindex = -1;
 688     nb_option_roms++;
 689
 690     return 0;
 691 }
 692
 693 static void do_vapic_enable(void *data)
 694 {
 695     VAPICROMState *s = data;
 696
 697     vapic_enable(s, first_cpu);
 698 }
 699
 700 static int vapic_post_load(void *opaque, int version_id)
 701 {
 702     VAPICROMState *s = opaque;
 703     uint8_t *zero;
 704
 705     /*
 706      * The old implementation of qemu-kvm did not provide the state
 707      * VAPIC_STANDBY. Reconstruct it.
 708      */
 709     if (s->state == VAPIC_INACTIVE && s->rom_state_paddr != 0) {
 710         s->state = VAPIC_STANDBY;
 711     }
 712
 713     if (s->state != VAPIC_INACTIVE) {
 714         if (vapic_prepare(s) < 0) {
 715             return -1;
 716         }
 717     }
 718     if (s->state == VAPIC_ACTIVE) {
 719         if (smp_cpus == 1) {
 720             run_on_cpu(first_cpu, do_vapic_enable, s);
 721         } else {
 722             zero = g_malloc0(s->rom_state.vapic_size);
 723             cpu_physical_memory_rw(s->vapic_paddr, zero,
 724                                    s->rom_state.vapic_size, 1);
 725             g_free(zero);
 726         }
 727     }
 728
 729     return 0;
 730 }
 731
 732 static const VMStateDescription vmstate_handlers = {
 733     .name = "kvmvapic-handlers",
 734     .version_id = 1,
 735     .minimum_version_id = 1,
 736     .minimum_version_id_old = 1,
 737     .fields = (VMStateField[]) {
 738         VMSTATE_UINT32(set_tpr, VAPICHandlers),
 739         VMSTATE_UINT32(set_tpr_eax, VAPICHandlers),
 740         VMSTATE_UINT32_ARRAY(get_tpr, VAPICHandlers, 8),
 741         VMSTATE_UINT32(get_tpr_stack, VAPICHandlers),
 742         VMSTATE_END_OF_LIST()
 743     }
 744 };
 745
 746 static const VMStateDescription vmstate_guest_rom = {
 747     .name = "kvmvapic-guest-rom",
 748     .version_id = 1,
 749     .minimum_version_id = 1,
 750     .minimum_version_id_old = 1,
 751     .fields = (VMStateField[]) {
 752         VMSTATE_UNUSED(8),     /* signature */
 753         VMSTATE_UINT32(vaddr, GuestROMState),
 754         VMSTATE_UINT32(fixup_start, GuestROMState),
 755         VMSTATE_UINT32(fixup_end, GuestROMState),
 756         VMSTATE_UINT32(vapic_vaddr, GuestROMState),
 757         VMSTATE_UINT32(vapic_size, GuestROMState),
 758         VMSTATE_UINT32(vcpu_shift, GuestROMState),
 759         VMSTATE_UINT32(real_tpr_addr, GuestROMState),
 760         VMSTATE_STRUCT(up, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
 761         VMSTATE_STRUCT(mp, GuestROMState, 0, vmstate_handlers, VAPICHandlers),
 762         VMSTATE_END_OF_LIST()
 763     }
 764 };
 765
 766 static const VMStateDescription vmstate_vapic = {
 767     .name = "kvm-tpr-opt",      /* compatible with qemu-kvm VAPIC */
 768     .version_id = 1,
 769     .minimum_version_id = 1,
 770     .minimum_version_id_old = 1,
 771     .post_load = vapic_post_load,
 772     .fields = (VMStateField[]) {
 773         VMSTATE_STRUCT(rom_state, VAPICROMState, 0, vmstate_guest_rom,
 774                        GuestROMState),
 775         VMSTATE_UINT32(state, VAPICROMState),
 776         VMSTATE_UINT32(real_tpr_addr, VAPICROMState),
 777         VMSTATE_UINT32(rom_state_vaddr, VAPICROMState),
 778         VMSTATE_UINT32(vapic_paddr, VAPICROMState),
 779         VMSTATE_UINT32(rom_state_paddr, VAPICROMState),
 780         VMSTATE_END_OF_LIST()
 781     }
 782 };
 783
 784 static void vapic_class_init(ObjectClass *klass, void *data)
 785 {
 786     SysBusDeviceClass *sc = SYS_BUS_DEVICE_CLASS(klass);
 787     DeviceClass *dc = DEVICE_CLASS(klass);
 788
 789     dc->no_user = 1;
 790     dc->reset   = vapic_reset;
 791     dc->vmsd    = &vmstate_vapic;
 792     sc->init    = vapic_init;
 793 }
 794
 795 static TypeInfo vapic_type = {
 796     .name          = "kvmvapic",
 797     .parent        = TYPE_SYS_BUS_DEVICE,
 798     .instance_size = sizeof(VAPICROMState),
 799     .class_init    = vapic_class_init,
 800 };
 801
 802 static void vapic_register(void)
 803 {
 804     type_register_static(&vapic_type);
 805 }
 806
 807 type_init(vapic_register);