qemu/dump/win_dump.c
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   1/*
   2 * Windows crashdump
   3 *
   4 * Copyright (c) 2018 Virtuozzo International GmbH
   5 *
   6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7 * See the COPYING file in the top-level directory.
   8 *
   9 */
  10
  11#include "qemu/osdep.h"
  12#include "qemu/cutils.h"
  13#include "elf.h"
  14#include "exec/hwaddr.h"
  15#include "monitor/monitor.h"
  16#include "sysemu/kvm.h"
  17#include "sysemu/dump.h"
  18#include "sysemu/memory_mapping.h"
  19#include "sysemu/cpus.h"
  20#include "qapi/error.h"
  21#include "qapi/qmp/qerror.h"
  22#include "qemu/error-report.h"
  23#include "hw/misc/vmcoreinfo.h"
  24#include "win_dump.h"
  25
  26static size_t win_dump_ptr_size(bool x64)
  27{
  28    return x64 ? sizeof(uint64_t) : sizeof(uint32_t);
  29}
  30
  31#define _WIN_DUMP_FIELD(f) (x64 ? h->x64.f : h->x32.f)
  32#define WIN_DUMP_FIELD(field) _WIN_DUMP_FIELD(field)
  33
  34#define _WIN_DUMP_FIELD_PTR(f) (x64 ? (void *)&h->x64.f : (void *)&h->x32.f)
  35#define WIN_DUMP_FIELD_PTR(field) _WIN_DUMP_FIELD_PTR(field)
  36
  37#define _WIN_DUMP_FIELD_SIZE(f) (x64 ? sizeof(h->x64.f) : sizeof(h->x32.f))
  38#define WIN_DUMP_FIELD_SIZE(field) _WIN_DUMP_FIELD_SIZE(field)
  39
  40static size_t win_dump_ctx_size(bool x64)
  41{
  42    return x64 ? sizeof(WinContext64) : sizeof(WinContext32);
  43}
  44
  45static size_t write_run(uint64_t base_page, uint64_t page_count,
  46        int fd, Error **errp)
  47{
  48    void *buf;
  49    uint64_t addr = base_page << TARGET_PAGE_BITS;
  50    uint64_t size = page_count << TARGET_PAGE_BITS;
  51    uint64_t len, l;
  52    size_t total = 0;
  53
  54    while (size) {
  55        len = size;
  56
  57        buf = cpu_physical_memory_map(addr, &len, false);
  58        if (!buf) {
  59            error_setg(errp, "win-dump: failed to map physical range"
  60                             " 0x%016" PRIx64 "-0x%016" PRIx64, addr, addr + size - 1);
  61            return 0;
  62        }
  63
  64        l = qemu_write_full(fd, buf, len);
  65        cpu_physical_memory_unmap(buf, addr, false, len);
  66        if (l != len) {
  67            error_setg(errp, QERR_IO_ERROR);
  68            return 0;
  69        }
  70
  71        addr += l;
  72        size -= l;
  73        total += l;
  74    }
  75
  76    return total;
  77}
  78
  79static void write_runs(DumpState *s, WinDumpHeader *h, bool x64, Error **errp)
  80{
  81    uint64_t BasePage, PageCount;
  82    Error *local_err = NULL;
  83    int i;
  84
  85    for (i = 0; i < WIN_DUMP_FIELD(PhysicalMemoryBlock.NumberOfRuns); i++) {
  86        BasePage = WIN_DUMP_FIELD(PhysicalMemoryBlock.Run[i].BasePage);
  87        PageCount = WIN_DUMP_FIELD(PhysicalMemoryBlock.Run[i].PageCount);
  88        s->written_size += write_run(BasePage, PageCount, s->fd, &local_err);
  89        if (local_err) {
  90            error_propagate(errp, local_err);
  91            return;
  92        }
  93    }
  94}
  95
  96static int cpu_read_ptr(bool x64, CPUState *cpu, uint64_t addr, uint64_t *ptr)
  97{
  98    int ret;
  99    uint32_t ptr32;
 100    uint64_t ptr64;
 101
 102    ret = cpu_memory_rw_debug(cpu, addr, x64 ? (void *)&ptr64 : (void *)&ptr32,
 103            win_dump_ptr_size(x64), 0);
 104
 105    *ptr = x64 ? ptr64 : ptr32;
 106
 107    return ret;
 108}
 109
 110static void patch_mm_pfn_database(WinDumpHeader *h, bool x64, Error **errp)
 111{
 112    if (cpu_memory_rw_debug(first_cpu,
 113            WIN_DUMP_FIELD(KdDebuggerDataBlock) + KDBG_MM_PFN_DATABASE_OFFSET,
 114            WIN_DUMP_FIELD_PTR(PfnDatabase),
 115            WIN_DUMP_FIELD_SIZE(PfnDatabase), 0)) {
 116        error_setg(errp, "win-dump: failed to read MmPfnDatabase");
 117        return;
 118    }
 119}
 120
 121static void patch_bugcheck_data(WinDumpHeader *h, bool x64, Error **errp)
 122{
 123    uint64_t KiBugcheckData;
 124
 125    if (cpu_read_ptr(x64, first_cpu,
 126            WIN_DUMP_FIELD(KdDebuggerDataBlock) + KDBG_KI_BUGCHECK_DATA_OFFSET,
 127            &KiBugcheckData)) {
 128        error_setg(errp, "win-dump: failed to read KiBugcheckData");
 129        return;
 130    }
 131
 132    if (cpu_memory_rw_debug(first_cpu, KiBugcheckData,
 133            WIN_DUMP_FIELD(BugcheckData),
 134            WIN_DUMP_FIELD_SIZE(BugcheckData), 0)) {
 135        error_setg(errp, "win-dump: failed to read bugcheck data");
 136        return;
 137    }
 138
 139    /*
 140     * If BugcheckCode wasn't saved, we consider guest OS as alive.
 141     */
 142
 143    if (!WIN_DUMP_FIELD(BugcheckCode)) {
 144        *(uint32_t *)WIN_DUMP_FIELD_PTR(BugcheckCode) = LIVE_SYSTEM_DUMP;
 145    }
 146}
 147
 148/*
 149 * This routine tries to correct mistakes in crashdump header.
 150 */
 151static void patch_header(WinDumpHeader *h, bool x64)
 152{
 153    Error *local_err = NULL;
 154
 155    if (x64) {
 156        h->x64.RequiredDumpSpace = sizeof(WinDumpHeader64) +
 157            (h->x64.PhysicalMemoryBlock.NumberOfPages << TARGET_PAGE_BITS);
 158        h->x64.PhysicalMemoryBlock.unused = 0;
 159        h->x64.unused1 = 0;
 160    } else {
 161        h->x32.RequiredDumpSpace = sizeof(WinDumpHeader32) +
 162            (h->x32.PhysicalMemoryBlock.NumberOfPages << TARGET_PAGE_BITS);
 163    }
 164
 165    patch_mm_pfn_database(h, x64, &local_err);
 166    if (local_err) {
 167        warn_report_err(local_err);
 168        local_err = NULL;
 169    }
 170    patch_bugcheck_data(h, x64, &local_err);
 171    if (local_err) {
 172        warn_report_err(local_err);
 173    }
 174}
 175
 176static bool check_header(WinDumpHeader *h, bool *x64, Error **errp)
 177{
 178    const char Signature[] = "PAGE";
 179
 180    if (memcmp(h->Signature, Signature, sizeof(h->Signature))) {
 181        error_setg(errp, "win-dump: invalid header, expected '%.4s',"
 182                         " got '%.4s'", Signature, h->Signature);
 183        return false;
 184    }
 185
 186    if (!memcmp(h->ValidDump, "DUMP", sizeof(h->ValidDump))) {
 187        *x64 = false;
 188    } else if (!memcmp(h->ValidDump, "DU64", sizeof(h->ValidDump))) {
 189        *x64 = true;
 190    } else {
 191        error_setg(errp, "win-dump: invalid header, expected 'DUMP' or 'DU64',"
 192                   " got '%.4s'", h->ValidDump);
 193        return false;
 194    }
 195
 196    return true;
 197}
 198
 199static void check_kdbg(WinDumpHeader *h, bool x64, Error **errp)
 200{
 201    const char OwnerTag[] = "KDBG";
 202    char read_OwnerTag[4];
 203    uint64_t KdDebuggerDataBlock = WIN_DUMP_FIELD(KdDebuggerDataBlock);
 204    bool try_fallback = true;
 205
 206try_again:
 207    if (cpu_memory_rw_debug(first_cpu,
 208            KdDebuggerDataBlock + KDBG_OWNER_TAG_OFFSET,
 209            (uint8_t *)&read_OwnerTag, sizeof(read_OwnerTag), 0)) {
 210        error_setg(errp, "win-dump: failed to read OwnerTag");
 211        return;
 212    }
 213
 214    if (memcmp(read_OwnerTag, OwnerTag, sizeof(read_OwnerTag))) {
 215        if (try_fallback) {
 216            /*
 217             * If attempt to use original KDBG failed
 218             * (most likely because of its encryption),
 219             * we try to use KDBG obtained by guest driver.
 220             */
 221
 222            KdDebuggerDataBlock = WIN_DUMP_FIELD(BugcheckParameter1);
 223            try_fallback = false;
 224            goto try_again;
 225        } else {
 226            error_setg(errp, "win-dump: invalid KDBG OwnerTag,"
 227                             " expected '%.4s', got '%.4s'",
 228                             OwnerTag, read_OwnerTag);
 229            return;
 230        }
 231    }
 232
 233    if (x64) {
 234        h->x64.KdDebuggerDataBlock = KdDebuggerDataBlock;
 235    } else {
 236        h->x32.KdDebuggerDataBlock = KdDebuggerDataBlock;
 237    }
 238}
 239
 240struct saved_context {
 241    WinContext ctx;
 242    uint64_t addr;
 243};
 244
 245static void patch_and_save_context(WinDumpHeader *h, bool x64,
 246                                   struct saved_context *saved_ctx,
 247                                   Error **errp)
 248{
 249    uint64_t KdDebuggerDataBlock = WIN_DUMP_FIELD(KdDebuggerDataBlock);
 250    uint64_t KiProcessorBlock;
 251    uint16_t OffsetPrcbContext;
 252    CPUState *cpu;
 253    int i = 0;
 254
 255    if (cpu_read_ptr(x64, first_cpu,
 256            KdDebuggerDataBlock + KDBG_KI_PROCESSOR_BLOCK_OFFSET,
 257            &KiProcessorBlock)) {
 258        error_setg(errp, "win-dump: failed to read KiProcessorBlock");
 259        return;
 260    }
 261
 262    if (cpu_memory_rw_debug(first_cpu,
 263            KdDebuggerDataBlock + KDBG_OFFSET_PRCB_CONTEXT_OFFSET,
 264            (uint8_t *)&OffsetPrcbContext, sizeof(OffsetPrcbContext), 0)) {
 265        error_setg(errp, "win-dump: failed to read OffsetPrcbContext");
 266        return;
 267    }
 268
 269    CPU_FOREACH(cpu) {
 270        X86CPU *x86_cpu = X86_CPU(cpu);
 271        CPUX86State *env = &x86_cpu->env;
 272        uint64_t Prcb;
 273        uint64_t Context;
 274        WinContext ctx;
 275
 276        if (cpu_read_ptr(x64, first_cpu,
 277                KiProcessorBlock + i * win_dump_ptr_size(x64),
 278                &Prcb)) {
 279            error_setg(errp, "win-dump: failed to read"
 280                             " CPU #%d PRCB location", i);
 281            return;
 282        }
 283
 284        if (cpu_read_ptr(x64, first_cpu,
 285                Prcb + OffsetPrcbContext,
 286                &Context)) {
 287            error_setg(errp, "win-dump: failed to read"
 288                             " CPU #%d ContextFrame location", i);
 289            return;
 290        }
 291
 292        saved_ctx[i].addr = Context;
 293
 294        if (x64) {
 295            ctx.x64 = (WinContext64){
 296                .ContextFlags = WIN_CTX64_ALL,
 297                .MxCsr = env->mxcsr,
 298
 299                .SegEs = env->segs[0].selector,
 300                .SegCs = env->segs[1].selector,
 301                .SegSs = env->segs[2].selector,
 302                .SegDs = env->segs[3].selector,
 303                .SegFs = env->segs[4].selector,
 304                .SegGs = env->segs[5].selector,
 305                .EFlags = cpu_compute_eflags(env),
 306
 307                .Dr0 = env->dr[0],
 308                .Dr1 = env->dr[1],
 309                .Dr2 = env->dr[2],
 310                .Dr3 = env->dr[3],
 311                .Dr6 = env->dr[6],
 312                .Dr7 = env->dr[7],
 313
 314                .Rax = env->regs[R_EAX],
 315                .Rbx = env->regs[R_EBX],
 316                .Rcx = env->regs[R_ECX],
 317                .Rdx = env->regs[R_EDX],
 318                .Rsp = env->regs[R_ESP],
 319                .Rbp = env->regs[R_EBP],
 320                .Rsi = env->regs[R_ESI],
 321                .Rdi = env->regs[R_EDI],
 322                .R8  = env->regs[8],
 323                .R9  = env->regs[9],
 324                .R10 = env->regs[10],
 325                .R11 = env->regs[11],
 326                .R12 = env->regs[12],
 327                .R13 = env->regs[13],
 328                .R14 = env->regs[14],
 329                .R15 = env->regs[15],
 330
 331                .Rip = env->eip,
 332                .FltSave = {
 333                    .MxCsr = env->mxcsr,
 334                },
 335            };
 336        } else {
 337            ctx.x32 = (WinContext32){
 338                .ContextFlags = WIN_CTX32_FULL | WIN_CTX_DBG,
 339
 340                .SegEs = env->segs[0].selector,
 341                .SegCs = env->segs[1].selector,
 342                .SegSs = env->segs[2].selector,
 343                .SegDs = env->segs[3].selector,
 344                .SegFs = env->segs[4].selector,
 345                .SegGs = env->segs[5].selector,
 346                .EFlags = cpu_compute_eflags(env),
 347
 348                .Dr0 = env->dr[0],
 349                .Dr1 = env->dr[1],
 350                .Dr2 = env->dr[2],
 351                .Dr3 = env->dr[3],
 352                .Dr6 = env->dr[6],
 353                .Dr7 = env->dr[7],
 354
 355                .Eax = env->regs[R_EAX],
 356                .Ebx = env->regs[R_EBX],
 357                .Ecx = env->regs[R_ECX],
 358                .Edx = env->regs[R_EDX],
 359                .Esp = env->regs[R_ESP],
 360                .Ebp = env->regs[R_EBP],
 361                .Esi = env->regs[R_ESI],
 362                .Edi = env->regs[R_EDI],
 363
 364                .Eip = env->eip,
 365            };
 366        }
 367
 368        if (cpu_memory_rw_debug(first_cpu, Context,
 369                &saved_ctx[i].ctx, win_dump_ctx_size(x64), 0)) {
 370            error_setg(errp, "win-dump: failed to save CPU #%d context", i);
 371            return;
 372        }
 373
 374        if (cpu_memory_rw_debug(first_cpu, Context,
 375                &ctx, win_dump_ctx_size(x64), 1)) {
 376            error_setg(errp, "win-dump: failed to write CPU #%d context", i);
 377            return;
 378        }
 379
 380        i++;
 381    }
 382}
 383
 384static void restore_context(WinDumpHeader *h, bool x64,
 385                            struct saved_context *saved_ctx)
 386{
 387    int i;
 388
 389    for (i = 0; i < WIN_DUMP_FIELD(NumberProcessors); i++) {
 390        if (cpu_memory_rw_debug(first_cpu, saved_ctx[i].addr,
 391                &saved_ctx[i].ctx, win_dump_ctx_size(x64), 1)) {
 392            warn_report("win-dump: failed to restore CPU #%d context", i);
 393        }
 394    }
 395}
 396
 397void create_win_dump(DumpState *s, Error **errp)
 398{
 399    WinDumpHeader *h = (void *)(s->guest_note + VMCOREINFO_ELF_NOTE_HDR_SIZE);
 400    X86CPU *first_x86_cpu = X86_CPU(first_cpu);
 401    uint64_t saved_cr3 = first_x86_cpu->env.cr[3];
 402    struct saved_context *saved_ctx = NULL;
 403    Error *local_err = NULL;
 404    bool x64 = true;
 405    size_t hdr_size;
 406
 407    if (s->guest_note_size != VMCOREINFO_WIN_DUMP_NOTE_SIZE32 &&
 408            s->guest_note_size != VMCOREINFO_WIN_DUMP_NOTE_SIZE64) {
 409        error_setg(errp, "win-dump: invalid vmcoreinfo note size");
 410        return;
 411    }
 412
 413    if (!check_header(h, &x64, &local_err)) {
 414        error_propagate(errp, local_err);
 415        return;
 416    }
 417
 418    hdr_size = x64 ? sizeof(WinDumpHeader64) : sizeof(WinDumpHeader32);
 419
 420    /*
 421     * Further access to kernel structures by virtual addresses
 422     * should be made from system context.
 423     */
 424
 425    first_x86_cpu->env.cr[3] = WIN_DUMP_FIELD(DirectoryTableBase);
 426
 427    check_kdbg(h, x64, &local_err);
 428    if (local_err) {
 429        error_propagate(errp, local_err);
 430        goto out_cr3;
 431    }
 432
 433    patch_header(h, x64);
 434
 435    saved_ctx = g_new(struct saved_context, WIN_DUMP_FIELD(NumberProcessors));
 436
 437    /*
 438     * Always patch context because there is no way
 439     * to determine if the system-saved context is valid
 440     */
 441
 442    patch_and_save_context(h, x64, saved_ctx, &local_err);
 443    if (local_err) {
 444        error_propagate(errp, local_err);
 445        goto out_free;
 446    }
 447
 448    s->total_size = WIN_DUMP_FIELD(RequiredDumpSpace);
 449
 450    s->written_size = qemu_write_full(s->fd, h, hdr_size);
 451    if (s->written_size != hdr_size) {
 452        error_setg(errp, QERR_IO_ERROR);
 453        goto out_restore;
 454    }
 455
 456    write_runs(s, h, x64, &local_err);
 457    if (local_err) {
 458        error_propagate(errp, local_err);
 459        goto out_restore;
 460    }
 461
 462out_restore:
 463    restore_context(h, x64, saved_ctx);
 464out_free:
 465    g_free(saved_ctx);
 466out_cr3:
 467    first_x86_cpu->env.cr[3] = saved_cr3;
 468
 469    return;
 470}
 471