LXR qemu/include/qemu/osdep.h

   1/*
   2 * OS includes and handling of OS dependencies
   3 *
   4 * This header exists to pull in some common system headers that
   5 * most code in QEMU will want, and to fix up some possible issues with
   6 * it (missing defines, Windows weirdness, and so on).
   7 *
   8 * To avoid getting into possible circular include dependencies, this
   9 * file should not include any other QEMU headers, with the exceptions
  10 * of config-host.h, config-target.h, qemu/compiler.h,
  11 * sysemu/os-posix.h, sysemu/os-win32.h, glib-compat.h and
  12 * qemu/typedefs.h, all of which are doing a similar job to this file
  13 * and are under similar constraints.
  14 *
  15 * This header also contains prototypes for functions defined in
  16 * os-*.c and util/oslib-*.c; those would probably be better split
  17 * out into separate header files.
  18 *
  19 * In an ideal world this header would contain only:
  20 *  (1) things which everybody needs
  21 *  (2) things without which code would work on most platforms but
  22 *      fail to compile or misbehave on a minority of host OSes
  23 *
  24 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  25 * See the COPYING file in the top-level directory.
  26 */
  27#ifndef QEMU_OSDEP_H
  28#define QEMU_OSDEP_H
  29
  30#include "config-host.h"
  31#ifdef NEED_CPU_H
  32#include CONFIG_TARGET
  33#else
  34#include "exec/poison.h"
  35#endif
  36
  37#include "qemu/compiler.h"
  38
  39/* Older versions of C++ don't get definitions of various macros from
  40 * stdlib.h unless we define these macros before first inclusion of
  41 * that system header.
  42 */
  43#ifndef __STDC_CONSTANT_MACROS
  44#define __STDC_CONSTANT_MACROS
  45#endif
  46#ifndef __STDC_LIMIT_MACROS
  47#define __STDC_LIMIT_MACROS
  48#endif
  49#ifndef __STDC_FORMAT_MACROS
  50#define __STDC_FORMAT_MACROS
  51#endif
  52
  53/* The following block of code temporarily renames the daemon() function so the
  54 * compiler does not see the warning associated with it in stdlib.h on OSX
  55 */
  56#ifdef __APPLE__
  57#define daemon qemu_fake_daemon_function
  58#include <stdlib.h>
  59#undef daemon
  60QEMU_EXTERN_C int daemon(int, int);
  61#endif
  62
  63#ifdef _WIN32
  64/* as defined in sdkddkver.h */
  65#ifndef _WIN32_WINNT
  66#define _WIN32_WINNT 0x0600 /* Vista */
  67#endif
  68/* reduces the number of implicitly included headers */
  69#ifndef WIN32_LEAN_AND_MEAN
  70#define WIN32_LEAN_AND_MEAN
  71#endif
  72#endif
  73
  74/* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */
  75#ifdef __MINGW32__
  76#define __USE_MINGW_ANSI_STDIO 1
  77#endif
  78
  79#include <stdarg.h>
  80#include <stddef.h>
  81#include <stdbool.h>
  82#include <stdint.h>
  83#include <sys/types.h>
  84#include <stdlib.h>
  85#include <stdio.h>
  86
  87#include <string.h>
  88#include <strings.h>
  89#include <inttypes.h>
  90#include <limits.h>
  91/* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
  92 * function availability on recentish Mingw-w64 platforms. */
  93#include <unistd.h>
  94#include <time.h>
  95#include <ctype.h>
  96#include <errno.h>
  97#include <fcntl.h>
  98#include <getopt.h>
  99#include <sys/stat.h>
 100#include <sys/time.h>
 101#include <assert.h>
 102/* setjmp must be declared before sysemu/os-win32.h
 103 * because it is redefined there. */
 104#include <setjmp.h>
 105#include <signal.h>
 106
 107#ifdef CONFIG_IOVEC
 108#include <sys/uio.h>
 109#endif
 110
 111#if defined(__linux__) && defined(__sparc__)
 112/* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */
 113#include <sys/shm.h>
 114#endif
 115
 116#ifndef _WIN32
 117#include <sys/wait.h>
 118#else
 119#define WIFEXITED(x)   1
 120#define WEXITSTATUS(x) (x)
 121#endif
 122
 123#ifdef __APPLE__
 124#include <AvailabilityMacros.h>
 125#endif
 126
 127/*
 128 * This is somewhat like a system header; it must be outside any extern "C"
 129 * block because it includes system headers itself, including glib.h,
 130 * which will not compile if inside an extern "C" block.
 131 */
 132#include "glib-compat.h"
 133
 134#ifdef _WIN32
 135#include "sysemu/os-win32.h"
 136#endif
 137
 138#ifdef CONFIG_POSIX
 139#include "sysemu/os-posix.h"
 140#endif
 141
 142#ifdef __cplusplus
 143extern "C" {
 144#endif
 145
 146#include "qemu/typedefs.h"
 147
 148/*
 149 * For mingw, as of v6.0.0, the function implementing the assert macro is
 150 * not marked as noreturn, so the compiler cannot delete code following an
 151 * assert(false) as unused.  We rely on this within the code base to delete
 152 * code that is unreachable when features are disabled.
 153 * All supported versions of Glib's g_assert() satisfy this requirement.
 154 */
 155#ifdef __MINGW32__
 156#undef assert
 157#define assert(x)  g_assert(x)
 158#endif
 159
 160/*
 161 * According to waitpid man page:
 162 * WCOREDUMP
 163 *  This  macro  is  not  specified  in POSIX.1-2001 and is not
 164 *  available on some UNIX implementations (e.g., AIX, SunOS).
 165 *  Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif.
 166 */
 167#ifndef WCOREDUMP
 168#define WCOREDUMP(status) 0
 169#endif
 170/*
 171 * We have a lot of unaudited code that may fail in strange ways, or
 172 * even be a security risk during migration, if you disable assertions
 173 * at compile-time.  You may comment out these safety checks if you
 174 * absolutely want to disable assertion overhead, but it is not
 175 * supported upstream so the risk is all yours.  Meanwhile, please
 176 * submit patches to remove any side-effects inside an assertion, or
 177 * fixing error handling that should use Error instead of assert.
 178 */
 179#ifdef NDEBUG
 180#error building with NDEBUG is not supported
 181#endif
 182#ifdef G_DISABLE_ASSERT
 183#error building with G_DISABLE_ASSERT is not supported
 184#endif
 185
 186#ifndef O_LARGEFILE
 187#define O_LARGEFILE 0
 188#endif
 189#ifndef O_BINARY
 190#define O_BINARY 0
 191#endif
 192#ifndef MAP_ANONYMOUS
 193#define MAP_ANONYMOUS MAP_ANON
 194#endif
 195#ifndef MAP_FIXED_NOREPLACE
 196#define MAP_FIXED_NOREPLACE 0
 197#endif
 198#ifndef MAP_NORESERVE
 199#define MAP_NORESERVE 0
 200#endif
 201#ifndef ENOMEDIUM
 202#define ENOMEDIUM ENODEV
 203#endif
 204#if !defined(ENOTSUP)
 205#define ENOTSUP 4096
 206#endif
 207#if !defined(ECANCELED)
 208#define ECANCELED 4097
 209#endif
 210#if !defined(EMEDIUMTYPE)
 211#define EMEDIUMTYPE 4098
 212#endif
 213#if !defined(ESHUTDOWN)
 214#define ESHUTDOWN 4099
 215#endif
 216
 217/* time_t may be either 32 or 64 bits depending on the host OS, and
 218 * can be either signed or unsigned, so we can't just hardcode a
 219 * specific maximum value. This is not a C preprocessor constant,
 220 * so you can't use TIME_MAX in an #ifdef, but for our purposes
 221 * this isn't a problem.
 222 */
 223
 224/* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
 225 * Gnulib, and are under the LGPL v2.1 or (at your option) any
 226 * later version.
 227 */
 228
 229/* True if the real type T is signed.  */
 230#define TYPE_SIGNED(t) (!((t)0 < (t)-1))
 231
 232/* The width in bits of the integer type or expression T.
 233 * Padding bits are not supported.
 234 */
 235#define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
 236
 237/* The maximum and minimum values for the integer type T.  */
 238#define TYPE_MAXIMUM(t)                                                \
 239  ((t) (!TYPE_SIGNED(t)                                                \
 240        ? (t)-1                                                        \
 241        : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
 242
 243#ifndef TIME_MAX
 244#define TIME_MAX TYPE_MAXIMUM(time_t)
 245#endif
 246
 247/* HOST_LONG_BITS is the size of a native pointer in bits. */
 248#if UINTPTR_MAX == UINT32_MAX
 249# define HOST_LONG_BITS 32
 250#elif UINTPTR_MAX == UINT64_MAX
 251# define HOST_LONG_BITS 64
 252#else
 253# error Unknown pointer size
 254#endif
 255
 256/* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
 257 * the wrong type. Our replacement isn't usable in preprocessor
 258 * expressions, but it is sufficient for our needs. */
 259#ifdef HAVE_BROKEN_SIZE_MAX
 260#undef SIZE_MAX
 261#define SIZE_MAX ((size_t)-1)
 262#endif
 263
 264/*
 265 * Two variations of MIN/MAX macros. The first is for runtime use, and
 266 * evaluates arguments only once (so it is safe even with side
 267 * effects), but will not work in constant contexts (such as array
 268 * size declarations) because of the '{}'.  The second is for constant
 269 * expression use, where evaluating arguments twice is safe because
 270 * the result is going to be constant anyway, but will not work in a
 271 * runtime context because of a void expression where a value is
 272 * expected.  Thus, both gcc and clang will fail to compile if you use
 273 * the wrong macro (even if the error may seem a bit cryptic).
 274 *
 275 * Note that neither form is usable as an #if condition; if you truly
 276 * need to write conditional code that depends on a minimum or maximum
 277 * determined by the pre-processor instead of the compiler, you'll
 278 * have to open-code it.  Sadly, Coverity is severely confused by the
 279 * constant variants, so we have to dumb things down there.
 280 */
 281#undef MIN
 282#define MIN(a, b)                                       \
 283    ({                                                  \
 284        typeof(1 ? (a) : (b)) _a = (a), _b = (b);       \
 285        _a < _b ? _a : _b;                              \
 286    })
 287#undef MAX
 288#define MAX(a, b)                                       \
 289    ({                                                  \
 290        typeof(1 ? (a) : (b)) _a = (a), _b = (b);       \
 291        _a > _b ? _a : _b;                              \
 292    })
 293
 294#ifdef __COVERITY__
 295# define MIN_CONST(a, b) ((a) < (b) ? (a) : (b))
 296# define MAX_CONST(a, b) ((a) > (b) ? (a) : (b))
 297#else
 298# define MIN_CONST(a, b)                                        \
 299    __builtin_choose_expr(                                      \
 300        __builtin_constant_p(a) && __builtin_constant_p(b),     \
 301        (a) < (b) ? (a) : (b),                                  \
 302        ((void)0))
 303# define MAX_CONST(a, b)                                        \
 304    __builtin_choose_expr(                                      \
 305        __builtin_constant_p(a) && __builtin_constant_p(b),     \
 306        (a) > (b) ? (a) : (b),                                  \
 307        ((void)0))
 308#endif
 309
 310/*
 311 * Minimum function that returns zero only if both values are zero.
 312 * Intended for use with unsigned values only.
 313 */
 314#ifndef MIN_NON_ZERO
 315#define MIN_NON_ZERO(a, b)                              \
 316    ({                                                  \
 317        typeof(1 ? (a) : (b)) _a = (a), _b = (b);       \
 318        _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b;  \
 319    })
 320#endif
 321
 322/*
 323 * Round number down to multiple. Safe when m is not a power of 2 (see
 324 * ROUND_DOWN for a faster version when a power of 2 is guaranteed).
 325 */
 326#define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
 327
 328/*
 329 * Round number up to multiple. Safe when m is not a power of 2 (see
 330 * ROUND_UP for a faster version when a power of 2 is guaranteed).
 331 */
 332#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
 333
 334/* Check if n is a multiple of m */
 335#define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
 336
 337/* n-byte align pointer down */
 338#define QEMU_ALIGN_PTR_DOWN(p, n) \
 339    ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
 340
 341/* n-byte align pointer up */
 342#define QEMU_ALIGN_PTR_UP(p, n) \
 343    ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
 344
 345/* Check if pointer p is n-bytes aligned */
 346#define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
 347
 348/*
 349 * Round number down to multiple. Requires that d be a power of 2 (see
 350 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
 351 * numbers); works even if d is a smaller type than n.
 352 */
 353#ifndef ROUND_DOWN
 354#define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d)))
 355#endif
 356
 357/*
 358 * Round number up to multiple. Requires that d be a power of 2 (see
 359 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
 360 * numbers); works even if d is a smaller type than n.
 361 */
 362#ifndef ROUND_UP
 363#define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d))
 364#endif
 365
 366#ifndef DIV_ROUND_UP
 367#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 368#endif
 369
 370/*
 371 * &(x)[0] is always a pointer - if it's same type as x then the argument is a
 372 * pointer, not an array.
 373 */
 374#define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
 375                                                        typeof(&(x)[0])))
 376#ifndef ARRAY_SIZE
 377#define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
 378                       QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
 379#endif
 380
 381int qemu_daemon(int nochdir, int noclose);
 382void *qemu_try_memalign(size_t alignment, size_t size);
 383void *qemu_memalign(size_t alignment, size_t size);
 384void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared,
 385                          bool noreserve);
 386void qemu_vfree(void *ptr);
 387void qemu_anon_ram_free(void *ptr, size_t size);
 388
 389/*
 390 * It's an analog of GLIB's g_autoptr_cleanup_generic_gfree(), used to define
 391 * g_autofree macro.
 392 */
 393static inline void qemu_cleanup_generic_vfree(void *p)
 394{
 395  void **pp = (void **)p;
 396  qemu_vfree(*pp);
 397}
 398
 399/*
 400 * Analog of g_autofree, but qemu_vfree is called on cleanup instead of g_free.
 401 */
 402#define QEMU_AUTO_VFREE __attribute__((cleanup(qemu_cleanup_generic_vfree)))
 403
 404/*
 405 * Abstraction of PROT_ and MAP_ flags as passed to mmap(), for example,
 406 * consumed by qemu_ram_mmap().
 407 */
 408
 409/* Map PROT_READ instead of PROT_READ | PROT_WRITE. */
 410#define QEMU_MAP_READONLY   (1 << 0)
 411
 412/* Use MAP_SHARED instead of MAP_PRIVATE. */
 413#define QEMU_MAP_SHARED     (1 << 1)
 414
 415/*
 416 * Use MAP_SYNC | MAP_SHARED_VALIDATE if supported. Ignored without
 417 * QEMU_MAP_SHARED. If mapping fails, warn and fallback to !QEMU_MAP_SYNC.
 418 */
 419#define QEMU_MAP_SYNC       (1 << 2)
 420
 421/*
 422 * Use MAP_NORESERVE to skip reservation of swap space (or huge pages if
 423 * applicable). Bail out if not supported/effective.
 424 */
 425#define QEMU_MAP_NORESERVE  (1 << 3)
 426
 427
 428#define QEMU_MADV_INVALID -1
 429
 430#if defined(CONFIG_MADVISE)
 431
 432#define QEMU_MADV_WILLNEED  MADV_WILLNEED
 433#define QEMU_MADV_DONTNEED  MADV_DONTNEED
 434#ifdef MADV_DONTFORK
 435#define QEMU_MADV_DONTFORK  MADV_DONTFORK
 436#else
 437#define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 438#endif
 439#ifdef MADV_MERGEABLE
 440#define QEMU_MADV_MERGEABLE MADV_MERGEABLE
 441#else
 442#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 443#endif
 444#ifdef MADV_UNMERGEABLE
 445#define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
 446#else
 447#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 448#endif
 449#ifdef MADV_DODUMP
 450#define QEMU_MADV_DODUMP MADV_DODUMP
 451#else
 452#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 453#endif
 454#ifdef MADV_DONTDUMP
 455#define QEMU_MADV_DONTDUMP MADV_DONTDUMP
 456#else
 457#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 458#endif
 459#ifdef MADV_HUGEPAGE
 460#define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
 461#else
 462#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
 463#endif
 464#ifdef MADV_NOHUGEPAGE
 465#define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
 466#else
 467#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
 468#endif
 469#ifdef MADV_REMOVE
 470#define QEMU_MADV_REMOVE MADV_REMOVE
 471#else
 472#define QEMU_MADV_REMOVE QEMU_MADV_DONTNEED
 473#endif
 474
 475#elif defined(CONFIG_POSIX_MADVISE)
 476
 477#define QEMU_MADV_WILLNEED  POSIX_MADV_WILLNEED
 478#define QEMU_MADV_DONTNEED  POSIX_MADV_DONTNEED
 479#define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 480#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 481#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 482#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 483#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 484#define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 485#define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 486#define QEMU_MADV_REMOVE QEMU_MADV_DONTNEED
 487
 488#else /* no-op */
 489
 490#define QEMU_MADV_WILLNEED  QEMU_MADV_INVALID
 491#define QEMU_MADV_DONTNEED  QEMU_MADV_INVALID
 492#define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 493#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 494#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 495#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 496#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 497#define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 498#define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 499#define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 500
 501#endif
 502
 503#ifdef _WIN32
 504#define HAVE_CHARDEV_SERIAL 1
 505#elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
 506    || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
 507    || defined(__GLIBC__) || defined(__APPLE__)
 508#define HAVE_CHARDEV_SERIAL 1
 509#endif
 510
 511#if defined(__linux__) || defined(__FreeBSD__) ||               \
 512    defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 513#define HAVE_CHARDEV_PARPORT 1
 514#endif
 515
 516#if defined(__HAIKU__)
 517#define SIGIO SIGPOLL
 518#endif
 519
 520#if defined(CONFIG_LINUX)
 521#ifndef BUS_MCEERR_AR
 522#define BUS_MCEERR_AR 4
 523#endif
 524#ifndef BUS_MCEERR_AO
 525#define BUS_MCEERR_AO 5
 526#endif
 527#endif
 528
 529#if defined(__linux__) && \
 530    (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
 531     || defined(__powerpc64__))
 532   /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
 533      Valgrind does not support alignments larger than 1 MiB,
 534      therefore we need special code which handles running on Valgrind. */
 535#  define QEMU_VMALLOC_ALIGN (512 * 4096)
 536#elif defined(__linux__) && defined(__s390x__)
 537   /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
 538#  define QEMU_VMALLOC_ALIGN (256 * 4096)
 539#elif defined(__linux__) && defined(__sparc__)
 540#  define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size, SHMLBA)
 541#else
 542#  define QEMU_VMALLOC_ALIGN qemu_real_host_page_size
 543#endif
 544
 545#ifdef CONFIG_POSIX
 546struct qemu_signalfd_siginfo {
 547    uint32_t ssi_signo;   /* Signal number */
 548    int32_t  ssi_errno;   /* Error number (unused) */
 549    int32_t  ssi_code;    /* Signal code */
 550    uint32_t ssi_pid;     /* PID of sender */
 551    uint32_t ssi_uid;     /* Real UID of sender */
 552    int32_t  ssi_fd;      /* File descriptor (SIGIO) */
 553    uint32_t ssi_tid;     /* Kernel timer ID (POSIX timers) */
 554    uint32_t ssi_band;    /* Band event (SIGIO) */
 555    uint32_t ssi_overrun; /* POSIX timer overrun count */
 556    uint32_t ssi_trapno;  /* Trap number that caused signal */
 557    int32_t  ssi_status;  /* Exit status or signal (SIGCHLD) */
 558    int32_t  ssi_int;     /* Integer sent by sigqueue(2) */
 559    uint64_t ssi_ptr;     /* Pointer sent by sigqueue(2) */
 560    uint64_t ssi_utime;   /* User CPU time consumed (SIGCHLD) */
 561    uint64_t ssi_stime;   /* System CPU time consumed (SIGCHLD) */
 562    uint64_t ssi_addr;    /* Address that generated signal
 563                             (for hardware-generated signals) */
 564    uint8_t  pad[48];     /* Pad size to 128 bytes (allow for
 565                             additional fields in the future) */
 566};
 567
 568int qemu_signalfd(const sigset_t *mask);
 569void sigaction_invoke(struct sigaction *action,
 570                      struct qemu_signalfd_siginfo *info);
 571#endif
 572
 573int qemu_madvise(void *addr, size_t len, int advice);
 574int qemu_mprotect_rw(void *addr, size_t size);
 575int qemu_mprotect_rwx(void *addr, size_t size);
 576int qemu_mprotect_none(void *addr, size_t size);
 577
 578/*
 579 * Don't introduce new usage of this function, prefer the following
 580 * qemu_open/qemu_create that take an "Error **errp"
 581 */
 582int qemu_open_old(const char *name, int flags, ...);
 583int qemu_open(const char *name, int flags, Error **errp);
 584int qemu_create(const char *name, int flags, mode_t mode, Error **errp);
 585int qemu_close(int fd);
 586int qemu_unlink(const char *name);
 587#ifndef _WIN32
 588int qemu_dup_flags(int fd, int flags);
 589int qemu_dup(int fd);
 590int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
 591int qemu_unlock_fd(int fd, int64_t start, int64_t len);
 592int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
 593bool qemu_has_ofd_lock(void);
 594#endif
 595
 596#if defined(__HAIKU__) && defined(__i386__)
 597#define FMT_pid "%ld"
 598#elif defined(WIN64)
 599#define FMT_pid "%" PRId64
 600#else
 601#define FMT_pid "%d"
 602#endif
 603
 604bool qemu_write_pidfile(const char *pidfile, Error **errp);
 605
 606int qemu_get_thread_id(void);
 607
 608#ifndef CONFIG_IOVEC
 609struct iovec {
 610    void *iov_base;
 611    size_t iov_len;
 612};
 613/*
 614 * Use the same value as Linux for now.
 615 */
 616#define IOV_MAX 1024
 617
 618ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
 619ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
 620#endif
 621
 622#ifdef _WIN32
 623static inline void qemu_timersub(const struct timeval *val1,
 624                                 const struct timeval *val2,
 625                                 struct timeval *res)
 626{
 627    res->tv_sec = val1->tv_sec - val2->tv_sec;
 628    if (val1->tv_usec < val2->tv_usec) {
 629        res->tv_sec--;
 630        res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
 631    } else {
 632        res->tv_usec = val1->tv_usec - val2->tv_usec;
 633    }
 634}
 635#else
 636#define qemu_timersub timersub
 637#endif
 638
 639void qemu_set_cloexec(int fd);
 640
 641/* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
 642 * instead of QEMU_VERSION, so setting hw_version on MachineClass
 643 * is no longer mandatory.
 644 *
 645 * Do NOT change this string, or it will break compatibility on all
 646 * machine classes that don't set hw_version.
 647 */
 648#define QEMU_HW_VERSION "2.5+"
 649
 650/* QEMU "hardware version" setting. Used to replace code that exposed
 651 * QEMU_VERSION to guests in the past and need to keep compatibility.
 652 * Do not use qemu_hw_version() in new code.
 653 */
 654void qemu_set_hw_version(const char *);
 655const char *qemu_hw_version(void);
 656
 657void fips_set_state(bool requested);
 658bool fips_get_state(void);
 659
 660/* Return a dynamically allocated pathname denoting a file or directory that is
 661 * appropriate for storing local state.
 662 *
 663 * @relative_pathname need not start with a directory separator; one will be
 664 * added automatically.
 665 *
 666 * The caller is responsible for releasing the value returned with g_free()
 667 * after use.
 668 */
 669char *qemu_get_local_state_pathname(const char *relative_pathname);
 670
 671/* Find program directory, and save it for later usage with
 672 * qemu_get_exec_dir().
 673 * Try OS specific API first, if not working, parse from argv0. */
 674void qemu_init_exec_dir(const char *argv0);
 675
 676/* Get the saved exec dir.  */
 677const char *qemu_get_exec_dir(void);
 678
 679/**
 680 * qemu_getauxval:
 681 * @type: the auxiliary vector key to lookup
 682 *
 683 * Search the auxiliary vector for @type, returning the value
 684 * or 0 if @type is not present.
 685 */
 686unsigned long qemu_getauxval(unsigned long type);
 687
 688void qemu_set_tty_echo(int fd, bool echo);
 689
 690void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus,
 691                     Error **errp);
 692
 693/**
 694 * qemu_get_pid_name:
 695 * @pid: pid of a process
 696 *
 697 * For given @pid fetch its name. Caller is responsible for
 698 * freeing the string when no longer needed.
 699 * Returns allocated string on success, NULL on failure.
 700 */
 701char *qemu_get_pid_name(pid_t pid);
 702
 703/**
 704 * qemu_fork:
 705 *
 706 * A version of fork that avoids signal handler race
 707 * conditions that can lead to child process getting
 708 * signals that are otherwise only expected by the
 709 * parent. It also resets all signal handlers to the
 710 * default settings.
 711 *
 712 * Returns 0 to child process, pid number to parent
 713 * or -1 on failure.
 714 */
 715pid_t qemu_fork(Error **errp);
 716
 717/* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
 718 * when intptr_t is 32-bit and we are aligning a long long.
 719 */
 720extern uintptr_t qemu_real_host_page_size;
 721extern intptr_t qemu_real_host_page_mask;
 722
 723extern int qemu_icache_linesize;
 724extern int qemu_icache_linesize_log;
 725extern int qemu_dcache_linesize;
 726extern int qemu_dcache_linesize_log;
 727
 728/*
 729 * After using getopt or getopt_long, if you need to parse another set
 730 * of options, then you must reset optind.  Unfortunately the way to
 731 * do this varies between implementations of getopt.
 732 */
 733static inline void qemu_reset_optind(void)
 734{
 735#ifdef HAVE_OPTRESET
 736    optind = 1;
 737    optreset = 1;
 738#else
 739    optind = 0;
 740#endif
 741}
 742
 743/**
 744 * qemu_get_host_name:
 745 * @errp: Error object
 746 *
 747 * Operating system agnostic way of querying host name.
 748 *
 749 * Returns allocated hostname (caller should free), NULL on failure.
 750 */
 751char *qemu_get_host_name(Error **errp);
 752
 753/**
 754 * qemu_get_host_physmem:
 755 *
 756 * Operating system agnostic way of querying host memory.
 757 *
 758 * Returns amount of physical memory on the system. This is purely
 759 * advisery and may return 0 if we can't work it out. At the other
 760 * end we saturate to SIZE_MAX if you are lucky enough to have that
 761 * much memory.
 762 */
 763size_t qemu_get_host_physmem(void);
 764
 765/*
 766 * Toggle write/execute on the pages marked MAP_JIT
 767 * for the current thread.
 768 */
 769#if defined(MAC_OS_VERSION_11_0) && \
 770    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_11_0
 771static inline void qemu_thread_jit_execute(void)
 772{
 773    if (__builtin_available(macOS 11.0, *)) {
 774        pthread_jit_write_protect_np(true);
 775    }
 776}
 777
 778static inline void qemu_thread_jit_write(void)
 779{
 780    if (__builtin_available(macOS 11.0, *)) {
 781        pthread_jit_write_protect_np(false);
 782    }
 783}
 784#else
 785static inline void qemu_thread_jit_write(void) {}
 786static inline void qemu_thread_jit_execute(void) {}
 787#endif
 788
 789/**
 790 * Platforms which do not support system() return ENOSYS
 791 */
 792#ifndef HAVE_SYSTEM_FUNCTION
 793#define system platform_does_not_support_system
 794static inline int platform_does_not_support_system(const char *command)
 795{
 796    errno = ENOSYS;
 797    return -1;
 798}
 799#endif /* !HAVE_SYSTEM_FUNCTION */
 800
 801#ifdef __cplusplus
 802}
 803#endif
 804
 805#endif
 806