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
  60 QEMU_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 __cplusplus
 135 extern "C" {
 136 #endif
 137
 138 #ifdef _WIN32
 139 #include "sysemu/os-win32.h"
 140 #endif
 141
 142 #ifdef CONFIG_POSIX
 143 #include "sysemu/os-posix.h"
 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 ENOMEDIUM
 199 #define ENOMEDIUM ENODEV
 200 #endif
 201 #if !defined(ENOTSUP)
 202 #define ENOTSUP 4096
 203 #endif
 204 #if !defined(ECANCELED)
 205 #define ECANCELED 4097
 206 #endif
 207 #if !defined(EMEDIUMTYPE)
 208 #define EMEDIUMTYPE 4098
 209 #endif
 210 #if !defined(ESHUTDOWN)
 211 #define ESHUTDOWN 4099
 212 #endif
 213
 214 /* time_t may be either 32 or 64 bits depending on the host OS, and
 215  * can be either signed or unsigned, so we can't just hardcode a
 216  * specific maximum value. This is not a C preprocessor constant,
 217  * so you can't use TIME_MAX in an #ifdef, but for our purposes
 218  * this isn't a problem.
 219  */
 220
 221 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
 222  * Gnulib, and are under the LGPL v2.1 or (at your option) any
 223  * later version.
 224  */
 225
 226 /* True if the real type T is signed.  */
 227 #define TYPE_SIGNED(t) (!((t)0 < (t)-1))
 228
 229 /* The width in bits of the integer type or expression T.
 230  * Padding bits are not supported.
 231  */
 232 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
 233
 234 /* The maximum and minimum values for the integer type T.  */
 235 #define TYPE_MAXIMUM(t)                                                \
 236   ((t) (!TYPE_SIGNED(t)                                                \
 237         ? (t)-1                                                        \
 238         : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
 239
 240 #ifndef TIME_MAX
 241 #define TIME_MAX TYPE_MAXIMUM(time_t)
 242 #endif
 243
 244 /* HOST_LONG_BITS is the size of a native pointer in bits. */
 245 #if UINTPTR_MAX == UINT32_MAX
 246 # define HOST_LONG_BITS 32
 247 #elif UINTPTR_MAX == UINT64_MAX
 248 # define HOST_LONG_BITS 64
 249 #else
 250 # error Unknown pointer size
 251 #endif
 252
 253 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
 254  * the wrong type. Our replacement isn't usable in preprocessor
 255  * expressions, but it is sufficient for our needs. */
 256 #if defined(HAVE_BROKEN_SIZE_MAX) && HAVE_BROKEN_SIZE_MAX
 257 #undef SIZE_MAX
 258 #define SIZE_MAX ((size_t)-1)
 259 #endif
 260
 261 /*
 262  * Two variations of MIN/MAX macros. The first is for runtime use, and
 263  * evaluates arguments only once (so it is safe even with side
 264  * effects), but will not work in constant contexts (such as array
 265  * size declarations) because of the '{}'.  The second is for constant
 266  * expression use, where evaluating arguments twice is safe because
 267  * the result is going to be constant anyway, but will not work in a
 268  * runtime context because of a void expression where a value is
 269  * expected.  Thus, both gcc and clang will fail to compile if you use
 270  * the wrong macro (even if the error may seem a bit cryptic).
 271  *
 272  * Note that neither form is usable as an #if condition; if you truly
 273  * need to write conditional code that depends on a minimum or maximum
 274  * determined by the pre-processor instead of the compiler, you'll
 275  * have to open-code it.  Sadly, Coverity is severely confused by the
 276  * constant variants, so we have to dumb things down there.
 277  */
 278 #undef MIN
 279 #define MIN(a, b)                                       \
 280     ({                                                  \
 281         typeof(1 ? (a) : (b)) _a = (a), _b = (b);       \
 282         _a < _b ? _a : _b;                              \
 283     })
 284 #undef MAX
 285 #define MAX(a, b)                                       \
 286     ({                                                  \
 287         typeof(1 ? (a) : (b)) _a = (a), _b = (b);       \
 288         _a > _b ? _a : _b;                              \
 289     })
 290
 291 #ifdef __COVERITY__
 292 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b))
 293 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b))
 294 #else
 295 # define MIN_CONST(a, b)                                        \
 296     __builtin_choose_expr(                                      \
 297         __builtin_constant_p(a) && __builtin_constant_p(b),     \
 298         (a) < (b) ? (a) : (b),                                  \
 299         ((void)0))
 300 # define MAX_CONST(a, b)                                        \
 301     __builtin_choose_expr(                                      \
 302         __builtin_constant_p(a) && __builtin_constant_p(b),     \
 303         (a) > (b) ? (a) : (b),                                  \
 304         ((void)0))
 305 #endif
 306
 307 /*
 308  * Minimum function that returns zero only if both values are zero.
 309  * Intended for use with unsigned values only.
 310  */
 311 #ifndef MIN_NON_ZERO
 312 #define MIN_NON_ZERO(a, b)                              \
 313     ({                                                  \
 314         typeof(1 ? (a) : (b)) _a = (a), _b = (b);       \
 315         _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b;  \
 316     })
 317 #endif
 318
 319 /* Round number down to multiple */
 320 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
 321
 322 /* Round number up to multiple. Safe when m is not a power of 2 (see
 323  * ROUND_UP for a faster version when a power of 2 is guaranteed) */
 324 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
 325
 326 /* Check if n is a multiple of m */
 327 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
 328
 329 /* n-byte align pointer down */
 330 #define QEMU_ALIGN_PTR_DOWN(p, n) \
 331     ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
 332
 333 /* n-byte align pointer up */
 334 #define QEMU_ALIGN_PTR_UP(p, n) \
 335     ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
 336
 337 /* Check if pointer p is n-bytes aligned */
 338 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
 339
 340 /* Round number up to multiple. Requires that d be a power of 2 (see
 341  * QEMU_ALIGN_UP for a safer but slower version on arbitrary
 342  * numbers); works even if d is a smaller type than n.  */
 343 #ifndef ROUND_UP
 344 #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
 345 #endif
 346
 347 #ifndef DIV_ROUND_UP
 348 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 349 #endif
 350
 351 /*
 352  * &(x)[0] is always a pointer - if it's same type as x then the argument is a
 353  * pointer, not an array.
 354  */
 355 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
 356                                                         typeof(&(x)[0])))
 357 #ifndef ARRAY_SIZE
 358 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
 359                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
 360 #endif
 361
 362 int qemu_daemon(int nochdir, int noclose);
 363 void *qemu_try_memalign(size_t alignment, size_t size);
 364 void *qemu_memalign(size_t alignment, size_t size);
 365 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared);
 366 void qemu_vfree(void *ptr);
 367 void qemu_anon_ram_free(void *ptr, size_t size);
 368
 369 #define QEMU_MADV_INVALID -1
 370
 371 #if defined(CONFIG_MADVISE)
 372
 373 #define QEMU_MADV_WILLNEED  MADV_WILLNEED
 374 #define QEMU_MADV_DONTNEED  MADV_DONTNEED
 375 #ifdef MADV_DONTFORK
 376 #define QEMU_MADV_DONTFORK  MADV_DONTFORK
 377 #else
 378 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 379 #endif
 380 #ifdef MADV_MERGEABLE
 381 #define QEMU_MADV_MERGEABLE MADV_MERGEABLE
 382 #else
 383 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 384 #endif
 385 #ifdef MADV_UNMERGEABLE
 386 #define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
 387 #else
 388 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 389 #endif
 390 #ifdef MADV_DODUMP
 391 #define QEMU_MADV_DODUMP MADV_DODUMP
 392 #else
 393 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 394 #endif
 395 #ifdef MADV_DONTDUMP
 396 #define QEMU_MADV_DONTDUMP MADV_DONTDUMP
 397 #else
 398 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 399 #endif
 400 #ifdef MADV_HUGEPAGE
 401 #define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
 402 #else
 403 #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
 404 #endif
 405 #ifdef MADV_NOHUGEPAGE
 406 #define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
 407 #else
 408 #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
 409 #endif
 410 #ifdef MADV_REMOVE
 411 #define QEMU_MADV_REMOVE MADV_REMOVE
 412 #else
 413 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 414 #endif
 415
 416 #elif defined(CONFIG_POSIX_MADVISE)
 417
 418 #define QEMU_MADV_WILLNEED  POSIX_MADV_WILLNEED
 419 #define QEMU_MADV_DONTNEED  POSIX_MADV_DONTNEED
 420 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 421 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 422 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 423 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 424 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 425 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 426 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 427 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 428
 429 #else /* no-op */
 430
 431 #define QEMU_MADV_WILLNEED  QEMU_MADV_INVALID
 432 #define QEMU_MADV_DONTNEED  QEMU_MADV_INVALID
 433 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 434 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 435 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 436 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 437 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 438 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 439 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 440 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 441
 442 #endif
 443
 444 #ifdef _WIN32
 445 #define HAVE_CHARDEV_SERIAL 1
 446 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
 447     || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
 448     || defined(__GLIBC__) || defined(__APPLE__)
 449 #define HAVE_CHARDEV_SERIAL 1
 450 #endif
 451
 452 #if defined(__linux__) || defined(__FreeBSD__) ||               \
 453     defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 454 #define HAVE_CHARDEV_PARPORT 1
 455 #endif
 456
 457 #if defined(__HAIKU__)
 458 #define SIGIO SIGPOLL
 459 #endif
 460
 461 #if defined(CONFIG_LINUX)
 462 #ifndef BUS_MCEERR_AR
 463 #define BUS_MCEERR_AR 4
 464 #endif
 465 #ifndef BUS_MCEERR_AO
 466 #define BUS_MCEERR_AO 5
 467 #endif
 468 #endif
 469
 470 #if defined(__linux__) && \
 471     (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
 472      || defined(__powerpc64__))
 473    /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
 474       Valgrind does not support alignments larger than 1 MiB,
 475       therefore we need special code which handles running on Valgrind. */
 476 #  define QEMU_VMALLOC_ALIGN (512 * 4096)
 477 #elif defined(__linux__) && defined(__s390x__)
 478    /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
 479 #  define QEMU_VMALLOC_ALIGN (256 * 4096)
 480 #elif defined(__linux__) && defined(__sparc__)
 481 #  define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size, SHMLBA)
 482 #else
 483 #  define QEMU_VMALLOC_ALIGN qemu_real_host_page_size
 484 #endif
 485
 486 #ifdef CONFIG_POSIX
 487 struct qemu_signalfd_siginfo {
 488     uint32_t ssi_signo;   /* Signal number */
 489     int32_t  ssi_errno;   /* Error number (unused) */
 490     int32_t  ssi_code;    /* Signal code */
 491     uint32_t ssi_pid;     /* PID of sender */
 492     uint32_t ssi_uid;     /* Real UID of sender */
 493     int32_t  ssi_fd;      /* File descriptor (SIGIO) */
 494     uint32_t ssi_tid;     /* Kernel timer ID (POSIX timers) */
 495     uint32_t ssi_band;    /* Band event (SIGIO) */
 496     uint32_t ssi_overrun; /* POSIX timer overrun count */
 497     uint32_t ssi_trapno;  /* Trap number that caused signal */
 498     int32_t  ssi_status;  /* Exit status or signal (SIGCHLD) */
 499     int32_t  ssi_int;     /* Integer sent by sigqueue(2) */
 500     uint64_t ssi_ptr;     /* Pointer sent by sigqueue(2) */
 501     uint64_t ssi_utime;   /* User CPU time consumed (SIGCHLD) */
 502     uint64_t ssi_stime;   /* System CPU time consumed (SIGCHLD) */
 503     uint64_t ssi_addr;    /* Address that generated signal
 504                              (for hardware-generated signals) */
 505     uint8_t  pad[48];     /* Pad size to 128 bytes (allow for
 506                              additional fields in the future) */
 507 };
 508
 509 int qemu_signalfd(const sigset_t *mask);
 510 void sigaction_invoke(struct sigaction *action,
 511                       struct qemu_signalfd_siginfo *info);
 512 #endif
 513
 514 int qemu_madvise(void *addr, size_t len, int advice);
 515 int qemu_mprotect_rwx(void *addr, size_t size);
 516 int qemu_mprotect_none(void *addr, size_t size);
 517
 518 /*
 519  * Don't introduce new usage of this function, prefer the following
 520  * qemu_open/qemu_create that take an "Error **errp"
 521  */
 522 int qemu_open_old(const char *name, int flags, ...);
 523 int qemu_open(const char *name, int flags, Error **errp);
 524 int qemu_create(const char *name, int flags, mode_t mode, Error **errp);
 525 int qemu_close(int fd);
 526 int qemu_unlink(const char *name);
 527 #ifndef _WIN32
 528 int qemu_dup_flags(int fd, int flags);
 529 int qemu_dup(int fd);
 530 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
 531 int qemu_unlock_fd(int fd, int64_t start, int64_t len);
 532 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
 533 bool qemu_has_ofd_lock(void);
 534 #endif
 535
 536 #if defined(__HAIKU__) && defined(__i386__)
 537 #define FMT_pid "%ld"
 538 #elif defined(WIN64)
 539 #define FMT_pid "%" PRId64
 540 #else
 541 #define FMT_pid "%d"
 542 #endif
 543
 544 bool qemu_write_pidfile(const char *pidfile, Error **errp);
 545
 546 int qemu_get_thread_id(void);
 547
 548 #ifndef CONFIG_IOVEC
 549 struct iovec {
 550     void *iov_base;
 551     size_t iov_len;
 552 };
 553 /*
 554  * Use the same value as Linux for now.
 555  */
 556 #define IOV_MAX 1024
 557
 558 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
 559 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
 560 #endif
 561
 562 #ifdef _WIN32
 563 static inline void qemu_timersub(const struct timeval *val1,
 564                                  const struct timeval *val2,
 565                                  struct timeval *res)
 566 {
 567     res->tv_sec = val1->tv_sec - val2->tv_sec;
 568     if (val1->tv_usec < val2->tv_usec) {
 569         res->tv_sec--;
 570         res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
 571     } else {
 572         res->tv_usec = val1->tv_usec - val2->tv_usec;
 573     }
 574 }
 575 #else
 576 #define qemu_timersub timersub
 577 #endif
 578
 579 void qemu_set_cloexec(int fd);
 580
 581 /* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
 582  * instead of QEMU_VERSION, so setting hw_version on MachineClass
 583  * is no longer mandatory.
 584  *
 585  * Do NOT change this string, or it will break compatibility on all
 586  * machine classes that don't set hw_version.
 587  */
 588 #define QEMU_HW_VERSION "2.5+"
 589
 590 /* QEMU "hardware version" setting. Used to replace code that exposed
 591  * QEMU_VERSION to guests in the past and need to keep compatibility.
 592  * Do not use qemu_hw_version() in new code.
 593  */
 594 void qemu_set_hw_version(const char *);
 595 const char *qemu_hw_version(void);
 596
 597 void fips_set_state(bool requested);
 598 bool fips_get_state(void);
 599
 600 /* Return a dynamically allocated pathname denoting a file or directory that is
 601  * appropriate for storing local state.
 602  *
 603  * @relative_pathname need not start with a directory separator; one will be
 604  * added automatically.
 605  *
 606  * The caller is responsible for releasing the value returned with g_free()
 607  * after use.
 608  */
 609 char *qemu_get_local_state_pathname(const char *relative_pathname);
 610
 611 /* Find program directory, and save it for later usage with
 612  * qemu_get_exec_dir().
 613  * Try OS specific API first, if not working, parse from argv0. */
 614 void qemu_init_exec_dir(const char *argv0);
 615
 616 /* Get the saved exec dir.  */
 617 const char *qemu_get_exec_dir(void);
 618
 619 /**
 620  * qemu_getauxval:
 621  * @type: the auxiliary vector key to lookup
 622  *
 623  * Search the auxiliary vector for @type, returning the value
 624  * or 0 if @type is not present.
 625  */
 626 unsigned long qemu_getauxval(unsigned long type);
 627
 628 void qemu_set_tty_echo(int fd, bool echo);
 629
 630 void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus,
 631                      Error **errp);
 632
 633 /**
 634  * qemu_get_pid_name:
 635  * @pid: pid of a process
 636  *
 637  * For given @pid fetch its name. Caller is responsible for
 638  * freeing the string when no longer needed.
 639  * Returns allocated string on success, NULL on failure.
 640  */
 641 char *qemu_get_pid_name(pid_t pid);
 642
 643 /**
 644  * qemu_fork:
 645  *
 646  * A version of fork that avoids signal handler race
 647  * conditions that can lead to child process getting
 648  * signals that are otherwise only expected by the
 649  * parent. It also resets all signal handlers to the
 650  * default settings.
 651  *
 652  * Returns 0 to child process, pid number to parent
 653  * or -1 on failure.
 654  */
 655 pid_t qemu_fork(Error **errp);
 656
 657 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
 658  * when intptr_t is 32-bit and we are aligning a long long.
 659  */
 660 extern uintptr_t qemu_real_host_page_size;
 661 extern intptr_t qemu_real_host_page_mask;
 662
 663 extern int qemu_icache_linesize;
 664 extern int qemu_icache_linesize_log;
 665 extern int qemu_dcache_linesize;
 666 extern int qemu_dcache_linesize_log;
 667
 668 /*
 669  * After using getopt or getopt_long, if you need to parse another set
 670  * of options, then you must reset optind.  Unfortunately the way to
 671  * do this varies between implementations of getopt.
 672  */
 673 static inline void qemu_reset_optind(void)
 674 {
 675 #ifdef HAVE_OPTRESET
 676     optind = 1;
 677     optreset = 1;
 678 #else
 679     optind = 0;
 680 #endif
 681 }
 682
 683 /**
 684  * qemu_get_host_name:
 685  * @errp: Error object
 686  *
 687  * Operating system agnostic way of querying host name.
 688  *
 689  * Returns allocated hostname (caller should free), NULL on failure.
 690  */
 691 char *qemu_get_host_name(Error **errp);
 692
 693 /**
 694  * qemu_get_host_physmem:
 695  *
 696  * Operating system agnostic way of querying host memory.
 697  *
 698  * Returns amount of physical memory on the system. This is purely
 699  * advisery and may return 0 if we can't work it out. At the other
 700  * end we saturate to SIZE_MAX if you are lucky enough to have that
 701  * much memory.
 702  */
 703 size_t qemu_get_host_physmem(void);
 704
 705 /*
 706  * Toggle write/execute on the pages marked MAP_JIT
 707  * for the current thread.
 708  */
 709 #if defined(MAC_OS_VERSION_11_0) && \
 710     MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_VERSION_11_0
 711 static inline void qemu_thread_jit_execute(void)
 712 {
 713     if (__builtin_available(macOS 11.0, *)) {
 714         pthread_jit_write_protect_np(true);
 715     }
 716 }
 717
 718 static inline void qemu_thread_jit_write(void)
 719 {
 720     if (__builtin_available(macOS 11.0, *)) {
 721         pthread_jit_write_protect_np(false);
 722     }
 723 }
 724 #else
 725 static inline void qemu_thread_jit_write(void) {}
 726 static inline void qemu_thread_jit_execute(void) {}
 727 #endif
 728
 729 /**
 730  * Platforms which do not support system() return ENOSYS
 731  */
 732 #ifndef HAVE_SYSTEM_FUNCTION
 733 #define system platform_does_not_support_system
 734 static inline int platform_does_not_support_system(const char *command)
 735 {
 736     errno = ENOSYS;
 737     return -1;
 738 }
 739 #endif /* !HAVE_SYSTEM_FUNCTION */
 740
 741 #ifdef __cplusplus
 742 }
 743 #endif
 744
 745 #endif