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 #if !defined _FORTIFY_SOURCE && defined __OPTIMIZE__ && __OPTIMIZE__ && defined __linux__ 31 # define _FORTIFY_SOURCE 2 32 #endif 33 34 #include "config-host.h" 35 #ifdef NEED_CPU_H 36 #include CONFIG_TARGET 37 #else 38 #include "exec/poison.h" 39 #endif 40 41 /* 42 * HOST_WORDS_BIGENDIAN was replaced with HOST_BIG_ENDIAN. Prevent it from 43 * creeping back in. 44 */ 45 #pragma GCC poison HOST_WORDS_BIGENDIAN 46 47 /* 48 * TARGET_WORDS_BIGENDIAN was replaced with TARGET_BIG_ENDIAN. Prevent it from 49 * creeping back in. 50 */ 51 #pragma GCC poison TARGET_WORDS_BIGENDIAN 52 53 #include "qemu/compiler.h" 54 55 /* Older versions of C++ don't get definitions of various macros from 56 * stdlib.h unless we define these macros before first inclusion of 57 * that system header. 58 */ 59 #ifndef __STDC_CONSTANT_MACROS 60 #define __STDC_CONSTANT_MACROS 61 #endif 62 #ifndef __STDC_LIMIT_MACROS 63 #define __STDC_LIMIT_MACROS 64 #endif 65 #ifndef __STDC_FORMAT_MACROS 66 #define __STDC_FORMAT_MACROS 67 #endif 68 69 /* The following block of code temporarily renames the daemon() function so the 70 * compiler does not see the warning associated with it in stdlib.h on OSX 71 */ 72 #ifdef __APPLE__ 73 #define daemon qemu_fake_daemon_function 74 #include <stdlib.h> 75 #undef daemon 76 QEMU_EXTERN_C int daemon(int, int); 77 #endif 78 79 #ifdef _WIN32 80 /* as defined in sdkddkver.h */ 81 #ifndef _WIN32_WINNT 82 #define _WIN32_WINNT 0x0602 /* Windows 8 API (should be >= the one from glib) */ 83 #endif 84 /* reduces the number of implicitly included headers */ 85 #ifndef WIN32_LEAN_AND_MEAN 86 #define WIN32_LEAN_AND_MEAN 87 #endif 88 #endif 89 90 /* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */ 91 #ifdef __MINGW32__ 92 #define __USE_MINGW_ANSI_STDIO 1 93 #endif 94 95 /* 96 * We need the FreeBSD "legacy" definitions. Rust needs the FreeBSD 11 system 97 * calls since it doesn't use libc at all, so we have to emulate that despite 98 * FreeBSD 11 being EOL'd. 99 */ 100 #ifdef __FreeBSD__ 101 #define _WANT_FREEBSD11_STAT 102 #define _WANT_FREEBSD11_STATFS 103 #define _WANT_FREEBSD11_DIRENT 104 #define _WANT_KERNEL_ERRNO 105 #define _WANT_SEMUN 106 #endif 107 108 #include <stdarg.h> 109 #include <stddef.h> 110 #include <stdbool.h> 111 #include <stdint.h> 112 #include <sys/types.h> 113 #include <stdlib.h> 114 #include <stdio.h> 115 116 #include <string.h> 117 #include <strings.h> 118 #include <inttypes.h> 119 #include <limits.h> 120 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r 121 * function availability on recentish Mingw-w64 platforms. */ 122 #include <unistd.h> 123 #include <time.h> 124 #include <ctype.h> 125 #include <errno.h> 126 #include <fcntl.h> 127 #include <getopt.h> 128 #include <sys/stat.h> 129 #include <sys/time.h> 130 #include <assert.h> 131 /* setjmp must be declared before sysemu/os-win32.h 132 * because it is redefined there. */ 133 #include <setjmp.h> 134 #include <signal.h> 135 136 #ifdef CONFIG_IOVEC 137 #include <sys/uio.h> 138 #endif 139 140 #if defined(__linux__) && defined(__sparc__) 141 /* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */ 142 #include <sys/shm.h> 143 #endif 144 145 #ifndef _WIN32 146 #include <sys/wait.h> 147 #else 148 #define WIFEXITED(x) 1 149 #define WEXITSTATUS(x) (x) 150 #endif 151 152 #ifdef __APPLE__ 153 #include <AvailabilityMacros.h> 154 #endif 155 156 /* 157 * This is somewhat like a system header; it must be outside any extern "C" 158 * block because it includes system headers itself, including glib.h, 159 * which will not compile if inside an extern "C" block. 160 */ 161 #include "glib-compat.h" 162 163 #ifdef _WIN32 164 #include "sysemu/os-win32.h" 165 #endif 166 167 #ifdef CONFIG_POSIX 168 #include "sysemu/os-posix.h" 169 #endif 170 171 #ifdef __cplusplus 172 extern "C" { 173 #endif 174 175 #include "qemu/typedefs.h" 176 177 /** 178 * Mark a function that executes in coroutine context 179 * 180 * Functions that execute in coroutine context cannot be called directly from 181 * normal functions. In the future it would be nice to enable compiler or 182 * static checker support for catching such errors. This annotation might make 183 * it possible and in the meantime it serves as documentation. 184 * 185 * For example: 186 * 187 * static void coroutine_fn foo(void) { 188 * .... 189 * } 190 */ 191 #ifdef __clang__ 192 #define coroutine_fn QEMU_ANNOTATE("coroutine_fn") 193 #else 194 #define coroutine_fn 195 #endif 196 197 /** 198 * Mark a function that can suspend when executed in coroutine context, 199 * but can handle running in non-coroutine context too. 200 */ 201 #ifdef __clang__ 202 #define coroutine_mixed_fn QEMU_ANNOTATE("coroutine_mixed_fn") 203 #else 204 #define coroutine_mixed_fn 205 #endif 206 207 /** 208 * Mark a function that should not be called from a coroutine context. 209 * Usually there will be an analogous, coroutine_fn function that should 210 * be used instead. 211 * 212 * When the function is also marked as coroutine_mixed_fn, the function should 213 * only be called if the caller does not know whether it is in coroutine 214 * context. 215 * 216 * Functions that are only no_coroutine_fn, on the other hand, should not 217 * be called from within coroutines at all. This for example includes 218 * functions that block. 219 * 220 * In the future it would be nice to enable compiler or static checker 221 * support for catching such errors. This annotation is the first step 222 * towards this, and in the meantime it serves as documentation. 223 * 224 * For example: 225 * 226 * static void no_coroutine_fn foo(void) { 227 * .... 228 * } 229 */ 230 #ifdef __clang__ 231 #define no_coroutine_fn QEMU_ANNOTATE("no_coroutine_fn") 232 #else 233 #define no_coroutine_fn 234 #endif 235 236 237 /* 238 * For mingw, as of v6.0.0, the function implementing the assert macro is 239 * not marked as noreturn, so the compiler cannot delete code following an 240 * assert(false) as unused. We rely on this within the code base to delete 241 * code that is unreachable when features are disabled. 242 * All supported versions of Glib's g_assert() satisfy this requirement. 243 */ 244 #ifdef __MINGW32__ 245 #undef assert 246 #define assert(x) g_assert(x) 247 #endif 248 249 /** 250 * qemu_build_not_reached() 251 * 252 * The compiler, during optimization, is expected to prove that a call 253 * to this function cannot be reached and remove it. If the compiler 254 * supports QEMU_ERROR, this will be reported at compile time; otherwise 255 * this will be reported at link time due to the missing symbol. 256 */ 257 G_NORETURN 258 void QEMU_ERROR("code path is reachable") 259 qemu_build_not_reached_always(void); 260 #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__) 261 #define qemu_build_not_reached() qemu_build_not_reached_always() 262 #else 263 #define qemu_build_not_reached() g_assert_not_reached() 264 #endif 265 266 /** 267 * qemu_build_assert() 268 * 269 * The compiler, during optimization, is expected to prove that the 270 * assertion is true. 271 */ 272 #define qemu_build_assert(test) while (!(test)) qemu_build_not_reached() 273 274 /* 275 * According to waitpid man page: 276 * WCOREDUMP 277 * This macro is not specified in POSIX.1-2001 and is not 278 * available on some UNIX implementations (e.g., AIX, SunOS). 279 * Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif. 280 */ 281 #ifndef WCOREDUMP 282 #define WCOREDUMP(status) 0 283 #endif 284 /* 285 * We have a lot of unaudited code that may fail in strange ways, or 286 * even be a security risk during migration, if you disable assertions 287 * at compile-time. You may comment out these safety checks if you 288 * absolutely want to disable assertion overhead, but it is not 289 * supported upstream so the risk is all yours. Meanwhile, please 290 * submit patches to remove any side-effects inside an assertion, or 291 * fixing error handling that should use Error instead of assert. 292 */ 293 #ifdef NDEBUG 294 #error building with NDEBUG is not supported 295 #endif 296 #ifdef G_DISABLE_ASSERT 297 #error building with G_DISABLE_ASSERT is not supported 298 #endif 299 300 #ifndef O_LARGEFILE 301 #define O_LARGEFILE 0 302 #endif 303 #ifndef O_BINARY 304 #define O_BINARY 0 305 #endif 306 #ifndef MAP_ANONYMOUS 307 #define MAP_ANONYMOUS MAP_ANON 308 #endif 309 #ifndef MAP_NORESERVE 310 #define MAP_NORESERVE 0 311 #endif 312 #ifndef ENOMEDIUM 313 #define ENOMEDIUM ENODEV 314 #endif 315 #if !defined(ENOTSUP) 316 #define ENOTSUP 4096 317 #endif 318 #if !defined(ECANCELED) 319 #define ECANCELED 4097 320 #endif 321 #if !defined(EMEDIUMTYPE) 322 #define EMEDIUMTYPE 4098 323 #endif 324 #if !defined(ESHUTDOWN) 325 #define ESHUTDOWN 4099 326 #endif 327 328 #define RETRY_ON_EINTR(expr) \ 329 (__extension__ \ 330 ({ typeof(expr) __result; \ 331 do { \ 332 __result = (expr); \ 333 } while (__result == -1 && errno == EINTR); \ 334 __result; })) 335 336 /* time_t may be either 32 or 64 bits depending on the host OS, and 337 * can be either signed or unsigned, so we can't just hardcode a 338 * specific maximum value. This is not a C preprocessor constant, 339 * so you can't use TIME_MAX in an #ifdef, but for our purposes 340 * this isn't a problem. 341 */ 342 343 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from 344 * Gnulib, and are under the LGPL v2.1 or (at your option) any 345 * later version. 346 */ 347 348 /* True if the real type T is signed. */ 349 #define TYPE_SIGNED(t) (!((t)0 < (t)-1)) 350 351 /* The width in bits of the integer type or expression T. 352 * Padding bits are not supported. 353 */ 354 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT) 355 356 /* The maximum and minimum values for the integer type T. */ 357 #define TYPE_MAXIMUM(t) \ 358 ((t) (!TYPE_SIGNED(t) \ 359 ? (t)-1 \ 360 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1))) 361 362 #ifndef TIME_MAX 363 #define TIME_MAX TYPE_MAXIMUM(time_t) 364 #endif 365 366 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with 367 * the wrong type. Our replacement isn't usable in preprocessor 368 * expressions, but it is sufficient for our needs. */ 369 #ifdef HAVE_BROKEN_SIZE_MAX 370 #undef SIZE_MAX 371 #define SIZE_MAX ((size_t)-1) 372 #endif 373 374 /* 375 * Two variations of MIN/MAX macros. The first is for runtime use, and 376 * evaluates arguments only once (so it is safe even with side 377 * effects), but will not work in constant contexts (such as array 378 * size declarations) because of the '{}'. The second is for constant 379 * expression use, where evaluating arguments twice is safe because 380 * the result is going to be constant anyway, but will not work in a 381 * runtime context because of a void expression where a value is 382 * expected. Thus, both gcc and clang will fail to compile if you use 383 * the wrong macro (even if the error may seem a bit cryptic). 384 * 385 * Note that neither form is usable as an #if condition; if you truly 386 * need to write conditional code that depends on a minimum or maximum 387 * determined by the pre-processor instead of the compiler, you'll 388 * have to open-code it. Sadly, Coverity is severely confused by the 389 * constant variants, so we have to dumb things down there. 390 * 391 * Preprocessor sorcery ahead: use different identifiers for the local 392 * variables in each expansion, so we can nest macro calls without 393 * shadowing variables. 394 */ 395 #define MIN_INTERNAL(a, b, _a, _b) \ 396 ({ \ 397 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 398 _a < _b ? _a : _b; \ 399 }) 400 #undef MIN 401 #define MIN(a, b) \ 402 MIN_INTERNAL((a), (b), MAKE_IDENTFIER(_a), MAKE_IDENTFIER(_b)) 403 404 #define MAX_INTERNAL(a, b, _a, _b) \ 405 ({ \ 406 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 407 _a > _b ? _a : _b; \ 408 }) 409 #undef MAX 410 #define MAX(a, b) \ 411 MAX_INTERNAL((a), (b), MAKE_IDENTFIER(_a), MAKE_IDENTFIER(_b)) 412 413 #ifdef __COVERITY__ 414 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b)) 415 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b)) 416 #else 417 # define MIN_CONST(a, b) \ 418 __builtin_choose_expr( \ 419 __builtin_constant_p(a) && __builtin_constant_p(b), \ 420 (a) < (b) ? (a) : (b), \ 421 ((void)0)) 422 # define MAX_CONST(a, b) \ 423 __builtin_choose_expr( \ 424 __builtin_constant_p(a) && __builtin_constant_p(b), \ 425 (a) > (b) ? (a) : (b), \ 426 ((void)0)) 427 #endif 428 429 /* 430 * Minimum function that returns zero only if both values are zero. 431 * Intended for use with unsigned values only. 432 * 433 * Preprocessor sorcery ahead: use different identifiers for the local 434 * variables in each expansion, so we can nest macro calls without 435 * shadowing variables. 436 */ 437 #define MIN_NON_ZERO_INTERNAL(a, b, _a, _b) \ 438 ({ \ 439 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 440 _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \ 441 }) 442 #define MIN_NON_ZERO(a, b) \ 443 MIN_NON_ZERO_INTERNAL((a), (b), MAKE_IDENTFIER(_a), MAKE_IDENTFIER(_b)) 444 445 /* 446 * Round number down to multiple. Safe when m is not a power of 2 (see 447 * ROUND_DOWN for a faster version when a power of 2 is guaranteed). 448 */ 449 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m)) 450 451 /* 452 * Round number up to multiple. Safe when m is not a power of 2 (see 453 * ROUND_UP for a faster version when a power of 2 is guaranteed). 454 */ 455 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m)) 456 457 /* Check if n is a multiple of m */ 458 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0) 459 460 /* n-byte align pointer down */ 461 #define QEMU_ALIGN_PTR_DOWN(p, n) \ 462 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n))) 463 464 /* n-byte align pointer up */ 465 #define QEMU_ALIGN_PTR_UP(p, n) \ 466 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n))) 467 468 /* Check if pointer p is n-bytes aligned */ 469 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n)) 470 471 /* 472 * Round number down to multiple. Requires that d be a power of 2 (see 473 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 474 * numbers); works even if d is a smaller type than n. 475 */ 476 #ifndef ROUND_DOWN 477 #define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d))) 478 #endif 479 480 /* 481 * Round number up to multiple. Requires that d be a power of 2 (see 482 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 483 * numbers); works even if d is a smaller type than n. 484 */ 485 #ifndef ROUND_UP 486 #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d)) 487 #endif 488 489 #ifndef DIV_ROUND_UP 490 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) 491 #endif 492 493 /* 494 * &(x)[0] is always a pointer - if it's same type as x then the argument is a 495 * pointer, not an array. 496 */ 497 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \ 498 typeof(&(x)[0]))) 499 #ifndef ARRAY_SIZE 500 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \ 501 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x))) 502 #endif 503 504 int qemu_daemon(int nochdir, int noclose); 505 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, 506 bool noreserve); 507 void qemu_anon_ram_free(void *ptr, size_t size); 508 509 #ifdef _WIN32 510 #define HAVE_CHARDEV_SERIAL 1 511 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 512 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \ 513 || defined(__GLIBC__) || defined(__APPLE__) 514 #define HAVE_CHARDEV_SERIAL 1 515 #endif 516 517 #if defined(__HAIKU__) 518 #define SIGIO SIGPOLL 519 #endif 520 521 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE 522 /* 523 * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion 524 * about Solaris missing the madvise() prototype. 525 */ 526 int madvise(char *, size_t, int); 527 #endif 528 529 #if defined(CONFIG_LINUX) 530 #ifndef BUS_MCEERR_AR 531 #define BUS_MCEERR_AR 4 532 #endif 533 #ifndef BUS_MCEERR_AO 534 #define BUS_MCEERR_AO 5 535 #endif 536 #endif 537 538 #if defined(__linux__) && \ 539 (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \ 540 || defined(__powerpc64__)) 541 /* Use 2 MiB alignment so transparent hugepages can be used by KVM. 542 Valgrind does not support alignments larger than 1 MiB, 543 therefore we need special code which handles running on Valgrind. */ 544 # define QEMU_VMALLOC_ALIGN (512 * 4096) 545 #elif defined(__linux__) && defined(__s390x__) 546 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ 547 # define QEMU_VMALLOC_ALIGN (256 * 4096) 548 #elif defined(__linux__) && defined(__sparc__) 549 # define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA) 550 #elif defined(__linux__) && defined(__loongarch__) 551 /* 552 * For transparent hugepage optimization, it has better be huge page 553 * aligned. LoongArch host system supports two kinds of pagesize: 4K 554 * and 16K, here calculate huge page size from host page size 555 */ 556 # define QEMU_VMALLOC_ALIGN (qemu_real_host_page_size() * \ 557 qemu_real_host_page_size() / sizeof(long)) 558 #else 559 # define QEMU_VMALLOC_ALIGN qemu_real_host_page_size() 560 #endif 561 562 #ifdef CONFIG_POSIX 563 struct qemu_signalfd_siginfo { 564 uint32_t ssi_signo; /* Signal number */ 565 int32_t ssi_errno; /* Error number (unused) */ 566 int32_t ssi_code; /* Signal code */ 567 uint32_t ssi_pid; /* PID of sender */ 568 uint32_t ssi_uid; /* Real UID of sender */ 569 int32_t ssi_fd; /* File descriptor (SIGIO) */ 570 uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */ 571 uint32_t ssi_band; /* Band event (SIGIO) */ 572 uint32_t ssi_overrun; /* POSIX timer overrun count */ 573 uint32_t ssi_trapno; /* Trap number that caused signal */ 574 int32_t ssi_status; /* Exit status or signal (SIGCHLD) */ 575 int32_t ssi_int; /* Integer sent by sigqueue(2) */ 576 uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */ 577 uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */ 578 uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */ 579 uint64_t ssi_addr; /* Address that generated signal 580 (for hardware-generated signals) */ 581 uint8_t pad[48]; /* Pad size to 128 bytes (allow for 582 additional fields in the future) */ 583 }; 584 585 int qemu_signalfd(const sigset_t *mask); 586 void sigaction_invoke(struct sigaction *action, 587 struct qemu_signalfd_siginfo *info); 588 #endif 589 590 /* 591 * Don't introduce new usage of this function, prefer the following 592 * qemu_open/qemu_create that take an "Error **errp" 593 */ 594 int qemu_open_old(const char *name, int flags, ...); 595 int qemu_open(const char *name, int flags, Error **errp); 596 int qemu_create(const char *name, int flags, mode_t mode, Error **errp); 597 int qemu_close(int fd); 598 int qemu_unlink(const char *name); 599 #ifndef _WIN32 600 int qemu_dup_flags(int fd, int flags); 601 int qemu_dup(int fd); 602 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); 603 int qemu_unlock_fd(int fd, int64_t start, int64_t len); 604 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); 605 bool qemu_has_ofd_lock(void); 606 #endif 607 608 #if defined(__HAIKU__) && defined(__i386__) 609 #define FMT_pid "%ld" 610 #elif defined(WIN64) 611 #define FMT_pid "%" PRId64 612 #else 613 #define FMT_pid "%d" 614 #endif 615 616 bool qemu_write_pidfile(const char *pidfile, Error **errp); 617 618 int qemu_get_thread_id(void); 619 620 #ifndef CONFIG_IOVEC 621 struct iovec { 622 void *iov_base; 623 size_t iov_len; 624 }; 625 /* 626 * Use the same value as Linux for now. 627 */ 628 #define IOV_MAX 1024 629 630 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt); 631 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt); 632 #endif 633 634 #ifdef _WIN32 635 static inline void qemu_timersub(const struct timeval *val1, 636 const struct timeval *val2, 637 struct timeval *res) 638 { 639 res->tv_sec = val1->tv_sec - val2->tv_sec; 640 if (val1->tv_usec < val2->tv_usec) { 641 res->tv_sec--; 642 res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000; 643 } else { 644 res->tv_usec = val1->tv_usec - val2->tv_usec; 645 } 646 } 647 #else 648 #define qemu_timersub timersub 649 #endif 650 651 ssize_t qemu_write_full(int fd, const void *buf, size_t count) 652 G_GNUC_WARN_UNUSED_RESULT; 653 654 void qemu_set_cloexec(int fd); 655 656 /* Return a dynamically allocated directory path that is appropriate for storing 657 * local state. 658 * 659 * The caller is responsible for releasing the value returned with g_free() 660 * after use. 661 */ 662 char *qemu_get_local_state_dir(void); 663 664 /** 665 * qemu_getauxval: 666 * @type: the auxiliary vector key to lookup 667 * 668 * Search the auxiliary vector for @type, returning the value 669 * or 0 if @type is not present. 670 */ 671 unsigned long qemu_getauxval(unsigned long type); 672 673 void qemu_set_tty_echo(int fd, bool echo); 674 675 typedef struct ThreadContext ThreadContext; 676 677 /** 678 * qemu_prealloc_mem: 679 * @fd: the fd mapped into the area, -1 for anonymous memory 680 * @area: start address of the are to preallocate 681 * @sz: the size of the area to preallocate 682 * @max_threads: maximum number of threads to use 683 * @tc: prealloc context threads pointer, NULL if not in use 684 * @async: request asynchronous preallocation, requires @tc 685 * @errp: returns an error if this function fails 686 * 687 * Preallocate memory (populate/prefault page tables writable) for the virtual 688 * memory area starting at @area with the size of @sz. After a successful call, 689 * each page in the area was faulted in writable at least once, for example, 690 * after allocating file blocks for mapped files. 691 * 692 * When setting @async, allocation might be performed asynchronously. 693 * qemu_finish_async_prealloc_mem() must be called to finish any asynchronous 694 * preallocation. 695 * 696 * Return: true on success, else false setting @errp with error. 697 */ 698 bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, 699 ThreadContext *tc, bool async, Error **errp); 700 701 /** 702 * qemu_finish_async_prealloc_mem: 703 * @errp: returns an error if this function fails 704 * 705 * Finish all outstanding asynchronous memory preallocation. 706 * 707 * Return: true on success, else false setting @errp with error. 708 */ 709 bool qemu_finish_async_prealloc_mem(Error **errp); 710 711 /** 712 * qemu_get_pid_name: 713 * @pid: pid of a process 714 * 715 * For given @pid fetch its name. Caller is responsible for 716 * freeing the string when no longer needed. 717 * Returns allocated string on success, NULL on failure. 718 */ 719 char *qemu_get_pid_name(pid_t pid); 720 721 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even 722 * when intptr_t is 32-bit and we are aligning a long long. 723 */ 724 static inline uintptr_t qemu_real_host_page_size(void) 725 { 726 return getpagesize(); 727 } 728 729 static inline intptr_t qemu_real_host_page_mask(void) 730 { 731 return -(intptr_t)qemu_real_host_page_size(); 732 } 733 734 /* 735 * After using getopt or getopt_long, if you need to parse another set 736 * of options, then you must reset optind. Unfortunately the way to 737 * do this varies between implementations of getopt. 738 */ 739 static inline void qemu_reset_optind(void) 740 { 741 #ifdef HAVE_OPTRESET 742 optind = 1; 743 optreset = 1; 744 #else 745 optind = 0; 746 #endif 747 } 748 749 int qemu_fdatasync(int fd); 750 751 /** 752 * Sync changes made to the memory mapped file back to the backing 753 * storage. For POSIX compliant systems this will fallback 754 * to regular msync call. Otherwise it will trigger whole file sync 755 * (including the metadata case there is no support to skip that otherwise) 756 * 757 * @addr - start of the memory area to be synced 758 * @length - length of the are to be synced 759 * @fd - file descriptor for the file to be synced 760 * (mandatory only for POSIX non-compliant systems) 761 */ 762 int qemu_msync(void *addr, size_t length, int fd); 763 764 /** 765 * qemu_get_host_physmem: 766 * 767 * Operating system agnostic way of querying host memory. 768 * 769 * Returns amount of physical memory on the system. This is purely 770 * advisery and may return 0 if we can't work it out. At the other 771 * end we saturate to SIZE_MAX if you are lucky enough to have that 772 * much memory. 773 */ 774 size_t qemu_get_host_physmem(void); 775 776 /* 777 * Toggle write/execute on the pages marked MAP_JIT 778 * for the current thread. 779 */ 780 #if defined(MAC_OS_VERSION_11_0) && \ 781 MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0 782 static inline void qemu_thread_jit_execute(void) 783 { 784 pthread_jit_write_protect_np(true); 785 } 786 787 static inline void qemu_thread_jit_write(void) 788 { 789 pthread_jit_write_protect_np(false); 790 } 791 #else 792 static inline void qemu_thread_jit_write(void) {} 793 static inline void qemu_thread_jit_execute(void) {} 794 #endif 795 796 /** 797 * Platforms which do not support system() return ENOSYS 798 */ 799 #ifndef HAVE_SYSTEM_FUNCTION 800 #define system platform_does_not_support_system 801 static inline int platform_does_not_support_system(const char *command) 802 { 803 errno = ENOSYS; 804 return -1; 805 } 806 #endif /* !HAVE_SYSTEM_FUNCTION */ 807 808 #ifdef __cplusplus 809 } 810 #endif 811 812 #endif 813