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 /* 38 * HOST_WORDS_BIGENDIAN was replaced with HOST_BIG_ENDIAN. Prevent it from 39 * creeping back in. 40 */ 41 #pragma GCC poison HOST_WORDS_BIGENDIAN 42 43 /* 44 * TARGET_WORDS_BIGENDIAN was replaced with TARGET_BIG_ENDIAN. Prevent it from 45 * creeping back in. 46 */ 47 #pragma GCC poison TARGET_WORDS_BIGENDIAN 48 49 #include "qemu/compiler.h" 50 51 /* Older versions of C++ don't get definitions of various macros from 52 * stdlib.h unless we define these macros before first inclusion of 53 * that system header. 54 */ 55 #ifndef __STDC_CONSTANT_MACROS 56 #define __STDC_CONSTANT_MACROS 57 #endif 58 #ifndef __STDC_LIMIT_MACROS 59 #define __STDC_LIMIT_MACROS 60 #endif 61 #ifndef __STDC_FORMAT_MACROS 62 #define __STDC_FORMAT_MACROS 63 #endif 64 65 /* The following block of code temporarily renames the daemon() function so the 66 * compiler does not see the warning associated with it in stdlib.h on OSX 67 */ 68 #ifdef __APPLE__ 69 #define daemon qemu_fake_daemon_function 70 #include <stdlib.h> 71 #undef daemon 72 QEMU_EXTERN_C int daemon(int, int); 73 #endif 74 75 #ifdef _WIN32 76 /* as defined in sdkddkver.h */ 77 #ifndef _WIN32_WINNT 78 #define _WIN32_WINNT 0x0601 /* Windows 7 API (should be in sync with glib) */ 79 #endif 80 /* reduces the number of implicitly included headers */ 81 #ifndef WIN32_LEAN_AND_MEAN 82 #define WIN32_LEAN_AND_MEAN 83 #endif 84 #endif 85 86 /* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */ 87 #ifdef __MINGW32__ 88 #define __USE_MINGW_ANSI_STDIO 1 89 #endif 90 91 #include <stdarg.h> 92 #include <stddef.h> 93 #include <stdbool.h> 94 #include <stdint.h> 95 #include <sys/types.h> 96 #include <stdlib.h> 97 #include <stdio.h> 98 99 #include <string.h> 100 #include <strings.h> 101 #include <inttypes.h> 102 #include <limits.h> 103 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r 104 * function availability on recentish Mingw-w64 platforms. */ 105 #include <unistd.h> 106 #include <time.h> 107 #include <ctype.h> 108 #include <errno.h> 109 #include <fcntl.h> 110 #include <getopt.h> 111 #include <sys/stat.h> 112 #include <sys/time.h> 113 #include <assert.h> 114 /* setjmp must be declared before sysemu/os-win32.h 115 * because it is redefined there. */ 116 #include <setjmp.h> 117 #include <signal.h> 118 119 #ifdef CONFIG_IOVEC 120 #include <sys/uio.h> 121 #endif 122 123 #if defined(__linux__) && defined(__sparc__) 124 /* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */ 125 #include <sys/shm.h> 126 #endif 127 128 #ifndef _WIN32 129 #include <sys/wait.h> 130 #else 131 #define WIFEXITED(x) 1 132 #define WEXITSTATUS(x) (x) 133 #endif 134 135 #ifdef __APPLE__ 136 #include <AvailabilityMacros.h> 137 #endif 138 139 /* 140 * This is somewhat like a system header; it must be outside any extern "C" 141 * block because it includes system headers itself, including glib.h, 142 * which will not compile if inside an extern "C" block. 143 */ 144 #include "glib-compat.h" 145 146 #ifdef _WIN32 147 #include "sysemu/os-win32.h" 148 #endif 149 150 #ifdef CONFIG_POSIX 151 #include "sysemu/os-posix.h" 152 #endif 153 154 #ifdef __cplusplus 155 extern "C" { 156 #endif 157 158 #include "qemu/typedefs.h" 159 160 /** 161 * Mark a function that executes in coroutine context 162 * 163 * Functions that execute in coroutine context cannot be called directly from 164 * normal functions. In the future it would be nice to enable compiler or 165 * static checker support for catching such errors. This annotation might make 166 * it possible and in the meantime it serves as documentation. 167 * 168 * For example: 169 * 170 * static void coroutine_fn foo(void) { 171 * .... 172 * } 173 */ 174 #ifdef __clang__ 175 #define coroutine_fn __attribute__((__annotate__("coroutine_fn"))) 176 #else 177 #define coroutine_fn 178 #endif 179 180 /** 181 * Mark a function that can suspend when executed in coroutine context, 182 * but can handle running in non-coroutine context too. 183 */ 184 #ifdef __clang__ 185 #define coroutine_mixed_fn __attribute__((__annotate__("coroutine_mixed_fn"))) 186 #else 187 #define coroutine_mixed_fn 188 #endif 189 190 /** 191 * Mark a function that should not be called from a coroutine context. 192 * Usually there will be an analogous, coroutine_fn function that should 193 * be used instead. 194 * 195 * When the function is also marked as coroutine_mixed_fn, the function should 196 * only be called if the caller does not know whether it is in coroutine 197 * context. 198 * 199 * Functions that are only no_coroutine_fn, on the other hand, should not 200 * be called from within coroutines at all. This for example includes 201 * functions that block. 202 * 203 * In the future it would be nice to enable compiler or static checker 204 * support for catching such errors. This annotation is the first step 205 * towards this, and in the meantime it serves as documentation. 206 * 207 * For example: 208 * 209 * static void no_coroutine_fn foo(void) { 210 * .... 211 * } 212 */ 213 #ifdef __clang__ 214 #define no_coroutine_fn __attribute__((__annotate__("no_coroutine_fn"))) 215 #else 216 #define no_coroutine_fn 217 #endif 218 219 220 /* 221 * For mingw, as of v6.0.0, the function implementing the assert macro is 222 * not marked as noreturn, so the compiler cannot delete code following an 223 * assert(false) as unused. We rely on this within the code base to delete 224 * code that is unreachable when features are disabled. 225 * All supported versions of Glib's g_assert() satisfy this requirement. 226 */ 227 #ifdef __MINGW32__ 228 #undef assert 229 #define assert(x) g_assert(x) 230 #endif 231 232 /** 233 * qemu_build_not_reached() 234 * 235 * The compiler, during optimization, is expected to prove that a call 236 * to this function cannot be reached and remove it. If the compiler 237 * supports QEMU_ERROR, this will be reported at compile time; otherwise 238 * this will be reported at link time due to the missing symbol. 239 */ 240 G_NORETURN extern 241 void QEMU_ERROR("code path is reachable") 242 qemu_build_not_reached_always(void); 243 #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__) 244 #define qemu_build_not_reached() qemu_build_not_reached_always() 245 #else 246 #define qemu_build_not_reached() g_assert_not_reached() 247 #endif 248 249 /** 250 * qemu_build_assert() 251 * 252 * The compiler, during optimization, is expected to prove that the 253 * assertion is true. 254 */ 255 #define qemu_build_assert(test) while (!(test)) qemu_build_not_reached() 256 257 /* 258 * According to waitpid man page: 259 * WCOREDUMP 260 * This macro is not specified in POSIX.1-2001 and is not 261 * available on some UNIX implementations (e.g., AIX, SunOS). 262 * Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif. 263 */ 264 #ifndef WCOREDUMP 265 #define WCOREDUMP(status) 0 266 #endif 267 /* 268 * We have a lot of unaudited code that may fail in strange ways, or 269 * even be a security risk during migration, if you disable assertions 270 * at compile-time. You may comment out these safety checks if you 271 * absolutely want to disable assertion overhead, but it is not 272 * supported upstream so the risk is all yours. Meanwhile, please 273 * submit patches to remove any side-effects inside an assertion, or 274 * fixing error handling that should use Error instead of assert. 275 */ 276 #ifdef NDEBUG 277 #error building with NDEBUG is not supported 278 #endif 279 #ifdef G_DISABLE_ASSERT 280 #error building with G_DISABLE_ASSERT is not supported 281 #endif 282 283 #ifndef O_LARGEFILE 284 #define O_LARGEFILE 0 285 #endif 286 #ifndef O_BINARY 287 #define O_BINARY 0 288 #endif 289 #ifndef MAP_ANONYMOUS 290 #define MAP_ANONYMOUS MAP_ANON 291 #endif 292 #ifndef MAP_FIXED_NOREPLACE 293 #define MAP_FIXED_NOREPLACE 0 294 #endif 295 #ifndef MAP_NORESERVE 296 #define MAP_NORESERVE 0 297 #endif 298 #ifndef ENOMEDIUM 299 #define ENOMEDIUM ENODEV 300 #endif 301 #if !defined(ENOTSUP) 302 #define ENOTSUP 4096 303 #endif 304 #if !defined(ECANCELED) 305 #define ECANCELED 4097 306 #endif 307 #if !defined(EMEDIUMTYPE) 308 #define EMEDIUMTYPE 4098 309 #endif 310 #if !defined(ESHUTDOWN) 311 #define ESHUTDOWN 4099 312 #endif 313 314 #define RETRY_ON_EINTR(expr) \ 315 (__extension__ \ 316 ({ typeof(expr) __result; \ 317 do { \ 318 __result = (expr); \ 319 } while (__result == -1 && errno == EINTR); \ 320 __result; })) 321 322 /* time_t may be either 32 or 64 bits depending on the host OS, and 323 * can be either signed or unsigned, so we can't just hardcode a 324 * specific maximum value. This is not a C preprocessor constant, 325 * so you can't use TIME_MAX in an #ifdef, but for our purposes 326 * this isn't a problem. 327 */ 328 329 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from 330 * Gnulib, and are under the LGPL v2.1 or (at your option) any 331 * later version. 332 */ 333 334 /* True if the real type T is signed. */ 335 #define TYPE_SIGNED(t) (!((t)0 < (t)-1)) 336 337 /* The width in bits of the integer type or expression T. 338 * Padding bits are not supported. 339 */ 340 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT) 341 342 /* The maximum and minimum values for the integer type T. */ 343 #define TYPE_MAXIMUM(t) \ 344 ((t) (!TYPE_SIGNED(t) \ 345 ? (t)-1 \ 346 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1))) 347 348 #ifndef TIME_MAX 349 #define TIME_MAX TYPE_MAXIMUM(time_t) 350 #endif 351 352 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with 353 * the wrong type. Our replacement isn't usable in preprocessor 354 * expressions, but it is sufficient for our needs. */ 355 #ifdef HAVE_BROKEN_SIZE_MAX 356 #undef SIZE_MAX 357 #define SIZE_MAX ((size_t)-1) 358 #endif 359 360 /* 361 * Two variations of MIN/MAX macros. The first is for runtime use, and 362 * evaluates arguments only once (so it is safe even with side 363 * effects), but will not work in constant contexts (such as array 364 * size declarations) because of the '{}'. The second is for constant 365 * expression use, where evaluating arguments twice is safe because 366 * the result is going to be constant anyway, but will not work in a 367 * runtime context because of a void expression where a value is 368 * expected. Thus, both gcc and clang will fail to compile if you use 369 * the wrong macro (even if the error may seem a bit cryptic). 370 * 371 * Note that neither form is usable as an #if condition; if you truly 372 * need to write conditional code that depends on a minimum or maximum 373 * determined by the pre-processor instead of the compiler, you'll 374 * have to open-code it. Sadly, Coverity is severely confused by the 375 * constant variants, so we have to dumb things down there. 376 */ 377 #undef MIN 378 #define MIN(a, b) \ 379 ({ \ 380 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 381 _a < _b ? _a : _b; \ 382 }) 383 #undef MAX 384 #define MAX(a, b) \ 385 ({ \ 386 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 387 _a > _b ? _a : _b; \ 388 }) 389 390 #ifdef __COVERITY__ 391 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b)) 392 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b)) 393 #else 394 # define MIN_CONST(a, b) \ 395 __builtin_choose_expr( \ 396 __builtin_constant_p(a) && __builtin_constant_p(b), \ 397 (a) < (b) ? (a) : (b), \ 398 ((void)0)) 399 # define MAX_CONST(a, b) \ 400 __builtin_choose_expr( \ 401 __builtin_constant_p(a) && __builtin_constant_p(b), \ 402 (a) > (b) ? (a) : (b), \ 403 ((void)0)) 404 #endif 405 406 /* 407 * Minimum function that returns zero only if both values are zero. 408 * Intended for use with unsigned values only. 409 */ 410 #ifndef MIN_NON_ZERO 411 #define MIN_NON_ZERO(a, b) \ 412 ({ \ 413 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 414 _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \ 415 }) 416 #endif 417 418 /* 419 * Round number down to multiple. Safe when m is not a power of 2 (see 420 * ROUND_DOWN for a faster version when a power of 2 is guaranteed). 421 */ 422 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m)) 423 424 /* 425 * Round number up to multiple. Safe when m is not a power of 2 (see 426 * ROUND_UP for a faster version when a power of 2 is guaranteed). 427 */ 428 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m)) 429 430 /* Check if n is a multiple of m */ 431 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0) 432 433 /* n-byte align pointer down */ 434 #define QEMU_ALIGN_PTR_DOWN(p, n) \ 435 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n))) 436 437 /* n-byte align pointer up */ 438 #define QEMU_ALIGN_PTR_UP(p, n) \ 439 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n))) 440 441 /* Check if pointer p is n-bytes aligned */ 442 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n)) 443 444 /* 445 * Round number down to multiple. Requires that d be a power of 2 (see 446 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 447 * numbers); works even if d is a smaller type than n. 448 */ 449 #ifndef ROUND_DOWN 450 #define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d))) 451 #endif 452 453 /* 454 * Round number up to multiple. Requires that d be a power of 2 (see 455 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 456 * numbers); works even if d is a smaller type than n. 457 */ 458 #ifndef ROUND_UP 459 #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d)) 460 #endif 461 462 #ifndef DIV_ROUND_UP 463 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) 464 #endif 465 466 /* 467 * &(x)[0] is always a pointer - if it's same type as x then the argument is a 468 * pointer, not an array. 469 */ 470 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \ 471 typeof(&(x)[0]))) 472 #ifndef ARRAY_SIZE 473 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \ 474 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x))) 475 #endif 476 477 int qemu_daemon(int nochdir, int noclose); 478 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, 479 bool noreserve); 480 void qemu_anon_ram_free(void *ptr, size_t size); 481 482 #ifdef _WIN32 483 #define HAVE_CHARDEV_SERIAL 1 484 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 485 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \ 486 || defined(__GLIBC__) || defined(__APPLE__) 487 #define HAVE_CHARDEV_SERIAL 1 488 #endif 489 490 #if defined(__HAIKU__) 491 #define SIGIO SIGPOLL 492 #endif 493 494 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE 495 /* 496 * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion 497 * about Solaris missing the madvise() prototype. 498 */ 499 extern int madvise(char *, size_t, int); 500 #endif 501 502 #if defined(CONFIG_LINUX) 503 #ifndef BUS_MCEERR_AR 504 #define BUS_MCEERR_AR 4 505 #endif 506 #ifndef BUS_MCEERR_AO 507 #define BUS_MCEERR_AO 5 508 #endif 509 #endif 510 511 #if defined(__linux__) && \ 512 (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \ 513 || defined(__powerpc64__)) 514 /* Use 2 MiB alignment so transparent hugepages can be used by KVM. 515 Valgrind does not support alignments larger than 1 MiB, 516 therefore we need special code which handles running on Valgrind. */ 517 # define QEMU_VMALLOC_ALIGN (512 * 4096) 518 #elif defined(__linux__) && defined(__s390x__) 519 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ 520 # define QEMU_VMALLOC_ALIGN (256 * 4096) 521 #elif defined(__linux__) && defined(__sparc__) 522 # define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA) 523 #else 524 # define QEMU_VMALLOC_ALIGN qemu_real_host_page_size() 525 #endif 526 527 #ifdef CONFIG_POSIX 528 struct qemu_signalfd_siginfo { 529 uint32_t ssi_signo; /* Signal number */ 530 int32_t ssi_errno; /* Error number (unused) */ 531 int32_t ssi_code; /* Signal code */ 532 uint32_t ssi_pid; /* PID of sender */ 533 uint32_t ssi_uid; /* Real UID of sender */ 534 int32_t ssi_fd; /* File descriptor (SIGIO) */ 535 uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */ 536 uint32_t ssi_band; /* Band event (SIGIO) */ 537 uint32_t ssi_overrun; /* POSIX timer overrun count */ 538 uint32_t ssi_trapno; /* Trap number that caused signal */ 539 int32_t ssi_status; /* Exit status or signal (SIGCHLD) */ 540 int32_t ssi_int; /* Integer sent by sigqueue(2) */ 541 uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */ 542 uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */ 543 uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */ 544 uint64_t ssi_addr; /* Address that generated signal 545 (for hardware-generated signals) */ 546 uint8_t pad[48]; /* Pad size to 128 bytes (allow for 547 additional fields in the future) */ 548 }; 549 550 int qemu_signalfd(const sigset_t *mask); 551 void sigaction_invoke(struct sigaction *action, 552 struct qemu_signalfd_siginfo *info); 553 #endif 554 555 /* 556 * Don't introduce new usage of this function, prefer the following 557 * qemu_open/qemu_create that take an "Error **errp" 558 */ 559 int qemu_open_old(const char *name, int flags, ...); 560 int qemu_open(const char *name, int flags, Error **errp); 561 int qemu_create(const char *name, int flags, mode_t mode, Error **errp); 562 int qemu_close(int fd); 563 int qemu_unlink(const char *name); 564 #ifndef _WIN32 565 int qemu_dup_flags(int fd, int flags); 566 int qemu_dup(int fd); 567 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); 568 int qemu_unlock_fd(int fd, int64_t start, int64_t len); 569 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); 570 bool qemu_has_ofd_lock(void); 571 #endif 572 573 #if defined(__HAIKU__) && defined(__i386__) 574 #define FMT_pid "%ld" 575 #elif defined(WIN64) 576 #define FMT_pid "%" PRId64 577 #else 578 #define FMT_pid "%d" 579 #endif 580 581 bool qemu_write_pidfile(const char *pidfile, Error **errp); 582 583 int qemu_get_thread_id(void); 584 585 #ifndef CONFIG_IOVEC 586 struct iovec { 587 void *iov_base; 588 size_t iov_len; 589 }; 590 /* 591 * Use the same value as Linux for now. 592 */ 593 #define IOV_MAX 1024 594 595 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt); 596 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt); 597 #endif 598 599 #ifdef _WIN32 600 static inline void qemu_timersub(const struct timeval *val1, 601 const struct timeval *val2, 602 struct timeval *res) 603 { 604 res->tv_sec = val1->tv_sec - val2->tv_sec; 605 if (val1->tv_usec < val2->tv_usec) { 606 res->tv_sec--; 607 res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000; 608 } else { 609 res->tv_usec = val1->tv_usec - val2->tv_usec; 610 } 611 } 612 #else 613 #define qemu_timersub timersub 614 #endif 615 616 ssize_t qemu_write_full(int fd, const void *buf, size_t count) 617 G_GNUC_WARN_UNUSED_RESULT; 618 619 void qemu_set_cloexec(int fd); 620 621 /* Return a dynamically allocated directory path that is appropriate for storing 622 * local state. 623 * 624 * The caller is responsible for releasing the value returned with g_free() 625 * after use. 626 */ 627 char *qemu_get_local_state_dir(void); 628 629 /** 630 * qemu_getauxval: 631 * @type: the auxiliary vector key to lookup 632 * 633 * Search the auxiliary vector for @type, returning the value 634 * or 0 if @type is not present. 635 */ 636 unsigned long qemu_getauxval(unsigned long type); 637 638 void qemu_set_tty_echo(int fd, bool echo); 639 640 typedef struct ThreadContext ThreadContext; 641 642 /** 643 * qemu_prealloc_mem: 644 * @fd: the fd mapped into the area, -1 for anonymous memory 645 * @area: start address of the are to preallocate 646 * @sz: the size of the area to preallocate 647 * @max_threads: maximum number of threads to use 648 * @errp: returns an error if this function fails 649 * 650 * Preallocate memory (populate/prefault page tables writable) for the virtual 651 * memory area starting at @area with the size of @sz. After a successful call, 652 * each page in the area was faulted in writable at least once, for example, 653 * after allocating file blocks for mapped files. 654 */ 655 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, 656 ThreadContext *tc, Error **errp); 657 658 /** 659 * qemu_get_pid_name: 660 * @pid: pid of a process 661 * 662 * For given @pid fetch its name. Caller is responsible for 663 * freeing the string when no longer needed. 664 * Returns allocated string on success, NULL on failure. 665 */ 666 char *qemu_get_pid_name(pid_t pid); 667 668 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even 669 * when intptr_t is 32-bit and we are aligning a long long. 670 */ 671 static inline uintptr_t qemu_real_host_page_size(void) 672 { 673 return getpagesize(); 674 } 675 676 static inline intptr_t qemu_real_host_page_mask(void) 677 { 678 return -(intptr_t)qemu_real_host_page_size(); 679 } 680 681 /* 682 * After using getopt or getopt_long, if you need to parse another set 683 * of options, then you must reset optind. Unfortunately the way to 684 * do this varies between implementations of getopt. 685 */ 686 static inline void qemu_reset_optind(void) 687 { 688 #ifdef HAVE_OPTRESET 689 optind = 1; 690 optreset = 1; 691 #else 692 optind = 0; 693 #endif 694 } 695 696 int qemu_fdatasync(int fd); 697 698 /** 699 * Sync changes made to the memory mapped file back to the backing 700 * storage. For POSIX compliant systems this will fallback 701 * to regular msync call. Otherwise it will trigger whole file sync 702 * (including the metadata case there is no support to skip that otherwise) 703 * 704 * @addr - start of the memory area to be synced 705 * @length - length of the are to be synced 706 * @fd - file descriptor for the file to be synced 707 * (mandatory only for POSIX non-compliant systems) 708 */ 709 int qemu_msync(void *addr, size_t length, int fd); 710 711 /** 712 * qemu_get_host_physmem: 713 * 714 * Operating system agnostic way of querying host memory. 715 * 716 * Returns amount of physical memory on the system. This is purely 717 * advisery and may return 0 if we can't work it out. At the other 718 * end we saturate to SIZE_MAX if you are lucky enough to have that 719 * much memory. 720 */ 721 size_t qemu_get_host_physmem(void); 722 723 /* 724 * Toggle write/execute on the pages marked MAP_JIT 725 * for the current thread. 726 */ 727 #if defined(MAC_OS_VERSION_11_0) && \ 728 MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0 729 static inline void qemu_thread_jit_execute(void) 730 { 731 pthread_jit_write_protect_np(true); 732 } 733 734 static inline void qemu_thread_jit_write(void) 735 { 736 pthread_jit_write_protect_np(false); 737 } 738 #else 739 static inline void qemu_thread_jit_write(void) {} 740 static inline void qemu_thread_jit_execute(void) {} 741 #endif 742 743 /** 744 * Platforms which do not support system() return ENOSYS 745 */ 746 #ifndef HAVE_SYSTEM_FUNCTION 747 #define system platform_does_not_support_system 748 static inline int platform_does_not_support_system(const char *command) 749 { 750 errno = ENOSYS; 751 return -1; 752 } 753 #endif /* !HAVE_SYSTEM_FUNCTION */ 754 755 #ifdef __cplusplus 756 } 757 #endif 758 759 #endif 760