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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 * system/os-posix.h, system/os-win32.h, system/os-wasm.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 COMPILING_PER_TARGET
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 <inttypes.h>
118 #include <limits.h>
119 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
120 * function availability on recentish Mingw-w64 platforms. */
121 #include <unistd.h>
122 #include <time.h>
123 #include <ctype.h>
124 #include <errno.h>
125 #include <fcntl.h>
126 #include <getopt.h>
127 #include <sys/stat.h>
128 #include <sys/time.h>
129 #include <assert.h>
130 /* setjmp must be declared before system/os-win32.h
131 * because it is redefined there. */
132 #include <setjmp.h>
133 #include <signal.h>
134
135 /*
136 * Avoid conflict with linux/arch/powerpc/include/uapi/asm/elf.h, included
137 * from <asm/sigcontext.h>, but we might as well do this unconditionally.
138 */
139 #undef ELF_CLASS
140 #undef ELF_DATA
141 #undef ELF_ARCH
142
143 /*
144 * Avoid conflict with Solaris FSCALE definition from <sys/param.h> header,
145 * but we might as well do this unconditionally.
146 */
147 #undef FSCALE
148
149 #ifdef CONFIG_IOVEC
150 #include <sys/uio.h>
151 #endif
152
153 #if defined(__linux__) && defined(__sparc__)
154 /* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */
155 #include <sys/shm.h>
156 #endif
157
158 #ifndef _WIN32
159 #include <sys/wait.h>
160 #else
161 #define WIFEXITED(x) 1
162 #define WEXITSTATUS(x) (x)
163 #endif
164
165 #ifdef __APPLE__
166 #include <AvailabilityMacros.h>
167 #endif
168
169 /*
170 * This is somewhat like a system header; it must be outside any extern "C"
171 * block because it includes system headers itself, including glib.h,
172 * which will not compile if inside an extern "C" block.
173 */
174 #include "glib-compat.h"
175
176 #ifdef _WIN32
177 #include "system/os-win32.h"
178 #endif
179
180 #if defined(CONFIG_POSIX) && !defined(EMSCRIPTEN)
181 #include "system/os-posix.h"
182 #endif
183
184 #if defined(EMSCRIPTEN)
185 #include "system/os-wasm.h"
186 #endif
187
188 #ifdef __cplusplus
189 extern "C" {
190 #endif
191
192 #include "qemu/typedefs.h"
193
194 /**
195 * Mark a function that executes in coroutine context
196 *
197 * Functions that execute in coroutine context cannot be called directly from
198 * normal functions. In the future it would be nice to enable compiler or
199 * static checker support for catching such errors. This annotation might make
200 * it possible and in the meantime it serves as documentation.
201 *
202 * For example:
203 *
204 * static void coroutine_fn foo(void) {
205 * ....
206 * }
207 */
208 #ifdef __clang__
209 #define coroutine_fn QEMU_ANNOTATE("coroutine_fn")
210 #else
211 #define coroutine_fn
212 #endif
213
214 /**
215 * Mark a function that can suspend when executed in coroutine context,
216 * but can handle running in non-coroutine context too.
217 */
218 #ifdef __clang__
219 #define coroutine_mixed_fn QEMU_ANNOTATE("coroutine_mixed_fn")
220 #else
221 #define coroutine_mixed_fn
222 #endif
223
224 /**
225 * Mark a function that should not be called from a coroutine context.
226 * Usually there will be an analogous, coroutine_fn function that should
227 * be used instead.
228 *
229 * When the function is also marked as coroutine_mixed_fn, the function should
230 * only be called if the caller does not know whether it is in coroutine
231 * context.
232 *
233 * Functions that are only no_coroutine_fn, on the other hand, should not
234 * be called from within coroutines at all. This for example includes
235 * functions that block.
236 *
237 * In the future it would be nice to enable compiler or static checker
238 * support for catching such errors. This annotation is the first step
239 * towards this, and in the meantime it serves as documentation.
240 *
241 * For example:
242 *
243 * static void no_coroutine_fn foo(void) {
244 * ....
245 * }
246 */
247 #ifdef __clang__
248 #define no_coroutine_fn QEMU_ANNOTATE("no_coroutine_fn")
249 #else
250 #define no_coroutine_fn
251 #endif
252
253
254 /*
255 * For mingw, as of v6.0.0, the function implementing the assert macro is
256 * not marked as noreturn, so the compiler cannot delete code following an
257 * assert(false) as unused. We rely on this within the code base to delete
258 * code that is unreachable when features are disabled.
259 * All supported versions of Glib's g_assert() satisfy this requirement.
260 */
261 #ifdef __MINGW32__
262 #undef assert
263 #define assert(x) g_assert(x)
264 #endif
265
266 /**
267 * qemu_build_not_reached()
268 *
269 * The compiler, during optimization, is expected to prove that a call
270 * to this function cannot be reached and remove it. If the compiler
271 * supports QEMU_ERROR, this will be reported at compile time; otherwise
272 * this will be reported at link time due to the missing symbol.
273 */
274 G_NORETURN
275 void QEMU_ERROR("code path is reachable")
276 qemu_build_not_reached_always(void);
277 #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__)
278 #define qemu_build_not_reached() qemu_build_not_reached_always()
279 #else
280 #define qemu_build_not_reached() g_assert_not_reached()
281 #endif
282
283 /**
284 * qemu_build_assert()
285 *
286 * The compiler, during optimization, is expected to prove that the
287 * assertion is true.
288 */
289 #define qemu_build_assert(test) while (!(test)) qemu_build_not_reached()
290
291 /*
292 * According to waitpid man page:
293 * WCOREDUMP
294 * This macro is not specified in POSIX.1-2001 and is not
295 * available on some UNIX implementations (e.g., AIX, SunOS).
296 * Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif.
297 */
298 #ifndef WCOREDUMP
299 #define WCOREDUMP(status) 0
300 #endif
301 /*
302 * We have a lot of unaudited code that may fail in strange ways, or
303 * even be a security risk during migration, if you disable assertions
304 * at compile-time. You may comment out these safety checks if you
305 * absolutely want to disable assertion overhead, but it is not
306 * supported upstream so the risk is all yours. Meanwhile, please
307 * submit patches to remove any side-effects inside an assertion, or
308 * fixing error handling that should use Error instead of assert.
309 */
310 #ifdef NDEBUG
311 #error building with NDEBUG is not supported
312 #endif
313 #ifdef G_DISABLE_ASSERT
314 #error building with G_DISABLE_ASSERT is not supported
315 #endif
316
317 #ifndef OFF_MAX
318 #define OFF_MAX (sizeof (off_t) == 8 ? INT64_MAX : INT32_MAX)
319 #endif
320
321 #ifndef O_LARGEFILE
322 #define O_LARGEFILE 0
323 #endif
324 #ifndef O_BINARY
325 #define O_BINARY 0
326 #endif
327 #ifndef MAP_ANONYMOUS
328 #define MAP_ANONYMOUS MAP_ANON
329 #endif
330 #ifndef MAP_NORESERVE
331 #define MAP_NORESERVE 0
332 #endif
333 #ifndef ENOMEDIUM
334 #define ENOMEDIUM ENODEV
335 #endif
336 #if !defined(ENOTSUP)
337 #define ENOTSUP 4096
338 #endif
339 #if !defined(ECANCELED)
340 #define ECANCELED 4097
341 #endif
342 #if !defined(EMEDIUMTYPE)
343 #define EMEDIUMTYPE 4098
344 #endif
345 #if !defined(ESHUTDOWN)
346 #define ESHUTDOWN 4099
347 #endif
348
349 #define RETRY_ON_EINTR(expr) \
350 (__extension__ \
351 ({ typeof(expr) __result; \
352 do { \
353 __result = (expr); \
354 } while (__result == -1 && errno == EINTR); \
355 __result; }))
356
357 /* time_t may be either 32 or 64 bits depending on the host OS, and
358 * can be either signed or unsigned, so we can't just hardcode a
359 * specific maximum value. This is not a C preprocessor constant,
360 * so you can't use TIME_MAX in an #ifdef, but for our purposes
361 * this isn't a problem.
362 */
363
364 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
365 * Gnulib, and are under the LGPL v2.1 or (at your option) any
366 * later version.
367 */
368
369 /* True if the real type T is signed. */
370 #define TYPE_SIGNED(t) (!((t)0 < (t)-1))
371
372 /* The width in bits of the integer type or expression T.
373 * Padding bits are not supported.
374 */
375 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
376
377 /* The maximum and minimum values for the integer type T. */
378 #define TYPE_MAXIMUM(t) \
379 ((t) (!TYPE_SIGNED(t) \
380 ? (t)-1 \
381 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
382
383 #ifndef TIME_MAX
384 #define TIME_MAX TYPE_MAXIMUM(time_t)
385 #endif
386
387 #ifndef PATH_MAX
388 #define PATH_MAX 1024
389 #endif
390
391 /*
392 * Use the same value as Linux for now.
393 */
394 #ifndef IOV_MAX
395 #define IOV_MAX 1024
396 #endif
397
398 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
399 * the wrong type. Our replacement isn't usable in preprocessor
400 * expressions, but it is sufficient for our needs. */
401 #ifdef HAVE_BROKEN_SIZE_MAX
402 #undef SIZE_MAX
403 #define SIZE_MAX ((size_t)-1)
404 #endif
405
406 /*
407 * Two variations of MIN/MAX macros. The first is for runtime use, and
408 * evaluates arguments only once (so it is safe even with side
409 * effects), but will not work in constant contexts (such as array
410 * size declarations) because of the '{}'. The second is for constant
411 * expression use, where evaluating arguments twice is safe because
412 * the result is going to be constant anyway, but will not work in a
413 * runtime context because of a void expression where a value is
414 * expected. Thus, both gcc and clang will fail to compile if you use
415 * the wrong macro (even if the error may seem a bit cryptic).
416 *
417 * Note that neither form is usable as an #if condition; if you truly
418 * need to write conditional code that depends on a minimum or maximum
419 * determined by the pre-processor instead of the compiler, you'll
420 * have to open-code it. Sadly, Coverity is severely confused by the
421 * constant variants, so we have to dumb things down there.
422 *
423 * Preprocessor sorcery ahead: use different identifiers for the local
424 * variables in each expansion, so we can nest macro calls without
425 * shadowing variables.
426 */
427 #define MIN_INTERNAL(a, b, _a, _b) \
428 ({ \
429 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
430 _a < _b ? _a : _b; \
431 })
432 #undef MIN
433 #define MIN(a, b) \
434 MIN_INTERNAL((a), (b), MAKE_IDENTIFIER(_a), MAKE_IDENTIFIER(_b))
435
436 #define MAX_INTERNAL(a, b, _a, _b) \
437 ({ \
438 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
439 _a > _b ? _a : _b; \
440 })
441 #undef MAX
442 #define MAX(a, b) \
443 MAX_INTERNAL((a), (b), MAKE_IDENTIFIER(_a), MAKE_IDENTIFIER(_b))
444
445 #ifdef __COVERITY__
446 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b))
447 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b))
448 #else
449 # define MIN_CONST(a, b) \
450 __builtin_choose_expr( \
451 __builtin_constant_p(a) && __builtin_constant_p(b), \
452 (a) < (b) ? (a) : (b), \
453 ((void)0))
454 # define MAX_CONST(a, b) \
455 __builtin_choose_expr( \
456 __builtin_constant_p(a) && __builtin_constant_p(b), \
457 (a) > (b) ? (a) : (b), \
458 ((void)0))
459 #endif
460
461 /*
462 * Minimum function that returns zero only if both values are zero.
463 * Intended for use with unsigned values only.
464 *
465 * Preprocessor sorcery ahead: use different identifiers for the local
466 * variables in each expansion, so we can nest macro calls without
467 * shadowing variables.
468 */
469 #define MIN_NON_ZERO_INTERNAL(a, b, _a, _b) \
470 ({ \
471 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
472 _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \
473 })
474 #define MIN_NON_ZERO(a, b) \
475 MIN_NON_ZERO_INTERNAL((a), (b), MAKE_IDENTIFIER(_a), MAKE_IDENTIFIER(_b))
476
477 /*
478 * Round number down to multiple. Safe when m is not a power of 2 (see
479 * ROUND_DOWN for a faster version when a power of 2 is guaranteed).
480 */
481 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
482
483 /*
484 * Round number up to multiple. Safe when m is not a power of 2 (see
485 * ROUND_UP for a faster version when a power of 2 is guaranteed).
486 */
487 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
488
489 /* Check if n is a multiple of m */
490 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
491
492 /* n-byte align pointer down */
493 #define QEMU_ALIGN_PTR_DOWN(p, n) \
494 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
495
496 /* n-byte align pointer up */
497 #define QEMU_ALIGN_PTR_UP(p, n) \
498 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
499
500 /* Check if pointer p is n-bytes aligned */
501 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
502
503 /*
504 * Round number down to multiple. Requires that d be a power of 2 (see
505 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
506 * numbers); works even if d is a smaller type than n.
507 */
508 #ifndef ROUND_DOWN
509 #define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d)))
510 #endif
511
512 /*
513 * Round number up to multiple. Requires that d be a power of 2 (see
514 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
515 * numbers); works even if d is a smaller type than n.
516 */
517 #ifndef ROUND_UP
518 #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d))
519 #endif
520
521 #ifndef DIV_ROUND_UP
522 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
523 #endif
524
525 /*
526 * &(x)[0] is always a pointer - if it's same type as x then the argument is a
527 * pointer, not an array.
528 */
529 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
530 typeof(&(x)[0])))
531 #ifndef ARRAY_SIZE
532 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
533 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
534 #endif
535
536 int qemu_daemon(int nochdir, int noclose);
537 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared,
538 bool noreserve);
539 void qemu_anon_ram_free(void *ptr, size_t size);
540 int qemu_shm_alloc(size_t size, Error **errp);
541
542 #ifdef _WIN32
543 #define HAVE_CHARDEV_SERIAL 1
544 #define HAVE_CHARDEV_PARALLEL 1
545 #else
546 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
547 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
548 || defined(__GLIBC__) || defined(__APPLE__)
549 #define HAVE_CHARDEV_SERIAL 1
550 #endif
551 #if defined(__linux__) || defined(__FreeBSD__) \
552 || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
553 #define HAVE_CHARDEV_PARALLEL 1
554 #endif
555 #endif
556
557 #if defined(__HAIKU__)
558 #define SIGIO SIGPOLL
559 #endif
560
561 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE
562 /*
563 * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion
564 * about Solaris missing the madvise() prototype.
565 */
566 int madvise(char *, size_t, int);
567 #endif
568
569 #if defined(CONFIG_LINUX)
570 #ifndef BUS_MCEERR_AR
571 #define BUS_MCEERR_AR 4
572 #endif
573 #ifndef BUS_MCEERR_AO
574 #define BUS_MCEERR_AO 5
575 #endif
576 #endif
577
578 #if defined(__linux__) && \
579 (defined(__x86_64__) || defined(__aarch64__) \
580 || defined(__powerpc64__) || defined(__riscv))
581 /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
582 Valgrind does not support alignments larger than 1 MiB,
583 therefore we need special code which handles running on Valgrind. */
584 # define QEMU_VMALLOC_ALIGN (512 * 4096)
585 #elif defined(__linux__) && defined(__s390x__)
586 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
587 # define QEMU_VMALLOC_ALIGN (256 * 4096)
588 #elif defined(__linux__) && defined(__sparc__)
589 # define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA)
590 #elif defined(__linux__) && defined(__loongarch__)
591 /*
592 * For transparent hugepage optimization, it has better be huge page
593 * aligned. LoongArch host system supports two kinds of pagesize: 4K
594 * and 16K, here calculate huge page size from host page size
595 */
596 # define QEMU_VMALLOC_ALIGN (qemu_real_host_page_size() * \
597 qemu_real_host_page_size() / sizeof(long))
598 #else
599 # define QEMU_VMALLOC_ALIGN qemu_real_host_page_size()
600 #endif
601
602 #ifdef CONFIG_POSIX
603 struct qemu_signalfd_siginfo {
604 uint32_t ssi_signo; /* Signal number */
605 int32_t ssi_errno; /* Error number (unused) */
606 int32_t ssi_code; /* Signal code */
607 uint32_t ssi_pid; /* PID of sender */
608 uint32_t ssi_uid; /* Real UID of sender */
609 int32_t ssi_fd; /* File descriptor (SIGIO) */
610 uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */
611 uint32_t ssi_band; /* Band event (SIGIO) */
612 uint32_t ssi_overrun; /* POSIX timer overrun count */
613 uint32_t ssi_trapno; /* Trap number that caused signal */
614 int32_t ssi_status; /* Exit status or signal (SIGCHLD) */
615 int32_t ssi_int; /* Integer sent by sigqueue(2) */
616 uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */
617 uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */
618 uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */
619 uint64_t ssi_addr; /* Address that generated signal
620 (for hardware-generated signals) */
621 uint8_t pad[48]; /* Pad size to 128 bytes (allow for
622 additional fields in the future) */
623 };
624
625 int qemu_signalfd(const sigset_t *mask);
626 void sigaction_invoke(struct sigaction *action,
627 struct qemu_signalfd_siginfo *info);
628 #endif
629
630 /*
631 * Don't introduce new usage of this function, prefer the following
632 * qemu_open/qemu_create that take an "Error **errp"
633 */
634 int qemu_open_old(const char *name, int flags, ...);
635 int qemu_open(const char *name, int flags, Error **errp);
636 int qemu_create(const char *name, int flags, mode_t mode, Error **errp);
637 int qemu_close(int fd);
638 int qemu_unlink(const char *name);
639 #ifndef _WIN32
640 int qemu_dup_flags(int fd, int flags);
641 int qemu_dup(int fd);
642 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
643 int qemu_unlock_fd(int fd, int64_t start, int64_t len);
644 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
645 bool qemu_has_ofd_lock(void);
646 int qemu_fcntl_addfl(int fd, int flag);
647 #endif
648
649 bool qemu_has_direct_io(void);
650
651 #ifdef WIN64
652 #define FMT_pid "%" PRId64
653 #else
654 #define FMT_pid "%d"
655 #endif
656
657 bool qemu_write_pidfile(const char *pidfile, Error **errp);
658
659 int qemu_get_thread_id(void);
660
661 /**
662 * qemu_kill_thread:
663 * @tid: thread id.
664 * @sig: host signal.
665 *
666 * Send @sig to one of QEMU's own threads with identifier @tid.
667 */
668 int qemu_kill_thread(int tid, int sig);
669
670 #ifndef CONFIG_IOVEC
671 struct iovec {
672 void *iov_base;
673 size_t iov_len;
674 };
675
676 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
677 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
678 #endif
679
680 #ifdef _WIN32
681 static inline void qemu_timersub(const struct timeval *val1,
682 const struct timeval *val2,
683 struct timeval *res)
684 {
685 res->tv_sec = val1->tv_sec - val2->tv_sec;
686 if (val1->tv_usec < val2->tv_usec) {
687 res->tv_sec--;
688 res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
689 } else {
690 res->tv_usec = val1->tv_usec - val2->tv_usec;
691 }
692 }
693 #else
694 #define qemu_timersub timersub
695 #endif
696
697 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
698 G_GNUC_WARN_UNUSED_RESULT;
699
700 void qemu_set_cloexec(int fd);
701 bool qemu_set_blocking(int fd, bool block, Error **errp);
702
703 /*
704 * Clear FD_CLOEXEC for a descriptor.
705 *
706 * The caller must guarantee that no other fork+exec's occur before the
707 * exec that is intended to inherit this descriptor, eg by suspending CPUs
708 * and blocking monitor commands.
709 */
710 void qemu_clear_cloexec(int fd);
711
712 /* Return a dynamically allocated directory path that is appropriate for storing
713 * local state.
714 *
715 * The caller is responsible for releasing the value returned with g_free()
716 * after use.
717 */
718 char *qemu_get_local_state_dir(void);
719
720 /**
721 * qemu_getauxval:
722 * @type: the auxiliary vector key to lookup
723 *
724 * Search the auxiliary vector for @type, returning the value
725 * or 0 if @type is not present.
726 */
727 unsigned long qemu_getauxval(unsigned long type);
728
729 void qemu_set_tty_echo(int fd, bool echo);
730
731 typedef struct ThreadContext ThreadContext;
732
733 /**
734 * qemu_prealloc_mem:
735 * @fd: the fd mapped into the area, -1 for anonymous memory
736 * @area: start address of the are to preallocate
737 * @sz: the size of the area to preallocate
738 * @max_threads: maximum number of threads to use
739 * @tc: prealloc context threads pointer, NULL if not in use
740 * @async: request asynchronous preallocation, requires @tc
741 * @errp: returns an error if this function fails
742 *
743 * Preallocate memory (populate/prefault page tables writable) for the virtual
744 * memory area starting at @area with the size of @sz. After a successful call,
745 * each page in the area was faulted in writable at least once, for example,
746 * after allocating file blocks for mapped files.
747 *
748 * When setting @async, allocation might be performed asynchronously.
749 * qemu_finish_async_prealloc_mem() must be called to finish any asynchronous
750 * preallocation.
751 *
752 * Return: true on success, else false setting @errp with error.
753 */
754 bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads,
755 ThreadContext *tc, bool async, Error **errp);
756
757 /**
758 * qemu_finish_async_prealloc_mem:
759 * @errp: returns an error if this function fails
760 *
761 * Finish all outstanding asynchronous memory preallocation.
762 *
763 * Return: true on success, else false setting @errp with error.
764 */
765 bool qemu_finish_async_prealloc_mem(Error **errp);
766
767 /**
768 * qemu_get_pid_name:
769 * @pid: pid of a process
770 *
771 * For given @pid fetch its name. Caller is responsible for
772 * freeing the string when no longer needed.
773 * Returns allocated string on success, NULL on failure.
774 */
775 char *qemu_get_pid_name(pid_t pid);
776
777 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
778 * when intptr_t is 32-bit and we are aligning a long long.
779 */
780 static inline uintptr_t qemu_real_host_page_size(void)
781 {
782 return getpagesize();
783 }
784
785 static inline intptr_t qemu_real_host_page_mask(void)
786 {
787 return -(intptr_t)qemu_real_host_page_size();
788 }
789
790 /*
791 * After using getopt or getopt_long, if you need to parse another set
792 * of options, then you must reset optind. Unfortunately the way to
793 * do this varies between implementations of getopt.
794 */
795 static inline void qemu_reset_optind(void)
796 {
797 #ifdef HAVE_OPTRESET
798 optind = 1;
799 optreset = 1;
800 #else
801 optind = 0;
802 #endif
803 }
804
805 int qemu_fdatasync(int fd);
806
807 /**
808 * qemu_close_all_open_fd:
809 *
810 * Close all open file descriptors except the ones supplied in the @skip array
811 *
812 * @skip: ordered array of distinct file descriptors that should not be closed
813 * if any, or NULL.
814 * @nskip: number of entries in the @skip array or 0 if @skip is NULL.
815 */
816 void qemu_close_all_open_fd(const int *skip, unsigned int nskip);
817
818 /**
819 * Sync changes made to the memory mapped file back to the backing
820 * storage. For POSIX compliant systems this will fallback
821 * to regular msync call. Otherwise it will trigger whole file sync
822 * (including the metadata case there is no support to skip that otherwise)
823 *
824 * @addr - start of the memory area to be synced
825 * @length - length of the are to be synced
826 * @fd - file descriptor for the file to be synced
827 * (mandatory only for POSIX non-compliant systems)
828 */
829 int qemu_msync(void *addr, size_t length, int fd);
830
831 /**
832 * qemu_get_host_physmem:
833 *
834 * Operating system agnostic way of querying host memory.
835 *
836 * Returns amount of physical memory on the system. This is purely
837 * advisery and may return 0 if we can't work it out. At the other
838 * end we saturate to SIZE_MAX if you are lucky enough to have that
839 * much memory.
840 */
841 size_t qemu_get_host_physmem(void);
842
843 /*
844 * Toggle write/execute on the pages marked MAP_JIT
845 * for the current thread.
846 */
847 #ifdef __APPLE__
848 static inline void qemu_thread_jit_execute(void)
849 {
850 pthread_jit_write_protect_np(true);
851 }
852
853 static inline void qemu_thread_jit_write(void)
854 {
855 pthread_jit_write_protect_np(false);
856 }
857 #else
858 static inline void qemu_thread_jit_write(void) {}
859 static inline void qemu_thread_jit_execute(void) {}
860 #endif
861
862 /**
863 * Platforms which do not support system() return ENOSYS
864 */
865 #ifndef HAVE_SYSTEM_FUNCTION
866 #define system platform_does_not_support_system
867 static inline int platform_does_not_support_system(const char *command)
868 {
869 errno = ENOSYS;
870 return -1;
871 }
872 #endif /* !HAVE_SYSTEM_FUNCTION */
873
874 #ifdef __cplusplus
875 }
876 #endif
877
878 #endif