xref: /openbmc/qemu/include/qemu/osdep.h (revision 05548400)
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 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 <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_IDENTIFIER(_a), MAKE_IDENTIFIER(_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_IDENTIFIER(_a), MAKE_IDENTIFIER(_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_IDENTIFIER(_a), MAKE_IDENTIFIER(_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 #define HAVE_CHARDEV_PARALLEL 1
512 #else
513 #if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)   \
514     || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
515     || defined(__GLIBC__) || defined(__APPLE__)
516 #define HAVE_CHARDEV_SERIAL 1
517 #endif
518 #if defined(__linux__) || defined(__FreeBSD__) \
519     || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
520 #define HAVE_CHARDEV_PARALLEL 1
521 #endif
522 #endif
523 
524 #if defined(__HAIKU__)
525 #define SIGIO SIGPOLL
526 #endif
527 
528 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE
529 /*
530  * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion
531  * about Solaris missing the madvise() prototype.
532  */
533 int madvise(char *, size_t, int);
534 #endif
535 
536 #if defined(CONFIG_LINUX)
537 #ifndef BUS_MCEERR_AR
538 #define BUS_MCEERR_AR 4
539 #endif
540 #ifndef BUS_MCEERR_AO
541 #define BUS_MCEERR_AO 5
542 #endif
543 #endif
544 
545 #if defined(__linux__) && \
546     (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
547      || defined(__powerpc64__))
548    /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
549       Valgrind does not support alignments larger than 1 MiB,
550       therefore we need special code which handles running on Valgrind. */
551 #  define QEMU_VMALLOC_ALIGN (512 * 4096)
552 #elif defined(__linux__) && defined(__s390x__)
553    /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
554 #  define QEMU_VMALLOC_ALIGN (256 * 4096)
555 #elif defined(__linux__) && defined(__sparc__)
556 #  define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA)
557 #elif defined(__linux__) && defined(__loongarch__)
558    /*
559     * For transparent hugepage optimization, it has better be huge page
560     * aligned. LoongArch host system supports two kinds of pagesize: 4K
561     * and 16K, here calculate huge page size from host page size
562     */
563 #  define QEMU_VMALLOC_ALIGN (qemu_real_host_page_size() * \
564                          qemu_real_host_page_size() / sizeof(long))
565 #else
566 #  define QEMU_VMALLOC_ALIGN qemu_real_host_page_size()
567 #endif
568 
569 #ifdef CONFIG_POSIX
570 struct qemu_signalfd_siginfo {
571     uint32_t ssi_signo;   /* Signal number */
572     int32_t  ssi_errno;   /* Error number (unused) */
573     int32_t  ssi_code;    /* Signal code */
574     uint32_t ssi_pid;     /* PID of sender */
575     uint32_t ssi_uid;     /* Real UID of sender */
576     int32_t  ssi_fd;      /* File descriptor (SIGIO) */
577     uint32_t ssi_tid;     /* Kernel timer ID (POSIX timers) */
578     uint32_t ssi_band;    /* Band event (SIGIO) */
579     uint32_t ssi_overrun; /* POSIX timer overrun count */
580     uint32_t ssi_trapno;  /* Trap number that caused signal */
581     int32_t  ssi_status;  /* Exit status or signal (SIGCHLD) */
582     int32_t  ssi_int;     /* Integer sent by sigqueue(2) */
583     uint64_t ssi_ptr;     /* Pointer sent by sigqueue(2) */
584     uint64_t ssi_utime;   /* User CPU time consumed (SIGCHLD) */
585     uint64_t ssi_stime;   /* System CPU time consumed (SIGCHLD) */
586     uint64_t ssi_addr;    /* Address that generated signal
587                              (for hardware-generated signals) */
588     uint8_t  pad[48];     /* Pad size to 128 bytes (allow for
589                              additional fields in the future) */
590 };
591 
592 int qemu_signalfd(const sigset_t *mask);
593 void sigaction_invoke(struct sigaction *action,
594                       struct qemu_signalfd_siginfo *info);
595 #endif
596 
597 /*
598  * Don't introduce new usage of this function, prefer the following
599  * qemu_open/qemu_create that take an "Error **errp"
600  */
601 int qemu_open_old(const char *name, int flags, ...);
602 int qemu_open(const char *name, int flags, Error **errp);
603 int qemu_create(const char *name, int flags, mode_t mode, Error **errp);
604 int qemu_close(int fd);
605 int qemu_unlink(const char *name);
606 #ifndef _WIN32
607 int qemu_dup_flags(int fd, int flags);
608 int qemu_dup(int fd);
609 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
610 int qemu_unlock_fd(int fd, int64_t start, int64_t len);
611 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
612 bool qemu_has_ofd_lock(void);
613 #endif
614 
615 bool qemu_has_direct_io(void);
616 
617 #if defined(__HAIKU__) && defined(__i386__)
618 #define FMT_pid "%ld"
619 #elif defined(WIN64)
620 #define FMT_pid "%" PRId64
621 #else
622 #define FMT_pid "%d"
623 #endif
624 
625 bool qemu_write_pidfile(const char *pidfile, Error **errp);
626 
627 int qemu_get_thread_id(void);
628 
629 #ifndef CONFIG_IOVEC
630 struct iovec {
631     void *iov_base;
632     size_t iov_len;
633 };
634 /*
635  * Use the same value as Linux for now.
636  */
637 #define IOV_MAX 1024
638 
639 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
640 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
641 #endif
642 
643 #ifdef _WIN32
qemu_timersub(const struct timeval * val1,const struct timeval * val2,struct timeval * res)644 static inline void qemu_timersub(const struct timeval *val1,
645                                  const struct timeval *val2,
646                                  struct timeval *res)
647 {
648     res->tv_sec = val1->tv_sec - val2->tv_sec;
649     if (val1->tv_usec < val2->tv_usec) {
650         res->tv_sec--;
651         res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
652     } else {
653         res->tv_usec = val1->tv_usec - val2->tv_usec;
654     }
655 }
656 #else
657 #define qemu_timersub timersub
658 #endif
659 
660 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
661     G_GNUC_WARN_UNUSED_RESULT;
662 
663 void qemu_set_cloexec(int fd);
664 
665 /* Return a dynamically allocated directory path that is appropriate for storing
666  * local state.
667  *
668  * The caller is responsible for releasing the value returned with g_free()
669  * after use.
670  */
671 char *qemu_get_local_state_dir(void);
672 
673 /**
674  * qemu_getauxval:
675  * @type: the auxiliary vector key to lookup
676  *
677  * Search the auxiliary vector for @type, returning the value
678  * or 0 if @type is not present.
679  */
680 unsigned long qemu_getauxval(unsigned long type);
681 
682 void qemu_set_tty_echo(int fd, bool echo);
683 
684 typedef struct ThreadContext ThreadContext;
685 
686 /**
687  * qemu_prealloc_mem:
688  * @fd: the fd mapped into the area, -1 for anonymous memory
689  * @area: start address of the are to preallocate
690  * @sz: the size of the area to preallocate
691  * @max_threads: maximum number of threads to use
692  * @tc: prealloc context threads pointer, NULL if not in use
693  * @async: request asynchronous preallocation, requires @tc
694  * @errp: returns an error if this function fails
695  *
696  * Preallocate memory (populate/prefault page tables writable) for the virtual
697  * memory area starting at @area with the size of @sz. After a successful call,
698  * each page in the area was faulted in writable at least once, for example,
699  * after allocating file blocks for mapped files.
700  *
701  * When setting @async, allocation might be performed asynchronously.
702  * qemu_finish_async_prealloc_mem() must be called to finish any asynchronous
703  * preallocation.
704  *
705  * Return: true on success, else false setting @errp with error.
706  */
707 bool qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads,
708                        ThreadContext *tc, bool async, Error **errp);
709 
710 /**
711  * qemu_finish_async_prealloc_mem:
712  * @errp: returns an error if this function fails
713  *
714  * Finish all outstanding asynchronous memory preallocation.
715  *
716  * Return: true on success, else false setting @errp with error.
717  */
718 bool qemu_finish_async_prealloc_mem(Error **errp);
719 
720 /**
721  * qemu_get_pid_name:
722  * @pid: pid of a process
723  *
724  * For given @pid fetch its name. Caller is responsible for
725  * freeing the string when no longer needed.
726  * Returns allocated string on success, NULL on failure.
727  */
728 char *qemu_get_pid_name(pid_t pid);
729 
730 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
731  * when intptr_t is 32-bit and we are aligning a long long.
732  */
qemu_real_host_page_size(void)733 static inline uintptr_t qemu_real_host_page_size(void)
734 {
735     return getpagesize();
736 }
737 
qemu_real_host_page_mask(void)738 static inline intptr_t qemu_real_host_page_mask(void)
739 {
740     return -(intptr_t)qemu_real_host_page_size();
741 }
742 
743 /*
744  * After using getopt or getopt_long, if you need to parse another set
745  * of options, then you must reset optind.  Unfortunately the way to
746  * do this varies between implementations of getopt.
747  */
qemu_reset_optind(void)748 static inline void qemu_reset_optind(void)
749 {
750 #ifdef HAVE_OPTRESET
751     optind = 1;
752     optreset = 1;
753 #else
754     optind = 0;
755 #endif
756 }
757 
758 int qemu_fdatasync(int fd);
759 
760 /**
761  * qemu_close_all_open_fd:
762  *
763  * Close all open file descriptors except the ones supplied in the @skip array
764  *
765  * @skip: ordered array of distinct file descriptors that should not be closed
766  *        if any, or NULL.
767  * @nskip: number of entries in the @skip array or 0 if @skip is NULL.
768  */
769 void qemu_close_all_open_fd(const int *skip, unsigned int nskip);
770 
771 /**
772  * Sync changes made to the memory mapped file back to the backing
773  * storage. For POSIX compliant systems this will fallback
774  * to regular msync call. Otherwise it will trigger whole file sync
775  * (including the metadata case there is no support to skip that otherwise)
776  *
777  * @addr   - start of the memory area to be synced
778  * @length - length of the are to be synced
779  * @fd     - file descriptor for the file to be synced
780  *           (mandatory only for POSIX non-compliant systems)
781  */
782 int qemu_msync(void *addr, size_t length, int fd);
783 
784 /**
785  * qemu_get_host_physmem:
786  *
787  * Operating system agnostic way of querying host memory.
788  *
789  * Returns amount of physical memory on the system. This is purely
790  * advisery and may return 0 if we can't work it out. At the other
791  * end we saturate to SIZE_MAX if you are lucky enough to have that
792  * much memory.
793  */
794 size_t qemu_get_host_physmem(void);
795 
796 /*
797  * Toggle write/execute on the pages marked MAP_JIT
798  * for the current thread.
799  */
800 #ifdef __APPLE__
qemu_thread_jit_execute(void)801 static inline void qemu_thread_jit_execute(void)
802 {
803     pthread_jit_write_protect_np(true);
804 }
805 
qemu_thread_jit_write(void)806 static inline void qemu_thread_jit_write(void)
807 {
808     pthread_jit_write_protect_np(false);
809 }
810 #else
qemu_thread_jit_write(void)811 static inline void qemu_thread_jit_write(void) {}
qemu_thread_jit_execute(void)812 static inline void qemu_thread_jit_execute(void) {}
813 #endif
814 
815 /**
816  * Platforms which do not support system() return ENOSYS
817  */
818 #ifndef HAVE_SYSTEM_FUNCTION
819 #define system platform_does_not_support_system
platform_does_not_support_system(const char * command)820 static inline int platform_does_not_support_system(const char *command)
821 {
822     errno = ENOSYS;
823     return -1;
824 }
825 #endif /* !HAVE_SYSTEM_FUNCTION */
826 
827 #ifdef __cplusplus
828 }
829 #endif
830 
831 #endif
832