specs/qcow2: Clarify that compressed clusters have the COPIED bit reset
[qemu.git] / include / qemu / osdep.h
blob41658060a7a83953c5063e2dc88cb2275557b890
1 /*
2 * OS includes and handling of OS dependencies
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).
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.
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.
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
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.
27 #ifndef QEMU_OSDEP_H
28 #define QEMU_OSDEP_H
30 #include "config-host.h"
31 #ifdef NEED_CPU_H
32 #include "config-target.h"
33 #else
34 #include "exec/poison.h"
35 #endif
36 #include "qemu/compiler.h"
38 /* Older versions of C++ don't get definitions of various macros from
39 * stdlib.h unless we define these macros before first inclusion of
40 * that system header.
42 #ifndef __STDC_CONSTANT_MACROS
43 #define __STDC_CONSTANT_MACROS
44 #endif
45 #ifndef __STDC_LIMIT_MACROS
46 #define __STDC_LIMIT_MACROS
47 #endif
48 #ifndef __STDC_FORMAT_MACROS
49 #define __STDC_FORMAT_MACROS
50 #endif
52 /* The following block of code temporarily renames the daemon() function so the
53 * compiler does not see the warning associated with it in stdlib.h on OSX
55 #ifdef __APPLE__
56 #define daemon qemu_fake_daemon_function
57 #include <stdlib.h>
58 #undef daemon
59 extern int daemon(int, int);
60 #endif
62 #include <stdarg.h>
63 #include <stddef.h>
64 #include <stdbool.h>
65 #include <stdint.h>
66 #include <sys/types.h>
67 #include <stdlib.h>
68 #include <stdio.h>
69 #include <string.h>
70 #include <strings.h>
71 #include <inttypes.h>
72 #include <limits.h>
73 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
74 * function availability on recentish Mingw-w64 platforms. */
75 #include <unistd.h>
76 #include <time.h>
77 #include <ctype.h>
78 #include <errno.h>
79 #include <fcntl.h>
80 #include <sys/stat.h>
81 #include <sys/time.h>
82 #include <assert.h>
83 /* setjmp must be declared before sysemu/os-win32.h
84 * because it is redefined there. */
85 #include <setjmp.h>
86 #include <signal.h>
88 #ifdef __OpenBSD__
89 #include <sys/signal.h>
90 #endif
92 #ifndef _WIN32
93 #include <sys/wait.h>
94 #else
95 #define WIFEXITED(x) 1
96 #define WEXITSTATUS(x) (x)
97 #endif
99 #ifdef _WIN32
100 #include "sysemu/os-win32.h"
101 #endif
103 #ifdef CONFIG_POSIX
104 #include "sysemu/os-posix.h"
105 #endif
107 #include "glib-compat.h"
108 #include "qemu/typedefs.h"
111 * We have a lot of unaudited code that may fail in strange ways, or
112 * even be a security risk during migration, if you disable assertions
113 * at compile-time. You may comment out these safety checks if you
114 * absolutely want to disable assertion overhead, but it is not
115 * supported upstream so the risk is all yours. Meanwhile, please
116 * submit patches to remove any side-effects inside an assertion, or
117 * fixing error handling that should use Error instead of assert.
119 #ifdef NDEBUG
120 #error building with NDEBUG is not supported
121 #endif
122 #ifdef G_DISABLE_ASSERT
123 #error building with G_DISABLE_ASSERT is not supported
124 #endif
126 #ifndef O_LARGEFILE
127 #define O_LARGEFILE 0
128 #endif
129 #ifndef O_BINARY
130 #define O_BINARY 0
131 #endif
132 #ifndef MAP_ANONYMOUS
133 #define MAP_ANONYMOUS MAP_ANON
134 #endif
135 #ifndef ENOMEDIUM
136 #define ENOMEDIUM ENODEV
137 #endif
138 #if !defined(ENOTSUP)
139 #define ENOTSUP 4096
140 #endif
141 #if !defined(ECANCELED)
142 #define ECANCELED 4097
143 #endif
144 #if !defined(EMEDIUMTYPE)
145 #define EMEDIUMTYPE 4098
146 #endif
147 #if !defined(ESHUTDOWN)
148 #define ESHUTDOWN 4099
149 #endif
151 /* time_t may be either 32 or 64 bits depending on the host OS, and
152 * can be either signed or unsigned, so we can't just hardcode a
153 * specific maximum value. This is not a C preprocessor constant,
154 * so you can't use TIME_MAX in an #ifdef, but for our purposes
155 * this isn't a problem.
158 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
159 * Gnulib, and are under the LGPL v2.1 or (at your option) any
160 * later version.
163 /* True if the real type T is signed. */
164 #define TYPE_SIGNED(t) (!((t)0 < (t)-1))
166 /* The width in bits of the integer type or expression T.
167 * Padding bits are not supported.
169 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
171 /* The maximum and minimum values for the integer type T. */
172 #define TYPE_MAXIMUM(t) \
173 ((t) (!TYPE_SIGNED(t) \
174 ? (t)-1 \
175 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
177 #ifndef TIME_MAX
178 #define TIME_MAX TYPE_MAXIMUM(time_t)
179 #endif
181 /* HOST_LONG_BITS is the size of a native pointer in bits. */
182 #if UINTPTR_MAX == UINT32_MAX
183 # define HOST_LONG_BITS 32
184 #elif UINTPTR_MAX == UINT64_MAX
185 # define HOST_LONG_BITS 64
186 #else
187 # error Unknown pointer size
188 #endif
190 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
191 * the wrong type. Our replacement isn't usable in preprocessor
192 * expressions, but it is sufficient for our needs. */
193 #if defined(HAVE_BROKEN_SIZE_MAX) && HAVE_BROKEN_SIZE_MAX
194 #undef SIZE_MAX
195 #define SIZE_MAX ((size_t)-1)
196 #endif
198 #ifndef MIN
199 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
200 #endif
201 #ifndef MAX
202 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
203 #endif
205 /* Minimum function that returns zero only iff both values are zero.
206 * Intended for use with unsigned values only. */
207 #ifndef MIN_NON_ZERO
208 #define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \
209 ((b) == 0 ? (a) : (MIN(a, b))))
210 #endif
212 /* Round number down to multiple */
213 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
215 /* Round number up to multiple. Safe when m is not a power of 2 (see
216 * ROUND_UP for a faster version when a power of 2 is guaranteed) */
217 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
219 /* Check if n is a multiple of m */
220 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
222 /* n-byte align pointer down */
223 #define QEMU_ALIGN_PTR_DOWN(p, n) \
224 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
226 /* n-byte align pointer up */
227 #define QEMU_ALIGN_PTR_UP(p, n) \
228 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
230 /* Check if pointer p is n-bytes aligned */
231 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
233 /* Round number up to multiple. Requires that d be a power of 2 (see
234 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
235 * numbers); works even if d is a smaller type than n. */
236 #ifndef ROUND_UP
237 #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
238 #endif
240 #ifndef DIV_ROUND_UP
241 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
242 #endif
245 * &(x)[0] is always a pointer - if it's same type as x then the argument is a
246 * pointer, not an array.
248 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
249 typeof(&(x)[0])))
250 #ifndef ARRAY_SIZE
251 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
252 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
253 #endif
255 int qemu_daemon(int nochdir, int noclose);
256 void *qemu_try_memalign(size_t alignment, size_t size);
257 void *qemu_memalign(size_t alignment, size_t size);
258 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared);
259 void qemu_vfree(void *ptr);
260 void qemu_anon_ram_free(void *ptr, size_t size);
262 #define QEMU_MADV_INVALID -1
264 #if defined(CONFIG_MADVISE)
266 #define QEMU_MADV_WILLNEED MADV_WILLNEED
267 #define QEMU_MADV_DONTNEED MADV_DONTNEED
268 #ifdef MADV_DONTFORK
269 #define QEMU_MADV_DONTFORK MADV_DONTFORK
270 #else
271 #define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
272 #endif
273 #ifdef MADV_MERGEABLE
274 #define QEMU_MADV_MERGEABLE MADV_MERGEABLE
275 #else
276 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
277 #endif
278 #ifdef MADV_UNMERGEABLE
279 #define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
280 #else
281 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
282 #endif
283 #ifdef MADV_DODUMP
284 #define QEMU_MADV_DODUMP MADV_DODUMP
285 #else
286 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
287 #endif
288 #ifdef MADV_DONTDUMP
289 #define QEMU_MADV_DONTDUMP MADV_DONTDUMP
290 #else
291 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
292 #endif
293 #ifdef MADV_HUGEPAGE
294 #define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
295 #else
296 #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
297 #endif
298 #ifdef MADV_NOHUGEPAGE
299 #define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
300 #else
301 #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
302 #endif
303 #ifdef MADV_REMOVE
304 #define QEMU_MADV_REMOVE MADV_REMOVE
305 #else
306 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
307 #endif
309 #elif defined(CONFIG_POSIX_MADVISE)
311 #define QEMU_MADV_WILLNEED POSIX_MADV_WILLNEED
312 #define QEMU_MADV_DONTNEED POSIX_MADV_DONTNEED
313 #define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
314 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
315 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
316 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
317 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
318 #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
319 #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
320 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
322 #else /* no-op */
324 #define QEMU_MADV_WILLNEED QEMU_MADV_INVALID
325 #define QEMU_MADV_DONTNEED QEMU_MADV_INVALID
326 #define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
327 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
328 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
329 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
330 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
331 #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
332 #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
333 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
335 #endif
337 #ifdef _WIN32
338 #define HAVE_CHARDEV_SERIAL 1
339 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
340 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
341 || defined(__GLIBC__)
342 #define HAVE_CHARDEV_SERIAL 1
343 #endif
345 #if defined(__linux__) || defined(__FreeBSD__) || \
346 defined(__FreeBSD_kernel__) || defined(__DragonFly__)
347 #define HAVE_CHARDEV_PARPORT 1
348 #endif
350 #if defined(CONFIG_LINUX)
351 #ifndef BUS_MCEERR_AR
352 #define BUS_MCEERR_AR 4
353 #endif
354 #ifndef BUS_MCEERR_AO
355 #define BUS_MCEERR_AO 5
356 #endif
357 #endif
359 #if defined(__linux__) && \
360 (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__))
361 /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
362 Valgrind does not support alignments larger than 1 MiB,
363 therefore we need special code which handles running on Valgrind. */
364 # define QEMU_VMALLOC_ALIGN (512 * 4096)
365 #elif defined(__linux__) && defined(__s390x__)
366 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
367 # define QEMU_VMALLOC_ALIGN (256 * 4096)
368 #elif defined(__linux__) && defined(__sparc__)
369 #include <sys/shm.h>
370 # define QEMU_VMALLOC_ALIGN MAX(getpagesize(), SHMLBA)
371 #else
372 # define QEMU_VMALLOC_ALIGN getpagesize()
373 #endif
375 #ifdef CONFIG_POSIX
376 struct qemu_signalfd_siginfo {
377 uint32_t ssi_signo; /* Signal number */
378 int32_t ssi_errno; /* Error number (unused) */
379 int32_t ssi_code; /* Signal code */
380 uint32_t ssi_pid; /* PID of sender */
381 uint32_t ssi_uid; /* Real UID of sender */
382 int32_t ssi_fd; /* File descriptor (SIGIO) */
383 uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */
384 uint32_t ssi_band; /* Band event (SIGIO) */
385 uint32_t ssi_overrun; /* POSIX timer overrun count */
386 uint32_t ssi_trapno; /* Trap number that caused signal */
387 int32_t ssi_status; /* Exit status or signal (SIGCHLD) */
388 int32_t ssi_int; /* Integer sent by sigqueue(2) */
389 uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */
390 uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */
391 uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */
392 uint64_t ssi_addr; /* Address that generated signal
393 (for hardware-generated signals) */
394 uint8_t pad[48]; /* Pad size to 128 bytes (allow for
395 additional fields in the future) */
398 int qemu_signalfd(const sigset_t *mask);
399 void sigaction_invoke(struct sigaction *action,
400 struct qemu_signalfd_siginfo *info);
401 #endif
403 int qemu_madvise(void *addr, size_t len, int advice);
404 int qemu_mprotect_rwx(void *addr, size_t size);
405 int qemu_mprotect_none(void *addr, size_t size);
407 int qemu_open(const char *name, int flags, ...);
408 int qemu_close(int fd);
409 #ifndef _WIN32
410 int qemu_dup(int fd);
411 #endif
412 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
413 int qemu_unlock_fd(int fd, int64_t start, int64_t len);
414 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
415 bool qemu_has_ofd_lock(void);
417 #if defined(__HAIKU__) && defined(__i386__)
418 #define FMT_pid "%ld"
419 #elif defined(WIN64)
420 #define FMT_pid "%" PRId64
421 #else
422 #define FMT_pid "%d"
423 #endif
425 int qemu_create_pidfile(const char *filename);
426 int qemu_get_thread_id(void);
428 #ifndef CONFIG_IOVEC
429 struct iovec {
430 void *iov_base;
431 size_t iov_len;
434 * Use the same value as Linux for now.
436 #define IOV_MAX 1024
438 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
439 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
440 #else
441 #include <sys/uio.h>
442 #endif
444 #ifdef _WIN32
445 static inline void qemu_timersub(const struct timeval *val1,
446 const struct timeval *val2,
447 struct timeval *res)
449 res->tv_sec = val1->tv_sec - val2->tv_sec;
450 if (val1->tv_usec < val2->tv_usec) {
451 res->tv_sec--;
452 res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
453 } else {
454 res->tv_usec = val1->tv_usec - val2->tv_usec;
457 #else
458 #define qemu_timersub timersub
459 #endif
461 void qemu_set_cloexec(int fd);
463 /* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
464 * instead of QEMU_VERSION, so setting hw_version on MachineClass
465 * is no longer mandatory.
467 * Do NOT change this string, or it will break compatibility on all
468 * machine classes that don't set hw_version.
470 #define QEMU_HW_VERSION "2.5+"
472 /* QEMU "hardware version" setting. Used to replace code that exposed
473 * QEMU_VERSION to guests in the past and need to keep compatibility.
474 * Do not use qemu_hw_version() in new code.
476 void qemu_set_hw_version(const char *);
477 const char *qemu_hw_version(void);
479 void fips_set_state(bool requested);
480 bool fips_get_state(void);
482 /* Return a dynamically allocated pathname denoting a file or directory that is
483 * appropriate for storing local state.
485 * @relative_pathname need not start with a directory separator; one will be
486 * added automatically.
488 * The caller is responsible for releasing the value returned with g_free()
489 * after use.
491 char *qemu_get_local_state_pathname(const char *relative_pathname);
493 /* Find program directory, and save it for later usage with
494 * qemu_get_exec_dir().
495 * Try OS specific API first, if not working, parse from argv0. */
496 void qemu_init_exec_dir(const char *argv0);
498 /* Get the saved exec dir.
499 * Caller needs to release the returned string by g_free() */
500 char *qemu_get_exec_dir(void);
503 * qemu_getauxval:
504 * @type: the auxiliary vector key to lookup
506 * Search the auxiliary vector for @type, returning the value
507 * or 0 if @type is not present.
509 unsigned long qemu_getauxval(unsigned long type);
511 void qemu_set_tty_echo(int fd, bool echo);
513 void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus,
514 Error **errp);
517 * qemu_get_pid_name:
518 * @pid: pid of a process
520 * For given @pid fetch its name. Caller is responsible for
521 * freeing the string when no longer needed.
522 * Returns allocated string on success, NULL on failure.
524 char *qemu_get_pid_name(pid_t pid);
527 * qemu_fork:
529 * A version of fork that avoids signal handler race
530 * conditions that can lead to child process getting
531 * signals that are otherwise only expected by the
532 * parent. It also resets all signal handlers to the
533 * default settings.
535 * Returns 0 to child process, pid number to parent
536 * or -1 on failure.
538 pid_t qemu_fork(Error **errp);
540 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
541 * when intptr_t is 32-bit and we are aligning a long long.
543 extern uintptr_t qemu_real_host_page_size;
544 extern intptr_t qemu_real_host_page_mask;
546 extern int qemu_icache_linesize;
547 extern int qemu_dcache_linesize;
549 #endif