xref: /qemu/include/qemu/osdep.h (revision ac06724a)
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.h"
33 #else
34 #include "exec/poison.h"
35 #endif
36 #include "qemu/compiler.h"
37 
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.
41  */
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
51 
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
54  */
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
61 
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>
87 
88 #ifdef __OpenBSD__
89 #include <sys/signal.h>
90 #endif
91 
92 #ifndef _WIN32
93 #include <sys/wait.h>
94 #else
95 #define WIFEXITED(x)   1
96 #define WEXITSTATUS(x) (x)
97 #endif
98 
99 #ifdef _WIN32
100 #include "sysemu/os-win32.h"
101 #endif
102 
103 #ifdef CONFIG_POSIX
104 #include "sysemu/os-posix.h"
105 #endif
106 
107 #include "glib-compat.h"
108 #include "qemu/typedefs.h"
109 
110 #ifndef O_LARGEFILE
111 #define O_LARGEFILE 0
112 #endif
113 #ifndef O_BINARY
114 #define O_BINARY 0
115 #endif
116 #ifndef MAP_ANONYMOUS
117 #define MAP_ANONYMOUS MAP_ANON
118 #endif
119 #ifndef ENOMEDIUM
120 #define ENOMEDIUM ENODEV
121 #endif
122 #if !defined(ENOTSUP)
123 #define ENOTSUP 4096
124 #endif
125 #if !defined(ECANCELED)
126 #define ECANCELED 4097
127 #endif
128 #if !defined(EMEDIUMTYPE)
129 #define EMEDIUMTYPE 4098
130 #endif
131 #if !defined(ESHUTDOWN)
132 #define ESHUTDOWN 4099
133 #endif
134 #ifndef TIME_MAX
135 #define TIME_MAX LONG_MAX
136 #endif
137 
138 /* HOST_LONG_BITS is the size of a native pointer in bits. */
139 #if UINTPTR_MAX == UINT32_MAX
140 # define HOST_LONG_BITS 32
141 #elif UINTPTR_MAX == UINT64_MAX
142 # define HOST_LONG_BITS 64
143 #else
144 # error Unknown pointer size
145 #endif
146 
147 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
148  * the wrong type. Our replacement isn't usable in preprocessor
149  * expressions, but it is sufficient for our needs. */
150 #if defined(HAVE_BROKEN_SIZE_MAX) && HAVE_BROKEN_SIZE_MAX
151 #undef SIZE_MAX
152 #define SIZE_MAX ((size_t)-1)
153 #endif
154 
155 #ifndef MIN
156 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
157 #endif
158 #ifndef MAX
159 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
160 #endif
161 
162 /* Minimum function that returns zero only iff both values are zero.
163  * Intended for use with unsigned values only. */
164 #ifndef MIN_NON_ZERO
165 #define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \
166                                 ((b) == 0 ? (a) : (MIN(a, b))))
167 #endif
168 
169 /* Round number down to multiple */
170 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
171 
172 /* Round number up to multiple. Safe when m is not a power of 2 (see
173  * ROUND_UP for a faster version when a power of 2 is guaranteed) */
174 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
175 
176 /* Check if n is a multiple of m */
177 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
178 
179 /* n-byte align pointer down */
180 #define QEMU_ALIGN_PTR_DOWN(p, n) \
181     ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
182 
183 /* n-byte align pointer up */
184 #define QEMU_ALIGN_PTR_UP(p, n) \
185     ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
186 
187 /* Check if pointer p is n-bytes aligned */
188 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
189 
190 /* Round number up to multiple. Requires that d be a power of 2 (see
191  * QEMU_ALIGN_UP for a safer but slower version on arbitrary
192  * numbers) */
193 #ifndef ROUND_UP
194 #define ROUND_UP(n,d) (((n) + (d) - 1) & -(d))
195 #endif
196 
197 #ifndef DIV_ROUND_UP
198 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
199 #endif
200 
201 /*
202  * &(x)[0] is always a pointer - if it's same type as x then the argument is a
203  * pointer, not an array.
204  */
205 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
206                                                         typeof(&(x)[0])))
207 #ifndef ARRAY_SIZE
208 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
209                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
210 #endif
211 
212 int qemu_daemon(int nochdir, int noclose);
213 void *qemu_try_memalign(size_t alignment, size_t size);
214 void *qemu_memalign(size_t alignment, size_t size);
215 void *qemu_anon_ram_alloc(size_t size, uint64_t *align);
216 void qemu_vfree(void *ptr);
217 void qemu_anon_ram_free(void *ptr, size_t size);
218 
219 #define QEMU_MADV_INVALID -1
220 
221 #if defined(CONFIG_MADVISE)
222 
223 #define QEMU_MADV_WILLNEED  MADV_WILLNEED
224 #define QEMU_MADV_DONTNEED  MADV_DONTNEED
225 #ifdef MADV_DONTFORK
226 #define QEMU_MADV_DONTFORK  MADV_DONTFORK
227 #else
228 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
229 #endif
230 #ifdef MADV_MERGEABLE
231 #define QEMU_MADV_MERGEABLE MADV_MERGEABLE
232 #else
233 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
234 #endif
235 #ifdef MADV_UNMERGEABLE
236 #define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
237 #else
238 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
239 #endif
240 #ifdef MADV_DODUMP
241 #define QEMU_MADV_DODUMP MADV_DODUMP
242 #else
243 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
244 #endif
245 #ifdef MADV_DONTDUMP
246 #define QEMU_MADV_DONTDUMP MADV_DONTDUMP
247 #else
248 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
249 #endif
250 #ifdef MADV_HUGEPAGE
251 #define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
252 #else
253 #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
254 #endif
255 #ifdef MADV_NOHUGEPAGE
256 #define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
257 #else
258 #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
259 #endif
260 
261 #elif defined(CONFIG_POSIX_MADVISE)
262 
263 #define QEMU_MADV_WILLNEED  POSIX_MADV_WILLNEED
264 #define QEMU_MADV_DONTNEED  POSIX_MADV_DONTNEED
265 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
266 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
267 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
268 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
269 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
270 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
271 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
272 
273 #else /* no-op */
274 
275 #define QEMU_MADV_WILLNEED  QEMU_MADV_INVALID
276 #define QEMU_MADV_DONTNEED  QEMU_MADV_INVALID
277 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
278 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
279 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
280 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
281 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
282 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
283 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
284 
285 #endif
286 
287 #if defined(CONFIG_LINUX)
288 #ifndef BUS_MCEERR_AR
289 #define BUS_MCEERR_AR 4
290 #endif
291 #ifndef BUS_MCEERR_AO
292 #define BUS_MCEERR_AO 5
293 #endif
294 #endif
295 
296 #if defined(__linux__) && \
297     (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__))
298    /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
299       Valgrind does not support alignments larger than 1 MiB,
300       therefore we need special code which handles running on Valgrind. */
301 #  define QEMU_VMALLOC_ALIGN (512 * 4096)
302 #elif defined(__linux__) && defined(__s390x__)
303    /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
304 #  define QEMU_VMALLOC_ALIGN (256 * 4096)
305 #else
306 #  define QEMU_VMALLOC_ALIGN getpagesize()
307 #endif
308 
309 #ifdef CONFIG_POSIX
310 struct qemu_signalfd_siginfo {
311     uint32_t ssi_signo;   /* Signal number */
312     int32_t  ssi_errno;   /* Error number (unused) */
313     int32_t  ssi_code;    /* Signal code */
314     uint32_t ssi_pid;     /* PID of sender */
315     uint32_t ssi_uid;     /* Real UID of sender */
316     int32_t  ssi_fd;      /* File descriptor (SIGIO) */
317     uint32_t ssi_tid;     /* Kernel timer ID (POSIX timers) */
318     uint32_t ssi_band;    /* Band event (SIGIO) */
319     uint32_t ssi_overrun; /* POSIX timer overrun count */
320     uint32_t ssi_trapno;  /* Trap number that caused signal */
321     int32_t  ssi_status;  /* Exit status or signal (SIGCHLD) */
322     int32_t  ssi_int;     /* Integer sent by sigqueue(2) */
323     uint64_t ssi_ptr;     /* Pointer sent by sigqueue(2) */
324     uint64_t ssi_utime;   /* User CPU time consumed (SIGCHLD) */
325     uint64_t ssi_stime;   /* System CPU time consumed (SIGCHLD) */
326     uint64_t ssi_addr;    /* Address that generated signal
327                              (for hardware-generated signals) */
328     uint8_t  pad[48];     /* Pad size to 128 bytes (allow for
329                              additional fields in the future) */
330 };
331 
332 int qemu_signalfd(const sigset_t *mask);
333 void sigaction_invoke(struct sigaction *action,
334                       struct qemu_signalfd_siginfo *info);
335 #endif
336 
337 int qemu_madvise(void *addr, size_t len, int advice);
338 
339 int qemu_open(const char *name, int flags, ...);
340 int qemu_close(int fd);
341 #ifndef _WIN32
342 int qemu_dup(int fd);
343 #endif
344 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
345 int qemu_unlock_fd(int fd, int64_t start, int64_t len);
346 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
347 
348 #if defined(__HAIKU__) && defined(__i386__)
349 #define FMT_pid "%ld"
350 #elif defined(WIN64)
351 #define FMT_pid "%" PRId64
352 #else
353 #define FMT_pid "%d"
354 #endif
355 
356 int qemu_create_pidfile(const char *filename);
357 int qemu_get_thread_id(void);
358 
359 #ifndef CONFIG_IOVEC
360 struct iovec {
361     void *iov_base;
362     size_t iov_len;
363 };
364 /*
365  * Use the same value as Linux for now.
366  */
367 #define IOV_MAX 1024
368 
369 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
370 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
371 #else
372 #include <sys/uio.h>
373 #endif
374 
375 #ifdef _WIN32
376 static inline void qemu_timersub(const struct timeval *val1,
377                                  const struct timeval *val2,
378                                  struct timeval *res)
379 {
380     res->tv_sec = val1->tv_sec - val2->tv_sec;
381     if (val1->tv_usec < val2->tv_usec) {
382         res->tv_sec--;
383         res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
384     } else {
385         res->tv_usec = val1->tv_usec - val2->tv_usec;
386     }
387 }
388 #else
389 #define qemu_timersub timersub
390 #endif
391 
392 void qemu_set_cloexec(int fd);
393 
394 /* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
395  * instead of QEMU_VERSION, so setting hw_version on MachineClass
396  * is no longer mandatory.
397  *
398  * Do NOT change this string, or it will break compatibility on all
399  * machine classes that don't set hw_version.
400  */
401 #define QEMU_HW_VERSION "2.5+"
402 
403 /* QEMU "hardware version" setting. Used to replace code that exposed
404  * QEMU_VERSION to guests in the past and need to keep compatibility.
405  * Do not use qemu_hw_version() in new code.
406  */
407 void qemu_set_hw_version(const char *);
408 const char *qemu_hw_version(void);
409 
410 void fips_set_state(bool requested);
411 bool fips_get_state(void);
412 
413 /* Return a dynamically allocated pathname denoting a file or directory that is
414  * appropriate for storing local state.
415  *
416  * @relative_pathname need not start with a directory separator; one will be
417  * added automatically.
418  *
419  * The caller is responsible for releasing the value returned with g_free()
420  * after use.
421  */
422 char *qemu_get_local_state_pathname(const char *relative_pathname);
423 
424 /* Find program directory, and save it for later usage with
425  * qemu_get_exec_dir().
426  * Try OS specific API first, if not working, parse from argv0. */
427 void qemu_init_exec_dir(const char *argv0);
428 
429 /* Get the saved exec dir.
430  * Caller needs to release the returned string by g_free() */
431 char *qemu_get_exec_dir(void);
432 
433 /**
434  * qemu_getauxval:
435  * @type: the auxiliary vector key to lookup
436  *
437  * Search the auxiliary vector for @type, returning the value
438  * or 0 if @type is not present.
439  */
440 unsigned long qemu_getauxval(unsigned long type);
441 
442 void qemu_set_tty_echo(int fd, bool echo);
443 
444 void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus,
445                      Error **errp);
446 
447 int qemu_read_password(char *buf, int buf_size);
448 
449 /**
450  * qemu_get_pid_name:
451  * @pid: pid of a process
452  *
453  * For given @pid fetch its name. Caller is responsible for
454  * freeing the string when no longer needed.
455  * Returns allocated string on success, NULL on failure.
456  */
457 char *qemu_get_pid_name(pid_t pid);
458 
459 /**
460  * qemu_fork:
461  *
462  * A version of fork that avoids signal handler race
463  * conditions that can lead to child process getting
464  * signals that are otherwise only expected by the
465  * parent. It also resets all signal handlers to the
466  * default settings.
467  *
468  * Returns 0 to child process, pid number to parent
469  * or -1 on failure.
470  */
471 pid_t qemu_fork(Error **errp);
472 
473 #endif
474