include/qemu/osdep.h

   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(__linux__) && \
 288     (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__))
 289    /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
 290       Valgrind does not support alignments larger than 1 MiB,
 291       therefore we need special code which handles running on Valgrind. */
 292 #  define QEMU_VMALLOC_ALIGN (512 * 4096)
 293 #elif defined(__linux__) && defined(__s390x__)
 294    /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
 295 #  define QEMU_VMALLOC_ALIGN (256 * 4096)
 296 #else
 297 #  define QEMU_VMALLOC_ALIGN getpagesize()
 298 #endif
 299
 300 int qemu_madvise(void *addr, size_t len, int advice);
 301
 302 int qemu_open(const char *name, int flags, ...);
 303 int qemu_close(int fd);
 304 #ifndef _WIN32
 305 int qemu_dup(int fd);
 306 #endif
 307
 308 #if defined(__HAIKU__) && defined(__i386__)
 309 #define FMT_pid "%ld"
 310 #elif defined(WIN64)
 311 #define FMT_pid "%" PRId64
 312 #else
 313 #define FMT_pid "%d"
 314 #endif
 315
 316 int qemu_create_pidfile(const char *filename);
 317 int qemu_get_thread_id(void);
 318
 319 #ifndef CONFIG_IOVEC
 320 struct iovec {
 321     void *iov_base;
 322     size_t iov_len;
 323 };
 324 /*
 325  * Use the same value as Linux for now.
 326  */
 327 #define IOV_MAX 1024
 328
 329 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
 330 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
 331 #else
 332 #include <sys/uio.h>
 333 #endif
 334
 335 #ifdef _WIN32
 336 static inline void qemu_timersub(const struct timeval *val1,
 337                                  const struct timeval *val2,
 338                                  struct timeval *res)
 339 {
 340     res->tv_sec = val1->tv_sec - val2->tv_sec;
 341     if (val1->tv_usec < val2->tv_usec) {
 342         res->tv_sec--;
 343         res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
 344     } else {
 345         res->tv_usec = val1->tv_usec - val2->tv_usec;
 346     }
 347 }
 348 #else
 349 #define qemu_timersub timersub
 350 #endif
 351
 352 void qemu_set_cloexec(int fd);
 353
 354 /* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
 355  * instead of QEMU_VERSION, so setting hw_version on MachineClass
 356  * is no longer mandatory.
 357  *
 358  * Do NOT change this string, or it will break compatibility on all
 359  * machine classes that don't set hw_version.
 360  */
 361 #define QEMU_HW_VERSION "2.5+"
 362
 363 /* QEMU "hardware version" setting. Used to replace code that exposed
 364  * QEMU_VERSION to guests in the past and need to keep compatibility.
 365  * Do not use qemu_hw_version() in new code.
 366  */
 367 void qemu_set_hw_version(const char *);
 368 const char *qemu_hw_version(void);
 369
 370 void fips_set_state(bool requested);
 371 bool fips_get_state(void);
 372
 373 /* Return a dynamically allocated pathname denoting a file or directory that is
 374  * appropriate for storing local state.
 375  *
 376  * @relative_pathname need not start with a directory separator; one will be
 377  * added automatically.
 378  *
 379  * The caller is responsible for releasing the value returned with g_free()
 380  * after use.
 381  */
 382 char *qemu_get_local_state_pathname(const char *relative_pathname);
 383
 384 /* Find program directory, and save it for later usage with
 385  * qemu_get_exec_dir().
 386  * Try OS specific API first, if not working, parse from argv0. */
 387 void qemu_init_exec_dir(const char *argv0);
 388
 389 /* Get the saved exec dir.
 390  * Caller needs to release the returned string by g_free() */
 391 char *qemu_get_exec_dir(void);
 392
 393 /**
 394  * qemu_getauxval:
 395  * @type: the auxiliary vector key to lookup
 396  *
 397  * Search the auxiliary vector for @type, returning the value
 398  * or 0 if @type is not present.
 399  */
 400 unsigned long qemu_getauxval(unsigned long type);
 401
 402 void qemu_set_tty_echo(int fd, bool echo);
 403
 404 void os_mem_prealloc(int fd, char *area, size_t sz, Error **errp);
 405
 406 int qemu_read_password(char *buf, int buf_size);
 407
 408 /**
 409  * qemu_get_pid_name:
 410  * @pid: pid of a process
 411  *
 412  * For given @pid fetch its name. Caller is responsible for
 413  * freeing the string when no longer needed.
 414  * Returns allocated string on success, NULL on failure.
 415  */
 416 char *qemu_get_pid_name(pid_t pid);
 417
 418 /**
 419  * qemu_fork:
 420  *
 421  * A version of fork that avoids signal handler race
 422  * conditions that can lead to child process getting
 423  * signals that are otherwise only expected by the
 424  * parent. It also resets all signal handlers to the
 425  * default settings.
 426  *
 427  * Returns 0 to child process, pid number to parent
 428  * or -1 on failure.
 429  */
 430 pid_t qemu_fork(Error **errp);
 431
 432 #endif