4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010 Red Hat, Inc.
7 * QEMU library functions on POSIX which are shared between QEMU and
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
29 /* The following block of code temporarily renames the daemon() function so the
30 compiler does not see the warning associated with it in stdlib.h on OSX */
32 #define daemon qemu_fake_daemon_function
35 extern int daemon(int, int);
38 #if defined(__linux__) && (defined(__x86_64__) || defined(__arm__))
39 /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
40 Valgrind does not support alignments larger than 1 MiB,
41 therefore we need special code which handles running on Valgrind. */
42 # define QEMU_VMALLOC_ALIGN (512 * 4096)
43 # define CONFIG_VALGRIND
44 #elif defined(__linux__) && defined(__s390x__)
45 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
46 # define QEMU_VMALLOC_ALIGN (256 * 4096)
48 # define QEMU_VMALLOC_ALIGN getpagesize()
51 #include "config-host.h"
52 #include "sysemu/sysemu.h"
54 #include "qemu/sockets.h"
56 #if defined(CONFIG_VALGRIND)
57 static int running_on_valgrind
= -1;
59 # define running_on_valgrind 0
62 #include <sys/syscall.h>
65 int qemu_get_thread_id(void)
67 #if defined(__linux__)
68 return syscall(SYS_gettid
);
74 int qemu_daemon(int nochdir
, int noclose
)
76 return daemon(nochdir
, noclose
);
79 void *qemu_oom_check(void *ptr
)
82 fprintf(stderr
, "Failed to allocate memory: %s\n", strerror(errno
));
88 void *qemu_memalign(size_t alignment
, size_t size
)
91 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
93 ret
= posix_memalign(&ptr
, alignment
, size
);
95 fprintf(stderr
, "Failed to allocate %zu B: %s\n",
99 #elif defined(CONFIG_BSD)
100 ptr
= qemu_oom_check(valloc(size
));
102 ptr
= qemu_oom_check(memalign(alignment
, size
));
104 trace_qemu_memalign(alignment
, size
, ptr
);
108 /* alloc shared memory pages */
109 void *qemu_vmalloc(size_t size
)
112 size_t align
= QEMU_VMALLOC_ALIGN
;
114 #if defined(CONFIG_VALGRIND)
115 if (running_on_valgrind
< 0) {
116 /* First call, test whether we are running on Valgrind.
117 This is a substitute for RUNNING_ON_VALGRIND from valgrind.h. */
118 const char *ld
= getenv("LD_PRELOAD");
119 running_on_valgrind
= (ld
!= NULL
&& strstr(ld
, "vgpreload"));
123 if (size
< align
|| running_on_valgrind
) {
124 align
= getpagesize();
126 ptr
= qemu_memalign(align
, size
);
127 trace_qemu_vmalloc(size
, ptr
);
131 void qemu_vfree(void *ptr
)
133 trace_qemu_vfree(ptr
);
137 void qemu_set_block(int fd
)
140 f
= fcntl(fd
, F_GETFL
);
141 fcntl(fd
, F_SETFL
, f
& ~O_NONBLOCK
);
144 void qemu_set_nonblock(int fd
)
147 f
= fcntl(fd
, F_GETFL
);
148 fcntl(fd
, F_SETFL
, f
| O_NONBLOCK
);
151 void qemu_set_cloexec(int fd
)
154 f
= fcntl(fd
, F_GETFD
);
155 fcntl(fd
, F_SETFD
, f
| FD_CLOEXEC
);
159 * Creates a pipe with FD_CLOEXEC set on both file descriptors
161 int qemu_pipe(int pipefd
[2])
166 ret
= pipe2(pipefd
, O_CLOEXEC
);
167 if (ret
!= -1 || errno
!= ENOSYS
) {
173 qemu_set_cloexec(pipefd
[0]);
174 qemu_set_cloexec(pipefd
[1]);
180 int qemu_utimens(const char *path
, const struct timespec
*times
)
182 struct timeval tv
[2], tv_now
;
185 #ifdef CONFIG_UTIMENSAT
188 ret
= utimensat(AT_FDCWD
, path
, times
, AT_SYMLINK_NOFOLLOW
);
189 if (ret
!= -1 || errno
!= ENOSYS
) {
193 /* Fallback: use utimes() instead of utimensat() */
195 /* happy if special cases */
196 if (times
[0].tv_nsec
== UTIME_OMIT
&& times
[1].tv_nsec
== UTIME_OMIT
) {
199 if (times
[0].tv_nsec
== UTIME_NOW
&& times
[1].tv_nsec
== UTIME_NOW
) {
200 return utimes(path
, NULL
);
203 /* prepare for hard cases */
204 if (times
[0].tv_nsec
== UTIME_NOW
|| times
[1].tv_nsec
== UTIME_NOW
) {
205 gettimeofday(&tv_now
, NULL
);
207 if (times
[0].tv_nsec
== UTIME_OMIT
|| times
[1].tv_nsec
== UTIME_OMIT
) {
211 for (i
= 0; i
< 2; i
++) {
212 if (times
[i
].tv_nsec
== UTIME_NOW
) {
213 tv
[i
].tv_sec
= tv_now
.tv_sec
;
214 tv
[i
].tv_usec
= tv_now
.tv_usec
;
215 } else if (times
[i
].tv_nsec
== UTIME_OMIT
) {
216 tv
[i
].tv_sec
= (i
== 0) ? st
.st_atime
: st
.st_mtime
;
219 tv
[i
].tv_sec
= times
[i
].tv_sec
;
220 tv
[i
].tv_usec
= times
[i
].tv_nsec
/ 1000;
224 return utimes(path
, &tv
[0]);