Archipelago » qemu

/*

 * os-posix-lib.c

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 * Copyright (c) 2010 Red Hat, Inc.

 *

 * QEMU library functions on POSIX which are shared between QEMU and

 * the QEMU tools.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

/* The following block of code temporarily renames the daemon() function so the

   compiler does not see the warning associated with it in stdlib.h on OSX */

#ifdef __APPLE__

#define daemon qemu_fake_daemon_function

#include <stdlib.h>

#undef daemon

extern int daemon(int, int);

#endif

#if defined(__linux__) && (defined(__x86_64__) || defined(__arm__))

   /* Use 2 MiB alignment so transparent hugepages can be used by KVM.

      Valgrind does not support alignments larger than 1 MiB,

      therefore we need special code which handles running on Valgrind. */

#  define QEMU_VMALLOC_ALIGN (512 * 4096)

#elif defined(__linux__) && defined(__s390x__)

   /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */

#  define QEMU_VMALLOC_ALIGN (256 * 4096)

#else

#  define QEMU_VMALLOC_ALIGN getpagesize()

#endif

#include <termios.h>

#include <unistd.h>

#include <glib/gprintf.h>

#include "config-host.h"

#include "sysemu/sysemu.h"

#include "trace.h"

#include "qemu/sockets.h"

#include <sys/mman.h>

#include <libgen.h>

#ifdef CONFIG_LINUX

#include <sys/syscall.h>

#endif

int qemu_get_thread_id(void)

{

#if defined(__linux__)

    return syscall(SYS_gettid);

#else

    return getpid();

#endif

}

int qemu_daemon(int nochdir, int noclose)

{

    return daemon(nochdir, noclose);

}

void *qemu_oom_check(void *ptr)

{

    if (ptr == NULL) {

        fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));

        abort();

    }

    return ptr;

}

void *qemu_memalign(size_t alignment, size_t size)

{

    void *ptr;

    if (alignment < sizeof(void*)) {

        alignment = sizeof(void*);

    }

#if defined(_POSIX_C_SOURCE) && !defined(__sun__)

    int ret;

    ret = posix_memalign(&ptr, alignment, size);

    if (ret != 0) {

        fprintf(stderr, "Failed to allocate %zu B: %s\n",

                size, strerror(ret));

        abort();

    }

#elif defined(CONFIG_BSD)

    ptr = qemu_oom_check(valloc(size));

#else

    ptr = qemu_oom_check(memalign(alignment, size));

#endif

    trace_qemu_memalign(alignment, size, ptr);

    return ptr;

}

/* alloc shared memory pages */

void *qemu_anon_ram_alloc(size_t size)

{

    size_t align = QEMU_VMALLOC_ALIGN;

    size_t total = size + align - getpagesize();

    void *ptr = mmap(0, total, PROT_READ | PROT_WRITE,

                     MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);

    size_t offset = QEMU_ALIGN_UP((uintptr_t)ptr, align) - (uintptr_t)ptr;

    if (ptr == MAP_FAILED) {

        return NULL;

    }

    ptr += offset;

    total -= offset;

    if (offset > 0) {

        munmap(ptr - offset, offset);

    }

    if (total > size) {

        munmap(ptr + size, total - size);

    }

    trace_qemu_anon_ram_alloc(size, ptr);

    return ptr;

}

void qemu_vfree(void *ptr)

{

    trace_qemu_vfree(ptr);

    free(ptr);

}

void qemu_anon_ram_free(void *ptr, size_t size)

{

    trace_qemu_anon_ram_free(ptr, size);

    if (ptr) {

        munmap(ptr, size);

    }

}

void qemu_set_block(int fd)

{

    int f;

    f = fcntl(fd, F_GETFL);

    fcntl(fd, F_SETFL, f & ~O_NONBLOCK);

}

void qemu_set_nonblock(int fd)

{

    int f;

    f = fcntl(fd, F_GETFL);

    fcntl(fd, F_SETFL, f | O_NONBLOCK);

}

int socket_set_fast_reuse(int fd)

{

    int val = 1, ret;

    ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,

                     (const char *)&val, sizeof(val));

    assert(ret == 0);

    return ret;

}

void qemu_set_cloexec(int fd)

{

    int f;

    f = fcntl(fd, F_GETFD);

    fcntl(fd, F_SETFD, f | FD_CLOEXEC);

}

/*

 * Creates a pipe with FD_CLOEXEC set on both file descriptors

 */

int qemu_pipe(int pipefd[2])

{

    int ret;

#ifdef CONFIG_PIPE2

    ret = pipe2(pipefd, O_CLOEXEC);

    if (ret != -1 || errno != ENOSYS) {

        return ret;

    }

#endif

    ret = pipe(pipefd);

    if (ret == 0) {

        qemu_set_cloexec(pipefd[0]);

        qemu_set_cloexec(pipefd[1]);

    }

    return ret;

}

int qemu_utimens(const char *path, const struct timespec *times)

{

    struct timeval tv[2], tv_now;

    struct stat st;

    int i;

#ifdef CONFIG_UTIMENSAT

    int ret;

    ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);

    if (ret != -1 || errno != ENOSYS) {

        return ret;

    }

#endif

    /* Fallback: use utimes() instead of utimensat() */

    /* happy if special cases */

    if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {

        return 0;

    }

    if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {

        return utimes(path, NULL);

    }

    /* prepare for hard cases */

    if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {

        gettimeofday(&tv_now, NULL);

    }

    if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {

        stat(path, &st);

    }

    for (i = 0; i < 2; i++) {

        if (times[i].tv_nsec == UTIME_NOW) {

            tv[i].tv_sec = tv_now.tv_sec;

            tv[i].tv_usec = tv_now.tv_usec;

        } else if (times[i].tv_nsec == UTIME_OMIT) {

            tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;

            tv[i].tv_usec = 0;

        } else {

            tv[i].tv_sec = times[i].tv_sec;

            tv[i].tv_usec = times[i].tv_nsec / 1000;

        }

    }

    return utimes(path, &tv[0]);

}

char *

qemu_get_local_state_pathname(const char *relative_pathname)

{

    return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,

                           relative_pathname);

}

void qemu_set_tty_echo(int fd, bool echo)

{

    struct termios tty;

    tcgetattr(fd, &tty);

    if (echo) {

        tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN;

    } else {

        tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);

    }

    tcsetattr(fd, TCSANOW, &tty);

}

static char exec_dir[PATH_MAX];

void qemu_init_exec_dir(const char *argv0)

{

    char *dir;

    char *p = NULL;

    char buf[PATH_MAX];

    assert(!exec_dir[0]);

#if defined(__linux__)

    {

        int len;

        len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);

        if (len > 0) {

            buf[len] = 0;

            p = buf;

        }

    }

#elif defined(__FreeBSD__)

    {

        static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};

        size_t len = sizeof(buf) - 1;

        *buf = '\0';

        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&

            *buf) {

            buf[sizeof(buf) - 1] = '\0';

            p = buf;

        }

    }

#endif

    /* If we don't have any way of figuring out the actual executable

       location then try argv[0].  */

    if (!p) {

        if (!argv0) {

            return;

        }

        p = realpath(argv0, buf);

        if (!p) {

            return;

        }

    }

    dir = dirname(p);

    pstrcpy(exec_dir, sizeof(exec_dir), dir);

}

char *qemu_get_exec_dir(void)

{

    return g_strdup(exec_dir);

}