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-rw-r--r--util/oslib-posix.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 8e9c770d28..1524ead755 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -46,6 +46,7 @@ extern int daemon(int, int);
#else
# define QEMU_VMALLOC_ALIGN getpagesize()
#endif
+#define HUGETLBFS_MAGIC 0x958458f6
#include <termios.h>
#include <unistd.h>
@@ -58,9 +59,12 @@ extern int daemon(int, int);
#include "qemu/sockets.h"
#include <sys/mman.h>
#include <libgen.h>
+#include <setjmp.h>
+#include <sys/signal.h>
#ifdef CONFIG_LINUX
#include <sys/syscall.h>
+#include <sys/vfs.h>
#endif
#ifdef __FreeBSD__
@@ -332,3 +336,72 @@ char *qemu_get_exec_dir(void)
{
return g_strdup(exec_dir);
}
+
+static sigjmp_buf sigjump;
+
+static void sigbus_handler(int signal)
+{
+ siglongjmp(sigjump, 1);
+}
+
+static size_t fd_getpagesize(int fd)
+{
+#ifdef CONFIG_LINUX
+ struct statfs fs;
+ int ret;
+
+ if (fd != -1) {
+ do {
+ ret = fstatfs(fd, &fs);
+ } while (ret != 0 && errno == EINTR);
+
+ if (ret == 0 && fs.f_type == HUGETLBFS_MAGIC) {
+ return fs.f_bsize;
+ }
+ }
+#endif
+
+ return getpagesize();
+}
+
+void os_mem_prealloc(int fd, char *area, size_t memory)
+{
+ int ret, i;
+ struct sigaction act, oldact;
+ sigset_t set, oldset;
+ size_t hpagesize = fd_getpagesize(fd);
+
+ memset(&act, 0, sizeof(act));
+ act.sa_handler = &sigbus_handler;
+ act.sa_flags = 0;
+
+ ret = sigaction(SIGBUS, &act, &oldact);
+ if (ret) {
+ perror("os_mem_prealloc: failed to install signal handler");
+ exit(1);
+ }
+
+ /* unblock SIGBUS */
+ sigemptyset(&set);
+ sigaddset(&set, SIGBUS);
+ pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
+
+ if (sigsetjmp(sigjump, 1)) {
+ fprintf(stderr, "os_mem_prealloc: failed to preallocate pages\n");
+ exit(1);
+ }
+
+ /* MAP_POPULATE silently ignores failures */
+ memory = (memory + hpagesize - 1) & -hpagesize;
+ for (i = 0; i < (memory/hpagesize); i++) {
+ memset(area + (hpagesize*i), 0, 1);
+ }
+
+ ret = sigaction(SIGBUS, &oldact, NULL);
+ if (ret) {
+ perror("os_mem_prealloc: failed to reinstall signal handler");
+ exit(1);
+ }
+
+ pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+}