X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/c7f4111a06208b46c6d05934d2a1e5cfbebc0180..fe1755cbb21c34a40234e2c380d049b9b031c4e2:/oslib-posix.c

diff --git a/oslib-posix.c b/oslib-posix.c
index 196099cc77..dbeb6272b8 100644
--- a/oslib-posix.c
+++ b/oslib-posix.c
@@ -35,12 +35,44 @@
 extern int daemon(int, int);
 #endif
 
+#if defined(__linux__) && defined(__x86_64__)
+   /* 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)
+#  define CONFIG_VALGRIND
+#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 "config-host.h"
 #include "sysemu.h"
 #include "trace.h"
 #include "qemu_socket.h"
 
+#if defined(CONFIG_VALGRIND)
+static int running_on_valgrind = -1;
+#else
+#  define running_on_valgrind 0
+#endif
+#ifdef CONFIG_LINUX
+#include <sys/syscall.h>
+#endif
+#ifdef CONFIG_EVENTFD
+#include <sys/eventfd.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)
 {
@@ -76,14 +108,31 @@ void *qemu_memalign(size_t alignment, size_t size)
     return ptr;
 }
 
+/* conflicts with qemu_vmalloc in bsd-user/mmap.c */
+#if !defined(CONFIG_BSD_USER)
 /* alloc shared memory pages */
 void *qemu_vmalloc(size_t size)
 {
     void *ptr;
-    ptr = qemu_memalign(getpagesize(), size);
+    size_t align = QEMU_VMALLOC_ALIGN;
+
+#if defined(CONFIG_VALGRIND)
+    if (running_on_valgrind < 0) {
+        /* First call, test whether we are running on Valgrind.
+           This is a substitute for RUNNING_ON_VALGRIND from valgrind.h. */
+        const char *ld = getenv("LD_PRELOAD");
+        running_on_valgrind = (ld != NULL && strstr(ld, "vgpreload"));
+    }
+#endif
+
+    if (size < align || running_on_valgrind) {
+        align = getpagesize();
+    }
+    ptr = qemu_memalign(align, size);
     trace_qemu_vmalloc(size, ptr);
     return ptr;
 }
+#endif
 
 void qemu_vfree(void *ptr)
 {
@@ -91,6 +140,13 @@ void qemu_vfree(void *ptr)
     free(ptr);
 }
 
+void socket_set_block(int fd)
+{
+    int f;
+    f = fcntl(fd, F_GETFL);
+    fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
+}
+
 void socket_set_nonblock(int fd)
 {
     int f;
@@ -127,8 +183,35 @@ int qemu_pipe(int pipefd[2])
     return ret;
 }
 
-int qemu_utimensat(int dirfd, const char *path, const struct timespec *times,
-                   int flags)
+/*
+ * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
+ */
+int qemu_eventfd(int fds[2])
+{
+#ifdef CONFIG_EVENTFD
+    int ret;
+
+    ret = eventfd(0, 0);
+    if (ret >= 0) {
+        fds[0] = ret;
+        fds[1] = dup(ret);
+        if (fds[1] == -1) {
+            close(ret);
+            return -1;
+        }
+        qemu_set_cloexec(ret);
+        qemu_set_cloexec(fds[1]);
+        return 0;
+    }
+    if (errno != ENOSYS) {
+        return -1;
+    }
+#endif
+
+    return qemu_pipe(fds);
+}
+
+int qemu_utimens(const char *path, const struct timespec *times)
 {
     struct timeval tv[2], tv_now;
     struct stat st;
@@ -136,7 +219,7 @@ int qemu_utimensat(int dirfd, const char *path, const struct timespec *times,
 #ifdef CONFIG_UTIMENSAT
     int ret;
 
-    ret = utimensat(dirfd, path, times, flags);
+    ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
     if (ret != -1 || errno != ENOSYS) {
         return ret;
     }