ivshmem-server: fix hugetlbfs support
As pointed out on the ML by Andrew Jones, glibc no longer permits
creating POSIX shm on hugetlbfs directly. When given a hugetlbfs path,
create a shareable file there.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
diff --git a/contrib/ivshmem-server/ivshmem-server.c b/contrib/ivshmem-server/ivshmem-server.c
index 53a5173..01c8920 100644
--- a/contrib/ivshmem-server/ivshmem-server.c
+++ b/contrib/ivshmem-server/ivshmem-server.c
@@ -12,6 +12,9 @@
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
+#ifdef CONFIG_LINUX
+#include <sys/vfs.h>
+#endif
#include "ivshmem-server.h"
@@ -271,6 +274,31 @@
return 0;
}
+#ifdef CONFIG_LINUX
+
+#define HUGETLBFS_MAGIC 0x958458f6
+
+static long gethugepagesize(const char *path)
+{
+ struct statfs fs;
+ int ret;
+
+ do {
+ ret = statfs(path, &fs);
+ } while (ret != 0 && errno == EINTR);
+
+ if (ret != 0) {
+ return -1;
+ }
+
+ if (fs.f_type != HUGETLBFS_MAGIC) {
+ return -1;
+ }
+
+ return fs.f_bsize;
+}
+#endif
+
/* open shm, create and bind to the unix socket */
int
ivshmem_server_start(IvshmemServer *server)
@@ -279,7 +307,29 @@
int shm_fd, sock_fd, ret;
/* open shm file */
- shm_fd = shm_open(server->shm_path, O_CREAT|O_RDWR, S_IRWXU);
+#ifdef CONFIG_LINUX
+ long hpagesize;
+
+ hpagesize = gethugepagesize(server->shm_path);
+ if (hpagesize < 0 && errno != ENOENT) {
+ IVSHMEM_SERVER_DEBUG(server, "cannot stat shm file %s: %s\n",
+ server->shm_path, strerror(errno));
+ }
+
+ if (hpagesize > 0) {
+ gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX", server->shm_path);
+ IVSHMEM_SERVER_DEBUG(server, "Using hugepages: %s\n", server->shm_path);
+ shm_fd = mkstemp(filename);
+ unlink(filename);
+ g_free(filename);
+ } else
+#endif
+ {
+ IVSHMEM_SERVER_DEBUG(server, "Using POSIX shared memory: %s\n",
+ server->shm_path);
+ shm_fd = shm_open(server->shm_path, O_CREAT|O_RDWR, S_IRWXU);
+ }
+
if (shm_fd < 0) {
fprintf(stderr, "cannot open shm file %s: %s\n", server->shm_path,
strerror(errno));
diff --git a/contrib/ivshmem-server/ivshmem-server.h b/contrib/ivshmem-server/ivshmem-server.h
index 83c751c..8261e86 100644
--- a/contrib/ivshmem-server/ivshmem-server.h
+++ b/contrib/ivshmem-server/ivshmem-server.h
@@ -82,8 +82,7 @@
* @server: A pointer to an uninitialized IvshmemServer structure
* @unix_sock_path: The pointer to the unix socket file name
* @shm_path: Path to the shared memory. The path corresponds to a POSIX
- * shm name. To use a real file, for instance in a hugetlbfs,
- * it is possible to use /../../abspath/to/file.
+ * shm name or a hugetlbfs mount point.
* @shm_size: Size of shared memory
* @n_vectors: Number of interrupt vectors per client
* @verbose: True to enable verbose mode
diff --git a/contrib/ivshmem-server/main.c b/contrib/ivshmem-server/main.c
index 064de02..b960048 100644
--- a/contrib/ivshmem-server/main.c
+++ b/contrib/ivshmem-server/main.c
@@ -47,9 +47,8 @@
" to listen to.\n"
" Default=%s\n", IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH);
fprintf(stderr, " -m <shm_path>: path to the shared memory.\n"
- " The path corresponds to a POSIX shm name. To use a\n"
- " real file, for instance in a hugetlbfs, use\n"
- " /../../abspath/to/file.\n"
+ " The path corresponds to a POSIX shm name or a\n"
+ " hugetlbfs mount point.\n"
" default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH);
fprintf(stderr, " -l <size>: size of shared memory in bytes. The suffix\n"
" K, M and G can be used (ex: 1K means 1024).\n"
