From: Marc-André Lureau <marcandre.lur...@gmail.com>
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.lur...@redhat.com>
---
contrib/ivshmem-server/ivshmem-server.c | 47 ++++++++++++++++++++++++++++++++-
contrib/ivshmem-server/ivshmem-server.h | 3 +--
contrib/ivshmem-server/main.c | 5 ++--
3 files changed, 49 insertions(+), 6 deletions(-)
diff --git a/contrib/ivshmem-server/ivshmem-server.c
b/contrib/ivshmem-server/ivshmem-server.c
index 972fda2..4bf774b 100644
--- a/contrib/ivshmem-server/ivshmem-server.c
+++ b/contrib/ivshmem-server/ivshmem-server.c
@@ -11,6 +11,7 @@
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/eventfd.h>
+#include <sys/vfs.h>
#include "qemu-common.h"
#include "qemu/queue.h"
@@ -271,15 +272,59 @@ ivshmem_server_init(IvshmemServer *server, const char
*unix_sock_path,
return 0;
}
+#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) {
+ if (errno != ENOENT) {
+ fprintf(stderr, "cannot stat shm file %s: %s\n", path,
+ strerror(errno));
+ }
+ return -1;
+ }
+
+ if (fs.f_type != HUGETLBFS_MAGIC) {
+ return -1;
+ }
+
+ return fs.f_bsize;
+}
+
+
+
/* open shm, create and bind to the unix socket */
int
ivshmem_server_start(IvshmemServer *server)
{
struct sockaddr_un sun;
int shm_fd, sock_fd, ret;
+ long hpagesize;
+ gchar *filename;
/* open shm file */
- shm_fd = shm_open(server->shm_path, O_CREAT|O_RDWR, S_IRWXU);
+ hpagesize = gethugepagesize(server->shm_path);
+ if (hpagesize > 0) {
+ if (server->shm_size < hpagesize) {
+ fprintf(stderr, "hugepage must be at least of size: %ld\n",
+ hpagesize);
+ return -1;
+ }
+ filename = g_strdup_printf("%s/ivshmem.XXXXXX", server->shm_path);
+ shm_fd = mkstemp(filename);
+ unlink(filename);
+ g_free(filename);
+ } else {
+ 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 2176d5e..e9b0e7a 100644
--- a/contrib/ivshmem-server/ivshmem-server.h
+++ b/contrib/ivshmem-server/ivshmem-server.h
@@ -81,8 +81,7 @@ typedef struct IvshmemServer {
* @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 84ffc4d..cd8d9ed 100644
--- a/contrib/ivshmem-server/main.c
+++ b/contrib/ivshmem-server/main.c
@@ -47,9 +47,8 @@ ivshmem_server_usage(const char *name, int code)
" 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"
--
2.4.3
