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[Qemu-devel] [PULL v3 36/51] ivshmem-server: fix hugetlbfs support
From: |
marcandre . lureau |
Subject: |
[Qemu-devel] [PULL v3 36/51] ivshmem-server: fix hugetlbfs support |
Date: |
Tue, 13 Oct 2015 16:26:03 +0200 |
From: Marc-André Lureau <address@hidden>
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 <address@hidden>
Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
contrib/ivshmem-server/ivshmem-server.c | 50 ++++++++++++++++++++++++++++++++-
contrib/ivshmem-server/ivshmem-server.h | 3 +-
contrib/ivshmem-server/main.c | 5 ++--
3 files changed, 52 insertions(+), 6 deletions(-)
diff --git a/contrib/ivshmem-server/ivshmem-server.c
b/contrib/ivshmem-server/ivshmem-server.c
index ea2b65e..e2d81f7 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"
@@ -272,6 +275,35 @@ ivshmem_server_init(IvshmemServer *server, const char
*unix_sock_path,
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) {
+ 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;
+}
+#endif
+
/* open shm, create and bind to the unix socket */
int
ivshmem_server_start(IvshmemServer *server)
@@ -280,7 +312,23 @@ ivshmem_server_start(IvshmemServer *server)
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) {
+ gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX",
server->shm_path);
+ fprintf(stdout, "Using hugepages: %s\n", server->shm_path);
+ shm_fd = mkstemp(filename);
+ unlink(filename);
+ g_free(filename);
+ } else
+#endif
+ {
+ fprintf(stdout, "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 @@ 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 064de02..b960048 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
- [Qemu-devel] [PULL v3 24/51] ivshmem: migrate with VMStateDescription, (continued)
- [Qemu-devel] [PULL v3 24/51] ivshmem: migrate with VMStateDescription, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 28/51] ivshmem: fix pci_ivshmem_exit(), marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 31/51] ivshmem: reset mask on device reset, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 35/51] ivshmem-server: use a uint16 for client ID, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 29/51] ivshmem: replace 'guest' for 'peer' appropriately, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 34/51] ivshmem-client: check the number of vectors, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 30/51] ivshmem: error on too many eventfd received, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 33/51] contrib: add ivshmem client and server, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 43/51] tests: add ivshmem qtest, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 44/51] ivshmem: do not keep shm_fd open, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 36/51] ivshmem-server: fix hugetlbfs support,
marcandre . lureau <=
- [Qemu-devel] [PULL v3 37/51] docs: update ivshmem device spec, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 42/51] glib-compat: add 2.38/2.40/2.46 asserts, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 48/51] ivshmem: rename MSI eventfd_table, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 50/51] ivshmem: use little-endian int64_t for the protocol, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 47/51] ivshmem: remove EventfdEntry.vector, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 51/51] doc: document ivshmem & hugepages, marcandre . lureau, 2015/10/13
- [Qemu-devel] [PULL v3 12/51] ivshmem: limit maximum number of peers to G_MAXUINT16, marcandre . lureau, 2015/10/15
- [Qemu-devel] [PULL v3 14/51] ivshmem: allocate eventfds in resize_peers(), marcandre . lureau, 2015/10/15
- [Qemu-devel] [PULL v3 27/51] ivshmem: add device description, marcandre . lureau, 2015/10/15
- [Qemu-devel] [PULL v3 13/51] ivshmem: simplify around increase_dynamic_storage(), marcandre . lureau, 2015/10/15