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[Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem and file name |
Date: |
Mon, 7 Mar 2016 20:25:17 +0100 |
Option -m NAME is interpreted as directory name if we can statfs() it
and its on hugetlbfs. Else it's interpreted as POSIX shared memory
object name. This is nuts.
Always interpret -m as directory. Create new -M for POSIX shared
memory. Last of -m or -M wins.
Signed-off-by: Markus Armbruster <address@hidden>
---
contrib/ivshmem-server/ivshmem-server.c | 56 ++++++---------------------------
contrib/ivshmem-server/ivshmem-server.h | 4 ++-
contrib/ivshmem-server/main.c | 15 +++++++--
tests/ivshmem-test.c | 2 +-
4 files changed, 27 insertions(+), 50 deletions(-)
diff --git a/contrib/ivshmem-server/ivshmem-server.c
b/contrib/ivshmem-server/ivshmem-server.c
index bfd0fad..41aee35 100644
--- a/contrib/ivshmem-server/ivshmem-server.c
+++ b/contrib/ivshmem-server/ivshmem-server.c
@@ -12,9 +12,6 @@
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/un.h>
-#ifdef CONFIG_LINUX
-#include <sys/vfs.h>
-#endif
#include "ivshmem-server.h"
@@ -257,7 +254,8 @@ ivshmem_server_ftruncate(int fd, unsigned shmsize)
/* Init a new ivshmem server */
int
ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path,
- const char *shm_path, size_t shm_size, unsigned n_vectors,
+ const char *shm_path, bool use_shm_open,
+ size_t shm_size, unsigned n_vectors,
bool verbose)
{
int ret;
@@ -278,6 +276,7 @@ ivshmem_server_init(IvshmemServer *server, const char
*unix_sock_path,
return -1;
}
+ server->use_shm_open = use_shm_open;
server->shm_size = shm_size;
server->n_vectors = n_vectors;
@@ -286,31 +285,6 @@ 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) {
- 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)
@@ -319,27 +293,17 @@ ivshmem_server_start(IvshmemServer *server)
int shm_fd, sock_fd, ret;
/* open shm file */
-#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) {
+ if (server->use_shm_open) {
+ 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);
+ } else {
gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX",
server->shm_path);
- IVSHMEM_SERVER_DEBUG(server, "Using hugepages: %s\n",
server->shm_path);
+ IVSHMEM_SERVER_DEBUG(server, "Using file-backed shared memory: %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) {
diff --git a/contrib/ivshmem-server/ivshmem-server.h
b/contrib/ivshmem-server/ivshmem-server.h
index e9de8a3..3851639 100644
--- a/contrib/ivshmem-server/ivshmem-server.h
+++ b/contrib/ivshmem-server/ivshmem-server.h
@@ -66,6 +66,7 @@ typedef struct IvshmemServer {
char unix_sock_path[PATH_MAX]; /**< path to unix socket */
int sock_fd; /**< unix sock file descriptor */
char shm_path[PATH_MAX]; /**< path to shm */
+ bool use_shm_open;
size_t shm_size; /**< size of shm */
int shm_fd; /**< shm file descriptor */
unsigned n_vectors; /**< number of vectors */
@@ -89,7 +90,8 @@ typedef struct IvshmemServer {
*/
int
ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path,
- const char *shm_path, size_t shm_size, unsigned n_vectors,
+ const char *shm_path, bool use_shm_open,
+ size_t shm_size, unsigned n_vectors,
bool verbose);
/**
diff --git a/contrib/ivshmem-server/main.c b/contrib/ivshmem-server/main.c
index e9b4388..2795db5 100644
--- a/contrib/ivshmem-server/main.c
+++ b/contrib/ivshmem-server/main.c
@@ -29,6 +29,7 @@ typedef struct IvshmemServerArgs {
const char *pid_file;
const char *unix_socket_path;
const char *shm_path;
+ bool use_shm_open;
uint64_t shm_size;
unsigned n_vectors;
} IvshmemServerArgs;
@@ -44,8 +45,9 @@ ivshmem_server_usage(const char *progname)
" default " IVSHMEM_SERVER_DEFAULT_PID_FILE "\n"
" -S <unix_socket_path>: path to the unix socket to listen to\n"
" default " IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "\n"
- " -m <shm_path>: POSIX shared memory object name or a hugetlbfs
mount point\n"
+ " -M <name>: POSIX shared memory object to use\n"
" default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n"
+ " -m <dirname>: where to create shared memory\n"
" -l <size>: size of shared memory in bytes\n"
" suffixes K, M and G can be used, e.g. 1K means 1024\n"
" default %u\n"
@@ -76,6 +78,7 @@ ivshmem_server_parse_args(IvshmemServerArgs *args, int argc,
char *argv[])
"p:" /* pid_file */
"S:" /* unix_socket_path */
"m:" /* shm_path */
+ "M:" /* shm_path */
"l:" /* shm_size */
"n:" /* n_vectors */
)) != -1) {
@@ -102,8 +105,14 @@ ivshmem_server_parse_args(IvshmemServerArgs *args, int
argc, char *argv[])
args->unix_socket_path = optarg;
break;
+ case 'M': /* shm_path */
+ args->shm_path = optarg;
+ args->use_shm_open = true;
+ break;
+
case 'm': /* shm_path */
args->shm_path = optarg;
+ args->use_shm_open = false;
break;
case 'l': /* shm_size */
@@ -199,6 +208,7 @@ main(int argc, char *argv[])
.pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE,
.unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
.shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
+ .use_shm_open = true,
.shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
.n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS,
};
@@ -226,7 +236,8 @@ main(int argc, char *argv[])
}
/* init the ivshms structure */
- if (ivshmem_server_init(&server, args.unix_socket_path, args.shm_path,
+ if (ivshmem_server_init(&server, args.unix_socket_path,
+ args.shm_path, args.use_shm_open,
args.shm_size, args.n_vectors, args.verbose) < 0) {
fprintf(stderr, "cannot init server\n");
goto err;
diff --git a/tests/ivshmem-test.c b/tests/ivshmem-test.c
index e184c67..4efa433 100644
--- a/tests/ivshmem-test.c
+++ b/tests/ivshmem-test.c
@@ -294,7 +294,7 @@ static void test_ivshmem_server(bool msi)
guint64 end_time = g_get_monotonic_time() + 5 * G_TIME_SPAN_SECOND;
memset(tmpshmem, 0x42, TMPSHMSIZE);
- ret = ivshmem_server_init(&server, tmpserver, tmpshm,
+ ret = ivshmem_server_init(&server, tmpserver, tmpshm, true,
TMPSHMSIZE, nvectors,
g_test_verbose());
g_assert_cmpint(ret, ==, 0);
--
2.4.3
- Re: [Qemu-devel] [PATCH v2 02/42] exec: Fix memory allocation when memory path isn't on hugetlbfs, (continued)
- [Qemu-devel] [PATCH v2 21/42] ivshmem: Clean up MSI-X conditions, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 03/42] target-ppc: Document TOCTTOU in hugepage support, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 06/42] qemu-doc: Fix ivshmem huge page example, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 35/42] ivshmem: Inline check_shm_size() into its only caller, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 20/42] ivshmem: Clean up register callbacks, Markus Armbruster, 2016/03/07
- [Qemu-devel] [PATCH v2 05/42] ivshmem-server: Don't overload POSIX shmem and file name,
Markus Armbruster <=
[Qemu-devel] [PATCH v2 16/42] ivshmem: Drop ivshmem_event() stub, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 23/42] ivshmem: Assert interrupts are set up once, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 24/42] ivshmem: Simplify rejection of invalid peer ID from server, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 36/42] qdev: New DEFINE_PROP_ON_OFF_AUTO, Markus Armbruster, 2016/03/07
[Qemu-devel] [PATCH v2 25/42] ivshmem: Disentangle ivshmem_read(), Markus Armbruster, 2016/03/07