[Qemu-devel] [RFC PATCH 5/6] module: load modules at start

[Fam Zheng <famz@redhat.com>]

Add module_load_all to load all DSO modules under:
    /usr/lib/qemu/block/
    /usr/lib/qemu/net/
    /usr/lib/qemu/ui/
when starting process.

Requires gmodule-2.0 from glib.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 configure             | 20 +++++++++++---------
 include/qemu/module.h |  2 ++
 qemu-img.c            |  2 ++
 qemu-io.c             |  1 +
 qemu-nbd.c            |  1 +
 scripts/create_config |  3 +++
 util/Makefile.objs    |  2 ++
 util/module.c         | 40 ++++++++++++++++++++++++++++++++++++++++
 vl.c                  |  1 +
 9 files changed, 63 insertions(+), 9 deletions(-)

diff --git a/configure b/configure
index 8f0a882..975853e 100755
--- a/configure
+++ b/configure
@@ -2238,15 +2238,17 @@ if test "$mingw32" = yes; then
 else
     glib_req_ver=2.12
 fi
-if $pkg_config --atleast-version=$glib_req_ver gthread-2.0 > /dev/null 2>&1
-then
-    glib_cflags=`$pkg_config --cflags gthread-2.0 2>/dev/null`
-    glib_libs=`$pkg_config --libs gthread-2.0 2>/dev/null`
-    LIBS="$glib_libs $LIBS"
-    libs_qga="$glib_libs $libs_qga"
-else
-    error_exit "glib-$glib_req_ver required to compile QEMU"
-fi
+for i in gthread-2.0 gmodule-2.0; do
+    if $pkg_config --atleast-version=$glib_req_ver $i > /dev/null 2>&1
+    then
+        glib_cflags=`$pkg_config --cflags $i 2>/dev/null`
+        glib_libs=`$pkg_config --libs $i 2>/dev/null`
+        LIBS="$glib_libs $LIBS"
+        libs_qga="$glib_libs $libs_qga"
+    else
+        error_exit "glib-$glib_req_ver required to compile QEMU"
+    fi
+done
 
 ##########################################
 # pixman support probe
diff --git a/include/qemu/module.h b/include/qemu/module.h
index c4ccd57..d3500be 100644
--- a/include/qemu/module.h
+++ b/include/qemu/module.h
@@ -37,4 +37,6 @@ void register_module_init(void (*fn)(void), module_init_type type);
 
 void module_call_init(module_init_type type);
 
+void module_load_all(void);
+
 #endif
diff --git a/qemu-img.c b/qemu-img.c
index b9a848d..e761027 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -34,6 +34,7 @@
 #include <getopt.h>
 #include <stdio.h>
 #include <stdarg.h>
+#include "qemu/module.h"
 
 #ifdef _WIN32
 #include <windows.h>
@@ -2328,6 +2329,7 @@ int main(int argc, char **argv)
 
     error_set_progname(argv[0]);
 
+    module_load_all();
     qemu_init_main_loop();
     bdrv_init();
     if (argc < 2)
diff --git a/qemu-io.c b/qemu-io.c
index d54dc86..d02e8f5 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -398,6 +398,7 @@ int main(int argc, char **argv)
         exit(1);
     }
 
+    module_load_all();
     qemu_init_main_loop();
     bdrv_init();
 
diff --git a/qemu-nbd.c b/qemu-nbd.c
index f044546..ecea543 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -558,6 +558,7 @@ int main(int argc, char **argv)
         snprintf(sockpath, 128, SOCKET_PATH, basename(device));
     }
 
+    module_load_all();
     qemu_init_main_loop();
     bdrv_init();
     atexit(bdrv_close_all);
diff --git a/scripts/create_config b/scripts/create_config
index b1adbf5..3ecb789 100755
--- a/scripts/create_config
+++ b/scripts/create_config
@@ -104,6 +104,9 @@ case $line in
     value=${line#*=}
     echo "#define $name $value"
     ;;
+ DSOSUF=*)
+    echo "#define HOST_DSOSUF \"${line#*=}\""
+    ;;
 esac
 
 done # read
diff --git a/util/Makefile.objs b/util/Makefile.objs
index dc72ab0..33e56b0 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -11,3 +11,5 @@ util-obj-y += iov.o aes.o qemu-config.o qemu-sockets.o uri.o notify.o
 util-obj-y += qemu-option.o qemu-progress.o
 util-obj-y += hexdump.o
 util-obj-y += crc32c.o
+
+$(obj)/module.o-libs := -lglib
diff --git a/util/module.c b/util/module.c
index 7acc33d..29d3a4f 100644
--- a/util/module.c
+++ b/util/module.c
@@ -13,6 +13,8 @@
  * GNU GPL, version 2 or (at your option) any later version.
  */
 
+#include <gmodule.h>
+#include <dirent.h>
 #include "qemu-common.h"
 #include "qemu/queue.h"
 #include "qemu/module.h"
@@ -79,3 +81,41 @@ void module_call_init(module_init_type type)
         e->init();
     }
 }
+
+void module_load_all(void)
+{
+    static const char *module_dir_list[] = {
+        "/usr/lib/qemu/block/",
+        "/usr/lib/qemu/net/",
+        "/usr/lib/qemu/ui/",
+        NULL
+    };
+    const char **path;
+    const char *dsosuf = HOST_DSOSUF;
+    char fname[1024];
+    int suf_len = strlen(dsosuf);
+    DIR *dp;
+    struct dirent *ep = NULL;
+    GModule *g_module;
+    for (path = &module_dir_list[0]; *path != NULL; path++) {
+        dp = opendir(*path);
+        if (!dp) {
+            fprintf(stderr, "Failed to open dir %s\n", *path);
+        }
+        for (ep = readdir(dp); ep; ep = readdir(dp)) {
+            int len = strlen(ep->d_name);
+            if (len > suf_len &&
+                !strcmp(&ep->d_name[len - suf_len], dsosuf)) {
+                pstrcpy(fname, sizeof(fname), *path);
+                pstrcat(fname, sizeof(fname), ep->d_name);
+                g_module = g_module_open(fname, G_MODULE_BIND_LAZY);
+                if (!g_module) {
+                    fprintf(stderr, "Failed to open module file %s\n",
+                            g_module_error());
+                    continue;
+                }
+                printf("Loaded module %s\n", fname);
+            }
+        }
+    }
+}
diff --git a/vl.c b/vl.c
index dfbc071..c72e5a8 100644
--- a/vl.c
+++ b/vl.c
@@ -3873,6 +3873,7 @@ int main(int argc, char **argv, char **envp)
     }
     loc_set_none();
 
+    module_load_all();
     if (qemu_init_main_loop()) {
         fprintf(stderr, "qemu_init_main_loop failed\n");
         exit(1);
-- 
1.8.3.1