1 files changed, 387 insertions, 0 deletions
diff --git a/util/module.c b/util/module.c
new file mode 100644
index 000000000..6bb4ad915
--- /dev/null
+++ b/util/module.c
@@ -0,0 +1,387 @@
+/*
+ * QEMU Module Infrastructure
+ *
+ * Copyright IBM, Corp. 2009
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#include "qemu/osdep.h"
+#ifdef CONFIG_MODULES
+#include <gmodule.h>
+#endif
+#include "qemu/queue.h"
+#include "qemu/module.h"
+#include "qemu/cutils.h"
+#include "qemu/config-file.h"
+#ifdef CONFIG_MODULE_UPGRADES
+#include "qemu-version.h"
+#endif
+#include "trace.h"
+
+typedef struct ModuleEntry
+{
+    void (*init)(void);
+    QTAILQ_ENTRY(ModuleEntry) node;
+    module_init_type type;
+} ModuleEntry;
+
+typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList;
+
+static ModuleTypeList init_type_list[MODULE_INIT_MAX];
+static bool modules_init_done[MODULE_INIT_MAX];
+
+static ModuleTypeList dso_init_list;
+
+static void init_lists(void)
+{
+    static int inited;
+    int i;
+
+    if (inited) {
+        return;
+    }
+
+    for (i = 0; i < MODULE_INIT_MAX; i++) {
+        QTAILQ_INIT(&init_type_list[i]);
+    }
+
+    QTAILQ_INIT(&dso_init_list);
+
+    inited = 1;
+}
+
+
+static ModuleTypeList *find_type(module_init_type type)
+{
+    init_lists();
+
+    return &init_type_list[type];
+}
+
+void register_module_init(void (*fn)(void), module_init_type type)
+{
+    ModuleEntry *e;
+    ModuleTypeList *l;
+
+    e = g_malloc0(sizeof(*e));
+    e->init = fn;
+    e->type = type;
+
+    l = find_type(type);
+
+    QTAILQ_INSERT_TAIL(l, e, node);
+}
+
+void register_dso_module_init(void (*fn)(void), module_init_type type)
+{
+    ModuleEntry *e;
+
+    init_lists();
+
+    e = g_malloc0(sizeof(*e));
+    e->init = fn;
+    e->type = type;
+
+    QTAILQ_INSERT_TAIL(&dso_init_list, e, node);
+}
+
+void module_call_init(module_init_type type)
+{
+    ModuleTypeList *l;
+    ModuleEntry *e;
+
+    if (modules_init_done[type]) {
+        return;
+    }
+
+    l = find_type(type);
+
+    QTAILQ_FOREACH(e, l, node) {
+        e->init();
+    }
+
+    modules_init_done[type] = true;
+}
+
+#ifdef CONFIG_MODULES
+
+static const QemuModinfo module_info_stub[] = { {
+    /* end of list */
+} };
+static const QemuModinfo *module_info = module_info_stub;
+static const char *module_arch;
+
+void module_init_info(const QemuModinfo *info)
+{
+    module_info = info;
+}
+
+void module_allow_arch(const char *arch)
+{
+    module_arch = arch;
+}
+
+static bool module_check_arch(const QemuModinfo *modinfo)
+{
+    if (modinfo->arch) {
+        if (!module_arch) {
+            /* no arch set -> ignore all */
+            return false;
+        }
+        if (strcmp(module_arch, modinfo->arch) != 0) {
+            /* mismatch */
+            return false;
+        }
+    }
+    return true;
+}
+
+static int module_load_file(const char *fname, bool mayfail, bool export_symbols)
+{
+    GModule *g_module;
+    void (*sym)(void);
+    const char *dsosuf = CONFIG_HOST_DSOSUF;
+    int len = strlen(fname);
+    int suf_len = strlen(dsosuf);
+    ModuleEntry *e, *next;
+    int ret, flags;
+
+    if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
+        /* wrong suffix */
+        ret = -EINVAL;
+        goto out;
+    }
+    if (access(fname, F_OK)) {
+        ret = -ENOENT;
+        goto out;
+    }
+
+    assert(QTAILQ_EMPTY(&dso_init_list));
+
+    flags = 0;
+    if (!export_symbols) {
+        flags |= G_MODULE_BIND_LOCAL;
+    }
+    g_module = g_module_open(fname, flags);
+    if (!g_module) {
+        if (!mayfail) {
+            fprintf(stderr, "Failed to open module: %s\n",
+                    g_module_error());
+        }
+        ret = -EINVAL;
+        goto out;
+    }
+    if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) {
+        fprintf(stderr, "Failed to initialize module: %s\n",
+                fname);
+        /* Print some info if this is a QEMU module (but from different build),
+         * this will make debugging user problems easier. */
+        if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) {
+            fprintf(stderr,
+                    "Note: only modules from the same build can be loaded.\n");
+        }
+        g_module_close(g_module);
+        ret = -EINVAL;
+    } else {
+        QTAILQ_FOREACH(e, &dso_init_list, node) {
+            e->init();
+            register_module_init(e->init, e->type);
+        }
+        ret = 0;
+    }
+
+    trace_module_load_module(fname);
+    QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
+        QTAILQ_REMOVE(&dso_init_list, e, node);
+        g_free(e);
+    }
+out:
+    return ret;
+}
+#endif
+
+bool module_load_one(const char *prefix, const char *lib_name, bool mayfail)
+{
+    bool success = false;
+
+#ifdef CONFIG_MODULES
+    char *fname = NULL;
+#ifdef CONFIG_MODULE_UPGRADES
+    char *version_dir;
+#endif
+    const char *search_dir;
+    char *dirs[5];
+    char *module_name;
+    int i = 0, n_dirs = 0;
+    int ret;
+    bool export_symbols = false;
+    static GHashTable *loaded_modules;
+    const QemuModinfo *modinfo;
+    const char **sl;
+
+    if (!g_module_supported()) {
+        fprintf(stderr, "Module is not supported by system.\n");
+        return false;
+    }
+
+    if (!loaded_modules) {
+        loaded_modules = g_hash_table_new(g_str_hash, g_str_equal);
+    }
+
+    module_name = g_strdup_printf("%s%s", prefix, lib_name);
+
+    if (g_hash_table_contains(loaded_modules, module_name)) {
+        g_free(module_name);
+        return true;
+    }
+    g_hash_table_add(loaded_modules, module_name);
+
+    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
+        if (modinfo->arch) {
+            if (strcmp(modinfo->name, module_name) == 0) {
+                if (!module_check_arch(modinfo)) {
+                    return false;
+                }
+            }
+        }
+        if (modinfo->deps) {
+            if (strcmp(modinfo->name, module_name) == 0) {
+                /* we depend on other module(s) */
+                for (sl = modinfo->deps; *sl != NULL; sl++) {
+                    module_load_one("", *sl, false);
+                }
+            } else {
+                for (sl = modinfo->deps; *sl != NULL; sl++) {
+                    if (strcmp(module_name, *sl) == 0) {
+                        /* another module depends on us */
+                        export_symbols = true;
+                    }
+                }
+            }
+        }
+    }
+
+    search_dir = getenv("QEMU_MODULE_DIR");
+    if (search_dir != NULL) {
+        dirs[n_dirs++] = g_strdup_printf("%s", search_dir);
+    }
+    dirs[n_dirs++] = get_relocated_path(CONFIG_QEMU_MODDIR);
+    dirs[n_dirs++] = g_strdup(qemu_get_exec_dir());
+
+#ifdef CONFIG_MODULE_UPGRADES
+    version_dir = g_strcanon(g_strdup(QEMU_PKGVERSION),
+                             G_CSET_A_2_Z G_CSET_a_2_z G_CSET_DIGITS "+-.~",
+                             '_');
+    dirs[n_dirs++] = g_strdup_printf("/var/run/qemu/%s", version_dir);
+#endif
+
+    assert(n_dirs <= ARRAY_SIZE(dirs));
+
+    for (i = 0; i < n_dirs; i++) {
+        fname = g_strdup_printf("%s/%s%s",
+                dirs[i], module_name, CONFIG_HOST_DSOSUF);
+        ret = module_load_file(fname, mayfail, export_symbols);
+        g_free(fname);
+        fname = NULL;
+        /* Try loading until loaded a module file */
+        if (!ret) {
+            success = true;
+            break;
+        }
+    }
+
+    if (!success) {
+        g_hash_table_remove(loaded_modules, module_name);
+        g_free(module_name);
+    }
+
+    for (i = 0; i < n_dirs; i++) {
+        g_free(dirs[i]);
+    }
+
+#endif
+    return success;
+}
+
+#ifdef CONFIG_MODULES
+
+static bool module_loaded_qom_all;
+
+void module_load_qom_one(const char *type)
+{
+    const QemuModinfo *modinfo;
+    const char **sl;
+
+    if (!type) {
+        return;
+    }
+
+    trace_module_lookup_object_type(type);
+    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
+        if (!modinfo->objs) {
+            continue;
+        }
+        if (!module_check_arch(modinfo)) {
+            continue;
+        }
+        for (sl = modinfo->objs; *sl != NULL; sl++) {
+            if (strcmp(type, *sl) == 0) {
+                module_load_one("", modinfo->name, false);
+            }
+        }
+    }
+}
+
+void module_load_qom_all(void)
+{
+    const QemuModinfo *modinfo;
+
+    if (module_loaded_qom_all) {
+        return;
+    }
+
+    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
+        if (!modinfo->objs) {
+            continue;
+        }
+        if (!module_check_arch(modinfo)) {
+            continue;
+        }
+        module_load_one("", modinfo->name, false);
+    }
+    module_loaded_qom_all = true;
+}
+
+void qemu_load_module_for_opts(const char *group)
+{
+    const QemuModinfo *modinfo;
+    const char **sl;
+
+    for (modinfo = module_info; modinfo->name != NULL; modinfo++) {
+        if (!modinfo->opts) {
+            continue;
+        }
+        for (sl = modinfo->opts; *sl != NULL; sl++) {
+            if (strcmp(group, *sl) == 0) {
+                module_load_one("", modinfo->name, false);
+            }
+        }
+    }
+}
+
+#else
+
+void module_allow_arch(const char *arch) {}
+void qemu_load_module_for_opts(const char *group) {}
+void module_load_qom_one(const char *type) {}
+void module_load_qom_all(void) {}
+
+#endif