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authorTimos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>2023-10-10 11:40:56 +0000
committerTimos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>2023-10-10 11:40:56 +0000
commite02cda008591317b1625707ff8e115a4841aa889 (patch)
treeaee302e3cf8b59ec2d32ec481be3d1afddfc8968 /util/module.c
parentcc668e6b7e0ffd8c9d130513d12053cf5eda1d3b (diff)
Introduce Virtio-loopback epsilon release:
Epsilon release introduces a new compatibility layer which make virtio-loopback design to work with QEMU and rust-vmm vhost-user backend without require any changes. Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com> Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9
Diffstat (limited to 'util/module.c')
-rw-r--r--util/module.c387
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