Andrew Fasano <fas...@mit.edu> writes:
> From: Elysia Witham <elysia.wit...@ll.mit.edu> > > Plugins are able to use API functions which are explained in > <qemu-plugin.h> to create and run their own callbacks and register > functions on another plugin's callbacks. > > Signed-off-by: Elysia Witham <elysia.wit...@ll.mit.edu> > Signed-off-by: Andrew Fasano <fas...@mit.edu> > --- > include/qemu/qemu-plugin.h | 46 +++++++++++++++ > plugins/api.c | 111 +++++++++++++++++++++++++++++++++++ > plugins/loader.c | 1 + > plugins/qemu-plugins.symbols | 4 ++ > 4 files changed, 162 insertions(+) > > diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h > index 3ec82ce97f..4221545015 100644 > --- a/include/qemu/qemu-plugin.h > +++ b/include/qemu/qemu-plugin.h > @@ -354,6 +354,52 @@ size_t qemu_plugin_tb_n_insns(const struct > qemu_plugin_tb *tb); > */ > uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb); > > +/** > + * qemu_plugin_create_callback() - create a new cb with given name > + * @id: unique plugin id > + * @name: name of cb > + * > + * Returns: true on success, false otherwise > + */ > +bool qemu_plugin_create_callback(qemu_plugin_id_t id, const char *name); > + > +/** > + * qemu_plugin_run_callback() - run all functions registered to cb with given > + * name using given args > + * @id: unique plugin id > + * @name: name of cb > + * @evdata: pointer to evdata struct > + * @udata: pointer to udata struct > + * > + * Returns: true if any registerd functions were run, false otherwise > + */ > +bool qemu_plugin_run_callback(qemu_plugin_id_t id, const char *name, > + gpointer evdata, gpointer udata); > + > +/** > + * qemu_plugin_reg_callback() - register a function to be called on cb with > + * given name > + * @target_plugin: name of plugin that provides the callback > + * @cb_name: name of the callback > + * @function_pointer: pointer to function being registered > + * > + * Returns: true if function was registered successfully, false otherwise > + */ > +bool qemu_plugin_reg_callback(const char *target_plugin, const char *cb_name, > + cb_func_t function_pointer); > + > +/** > + * qemu_plugin_unreg_callback() - unregister a function to be called on cb > + * with given name > + * @target_plugin: name of plugin that provides the callback > + * @cb_name: name of the callback > + * @function_pointer: pointer to function being unregistered > + * > + * Returns: true if function was unregistered successfully, false otherwise > + */ > +bool qemu_plugin_unreg_callback(const char *target_plugin, const char > *cb_name, > + cb_func_t function_pointer); > + > /** > * qemu_plugin_tb_get_insn() - retrieve handle for instruction > * @tb: opaque handle to TB passed to callback > diff --git a/plugins/api.c b/plugins/api.c > index 2078b16edb..1f7ea718dc 100644 > --- a/plugins/api.c > +++ b/plugins/api.c > @@ -400,6 +400,117 @@ bool qemu_plugin_bool_parse(const char *name, const > char *value, bool *ret) > return name && value && qapi_bool_parse(name, value, ret, NULL); > } > > +bool qemu_plugin_create_callback(qemu_plugin_id_t id, const char *cb_name) > +{ > + struct qemu_plugin_ctx *ctx = plugin_id_to_ctx_locked(id); c.f. last patch. I see no locking going on here. > + if (ctx == NULL) { > + error_report("Cannot create callback with invalid plugin ID"); > + return false; > + } > + > + if (ctx->version < QPP_MINIMUM_VERSION) { > + error_report("Plugin %s cannot create callbacks as its > PLUGIN_VERSION" > + " %d is below QPP_MINIMUM_VERSION (%d).", > + ctx->name, ctx->version, QPP_MINIMUM_VERSION); > + return false; > + } > + > + if (plugin_find_qpp_cb(ctx, cb_name)) { > + error_report("Plugin %s already created callback %s", ctx->name, > + cb_name); > + return false; > + } > + > + plugin_add_qpp_cb(ctx, cb_name); > + return true; > +} > + > +bool qemu_plugin_run_callback(qemu_plugin_id_t id, const char *cb_name, > + gpointer evdata, gpointer udata) { > + struct qemu_plugin_ctx *ctx = plugin_id_to_ctx_locked(id); Or here. > + if (ctx == NULL) { > + error_report("Cannot run callback with invalid plugin ID"); > + return false; > + } > + > + struct qemu_plugin_qpp_cb *cb = plugin_find_qpp_cb(ctx, cb_name); > + if (!cb) { > + error_report("Can not run previously-unregistered callback %s in " > + "plugin %s", cb_name, ctx->name); > + return false; > + } > + > + for (int i = 0; i < cb->counter; i++) { > + cb_func_t qpp_cb_func = cb->registered_cb_funcs[i]; > + qpp_cb_func(evdata, udata); > + } > + > + return (cb->registered_cb_funcs[0] != NULL); > +} > + > +bool qemu_plugin_reg_callback(const char *target_plugin, const char *cb_name, > + cb_func_t function_pointer) { > + struct qemu_plugin_ctx *ctx = plugin_name_to_ctx_locked(target_plugin); > + if (ctx == NULL) { > + error_report("Cannot register callback with unknown plugin %s", > + target_plugin); > + return false; > + } > + > + struct qemu_plugin_qpp_cb *cb = plugin_find_qpp_cb(ctx, cb_name); > + if (!cb) { > + error_report("Cannot register a function to run on callback %s in " > + "plugin %s as that callback does not exist", > + cb_name, target_plugin); > + return false; > + } > + > + if (cb->counter == QEMU_PLUGIN_EV_MAX) { I'm a little confused why there is a relation to the number of callbacks QPP can support and the list of qemu callback events. > + error_report("The maximum number of allowed callbacks are already " > + "registered for callback %s in plugin %s", > + cb_name, target_plugin); > + return false; > + } > + > + cb->registered_cb_funcs[cb->counter] = function_pointer; > + cb->counter++; > + return true; > +} > + > +bool qemu_plugin_unreg_callback(const char *target_plugin, const char > *cb_name, > + cb_func_t function_pointer) { > + struct qemu_plugin_ctx *ctx = > plugin_name_to_ctx_locked(target_plugin); Locking. > + if (ctx == NULL) { > + error_report("Cannot remove callback function from unknown plugin > %s", > + target_plugin); > + return false; > + } > + > + struct qemu_plugin_qpp_cb *cb = plugin_find_qpp_cb(ctx, cb_name); > + if (!cb) { > + error_report("Cannot remove a function to run on callback %s in " > + "plugin %s as that callback does not exist", > + cb_name, target_plugin); > + return false; > + } > + > + for (int i = 0; i < cb->counter; i++) { > + if (cb->registered_cb_funcs[i] == function_pointer) { > + for (int j = i + 1; j < cb->counter; j++) { > + cb->registered_cb_funcs[i] = cb->registered_cb_funcs[j]; > + i++; > + } > + cb->registered_cb_funcs[i] = NULL; > + cb->counter--; > + return true; > + } > + } > + error_report("Function to remove not found in registered functions " > + "for callback %s in plugin %s", > + cb_name, target_plugin); > + return false; > +} > + > /* > * Binary path, start and end locations > */ > diff --git a/plugins/loader.c b/plugins/loader.c > index ab01d0753c..7f047ebc99 100644 > --- a/plugins/loader.c > +++ b/plugins/loader.c > @@ -310,6 +310,7 @@ void plugin_add_qpp_cb(struct qemu_plugin_ctx *ctx, const > char *name) > new_cb = qemu_memalign(qemu_dcache_linesize, sizeof(*new_cb)); > memset(new_cb, 0, sizeof(*new_cb)); > new_cb->name = name; > + new_cb->counter = 0; > QTAILQ_INSERT_TAIL(&ctx->qpp_cbs, new_cb, entry); > } > > diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols > index 71f6c90549..b7013980cf 100644 > --- a/plugins/qemu-plugins.symbols > +++ b/plugins/qemu-plugins.symbols > @@ -3,6 +3,10 @@ > qemu_plugin_end_code; > qemu_plugin_entry_code; > qemu_plugin_get_hwaddr; > + qemu_plugin_create_callback; > + qemu_plugin_run_callback; > + qemu_plugin_reg_callback; > + qemu_plugin_unreg_callback; > qemu_plugin_hwaddr_device_name; > qemu_plugin_hwaddr_is_io; > qemu_plugin_hwaddr_phys_addr; -- Alex Bennée Virtualisation Tech Lead @ Linaro