From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57107) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g8SMF-0006fM-Fj for qemu-devel@nongnu.org; Fri, 05 Oct 2018 11:49:41 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g8SM9-0006Ft-Uw for qemu-devel@nongnu.org; Fri, 05 Oct 2018 11:49:39 -0400 Received: from mail-wm1-x343.google.com ([2a00:1450:4864:20::343]:51342) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1g8SM9-00066X-AT for qemu-devel@nongnu.org; Fri, 05 Oct 2018 11:49:33 -0400 Received: by mail-wm1-x343.google.com with SMTP id 143-v6so2304750wmf.1 for ; Fri, 05 Oct 2018 08:49:26 -0700 (PDT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= Date: Fri, 5 Oct 2018 16:49:03 +0100 Message-Id: <20181005154910.3099-15-alex.bennee@linaro.org> In-Reply-To: <20181005154910.3099-1-alex.bennee@linaro.org> References: <20181005154910.3099-1-alex.bennee@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [RFC PATCH 14/21] trace: add support for plugin infrastructure List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Pavel.Dovgaluk@ispras.ru, vilanova@ac.upc.edu, cota@braap.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= , Stefan Hajnoczi , Paolo Bonzini From: Pavel Dovgalyuk This patch adds support for dynamically loaded plugins. Every plugin is a dynamic library with a set of optional exported functions that will be called from QEMU. Signed-off-by: Pavel Dovgalyuk [AJB: moved to using trace point API] Signed-off-by: Alex Bennée --- ajb - moved to tracepoint interface (bind_to_tracepoints) - now in trace/ and include/plugins/ --- include/plugins/plugins.h | 14 ++++ include/qemu/plugins.h | 18 +++++ qemu-options.hx | 10 +++ trace/Makefile.objs | 1 + trace/plugins.c | 139 ++++++++++++++++++++++++++++++++++++++ vl.c | 8 +++ 6 files changed, 190 insertions(+) create mode 100644 include/plugins/plugins.h create mode 100644 include/qemu/plugins.h create mode 100644 trace/plugins.c diff --git a/include/plugins/plugins.h b/include/plugins/plugins.h new file mode 100644 index 0000000000..54ac53cb32 --- /dev/null +++ b/include/plugins/plugins.h @@ -0,0 +1,14 @@ +#ifndef PLUGINS_INTERFACE_H +#define PLUGINS_INTERFACE_H + +#include +#include + +/* Mandatory Plugin interfaces */ + +bool plugin_init(const char *args); +char *plugin_status(void); + +/* Other optional hooks are defined by available trace-points */ + +#endif /* PLUGINS_INTERFACE_H */ diff --git a/include/qemu/plugins.h b/include/qemu/plugins.h new file mode 100644 index 0000000000..c86bb7ae67 --- /dev/null +++ b/include/qemu/plugins.h @@ -0,0 +1,18 @@ +#ifndef PLUGINS_H +#define PLUGINS_H + +#ifdef CONFIG_TRACE_PLUGIN + +void qemu_plugin_parse_cmd_args(const char *optarg); +void qemu_plugin_load(const char *filename, const char *args); +void qemu_plugins_init(void); + +#else + +static inline void qemu_plugin_parse_cmd_args(const char *optarg) { } +static inline void qemu_plugin_load(const char *filename, const char *args) { } +static inline void qemu_plugins_init(void) { } + +#endif + +#endif /* PLUGINS_H */ diff --git a/qemu-options.hx b/qemu-options.hx index f139459e80..87206dd79f 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3892,6 +3892,16 @@ STEXI Enable synchronization profiling. ETEXI +#ifdef CONFIG_TRACE_PLUGIN +DEF("plugin", HAS_ARG, QEMU_OPTION_plugin, \ + "-plugin file=[,args=] load plugin with \n", QEMU_ARCH_ALL) +STEXI +@item -plugin file=@var{file}[,args=@var{args}] +@findex -plugin +Load @var{file} plugin passing @var{args} arguments. +ETEXI +#endif + STEXI @end table ETEXI diff --git a/trace/Makefile.objs b/trace/Makefile.objs index afd571c3ec..4977f654a5 100644 --- a/trace/Makefile.objs +++ b/trace/Makefile.objs @@ -54,6 +54,7 @@ $(obj)/generated-tcg-tracers.h-timestamp: $(SRC_PATH)/trace-events $(BUILD_DIR)/ util-obj-$(CONFIG_TRACE_SIMPLE) += simple.o util-obj-$(CONFIG_TRACE_FTRACE) += ftrace.o +util-obj-$(CONFIG_TRACE_PLUGIN) += plugins.o util-obj-y += control.o target-obj-y += control-target.o util-obj-y += qmp.o diff --git a/trace/plugins.c b/trace/plugins.c new file mode 100644 index 0000000000..25aec2ff70 --- /dev/null +++ b/trace/plugins.c @@ -0,0 +1,139 @@ +/* + * Plugin Support + * + * + * Copyright (c) 2018 Pavel Dovgalyuk + * Copyright (c) 2018 Alex Bennée + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include +#include "qemu-common.h" +#include "qemu/error-report.h" +#include "qemu/plugins.h" +#include "qemu/queue.h" +#include "qemu/option.h" +#include "trace/control.h" + +typedef bool (*PluginInitFunc)(const char *); +typedef char * (*PluginStatusFunc)(void); + +typedef struct QemuPluginInfo { + const char *filename; + const char *args; + GModule *g_module; + + PluginInitFunc init; + PluginStatusFunc status; + + GPtrArray *events; + + QLIST_ENTRY(QemuPluginInfo) next; +} QemuPluginInfo; + +static QLIST_HEAD(, QemuPluginInfo) qemu_plugins + = QLIST_HEAD_INITIALIZER(qemu_plugins); + +static QemuOptsList qemu_plugin_opts = { + .name = "plugin", + .head = QTAILQ_HEAD_INITIALIZER(qemu_plugin_opts.head), + .desc = { + { + .name = "file", + .type = QEMU_OPT_STRING, + },{ + .name = "args", + .type = QEMU_OPT_STRING, + }, + { /* end of list */ } + }, +}; + +void qemu_plugin_parse_cmd_args(const char *optarg) +{ + QemuOpts *opts = qemu_opts_parse_noisily(&qemu_plugin_opts, optarg, false); + qemu_plugin_load(qemu_opt_get(opts, "file"), + qemu_opt_get(opts, "args")); +} + +static int bind_to_tracepoints(GModule *g_module, GPtrArray *events) +{ + int count = 0; + TraceEventIter iter; + TraceEvent *ev; + + trace_event_iter_init(&iter, "*"); + while ((ev = trace_event_iter_next(&iter)) != NULL) { + const char *name = trace_event_get_name(ev); + gpointer fn; + + if (g_module_symbol(g_module, name, &fn)) { + ev->plugin = (uintptr_t) fn; + trace_event_set_state_dynamic(ev, true); + count++; + } + } + + return count; +} + +void qemu_plugin_load(const char *filename, const char *args) +{ + GModule *g_module; + QemuPluginInfo *info = NULL; + if (!filename) { + error_report("plugin name was not specified"); + return; + } + g_module = g_module_open(filename, + G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL); + if (!g_module) { + error_report("can't load plugin '%s'", filename); + return; + } + info = g_new0(QemuPluginInfo, 1); + info->filename = g_strdup(filename); + info->g_module = g_module; + + if (!g_module_symbol(g_module, "plugin_init", + (gpointer *) &info->init)) { + error_report("all plugins must provide a plugin_init hook"); + return; + } + + if (!g_module_symbol(g_module, "plugin_status", + (gpointer *) &info->status)) { + error_report("all plugins must provide a plugin_status hook"); + return; + } + + /* OK we can now see how many events might have bindings */ + info->events = g_ptr_array_new(); + + if (bind_to_tracepoints(g_module, info->events) < 0) { + error_report("failed to bind any events"); + return; + } + + /* Save the args, we will initialise later on once everything is + set up */ + if (args) { + info->args = g_strdup(args); + } + + QLIST_INSERT_HEAD(&qemu_plugins, info, next); + + return; +} + +void qemu_plugins_init(void) +{ + QemuPluginInfo *info; + QLIST_FOREACH(info, &qemu_plugins, next) { + if (info->init) { + info->init(info->args); + } + } +} diff --git a/vl.c b/vl.c index 795e025445..b46ef5032f 100644 --- a/vl.c +++ b/vl.c @@ -130,6 +130,7 @@ int main(int argc, char **argv) #include "qapi/qapi-commands-run-state.h" #include "qapi/qmp/qerror.h" #include "sysemu/iothread.h" +#include "qemu/plugins.h" #define MAX_VIRTIO_CONSOLES 1 @@ -3884,6 +3885,11 @@ int main(int argc, char **argv, char **envp) case QEMU_OPTION_enable_sync_profile: qsp_enable(); break; +#ifdef CONFIG_TRACE_PLUGIN + case QEMU_OPTION_plugin: + qemu_plugin_parse_cmd_args(optarg); + break; +#endif case QEMU_OPTION_nouserconfig: /* Nothing to be parsed here. Especially, do not error out below. */ break; @@ -4449,6 +4455,8 @@ int main(int argc, char **argv, char **envp) } parse_numa_opts(current_machine); + qemu_plugins_init(); + /* do monitor/qmp handling at preconfig state if requested */ main_loop(); -- 2.17.1