[v5,09/22] instrument: Add basic control interface

Message ID	150525228289.15988.9844115871305476442.stgit@frigg.lan (mailing list archive)
State	New, archived
Headers	show Return-Path: <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org> From: =?utf-8?b?TGx1w61z?= Vilanova <vilanova@ac.upc.edu> To: qemu-devel@nongnu.org Date: Wed, 13 Sep 2017 00:38:03 +0300 Message-Id: <150525228289.15988.9844115871305476442.stgit@frigg.lan> In-Reply-To: <150525010239.15988.8172586618197849619.stgit@frigg.lan> References: <150525010239.15988.8172586618197849619.stgit@frigg.lan> User-Agent: StGit/0.18 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v5 09/22] instrument: Add basic control interface Precedence: list Cc: Markus Armbruster <armbru@redhat.com>, "Emilio G. Cota" <cota@braap.org>, Stefan Hajnoczi <stefanha@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, =?UTF-8?q?Llu=C3=ADs=20Vilanova?= <vilanova@ac.upc.edu> Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" <qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org>

diff --git a/Makefile b/Makefile index 3861b3f49c..c3d9a4bcd9 100644 --- a/Makefile +++ b/Makefile @@ -599,6 +599,10 @@ ifdef CONFIG_VIRTFS $(INSTALL_DIR) "$(DESTDIR)$(mandir)/man1" $(INSTALL_DATA) fsdev/virtfs-proxy-helper.1 "$(DESTDIR)$(mandir)/man1" endif +ifdef CONFIG_INSTRUMENT + $(INSTALL_DIR) "$(DESTDIR)$(includedir)/qemu-instr/" + $(INSTALL_DATA) $(SRC_PATH)/instrument/qemu-instr/control.h "$(DESTDIR)$(includedir)/qemu-instr/" +endif install-datadir: $(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)" diff --git a/configure b/configure index 5175151317..18810eae84 100755 --- a/configure +++ b/configure @@ -6030,6 +6030,7 @@ if test "$instrument" = "yes"; then LIBS="-ldl $LIBS" echo "CONFIG_INSTRUMENT=y" >> $config_host_mak fi +QEMU_INCLUDES="-I\$(SRC_PATH)/instrument $QEMU_INCLUDES" if test "$rdma" = "yes" ; then echo "CONFIG_RDMA=y" >> $config_host_mak diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index 340e5fdc09..e86bd34e2c 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -111,4 +111,23 @@ #define GCC_FMT_ATTR(n, m) #endif +/* + * Export symbol to dlopen()'ed libraries'. + * + * This code is taken from http://gcc.gnu.org/wiki/Visibility. + */ +#if defined _WIN32 || defined __CYGWIN__ + #ifdef __GNUC__ + #define SYM_PUBLIC __attribute__ ((dllimport)) + #else + #define SYM_PUBLIC __declspec(dllimport) + #endif +#else + #if __GNUC__ >= 4 + #define SYM_PUBLIC __attribute__ ((visibility("default"))) + #else + #define SYM_PUBLIC + #endif +#endif + #endif /* COMPILER_H */ diff --git a/instrument/Makefile.objs b/instrument/Makefile.objs index 7bf4e27e3c..ec76b2080b 100644 --- a/instrument/Makefile.objs +++ b/instrument/Makefile.objs @@ -3,3 +3,4 @@ target-obj-$(CONFIG_INSTRUMENT) += cmdline.o target-obj-$(CONFIG_INSTRUMENT) += load.o target-obj-$(CONFIG_INSTRUMENT) += qmp.o +target-obj-$(CONFIG_INSTRUMENT) += control.o diff --git a/instrument/control.c b/instrument/control.c new file mode 100644 index 0000000000..3630d6b3be --- /dev/null +++ b/instrument/control.c @@ -0,0 +1,28 @@ +/* + * Control instrumentation during program (de)initialization. + * + * Copyright (C) 2012-2017 Lluís Vilanova <vilanova@ac.upc.edu> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "instrument/control.h" +#include "instrument/error.h" +#include "instrument/events.h" +#include "instrument/load.h" +#include "instrument/qemu-instr/control.h" +#include "qemu/compiler.h" + +__thread InstrState instr_cur_state; + + +qi_fini_fn instr_event__fini_fn; +void *instr_event__fini_data; + +SYM_PUBLIC void qi_set_fini(qi_fini_fn fn, void *data) +{ + ERROR_IF(!instr_get_state(), "called outside instrumentation"); + instr_set_event(fini_fn, fn); + instr_set_event(fini_data, data); +} diff --git a/instrument/control.h b/instrument/control.h new file mode 100644 index 0000000000..f2b085f69b --- /dev/null +++ b/instrument/control.h @@ -0,0 +1,44 @@ +/* + * Control instrumentation during program (de)initialization. + * + * Copyright (C) 2012-2017 Lluís Vilanova <vilanova@ac.upc.edu> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef INSTRUMENT__CONTROL_H +#define INSTRUMENT__CONTROL_H + + +/** + * InstrState: + * @INSTR_STATE_DISABLE: Intrumentation API not available. + * @INSTR_STATE_ENABLE: Intrumentation API available. + * + * Instrumentation state of current host thread. Used to ensure instrumentation + * clients use QEMU's API only in expected points. + */ +typedef enum { + INSTR_STATE_DISABLE, + INSTR_STATE_ENABLE, +} InstrState; + +/** + * instr_set_state: + * + * Set the instrumentation state of the current host thread. + */ +static inline void instr_set_state(InstrState state); + +/** + * instr_get_state: + * + * Get the instrumentation state of the current host thread. + */ +static inline InstrState instr_get_state(void); + + +#include "instrument/control.inc.h" + +#endif /* INSTRUMENT__CONTROL_H */ diff --git a/instrument/control.inc.h b/instrument/control.inc.h new file mode 100644 index 0000000000..0f649f4caa --- /dev/null +++ b/instrument/control.inc.h @@ -0,0 +1,25 @@ +/* + * Control instrumentation during program (de)initialization. + * + * Copyright (C) 2012-2017 Lluís Vilanova <vilanova@ac.upc.edu> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/atomic.h" +#include "qemu/compiler.h" +#include <stdbool.h> + + +extern __thread InstrState instr_cur_state; + +static inline void instr_set_state(InstrState state) +{ + atomic_store_release(&instr_cur_state, state); +} + +static inline InstrState instr_get_state(void) +{ + return atomic_load_acquire(&instr_cur_state); +} diff --git a/instrument/error.h b/instrument/error.h new file mode 100644 index 0000000000..f8d1dd4b16 --- /dev/null +++ b/instrument/error.h @@ -0,0 +1,28 @@ +/* + * Helpers for controlling errors in instrumentation libraries. + * + * Copyright (C) 2012-2017 Lluís Vilanova <vilanova@ac.upc.edu> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef INSTRUMENT_ERROR_H +#define INSTRUMENT_ERROR_H + +#include "qemu/osdep.h" +#include "qemu/error-report.h" + + +#define _ERROR(msg, args...) \ + do { \ + error_report("%s:" msg, __func__, ##args); \ + } while (0) + +#define ERROR_IF(cond, msg, args...) \ + if (unlikely(cond)) { \ + _ERROR(msg, ##args); \ + return; \ + } + +#endif /* INSTRUMENT_ERROR_H */ diff --git a/instrument/events.h b/instrument/events.h new file mode 100644 index 0000000000..82ad0bd827 --- /dev/null +++ b/instrument/events.h @@ -0,0 +1,37 @@ +/* + * Internal API for triggering instrumentation events. + * + * Copyright (C) 2017 Lluís Vilanova <vilanova@ac.upc.edu> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef INSTRUMENT__EVENTS_H +#define INSTRUMENT__EVENTS_H + +#include "instrument/qemu-instr/control.h" + +/** + * instr_get_event: + * + * Get value set by instrumentation library. + */ +#define instr_get_event(name) \ + atomic_load_acquire(&instr_event__ ## name) + +/** + * instr_get_event: + * + * Set value from instrumentation library. + */ +#define instr_set_event(name, fn) \ + atomic_store_release(&instr_event__ ## name, fn) + + +extern qi_fini_fn instr_event__fini_fn; +extern void *instr_event__fini_data; + +#include "instrument/events.inc.h" + +#endif /* INSTRUMENT__EVENTS_H */ diff --git a/instrument/events.inc.h b/instrument/events.inc.h new file mode 100644 index 0000000000..8b1ce7fcb2 --- /dev/null +++ b/instrument/events.inc.h @@ -0,0 +1,11 @@ +/* + * Internal API for triggering instrumentation events. + * + * Copyright (C) 2017 Lluís Vilanova <vilanova@ac.upc.edu> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + + + diff --git a/instrument/load.c b/instrument/load.c index af98f4ce38..a01d66a4d4 100644 --- a/instrument/load.c +++ b/instrument/load.c @@ -11,6 +11,8 @@ #include "qemu-common.h" #include <dlfcn.h> +#include "instrument/control.h" +#include "instrument/events.h" #include "instrument/load.h" #include "qemu/config-file.h" #include "qemu/error-report.h" @@ -96,8 +98,11 @@ InstrLoadError instr_load(const char *path, int argc, const char **argv, res = INSTR_LOAD_DLERROR; goto err; } + instr_set_event(fini_fn, NULL); + instr_set_state(INSTR_STATE_ENABLE); main_res = main_cb(argc, argv); + instr_set_state(INSTR_STATE_DISABLE); if (main_res != 0) { res = INSTR_LOAD_ERROR; @@ -126,6 +131,14 @@ InstrUnloadError instr_unload(const char *id) goto out; } + qi_fini_fn fini_fn = instr_get_event(fini_fn); + if (fini_fn) { + void *fini_data = instr_get_event(fini_data); + fini_fn(fini_data); + } + + instr_set_event(fini_fn, NULL); + /* this should never fail */ if (dlclose(handle->dlhandle) < 0) { res = INSTR_UNLOAD_DLERROR; diff --git a/instrument/qemu-instr/control.h b/instrument/qemu-instr/control.h new file mode 100644 index 0000000000..b841afaa31 --- /dev/null +++ b/instrument/qemu-instr/control.h @@ -0,0 +1,46 @@ +/* + * Main instrumentation interface for QEMU. + * + * Copyright (C) 2012-2017 Lluís Vilanova <vilanova@ac.upc.edu> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef QI__CONTROL_H +#define QI__CONTROL_H + +#ifdef __cplusplus +extern "C" { +#endif + +#include <stdbool.h> +#include <stddef.h> + + +/** + * SECTION:control + * @section_id: qi-control + * @title: Event control API for QEMU event instrumentation + */ + +typedef void (*qi_fini_fn)(void *arg); + +/** + * qi_set_fini: + * @fn: Finalization function. + * @data: Argument to pass to the finalization function. + * + * Set the function to call when finalizing (unloading) the instrumentation + * library. + * + * NOTE: Calls to printf() might not be shown if the library is unloaded when + * QEMU terminates. + */ +void qi_set_fini(qi_fini_fn fn, void *data); + +#ifdef __cplusplus +} +#endif + +#endif /* QI__CONTROL_H */ diff --git a/stubs/instrument.c b/stubs/instrument.c index 79cd0fd2d1..9498fcdfe5 100644 --- a/stubs/instrument.c +++ b/stubs/instrument.c @@ -10,6 +10,7 @@ #include "qemu/osdep.h" #include "instrument/cmdline.h" +#include "instrument/control.h" #include "qapi/error.h" #include "qapi/qmp/qerror.h" @@ -42,3 +43,6 @@ void qmp_instr_unload(const char *id, Error **errp) { error_setg(errp, QERR_UNSUPPORTED); } + + +__thread InstrState instr_cur_state;

[v5,09/22] instrument: Add basic control interface

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