diff options
| -rwxr-xr-x | configure | 8 | ||||
| -rw-r--r-- | docs/tracing.txt | 16 | ||||
| -rw-r--r-- | kvm-all.c | 5 | ||||
| -rw-r--r-- | scripts/tracetool/backend/ftrace.py | 54 | ||||
| -rw-r--r-- | trace-events | 7 | ||||
| -rw-r--r-- | trace/Makefile.objs | 1 | ||||
| -rw-r--r-- | trace/ftrace.c | 102 | ||||
| -rw-r--r-- | trace/ftrace.h | 10 |
8 files changed, 203 insertions, 0 deletions
@@ -4004,6 +4004,14 @@ if test "$trace_backend" = "dtrace"; then echo "CONFIG_TRACE_SYSTEMTAP=y" >> $config_host_mak fi fi +if test "$trace_backend" = "ftrace"; then + if test "$linux" = "yes" ; then + echo "CONFIG_TRACE_FTRACE=y" >> $config_host_mak + trace_default=no + else + feature_not_found "ftrace(trace backend)" + fi +fi echo "CONFIG_TRACE_FILE=$trace_file" >> $config_host_mak if test "$trace_default" = "yes"; then echo "CONFIG_TRACE_DEFAULT=y" >> $config_host_mak diff --git a/docs/tracing.txt b/docs/tracing.txt index cf53c17..60ff9c5 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -175,6 +175,22 @@ unless you have specific needs for more advanced backends. The "simple" backend currently does not capture string arguments, it simply records the char* pointer value instead of the string that is pointed to. +=== Ftrace === + +The "ftrace" backend writes trace data to ftrace marker. This effectively +sends trace events to ftrace ring buffer, and you can compare qemu trace +data and kernel(especially kvm.ko when using KVM) trace data. + +if you use KVM, enable kvm events in ftrace: + + # echo 1 > /sys/kernel/debug/tracing/events/kvm/enable + +After running qemu by root user, you can get the trace: + + # cat /sys/kernel/debug/tracing/trace + +Restriction: "ftrace" backend is restricted to Linux only. + ==== Monitor commands ==== * trace-file on|off|flush|set <path> @@ -33,6 +33,7 @@ #include "exec/memory.h" #include "exec/address-spaces.h" #include "qemu/event_notifier.h" +#include "trace.h" /* This check must be after config-host.h is included */ #ifdef CONFIG_EVENTFD @@ -1626,6 +1627,7 @@ int kvm_cpu_exec(CPUArchState *env) abort(); } + trace_kvm_run_exit(cpu->cpu_index, run->exit_reason); switch (run->exit_reason) { case KVM_EXIT_IO: DPRINTF("handle_io\n"); @@ -1687,6 +1689,7 @@ int kvm_ioctl(KVMState *s, int type, ...) arg = va_arg(ap, void *); va_end(ap); + trace_kvm_ioctl(type, arg); ret = ioctl(s->fd, type, arg); if (ret == -1) { ret = -errno; @@ -1704,6 +1707,7 @@ int kvm_vm_ioctl(KVMState *s, int type, ...) arg = va_arg(ap, void *); va_end(ap); + trace_kvm_vm_ioctl(type, arg); ret = ioctl(s->vmfd, type, arg); if (ret == -1) { ret = -errno; @@ -1721,6 +1725,7 @@ int kvm_vcpu_ioctl(CPUState *cpu, int type, ...) arg = va_arg(ap, void *); va_end(ap); + trace_kvm_vcpu_ioctl(cpu->cpu_index, type, arg); ret = ioctl(cpu->kvm_fd, type, arg); if (ret == -1) { ret = -errno; diff --git a/scripts/tracetool/backend/ftrace.py b/scripts/tracetool/backend/ftrace.py new file mode 100644 index 0000000..888c361 --- /dev/null +++ b/scripts/tracetool/backend/ftrace.py @@ -0,0 +1,54 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +""" +Ftrace built-in backend. +""" + +__author__ = "Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com>" +__copyright__ = "Copyright (C) 2013 Hitachi, Ltd." +__license__ = "GPL version 2 or (at your option) any later version" + +__maintainer__ = "Stefan Hajnoczi" +__email__ = "stefanha@redhat.com" + + +from tracetool import out + + +PUBLIC = True + + +def c(events): + pass + +def h(events): + out('#include "trace/ftrace.h"', + '#include "trace/control.h"', + '', + ) + + for e in events: + argnames = ", ".join(e.args.names()) + if len(e.args) > 0: + argnames = ", " + argnames + + out('static inline void trace_%(name)s(%(args)s)', + '{', + ' char ftrace_buf[MAX_TRACE_STRLEN];', + ' int unused __attribute__ ((unused));', + ' int trlen;', + ' bool _state = trace_event_get_state(%(event_id)s);', + ' if (_state) {', + ' trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,', + ' "%(name)s " %(fmt)s "\\n" %(argnames)s);', + ' trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);', + ' unused = write(trace_marker_fd, ftrace_buf, trlen);', + ' }', + '}', + name = e.name, + args = e.args, + event_id = "TRACE_" + e.name.upper(), + fmt = e.fmt.rstrip("\n"), + argnames = argnames, + ) diff --git a/trace-events b/trace-events index 55e80be..17d75ab 100644 --- a/trace-events +++ b/trace-events @@ -1153,3 +1153,10 @@ virtio_ccw_new_device(int cssid, int ssid, int schid, int devno, const char *dev # migration.c migrate_set_state(int new_state) "new state %d" + +# kvm-all.c +kvm_ioctl(int type, void *arg) "type %d, arg %p" +kvm_vm_ioctl(int type, void *arg) "type %d, arg %p" +kvm_vcpu_ioctl(int cpu_index, int type, void *arg) "cpu_index %d, type %d, arg %p" +kvm_run_exit(int cpu_index, uint32_t reason) "cpu_index %d, reason %d" + diff --git a/trace/Makefile.objs b/trace/Makefile.objs index a043072..3b88e49 100644 --- a/trace/Makefile.objs +++ b/trace/Makefile.objs @@ -76,5 +76,6 @@ endif util-obj-$(CONFIG_TRACE_DEFAULT) += default.o util-obj-$(CONFIG_TRACE_SIMPLE) += simple.o util-obj-$(CONFIG_TRACE_STDERR) += stderr.o +util-obj-$(CONFIG_TRACE_FTRACE) += ftrace.o util-obj-y += control.o util-obj-y += generated-tracers.o diff --git a/trace/ftrace.c b/trace/ftrace.c new file mode 100644 index 0000000..46b7fdb --- /dev/null +++ b/trace/ftrace.c @@ -0,0 +1,102 @@ +/* + * Ftrace trace backend + * + * Copyright (C) 2013 Hitachi, Ltd. + * Created by Eiichi Tsukata <eiichi.tsukata.xh@hitachi.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + */ + +#include <stdio.h> +#include <string.h> +#include <fcntl.h> +#include <limits.h> +#include "trace.h" +#include "trace/control.h" + +int trace_marker_fd; + +static int find_debugfs(char *debugfs) +{ + char type[100]; + FILE *fp; + + fp = fopen("/proc/mounts", "r"); + if (fp == NULL) { + return 0; + } + + while (fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n", + debugfs, type) == 2) { + if (strcmp(type, "debugfs") == 0) { + break; + } + } + fclose(fp); + + if (strcmp(type, "debugfs") != 0) { + return 0; + } + return 1; +} + +void trace_print_events(FILE *stream, fprintf_function stream_printf) +{ + TraceEventID i; + + for (i = 0; i < trace_event_count(); i++) { + TraceEvent *ev = trace_event_id(i); + stream_printf(stream, "%s [Event ID %u] : state %u\n", + trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev)); + } +} + +void trace_event_set_state_dynamic_backend(TraceEvent *ev, bool state) +{ + ev->dstate = state; +} + +bool trace_backend_init(const char *events, const char *file) +{ + char debugfs[PATH_MAX]; + char path[PATH_MAX]; + int debugfs_found; + int trace_fd = -1; + + if (file) { + fprintf(stderr, "error: -trace file=...: " + "option not supported by the selected tracing backend\n"); + return false; + } + + debugfs_found = find_debugfs(debugfs); + if (debugfs_found) { + snprintf(path, PATH_MAX, "%s/tracing/tracing_on", debugfs); + trace_fd = open(path, O_WRONLY); + if (trace_fd < 0) { + perror("Could not open ftrace 'tracing_on' file"); + return false; + } else { + if (write(trace_fd, "1", 1) < 0) { + perror("Could not write to 'tracing_on' file"); + close(trace_fd); + return false; + } + close(trace_fd); + } + snprintf(path, PATH_MAX, "%s/tracing/trace_marker", debugfs); + trace_marker_fd = open(path, O_WRONLY); + if (trace_marker_fd < 0) { + perror("Could not open ftrace 'trace_marker' file"); + return false; + } + } else { + fprintf(stderr, "debugfs is not mounted\n"); + return false; + } + + trace_backend_init_events(events); + return true; +} diff --git a/trace/ftrace.h b/trace/ftrace.h new file mode 100644 index 0000000..94cb8d5 --- /dev/null +++ b/trace/ftrace.h @@ -0,0 +1,10 @@ +#ifndef TRACE_FTRACE_H +#define TRACE_FTRACE_H + +#define MAX_TRACE_STRLEN 512 +#define _STR(x) #x +#define STR(x) _STR(x) + +extern int trace_marker_fd; + +#endif /* ! TRACE_FTRACE_H */ |
