xemu/Makefile.target
Daniel P. Berrangé 62dd1048c0 trace: add ability to do simple printf logging via systemtap
The dtrace systemtap trace backend for QEMU is very powerful but it is
also somewhat unfriendly to users who aren't familiar with systemtap,
or who don't need its power right now.

  stap -e "....some strange script...."

The 'log' backend for QEMU by comparison is very crude but incredibly
easy to use:

 $ qemu -d trace:qio* ...some args...
 23266@1547735759.137292:qio_channel_socket_new Socket new ioc=0x563a8a39d400
 23266@1547735759.137305:qio_task_new Task new task=0x563a891d0570 source=0x563a8a39d400 func=0x563a86f1e6c0 opaque=0x563a89078000
 23266@1547735759.137326:qio_task_thread_start Task thread start task=0x563a891d0570 worker=0x563a86f1ce50 opaque=0x563a891d9d90
 23273@1547735759.137491:qio_task_thread_run Task thread run task=0x563a891d0570
 23273@1547735759.137503:qio_channel_socket_connect_sync Socket connect sync ioc=0x563a8a39d400 addr=0x563a891d9d90
 23273@1547735759.138108:qio_channel_socket_connect_fail Socket connect fail ioc=0x563a8a39d400

This commit introduces a way to do simple printf style logging of probe
points using systemtap. In particular it creates another set of tapsets,
one per emulator:

  /usr/share/systemtap/tapset/qemu-*-log.stp

These pre-define probe functions which simply call printf() on their
arguments. The printf() format string is taken from the normal
trace-events files, with a little munging to the format specifiers
to cope with systemtap's more restrictive syntax.

With this you can now do

 $ stap -e 'probe qemu.system.x86_64.log.qio*{}'
 22806@1547735341399856820 qio_channel_socket_new Socket new ioc=0x56135d1d7c00
 22806@1547735341399862570 qio_task_new Task new task=0x56135cd66eb0 source=0x56135d1d7c00 func=0x56135af746c0 opaque=0x56135bf06400
 22806@1547735341399865943 qio_task_thread_start Task thread start task=0x56135cd66eb0 worker=0x56135af72e50 opaque=0x56135c071d70
 22806@1547735341399976816 qio_task_thread_run Task thread run task=0x56135cd66eb0

We go one step further though and introduce a 'qemu-trace-stap' tool to
make this even easier

 $ qemu-trace-stap run qemu-system-x86_64 'qio*'
 22806@1547735341399856820 qio_channel_socket_new Socket new ioc=0x56135d1d7c00
 22806@1547735341399862570 qio_task_new Task new task=0x56135cd66eb0 source=0x56135d1d7c00 func=0x56135af746c0 opaque=0x56135bf06400
 22806@1547735341399865943 qio_task_thread_start Task thread start task=0x56135cd66eb0 worker=0x56135af72e50 opaque=0x56135c071d70
 22806@1547735341399976816 qio_task_thread_run Task thread run task=0x56135cd66eb0

This tool is clever in that it will automatically change the
SYSTEMTAP_TAPSET env variable to point to the directory containing the
right set of probes for the QEMU binary path you give it. This is useful
if you have QEMU installed in /usr but are trying to test and trace a
binary in /home/berrange/usr/qemu-git. In that case you'd do

 $ qemu-trace-stap run /home/berrange/usr/qemu-git/bin/qemu-system-x86_64 'qio*'

And it'll make sure /home/berrange/usr/qemu-git/share/systemtap/tapset
is used for the trace session

The 'qemu-trace-stap' script takes a verbose arg so you can understand
what it is running

 $ qemu-trace-stap run /home/berrange/usr/qemu-git/bin/qemu-system-x86_64 'qio*'
 Using tapset dir '/home/berrange/usr/qemu-git/share/systemtap/tapset' for binary '/home/berrange/usr/qemu-git/bin/qemu-system-x86_64'
 Compiling script 'probe qemu.system.x86_64.log.qio* {}'
 Running script, <Ctrl>-c to quit
 ...trace output...

It can enable multiple probes at once

 $ qemu-trace-stap run qemu-system-x86_64 'qio*' 'qcrypto*' 'buffer*'

By default it monitors all existing running processes and all future
launched proceses. This can be restricted to a specific PID using the
--pid arg

 $ qemu-trace-stap run --pid 2532 qemu-system-x86_64 'qio*'

Finally if you can't remember what probes are valid it can tell you

 $ qemu-trace-stap list qemu-system-x86_64
 ahci_check_irq
 ahci_cmd_done
 ahci_dma_prepare_buf
 ahci_dma_prepare_buf_fail
 ahci_dma_rw_buf
 ahci_irq_lower
 ...snip...

Or list just those matching a prefix pattern

 $ qemu-trace-stap list -v qemu-system-x86_64 'qio*'
 Using tapset dir '/home/berrange/usr/qemu-git/share/systemtap/tapset' for binary '/home/berrange/usr/qemu-git/bin/qemu-system-x86_64'
 Listing probes with name 'qemu.system.x86_64.log.qio*'
 qio_channel_command_abort
 qio_channel_command_new_pid
 qio_channel_command_new_spawn
 qio_channel_command_wait
 qio_channel_file_new_fd
 ...snip...

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20190123120016.4538-5-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-01-24 14:16:56 +00:00

243 lines
7.0 KiB
Makefile

# -*- Mode: makefile -*-
BUILD_DIR?=$(CURDIR)/..
include ../config-host.mak
include config-target.mak
include config-devices.mak
include $(SRC_PATH)/rules.mak
$(call set-vpath, $(SRC_PATH):$(BUILD_DIR))
ifdef CONFIG_LINUX
QEMU_CFLAGS += -I../linux-headers
endif
QEMU_CFLAGS += -iquote .. -iquote $(SRC_PATH)/target/$(TARGET_BASE_ARCH) -DNEED_CPU_H
QEMU_CFLAGS+=-iquote $(SRC_PATH)/include
ifdef CONFIG_USER_ONLY
# user emulator name
QEMU_PROG=qemu-$(TARGET_NAME)
QEMU_PROG_BUILD = $(QEMU_PROG)
else
# system emulator name
QEMU_PROG=qemu-system-$(TARGET_NAME)$(EXESUF)
ifneq (,$(findstring -mwindows,$(SDL_LIBS)))
# Terminate program name with a 'w' because the linker builds a windows executable.
QEMU_PROGW=qemu-system-$(TARGET_NAME)w$(EXESUF)
$(QEMU_PROG): $(QEMU_PROGW)
$(call quiet-command,$(OBJCOPY) --subsystem console $(QEMU_PROGW) $(QEMU_PROG),"GEN","$(TARGET_DIR)$(QEMU_PROG)")
QEMU_PROG_BUILD = $(QEMU_PROGW)
else
QEMU_PROG_BUILD = $(QEMU_PROG)
endif
endif
PROGS=$(QEMU_PROG) $(QEMU_PROGW)
STPFILES=
# Makefile Tests
ifdef CONFIG_USER_ONLY
include $(SRC_PATH)/tests/tcg/Makefile.include
endif
config-target.h: config-target.h-timestamp
config-target.h-timestamp: config-target.mak
ifdef CONFIG_TRACE_SYSTEMTAP
stap: $(QEMU_PROG).stp-installed $(QEMU_PROG).stp $(QEMU_PROG)-simpletrace.stp $(QEMU_PROG)-log.stp
ifdef CONFIG_USER_ONLY
TARGET_TYPE=user
else
TARGET_TYPE=system
endif
tracetool-y = $(SRC_PATH)/scripts/tracetool.py
tracetool-y += $(shell find $(SRC_PATH)/scripts/tracetool -name "*.py")
$(QEMU_PROG).stp-installed: $(BUILD_DIR)/trace-events-all $(tracetool-y)
$(call quiet-command,$(TRACETOOL) \
--group=all \
--format=stap \
--backends=$(TRACE_BACKENDS) \
--binary=$(bindir)/$(QEMU_PROG) \
--target-name=$(TARGET_NAME) \
--target-type=$(TARGET_TYPE) \
$< > $@,"GEN","$(TARGET_DIR)$(QEMU_PROG).stp-installed")
$(QEMU_PROG).stp: $(BUILD_DIR)/trace-events-all $(tracetool-y)
$(call quiet-command,$(TRACETOOL) \
--group=all \
--format=stap \
--backends=$(TRACE_BACKENDS) \
--binary=$(realpath .)/$(QEMU_PROG) \
--target-name=$(TARGET_NAME) \
--target-type=$(TARGET_TYPE) \
$< > $@,"GEN","$(TARGET_DIR)$(QEMU_PROG).stp")
$(QEMU_PROG)-simpletrace.stp: $(BUILD_DIR)/trace-events-all $(tracetool-y)
$(call quiet-command,$(TRACETOOL) \
--group=all \
--format=simpletrace-stap \
--backends=$(TRACE_BACKENDS) \
--probe-prefix=qemu.$(TARGET_TYPE).$(TARGET_NAME) \
$< > $@,"GEN","$(TARGET_DIR)$(QEMU_PROG)-simpletrace.stp")
$(QEMU_PROG)-log.stp: $(BUILD_DIR)/trace-events-all $(tracetool-y)
$(call quiet-command,$(TRACETOOL) \
--group=all \
--format=log-stap \
--backends=$(TRACE_BACKENDS) \
--probe-prefix=qemu.$(TARGET_TYPE).$(TARGET_NAME) \
$< > $@,"GEN","$(TARGET_DIR)$(QEMU_PROG)-log.stp")
else
stap:
endif
.PHONY: stap
all: $(PROGS) stap
# Dummy command so that make thinks it has done something
@true
#########################################################
# cpu emulator library
obj-y += exec.o
obj-y += accel/
obj-$(CONFIG_TCG) += tcg/tcg.o tcg/tcg-op.o tcg/tcg-op-vec.o tcg/tcg-op-gvec.o
obj-$(CONFIG_TCG) += tcg/tcg-common.o tcg/optimize.o
obj-$(CONFIG_TCG_INTERPRETER) += tcg/tci.o
obj-$(CONFIG_TCG_INTERPRETER) += disas/tci.o
obj-$(CONFIG_TCG) += fpu/softfloat.o
obj-y += target/$(TARGET_BASE_ARCH)/
obj-y += disas.o
obj-$(call notempty,$(TARGET_XML_FILES)) += gdbstub-xml.o
#########################################################
# Linux user emulator target
ifdef CONFIG_LINUX_USER
QEMU_CFLAGS+=-I$(SRC_PATH)/linux-user/$(TARGET_ABI_DIR) \
-I$(SRC_PATH)/linux-user/host/$(ARCH) \
-I$(SRC_PATH)/linux-user
obj-y += linux-user/
obj-y += gdbstub.o thunk.o
endif #CONFIG_LINUX_USER
#########################################################
# BSD user emulator target
ifdef CONFIG_BSD_USER
QEMU_CFLAGS+=-I$(SRC_PATH)/bsd-user -I$(SRC_PATH)/bsd-user/$(TARGET_ABI_DIR) \
-I$(SRC_PATH)/bsd-user/$(HOST_VARIANT_DIR)
obj-y += bsd-user/
obj-y += gdbstub.o
endif #CONFIG_BSD_USER
#########################################################
# System emulator target
ifdef CONFIG_SOFTMMU
obj-y += arch_init.o cpus.o monitor.o gdbstub.o balloon.o ioport.o numa.o
obj-y += qtest.o
obj-y += hw/
obj-y += memory.o
obj-y += memory_mapping.o
obj-y += dump.o
obj-$(TARGET_X86_64) += win_dump.o
obj-y += migration/ram.o
LIBS := $(libs_softmmu) $(LIBS)
# Hardware support
ifeq ($(TARGET_NAME), sparc64)
obj-y += hw/sparc64/
else
obj-y += hw/$(TARGET_BASE_ARCH)/
endif
GENERATED_FILES += hmp-commands.h hmp-commands-info.h
endif # CONFIG_SOFTMMU
dummy := $(call unnest-vars,,obj-y)
all-obj-y := $(obj-y)
target-obj-y :=
block-obj-y :=
common-obj-y :=
chardev-obj-y :=
slirp-obj-y :=
include $(SRC_PATH)/Makefile.objs
dummy := $(call unnest-vars,,target-obj-y)
target-obj-y-save := $(target-obj-y)
dummy := $(call unnest-vars,.., \
block-obj-y \
block-obj-m \
chardev-obj-y \
crypto-obj-y \
crypto-aes-obj-y \
qom-obj-y \
io-obj-y \
common-obj-y \
common-obj-m \
slirp-obj-y)
target-obj-y := $(target-obj-y-save)
all-obj-y += $(common-obj-y)
all-obj-y += $(target-obj-y)
all-obj-y += $(qom-obj-y)
all-obj-$(CONFIG_SOFTMMU) += $(block-obj-y) $(chardev-obj-y)
all-obj-$(CONFIG_USER_ONLY) += $(crypto-aes-obj-y)
all-obj-$(CONFIG_SOFTMMU) += $(crypto-obj-y)
all-obj-$(CONFIG_SOFTMMU) += $(io-obj-y)
all-obj-$(CONFIG_SOFTMMU) += $(slirp-obj-y)
$(QEMU_PROG_BUILD): config-devices.mak
COMMON_LDADDS = ../libqemuutil.a
# build either PROG or PROGW
$(QEMU_PROG_BUILD): $(all-obj-y) $(COMMON_LDADDS)
$(call LINK, $(filter-out %.mak, $^))
ifdef CONFIG_DARWIN
$(call quiet-command,Rez -append $(SRC_PATH)/pc-bios/qemu.rsrc -o $@,"REZ","$(TARGET_DIR)$@")
$(call quiet-command,SetFile -a C $@,"SETFILE","$(TARGET_DIR)$@")
endif
gdbstub-xml.c: $(TARGET_XML_FILES) $(SRC_PATH)/scripts/feature_to_c.sh
$(call quiet-command,rm -f $@ && $(SHELL) $(SRC_PATH)/scripts/feature_to_c.sh $@ $(TARGET_XML_FILES),"GEN","$(TARGET_DIR)$@")
hmp-commands.h: $(SRC_PATH)/hmp-commands.hx $(SRC_PATH)/scripts/hxtool
$(call quiet-command,sh $(SRC_PATH)/scripts/hxtool -h < $< > $@,"GEN","$(TARGET_DIR)$@")
hmp-commands-info.h: $(SRC_PATH)/hmp-commands-info.hx $(SRC_PATH)/scripts/hxtool
$(call quiet-command,sh $(SRC_PATH)/scripts/hxtool -h < $< > $@,"GEN","$(TARGET_DIR)$@")
clean: clean-target
rm -f *.a *~ $(PROGS)
rm -f $(shell find . -name '*.[od]')
rm -f hmp-commands.h gdbstub-xml.c
ifdef CONFIG_TRACE_SYSTEMTAP
rm -f *.stp
endif
install: all
ifneq ($(PROGS),)
$(call install-prog,$(PROGS),$(DESTDIR)$(bindir))
endif
ifdef CONFIG_TRACE_SYSTEMTAP
$(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset"
$(INSTALL_DATA) $(QEMU_PROG).stp-installed "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset/$(QEMU_PROG).stp"
$(INSTALL_DATA) $(QEMU_PROG)-simpletrace.stp "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset/$(QEMU_PROG)-simpletrace.stp"
$(INSTALL_DATA) $(QEMU_PROG)-log.stp "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset/$(QEMU_PROG)-log.stp"
endif
GENERATED_FILES += config-target.h
Makefile: $(GENERATED_FILES)