qemu/contrib/plugins/Makefile
Pierrick Bouvier 72db6d54a4 contrib/plugins: add Instructions Per Second (IPS) example for cost modeling
This plugin uses the new time control interface to make decisions
about the state of time during the emulation. The algorithm is
currently very simple. The user specifies an ips rate which applies
per core. If the core runs ahead of its allocated execution time the
plugin sleeps for a bit to let real time catch up. Either way time is
updated for the emulation as a function of total executed instructions
with some adjustments for cores that idle.

Examples
--------

Slow down execution of /bin/true:
$ num_insn=$(./build/qemu-x86_64 -plugin ./build/tests/plugin/libinsn.so -d plugin /bin/true |& grep total | sed -e 's/.*: //')
$ time ./build/qemu-x86_64 -plugin ./build/contrib/plugins/libips.so,ips=$(($num_insn/4)) /bin/true
real 4.000s

Boot a Linux kernel simulating a 250MHz cpu:
$ /build/qemu-system-x86_64 -kernel /boot/vmlinuz-6.1.0-21-amd64 -append "console=ttyS0" -plugin ./build/contrib/plugins/libips.so,ips=$((250*1000*1000)) -smp 1 -m 512
check time until kernel panic on serial0

Tested in system mode by booting a full debian system, and using:
$ sysbench cpu run
Performance decrease linearly with the given number of ips.

Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240530220610.1245424-7-pierrick.bouvier@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240620152220.2192768-11-alex.bennee@linaro.org>
2024-06-24 10:15:10 +01:00

70 lines
1.5 KiB
Makefile

# -*- Mode: makefile -*-
#
# This Makefile example is fairly independent from the main makefile
# so users can take and adapt it for their build. We only really
# include config-host.mak so we don't have to repeat probing for
# programs that the main configure has already done for us.
#
include config-host.mak
TOP_SRC_PATH = $(SRC_PATH)/../..
VPATH += $(SRC_PATH)
NAMES :=
NAMES += execlog
NAMES += hotblocks
NAMES += hotpages
NAMES += howvec
# The lockstep example communicates using unix sockets,
# and can't be easily made to work on windows.
ifneq ($(CONFIG_WIN32),y)
NAMES += lockstep
endif
NAMES += hwprofile
NAMES += cache
NAMES += drcov
NAMES += ips
ifeq ($(CONFIG_WIN32),y)
SO_SUFFIX := .dll
LDLIBS += $(shell $(PKG_CONFIG) --libs glib-2.0)
else
SO_SUFFIX := .so
endif
SONAMES := $(addsuffix $(SO_SUFFIX),$(addprefix lib,$(NAMES)))
# The main QEMU uses Glib extensively so it's perfectly fine to use it
# in plugins (which many example do).
PLUGIN_CFLAGS := $(shell $(PKG_CONFIG) --cflags glib-2.0)
PLUGIN_CFLAGS += -fPIC -Wall
PLUGIN_CFLAGS += -I$(TOP_SRC_PATH)/include/qemu
all: $(SONAMES)
%.o: %.c
$(CC) $(CFLAGS) $(PLUGIN_CFLAGS) -c -o $@ $<
ifeq ($(CONFIG_WIN32),y)
lib%$(SO_SUFFIX): %.o win32_linker.o ../../plugins/libqemu_plugin_api.a
$(CC) -shared -o $@ $^ $(LDLIBS)
else ifeq ($(CONFIG_DARWIN),y)
lib%$(SO_SUFFIX): %.o
$(CC) -bundle -Wl,-undefined,dynamic_lookup -o $@ $^ $(LDLIBS)
else
lib%$(SO_SUFFIX): %.o
$(CC) -shared -o $@ $^ $(LDLIBS)
endif
clean:
rm -f *.o *$(SO_SUFFIX) *.d
rm -Rf .libs
.PHONY: all clean
.SECONDARY: