tests/tcg: reduce the number of plugin tests combinations

As our set of multiarch tests has grown the practice of running every
plugin with every test is becoming unsustainable. If we switch to
ensuring every test gets run with at least one plugin we can speed
things up.

Some plugins do need to be run with specific tests (for example the
memory instrumentation test). We can handle this by manually adding
them to EXTRA_RUNS. We also need to wrap rules in a CONFIG_PLUGIN test
so we don't enable the runs when plugins are not enabled.

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-ID: <20250725154517.3523095-12-alex.bennee@linaro.org>

tests/tcg/Makefile.target

@@ -173,14 +173,25 @@ PLUGINS=$(filter-out $(DISABLE_PLUGINS), \
 # We need to ensure expand the run-plugin-TEST-with-PLUGIN
 # pre-requistes manually here as we can't use stems to handle it. We
 # only expand MULTIARCH_TESTS which are common on most of our targets
-# to avoid an exponential explosion as new tests are added. We also
-# add some special helpers the run-plugin- rules can use below.
+# and rotate the plugins so we don't grow too out of control as new
+# tests are added. Plugins that need to run with a specific test
+# should ensure they add their combination to EXTRA_RUNS.
 
 ifneq ($(MULTIARCH_TESTS),)
-$(foreach p,$(PLUGINS), \
-	$(foreach t,$(MULTIARCH_TESTS),\
-		$(eval run-plugin-$(t)-with-$(p): $t $p) \
-		$(eval RUN_TESTS+=run-plugin-$(t)-with-$(p))))
+
+NUM_PLUGINS := $(words $(PLUGINS))
+NUM_TESTS := $(words $(MULTIARCH_TESTS))
+
+define mod_plus_one
+  $(shell $(PYTHON) -c "print( ($(1) % $(2)) + 1 )")
+endef
+
+$(foreach _idx, $(shell seq 1 $(NUM_TESTS)), \
+	$(eval _test := $(word $(_idx), $(MULTIARCH_TESTS))) \
+	$(eval _plugin := $(word $(call mod_plus_one, $(_idx), $(NUM_PLUGINS)), $(PLUGINS))) \
+	$(eval run-plugin-$(_test)-with-$(_plugin): $(_test) $(_plugin)) \
+	$(eval RUN_TESTS+=run-plugin-$(_test)-with-$(_plugin)))
+
 endif # MULTIARCH_TESTS
 endif # CONFIG_PLUGIN
 

tests/tcg/multiarch/Makefile.target

@@ -189,6 +189,10 @@ run-plugin-semiconsole-with-%:
 TESTS += semihosting semiconsole
 endif
 
+test-plugin-mem-access: CFLAGS+=-pthread -O0
+test-plugin-mem-access: LDFLAGS+=-pthread -O0
+
+ifeq ($(CONFIG_PLUGIN),y)
 # Test plugin memory access instrumentation
 run-plugin-test-plugin-mem-access-with-libmem.so: \
 	PLUGIN_ARGS=$(COMMA)print-accesses=true
@@ -197,8 +201,8 @@ run-plugin-test-plugin-mem-access-with-libmem.so: \
 	$(SRC_PATH)/tests/tcg/multiarch/check-plugin-output.sh \
 	$(QEMU) $<
 
-test-plugin-mem-access: CFLAGS+=-pthread -O0
-test-plugin-mem-access: LDFLAGS+=-pthread -O0
+EXTRA_RUNS += run-plugin-test-plugin-mem-access-with-libmem.so
+endif
 
 # Update TESTS
 TESTS += $(MULTIARCH_TESTS)

tests/tcg/multiarch/system/Makefile.softmmu-target

@@ -71,8 +71,11 @@ endif
 MULTIARCH_RUNS += run-gdbstub-memory run-gdbstub-interrupt \
 	run-gdbstub-untimely-packet run-gdbstub-registers
 
+ifeq ($(CONFIG_PLUGIN),y)
 # Test plugin memory access instrumentation
-run-plugin-memory-with-libmem.so: 		\
-	PLUGIN_ARGS=$(COMMA)region-summary=true
-run-plugin-memory-with-libmem.so: 		\
-	CHECK_PLUGIN_OUTPUT_COMMAND=$(MULTIARCH_SYSTEM_SRC)/validate-memory-counts.py $@.out
+run-plugin-memory-with-libmem.so: memory libmem.so
+run-plugin-memory-with-libmem.so: PLUGIN_ARGS=$(COMMA)region-summary=true
+run-plugin-memory-with-libmem.so: CHECK_PLUGIN_OUTPUT_COMMAND=$(MULTIARCH_SYSTEM_SRC)/validate-memory-counts.py $@.out
+
+EXTRA_RUNS += run-plugin-memory-with-libmem.so
+endif