Message ID | 20230210084326.1802597-1-bjorn@kernel.org (mailing list archive) |
---|---|
State | New |
Headers | show |
Series | [bpf-next] selftests/bpf: Cross-compile bpftool | expand |
Björn Töpel <bjorn@kernel.org> writes: > From: Björn Töpel <bjorn@rivosinc.com> > > When the BPF selftests are cross-compiled, only the a host version of > bpftool is built. This version of bpftool is used to generate various > intermediates, e.g., skeletons. > > The test runners are also using bpftool. The Makefile will symlink > bpftool from the selftest/bpf root, where the test runners will look > for the tool: > > | ... > | $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ > | $(OUTPUT)/$(if $2,$2/)bpftool > > There are two issues for cross-compilation builds: > > 1. There is no native (cross-compilation target) build of bpftool > 2. The bootstrap variant of bpftool is never cross-compiled (by > design) > > Make sure that a native/cross-compiled version of bpftool is built, > and if CROSS_COMPILE is set, symlink to the native/non-bootstrap > version. ...and the grand master plan is to add BPF CI support for riscv64, where this patch a prerequisite to [1]. I would suspect that other platforms might benefit from cross-compilation builds as well. [1] https://github.com/kernel-patches/vmtest/pull/194
2023-02-10 09:43 UTC+0100 ~ Björn Töpel <bjorn@kernel.org> > From: Björn Töpel <bjorn@rivosinc.com> > > When the BPF selftests are cross-compiled, only the a host version of > bpftool is built. This version of bpftool is used to generate various > intermediates, e.g., skeletons. > > The test runners are also using bpftool. The Makefile will symlink > bpftool from the selftest/bpf root, where the test runners will look > for the tool: > > | ... > | $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ > | $(OUTPUT)/$(if $2,$2/)bpftool > > There are two issues for cross-compilation builds: > > 1. There is no native (cross-compilation target) build of bpftool > 2. The bootstrap variant of bpftool is never cross-compiled (by > design) > > Make sure that a native/cross-compiled version of bpftool is built, > and if CROSS_COMPILE is set, symlink to the native/non-bootstrap > version. > > Signed-off-by: Björn Töpel <bjorn@rivosinc.com> > --- > tools/testing/selftests/bpf/Makefile | 28 +++++++++++++++++++++++++--- > 1 file changed, 25 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > index b2eb3201b85a..b706750f71e2 100644 > --- a/tools/testing/selftests/bpf/Makefile > +++ b/tools/testing/selftests/bpf/Makefile > @@ -157,8 +157,9 @@ $(notdir $(TEST_GEN_PROGS) \ > $(TEST_CUSTOM_PROGS)): %: $(OUTPUT)/% ; > > # sort removes libbpf duplicates when not cross-building > -MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \ > - $(HOST_BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/resolve_btfids \ > +MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \ > + $(BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/bpftool \ > + $(HOST_BUILD_DIR)/resolve_btfids \ > $(RUNQSLOWER_OUTPUT) $(INCLUDE_DIR)) > $(MAKE_DIRS): > $(call msg,MKDIR,,$@) > @@ -208,6 +209,14 @@ $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_tes > $(Q)cp bpf_testmod/bpf_testmod.ko $@ > > DEFAULT_BPFTOOL := $(HOST_SCRATCH_DIR)/sbin/bpftool > +ifneq ($(CROSS_COMPILE),) > +CROSS_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool > +TRUNNER_BPFTOOL := $(CROSS_BPFTOOL) > +USE_BOOTSTRAP := "" > +else > +TRUNNER_BPFTOOL := $(DEFAULT_BPFTOOL) > +USE_BOOTSTRAP := "bootstrap" > +endif > > $(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(RUNQSLOWER_OUTPUT) > $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \ > @@ -255,6 +264,18 @@ $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ > LIBBPF_DESTDIR=$(HOST_SCRATCH_DIR)/ \ > prefix= DESTDIR=$(HOST_SCRATCH_DIR)/ install-bin > > +ifneq ($(CROSS_COMPILE),) > +$(CROSS_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ > + $(BPFOBJ) | $(BUILD_DIR)/bpftool > + $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \ > + ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) \ > + EXTRA_CFLAGS='-g -O0' \ > + OUTPUT=$(BUILD_DIR)/bpftool/ \ > + LIBBPF_OUTPUT=$(BUILD_DIR)/libbpf/ \ > + LIBBPF_DESTDIR=$(SCRATCH_DIR)/ \ > + prefix= DESTDIR=$(SCRATCH_DIR)/ install-bin > +endif > + > all: docs > > docs: > @@ -518,11 +539,12 @@ endif > $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \ > $(TRUNNER_EXTRA_OBJS) $$(BPFOBJ) \ > $(RESOLVE_BTFIDS) \ > + $(TRUNNER_BPFTOOL) \ > | $(TRUNNER_BINARY)-extras > $$(call msg,BINARY,,$$@) > $(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) -o $$@ > $(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@ > - $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ > + $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/$(USE_BOOTSTRAP)/bpftool \ Nit: You'll have a double slash in this path when USE_BOOSTRAP is empty (.../tools/build/bpftool//bpftool), but it probably doesn't matter much. > $(OUTPUT)/$(if $2,$2/)bpftool > > endef > > base-commit: 06744f24696e1e7598412c3df61a538b57ebec22 The changes look good to me, thanks! Acked-by: Quentin Monnet <quentin@isovalent.com> Jean-Philippe, I know you do some cross-compiling with bpftool, how does this look from your side?
Hi Bjorn, Thanks for the patch, I've tested it and it works for me. I have a minor suggestion but otherwise happy to see this getting fixed. On 10/02/2023 08:43, Björn Töpel wrote: > From: Björn Töpel <bjorn@rivosinc.com> > > When the BPF selftests are cross-compiled, only the a host version of > bpftool is built. This version of bpftool is used to generate various > intermediates, e.g., skeletons. > > The test runners are also using bpftool. The Makefile will symlink > bpftool from the selftest/bpf root, where the test runners will look > for the tool: > > | ... > | $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ > | $(OUTPUT)/$(if $2,$2/)bpftool > > There are two issues for cross-compilation builds: > > 1. There is no native (cross-compilation target) build of bpftool > 2. The bootstrap variant of bpftool is never cross-compiled (by > design) > > Make sure that a native/cross-compiled version of bpftool is built, > and if CROSS_COMPILE is set, symlink to the native/non-bootstrap > version. > > Signed-off-by: Björn Töpel <bjorn@rivosinc.com> > --- > tools/testing/selftests/bpf/Makefile | 28 +++++++++++++++++++++++++--- > 1 file changed, 25 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > index b2eb3201b85a..b706750f71e2 100644 > --- a/tools/testing/selftests/bpf/Makefile > +++ b/tools/testing/selftests/bpf/Makefile > @@ -157,8 +157,9 @@ $(notdir $(TEST_GEN_PROGS) \ > $(TEST_CUSTOM_PROGS)): %: $(OUTPUT)/% ; > > # sort removes libbpf duplicates when not cross-building > -MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \ > - $(HOST_BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/resolve_btfids \ > +MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \ > + $(BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/bpftool \ > + $(HOST_BUILD_DIR)/resolve_btfids \ > $(RUNQSLOWER_OUTPUT) $(INCLUDE_DIR)) > $(MAKE_DIRS): > $(call msg,MKDIR,,$@) > @@ -208,6 +209,14 @@ $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_tes > $(Q)cp bpf_testmod/bpf_testmod.ko $@ > > DEFAULT_BPFTOOL := $(HOST_SCRATCH_DIR)/sbin/bpftool > +ifneq ($(CROSS_COMPILE),) > +CROSS_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool > +TRUNNER_BPFTOOL := $(CROSS_BPFTOOL) > +USE_BOOTSTRAP := "" > +else > +TRUNNER_BPFTOOL := $(DEFAULT_BPFTOOL) > +USE_BOOTSTRAP := "bootstrap" > +endif > > $(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(RUNQSLOWER_OUTPUT) > $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \ ... -TEST_GEN_PROGS_EXTENDED += $(DEFAULT_BPFTOOL) +TEST_GEN_PROGS_EXTENDED += $(TRUNNER_BPFTOOL) Ensure the target arch bpftool is copied into the kselftest_bpf_install dir by selftests/lib.mk instead of always the default/host version. Thanks, Zach > @@ -255,6 +264,18 @@ $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ > LIBBPF_DESTDIR=$(HOST_SCRATCH_DIR)/ \ > prefix= DESTDIR=$(HOST_SCRATCH_DIR)/ install-bin > > +ifneq ($(CROSS_COMPILE),) > +$(CROSS_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ > + $(BPFOBJ) | $(BUILD_DIR)/bpftool > + $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \ > + ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) \ > + EXTRA_CFLAGS='-g -O0' \ > + OUTPUT=$(BUILD_DIR)/bpftool/ \ > + LIBBPF_OUTPUT=$(BUILD_DIR)/libbpf/ \ > + LIBBPF_DESTDIR=$(SCRATCH_DIR)/ \ > + prefix= DESTDIR=$(SCRATCH_DIR)/ install-bin > +endif > + > all: docs > > docs: > @@ -518,11 +539,12 @@ endif > $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TESAT_OBJS) \ > $(TRUNNER_EXTRA_OBJS) $$(BPFOBJ) \ > $(RESOLVE_BTFIDS) related to \ > + $(TRUNNER_BPFTOOL) \ > | $(TRUNNER_BINARY)-extras > $$(call msg,BINARY,,$$@) > $(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) -o $$@ > $(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@ > - $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ > + $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/$(USE_BOOTSTRAP)/bpftool \> $(OUTPUT)/$(if $2,$2/)bpftool > > endef > > base-commit: 06744f24696e1e7598412c3df61a538b57ebec22
On 13/02/2023 14:30, Björn Töpel wrote: > Björn Töpel <bjorn@kernel.org> writes: > >> From: Björn Töpel <bjorn@rivosinc.com> >> >> When the BPF selftests are cross-compiled, only the a host version of >> bpftool is built. This version of bpftool is used to generate various >> intermediates, e.g., skeletons. >> >> The test runners are also using bpftool. The Makefile will symlink >> bpftool from the selftest/bpf root, where the test runners will look >> for the tool: >> >> | ... >> | $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ >> | $(OUTPUT)/$(if $2,$2/)bpftool >> >> There are two issues for cross-compilation builds: >> >> 1. There is no native (cross-compilation target) build of bpftool >> 2. The bootstrap variant of bpftool is never cross-compiled (by >> design) >> >> Make sure that a native/cross-compiled version of bpftool is built, >> and if CROSS_COMPILE is set, symlink to the native/non-bootstrap >> version. > > ...and the grand master plan is to add BPF CI support for riscv64, where > this patch a prerequisite to [1]. I would suspect that other platforms > might benefit from cross-compilation builds as well. Similar use case. There also seems to be a lot of issues building these tests out of tree. I have some potential fixes up to 6.1 but linux-next seems to have introduced a few more issues on top. > > [1] https://github.com/kernel-patches/vmtest/pull/194
Zachary Leaf <zachary.leaf@arm.com> writes: > Hi Bjorn, > > Thanks for the patch, I've tested it and it works for me. Good! > I have a minor suggestion but otherwise happy to see this getting fixed. > > ... > > > -TEST_GEN_PROGS_EXTENDED += $(DEFAULT_BPFTOOL) > +TEST_GEN_PROGS_EXTENDED += $(TRUNNER_BPFTOOL) > > Ensure the target arch bpftool is copied into the kselftest_bpf_install > dir by selftests/lib.mk instead of always the default/host version. Good one. I'll spin a v2, and also fix Quentin's "double-slash". Björn
Zachary Leaf <zachary.leaf@arm.com> writes: > On 13/02/2023 14:30, Björn Töpel wrote: >> Björn Töpel <bjorn@kernel.org> writes: >> >>> From: Björn Töpel <bjorn@rivosinc.com> >>> >>> When the BPF selftests are cross-compiled, only the a host version of >>> bpftool is built. This version of bpftool is used to generate various >>> intermediates, e.g., skeletons. >>> >>> The test runners are also using bpftool. The Makefile will symlink >>> bpftool from the selftest/bpf root, where the test runners will look >>> for the tool: >>> >>> | ... >>> | $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ >>> | $(OUTPUT)/$(if $2,$2/)bpftool >>> >>> There are two issues for cross-compilation builds: >>> >>> 1. There is no native (cross-compilation target) build of bpftool >>> 2. The bootstrap variant of bpftool is never cross-compiled (by >>> design) >>> >>> Make sure that a native/cross-compiled version of bpftool is built, >>> and if CROSS_COMPILE is set, symlink to the native/non-bootstrap >>> version. >> >> ...and the grand master plan is to add BPF CI support for riscv64, where >> this patch a prerequisite to [1]. I would suspect that other platforms >> might benefit from cross-compilation builds as well. > > Similar use case. There also seems to be a lot of issues building these > tests out of tree. > > I have some potential fixes up to 6.1 but linux-next seems to have > introduced a few more issues on top. Ah, yes. FWIW, the BPF CI builds the selftests *in-tree*, so with this patch (and my PRs) the BPF CI is capable of cross-compiling. Björn
Hi Quentin, On Mon, Feb 13, 2023 at 08:53:31PM +0000, Quentin Monnet wrote: > Jean-Philippe, I know you do some cross-compiling with bpftool, how does > this look from your side? I don't have enough time for BPF at the moment unfortunately. Zachary is looking at cross-compiling the selftests for arm64 Thanks, Jean
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index b2eb3201b85a..b706750f71e2 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -157,8 +157,9 @@ $(notdir $(TEST_GEN_PROGS) \ $(TEST_CUSTOM_PROGS)): %: $(OUTPUT)/% ; # sort removes libbpf duplicates when not cross-building -MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \ - $(HOST_BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/resolve_btfids \ +MAKE_DIRS := $(sort $(BUILD_DIR)/libbpf $(HOST_BUILD_DIR)/libbpf \ + $(BUILD_DIR)/bpftool $(HOST_BUILD_DIR)/bpftool \ + $(HOST_BUILD_DIR)/resolve_btfids \ $(RUNQSLOWER_OUTPUT) $(INCLUDE_DIR)) $(MAKE_DIRS): $(call msg,MKDIR,,$@) @@ -208,6 +209,14 @@ $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_tes $(Q)cp bpf_testmod/bpf_testmod.ko $@ DEFAULT_BPFTOOL := $(HOST_SCRATCH_DIR)/sbin/bpftool +ifneq ($(CROSS_COMPILE),) +CROSS_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool +TRUNNER_BPFTOOL := $(CROSS_BPFTOOL) +USE_BOOTSTRAP := "" +else +TRUNNER_BPFTOOL := $(DEFAULT_BPFTOOL) +USE_BOOTSTRAP := "bootstrap" +endif $(OUTPUT)/runqslower: $(BPFOBJ) | $(DEFAULT_BPFTOOL) $(RUNQSLOWER_OUTPUT) $(Q)$(MAKE) $(submake_extras) -C $(TOOLSDIR)/bpf/runqslower \ @@ -255,6 +264,18 @@ $(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ LIBBPF_DESTDIR=$(HOST_SCRATCH_DIR)/ \ prefix= DESTDIR=$(HOST_SCRATCH_DIR)/ install-bin +ifneq ($(CROSS_COMPILE),) +$(CROSS_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \ + $(BPFOBJ) | $(BUILD_DIR)/bpftool + $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \ + ARCH=$(ARCH) CROSS_COMPILE=$(CROSS_COMPILE) \ + EXTRA_CFLAGS='-g -O0' \ + OUTPUT=$(BUILD_DIR)/bpftool/ \ + LIBBPF_OUTPUT=$(BUILD_DIR)/libbpf/ \ + LIBBPF_DESTDIR=$(SCRATCH_DIR)/ \ + prefix= DESTDIR=$(SCRATCH_DIR)/ install-bin +endif + all: docs docs: @@ -518,11 +539,12 @@ endif $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \ $(TRUNNER_EXTRA_OBJS) $$(BPFOBJ) \ $(RESOLVE_BTFIDS) \ + $(TRUNNER_BPFTOOL) \ | $(TRUNNER_BINARY)-extras $$(call msg,BINARY,,$$@) $(Q)$$(CC) $$(CFLAGS) $$(filter %.a %.o,$$^) $$(LDLIBS) -o $$@ $(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.bpf.o $$@ - $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ + $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/$(USE_BOOTSTRAP)/bpftool \ $(OUTPUT)/$(if $2,$2/)bpftool endef