[PATCH] KVM: selftests: Only link to VFIO library on x86

[Sean Christopherson <seanjc@google.com>]

Link to the VFIO library only on architectures where it's actually needed,
i.e. only on architectures that support irq_test, which is currently
x86-only.  The irq_test series, which pulled in VFIO support, effectively
raced with commit e65f1bf8a2db ("vfio: selftests: Extend container/iommufd
setup for passing vf_token").  I.e. when the KVM test was posted, pulling
in libvfio.mk didn't require linking to any new libraries other than VFIO
itself.

Now that libvfio.mk pulls in luuid, unconditionally linking in support for
VFIO is quite onerous, especially when cross-compiling, as it requires
installing what is effectively an unused library on four architectures.

Eventually KVM selftests will likely support irq_test and thus need to link
to VFIO on architectures other than x86, but at least then there will be
some amount of gain for the pain.

Fixes: a262fc49e0aa ("KVM: selftests: Build and link selftests/vfio/lib into KVM selftests")
Cc: David Matlack <dmatlack@google.com>
Cc: Josh Hilke <jrhilke@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 tools/testing/selftests/kvm/Makefile.kvm | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 88c6c8046dde..ee91051786d8 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -261,7 +261,10 @@ OVERRIDE_TARGETS = 1
 # which causes the environment variable to override the makefile).
 include ../lib.mk
 include ../cgroup/lib/libcgroup.mk
+
+ifeq ($(ARCH),x86)
 include ../vfio/lib/libvfio.mk
+endif
 
 INSTALL_HDR_PATH = $(top_srcdir)/usr
 LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
@@ -318,7 +321,9 @@ LIBKVM_S_OBJ := $(patsubst %.S, $(OUTPUT)/%.o, $(LIBKVM_S))
 LIBKVM_STRING_OBJ := $(patsubst %.c, $(OUTPUT)/%.o, $(LIBKVM_STRING))
 LIBKVM_OBJS = $(LIBKVM_C_OBJ) $(LIBKVM_S_OBJ) $(LIBKVM_STRING_OBJ)
 LIBKVM_OBJS += $(LIBCGROUP_O)
+ifeq ($(ARCH),x86)
 LIBKVM_OBJS += $(LIBVFIO_O)
+endif
 SPLIT_TEST_GEN_PROGS := $(patsubst %, $(OUTPUT)/%, $(SPLIT_TESTS))
 SPLIT_TEST_GEN_OBJ := $(patsubst %, $(OUTPUT)/$(ARCH)/%.o, $(SPLIT_TESTS))
 

base-commit: 3c7d7f908d574277a845423ec32250a8d8df44c8
-- 
2.55.0.508.g3f0d502094-goog