[PATCH] KVM: selftests: Install sanitised kernel headers before compilation

[Like Xu]

From: Like Xu <likexu@xxxxxxxxxxx>

On many automated test boxes, selftests in a completely clean src tree
will be compiled independently: "make -j -C tools/testing/selftests/kvm".
Sometimes the compilation will fail and produce a false positive just
due to missing kernel headers (or others hidden behind the complete
kernel compilation or installation).

Optimize this situation by explicitly adding the installation of sanitised
kernel headers before compilation to the Makefile.

Reported-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
---
 tools/testing/selftests/kvm/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 947676983da1..a33e2f72d745 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -202,6 +202,11 @@ TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(UNAME_M))
 LIBKVM += $(LIBKVM_$(UNAME_M))
 
 INSTALL_HDR_PATH = $(top_srcdir)/usr
+
+ifeq ($(shell make -j -C ../../../.. headers_install),)
+	$(error "Please install sanitised kernel headers manually.")
+endif
+
 LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
 LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
 ifeq ($(ARCH),x86_64)
-- 
2.39.0