KVM: selftests: Rename UNAME_M to ARCH_DIR, fill explicitly for x86

Rename UNAME_M to ARCH_DIR and explicitly set it directly for x86.  At
this point, the name of the arch directory really doesn't have anything
to do with `uname -m`, and UNAME_M is unnecessarily confusing given that
its purpose is purely to identify the arch specific directory.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221213001653.3852042-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/Makefile

@@ -7,35 +7,14 @@ top_srcdir = ../../../..
 include $(top_srcdir)/scripts/subarch.include
 ARCH            ?= $(SUBARCH)
 
-# For cross-builds to work, UNAME_M has to map to ARCH and arch specific
-# directories and targets in this Makefile. "uname -m" doesn't map to
-# arch specific sub-directory names.
-#
-# UNAME_M variable to used to run the compiles pointing to the right arch
-# directories and build the right targets for these supported architectures.
-#
-# TEST_GEN_PROGS and LIBKVM are set using UNAME_M variable.
-# LINUX_TOOL_ARCH_INCLUDE is set using ARCH variable.
-#
-# x86_64 targets are named to include x86_64 as a suffix and directories
-# for includes are in x86_64 sub-directory. s390x and aarch64 follow the
-# same convention. "uname -m" doesn't result in the correct mapping for
-# s390x and aarch64.
-#
-# No change necessary for x86_64
-UNAME_M := $(shell uname -m)
-
-# Set UNAME_M for arm64 compile/install to work
-ifeq ($(ARCH),arm64)
-	UNAME_M := aarch64
-endif
-# Set UNAME_M s390x compile/install to work
-ifeq ($(ARCH),s390)
-	UNAME_M := s390x
-endif
-# Set UNAME_M riscv compile/install to work
-ifeq ($(ARCH),riscv)
-	UNAME_M := riscv
+ifeq ($(ARCH),x86)
+	ARCH_DIR := x86_64
+else ifeq ($(ARCH),arm64)
+	ARCH_DIR := aarch64
+else ifeq ($(ARCH),s390)
+	ARCH_DIR := s390x
+else
+	ARCH_DIR := $(ARCH)
 endif
 
 LIBKVM += lib/assert.c
@@ -196,10 +175,10 @@ TEST_GEN_PROGS_riscv += kvm_page_table_test
 TEST_GEN_PROGS_riscv += set_memory_region_test
 TEST_GEN_PROGS_riscv += kvm_binary_stats_test
 
-TEST_PROGS += $(TEST_PROGS_$(UNAME_M))
-TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
-TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(UNAME_M))
-LIBKVM += $(LIBKVM_$(UNAME_M))
+TEST_PROGS += $(TEST_PROGS_$(ARCH_DIR))
+TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(ARCH_DIR))
+TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(ARCH_DIR))
+LIBKVM += $(LIBKVM_$(ARCH_DIR))
 
 INSTALL_HDR_PATH = $(top_srcdir)/usr
 LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
@@ -212,7 +191,7 @@ endif
 CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \
 	-fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \
 	-I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \
-	-I$(<D) -Iinclude/$(UNAME_M) -I ../rseq -I.. $(EXTRA_CFLAGS) \
+	-I$(<D) -Iinclude/$(ARCH_DIR) -I ../rseq -I.. $(EXTRA_CFLAGS) \
 	$(KHDR_INCLUDES)
 
 no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \