Revert "kvm: selftests: move base kvm_util.h declarations to kvm_util_base.h"

Effectively revert the movement of code from kvm_util.h => kvm_util_base.h,
as the TL;DR of the justification for the move was to avoid #idefs and/or
circular dependencies between what ended up being ucall_common.h and what
was (and now again, is), kvm_util.h.

But avoiding #ifdef and circular includes is trivial: don't do that.  The
cost of removing kvm_util_base.h is a few extra includes of ucall_common.h,
but that cost is practically nothing.  On the other hand, having a "base"
version of a header that is really just the header itself is confusing,
and makes it weird/hard to choose names for headers that actually are
"base" headers, e.g. to hold core KVM selftests typedefs.

For all intents and purposes, this reverts commit
7d9a662.

Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Link: https://lore.kernel.org/r/20240314232637.2538648-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

tools/testing/selftests/kvm/aarch64/arch_timer.c

@@ -10,6 +10,7 @@
 #include "gic.h"
 #include "processor.h"
 #include "timer_test.h"
+#include "ucall_common.h"
 #include "vgic.h"
 
 #define GICD_BASE_GPA			0x8000000ULL

tools/testing/selftests/kvm/arch_timer.c

@@ -26,6 +26,7 @@
 #include <sys/sysinfo.h>
 
 #include "timer_test.h"
+#include "ucall_common.h"
 
 struct test_args test_args = {
 	.nr_vcpus = NR_VCPUS_DEF,

tools/testing/selftests/kvm/demand_paging_test.c

@@ -19,6 +19,7 @@
 #include "test_util.h"
 #include "memstress.h"
 #include "guest_modes.h"
+#include "ucall_common.h"
 #include "userfaultfd_util.h"
 
 #ifdef __NR_userfaultfd

tools/testing/selftests/kvm/dirty_log_perf_test.c

@@ -18,6 +18,7 @@
 #include "test_util.h"
 #include "memstress.h"
 #include "guest_modes.h"
+#include "ucall_common.h"
 
 #ifdef __aarch64__
 #include "aarch64/vgic.h"

tools/testing/selftests/kvm/dirty_log_test.c

@@ -20,6 +20,7 @@
 #include "test_util.h"
 #include "guest_modes.h"
 #include "processor.h"
+#include "ucall_common.h"
 
 #define DIRTY_MEM_BITS 30 /* 1G */
 #define PAGE_SHIFT_4K  12

tools/testing/selftests/kvm/guest_memfd_test.c

@@ -17,8 +17,8 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
+#include "kvm_util.h"
 #include "test_util.h"
-#include "kvm_util_base.h"
 
 static void test_file_read_write(int fd)
 {

tools/testing/selftests/kvm/guest_print_test.c

@@ -13,6 +13,7 @@
 #include "test_util.h"
 #include "kvm_util.h"
 #include "processor.h"
+#include "ucall_common.h"
 
 struct guest_vals {
 	uint64_t a;

tools/testing/selftests/kvm/include/aarch64/processor.h

@@ -8,6 +8,8 @@
 #define SELFTEST_KVM_PROCESSOR_H
 
 #include "kvm_util.h"
+#include "ucall_common.h"
+
 #include <linux/stringify.h>
 #include <linux/types.h>
 #include <asm/sysreg.h>

tools/testing/selftests/kvm/include/aarch64/ucall.h

@@ -2,7 +2,7 @@
 #ifndef SELFTEST_KVM_UCALL_H
 #define SELFTEST_KVM_UCALL_H
 
-#include "kvm_util_base.h"
+#include "kvm_util.h"
 
 #define UCALL_EXIT_REASON       KVM_EXIT_MMIO