x86/build: Use obj-y to descend into arch/x86/virt/

Commit c33621b4c5ad ("x86/virt/tdx: Wire up basic SEAMCALL functions")
introduced a new instance of core-y instead of the standardized obj-y
syntax.

X86 Makefiles descend into subdirectories of arch/x86/virt inconsistently;
into arch/x86/virt/ via core-y defined in arch/x86/Makefile, but into
arch/x86/virt/svm/ via obj-y defined in arch/x86/Kbuild.

This is problematic when you build a single object in parallel because
multiple threads attempt to build the same file.

  $ make -j$(nproc) arch/x86/virt/vmx/tdx/seamcall.o
    [ snip ]
    AS      arch/x86/virt/vmx/tdx/seamcall.o
    AS      arch/x86/virt/vmx/tdx/seamcall.o
  fixdep: error opening file: arch/x86/virt/vmx/tdx/.seamcall.o.d: No such file or directory
  make[4]: *** [scripts/Makefile.build:362: arch/x86/virt/vmx/tdx/seamcall.o] Error 2

Use the obj-y syntax, as it works correctly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240330060554.18524-1-masahiroy@kernel.org

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/x86/virt/Makefile b/arch/x86/virt/Makefile
index 1e36502cd738..ea343fc392dc 100644
--- a/arch/x86/virt/Makefile
+++ b/arch/x86/virt/Makefile
@@ -1,2 +1,2 @@
 # SPDX-License-Identifier: GPL-2.0-only
-obj-y	+= vmx/
+obj-y	+= svm/ vmx/