[tip: x86/urgent] x86/build: Use obj-y to descend into arch/x86/virt/

[tip-bot2 for Masahiro Yamada]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     3f1a9bc5d878004ed4bc3904e5cb9b7fb317fbe2
Gitweb:        https://git.kernel.org/tip/3f1a9bc5d878004ed4bc3904e5cb9b7fb317fbe2
Author:        Masahiro Yamada <masahiroy@xxxxxxxxxx>
AuthorDate:    Sat, 30 Mar 2024 15:05:54 +09:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Sat, 30 Mar 2024 10:41:49 +01:00

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@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240330060554.18524-1-masahiroy@xxxxxxxxxx
---
 arch/x86/Kbuild        | 2 +-
 arch/x86/Makefile      | 2 --
 arch/x86/virt/Makefile | 2 +-
 3 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild
index 6a1f36d..cf0ad89 100644
--- a/arch/x86/Kbuild
+++ b/arch/x86/Kbuild
@@ -28,7 +28,7 @@ obj-y += net/
 
 obj-$(CONFIG_KEXEC_FILE) += purgatory/
 
-obj-y += virt/svm/
+obj-y += virt/
 
 # for cleaning
 subdir- += boot tools
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 662d9d4..5ab93fc 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -251,8 +251,6 @@ archheaders:
 
 libs-y  += arch/x86/lib/
 
-core-y += arch/x86/virt/
-
 # drivers-y are linked after core-y
 drivers-$(CONFIG_MATH_EMULATION) += arch/x86/math-emu/
 drivers-$(CONFIG_PCI)            += arch/x86/pci/
diff --git a/arch/x86/virt/Makefile b/arch/x86/virt/Makefile
index 1e36502..ea343fc 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/