2024-03-30 06:06:10

by Masahiro Yamada

Subject: [PATCH] x86/virt: 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 <[email protected]>
---

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 6a1f36df6a18..cf0ad89f5639 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 662d9d4033e6..5ab93fcdd691 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 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/
--
2.40.1

2024-03-30 09:57:31

by tip-bot2 for Jacob Pan

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

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 <[email protected]>
AuthorDate: Sat, 30 Mar 2024 15:05:54 +09:00
Committer: Ingo Molnar <[email protected]>
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 <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
---
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/

2024-04-02 12:02:50

by Huang, Kai

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

On Sat, 2024-03-30 at 09:57 +0000, tip-bot2 for Masahiro Yamada wrote:
> 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 <[email protected]>
> AuthorDate: Sat, 30 Mar 2024 15:05:54 +09:00
> Committer: Ingo Molnar <[email protected]>
> 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 <[email protected]>
> Signed-off-by: Ingo Molnar <[email protected]>
> Link: https://lore.kernel.org/r/[email protected]

Thanks. Should this be included into stable kernel?

As stated in the changelog, the problem starts to exist since commit

c33621b4c5ad ("x86/virt/tdx: Wire up basic SEAMCALL functions")

> ---
> 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/
>