Re: [PATCH] vfio: selftests: Ensure libvfio output dirs are always created

[Alex Williamson <alex@shazbot.org>]

On Thu, 11 Jun 2026 21:39:45 +0000
David Matlack <dmatlack@google.com> wrote:

> Add an explicit dependency between the output object files and the
> output directories that need to be created to hold those files. This
> ensures that the output directories are always created.
> 
> Creating the output directories at parse time (current behavior) doesn't
> support the scenario where someone does "make clean all". The
> directories will be created during parsing, deleted during "clean" and
> then not available for the "all" target.
> 
> Use an order-only prerequisite for the output directories, rather than a
> normal prerequisite, to avoid unnecessary recompilations.
> 
> Fixes: 19faf6fd969c ("vfio: selftests: Add a helper library for VFIO selftests")
> Reported-by: Sashiko <sashiko-bot@kernel.org>
> Closes: https://lore.kernel.org/kvm/20260610010314.DB8861F00893@smtp.kernel.org/
> Signed-off-by: David Matlack <dmatlack@google.com>
> ---
> Cc: Sean Christopherson <seanjc@google.com>
> 
>  tools/testing/selftests/vfio/lib/libvfio.mk | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/vfio/lib/libvfio.mk b/tools/testing/selftests/vfio/lib/libvfio.mk
> index b7857319c3f1..2b8d73b7d329 100644
> --- a/tools/testing/selftests/vfio/lib/libvfio.mk
> +++ b/tools/testing/selftests/vfio/lib/libvfio.mk
> @@ -20,11 +20,13 @@ LIBVFIO_OUTPUT := $(OUTPUT)/libvfio
>  LIBVFIO_O := $(patsubst %.c, $(LIBVFIO_OUTPUT)/%.o, $(LIBVFIO_C))
>  
>  LIBVFIO_O_DIRS := $(shell dirname $(LIBVFIO_O) | uniq)
> -$(shell mkdir -p $(LIBVFIO_O_DIRS))
> +
> +$(LIBVFIO_O_DIRS):
> +	mkdir -p $@
>  
>  CFLAGS += -I$(LIBVFIO_SRCDIR)/include
>  
> -$(LIBVFIO_O): $(LIBVFIO_OUTPUT)/%.o : $(LIBVFIO_SRCDIR)/%.c
> +$(LIBVFIO_O): $(LIBVFIO_OUTPUT)/%.o : $(LIBVFIO_SRCDIR)/%.c | $(LIBVFIO_O_DIRS)
>  	$(CC) $(CFLAGS) $(CPPFLAGS) $(TARGET_ARCH) -c $< -o $@
>  
>  EXTRA_CLEAN += $(LIBVFIO_OUTPUT)
> 
> base-commit: a26b499b757cfc8bbff1088bb1b844639e250893

Applied to vfio next branch for v7.2.  Thanks,

Alex