Re: [PATCH v8 01/20] KVM: selftests: Build and link selftests/vfio/lib into KVM selftests

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The use of `dirname` with multiple arguments in `libvfio.mk` is a GNU-ism that breaks the build on POSIX/BSD systems.
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commit 070d3095b74eed8d9c8207b3141eb0bb2449cb39
Author: David Matlack <dmatlack@google.com>

KVM: selftests: Build and link selftests/vfio/lib into KVM selftests

This commit includes libvfio.mk into the KVM selftests Makefile and links it
into all KVM selftests by adding it to LIBKVM_OBJS. This lays the groundwork
for future changes to utilize VFIO devices to verify IRQ bypass in KVM
selftests.

> diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
> index 4ace12606e937..ae0dfd67dd31e 100644
> --- a/tools/testing/selftests/kvm/Makefile.kvm
> +++ b/tools/testing/selftests/kvm/Makefile.kvm
> @@ -259,6 +259,7 @@ OVERRIDE_TARGETS = 1
>  # which causes the environment variable to override the makefile).
>  include ../lib.mk
>  include ../cgroup/lib/libcgroup.mk
> +include ../vfio/lib/libvfio.mk

[Severity: Low]
Does including libvfio.mk here break the build for KVM selftests on
environments with a non-GNU dirname?

Looking at tools/testing/selftests/vfio/lib/libvfio.mk, it contains:

    LIBVFIO_O_DIRS := $(shell dirname $(LIBVFIO_O) | uniq)

Passing multiple arguments to dirname is a GNU extension. On POSIX or BSD
systems, this command fails and returns an empty string. The subsequent mkdir
command then fails to create the required output directories, which causes the
compiler to fail with a "No such file or directory" error when attempting to
write the libvfio object files.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260626213534.3866178-1-seanjc@google.com?part=1