Re: [PATCH v2] vfio: selftests: only build tests on arm64 and x86_64

[David Matlack <dmatlack@google.com>]

On 2026-04-28 07:55 PM, Jason Gunthorpe wrote:
> On Tue, Apr 28, 2026 at 03:53:01PM -0700, David Matlack wrote:
> > > > If it is then we don't even need the __LP64__ stuff I posted.
> > > >
> > > > But when I look at the top-level Makefile and imagine running make
> > > > without setting ARCH on the command line on a 32-bit x86 host, ARCH
> > > > will be set to SUBARCH, which will be x86.
> > >
> > > Yep.  So the big question is, why doesn't anyone complain about KVM selftests not
> > > building on 32-bit?  Because they most definitely don't build.
> > 
> > I guess no one's building on 32-bit hosts anymore? :)
> 
> Well, if that's the case and kvm is broken too, then just ignore it
> and turn on vfio for x86 like kvm does?
> 
> No sense in just fixing it for VFIO..

That's fair... So something like this?

From: David Matlack <dmatlack@google.com>
Date: Tue, 28 Apr 2026 22:57:48 +0000
Subject: [PATCH] vfio: selftests: Allow builds when ARCH=x86

Allow builds when ARCH=x86 since the top-level Makefile can set ARCH=x86
even for 64-bit x86 builds. ARCH=x86 can also be set if the host is
32-bit x86, but based on the fact that KVM selftests allow ARCH=x86 but
also don't build for 32-bit x86, this isn't an issue in practice.

Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: David Matlack <dmatlack@google.com>

diff --git a/tools/testing/selftests/vfio/Makefile b/tools/testing/selftests/vfio/Makefile
index 0684932d91bf..40165d087a0b 100644
--- a/tools/testing/selftests/vfio/Makefile
+++ b/tools/testing/selftests/vfio/Makefile
@@ -1,6 +1,6 @@
 ARCH ?= $(shell uname -m)

-ifeq (,$(filter $(ARCH),aarch64 arm64 x86_64))
+ifeq (,$(filter $(ARCH),aarch64 arm64 x86 x86_64))
 # Do nothing on unsupported architectures
 include ../lib.mk
 else
/usr/local/google/home/dmatlack/kernel/trees/vfio