Re: [kvm-unit-tests PATCH] arm/run: Use TCG with qemu-system-arm on arm64 systems

[Alexandru Elisei <alexandru.elisei@arm.com>]

Hi,

On Thu, Mar 17, 2022 at 06:45:07PM +0100, Andrew Jones wrote:
> On Thu, Mar 17, 2022 at 04:56:01PM +0000, Alexandru Elisei wrote:
> > From: Andrew Jones <drjones@redhat.com>
> > 
> > If the user sets QEMU=qemu-system-arm on arm64 systems, the tests can only
> > be run by using the TCG accelerator. In this case use TCG instead of KVM.
> > 
> > Signed-off-by: Andrew Jones <drjones@redhat.com>
> > [ Alex E: Added commit message ]
> > Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> > ---
> >  arm/run | 12 ++++++++++--
> >  1 file changed, 10 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arm/run b/arm/run
> > index 28a0b4ad2729..128489125dcb 100755
> > --- a/arm/run
> > +++ b/arm/run
> > @@ -10,16 +10,24 @@ if [ -z "$KUT_STANDALONE" ]; then
> >  fi
> >  processor="$PROCESSOR"
> >  
> > -ACCEL=$(get_qemu_accelerator) ||
> > +accel=$(get_qemu_accelerator) ||
> >  	exit $?
> >  
> > -if [ "$ACCEL" = "kvm" ]; then
> > +if [ "$accel" = "kvm" ]; then
> >  	QEMU_ARCH=$HOST
> >  fi
> >  
> >  qemu=$(search_qemu_binary) ||
> >  	exit $?
> >  
> > +if [ "$QEMU" ] && [ -z "$ACCEL" ] &&
> > +   [ "$HOST" = "aarch64" ] && [ "$ARCH" = "arm" ] &&
> > +   [ "$(basename $QEMU)" = "qemu-system-arm" ]; then
> > +	accel=tcg
> > +fi
> > +
> > +ACCEL=$accel
> > +
> >  if ! $qemu -machine '?' 2>&1 | grep 'ARM Virtual Machine' > /dev/null; then
> >  	echo "$qemu doesn't support mach-virt ('-machine virt'). Exiting."
> >  	exit 2
> > -- 
> > 2.35.1
> >
> 
> Ha, OK, I guess you posting this is a strong vote in favor of this
> behavior. I've queued it

Ah, yes, maybe I should've been more clear about it. I think this is more
intuitive for the new users who might not be very familiar with
run_tests.sh internals, and like you've said it won't break existing users
who had to set ACCEL=tcg to get the desired behaviour anyway.

Thanks you for queueing it so fast! Should probably have also mentioned
this as a comment in the commit, but I take full responsibility for
breaking stuff.

Alex

> 
> https://gitlab.com/rhdrjones/kvm-unit-tests/-/commits/arm/queue
> 
> Thanks,
> drew 
>